A uni-directional satellite paging system for land mobile users

A satellite ground segment which is capable of supporting a uni-directional paging service for land mobile users is described. The system is configured around existing satellites and the VHF wide-area paging network. A suitable transmission format is proposed which employs multi-level frequency shift keying, dual time diversity and Reed-Solomon forward error correction. The anticipated performance of the transmission format is discussed. Proposed implementations of the mobile paging receiver and transmitter data-formatting modulation equipment are presented.