1,046 research outputs found

    Benchmarking and viability assessment of optical packet switching for metro networks

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    Optical packet switching (OPS) has been proposed as a strong candidate for future metro networks. This paper assesses the viability of an OPS-based ring architecture as proposed within the research project DAVID (Data And Voice Integration on DWDM), funded by the European Commission through the Information Society Technologies (IST) framework. Its feasibility is discussed from a physical-layer point of view, and its limitations in size are explored. Through dimensioning studies, we show that the proposed OPS architecture is competitive with respect to alternative metropolitan area network (MAN) approaches, including synchronous digital hierarchy, resilient packet rings (RPR), and star-based Ethernet. Finally, the proposed OPS architectures are discussed from a logical performance point of view, and a high-quality scheduling algorithm to control the packet-switching operations in the rings is explained

    Regulatory Approaches to NGNs: An International Comparison

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    The emergence of Next Generation Networks (NGNs) raises profound challenges for regulators everywhere. Different regulatory authorities have approached these problems in strikingly different ways, depending in part on the overall regulatory milieu in which they operate, and in part on the nature of the NGN migration envisioned by major market players. Also, the NGN core network raises significantly different issues from those of the NGN access network. The migration to NGN raises many of the same issues that were already on the table as a result of the broader migration to IP-based services, notably in regard to the de-coupling of the service from the underlying network. To these concerns are added profound questions related to the nature of market power. Will NGNs enable new forms of competition? Will competitive bottlenecks remain, especially in the last mile? Will NGN enable new forms of bottlenecks to emerge, especially in the upper layers of the network, perhaps as a result of new IMS capabilities? Regulators in the UK, Netherlands, Germany, Japan and the United States have been forced to deal with these issues due to relatively rapid migration to NGNs proposed by their respective incumbent telecoms operators. Many of the same issues are also visible in the recommendations that the European Commission finalised on 13 November 2007 as part of the ongoing review of the European regulatory framework for electronic communications. In this paper, we compare and contrast the many regulatory proceedings that have been produced by these regulatory authorities.Regulation; Next Generation Networks; access network; core network; all-IP; competition; market power; international comparison

    Regulatory Approaches to NGNs: An International Comparison

    Get PDF
    The emergence of Next Generation Networks (NGNs) raises profound challenges for regulators everywhere. Different regulatory authorities have approached these problems in strikingly different ways, depending in part on the overall regulatory milieu in which they operate, and in part on the nature of the NGN migration envisioned by major market players. Also, the NGN core network raises significantly different issues from those of the NGN access network. The migration to NGN raises many of the same issues that were already on the table as a result of the broader migration to IP-based services,notably in regard to the de-coupling of the service from the underlying network. To these concerns are added profound questions related to the nature of market power. Will NGNs enable new forms of competition? Will competitive bottlenecks remain, especially in the last mile? Will NGN enable new forms of bottlenecks to emerge, especially in the upper layers of the network, perhaps as a result of new IMS capabilities? Regulators in the UK, Netherlands, Germany, Japan and the United States have been forced to deal with these issues due to relatively rapid migration to NGNs proposed by their respective incumbent telecoms operators. Many of the same issues are also visible in the recommendations that the European Commission finalised on 13 November 2007 as part of the ongoing review of the European regulatory framework for electronic communications. In this paper, we compare and contrast the many regulatory proceedings that have been produced by these regulatory authorities.Regulation; Next Generation Networks; access network; core network; all-IP; competition; market power; international comparison.

    Time Shared Optical Network (TSON): a novel metro architecture for flexible multi-granular services

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    This paper presents the Time Shared Optical Network (TSON) as metro mesh network architecture for guaranteed, statistically-multiplexed services. TSON proposes a flexible and tunable time-wavelength assignment along with one-way tree-based reservation and node architecture. It delivers guaranteed sub-wavelength and multi-granular network services without wavelength conversion, time-slice interchange and optical buffering. Simulation results demonstrate high network utilization, fast service delivery, and low end-to-end delay on a contention-free sub-wavelength optical transport network. In addition, implementation complexity in terms of Layer 2 aggregation, grooming and optical switching has been evaluated

    Ethernet - a survey on its fields of application

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    During the last decades, Ethernet progressively became the most widely used local area networking (LAN) technology. Apart from LAN installations, Ethernet became also attractive for many other fields of application, ranging from industry to avionics, telecommunication, and multimedia. The expanded application of this technology is mainly due to its significant assets like reduced cost, backward-compatibility, flexibility, and expandability. However, this new trend raises some problems concerning the services of the protocol and the requirements for each application. Therefore, specific adaptations prove essential to integrate this communication technology in each field of application. Our primary objective is to show how Ethernet has been enhanced to comply with the specific requirements of several application fields, particularly in transport, embedded and multimedia contexts. The paper first describes the common Ethernet LAN technology and highlights its main features. It reviews the most important specific Ethernet versions with respect to each application field’s requirements. Finally, we compare these different fields of application and we particularly focus on the fundamental concepts and the quality of service capabilities of each proposal

    Optical fibre local area networks

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    All-optical aggregation and distribution of traffic in large metropolitan area networks using multi-Tb/s S-BVTs

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    Current metropolitan area network architectures are based on a number of hierarchical levels that aggregate traffic toward the core at the IP layer. In this setting, routers are interconnected by means of fixed transceivers operating on a point-to-point basis where the rates of transceivers need to match. This implies a great deal of intermediate transceivers to collect traffic and groom and send it to the core. This paper proposes an alternative scheme based on sliceable bandwidth/bitrate variable transceivers (S-BVTs) where the slice-ability property is exploited to perform the aggregation of traffic from multiple edges �� -to-1 rather than 1-to-1. This approach can feature relevant cost reductions through IP offloading at intermediate transit nodes but requires viable optical signal-to-noise ratio (OSNR) margins for all-optical transmission through the network. In this work, we prove through simulation the viability and applicability of this technique in large metro networks with a vertical-cavity-surface-emitting laser-based S-BVT design to target net capacities per channel of 25, 40, and 50 Gb/s. The study reveals that this technology can support most of the paths required for IP offloading after simulation in a semi-synthetic topology modeling a 20-million-inhabitant metropolitan area. Moreover, OSNR margins enable the use of protection paths (secondary disjoint paths) between the target node and the core much longer than primary paths in terms of both the number of intermediate hops and kilometers.European Union H2020 project PASSION, grant no. 780326 (http://www.passion-project.eu/)
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