QoS multicast tree construction in IP/DWDM optical internet by bio-inspired algorithms

Copyright @ Elsevier Ltd. All rights reserved.In this paper, two bio-inspired Quality of Service (QoS) multicast algorithms are proposed in IP over dense wavelength division multiplexing (DWDM) optical Internet. Given a QoS multicast request and the delay interval required by the application, both algorithms are able to find a flexible QoS-based cost suboptimal routing tree. They first construct the multicast trees based on ant colony optimization and artificial immune algorithm, respectively. Then a dedicated wavelength assignment algorithm is proposed to assign wavelengths to the trees aiming to minimize the delay of the wavelength conversion. In both algorithms, multicast routing and wavelength assignment are integrated into a single process. Therefore, they can find the multicast trees on which the least wavelength conversion delay is achieved. Load balance is also considered in both algorithms. Simulation results show that these two bio-inspired algorithms can construct high performance QoS routing trees for multicast applications in IP/DWDM optical Internet.This work was supported in part ny the Program for New Century Excellent Talents in University, the Engineering and Physical Sciences Research Council (EPSRC) of UK under Grant EP/E060722/1, the National Natural Science Foundation of China under Grant no. 60673159 and 70671020, the National High-Tech Reasearch and Development Plan of China under Grant no. 2007AA041201, and the Specialized Research Fund for the Doctoral Program of Higher Education under Grant no. 20070145017

A multipopulation parallel genetic simulated annealing based QoS routing and wavelength assignment integration algorithm for multicast in optical networks

Copyright @ 2008 Elsevier B.V. All rights reserved.In this paper, we propose an integrated Quality of Service (QoS) routing algorithm for optical networks. Given a QoS multicast request and the delay interval specified by users, the proposed algorithm can find a flexible-QoS-based cost suboptimal routing tree. The algorithm first constructs the multicast tree based on the multipopulation parallel genetic simulated annealing algorithm, and then assigns wavelengths to the tree based on the wavelength graph. In the algorithm, routing and wavelength assignment are integrated into a single process. For routing, the objective is to find a cost suboptimal multicast tree. For wavelength assignment, the objective is to minimize the delay of the multicast tree, which is achieved by minimizing the number of wavelength conversion. Thus both the cost of multicast tree and the user QoS satisfaction degree can approach the optimal. Our algorithm also considers load balance. Simulation results show that the proposed algorithm is feasible and effective. We also discuss the practical realization mechanisms of the algorithm.This work was supported in part by the Engineering and Physical Sciences Research Council (EPSRC) of UK under Grant EP/E060722/1, the National Natural Science Foundation of China under Grant nos. 60673159 and 70671020, the National High-Tech Research and Development Plan of China under Grant no. 2006AA01Z214, Program for New Century Excellent Talents in University, and the Key Project of Chinese Ministry of Education under Grant no. 108040

Sub-graph based Multicast Protection in WDM Networks: A Multi/Many-Objective Evolutionary Algorithms approaches

In this paper is addressed the multicast routing-and-protection, and wavelength assignment (MRPWA) problem which is critical for the success of applications point-multipoint in WDM networks. Basically, it is proposed the design of the primary and protection multicast routes, where the resources protection are based on sub-graph protection strategy subject to the quality requirements of the QoP protection: dedicated (1 + 1), shared (M: N) and better effort (without protection). In this way, NSGA-II and NSGA-III, evolutionary algorithms, are applied to MRPWA considering multi- and many-objectives optimization context, respectively. The evolutionary algorithms optimize simultaneously: (i) the total number of links used, (ii) the number of wavelength converters, (iii) the number of splitter nodes, and (iv) the number of destinations served-and-protected. Considering Hyper-volume measure, the experimental tests on a set of instances indicate that the protection approach based on sub-graph proves to be promising in comparison to the dualtree protection strategy. On the other hand, the evolutionary technique oriented to many-objectives (NSGA-III) is more convenient than the oriented towards multi-objectives (NSGA-II) in the study problem.XIII Workshop Arquitectura, Redes (WARSO)Red de Universidades con Carreras en Informática (RedUNCI

Sub-graph based Multicast Protection in WDM Networks: A Multi/Many-Objective Evolutionary Algorithms approaches

In this paper is addressed the multicast routing-and-protection, and wavelength assignment (MRPWA) problem which is critical for the success of applications point-multipoint in WDM networks. Basically, it is proposed the design of the primary and protection multicast routes, where the resources protection are based on sub-graph protection strategy subject to the quality requirements of the QoP protection: dedicated (1 + 1), shared (M: N) and better effort (without protection). In this way, NSGA-II and NSGA-III, evolutionary algorithms, are applied to MRPWA considering multi- and many-objectives optimization context, respectively. The evolutionary algorithms optimize simultaneously: (i) the total number of links used, (ii) the number of wavelength converters, (iii) the number of splitter nodes, and (iv) the number of destinations served-and-protected. Considering Hyper-volume measure, the experimental tests on a set of instances indicate that the protection approach based on sub-graph proves to be promising in comparison to the dualtree protection strategy. On the other hand, the evolutionary technique oriented to many-objectives (NSGA-III) is more convenient than the oriented towards multi-objectives (NSGA-II) in the study problem.XIII Workshop Arquitectura, Redes (WARSO)Red de Universidades con Carreras en Informática (RedUNCI

A new proposal of an efficient algorithm for routing and wavelength assignment in optical networks.

The routing and wavelength assignment (RWA) algorithms used in optical networks are critical to achieve good network performance. However, despite several previous studies to optimize the RWA, which is classified as an NP-Hard, it seems that there is not, a priori, any solution that would lead to standardization of this process. This article presents the proposed RWA algorithm based on a Generic Objective Function (GOF) which aims to establish a base from which it is possible to develop a standard or multiple standards for optical networks. The GOF algorithm introduces the concept of implicit constraint, which guarantees a simple solution to a problem not as trivial as the RWA

Cellular Underwater Wireless Optical CDMA Network: Potentials and Challenges

Underwater wireless optical communications is an emerging solution to the expanding demand for broadband links in oceans and seas. In this paper, a cellular underwater wireless optical code division multiple-access (UW-OCDMA) network is proposed to provide broadband links for commercial and military applications. The optical orthogonal codes (OOC) are employed as signature codes of underwater mobile users. Fundamental key aspects of the network such as its backhaul architecture, its potential applications and its design challenges are presented. In particular, the proposed network is used as infrastructure of centralized, decentralized and relay-assisted underwater sensor networks for high-speed real-time monitoring. Furthermore, a promising underwater localization and positioning scheme based on this cellular network is presented. Finally, probable design challenges such as cell edge coverage, blockage avoidance, power control and increasing the network capacity are addressed.Comment: 11 pages, 10 figure

Wavelength reconfigurability for next generation optical access networks

Next generation optical access networks should not only increase the capacity but also be able to redistribute the capacity on the fly in order to manage larger variations in traffic patterns. Wavelength reconfigurability is the instrument to enable such capability of network-wide bandwidth redistribution since it allows dynamic sharing of both wavelengths and timeslots in WDM-TDM optical access networks. However, reconfigurability typically requires tunable lasers and tunable filters at the user side, resulting in cost-prohibitive optical network units (ONU). In this dissertation, I propose a novel concept named cyclic-linked flexibility to address the cost-prohibitive problem. By using the cyclic-linked flexibility, the ONU needs to switch only within a subset of two pre-planned wavelengths, however, the cyclic-linked structure of wavelengths allows free bandwidth to be shifted to any wavelength by a rearrangement process. Rearrangement algorithm are developed to demonstrate that the cyclic-linked flexibility performs close to the fully flexible network in terms of blocking probability, packet delay, and packet loss. Furthermore, the evaluation shows that the rearrangement process has a minimum impact to in-service ONUs. To realize the cyclic-linked flexibility, a family of four physical architectures is proposed. PRO-Access architecture is suitable for new deployments and disruptive upgrades in which the network reach is not longer than 20 km. WCL-Access architecture is suitable for metro-access merger with the reach up to 100 km. PSB-Access architecture is suitable to implement directly on power-splitter-based PON deployments, which allows coexistence with current technologies. The cyclically-linked protection architecture can be used with current and future PON standards when network protection is required

Sub-graph based Multicast Protection in WDM Networks: A Multi/Many-Objective Evolutionary Algorithms approaches

In this paper is addressed the multicast routing-and-protection, and wavelength assignment (MRPWA) problem which is critical for the success of applications point-multipoint in WDM networks. Basically, it is proposed the design of the primary and protection multicast routes, where the resources protection are based on sub-graph protection strategy subject to the quality requirements of the QoP protection: dedicated (1 + 1), shared (M: N) and better effort (without protection). In this way, NSGA-II and NSGA-III, evolutionary algorithms, are applied to MRPWA considering multi- and many-objectives optimization context, respectively. The evolutionary algorithms optimize simultaneously: (i) the total number of links used, (ii) the number of wavelength converters, (iii) the number of splitter nodes, and (iv) the number of destinations served-and-protected. Considering Hyper-volume measure, the experimental tests on a set of instances indicate that the protection approach based on sub-graph proves to be promising in comparison to the dualtree protection strategy. On the other hand, the evolutionary technique oriented to many-objectives (NSGA-III) is more convenient than the oriented towards multi-objectives (NSGA-II) in the study problem.XIII Workshop Arquitectura, Redes (WARSO)Red de Universidades con Carreras en Informática (RedUNCI