Smart collaborative video caching for energy efficiency in cognitive Content Centric Networks

Abstract Due to the prosperity of online videos, caching video content has become an important measure to improve the user experience and alleviate the link burden in the wireless caching networks. However, facing to the perceptual requirements of video users, Scalable Video Coding (SVC) technique has been cumulatively used in wireless caching networks, which can guarantee acceptable video quality. In this paper, we propose a smart collaborative video caching policy to boost energy efficiency (EE) in Cognitive Content Centric networking (C-CCN), where the spectrum sharing characteristic of cognitive ratio (CR) is integrated into CCN. With consideration of the imperfect channel-state information (CSI), the collision interference exists between the primary users (PUs) and secondary base stations (SBs). Inspired by this, we derive the expressions of successful content delivery rate (SCDR) and total power consumption for proposed caching policy. Using these expressions, the optimal EE model under the caching size constraint is formulated as an optimal content placement problem, which can be solved by the standard gradient projection method. Numerical and simulation results show the efficacy and superiority of the proposed caching policy compared with some traditional caching schemes.