Implementing TCP extensions for error-prone satellite communications
Thomas Griffith, Stefan Van Rafelghem, David J. Legare · Space Technology Conference and Exposition · 1999
Increasing demands for global connectivity is causing an explosion in the satellite communications industry, including the increased use of Low Earth Orbit (LEO) constellations. In the space research industry, Mars PathfinderJnternational Space Station and other recent missions, are demonstrating information transfer requirements between ground and space systems. This demand relates to Telemetry, Tracking and Control (TTK) information as well as payload traffic. The ability to use a common suite of protocols, such as TCP/IP would simplify future space system designs. However, TCP must be optimized for space environments to minimize impacts of propagation delays and packet loss. One major consideration is the protocol’s reaction to packet loss in this environment. Terrestrial TCP links assume network congestion causes packet loss. Within a space or wireless environment, packet loss is more likely to be caused by error-induced corruption (due to noise on the communications channel). The Satellite Communications Protocol Standards-Transport Protocol (SCPS-TP) offers TCP enhancements that address corruption-induced losses. In both laboratory and satellite experiments, SCPS-TP’s extensions have demonstrated significant improvements in throughput and link utilization over TCP. The more immediate need is to expand the SCPS protocol suite’s implementation base to support actual mission operating conditions.