Abstract
Recent research on cognitive radio networks has mainly focused on MAC and physical layers. However, cognitive radio has a significant impact on upper layer performance in wireless networks, particularly in cognitive radio mobile ad hoc networks (CR-MANETs). In this paper, we study routing issues and propose a Group-Based Routing Protocol (GBRP) for CR-MANET. The cognitive radio network is divided into several non-overlapping groups. Each Secondary user (SU) only knows the SU connectivity within its group and the group connectivity of the whole network. SU and group level topological information are distributed to all SUs. In the flat architecture routing protocols, routing path containing the SUs between a source and a destination is needed for routing. Any intermediate link breakage will invalidate the path. On the contrary, in GBRP, only the group ID and the SU ID of a destination are needed for routing. The actual routing path is adaptable to the changing topology. Simulation results show that our routing protocol generates less control overhead than the DSDV and the number of hop counts and interfaces used in our protocol are smaller than the AODV.