TCP WELCOME TCP variant for Wireless Environment, Link losses, and COngestion packet loss ModEls

The problem of TCP and all its existing variations within MANETs resides in its inability to distinguish between different data packet loss causes. Thus, TCP has not always the optimum behaviour in front of packet losses which might cause network performance degradation and resources waste. Multiple loss differentiation algorithms (LDAs) have been designed to improve TCP performances. They had been optimized for data networks where only the last link is a wireless link. In these LDAs the most common packet losses that are handled are those due to wireless channel errors or congestion. We show in this paper that a third common packet loss cause, link failure, has to be handled in multi-hop wireless networks such as mobile ad hoc networks (MANETs). In order to handle these three packet loss causes, we propose TCP-WELCOME. This latter follows a two-step process: (i) first, distinguish between most common packet loss causes, and (ii) then, triggers the most appropriate packet loss recovery according to the identified loss cause. The performance evaluation shows that TCP-WELCOME optimizes both energy consumption and throughput. Also, TCP-WELCOME does not change the standard as its loss differentiation and recovery algorithms can operate with the already existing TCP variants.