TCP WestwoodVT: A Novel Technique for Discriminating the Cause of Packet Loss in Wireless Networks

Springer-Verlag Lecture Notes in Computer Science, vol. 4479, pp. 391-402, May 2007

Jahwan Koo, Sung-Gon Mun, and Hyunseung Choo


Conventional TCP in wireless environment cannot differentiate packet losses caused by network congestion from those caused by wireless link errors, thus, resulting in severe performance degradation. Accordingly, efficient operation of TCP in wireless networks is a critical issue in the context of differentiation between packet loss. Towards this issue, we proposes a novel technique, WestwoodVT (WestwoodNR based on TCP Vegas buffer Thresholds), which is a sender-based TCP congestion control mechanism for discriminating the cause of packet loss to enhance the performance of TCP in wireless environment. Simulation results show that, under various wireless link error rates, it achieves a maximum of 41% and 118% improvements in goodput over WestwoodNR and TCP Reno, respectively. WestwoodVT only requires changes at the send-side. Thus, it eliminates any changes to the intermediate routers unlike TCP New Jersey. Therefore, it is cost effective to implement in already deployed networks. Moreover, its fairness and friendliness are also satisfied.




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