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Wireless_network
Wireless network
From Wikipedia, the free encyclopedia This article may require cleanup to meet Wikipedia's quality standards.
Please improve this article if you can. (October 2006)
While the term wireless network may technically be used to refer to any type of network that is wireless, the term is most commonly used to refer to a telecommunications network whose interconnections between nodes is implemented without the use of wires, such as a computer network (which is a type of communications network). Wireless telecommunications networks are generally implemented with some type of remote information transmission system that uses electromagnetic waves, such as radio waves, for the carrier and this implementation usually takes place at the physical level or "layer" of the network. (For example, see the Physical Layer of the OSI Model).Contents [hide]
1 Types
2 Uses
3 Articles
4 Research institutes
5 Communities
6 Ideas
7 Environmental concerns and health hazard
8 See also
9 References
9.1 Annotated bibliography
10 External links
[edit]
Types
Wireless LAN
One type of wireless network is a WLAN or Wireless Local Area Network. Similar to other wireless devices, it uses radio instead of wires to transmit data back and forth between computers on the same network.
Screenshots of wireless LAN Networks. Figure 1, left, shows that not all networks are encrypted (locked unless you have the code), which means anyone can get onto them. Figures 2 and 3, middle and right, however, show that a lot of networks are encrypted.
Wi-Fi: Wi-Fi is a commonly used wireless network in computer systems which enable connection to the internet or other machines that have Wi-Fi functionalities. Wi-Fi networks broadcast radio waves that can be picked up by Wi-Fi receivers that are attached to different computers or mobile phones.
Fixed Wireless Data: Fixed wireless data is a type of wireless data network that can be used to connect two or more buildings together in order to extend or share the network bandwidth without physically wiring the buildings together.
Wireless MAN
A type of wireless network that connects several Wireless LANs.
WiMAX: WiMAX is the term used to refer to wireless MANs.
Mobile devices networks
Global System for Mobile Communications (GSM): The GSM network is divided into three major systems which are the switching system, the base station system, and the operation and support system (Global System for Mobile Communication (GSM)). The cell phone connects to the base system station which then connects to the operation and support station; it then connects to the switching station where the call is transferred where it needs to go (Global System for Mobile Communication (GSM)). This is used for cellular phones, is the most common standard and is used for a majority of cellular providers.
Personal Communications Service (PCS): PCS is a radio band that can be used by mobile phones in North America. Sprint happened to be the first service to set up a PCS.
D-AMPS: D-AMPS, which stands for Digital Advanced Mobile Phone Service, is an upgraded version of AMPS but it is being phased out due to advancement in technology. The newer GSM networks are replacing the older system.
[edit]
Uses
Wireless networks have significantly impacted the world as far back as World War II. Through the use of wireless networks, information could be sent overseas or behind enemy lines easily and quickly and was more reliable. Since then wireless networks have continued to develop and its uses have significantly grown. Cellular phones are part of huge wireless network systems. People use these phones daily to communicate with one another. Sending information over seas is possible through wireless network systems using satellites and other signals to communicate across the world. Emergency services such as the police department utilize wireless networks to communicate important information quickly. People and businesses use wireless networks to send and share data quickly whether it be in a small office building or across the world. Another important use for wireless networks is as an inexpensive and rapid way to be connected to the Internet in countries and regions where the telecom infrastructure is poor or there is a lack of resources, like most Developing Countries.
Wireless networks allow you to eliminate messy cables. Wireless connections offer more mobility, the downside is there can sometimes be interference that might block the radio signals from passing through. One way to avoid this is by putting the source of your wireless connection in a place where the signal will have as little interference as possible. Sometimes nearby networks are using the same frequencies, and this can also cause interference within the network and can reduce its performance.
Compatibility issues also arise when dealing with wireless networks. Different components not made by the same company may not work together, or might require extra work to fix compatibility issues. To avoid this, purchase products made by the same company so that there are fewer compatibility issues.
Wireless networks, in terms of internet connections, are typically slower than those that are directly connected through an Ethernet cable. Though the speed is slower, most things will still move at the same speed except for things like video downloads. Though wireless technology continues to develop, it is now easier to get networks up and running cheaper and faster than ever before.
A wireless network is more vulnerable because anyone can try to break into a network broadcasting a signal. Many networks offer WEP - Wired Equivalent Privacy - security systems which have been found to be vulnerable to intrusion. Though WEP does block some intruders, the security problems have caused some businesses to stick with wired networks until security can be improved. Another type of security for wireless networks is WPA - Wi-Fi Protected Access. WPA provides more security to wireless networks than a WEP security set up. The use of firewalls will help with security breaches which can help to fix security problems in some wireless networks that are more vulnerable.
[edit]
Articles
Wireless MAN - metropolitan area network
Wireless LAN - local area networks
Wireless PAN - personal area networks
GSM - Global standard for digital mobile communication, common in most countries except South Korea and Japan
PCS - Personal communication system - not a single standard, this covers both CDMA and GSM networks operating at 1900 MHz in North America
Mobitex - pager-based network in the USA and Canada, built by Ericsson, now used by PDAs such as the Palm VII and Research in Motion BlackBerry
GPRS - General Packet Radio Service, upgraded packet-based service within the GSM framework, gives higher data rates and always-on service
UMTS - Universal Mobile Telephone Service (3rd generation cell phone network), based on the W-CDMA radio access network
AX.25 - amateur packet radio
NMT - Nordic Mobile Telephony, analog system originally developed by PTTs in the Nordic countries
AMPS - Advanced Mobile Phone System introduced in the Americas in about 1984.
D-AMPS - Digital AMPS, also known as TDMA
Wi-Fi - Wireless Fidelity, widely used for Wireless LAN, and based on IEEE 802.11 standards.
Wimax - A solution for BWA (Broadband Wireless Access) and conforms to IEEE 802.16 standard.
Canopy - A wide-area broadband wireless solution from Motorola.
[edit]
Research institutes
The following institutions conduct wireless network related research:
National University San Diego, Califirnia [[1]]
Indian Institute of Science, Bangalore
G S Sanyal school of Telecommunications, IIT Kharagpur, India
University of California, Santa Barbara
University of California, Berkeley
İzmir Institute of Technology, Turkey
University of Pennsylvania
Massachusetts Institute of Technology
Helsinki University of Technology
Royal Institute of Technology (Stockholm, Sweden)
Stanford University
Iowa State University
Center for Wireless Information Network Studies, Worcester Polytechnic Institute
University of Southern California
University of Edinburgh Edinburgh, UK
Nanyang Technological University, Singapore
University of South Australia, Australia
University of Toronto, Canada
University of Alberta, Canada
Drexel University
University of Houston–Clear Lake
[edit]
Communities
Qualcomm [2]
SeattleWireless
NYCwireless
RedLibre
Personal Telco
Downtown Toronto
[edit]
Ideas
Warchalking
[edit]
Environmental concerns and health hazard
In recent time there are increased concerns and research linking usage of wireless communications with poor concentration, memory loss, nausea, premature senility and even cancer. Questions of safety have been raised, citing that long term exposure to electromagnetic radiation of the sort emitted by wireless networks may someday prove to be dangerous
From Wikipedia, the free encyclopedia This article may require cleanup to meet Wikipedia's quality standards.
Please improve this article if you can. (October 2006)
While the term wireless network may technically be used to refer to any type of network that is wireless, the term is most commonly used to refer to a telecommunications network whose interconnections between nodes is implemented without the use of wires, such as a computer network (which is a type of communications network). Wireless telecommunications networks are generally implemented with some type of remote information transmission system that uses electromagnetic waves, such as radio waves, for the carrier and this implementation usually takes place at the physical level or "layer" of the network. (For example, see the Physical Layer of the OSI Model).Contents [hide]
1 Types
2 Uses
3 Articles
4 Research institutes
5 Communities
6 Ideas
7 Environmental concerns and health hazard
8 See also
9 References
9.1 Annotated bibliography
10 External links
[edit]
Types
Wireless LAN
One type of wireless network is a WLAN or Wireless Local Area Network. Similar to other wireless devices, it uses radio instead of wires to transmit data back and forth between computers on the same network.
Screenshots of wireless LAN Networks. Figure 1, left, shows that not all networks are encrypted (locked unless you have the code), which means anyone can get onto them. Figures 2 and 3, middle and right, however, show that a lot of networks are encrypted.
Wi-Fi: Wi-Fi is a commonly used wireless network in computer systems which enable connection to the internet or other machines that have Wi-Fi functionalities. Wi-Fi networks broadcast radio waves that can be picked up by Wi-Fi receivers that are attached to different computers or mobile phones.
Fixed Wireless Data: Fixed wireless data is a type of wireless data network that can be used to connect two or more buildings together in order to extend or share the network bandwidth without physically wiring the buildings together.
Wireless MAN
A type of wireless network that connects several Wireless LANs.
WiMAX: WiMAX is the term used to refer to wireless MANs.
Mobile devices networks
Global System for Mobile Communications (GSM): The GSM network is divided into three major systems which are the switching system, the base station system, and the operation and support system (Global System for Mobile Communication (GSM)). The cell phone connects to the base system station which then connects to the operation and support station; it then connects to the switching station where the call is transferred where it needs to go (Global System for Mobile Communication (GSM)). This is used for cellular phones, is the most common standard and is used for a majority of cellular providers.
Personal Communications Service (PCS): PCS is a radio band that can be used by mobile phones in North America. Sprint happened to be the first service to set up a PCS.
D-AMPS: D-AMPS, which stands for Digital Advanced Mobile Phone Service, is an upgraded version of AMPS but it is being phased out due to advancement in technology. The newer GSM networks are replacing the older system.
[edit]
Uses
Wireless networks have significantly impacted the world as far back as World War II. Through the use of wireless networks, information could be sent overseas or behind enemy lines easily and quickly and was more reliable. Since then wireless networks have continued to develop and its uses have significantly grown. Cellular phones are part of huge wireless network systems. People use these phones daily to communicate with one another. Sending information over seas is possible through wireless network systems using satellites and other signals to communicate across the world. Emergency services such as the police department utilize wireless networks to communicate important information quickly. People and businesses use wireless networks to send and share data quickly whether it be in a small office building or across the world. Another important use for wireless networks is as an inexpensive and rapid way to be connected to the Internet in countries and regions where the telecom infrastructure is poor or there is a lack of resources, like most Developing Countries.
Wireless networks allow you to eliminate messy cables. Wireless connections offer more mobility, the downside is there can sometimes be interference that might block the radio signals from passing through. One way to avoid this is by putting the source of your wireless connection in a place where the signal will have as little interference as possible. Sometimes nearby networks are using the same frequencies, and this can also cause interference within the network and can reduce its performance.
Compatibility issues also arise when dealing with wireless networks. Different components not made by the same company may not work together, or might require extra work to fix compatibility issues. To avoid this, purchase products made by the same company so that there are fewer compatibility issues.
Wireless networks, in terms of internet connections, are typically slower than those that are directly connected through an Ethernet cable. Though the speed is slower, most things will still move at the same speed except for things like video downloads. Though wireless technology continues to develop, it is now easier to get networks up and running cheaper and faster than ever before.
A wireless network is more vulnerable because anyone can try to break into a network broadcasting a signal. Many networks offer WEP - Wired Equivalent Privacy - security systems which have been found to be vulnerable to intrusion. Though WEP does block some intruders, the security problems have caused some businesses to stick with wired networks until security can be improved. Another type of security for wireless networks is WPA - Wi-Fi Protected Access. WPA provides more security to wireless networks than a WEP security set up. The use of firewalls will help with security breaches which can help to fix security problems in some wireless networks that are more vulnerable.
[edit]
Articles
Wireless MAN - metropolitan area network
Wireless LAN - local area networks
Wireless PAN - personal area networks
GSM - Global standard for digital mobile communication, common in most countries except South Korea and Japan
PCS - Personal communication system - not a single standard, this covers both CDMA and GSM networks operating at 1900 MHz in North America
Mobitex - pager-based network in the USA and Canada, built by Ericsson, now used by PDAs such as the Palm VII and Research in Motion BlackBerry
GPRS - General Packet Radio Service, upgraded packet-based service within the GSM framework, gives higher data rates and always-on service
UMTS - Universal Mobile Telephone Service (3rd generation cell phone network), based on the W-CDMA radio access network
AX.25 - amateur packet radio
NMT - Nordic Mobile Telephony, analog system originally developed by PTTs in the Nordic countries
AMPS - Advanced Mobile Phone System introduced in the Americas in about 1984.
D-AMPS - Digital AMPS, also known as TDMA
Wi-Fi - Wireless Fidelity, widely used for Wireless LAN, and based on IEEE 802.11 standards.
Wimax - A solution for BWA (Broadband Wireless Access) and conforms to IEEE 802.16 standard.
Canopy - A wide-area broadband wireless solution from Motorola.
[edit]
Research institutes
The following institutions conduct wireless network related research:
National University San Diego, Califirnia [[1]]
Indian Institute of Science, Bangalore
G S Sanyal school of Telecommunications, IIT Kharagpur, India
University of California, Santa Barbara
University of California, Berkeley
İzmir Institute of Technology, Turkey
University of Pennsylvania
Massachusetts Institute of Technology
Helsinki University of Technology
Royal Institute of Technology (Stockholm, Sweden)
Stanford University
Iowa State University
Center for Wireless Information Network Studies, Worcester Polytechnic Institute
University of Southern California
University of Edinburgh Edinburgh, UK
Nanyang Technological University, Singapore
University of South Australia, Australia
University of Toronto, Canada
University of Alberta, Canada
Drexel University
University of Houston–Clear Lake
[edit]
Communities
Qualcomm [2]
SeattleWireless
NYCwireless
RedLibre
Personal Telco
Downtown Toronto
[edit]
Ideas
Warchalking
[edit]
Environmental concerns and health hazard
In recent time there are increased concerns and research linking usage of wireless communications with poor concentration, memory loss, nausea, premature senility and even cancer. Questions of safety have been raised, citing that long term exposure to electromagnetic radiation of the sort emitted by wireless networks may someday prove to be dangerous
Wireless_LAN
ireless LAN
From Wikipedia, the free encyclopedia This article may require cleanup to meet Wikipedia's quality standards.
Please improve this article if you can. (December 2007)
"WLAN" redirects here. For other uses, see WLAN (disambiguation).
The notebook is connected to the wireless access point using a PC card wireless card.
54 MBit/s WLAN PCI Card (802.11g)
See also: Virtual LAN
A wireless LAN or WLAN is a wireless local area network, which is the linking of two or more computers without using wires. WLAN utilizes spread-spectrum or OFDM modulation technology based on radio waves to enable communication between devices in a limited area, also known as the basic service set. This gives users the mobility to move around within a broad coverage area and still be connected to the network.
For the home user, wireless has become popular due to ease of installation, and location freedom with the gaining popularity of laptops. Public businesses such as coffee shops or malls have begun to offer wireless access to their customers; some are even provided as a free service. Large wireless network projects are being put up in many major cities. Google is even providing a free service to Mountain View, California[1] and has entered a bid to do the same for San Francisco.[2] New York City has also begun a pilot program to cover all five boroughs of the city with wireless Internet access.Contents [hide]
1 History
2 Benefits
3 Disadvantages
4 Architecture
4.1 Stations
4.2 Basic service set
4.3 Extended service set
4.4 Distribution system
5 Types of wireless LANs
5.1 Peer-to-peer
5.2 Bridge
5.3 Wireless distribution system
6 See also
7 References
8 External links
[edit]
History
In 1970 University of Hawaii, under the leadership of Norman Abramson, developed the world’s first computer communication network using low-cost ham-like radios, named ALOHAnet. The bi-directional star topology of the system included seven computers deployed over four islands to communicate with the central computer on the Oahu Island without using phone lines.[3]
"In 1979, F.R. Gfeller and U. Bapst published a paper in the IEEE Proceedings reporting an experimental wireless local area network using diffused infrared communications. Shortly thereafter, in 1980, P. Ferrert reported on an experimental application of a single code spread spectrum radio for wireless terminal communications in the IEEE National Telecommunications Conference. In 1984, a comparison between Infrared and CDMA spread spectrum communications for wireless office information networks was published by Kaveh Pahlavan in IEEE Computer Networking Symposium which appeared later in the IEEE Communication Society Magazine. In May 1985, the efforts of Marcus led the FCC to announce experimental ISM bands for commercial application of spread spectrum technology. Later on, M. Kavehrad reported on an experimental wireless PBX system using code division multiple access. These efforts prompted significant industrial activities in the development of a new generation of wireless local area networks and it updated several old discussions in the portable and mobile radio industry.
The first generation of wireless data modems was developed in the early 1980's by amateur radio operators. They added a voice band data communication modem, with data rates below 9600 bit/s, to an existing short distance radio system, typically in the two meter amateur band. The second generation of wireless modems was developed immediately after the FCC announcement in the experimental bands for non-military use of the spread spectrum technology. These modems provided data rates on the order of hundreds of kbit/s. The third generation of wireless modem [then] aimed at compatibility with the existing LANs with data rates on the order of Mbit/s. Several companies [developed] the third generation products with data rates above 1 Mbit/s and a couple of products [had] already been announced [by the time of the first IEEE Workshop on Wireless LANs]."[4]
"The first of the IEEE Workshops on Wireless LAN was held in 1991. At that time early wireless LAN products had just appeared in the market and the IEEE 802.11 committee had just started its activities to develop a standard for wireless LANs. The focus of that first workshop was evaluation of the alternative technologies. [By 1996], the technology [was] relatively mature, a variety of applications [had] been identified and addressed and technologies that enable these applications [were] well understood. Chip sets aimed at wireless LAN implementations and applications, a key enabling technology for rapid market growth, [were] emerging in the market. Wireless LANs [were being] used in hospitals, stock exchanges, and other in building and campus settings for nomadic access, point-to-point LAN bridges, ad-hoc networking, and even larger applications through internetworking. The IEEE 802.11 standard and variants and alternatives, such as the wireless LAN interoperability forum and the European HIPERLAN specification [had] made rapid progress, and the unlicensed PCS [ Unlicensed Personal Communications Services ]
| publisher = Worcester Polytechnic Institute, Worcester, Massachusetts, October 24-25, 1996.
| url = http://www.cwins.wpi.edu/wlans96/scripts/summary.html
}}
On July 21, 1999, AirPort debuted at the Macworld Expo in New York City with Steve Jobs picking up an iBook supposedly to give the cameraman a better shot as he surfed the Web. Applause quickly built as people realized there were no wires. This was the first time Wireless LAN became publicly available at consumer pricing and easily available for home use. Before the release of the Airport, Wireless LAN was too expensive for consumer use and used exclusively in large corporate settings.
Originally WLAN hardware was so expensive that it was only used as an alternative to cabled LAN in places where cabling was difficult or impossible. Early development included industry-specific solutions and proprietary protocols, but at the end of the 1990s these were replaced by standards, primarily the various versions of IEEE 802.11 (Wi-Fi). An alternative ATM-like 5 GHz standardized technology, HIPERLAN, has so far not succeeded in the market, and with the release of the faster 54 Mbit/s 802.11a (5 GHz) and 802.11g (2.4 GHz) standards, almost certainly never will.
In November 2006, the Australian Commonwealth Scientific and Industrial Research Organisation (CSIRO) won a legal battle in the US federal court of Texas against Buffalo Technology which found the US manufacturer had failed to pay royalties on a US WLAN patent CSIRO had filed in 1996. CSIRO are currently engaged in legal cases with computer companies including Microsoft, Intel, Dell, Hewlett-Packard and Netgear which argue that the patent is invalid and should negate any royalties paid to CSIRO for WLAN-based products.[5]
[edit]
Benefits
The popularity of wireless LANs is a testament primarily to their convenience, cost efficiency, and ease of integration with other networks and network components. The majority of computers sold to consumers today come pre-equipped with all necessary wireless LAN technology.
The benefits of wireless LANs include:
Convenience: The wireless nature of such networks allows users to access network resources from nearly any convenient location within their primary networking environment (home or office). With the increasing saturation of laptop-style computers, this is particularly relevant.
Mobility: With the emergence of public wireless networks, users can access the internet even outside their normal work environment. Most chain coffee shops, for example, offer their customers a wireless connection to the internet at little or no cost.
Productivity: Users connected to a wireless network can maintain a nearly constant affiliation with their desired network as they move from place to place. For a business, this implies that an employee can potentially be more productive as his or her work can be accomplished from any convenient location.
Deployment: Initial setup of an infrastructure-based wireless network requires little more than a single access point. Wired networks, on the other hand, have the additional cost and complexity of actual physical cables being run to numerous locations (which can even be impossible for hard-to-reach locations within a building).
Expandability: Wireless networks can serve a suddenly-increased number of clients with the existing equipment. In a wired network, additional clients would require additional wiring.
Cost: Wireless networking hardware is at worst a modest increase from wired counterparts. This potentially increased cost is almost always more than outweighed by the savings in cost and labor associated to running physical cables.
[edit]
Disadvantages
Wireless LAN technology, while replete with the conveniences and advantages described above, has its share of downfalls. For a given networking situation, wireless LANs may not be desirable for a number of reasons. Most of these have to do with the inherent limitations of the technology.
Security: Wireless LAN transceivers are designed to serve computers throughout a structure with uninterrupted service using radio frequencies. Because of space and cost, the antennas typically present on wireless networking cards in the end computers are generally relatively poor. In order to properly receive signals using such limited antennas throughout even a modest area, the wireless LAN transceiver utilizes a fairly considerable amount of power. What this means is that not only can the wireless packets be intercepted by a nearby adversary's poorly-equipped computer, but more importantly, a user willing to spend a small amount of money on a good quality antenna can pick up packets at a remarkable distance; perhaps hundreds of times the radius as the typical user. In fact, there are even computer users dedicated to locating and sometimes even cracking into wireless networks, known as wardrivers. On a wired network, any adversary would first have to overcome the physical limitation of tapping into the actual wires, but this is not an issue with wireless packets. To combat this consideration, wireless networks users usually choose to utilize various encryption technologies available such as Wi-Fi Protected Access (WPA). Some of the older encryption methods, such as WEP are known to have weaknesses that a dedicated adversary can compromise. (See main article: Wireless security.)
Range: The typical range of a common 802.11g network with standard equipment is on the order of tens of meters. While sufficient for a typical home, it will be insufficient in a larger structure. To obtain additional range, repeaters or additional access points will have to be purchased. Costs for these items can add up quickly. Other technologies are in the development phase, however, which feature increased range, hoping to render this disadvantage irrelevant. (See WiMAX)
Reliability: Like any radio frequency transmission, wireless networking signals are subject to a wide variety of interference, as well as complex propagation effects (such as multipath, or especially in this case Rician fading) that are beyond the control of the network administrator. In the case of typical networks, modulation is achieved by complicated forms of phase-shift keying (PSK) or quadrature amplitude modulation (QAM), making interference and propagation effects all the more disturbing. As a result, important network resources such as servers are rarely connected wirelessly.
Speed: The speed on most wireless networks (typically 1-108 Mbit/s) is reasonably slow compared to the slowest common wired networks (100 Mbit/s up to several Gbit/s). There are also performance issues caused by TCP and its built-in congestion avoidance. For most users, however, this observation is irrelevant since the speed bottleneck is not in the wireless routing but rather in the outside network connectivity itself. For example, the maximum ADSL throughput (usually 8 Mbit/s or less) offered by telecommunications companies to general-purpose customers is already far slower than the slowest wireless network to which it is typically connected. That is to say, in most environments, a wireless network running at its slowest speed is still faster than the internet connection serving it in the first place. However, in specialized environments, the throughput of a wired network might be necessary. Newer standards such as 802.11n are addressing this limitation and will support peak throughputs in the range of 100-200 Mbit/s.
Wireless LANs present a host of issues for network managers. Unauthorized access points, broadcasted SSIDs, unknown stations, and spoofed MAC addresses are just a few of the problems addressed in WLAN troubleshooting. Most network analysis vendors, such as Network Instruments, Network General, and Fluke, offer WLAN troubleshooting tools or functionalities as part of their product line.
[edit]
Architecture
[edit]
Stations
All components that can connect into a wireless medium in a network are referred to as stations. All stations are equipped with wireless network interface cards (WNICs). Wireless stations fall into one of two categories: access points and clients.
Access points
Access points (APs) are base stations for the wireless network. They transmit and receive radio frequencies for wireless enabled devices to communicate with.
Clients
Wireless clients can be mobile devices such as laptops, personal digital assistants, IP phones, or fixed devices such as desktops and workstations that are equipped with a wireless network interface.
[edit]
Basic service set
The basic service set (BSS) is a set of all stations that can communicate with each other. There are two types of BSS: independent BSS and infrastructure BSS. Every BSS has an identification (ID) called the BSSID, which is the MAC address of the access point servicing the BSS.
Independent basic service set
An independent BSS is an ad-hoc network that contains no access points, which means they can not connect to any other basic service set.
Infrastructure basic service set
An infrastructure BSS can communicate with other stations not in the same basic service set by communicating through access points.
[edit]
Extended service set
An extended service set (ESS) is a set of connected BSSes. Access points in an ESS are connected by a distribution system. Each ESS has an ID called the SSID which is a 32-byte (maximum) character string. For example, "linksys" is the default SSID for Linksys routers.
[edit]
Distribution system
A distribution system connects access points in an extended service setup.
[edit]
Types of wireless LANs
[edit]
Peer-to-peer
Peer-to-Peer or ad-hoc wireless LAN
A peer-to-peer (P2P) allows wireless devices to directly communicate with each other. Wireless devices within range of each other can discover and communicate directly without involving central access points. This method is typically used by two computers so that they can connect to each other to form a network.
If a signal strength meter is used in this situation, it may not read the strength accurately and can be misleading, because it registers the strength of the strongest signal, which may be the closest computer.
802.11 specs define the physical layer (PHY) and MAC (Media Access Control) layers. However, unlike most other IEEE specs, 802.11 includes three alternative PHY standards: diffuse infrared operating at 1 Mbit/s in; frequency-hopping spread spectrum operating at 1 Mbit/s or 2 Mbit/s; and direct-sequence spread spectrum operating at 1 Mbit/s or 2 Mbit/s. A single 802.11 MAC standard is based on CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance). The 802.11 specification includes provisions designed to minimize collisions. Because two mobile units may both be in range of a common access point, but not in range of each other. The 802.11 has two basic modes of operation: Ad hoc mode enables peer-to-peer transmission between mobile units. Infrastructure mode in which mobile units communicate through an access point that serves as a bridge to a wired network infrastructure is the more common wireless LAN application the one being covered. Since wireless communication uses a more open medium for communication in comparison to wired LANs, the 802.11 designers also included a shared-key encryption mechanism, called wired equivalent privacy (WEP), or Wi-Fi Protected Access, (WPA, WPA2) to secure wireless computer networks.
[edit]
Bridge
A bridge can be used to connect networks, typically of different types. A wireless Ethernet bridge allows the connection of devices on a wired Ethernet network to a wireless network. The bridge acts as the connection point to the Wireless LAN.
[edit]
Wireless distribution system
Main article: Wireless Distribution System
When it is difficult to connect all of the access points in a network by wires, it is also possible to put up access points as repeaters.
[edit]
See also
Local area network
Wireless network
Exposed terminal problem
Hidden terminal problem
Fixed Wireless Data
Wireless LAN client comparison
Shared mesh
Switched mesh
USB
IEEE Workshops on Wireless LAN
[edit]
References
From Wikipedia, the free encyclopedia This article may require cleanup to meet Wikipedia's quality standards.
Please improve this article if you can. (December 2007)
"WLAN" redirects here. For other uses, see WLAN (disambiguation).
The notebook is connected to the wireless access point using a PC card wireless card.
54 MBit/s WLAN PCI Card (802.11g)
See also: Virtual LAN
A wireless LAN or WLAN is a wireless local area network, which is the linking of two or more computers without using wires. WLAN utilizes spread-spectrum or OFDM modulation technology based on radio waves to enable communication between devices in a limited area, also known as the basic service set. This gives users the mobility to move around within a broad coverage area and still be connected to the network.
For the home user, wireless has become popular due to ease of installation, and location freedom with the gaining popularity of laptops. Public businesses such as coffee shops or malls have begun to offer wireless access to their customers; some are even provided as a free service. Large wireless network projects are being put up in many major cities. Google is even providing a free service to Mountain View, California[1] and has entered a bid to do the same for San Francisco.[2] New York City has also begun a pilot program to cover all five boroughs of the city with wireless Internet access.Contents [hide]
1 History
2 Benefits
3 Disadvantages
4 Architecture
4.1 Stations
4.2 Basic service set
4.3 Extended service set
4.4 Distribution system
5 Types of wireless LANs
5.1 Peer-to-peer
5.2 Bridge
5.3 Wireless distribution system
6 See also
7 References
8 External links
[edit]
History
In 1970 University of Hawaii, under the leadership of Norman Abramson, developed the world’s first computer communication network using low-cost ham-like radios, named ALOHAnet. The bi-directional star topology of the system included seven computers deployed over four islands to communicate with the central computer on the Oahu Island without using phone lines.[3]
"In 1979, F.R. Gfeller and U. Bapst published a paper in the IEEE Proceedings reporting an experimental wireless local area network using diffused infrared communications. Shortly thereafter, in 1980, P. Ferrert reported on an experimental application of a single code spread spectrum radio for wireless terminal communications in the IEEE National Telecommunications Conference. In 1984, a comparison between Infrared and CDMA spread spectrum communications for wireless office information networks was published by Kaveh Pahlavan in IEEE Computer Networking Symposium which appeared later in the IEEE Communication Society Magazine. In May 1985, the efforts of Marcus led the FCC to announce experimental ISM bands for commercial application of spread spectrum technology. Later on, M. Kavehrad reported on an experimental wireless PBX system using code division multiple access. These efforts prompted significant industrial activities in the development of a new generation of wireless local area networks and it updated several old discussions in the portable and mobile radio industry.
The first generation of wireless data modems was developed in the early 1980's by amateur radio operators. They added a voice band data communication modem, with data rates below 9600 bit/s, to an existing short distance radio system, typically in the two meter amateur band. The second generation of wireless modems was developed immediately after the FCC announcement in the experimental bands for non-military use of the spread spectrum technology. These modems provided data rates on the order of hundreds of kbit/s. The third generation of wireless modem [then] aimed at compatibility with the existing LANs with data rates on the order of Mbit/s. Several companies [developed] the third generation products with data rates above 1 Mbit/s and a couple of products [had] already been announced [by the time of the first IEEE Workshop on Wireless LANs]."[4]
"The first of the IEEE Workshops on Wireless LAN was held in 1991. At that time early wireless LAN products had just appeared in the market and the IEEE 802.11 committee had just started its activities to develop a standard for wireless LANs. The focus of that first workshop was evaluation of the alternative technologies. [By 1996], the technology [was] relatively mature, a variety of applications [had] been identified and addressed and technologies that enable these applications [were] well understood. Chip sets aimed at wireless LAN implementations and applications, a key enabling technology for rapid market growth, [were] emerging in the market. Wireless LANs [were being] used in hospitals, stock exchanges, and other in building and campus settings for nomadic access, point-to-point LAN bridges, ad-hoc networking, and even larger applications through internetworking. The IEEE 802.11 standard and variants and alternatives, such as the wireless LAN interoperability forum and the European HIPERLAN specification [had] made rapid progress, and the unlicensed PCS [ Unlicensed Personal Communications Services ]
| publisher = Worcester Polytechnic Institute, Worcester, Massachusetts, October 24-25, 1996.
| url = http://www.cwins.wpi.edu/wlans96/scripts/summary.html
}}
On July 21, 1999, AirPort debuted at the Macworld Expo in New York City with Steve Jobs picking up an iBook supposedly to give the cameraman a better shot as he surfed the Web. Applause quickly built as people realized there were no wires. This was the first time Wireless LAN became publicly available at consumer pricing and easily available for home use. Before the release of the Airport, Wireless LAN was too expensive for consumer use and used exclusively in large corporate settings.
Originally WLAN hardware was so expensive that it was only used as an alternative to cabled LAN in places where cabling was difficult or impossible. Early development included industry-specific solutions and proprietary protocols, but at the end of the 1990s these were replaced by standards, primarily the various versions of IEEE 802.11 (Wi-Fi). An alternative ATM-like 5 GHz standardized technology, HIPERLAN, has so far not succeeded in the market, and with the release of the faster 54 Mbit/s 802.11a (5 GHz) and 802.11g (2.4 GHz) standards, almost certainly never will.
In November 2006, the Australian Commonwealth Scientific and Industrial Research Organisation (CSIRO) won a legal battle in the US federal court of Texas against Buffalo Technology which found the US manufacturer had failed to pay royalties on a US WLAN patent CSIRO had filed in 1996. CSIRO are currently engaged in legal cases with computer companies including Microsoft, Intel, Dell, Hewlett-Packard and Netgear which argue that the patent is invalid and should negate any royalties paid to CSIRO for WLAN-based products.[5]
[edit]
Benefits
The popularity of wireless LANs is a testament primarily to their convenience, cost efficiency, and ease of integration with other networks and network components. The majority of computers sold to consumers today come pre-equipped with all necessary wireless LAN technology.
The benefits of wireless LANs include:
Convenience: The wireless nature of such networks allows users to access network resources from nearly any convenient location within their primary networking environment (home or office). With the increasing saturation of laptop-style computers, this is particularly relevant.
Mobility: With the emergence of public wireless networks, users can access the internet even outside their normal work environment. Most chain coffee shops, for example, offer their customers a wireless connection to the internet at little or no cost.
Productivity: Users connected to a wireless network can maintain a nearly constant affiliation with their desired network as they move from place to place. For a business, this implies that an employee can potentially be more productive as his or her work can be accomplished from any convenient location.
Deployment: Initial setup of an infrastructure-based wireless network requires little more than a single access point. Wired networks, on the other hand, have the additional cost and complexity of actual physical cables being run to numerous locations (which can even be impossible for hard-to-reach locations within a building).
Expandability: Wireless networks can serve a suddenly-increased number of clients with the existing equipment. In a wired network, additional clients would require additional wiring.
Cost: Wireless networking hardware is at worst a modest increase from wired counterparts. This potentially increased cost is almost always more than outweighed by the savings in cost and labor associated to running physical cables.
[edit]
Disadvantages
Wireless LAN technology, while replete with the conveniences and advantages described above, has its share of downfalls. For a given networking situation, wireless LANs may not be desirable for a number of reasons. Most of these have to do with the inherent limitations of the technology.
Security: Wireless LAN transceivers are designed to serve computers throughout a structure with uninterrupted service using radio frequencies. Because of space and cost, the antennas typically present on wireless networking cards in the end computers are generally relatively poor. In order to properly receive signals using such limited antennas throughout even a modest area, the wireless LAN transceiver utilizes a fairly considerable amount of power. What this means is that not only can the wireless packets be intercepted by a nearby adversary's poorly-equipped computer, but more importantly, a user willing to spend a small amount of money on a good quality antenna can pick up packets at a remarkable distance; perhaps hundreds of times the radius as the typical user. In fact, there are even computer users dedicated to locating and sometimes even cracking into wireless networks, known as wardrivers. On a wired network, any adversary would first have to overcome the physical limitation of tapping into the actual wires, but this is not an issue with wireless packets. To combat this consideration, wireless networks users usually choose to utilize various encryption technologies available such as Wi-Fi Protected Access (WPA). Some of the older encryption methods, such as WEP are known to have weaknesses that a dedicated adversary can compromise. (See main article: Wireless security.)
Range: The typical range of a common 802.11g network with standard equipment is on the order of tens of meters. While sufficient for a typical home, it will be insufficient in a larger structure. To obtain additional range, repeaters or additional access points will have to be purchased. Costs for these items can add up quickly. Other technologies are in the development phase, however, which feature increased range, hoping to render this disadvantage irrelevant. (See WiMAX)
Reliability: Like any radio frequency transmission, wireless networking signals are subject to a wide variety of interference, as well as complex propagation effects (such as multipath, or especially in this case Rician fading) that are beyond the control of the network administrator. In the case of typical networks, modulation is achieved by complicated forms of phase-shift keying (PSK) or quadrature amplitude modulation (QAM), making interference and propagation effects all the more disturbing. As a result, important network resources such as servers are rarely connected wirelessly.
Speed: The speed on most wireless networks (typically 1-108 Mbit/s) is reasonably slow compared to the slowest common wired networks (100 Mbit/s up to several Gbit/s). There are also performance issues caused by TCP and its built-in congestion avoidance. For most users, however, this observation is irrelevant since the speed bottleneck is not in the wireless routing but rather in the outside network connectivity itself. For example, the maximum ADSL throughput (usually 8 Mbit/s or less) offered by telecommunications companies to general-purpose customers is already far slower than the slowest wireless network to which it is typically connected. That is to say, in most environments, a wireless network running at its slowest speed is still faster than the internet connection serving it in the first place. However, in specialized environments, the throughput of a wired network might be necessary. Newer standards such as 802.11n are addressing this limitation and will support peak throughputs in the range of 100-200 Mbit/s.
Wireless LANs present a host of issues for network managers. Unauthorized access points, broadcasted SSIDs, unknown stations, and spoofed MAC addresses are just a few of the problems addressed in WLAN troubleshooting. Most network analysis vendors, such as Network Instruments, Network General, and Fluke, offer WLAN troubleshooting tools or functionalities as part of their product line.
[edit]
Architecture
[edit]
Stations
All components that can connect into a wireless medium in a network are referred to as stations. All stations are equipped with wireless network interface cards (WNICs). Wireless stations fall into one of two categories: access points and clients.
Access points
Access points (APs) are base stations for the wireless network. They transmit and receive radio frequencies for wireless enabled devices to communicate with.
Clients
Wireless clients can be mobile devices such as laptops, personal digital assistants, IP phones, or fixed devices such as desktops and workstations that are equipped with a wireless network interface.
[edit]
Basic service set
The basic service set (BSS) is a set of all stations that can communicate with each other. There are two types of BSS: independent BSS and infrastructure BSS. Every BSS has an identification (ID) called the BSSID, which is the MAC address of the access point servicing the BSS.
Independent basic service set
An independent BSS is an ad-hoc network that contains no access points, which means they can not connect to any other basic service set.
Infrastructure basic service set
An infrastructure BSS can communicate with other stations not in the same basic service set by communicating through access points.
[edit]
Extended service set
An extended service set (ESS) is a set of connected BSSes. Access points in an ESS are connected by a distribution system. Each ESS has an ID called the SSID which is a 32-byte (maximum) character string. For example, "linksys" is the default SSID for Linksys routers.
[edit]
Distribution system
A distribution system connects access points in an extended service setup.
[edit]
Types of wireless LANs
[edit]
Peer-to-peer
Peer-to-Peer or ad-hoc wireless LAN
A peer-to-peer (P2P) allows wireless devices to directly communicate with each other. Wireless devices within range of each other can discover and communicate directly without involving central access points. This method is typically used by two computers so that they can connect to each other to form a network.
If a signal strength meter is used in this situation, it may not read the strength accurately and can be misleading, because it registers the strength of the strongest signal, which may be the closest computer.
802.11 specs define the physical layer (PHY) and MAC (Media Access Control) layers. However, unlike most other IEEE specs, 802.11 includes three alternative PHY standards: diffuse infrared operating at 1 Mbit/s in; frequency-hopping spread spectrum operating at 1 Mbit/s or 2 Mbit/s; and direct-sequence spread spectrum operating at 1 Mbit/s or 2 Mbit/s. A single 802.11 MAC standard is based on CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance). The 802.11 specification includes provisions designed to minimize collisions. Because two mobile units may both be in range of a common access point, but not in range of each other. The 802.11 has two basic modes of operation: Ad hoc mode enables peer-to-peer transmission between mobile units. Infrastructure mode in which mobile units communicate through an access point that serves as a bridge to a wired network infrastructure is the more common wireless LAN application the one being covered. Since wireless communication uses a more open medium for communication in comparison to wired LANs, the 802.11 designers also included a shared-key encryption mechanism, called wired equivalent privacy (WEP), or Wi-Fi Protected Access, (WPA, WPA2) to secure wireless computer networks.
[edit]
Bridge
A bridge can be used to connect networks, typically of different types. A wireless Ethernet bridge allows the connection of devices on a wired Ethernet network to a wireless network. The bridge acts as the connection point to the Wireless LAN.
[edit]
Wireless distribution system
Main article: Wireless Distribution System
When it is difficult to connect all of the access points in a network by wires, it is also possible to put up access points as repeaters.
[edit]
See also
Local area network
Wireless network
Exposed terminal problem
Hidden terminal problem
Fixed Wireless Data
Wireless LAN client comparison
Shared mesh
Switched mesh
USB
IEEE Workshops on Wireless LAN
[edit]
References
windows server 2008
Windows Server 2008
From Wikipedia, the free encyclopedia This article or section contains information about computer software currently in development.
The content may change as the software development progresses.
Windows Server 2008
(Part of the Microsoft Windows family)
Screenshot
Screenshot of Windows Server 2008 Beta 3 (Build 6001)
Developer
Microsoft
Web site: www.microsoft.com/windowsserver2008/
Release information
Preview version: Release Candidate 1 (December 5, 2007) info
Source model: Proprietary software
License: Microsoft EULA
Kernel type: Hybrid kernel
Support status
Currently Under Development
Further reading
Features new to Windows Vista
Development of Windows Vista
Windows Server 2008 is the next server operating system from Microsoft. It is the successor to Windows Server 2003. Windows Server 2008 introduces most of the new features from Windows Vista to Windows Server. This is a similar relationship to that between Windows Server 2003 and Windows XP.
It was known as Windows Server Codename "Longhorn" until May 16, 2007, when Bill Gates announced its official title during his keynote address at WinHEC.[1]
Beta 1 was released on July 27, 2005, Beta 2 was announced and released on May 23, 2006 at WinHEC 2006 and Beta 3 was released publicly on April 25, 2007.[2] Release Candidate 0 was released to the general public on September 24, 2007[3] and Release Candidate 1 was released to the general public on December 5, 2007. Windows Server 2008 will be released to manufacturing in the first quarter of 2008 with the official launch taking place on February 27, 2008.[4]Contents [hide]
1 Features
1.1 Server Core
1.2 Active Directory roles
1.3 Terminal Services
1.4 Windows PowerShell
1.5 Self-healing NTFS
1.6 Hyper-V
1.7 Windows System Resource Manager
1.8 Server Manager
1.9 Other features
1.9.1 Core OS improvements
1.9.2 Active Directory improvements
1.9.3 Policy related improvements
1.9.4 Disk management and file storage improvements
1.9.5 Protocol and cryptography improvements
1.9.6 Improvements due to client-side (Windows Vista) enhancements
1.9.7 Miscellaneous improvements
2 Supported platforms
3 Editions
4 See also
5 References
6 External links
6.1 Microsoft
6.2 Others
[edit]
Features
See also: Features new to Windows Vista
Windows Server 2008 is built from the same code base as Windows Vista Service Pack 1; therefore, it shares much of the same architecture and functionality. As the code base is common, it automatically benefits from most of the technical, security, management and administrative features new to Windows Vista such as the new improved rewritten networking stack (native IPv6, native wireless, speed and security improvements); improved image-based installation, deployment and recovery; improved diagnostics, monitoring, event logging and reporting tools; new security features such as Bitlocker and ASLR; improved Windows Firewall with secure default configuration; .NET Framework 3.0 technologies, specifically Windows Communication Foundation, Microsoft Message Queuing and Windows Workflow Foundation; and the core kernel, memory and file system improvements. Processors and memory devices are modelled as Plug and Play devices, to allow hot-plugging of these devices. This allows the system resources to be partitioned dynamically using Dynamic Hardware Partitioning; each partition having its own memory, processor and I/O host bridge devices independent of other partitions.[5]
[edit]
Server Core
Perhaps the most notable new feature of Windows Server 2008 is a new variation of installation called Server Core. Server Core is a significantly scaled-back installation where no Windows Explorer shell is installed, and all configuration and maintenance is done entirely through command line interface windows, or by connecting to the machine remotely using Microsoft Management Console. Server Core also does not include the .NET Framework, Internet Explorer or many other features not related to core server features. A Server Core machine can be configured for several basic roles: Domain controller/Active Directory Domain Services, ADLDS (ADAM), DNS Server, DHCP Server, file server, print server, Windows Media Server, Terminal Services Easy Print, TS Remote Programs, and TS Gateway, IIS 7 web server and Windows Server Virtualization virtual server. This last role is projected to be available at most 180 days after release of Windows Server 2008.
[edit]
Active Directory roles
Active Directory is expanded with identity, certificate and rights management services. Active Directory until Windows Server 2003 allowed network administrators to centrally manage connected computers, to set policies for groups of users, and to centrally deploy new applications to multiple computers. This role of Active Directory is being renamed as Active Directory Domain Services (ADDS).[6] A number of other additional services are being introduced, including Active Directory Federation Services (ADFS), Active Directory Lightweight Directory Services (ADLDS), (formerly Active Directory Application Mode, or ADAM), Active Directory Certificate Services (ADCS), and Active Directory Rights Management Services (ADRMS). Identity and certificate services allow administrators to manage user accounts and the digital certificates that allow them to access certain services and systems. Federation management services enable enterprises to share credentials with trusted partners and customers, allowing a consultant to use his company user name and password to log in on a client's network. Identity Integration Feature Pack is included as Active Directory Metadirectory Services. Each of these services represents a server role.
[edit]
Terminal Services
Windows Server 2008 features major upgrades to Terminal Services. Terminal Services now supports Remote Desktop Protocol 6.0. The most notable improvement is the ability to share a single application over a Remote Desktop connection, instead of the entire desktop. This feature is called Terminal Services Remote Programs. Other features new to Terminal Services include Terminal Services Gateway and Terminal Services Web Access (full web interface). With Terminal Services Gateway, authorized computers are able to connect securely to a Terminal Server or Remote Desktop from the Internet using RDP via HTTPS without implementing a VPN session first. Additional ports do not need to be opened in the firewall, RDP is tunneled through HTTPS. Terminal Services Web Access enables administrators to provide access to the Terminal Services Sessions via a Web interface. TS Web Access comes with an adjustable Webpart for IIS and Sharepoint, which advertises the possible applications and connections to the user. Using TS Gateway and TS Remote Programs, the whole communication is via HTTP(S) and the remote applications appear transparent to the user as if they are running locally. Multiple applications run in the same session to ensure that there is no need for additional licenses per user. Terminal Services Easy Print does not require administrators to install any printer drivers on the server, but guarantees successful client printer redirection and availability of all printer UI and properties for use in remote sessions. Terminal Services sessions are created in parallel, instead of a serial operation - the new session model can initiate at least four sessions in parallel, or more if a server has more than four processors.
[edit]
Windows PowerShell
Screenshot of a sample Windows PowerShell session.
Main article: Windows PowerShell
Windows Server 2008 is the first Windows operating system that will ship with Windows PowerShell, Microsoft's new extensible command line shell and task-based scripting technology.[7] PowerShell is based on object-oriented programming and version 2.0 of the Microsoft .NET Framework and includes more than 120 system administration utilities, consistent syntax and naming conventions, and built-in capabilities to work with common management data such as the Windows Registry, certificate store, or Windows Management Instrumentation. PowerShell's scripting language was specifically designed for IT administration, and can be used in place of cmd.exe and Windows Script Host.
[edit]
Self-healing NTFS
In previous Windows versions, if the operating system detected corruption in the file system of an NTFS volume, it marked the volume "dirty"; to correct errors on the volume, it had to be taken offline. With self-healing NTFS, an NTFS worker thread is spawned in the background which performs a localized fix-up of damaged data structures, with only the corrupted files/folders remaining unavailable without locking out the entire volume and needing the server to be taken down.[8]
[edit]
Hyper-V
Hyper-V architecture
Main article: Hyper-V
Hyper-V is an implementation of operating system-level virtualization, forming a core part of Microsoft's virtualization strategy. This hypervisor virtualizes servers on an operating system's kernel layer. It can be thought of as partitioning a single physical server into multiple small computational partitions. Hyper-V will include the ability to act as a Xen virtualization hypervisor host allowing Xen-enabled guest operating systems to run virtualized. This will not be a part of Windows Server 2008 initially, and will ship within 180 days after it.[9] It will be available only on x64 versions of Windows Server 2008.
[edit]
Windows System Resource Manager
Main article: Windows System Resource Manager
Windows System Resource Manager (WSRM) is being integrated into Windows Server 2008. It provides resource management and can be used to control how much resources a process or a user can use based on business priorities. Process Matching Criteria, which is defined by the name, type or owner of the process, enforces restrictions on the resource usage by a process that matches the criteria. CPU time, bandwidth that it can use, number of processors it can be run on, and memory allocated to a process can be restricted. Restrictions can be set to be imposed only on certain dates as well.
[edit]
Server Manager
Server Manager is a new roles-based management tool for Windows Server 2008[10]. It is a combination of Manage Your Server and Security Configuration Wizard from Windows Server 2003. Server Manager is an improvement of the Configure my server dialog that launches by default on Windows Server 2003 machines. However, rather than serve only as a starting point to configuring new roles, Server Manager gathers together all of the operations users would want to conduct on the server, such as, getting a remote deployment method set up, adding more server roles etc and provides a consolidated, portal-like view about the status of each role.
[edit]
Other features
Other new or enhanced features include:
[edit]
Core OS improvements
Fully multi-componentized operating system.
Improved hot patching, a feature that allows non-kernel patches to occur without the need for a reboot.
Support for being booted from Extensible Firmware Interface (EFI)-compliant firmware on x86-64 systems.
[edit]
Active Directory improvements
A new "Read-Only Domain Controller" operation mode in Active Directory, intended for use in branch office scenarios where a domain controller may reside in a low physical security environment. The RODC holds a non-writeable copy of Active Directory, and redirects all write attempts to a Full Domain Controller. It replicates all accounts except sensitive ones. In RODC mode, credentials are not cached by default. Moreover, only the Domain Controller running the PDC-Emulator needs to run Windows Server 2008. Also, local administrators can log on to the machine to perform maintenance tasks without requiring administrative rights on the domain.
Restartable Active Directory allows ADDS to be stopped and restarted from the Management Console or the command-line without rebooting the domain controller. This reduces downtime for offline operations and reduces overall DC servicing requirements with Server Core. ADDS is implemented as a Domain Controller Service in Windows Server 2008.
[edit]
Policy related improvements
All of the Group Policy improvements from Windows Vista. Group Policy Management Console (GPMC) is built-in. The Group Policy objects are indexed for search and can be commented on.[11]
Policy-based networking with Network Access Protection, improved branch management and enhanced end user collaboration. Policies can be created to ensure greater Quality of Service for certain applications or services that require prioritization of network bandwidth between client and server.
Granular password settings within a single domain - ability to implement different password policies for administrative accounts on a "group" and "user" basis, instead of a single set of password settings to the whole domain.
[edit]
Disk management and file storage improvements
The ability to resize hard disk partitions without stopping the server, even the system partition. (Note: this only applies to simple and spanned volumes. Stripes cannot be extended or shrunk.)
Shadow Copy based block-level backup which supports optical media, network shares and Windows Recovery Environment.
DFS enhancements - SYSVOL on DFS-R, Read-only Folder Replication Member. There is also support for domain-based DFS namespaces that exceed the previous size recommendation of 5,000 folders with targets in a namespace. [12]
Several improvements to failover clusters (High-availability clusters).[13]
Internet Storage Naming Server (iSNS) enables central registration, deregistration and queries for iSCSI hard drives.
[edit]
Protocol and cryptography improvements
Support for 128- and 256-bit AES encryption for the Kerberos authentication protocol.
New cryptography (CNG) API which supports elliptic curve cryptography and improved certificate management.
Secure Socket Tunneling Protocol, a new Microsoft proprietary VPN protocol.
AuthIP, a Microsoft proprietary extension of the IKE cryptographic protocol used in IPsec VPN networks.
Server Message Block 2.0 protocol in the new TCP/IP stack provides a number of communication enhancements, including greater performance when connecting to file shares over high-latency links and better security through the use of mutual authentication and message signing.
[edit]
Improvements due to client-side (Windows Vista) enhancements
Searching Windows Server 2008 servers from Windows Vista clients delegates the query to the server, which uses the Windows Search technology to search and transfer the results back to the client.
In a networked environment with a print server running Windows Vista, clients can render print jobs locally before sending them to print servers to reduce the load on the server and increase its availability.
Event forwarding aggregates and forwards logs of subscribed Windows Vista client computers back to a central console. Event forwarding can be enabled on the client subscribers from the central server directly from the event management console.
Offline Files are cached locally so that they are available even if the server is not, with copies seamlessly updating when the client and server are reconnected.
[edit]
Miscellaneous improvements
Windows Deployment Services replacing Automated Deployment Services and Remote Installation Services. Windows Deployment Services (WDS) support an enhanced multicast feature when deploying operating system images. [14]
Internet Information Services 7 - Increased security, xcopy-deployment, improved diagnostic tools, delegated administration.
An optional "Desktop Experience" component provides the same Windows Aero user interface as Windows Vista, both for local users, as well as remote users connecting through Remote Desktop.
[edit]
Supported platforms
Most editions of Windows Server 2008 will be available in x64 (64-bit) and x86 (32-bit) versions. Windows Server 2008 for Itanium-based Systems will support IA-64 processors. The IA-64 version will be optimized for high workload scenarios like database servers and Line of Business (LOB) applications. As such it will not be optimized for use as a file server or media server. Microsoft has announced that Windows Server 2008 will be the last 32-bit Windows server operating system.[15]
[edit]
Editions
Windows Server 2008 will be available in the editions listed below,[16] similar to Windows Server 2003.
Windows Server 2008 Standard Edition (x86 and x86-64)
Windows Server 2008 Enterprise Edition (x86 and x86-64)
Windows Server 2008 Datacenter Edition (x86 and x86-64)
Windows Web Server 2008 (x86 and x86-64)
Windows Storage Server 2008 (x86 and x86-64)
Windows Small Business Server 2008 (Codenamed "Cougar") (x86-64) for small businesses
Windows Essential Business Server 2008 (Codenamed "Centro") (x86-64) for medium-sized businesses [17]
Windows Server 2008 for Itanium-based Systems (IA-64)
Server Core is available in the Standard, Enterprise and Datacenter editions. It is not available in Web edition or in the Itanium edition. It is important to note that Server Core is simply a server role supported by some of the editions, and not a separate edition by itself. As of Beta 3, each edition has a separate evaluation DVD.
[edit]
See also
Development of Windows Vista
Windows Server System
List of Microsoft software codenames
[edit]
References
^ Miller, Michael J. (2007-05-15). Gates at WinHec 2007: Windows Server 2008, Rally, Home Server and More. Forward Thinking. Retrieved on 2007-07-09.
^ Lowe, David (2007-04-25). Beta 3 is Go!. Windows Server Division WebLog. Microsoft. Retrieved on 2007-04-25.
^ Ralston, Ward (2007-09-24). Windows Server 2008 Rc0 Released!. Windows Server Division WebLog. Microsoft. Retrieved on 2007-09-24.
^ Nate Mook. New Windows Server, Visual Studio, SQL Server to Launch in February. BetaNews. Retrieved on 2007-07-11.
^ Dynamic Hardware Partitioning Architecture. MSDN. Retrieved on 2007-07-23.
^ Hynes, Byron (November 2006). The Future of Windows: Directory Services in Windows Server 2008. TechNet Magazine. Retrieved on 2007-05-02.
^ Snover, Jeffrey (2007-03-28). Announced: PowerShell to Ship in Windows Server 2008. Blog of Windows PowerShell team. Microsoft. Retrieved on 2007-04-06.
^ Loveall, John (2006). Storage improvements in Windows Vista and Windows Server 2008 (PowerPoint). Microsoft Corporation. Retrieved on 2007-07-09.
^ Microsoft Extends Virtualization Strategy, Outlines Product Road Map. Microsoft (2006-05-22). Retrieved on 2007-07-09.
^ Server Manager. Windows Server 2008 Technical Library. Microsoft TechNet (2007-06-25). Retrieved on 2007-05-02.
^ Keith Ward. Top 10 Overlooked Windows Server 2008 Features, Part 2. Redmond Developer News.
^ Breaking the 5K Folder “Barrier” in Domain-Based Namespaces: Filing Cabinet blog
^ Failover Clustering with Windows Server 2008. Microsoft (2007-01-17). Retrieved on 2007-07-09.
^ Multicasting OS deployments with Windows Server 2008
^ Heaton, Alex (2007-05-18). On 64-bit and Windows Client. Windows Vista Team Blog. Retrieved on 2007-07-09.
^ Windows Server 2008 Product Editions. Microsoft (2007-04-25). Retrieved on 2007-07-09.
^ Annoucing Windows Essential Business Server
[edit]
External links
[edit]
Microsoft
Official site for Windows Server 2008
Microsoft TechCenter for Windows Server 2008
New Networking Features in Windows Server 2008 and Windows Vista — lengthy article from Microsoft Technet covering new networking features in detail
Changes in Functionality from Windows Server 2003 with SP1 to Windows Server 2008
Windows Server 2008 Technical Overview
[edit]
Others
Screenshots of Server Components from Latest Longhorn Builds
ZDnet UK article
News.com
winsupersite.com Preview
winsupersite.com Preview 2
Windows Server 2008 Updates site
From Wikipedia, the free encyclopedia This article or section contains information about computer software currently in development.
The content may change as the software development progresses.
Windows Server 2008
(Part of the Microsoft Windows family)
Screenshot
Screenshot of Windows Server 2008 Beta 3 (Build 6001)
Developer
Microsoft
Web site: www.microsoft.com/windowsserver2008/
Release information
Preview version: Release Candidate 1 (December 5, 2007) info
Source model: Proprietary software
License: Microsoft EULA
Kernel type: Hybrid kernel
Support status
Currently Under Development
Further reading
Features new to Windows Vista
Development of Windows Vista
Windows Server 2008 is the next server operating system from Microsoft. It is the successor to Windows Server 2003. Windows Server 2008 introduces most of the new features from Windows Vista to Windows Server. This is a similar relationship to that between Windows Server 2003 and Windows XP.
It was known as Windows Server Codename "Longhorn" until May 16, 2007, when Bill Gates announced its official title during his keynote address at WinHEC.[1]
Beta 1 was released on July 27, 2005, Beta 2 was announced and released on May 23, 2006 at WinHEC 2006 and Beta 3 was released publicly on April 25, 2007.[2] Release Candidate 0 was released to the general public on September 24, 2007[3] and Release Candidate 1 was released to the general public on December 5, 2007. Windows Server 2008 will be released to manufacturing in the first quarter of 2008 with the official launch taking place on February 27, 2008.[4]Contents [hide]
1 Features
1.1 Server Core
1.2 Active Directory roles
1.3 Terminal Services
1.4 Windows PowerShell
1.5 Self-healing NTFS
1.6 Hyper-V
1.7 Windows System Resource Manager
1.8 Server Manager
1.9 Other features
1.9.1 Core OS improvements
1.9.2 Active Directory improvements
1.9.3 Policy related improvements
1.9.4 Disk management and file storage improvements
1.9.5 Protocol and cryptography improvements
1.9.6 Improvements due to client-side (Windows Vista) enhancements
1.9.7 Miscellaneous improvements
2 Supported platforms
3 Editions
4 See also
5 References
6 External links
6.1 Microsoft
6.2 Others
[edit]
Features
See also: Features new to Windows Vista
Windows Server 2008 is built from the same code base as Windows Vista Service Pack 1; therefore, it shares much of the same architecture and functionality. As the code base is common, it automatically benefits from most of the technical, security, management and administrative features new to Windows Vista such as the new improved rewritten networking stack (native IPv6, native wireless, speed and security improvements); improved image-based installation, deployment and recovery; improved diagnostics, monitoring, event logging and reporting tools; new security features such as Bitlocker and ASLR; improved Windows Firewall with secure default configuration; .NET Framework 3.0 technologies, specifically Windows Communication Foundation, Microsoft Message Queuing and Windows Workflow Foundation; and the core kernel, memory and file system improvements. Processors and memory devices are modelled as Plug and Play devices, to allow hot-plugging of these devices. This allows the system resources to be partitioned dynamically using Dynamic Hardware Partitioning; each partition having its own memory, processor and I/O host bridge devices independent of other partitions.[5]
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Server Core
Perhaps the most notable new feature of Windows Server 2008 is a new variation of installation called Server Core. Server Core is a significantly scaled-back installation where no Windows Explorer shell is installed, and all configuration and maintenance is done entirely through command line interface windows, or by connecting to the machine remotely using Microsoft Management Console. Server Core also does not include the .NET Framework, Internet Explorer or many other features not related to core server features. A Server Core machine can be configured for several basic roles: Domain controller/Active Directory Domain Services, ADLDS (ADAM), DNS Server, DHCP Server, file server, print server, Windows Media Server, Terminal Services Easy Print, TS Remote Programs, and TS Gateway, IIS 7 web server and Windows Server Virtualization virtual server. This last role is projected to be available at most 180 days after release of Windows Server 2008.
[edit]
Active Directory roles
Active Directory is expanded with identity, certificate and rights management services. Active Directory until Windows Server 2003 allowed network administrators to centrally manage connected computers, to set policies for groups of users, and to centrally deploy new applications to multiple computers. This role of Active Directory is being renamed as Active Directory Domain Services (ADDS).[6] A number of other additional services are being introduced, including Active Directory Federation Services (ADFS), Active Directory Lightweight Directory Services (ADLDS), (formerly Active Directory Application Mode, or ADAM), Active Directory Certificate Services (ADCS), and Active Directory Rights Management Services (ADRMS). Identity and certificate services allow administrators to manage user accounts and the digital certificates that allow them to access certain services and systems. Federation management services enable enterprises to share credentials with trusted partners and customers, allowing a consultant to use his company user name and password to log in on a client's network. Identity Integration Feature Pack is included as Active Directory Metadirectory Services. Each of these services represents a server role.
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Terminal Services
Windows Server 2008 features major upgrades to Terminal Services. Terminal Services now supports Remote Desktop Protocol 6.0. The most notable improvement is the ability to share a single application over a Remote Desktop connection, instead of the entire desktop. This feature is called Terminal Services Remote Programs. Other features new to Terminal Services include Terminal Services Gateway and Terminal Services Web Access (full web interface). With Terminal Services Gateway, authorized computers are able to connect securely to a Terminal Server or Remote Desktop from the Internet using RDP via HTTPS without implementing a VPN session first. Additional ports do not need to be opened in the firewall, RDP is tunneled through HTTPS. Terminal Services Web Access enables administrators to provide access to the Terminal Services Sessions via a Web interface. TS Web Access comes with an adjustable Webpart for IIS and Sharepoint, which advertises the possible applications and connections to the user. Using TS Gateway and TS Remote Programs, the whole communication is via HTTP(S) and the remote applications appear transparent to the user as if they are running locally. Multiple applications run in the same session to ensure that there is no need for additional licenses per user. Terminal Services Easy Print does not require administrators to install any printer drivers on the server, but guarantees successful client printer redirection and availability of all printer UI and properties for use in remote sessions. Terminal Services sessions are created in parallel, instead of a serial operation - the new session model can initiate at least four sessions in parallel, or more if a server has more than four processors.
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Windows PowerShell
Screenshot of a sample Windows PowerShell session.
Main article: Windows PowerShell
Windows Server 2008 is the first Windows operating system that will ship with Windows PowerShell, Microsoft's new extensible command line shell and task-based scripting technology.[7] PowerShell is based on object-oriented programming and version 2.0 of the Microsoft .NET Framework and includes more than 120 system administration utilities, consistent syntax and naming conventions, and built-in capabilities to work with common management data such as the Windows Registry, certificate store, or Windows Management Instrumentation. PowerShell's scripting language was specifically designed for IT administration, and can be used in place of cmd.exe and Windows Script Host.
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Self-healing NTFS
In previous Windows versions, if the operating system detected corruption in the file system of an NTFS volume, it marked the volume "dirty"; to correct errors on the volume, it had to be taken offline. With self-healing NTFS, an NTFS worker thread is spawned in the background which performs a localized fix-up of damaged data structures, with only the corrupted files/folders remaining unavailable without locking out the entire volume and needing the server to be taken down.[8]
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Hyper-V
Hyper-V architecture
Main article: Hyper-V
Hyper-V is an implementation of operating system-level virtualization, forming a core part of Microsoft's virtualization strategy. This hypervisor virtualizes servers on an operating system's kernel layer. It can be thought of as partitioning a single physical server into multiple small computational partitions. Hyper-V will include the ability to act as a Xen virtualization hypervisor host allowing Xen-enabled guest operating systems to run virtualized. This will not be a part of Windows Server 2008 initially, and will ship within 180 days after it.[9] It will be available only on x64 versions of Windows Server 2008.
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Windows System Resource Manager
Main article: Windows System Resource Manager
Windows System Resource Manager (WSRM) is being integrated into Windows Server 2008. It provides resource management and can be used to control how much resources a process or a user can use based on business priorities. Process Matching Criteria, which is defined by the name, type or owner of the process, enforces restrictions on the resource usage by a process that matches the criteria. CPU time, bandwidth that it can use, number of processors it can be run on, and memory allocated to a process can be restricted. Restrictions can be set to be imposed only on certain dates as well.
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Server Manager
Server Manager is a new roles-based management tool for Windows Server 2008[10]. It is a combination of Manage Your Server and Security Configuration Wizard from Windows Server 2003. Server Manager is an improvement of the Configure my server dialog that launches by default on Windows Server 2003 machines. However, rather than serve only as a starting point to configuring new roles, Server Manager gathers together all of the operations users would want to conduct on the server, such as, getting a remote deployment method set up, adding more server roles etc and provides a consolidated, portal-like view about the status of each role.
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Other features
Other new or enhanced features include:
[edit]
Core OS improvements
Fully multi-componentized operating system.
Improved hot patching, a feature that allows non-kernel patches to occur without the need for a reboot.
Support for being booted from Extensible Firmware Interface (EFI)-compliant firmware on x86-64 systems.
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Active Directory improvements
A new "Read-Only Domain Controller" operation mode in Active Directory, intended for use in branch office scenarios where a domain controller may reside in a low physical security environment. The RODC holds a non-writeable copy of Active Directory, and redirects all write attempts to a Full Domain Controller. It replicates all accounts except sensitive ones. In RODC mode, credentials are not cached by default. Moreover, only the Domain Controller running the PDC-Emulator needs to run Windows Server 2008. Also, local administrators can log on to the machine to perform maintenance tasks without requiring administrative rights on the domain.
Restartable Active Directory allows ADDS to be stopped and restarted from the Management Console or the command-line without rebooting the domain controller. This reduces downtime for offline operations and reduces overall DC servicing requirements with Server Core. ADDS is implemented as a Domain Controller Service in Windows Server 2008.
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Policy related improvements
All of the Group Policy improvements from Windows Vista. Group Policy Management Console (GPMC) is built-in. The Group Policy objects are indexed for search and can be commented on.[11]
Policy-based networking with Network Access Protection, improved branch management and enhanced end user collaboration. Policies can be created to ensure greater Quality of Service for certain applications or services that require prioritization of network bandwidth between client and server.
Granular password settings within a single domain - ability to implement different password policies for administrative accounts on a "group" and "user" basis, instead of a single set of password settings to the whole domain.
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Disk management and file storage improvements
The ability to resize hard disk partitions without stopping the server, even the system partition. (Note: this only applies to simple and spanned volumes. Stripes cannot be extended or shrunk.)
Shadow Copy based block-level backup which supports optical media, network shares and Windows Recovery Environment.
DFS enhancements - SYSVOL on DFS-R, Read-only Folder Replication Member. There is also support for domain-based DFS namespaces that exceed the previous size recommendation of 5,000 folders with targets in a namespace. [12]
Several improvements to failover clusters (High-availability clusters).[13]
Internet Storage Naming Server (iSNS) enables central registration, deregistration and queries for iSCSI hard drives.
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Protocol and cryptography improvements
Support for 128- and 256-bit AES encryption for the Kerberos authentication protocol.
New cryptography (CNG) API which supports elliptic curve cryptography and improved certificate management.
Secure Socket Tunneling Protocol, a new Microsoft proprietary VPN protocol.
AuthIP, a Microsoft proprietary extension of the IKE cryptographic protocol used in IPsec VPN networks.
Server Message Block 2.0 protocol in the new TCP/IP stack provides a number of communication enhancements, including greater performance when connecting to file shares over high-latency links and better security through the use of mutual authentication and message signing.
[edit]
Improvements due to client-side (Windows Vista) enhancements
Searching Windows Server 2008 servers from Windows Vista clients delegates the query to the server, which uses the Windows Search technology to search and transfer the results back to the client.
In a networked environment with a print server running Windows Vista, clients can render print jobs locally before sending them to print servers to reduce the load on the server and increase its availability.
Event forwarding aggregates and forwards logs of subscribed Windows Vista client computers back to a central console. Event forwarding can be enabled on the client subscribers from the central server directly from the event management console.
Offline Files are cached locally so that they are available even if the server is not, with copies seamlessly updating when the client and server are reconnected.
[edit]
Miscellaneous improvements
Windows Deployment Services replacing Automated Deployment Services and Remote Installation Services. Windows Deployment Services (WDS) support an enhanced multicast feature when deploying operating system images. [14]
Internet Information Services 7 - Increased security, xcopy-deployment, improved diagnostic tools, delegated administration.
An optional "Desktop Experience" component provides the same Windows Aero user interface as Windows Vista, both for local users, as well as remote users connecting through Remote Desktop.
[edit]
Supported platforms
Most editions of Windows Server 2008 will be available in x64 (64-bit) and x86 (32-bit) versions. Windows Server 2008 for Itanium-based Systems will support IA-64 processors. The IA-64 version will be optimized for high workload scenarios like database servers and Line of Business (LOB) applications. As such it will not be optimized for use as a file server or media server. Microsoft has announced that Windows Server 2008 will be the last 32-bit Windows server operating system.[15]
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Editions
Windows Server 2008 will be available in the editions listed below,[16] similar to Windows Server 2003.
Windows Server 2008 Standard Edition (x86 and x86-64)
Windows Server 2008 Enterprise Edition (x86 and x86-64)
Windows Server 2008 Datacenter Edition (x86 and x86-64)
Windows Web Server 2008 (x86 and x86-64)
Windows Storage Server 2008 (x86 and x86-64)
Windows Small Business Server 2008 (Codenamed "Cougar") (x86-64) for small businesses
Windows Essential Business Server 2008 (Codenamed "Centro") (x86-64) for medium-sized businesses [17]
Windows Server 2008 for Itanium-based Systems (IA-64)
Server Core is available in the Standard, Enterprise and Datacenter editions. It is not available in Web edition or in the Itanium edition. It is important to note that Server Core is simply a server role supported by some of the editions, and not a separate edition by itself. As of Beta 3, each edition has a separate evaluation DVD.
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See also
Development of Windows Vista
Windows Server System
List of Microsoft software codenames
[edit]
References
^ Miller, Michael J. (2007-05-15). Gates at WinHec 2007: Windows Server 2008, Rally, Home Server and More. Forward Thinking. Retrieved on 2007-07-09.
^ Lowe, David (2007-04-25). Beta 3 is Go!. Windows Server Division WebLog. Microsoft. Retrieved on 2007-04-25.
^ Ralston, Ward (2007-09-24). Windows Server 2008 Rc0 Released!. Windows Server Division WebLog. Microsoft. Retrieved on 2007-09-24.
^ Nate Mook. New Windows Server, Visual Studio, SQL Server to Launch in February. BetaNews. Retrieved on 2007-07-11.
^ Dynamic Hardware Partitioning Architecture. MSDN. Retrieved on 2007-07-23.
^ Hynes, Byron (November 2006). The Future of Windows: Directory Services in Windows Server 2008. TechNet Magazine. Retrieved on 2007-05-02.
^ Snover, Jeffrey (2007-03-28). Announced: PowerShell to Ship in Windows Server 2008. Blog of Windows PowerShell team. Microsoft. Retrieved on 2007-04-06.
^ Loveall, John (2006). Storage improvements in Windows Vista and Windows Server 2008 (PowerPoint). Microsoft Corporation. Retrieved on 2007-07-09.
^ Microsoft Extends Virtualization Strategy, Outlines Product Road Map. Microsoft (2006-05-22). Retrieved on 2007-07-09.
^ Server Manager. Windows Server 2008 Technical Library. Microsoft TechNet (2007-06-25). Retrieved on 2007-05-02.
^ Keith Ward. Top 10 Overlooked Windows Server 2008 Features, Part 2. Redmond Developer News.
^ Breaking the 5K Folder “Barrier” in Domain-Based Namespaces: Filing Cabinet blog
^ Failover Clustering with Windows Server 2008. Microsoft (2007-01-17). Retrieved on 2007-07-09.
^ Multicasting OS deployments with Windows Server 2008
^ Heaton, Alex (2007-05-18). On 64-bit and Windows Client. Windows Vista Team Blog. Retrieved on 2007-07-09.
^ Windows Server 2008 Product Editions. Microsoft (2007-04-25). Retrieved on 2007-07-09.
^ Annoucing Windows Essential Business Server
[edit]
External links
[edit]
Microsoft
Official site for Windows Server 2008
Microsoft TechCenter for Windows Server 2008
New Networking Features in Windows Server 2008 and Windows Vista — lengthy article from Microsoft Technet covering new networking features in detail
Changes in Functionality from Windows Server 2003 with SP1 to Windows Server 2008
Windows Server 2008 Technical Overview
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Others
Screenshots of Server Components from Latest Longhorn Builds
ZDnet UK article
News.com
winsupersite.com Preview
winsupersite.com Preview 2
Windows Server 2008 Updates site
windows server 2003
Windows Server 2003
From Wikipedia, the free encyclopedia
Windows Server 2003
(Part of the Microsoft Windows family)
Screenshot
Screenshot of Windows Server 2003 Enterprise Edition
Developer
Microsoft
Web site: www.microsoft.com/windowsserver2003/
Release information
Release date: April 24, 2003 info
Current version: 2003 SP2 (5.2.3790.3959), March 13, 2007 info
Source model: Shared source
License: MS-EULA
Kernel type: Hybrid kernel
Support status
Current
Windows Server 2003 is a server operating system produced by Microsoft. Introduced on April 24, 2003 as the successor to Windows 2000 Server, it is considered by Microsoft to be the cornerstone of their Windows Server System line of business server products. An updated version, Windows Server 2003 R2 was released to manufacturing on 6 December 2005
According to Microsoft, Windows Server 2003 is more scalable and delivers better performance than its predecessor, Windows 2000.[1]Contents [hide]
1 Overview
2 New and updated features
3 Improvements
3.1 Service Pack 1
3.2 Windows Server 2003 R2
3.2.1 New features of Windows Server 2003 R2
3.3 Service Pack 2
4 Variants
4.1 Windows Small Business Server
4.2 Web Edition
4.3 Standard Edition
4.4 Enterprise Edition
4.5 Datacenter Edition
4.6 Windows Compute Cluster Server
4.7 Windows Storage Server
4.7.1 Features
4.7.2 Editions
4.8 Home Server
5 Editions and pricing
6 See also
7 References
8 External links
8.1 Microsoft
8.2 Other
[edit]
Overview
Released on April 24, 2003,[2] Windows Server 2003 (which carries the version number 5.2) is the follow-up to Windows 2000 Server, incorporating compatibility and other features from Windows XP. Unlike Windows 2000 Server, Windows Server 2003's default installation has none of the server components enabled, to reduce the attack surface of new machines. Windows Server 2003 includes compatibility modes to allow older applications to run with greater stability. It was made more compatible with Windows NT 4.0 domain-based networking. Incorporating and upgrading a Windows NT 4.0 domain to Windows 2000 was considered difficult and time-consuming, and generally was considered an all-or-nothing upgrade, particularly when dealing with Active Directory. Windows Server 2003 brought in enhanced Active Directory compatibility, and better deployment support, to ease the transition from Windows NT 4.0 to Windows Server 2003 and Windows XP Professional.
Changes to various services include the IIS web server (which was almost completely rewritten to improve performance and security), Distributed File System (which now supports hosting multiple DFS roots on a single server), Terminal Server, Active Directory, Print Server, and a number of other areas. Windows Server 2003 was also the first operating system released by Microsoft after the announcement of their Trustworthy Computing initiative, and as a result, contains a number of changes to security defaults and practices.
The product went through several name changes during the course of development. When first announced in 2000, it was known by its codename, "Whistler Server"; it was then named "Windows 2002 Server" for a brief time in mid-2001, before being renamed "Windows .NET Server" as part of Microsoft's effort to promote their new integrated enterprise and development framework, Microsoft .NET. It was later renamed to "Windows .NET Server 2003". Due to fears of confusing the market about what ".NET" represents and responding to criticism, Microsoft removed .NET from the name during the Release Candidate stage in late-2002. This allowed the name .NET to exclusively apply to the .NET Framework, as previously it had appeared that .NET was just a tag for a generation of Microsoft products.
In 2005, Microsoft announced Windows Server 2008 (at the time known as Windows Server "Longhorn") as the next major version of Windows Server after Windows Server 2003. Windows Server 2008 currently has a targeted release date of February 27, 2008.
[edit]
New and updated features
Manage Your Server
See also: Features new to Windows XP
Most versions of Windows Server include Terminal Services support (using the Remote Desktop Protocol), enabling multiple simultaneous remote graphical logins. This enables thin client computing on the windows platform, where all applications run remotely on the server. This feature was first introduced with a special "Terminal Server Edition" of Windows NT Server 4.0, but became more important when made a standard part of Windows 2000.
Internet Information Services (IIS) v6.0 - again, versions of IIS were available on Windows 2000 and earlier, but IIS is improved significantly in Windows Server 2003.
Active Directory - like Terminal Services, significantly improved since Windows 2000.
Increased default security over previous versions, due to the built-in firewall and most services being disabled by default.
Message Queuing - significantly improved since Windows 2000.
Manage Your Server - a role management administrative tool that allows an administrator to choose what functionality the server should provide.
[edit]
Improvements
There are a number of improvements from Windows 2000 server, notably:
Improvements to Active Directory (such as the ability to deactivate classes from the schema, or to run multiple instances of the directory server (ADAM))
Improvements to Group Policy handling and administration
Improved disk management, including the ability to back up from shadows of files, allowing the backup of open files.
Improved scripting and command line tools, which are part of Microsoft's initiative to bring a complete command shell to the next version of Windows.
Support for a hardware-based "watchdog timer", which can restart the server if the operating system does not respond within a certain amount of time.[3]
[edit]
Service Pack 1
On March 30, 2005, Microsoft released Service Pack 1 for Windows Server 2003. Among the improvements are many of the same updates that were provided to Windows XP users with Service Pack 2. Features that are added with Service Pack 1 include:
Security Configuration Wizard: A tool that allows administrators to more easily research, and make changes to, security policies.[4]
Hot Patching: This feature is set to extend Windows Server 2003 ability to take DLL, Driver, and non-kernel patches without a reboot.
IIS 6.0 Metabase Auditing: Allowing the tracking of metabase edits.[5]
Windows Firewall: Brings many of the improvements from Windows XP Service Pack 2 to Windows Server 2003; also with the Security Configuration Wizard, it allows administrators to more easily manage the incoming open ports, as it will automatically detect and select default roles.
Other networking improvements include support for Wireless Provisioning Services, better IPv6 support, and new protections against SYN flood TCP attacks.[6]
Post-Setup Security Updates: A default mode that is turned on when a Service Pack 1 server is first booted up after installation. It configures the firewall to block all incoming connections, and directs the user to install updates.
Data Execution Prevention (DEP): Support for the No Execute (NX) bit which helps to prevent buffer overflow exploits that are often the attack vector of Windows Server exploits.[7]
Windows Media Player version 10
A full list of updates is available in the Microsoft Knowledge Base.[8]
[edit]
Windows Server 2003 R2
Windows Server 2003 R2, an update of Windows Server 2003, was released to manufacturing on 6 December 2005. It is distributed on two CDs, with one CD being the Windows Server 2003 SP1 CD. The other CD adds many optionally installable features for Windows Server 2003. The R2 update was released for all x86 and x64 versions, but not for Itanium versions.[9]
[edit]
New features of Windows Server 2003 R2
Branch Office Server Management
Centralized management tools for file and printers
Enhanced Distributed File System (DFS) namespace management interface
More efficient WAN data replication with Remote Differential Compression.
Identity and Access Management
Extranet Single Sign-On and identity federation
Centralized administration of extranet application access
Automated disabling of extranet access based on Active Directory account information
User access logging
Cross-platform web Single Sign-On and password synchronization using Network Information Service (NIS)
Storage Management
File Server Resource Manager (storage utilization reporting)
Enhanced quota management
File screening limits files types allowed
Storage Manager for Storage Area Networks (SAN) (storage array configuration)
Server Virtualization
A new licensing policy allows up to 4 virtual instances on Enterprise Edition and Unlimited on Datacenter Edition
Utilities and SDK for UNIX-Based Applications add-on, giving a relatively full Unix development environment.
Base Utilities
SVR-5 Utilities
Base SDK
GNU SDK
GNU Utilities
Perl 5
Visual Studio Debugger Add-in
[edit]
Service Pack 2
Service Pack 2 for Windows Server 2003 was released on March 13, 2007.[10] The release date was originally scheduled for the first half of 2006.[11] On June 13, 2006, Microsoft made an initial test version of Service Pack 2 available to Microsoft Connect users, with a build number of 2721. This was followed by build 2805, known as Beta 2 Refresh. The latest build is the build 3959.
Microsoft has described Service Pack 2 as a "standard" service pack release containing previously-released security updates, hotfixes, and reliability and performance improvements.[12] In addition, Service Pack 2 contains Microsoft Management Console 3.0, Windows Deployment Services (which replaces Remote Installation Services), support for WPA2, and improvements to IPSec and MSConfig. Service Pack 2 also adds Windows Server 2003 Scalable Networking Pack (SNP),[13] which allows hardware acceleration for processing network packets, thereby enabling faster throughput. SNP was previously available as an out-of-band update for Windows Server 2003 Service Pack 1.
[edit]
Variants
This Microsoft server comes in several variants, each targeted towards a particular size and type of business: See Compare the Editions of Windows Server 2003 for a concise comparison. In general, all variants of Windows Server 2003 have the ability to share files and printers, act as an application server, and host message queues, provide email services, authenticate users, act as an X.509 certificate server, provide LDAP directory services, serve streaming media, and to perform other server-oriented functions.
[edit]
Windows Small Business Server
Main article: Windows Small Business Server
SBS includes Windows Server and additional technologies aimed at providing a small business with a complete technology solution. The technologies are integrated to enable small business with targeted solutions such as the Remote Web Workplace, and offer management benefits such as integrated setup, enhanced monitoring, a unified management console, and remote access.
The Standard Edition of SBS includes Windows SharePoint Services for collaboration, Microsoft Exchange server for e-mail, Fax Server, and the Active Directory for user management. The product also provides a basic firewall, DHCP server and NAT router using either two network cards or one network card in addition to a hardware router.
The Premium Edition of SBS includes the above plus Microsoft SQL Server 2000 and Microsoft Internet Security and Acceleration Server 2004.
SBS has its own type of Client Access License (CAL) that is different and costs slightly more than CALs for the other editions of Windows Server 2003. However, the SBS CAL encompasses the user CALs for Windows Server, Exchange Server, SQL Server, and ISA Server, and hence is less expensive than buying all the other CALs individually.
SBS server has the following design limitations:[14]
Only one computer in a domain can be running Windows Server 2003 for Small Business Server.
Windows Server 2003 for Small Business Server must be the root of the Active Directory forest.
Windows Server 2003 for Small Business Server cannot trust any other domains.
Windows Server 2003 for Small Business Server is limited to 75 users or devices depending on which type of CAL.
Windows Server 2003 for Small Business Server is limited to 4GB of RAM (Random Access Memory).
A Windows Server 2003 for Small Business Server domain cannot have any child domains.
Terminal Services only operates in remote administration mode on the server running SBS 2003, and only two simultaneous RDP sessions are allowed. (Change from SBS 2000 policy)[15]
To remove the limits from SBS server and upgrade from Small Business Server to regular Windows Server, Exchange Server, SQL and ISA server versions there is a Windows Small Business Server 2003 R2 Transition Pack.[1]
[edit]
Web Edition
Windows Server 2003, Web Edition is mainly for building and hosting Web applications, Web pages, and XML Web Services. It is designed to be used primarily as an IIS 6.0 Web server and provides a platform for rapidly developing and deploying XML Web services and applications that use ASP.NET technology, a key part of the .NET Framework. This edition does not require Client Access Licenses and Terminal Server mode is not included on Web Edition. However, Remote Desktop for Administration is available on Windows Server 2003, Web Edition. Only 10 concurrent file-sharing connections are allowed at any moment. It is not possible to install Microsoft SQL Server and Microsoft Exchange software in this edition. However MSDE and SQL Server 2005 Express are fully supported after service pack 1 is installed. Despite supporting XML Web Services and ASP.NET, UDDI cannot be deployed on Windows Server 2003, Web Edition. The .NET Framework version 2.0 is not included with Windows Server 2003, Web Edition, but can be installed as a separate update from Windows Update.
Windows Server 2003 Web Edition supports a maximum of 2 processors with support for a maximum of 2GB of RAM. Additionally, Windows Server 2003, Web Edition cannot act as a domain controller.[16] Additionally, it is the only version of Windows Server 2003 that does not include client number limitation upon Windows update services as it does not require Client Access Licenses.
[edit]
Standard Edition
Windows Server 2003, Standard Edition is aimed towards small to medium sized businesses. Standard Edition supports file and printer sharing, offers secure Internet connectivity, and allows centralized desktop application deployment. This edition of Windows will run on up to 4 processors with up to 4 GB RAM. 64-bit versions are also available for the x86-64 architecture (AMD64 and EM64T, called collectively x64 by Microsoft). The 64-bit version of Windows Server 2003, Standard Edition is capable of addressing up to 32 GB of RAM and it also supports Non-Uniform Memory Access (NUMA), something the 32-bit version does not do.
[edit]
Enterprise Edition
Windows Server 2003, Enterprise Edition is aimed towards medium to large businesses. It is a full-function server operating system that supports up to eight processors and provides enterprise-class features such as eight-node clustering using Microsoft Cluster Server (MSCS) software and support for up to 32 GB of memory with addition of the PAE parameter in the initialization file. Enterprise Edition also comes in 64-bit versions for the Itanium and x64 architectures. The 64-bit version of Windows Server 2003, Enterprise Edition [64-bit] is capable of addressing up to 1 Terabyte (1024 GB) of RAM. Both 32-bit and 64-bit versions support Non-Uniform Memory Access (NUMA). It also provides the ability to hot-add supported hardware.
[edit]
Datacenter Edition
Windows Server 2003, Datacenter Edition is designed[17] for infrastructures demanding high security and reliability. Windows Server 2003 is available for x86 32-bit, Itanium, and x64 processors. It supports a minimum of 8 processors and a maximum of 64 processors; however it is limited to 32 processors when run on 32-bit architecture. 32-bit architecture also limits memory addressability to 64GB, while the 64-bit versions support up to 512 GB. Windows Server 2003, Datacenter Edition, also allows limiting processor and memory usage on a per-application basis.
Windows Server 2003 Datacenter Edition also supports Non-Uniform Memory Access. If supported by the system, Windows, with help from the system firmware creates a Static Resource Affinity Table that defines the NUMA topology of the system. Windows then uses this table to optimize memory accesses, and provide NUMA awareness to applications, thereby increasing the efficiency of thread scheduling and memory management.
Windows Server 2003, Datacenter edition has better support for Storage Area Networks (SAN). It features a service which uses Windows sockets to emulate TCP/IP communication over native SAN service providers, thereby allowing a SAN to be accessed over any TCP/IP channel. With this, any application that can communicate over TCP/IP can use a SAN, without any modification to the application.
Windows Server 2003, Datacenter edition, also supports 8-node clustering. Clustering increases availability and fault tolerance of server installations, by distributing and replicating the service among many servers. Windows supports clustering, with each cluster having its own dedicated storage, or all clusters connected to a common Storage Area Network (SAN), which can be running on Windows as well as non-Windows Operating systems. The SAN may be connected to other computers as well.
[edit]
Windows Compute Cluster Server
Windows Compute Cluster Server 2003 (CCS), released in June 2006, is designed for high-end applications that require high performance computing clusters. It is designed to be deployed on numerous computers to be clustered together to achieve supercomputing speeds. Each Compute Cluster Server network comprises at least one controlling head node and subordinate processing nodes that carry out most of the work.
Computer Cluster Server uses the Microsoft Messaging Passing Interface v2 (MS-MPI) to communicate between the processing nodes on the cluster network. It ties nodes together with a powerful inter-process communication mechanism which can be complex because of communications between hundreds or even thousands of processors working in parallel.
The application programming interface consists of over 160 functions. A job launcher enables users to execute jobs to be executed in the computing cluster. MS MPI was designed to be compatible with the reference open source MPI2 specification which is widely used in High-performance computing (HPC). With some exceptions because of security considerations, MS MPI covers the complete set of MPI2 functionality as implemented in MPICH2, except for the planned future features of dynamic process spawn and publishing.
[edit]
Windows Storage Server
Windows Storage Server 2003, a part of the Windows Server 2003 series is a specialized server Operating System for Network Attached Storage (NAS). It is optimized for use in file and print sharing and also in Storage Area Network (SAN) scenarios. It is only available through OEMs. Unlike other Windows Server 2003 editions that provide file and printer sharing functionality, Windows Storage Server 2003 does not require any Client access licenses.
Windows Storage Server 2003 NAS equipment can be headless, which means that they are without any monitors, keyboards or mice, and are administered remotely. Such devices are plugged into any existing IP network and the storage capacity is available to all users. Windows Storage Server 2003 can use RAID arrays to provide data redundancy, fault-tolerance and high-performance. Multiple such NAS servers can be clustered to appear as a single device. This allows for very high performance as well as allowing the service to remain up even if one of the servers goes down.
Windows Storage Server 2003 can also be used to create a Storage Area Network, in which the data is transferred in terms of chunks rather than files, thus providing more granularity to the data that can be transferred. This provides higher performance to database and transaction processing applications. Windows Storage Server 2003 also allows NAS devices to be connected to a SAN.
Windows Storage Server 2003 R2, as a follow-up to Windows Storage Server 2003, adds file-server performance optimization, Single Instance Storage (SIS), and index-based search. Single instance storage (SIS) scans storage volumes for duplicate files, and moves the duplicate files to the common SIS store. The file on the volume is replaced with a link to the file. This substitution reduces the amount of storage space required, by as much as 70%.[18]
Windows Storage Server R2 provides an index-based, full-text search based on the indexing engine already built-in Windows server.[18] The updated search engine speeds up indexed searches on network shares. Storage Server R2 also provides filters for searching many standard file formats, such as .zip, AutoCAD, XML, MP3, and .pdf, and all Microsoft Office file formats.
Windows Storage Server 2003 R2 includes built in support for Windows SharePoint Services and Microsoft SharePoint Portal Server, and adds Storage Management snap-in for the Microsoft Management Console. It can be used to centrally manage storage volumes, including DFS shares, on servers running Windows Storage Server R2.
Windows Storage Server R2 can be used as an iSCSI target with standard and enterprise editions of Windows Storage Server R2, incorporating WinTarget iSCSI technology which Microsoft acquired in 2006 by from StringBean software.[19][20] This will be an add on feature available for purchase through OEM partners as an iSCSI feature pack, or is included in some versions of WSS as configured by OEMs.
[edit]
Features
Distributed File System (DFS): DFS allows multiple network shares to be aggregated as a virtual file system.
Support for SAN and iSCSI: Computers can connect to a Storage Server over the LAN, and there is no need for a separate fibre channel network. Thus a Storage Area Network can be created over the LAN itself. iSCSI uses the SCSI protocol to transfer data as a block of bytes, rather than as a file. This increases performance of the Storage network in some scenarios, such as using a database server.
Virtual Disc Service: It allows NAS devices, RAID devices and SAN shares to be exposed and managed as if they were normal hard drives.
JBOD systems: JBOD (Just a bunch of discs) systems, by using VDS, can manage a group of individual storage devices as a single unit. There is no need for the storage units to be of the same make and model.
Software and Hardware RAID: Windows Storage Server 2003 has intrinsic support for hardware implementation of RAID. In case hardware support is not available, it can use software enabled RAID. In that case, all processing is done by the OS.
Multi Path IO (MPIO): It provides an alternate connection to IO devices in case the primary path is down.
[edit]
Editions
Windows Storage Server 2003 R2 is available in the following versions: Standard Edition Enterprise Edition
Number of physical* CPUs 1-4 1-8
32-bit and 64-bit versions available Yes Yes
Numbers of disk drives Unlimited Unlimited
NICs Unlimited Unlimited
Print service Yes Yes
CALs required No No
iSCSI target support Optional Optional
Windows Unified Data Storage Server is a version of Windows Storage Server 2003 R2 with iSCSI target support standard, available in only the standard and enterprise editions.
Microsoft defines a physical CPU/processor as a single socket/node on the systemboard. For O/S licensing purposes, a dual-socket single-core (Intel Pentium/4 Xeon, AMD Athlon/64) system counts as a total of 2 processors, whereas a single-socket quad-core CPU (such as AMD's Barcelona and Intel's Core 2 Quad) counts as 1 processor. Microsoft's policy has no bearing on how third-party software vendors (such as Oracle) administer CPU licensing for their server applications.
[edit]
Home Server
Main article: Windows Home Server
Windows Home Server is an operating system from Microsoft based on Windows Server 2003 SP2. Announced on January 7, 2007 at the Consumer Electronics Show by Bill Gates, Windows Home Server is intended to be a solution for homes with multiple connected PCs to offer file sharing, automated backups, and remote access.
Windows Home Server began shipment to OEMs on 15th September 2007.[21]
[edit]
Editions and pricing
Small Business Server
Average cost is US$599, the product is purchased through a brick-and-mortar retailer, while an open new license must be purchased through a volume license reseller.
Web Edition
This operating system is priced at US$397. Client Access Licenses are not required.
Standard Edition
This operating system is priced at US$999, although licenses may be purchased for less from a reseller. For more than 5 Active Directory remote-connected users (users of Exchange, for example) additional costs are incurred.
Enterprise Edition
This operating system is priced at US$3,999. For more than 25 remote-connected users, additional costs are incurred (either CALs or the EC license).
Datacenter Edition
Microsoft's website shows Datacenter Edition R2 expansion for US$2,999.
Compute Cluster Edition
This operating system's price is US$469.
Storage Server
This operating system's price is unknown, since it must be obtained through an OEM. It is rumored to cost between US$500 and US$1000. Smaller OEMs interested in shipping systems which include Windows Storage Server (and Microsoft iSCSI Target Software) may find the following article of interest.
External Connector
An additional license required when non-employees authenticate to Windows applications, for example on an Internet-connected application server. Priced at US$3999 per server.
USA Nonprofit Pricing
In the USA, Microsoft products, including Windows Server, are available under the Microsoft Donation Program for qualifying 501(c)(3) educational nonprofit organizations for a nominal administrative fee. The program is administered at http://www.techsoup.org/stock.
All these prices are estimated retail; actual prices will vary depending on the reseller.
Free trial versions of Windows Server 2003 x86 and Windows Server 2003 for Itanium 64 can be downloaded from microsoft.com and used for 180 days.[22]
[edit]
See also
Comparison of operating systems
Windows Server System
From Wikipedia, the free encyclopedia
Windows Server 2003
(Part of the Microsoft Windows family)
Screenshot
Screenshot of Windows Server 2003 Enterprise Edition
Developer
Microsoft
Web site: www.microsoft.com/windowsserver2003/
Release information
Release date: April 24, 2003 info
Current version: 2003 SP2 (5.2.3790.3959), March 13, 2007 info
Source model: Shared source
License: MS-EULA
Kernel type: Hybrid kernel
Support status
Current
Windows Server 2003 is a server operating system produced by Microsoft. Introduced on April 24, 2003 as the successor to Windows 2000 Server, it is considered by Microsoft to be the cornerstone of their Windows Server System line of business server products. An updated version, Windows Server 2003 R2 was released to manufacturing on 6 December 2005
According to Microsoft, Windows Server 2003 is more scalable and delivers better performance than its predecessor, Windows 2000.[1]Contents [hide]
1 Overview
2 New and updated features
3 Improvements
3.1 Service Pack 1
3.2 Windows Server 2003 R2
3.2.1 New features of Windows Server 2003 R2
3.3 Service Pack 2
4 Variants
4.1 Windows Small Business Server
4.2 Web Edition
4.3 Standard Edition
4.4 Enterprise Edition
4.5 Datacenter Edition
4.6 Windows Compute Cluster Server
4.7 Windows Storage Server
4.7.1 Features
4.7.2 Editions
4.8 Home Server
5 Editions and pricing
6 See also
7 References
8 External links
8.1 Microsoft
8.2 Other
[edit]
Overview
Released on April 24, 2003,[2] Windows Server 2003 (which carries the version number 5.2) is the follow-up to Windows 2000 Server, incorporating compatibility and other features from Windows XP. Unlike Windows 2000 Server, Windows Server 2003's default installation has none of the server components enabled, to reduce the attack surface of new machines. Windows Server 2003 includes compatibility modes to allow older applications to run with greater stability. It was made more compatible with Windows NT 4.0 domain-based networking. Incorporating and upgrading a Windows NT 4.0 domain to Windows 2000 was considered difficult and time-consuming, and generally was considered an all-or-nothing upgrade, particularly when dealing with Active Directory. Windows Server 2003 brought in enhanced Active Directory compatibility, and better deployment support, to ease the transition from Windows NT 4.0 to Windows Server 2003 and Windows XP Professional.
Changes to various services include the IIS web server (which was almost completely rewritten to improve performance and security), Distributed File System (which now supports hosting multiple DFS roots on a single server), Terminal Server, Active Directory, Print Server, and a number of other areas. Windows Server 2003 was also the first operating system released by Microsoft after the announcement of their Trustworthy Computing initiative, and as a result, contains a number of changes to security defaults and practices.
The product went through several name changes during the course of development. When first announced in 2000, it was known by its codename, "Whistler Server"; it was then named "Windows 2002 Server" for a brief time in mid-2001, before being renamed "Windows .NET Server" as part of Microsoft's effort to promote their new integrated enterprise and development framework, Microsoft .NET. It was later renamed to "Windows .NET Server 2003". Due to fears of confusing the market about what ".NET" represents and responding to criticism, Microsoft removed .NET from the name during the Release Candidate stage in late-2002. This allowed the name .NET to exclusively apply to the .NET Framework, as previously it had appeared that .NET was just a tag for a generation of Microsoft products.
In 2005, Microsoft announced Windows Server 2008 (at the time known as Windows Server "Longhorn") as the next major version of Windows Server after Windows Server 2003. Windows Server 2008 currently has a targeted release date of February 27, 2008.
[edit]
New and updated features
Manage Your Server
See also: Features new to Windows XP
Most versions of Windows Server include Terminal Services support (using the Remote Desktop Protocol), enabling multiple simultaneous remote graphical logins. This enables thin client computing on the windows platform, where all applications run remotely on the server. This feature was first introduced with a special "Terminal Server Edition" of Windows NT Server 4.0, but became more important when made a standard part of Windows 2000.
Internet Information Services (IIS) v6.0 - again, versions of IIS were available on Windows 2000 and earlier, but IIS is improved significantly in Windows Server 2003.
Active Directory - like Terminal Services, significantly improved since Windows 2000.
Increased default security over previous versions, due to the built-in firewall and most services being disabled by default.
Message Queuing - significantly improved since Windows 2000.
Manage Your Server - a role management administrative tool that allows an administrator to choose what functionality the server should provide.
[edit]
Improvements
There are a number of improvements from Windows 2000 server, notably:
Improvements to Active Directory (such as the ability to deactivate classes from the schema, or to run multiple instances of the directory server (ADAM))
Improvements to Group Policy handling and administration
Improved disk management, including the ability to back up from shadows of files, allowing the backup of open files.
Improved scripting and command line tools, which are part of Microsoft's initiative to bring a complete command shell to the next version of Windows.
Support for a hardware-based "watchdog timer", which can restart the server if the operating system does not respond within a certain amount of time.[3]
[edit]
Service Pack 1
On March 30, 2005, Microsoft released Service Pack 1 for Windows Server 2003. Among the improvements are many of the same updates that were provided to Windows XP users with Service Pack 2. Features that are added with Service Pack 1 include:
Security Configuration Wizard: A tool that allows administrators to more easily research, and make changes to, security policies.[4]
Hot Patching: This feature is set to extend Windows Server 2003 ability to take DLL, Driver, and non-kernel patches without a reboot.
IIS 6.0 Metabase Auditing: Allowing the tracking of metabase edits.[5]
Windows Firewall: Brings many of the improvements from Windows XP Service Pack 2 to Windows Server 2003; also with the Security Configuration Wizard, it allows administrators to more easily manage the incoming open ports, as it will automatically detect and select default roles.
Other networking improvements include support for Wireless Provisioning Services, better IPv6 support, and new protections against SYN flood TCP attacks.[6]
Post-Setup Security Updates: A default mode that is turned on when a Service Pack 1 server is first booted up after installation. It configures the firewall to block all incoming connections, and directs the user to install updates.
Data Execution Prevention (DEP): Support for the No Execute (NX) bit which helps to prevent buffer overflow exploits that are often the attack vector of Windows Server exploits.[7]
Windows Media Player version 10
A full list of updates is available in the Microsoft Knowledge Base.[8]
[edit]
Windows Server 2003 R2
Windows Server 2003 R2, an update of Windows Server 2003, was released to manufacturing on 6 December 2005. It is distributed on two CDs, with one CD being the Windows Server 2003 SP1 CD. The other CD adds many optionally installable features for Windows Server 2003. The R2 update was released for all x86 and x64 versions, but not for Itanium versions.[9]
[edit]
New features of Windows Server 2003 R2
Branch Office Server Management
Centralized management tools for file and printers
Enhanced Distributed File System (DFS) namespace management interface
More efficient WAN data replication with Remote Differential Compression.
Identity and Access Management
Extranet Single Sign-On and identity federation
Centralized administration of extranet application access
Automated disabling of extranet access based on Active Directory account information
User access logging
Cross-platform web Single Sign-On and password synchronization using Network Information Service (NIS)
Storage Management
File Server Resource Manager (storage utilization reporting)
Enhanced quota management
File screening limits files types allowed
Storage Manager for Storage Area Networks (SAN) (storage array configuration)
Server Virtualization
A new licensing policy allows up to 4 virtual instances on Enterprise Edition and Unlimited on Datacenter Edition
Utilities and SDK for UNIX-Based Applications add-on, giving a relatively full Unix development environment.
Base Utilities
SVR-5 Utilities
Base SDK
GNU SDK
GNU Utilities
Perl 5
Visual Studio Debugger Add-in
[edit]
Service Pack 2
Service Pack 2 for Windows Server 2003 was released on March 13, 2007.[10] The release date was originally scheduled for the first half of 2006.[11] On June 13, 2006, Microsoft made an initial test version of Service Pack 2 available to Microsoft Connect users, with a build number of 2721. This was followed by build 2805, known as Beta 2 Refresh. The latest build is the build 3959.
Microsoft has described Service Pack 2 as a "standard" service pack release containing previously-released security updates, hotfixes, and reliability and performance improvements.[12] In addition, Service Pack 2 contains Microsoft Management Console 3.0, Windows Deployment Services (which replaces Remote Installation Services), support for WPA2, and improvements to IPSec and MSConfig. Service Pack 2 also adds Windows Server 2003 Scalable Networking Pack (SNP),[13] which allows hardware acceleration for processing network packets, thereby enabling faster throughput. SNP was previously available as an out-of-band update for Windows Server 2003 Service Pack 1.
[edit]
Variants
This Microsoft server comes in several variants, each targeted towards a particular size and type of business: See Compare the Editions of Windows Server 2003 for a concise comparison. In general, all variants of Windows Server 2003 have the ability to share files and printers, act as an application server, and host message queues, provide email services, authenticate users, act as an X.509 certificate server, provide LDAP directory services, serve streaming media, and to perform other server-oriented functions.
[edit]
Windows Small Business Server
Main article: Windows Small Business Server
SBS includes Windows Server and additional technologies aimed at providing a small business with a complete technology solution. The technologies are integrated to enable small business with targeted solutions such as the Remote Web Workplace, and offer management benefits such as integrated setup, enhanced monitoring, a unified management console, and remote access.
The Standard Edition of SBS includes Windows SharePoint Services for collaboration, Microsoft Exchange server for e-mail, Fax Server, and the Active Directory for user management. The product also provides a basic firewall, DHCP server and NAT router using either two network cards or one network card in addition to a hardware router.
The Premium Edition of SBS includes the above plus Microsoft SQL Server 2000 and Microsoft Internet Security and Acceleration Server 2004.
SBS has its own type of Client Access License (CAL) that is different and costs slightly more than CALs for the other editions of Windows Server 2003. However, the SBS CAL encompasses the user CALs for Windows Server, Exchange Server, SQL Server, and ISA Server, and hence is less expensive than buying all the other CALs individually.
SBS server has the following design limitations:[14]
Only one computer in a domain can be running Windows Server 2003 for Small Business Server.
Windows Server 2003 for Small Business Server must be the root of the Active Directory forest.
Windows Server 2003 for Small Business Server cannot trust any other domains.
Windows Server 2003 for Small Business Server is limited to 75 users or devices depending on which type of CAL.
Windows Server 2003 for Small Business Server is limited to 4GB of RAM (Random Access Memory).
A Windows Server 2003 for Small Business Server domain cannot have any child domains.
Terminal Services only operates in remote administration mode on the server running SBS 2003, and only two simultaneous RDP sessions are allowed. (Change from SBS 2000 policy)[15]
To remove the limits from SBS server and upgrade from Small Business Server to regular Windows Server, Exchange Server, SQL and ISA server versions there is a Windows Small Business Server 2003 R2 Transition Pack.[1]
[edit]
Web Edition
Windows Server 2003, Web Edition is mainly for building and hosting Web applications, Web pages, and XML Web Services. It is designed to be used primarily as an IIS 6.0 Web server and provides a platform for rapidly developing and deploying XML Web services and applications that use ASP.NET technology, a key part of the .NET Framework. This edition does not require Client Access Licenses and Terminal Server mode is not included on Web Edition. However, Remote Desktop for Administration is available on Windows Server 2003, Web Edition. Only 10 concurrent file-sharing connections are allowed at any moment. It is not possible to install Microsoft SQL Server and Microsoft Exchange software in this edition. However MSDE and SQL Server 2005 Express are fully supported after service pack 1 is installed. Despite supporting XML Web Services and ASP.NET, UDDI cannot be deployed on Windows Server 2003, Web Edition. The .NET Framework version 2.0 is not included with Windows Server 2003, Web Edition, but can be installed as a separate update from Windows Update.
Windows Server 2003 Web Edition supports a maximum of 2 processors with support for a maximum of 2GB of RAM. Additionally, Windows Server 2003, Web Edition cannot act as a domain controller.[16] Additionally, it is the only version of Windows Server 2003 that does not include client number limitation upon Windows update services as it does not require Client Access Licenses.
[edit]
Standard Edition
Windows Server 2003, Standard Edition is aimed towards small to medium sized businesses. Standard Edition supports file and printer sharing, offers secure Internet connectivity, and allows centralized desktop application deployment. This edition of Windows will run on up to 4 processors with up to 4 GB RAM. 64-bit versions are also available for the x86-64 architecture (AMD64 and EM64T, called collectively x64 by Microsoft). The 64-bit version of Windows Server 2003, Standard Edition is capable of addressing up to 32 GB of RAM and it also supports Non-Uniform Memory Access (NUMA), something the 32-bit version does not do.
[edit]
Enterprise Edition
Windows Server 2003, Enterprise Edition is aimed towards medium to large businesses. It is a full-function server operating system that supports up to eight processors and provides enterprise-class features such as eight-node clustering using Microsoft Cluster Server (MSCS) software and support for up to 32 GB of memory with addition of the PAE parameter in the initialization file. Enterprise Edition also comes in 64-bit versions for the Itanium and x64 architectures. The 64-bit version of Windows Server 2003, Enterprise Edition [64-bit] is capable of addressing up to 1 Terabyte (1024 GB) of RAM. Both 32-bit and 64-bit versions support Non-Uniform Memory Access (NUMA). It also provides the ability to hot-add supported hardware.
[edit]
Datacenter Edition
Windows Server 2003, Datacenter Edition is designed[17] for infrastructures demanding high security and reliability. Windows Server 2003 is available for x86 32-bit, Itanium, and x64 processors. It supports a minimum of 8 processors and a maximum of 64 processors; however it is limited to 32 processors when run on 32-bit architecture. 32-bit architecture also limits memory addressability to 64GB, while the 64-bit versions support up to 512 GB. Windows Server 2003, Datacenter Edition, also allows limiting processor and memory usage on a per-application basis.
Windows Server 2003 Datacenter Edition also supports Non-Uniform Memory Access. If supported by the system, Windows, with help from the system firmware creates a Static Resource Affinity Table that defines the NUMA topology of the system. Windows then uses this table to optimize memory accesses, and provide NUMA awareness to applications, thereby increasing the efficiency of thread scheduling and memory management.
Windows Server 2003, Datacenter edition has better support for Storage Area Networks (SAN). It features a service which uses Windows sockets to emulate TCP/IP communication over native SAN service providers, thereby allowing a SAN to be accessed over any TCP/IP channel. With this, any application that can communicate over TCP/IP can use a SAN, without any modification to the application.
Windows Server 2003, Datacenter edition, also supports 8-node clustering. Clustering increases availability and fault tolerance of server installations, by distributing and replicating the service among many servers. Windows supports clustering, with each cluster having its own dedicated storage, or all clusters connected to a common Storage Area Network (SAN), which can be running on Windows as well as non-Windows Operating systems. The SAN may be connected to other computers as well.
[edit]
Windows Compute Cluster Server
Windows Compute Cluster Server 2003 (CCS), released in June 2006, is designed for high-end applications that require high performance computing clusters. It is designed to be deployed on numerous computers to be clustered together to achieve supercomputing speeds. Each Compute Cluster Server network comprises at least one controlling head node and subordinate processing nodes that carry out most of the work.
Computer Cluster Server uses the Microsoft Messaging Passing Interface v2 (MS-MPI) to communicate between the processing nodes on the cluster network. It ties nodes together with a powerful inter-process communication mechanism which can be complex because of communications between hundreds or even thousands of processors working in parallel.
The application programming interface consists of over 160 functions. A job launcher enables users to execute jobs to be executed in the computing cluster. MS MPI was designed to be compatible with the reference open source MPI2 specification which is widely used in High-performance computing (HPC). With some exceptions because of security considerations, MS MPI covers the complete set of MPI2 functionality as implemented in MPICH2, except for the planned future features of dynamic process spawn and publishing.
[edit]
Windows Storage Server
Windows Storage Server 2003, a part of the Windows Server 2003 series is a specialized server Operating System for Network Attached Storage (NAS). It is optimized for use in file and print sharing and also in Storage Area Network (SAN) scenarios. It is only available through OEMs. Unlike other Windows Server 2003 editions that provide file and printer sharing functionality, Windows Storage Server 2003 does not require any Client access licenses.
Windows Storage Server 2003 NAS equipment can be headless, which means that they are without any monitors, keyboards or mice, and are administered remotely. Such devices are plugged into any existing IP network and the storage capacity is available to all users. Windows Storage Server 2003 can use RAID arrays to provide data redundancy, fault-tolerance and high-performance. Multiple such NAS servers can be clustered to appear as a single device. This allows for very high performance as well as allowing the service to remain up even if one of the servers goes down.
Windows Storage Server 2003 can also be used to create a Storage Area Network, in which the data is transferred in terms of chunks rather than files, thus providing more granularity to the data that can be transferred. This provides higher performance to database and transaction processing applications. Windows Storage Server 2003 also allows NAS devices to be connected to a SAN.
Windows Storage Server 2003 R2, as a follow-up to Windows Storage Server 2003, adds file-server performance optimization, Single Instance Storage (SIS), and index-based search. Single instance storage (SIS) scans storage volumes for duplicate files, and moves the duplicate files to the common SIS store. The file on the volume is replaced with a link to the file. This substitution reduces the amount of storage space required, by as much as 70%.[18]
Windows Storage Server R2 provides an index-based, full-text search based on the indexing engine already built-in Windows server.[18] The updated search engine speeds up indexed searches on network shares. Storage Server R2 also provides filters for searching many standard file formats, such as .zip, AutoCAD, XML, MP3, and .pdf, and all Microsoft Office file formats.
Windows Storage Server 2003 R2 includes built in support for Windows SharePoint Services and Microsoft SharePoint Portal Server, and adds Storage Management snap-in for the Microsoft Management Console. It can be used to centrally manage storage volumes, including DFS shares, on servers running Windows Storage Server R2.
Windows Storage Server R2 can be used as an iSCSI target with standard and enterprise editions of Windows Storage Server R2, incorporating WinTarget iSCSI technology which Microsoft acquired in 2006 by from StringBean software.[19][20] This will be an add on feature available for purchase through OEM partners as an iSCSI feature pack, or is included in some versions of WSS as configured by OEMs.
[edit]
Features
Distributed File System (DFS): DFS allows multiple network shares to be aggregated as a virtual file system.
Support for SAN and iSCSI: Computers can connect to a Storage Server over the LAN, and there is no need for a separate fibre channel network. Thus a Storage Area Network can be created over the LAN itself. iSCSI uses the SCSI protocol to transfer data as a block of bytes, rather than as a file. This increases performance of the Storage network in some scenarios, such as using a database server.
Virtual Disc Service: It allows NAS devices, RAID devices and SAN shares to be exposed and managed as if they were normal hard drives.
JBOD systems: JBOD (Just a bunch of discs) systems, by using VDS, can manage a group of individual storage devices as a single unit. There is no need for the storage units to be of the same make and model.
Software and Hardware RAID: Windows Storage Server 2003 has intrinsic support for hardware implementation of RAID. In case hardware support is not available, it can use software enabled RAID. In that case, all processing is done by the OS.
Multi Path IO (MPIO): It provides an alternate connection to IO devices in case the primary path is down.
[edit]
Editions
Windows Storage Server 2003 R2 is available in the following versions: Standard Edition Enterprise Edition
Number of physical* CPUs 1-4 1-8
32-bit and 64-bit versions available Yes Yes
Numbers of disk drives Unlimited Unlimited
NICs Unlimited Unlimited
Print service Yes Yes
CALs required No No
iSCSI target support Optional Optional
Windows Unified Data Storage Server is a version of Windows Storage Server 2003 R2 with iSCSI target support standard, available in only the standard and enterprise editions.
Microsoft defines a physical CPU/processor as a single socket/node on the systemboard. For O/S licensing purposes, a dual-socket single-core (Intel Pentium/4 Xeon, AMD Athlon/64) system counts as a total of 2 processors, whereas a single-socket quad-core CPU (such as AMD's Barcelona and Intel's Core 2 Quad) counts as 1 processor. Microsoft's policy has no bearing on how third-party software vendors (such as Oracle) administer CPU licensing for their server applications.
[edit]
Home Server
Main article: Windows Home Server
Windows Home Server is an operating system from Microsoft based on Windows Server 2003 SP2. Announced on January 7, 2007 at the Consumer Electronics Show by Bill Gates, Windows Home Server is intended to be a solution for homes with multiple connected PCs to offer file sharing, automated backups, and remote access.
Windows Home Server began shipment to OEMs on 15th September 2007.[21]
[edit]
Editions and pricing
Small Business Server
Average cost is US$599, the product is purchased through a brick-and-mortar retailer, while an open new license must be purchased through a volume license reseller.
Web Edition
This operating system is priced at US$397. Client Access Licenses are not required.
Standard Edition
This operating system is priced at US$999, although licenses may be purchased for less from a reseller. For more than 5 Active Directory remote-connected users (users of Exchange, for example) additional costs are incurred.
Enterprise Edition
This operating system is priced at US$3,999. For more than 25 remote-connected users, additional costs are incurred (either CALs or the EC license).
Datacenter Edition
Microsoft's website shows Datacenter Edition R2 expansion for US$2,999.
Compute Cluster Edition
This operating system's price is US$469.
Storage Server
This operating system's price is unknown, since it must be obtained through an OEM. It is rumored to cost between US$500 and US$1000. Smaller OEMs interested in shipping systems which include Windows Storage Server (and Microsoft iSCSI Target Software) may find the following article of interest.
External Connector
An additional license required when non-employees authenticate to Windows applications, for example on an Internet-connected application server. Priced at US$3999 per server.
USA Nonprofit Pricing
In the USA, Microsoft products, including Windows Server, are available under the Microsoft Donation Program for qualifying 501(c)(3) educational nonprofit organizations for a nominal administrative fee. The program is administered at http://www.techsoup.org/stock.
All these prices are estimated retail; actual prices will vary depending on the reseller.
Free trial versions of Windows Server 2003 x86 and Windows Server 2003 for Itanium 64 can be downloaded from microsoft.com and used for 180 days.[22]
[edit]
See also
Comparison of operating systems
Windows Server System
wimax
iMAX
From Wikipedia, the free encyclopedia
(Redirected from Wimax)
WiMAX, the Worldwide Interoperability for Microwave Access, is a telecommunications technology aimed at providing wireless data over long distances in a variety of ways, from point-to-point links to full mobile cellular type access. It is based on the IEEE 802.16 standard, which is also called WirelessMAN. The name WiMAX was created by the WiMAX Forum, which was formed in June 2001 to promote conformance and interoperability of the standard. The forum describes WiMAX as "a standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL."Contents [hide]
1 Definitions of terms
1.1 802.16d
1.2 802.16e
1.3 Fixed WiMAX
1.4 Mobile WiMAX
2 Uses
2.1 Broadband access
2.1.1 Subscriber units
2.2 Mobile applications
3 Technical information
3.1 MAC layer/data link layer
3.2 Physical layer
3.3 Architecture
3.4 Comparison with Wi-Fi
3.5 Spectrum allocation issues
3.6 Spectral Efficiency
3.7 Limitations
3.8 Silicon implementations
4 Standards
4.1 IEEE 802.16e-2005
5 Associations
5.1 WiMAX Forum
5.2 WiMAX Spectrum Owners Alliance - WiSOA
6 Competing technologies
6.1 3G and 4G cellular phone Systems
6.1.1 Mobile Broadband Wireless Access
6.2 Internet-oriented systems
6.3 Comparison
7 Future development
8 Current deployments
9 See also
10 Notes
11 Literature
12 External links
[edit]
Definitions of terms
The terms "fixed WiMAX", "mobile WiMAX", "802.16d" and "802.16e" are frequently used incorrectly.[1] Correct definitions are:Mobile communication standards
GSM / UMTS (3GPP) Family
2G
GSM
GPRS
EDGE (EGPRS)
EDGE Evolution
HSCSD
3G
UMTS (3GSM)
HSPA
HSDPA
HSUPA
HSPA+
UMTS-TDD
TD-CDMA
TD-SCDMA
FOMA
Pre-4G
UMTS Revision 8
LTE
HSOPA (Super 3G)
cdmaOne / CDMA2000 (3GPP2) Family
2G
cdmaOne
3G
CDMA2000
EV-DO
Pre-4G
UMB
Widely Used Other Technologies
1G
AMPS
2G
D-AMPS
Other Technologies
0G
PTT
MTS
IMTS
AMTS
OLT
MTD
Autotel / PALM
ARP
1G
NMT
TACS / ETACS
Hicap
CDPD
Mobitex
DataTAC
2G
iDEN
PDC
CSD
PHS
WiDEN
Pre-4G
iBurst
HIPERMAN
WiMAX
WiBro (Mobile WiMAX)
GAN (UMA)
Frequency bands
SMR
Cellular
PCS
[edit]
802.16d
Strictly speaking, 802.16d has never existed as a standard. The standard is correctly called 802.16-2004 and was developed by the IEEE 802.16 Task Group d. Therefore the project was called 802.16d, but the standard never was. However, since this standard is frequently called 802.16d, that term is also used in this article to assist readability.
[edit]
802.16e
Just as 802.16d has never existed as a standard, neither has 802.16e. 802.16e is an amendment to 802.16-2004, and the amendment is properly referred to as 802.16e-2005. 802.16e-2005 is not a standard in its own right - since it is only an amendment, the original document (802.16-2004) has to be read and then the amendments added to it.
[edit]
Fixed WiMAX
This is a phrase frequently used to refer to systems built using 802.16-2004 ('802.16d') and the OFDM PHY as the air interface technology.
Fixed WiMAX deployments do not cater for handoff between Base Stations, therefore the service provider cannot offer mobility.
[edit]
Mobile WiMAX
A phrase frequently used to refer to systems built using 802.16e-2005 and the OFDMA PHY as the air interface technology. "Mobile WiMAX" implementations can be used to deliver both fixed and mobile services.
[edit]
Uses
The bandwidth and reach of WiMAX make it suitable for the following potential applications:
Connecting Wi-Fi hotspots with each other and to other parts of the Internet.
Providing a wireless alternative to cable and DSL for last mile broadband access.
Providing high-speed data and telecommunications services.
Providing a diverse source of Internet connectivity as part of a business continuity plan. That is, if a business has a fixed and a wireless Internet connection, especially from unrelated providers, they are unlikely to be affected by the same service outage.
Providing nomadic connectivity.
[edit]
Broadband access
Many companies are closely examining WiMAX for "last mile" connectivity at high data rates. The resulting competition may bring lower pricing for both home and business customers or bring broadband access to places where it has been economically unavailable. Prior to WiMAX, many operators have been using proprietary fixed wireless technologies for broadband services.
WiMAX access was used to assist with communications in Aceh, Indonesia, after the tsunami in December 2004. All communication infrastructure in the area, other than Ham Radio, was destroyed, making the survivors unable to communicate with people outside the disaster area and vice versa. WiMAX provided broadband access that helped regenerate communication to and from Aceh.
WiMAX was used by Intel to assist the FCC and FEMA in their communications efforts in the areas affected by Hurricane Katrina. [1]
[edit]
Subscriber units
WiMAX subscriber units are available in both indoor and outdoor versions from several manufacturers. Self-install indoor units are convenient, but radio losses mean that the subscriber must be significantly closer to the WiMAX base station than with professionally-installed external units. As such, indoor-installed units require a much higher infrastructure investment as well as operational cost (site lease, backhaul, maintenance) due to the high number of base stations required to cover a given area. Indoor units are comparable in size to a cable modem or DSL modem. Outdoor units are roughly the size of a laptop PC, and their installation is comparable to a residential satellite dish.
With the advent of mobile WiMAX, there is an increasing focus on portable units. This includes handsets (similar to cellular smartphones) and PC peripherals (PC Cards or USB dongles). In addition, there is much emphasis from operators on consumer electronics devices (games terminals, MP3 players and the like); it is notable this is more similar to WiFi than 3G cellular technologies.
[edit]
Mobile applications
Some cellular companies are evaluating WiMAX as a means of increasing bandwidth for a variety of data-intensive applications; Sprint Nextel announced in mid-2006 that it would invest about US$ 5 billion in a WiMAX technology buildout over the next few years.[2] As of Friday, November 9, 2007, this project in partnership with Clearwire has been shelved, but the project could be revived with or without Clearwire once Sprint hires a new CEO. On December 5, 2007, Bin Shen, Sprint's VP of Product Management and Partnership Development, announced that Sprint's WiMAX network will go live in a soft launch in Chicago, Baltimore, and Washington DC. Full commercial launch is still expected to be approximately spring of 2008.[3] In December 2007 Wateen Telecom Pakistan deployed the largest and the first in the world to roll-out WiMAX 802.16e network in 22 cities of Pakistan. In line with these possible applications is the technology's ability to serve as a high bandwidth "backhaul" for Internet or cellular phone traffic from remote areas back to an Internet backbone. Although the cost per user/point of WiMAX in a remote application will be higher, it is not limited to such applications, and may be an answer to reducing the cost of T1/E1 backhaul as well. Given the limited wired infrastructure in some developing countries, the costs to install a WiMAX station in conjunction with an existing cellular tower or even as a solitary hub are likely to be small in comparison to developing a wired solution. Areas of low population density and flat terrain are particularly suited to WiMAX and its range. For countries that have skipped wired infrastructure as a result of prohibitive costs and unsympathetic geography, WiMAX can enhance wireless infrastructure in an inexpensive, decentralized, deployment-friendly and effective manner.
[edit]
Technical information
WiMAX is a term coined to describe standard, interoperable implementations of IEEE 802.16 wireless networks, similar to the way the term Wi-Fi is used for interoperable implementations of the IEEE 802.11 Wireless LAN standard. However, WiMAX is very different from Wi-Fi in the way it works.
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MAC layer/data link layer
In Wi-Fi the media access controller (MAC) uses contention access — all subscriber stations that wish to pass data through a wireless access point (AP) are competing for the AP's attention on a random interrupt basis. This can cause subscriber stations distant from the AP to be repeatedly interrupted by closer stations, greatly reducing their throughput. This makes services such as Voice over IP (VoIP) or IPTV, which depend on an essentially-constant Quality of Service (QoS) depending on data rate and interruptibility, difficult to maintain for more than a few simultaneous users.
In contrast, the 802.16 MAC uses a scheduling algorithm for which the subscriber station need compete once (for initial entry into the network). After that it is allocated an access slot by the base station. The time slot can enlarge and contract, but remains assigned to the subscriber station, which means that other subscribers cannot use it. In addition to being stable under overload and over-subscription (unlike 802.11), the 802.16 scheduling algorithm can also be more bandwidth efficient. The scheduling algorithm also allows the base station to control QoS parameters by balancing the time-slot assignments among the application needs of the subscriber stations.
[edit]
Physical layer
The original WiMAX standard (IEEE 802.16) specified WiMAX for the 10 to 66 GHz range. 802.16a, updated in 2004 to 802.16-2004, added specifications for the 2 to 11 GHz range. 802.16-2004 was updated to 802.16e in 2005 and uses scalable orthogonal frequency-division multiple access (SOFDMA) as opposed to the OFDM version with 256 sub-carriers (of which 200 are used) in 802.16d. More advanced versions, including 802.16e, also bring Multiple Antenna Support through Multiple-input multiple-output communications (MIMO) See WiMAX MIMO. This brings potential benefits in terms of coverage, self installation, power consumption, frequency re-use and bandwidth efficiency. 802.16e also adds a capability for full mobility support. The WiMAX certification allows vendors with 802.16d products to sell their equipment as WiMAX certified, thus ensuring a level of interoperability with other certified products, as long as they fit the same profile.
Most commercial interest is in the 802.16d and .16e standards, since the lower frequencies used in these variants suffer less from inherent signal attenuation and therefore give improved range and in-building penetration. Already today, a number of networks throughout the world are in commercial operation using certified WiMAX equipment compliant with the 802.16d standard.
[edit]
Architecture
The WiMAX Forum has defined an architecture that defines how a WiMAX network connects with other networks, and a variety of other aspects of operating such a network, including address allocation, authentication, etc. An overview of the architecture is given in the illustration. This defines the following components:
SS/MS: the Subscriber Station/Mobile Station
ASN: the Access Service Network
BS: Base station, belongs to ASN
ASN-GW: belongs to ASN
CSN: the Connectivity Service Network
HA: Home Agent, belongs to CSN
AAA: AAA Server, belongs to CSN
NAP: a Network Access Provider
NSP: a Network Service Provider
plus a number of interconnections (or reference points) between these, labeled R1 to R5 and R8.
It's important to note that the functional architecture can be designed into various hardware configurations rather than fixed configurations. For example, the architecture is flexible to allow various scale and functionality of remote/mobile stations and collaborative aggregations of femto, pico, and mini RS/MS.
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Comparison with Wi-Fi
Possibly due to the fact both WiMAX and Wi-Fi begin with the same two letters, are based upon IEEE standards beginning with "802.", and both have a connection to wireless connectivity and the Internet, comparisons and confusion between the two are frequent. Despite this, the two standards are aimed at different applications.
WiMAX is a long-range system, covering many kilometers that typically uses licensed spectrum (although it is also possible to use unlicensed spectrum) to deliver a point-to-point connection to the Internet from an ISP to an end user. Different 802.16 standards provide different types of access, from mobile (analogous to access via a cellphone) to fixed (an alternative to wired access, where the end user's wireless termination point is fixed in location.)
Wi-Fi is a shorter range system, typically hundreds of meters, that uses unlicensed spectrum to provide access to a network, typically covering only the network operator's own property. Typically Wi-Fi is used by an end user to access their own network, which may or may not be connected to the Internet. If WiMAX provides services analogous to a cellphone, Wi-Fi is more analogous to a cordless phone.
WiMAX and Wi-Fi have quite different Quality of Service (QoS) mechanisms. WiMAX uses a mechanism based on setting up connections between the Base Station and the user device. Each connection is based on specific scheduling algorithms, which means that QoS parameters can be guaranteed for each flow. WiFi has introduced a QoS mechanism similar to fixed Ethernet, where packets can receive different priorities based on their tags. This means that QoS is relative between packets/flows, as opposed to guaranteed.
WiMAX is highly scalable from what are called "femto"-scale remote stations to multi-sector 'maxi' scale base that handle complex tasks of management and mobile handoff functions and include MIMO-AAS smart antenna subsystems.
Due to the ease and low cost with which Wi-Fi can be deployed, it is sometimes used to provide Internet access to third parties within a single room or building available to the provider, often informally, and sometimes as part of a business relationship. For example, many coffee shops, hotels, and transportation hubs contain Wi-Fi access points providing access to the Internet for customers.
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Spectrum allocation issues
The 802.16 specification applies across a wide swath of the RF spectrum, and WiMAX could function on any frequency below 66GHz"IEEE Standard for Local and metropolitan area networks Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems Amendment 2: Physical and Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bands and Corrigendum 1," IEEE Std 802.16e-2005 and IEEE Std 802.16-2004/Cor 1-2005 (Amendment and Corrigendum to IEEE Std 802.16-2004), 2006, pp. 3, (higher frequencies would decrease the range of a Base Station to a few hundred meters in an urban environment).
There is no uniform global licensed spectrum for WiMAX, although the WiMAX Forum has published three licensed spectrum profiles: 2.3GHz, 2.5GHz and 3.5GHz, in an effort to decrease cost: economies of scale dictate that the more WiMAX embedded devices (such as mobile phones and WiMAX-embedded laptops) are produced, the lower the unit cost. (The two highest cost components of producing a mobile phone are the silicon and the extra radio needed for each band.) Similar economy of scale benefits apply to the production of Base Stations.
In the unlicensed band, 5.x GHz is the approved profile. Telecom companies are unlikely to use this spectrum widely other than for backhaul, as they do not own and control the spectrum.
In the USA, the biggest segment available is around 2.5 GHz,[4] and is already assigned, primarily to Sprint Nextel and Clearwire. Elsewhere in the world, the most-likely bands used will be the Forum approved ones, with 2.3 GHz probably being most important in Asia. Some countries in Asia like India, Vietnam and Indonesia will use a mix of 3.3 GHz and other frequencies.
Analog TV bands (700MHz) may become available for WiMAX use, but await the complete rollout of digital TV, and there will be other uses suggested for that spectrum. In the USA the FCC auction for this spectrum is scheduled for January 2008 [2]. EU commissioner Viviane Reding has suggested re-allocation of 500-800 MHz spectrum for wireless communication, including WiMAX [3].
WiMAX profiles define channel size, TDD/FDD and other necessary attributes in order to have inter-operating products. The current fixed profiles are defined for both TDD and FDD profiles. At this point, all of the mobile profiles are TDD only. The fixed profiles have channel sizes of 3.5 MHz, 5 MHz, 7 MHz and 10 MHz. The mobile profiles are 5 MHz, 8.75 MHz and 10 MHz. (Note: the 802.16 standard allows a far wider variety of channels, but only the above subsets are supported as WiMAX profiles).
Since October 2007, the Radiocommunication Sector of the International Telecommunication Union (ITU-R) has decided to include WiMAX technology in the IMT-2000 set of standards. This enables spectrum owners (specifically in the 2.5-2.69GHz band at this stage) to use Mobile WiMAX equipment in any country that recognizes the IMT-2000.
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Spectral Efficiency
One of the significant advantages of advanced wireless systems such as WiMAX is spectral efficiency. For example, 802.16-2004 (fixed) has a spectral efficiency of 3.7 bit/s/Hertz, and other 3.5-4G wireless systems offer spectral efficiencies that are similar to within a few tenths of a percent. The notable advantage of WiMAX comes from combining SOFDMA with smart antenna technologies. This multiplies the effective spectral efficiency through multiple reuse and smart network deployment topologies. The direct use of frequency domain organization simplifies designs using MIMO-AAS compared to CDMA/WCDMA methods, resulting in more-effective systems.[citation needed]
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Limitations
A commonly-held misconception is that WiMAX will deliver 70 Mbit/s over 50 kilometers. In reality, WiMAX can do one or the other - operating over maximum range (50 km) increases bit error rate and thus must use a lower bitrate. Lowering the range allows a device to operate at higher bitrates.
Typically, fixed WiMAX networks have a higher-gain directional antenna installed near the client (customer) which results in greatly increased range and throughput. Mobile WiMAX networks are usually made of indoor "customer premises equipment" (CPE) such as desktop modems, laptops with integrated Mobile WiMAX or other Mobile WiMAX devices. Mobile WiMAX devices typically have an omni-directional antenna which is of lower-gain compared to directional antennas but are more portable. In practice, this means that in a line-of-sight environment with a portable Mobile WiMAX CPE, speeds of 10 Mbit/s at 10 km could be delivered However, in urban environments they may not have line-of-sight and therefore users may only receive 10 Mbit/s over 2 km. Higher-gain directional antennas can be used with a Mobile WiMAX network with range and throughput benefits but the obvious loss of practical mobility.
Like most wireless systems, available bandwidth is shared between users in a given radio sector, so performance could deteriorate in the case of many active users in a single sector. In practice, many users will have a range of 2-, 4-, 6-, 8-, 10- or 12 Mbit/s services and additional radio cards will be added to the base station to increase the capacity as required.
Because of this, various granular and distributed network architectures are being incorporated into WiMAX through independent development and within the 802.16j mobile multi-hop relay (MMR) task group. This includes wireless mesh, grids, network remote station repeaters which can extend networks and connect to backhaul.
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Silicon implementations
A critical requirement for the success of a new technology is the availability of low-cost chipsets and silicon implementations.
Intel is a leader in promoting WiMAX, and has developed its own chipset. However, it is notable that most of the major semiconductor companies have to date been more cautious of involvement and most of the solutions come from specialist smaller or start-up suppliers. For the client-side these include GCT, Altair, Beceem, GCI, Runcom, Motorola with TI, NextWave, Sequans, Redpine signals[4] and a number of others. Both Sequans and Wavesat manufacture solutions for both clients and network while TI, DesignArt, and picoChip are focused on WiMAX chipsets for basestations.
[edit]
Standards
The current WiMAX incarnation, Mobile WiMAX, is based upon IEEE Std 802.16e-2005,[5] approved in December 2005. It is an amendment of IEEE Std 802.16-2004[6] and so the actual standard is 802.16-2004 as amended by 802.16e-2005 - the specifications need to be read together to understand them.
IEEE Std 802.16-2004 addresses only fixed systems. It replaced IEEE Standards 802.16-2001, 802.16c-2002, and 802.16a-2003.
[edit]
IEEE 802.16e-2005
IEEE 802.16e-2005 improves upon IEEE 802.16-2004 by:
Adding support for mobility (soft and hard handover between base stations). This is seen as one of the most important aspects of 802.16e-2005, and is the very basis of 'Mobile WiMAX'.
Scaling of the Fast Fourier Transform (FFT) to the channel bandwidth in order to keep the carrier spacing constant across different channel bandwidths (1.25-20 MHz). Constant carrier spacing results in a higher spectrum efficiency in wide channels, and a cost reduction in narrow channels. Also known as Scalable OFDMA (SOFDMA).
Improving NLOS coverage by utilizing advanced antenna diversity schemes, and hybrid-Automatic Retransmission Request (HARQ)
Improving capacity and coverage by introducing Adaptive Antenna Systems (AAS) and Multiple Input Multiple Output (MIMO) technology
Increasing system gain by use of denser sub-channelization, thereby improving indoor penetration
Introducing high-performance coding techniques such as Turbo Coding and Low-Density Parity Check (LDPC), enhancing security and NLOS performance
Introducing downlink sub-channelization, allowing administrators to trade coverage for capacity or vice versa
Enhanced Fast Fourier Transform algorithm can tolerate larger delay spreads, increasing resistance to multipath interference
Adding an extra QoS class (enhanced real-time Polling Service) more appropriate for VoIP applications.
802.16d vendors point out that fixed WiMAX offers the benefit of available commercial products and implementations optimized for fixed access. It is a popular standard among alternative service providers and operators in developing areas due to its low cost of deployment and advanced performance in a fixed environment. Fixed WiMAX is also seen as a potential standard for backhaul of wireless base stations such as cellular, WiFi or even Mobile WiMAX.
SOFDMA (used in 802.16e-2005) and OFDM256 (802.16d) are not compatible so most equipment will have to be replaced if an operator wants or needs to move to the later standard. However, some manufacturers are planning to provide a migration path for older equipment to SOFDMA compatibility which would ease the transition for those networks which have already made the OFDM256 investment. Intel provides a dual-mode 802.16-2004 802.16-2005 chipset for subscriber units. This affects a relatively small number users and operators.
[edit]
Associations
[edit]
WiMAX Forum
The WiMAX Forum is the organization dedicated to certifying the interoperability of WiMAX products. Those that pass conformance and interoperability testing achieve the "WiMAX Forum Certified" designation and can display this mark on their products and marketing materials. Some vendors claim that their equipment is "WiMAX-ready", "WiMAX-compliant", or "pre-WiMAX", if they are not officially WiMAX Forum Certified.[7]
[edit]
WiMAX Spectrum Owners Alliance - WiSOA
WiSOA is the first global organization composed exclusively of owners of WiMAX spectrum with plans to deploy WiMAX technology in those bands. WiSOA is focussed on the regulation, commercialisation, and deployment of WiMAX spectrum in the 2.3–2.5 GHz and the 3.4–3.5 GHz ranges. WiSOA are dedicated to educating and informing its members, industry representatives and government regulators of the importance of WiMAX spectrum, its use, and the potential for WiMAX to revolutionise broadband.[8]
[edit]
Competing technologies
Within the marketplace, WiMAX's main competition comes from existing widely deployed wireless systems such as UMTS and CDMA2000, as well as a number of Internet oriented systems such as HIPERMAN and WiBro.
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3G and 4G cellular phone Systems
Both major 3G systems, CDMA2000 and UMTS, compete with WiMAX. Both aim to offer DSL-class Internet access in addition to phone service. UMTS has also been enhanced to compete directly with WiMAX in the form of UMTS-TDD, which can use WiMAX oriented spectrum and provides a more consistent, if lower bandwidth at peak, user experience than WiMAX.
3G cellular phone systems usually benefit from already having entrenched infrastructure, being upgraded from earlier systems. Users can usually fall back to older systems when they move out of range of upgraded equipment, often relatively seamlessly.
The major cellular standards are being evolved to so-called 4G, high bandwidth, low latency, all-IP networks with voice services built on top. With GSM/UMTS, the move to 4G is the 3GPP Long Term Evolution effort. For AMPS/TIA derived standards such as CDMA2000, a replacement called Ultra Mobile Broadband is under development. In both cases, existing air interfaces are being discarded, in favour of OFDMA for the downlink and a variety of OFDM based solutions for the uplink, much akin to WiMAX.
In some areas of the world the wide availability of UMTS and a general desire for standardization has meant spectrum has not been allocated for WiMAX: in July 2005, the EU-wide frequency allocation for WiMAX was blocked.
[edit]
Mobile Broadband Wireless Access
Mobile Broadband Wireless Access (MBWA) is a technology being developed by IEEE 802.20 and is aimed at wireless mobile broadband for operations from 120 to 350 km/h. The 802.20 standard committee was first to define many of the methods which were later funneled into Mobile WiMAX, including high speed dynamic modulation and similar scalable OFDMA capabilities. It apparently retains fast hand-off, Forward Error Correction (FEC) and cell edge enhancements.
The Working Group was temporarily suspended in mid 2006 by the IEEE-SA Standards Board since it had been the subject of a number of appeals, and a preliminary investigation of one of these "revealed a lack of transparency, possible 'dominance,' and other irregularities in the Working Group".[9]
In September 2006 the IEEE-SA Standards Board approved a plan to enable the working group to continue under new conditions, and the standard is now expected to be finalized by Q2 2008.
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Internet-oriented systems
Early WirelessMAN standards, the European standard HIPERMAN and Korean standard WiBro have been harmonized as part of WiMAX and are no longer seen as competition but as complementary. All networks now being deployed in South Korea, the home of the Wibro standard, are now WiMAX.
As a short-range mobile Internet solution, such as in cafes and at transportation hubs like airports, the popular Wi-Fi 802.11b/g system is widely deployed, and provides enough coverage for some users to feel subscription to a WiMAX service is unnecessary.
[edit]
Comparison
Main article: Comparison of wireless data standards
The following table should be treated with caution as it only shows peak rates which are potentially very misleading. In addition the comparisons listed are not normalized by physical channel size (i.e. spectrum used to achieve the listed peak rates); this obfuscates spectral efficiency and net through-put capabilities of the different wireless technologies listed below.
v • d • e
Comparison of Mobile Internet Access methodsStandard Family Primary Use Radio Tech Downlink (Mbps) Uplink (Mbps) Notes
802.16e WiMAX Mobile Internet MIMO-SOFDMA 70 70 Quoted speeds only achievable at very short ranges, more practically 10 Mbps at 10 km.
HIPERMAN HIPERMAN Mobile Internet OFDM 56.9 56.9
WiBro WiBro Mobile Internet OFDMA 50 50 Mobile range (900 m)
iBurst iBurst 802.20 Mobile Internet HC-SDMA/TDD/MIMO 64 64 3-12 km
EDGE Evolution GSM Mobile Internet TDMA/FDD 1.9 0.9 3GPP Release 7
UMTS W-CDMA
HSDPA+HSUPA
HSPA+ UMTS/3GSM Mobile phone CDMA/FDD
CDMA/FDD/MIMO .384
14.4
42 .384
5.76
11.5 HSDPA widely deployed. Typical downlink rates today 1-2Mbps, ~200kbps uplink; future downlink up to 28.8Mbps.
UMTS-TDD UMTS/3GSM Mobile Internet CDMA/TDD 16 16 Reported speeds according to IPWireless using 16QAM modulation similar to HSDPA+HSUPA
LTE UMTS UMTS/4GSM General 4G OFDMA/MIMO/SC-FDMA (HSOPA) >100 >50 Still in development
1xRTT CDMA2000 Mobile phone CDMA 0.144 0.144 Obsoleted by EV-DO
EV-DO 1x Rev. 0
EV-DO 1x Rev.A
EV-DO Rev.B CDMA2000 Mobile Internet CDMA/FDD 2.45
3.1
4.9xN 0.15
1.8
1.8xN Rev B note: N is the number of 1.25 MHz chunks of spectrum used. Not yet deployed.
Notes: All speeds are theoretical maximums and will vary by a number of factors, including the use of external antennae, distance from the tower and the ground speed (i.e. communications on a train may be poorer than when standing still.) Usually the bandwidth is shared between several terminals. The performance of each technology is determined by a number of constraints, including the spectral efficiency of the technology, the cell sizes used, and the amount of spectrum available. For more information, see Comparison of wireless data standards.
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Future development
Mobile WiMAX based upon 802.16e-2005 has been accepted as IP-OFDMA for inclusion as the sixth wireless link system under IMT-2000. This can hasten acceptance by regulatory authorities and operators for use in cellular spectrum. WiMAX II, 802.16m will be proposed for IMT-Advanced 4G.
The goal for the long term evolution of both WiMAX and LTE is to achieve 100 Mbit/s mobile and 1 Gbit/s fixed-nomadic bandwidth as set by ITU for 4G NGMN (Next Generation Mobile Network) systems through the adaptive use of MIMO-AAS and smart, granular network topologies. 3GPP LTE and WiMAX-m are concentrating much effort on MIMO-AAS, mobile multi-hop relay networking and related developments needed to deliver 10X and higher Co-Channel reuse multiples.
Since the evolution of core air-link technologies has approached the practical limits imposed by Shannon's Theorem, the evolution of wireless has embarked on pursuit of the 3X to 10X+ greater bandwidth and network efficiency gains that are expected by advances in the spatial and smart wireless broadband networking technologies. What will clearly define 4G more than either WCDMA or OFDMA wireless link methods will be wireless networks that more effectively adapt to and take advantage of available spectrum.
From Wikipedia, the free encyclopedia
(Redirected from Wimax)
WiMAX, the Worldwide Interoperability for Microwave Access, is a telecommunications technology aimed at providing wireless data over long distances in a variety of ways, from point-to-point links to full mobile cellular type access. It is based on the IEEE 802.16 standard, which is also called WirelessMAN. The name WiMAX was created by the WiMAX Forum, which was formed in June 2001 to promote conformance and interoperability of the standard. The forum describes WiMAX as "a standards-based technology enabling the delivery of last mile wireless broadband access as an alternative to cable and DSL."Contents [hide]
1 Definitions of terms
1.1 802.16d
1.2 802.16e
1.3 Fixed WiMAX
1.4 Mobile WiMAX
2 Uses
2.1 Broadband access
2.1.1 Subscriber units
2.2 Mobile applications
3 Technical information
3.1 MAC layer/data link layer
3.2 Physical layer
3.3 Architecture
3.4 Comparison with Wi-Fi
3.5 Spectrum allocation issues
3.6 Spectral Efficiency
3.7 Limitations
3.8 Silicon implementations
4 Standards
4.1 IEEE 802.16e-2005
5 Associations
5.1 WiMAX Forum
5.2 WiMAX Spectrum Owners Alliance - WiSOA
6 Competing technologies
6.1 3G and 4G cellular phone Systems
6.1.1 Mobile Broadband Wireless Access
6.2 Internet-oriented systems
6.3 Comparison
7 Future development
8 Current deployments
9 See also
10 Notes
11 Literature
12 External links
[edit]
Definitions of terms
The terms "fixed WiMAX", "mobile WiMAX", "802.16d" and "802.16e" are frequently used incorrectly.[1] Correct definitions are:Mobile communication standards
GSM / UMTS (3GPP) Family
2G
GSM
GPRS
EDGE (EGPRS)
EDGE Evolution
HSCSD
3G
UMTS (3GSM)
HSPA
HSDPA
HSUPA
HSPA+
UMTS-TDD
TD-CDMA
TD-SCDMA
FOMA
Pre-4G
UMTS Revision 8
LTE
HSOPA (Super 3G)
cdmaOne / CDMA2000 (3GPP2) Family
2G
cdmaOne
3G
CDMA2000
EV-DO
Pre-4G
UMB
Widely Used Other Technologies
1G
AMPS
2G
D-AMPS
Other Technologies
0G
PTT
MTS
IMTS
AMTS
OLT
MTD
Autotel / PALM
ARP
1G
NMT
TACS / ETACS
Hicap
CDPD
Mobitex
DataTAC
2G
iDEN
PDC
CSD
PHS
WiDEN
Pre-4G
iBurst
HIPERMAN
WiMAX
WiBro (Mobile WiMAX)
GAN (UMA)
Frequency bands
SMR
Cellular
PCS
[edit]
802.16d
Strictly speaking, 802.16d has never existed as a standard. The standard is correctly called 802.16-2004 and was developed by the IEEE 802.16 Task Group d. Therefore the project was called 802.16d, but the standard never was. However, since this standard is frequently called 802.16d, that term is also used in this article to assist readability.
[edit]
802.16e
Just as 802.16d has never existed as a standard, neither has 802.16e. 802.16e is an amendment to 802.16-2004, and the amendment is properly referred to as 802.16e-2005. 802.16e-2005 is not a standard in its own right - since it is only an amendment, the original document (802.16-2004) has to be read and then the amendments added to it.
[edit]
Fixed WiMAX
This is a phrase frequently used to refer to systems built using 802.16-2004 ('802.16d') and the OFDM PHY as the air interface technology.
Fixed WiMAX deployments do not cater for handoff between Base Stations, therefore the service provider cannot offer mobility.
[edit]
Mobile WiMAX
A phrase frequently used to refer to systems built using 802.16e-2005 and the OFDMA PHY as the air interface technology. "Mobile WiMAX" implementations can be used to deliver both fixed and mobile services.
[edit]
Uses
The bandwidth and reach of WiMAX make it suitable for the following potential applications:
Connecting Wi-Fi hotspots with each other and to other parts of the Internet.
Providing a wireless alternative to cable and DSL for last mile broadband access.
Providing high-speed data and telecommunications services.
Providing a diverse source of Internet connectivity as part of a business continuity plan. That is, if a business has a fixed and a wireless Internet connection, especially from unrelated providers, they are unlikely to be affected by the same service outage.
Providing nomadic connectivity.
[edit]
Broadband access
Many companies are closely examining WiMAX for "last mile" connectivity at high data rates. The resulting competition may bring lower pricing for both home and business customers or bring broadband access to places where it has been economically unavailable. Prior to WiMAX, many operators have been using proprietary fixed wireless technologies for broadband services.
WiMAX access was used to assist with communications in Aceh, Indonesia, after the tsunami in December 2004. All communication infrastructure in the area, other than Ham Radio, was destroyed, making the survivors unable to communicate with people outside the disaster area and vice versa. WiMAX provided broadband access that helped regenerate communication to and from Aceh.
WiMAX was used by Intel to assist the FCC and FEMA in their communications efforts in the areas affected by Hurricane Katrina. [1]
[edit]
Subscriber units
WiMAX subscriber units are available in both indoor and outdoor versions from several manufacturers. Self-install indoor units are convenient, but radio losses mean that the subscriber must be significantly closer to the WiMAX base station than with professionally-installed external units. As such, indoor-installed units require a much higher infrastructure investment as well as operational cost (site lease, backhaul, maintenance) due to the high number of base stations required to cover a given area. Indoor units are comparable in size to a cable modem or DSL modem. Outdoor units are roughly the size of a laptop PC, and their installation is comparable to a residential satellite dish.
With the advent of mobile WiMAX, there is an increasing focus on portable units. This includes handsets (similar to cellular smartphones) and PC peripherals (PC Cards or USB dongles). In addition, there is much emphasis from operators on consumer electronics devices (games terminals, MP3 players and the like); it is notable this is more similar to WiFi than 3G cellular technologies.
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Mobile applications
Some cellular companies are evaluating WiMAX as a means of increasing bandwidth for a variety of data-intensive applications; Sprint Nextel announced in mid-2006 that it would invest about US$ 5 billion in a WiMAX technology buildout over the next few years.[2] As of Friday, November 9, 2007, this project in partnership with Clearwire has been shelved, but the project could be revived with or without Clearwire once Sprint hires a new CEO. On December 5, 2007, Bin Shen, Sprint's VP of Product Management and Partnership Development, announced that Sprint's WiMAX network will go live in a soft launch in Chicago, Baltimore, and Washington DC. Full commercial launch is still expected to be approximately spring of 2008.[3] In December 2007 Wateen Telecom Pakistan deployed the largest and the first in the world to roll-out WiMAX 802.16e network in 22 cities of Pakistan. In line with these possible applications is the technology's ability to serve as a high bandwidth "backhaul" for Internet or cellular phone traffic from remote areas back to an Internet backbone. Although the cost per user/point of WiMAX in a remote application will be higher, it is not limited to such applications, and may be an answer to reducing the cost of T1/E1 backhaul as well. Given the limited wired infrastructure in some developing countries, the costs to install a WiMAX station in conjunction with an existing cellular tower or even as a solitary hub are likely to be small in comparison to developing a wired solution. Areas of low population density and flat terrain are particularly suited to WiMAX and its range. For countries that have skipped wired infrastructure as a result of prohibitive costs and unsympathetic geography, WiMAX can enhance wireless infrastructure in an inexpensive, decentralized, deployment-friendly and effective manner.
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Technical information
WiMAX is a term coined to describe standard, interoperable implementations of IEEE 802.16 wireless networks, similar to the way the term Wi-Fi is used for interoperable implementations of the IEEE 802.11 Wireless LAN standard. However, WiMAX is very different from Wi-Fi in the way it works.
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MAC layer/data link layer
In Wi-Fi the media access controller (MAC) uses contention access — all subscriber stations that wish to pass data through a wireless access point (AP) are competing for the AP's attention on a random interrupt basis. This can cause subscriber stations distant from the AP to be repeatedly interrupted by closer stations, greatly reducing their throughput. This makes services such as Voice over IP (VoIP) or IPTV, which depend on an essentially-constant Quality of Service (QoS) depending on data rate and interruptibility, difficult to maintain for more than a few simultaneous users.
In contrast, the 802.16 MAC uses a scheduling algorithm for which the subscriber station need compete once (for initial entry into the network). After that it is allocated an access slot by the base station. The time slot can enlarge and contract, but remains assigned to the subscriber station, which means that other subscribers cannot use it. In addition to being stable under overload and over-subscription (unlike 802.11), the 802.16 scheduling algorithm can also be more bandwidth efficient. The scheduling algorithm also allows the base station to control QoS parameters by balancing the time-slot assignments among the application needs of the subscriber stations.
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Physical layer
The original WiMAX standard (IEEE 802.16) specified WiMAX for the 10 to 66 GHz range. 802.16a, updated in 2004 to 802.16-2004, added specifications for the 2 to 11 GHz range. 802.16-2004 was updated to 802.16e in 2005 and uses scalable orthogonal frequency-division multiple access (SOFDMA) as opposed to the OFDM version with 256 sub-carriers (of which 200 are used) in 802.16d. More advanced versions, including 802.16e, also bring Multiple Antenna Support through Multiple-input multiple-output communications (MIMO) See WiMAX MIMO. This brings potential benefits in terms of coverage, self installation, power consumption, frequency re-use and bandwidth efficiency. 802.16e also adds a capability for full mobility support. The WiMAX certification allows vendors with 802.16d products to sell their equipment as WiMAX certified, thus ensuring a level of interoperability with other certified products, as long as they fit the same profile.
Most commercial interest is in the 802.16d and .16e standards, since the lower frequencies used in these variants suffer less from inherent signal attenuation and therefore give improved range and in-building penetration. Already today, a number of networks throughout the world are in commercial operation using certified WiMAX equipment compliant with the 802.16d standard.
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Architecture
The WiMAX Forum has defined an architecture that defines how a WiMAX network connects with other networks, and a variety of other aspects of operating such a network, including address allocation, authentication, etc. An overview of the architecture is given in the illustration. This defines the following components:
SS/MS: the Subscriber Station/Mobile Station
ASN: the Access Service Network
BS: Base station, belongs to ASN
ASN-GW: belongs to ASN
CSN: the Connectivity Service Network
HA: Home Agent, belongs to CSN
AAA: AAA Server, belongs to CSN
NAP: a Network Access Provider
NSP: a Network Service Provider
plus a number of interconnections (or reference points) between these, labeled R1 to R5 and R8.
It's important to note that the functional architecture can be designed into various hardware configurations rather than fixed configurations. For example, the architecture is flexible to allow various scale and functionality of remote/mobile stations and collaborative aggregations of femto, pico, and mini RS/MS.
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Comparison with Wi-Fi
Possibly due to the fact both WiMAX and Wi-Fi begin with the same two letters, are based upon IEEE standards beginning with "802.", and both have a connection to wireless connectivity and the Internet, comparisons and confusion between the two are frequent. Despite this, the two standards are aimed at different applications.
WiMAX is a long-range system, covering many kilometers that typically uses licensed spectrum (although it is also possible to use unlicensed spectrum) to deliver a point-to-point connection to the Internet from an ISP to an end user. Different 802.16 standards provide different types of access, from mobile (analogous to access via a cellphone) to fixed (an alternative to wired access, where the end user's wireless termination point is fixed in location.)
Wi-Fi is a shorter range system, typically hundreds of meters, that uses unlicensed spectrum to provide access to a network, typically covering only the network operator's own property. Typically Wi-Fi is used by an end user to access their own network, which may or may not be connected to the Internet. If WiMAX provides services analogous to a cellphone, Wi-Fi is more analogous to a cordless phone.
WiMAX and Wi-Fi have quite different Quality of Service (QoS) mechanisms. WiMAX uses a mechanism based on setting up connections between the Base Station and the user device. Each connection is based on specific scheduling algorithms, which means that QoS parameters can be guaranteed for each flow. WiFi has introduced a QoS mechanism similar to fixed Ethernet, where packets can receive different priorities based on their tags. This means that QoS is relative between packets/flows, as opposed to guaranteed.
WiMAX is highly scalable from what are called "femto"-scale remote stations to multi-sector 'maxi' scale base that handle complex tasks of management and mobile handoff functions and include MIMO-AAS smart antenna subsystems.
Due to the ease and low cost with which Wi-Fi can be deployed, it is sometimes used to provide Internet access to third parties within a single room or building available to the provider, often informally, and sometimes as part of a business relationship. For example, many coffee shops, hotels, and transportation hubs contain Wi-Fi access points providing access to the Internet for customers.
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Spectrum allocation issues
The 802.16 specification applies across a wide swath of the RF spectrum, and WiMAX could function on any frequency below 66GHz"IEEE Standard for Local and metropolitan area networks Part 16: Air Interface for Fixed and Mobile Broadband Wireless Access Systems Amendment 2: Physical and Medium Access Control Layers for Combined Fixed and Mobile Operation in Licensed Bands and Corrigendum 1," IEEE Std 802.16e-2005 and IEEE Std 802.16-2004/Cor 1-2005 (Amendment and Corrigendum to IEEE Std 802.16-2004), 2006, pp. 3, (higher frequencies would decrease the range of a Base Station to a few hundred meters in an urban environment).
There is no uniform global licensed spectrum for WiMAX, although the WiMAX Forum has published three licensed spectrum profiles: 2.3GHz, 2.5GHz and 3.5GHz, in an effort to decrease cost: economies of scale dictate that the more WiMAX embedded devices (such as mobile phones and WiMAX-embedded laptops) are produced, the lower the unit cost. (The two highest cost components of producing a mobile phone are the silicon and the extra radio needed for each band.) Similar economy of scale benefits apply to the production of Base Stations.
In the unlicensed band, 5.x GHz is the approved profile. Telecom companies are unlikely to use this spectrum widely other than for backhaul, as they do not own and control the spectrum.
In the USA, the biggest segment available is around 2.5 GHz,[4] and is already assigned, primarily to Sprint Nextel and Clearwire. Elsewhere in the world, the most-likely bands used will be the Forum approved ones, with 2.3 GHz probably being most important in Asia. Some countries in Asia like India, Vietnam and Indonesia will use a mix of 3.3 GHz and other frequencies.
Analog TV bands (700MHz) may become available for WiMAX use, but await the complete rollout of digital TV, and there will be other uses suggested for that spectrum. In the USA the FCC auction for this spectrum is scheduled for January 2008 [2]. EU commissioner Viviane Reding has suggested re-allocation of 500-800 MHz spectrum for wireless communication, including WiMAX [3].
WiMAX profiles define channel size, TDD/FDD and other necessary attributes in order to have inter-operating products. The current fixed profiles are defined for both TDD and FDD profiles. At this point, all of the mobile profiles are TDD only. The fixed profiles have channel sizes of 3.5 MHz, 5 MHz, 7 MHz and 10 MHz. The mobile profiles are 5 MHz, 8.75 MHz and 10 MHz. (Note: the 802.16 standard allows a far wider variety of channels, but only the above subsets are supported as WiMAX profiles).
Since October 2007, the Radiocommunication Sector of the International Telecommunication Union (ITU-R) has decided to include WiMAX technology in the IMT-2000 set of standards. This enables spectrum owners (specifically in the 2.5-2.69GHz band at this stage) to use Mobile WiMAX equipment in any country that recognizes the IMT-2000.
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Spectral Efficiency
One of the significant advantages of advanced wireless systems such as WiMAX is spectral efficiency. For example, 802.16-2004 (fixed) has a spectral efficiency of 3.7 bit/s/Hertz, and other 3.5-4G wireless systems offer spectral efficiencies that are similar to within a few tenths of a percent. The notable advantage of WiMAX comes from combining SOFDMA with smart antenna technologies. This multiplies the effective spectral efficiency through multiple reuse and smart network deployment topologies. The direct use of frequency domain organization simplifies designs using MIMO-AAS compared to CDMA/WCDMA methods, resulting in more-effective systems.[citation needed]
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Limitations
A commonly-held misconception is that WiMAX will deliver 70 Mbit/s over 50 kilometers. In reality, WiMAX can do one or the other - operating over maximum range (50 km) increases bit error rate and thus must use a lower bitrate. Lowering the range allows a device to operate at higher bitrates.
Typically, fixed WiMAX networks have a higher-gain directional antenna installed near the client (customer) which results in greatly increased range and throughput. Mobile WiMAX networks are usually made of indoor "customer premises equipment" (CPE) such as desktop modems, laptops with integrated Mobile WiMAX or other Mobile WiMAX devices. Mobile WiMAX devices typically have an omni-directional antenna which is of lower-gain compared to directional antennas but are more portable. In practice, this means that in a line-of-sight environment with a portable Mobile WiMAX CPE, speeds of 10 Mbit/s at 10 km could be delivered However, in urban environments they may not have line-of-sight and therefore users may only receive 10 Mbit/s over 2 km. Higher-gain directional antennas can be used with a Mobile WiMAX network with range and throughput benefits but the obvious loss of practical mobility.
Like most wireless systems, available bandwidth is shared between users in a given radio sector, so performance could deteriorate in the case of many active users in a single sector. In practice, many users will have a range of 2-, 4-, 6-, 8-, 10- or 12 Mbit/s services and additional radio cards will be added to the base station to increase the capacity as required.
Because of this, various granular and distributed network architectures are being incorporated into WiMAX through independent development and within the 802.16j mobile multi-hop relay (MMR) task group. This includes wireless mesh, grids, network remote station repeaters which can extend networks and connect to backhaul.
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Silicon implementations
A critical requirement for the success of a new technology is the availability of low-cost chipsets and silicon implementations.
Intel is a leader in promoting WiMAX, and has developed its own chipset. However, it is notable that most of the major semiconductor companies have to date been more cautious of involvement and most of the solutions come from specialist smaller or start-up suppliers. For the client-side these include GCT, Altair, Beceem, GCI, Runcom, Motorola with TI, NextWave, Sequans, Redpine signals[4] and a number of others. Both Sequans and Wavesat manufacture solutions for both clients and network while TI, DesignArt, and picoChip are focused on WiMAX chipsets for basestations.
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Standards
The current WiMAX incarnation, Mobile WiMAX, is based upon IEEE Std 802.16e-2005,[5] approved in December 2005. It is an amendment of IEEE Std 802.16-2004[6] and so the actual standard is 802.16-2004 as amended by 802.16e-2005 - the specifications need to be read together to understand them.
IEEE Std 802.16-2004 addresses only fixed systems. It replaced IEEE Standards 802.16-2001, 802.16c-2002, and 802.16a-2003.
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IEEE 802.16e-2005
IEEE 802.16e-2005 improves upon IEEE 802.16-2004 by:
Adding support for mobility (soft and hard handover between base stations). This is seen as one of the most important aspects of 802.16e-2005, and is the very basis of 'Mobile WiMAX'.
Scaling of the Fast Fourier Transform (FFT) to the channel bandwidth in order to keep the carrier spacing constant across different channel bandwidths (1.25-20 MHz). Constant carrier spacing results in a higher spectrum efficiency in wide channels, and a cost reduction in narrow channels. Also known as Scalable OFDMA (SOFDMA).
Improving NLOS coverage by utilizing advanced antenna diversity schemes, and hybrid-Automatic Retransmission Request (HARQ)
Improving capacity and coverage by introducing Adaptive Antenna Systems (AAS) and Multiple Input Multiple Output (MIMO) technology
Increasing system gain by use of denser sub-channelization, thereby improving indoor penetration
Introducing high-performance coding techniques such as Turbo Coding and Low-Density Parity Check (LDPC), enhancing security and NLOS performance
Introducing downlink sub-channelization, allowing administrators to trade coverage for capacity or vice versa
Enhanced Fast Fourier Transform algorithm can tolerate larger delay spreads, increasing resistance to multipath interference
Adding an extra QoS class (enhanced real-time Polling Service) more appropriate for VoIP applications.
802.16d vendors point out that fixed WiMAX offers the benefit of available commercial products and implementations optimized for fixed access. It is a popular standard among alternative service providers and operators in developing areas due to its low cost of deployment and advanced performance in a fixed environment. Fixed WiMAX is also seen as a potential standard for backhaul of wireless base stations such as cellular, WiFi or even Mobile WiMAX.
SOFDMA (used in 802.16e-2005) and OFDM256 (802.16d) are not compatible so most equipment will have to be replaced if an operator wants or needs to move to the later standard. However, some manufacturers are planning to provide a migration path for older equipment to SOFDMA compatibility which would ease the transition for those networks which have already made the OFDM256 investment. Intel provides a dual-mode 802.16-2004 802.16-2005 chipset for subscriber units. This affects a relatively small number users and operators.
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Associations
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WiMAX Forum
The WiMAX Forum is the organization dedicated to certifying the interoperability of WiMAX products. Those that pass conformance and interoperability testing achieve the "WiMAX Forum Certified" designation and can display this mark on their products and marketing materials. Some vendors claim that their equipment is "WiMAX-ready", "WiMAX-compliant", or "pre-WiMAX", if they are not officially WiMAX Forum Certified.[7]
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WiMAX Spectrum Owners Alliance - WiSOA
WiSOA is the first global organization composed exclusively of owners of WiMAX spectrum with plans to deploy WiMAX technology in those bands. WiSOA is focussed on the regulation, commercialisation, and deployment of WiMAX spectrum in the 2.3–2.5 GHz and the 3.4–3.5 GHz ranges. WiSOA are dedicated to educating and informing its members, industry representatives and government regulators of the importance of WiMAX spectrum, its use, and the potential for WiMAX to revolutionise broadband.[8]
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Competing technologies
Within the marketplace, WiMAX's main competition comes from existing widely deployed wireless systems such as UMTS and CDMA2000, as well as a number of Internet oriented systems such as HIPERMAN and WiBro.
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3G and 4G cellular phone Systems
Both major 3G systems, CDMA2000 and UMTS, compete with WiMAX. Both aim to offer DSL-class Internet access in addition to phone service. UMTS has also been enhanced to compete directly with WiMAX in the form of UMTS-TDD, which can use WiMAX oriented spectrum and provides a more consistent, if lower bandwidth at peak, user experience than WiMAX.
3G cellular phone systems usually benefit from already having entrenched infrastructure, being upgraded from earlier systems. Users can usually fall back to older systems when they move out of range of upgraded equipment, often relatively seamlessly.
The major cellular standards are being evolved to so-called 4G, high bandwidth, low latency, all-IP networks with voice services built on top. With GSM/UMTS, the move to 4G is the 3GPP Long Term Evolution effort. For AMPS/TIA derived standards such as CDMA2000, a replacement called Ultra Mobile Broadband is under development. In both cases, existing air interfaces are being discarded, in favour of OFDMA for the downlink and a variety of OFDM based solutions for the uplink, much akin to WiMAX.
In some areas of the world the wide availability of UMTS and a general desire for standardization has meant spectrum has not been allocated for WiMAX: in July 2005, the EU-wide frequency allocation for WiMAX was blocked.
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Mobile Broadband Wireless Access
Mobile Broadband Wireless Access (MBWA) is a technology being developed by IEEE 802.20 and is aimed at wireless mobile broadband for operations from 120 to 350 km/h. The 802.20 standard committee was first to define many of the methods which were later funneled into Mobile WiMAX, including high speed dynamic modulation and similar scalable OFDMA capabilities. It apparently retains fast hand-off, Forward Error Correction (FEC) and cell edge enhancements.
The Working Group was temporarily suspended in mid 2006 by the IEEE-SA Standards Board since it had been the subject of a number of appeals, and a preliminary investigation of one of these "revealed a lack of transparency, possible 'dominance,' and other irregularities in the Working Group".[9]
In September 2006 the IEEE-SA Standards Board approved a plan to enable the working group to continue under new conditions, and the standard is now expected to be finalized by Q2 2008.
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Internet-oriented systems
Early WirelessMAN standards, the European standard HIPERMAN and Korean standard WiBro have been harmonized as part of WiMAX and are no longer seen as competition but as complementary. All networks now being deployed in South Korea, the home of the Wibro standard, are now WiMAX.
As a short-range mobile Internet solution, such as in cafes and at transportation hubs like airports, the popular Wi-Fi 802.11b/g system is widely deployed, and provides enough coverage for some users to feel subscription to a WiMAX service is unnecessary.
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Comparison
Main article: Comparison of wireless data standards
The following table should be treated with caution as it only shows peak rates which are potentially very misleading. In addition the comparisons listed are not normalized by physical channel size (i.e. spectrum used to achieve the listed peak rates); this obfuscates spectral efficiency and net through-put capabilities of the different wireless technologies listed below.
v • d • e
Comparison of Mobile Internet Access methodsStandard Family Primary Use Radio Tech Downlink (Mbps) Uplink (Mbps) Notes
802.16e WiMAX Mobile Internet MIMO-SOFDMA 70 70 Quoted speeds only achievable at very short ranges, more practically 10 Mbps at 10 km.
HIPERMAN HIPERMAN Mobile Internet OFDM 56.9 56.9
WiBro WiBro Mobile Internet OFDMA 50 50 Mobile range (900 m)
iBurst iBurst 802.20 Mobile Internet HC-SDMA/TDD/MIMO 64 64 3-12 km
EDGE Evolution GSM Mobile Internet TDMA/FDD 1.9 0.9 3GPP Release 7
UMTS W-CDMA
HSDPA+HSUPA
HSPA+ UMTS/3GSM Mobile phone CDMA/FDD
CDMA/FDD/MIMO .384
14.4
42 .384
5.76
11.5 HSDPA widely deployed. Typical downlink rates today 1-2Mbps, ~200kbps uplink; future downlink up to 28.8Mbps.
UMTS-TDD UMTS/3GSM Mobile Internet CDMA/TDD 16 16 Reported speeds according to IPWireless using 16QAM modulation similar to HSDPA+HSUPA
LTE UMTS UMTS/4GSM General 4G OFDMA/MIMO/SC-FDMA (HSOPA) >100 >50 Still in development
1xRTT CDMA2000 Mobile phone CDMA 0.144 0.144 Obsoleted by EV-DO
EV-DO 1x Rev. 0
EV-DO 1x Rev.A
EV-DO Rev.B CDMA2000 Mobile Internet CDMA/FDD 2.45
3.1
4.9xN 0.15
1.8
1.8xN Rev B note: N is the number of 1.25 MHz chunks of spectrum used. Not yet deployed.
Notes: All speeds are theoretical maximums and will vary by a number of factors, including the use of external antennae, distance from the tower and the ground speed (i.e. communications on a train may be poorer than when standing still.) Usually the bandwidth is shared between several terminals. The performance of each technology is determined by a number of constraints, including the spectral efficiency of the technology, the cell sizes used, and the amount of spectrum available. For more information, see Comparison of wireless data standards.
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Future development
Mobile WiMAX based upon 802.16e-2005 has been accepted as IP-OFDMA for inclusion as the sixth wireless link system under IMT-2000. This can hasten acceptance by regulatory authorities and operators for use in cellular spectrum. WiMAX II, 802.16m will be proposed for IMT-Advanced 4G.
The goal for the long term evolution of both WiMAX and LTE is to achieve 100 Mbit/s mobile and 1 Gbit/s fixed-nomadic bandwidth as set by ITU for 4G NGMN (Next Generation Mobile Network) systems through the adaptive use of MIMO-AAS and smart, granular network topologies. 3GPP LTE and WiMAX-m are concentrating much effort on MIMO-AAS, mobile multi-hop relay networking and related developments needed to deliver 10X and higher Co-Channel reuse multiples.
Since the evolution of core air-link technologies has approached the practical limits imposed by Shannon's Theorem, the evolution of wireless has embarked on pursuit of the 3X to 10X+ greater bandwidth and network efficiency gains that are expected by advances in the spatial and smart wireless broadband networking technologies. What will clearly define 4G more than either WCDMA or OFDMA wireless link methods will be wireless networks that more effectively adapt to and take advantage of available spectrum.
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