Cooperative Transmission and Probabilistic Caching for Clustered D2D Networks

Abstract

Caching at mobile devices and leveraging device-to-device (D2D) communication are two promising approaches to support massive content delivery over wireless networks. Analysis of such D2D caching networks based on a physical interference model is usually carried out by assuming uniformly distributed devices. However, this approach does not capture the notion of device clustering. In this regard, this paper proposes a joint communication and caching optimization framework for clustered D2D networks. Devices are spatially distributed into disjoint clusters and are assumed to have a surplus memory that is utilized to proactively cache files, following a random probabilistic caching scheme. The cache offloading gain is maximized by jointly optimizing channel access and caching scheme. A closed-form caching solution is obtained and bisection search method is adopted to heuristically obtain the optimal channel access probability. Results show significant improvement in the offloading gain reaching up to 10% compared to the Zipf caching baseline.

On LOS Contribution to Ultra-Dense Network

“…By replacing (23), (24) and (25) in (16), we have derived our approximation¯ M . Note that in case the approximated terms in (11) and (14) were not considered, the derived SCDP in (15) and (16) would write as a non solvable integral which involves a modified Bessel function of the first kind as in [10]. Also, it is known that a closed-form solution for…”

“…jointly transmitted contents has not been found yet, even for the simple full NLOS network [13]- [15]. Thus, when maximizing the SCDP (or minimizing the outage probability) over some network parameters, an iterative solution is generally required to achieve a sub-optimal feasible set of decision variables.…”

“…Thus, when maximizing the SCDP (or minimizing the outage probability) over some network parameters, an iterative solution is generally required to achieve a sub-optimal feasible set of decision variables. Based on our proposed approximation, existing solutions in the literature which aim to find sub-optimal network parameters can be updated by scaling the SCDP for a full NLOS network with the proposed LOS contribution as in (15) and (16).…”

“…In particular, referring to Conjecture 2, the typical full NLOS SCDP terms in (15) and (16) have to be scaled, respectively, by…”

On Minimizing Energy Consumption for D2D Clustered Caching Networks

“…Proof. Due to lack of space, we delegate this proof to the journal version of this paper [19]. At first, we validate the developed mathematical model via Monte Carlo simulations.…”