Performance Evaluation of LEO Satellite-assisted Caching: A Stochastic Geometry Approach

In order to satisfy the rapidly growing demand for data traffic from massive users, this study investigates a space-ground LEO satellite-assisted edge caching network framework and analyses the downlink transmission performance of this edge caching network. The aim is to enhance the quality of service provided by the edge caching network to users through the utilisation of LEO satellites. We use stochastic geometry to analyse the downlink performance. The spatial locations of the LEO satellites are modeled as Binomial Point Process (BPP) distribution deployed at a specific space altitude, and the locations of the terrestrial cloud servers (CSs) and mobile users (MUs) are modelled as independent Poisson Point Process (PPP), respectively. We establish the association strategy of typical MUs to LEO satellites (SATs) and CSs, based on which we derive the coverage probability analytical expression and average delay numerical solution for this network system. Finally, we verify the correctness of the numerical result through Monte Carlo simulation and study the network performance as a function of key constellation design parameters. We also analyse the impact of LEO SAT constellation parameters on the coverage capability and the average delay of MUs in this edge caching network. The simulation and analysis results provide constructive insights into the network design.