Research On Transmission Technology Of Elastic Satellite Network Based On SDN

Facing the future satellite communication network,this paper studies new technologies such as SDN,NFV,OBS,etc.,and the research content constitutes a complete satellite communication traffic engineering solution.It includes the following aspects:SDN technology introduces satellite network and network architecture design,atmospheric channel modeling and simulation based on random phase screen,ACM and multi-site strategies under SDN satellite network architecture jointly fight against channel attenuation strategy,research multi priority traffic balance and dual polling strategy of node traffic balance in OBS burst network.The main research work is as follows.(1)This paper studies the emerging examples of SDN and nfv that can be applied to satellite network,and then proposes the architecture of the integration of elastic satellite network and ground network based on SDN,and introduces the applicable scenarios of the architecture.The application of software defined network technology and network virtualization technology brings some opportunities to broadband satellite network.SDN and nfv are complementary solutions.Satellite networks based on these two technologies can promote the integration of satellite and ground networks,and provide users with more kinds of services and customized services.(2)The random phase screen is used to simulate the atmospheric turbulence,and the step-by-step numerical simulation method is used to study the satellite ground laser link model.Based on the study of the representation and theory of atmospheric turbulence,the number and position of phase screens under various zenith angles are calculated according to the theoretical principle of simulating atmospheric turbulence with random phase screens.After the simulation model is established,the intensity fluctuation distribution of the light beam passing through the atmospheric turbulence is simulated under different atmospheric coherence length and 7 zenith angles,and the results are analyzed.(3)In this chapter,we study how to resist the serious channel attenuation of satellite,and design adaptive coding strategy and multi site cooperation strategy to alleviate the serious channel attenuation.Among the 28 modcod of DVB-S2 standard,8 equal ES/NO interval modulation coding schemes are selected as ACM schemes to alleviate the channel suffering from attenuation.In addition,SDN controller is used to coordinate the multi site cooperation strategy and forward the remaining data of the link to other sites to reduce the throughput loss.The combination of ACM and multisite strategy can reduce the throughput loss under the condition of satisfying the requirement of link bit error rate.(4)In order to solve the problem of satellite burst service priority and site traffic balance,the feasibility of the combination of satellite SDN technology and optical burst technology is analyzed,and a weighted dual polling burst assembly scheduling strategy is proposed to ensure the service priority and node load balance.Through the simulation,the strategy can guarantee the service data of users' various QoS requirements according to the queue status of edge nodes,and can also balance the load of edge nodes in the sending queue of burst packets,reduce the network congestion,which can be applied to the scene of satellite network exchange.