星地一体化网络中引入软件定义网络(software defined network,SDN)可以解决网络管理、信息交互等问题.由于网络结构异构、网络拓扑动态,链路时变、节点容量有限等特点,使得控制器和卫星网关的部署问题日益凸显,不同的控制器和卫星网关的部署方案会产生不同的网络性能.针对星地一体化网络异构性和时变性导致的传播时延增大问题,提出了 一种控制器和网关的联合部署方案,以网络时延和部署成本为目标建立部署模型,利用基于K-means的模拟退火算法求得控制器与网关最佳部署位置,提出利用可靠性划分时间片屏蔽卫星网络动态性,并以可靠性为约束,通过最短路径算法对不同时间片的交换机与控制器关系进行重分配,进一步降低了时延.用实际的卫星星座评估部署方案的性能,结果表明,所提出的部署方案在减少时延和成本方面优于现有方法,并且保证了网络可靠性.
Joint placement of SDN controllers and gateways in satellite-terrestrial integrated network
The introduction of software defined network(SDN)in the satellite-ground integrated network can solve prob-lems such as network management and information exchange.Due to the heterogeneous network structure,dynamic network topology,link time change,and limited node capacity,the placement of controllers and satellite gateways is increasingly prominent,and the placement schemes of different controllers and satellite gateways will produce different network perform-ance.Aiming at the problem of increasing propagation latency caused by heterogeneity and time-variability of satellite-terres-trial integrated network,a joint placement scheme of controller and gateway is proposed.The deployment model aims to minimize network delay and deployment cost,using a K-means-based simulated annealing algorithm to determine the opti-mal positions for controllers and gateways.A reliability-based time slicing approach is introduced to mask satellite network dynamics,and the relationship between switches and controllers in different time slices is reallocated using the shortest path algorithm,further reducing latency.Performance evaluations using a real satellite constellation show that the proposed de-ployment scheme outperforms existing methods in terms of reducing delay and cost while ensuring network reliability.
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维普
