CREATE-NEST: A Distributed Cognitive Radio Network Platform with Physical Channel Awareness

We propose a Cognitive Radio nEtworking ArchiTecture (CREATE) with joint cross-layer design of routing and dynamic spectrum allocation that balances the throughput-delay trade-offs under realistic physical channel effects. Dynamic routing is implemented by integrating a spectrum-aware backpressure-like algorithm with shortest-path routing to improve both the average delay and the achievable throughput under hard deadline constraints. CREATE supports spectrum adaptability by establishing asynchronous negotiation and coordination channels instead of a dedicated common control channel. For end-to-end experimental evaluation of CREATE, we propose NEST, a Network Emulator and Simulator Testbed, to deploy and experiment with cognitive radio (CR) networking protocols and applications on real programmable radios. NEST combines a low-cost and scalable simulation environment with realistic hardware performance to provide high fidelity and repeatable CR network experiments. Our experimental results characterize the effects of network topology and physical channel on the spectrum agility, situational awareness and resiliency across the protocol stack in multi-hop CR networks.