TCP performances over wireless link deploying delayed ACK

Understanding the impact of TCP techniques toward wireless environment is important because the need of mobile devices have been significantly increased. Often, many studies showed that wireless environments have crucial impacts to TCP performance. Yet, the effects of delayed acknowledgement over wireless link have not thoroughly been studied. This paper, therefore, investigated the impact of delayed acknowledgement of TCP connection over wireless link focusing not only throughput but also the bandwidth and energy consumption. Those metrics are crucial to wireless networks. The variations used in this study, widely implemented and experimented, are Reno, Newreno, Sack (selective acknowledgement), and Vegas. The results showed interestingly that with delayed acknowledgement employment, Vegas could improve throughput 3-15% whereas, as expected, Reno/Newreno and Sack throughputs suffer 5-40% comparing to standard acknowledgement. All variations with delayed ACKs consume less bandwidth usage, however, the benefit is not significant. For the energy performance, Reno with delayed acknowledgement can perform better in case of excluding idle energy, even though the amount is trivial. On the other hand, when idle energy is concerned, Vegas shows 1-15% less energy consumption compare to standard acknowledgement.