Overview

Wireless networks interconnect wireless telephones 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.

Wireless networks consist of cell site radio towers (called node Bs in 3G systems), communication links, switching center, network databases, and link to public telephone and data networks.

The main switching system in the universal mobile telephone service (UMTS) wireless network is the mobile switching center (MSC). The MSC coordinates the overall allocation and routing of calls throughout the wireless system. Inter-system connections can link different wireless network systems to allow wireless telephones to move from cell site to cell site and system to system. The UMTS system defines intersystem connections in detail to allow universal and uniform service availability for 3rd generation wireless devices.

Figure 8.1 illustrates the fundamental parts and interconnections in a UMTS network. The user equipment (UE) is a wireless telephone. The UE is the combination of the physical mobile equipment (ME) and the UMTS subscriber identity module (USIM). The network radio parts of the UMTS system is called UMTS terrestrial radio access network (UTRAN). The UTRAN is composed of node Bs and radio network controllers (RNCs). The base stations convert radio signals from wireless telephones to a form suitable for transfer to the telephone or...