AMCM: Adaptive Multi-Channel MAC Protocol for IEEE 802.11 Wireless Networks

Abstract

This paper presents AMCM, a traffic-adaptive multichannel MAC protocol that increases the capacity of wireless network by enabling multiple concurrent transmissions on orthogonal frequency channels using a single half- duplex transceiver. AMCM is based on the IEEE 802.11 MAC but provides fine-grain, asynchronous coordination among locally interfering nodes for channel negotiation. By incorporating load-awareness, channel availability awareness and batch transmissions, our window-based approach achieves high channel utilization under varying load, while avoiding the control-window saturation problem as the number of channels increases. For single-hop scenarios, we show that, at low load, AMCM is comparable to IEEE 802.11 MAC, while under high load, AMCM delivers almost Nx improvement gain over IEEE 802.11 MAC protocol, where N is the number of channels. AMCM also outperforms existing multi-channel MAC protocols by 100% and 150% respectively under high load at a lower hardware cost and complexity. In multi-hop scenarios, AMCM achieves performance improvement of 190% and 90% for both dense and sparse network over IEEE 802.11 MAC respectively. In both scenarios, AMCM achieves close to full utilization of all channels with good protocol efficiency.