Offloading on the edge: Performance and cost analysis of local data storage and offloading in HetNets

Abstract

The rapid increase in data traffic demand has overloaded existing cellular networks. Planned upgrades in the communication architecture (e.g. LTE), while helpful, are not expected to keep up with demand. As a result, extensive densification through small cells, caching content closer to or even at the device, device-to-device (D2D) communications, and delayed content delivery are seen as necessary components for future heterogeneous cellular networks to withstand the data crunch. Nevertheless, these options imply new CAPEX and OPEX costs, extensive backhaul support, and contract plan incentives for D2D. A number of interesting tradeoffs, relating to performance and costs, arise thus for the operator. In this paper, we analytically investigate the extent to which local storage and communication through “edge” nodes could help offload traffic in a heterogeneous network (HetNet). We propose a model that can capture generic HetNet setups (comprising small cells, D2D communication, delayed delivery schemes, transmission costs, etc.). We analyse (a) the offloading performance and (b) the costs involved for the operator, and derive simple closed-form expressions as a function of the network parameters. Our results can be useful in performance evaluation and optimization of offloading and caching strategies, network dimensioning, pricing policies, etc.