Nationwide mobile telephone operation

Growing demand for more efficient communications combined with increasing mobility of system users has resulted in plans for very large mobile telephone systems. Systems cover large cities, states or even entire countries. A service need has developed for nationwide roaming operation. Since mobile telephone is connected to the wireline telephone system, call placement, routing and control must be coordinated between them. The mobile system must deal with the changing location of the subscriber and still meet land network interface requirements. Ideally, the mobile system should make maximum use of land network facilities as they are. The most difficult problem is selection of a numbering and routing plan for mobile users which is compatible with existing land network conventions. The optimum solution is a mobile network which is "overlaid" on the land network and is accessed by a nationwide "area" or access code. The mobile network then deals with the RF management and user mobility independently of land network hiearchy while maintaining a fully coordinated interface between the two systems.