In a satellite based cellular communication system where the satellites move with respect to the surface of the Earth and have antenna patterns covering thousands of miles, subscriber units must initially access the communication system at a proper frequency and during a proper time slot. Subscriber...http://www.google.de/patents/US5463400?utm_source=gb-gplus-sharePatent US5463400 - Method and apparatus for synchronizing to a multi-beam satellite TDMA communication system
