Edge Caching with Real-Time Guarantees

In recent years, optimization of the successful transmission probability (STP) in wireless cache-enabled networks has been studied extensively. However, few works have examined the real-time performance of the cache-enabled networks. In this paper, we investigate the performance of the cache-enabled networks with real-time guarantees by adopting age of information (AoI) as the metric to characterize the timeliness of the delivered information. We establish a spatial-temporal model by utilizing stochastic geometry and queueing 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 than both the most popular caching (MPC) and uniform caching (UC) strategies when it comes to improving the real-time performance for the cached files as well as maintaining the file diversity.