The message of the cellular industry today has migrated from “the fewest dropped calls” to “the fastest network” as users, handset manufacturers, application developers, and service providers alike focus on the next great application that will drive the market. This growth is focused around the delivery of data.

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Mobile data service has grown from so slow that it was practically useless to as good as Wi-Fi in just a few short years. As consumer and business application developers rush to find ways to take advantage of improved mobile data service, technologists are struggling to deliver newer, faster, and more robust broadband wireless networks to support it.

Graham Celine has 20 years of high-tech experience, joining Azimuth after a 13-year career focused on data networking. He received a BSc in electrical engineering from University of the Witwatersrand in South Africa. He can be reached at graham_celine@azimuthsystems.com

Existing wireless network capacity is constrained. As a result, sustaining this growth will require networks with flat, all-IP (Internet protocol) architectures, greater capacity, lower costs per bit, faster connections, lower latencies, and enhanced video capabilities. As data services continue to explode, how will manufacturers and service providers ensure that new devices and applications deliver the quality, throughput, and performance that users expect?

Powering The 4G Network

The standards for the technologies that will power the 4G broadband wireless network and enable these increasingly complex devices and demanding applications to perform are currently being defined within several leading industry groups, including the 3rd Generation Partnership Project (3GPP) and the Institute of Electrical and Electronics Engineers (IEEE) in concert with the WiMAX Forum. The standards under development by these organizations are commonly known as Long-Term Evolution (LTE) and 802.16e-2005, or Mobile WiMAX.

LTE and Mobile WiMAX have two major characteristics in common—orthogonal frequency-division multiplexing (OFDM) and multiple-input multiple-output (MIMO). Essentially, OFDM and MIMO are designed to deliver higher levels of throughput in smaller amounts of bandwidth.

OFDM and MIMO systems enhance the overall performance of radio transmitters and receivers with respect to the effects of the air interface—the physical paths that a radio signal travels between a transmitter and receiver. The radio path is subjected to numerous effects such as signal delay, fading, and obstructions that may combine to improve the conditions or may serve to corrupt the transmitted signal, positively or negatively affecting the overall channel throughput/data rate.