保证服务质量的QoS(Quality of Service)路由是网络中解决QoS问题的一项关键技术.具有QoS约束的多播路由技术已成为网络领域的一个重要研究课题.该文研讨了具有QoS约束的动态多播路由问题.文中描述了一种适应于QoS多播路由的网络模型,...保证服务质量的QoS(Quality of Service)路由是网络中解决QoS问题的一项关键技术.具有QoS约束的多播路由技术已成为网络领域的一个重要研究课题.该文研讨了具有QoS约束的动态多播路由问题.文中描述了一种适应于QoS多播路由的网络模型,提出了一种QoS动态多播路由协议(QDMRP).QDMRP只要求网络链路(或节点)的局部状态信息,不需要维护全局状态信息.QDMRP较好地减少构造一棵多播树的开销.仿真实验结果表明:QDMRP具有较低的控制信息开销和节点加入时延,较好地适合于网络状态变化比较频繁的环境以及实时多媒体应用.展开更多
To solve the load balancing problem in a triplet-based hierarchical interconnection network（THIN） system, a dynamic load balancing （DLB）algorithm--THINDLBA, which adopts multicast tree （MT）technology to improve ...To solve the load balancing problem in a triplet-based hierarchical interconnection network（THIN） system, a dynamic load balancing （DLB）algorithm--THINDLBA, which adopts multicast tree （MT）technology to improve the efficiency of interchanging load information, is presented. To support the algorithm, a complete set of DLB messages and a schema of maintaining DLB information in each processing node are designed. The load migration request messages from the heavily loaded node （HLN）are spread along an MT whose root is the HLN. And the lightly loaded nodes（LLNs） covered by the MT are the candidate destinations of load migration; the load information interchanged between the LLNs and the HLN can be transmitted along the MT. So the HLN can migrate excess loads out as many as possible during a one time execution of the THINDLBA, and its load state can be improved as quickly as possible. To avoid wrongly transmitted or redundant DLB messages due to MT overlapping, the MT construction is restricted in the design of the THINDLBA. Through experiments, the effectiveness of four DLB algorithms are compared, and the results show that the THINDLBA can effectively decrease the time costs of THIN systems in dealing with large scale computeintensive tasks more than others.展开更多
A Minimizing Intermediate Multicast Routing protocol (MIMR) is proposed for dynamic multi-hop ad hoc networks. In MIMR,multicast sessions are created and released only by source nodes. In each multicast session proces...A Minimizing Intermediate Multicast Routing protocol (MIMR) is proposed for dynamic multi-hop ad hoc networks. In MIMR,multicast sessions are created and released only by source nodes. In each multicast session process,the source node keeps a list of intermediate nodes and destinations,which is encapsulated into the packet header when the source node sends a multicast packet. Nodes receiving multicast packets decide to accept or forward the packet according to the list. Depending on topology matrix maintained by unicast routing,the shortest virtual hierarchy routing tree is con-structed by improved Dijkstra algorithm. MIMR can achieve the minimum number of intermediate nodes,which are computed through the tree. No control packet is transmitted in the process of mul-ticast session. Load of the network is largely decreased. Experimental result shows that MIMR is flexible and robust for dynamic ad hoc networks.展开更多
The delay and DVBMT problem is known to be NP-complete. In this paper,an efficient distributed dynamic multicast routing algorithm was proposed to produce routing trees with delay and delay variation constraints. The ...The delay and DVBMT problem is known to be NP-complete. In this paper,an efficient distributed dynamic multicast routing algorithm was proposed to produce routing trees with delay and delay variation constraints. The proposed algorithm is fully distributed,and supports the dynamic reorganizing of the multicast tree in response to changes for the destination. Simulations demonstrate that our algorithm is better in terms of tree delay and routing success ratio as compared with other existing algorithms,and performs excellently in delay variation performance under lower time complexity,which ensures it to support the requirements of real-time multimedia communications more effectively.展开更多
文摘保证服务质量的QoS(Quality of Service)路由是网络中解决QoS问题的一项关键技术.具有QoS约束的多播路由技术已成为网络领域的一个重要研究课题.该文研讨了具有QoS约束的动态多播路由问题.文中描述了一种适应于QoS多播路由的网络模型,提出了一种QoS动态多播路由协议(QDMRP).QDMRP只要求网络链路(或节点)的局部状态信息,不需要维护全局状态信息.QDMRP较好地减少构造一棵多播树的开销.仿真实验结果表明:QDMRP具有较低的控制信息开销和节点加入时延,较好地适合于网络状态变化比较频繁的环境以及实时多媒体应用.
基金The National Natural Science Foundation of China(No.69973007).
文摘To solve the load balancing problem in a triplet-based hierarchical interconnection network（THIN） system, a dynamic load balancing （DLB）algorithm--THINDLBA, which adopts multicast tree （MT）technology to improve the efficiency of interchanging load information, is presented. To support the algorithm, a complete set of DLB messages and a schema of maintaining DLB information in each processing node are designed. The load migration request messages from the heavily loaded node （HLN）are spread along an MT whose root is the HLN. And the lightly loaded nodes（LLNs） covered by the MT are the candidate destinations of load migration; the load information interchanged between the LLNs and the HLN can be transmitted along the MT. So the HLN can migrate excess loads out as many as possible during a one time execution of the THINDLBA, and its load state can be improved as quickly as possible. To avoid wrongly transmitted or redundant DLB messages due to MT overlapping, the MT construction is restricted in the design of the THINDLBA. Through experiments, the effectiveness of four DLB algorithms are compared, and the results show that the THINDLBA can effectively decrease the time costs of THIN systems in dealing with large scale computeintensive tasks more than others.
文摘A Minimizing Intermediate Multicast Routing protocol (MIMR) is proposed for dynamic multi-hop ad hoc networks. In MIMR,multicast sessions are created and released only by source nodes. In each multicast session process,the source node keeps a list of intermediate nodes and destinations,which is encapsulated into the packet header when the source node sends a multicast packet. Nodes receiving multicast packets decide to accept or forward the packet according to the list. Depending on topology matrix maintained by unicast routing,the shortest virtual hierarchy routing tree is con-structed by improved Dijkstra algorithm. MIMR can achieve the minimum number of intermediate nodes,which are computed through the tree. No control packet is transmitted in the process of mul-ticast session. Load of the network is largely decreased. Experimental result shows that MIMR is flexible and robust for dynamic ad hoc networks.
文摘The delay and DVBMT problem is known to be NP-complete. In this paper,an efficient distributed dynamic multicast routing algorithm was proposed to produce routing trees with delay and delay variation constraints. The proposed algorithm is fully distributed,and supports the dynamic reorganizing of the multicast tree in response to changes for the destination. Simulations demonstrate that our algorithm is better in terms of tree delay and routing success ratio as compared with other existing algorithms,and performs excellently in delay variation performance under lower time complexity,which ensures it to support the requirements of real-time multimedia communications more effectively.
