18 research outputs found

    Integrated control platform for converged optical and wireless networks

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    Dynamic bandwidth allocation algorithms for differentiated services enabled Ethernet Passive Optical Networks with centralized admission control

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    Fiber based access networks can deliver performance that can support the increasing demands for high speed connections. One of the new technologies that has emerged in recent years is Ethernet Passive Optical Networks. The key features of this approach are the simplicity of the architecture and compatibility with existing Ethernet based local area networks. To make Ethernet Passive Optical Networks (EPONs) a fully functional part of the telecommunication system, support for classes of traffic with different Quality of Service (QoS) requirements is mandatory. Much research has been done on the optimal bandwidth allocation algorithms that would have the capability of supporting Differentiated Services (DiffServ) in EPONs. This thesis proposes that the access control mechanism should be centralized and performed by the Optical Line Terminal (OLT). It is shown that this approach can give greater flexibility to adjust to changing traffic conditions, can simplify the structure of the Optical Network Units, and can allow the easy adoption of Service Level Agreements. This thesis introduces a novel EPON simulator that allows testing of various types of bandwidth allocation algorithms. It is possible to evaluate the allocation mechanism under different traffic conditions and with network configurations that closely resemble real systems. New algorithms are presented based on a paradigm of centralized access control. Simulation results showed that they offer good performance and support for the DiffServ architecture

    Multichannel optical access networks : design and resource management

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    At present there is a strong worldwide push towards bringing fiber closer to individual homes and businesses. The next evolutionary step is the cost-effective all-optical integration of fiber-based access and metro networks. STARGATE [1] is an all-optical access-metro architecture which does not rely on costly active devices, e.g., Optical Cross-Connects (OXCs) or Fixed Wavelength Converters (FWCs), and allow low-cost PON technologies to follow low-cost Ethernet technologies from EPON access into metro networks, resulting in significantly reduced cost and complexity. It makes use of an overlay island of transparency with optical bypassing capabilities. In this thesis we first propose Optical Network Unit (ONU) architectures, and discuss several technical challenges, which allow STARGATE EPONs (SG-EPONs) to evolve in a pay-as-you-grow manner while providing backward compatibility with legacy infrastructure and protecting previous investment. Second, and considering all the hardware constraints, we present the corresponding dynamic bandwidth allocation algorithm for effective resource management in these networks and investigate their performances (delay, throughput) through simulation experiments. We further investigate the problem of transmission grant scheduling in multichannel optical access networks using a scheduling theoretic approach. We show that the problem can be modeled as an Open Shop and we formulate the joint scheduling and wavelength assignment problem as a Mixed Integer Linear Program (MJLP) whose objective is to reduce the length of a scheduling period. Since the problem is known to be NP-hard, we introduce a Tabu Search based heuristic for solving the joint problem. Different other heuristics are also considered and their performances are compared with those of Tabu and MILP. Results indicate that by appropriately scheduling transmission grants and assigning wavelengths, substantial and consistent improvements may be obtained in the network performance. For example, Tabu shows a reduction of up to 29% in the schedule length with substantial reduction in channel idle gaps yielding to both higher channel utilization and lower queuing delays. Additionally, when the number of channels in the network is not small, the benefits of performing appropriate wavelength assignment, together with transmission scheduling, are observed and discussed. We further perform a packet-level simulation on the considered network to study the benefits of efficient grant scheduling; significant improvements are shown both in terms of system utilization and packet queuing delays

    A Comprehensive Survey of the Tactile Internet: State of the art and Research Directions

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    The Internet has made several giant leaps over the years, from a fixed to a mobile Internet, then to the Internet of Things, and now to a Tactile Internet. The Tactile Internet goes far beyond data, audio and video delivery over fixed and mobile networks, and even beyond allowing communication and collaboration among things. It is expected to enable haptic communication and allow skill set delivery over networks. Some examples of potential applications are tele-surgery, vehicle fleets, augmented reality and industrial process automation. Several papers already cover many of the Tactile Internet-related concepts and technologies, such as haptic codecs, applications, and supporting technologies. However, none of them offers a comprehensive survey of the Tactile Internet, including its architectures and algorithms. Furthermore, none of them provides a systematic and critical review of the existing solutions. To address these lacunae, we provide a comprehensive survey of the architectures and algorithms proposed to date for the Tactile Internet. In addition, we critically review them using a well-defined set of requirements and discuss some of the lessons learned as well as the most promising research directions

    Design and Performance Evaluation of Passive Optical Networks

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    Currently, new housing developments in many places around the world are built with fiber-based connections to the home, and network providers are conducting field-testing and experiments with fiber access. In order to provide a worthy alternative to the existing infrastructures, the new technology should be, among other things, cost-efficient, broad-banded, and easy to maintain and deploy. It must also support all existing services as well as offer new required services. These services include voice, data, and video/television-broadcast traffic. In this project we will carry out exploration of some of the aspects of the QoS bandwidth allocation in the 802.3ah EPON architecture and the GPON architecture in a multimedia environment. Several general traffic types will be defined, that would represent real traffic in the network, each with its own QoS requirements (bandwidth, delay, etc.). Sometimes we will use real traffic (voice, video, data). Moreover, another goal of this project is to provide an operating and configuration reference tool-like manual facilitating the functional and performance analysis of this kind of networks. This tool-like manual will include step-by-step the way to discover the behaviour of these networks. Due to the required extension of this document, the manual has been included in Annex C

    Allocation des ressources et des solutions pour économiser de l'énergie dans les réseaux optiques d'accÚs

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    In this thesis, general overview about PON systems is presented and existing PON mechanisms and classification are investigated. After, a novel dynamic bandwidth allocation algorithm for EPON is introduced. This proposed algorithm is named as “Half Cycling Dynamic Bandwidth Allocation-hcDBA” by the inspiration of its half cycling processing mode. Later, an improvement of hcDBA algorithm with early prediction mechanism is presented. As a result statement of the study, hcDBA algorithm performs better than existing mechanism in terms of packet loss ratio and access delays. Beside, simulation traffic behavior of EPON’s upstream channel has been investigated in order to support the decision of selecting suitable traffic generator in further studies. Energy conversation is one of the hot topics in telecommunication networks. Access networks constitute remarkable portion of the total energy consumption in telecommunication networks. ITU-T and IEEE organizations published recommendation for energy conversation in PONs. While, total energy consumption of ONUs is more than other equipment in fix access network the standards and most of the researches focused on saving energy at ONU side. In this thesis I focused on an energy efficiency method based on energy conversation on OLT side. The proposed method save energy by dynamically moving OLT cards to deep sleep mode according to the incoming and outgoing traffic loadsDans ce travail de thĂšse, un aperçu gĂ©nĂ©ral sur les systĂšmes PON est prĂ©sentĂ© et sont Ă©tudiĂ©s les mĂ©canismes et classification PON existants. AprĂšs, nous introduisons notre premiĂšre contribution qui est un algorithme d'allocation dynamique de bande passante pour EPON. Cet algorithme proposĂ© est dĂ©signĂ© comme «hcDBA». Par la suite, une amĂ©lioration de l'algorithme de hcDBA avec mĂ©canisme de prĂ©diction prĂ©coce est prĂ©sentĂ©e. Notre simulation montre bien que notre algorithme hcDBA est performant comparĂ© aux mĂ©canismes existants en termes de taux de perte de paquets et de dĂ©lai d’accĂšs. Dans notre seconde contribution, nous sommes intĂ©ressĂ©s au problĂšme de consommation d’énergie qui est un sujet d’actualitĂ© dans les rĂ©seaux de tĂ©lĂ©communication. Les Ă©tudes montrent aujourd’hui que les rĂ©seaux d'accĂšs constituent une partie remarquable de la consommation totale d'Ă©nergie dans les rĂ©seaux de tĂ©lĂ©communication. Les organisations ITU-T et IEEE ont publiĂ© la recommandation pour la conversation de l'Ă©nergie pour les rĂ©seaux PONs. Bien que, la consommation totale d'Ă©nergie des nƓuds ONU est plus importantes que d'autres Ă©quipements dans le rĂ©seau d'accĂšs fixe, les normes et la plupart des travaux de recherches ont portĂ© sur les Ă©conomies d'Ă©nergie du cĂŽtĂ© de ONU. Dans cette thĂšse, nous sommes concentrĂ©s sur une mĂ©thode d'efficacitĂ© Ă©nergĂ©tique basĂ©e sur la conservation de l'Ă©nergie du cĂŽtĂ© de l’OLT. La mĂ©thode proposĂ©e permet d’économiser de l'Ă©nergie en dĂ©plaçant dynamiquement des cartes d’OLT en mode de sommeil profond en fonction des charges de trafic entrant et sortan

    Design and Analysis of Green Mission-Critical Fiber-Wireless Broadband Access Networks

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    In recent years, the ever-increasing environmental friendliness concern has made energy efficiency in telecom networks as an important theme in their operations. Meanwhile, mission-critical (MC) services and systems (such as healthcare, police, and firefighting) have been acquiring special attention from telecom designers and operators. The currently deployed MC network technologies are indigent in terms of bandwidth capacity, and thus they are not able to support the emerging MC multimedia applications. Therefore in this thesis, we first explore the possibility of provisioning the MC services over the integration of fiber-wireless (FiWi) technologies, which has been considered as a promising candidate for the deployment of high-speed and mobile broadband access networks. We then investigate the energy efficiency problem in the FiWi integration, which consists of WiMAX in the wireless plane, and of Ethernet Passive Optical Network (EPON) - the most popular variant of the next-generation PON (NG-PON) technology, in the optical plane. In WiMAX, the energy saving protocol has been extensively investigated and standardized. Conversely, it has been recently studied in NG-PON, which currently consumes the least power among all the high-speed access networks. However, NG-PON has notably matured in the past few years and is envisioned to massively evolve in the near future. This trend will increase the power requirements of NG-PON and make it no longer coveted. Therefore we address the energy efficiency problem in NG-PON. For each of our contributions, we conduct extensive simulations to demonstrate the effectiveness and advantages of the proposed solutions
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