An enhanced multi-channel MAC protocol for wireless ad hoc networks
In the wireless ad hoc network, utilizing the multiple channels at Medium Access Control (MAC) layer is on of the key techniques to improve the network performance. It can be done by multi-channel MAC to utilize the channels resource as much as possible. Wireless nodes are usually powered by battery and thus are limited in power capacity. The IEEE 802.11 Power Saving Mechanism (PSM) is used to conserve energy for the ad hoc networks by allowing nodes to enter doze mode when there is no need for data exchange. In this paper, we propose a hybrid and adaptive protocol, named H-MMAC, by adopting IEEE 802.11 PSM. In H-MMAC, nodes exchange control messages on default channel to negotiate the data channel during the ATIM (Ad hoc traffic Indication Message) window. The difference of H-MMAC compared to other multi-channel MAC protocols is that the other nodes can transmit data packets on data channels based on the network traffic load. This means H-MMAC can utilize the channel resources more efficiently. The simulation results show that our proposed H-MMAC improves the network performance significantly in terms of aggregate throughput, average delay and energy efficiency.