Analysis and Improvement Strategy of TCP Performance for Ad Hoc Networks

Ad Hoc as a special kind of wireless network , with the advantages of quick and easy networking , communication protocol is simple , without any infrastructure , survivability , distributed topology , less energy consumption , which has broad application prospects . Recent studies have found that the TCP protocol , widely used in wired networks can not be applied to the wireless network . This is because the wired network packet loss as the only sign of congestion in the wireless network packet loss in addition to congestion reasons , but also with the high error rate of the wireless environment , interference, channel competition , mobility routing failure related. TCP does not distinguish between the specific causes of packet loss , all as congestion , thus causing TCP performance dropped significantly in Ad Hoc Networks . How to troubleshoot TCP for Ad Hoc network performance deterioration of the current problems to be solved . Ad Hoc Networks improve TCP performance research direction is focused on the improvement of the MAC layer , network layer, transport layer mechanism . The program summary and evaluation of a variety of topics in the published literature to improve TCP performance in Ad Hoc Networks . The focus of analysis of the topic in the OPNET network simulation platform stability and fairness of Ad Hoc Networks TCP , pointed out that the main reason of the TCP performance impact of Ad Hoc Networks channel is the MAC layer IEEE802.11DCF the unfair competition , hidden and exposed terminal problems . MAC layer of the Ad Hoc network improvements, and simulation analysis to improve the results verify that this improvement can improve stability and TCP connection fairness issues . The subject of the congestion phenomenon is a description and analysis of several major TCP congestion control algorithm . On this basis , a new improved congestion control algorithm for TCP Veno through simulation to study the characteristics of TCP Veno . Last for less congestion , high error rate and node mobility environment , TCP Veno suggest improvements freeze retransmission timeout timer and slow down the growth in the round-trip time . Simulation results verify that the improvements can increase the throughput of TCP Veno , to improve the performance of TCP .