Abstract: The Satellite Communication System disclosed in the specification is a dynamic constellation (C) of satellites (S). The present invention is capable of offering continuous voice, data and video service to customers across the globe on the land, on the sea, or in the air. The preferred embodiment of the invention comprises a low Earth orbit satellite system that includes 40 spacecraft (S) traveling in each of 21 orbital planes at an altitude of 700 km (435 miles). This relatively large number of satellites employed by the preferred embodiment was selected to provide continuous coverage of the Earth's surface at a high minimum mask angle (1230a) of forty degrees. Each of the individual 840 spacecraft (S) functions as an independent sovereign switch of equal rank which knows the position of its neighbors, and independently handles traffic without ground control.

Abstract: The exchange includes an input-output bus having a plurality of lines, predetermined ones of which are coupled to a different one of a plurality of peripheral information units. Each of the units are coupled to an associated one of the predetermined one of the lines through a transmission gate under control of an address detector. A random access memory is coupled to each of the predetermined ones of the plurality of lines to sequentially store and release the information of an addressed unit in the exchange selectively on command. A stored program is coupled to the random access memory to selectively command the random access memory and is coupled to others of the plurality of lines which are in turn coupled to the address detectors to selectively control the routing of the information of an addressed unit through the exchange.

Abstract: Each of the FDM frequency channel units of a FDM system include a physically programmable voltage controlled oscillator and a phase locked loop coupled therewith responsive to a reference signal or a physically programmable counter responsive to the reference signal. Each of these arrangements produce a carrier signal having a different predetermined frequency for each of a plurality of FDM frequency channel units. A balanced modulator modulates and transmits an associated one of the carrier signals with information and a balanced demodulator responsive to an associated one of the produced carrier signals demodulates an associated one of a plurality of received information bearing carrier signals.