Modeling the Delivery of Coded Packets in D2D Mobile Caching Networks

Caching popular files on the mobile nodes have been seen as a promising solution to improve the network performance. In this paper, we analyze the delivery of coded packets of the requested file in a mobile caching network of nodes each with a few pre-cached packets of different files from a large file library. To model the packet delivery process, we develop a two-dimensional Markov chain framework where each request has a deadline requirement. For the delivery of packets, we consider the mobility aspect of caching network where the nodes request the files from other neighbors while moving among different cells and offload the requested files on the device-to-device link. To characterize the network performance, we derive closed-form expressions for file outage probability, the average delay in receiving file, and average throughput to provide some valuable insights on different parameter settings. The simulation results not only verify the accuracy of the analysis but also shed some light on the scenarios where the performance gap between the mobile and fixed caching networks is prominent.