为了提高网络路由性能,提出并设计了一种基于遗传-蚁群优化算法的服务质量(quality of service,QoS)组播路由算法。首先,设计了自适应变频采集策略用于采集网络与节点信息,以此获得网络和节点的状态,为后续路由优化提供数据支持;其次,...为了提高网络路由性能,提出并设计了一种基于遗传-蚁群优化算法的服务质量(quality of service,QoS)组播路由算法。首先,设计了自适应变频采集策略用于采集网络与节点信息,以此获得网络和节点的状态,为后续路由优化提供数据支持;其次,计算路径代价,将路径代价最小作为优化目标,建立QoS组播路由优化模型,并设置相关约束条件;最后,结合遗传算法和蚁群算法提出一种遗传-蚁群优化算法求解上述模型,输出最优路径,完成路由优化。实验结果表明,所提算法可有效降低路径长度与路径代价,提高搜索效率与路由请求成功率,优化后的路由时延抖动较小。展开更多
针对无线Mesh网络组播中包丢失严重的问题,提出了保持包的IP层不变,而改变包的目的MAC域,进而MAC层以单播形式向组成员发送包的M2U(Multicast to Unicast)优化解决方案.为了满足组成员增加时不影响用户的性能,提出在M2U中引入了机会路由...针对无线Mesh网络组播中包丢失严重的问题,提出了保持包的IP层不变,而改变包的目的MAC域,进而MAC层以单播形式向组成员发送包的M2U(Multicast to Unicast)优化解决方案.为了满足组成员增加时不影响用户的性能,提出在M2U中引入了机会路由的M2UO(Multicast to Unicast Opportunistic Routing)算法,对候选节点采用单播形式发送包,对其它节点采用组播形式发送包.在实际网络环境中的大量实验表明,优化组播减小了数据包的丢失率,提高了网络的吞吐量,具有较好的组播视频流效果.展开更多
为了使组播路由与组播用户的服务需求相匹配,提升用户的组播使用体验,结合软件定义网络(software defined network,SDN)独有的路由与转发分离特点,设计并实现了基于SDN的服务驱动组播路由方案。该方案通过对Dijkstra算法进行改进,将组...为了使组播路由与组播用户的服务需求相匹配,提升用户的组播使用体验,结合软件定义网络(software defined network,SDN)独有的路由与转发分离特点,设计并实现了基于SDN的服务驱动组播路由方案。该方案通过对Dijkstra算法进行改进,将组播用户的服务需求加入到组播路由的计算过程中,控制器可以根据用户需求实时更新组播路由并下发符合需求的新流表到交换机,实现根据用户需求动态调整组播路由的基于SDN的服务驱动组播路由机制。该机制拥有完整的组播流程,集组播建立、组播接收者加入/离开、组播管理、根据用户需求动态调整组播路由等功能为一体,创新性地根据用户的不同服务需求,随时变更并下发符合用户需求的组播路径。使用Mininet平台等仿真工具对提出的方案进行了功能测试和性能测试,结果表明,基于SDN的服务驱动组播在满足用户服务需求的情况下,不会对原有组播性能造成较大影响。展开更多
Minimizing network coding resources of multicast networks,such as the number of coding nodes or links,has been proved to be NP-hard,and taking propagation delay into account makes the problem more complicated. To reso...Minimizing network coding resources of multicast networks,such as the number of coding nodes or links,has been proved to be NP-hard,and taking propagation delay into account makes the problem more complicated. To resolve this optimal problem,an integer encoding routing-based genetic algorithm( REGA) is presented to map the optimization problem into a genetic algorithm( GA)framework. Moreover,to speed up the search process of the algorithm,an efficient local search procedure which can reduce the searching space size is designed for searching the feasible solution.Compared with the binary link state encoding representation genetic algorithm( BLSGA),the chromosome length of REGA is shorter and just depends on the number of sinks. Simulation results show the advantages of the algorithm in terms of getting the optimal solution and algorithmic convergence speed.展开更多
Mobile Ad hoc Networks(MANETs) play an important role in emergency communications where network needs to be constructed temporarily and quickly.Since the nodes move randomly,routing protocols must be highly effective ...Mobile Ad hoc Networks(MANETs) play an important role in emergency communications where network needs to be constructed temporarily and quickly.Since the nodes move randomly,routing protocols must be highly effective and reliable to guarantee successful packet delivery.Based on the data delivery structure,most of the existing multicast routing protocols can be classified into two folders:tree-based and mesh-based.We observe that tree-based ones have high forwarding efficiency and low consumptions of bandwidth,and they may have poor robustness because only one link exists between two nodes.As a treebased multicast routing protocol,MAODV(Multicast Ad hoc On-demand Vector) shows an excellent performance in lightweight ad hoc networks.As the load of network increases,QoS(Quality of Service) is degraded obviously.In this paper,we analyze the impact of network load on MAODV protocol,and propose an optimized protocol MAODV-BB(Multicast Ad hoc On-demand Vector with Backup Branches),which improves robustness of the MAODV protocol by combining advantages of the tree structure and the mesh structure.It not only can update shorter tree branches but also construct a multicast tree with backup branches.Mathematical analysis and simulation results both demonstrate that the MAODV-BB protocol improves the network performance over conventional MAODV in heavy load ad hoc networks.展开更多
文摘为了提高网络路由性能,提出并设计了一种基于遗传-蚁群优化算法的服务质量(quality of service,QoS)组播路由算法。首先,设计了自适应变频采集策略用于采集网络与节点信息,以此获得网络和节点的状态,为后续路由优化提供数据支持;其次,计算路径代价,将路径代价最小作为优化目标,建立QoS组播路由优化模型,并设置相关约束条件;最后,结合遗传算法和蚁群算法提出一种遗传-蚁群优化算法求解上述模型,输出最优路径,完成路由优化。实验结果表明,所提算法可有效降低路径长度与路径代价,提高搜索效率与路由请求成功率,优化后的路由时延抖动较小。
文摘针对无线Mesh网络组播中包丢失严重的问题,提出了保持包的IP层不变,而改变包的目的MAC域,进而MAC层以单播形式向组成员发送包的M2U(Multicast to Unicast)优化解决方案.为了满足组成员增加时不影响用户的性能,提出在M2U中引入了机会路由的M2UO(Multicast to Unicast Opportunistic Routing)算法,对候选节点采用单播形式发送包,对其它节点采用组播形式发送包.在实际网络环境中的大量实验表明,优化组播减小了数据包的丢失率,提高了网络的吞吐量,具有较好的组播视频流效果.
文摘为了使组播路由与组播用户的服务需求相匹配,提升用户的组播使用体验,结合软件定义网络(software defined network,SDN)独有的路由与转发分离特点,设计并实现了基于SDN的服务驱动组播路由方案。该方案通过对Dijkstra算法进行改进,将组播用户的服务需求加入到组播路由的计算过程中,控制器可以根据用户需求实时更新组播路由并下发符合需求的新流表到交换机,实现根据用户需求动态调整组播路由的基于SDN的服务驱动组播路由机制。该机制拥有完整的组播流程,集组播建立、组播接收者加入/离开、组播管理、根据用户需求动态调整组播路由等功能为一体,创新性地根据用户的不同服务需求,随时变更并下发符合用户需求的组播路径。使用Mininet平台等仿真工具对提出的方案进行了功能测试和性能测试,结果表明,基于SDN的服务驱动组播在满足用户服务需求的情况下,不会对原有组播性能造成较大影响。
基金Supported by the National Natural Science Foundation of China(No.61473179)Shandong Province Higher Educational Science and Technology Program(No.J16LN20)+1 种基金Natural Science Foundation of Shandong Province(No.ZR2016FM18)the Youth Scholars Development Program of Shandong University of Technology
文摘Minimizing network coding resources of multicast networks,such as the number of coding nodes or links,has been proved to be NP-hard,and taking propagation delay into account makes the problem more complicated. To resolve this optimal problem,an integer encoding routing-based genetic algorithm( REGA) is presented to map the optimization problem into a genetic algorithm( GA)framework. Moreover,to speed up the search process of the algorithm,an efficient local search procedure which can reduce the searching space size is designed for searching the feasible solution.Compared with the binary link state encoding representation genetic algorithm( BLSGA),the chromosome length of REGA is shorter and just depends on the number of sinks. Simulation results show the advantages of the algorithm in terms of getting the optimal solution and algorithmic convergence speed.
基金This work is supported by the NSFC （National Natural Science Foundation of China） No. 61371068 and No. 61172130, the National 863 program No.2011AA11A102-04-02 and Shenzhen Technology Research and Development Program No. CXZZ20120830100839333.
文摘Mobile Ad hoc Networks(MANETs) play an important role in emergency communications where network needs to be constructed temporarily and quickly.Since the nodes move randomly,routing protocols must be highly effective and reliable to guarantee successful packet delivery.Based on the data delivery structure,most of the existing multicast routing protocols can be classified into two folders:tree-based and mesh-based.We observe that tree-based ones have high forwarding efficiency and low consumptions of bandwidth,and they may have poor robustness because only one link exists between two nodes.As a treebased multicast routing protocol,MAODV(Multicast Ad hoc On-demand Vector) shows an excellent performance in lightweight ad hoc networks.As the load of network increases,QoS(Quality of Service) is degraded obviously.In this paper,we analyze the impact of network load on MAODV protocol,and propose an optimized protocol MAODV-BB(Multicast Ad hoc On-demand Vector with Backup Branches),which improves robustness of the MAODV protocol by combining advantages of the tree structure and the mesh structure.It not only can update shorter tree branches but also construct a multicast tree with backup branches.Mathematical analysis and simulation results both demonstrate that the MAODV-BB protocol improves the network performance over conventional MAODV in heavy load ad hoc networks.
