Fairness oriented MAC protocol for the next generation WLAN

Due to the dramatic growth of human demands for wireless business, wireless local area network (WLAN) achieves rapid popularization and world-wide development recently. In order to improve the efficiency of the next generation WLAN, especially in the dense deployment scenarios, IEEE sets up a new task group named TGax to draft out the amendment 802.11ax in 2014. The motion of TGax confirms that Enhanced Distributed Channel Access (EDCA) is still one important method of channel access in 802.11ax. In this paper, we show that the traditional EDCA mechanism faces the fairness issues, including intra-node problem and inter-node problem, in the next generation WLAN. Thus, we propose an enhanced virtual collision management mechanism named EVCM by introducing access weight factor and rate of successful access to improve fairness of EDCA. Simulation results show that the EVCM significantly improves both the intra-node fairness and inter-node fairness in the dense deployment scenarios. Especially, it obtains ten-fold intra-node fairness compared with EDCA, and three times inter-node fairness than that in EDCA.