Energy efficient cognitive radio MAC protocol for battlefield communications

This paper presents an energy efficient cognitive radio multichannel medium access control (MAC) protocol called ECR-MAC for battlefield communications. ECR-MAC requires only a single half-duplex radio transceiver on each node that integrates the spectrum sensing at physical (PHY) layer and the packet scheduling at MAC layer. In addition to explicit frequency negotiation which is adopted by conventional multichannel MAC protocols, ECR-MAC introduces lightweight explicit time negotiation. This two-dimensional negotiation enables ECR-MAC to exploit the advantage of both multiple channels and TDMA, and achieves aggressive power savings by allowing nodes that are not involved in communication to go into doze mode. The proposed energy efficient ECR-MAC protocol allows secondary users (SUs) to identify and use the unused frequency spectrum in a way that constrains the level of interference to the primary users (PUs). Extensive simulation results show that our proposed ECR-MAC protocol successfully exploits multiple channels and significantly improves network performance by using the licensed spectrum band opportunistically and protects QoS provisioning over cognitive radio ad hoc networks.