RMC-MAC: A Reactive Multi-Channel MAC Protocol for Opportunistic Spectrum Access

The development of mobile communication services has lead to the increase the use of wireless spectrum. However, the persuasion of the overly crowded spectrum is not due to the scarcity of usable radio frequencies but to the current static spectrum management policy. This reveals many idle frequency bands in both time and space. The cognitive radio network (CRN) is a key solution to exploit the existing spectrum dynamically. In this paper, we propose a new Reactive Multi-Channel cognitive MAC protocol (RMC-MAC) that integrates a novel cooperative sensing scheme which reliably detects the presence of incumbents even if the secondary users are transmitting. Then, a recovery scheme is proposed to ensure the continuity of SU transmission and to reduce the forced termination probability. This recovery solution also shows that bandwidth utilization is higher than the one achieved by a common protocol without handoff and another buffering based protocol.