A new wireless technology that is
poised to revolutionize broadband wireless access (BWA)
communications is Worldwide Interoperability for Microwave Access
(WiMAX), the IEEE 802.16 standard for broadband—big brother
to the popular wireless fidelity (Wi-Fi). WiMAX is designed for
metropolitan area networks (MANs) whereas Wi-Fi is designed for
local area networks (LANs). While Wi-Fi is intended to provide coverage
over relatively small areas, such as in offices or hotspots, WiMAX
can transfer around 70 Mbps over a distance of 30 miles (48 kilometers)
to thousand of users from a single base station. By comparison,
the most commonly used standard of Wi-Fi 802.11b can transfer data
at speeds up to 11 Mbps over ranges up to 1,000 feet (300 meters)
in open areas from a single base station.
The initial version of the WiMAX standard operates in the 10–66
GHz frequency band and requires lineof-sight towers, but the 802.16a
extension, ratified in January 2003, uses the lower frequency of
2-11 GHz, enabling nonline-of-sight connections, making it an appropriate
technology for last-mile applications where obstacles like trees
and buildings are often present. Hence, this constitutes a major
breakthrough in wireless broadband access as line-of-sight between
your transmission point and the receiving antenna is not necessary.
Approved in December 2002, 802.16c is aimed at improving interoperability
by specifying system profiles in the 10–66 GHz range.