Issue No. 05 - May (2016 vol. 15)
Shiva Raj Pokhrel , Faculty of Science, Engineering and Technology, Swinburne University of Technology, Melbourne, Victoria, Australia
Manoj Panda , Faculty of Science, Engineering and Technology, Swinburne University of Technology, Melbourne, Victoria, Australia
Hai L. Vu , Faculty of Science, Engineering and Technology, Swinburne University of Technology, Melbourne, Victoria, Australia
Michel Mandjes , Korteweg-de Vries Inst. for Mathematics, University of Amsterdam, The Netherlands
We propose an analytical model for a Wi-Fi network acting as a last-mile Internet access with multiple long-lived TCP connections on both the up and down links. Our model considers the joint impact of buffer losses at the access point, contention at the medium access control layer, and packet losses due to the wireless channel being erroneous. We show that the model accurately quantifies the probability of an arbitrary TCP packet being discarded, and the total throughput obtained on the up and down links. Furthermore, quantitative insights can be gained into the throughput that long-lived TCP flows achieve under the joint impact of all aforementioned types of losses. In particular, we find that the wireless channel errors and buffer overflows both lead to throughput unfairness, but that they do so in the opposite direction on the up and down links, respectively. We demonstrate that this insight can be exploited so as to significantly mitigate the throughput unfairness without compromising the total obtainable network throughput.
Throughput, Wireless communication, IEEE 802.11 Standard, Analytical models, Wireless LAN, Wireless sensor networks, Media Access Protocol
S. R. Pokhrel, M. Panda, H. L. Vu and M. Mandjes, "TCP Performance over Wi-Fi: Joint Impact of Buffer and Channel Losses," in IEEE Transactions on Mobile Computing, vol. 15, no. 5, pp. 1279-1291, 2016.