WiMAX is defined as Worldwide Interoperability for Microwave Access by the WiMAX Forum, formed in June 2001 to promote conformance and interoperability of the IEEE 802.16 standard, officially known as WirelessMAN. 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".

WiMAX is a wireless digital communications system, also known as IEEE 802.16, that is intended for wireless "metropolitan area networks". WiMAX can provide broadband wireless access (BWA) up to 30 miles (50 km) for fixed stations with a direct line of sight, and 3 - 10 miles (5 - 15 km) for mobile stations. Near-line-of-sight (NLOS) conditions will seriously limit the potential range. In contrast, the WiFi/802.11 wireless local area network standard is limited in most cases.

Radio frequencies that can be utilized by WiMAX are bands centered roughly on 2300 ~ 2400 MHz, 2500 ~ 2690 MHz, and 3400 ~ 3600 MHz. These are designated by the International Telecommunications Union (ITU) as bands that require licensing from telecommunications regulators. Licenses are typically acquired at public auction in the country where the license is granted, and for a term of use up to 25 years or granted for fixed terms for a specified annual fee.

WiMAX has a theoretical maximum bandwidth of 75Mbps. This bandwidth can be achieved using 64QAM 3/4 modulation. 64QAM can only be utilized under optimal transmission conditions. WiMAX supports the use of a wide range of modulation algorithms to enable the most bandwidth to be realized under all conditions.

With WiMAX, WiFi-like data rates are easily supported, but the issue of interference is lessened. WiMAX operates on both licensed and non-licensed frequencies, providing a regulated environment and viable economic model for wireless carriers.

WiMAX can be used for wireless networking in much the same way as the more common WiFi protocol. WiMAX is a second-generation protocol that allows for more efficient bandwidth use, interference avoidance, and is intended to allow higher data rates over longer distances.

The IEEE 802.16 standard defines the technical features of the communications protocol. The WiMAX Forum offers a means of testing manufacturer's equipment for compatibility, as well as an industry group dedicated to fostering the development and commercialization of the technology.

Some of the frequencies utilized by WiMAX are subject to interference from rainfade. The unlicensed WiMAX frequencies are subject to RF interference from competing technologies and competing WiMAX networks.

Advantage and Applications:

As it is possible to use WiMAX over longer distances, this technology may come in handy in creating city wide networks. It is also better suited than WiFi for large area public places like airports, college and university campuses and large office set ups. It also provides for greater mobility to users.

As WiMAX follows a point-to-multipoint architecture, it is an ideal solution for delivering broadband to places where it would not be viable to establish wired connections. Rural areas and high rises are examples for this situation. Currently this last mile part of the connectivity is the biggest stumbling block to broadband providers, in terms of cost and manpower requirements. WiMAX can bring down the costs and subsequently make internet connectivity cheaper to the end user.

Another advantage over some other wireless technologies is that WiMAX does not need a direct line of sight between the source and the receptor. It also has a comparatively high shared data rate at 70Mbps, which is good enough to reach about a thousand homes.

WiMAX is also an excellent saver of time. As it does not need cables to connect with the receptors, it is possible to establish connection to an entire campus or even city in a matter of a few days.

WiMAX also allows for greater convergence of diverse applications such as fixed and mobile telephony, apart from entertainment sectors like television.

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.

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