Edge Caching with Real-Time Guarantees

TL;DR

This paper analyzes the real-time performance of cache-enabled wireless networks using AoI as a metric, proposing a stochastic geometry and queuing theory model, and optimizing caching strategies to minimize Peak AoI.

Contribution

It introduces a spatial-temporal model for cache networks with AoI, deriving a closed-form AoI expression, and optimizing caching probabilities for real-time performance improvement.

Findings

Random caching outperforms popular content and uniform strategies.

Optimized caching reduces Peak AoI effectively.

File diversity is maintained at a high level.

Abstract

In recent years, optimization of the success transmission probability in wireless cache-enabled networks has been studied extensively. However, few works have concerned about the real-time performance of the cache-enabled networks. In this paper, we investigate the performance of the cache-enabled with real-time guarantees by adopting the age of information (AoI) as the metric to characterize the timeliness of the delivered information. We establish a spatial-temporal model by utilizing the stochastic geometry and queuing theory which captures both the temporal traffic dynamics and the interferers' geographic distribution. Under the random caching framework, we achieve the closed-form expression of AoI by adopting the maximum average received power criterion for the user association. Finally, we formulate a convex optimization problem for the minimization of the Peak AoI (PAoI) and obtain the optimal caching probabilities by utilizing the Karush-Kuhn-Tucker (KKT) conditions. Numerical results demonstrate that the random caching strategy is a better choice rather than the most popular content and uniform caching strategy to improve the real-time performance for the cached file as well as maintaining the file diversity at a relatively high level.