Initial Performance of an Onboard Packet Switch for High-Data-Rate Mobile Satellite Communications

Abstract

The use of an onboard switch results in a more effective multi-beam satellite communications system. The National Institute of Information and Communications Technology has been studying a mobile satellite communications network, and developing an onboard packet switch. A compact mobile earth station that can be installed in mobile systems or easily carried anywhere has been assumed for this communication system. This system is used to realize mobile satellite communications networks with a signal transmission rate of more than several hundred kilobits per second. The onboard packet switch functions as bridges operating in the data link layer of the open systems interconnect networking model. When the switch is located in a satellite, the satellite can be regarded as the central hub. One beam of the mobile link corresponds to one segment of the network. The bridges’ learning process is carried out between the beams, and the switching system builds and maintains tables with media access control address information. The onboard packet switch was installed in the Engineering Test Satellite Eight, which was launched by the H-IIA rocket in December 2006. An initial test in the geostationary satellite orbit has already been conducted. The results of the test show that the onboard packet switch satisfied system requirements.