Figure 8.1Precellular mobile service.

Figure 8.2Cellular service.

Figure 8.3The mobile telephone switching office (MTSO) connects the cellular network to thepublic switched telephone network. The backhaul network connects cells to themobile switch.

Figure 8.4Mobile switching center, Signaling System 7 (SS7), and registers containing subscriber databases.

Figure 8.5The Nextel nationwide push-to-talk service used for nationwide service.

Figure 8.6Kodiak push-to-talk between cellular networks. Figure courtesy of Kodiak Networks.

Figure 8.7Third generation network architecture as defined by the 3GPP.