Energy-Efficient Hybrid CCC-Based MAC Protocol for Cognitive Radio Ad Hoc Networks

Transmitter power consumption and application throughput in cognitive radio-medium access control (CR-MAC) protocol has direct impact on control message overhead and common control channel (CCC). Hence, the design of CCC in CR-MAC plays a pivotal role in selecting an energy-efficient channel path for enhanced throughput. State-of-the-art CR-MAC protocols design CCC in in-band or out-of-band overlay spectrum bands. With in-band, imperfect node synchronization due to per-hop and group CCC coverage leads to multichannel hidden terminal and longer network access delays. Global coverage with dedicated out-of-band CCC is subject to saturation and intruder attacks, which results in single point of network failure and increased power consumption. To overcome existing problems, an energy-efficient hybrid CCC based CR-MAC protocol with omnidirectional control and directional data transmission is proposed to reduce power consumption due to link access overhead, multichannel hidden terminal, deafness, and spectrum mobility. In this paper, antenna index numbers through Global Positioning System and angle-of-arrival estimation are used for directional data transmission, whereas hybrid CCC is used to avoid interference due to multichannel hidden terminals. Experimental results reveal that the proposed hybrid CCC-MAC with directional antennas has increased network throughput and reduced transmit power consumption when compared with existing in/out-of-band omnidirectional CCC-based CR-MAC protocols.