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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

SWITCHING TO THE FUTURE OF RANGE COMMUNICATIONS AT EDWARDS AFB

Gribble, Simeon S., Switzer, Earl R. 10 1900 (has links)
International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / The Edwards Digital Switch (EDS) provides mission critical voice and time-spaceposition information (TSPI) communication switching capability to the Edwards Test Range. The present system has been in operation for about 10 years. The core of this system is based on widely used commercial-off-the-shelf (COTS) time-slot interchange switches that were designed for a 40-year service life. The application layers of the system, comprising the command/control elements and the communications and user interfaces, were custom developed by the prime contractor to satisfy the performance requirements of the Air Force Flight Test Center (AFFTC). Problems with the current system include difficulty in obtaining replacement items for equipment developed by the prime contractor and higher than expected failure rates for this equipment. Based on experience, the service life for the equipment developed by the prime contractor appears to be about 15 years. Another problem is that lower cost packet switches are taking market share from the more traditional time-slot interchange switches. This factor tends to accelerate the obsolescence of the existing COTS equipment. Solutions are being investigated to update or replace the EDS. One solution is to reuse the existing COTS core equipment and replace the present application layers, preferably with COTS. Another solution is to replace the entire system with COTS or vendormodified COTS hardware and software.
2

Optimisation of multi-purpose switch centres

Raby, P. S. January 1987 (has links)
No description available.
3

Ethernetswitch med HDL

Jonsson, Andreas, Rousk, Niclas Unknown Date (has links)
No description available.
4

Design of switch architecture for the geographical cell transport protocol

Gyawali, Umesh 25 February 2009
The Internet is divided into multiple layers to reduce and manage complexity. The International Organization for Standardization (ISO) developed a 7 layer network model and had been revised to a 5 layer TCP/IP based Internet Model. The layers of the Internet can also be divided into top layer TCP/IP protocol suite layers and the underlying transport network layers. SONET/SDH, a dominant transport network, was designed initially for circuit based telephony services. Advancement in the internet world with voice and video services had pushed SONET/SDH to operate with reduced efficiencies and increased costs. Hence, redesign and redeployment of the transport network has been and continues to be a subject of research and development. Several projects are underway to explore new transport network ideas such as G.709 and GMPLS.<p> This dissertation presents the Geographical Cell Transport (GCT) protocol as a candidate for a next generation transport network. The GCT transport protocol and its cell format are described. The benefits provided by the proposed GCT transport protocol as compared to the existing transport networks are investigated. Existing switch architectures are explored and a best architecture to be implemented in VLSI for the proposed transport network input queued virtual output queuing is obtained. The objectives of this switch are high performance, guaranteed fairness among all inputs and outputs, robust behavior under different traffic patterns, and support for Quality of Service (QoS) provisioning. An implementation of this switch architecture is carried out using HDL.<p> A novel pseudo random number generation unit is designed to nullify the bias present in an arbitration unit. The validity of the designed is checked by developing a traffic load model. The speedup factor required in the switch to maintain desired throughput is explored and is presented in detail. Various simulation results are shown to study the behavior of the designed switch under uniform and hotspot traffic. The simulation results show that QoS behavior and the crossing traffic through the switch has not been affected by hotspots.
5

Ethernetswitch med HDL

Jonsson, Andreas, Rousk, Niclas Unknown Date (has links)
No description available.
6

Design of switch architecture for the geographical cell transport protocol

Gyawali, Umesh 25 February 2009 (has links)
The Internet is divided into multiple layers to reduce and manage complexity. The International Organization for Standardization (ISO) developed a 7 layer network model and had been revised to a 5 layer TCP/IP based Internet Model. The layers of the Internet can also be divided into top layer TCP/IP protocol suite layers and the underlying transport network layers. SONET/SDH, a dominant transport network, was designed initially for circuit based telephony services. Advancement in the internet world with voice and video services had pushed SONET/SDH to operate with reduced efficiencies and increased costs. Hence, redesign and redeployment of the transport network has been and continues to be a subject of research and development. Several projects are underway to explore new transport network ideas such as G.709 and GMPLS.<p> This dissertation presents the Geographical Cell Transport (GCT) protocol as a candidate for a next generation transport network. The GCT transport protocol and its cell format are described. The benefits provided by the proposed GCT transport protocol as compared to the existing transport networks are investigated. Existing switch architectures are explored and a best architecture to be implemented in VLSI for the proposed transport network input queued virtual output queuing is obtained. The objectives of this switch are high performance, guaranteed fairness among all inputs and outputs, robust behavior under different traffic patterns, and support for Quality of Service (QoS) provisioning. An implementation of this switch architecture is carried out using HDL.<p> A novel pseudo random number generation unit is designed to nullify the bias present in an arbitration unit. The validity of the designed is checked by developing a traffic load model. The speedup factor required in the switch to maintain desired throughput is explored and is presented in detail. Various simulation results are shown to study the behavior of the designed switch under uniform and hotspot traffic. The simulation results show that QoS behavior and the crossing traffic through the switch has not been affected by hotspots.
7

A Study on the Design and Analysis of 3-Dimensional Micro-Optical Switch

Hsieh, Tsung-Fu 19 July 2002 (has links)
Presently, the two-dimensional optical switch is widely applied in the field of the optics communication. Due to the restrictions of the Surface Micro-Machining in MEMS (Micro Electric-Mechanical System), the traditional optical switch can only deliver the signal of fibers in a two-dimensional plane. The common frameworks and principles of two-dimensional optical switch, array of optical switches and micro-actuators are developed. Take the advantage of developed technologies and the concept of the spatial mechanisms, a three-dimensional optical switch possessing two degree of freedoms is designed in this study. Different from the single selectivity of the signal transmission delivered by the two-dimensional optical switch, the three-dimensional optical switch designed in this study possesses two main functions of signal transmission in vertical and horizontal directions. By means of function of these two transmission directions, the signal of fibers of two different silicon substrates can be easily connected. It is believed that, the possibility and the selectivity of the signal transmission of fibers are increased.
8

Enhancing progress in bi-lateral switching in power converters

Ehlers, PJ, Richards, CG, Nicolae, DV 15 April 2011 (has links)
To enhance the progress of control of switching converters, IP blocks should be identified and be made available. These power technologies can be readily implemented and the pace of progress be enhanced. This article discusses the implementation of bi-lateral switches. From the example presented, it will be clear that control of the switches is a combination of fixed commutation techniques and variable intelligent control.
9

SWITCH, a computer peripheral device which monitors 256 points

Vallino, James Richard, January 1976 (has links)
Thesis--Wisconsin. / Includes bibliographical references (leaf 39).
10

Finite Difference Time Domain Analysis of MEMS Transfer Switch

Gupta, Munish January 2005 (has links)
No description available.

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