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 single. channel 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.