The Experts below are selected from a list of 8295 Experts worldwide ranked by ideXlab platform
Xiaohua Jia - One of the best experts on this subject based on the ideXlab platform.
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A distributed routing and Wavelength Assignment algorithm for real-time multicast in WDM networks
Computer Communications, 2002Co-Authors: Chuanhe Huang, Xiaohua Jia, Yongbing ZhangAbstract:Routing and Wavelength Assignment for online real-time multicast connection setup is a difficult task due to the dynamic change of availabilities of Wavelengths and the consideration of Wavelength conversion delay in Wavelength division multiplexing (WDM) networks. This paper presents a distributed routing and Wavelength Assignment scheme for the setup of real-time multicast connections. It integrates routing and Wavelength Assignment as a single process, which greatly reduces the connection setup time. The proposed routing method is based on the Prim's minimum spanning tree (MST) algorithm and the K-restricted breadth-first search method, which can produce a sub-minimal cost tree under a given delay bound. The Wavelength Assignment uses the least-conversion and load balancing strategies.
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Optimization of Wavelength Assignment for QoS multicast in WDM networks
IEEE Transactions on Communications, 2001Co-Authors: Xiaohua Jia, Man-kei LeeAbstract:This paper discusses quality-of-service (QoS) multicast in Wavelength-division multiplexing (WDM) networks. Given a set of QoS multicast requests, we are to find a set of cost suboptimal QoS routing trees and assign Wavelengths to them. The objective is to minimize the number of Wavelengths in the system. This is a challenging issue. It involves not only optimal QoS multicast routing, but also optimal Wavelength Assignment. Existing methods consider channel setup in WDM networks in two separate steps: routing and Wavelength Assignment, which has limited power in minimizing the number of Wavelengths. In this paper, we propose a new optimization method, which integrates routing and Wavelength Assignment in optimization of Wavelengths. Two optimization algorithms are also proposed in minimizing the number of Wavelengths. One algorithm minimizes the number of Wavelengths through reducing the maximal link load in the system; while the other does it by trying to free out the least used Wavelengths. Simulation results demonstrate that the proposed algorithms can produce suboptimal QoS routing trees and substantially save the number of Wavelengths.
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A distributed routing and Wavelength Assignment algorithm for real-time multicast in WDM networks
2001 International Conferences on Info-Tech and Info-Net. Proceedings (Cat. No.01EX479), 1Co-Authors: Chuanhe Huang, Xinmeng Chen, Xiaohua JiaAbstract:Routing and Wavelength Assignment for online real-time multicast connection setup is difficult due to the dynamic change of availabilities of Wavelengths on links and the consideration of Wavelength conversion delay in WDM networks. This paper presents a distributed routing and Wavelength Assignment algorithm for the setup of real-time multicast connections. It integrates routing and Wavelength Assignment as a single process, which greatly reduces the connection setup fine. The multicast routing algorithm is based on Prim's MST (minimum spanning tree) algorithm and K-restricted breadth-first search method, which can produce a subminimal cost tree under a given delay bound. The Wavelength Assignment uses least-conversion and load balancing strategies.
Jianping Wang - One of the best experts on this subject based on the ideXlab platform.
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A multicast dynamic Wavelength Assignment algorithm based on matching degree
Optoelectronics Letters, 2009Co-Authors: Xianwei Zhou, Jianping Wang, Zhizhong Yin, Long ZhangAbstract:The Wavelength Assignment with multiple multicast requests in fixed routing WDM network is studied. A new multicast dynamic Wavelength Assignment algorithm is presented based on matching degree. First, the Wavelength matching degree between available Wavelengths and multicast routing trees is introduced into the algorithm. Then, the Wavelength Assignment is translated into the maximum weight matching in bipartite graph, and this matching problem is solved by using an extended Kuhn-Munkres algorithm. The simulation results prove that the overall optimal Wavelength Assignment scheme is obtained in polynomial time. At the same time, the proposed algorithm can reduce the connecting blocking probability and improve the system resource utilization.
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A Novel Wavelength Assignment Algorithm for Distributed Optical Networks
2009 Symposium on Photonics and Optoelectronics, 2009Co-Authors: Jianping Wang, Shijun QiaoAbstract:In this paper, the Wavelength Assignment problem in distributed optical networks is studied. We propose an improved dynamic and priority-based Wavelength Assignment algorithm- DPWA (Dynamic and priority-based Wavelength Assignment algorithm). This proposed DPWA algorithm can effectively reduce the average blocking probability and improve the Wavelength utilization ratio by adding two dynamic factors related to the present Wavelength utilization state. This improved algorithm can also satisfy different Wavelength resources Assignment aware of different service-level connection requests, which is more necessary and important in practical networks.
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A New Multicast Wavelength Assignment Algorithm in Wavelength-Converted Optical Networks
International Journal of Communications Network and System Sciences, 2009Co-Authors: Anping Wang, Xianwei Zhou, Jianping WangAbstract:In this paper, we propose a new multicast Wavelength Assignment algorithm called NGWA with complexity of O(N), where N is the number of nodes on a multicast tree. The whole procedure of NGWA algorithm is separated into two phases: the partial Wavelength Assignment phase and the complete Wavelength Assignment phase. It tries to minimize the total number of Wavelength conversions of the multicast tree. Meanwhile, the number of different Wavelengths used is minimized locally. Through illustrative example and simulation experiments, it is proved that the NGWA algorithm works well and achieves satisfactory performance in terms of the average number of Wavelength conversions and the average blocking probability
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dynamic Wavelength Assignment for multicast in all optical wdm networks to maximize the network capacity
IEEE Journal on Selected Areas in Communications, 2003Co-Authors: Jianping Wang, Biao Chen, R N UmaAbstract:We study the problem of Wavelength Assignment for multicast in order to maximize the network capacity in all-optical Wavelength-division multiplexing networks. The motivation behind this work is to minimize the call blocking probability by maximizing the remaining network capacity after each Wavelength Assignment. While all previous studies on the same objective concentrate only on the unicast case, we study the problem for the multicast case. For a general multicast tree, we prove that the multicast Wavelength Assignment problem of maximizing the network capacity is NP-hard and propose two efficient greedy algorithms. We also study the same problem for a special network topology, a bidirectional ring network, which is practically the most important topology for optical networks. For bidirectional ring networks, a special multicast tree with at most two leaf nodes is constructed. Polynomial time algorithms for multicast Wavelength Assignment to maximize the network capacity exist under such a special multicast tree with regard to different splitting capabilities. Our work is the first effort to study the multicast Wavelength Assignment problem under the objective of maximizing network capacity.
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Efficient routing and Wavelength Assignment for multicast in WDM networks
IEEE Journal on Selected Areas in Communications, 2002Co-Authors: Biao Chen, Jianping WangAbstract:The next generation multimedia applications such as video conferencing and HDTV have raised tremendous challenges on the network design, both in bandwidth and service. As Wavelength-division-multiplexing (WDM) networks have emerged as a promising candidate for future networks with large bandwidth, supporting efficient multicast in WDM networks becomes eminent. Different from the IP layer, the cost of multicast at the WDM layer involves not only bandwidth (Wavelength) cost, but also Wavelength conversion cost and light splitting cost. It is well known that the optimal multicast problem in WDM networks is NP-hard. In this paper, we develop an efficient approximation algorithm consisting of two separate but integrated steps: multicast routing and Wavelength Assignment. We prove that the problem of optimal Wavelength Assignment on a multicast tree is not NP-hard; in fact, an optimal Wavelength Assignment algorithm with complexity of O(NW) is presented. Simulation results have revealed that the optimal Wavelength Assignment beats greedy algorithms by a large margin in networks using many Wavelengths on each link such as dense Wavelength-division-multiplexing (DWDM) networks. Our proposed heuristic multicast routing algorithm takes into account both the cost of using Wavelength on links and the cost of Wavelength conversion. The resulting multicast tree is derived from the optimal lightpaths used for unicast.
Sartaj Sahni - One of the best experts on this subject based on the ideXlab platform.
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ISCC - Performance evaluation of routing and Wavelength Assignment algorithms for optical networks
2008 IEEE Symposium on Computers and Communications, 2008Co-Authors: Eun-sung Jung, Sanjay Ranka, Sartaj SahniAbstract:Several routing and Wavelength Assignment algorithms have been developed to reserve dedicated connections for high-performance applications on optical networks. In this paper, we present an analytical and experimental evaluation of these algorithms. Our experiments indicate that the minimum-hop feasible path algorithm maximizes network utilization. We also present novel algorithms for deferred Wavelength Assignment that can be used for reducing the space and time requirements of many Wavelength Assignment algorithms.
Yinzhu Zhou - One of the best experts on this subject based on the ideXlab platform.
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A, new multicast Wavelength Assignment algorithm in Wavelength-routed WDM networks
IEEE Journal on Selected Areas in Communications, 2006Co-Authors: Gee-swee Poo, Yinzhu ZhouAbstract:This paper addresses the multicast Wavelength Assignment (MC-WA) problem in Wavelength-routed WDM networks with full light splitting and Wavelength conversion capabilities. Current approaches are based on the multicast switch model that supports only split-convert (S-C) switch scheme. This scheme leads to redundant Wavelength conversions for a given multicast request. In this paper, we propose a new split-convert-split (S-C-S) switch scheme capable of eliminating the redundant Wavelength conversions. In order to implement this new switch scheme, we develop a new multicast switch model based on the concept of sharing of light splitters and Wavelength converters. Furthermore, existing multicast Wavelength Assignment algorithm allows only one Wavelength to carry the light signal on a fiber link, the so-called single-Wavelength Assignment strategy. In this paper, we explore the advantages of a new multi-Wavelength Assignment strategy which allows multiple available Wavelengths in a link to carry the multicast signal. This will reduce the number of Wavelength conversions required for the multicast request. Consequently, based on the new S-C-S multicast switch model and the new multi-Wavelength Assignment strategy, we generalize the existing algorithms to produce a new Multicast 'Wavelength Assignment Algorithm (MWAA) to support both the new switch model and the new Wavelength Assignment strategy. Compared with the existing algorithm, our new algorithm is a more general one which makes the multicast Wavelength Assignment more flexible, covering different switch schemes and different Assignment strategies. In addition, it delivers good performance in term of minimizing the number of Wavelength conversions. The improvement percentage is sensitive to the maximum out-degree value of a node, D. For a 100-node multicast tree, the improvement percentage increases from 38% at D = 3 to about 73% at D = 16. This is highly significant
Biao Chen - One of the best experts on this subject based on the ideXlab platform.
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dynamic Wavelength Assignment for multicast in all optical wdm networks to maximize the network capacity
IEEE Journal on Selected Areas in Communications, 2003Co-Authors: Jianping Wang, Biao Chen, R N UmaAbstract:We study the problem of Wavelength Assignment for multicast in order to maximize the network capacity in all-optical Wavelength-division multiplexing networks. The motivation behind this work is to minimize the call blocking probability by maximizing the remaining network capacity after each Wavelength Assignment. While all previous studies on the same objective concentrate only on the unicast case, we study the problem for the multicast case. For a general multicast tree, we prove that the multicast Wavelength Assignment problem of maximizing the network capacity is NP-hard and propose two efficient greedy algorithms. We also study the same problem for a special network topology, a bidirectional ring network, which is practically the most important topology for optical networks. For bidirectional ring networks, a special multicast tree with at most two leaf nodes is constructed. Polynomial time algorithms for multicast Wavelength Assignment to maximize the network capacity exist under such a special multicast tree with regard to different splitting capabilities. Our work is the first effort to study the multicast Wavelength Assignment problem under the objective of maximizing network capacity.
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Efficient routing and Wavelength Assignment for multicast in WDM networks
IEEE Journal on Selected Areas in Communications, 2002Co-Authors: Biao Chen, Jianping WangAbstract:The next generation multimedia applications such as video conferencing and HDTV have raised tremendous challenges on the network design, both in bandwidth and service. As Wavelength-division-multiplexing (WDM) networks have emerged as a promising candidate for future networks with large bandwidth, supporting efficient multicast in WDM networks becomes eminent. Different from the IP layer, the cost of multicast at the WDM layer involves not only bandwidth (Wavelength) cost, but also Wavelength conversion cost and light splitting cost. It is well known that the optimal multicast problem in WDM networks is NP-hard. In this paper, we develop an efficient approximation algorithm consisting of two separate but integrated steps: multicast routing and Wavelength Assignment. We prove that the problem of optimal Wavelength Assignment on a multicast tree is not NP-hard; in fact, an optimal Wavelength Assignment algorithm with complexity of O(NW) is presented. Simulation results have revealed that the optimal Wavelength Assignment beats greedy algorithms by a large margin in networks using many Wavelengths on each link such as dense Wavelength-division-multiplexing (DWDM) networks. Our proposed heuristic multicast routing algorithm takes into account both the cost of using Wavelength on links and the cost of Wavelength conversion. The resulting multicast tree is derived from the optimal lightpaths used for unicast.
