129,337 research outputs found

    Ordinance on technical requirements and conditions of use of optical distribution networks of the Croatian regulatory agency - Analysis and outlook

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    In September 2010 the Croatian regulatory agency (HAKOM) put in force the ordinance on technical requirements and conditions of use of optical distribution networks. With this ordinance the Croatian regulatory agency is looking over the rim by proposing a rather technical approach for the rollout of optical access networks which will have significant influence on the deployment of next generation access networks (NGAN) in Croatia. The ordinance stipulates the requirements that have to be fulfilled in developing, planning, designing, building, using and maintaining optical access networks. Some of the main issues are the obligation of a point-to-point architecture, the focus on open access and the incorporation of municipalities in planning fibre distribution networks. In this way the agency is following a path which is unique in Europe and which is incorporating new players for building the optical network infrastructure. For Croatia an additional aspect is related to the expected accession to the European Union by mid 2013, putting the Government into the position of receiving financial support provided by the structural and cohesion fund of the EU in the amount of 7.6 billion Euros. --optical access networks,next generation access (NGA),regulatory framework,passive infrastructure,fibre to the home (FTTH)

    Subsystems for future access networks

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    Current evolution and tendencies of Telecom Networks in general and more specifically optical Metro and Access Networks and their convergence are reported. Based on this evolution, a set of research lines are foreseen regarding subsystems and devices as: high speed optical sources, modulators and receivers, for the next generation of Passive Optical Networks. The ICT project EURO-FOS is achieving European level cooperative research among academia and industry, enabling future telecommunication networks

    Wavelength switched hybrid TDMA/WDM (TWDM) PON: a flexible next-generation optical access solution

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    In this paper, we propose the system concepts of a next-generation wavelength switched hybrid time division multiple access and wavelength division multiplexing (TWDM) passive optical network (PON) architecture. In this architecture, wavelength selective switches (WSSs) are used at the remote node to improve flexibility, data security and power budget compared to other TWDM-PON variants. We map the proposed architecture to the requirements of next-generation optical access networks in a 2020 perspective. Finally, we benchmark the proposed architecture with other proposed TWDM-PON solutions

    Wavelength reconfigurability for next generation optical access networks

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    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

    Next Generation Optical Access Networks

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    Modeling the video distribution link in the Next Generation Optical Access Networks

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    In this work we present a model for the design and optimization of the video distribution link in the next generation optical access network. We analyze the video distribution performance in a SCM-WDM link, including the noise, the distortion and the fiber optic nonlinearities. Additionally, we consider in the model the effect of distributed Raman amplification, used to extent the capacity and the reach of the optical link. In the model, we use the nonlinear Schrödinger equation with the purpose to obtain capacity limitations and design constrains of the next generation optical access networks. In this work we present a model for the design and optimization of the video distribution link in the next generation optical access network. We analyze the video distribution performance in a SCM-WDM link, including the noise, the distortion and the fiber optic nonlinearities. Additionally, we consider in the model the effect of distributed Raman amplification, used to extent the capacity and the reach of the optical link. In the model, we use the nonlinear Schrödinger equation with the purpose to obtain capacity limitations and design constrains of the next generation optical access networks

    Next-Generation Optical Access Networks

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    Unbundling in Current Broadband and Next-Generation Ultra-Broadband Access Networks

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    This article overviews the methods that are currently under investigation for implementing multi-operator open-access/shared-access techniques in next-generation access ultra-broadband architectures, starting from the traditional "unbundling-of-the-local-loop" techniques implemented in legacy twisted-pair digital subscriber line access networks. A straightforward replication of these copper-based unbundling-of-the-local-loop techniques is usually not feasible on next-generation access networks, including fiber-to-the-home point-to-multipoint passive optical networks. To investigate this issue, the article first gives a concise description of traditional copper-based unbundling-of-the-local-loop solutions, then focalizes on both next-generation access hybrid fiber-copper digital subscriber line fiber-to-the-cabinet scenarios and on fiber to the home by accounting for the mix of regulatory and technological reasons driving the next-generation access migration path, focusing mostly on the European situation. © 2014 Taylor and Francis Group, LLC

    Optimizing resource allocation in next-generation optical access networks

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    To meet rapidly increasing traffic demands caused by the popularization of Internet and the spouting of bandwidth-demanding applications, Passive Optical Networks (PONs) exploit the potential capacities of optical fibers, and are becoming promising future-proof access network technologies. On the other hand, for a broader coverage area and higher data rate, integrated optical and wireless access is becoming a future trend for wireless access. This thesis investigates three next-generation access networks: Time Division Multiplexing (TDM) PONs, Wavelength Division Multiplexing (WDM) PONs, and WDM Radio-Over-Fiber (RoF) Picocellular networks. To address resource allocation problems in these three networks, this thesis first investigates respective characteristics of these networks, and then presents solutions to address respective challenging problems in these networks. In particular, three main problems are addressed: arbitrating time allocation among different applications to guarantee user quality of experience (QoE) in TDM PONs, scheduling wavelengths optimally in WDM PONs, and jointly allocating fiber and radio resources in WDM RoF Picocellular networks. In-depth theoretical analysis and extensive simulations have been performed in evaluating and demonstrating the performances of the proposed schemes
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