Optical Multicast Routing Under Light Splitter Constraints

During the past few years, we have observed the emergence of new applications that use multicast transmission. For a multicast routing algorithm to be applicable in optical networks, it must route data only to group members, optimize and maintain loop-free routes, and concentrate the routes on a subset of network links. For an all-optical switch to play the role of a branching router, it must be equipped with a light splitter. Light splitters are expensive equipments and therefore it will be very expensive to implement splitters on all optical switches. Optical light splitters are only implemented on some optical switches. That limited availability of light splitters raises a new problem when we want to implement multicast protocols in optical network (because usual multicast protocols make the assumption that all nodes have branching capabilities). Another issue is the knowledge of the locations of light splitters in the optical network. Nodes in the network should be able to identify the locations of light splitters scattered in the optical network so it can construct multicast trees. These problems must be resolved by implementing a multicast routing protocol that must take into consideration that not all nodes can be branching node. As a result, a new signaling process must be implemented so that light paths can be created, spanning from source to the group members

Power-cost-effective node architecture for light-tree routing in WDM networks

6 pages, 10 figures.-- Contributed to: IEEE Globecom 2008 Optical Networks and Systems Symposium (GC'08 ONS), New Orleans, Louisiana, USA, Nov 30-Dec 4, 2008.We present a novel cost-effective multicast capable optical cross connect (MC-OXC) node architecture which improves efficiency of optical power by constraining splitting to only two output ports, in order to reduce power losses derived from splitting into more than two output ports. This node would manage the following actions when necessary: (a) tap and binary- splitting, which consists of tapping a small percentage of the signal power to the local node (4-8%) and an w-splitting action (n=2); and (b) tap-and-continue. We call this type of node 2-STC node (binary-split-tap-continue). We compare it with other well known state-of-art proposals and analyze its benefits in terms of number of devices and power losses. An evaluation of applicability is given, showing that the binary-split restriction shows a good trade-off between power losses, bandwidth consumption and architectural simplicity. We conclude that the 2-STC node improves power efficiency and contributes to get a good trade-off between use of resources and optical power.The work described in this paper was carried out with the support of the BONE-project ("Building the Future Optical Network in Europe"), a Network of Excellence funded by the European Commission through the 7th ICT-Framework Program. It has also been supported by the Spanish MEC grant TSI2005-07384-C03-02 and PRICIT CCG07-UC3M/TIC-3356.Publicad

WDM Network Design with Node Protection : An approach based on MOACO

This work studies the survivable optical network design prob- lem subject to simple node failure where disruption by network recon g- uration degrades the Quality of Service. The impact of the number of recon gurations when a node fails over other objective functions is crit- ical. Therefore, a Multi-Objective Ant Colony Optimization (MOACO) Algorithm is proposed, which tries to nd the best network design as well as the primary and back-up multicast trees considering a multicast re- quest set. The MOACO algorithm simultaneously minimizes the network design cost, the maximum end-to-end optical delay, the total number of recon gurations and the maximum number of recon gurations. The ex- perimental results over di erent instances show the bene ts of the pro- posed approach front to two state-of-the-art protection approaches based on total or partial recon guration.IX Workshop de Arquitecturas, Redes y Sistemas OperativosRed de Universidades con Carreras en Informática (RedUNCI

WDM Network Design with Node Protection : An approach based on MOACO

This work studies the survivable optical network design prob- lem subject to simple node failure where disruption by network recon g- uration degrades the Quality of Service. The impact of the number of recon gurations when a node fails over other objective functions is crit- ical. Therefore, a Multi-Objective Ant Colony Optimization (MOACO) Algorithm is proposed, which tries to nd the best network design as well as the primary and back-up multicast trees considering a multicast re- quest set. The MOACO algorithm simultaneously minimizes the network design cost, the maximum end-to-end optical delay, the total number of recon gurations and the maximum number of recon gurations. The ex- perimental results over di erent instances show the bene ts of the pro- posed approach front to two state-of-the-art protection approaches based on total or partial recon guration.IX Workshop de Arquitecturas, Redes y Sistemas OperativosRed de Universidades con Carreras en Informática (RedUNCI

Multicast Routing In Optical Access Networks

Widely available broadband services in the Internet require high capacity access networks. Only optical networking is able to efficiently provide the huge bandwidth required by multimedia applications. Distributed applications such as Video-Conferencing, HDTV, VOD and Distance Learning are increasingly common and produce a large amount of data traffic, typically between several terminals. Multicast is a bandwidth-efficient technique for one-to-many or many-to-many communications, and will be indispensable for serving multimedia applications in future optical access networks. These applications require robust and reliable connections as well as the satisfaction of QoS criteria. In this chapter, several access network architectures and related multicast routing methods are analyzed. Overall network performance and dependability are the focus of our analysis

Multicast protection and energy efficient traffic grooming in optical wavelength routing networks.

Zhang, Shuqiang.Thesis (M.Phil.)--Chinese University of Hong Kong, 2010.Includes bibliographical references (p. 74-80).Abstracts in English and Chinese.Abstract --- p.i摘要 --- p.ivAcknowledgements --- p.vTable of Contents --- p.viChapter Chapter 1 --- Background --- p.1Chapter 1.1 --- Routing and Wavelength Assignment --- p.1Chapter 1.2 --- Survivability in Optical Networks --- p.3Chapter 1.3 --- Optical Multicasting --- p.4Chapter 1.3.1 --- Routing and Wavelength Assignment of Optical Multicast --- p.5Chapter 1.3.2 --- Current Research Topics about Optical Multicast --- p.8Chapter 1.4 --- Traffic Grooming --- p.10Chapter 1.4.1 --- Static Traffic Grooming --- p.11Chapter 1.4.2 --- Dynamic Traffic Grooming --- p.13Chapter 1.5 --- Contributions --- p.15Chapter 1.5.1 --- Multicast Protection with Scheduled Traffic Model --- p.15Chapter 1.5.2 --- Energy Efficient Time-Aware Traffic Grooming --- p.16Chapter 1.6 --- Organization of Thesis --- p.18Chapter Chapter 2 --- Multicast Protection in WDM Optical Network with Scheduled Traffic --- p.19Chapter 2.1 --- Introduction --- p.19Chapter 2.2 --- Multicast Protection under FSTM --- p.22Chapter 2.3 --- Illustrative Examples --- p.28Chapter 2.4 --- Two-Step Optimization under SSTM --- p.37Chapter 2.5 --- Summary --- p.40Chapter Chapter 3 --- Energy Efficient Time-Aware Traffic Grooming in Wavelength Routing Networks --- p.41Chapter 3.1 --- Introduction --- p.41Chapter 3.2 --- Energy consumption model --- p.43Chapter 3.3 --- Static Traffic Grooming with Time awareness --- p.44Chapter 3.3.1 --- Scheduled Traffic Model for Traffic Grooming --- p.44Chapter 3.3.2 --- ILP Formulation --- p.44Chapter 3.3.3 --- Illustrative Numerical Example --- p.48Chapter 3.4 --- Dynamic Traffic Grooming with Time Awareness --- p.49Chapter 3.4.1 --- Time-Aware Traffic Grooming (TATG) --- p.51Chapter 3.5 --- Simulation Results of Dynamic Traffic Grooming --- p.54Chapter 3.5.1 --- 24-node USNET: --- p.55Chapter 3.5.2 --- 15-node Pacific Bell Network: --- p.59Chapter 3.5.3 --- 14-node NSFNET: --- p.63Chapter 3.5.4 --- Alternative Configuration of Simulation Parameters: --- p.67Chapter 3.6 --- Summary --- p.71Chapter Chapter 4 --- Conclusions and Future Work --- p.72Chapter 4.1 --- Conclusions --- p.72Chapter 4.2 --- Future Work --- p.73Bibliography --- p.74Publications during M.Phil Study --- p.8

All optical multicasting in wavelength routing mesh networks with power considerations: design and operation

Wavelength routing Wavelength Division Multiplexing (WDM) are optical networks that support all-optical services. They have become the most appealing candidate for wide area backbone networks. Their huge available bandwidth provides the solution for the exponential growth in trayc demands that is due to the increase in the number of users and the surge of more bandwidth intensive network applications and services. A sizable fraction of these applications and services are of multi-point nature. Therefore, supporting multicast service in this network environment is very critical and unique. The all-optical support of various services has advantages, which includes achieving the signal transparency to its content. Nevertheless, the all-optical operational support comes with an associated cost and new issues that make this problem very challenging. In this thesis, we investigate the power-related issues for supporting multicast service in the optical domain, referred to as All-Optical Multicasting (AOM). Our study treats these issues from two networking contexts, namely, Network Provisioning and Connection Provisioning. We propose a number of optimal and heuristic solutions with a unique objective function for each context. In this regard, the objective function for the network provisioning problem is to reduce the network cost, while the solutions for the connection provisioning problem aim to reduce the connection blocking ratio. The optimal formulations are inherently non-linear. However, we introduce novel methods for linearizing them and formulate the problems as Mixed Integer Linear Programs. Also, the design of the heuristic solutions takes into account various optimization factors which results in efficient heuristics that can produce fast solutions that are relatively close to their optimal counterparts, as shown in the numerical results we present

Optical Wireless Data Center Networks

Bandwidth and computation-intensive Big Data applications in disciplines like social media, bio- and nano-informatics, Internet-of-Things (IoT), and real-time analytics, are pushing existing access and core (backbone) networks as well as Data Center Networks (DCNs) to their limits. Next generation DCNs must support continuously increasing network traffic while satisfying minimum performance requirements of latency, reliability, flexibility and scalability. Therefore, a larger number of cables (i.e., copper-cables and fiber optics) may be required in conventional wired DCNs. In addition to limiting the possible topologies, large number of cables may result into design and development problems related to wire ducting and maintenance, heat dissipation, and power consumption. To address the cabling complexity in wired DCNs, we propose OWCells, a class of optical wireless cellular data center network architectures in which fixed line of sight (LOS) optical wireless communication (OWC) links are used to connect the racks arranged in regular polygonal topologies. We present the OWCell DCN architecture, develop its theoretical underpinnings, and investigate routing protocols and OWC transceiver design. To realize a fully wireless DCN, servers in racks must also be connected using OWC links. There is, however, a difficulty of connecting multiple adjacent network components, such as servers in a rack, using point-to-point LOS links. To overcome this problem, we propose and validate the feasibility of an FSO-Bus to connect multiple adjacent network components using NLOS point-to-point OWC links. Finally, to complete the design of the OWC transceiver, we develop a new class of strictly and rearrangeably non-blocking multicast optical switches in which multicast is performed efficiently at the physical optical (lower) layer rather than upper layers (e.g., application layer). Advisors: Jitender S. Deogun and Dennis R. Alexande

Multicast Routing Under Optical Layer Constraints

It has been widely recognized that physical layer impairments, including power losses, must be taken into account when routing optical connections in transparent networks. In this paper we study the problem of constructing light-trees under optical layer power budget constraints, with a focus on algorithms which can guarantee a certain level of quality for the signals received by the destination nodes. We define a new constrained light-tree routing problem by introducing a set of constraints on the source-destination paths to account for the power losses at the optical layer. We investigate a number of variants of this problem, we characterize their complexity, and we develop a suite of corresponding routing algorithm