Analysis of multi-hop opportunistic communications in cognitive radio network

Cognitive wireless networks consist of cognitive radio devices which enable dynamic spectrum access for unlicensed secondary users. Multi-hop cognitive radio network (MHCRN) offers connectivity when transmitter and receiver are not within the communication range of each other using single hop. However, joint effect of multi-hop and dynamic spectrum access introduces many challenges in MAC and routing layer. Note that the devices through MAC layer make spectrum access decision without disturbing the licensed users. Effective routing protocols in MHCRN are required to provide shortest path between transmitter and receiver. In this paper, several MAC layer and routing layer problem and solutions are presented.