Sinopsis
For people on the move, voice communication has been the killer application for many years. The demand for data services by mobile users has increased in recent years, and as a result, new protocols have emerged for providing wireless Internet access. The demand for multimedia services is now paving the way for high-speed, wireless networks that can support innovative applications combining data, graphics, voice, and video. In this chapter, we review the evolution of wireless networks and the applications supported by these networks. We also look at the new languages and tools used to develop content for various applications. Because of industry efforts to support multimedia services, mobile devices are evolving into powerful gadgets. This chapter also contains a brief overview of these developments.
The cellular networks developed in the 1960s and 1970s were mostly analog systems that supported voice communication. Subsequently, digital mobile communication networks, which are known as the second generation (2G) wireless networks, came into vogue. The 2G networks aren’t based on international standards, but on regional standards developed in North America and Europe. North American standards include IS 136 and IS 95A (IS stands for Interim Standard), and the European systems are based on GSM (Global System for Mobile Communications). Asian and African countries adapted the North American and European standards. These 2G networks support data rates up to a maximum of 14.4 Kbps. Hence, applications supported on these networks are capable of handling only text and low-resolution graphics.
The 2G networks are now evolving into 2.5G networks, which can support data rates in the range of 64 to 144 Kbps. Examples of 2.5G networks are the IS 95B standard-based networks that evolved from IS95A networks and the GPRS (General Packet Radio Service) networks built over the GSM networks. These networks can support high-speed data services such as high-resolution graphics and animation, audio, and low bit rate video services.
The 2.5G networks will, in turn, evolve into third generation (3G) networks, which will support data rates in the range of 384 to 2048 Kbps. The standardization efforts of many international bodies resulted in a few proposals for 3G networks; however, a single standard has not evolved, mainly because the 3G networks have to evolve from the existing networks. Two standards that are likely to find wide acceptance are W-CDMA (Wideband Code Division Multiple Access) systems, which evolve from GSM systems; and cdma2000 systems, which evolve from IS 95B systems. As these networks support higher data rates, they will be able to support full-fledged multimedia applications with streaming audio and video.
Content
- WAP, Bluetooth, and 3G: A Brief Introduction
- WML and WML Script Programming: A Case Study
- WAP Using Cold Fusion: A Project
- WTA: An Advanced Interaction Technique for Mobile Phones
- Integrating Java with WAP
- Push Technology in WAP
- Bluetooth: A Basic Introduction
- Using WAP with Bluetooth
- Bluetooth Programming
- An Overview of 3G
- Advanced 3G Programming
- 3G Programming Using BREW
- Voice and Video Communication over IP and Mobile IP Networks
- The Future of Wireless Networks
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