291 research outputs found

    Optical fibre local area networks

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    FirstLight: Pluggable Optical Interconnect Technologies for Polymeric Electro-Optical Printed Circuit Boards in Data Centers

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    The protocol data rate governing data storage devices will increase to over 12 Gb/s by 2013 thereby imposing unmanageable cost and performance burdens on future digital data storage systems. The resulting performance bottleneck can be substantially reduced by conveying high-speed data optically instead of electronically. A novel active pluggable 82.5 Gb/s aggregate bit rate optical connector technology, the design and fabrication of a compact electro-optical printed circuit board to meet exacting specifications, and a method for low cost, high precision, passive optical assembly are presented. A demonstration platform was constructed to assess the viability of embedded electro-optical midplane technology in such systems including the first ever demonstration of a pluggable active optical waveguide printed circuit board connector. High-speed optical data transfer at 10.3125 Gb/s was demonstrated through a complex polymer waveguide interconnect layer embedded into a 262 mm × 240 mm × 4.3 mm electro-optical midplane. Bit error rates of less than 10-12 and optical losses as low as 6 dB were demonstrated through nine multimode polymer wave guides with an aggregate data bandwidth of 92.8125 Gb/s

    The creation and early implementation of a high speed fiber optic network for a university health sciences center

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    pre-printIn late 1989 the University of Missouri Health Sciences Center began the process of creating an extensive fiber optic network throughout its facilities, with the intent to provide networked computer access to anyone in the Center desiring such access, regardless of geographic location or organizational affiliation. A committee representing all disciplines within the Center produced and, in conjunction with independent consultants, approved a comprehensive design for the network. Installation of network backbone components commenced in the second half of 1990 and was completed in early 1991. As the network entered its initial phases of operation, the first realities of this important new resource began to manifest themselves as enhanced functional capacity in the Health Sciences Center. This paper describes the development of the network, with emphasis on its design criteria, installation, early operation, and management. Also included are discussions on its organizational impact and its evolving significance as a medical community resource

    Information engineering

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    SDN-based control and orchestration of optical data centre networks

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    The use of the Internet is linked with the constant technological change that the world is suffering nowadays, which is responsible for the important need to update the infrastructure of current data centers. The amount of traffic that is moving in data centers has increased significantly in the past few years, so a better alternative for them should be studied, as the use of Ethernet or InfiniBand is no longer appropriate in terms of scalability and flexibility. Optical technology is one possible solution for it, as it provides a big bandwidth, low latency and an overall better performance. However, the physical resources that form a data center should be managed in an efficient way. To perform an optimum use of them, the new concept of virtual data center appeared, where the orchestration of the resources is done with the aim of offering to a cloud infrastructure to a third party. In this context, OpenStack has become one of the most popular open source platforms when building public or private clouds, based on three important aspects: compute, storage and network. But the flexibility of these cloud infrastructures is attached to being scalable or dynamic. In this case, Software Definiton Network (SDN) and Network Function Virtualization (NFV) play an important role in data centers, as they allow to build complex network capabilities on demand. In this project, we experimentally demonstrate the programmable OPsquare data center network empowered by an SDN control plane. The implementation is based on monitoring the real-time statistics of the network, so some actions such as network slices provisioning and reconfiguration, packet priority class assignment or dynamic load balancing operations can be done in order to achieve the required Quality of Service level. This project is a cooperation between TU/e (Eindhoven University of Technology, The Netherlands) and UPC (Universitat PolitĂšcnica de Catalunya, Barcelona)

    Journal of Telecommunications in Higher Education

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    In This Issue 6 Lead, Follow or Get Out of the Way! 12 Bringing Private Housing onto the Campus LAN 16 Bundling Internet Data and Voice Technologies on the Same T3 Span 20 Mission Possible: Harper College Equips for the Future 30 UCSD Maximizes Network with One-Wire Solution 34 Optical Fiber Helps Construct a Campus for the 21st Century 38 The Laptop Initiative at Longwood Colleg

    Multilevel Modulation and Transmission in VCSEL-based Short-range Fiber Optic Links

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    As the demand for ever higher throughput short-range optical links is growing, research and industry associations have shown increased interest in multilevel modulation formats, such as the four leveled pulse amplitude modulation, referred to as 4-PAM. As on-off keying (OOK) persists to be the choice for low latency applications, for example high performance computing, datacenter operators see 4-PAM as the next format to succeed current OOK-based optical interconnects. Throughput can be increased in many ways: parallel links can be deployed, multicore fibers can be used or more efficient modulation formats with digital signal processing is an alternative. Therefore, to improve link data rates, the introduction of new modulation formats and pre-emphasis are primarily considered in this thesis. In a bandwidth-limited link, turning towards spectrally efficient formats is one of the methods to\ua0 overcome the bandwidth requirements of OOK. Such are the considerations when opting for 3-PAM or 4-PAM schemes. Both require lower bandwidth than OOK and are potential candidates in such scenarios. 4-PAM provides double spectral efficiency and double data rate at the same symbol rate as on-off keying, but, as with any technology transition, new challenges emerge, such as a higher SNR requirement, a lower tolerance to VCSEL nonlinearities and skewing of the signal in the time domain. 3-PAM could potentially be an in-between solution, as it requires 33% less bandwidth than OOK and is less sensitive to VCSEL dynamics which could impair the transmission. A study is presented where 3-PAM has outperformed both OOK and 4-PAM in the same link. Detailed investigation of legacy 25G class VCSELs has shown that devices with moderate damping are suitable for the transition to 4-PAM. The pre-emphasis of signals is a powerful tool to increase link bandwidth at the cost of modulation amplitude. This has been investigated in this thesis for on-offkeying and has shown 9% and 27% increase in bit rate for error-free operation with two pre-emphasis approaches. Similarly, pre-emphasis of a 4-PAM electrical signals has enabled 71.8 Gbps transmission back-to-back with lightweight forward error correction and 94 Gbps net data rate was achieved with the same pre-emphasis and post-processing using an offline least-mean-square equalizer

    Image acquisition and storage for medical imaging systems

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    Image Acquisition and Storage for Medical Imaging Systems investigates the issues and requirements to develop a medical imaging system for the dental industry. Research was conducted through studying image acquisition and digitization systems, image file format standards, and data image distribution techniques in a medical facility. Furthermore, the future trends in medical imaging industry were identified; From the studies gathered, a medical imaging system called Miniature Image and Data Acquisition System (MIDAS) was created. MIDAS is an intraoral camera imaging system, which has the capability to capture images of patient\u27s teeth and gums, track images with patient data, and distributes images and data over a Local Area Network (LAN). These capabilities match or exceed those found in most intraoral camera systems
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