An Intelligent Caching and Replacement Strategy Based on Cache Profit Model for Space-Ground Integrated Network

Li Yang,Chengsheng Pan,Cheng Chi,Yaowen Qi,Sang-Bing Tsai

doi:10.1155/2021/7844929

Abstract

Compared with the stable states of the ground networks, the space-ground integrated networks (SGIN) have limited resources, high transmission delay, and vulnerable topology, which make traditional caching strategies unable to adapt to the complex space network environment. An intelligent and efficient caching strategy is required to improve the edge service capabilities of satellites. Therefore, we investigate these problems in this paper and make the following contributions. First, the content value evaluation model based on classification and regression tree is proposed to solve the problem of “what to cache” by describing the cache value of content, which considers the multidimensional content characteristics. Second, we propose a cache decision strategy based on the node caching cost model to answer “where to cache.” This strategy modified the genetic algorithm to adapt the 0-1 knapsack problem under SDN architecture, which greatly improved the cache hit rate and the network service quality. Finally, we propose a cache replacement strategy by establishing an effective service time model between the satellite and ground transmission link, which solves the problem of “when to replace.” Numerical results demonstrate that the proposed strategy in SGIN can improve the nodes’ cache hit rate and reduce the network transmission delay and transmission hops.

Highlights

In recent years, the space-ground integrated network (SGIN) has attracted much attention by its broader coverage and higher communication ability
The high transmission delay, heavy forwarding burden, and dynamic topology of satellite networks will make the traditional caching strategy not be directly applied in SGIN, decreasing the cache hit rate and network service quality [8, 9]. erefore, it is of great practical interest to design an intelligent caching and replacement strategy for efficiently enhancing the overall distribution performance in SGIN
E caching strategy is mainly divided into cache decision strategy and cache replacement strategy. e cache decision strategy determines whether the content be cached, and the cache replacement strategy determines whether the cached content is replaced. e computing resources of satellite nodes are limited while the content is transmitted

Summary

Introduction

The space-ground integrated network (SGIN) has attracted much attention by its broader coverage and higher communication ability. With the improvement of satellite service capabilities, the coordinated transmission of data in SGIN will be the trend of the future network [1]. SGIN can supplement the extensive communication services, providing wider coverage area and higher reliable data transmission schemes [2,3,4,5]. E caching service of the SGIN can effectively reduce repetitive transmission of the large number of multimedia services, which will improve satellite network efficiency [6, 7]. The high transmission delay, heavy forwarding burden, and dynamic topology of satellite networks will make the traditional caching strategy not be directly applied in SGIN, decreasing the cache hit rate and network service quality [8, 9]. Among the existing cache decision strategies, the lightweight caching strategies such as leave copy everywhere [10], leave

Objectives

Results

Conclusion