Android Application Development

Appendix A. Wireless Protocols

If you’re new to mobile development, the plethora of wireless telephony acronyms can be confusing at first. The good news is that, for the most part, you can ignore them because you don’t know exactly which environment your application will run in. The bad news is that your application should be prepared to run in all of the environments.

To help you follow the debates, standards, and discussions that inevitably arise when discussing cellular and wireless technologies, this appendix introduces the main protocols in historical order.

Prehistory

When mobile phones were first invented in the 1940s, they were just analog radios driven from a car battery. The system was aptly named Mobile Telephone System (MTS), and it was woefully inadequate. In spite of the high cost of service, waiting lists to obtain the service were long because MTS offered only a few channels in any geography. An “improved” version called IMTS, introduced in the 1960s, helped some, but was still far short of the demand.

The first analog cellular radio mobile phone systems started to appear in 1969 and the early 1970s—with phones still the size of a briefcase. The various cellular technologies in North America converged around the Advanced Mobile Phone Service (AMPS) standard, still analog technology but now based on cellular radios that could reuse the frequency spectrum and were standardized across manufacturers. At this time Europe had no less than nine different analog mobile phone ...