Satellite selective call signalling system

摘要

A signalling system provides for efficient reception of message by a plurality of Earth based selective call receivers such as pagers. The signals are transmitted from satellites in orbit above the Earth. Each satellite includes a multiple lobe antenna capable of transmitting messages to a selected portion of the surface of the Earth. Methods for conserving satellite transmission power in the communication of message information are described. Furthermore, a signalling protocol transmitted by the satellite provides for power conservation by Earth based selective call receivers. Additionally, a method enabling an area of the Earth to receive messages from multiple satellites is described.