A flow control scheme based on buffer state for wireless TCP

Reliable transport protocols such as TCP (Transmission Control Protocol) are tuned to perform well in traditional networks where packet losses occur mostly because of congestion. However, on the wireless links where packet losses frequently happen, TCP shows a serious drop in performance. In this paper, we propose a scheme, called BSF (Buffer State based Flow control), which can solve this problem. BSF is implemented at the base station of a wireless network. So, it does not need any modification of TCP stacks in the end system. BSF uses the buffer state of base station as the criterion to detect wireless link error and reduces unnecessary contraction of congestion window in TCP. As a result, the buffer of base station maintains non-empty state to maximize the link utilization. In our simulation study, this approach achieved up to 250 % improvement in performance. Keywords— TCP, heterogeneous network, flow control, performance evaluation, RED, wireless network