Overview

The EVDO system is an upgraded version of an IS-95 CDMA mobile radio communication system that provides for high-speed data and voice communication services. Upgrading to EVDO capability allows CDMA cellular and PCS service providers to offer their customers wireless broadband (highspeed Internet) services by upgrading one or more of their IS-95 CDMA radio channels to the EVDO technology. Customers can access the highspeed Internet services through EVDO capable handsets or external modems that connect to their desktop or laptop computers. The EVDO radio channels are an "always-on" system that allows users to browse the Internet without complicated dialup connections.

The EVDO system is composed of access terminals (mobile devices), access points (base stations), and a packet data distribution network (the Internet). Because the EVDO system was primarily designed to use Internet Protocol (IP), it is plug-and-play with most computer operating systems.

Figure 1.1 shows a simplified diagram of an EVDO system. This diagram shows that the EVDO system includes mobile communication devices (called access terminals) that communicate through access points (base stations) and a mobile switching center (MSC) or data routing networks to connect to other mobile telephones, public telephones, or to the Internet. This diagram shows that the EVDO system contains both EVDO data radio channels and IS-95 voice radio channels. EVDO devices can be data only (such as a computer browsing the Internet), they can be single mode (such as in IS-95 telephone), or they can be dual mode (able to access either or both the...