Fundamental study on adaptive ACK link control for downloading based on TCP connection in mobile wireless communication

TCP service constructs high quality end-to-end communication link. TCP needs two way communication links. First link and second one are necessary for transmitting data packet from source to destination and ACK packet form destination to source, respectively. Therefore, TCP throughput strictly depends on both links. In wireless communication, the link speed is time selective due to shadowing effect. When the link speed is dramatically changed during the event of downloading, the impact of time selective link speed should be significant. In this paper, we clarify the impact of fluctuating link speed to TCP throughput by network simulator. In addition, we propose the adaptive link speed control of ACK link for achieving large ACK throughput. We also confirm the effect of proposed technique by network simulator.