Research On CGR Routing Algorithm Based On DTN Satellite Network

In recent years,with the development of science and technology,the scene in which people need to communicate data transmission has become increasingly rich,and many new communication scenarios have emerged.Among them,the space communication network is a major communication scenario.The space communication network scenario is different from the traditional communication network scenario in that the communication link path has a high delay,the transmission data rate is low,and the connection between the communication nodes may be in an unstable state for a long time.In order to solve the problem of data transmission in space communication network scenarios,the concept of a Delay Tolerant Network(DTN)network has also arisen.The Internet Research Task Force(IRTF)published the Delay Tolerant Network(DTN)network guide and proposed the concept of the DTN network.Based on the traditional communication protocol,the DTN network protocol adds a Bundle Layer between the transport layer and the application layer,and implements data transmission in the DTN network in a store-and-forward manner.Because the movement of the transmission nodes in the spatial DTN communication network is regular and periodic,NASA proposed a Contact Graph Routing(CGR)routing algorithm based on prior knowledge of the communication network.This paper studies the CGR routing algorithm in the spatial DTN network,and improves the CGR routing algorithm based on the design of other types of DTN routing algorithms to improve the communication efficiency of the CGR routing algorithm.The main content of this article is as follows:First of all,this paper introduces the different characteristics of DTN network and traditional network,and then studies and analyzes the structural characteristics of DTN network protocol system.The role of the binding layer protocol in the DTN network protocol system was highlighted.Then,this paper introduced the CGR routing algorithm,explained the design ideas of the CGR routing algorithm and the data transmission process of the CGR routing algorithm,and proposed the remaining shortcomings of the CGR routing algorithm.Secondly,based on CGR routing algorithm,this paper proposed a multi-path transmission-based CGR routing algorithm improved algorithm Multipath Probabilistic Contact Graph Routing(MP-CGR)routing algorithm.In order to cope with the space communication network scenario,the MP-CGR routing algorithm adopts different data transmission methods in the face of successful or failed packet transmission.The MP-CGR routing algorithm adds a multicast data transmission method to the routing algorithm,and selects the transmission node through the transmission probability.The MP-CGR routing algorithm implements optimization of the CGR routing algorithm through the above improvements.Finally,this paper designs a Mars-Earth spatial network communication scenario model,and builds a DTN network simulation platform to simulate the CGR routing algorithm and MP-CGR routing algorithm in this communication scenario.This paper uses the Satellite Tool Kit(STK)simulation software to construct the topology structure of the Mars-Earth communication scenario model,simulate the trajectory of nodes in the communication network and generate corresponding contact maps.Then,the data obtained from the STK simulation software is imported into the Interplanetary Overlay Network(ION)simulation software,and the ION software is used to compare the communication efficiency of the CGR routing algorithm with the MP-CGR routing algorithm.The simulation results show that the MP-CGR routing algorithm is superior to the CGR routing algorithm in both packet delivery rate and transmission average delay.