The eXtended Satellite Transport Protocol: Its Design and Evaluation

Being both wireless and mobile, LEO satellite access networks have a unique set of link errors including bit corruption, handoff and limited connectivity. Unfortunately, most transport protocols are only designed to handle congestion–related errors common in wired networks. This inability to handle multiple kinds of errors results in severe degradation in effective throughput and energy saving, which are relevant metrics for a wireless and mobile environment. A recent study proposed a new transport protocol for satellites called STP that addresses many of the unique problems of satellite networks. There was, however, no explicit attempt to implement a differentiating error control strategy in that protocol. This paper proposes grafting a new probing mechanism in STP to make it more responsive to the prevailing error conditions in the network. The mechanism works by investing some time and transmission effort to determine the cause of error. This overhead is, however, recouped by handsome gains in both the connection’s effective throughput and its energy efficiency.