Improving TCP performance through enhanced path recovery notification

Abstract

Handoff in wireless networks causes temporal link disconnection which introduces consecutive packet losses in the network. This degrades the performance of the Transmission Control Protocol and forces it to aggravate the bandwidth utilization of wireless networks. TCP Path Recovery Notification mechanism recovers the lost packets during handoff by keeping the congestion window and slow start threshold unaltered to maintain its throughput. The losses that occur due to handoff cannot be distinguished from that due to congestion by TCP-Path Recovery Notification. The proposed protocol, Enhanced Path Recovery Notification, classifies the packet losses into congestion loss and link error loss. The protocol measures the one way delay, if measured one way delay is less than that of the Delay Threshold, then it is identified as link failure and Path Recovery Notification is immediately invoked to retransmit the lost packets. If measured one way delay is greater than that of Delay Threshold then it is identified as congestion loss and slow start procedure in TCP is initiated to retransmit the lost packet. The result of Enhanced Path Recovery Notification shows that it outperforms both Path Recovery Notification and TCP-SACK in terms of throughput. © Springer-Verlag Berlin Heidelberg 2011.