Emerging Wireless Technologies - 4G technologies

Although the new, third generation (3G) wireless technology has not yet been implemented, leading companies in the industry are already laying the groundwork for what some are calling fourth generation (4G) technology. For the purposes of this article, 4G will be considered those technologies that are still in the planning stages and will not be deployed within the next five years. Researchers are continuing their ideas in the development of an undefined wireless world, which could become operational by 2010.

One of the most challenging issues facing deployment of 4G technologies is how to make the network architectures compatible with each other. New signaling techniques are being designed specifically to enhance today's second generation (2G) networks, deliver unprecedented functionality for 3G, and successfully drive the Fourth Generation (4G) of wireless, thus delivering immediate and long-term benefits to carriers. With the architecture of each generation of wireless devices addressed in the development of advanced technologies, carriers can easily evolve their systems without additional network modifications, significantly reducing costs and implementation time. Currently, different wireless technologies (e.g., GSM, CDMA, and TDMA are used throughout the world for the 2G, 2.5G, and eventually 3G networks.

There are two approaches being used to develop 4G access techniques: 3xRTT (currently 1xRTT for 2.5 and 3G) and Wideband CDMA (W-CDMA). These disparate access techniques currently do not interoperate. This issue may be solved with software defined radios.

LinkAir Communications is developing a new access technology calledlarge-area-synchronized code-division multiple access (LAS-CDMA). LASCDMA will be compatible with all current and future standards, and there is a relatively easy transition from existing systems to LAS-CDMA (using software defined radios). LinkAir emphasizes that LASCDMA will accommodate all the advanced technologies planned for 4G and that LASCDMA will further enhance either 3xRTT or W-CDMA system’s performance and capacity.