Chapter 4. PCS Standards

In this chapter…

• Cellular Voice and Data

• Packet Data Systems

• MCDN

• Private Mobile Radio

• Summary

The mobile technologies invented in the late 1990s are collectively known as PCS (Personal Communications Services). This term was originally used by the FCC to describe a particular group of licenses in the 1900 MHz band, but has been hijacked by marketers to include any digital system that provides high-quality voice and narrowband data. In the greater scheme of things, it is the second generation of wireless technology, between analog cellphones and broadband mobile multimedia.

There are three main categories of PCS in use today, all providing different features to the end user as shown in Table 4.1. Digital cellphones are by far the most popular, offering high-quality voice and limited data, usually text-only. Other services still use a cellular network but concentrate on data only, either to make the terminal smaller and cheaper or to provide simple graphics. Non-cellular technologies are relatively little-known, but important for many emergency services and some large businesses. They can work without a base station and support automatic conference calls between predefined groups.

Also classified as PCS are the 2½ G systems, which offer higher data rates through relatively simple upgrades to twentieth-century networks. The difference between one of these and a genuine 3G network is open to some debate, and really just depends on the speed; a 2½ G system ought to provide performance similar to that of a fast mode, while 3G's should be significantly higher.