星地融合网络中的流量卸载研究

Survey on traffic offloading in satellite-terrestrial integrated networks

卫星网络与地面网络融合,可以拓展网络覆盖范围、提高网络灵活性以及提升网络资源利用率。针对地面网络流量激增带来的网络拥塞、传输时延长、数据吞吐量低等问题,从网络架构、流量卸载方案、流量卸载决策等3个方面对星地融合网络中的流量卸载进行了研究。从网络架构来看,未来通信网络正逐渐走向卫星网络和地面网络融合的一体化网络;从流量卸载方案来看,星地融合网络中流量卸载的关键技术主要包括软件定义网络、网络功能虚拟化、移动边缘计算以及星间链路协作;从流量卸载决策策略来看,分别基于时延、能耗和吞吐量分析归纳总结了几种主流流量卸载决策策略;指出了星地融合网络中流量卸载研究存在的主要挑战及下一步的潜在研究方向。

The satellite-terrestrial integrated networks(STINs)can expand network coverage,improve the network flexibility,as well as resource utilization.Aiming at the problems of network congestion,long transmission delay,and low throughput caused by the surge of terrestrial network traffic,the traffic offloading in STIN is studied via three aspects,viz,network architecture,traffic offloading schemes,and traffic offloading decisions.From the perspective of network architecture,the trend of future communication network is the integration of satellite networks and terrestrial networks.From the perspective of traffic offloading schemes,the key technologies of traffic offloading in STIN mainly include software defined network(SDN),network functions virtualization(NFV),mobile edge computing(MEC),and inter-satellite link(ISL)cooperation.From the perspective of traffic offloading decisions,major strategies are summarized based on the analysis of time delay,energy consumption,and throughput.Finally,potential challenges and research directions of traffic offloading in STIN are pointed out.