  Cognitive Radio Networks (CRNs) are being studied intensively and gaining
importance as spectrum is the heavily underutilized. CRN has the capability to
exploit smartly the unutilized frequency spectrum. Recently, the research
community started to work in the area of cognitive radio routing. In a flat
topology, all nodes are of the same level and functionality, thus making it
simple and efficient for smaller networks. However, when the network is large
with sparse nodes, the routing information becomes more complex making
cluster-based techniques really relevant to tackle such situations. In a
cluster-based routing, all nodes in the network are dynamically organized into
partitions called groups or clusters. In each cluster, a cluster head is chosen
to help in the data transmission management and to maintain cluster membership
information. This paper proposes a novel routing protocol for cognitive radio
ad hoc networks (CRAHNs) based on clustering model which amends swiftly to the
topological changes and establishes the routing efficiently. Our proposed
approach is thoroughly evaluated through simulation study. The results state
the suitability of the proposed protocol for cognitive radio ad hoc networks
and demonstrate that it has better performance in terms of finding the
source-destination route, reducing the amount of messages that are transmitted
all over the network and minimizing the routing delay.
