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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.
361

Propuesta de migración de la red NGN de una operadora implementada en IP hacia MPLS / Giancarlo García Girón.

García Girón, Giancarlo. 09 May 2011 (has links)
La presente tesis consiste en brindar una propuesta técnica para la migración del core de la red NGN de una operadora implementada en IP hacia IPMPLS. Durante el desarrollo de este proyecto se presenta el marco teórico de las redes NGN y se realiza la comparación entre las tecnologías IP y MPLS con el objetivo de observar las ventajas que presenta MPLS al brindar QoS. Luego, se presenta la Propuesta de migración en la cual se presenta el escenario inicial así como los aspectos técnicos, plan de trabajo y el escenario final de la migración. Por último, se detallan las conclusiones obtenidas al final de este proyecto, recomendaciones y trabajos futuros.
362

Design of a channel board used in an electronic warfare target simulator

Andersson, Peter January 2006 (has links)
A channel board was designed for a DRFM circuit. The DRFM is implemented in a Virtex-4 FPGA from Xilinx. In the future a similar channel board is intended to be used for target echo generation in ELSI which is an electronic warfare simulator at Saab Bofors Dynamics in Linköping. Besides the DRFM circuit the channel board consists of analog-to-digital converters, digital-to-analog converters, Ethernet plug-in board with a microcontroller, voltage regulators, FPGA configuration memory, voltage amplifiers, current amplifiers, oscillator, buffers/drivers and bus transceivers. The sample rate is 200 MHz and LVDS signalling standard is used between the DRFM circuit and the converters. The channel board has a JTAG interface which enables in-system programming of the FPGA. This implies that the DRFM can easily be redesigned. An external computer can manage the channel board via Ethernet. Software was developed for the microcontroller on the channel board and for the external computer. The function of the channel board is heavily dependent on the DRFM circuit. The channel board design resulted in the assembly of a prototype circuit board. Measurements were performed in a lab and the channel board was approved to be integrated in ELSI for further tests.
363

Energy Efficiency and Differentiated QoS in Next Generation PONs

Chen, Shen 03 February 2012 (has links)
Energy conservation in next generation Passive Optical Network system (NG-PON) has gained more and more attention. NG-PON system can not only deliver best-effort data traffic, but also real-time data traffic, e.g. voice and video, that have strict bandwidth, delay, and jitter requirements. To meet the energy and service requirements, a NG-PON system must have energy efficiency and differentiated QoS mechanism built in. Few research efforts have been reported on maximizing energy efficiency while maintaining QoS in the fairly new PON system design. We have extended the Upstream Centric Scheme (UCS-based) scheduling scheme idea into a novel QoS-differentiated energy-efficient PON system consisting of two main modules: firstly, the proposed differentiated QoS analytical model is described in detail to reduce the packet delay in the upstream traffic scheduling. The simulations further demonstrate the QoS metrics of the system: packet delay, bandwidth utilization, dropped packet rate, and queue length. Secondly, a novel analysis is proposed for downstream traffic scheduling with limited service discipline at Optical Line Terminal (OLT) side under the UCS-based Green Bandwidth Allocation (GBA) framework. We, first, derive the mean packet delay expression of this model. Then, the sleep time for each Optical Network Unit (ONU) is derived by setting identical upstream/downstream transmission cycle time. Based on the analytical model, an approach is developed to save the maximum energy in a dynamic PON system while without violating the delay requirement. Moreover, simulation is conducted to verify the developed analytical model and the proposed approach. In the end, considering the differentiated QoS and downstream traffic scheduling, an algorithm of the energy efficient scheduling scheme is proposed as well under the UCS-based GBA.
364

Spatially Resolved Equalization: A New Concept in Intermodal Dispersion Compensation for Multimode Fiber

Patel, Ketan M. January 2004 (has links)
The use of optical fiber is of great interest in developing extensive, high-speed networking infrastructures. Optical fiber provide many advantages over traditional copper cables and wireless links. Among them are high security, low electromagnetic interference, extremely low loss and high bandwidths, light weight and manageability. However, the very small wavelengths associated with optical radiation requires very small waveguide dimensions. Waveguide dimension of single mode fiber (SMF) are < 10µm, resulting in relatively poor yield in device manufacturing. For residential and other last-mile networks topologies, cost constraints limit the appeal of SMF. Multimode fiber (MMF) allow for less restrictive manufacturing tolerances; however, the distortion that results from the dispersion in propagation among the many modes can be prohibitively large for data rates approaching and exceeding 1 Gb/s. To improve the deployability of MMF, a method of dispersion compensation that maintains the ease-of-use characteristic of MMF is required This dissertation demonstrates an opto-electronic method of dispersion compensation by the use of a multisegment photodetector. It is shown the modes of the fiber can be seperated such that when the individual photodetector signals are combined, the resulting temporal response of the fiber link is improved from that of a conventional fiber link. This method is extremely robust to system variation and is independent of data rate and transmission format, allowing it to be employed in a wide variety of optical links. More importantly, the implementation demonstrated is comparable, in simplicity and alignment tolerance, to a conventional photodetector. System performance is shown using both temporal and frequency response as well as real bit error rate and eye diagram measurements.
365

Soft Afdx (avionics Full Duplex Switched Ethernet) End System Implementation With Standard Pc And Ethernet Card

Erdinc, Emre 01 May 2010 (has links) (PDF)
ARINC 664/AFDX (Avionics Full Duplex Switched Ethernet) protocol is a leading onboard communication technology in civil aviation. As AFDX is a new technology, unit cost of the hardware devices are high and protocol is open to changes. This thesis discusses the design of an AFDX End System application for test environment with a software based solution with cheap COTS (Commercial offthe shelf) equipment, explains the implementation of the software and analysis the performance.
366

Workshop Intranet 1997

Ehrig, Matthias 02 December 1997 (has links) (PDF)
Vortragsfolge: Karsten Priemer: Integration heterogener Applikationsumgebungen in Intranets mit Web - Technologien Swen Gerber: Netzcomputer-Konzepte Sven Graupner: JavaOS - Ein Betriebssystem für Intranets? Patrick Voigt: Netscape Internet Foundation Classes (IFC) Christoph Ziegler: MONARCH - Stand und künftige Aufgaben Holger Trinks: WWW-Robots Frank Richter: ¨Das richtige Mailprogramm¨ Bert Auerbach: Internet-Suchsysteme Frank Richter: Directories - Technologien und Datenadministration Ralph Sontag: Aufbau einer Certification Authority Jörg Hüttmann: Digitales Geld Mario Küchler: Internet-Telefonie Torsten Naumann: Ressourcensteuerung für Internet-Zugänge Michael Hasenstein: Eine zentrale Faxserverlösung auf Basis Hylafax+Web-Frontend Ronald Wahl: Intranet-Nutzermanagement Wolfgang Riedel: Konzepte der Software-Refinanzierung Marco Günther: Linux kontra NT - ¨strategische Plattformen¨? - Teil I Thomas Riedel: Linux kontra NT - ¨strategische Plattformen¨? - Teil II Dietmar Grunewald: WINDOWS-NT im öffentlichen PC-Pool Teil I: Servereinsatz und Nutzerverwaltung Jens Wagner: WINDOWS-NT im öffentlichen PC-Pool Teil II: Anwendungssoftware Matthias Ehrig: Diskless Linux - Möglichkeiten der SysAdmin Matthias Clauß: Skalierbare Systemadministration von LINUX-Rechnern Christian Bobber: WWW-Sicherheitsaspekte Thomas Müller: Authentisierung und Verteilung von Konfigurationsfiles Thomas Förster: Verzeichnissysteme für neue Anwendungen Jürgen Winkler: MathLink - der Kommunikations-Standard von Mathematica Ludwig Wolf: Ethernet - neue Normen, neue Perspektiven Thomas Schier: ATM - Standards und deren praktischer Einsatz Günther Fischer: IP-Routing in unserem (ATM-)Netz Prof. Uwe Hübner: Intranet - Erwartungen und Entwicklungen
367

Ethernet-basierte dynamisch partielle Rekonfiguration in Netzwerken

Proß, Uwe, Goller, Sebastian, Schneider, Axel, Knäblein, Joachim, Müller, Bernd, Putsche, Marcel, Heinkel, Ulrich 08 June 2007 (has links) (PDF)
Die Entwicklung von Telekommunikationsnetzwerken unterliegt einer Reihe von Herausforderungen. Hohe Komplexität, hohe Bandbreite mit veränderlichen Anforderungen, kurze Entwicklungszyklen und sich ständig ändernde Marktanforderungen sind verbunden mit sich immer schneller ändernden Standards. Daraus resultieren hohe Risiken für die Entwicklung von Kommunikationslösungen. Die Kombination von rekonfigurierbaren und ASIC-Technologien bietet eine Möglichkeit, die Vorteile der ASICTechnologie weitestgehend zu erhalten und dem Risiko von Standardänderungen und Designfehlern zu begegnen. Dieser Beitrag stellt anhand eines Ethernet-verarbeitenden SoC eine Möglichkeit vor, paketorientierte Netzwerkknoten hinsichtlich zukünftiger Änderungen flexibel zu implementieren. Der Netzwerkknoten kann über spezielle Ethernet-Pakete rekonfiguriert und somit an geänderte Anforderungen angepasst werden.
368

Testbed evaluation of integrating ethernet switches in the differentiated services architecture using virtual LANs

Fornaro, Antony 05 1900 (has links)
No description available.
369

Energy Efficiency and Differentiated QoS in Next Generation PONs

Chen, Shen 03 February 2012 (has links)
Energy conservation in next generation Passive Optical Network system (NG-PON) has gained more and more attention. NG-PON system can not only deliver best-effort data traffic, but also real-time data traffic, e.g. voice and video, that have strict bandwidth, delay, and jitter requirements. To meet the energy and service requirements, a NG-PON system must have energy efficiency and differentiated QoS mechanism built in. Few research efforts have been reported on maximizing energy efficiency while maintaining QoS in the fairly new PON system design. We have extended the Upstream Centric Scheme (UCS-based) scheduling scheme idea into a novel QoS-differentiated energy-efficient PON system consisting of two main modules: firstly, the proposed differentiated QoS analytical model is described in detail to reduce the packet delay in the upstream traffic scheduling. The simulations further demonstrate the QoS metrics of the system: packet delay, bandwidth utilization, dropped packet rate, and queue length. Secondly, a novel analysis is proposed for downstream traffic scheduling with limited service discipline at Optical Line Terminal (OLT) side under the UCS-based Green Bandwidth Allocation (GBA) framework. We, first, derive the mean packet delay expression of this model. Then, the sleep time for each Optical Network Unit (ONU) is derived by setting identical upstream/downstream transmission cycle time. Based on the analytical model, an approach is developed to save the maximum energy in a dynamic PON system while without violating the delay requirement. Moreover, simulation is conducted to verify the developed analytical model and the proposed approach. In the end, considering the differentiated QoS and downstream traffic scheduling, an algorithm of the energy efficient scheduling scheme is proposed as well under the UCS-based GBA.
370

Improving resource utilization in carrier ethernet technologies

Caro Perez, Luis Fernando 19 January 2010 (has links)
Ethernet está empezando a pasar de las redes de área local a una red de transporte. Sin embargo, como los requisitos de las redes de transporte son más exigentes, la tecnología necesita ser mejorada. Esquemas diseñados para mejorar Ethernet para que cumpla con las necesidades de transporte se pueden categorizar en dos clases. La primera clase mejora solo los componentes de control de Ethernet (Tecnologías basadas en STP), y la segunda clase mejora tanto componentes de control como de encaminamiento de Ethernet (tecnologías basadas en etiquetas). Esta tesis analiza y compara el uso de espacio en las etiquetas de las tecnologias basadas en ellas para garantizar su escalabilidad. La aplicabilidad de las técnicas existentes y los estudios que se pueden utilizar para superar o reducir los problemas de escalabilidad de la etiqueta son evaluados. Además, esta tesis propone un ILP para calcular el óptimo rendimiento de las technologias basadas en STP y las compara con las basadas en etiquetas para ser capaz de determinar, dada una específica situacion, que technologia utilizar. / Ethernet is starting to move from Local area networks to carrier networks. Nevertheless as the requirements of carrier networks are more demanding, the technology needs to be enhanced. Schemes designed for improving Ethernet to match carrier requirements can be categorized in two classes. The first class improves Ethernet control components only (STP based technologies), and the second class improves both Ethernet control and forwarding components (label based forwarding technologies). This thesis analyzes and compares label space usage for the label based forwarding technologies to ensure their scalability. The applicability of existing techniques and studies that can be used to overcome or reduce label scalability issues is evaluated. Additionally this thesis proposes an ILP to calculate optimal performance of STP based approaches and compares them with label based forwarding technologies to be able to determine, given a specific scenario, which approach to use.

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