Analysis and Optimization on Partition-Based Caching and Delivery in Satellite-Terrestrial Edge Computing Networks

As a viable component of 6G wireless communication architecture,satellite-terrestrial net-works support efficient file delivery by leveraging the innate broadcast ability of satellite and the enhanced powerful file transmission approaches of multi-tier ter-restrial networks.In the paper,we introduce edge computing technology into the satellite-terrestrial net-work and propose a partition-based cache and delivery strategy to make full use of the integrated resources and reducing the backhaul load.Focusing on the in-terference effect from varied nodes in different geo-graphical distances,we derive the file successful trans-mission probability of the typical user and by utilizing the tool of stochastic geometry.Considering the con-straint of nodes cache space and file sets parameters,we propose a near-optimal partition-based cache and delivery strategy by optimizing the asymptotic suc-cessful transmission probability of the typical user.The complex nonlinear programming problem is set-tled by jointly utilizing standard particle-based swarm optimization(PSO)method and greedy based multi-ple knapsack choice problem(MKCP)optimization method.Numerical results show that compared with the terrestrial only cache strategy,Ground Popular Strategy,Satellite Popular Strategy,and Independent and identically distributed popularity strategy,the per-formance of the proposed scheme improve by 30.5％,9.3％,12.5％and 13.7％.