Comparative study of switching methods for the on-board processor in a mobile satellite communications system

on-board processor makes efficient use of the channel capacities in a satel lite communications system employing multibeam technology, and an on-board processor has been developed for the Engineering Test Satellite VIII (ETS-V III), which is the experimental satellite for a multibeam mobile satellite communications system. The multicarrier time division multiple access (MC-T DMA) system used in this communications system, however, sometimes causes i nternal congestion in the on-board processor. This paper describes the resu lts of computer simulation studies of the traffic capacity obtained using t hree baseband switching methods and also describes the results of studies o f the on-board processor design for each of the methods. The computer simul ation results indicate that the probability of internal congestion due to t he TDMA system is very small when the simultaneous-slot switching method is used, and the design study results reveal that an on-board processor using the simultaneous-slot switching method will be compact and lightweight and will consume little power. (C) 1998 John Wiley & Sons, Ltd.