Receiver assistant congestion control in high speed and lossy networks

Abstract

Many applications require fast data transfer in high speed wireless networks. A representative example is that EAST experiment data are retrieved by some physics researchers using the TCP (Transmission Control Protocol). However, due to the limitation in its conservative congestion control algorithm, TCP can not effectively utilize the network capacity. Furthermore, TCP assumes that every packet loss is caused by network congestion and invokes congestion control and avoidance. TCP's blind congestion control aggravates the performance degradation in high speed and lossy wireless networks. In this paper, we propose a receiver assistant congestion control mechanism (RACC), in which the sender still performs loss-based control, while the receiver performs delay-based control. The receiver measures the network bandwidth based on the interpacket delay gaps, and computes an appropriate congestion window size according to the measured bandwidth and then feedbacks the value to the sender. The sender adjusts the congestion window size based on the value informed by the receiver and the AIMD (Additive-Increase Multiplicative-Decrease) mechanism. By integrating the loss-based and delay-based congestion controls, our mechanism can mitigate the effect of wireless losses, alleviate the timeout effect, and therefore make better use of network bandwidth. The simulation results in various scenarios show that our mechanism can have better performance than conventional TCP in high speed and lossy wireless environment.