A double-stage reservation-based MAC scheme for distributed cognitive radio networks

In this work we address a scenario where multiple non-licensed cognitive radios communicate with a receiving node (e.g. an access point) when licensed users do not use the spectrum. A Medium Access Control (MAC) protocol is proposed for the non-licensed users, denominated Cognitive Radio Reservation MAC (C2RMAC), which adopts a double stage scheme to schedule each node´s transmission. In the first stage the number of competing non-licensed nodes is decreased to reduce their probability of collision. In the second stage a reservation procedure is employed to schedule the transmission of the non-licensed users. Several simulation results evaluate the performance of C2RMAC showing the effectiveness of the proposed solution.