BaseStation Assisted TCP: A Simple Way to Improve Wireless TCP

In recent years, extensive research effort has been devoted to TCP congestion control in hybrid wired-wireless networks. A general agreement is that the TCP sender should respond differently to wireless losses and disconnection, i.e., not slow down as drastically as for congestion losses. Thus, research focus for wireless TCP congestion control is the discrimination between the wireless inherent packet losses and the network congestion packet losses in wired network. In addition, researchers attempt to detect temporary or lengthy wireless disconnection. This paper proposes a simple but novel strategy, dubbed BSA-TCP (Base Station Assisted TCP), (1) to accurately discriminate wireless losses from wired network congestion losses and (2) to detect and notify a TCP sender about wireless disconnections. The key distinctive feature of the proposed scheme is its general use for most issues at stake for TCP over wireless: loss discrimination, wireless disconnection and handoffs. It also circumvents the asymmetric problem that acknowledgements might follow different paths from those of data packets. Such asymmetry problem is common to mechanisms that buffer and retransmit wireless lost data packets locally at the base station. The proposed method also addresses energy efficiency.