In this paper, a novel method is proposed to address the problem of designing virtual topology over wavelength division multiplexing （WDM） networks under bandwidth demand uncertainties. And a bandwidth demand model ...In this paper, a novel method is proposed to address the problem of designing virtual topology over wavelength division multiplexing （WDM） networks under bandwidth demand uncertainties. And a bandwidth demand model under uncertainties is presented. The optimization goal of virtual topology design is defined as minimizing the maximum value amongp percentiles of the bandwidth demand distribution on all Hght-paths. Correspondingly, we propose a heuristic algorithm called an improved decreasing multi-hop logical topology design algorithm （ID-MLTDA） that involves with a degree of uncertainties to design virtual topology. The proposed algorithm yields better performance than previous algorithms. Additionally, the simplicity and efficiency of the proposed algorithm can be in favor of the feasibility for topology design of large networks.展开更多
In wireless sensor networks, topology control plays an important role for data forwarding efficiency in the data gathering applications. In this paper, we present a novel topology control and data forwarding mechanism...In wireless sensor networks, topology control plays an important role for data forwarding efficiency in the data gathering applications. In this paper, we present a novel topology control and data forwarding mechanism called REMUDA, which is designed for a practical indoor parking lot management system. REMUDA forms a tree-based hierarchical network topology which brings as many nodes as possible to be leaf nodes and constructs a virtual cluster structure. Meanwhile, it takes the reliability, stability and path length into account in the tree construction process. Through an experiment in a network of 30 real sensor nodes, we evaluate the performance of REMUDA and compare it with LEPS which is also a practical routing protocol in TinyOS. Experiment results show that REMUDA can achieve better performance than LEPS.展开更多
Network virtualization(NV)is a highprofile way to solve the ossification problem of the nowadays Internet,and be able to support the diversified network naturally.In NV,Virtual Network Embedding(VNE)problem has been w...Network virtualization(NV)is a highprofile way to solve the ossification problem of the nowadays Internet,and be able to support the diversified network naturally.In NV,Virtual Network Embedding(VNE)problem has been widely considered as a crucial issue,which is aimed to embed Virtual Networks(VNs)onto the shared substrate networks(SNs)efficiently.Recently,some VNE approaches have developed Node Ranking strategies to drive and enhance the embedding efficiency.Node Ranking Strategy rank/sort the nodes according to the attributes of the node,including both residual local attributes(CPU,Bandwidth,storage,Etc.)and the global topology attributes(Number of neighborhood Nodes,Delay to other nodes,Etc.).This paper presents an overview of Node Ranking Strategies in Virtual Network Embedding,and possible directions of VNE Node Ranking Strategy.展开更多
当前拓扑识别技术难以反映潮流特性对拓扑识别的影响,基于配电网现有量测数据,通过分析节点间的电气距离,提出了虚拟阻抗的概念。将节点间具备电气意义的且与电气距离成正相关的连续变量定义为虚拟阻抗,并提出了一种基于虚拟阻抗的低压...当前拓扑识别技术难以反映潮流特性对拓扑识别的影响,基于配电网现有量测数据,通过分析节点间的电气距离,提出了虚拟阻抗的概念。将节点间具备电气意义的且与电气距离成正相关的连续变量定义为虚拟阻抗,并提出了一种基于虚拟阻抗的低压配电网拓扑识别方法。首先,构建以节点间虚拟阻抗为因变量的多元线性回归方程。然后,通过岭回归计算每一个单相电表与关口电表构成的回归方程的虚拟阻抗,根据计算结果快速判别出拓扑关系异常的电气设备。最后,建立基于导数动态时间弯曲(derivative dynamic time warping,DDTW)距离的校验模型,重新构建得到电气设备的正确拓扑关系,实现低压配电网拓扑关系的修正。以实际的低压配电网台区样本数据为依据,验证了所提方法的有效性。展开更多
Network virtualization is recognized as an effective way to overcome the ossification of the Internet. However, the virtual network mapping problem (VNMP) is a critical challenge, focusing on how to map the virtual ne...Network virtualization is recognized as an effective way to overcome the ossification of the Internet. However, the virtual network mapping problem (VNMP) is a critical challenge, focusing on how to map the virtual networks to the substrate network with efficient utilization of infrastructure resources. The problem can be divided into two phases: node mapping phase and link mapping phase. In the node mapping phase, the existing algorithms usually map those virtual nodes with a complete greedy strategy, without considering the topology among these virtual nodes, resulting in too long substrate paths (with multiple hops). Addressing this problem, we propose a topology awareness mapping algorithm, which considers the topology among these virtual nodes. In the link mapping phase, the new algorithm adopts the k-shortest path algorithm. Simulation results show that the new algorithm greatly increases the long-term average revenue, the acceptance ratio, and the long-term revenue-to-cost ratio (R/C).展开更多
基金Supported by the National Natural Science Foundation of China (No.90604002)Program for New Century Excellent Talents in University (No. 05-0807).
文摘In this paper, a novel method is proposed to address the problem of designing virtual topology over wavelength division multiplexing （WDM） networks under bandwidth demand uncertainties. And a bandwidth demand model under uncertainties is presented. The optimization goal of virtual topology design is defined as minimizing the maximum value amongp percentiles of the bandwidth demand distribution on all Hght-paths. Correspondingly, we propose a heuristic algorithm called an improved decreasing multi-hop logical topology design algorithm （ID-MLTDA） that involves with a degree of uncertainties to design virtual topology. The proposed algorithm yields better performance than previous algorithms. Additionally, the simplicity and efficiency of the proposed algorithm can be in favor of the feasibility for topology design of large networks.
基金Supported by National Natural Science Foundation of P. R. China (60673178) National Basic Research Program of P.R. China (2006 CB 303000)
文摘In wireless sensor networks, topology control plays an important role for data forwarding efficiency in the data gathering applications. In this paper, we present a novel topology control and data forwarding mechanism called REMUDA, which is designed for a practical indoor parking lot management system. REMUDA forms a tree-based hierarchical network topology which brings as many nodes as possible to be leaf nodes and constructs a virtual cluster structure. Meanwhile, it takes the reliability, stability and path length into account in the tree construction process. Through an experiment in a network of 30 real sensor nodes, we evaluate the performance of REMUDA and compare it with LEPS which is also a practical routing protocol in TinyOS. Experiment results show that REMUDA can achieve better performance than LEPS.
基金The authors would like to thank the reviewers for their detailed reviews and constructive comments,which have helped improve the quality of this paper.This work was supported by National Science Foundation of China under Grants 6187144。
文摘Network virtualization(NV)is a highprofile way to solve the ossification problem of the nowadays Internet,and be able to support the diversified network naturally.In NV,Virtual Network Embedding(VNE)problem has been widely considered as a crucial issue,which is aimed to embed Virtual Networks(VNs)onto the shared substrate networks(SNs)efficiently.Recently,some VNE approaches have developed Node Ranking strategies to drive and enhance the embedding efficiency.Node Ranking Strategy rank/sort the nodes according to the attributes of the node,including both residual local attributes(CPU,Bandwidth,storage,Etc.)and the global topology attributes(Number of neighborhood Nodes,Delay to other nodes,Etc.).This paper presents an overview of Node Ranking Strategies in Virtual Network Embedding,and possible directions of VNE Node Ranking Strategy.
文摘当前拓扑识别技术难以反映潮流特性对拓扑识别的影响,基于配电网现有量测数据,通过分析节点间的电气距离,提出了虚拟阻抗的概念。将节点间具备电气意义的且与电气距离成正相关的连续变量定义为虚拟阻抗,并提出了一种基于虚拟阻抗的低压配电网拓扑识别方法。首先,构建以节点间虚拟阻抗为因变量的多元线性回归方程。然后,通过岭回归计算每一个单相电表与关口电表构成的回归方程的虚拟阻抗,根据计算结果快速判别出拓扑关系异常的电气设备。最后,建立基于导数动态时间弯曲(derivative dynamic time warping,DDTW)距离的校验模型,重新构建得到电气设备的正确拓扑关系,实现低压配电网拓扑关系的修正。以实际的低压配电网台区样本数据为依据,验证了所提方法的有效性。
基金supported by the National Basic Research Program (973) of China (No. 2011CB302601)the National Natural Science Foundation of China (No. 90818028)the National High-Tech R&D Program (863) of China (No. 2007AA010301)
文摘Network virtualization is recognized as an effective way to overcome the ossification of the Internet. However, the virtual network mapping problem (VNMP) is a critical challenge, focusing on how to map the virtual networks to the substrate network with efficient utilization of infrastructure resources. The problem can be divided into two phases: node mapping phase and link mapping phase. In the node mapping phase, the existing algorithms usually map those virtual nodes with a complete greedy strategy, without considering the topology among these virtual nodes, resulting in too long substrate paths (with multiple hops). Addressing this problem, we propose a topology awareness mapping algorithm, which considers the topology among these virtual nodes. In the link mapping phase, the new algorithm adopts the k-shortest path algorithm. Simulation results show that the new algorithm greatly increases the long-term average revenue, the acceptance ratio, and the long-term revenue-to-cost ratio (R/C).
