TCP/IP over low rate ATM-SATCOM links

The performance of TCP/IP over low-rate ATM-SATCOM links is examined this paper. The affects of delay and bit-error rate (BER) were evaluated using a standard physical layer convergence procedure (PLCP) (ETS 300 213) on an E1 carrier operating at 2.048 Mbps. Transmission at 2.048 Mbps is consistent with tactical satellite links, commercial public access, as well as, the capabilities of the NATO satellite communications (SATCOM) system. The results are presented in terms of throughput, which was found to vary substantially depending on the error rate, the delay, the site of the maximum transmission unit (MTU) and the TCP window size. Several conclusions have been reached based on analysis of test data and modelling: low-data-rate ATM cell relay operations over NATO SATCOM is viable and practical for tactical communications; BER, delay and protocol implementation can have a significant impact on the ATM performance; the impact of higher layer protocols, such as the Internet's transmission control protocol (TCP), may overshadow the impact of the ATM protocol.