Proxy-Based TCP with Adaptive Rate Control and Intentional Flow Control in Ad Hoc Networks

In ad hoc networks, a TCP session can obtain very low throughput with increase of the number of hops. One promising way to resolve this technical problem of TCP throughput degradation is proxy-based TCP. In proxy-based TCP, an end- to-end TCP session is divided by (an) intermediate proxy host(s), which leads to reduction of RTT of each divided session and improvement of TCP throughput. We evaluate proxy-based TCP in ad hoc networks with a realistic assumption of finite buffer in proxy hosts. Our simulation results show that proxy-based TCP surprisingly does not bring performance improvement and obtain lower throughput than conventional end-to-end TCP. In the paper, we show that wireless channel capture around the proxy host is the reason for this degradation. And we propose adaptive rate control method and intentional flow control method at the proxy host which improves throughput performance of proxy- based TCP. Performance evaluation results show that proxy- based TCP with our proposed methods outperforms conventional end-to-end TCP.