Device Caching for Network Offloading: Delay Minimization with Presence of User Mobility

TL;DR

This paper addresses delay minimization in device-to-device networks with user mobility by formulating a caching problem that balances network load reduction and delay, proposing an effective search algorithm and benchmarking its performance.

Contribution

It introduces a delay-optimal caching model considering mobility, derives a lower bound for optimality, and proposes an effective search algorithm for solution optimization.

Findings

ESA outperforms baseline algorithms in simulations

Lower bound provides a benchmark for performance evaluation

Mobility-aware caching reduces network load and delay

Abstract

A delay-optimal caching problem (DOCP) in deviceto- device (D2D) networks with moblity is modelled. The problem arises in the context of achieving offloading using device caching, and the offloading effect is represented by the expected network load ratio (NLR) which is the percentage of data that has to be downloaded from the network. Compared with the related studies, this work considers minimizing delay with NLR guarantee in mobility scenarios. A lower bound of global optimum is derived, thus enabling performance benchmarking of any sub-optimal algorithm. For problem-solving, an effective search algorithm (ESA) is proposed based on the bound. Simulations are conducted to evaluate the effectiveness of the ESA algorithm.