73,805 research outputs found

    A tunable-channel multi-access wavelength division multiplexed network and surveillance schemes for optical cross-connects.

    Get PDF
    by Eddie Ting Pong Kong.Thesis (M.Phil.)--Chinese University of Hong Kong, 1999.Includes bibliographical references (leaves 61-68).Abstracts in English and Chinese.Chapter 1 --- Introduction --- p.1Chapter 1.1 --- Optical Network Architecture --- p.1Chapter 1.2 --- High-Speed All-Optical Tunable-Channel Multi-Access Networks --- p.3Chapter 1.3 --- Fault Surveillance of Optical Cross-Connects in Wavelength Routing Network --- p.3Chapter 1.4 --- Outline of the Thesis --- p.5Chapter 2 --- Optical Multi-Access Networks --- p.6Chapter 2.1 --- All-Optical Networks --- p.6Chapter 2.2 --- Optical Multi-Access Schemes --- p.8Chapter 2.2.1 --- Wavelength-Division Multi-Access (WDMA) --- p.9Chapter 2.2.2 --- Time-Division Multi-Access (TDMA) --- p.12Chapter 2.2.3 --- Subcarrier Multi-Access (SCMA) --- p.14Chapter 2.3 --- Design Considerations --- p.14Chapter 3 --- All-Optical Tunable-Channel Multi-Access Networks --- p.18Chapter 3.1 --- Tunable-Channel Multi-Access Networks --- p.19Chapter 3.2 --- Protocols for TCMA Networks --- p.20Chapter 3.3 --- Photonic Implementation of a Wavelength Division TCMA Network with Time- Slot Access --- p.23Chapter 3.3.1 --- Proposed Network Architecture --- p.25Chapter 3.3.2 --- Experimental Results --- p.30Chapter 3.3.3 --- Discussion --- p.34Chapter 3.3.4 --- Summary --- p.35Chapter 4 --- Fault Surveillance for Optical Cross-Connects in Wavelength Routing Networks --- p.36Chapter 4.1 --- Wavelength Routing Networks --- p.37Chapter 4.2 --- Options in Fault Surveillance --- p.39Chapter 4.3 --- Optical Path Surveillance of Optical Cross-Connects in Wavelength Routing Networks --- p.41Chapter 4.3.1 --- Scanning Amplified Spontaneous Emission Identification Surveillance Scheme --- p.43Chapter 4.3.2 --- Pilot-Tone Based Surveillance and Removal Scheme --- p.49Chapter 4.4 --- Summary --- p.55Chapter 5 --- Conclusion --- p.57Chapter 5.1 --- Summary of the Thesis --- p.57Chapter 5.2 --- Future Work --- p.60Bibliography --- p.61Publication List --- p.5

    Optical Transport Network Design for 5G Fixed Wireless Access

    Get PDF
    The fifth generation (5G) of mobile technology, 5G is anticipated to be a significant leap in the evolution of mobile communication. 5G will be designed to attain 1000 times higher data volumes, 10 times lower latency, and 100 times more connected devices than its predecessor, 4G. Due to 5Gs ability to sustain high bandwidth per unit area, 5G is considered to be a cost-efficient solution to provide fixed wireless access (FWA) to households on a large scale. FWA is seen as an attractive alternative for fixed broadband access in scenarios where last mile access based on wired technologies is not economically viable. While approaches for enhancing user experience in a 5G FWA environment are investigated in the research community, the problem of providing cost-effective high capacity transport for FWA deployments still remains a major challenge. This is particularly challenging due to diverse transport network architectures and requirements imposed by different 5G deployment models. This paper addresses this problem by formulating a generalized joint-optimization framework to simultaneously plan wireless access and optical transport for 5G FWA networks in order to minimize the deployment cost while meeting various network requirements. We demonstrate the applicability of the proposed framework by applying it to a real scenario with a range of deployment options and where different types of optical x-haul solutions are considered. The results provide a cornerstone for deployment strategies that will be imperative for realizing a future-proof and cost-effective broadband access network

    Valuing flexibility in the migration to flexible-grid networks

    Get PDF
    Increasing network demand is expected to put pressure on the available capacity in core networks. Flexible optical networking can now be installed to increase network capacity in light of future traffic demands. However, this technology is still in its infancy and might lack the full functionality that may appear within a few years. When replacing core network equipment, it is therefore important to make the right investment decision between upgrading toward flexible-grid or fixed-grid equipment. This paper researches various installation options using a techno-economic analysis, extended with real option insights, showing the impact of uncertainty and flexibility on the investment decision. By valuing the different options, a correct investment decision can be made

    Energy efficiency of optically backhauled LTE: a case study

    Get PDF

    A cross-layer heuristic algorithm for addressing shadowing problem in optical attocell networks

    Get PDF
    The performance of visible light communication (VLC)-based optical attocell networks degrades due to shadowing caused by opaque objects. In order to improve reliability, we propose a cross-layer algorithm to find the optimal routing and resource allocation schemes when shadowing occurs. Simulation results show that the optimal scheme found by the proposed algorithm significantly improves the performance of optical attocell networks with one randomly shadowed link

    Joint Access-Backhaul Perspective on Mobility Management in 5G Networks

    Get PDF
    The ongoing efforts in the research development and standardization of 5G, by both industry and academia, have resulted in the identification of enablers (Software Defined Networks, Network Function Virtualization, Distributed Mobility Management, etc.) and critical areas (Mobility management, Interference management, Joint access-backhaul mechanisms, etc.) that will help achieve the 5G objectives. During these efforts, it has also been identified that the 5G networks due to their high degree of heterogeneity, high QoS demand and the inevitable density (both in terms of access points and users), will need to have efficient joint backhaul and access mechanisms as well as enhanced mobility management mechanisms in order to be effective, efficient and ubiquitous. Therefore, in this paper we first provide a discussion on the evolution of the backhaul scenario, and the necessity for joint access and backhaul optimization. Subsequently, and since mobility management mechanisms can entail the availability, reliability and heterogeneity of the future backhaul/fronthaul networks as parameters in determining the most optimal solution for a given context, a study with regards to the effect of future backhaul/fronthaul scenarios on the design and implementation of mobility management solutions in 5G networks has been performed.Comment: IEEE Conference on Standards for Communications & Networking, September 2017, Helsinki, Finlan

    Access and metro network convergence for flexible end-to-end network design

    Get PDF
    This paper reports on the architectural, protocol, physical layer, and integrated testbed demonstrations carried out by the DISCUS FP7 consortium in the area of access - metro network convergence. Our architecture modeling results show the vast potential for cost and power savings that node consolidation can bring. The architecture, however, also recognizes the limits of long-reach transmission for low-latency 5G services and proposes ways to address such shortcomings in future projects. The testbed results, which have been conducted end-to-end, across access - metro and core, and have targeted all the layers of the network from the application down to the physical layer, show the practical feasibility of the concepts proposed in the project

    40 Gbps Access for Metro networks: Implications in terms of Sustainability and Innovation from an LCA Perspective

    Full text link
    In this work, the implications of new technologies, more specifically the new optical FTTH technologies, are studied both from the functional and non-functional perspectives. In particular, some direct impacts are listed in the form of abandoning non-functional technologies, such as micro-registration, which would be implicitly required for having a functioning operation before arrival the new high-bandwidth access technologies. It is shown that such abandonment of non-functional best practices, which are mainly at the management level of ICT, immediately results in additional consumption and environmental footprint, and also there is a chance that some other new innovations might be 'missed.' Therefore, unconstrained deployment of these access technologies is not aligned with a possible sustainable ICT picture, except if they are regulated. An approach to pricing the best practices, including both functional and non-functional technologies, is proposed in order to develop a regulation and policy framework for a sustainable broadband access.Comment: 10 pages, 6 Tables, 1 Figure. Accepted to be presented at the ICT4S'15 Conferenc
    • …
    corecore