Research On Key Technologies Of Nodes Emulation In Space-ground Integrated Network

The space-ground integrated network,which has many kinds of nodes and complex structure,has become the research priority all over the world nowadays.For it needs plenty of works in simulation and emulation before the deployment,network simulation software,e.g.,OPNET and NS2,is favored by researchers due to light weight and high efficiency.However,the software cannot simulate a continuous and huge network topology,and the simulated node cannot deploy the network protocols and software which are from actual node.To improve simulated nodes’ fidelity,the network emulation platform based on cloud has much more advantages than it.This paper introduced the principle of space-ground integrated network’s emulation and test.And we proposed two node emulation schemes using full virtualization technology and container technology.The emulated nodes are portable,which look like actual nodes’ software environment.At the same time,the cloud platform can manage the emulated nodes effectively,and can build much more dynamic and complex network topology.Moreover,as the related technology of space-ground network matures,a more realistic emulated node model is desperately needed by a growing number of researchers.At present,most of the cloud-based emulators in the industry are x86 servers.Because the cloud platform itself limits the virtualization technology,the virtual machine that can be generated is only x86 architecture.To further improve simulated nodes’ fidelity,this paper proposed two emulation enhancement schemes for heterogeneous nodes.One used full virtualization technology based on QEMU,which can emulate heterogeneous nodes in the hardware layer.Another used the QEMU-based para-virtualization technology and container technology,which can emulate heterogeneous nodes in the system layer.To test the availability of these two schemes,firstly,we tested the computing and network performances of the heterogeneous nodes using the common performance test software.And according to the test results,we analyzed the relationship between the performance of heterogeneous nodes and the number of CPUs.Secondly,according to the types of the underlying hardware emulated by two schemes,we compared the node fidelity of two emulation schemes.And finally,considering the nodes’ performance and function requirements in the space-ground integrated network,we presented the advantages and disadvantages of two emulation schemes together and the scope of application.On the basis of the test results,both of heterogeneous node emulation schemes in our paper can emulate the heterogeneous nodes of the space-ground network both in the hardware layer and the system layer.The emulation fidelity of the former is higher than the latter,while the performance is lower than the latter.The user can flexibly establish the network topology according to different emulation requirements in the space-ground network.