Spectrum-aware cross-layered routing protocol for cognitive radio ad hoc networks

摘要

Cognitive radio network has been proposed as a promising technology to satisfy the manifold requirements of future generation (5G) wireless system by intelligently accessing the underutilized channel of a primary user. However, due to the heterogeneity in channel propagation characteristics, intermittent availability of licensed channel, recurrent hand-offs, and need of a protection to primary users, finding a successful route is more challenging. Also, incorporation of opportunistic spectrum access in cognitive radio network requires a potential spectrum management functions across the network layers. Hence, a cross-layered channel assignment algorithm and routing algorithm is proposed for a cognitive radio ad hoc network which can overcome above-mentioned challenges and provide a stable path for routing of data packets. A novel metric, for the probability of successful transmission of a channel is derived by considering channel statistics, sensing periodicity of the cognitive user, and time-varying channel quality. Also, the number of available channels and their characteristics is considered for the selection of a next-hop node with an aim to avoid the one-hop neighbors located in the PU transmission range. The proposed routing protocol is simulated in ns-2 and compared with the existing similar protocols. The performance shows that the proposed algorithm performs better in terms of throughput, end-to-end delay, number of spectrum hand-offs, and interference to the primary user in a significant manner.