Asynchronous Multichannel MAC Design With Difference-Set-Based Hopping Sequences

Most existing multichannel medium access control (MAC) protocols have at least one of the following four performance bottlenecks: 1) global synchronization among users; 2) dedicated control channel for signaling exchange; 3) dedicated control phase for signaling exchange; and 4) complete knowledge of all users' channel selection strategies. In this paper, we first design a hopping sequence by combining multiple difference sets to ensure a high rendezvous probability of users over multiple channels. Applying the hopping sequence to all users, we then propose a difference-set-based multichannel MAC (DSMMAC) protocol to overcome the performance bottlenecks. Because all users use the same sequence for frequency hopping and channel access, significant signaling overheads can be reduced. The proposed protocol achieves high system throughput and low access delay without the need for global synchronization or a dedicated control channel/phase. Our analytical and simulation results show that the proposed DSMMAC protocol can achieve up to a 100% improvement in system throughput and a 150% reduction in channel access delay compared with an existing multichannel MAC protocol.