A new channel hopping MAC protocol for mobile ad hoc networks

Although multiple channels are supported in the physical layer, the IEEE 802.11 MAC layer mechanism is designed for using a single channel. Exploiting multiple channels enhances spatial reuse and reduces transmission collisions and thus improves network throughput. Designing a multi-channel MAC protocol is much more difficult than designing a singlechannel one. New challenges, such as the channel allocation problem and the missing receiver problem, must be overcome. Existing multi-channel MAC protocols suffer from either higher hardware cost (because of applying multiple transceivers) or lower channel utilization (due to limited transmission opportunity). In this paper, a fully distributed channel hopping solution, the Cyclic-Quorum-based Multi-channel (CQM) MAC protocol, is proposed. We use the cyclic quorum in a novel way and the proposed protocol has several attractive features. First, only a single transceiver is needed for each node. Second, any sender is guaranteed to meet its receiver in a short time. Third, each node´s channel hopping sequence is derived from its node ID. This avoids exchanging control messages, such as each node´s hopping sequence or available channel list. Fourth, multiple transmission pairs can accomplish handshaking simultaneously. The proposed protocol is simple and efficient. Simulations results verify that our mechanism is a promising multi-channel MAC protocol for mobile ad hoc networks.