Linux Unwired

Chapter 9. Cellular Networking

The widest of the wide area wireless networks are the cellular networks. They’re also among the slowest, unless you’re in one of the markets where third-generation (3G) cellular networks are available. At the time of this writing, San Diego and Washington, D.C. users could receive between 300 and 500 kbps from Verizon for $80 a month. The rest of the United States, and much of the world, is still plodding along at between 30 and 130 kbps, depending on several variables: the type of network, capabilities of their terminal (a phone or PC Card), and quality of coverage. This chapter explains these variables to help you make the best choice in cellular data service, and also talks about configuring a cellular phone or PC Card with Linux (although this is usually just a small matter of PPP chat scripting).

Cellular Data

There are several types of cellular data networks. The most popular are General Packet Radio Services (GPRS) and 1x Radio Transmission Technology (1xRTT). At the time of this writing, slightly faster Enhanced Data rates for GSM Evolution (EDGE) and 1x Evolution Data Only (1xEV-DO) networks are emerging.

CSD

You use Circuit Switched Data (CSD) when you use your cellular phone as a dial-up modem. When you do this, you use your voice plan. Generally, this is not the best option: CSD calls typically don’t receive the full throughput that’s available to a data connection. However, there is a high-speed variant called High Speed CSD (HSCSD) that ...