4,989 research outputs found
A simulated annealing based genetic local search algorithm for multi-objective multicast routing problems
This paper presents a new hybrid evolutionary algorithm to solve multi-objective multicast routing problems in telecommunication networks. The algorithm combines simulated annealing based strategies and a genetic local search, aiming at a more flexible and effective exploration and exploitation in the search space of the complex problem to find more non-dominated solutions in the Pareto Front. Due to the complex structure of the multicast tree, crossover and mutation operators have been specifically devised concerning the features and constraints in the problem. A new adaptive mutation probability based on simulated annealing is proposed in the hybrid algorithm to adaptively adjust the mutation rate according to the fitness of the new solution against the average quality of the current population during the evolution procedure. Two simulated annealing based search direction tuning strategies are applied to improve the efficiency and effectiveness of the hybrid evolutionary algorithm. Simulations have been carried out on some benchmark multi-objective multicast routing instances and a large amount of random networks with five real world objectives including cost, delay, link utilisations, average delay and delay variation in telecommunication networks. Experimental results demonstrate that both the simulated annealing based strategies and the genetic local search within the proposed multi-objective algorithm, compared with other multi-objective evolutionary algorithms, can efficiently identify high quality non-dominated solution set for multi-objective multicast routing problems and outperform other conventional multi-objective evolutionary algorithms in the literature
On application of least-delay variation problem in ethernet networks using SDN concept
The goal of this paper is to present an application idea of SDN in Smart Grids, particularly, in the area of L2 multicast as defined by IEC 61850-9-2. Authors propose an Integer Linear Formulation (ILP) dealing with a Least-Delay-Variation multicast forwarding problem that has a potential to utilize Ethernet networks in a new way. The proposed ILP formulation is numerically evaluated on random graph topologies and results are compared to a shortest path tree approach that is traditionally a product of Spanning Tree Protocols. Results confirm the correctness of the ILP formulation and illustrate dependency of a solution quality on the selected graph models, especially, in a case of scale-free topologies
TINA as a virtual market place for telecommunication and information services: the VITAL experiment
The VITAL (Validation of Integrated Telecommunication Architectures for the Long-Term) project has defined, implemented and demonstrated an open distributed telecommunication architecture (ODTA) for deploying, managing and using a set of heterogeneous multimedia, multi-party, and mobility services. The architecture was based on the latest specifications released by TINA-C. The architecture was challenged in a set of trials by means of a heterogeneous set of applications. Some of the applications were developed within the project from scratch, while some others focused on integrating commercially available applications. The applications were selected in such a way as to assure full coverage of the architecture implementation and reflect a realistic use of it. The VITAL experience of refining and implementing TINA specifications and challenging the resulting platform by a heterogeneous set of services has proven the openness, flexibility and reusability of TINA. This paper describes the VITAL approach when choosing the different services and how they challenge and interact with the architecture, focusing especially on the service architecture and the Ret reference point definitions. The VITAL adjustments and enhancements to the TINA architecture are described. This paper contributes to proving that the TINA-based VITAL ODTA allows for easy and cost-effective development and deployment of advanced end-user and operator services, and can indeed act as the basis for a virtual market place for telecommunications service
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