Further Improving TCP Performance on Satellite Channel

Satellite systems offer several advantages to wireless Internet communications. Nevertheless, satellite radio links are affected by two severe problems, namely long propagation delays and relatively high error rates, which pose a difficult challenge to the Internet protocols and in particular to TCP. Among the potential solutions, we are specifically interested in the TCP enhancements that preserve the end-to-end semantics of TCP. In this paper, the authors evaluate the performance improvements provided by some additional features, when applied to TCP Westwood (TCPW), a promising transport protocol specifically designed to cope with errors on wireless links. This enhanced version (E-TCPW) is compared with both the original TCPW and other known TCP variants (NewReno, SACK, Hybla), considering goodput, fairness and friendliness as performance figures. Results, obtained through ns-2 simulations, seem very encouraging and suggest the inclusion of the proposed additional features in the future official versions of TCPW