节点移动是导致移动自组织网络性能下降、限制网络规模扩展的关键因素之一.寻找稳定路径是减小节点移动影响的有效手段.现有的稳定路径寻找方法存在以下局限:需要节点具有地理位置定位的硬件功能支持,或需要信号强度上传的交叉层功能支...节点移动是导致移动自组织网络性能下降、限制网络规模扩展的关键因素之一.寻找稳定路径是减小节点移动影响的有效手段.现有的稳定路径寻找方法存在以下局限:需要节点具有地理位置定位的硬件功能支持,或需要信号强度上传的交叉层功能支持.为此,提出了不需要特殊硬件支持、可独立于底层协议工作、基于邻居变化率的稳定路径选择方法.以AODV(Ad hoc on-demand distance vector)按需路由协议为基础,扩展为NCR-AODV(Neighbor change ratio Ad hoc on-demand distance vector)路由协议.新协议选择转发跳数少并且局部拓扑变化小的路径进行数据转发.仿真结果表明,NCR-AODV协议减小了长路径中断概率,提高了网络性能.展开更多
为了提高无线传感网络的数据传输的稳定性和网络能量利用率,提出基于路径稳定和路径能量的改进AODV路由I-AODV-SE(An Improved AODV Routing based on Stability and Energy of Path)协议。I-AODV-SE协议以按需距离矢量AODV(Ad Hoc On-d...为了提高无线传感网络的数据传输的稳定性和网络能量利用率,提出基于路径稳定和路径能量的改进AODV路由I-AODV-SE(An Improved AODV Routing based on Stability and Energy of Path)协议。I-AODV-SE协议以按需距离矢量AODV(Ad Hoc On-demand Distance Vector)为基础,对其路由决策机制进行改进。传统的AODV是将目的节点最先接收的RREQ传输通路作为数据包传输路径,而提出的I-AODV-SE是通过路径的权重决策数据传输路径。首先,I-AODV-SE协议先计算邻居变化率,再估计路径稳定性,然后,再计算路径能量,最后,基于路径稳定和路径能量计算路径权重,并择优选择权重小的路径传输数据。仿真数据表明,提出的I-AODV-SE协议提升了网络生存时间和数据包传递率。展开更多
The high-speed movement of satellites makes it not feasible to directly apply the mature routing scheme on the ground to the satellite network.DT-DVTR in the snapshot-based connectionoriented routing strategy is one o...The high-speed movement of satellites makes it not feasible to directly apply the mature routing scheme on the ground to the satellite network.DT-DVTR in the snapshot-based connectionoriented routing strategy is one of the representative solutions,but it still has room for improvement in terms of routing stability.In this paper,we propose an improved scheme for connection-oriented routing strategy named the Minimal Topology Change Routing based on Collaborative Rules(MTCR-CR).The MTCR-CR uses continuous time static topology snapshots based on satellite status to search for intersatellite link(ISL)construction solutions that meet the minimum number of topology changes to avoid route oscillations.The simulation results in Beidou-3 show that compared with DT-DVTR,MTCR-CR reduces the number of routing changes by about 92%,the number of path changes caused by routing changes is about38%,and the rerouting time is reduced by approximately 47%.At the same time,in order to show our algorithm more comprehensively,the same experimental index test was also carried out on the Globalstar satellite constellation.展开更多
为了增强城市车载网的链路稳定性,提出一种基于链路生存时间的改进的AODV(Enhanced Routing Protocol on Ad Hoc On-demand Distance Vector with Speed Variance,SV_AODV)路由协议。SV_AODV要求源节点转发路由请求至目的节点时包含节...为了增强城市车载网的链路稳定性,提出一种基于链路生存时间的改进的AODV(Enhanced Routing Protocol on Ad Hoc On-demand Distance Vector with Speed Variance,SV_AODV)路由协议。SV_AODV要求源节点转发路由请求至目的节点时包含节点的移动速度和方向,目的节点通过搜集路径上节点的速度信息得出每条链路的速度方差,并反馈给源节点,使其能够选择链路较稳定的传输路径。网络模拟软件仿真实验表明,改进的SV_AODV协议在节点快速移动的情况下能够减少数据包的丢失,缩短端到端的时延,更适用于城市车载网。展开更多
针对海上无线网状网通信环境复杂多变、船舶节点具有特殊移动模型等特点,提出一种基于Q-Learning的自适应路由(Q-Learning Based Adaptive Routing,QLAR)算法。综合考虑海上无线电波传播特性、船舶航程信息以及相应海区气象信息等因素...针对海上无线网状网通信环境复杂多变、船舶节点具有特殊移动模型等特点,提出一种基于Q-Learning的自适应路由(Q-Learning Based Adaptive Routing,QLAR)算法。综合考虑海上无线电波传播特性、船舶航程信息以及相应海区气象信息等因素的影响,提出链路可靠性、链路稳定性和节点航程相似度等概念,并对链路状态进行评估;然后,根据链路状态评估结果,利用Q-Learning算法寻找源、目的节点间最稳定的路径以传输数据分组;最后,利用OPNET搭建仿真平台对算法进行测试。仿真结果表明,与4种对比算法中性能最优的算法相比,QLAR算法最高可提升分组投递率4.89%,降低平均分组时延17.42%,减少归一化路由开销21.99%。展开更多
Greening Internet is an important issue now, which studies the way to reduce the increas- ing energy expenditure. Our work focuses on the network infrastructure and considers its energy awareness in traffic routing. W...Greening Internet is an important issue now, which studies the way to reduce the increas- ing energy expenditure. Our work focuses on the network infrastructure and considers its energy awareness in traffic routing. We formulate the model by traffic engineering to achieve link rate a- daption, and also predict traffic matrices to pre- serve network stability. However, we realize that there is a tradeoff between network performance and energy efficiency, which is an obvious issue as Internet grows larger and larger. An essential cause is the huge traffic, and thus we try to fred its so- lution from a novel architecture called Named Data Networking （NDN） which tent in edge routers and can flexibly cache con- decrease the backbone traffic. We combine our methods with NDN, and finally improve both the network performance and the energy efficiency. Our work shows that it is effective, necessary and feasible to consider green- ing idea in the design of future Internet.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.60403031(国家自然科学基金)the National HighTech Research and Development Plan of China under Grant No.2005AA121560(国家高技术研究发展计划(863))+3 种基金the Fundamental Research Project of the Institute of Computing Technology the Chinese Academy of Sciences (中国科学院计算技术研究所基础研究项目)the Youth Innovation Foundation of the Institute of Computing Technology the Chinese Academy of Sciences(中国科学院计算技术研究所青年创新基金)
文摘节点移动是导致移动自组织网络性能下降、限制网络规模扩展的关键因素之一.寻找稳定路径是减小节点移动影响的有效手段.现有的稳定路径寻找方法存在以下局限:需要节点具有地理位置定位的硬件功能支持,或需要信号强度上传的交叉层功能支持.为此,提出了不需要特殊硬件支持、可独立于底层协议工作、基于邻居变化率的稳定路径选择方法.以AODV(Ad hoc on-demand distance vector)按需路由协议为基础,扩展为NCR-AODV(Neighbor change ratio Ad hoc on-demand distance vector)路由协议.新协议选择转发跳数少并且局部拓扑变化小的路径进行数据转发.仿真结果表明,NCR-AODV协议减小了长路径中断概率,提高了网络性能.
文摘为了提高无线传感网络的数据传输的稳定性和网络能量利用率,提出基于路径稳定和路径能量的改进AODV路由I-AODV-SE(An Improved AODV Routing based on Stability and Energy of Path)协议。I-AODV-SE协议以按需距离矢量AODV(Ad Hoc On-demand Distance Vector)为基础,对其路由决策机制进行改进。传统的AODV是将目的节点最先接收的RREQ传输通路作为数据包传输路径,而提出的I-AODV-SE是通过路径的权重决策数据传输路径。首先,I-AODV-SE协议先计算邻居变化率,再估计路径稳定性,然后,再计算路径能量,最后,基于路径稳定和路径能量计算路径权重,并择优选择权重小的路径传输数据。仿真数据表明,提出的I-AODV-SE协议提升了网络生存时间和数据包传递率。
基金supported by the National Key Research and Development Program of China(No.2020YFB1806000)。
文摘The high-speed movement of satellites makes it not feasible to directly apply the mature routing scheme on the ground to the satellite network.DT-DVTR in the snapshot-based connectionoriented routing strategy is one of the representative solutions,but it still has room for improvement in terms of routing stability.In this paper,we propose an improved scheme for connection-oriented routing strategy named the Minimal Topology Change Routing based on Collaborative Rules(MTCR-CR).The MTCR-CR uses continuous time static topology snapshots based on satellite status to search for intersatellite link(ISL)construction solutions that meet the minimum number of topology changes to avoid route oscillations.The simulation results in Beidou-3 show that compared with DT-DVTR,MTCR-CR reduces the number of routing changes by about 92%,the number of path changes caused by routing changes is about38%,and the rerouting time is reduced by approximately 47%.At the same time,in order to show our algorithm more comprehensively,the same experimental index test was also carried out on the Globalstar satellite constellation.
文摘为了增强城市车载网的链路稳定性,提出一种基于链路生存时间的改进的AODV(Enhanced Routing Protocol on Ad Hoc On-demand Distance Vector with Speed Variance,SV_AODV)路由协议。SV_AODV要求源节点转发路由请求至目的节点时包含节点的移动速度和方向,目的节点通过搜集路径上节点的速度信息得出每条链路的速度方差,并反馈给源节点,使其能够选择链路较稳定的传输路径。网络模拟软件仿真实验表明,改进的SV_AODV协议在节点快速移动的情况下能够减少数据包的丢失,缩短端到端的时延,更适用于城市车载网。
文摘针对海上无线网状网通信环境复杂多变、船舶节点具有特殊移动模型等特点,提出一种基于Q-Learning的自适应路由(Q-Learning Based Adaptive Routing,QLAR)算法。综合考虑海上无线电波传播特性、船舶航程信息以及相应海区气象信息等因素的影响,提出链路可靠性、链路稳定性和节点航程相似度等概念,并对链路状态进行评估;然后,根据链路状态评估结果,利用Q-Learning算法寻找源、目的节点间最稳定的路径以传输数据分组;最后,利用OPNET搭建仿真平台对算法进行测试。仿真结果表明,与4种对比算法中性能最优的算法相比,QLAR算法最高可提升分组投递率4.89%,降低平均分组时延17.42%,减少归一化路由开销21.99%。
基金This work was supported by the National Key Basic Re- search Program of China under Grant No. 2011 CB302702 the National Natural Science Foundation of China under Grants No. 61132001, No. 61120106008, No. 61070187, No. 60970133, No. 61003225 the Beijing Nova Program.
文摘Greening Internet is an important issue now, which studies the way to reduce the increas- ing energy expenditure. Our work focuses on the network infrastructure and considers its energy awareness in traffic routing. We formulate the model by traffic engineering to achieve link rate a- daption, and also predict traffic matrices to pre- serve network stability. However, we realize that there is a tradeoff between network performance and energy efficiency, which is an obvious issue as Internet grows larger and larger. An essential cause is the huge traffic, and thus we try to fred its so- lution from a novel architecture called Named Data Networking （NDN） which tent in edge routers and can flexibly cache con- decrease the backbone traffic. We combine our methods with NDN, and finally improve both the network performance and the energy efficiency. Our work shows that it is effective, necessary and feasible to consider green- ing idea in the design of future Internet.
