Performance Comparison of CAODV, SEARCH, and WCETT Routing Protocols in CRAHNs

Cognitive radio ad hoc networks (CRAHNs) can efficiently utilize the spectrum in an opportunistic way by dynamically accessing different licensed portions of the spectrum. In CRAHNs, which operate without centralized management, data routing is one of the most important issues to be taken into account and requires intensive study. This paper analyzes three of the most common CRAHN routing protocols, namely, Cognitive Ad-hoc On-demand Distance Vector (CAODV), SpEctrum Aware Routing protocol for Cognitive ad-Hoc networks (SEARCH), and Weighted Cumulative Estimation of Transmission Time (WCETT). The analysis is carried out using NS-2 simulator to evaluate and compare the network performance in terms of packet delivery ratio (PDR), end-to-end delay, hop count, and routing overhead under the same environment conditions with varying number of nodes to study the effect of nodes density and traffic load. Simulation results show that the performance of SEARCH is better than CAODV and WCETT in terms of PDR with little increased overhead, average end-to-end delay, and hop count compared to CAODV because of its better route selection strategy in CRAHNs.