Abstract:Routing fails frequently because of the node mobility of MANET. The regular TCP works badly in MANET because the congestion control algorithm takes all the problems in MANET (disconnections, route changes, etc.) as congestion. To improve the efficiency of end to end transmission, this paper proposes a cross-layer transmission control protocol that interacts with link reliable routing protocols, which are called TCP-PLRT (transmission control protocol based on probability of link residual lifetime). TCP-PLRT judges the stability of end to end connection through information about the probability of the link residual lifetime that feedback from routing layer. Three complementary mechanisms have been proposed: ROUTING SWITCH, if the link is not stable enough, SAVE THEN FORWARD, if the link is about to break, and ACK RECONFIRM, if the routing has been rebuilt. Therefore, TCP-PLRT can do prediction before routing failure, and do remediation after it happens. It has been shown by computer simulation that results of TCP-PLRT have significantly improved the packet loss, caused by routing failure, and have increased the throughput much more.