Wide area radio paging system

摘要

A system for delivering page messages to paging units over a wide area is provided through multiple transmission systems. The system has a controller for routing page messages to each paging unit through the transmission system to which the paging unit is registered. Each transmission system periodically sends a system message having at least a unique identifier for the transmission system. Each paging unit receives system messages of at least one of the transmission systems when located in the transmission system's coverage area, and receives page messages from the transmission system registered to the paging unit when located in that transmission system's coverage area. Paging units update their registration with the controller in accordance with the identifier of received system messages different from their current registered identifier via user enabled or automatic means. The controller may resend messages to paging units which were sent during periods of unlikely reception.