New TCP Mechanism over Heterogeneous Networks

With the development of the communication technology, computer networks present characteristics of scale, heterogeneous and dynamic. Traditional TCP has been designed and turned to perform well under the wired network. However, it is not ready for the heterogeneous networks. In order to improve the TCP performance over the heterogeneous networks, this paper proposes a modified TCP congestion control mechanism based on bandwidth estimation and double AIMD (additive-increase multiplicative-decrease) algorithm, named switch-TCP. Switch-TCP performances are investigated through simulations. Comparing with TCP Reno, the throughput may be improved; the retransmit probability may be decreased. Switch-TCP can coexist with TCP Reno very friendly. In addition, switch-TCP is obtained through a little modification at the sender side, so switch-TCP can be easily developed and the additional overheads are very low.