A New Data Link Protocol for Improved Satellite Data Communications

Current TCP/IP protocols and emerging data commuications standards such as Asynchronous Transfer Mode (ATM) are not designed for the high error rates and long delays characteristic of wireless liks such as satellite hops. Even on error-free links, TCP/IP is vulnerable to throughput ceilings when the channel has a high bandwidth-delay product relative to the flow control window size, such as that encountered over fractional T1 and greater satellite links. In order to permit the efficient transmission of current and future network protocols over satellite links, we propose a new data link protocol which minimizes link retransmissions while interfacing to standard network and transport layer protocols. The new protocol builds on a novel data link protocol dveloped to combat error rates on wireless terrestrial data communication links. It features a dynamically varying protocol delay which will only impact satellite link delay under severe burst-error conditions. We propose to analyze performance improvement relative to current data link protocols. The protocol will be throughhly tested with computer simulations. A design of a protocol interface unit for existing satellite radios will be developed. A working prototype will be built, tested, and demonstrated in a multiprotocol WAN environment in Phase II.