Research Of ACK Compression And Routing For Semi-TCP

With the development of communication technology, the increasing requirementof communicating anytime anywhere promotes the development of multi-hop wirelessnetworks. Due to the characteristics of radio channels and multi-hop wirelessnetworks, the TCP protocol performs poorly in such kind of networks. It is mainlybecause the TCP and its window-based congestion control algorithms often misjudgethe congestion status in the networks with slow reaction to both ongoing and releasedcongestions. In order to solve these problems, Semi-TCP suggests decouplingcongestion control from TCP and keeps other functionalities intact. Studies haveshown that Semi-TCP and its hop by hop congestion control are more appropriate formulti-hop wireless networks.In order to further improve the performance of Semi-TCP in multi-hop wirelessnetwork, an ACK compression method has been proposed for Semi-TCP in this thesis.This method can effectively reduce the number of reverse ACKs. Computersimulations shows that Semi-TCP with the proposed algorithm can further improvenetwork performance in terms of throughput and delay.To make the Semi-TCP better adapt to the dynamically changing networkenvironment in multi-hop wireless networks, this thesis also proposes an opportunisticrouting method based on an traditional routing protocol AODV, and this proposedrouting protocol is called NEWAODV. NEWAODV changes the transmission modeto reply routing requests in order to reduce the routing control information effectively.Computer simulations demonstrate that NEWAODV is able to outperform AODV inthroughput and delay.