crSimulator: A Discrete Simulation Model for Cognitive Radio Ad hoc Networks in OMNeT plus

Cognitive Radio is an exciting new technology for efficient use of radio spectrum. Research on cognitive radio has for a large part, focused on physical layer issues such as robust spectrum sensing and radio environment characterization. The networking of cognitive radio nodes is equally important however as new protocols need to be developed to cope with physical layer dynamics. The lack of a widely used and open source simulation platform has been a hindrance in this regard. In this paper, we present crSimulator, which is a discrete simulation model for cognitive radio ad hoc networks in OMNeT++. We present the core concepts, major requirements, architectural model of cognitive radio nodes, and the implementation details of crSimulator. The crSimulator model effectively captures the physical layer level dynamics and facilitates higher layers protocol research. The model is validated with an implementation of cognitive radio MAC protocol having spectrum sensing and handover features together with a node architecture designed to operate in ad hoc networks.