Patent ID: 6195555
Filing Date: 2001-02-27
Classification: H04B,H04W

Abstract:
A method of directing a call to a mobile telephone in a dual-mode cellular-satellite communications network, comprising the steps of:transmitting an alert signal to said mobile telephone using base stations of said cellular network if the mobile telephone is currently registered as active in a cellular network;receiving said alert signal at said mobile telephone;transmitting a response to said cellular network as an acknowledgement;upon non-receipt of said acknowledgement by the cellular network within a defined period of time, transmitting a last known location of the mobile telephone from said cellular network to a satellite earth station; andupon receipt of said last known location of the mobile telephone at said satellite earth station, using said last known location to determine a satellite antenna beam most likely to be received by said mobile telephone and transmitting an alert signal to said mobile telephone via a satellite using said antenna beam.