Control information exchange in cognitive radio ad hoc networks with heterogeneous spectrum

To overcome the constraint of spectrum heterogeneity, i.e., different spatial locations may have different available spectrum resources, a cognitive radio ad hoc network (CRAHN) should exchange necessary control information among nodes. To improve the performance of this exchange, the present paper proposes to establish a cluster-based Hamiltonian cycle within the CRAHN to provide an ordered flow of control information among clusters and reduce the collision and delay for control information exchange. Moreover, to offer a better clustering result for this establishment, we also design a novel distributed mechanism for randomly selecting a unique node to collect network information and develop an efficient layered clustering algorithm based on the collected information. Numerical simulation shows that, compared with the existing methods, the proposed collection mechanism is more efficient and incurs less packet collisions in collecting network information, while the proposed clustering algorithm yields a smaller average number of clusters under the condition that each cluster has at least one control channel and helps reducing the overhead of control information exchange.