Segment Based Distributed Routing Protocol With QoS in Cognitive Radio Ad hoc Networks

Cognitive radio will enable dynamic spectrum allocation and makes the wireless technologies to coexist intelligently. Channel switching is one of the key factors affecting the end-to-end delay in multi hop cognitive radio networks. Hidden and exposed node problems not only create interference but also triggers false alarms on channel occupancy for secondary users in the network. We propose a routing protocol where secondary nodes creates segments with common available channels with minimum overhead. The route decision will be made in a distributed manner to find a switching free path to destination. This protocol will also addresses the issues like multi flow and offers prioritization of delay sensitive traffic happening in the network. This protocol is demonstrated and analyzed by altering the basic AODV routing protocol and tested in ns2 based cognitive radio test bed. This protocol has performed well by reducing overall end-to-end delay and increased overall throughput. At the same time it can offer priority to delay sensitive traffic thereby ensuring better QoS.