A Cross-layer Framework for Symbiotic Relaying in Cognitive Radio Networks

The prime focus of this work is in developing a Symbiotic Cooperative Relaying (SCR) architecture for the Commons model of Dynamic Spectrum Access. The incumbent Primary User (PU) of the spectrum, with a weak transmission link, seeks cooperation from the cognitive Secondary User (SU) nodes in its vicinity, and in return rewards them with a suitable incentive. The incentive may be offered in terms of time (Cognitive Relaying with Time Incentive), frequency bands (Cognitive Relaying with Frequency Incentive), or both (Cognitive Relaying with Time and Frequency Incentive). Cross-layer optimization problems are formulated, which maximize the transmission opportunities for the SUs in the multi-hop multi-channel relay network, and offer a guaranteed throughput to the PU. To make the SCR scheme practically realizable, a MAC scheduling protocol is proposed within a unified framework for both the PU and SUs. Furthermore, cross-layer formulations are also proposed for multiple SUs to efficiently access the Time or Frequency Incentive for their own communication. Simulation results are furnished for each of the proposed SCR schemes to demonstrate their effectiveness from the perspective of both the PU and SUs.