Channel-Aware D2D-Assisted Wireless Distributed Storage Systems

Device-to-device (D2D) communications and distributed storage are enabling technologies for the future Internet of Things systems. In this article, we consider power-efficient content delivery in a D2D-assisted wireless distributed storage system, where the partial downloading scheme is employed such that the content requester can download a portion of the stored content from neighboring storage devices. The basic idea is that by downloading a small amount of data from many storage devices, the power consumption is much lower than downloading the entire content from a single device. In designing such a system, we aim to minimize the total power consumption by properly allocating the channel and the amount of transmitted data for each storage device. Moreover, to account for the case that there are more devices than communication channels, we allow multiple devices to share the same channel by employing successive interference cancelation (SIC) decoding. The optimization problem is an integer program and by taking the alternative minimization approach, we decouple it into two subproblems: 1) the packet allocation subproblem, for which we provide the optimal solution and 2) the channel allocation subproblem, for which we provide the efficient suboptimal solution.