Research Progresses and Trends of Onboard Switching for Satellite Communications

Abstract

As broadband satellite communication (SAT-COM) systems develop rapidly, Onboard Switching (OBS) technologies with flexible connectivity has attracted much attention by academic researchers and industry. However, due to the threat by the space radiation effects and the firm constraints of payload processing and power resources, OBS technologies are facing to great challenges in terms of its reliability and scalability. In the past literatures, in order to improve the connectivity and reliability of the single-path Crossbar switch, the multi-path Clos network is widely investigated for preferable adoption in OBS. Nevertheless, due to the extensive use of centralized scheduling, the current Clos network with low scalability is not applicable for high-throughput OBS systems. In this paper, by analyzing progresses and trends of decades of related researches, the developing directions of OBS are provided and discussed, combining the switching architecture, the queuing strategy and the corresponding scheduling algorithms. By employing specific queuing structure to sup-port distributed scheduling in the Clos network and along with distributed, fault-tolerant scheduling algorithms, the requirements for high scalability and fault tolerance of the OBS systems can be efficiently guaranteed, which is expected to be a new trend of OBS researches.