Towards High-performance Dedicated Control Channel in Multi-radio Multi-channel Networks

Multi-radio Multi-channel MAC protocols with a dedicated control channel (DCC) for data channel reservation are promising but they inherently face the problem of control channel saturation. In this paper, we identify the control channel saturation problem using simulation results, and then we propose a novel method, called persistent semi-random backoff (P-SRB), to operate on the control channel. P-SRB strategically arranges the backoff counters to achieve efficient resource reservations among stations. It requires minimal modification of the current 802.11 DCF implementation, but has significant performance improvements in terms of lower network collision rates, bounded transmission delay, as well as improved fairness. Results show that the control channel with P-SRB can provide 42.1% more reservation capacity compared to that of 802.11 DCF. Moreover, it is robust against interference from hidden terminals, and is fully backward compatible with devices using legacy 802.11 DCF.