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Wavelengths Switching and Allocation Algorithms in Multicast Technology using M-Arity Tree Networks Topology

Multicast routing and wavelength assignment is an important problem in optical fiber networks where dedicated connections are required to be established between a source and multiple number of destinations. To establish such a multicast session, some of the nodes in the network should be capable of splitting an incoming message, in the form of light signal, into multiple outgoing signals. These nodes, also known as multicast capable (MC) nodes, are very costly due to the requirement of signal amplification and difficulty in fabrication. In this paper, we study routing and wavelength assignment problem for multicast communication in WDM mesh network to minimize splitting requirement as well as the delay in communication, which is a major QoS parameter in one-to-many data communication. As the objectives show an opposing behavior, a tread-off solution is often required. Here we have proposed a heuristic based algorithm, which gives an efficient trade-off solution for the problem. On comparison under different network topologies, the proposed algorithm is found to be more efficient than the existing algorithms.

Splitting minimization: a novel approach for multicasting in WDM mesh networks

We propose novel tree construction algorithms for multicast communication in photonic networks. Since multicast communications consume many more link resources than unicast communications, effective algorithms for route selection and wavelength assignment are required. We propose a novel tree construction algorithm, called the Weighted Steiner Tree (WST) algorithm and a variation of the WST algorithm, called the Composite Weighted Steiner Tree (CWST) algorithm. Because these algorithms are based on the Steiner Tree algorithm, link resources among source and destination pairs tend to be commonly used and link utilization ratios are improved. Because of this, these algorithms can accept many more multicast requests than other multicast tree construction algorithms based on the Dijkstra algorithm. However, under certain delay constraints, the blocking characteristics of the proposed Weighted Steiner Tree algorithm deteriorate since some light paths between source and destinations use many hops and cannot satisfy the delay constraint. In order to adapt the approach to the delay-sensitive environments, we have devised the Composite Weighted Steiner Tree algorithm comprising the Weighted Steiner Tree algorithm and the Dijkstra algorithm for use in a delay constrained environment such as an IPTV application. In this paper, we also give the results of simulation experiments which demonstrate the superiority of the proposed Composite Weighted Steiner Tree algorithm compared with the Distributed Minimum Hop Tree (DMHT) algorithm, from the viewpoint of the light-tree request blocking.

WDM Multicast Tree Construction Algorithms and Their Comparative Evaluations

In recent years, the rapid growth of network traffic and the emergence of new Internet applications have required optical networks to continuously improve their capacity and flexible transmission capability. Spatial division multiplexed elastic optical networks (SDM-EONs) have become the most promising core architectures for future optical networks with their fine granularity, high capacity, and high transmission rate. In the paper, we study the routing, modulation level, spectrum, and core allocation (MC-RMSCA) problem for multicast services in SDM-EONs, building a network model using all-optical multicast in SDM-EONs, and then propose two heuristic algorithms for the problem to solve MC-RMSCA in dynamic scenarios. Simulation results show that, compared with the shortest-path-tree-based routing, modulation level spectrum, and core allocation (SPT-RMSCA) algorithm, the subtree-assisted routing, modulation level spectrum, and core allocation (STA-RMSCA) algorithm performs better in terms of blocking probability and spectrum utilization.

Dynamic Resource Allocation for All-Optical Multicast in Space Division Multiplexed Elastic Optical Networks

In recent years, the rapid growth of network traffic and the emergence of new Internet applications have required optical networks to continuously improve their capacity and flexible transmission capability. Spatial division multiplexed elastic optical networks (SDM-EONs) have become the most promising core architectures for future optical networks with their fine granularity, high capacity, and high transmission rate. In the paper, we study the routing, modulation level, spectrum, and core allocation (MC-RMSCA) problem for multicast services in SDM-EONs, building a network model using all-optical multicast in SDM-EONs, and then propose two heuristic algorithms for the problem to solve MC-RMSCA in dynamic scenarios. Simulation results show that, compared with the shortest-path-tree-based routing, modulation level spectrum, and core allocation (SPT-RMSCA) algorithm, the subtree-assisted routing, modulation level spectrum, and core allocation (STA-RMSCA) algorithm performs better in terms of blocking probability and spectrum utilization. 

We propose novel tree construction algorithms for multicast communication in photonic networks. Since multicast communications consume many more link resources than unicast communications, effective algorithms for route selection and wavelength allocation are required. We propose novel tree construction algorithms called the weighted Steiner tree (WST) algorithm and the composite weighted Steiner tree (CWST) algorithm. Since the proposed Weighted Steiner Tree algorithm takes account of the number of wavelengths available for each link, this algorithm can select those links which have larger number of available wavelengths. By using this link selection technique, this algorithm can accept many more multicast requests than other multicast tree construction algorithms. However, under certain delay constraints, the blocking characteristics of the proposed weighted Steiner tree algorithm deteriorate since some light paths between source and destination use long hops and cannot satisfy the delay constraint. In order to adapt the approach to the delay-sensitive environments, we have devised the composite weighted Steiner tree algorithm comprising the weighted Steiner tree algorithm and the Dijkstra algorithm for use in a delay constrained environment such as an IPTV application. In this paper, we also give the results of simulation experiments which demonstrate the superiority of the proposed composite weighted Steiner tree algorithm compared with the distributed minimum hop tree (DMHT) algorithm, from the viewpoint of the light-tree request blocking probability.

T. Makabe

Papers

WDM Multicast Tree Construction Algorithms for Minimizing Blocking Probability under a Delay Constraint