Abstract
1- Introduction
2- Network model
3- Transmission probability
4- Successful content delivery probability
5- Numerical results
6- Conclusion
References
Abstract
We investigate a novel file-level carrier sensing based content delivery (FL-CSBCD) protocol to accommodate the transmission of multimedia files in fog-aided wireless networks. Particularly, the proposed FL-CSBCD protocol contains two phases, i.e., the file contention phase and the communication contention phase. The file contention phase aims to resolve the contentions among the requested multimedia files at each fog user equipments (F-UEs), such that the cache-hit performance is maximized. The communication contention phase is designed to resolve the collisions among concurrent content deliveries of the same file, such that the mutual interference can be suppressed. By modeling the fog-aided wireless networks with Poisson point process, we capture the density of active F-UEs, and evaluate the successful content delivery probability (SCDP) with the FL-CSBCD protocol. We show by simulations that the FL-CSBCD protocol can enhance the cache-hit performance while guarantee the coverage probability of content delivery.
Introduction
Recent advancements in smartphone industry and wireless internet technology have triggered a dramatic increase in the demand of bandwidth-hungry multimedia services [12]. Particularly, according to recent industry predictions [3], the annual traffic generated by multimedia content delivery in 2021 will be 4 times of that in 2016 with an increasing rate of 26% per year. To satisfy such unprecedented growth of user demands on multimedia services, it is necessary to investigate novel network architectures and develop advanced transmission techniques for the next generation wireless networks [2,7,10,11,19,23,29]. Fog-aided wireless network is considered to be a promising content-centric network architecture to alleviate the congestion of current cellular networks induced by the massive and redundant downloadings of multimedia contents [15–17,28]. Particularly, by deploying a generic caching, computing, and communication platform across the wireless edges, fog-aided wireless network can effectively offload the data traffic from the remote cloud sever and execute the delay-sensitive tasks in the proximity of the end users, which thereby substantially improves the network performance. To further enhance the spectral efficiency of the fog-aided wireless networks, the innovative technique of cache-enabled D2D communication [4,9,14,26] is utilized for multimedia content delivery. Particularly, by leveraging the cache-enabled D2D communications, a conventional cellular user equipment (C-UE) can directly obtain the multimedia content from a fog user equipment (F-UE) with caching capability in its proximity without the use of infrastructure based edge nodes.