Mobile Wireless Communications Today

by Puneet Gupta

Introduction

Everything is converging. The wired world and the wireless world are converging. The Internet and mobile wireless is converging. The distinction between the wireless, wireline and the Internet service providers is beginning to blur. And the glue certainly is "mobile wireless".

Mobile wireless has exploded in popularity because of the fact that it simplifies and revolutionizes communication. The market for mobile wireless is increasing by leaps and bounds. The success of mobile communications lies in the ability to provide instant connectivity anytime and anywhere and the ability to provide high-speed data services to the mobile user. The quality and speeds available in the mobile environment must match the fixed networks if the convergence of the mobile wireless and fixed communication networks is to happen in the real sense. So, the challenges for the mobile networks lie in providing a very large footprint of mobile services (to make the movement from one network to another as transparent to the user as possible) and the availability of high speed reliable data services along with high quality voice. A range of successful mobile technologies exists today in various parts of the world and every technology must evolve to fulfill all these requirements. In the following sections I'll talk about the mobile technologies existing today, how these technologies compare, how these technologies are shaping up and what we can expect to see in the near future.

The mobile wireless market is predominantly voice-oriented with low speed data services. The popularity of mobile voice services has been the deciding factor for the development of mobile networks so far. Data, mainly in the form of SMS has basically been an extra service. However, SMS is fast becoming very popular and in many European countries subscribers are spending more on SMS than voice. Both the voice and data markets continue to grow and the 2nd Generation networks are evolving to keep up and, in fact, are generating demands for newer services. Although digital technologies have improved the quality of service provided by the mobile networks, the voice quality is still not the same as the toll quality. New speech coding techniques like EFR and adaptive multi-rate are bridging this gap.

Technologies And Services Existing Today

Many second-generation mobile technologies exist today each having influence in specific parts of the world. GSM, TDMA (IS 136), and CDMA (IS 95) are the main technologies in the second-generation mobile market. GSM by far has been the most successful standard in terms of it's coverage. All these systems have different features and capabilities. Although both GSM and TDMA based networks use time division multiplexing on the air interfaces, their channel sizes, structures and core networks are different. CDMA has an entirely different air interface.

In the following sections I will discuss the existing standards, the technologies, the situation today and also talk about some of the forecasts for these technologies. This should help you understand the situation today and also dispel some of the basic misconceptions about the viability of these technologies.