Low rate Common Control Channel based AODV routing protocol for Cognitive Radio Ad-hoc Networks

In Cognitive Radio Ad-hoc Networks, dynamic spectrum Access (DSA) and opportunistic routing introduces concurrent channel-path selection with appropriate PU free spectrum hole (white space) to cater end-to-end connectivity for application data transmission. Most state-of-the-art cognitive routing protocols either uses 2.4 GHz unlicensed dedicated common control channel (CCC) or licensed PU free CCC for channel-path selection and CR node co-ordination message exchange. With licensed CCC, channel-path selection and CR node co-ordination time will be high due to sequential or group based CCC coverage whereas dedicated 2.4GHz unlicensed CCC is subject to saturation and interference with other services. Hence, there is a greater extent for 2.4 GHz CCC to be congested which increases link failures and routing control overhead that successively degrade the performance of routing protocol. Several small slices of unlicensed frequencies (433MHz/868 MHz/902-928 MHz) are existing in lower spectral bands which are not efficiently utilized. Our Proposed work make use of low unlicensed spectrum band (902-928 MHz) as a low rate AODV common control channel for broadcasting route control(channel-path) and CR coordination messages which abbreviates hop count, link failures, routing overhead and end-to-end data transmission delay. Simulation (NS-2.31) results shows that performance of low rate common control channel based AODV routing protocol outperforms compared with 2.4GHz saturated AODV control channel especially for delay sensitive CR networks.