A lot of routing algorithms have been proposed for low earth orbit（LEO） satellite IP networks in recent years,but most of them cannot achieve global optimization.The dynamic characters of LEO satellite networks are ...A lot of routing algorithms have been proposed for low earth orbit（LEO） satellite IP networks in recent years,but most of them cannot achieve global optimization.The dynamic characters of LEO satellite networks are reflected in two aspects：topology and traffic change.The algorithms mentioned above are ＂hard routing＂ which only realize local optimization.A distributed soft routing algorithm combined with multi-agent system（MASSR） is proposed.In MASSR,mobile agents are used to gather routing information actively,and blackboard is introduced to achieve direct information exchange between agents.MASSR provides traffic adaptive routing and tracks the change of LEO satellite network topology.The performance of ant colony optimization（ACO） and MASSR are compared in Iridium constellation,and MASSR presents better end-to-end delay as well as enhanced robustness.展开更多
随着云计算的兴起与发展,人们对网络资源也有了按需取用按量收费的需求,尽管市面上的各类Iaa S(Infrastructure as a Service)供应商也都在平台上提供了相应的虚拟网络资源,但是单纯建立在云平台上的虚拟网络的性能和实际硬件网络性能...随着云计算的兴起与发展,人们对网络资源也有了按需取用按量收费的需求,尽管市面上的各类Iaa S(Infrastructure as a Service)供应商也都在平台上提供了相应的虚拟网络资源,但是单纯建立在云平台上的虚拟网络的性能和实际硬件网络性能之间仍存在着较大差异。为了提高云平台上的虚拟网络的性能,SDN(Software Define Network)与虚拟网络的结合就尤为重要,目前已成为云计算网络研究中最热门也最重要的项目。本文首先介绍Open Stack中Neutron的虚拟网络实现原理,然后介绍解决部分南北流量集中问题的插件DVR的实现原理,最后分析和研究致力于全面解决南北流量集中问题的分布式SDN控制器插件Dragonflow的实现原理。展开更多
针对无线传感器网络特点和节点的剩余能量、延时、延时抖动、带宽等QoS约束问题,提出了基于WSN节点最大剩余能量的多QoS约束多播路由算法SEQMRA-W(Surplus Energy Qos Multicast Routing Algorithm based on WSN).该算法把最大剩余能量...针对无线传感器网络特点和节点的剩余能量、延时、延时抖动、带宽等QoS约束问题,提出了基于WSN节点最大剩余能量的多QoS约束多播路由算法SEQMRA-W(Surplus Energy Qos Multicast Routing Algorithm based on WSN).该算法把最大剩余能量作为第一度量,同时考虑节点带宽、延时、延时抖动等因素.并对算法进行了复杂性分析.仿真实验表明:算法在路由成功率、多播树费用、能量消耗方面均具有较好特性.展开更多
Vehicular networks have been envisioned to provide us with numerous interesting services such as dissemination of real-time safety warnings and commercial advertisements via car-to-car communication. However, efficien...Vehicular networks have been envisioned to provide us with numerous interesting services such as dissemination of real-time safety warnings and commercial advertisements via car-to-car communication. However, efficient routing is a research challenge due to the highly dynamic nature of these networks. Nevertheless, the availability of connections imposes additional constraint. Our earlier works in the area of efficient dissemination integrates the advantages of middleware operations with muhicast routing to de- sign a framework for distributed routing in vehicular networks. Cloud computing makes use of pools of physical computing resourc- es to meet the requirements of such highly dynamic networks. The proposed solution in this paper applies the principles of cloud computing to our existing framework. The routing protocol works at the network layer for the formation of clouds in specific geo- graphic regions. Simulation results present the effieiency of the model in terms of serviee discovery, download time and the queu- ing delay at the controller nodes.展开更多
基金supported by the National Natural Science Foundation of China (60532030)
文摘A lot of routing algorithms have been proposed for low earth orbit（LEO） satellite IP networks in recent years,but most of them cannot achieve global optimization.The dynamic characters of LEO satellite networks are reflected in two aspects：topology and traffic change.The algorithms mentioned above are ＂hard routing＂ which only realize local optimization.A distributed soft routing algorithm combined with multi-agent system（MASSR） is proposed.In MASSR,mobile agents are used to gather routing information actively,and blackboard is introduced to achieve direct information exchange between agents.MASSR provides traffic adaptive routing and tracks the change of LEO satellite network topology.The performance of ant colony optimization（ACO） and MASSR are compared in Iridium constellation,and MASSR presents better end-to-end delay as well as enhanced robustness.
文摘随着云计算的兴起与发展,人们对网络资源也有了按需取用按量收费的需求,尽管市面上的各类Iaa S(Infrastructure as a Service)供应商也都在平台上提供了相应的虚拟网络资源,但是单纯建立在云平台上的虚拟网络的性能和实际硬件网络性能之间仍存在着较大差异。为了提高云平台上的虚拟网络的性能,SDN(Software Define Network)与虚拟网络的结合就尤为重要,目前已成为云计算网络研究中最热门也最重要的项目。本文首先介绍Open Stack中Neutron的虚拟网络实现原理,然后介绍解决部分南北流量集中问题的插件DVR的实现原理,最后分析和研究致力于全面解决南北流量集中问题的分布式SDN控制器插件Dragonflow的实现原理。
文摘针对无线传感器网络特点和节点的剩余能量、延时、延时抖动、带宽等QoS约束问题,提出了基于WSN节点最大剩余能量的多QoS约束多播路由算法SEQMRA-W(Surplus Energy Qos Multicast Routing Algorithm based on WSN).该算法把最大剩余能量作为第一度量,同时考虑节点带宽、延时、延时抖动等因素.并对算法进行了复杂性分析.仿真实验表明:算法在路由成功率、多播树费用、能量消耗方面均具有较好特性.
文摘Vehicular networks have been envisioned to provide us with numerous interesting services such as dissemination of real-time safety warnings and commercial advertisements via car-to-car communication. However, efficient routing is a research challenge due to the highly dynamic nature of these networks. Nevertheless, the availability of connections imposes additional constraint. Our earlier works in the area of efficient dissemination integrates the advantages of middleware operations with muhicast routing to de- sign a framework for distributed routing in vehicular networks. Cloud computing makes use of pools of physical computing resourc- es to meet the requirements of such highly dynamic networks. The proposed solution in this paper applies the principles of cloud computing to our existing framework. The routing protocol works at the network layer for the formation of clouds in specific geo- graphic regions. Simulation results present the effieiency of the model in terms of serviee discovery, download time and the queu- ing delay at the controller nodes.
