Congestion Coherence: A Local Enhancement for TCP over Wireless Links

TCP traffic may have poor performance over unreliable wireless links if packet losses due to transmission errors are misinterpreted as indications of network congestion. TCP enhancements proposed in the literature differ in their signaling and data recovery mechanisms, applicable network configurations, traffic scenarios and locations where required changes are made. In this paper we summarize the approaches used in existing enhancements and analyze their practicality, generality and impacts on performance. Motivated by this analysis, we propose an enhancement that requires only local changes, but applies to a broader range of network configurations and traffic scenarios. Simulation comparison with existing algorithms shows that this new enhancement can analyze the cause of packet losses and can achieve much better performance.