In this chapter, we use a statistical approach based on stochastic geometry to model and evaluate the performance of a cognitive D2D-enabled wireless multimedia sensor network (WMSN) in the presence of a multi-tier multi-channel cellular network. It will be shown that energy harvesting can efficiently power D2D com- munications in the WMSN. We will also observe that cognitive channel access can help improve the quality of service of D2D connections in the WMSN.
