Research And Implementation Of Remote Sensing Satellite Network Routing Protocol

Since the 1960 s,humans have made remarkable achievements in the acquisition of aerospace information and satellite Earth observation.Satellite remote sensing technology has developed rapidly.Remote sensing satellite data is characterized by real-time processing on the star and real-time downlink.The remote sensing satellite network is a typical intermittent connected network with the characteristics of time-varying topology,long delay and high error,which cannot provide long time connection end-to-end paths as the terrestrial networks.In addition,remote sensing satellite nodes rely too much on energy resources,and the on-board remote sensing task execution and on-board computing require a large amount of node energy.How to ensure high-throughput distribution of remote sensing data under energy-constrained conditions is still a challenging problem.To solve this problem,this paper conducts the following researches:Firstly,based on the basic principle of network routing,this paper divides remote sensing data routing into two phases: topology discovery process and route planning.Aiming at the problem that the traditional topology discovery mechanism used in remote sensing network consumes too much energy and prone to obsolescence routing problems,a routing flooding algorithm based on orbit information discrimination is designed.Such algorithm adds the information of the six elements of the satellite orbit in the node routing interactive message,calculates the position information of the neighbor node and the relative movement speed of the node in real time according to the six elements of the satellite orbit.Then the algorithm adaptively changes the interaction cycle of Hello message according to the position information and the relative movement speed of the node.This algorithm adopts the idea of distributed dynamic topology discovery and maintenance,and can timely discover neighbor nodes and update routing tables in the time-varying space network environment.At the same time,the energy consumption of nodes is reduced,and enough energy is reserved for the actual remote sensing service transmission.Secondly,aiming at the characteristics of limited energy and large amount of data transmission in remote sensing satellite network,the maximum flow routing algorithm of remote sensing satellite network with limited energy is proposed.The algorithm considers the energy resources of nodes and the time-varying of satellite network topology.We modify the traditional time-expansion diagram model by adding virtual nodes and the limited energy link,and build the energy limited time extension graph model,which can accurately characterize the energy resource constraint of satellite nodes and is convenient for calculation and solution.Then,based on the constructed graph model,the maximum flow routing algorithm of remote sensing satellite network with limited energy is proposed.In the algorithm step,the dynamic updating mechanism of the energy constrained link is added to ensure the consistency of energy of different time slots of nodes and the accuracy of solving the maximum flow.This algorithm effectively improves the data transmission amount of remote sensing satellite network,solves the maximum flow problem of end-to-end data transmission in remote sensing satellite network under the condition of limited energy,and provides a method for designing the maximum throughput routing protocol of remote sensing satellite network.Finally,in order to verify the feasibility of the proposed algorithm,this paper designs a simulation platform of remote sensing satellite network routing protocol.The platform consists of a link simulation system,a simulation scenario control system,a routing protocol simulation module and a protocol performance evaluation system.Based on the platform,a simulation test scenario is constructed to test and verify the feasibility and efficiency of the topology discovery and routing planning algorithm proposed in this paper.