Research Of Satellite Network Routing And Caching Strategy Based On SDN And ICN

With the continuous development of space communication research,the application demand of Space-earth integrated network in military,meteorological,emergency and other fields is expanding,and the emergence of new business makes network management more and more complex.At the same time,with the upgrade of user behavior and industrial data,video and other big data become the main object of network transmission and explosive growth.In the network mode with IP as the thin waist of protocol stack,the end-to-end transmission mode becomes the bottleneck of network request response delay.The Space-earth integrated network which is based on traditional TCP/IP protocol needs a new network architecture to address the challenges what are big-data and more new business environment.Therefore,aiming at the above problems,this paper carries out the research of satellite network architecture design and related technologies based on SDN and ICN technology.In this paper,SDICSN,a satellite network architecture based on SDN and ICN technology,is proposed by introducing two new network architecture ideas,Software Define Networking and Information-Centric Networking.Three high orbit satellites are used as SDN controllers and low orbit satellites are used as SDN forwarding layers through Iridium and Walker constellations.SDN controller implements key technologies such as name resolution,name routing and content caching in ICN through application layer development.In order to make SDICSN architecture compatible with existing network infrastructure,this paper reuses IP protocol to enable OpenFlow protocol to identify ICN requests and IP requests.The simulation results show that SDICSN architecture can achieve better ICN cache characteristics.In SDICSN architecture,ICN request and data transmission no longer depend on IP address,so IP address-based routing algorithm is no longer applicable.The idea of trying to return in the original path in ICN is no longer applicable to the return of ICN data in satellite networks because of the high dynamic nature of satellite nodes.Therefore,under the proposed SDICSN architecture,a routing algorithm based on virtual node matrix is proposed through SDN controller topology calculation and constellation-dependent virtual node topology strategy.(VNMR).According to the satellite constellation,the algorithm defines the partition rules of virtual nodes and gets the routing matrix.According to the parameters of satellite communication bandwidth,node load,link length between satellite nodes and signal transmission speed,the load rate of virtual nodes and link weight of routing matrix are defined.Then,according to the routing matrix,the shortest path algorithm is used to get the transmission path of ICN request and data return.Cache replacement strategy design is the core of ICN.Under SDICSN architecture,due to the high dynamic nature of satellite network topology,the limited computing resources and cache space of satellite nodes,traditional cache replacement strategies will cause a large number of large cache redundancy of Intranet caches,low direct hit rate of nodes and high cache replacement rate.And in big-data environment,content transmission is based on user-driven mode.Therefore,this paper designs a user-driven popularity-aware cache replacement strategy(UDPAM),which combines the characteristics of satellite network such as high dynamic and limited cache resources.By introducing such factors as user behavior,user social network and content hierarchy,the popularity perception model of content early dissemination is established,and then the popularity of content is predicted by user behavior model,and cache replacement strategy is implemented.The simulation results show that UDPAM cache replacement strategy has higher cache hit rate and lower cache replacement rate in satellite networks than LCE and LRU cache replacement strategies.