720 research outputs found
The use of Ethernet in the DataFlow of the ATLAS Trigger & DAQ
The article analyzes a proposed network topology for the ATLAS DAQ DataFlow,
and identifies the Ethernet features required for a proper operation of the
network: MAC address table size, switch performance in terms of throughput and
latency, the use of Flow Control, Virtual LANs and Quality of Service. We
investigate these features on some Ethernet switches, and conclude on their
usefulness for the ATLAS DataFlow network.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics
(CHEP03), La Jolla, Ca, March 2003, 10 pages, LaTeX, 10 eps figures. PSN
MOGT01
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Application priority framework for fixed mobile converged communication networks
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The current prospects in wired and wireless access networks, it is becoming increasingly important to address potential convergence in order to offer integrated broadband services. These systems will need to offer higher data transmission capacities and long battery life, which is the catalyst for an everincreasing variety of air interface technologies targeting local area to wide area connectivity. Current integrated industrial networks do not offer application aware context delivery and enhanced services for optimised networks. Application aware services provide value-added functionality to business applications by capturing, integrating, and consolidating intelligence about users and their endpoint devices from various points in the network. This thesis mainly intends to resolve the issues related to ubiquitous application aware service, fair allocation of radio access, reduced energy consumption and improved capacity. A technique that measures and evaluates the data rate demand to reduce application response time and queuing delay for multi radio interfaces is proposed. The technique overcomes the challenges of network integration, requiring no user intervention, saving battery life and selecting the radio access connection for the application requested by the end user. This study is split in two parts. The first contribution identifies some constraints of the services towards the application layer in terms of e.g. data rate and signal strength. The objectives are achieved by application controlled handover (ACH) mechanism in order to maintain acceptable data rate for real-time application services. It also looks into the impact of the radio link on the application and identifies elements and parameters like wireless link quality and handover that will influence the application type. It also identifies some enhanced traditional mechanisms such as distance controlled multihop and mesh topology required in order to support energy efficient multimedia applications. The second contribution unfolds an intelligent application priority assignment mechanism (IAPAM) for medical applications using wireless sensor networks. IAPAM proposes and evaluates a technique based on prioritising multiple virtual queues for the critical nature of medical data to improve instant transmission. Various mobility patterns (directed, controlled and random waypoint) has been investigated and compared by simulating IAPAM enabled mobile BWSN. The following topics have been studied, modelled, simulated and discussed in this thesis: 1. Application Controlled Handover (ACH) for multi radios over fibre 2. Power Controlled Scheme for mesh multi radios over fibre using ACH 3. IAPAM for Biomedical Wireless Sensor Networks (BWSN) and impact of mobility over IAPAM enabled BWSN. Extensive simulation studies are performed to analyze and to evaluate the proposed techniques. Simulation results demonstrate significant improvements in multi radios over fibre performance in terms of application response delay and power consumption by upto 75% and 15 % respectively, reduction in traffic loss by upto 53% and reduction in delay for real time application by more than 25% in some cases
Convergencia de tecnologĂas Ăłpticas y Ethernet en LAN, MAN y SAN: nuevas arquitecturas, anĂĄlisis de prestaciones y eficiencia energĂ©tica
MenciĂłn Internacional en el tĂtulo de doctorThe development of Information Technologies in the last decades, especially the last two, together with the introduction of computing devices to the mainstream consumer market, has had the logical consequence of the generalisation of the Internet access. The explosive development of the smartphone market has brought ubiquity to that generalisation, to the point that social interaction, content sharing and content production happens all the time.
Social networks have all but increased that trend, maximising the diffusion of multimedia content: images, audio and video, which require high network capacities to be enjoyed quickly.
This need for endless bandwidth and speed in information sharing brings challenges
that affect mainly optical Metropolitan Area Networks (MANs) and Wide Area Networks
(WANs). Furthermore, the wide spreading of Ethernet technologies has also brought the possibility to achieve economies of scale by either extending the reach of Ethernet Local Area Networks (LANs) to the MAN and WAN environment or even integrating them with Storage Area Networks (SANs). Finally, this generalisation of telecommunication technologies in every day life has as a consequence an important rise in energy consumption as well.
Because of this, providing energy efficient strategies in networking is key to ensure the scalability of the whole Internet.
In this thesis, the main technologies in all the fields mentioned above are reviewed, its
core challenges identified and several contributions beyond the state of the art are suggested to improve todayâs MANs andWANs. In the first contribution of this thesism, the integration between Metro Ethernet and Wavelength Division Multiplexion (WDM) optical transparent rings is explored by proposing an adaptation architecture to provide efficient broadcast and multicast. The second contribution explores the fusion between transparent WDM and OCDMA architectures to simplify medium access in a ring.
Regarding SANs, the third contribution explores the challenges in SANs through the
problems of Fibre Channel over Ethernet due to buffer design issues. In this contribution, analysis, design and validation with FCoE traces and simulation is provided to calculate buffer overflow probabilities in the absence of flow control mechanisms taking into account the bursty nature of SAN traffic.
Finally, the fourth and last contribution addresses the problems of energy efficiency in
Plastic Optical Fibres (POF), a new kind of optical fibre more suitable for transmission
in vehicles and for home networking. This contribution suggests two packet coalescing
strategies to further improve the energy effiency mechanisms in POFs.El desarrollo de las TecnologĂas de la InformaciĂłn en las Ășltimas dĂ©cadas, especialmente las Ășltimas dos, junto con la introducciĂłn de dispositivos informĂĄticos al mercado de masas, ha tenido como consecuencia lĂłgica la generalizaciĂłn del acceso a Internet. El explosivo desarrollo del mercado de telĂ©fonos inteligentes ha añadido un factor de ubicuidad a tal generalizaciĂłn, al extremo de que la interacciĂłn social, la comparticiĂłn y producciĂłn de contenidos sucede a cada instante. Las redes sociales no han hecho sino incrementar tal tendencia, maximizando la difusiĂłn de contenido multimedia: imĂĄgenes, audio y vĂdeo, los cuales requieren gran capacidad en las redes para poder obtenerse con rapidez. Esta necesidad de ancho de banda ilimitado y velocidad en la comparticiĂłn de informaciĂłn trae consigo retos que afectan principalmente a las Redes de Ărea Metropolitana (Metropolitan Area Networks, MANs) y Redes de Ărea Extensa (Wide Area Networks, WANs). AdemĂĄs, la gran difusiĂłn de las tecnologĂas Ethernet ha traĂdo la posibilidad de alcanzar economĂas de escala bien extendiendo el alcance de Ethernet mĂĄs allĂĄ de las Redes de Ărea Local (Local Area Networks, LANs) al entorno de las MAN y las WAN o incluso integrĂĄndolas con Redes de Almacenamiento (Storage Area Networks, SANs). Finalmente, esta generalizaciĂłn de las tecnologĂas de la comunicaciĂłn en la vida cotidiana tiene tambiĂ©n como consecuencia un importante aumento en el consumo de energĂa. Por tanto, desarrollar estrategias de transmisiĂłn en red eficientes energĂ©ticamente es clave para asegurar la escalabilidad de Internet. En esta tesis, las principales tecnologĂas de todos los campos mencionados arriba serĂĄn estudiadas, sus mĂĄs importantes retos identificados y se sugieren varias contribuciones mĂĄs allĂĄ del actual estado del arte para mejorar las actuales MANs y WANs. En la primera contribuciĂłn de esta tesis, se explora la integraciĂłn entre Metro Ethernet y anillos Ăłpticos transparentes por MultiplexiĂłn en Longitud de Onda (Wavelength Division Multiplex, WDM) mediante la proposiciĂłn de una arquitectura de adaptaciĂłn para permitir la difusiĂłn y multidifusiĂłn eficiente. La segunda contribuciĂłn explora la fusiĂłn entre las arquitecturas transparentes WDM y arquitecturas por Accesso Dividido MĂșltiple por CĂłdigos Ăpticos (OCDMA) para simplificar el acceso en una red en anillo. En lo referente a las SANs, la tercera contribuciĂłn explora los retos en SANs a travĂ©s de los problemas de Fibre Channel sobre Ethernet debido a los problemas en el diseño de bĂșferes. En esta contribuciĂłn, se provee un anĂĄlisis, diseño y validaciĂłn con trazas FCoE para calcular las probabilidades de desbordamiento de buffer en ausencia de mecanismos de control de flujo teniendo en cuenta la naturaleza rafagosa del trĂĄfico de SAN. Finalmente, la cuarta y Ășltima contribuciĂłn aborda los problemas de eficiencia energĂ©tica en Fibras Ăpticas PlĂĄsticas (POF), una nueva variedad de fibra Ăłptica mĂĄs adecuada para la transmisiĂłn en vehĂculos y para entornos de red caseros. Esta contribuciĂłn sugiere dos estrategias de agrupamiento de paquetes para mejorar los mecanismos de eficiencia energĂ©tica en POFs.Programa Oficial de Posgrado en IngenierĂa TelemĂĄticaPresidente: Luca Valcarenghi.- Secretario: Ignacio Soto Campos.- Vocal: Bas Huiszoo
Application of Asynchronous Transfer Mode (Atm) technology to Picture Archiving and Communication Systems (Pacs): A survey
Broadband Integrated Services Digital Network (R-ISDN) provides a range of narrowband and broad-band services for voice, video, and multimedia. Asynchronous Transfer Mode (ATM) has been selected by the standards bodies as the transfer mode for implementing B-ISDN; The ability to digitize images has lead to the prospect of reducing the physical space requirements, material costs, and manual labor of traditional film handling tasks in hospitals. The system which handles the acquisition, storage, and transmission of medical images is called a Picture Archiving and Communication System (PACS). The transmission system will directly impact the speed of image transfer. Today the most common transmission means used by acquisition and display station products is Ethernet. However, when considering network media, it is important to consider what the long term needs will be. Although ATM is a new standard, it is showing signs of becoming the next logical step to meet the needs of high speed networks; This thesis is a survey on ATM, and PACS. All the concepts involved in developing a PACS are presented in an orderly manner. It presents the recent developments in ATM, its applicability to PACS and the issues to be resolved for realising an ATM-based complete PACS. This work will be useful in providing the latest information, for any future research on ATM-based networks, and PACS
Achieving the Internal Market for e-communications. CEPS Task Force Reports, 20 June 2008
Over the past two years, the debate on the review of the EU regulatory framework for electronic communications has become hectic. After the European Commission adopted its proposed set of measures in November 2007, the European Parliament has shown an unprecedented interest in topics such as spectrum policy, functional separation of the incumbentsâ networks, the creation of a new European authority on telecoms, etc. After the successful experience of the first CEPS Task Force on âPolicy Challenges for the Information Superhighwayâ, which ended in June 2006, a new Task Force on âAchieving the Internal Market for e-communicationsâ was launched by CEPS with the explicit aim to provide expertise to Members of the European Parliament in their reading of the proposed review. The Task Force was chaired by Magnus Lemmel, former Acting Director General at DG Enterprise, European Commission, and currently Senior Advisor at KREAB. This report summarises the results of the opinions that were expressed over five meetings, the last two of which took place inside the European Parliament. This highly influential report was drafted by Andrea Renda, Senior Research Fellow at CEPS
CSCI 2017
ProducciĂłn CientĂficaElastic Optical Networks (EON) are seen as an essential technology to implement the backhaul of Future Internet allowing the deployment of emerging paradigms like the Internet of Things (IoT), Tactile Internet, or Industry 4.0. When designing those Elastic Optical Networks (EONs), the Routing and Spectrum Assignment (RSA) problem has to be solved. In this paper, we analyse the effect of using two types of flexibility in a wellâknown RSA method. A simulation study will be presented with the main results of this comparison.Ministerio de EconomĂa, Industria y Competitividad (Projects TEC2014-53071-C3-2-P, TEC2015-71932-REDT)Ministerio de EducaciĂłn, Cultura y Deporte (Proyect BES-2015-074514
Techniques for signal to noise ratio adaptation in infared optical wireless for optimisation of receiver performance
The challenge of creating a new environment of links for wireless infrared and optical local area networks (LANs) is driving new innovations in the design of optical transceivers. This thesis is concerned with a systematic approach to the design of receivers for indoor optical wireless communication. In particular, it is concerned with how to offer bandwidth adjustment capability in a receiver according to the dynamic service quality of the incoming signals. Another part of the discussion of the thesis is how one can properly choose the front-end preamplifier and biasing circuitry for the photodetector. Also, comparison is made between different types of amplifier, and the methods of bandwidth enhancement.
The designs of six different techniques of integrating transimpedance amplifiers, with photodetectors to adapt an adjustable bandwidth control receiver are discussed. The proposed topologies provide an adjustable range of bandwidths for different frequency ranges, typically between 52Hz to 115MHz. The composite technique designs were used to incorporate into a system with an automatic gain control to study its effect, on an optical wireless receiver which had bandwidth adjustment and automatic gain adjustment. Theoretical analysis of noise performance for all the designed circuits is also presented. The theory and design of obstacles of indoor optical wireless receiver delivery, in addition to techniques for mitigating these effects, are discussed. This shows that infrared is a viable alternative to ratio for certain applications
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