The proliferation of cellular telephone systems has made them a convenient choice for nation-wide communications. However, cellular air time is relatively expensive, and there is, therefore, a need to control the amount of time that nation-wide systems use cellular telephone networks. For example, a nation-wide trucking system requires centralized information on the current status of the fleet of trucks. Although such information can be sent through cellular telephone systems to a central location, the cost of using such cellular networks is prohibitive absent some way of controlling access to and information sent across the cellular network.
Another problem is that of roaming cellular phones. With present systems, a "roamer" must manually register its location each time it enters a new cellular system. This registration is then forwarded to the roamer's home system. This manual registration is inconvenient and is consequently often overlooked, resulting in missed calls. Moreover, calls placed to roamers must be routed through the home system, and are often expensive.
Furthermore, the fragmentation of cellular service providers results in disintegrated monitoring and control, often contributing to fraudulent use of the cellular telephone networks. The increasing fraud adds significantly to the cost of cellular air time, especially for nation-wide users of the cellular network.
Therefore, a need has arisen for a method and apparatus for controlling access to cellular telephone networks in an integrated nation-wide system. A need has also arisen for a call delivery system that reduces costs, inconvenience, and missed calls.