Modeling and Analysis of Content Delivery over Satellite Integrated Cognitive Radio Networks

Although spectral resources are scarce while being critical for wireless system performance, their utilization in various frequency bands are shown to be very low. Cognitive radio (CR) concept, where licensed bands are allowed to be used by a secondary network, is proposed as a general paradigm to address this limitation. Moreover, the effects of this deficiency in spectral resource management have been aggravated with the exploding content consumption through wireless networks. In emerging 5G wireless systems, Device-to-Device (D2D) communications and heterogeneous architectures composed of different network tiers are posed as two vital apparatus to alleviate the "capacity crunch". However, the interplay/integration of these different techniques and approaches are yet to be comprehensively explored by research efforts. In this work, we consider this issue and develop an analytical Markovian model for content delivery over satellite integrated cognitive radio networks which can utilize D2D operation mode. We focus on throughput and energy efficiency as key metrics for depicting the system operation. We also investigate the effects of various system parameters on the performance such as cache size, mode preference for content retrieval from different content holders and primary user activity.