Research On Software-Defined Satellite Network Routing Technology

Satellite network has many advantages,such as wide coverage and immunity from geographical constraints.It not only finds its way in remote communication and emergency relief operations,but also is an important way to achieve global coverage of network.However,there are many shortcomings in the traditional architecture of satellite network in terms of efficiency,flexibility and system combination.In order to solve these problems,some researchers have proposed to use software-defined satellite network.Software-defined satellite network inherits the advantages of traditional network,like unified control panel,centralized network view,flexibility and scalability.The routing algorithms in software-defined satellite network should be fine-grained adjusted according to the quality of service and the states of networks.The goal of the algorithms is to allocate resource efficiently while guaranteeing the quality of service.However,the high dynamism of software-defined satellite network presents great challenge for routing strategies.On the one hand,the fast changing topology leads to frequent switches of routing,which degrades the quality of service.On the other hand,the heterogeneity of ground sub-networks makes the software-defined satellite networks deal with complex requirements.The randomness of workloads results in highly dynamic resource requirement and network states.This paper aims to solve the above-mentioned problems.The main work is as follows:Firstly,the routing algorithm towards real-time service in software-defined satellite network is studied.To solve the problem of latency thrashing and service termination caused by frequent topology switching in software-defined satellite networks in real-time services,we proposed a new routing algorithm,called Link Intersection of Multiple Snapshots based Routing algorithm(LIMSR).LIMSR calculates a stable route for real-time services from the target topology formed by the links intersection of multiple snapshots.The simulation results show that LIMSR can effectively reduce the delay jitter caused by topology switching to real-time service.Secondly,the dynamic fine-grained routing algorithm in software-defined satellite network is studied.We propose service satisfaction based fine-grained routing algorithm(SSFGR)to meet the demands of various workloads and changing network states.SSFGR takes advantages of the centralized view and resource virtualization to achieve fine-grained routing policies according to user and service needs.At the beginning,SSFGR classifies the services and defines its priority,then defines the business satisfaction,that is,the business satisfaction of the current path service.Each service is assigned a path that maximizes its satisfaction according to the order of business priorities,and the path allocation is adjusted periodically.Simulation results show that SSFGR can effectively improve the overall business satisfaction,and can improve system resource utilization and user capacity.