A Centralized Multiple Satellite Network for Real Time Global Space, Land, and Mobile Communications

As satellite communications networks grow in capacity and complexity, multiple satellite systems are expected to play a significant role in future space, land, and mobile communications. Lack of orbital slots for geosynchronous satellites; space shuttle program to launch, collect, and repair to low orbit satellites; and growth of scientific and experimental satellites make the use of low orbit satellites more attractive. The problem of using low orbit satellites is that the ground stations are able to communicate with these satellites only for the limited time that the satellites are in their field of view. A possible solution to this problem is multiple satellite networking. Advances in satellite and ground station technologies such as using regional and spot beams, frequency selective routing, onboard processing, switching, higher G/T, EIRP, Solid State Power Amplifier (SSPA), advance digital signal processing, and small antennas allow design of an integrated multiple satellite network using low cost low orbit satellites and Very Small Aperture Terminals (VSAT). The objective of this paper is to a) define a general purpose network consisting of two geosynchronous satellites called central satellite stations (CSS), a large number of low orbit satellites; and a large number of land, sea, and mobile small terminals; b) define access techniques to be used; c) Analyze the delay-throughput performance of the central satellite stations and the network; and d) define a highly reliable and robust network synchronization methodology for multiple satellite networking with mobile users.