Joint Spatial and Temporal Spectrum Sharing for Demand Response Management in Cognitive Radio Enabled Smart Grid

Real-time demand response management (DRM) in smart grid (SG) requires a reliable wireless communication network with sufficient spectrum resources. However, the allocated spectrum for wireless communications is heavily under-utilized in the spatial and temporal dimensions. To solve the spectrum scarcity problem, cognitive radio (CR) and dynamic spectrum sharing have been proposed, but this can result in poor reliability. In this paper, the influence of wireless communication reliability on DRM is analyzed and the relationship between outage and DRM performance is derived. Outage results from not only interference and noise, but also the unavailability of spectrum resources. Therefore, joint spatial and temporal spectrum sharing is proposed to improve spectrum utilization. The SG network is divided into a Temporal Spectrum Sharing Region (TSSR) and a Free Spatial Spectrum Sharing Region (Free-SSSR). SG nodes in the TSSR can utilize the licensed spectrum when primary users (PUs) are idle, while in the Free-SSSR they can simultaneously share this spectrum with the PUs without using power control. Performance results are presented which show that joint spatial and temporal spectrum sharing can increase the SG spectrum utilization opportunities and lower the outage probability, which is beneficial for DRM performance.