Architecture, design, and modeling of the OPSnet asynchronous optical packet switching node

An all-optical packet-switched network supporting multiple services represents a long-term goal for network operators and service providers alike. The EPSRC-funded OPSnet project partnership addresses this issue from device through to network architecture perspectives with the key objective of the design, development, and demonstration of a fully operational asynchronous optical packet switch (OPS) suitable for 100 Gb/s dense-wavelength-division multiplexing (DWDM) operation. The OPS is built around a novel buffer and control architecture that has been shown to be highly flexible and to offer the promise of fair and consistent packet delivery at high load conditions with full support for quality of service (QoS) based on differentiated services over generalized multiprotocol label switching

Scalable shared protection approach for mesh WDM-routed networks

The paper proposes an approach for calculating the protection pool size on each link in a mesh WDMrouted network. The protection pool evaluation is part of a shared protection scheme applied to a failure dependent scenario and based on aggregated information dissemination. Two models based on a probabilistic approach are proposed to provide a scheme that is scalable as the number of optical cross-connects (OXC), fibres and wavelength multiplexing in a core network increases. Precisely, two models based on a binomial and a beta-binomial distribution are presented. The evaluation of the models by simulation shows that both models are attractive propositions to offer protected ¸-services that do not require an absolute protection guarantee offered by (1:1) schemes or shared protection schemes requiring full network state information, or using partial information but with less efficient use of the fibre utilisation

Spare capacity modelling and its applications in survivable iP-over-optical networks

As the interest in IP-over-optical networks are becoming the preferred core network architecture, survivability has emerged as a major concern for network service providers; a result of the potentially huge traffic volumes that will be supported by optical infrastructure. Therefore, implementing recovery strategies is critical. In addition to the traditional recovery schemes based around protection and restoration mechanisms, pre-allocated restoration represents a potential candidate to effect and maintain network resilience under failure conditions. Preallocated restoration technique is particularly interesting because it provides a trade-off in terms of recovery performance and resources between protection and restoration schemes. In this paper, the pre-allocated restoration performance is investigated under single and dual-link failures considering a distributed GMPLSbased IP/WDM mesh network. Two load-based spare capacity optimisation methods are proposed in this paper; Local Spare Capacity Optimisation (LSCO) and Global Spare Capacity Optimisation (GSCO)

Performance analysis of a 2-D time-wavelength OCDMA wavelength-aware receiver with beat noise

The effect of beat noise on two-dimensional time-wavelength optical code-division multiple-access systems utilising wavelength-aware receivers is examined. A derivation of a general formula for the bit error probability taking into consideration multiple access interference (MAI) and other noise sources is given. In addition, a comparison between the system performance of such a receiver and the traditional configuration is presented. Studies to date that have focused only on the MAI limited case showed that the wavelength-aware configuration yields a better performance when compared to the traditional receiver. When beat noise is considered, the numerical results reveal that the performance of wavelength-aware receiver is very sensitive to beat noise and is not superior over the traditional receiver

A novel optical passive router ring architecture using MAGNet protocol

This paper introduces a family of bidirectional multi-fibre passive photonic ring architectures that may serve as a high-capacity network backbone for supporting next-generation data-centric services. We introduce a novel dual-router node design that avoids several non-ideal routing phenomena typically associated with passive networks based on cyclic graphs. Our design also achieves the requisite single-hop full-mesh connectivity needed for arbitrary node-to-node communications. A ring enlargement strategy is presented that allows this architecture to scale across a wide range of networking domains. A medium access protocol will also briefly elaborated

Optical packet switching over arbitrary physical topologies using the Manhattan street network : an evolutionary approach

Published in "Towards an Optical Internet", A. Jukan (Ed.). Optical packet switching over arbitrary physical topologies typically mandates complex routing schemes and the use of buffers to resolve the likely contentions. However, the relatively immature nature of optical logic devices and the limitations with optical buffering provide significant incentive to reduce the routing complexity and avoid optical domain contentions. This paper examines how the Manhattan Street Network (MSN) and a particular routing scheme may be used to facilitate optical packet switching over arbitrary physical topologies. A novel approach, genetic algorithms (GA), is applied to the problem of deploying the MSN (near) optimally in arbitrary physical topologies. A problem encoding is proposed and different implementations of GA described. The optimum GA parameters are empirically selected and GA is successfully used to deploy the MSN in physical topologies of up to 100 nodes. Favourable results are obtained. GA are also seen to out-perform other heuristics at deploying the MSN in arbitrary physical topologies for optical packet switching

The interplay between market factors and regulation in next-generation broadband: evidence from Europe

Although many factors affect next-generation access (NGA) deployment, regulatory frameworks have the power to guide future investments, further development and, consequently, the competitiveness of a next-generation broadband market. Understanding the link between markets and regulatory requirements, therefore, is essential. Using data collected from broadband stakeholders in three markets, this paper provides an empirical analysis of this relationship. The market conditions in The Netherlands, Sweden and the United Kingdom (UK) and their roles in influencing the regulatory decisions made by the respective national regulatory authorities (NRAs) are examined. Such analysis first shows that market conditions present different priorities for regulators and policymakers. While markets with weaker incentives for investment, such as the UK, are in need of regulatory and public policy intervention, The Netherlands and Sweden require less stringent measures. Despite this, evidence shows that some level of NGA regulation is presently required in all three markets, albeit to varying degrees and with different foci. The paper then highlights the interaction of the market factors, explaining that this interrelationship is more important for policymakers than the effects of a single factor. The findings of the paper are useful for regulators in addressing the challenges of next-generation broadband deployment. --Next-generation access,Regulation,The Netherlands,Sweden,United Kingdom,Comparison

High prices to access scholarly research could drive developing country researchers to use pirate sites like SciHub

Developing countries are investing more in research and higher education and it should be no surprise that publishers are building commercial relationships to expand access and services. But prices are often still too high. Jonathan Harle argues now is a good time for the research community to reflect on what we can do to bring the cost of access down. If we don’t, we can’t be surprised when pirate alternatives like SciHub crop up