A Coordinated Channel Reservation MAC Protocol for Dynamic Spectrum Access Networks

Abstract

We propose a coordinated medium access control (MAC) protocol in dynamic spectrum access networks namely distributed coordinated dynamic spectrum reservation (DCDSR) protocol. All primary users (PUs) and secondary users (SUs) are equipped with two transceivers operating in a dedicated control channel and licensed data channels to transmit/receive control and data packets in the corresponding control and data frames, respectively. PUs will inform SUs which channels will be used in next data frame and then SUs reserve those unused channels by contending with each other during contention interval (CI) in control frame. The available channels which can be reserved by SUs will depend on the channel usage of PUs and further affect the throughput of SUs. Whenever SUs successfully reserve channel in CI, they will start access reserved channel in next data frame after the end of CI. This will cause the wasted idle waiting time for those SUs which have successfully reserved channel whenever the CI doesn't finish. SUs which couldn't successfully reserve channel in current control frame should try to reserve again in next control frame. Thus, the duration of CI will affect the delay and wasted idle waiting time of SUs. We analyze and simulate the performance of throughput, delay and wasted idle waiting time in DCDSR. The analytical and simulation results show that the proposed DCDSR performs very well.