Structure and network control of a hierarchical mobile network architecture

The increase in demand for mobile telecommunication systems, and the limited bandwidth allocated to these systems, have led to systems with smaller cell dimensions. In this paper a mobile network structure, characterized by its hierarchical and decentralized network control is presented. The area served by the mobile system is divided into regions, and the regions are further divided into cells. Each cell is served by a base station, each base station is connected to a regional network through a base station interface unit (BIU). Each region has its own regional network. Connected to each regional network are the cellular controller, the home database, the visitor database, the trunk interface unit (TIU) and the gateway interface unit (GIU). The TIU connects the regional network to the public switched telephone network (PSTN). The GIU connects the regional network to other regional networks through the gateway network. This architecture distributes the network control functions among a large number of processing elements thus preventing controller bottlenecks, a problem faced by centralized controlled systems. The information and network control messages are transferred in the form of packets across this network. Processes inherent into the operation of this network structure are illustrated and discussed. These processes include, the location update process, the setting up of a call, as an example setting up a call between two mobile terminals is considered, the handoff process, both the intra-region handoff process and the inter-region handoff process are considered, and the process of terminating a call, as an example terminating the call between two mobile terminals is considered