Overview

The EVDO system includes access points (APs), various data processing functions, and a data distribution network. The EVDO network is also called a radio access network (RAN).

The functional structure (network parts) of the EVDO system is covered in the TIA technical service bulletin 100 (TSB100-A). Network parts may be dedicated equipment assemblies or software programs that run on computer servers. EVDO networks inter-connect wireless devices with nearby radio towers (base stations) that route calls through switching systems to other wireless telephone to other telephone or data networks. Creating and managing a wireless network involves equipment selection and installation, implementation methods, inter-connection to the public switched telephone network (PTSN) and other networks such as the Internet, and system planning.

The main switching system in the EVDO wireless network is a packet data service node (PDSN) for high-speed data and a mobile switching center (MSC) for voice and medium-speed data. The PDSN ensures packets from the access terminals can reach their destination. The MSC coordinates the overall allocation and routing of calls throughout the wireless system.

Figure 1.17 shows a simplified functional diagram of an EVDO network. This diagram shows that the EVDO system provides for high-speed data, medium speed-data, and voice services. High-speed data services are provided by the EVDO data only through radio channels. Using data transmission services of IS-95 CDMA radio channels provides medium-speed data and voice services. This diagram shows that the access point (BTS) contains a radio transceiver (radio and transmitter) that converts the radio...