基于网络编码的空间DTN中CGR改进算法

摘要

随着空间通信技术的发展,卫星节点的增多,以及容延迟容中断通信需求的不断提高,空间DTN (DelayTolerant Network,容延迟网络)环境中各通信节点间的路由技术日益重要,相继出现了多种适用于DTN的路由技术.基于空间DTN的结构与特点,对CGR(Contact Graph Routing,接触图路由)算法以及基于编码的路由算法进行了分析比较,然后针对空间DTN中CGR算法的缺点和不足,研究提出了基于NC(Network Coding,网络编码)的空间DTN中的CGR改进算法(NC-CGR),并通过仿真实验平台对算法性能进行了分析评估.仿真结果表明,相比于CGR算法,NC-CGR算法在链路传输时延、传输包裹数目、中继缓存大小、链路丢包率等不同条件下的适应性方面均表现出较大优势,更适用于具有复杂拓扑、带宽受限、高动态特性的空间DTN环境.%With the development of technology and application in the space Delay Tolerant Networks (DTN),as well as the continuous increase of space communication nodes,more and more attention have been paid on routing technologies between different DTN nodes.This paper analyzes the structure of space DTN networks and the characteristics of Contact Graph Routing (CGR) algorithms,compares the design and performance differences of several routing algorithms based on coding.Then,it proposes an enhancement of CGR in space DTN networks based on Network Coding (NC-CGR).In order to verify the new approach's performance,research work has been carried out to prove its availability,such as communication simulation and analysis based on testbed.The simulation results show that,compared with CGR,the new NC-CGR performs well in terms of capabilities of time delay,bundle number,buffer size,and transmission overhead,which proves to be suitable for the highly dynamic,bandwidthlimited space DTN networks.