Improving TCP Performance Using BADA (Base-station Aided Delayed ACKs) Algorithm in Wired-Cum-Wireless Environment

摘要

TCP (Transmission Control Protocol) is the prevalent reliable transport protocol used for many kinds of the popular Internet services like web browsing and e-mail. Because these services are the dominant applications on the Internet, TCP can be said to control the large majority of today's Internet traffic and we can say the enhancement of TCP performance means the improvement of the most Internet performance. This paper compares various ACK generation TCP strategies that play very important roles in TCP operation and proposes advanced delayed ACK algorithms to mitigate the negative effect of delayed ACK algorithm. Even if delayed ACK has the bright side to save network resources and power consumption that are the very important factors especially for mobile and wireless environment, it has also dark side not to take full advantage of network bandwidth in Slow Start phase. It is reported that delayed ACK timeout of the first and last segment causes severe degradation problem in TCP throughput performance. We suggest new algorithms to solve delayed ACK penalty and to guarantee fairness with other traffics in Slow Start. In wired-cum-wireless network environments, 'BADA (Base station Aided Delayed ACK)' with SNDA (Sender Notification Delayed ACK), the combination of our proposed algorithm shows the best performance in terms of throughput as well as in terms of network resource sharing. Our simulation shows significantly improved performance in TCP throughput.