An Updated Discrete Graph Assisted Research Of Transmission Strategy Optimization For Satellite-UAV Hybrid Network

With the development of communication technology,people’s demand for communications in complex scenarios has gradually increased.The limitations of a single network have restricted people’s access to and use of comprehensive information in different scenarios.Adding nodes such as drones to the space network to complement space-based and space-based resources can ensure wide-area coverage and efficient transmission capabilities of the network.Howev er,the introduction of nodes with high dynamic characteristics in different spatial ranges has caused traditional single-space communication protocols to no longer be applicable.Because satellites and unmanned aerial vehicles have certain motion characteristics,the nodes’ on-off links are frequent and the link quality is time varying,which seriously affects the construction of the network topology model.Unlike satellite network nodes,the movement of nodes such as unmanned aerial vehicles is random,and it is difficult to obtain link information on some networks.As the hybrid Satellite-UAVs-Terrestrial Network belongs to the space hybrid Network background,the Delay/Disrupt Tolerant Network(DTN)protocol architecture widely used at present has used in this paper to cover a variety of single networks and achieve reliable data transmission between nodes of different types of networks.In order to ensure the global optimal routing decision,the global information of the network needed in the formulation of data transmission strategy.At present,time-varying graph model is widely used to construct dynamic network topology.The connection information of the dynamic network topology has obtained by predicting the location of the random UAV nodes.Provide priori information for the data.Based on the kinematic characteristics of UAV network nodes,this paper improves the model deceleration process and the transition relationship between different operating states based on the mobile model of the aviation ad h oc network node.Based on the improved mobile model,a node link connection prediction method based on the hidden Markov model has proposed to obtain the connection information of uncertain connections in a hybrid network.Combined with a satellite network node with a determined orbit,the network connection information needed to build a time-varying graph model has obtained.In addition,this paper analyzes the impact of different time-varying graph models on network data transmission,uses updated discrete graphs to model the topology of a hybrid network of satellites and drones,and introduces connection probabilities.A specific construction algorithm for updating discrete graphs proposed.According to the DTN data transmission process,this paper uses network flow theory to design a TMDR routing decision algorithm based on the updated discrete graph,and designs a VMPR based on the updated discrete graph and a CTG-based EAMP algorithm as comparison algorithms.TMDR can achieve the minimum transmission de lay in the case of meeting the constraint task requirements,which verifies the feasibility of data transmission based on updating the discrete graph.