An improved TCP congestion control mechanism with adaptive congestion window

In the standard TCP congestion control mechanism such as TCP Reno, it may cause the issue that packet sending rate increase exponentially in the slow start phase so significantly that it leads to the decline of TCP performance due to the overflow of bottleneck link buffer. One of the ways of TCP modification is based on estimation of the fair share of the available bandwidth for each flow and adjustment of the transmission window accordingly. This paper analyzes limitations of the standard TCP congestion control mechanism and proposes a novel TCP congestion control mechanism named ABE_TCP using adaptive bandwidth estimation in wired-wireless networks. Based on the estimation of the end-to-end available bandwidth, ABE_TCP dynamically adjusts the congestion window according to the congestion degree and the slow start threshold which builds a flexible slow-start parameter model and realizes the adaptive parameter setting. Simulation results show that the probability of multi-packet loss in the congestion window has been significantly decreased and TCP performance has been improved effectively by implementation of ABE_TCP.