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

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 absence 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.