Satellite channels in packet-switching networks

The separate and combined use of terrestrial and satellite channels in computer communications networks is examined for varying traffic loads and for different communications system parameters. The division of traffic between the terrestrial and satellite legs used to minimize the average packet delivery time through the network is analyzed. The terrestrial leg consists of several repeater sections connected by multichannel transmission circuits. It is found that inclusion of a satellite channel in a system improves system characteristics upon reaching a certain network load threshold, which depends upon the throughput capacity of the terrestrial leg, the number of channels on that leg and the number of legs in the network. When the throughput capacities are the same, the combined use of terrestrial and satellite channels is feasible only for a network load of rho = 0.4-0.5 for single channel sections and rho = 0.1-0.2 for multichannel sections.