Tuning the TCP Timeout Mechanism in Wireless Networks to Maximize Throughput via Stochastic Stopping Time Methods

G. Papageorgiou and J.S. Baras

Proceedings of the 19th International Symposium on Mathematical Theory of Networks and Systems (MTNS 2010), pp.1-7, Budapest, Hungary, July 5-9, 2010.

Abstract

We present an optimization problem that aims to maximize the throughput of a Transmission Control Protocol (TCP) connection between two nodes in a wireless adhoc network. More specifically, we focus on a persistent TCP connection between two nodes that are one hop away in a wireless unslotted Aloha network. The optimization is over the TCP timeout period, i.e. the problem is to find the optimal waiting period before the TCP sender declares a timeout event in the absence of a received acknowledgement for a transmitted packet. The problem is formulated as an optimal stochastic stopping time problem. In the avsence of a tractable analytical solution to the problem, a numerical method based on dynamic programming is used instead. We verify the performance increase by comparing our solution to the standard TCP timeout mechanism using simulations for a range of values of the involved parameters.