Apr 18, 2009

Uses of WiMAX

WiMAX is designed as a wireless alternative to DSL and cable for last mile broadband access and as way to interconnect Wi-Fi hotspots into a Metropolitan Area Network. Although, the actual uses for WiMAX overlaps those for Wireless Local Area Network up until the mobile Wide Area Network level. Telephone and cable companies are closely probing the potential of WiMAX as a "last mile" connectivity option. This will result to a better-priced service for both home and business customers and not to mention the elimination of the "captive" customer bases for both telephone and cable networks.

In theory, WiMAX can provide connectivity to users within a 31 mile radius even if there is no direct line if sight. However, actual field tests show that the practical limits seem to be just around 3 to 5 miles. According to WiMAX proponents, the technology can provide shared data rates up to 70 Mbit/s. This is enough to connect 60 T1-type connections simultaneously and over a thousand homes running at 1 Mbit/s DSL level connectivity. Practical maximum data rates in actual field tests show can only go between 500 kbit/s to 2 Mbit/s and is quite dependent on the conditions at a given site.

Despite the numbers given, there are a lot of ways to improve the speed and range of a WiMAX connection using pre-existing technology. One interesting option for companies with analog cellular network is to let WiMAX "share" a cell tower since it will not interfere with any of the function of the cellular arrays while utilizing the licensed radio frequencies of the analog cellular network to increase its speed and range. A WiMAX antenna can also be directly connected to an Internet backbone using a fiber optic cable. This is one of the means to increase bandwidth for data-intensive applications running across a wireless network or as a back-haul for cellular phone and Internet traffic from a remote area back to a backbone. WiMAX can effectively improve a wireless infrastructure in a decentralized, inexpensive and deployment-friendly manner.

WiMAX is seen as a very good alternative to expensive urban deployments of T1 back-hauls in developing countries with limited wired infrastructure and cruel geography. The cost to install a WiMAX station as a single hub or using an existing cellular tower will be very small compared to a wired solution. WiMAX's 31-mile diametrical range also works well with the low population density and the wide flat areas common to developing countries. Some areas have skipped wired structures due to inhibitive costs and WiMAX can easily fill the gap in-between with its low-cost wireless solution.

There is no global license assigned for WiMAX although it has a very wide RF spectrum under the IEEE 802.16 specifications. The primary band used in the US for WiMAX is around 2.5 GHz although majority of the band is already assigned to Sprint Nextel. In other parts of the world, the bands used are usually around 2.3/2.5 GHz, 3.5 GHz and 5 GHz where the 2.3/2.5 GHz is widely used in Asia.

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