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Monday, February 25, 2008

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."

The terms "fixed WiMAX", "mobile WiMAX", "802.16d" and "802.16e" are frequently used incorrectly.[1] Correct definitions are:

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.

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.

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.

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.

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.

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.

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