Delay-Oriented Caching Strategy for LEO Satellite-Assisted Edge Caching Network

Since the terrestrial edge caching network has insufficient service coverage for remote and maritime areas, and considering that LEO satellite (SAT) network has the advantages of full coverage of the earth and low latency, we investigate an edge caching network with LEO SAT space caching. Using stochastic geometry tools, we establish an analytical framework and derive the analytical expression for the average transmission delay. Considering mobile user (MU) preferences for content requests in real situation, we develop the task request and service caching model for the network. To achieve lower transmission delay of the network, this paper proposes a minimum delay based on particle swarm optimization (MDPSO) caching strategy, which optimizes the caching probabilities of LEO SAT space caching for different service types. The results show that MDPSO outperforms the classical caching strategy in terms of average transmission delay, and optimizing the caching probability for SAT space caching is beneficial to improve the delay performance of edge caching network.