In the works for years, WiMax (Worldwide Interoperability for Microwave Access), is a wireless technology that provides high-speed broadband connectivity over long distances. It can be used for several applications including last mile/last km broadband connections, high speed connectivity for businesses, and cellular/hot-spot backhaul applications. WiMax is the popular name for the IEEE 802.16 wireless MAN (Metropolitan Access Network) standard.

While Wi-Fi is suited for a small coverage area like a hot-spot, WiMax has been designed for metropolitan area networks. A single WiMax tower can transmit a signal as far as 50 km (30 mi) to offer high-speed connectivity to thousands of business and residential users within that radius. WiMax can provide true wireless mobility coverage throughout an entire town or campus, as opposed to Wi-Fi hot-spot hopping.

Potential applications for WiMax include:

- Last mile/last km connectivity applications: Network operators, like traditional phone companies and cable providers, see WiMax as a great alternative for last mile connectivity. Certainly cheaper than deploying fiber, WiMax can serve customers in rural areas who do not have access to broadband cable or DSL.

- Backhaul applications: WiMax can also effectively connect Wi-Fi hotspots and cellular towers to the Internet.

- Network overlay: 3G service providers can offer an overlaid WiMax service targeted towards laptop subscribers. Some experts believe WiMax can bridge the gap between applications designed for broadband landline and mobile wireless networks.

The WiMax network is relatively simple; it consists of two parts:

- WiMax tower (or transmitter): this is similar to a cellular tower. One WiMax tower can cover a wide area, as large as 8000 square km (3,000 sq miles). And WiMax antennas can even share a cell tower without affecting existing cellular service.

- WiMax receiver: The receiving antenna can be a PCMCIA card, a small box, or even integrated into a laptop like WiFi is today.

Intel, chip giant and one of the largest proponents of this technology, plans to have WiMax functionality in laptops by 2007 The WiMax tower can connect directly to the Internet using a high-speed landline connection, like PDH or SDH links. Or, it can also connect to another WiMax tower using a line-of-sight microwave link. This enables WiMax to further increase its coverage in remote areas.

There are two technical applications for WiMax. The first is the non line-of-sight deployment. In this application, a small antenna on your laptop connects to the tower for WiFi-like service. This mode employs a lower frequency range from 2 to 11 GHz (as lower wavelengths are less likely to be disrupted by physical obstacles). This application is ideal for mobile subscribers. The second application is line-of-sight service. Here, a fixed dish antenna sits on a rooftop or pole pointing at the WiMax tower. The line-of-sight transmission uses higher frequencies, as high as 66 GHz, offering more bandwidth and less interference. This deployment is ideal for service provider backhaul applications and broadband enterprise/business connectivity.

The WiMax forum is a non-profit organization dedicated to open interoperability of broadband wireless equipment based on the IEEE 802.16 standard. Much like the Wi-Fi Alliance did for WiFi, the WiMax Forum aims to accelerate the deployment of broadband wireless networks by ensuring industry compatibility and offering service providers a broad range of fairly priced equipment. Formed in June 2001, the forum now consists of more than 100 companies that include equipment and component suppliers, as well as content and service providers.

The organization plans to certify a first group of hardware vendors at their test lab in Spain in November 2005. You can learn more about the WiMax Forum and its members at their website: www.wimaxforum.org.

IEEE 802.16 Specifications Summary:

Point-to-multipoint broadband microwave access
Range: 50 km (30 mile) radius from tower
Speed: up to 70 Mbit/s
Frequency Bands: 2 to 11 GHz and 10 to 66 GHz (licensed and unlicensed bands)