First-generation proprietary technology for broadband fixed wireless networks had lackluster non-line-of-sight performance, and the equipment was relatively expensive. Both of these drawbacks delayed widespread deployment of broadband wireless networks. However, the advent of the IEEE 802.16a standard for wireless metropolitan-area networks is likely to accelerate adoption.

Approved in January, 802.16a provides wireless, last-mile broadband access over the frequency bands below 11 GHz to connect homes, businesses and wireless LAN hot spots. 802.16a also is known as WiMAX because the Worldwide Interoperability for Microwave Access Forum industry group is working to promote the standard's deployment.

802.16a greatly improves non-line-of-sight performance, and it is the most appropriate technology available when obstacles such as trees and buildings are present. Stations can be mounted on homes or buildings rather than towers on mountains.

Just as important, standards-based products are less expensive to manufacture, and interoperability reduces the risk to carriers that wish to roll out service. Both of these factors should help spur deployment. Equipment manufacturers are expected to start implementing 802.16a in systems in the second half of next year.

With throughput up to 75M bit/sec, the wireless standard gives companies another way to get business-quality broadband service. While it could take several months for a carrier to provision a T-1 line, service providers could provision wireless service in a matter of days.

802.16a provides flexibility not possible with wired services, such as high-speed backhaul for events such as trade shows, with hundreds or even thousands of 802.11 hot-spot users. On-demand connectivity also could benefit businesses such as construction companies that have sporadic or nomadic connectivity needs. The 802.16e extension to 802.16a introduces nomadic capabilities that let users connect while roaming outside their home service areas.

The technology also offers privacy and Triple-DES encryption features to support secure transmissions and authentication.

In a typical enterprise deployment, laptop and desktop computers are connected via wired Ethernet or 802.11 Wi-Fi access points located throughout the campus. An 802.16a directional antenna provides the connection from the business to a service provider's cell tower. Even if there is no line of sight between the antenna and the tower, signal still can be received after it reflects off buildings or other obstructions and reaches the tower indirectly. At the base station, 802.16a technology correctly interprets the information even though reflections distort the radio frequency signal. Backhaul to the Internet is then provided via wireless 802.16 point-to-point links or by traditional wired backhaul such as DS3 and OCX.