文件名称：GSM, GPRS AND EDGE Performance
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更新时间：2012-04-19 20:08:22
GSM, GPRS AND EDGE
I have worked in the mobile communications industry longer than I would like to admit. In the early 1970s, I started my career as a radio engineer for Motorola. At that time, Motorola designed and manufactured low-, mid- and high-tier private land mobile radios. Motorola had few competitors for the mid- and high-tier product lines (50- to 100-W radios). However, in the low tier, less than 25-W radio category, there were numerous contenders, mostly from European manufacturers with a ‘Nordic Mobile Telephone’ heritage. But times were changing. In the late 1970s, the American public got their first taste of mobile communications when Citizen Band (CB) radio became popular (‘10–4, good buddy’). It was an unlicensed, short-range, ‘party-line’ experience. Those skilled in the art knew that something better was needed. And the American communications industry responded. The Federal Communications Commission and major industry players, like AT&T and Motorola, specified America’s first public mobile radio telephone system, AMPS (Advanced Mobile Telephone System). By the mid-1980s, AMPS was a proven technology and cellular subscriber growth was constantly exceeding forecasts. By the early 1990s, cellular technology had become so popular that the first-generation analog systems could not keep up with the demand. New second-generation digital systems were developed to address the capacity shortfall. In the United States, three digital technologies were standardized and deployed: IS-136 (a TDMA technology utilizing the AMPS 30-kHz structure), IS-95 (a 1.25-MHz CDMA carrier scheme) and GSM (the European 200-kHz TDMA standard). This multi-standard wireless environment provided a unique proving ground for the three technologies. While IS-136 and IS-95 engaged in ‘standards wars,’ GSM gained a foothold in America. At the same time, GSM was achieving global acceptance because it offered a rich selection of capabilities and features that provided real incremental revenues for operators. As more and more countries adopted the technology, GSM experienced tremendous economies of scale for everything from chipsets to handsets, infrastructure and applications. While the industry continued to experience stellar growth, American manufacturer dominance was challenged by Nordic companies, especially for the GSM technology. They brought to the United States, innovative, competitively priced products, backed by talented communications professionals with years of experience in designing, manufacturing, engineering and installing cellular equipment and systems throughout the world. By the late 1990s, the Internet was pervasive and the wireless industry looked to mobile data as the growth opportunity. Once again, the industry undertook the task of defining new wireless systems—this third generation, 3G, was to be based on packet data. Three new wireless standards emerged; CDMA2000 (evolution of IS-95), EDGE (evolution of xx Forewords GSM for existing spectrum) and WCDMA (evolution of GSM for new spectrum using a 5-MHz WCDMA carrier). The evolution of GSM to 3G is about gradually adding more functionality, possibilities and value to the existing GSM network and business. The evolution begins with an upgrade of the GSM network to 2.5G by introducing GPRS technology. GPRS provides GSM with a packet data air interface and an IP-based core network. EDGE is a further evolutionary step of GSM packet data. EDGE can handle about three times more data subscribers than GPRS, or triple the data rate for one end-user. EDGE can be achieved through a very fast and cost-effective implementation. The only requirement is to add EDGE-capable transceivers and software. With the continuation of EDGE standardisation towards GERAN (GSM/EDGE Radio access network), EDGE will achieve a full alignment with WCDMA. The goal for EDGE is to boost system capacity, both for real-time and best-effort services, and to become perfectly competitive with other 3G technologies. What emerges with these evolutionary steps from GSM to GPRS, EDGE and WCDMA is a seamless 3G UMTS (Universal Mobile Telecommunications System) Multi-Radio network, one that maximizes the investments in GSM and GPRS. It stands to reason that both EDGE and WCDMA will be mainstream 3G UMTS products from Nordic companies. This book, written by engineers from one of these Nordic companies, is an authoritative treatise on GSM evolution to 3G. The book provides an in-depth performance analysis of current and future GSM speech and GPRS/EDGE packet data functionality. Furthermore, the concept of a 3G UMTS Multi-Radio network (GSM/EDGE/WCDMA) is presented in depth as the best solution for wireless operators to evolve their networks towards 3G. Times change, but some things do not. Nordic companies have been at the forefront of wireless communications for more than a half of a century. They have earned their pre-eminent position in the industry. I encourage you to listen to what this book has to say.