Fixed WiMAX – Last-mile broadband

By Vijay Nagarajan, Guest Author

Today belongs to CDMA-based wireless technologies. These technologies will continue to dominate the wireless market at least until 2012, beyond which they will slowly be phased out by 4G technologies based on Orthogonal Frequency Division Multiple Access (OFDMA). OFDMA is a multi-user version of OFDM systems that transmit data by efficiently slicing the bandwidth. WiMAX is a leading candidate for 4G and versions of this standard have already been implemented around the world today.

WiMAX-related work dates back to the 1990s when groups initiated efforts to provide last-mile fixed wireless access. The goals were to overlay the flexibility of wireless with the reliability of wireline systems. As efforts from carriers such as AT&T failed, these efforts took a backseat until the new millennium. Intel, spurred by the need to continually feed its microprocessor business, spearheaded the adoption of WiMAX. It sought to enable the sales of its chips by popularizing broadband wireless technologies. Intel found a powerful ally in Samsung, whose eyes were on the network equipment business and the opportunity to increase its mobile handset market share. With Motorola, Sprint and partial support from Nokia the WiMAX effort quickly had a section of the entire mobile value chain behind it.

Though the IEEE 802.16 came about in 1999, much of WiMAX as we know it today started consolidating with the completion of 802.16a in 2003. This standard allowed for multiple access and advanced features such as Space-time coding providing for efficient high-rate data transfer. The current fixed WiMAX equipment is based on the 802.16-2004. The standard allowed for a line of sight range of about 12-15 kilometers with data-rates of up to 100 Mbps. Fixed WiMAX made wireless broadband a reality with a high spectral efficiency and flexible bandwidth utilization of up to 20 MHz.

In the sequel, we will look into WiMAX’s transition towards mobilility and its future prospects.