Wednesday, August 12, 2009

Fixed WiMAX

Fixed wireless is the use of wireless technology to provide voice, data, or video service to fixed locations. Fixed wireless services include wireless local loop (WLL), point-to-point microwave, wireless broadband, and free-space optical communication. Fixed wireless systems may replace or bypass wired telephone service, high-speed telephone communication links, and cable television systems.

Figure 1: WiMax Spectral Efficiency

The initial WiMAX 802.16 standard was developed to provide high-speed data communication for licensed fixed applications at microwave frequencies (10-66 GHz). Shortly after the development of the initial 802.16 standard started, several versions were created to provide different service types and to operate in lower frequencies (2-11 GHz).

The 802.16a specification was created to allow WiMAX to operate in the 2-11 GHz range. This was followed by the 802.16c specification, which contained profiles for 10-66 GHz systems. Development of an 802.16d specification was started to define profiles for 2-11 GHz range. Eventually, all of the variations (802.16a, 802.16c and 802.16d) were merged into a single 802.16 specification (802.16-2004).

Figure 2 illustrates that point to point communication can reach up to approximately 50 km (30 miles) with a data rate of over 72 Mbps. For multipoint communication that can operate in partially blocked (near line of sight) terrain, the WiMAX system can reach up to 10 km (6 miles) with a data rate of over 40 Mbps.

Figure 2: WiMax Fixed Communication Services
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