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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

Characterization and design of multifunction photonic devices for next-generation fiber-to-the-home optical network units

Schrenk, Bernhard 28 April 2011 (has links)
El estudio e investigación en el campo de las redes ópticas de acceso han sido fomentadas en años recientes debido a la continua migración de Servicios multimedia que son ofrecidos a través de Internet. Aunque los dispositivos utilizados para implementar Fiber-to-the-Home (fibra a casa), que reemplazan las soluciones tradicionales basadas en cable de cobre, están basadas aún en micro-óptica, se puede prever una evolución hacia integración fotónica. Todavía queda la pregunta acerca de los diseños necesarios para este paso importante de integración, que debe ser optimizado en términos del desempeño de transmisión, eficiencia energética y costo con el fin de lograr todos los requerimientos de las redes fotónicas de siguiente generación. Como elemento más crítico en las redes de acceso ópticas es el equipo en los clientes, este trabajo se centra en éste. Los temes cubiertos abarcan una gama amplia e incluyen: el reciclado de longitudes de onda para transmisión de datos en full-dúplex a través de una sola frecuencia óptica; la generación de formatos de modulación avanzados con moduladores semiconductores de bajo costo y factor pequeño de integración; soporte de amplificación óptica a través de técnicas de sembrado y el soporte de funcionalidades de capes superiores en la capa física. Después de la prueba principal de las técnicas propuestas, se resaltan los beneficios, impedimentos y caminos de reemplazo hacia sistemas fotónicos multifuncionales a través de casos de estudio. Por su parte, los diseños más representativos se profundizan más sobre todo por su posibilidad de ser integrados fotónicamente. / Optical access technology has experienced a boost in the last years, thanks to the continuously migrating multimedia services that are offered over the internet. Though the devices used for deploying Fiber-to-the-Home instead of traditional copper-based solutions are still based on micro-optics, an evolution towards photonic integration can be foreseen. What remains is the question about the exact designs for this important step of integration, which should be optimized in terms of transmission performance, energy efficiency and cost to address all requirements of next-generation photonic networks. As the most critical element in optical access, the customer premises equipment is in primary focus of this discussion. The covered topics span over a wide range and include wavelength recycling for full-duplex data transmission on a single optical frequency, the generation of advanced modulation formats with low-cost semiconductor modulators with small form factor, support for optical amplification by means of seeding techniques and the support of higher layer functionality at the physical layer. Next to the principal proof of the proposed techniques, the benefits, impediments and upgrade paths towards multifunctional photonic systems are highlighted in different case studies, while the most representative designs are further discussed in their capability of being photonically integrated.
2

Transimpedance amplifier design using 0.18 um CMOS technology

Bespalko, Ryan Douglas 19 July 2007 (has links)
This thesis examines the design of high speed transimpedance amplifiers (TIAs) in low cost complimentary metal oxide semiconductor (CMOS) technology. Due to aggressive scaling, CMOS has become an attractive technology for high speed analog circuits. Besides the cost advantage, CMOS offers the potential for higher levels of integration since the analog circuits can be integrated with digital electronics on the same substrate. A 2.5 Gbps transimpedance amplifier fabricated using 0.18 um CMOS technology is presented. The TIA uses a shunt-shunt feedback topology with a cascode gain stage. Measurements of the transimpedance gain, group delay, and common mode rejection ratio are presented for the TIA and show a good match to simulated results. The noise of the TIA was characterized by measuring the noise parameters of the TIA. The noise parameters are then used to determine the input referred noise current spectral density. A 10 Gbps transimpedance amplifier fabricated using 0.18 um CMOS technology is also presented. This TIA uses a shunt-shunt feedback topology with a common source gain stage. In order to achieve the required bandwidth, the TIA uses a bandwidth extension technique called shunt-series inductive peaking. A discussion of the different methods of bandwidth extension using inductive peaking is included, and the optimal configurations for maximally flat responses are shown for shunt inductive peaking,series inductive peaking, and shunt-series inductive peaking. The TIA circuit topology is optimized using a novel noise analysis that uses a high frequency noise model for the transistor. The optimum transistor size and bias current are determined to minimize the amplifier noise. Unfortunately differential measured results are not available due to a stability problem in the amplifier. The cause of this instability is further explored and modifications to solve the problem are discussed. Single-ended results are presented and show reasonable agreement with simulated results. Differences in the results are attributed to poor modelling of the on-chip spiral inductors. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2007-07-16 13:34:41.46
3

Laser Driver Design in 0.18 um CMOS Technology

O'FARRELL, Michael 24 September 2010 (has links)
This thesis presents the design and analysis of two high speed analog laser driver stages (LDS) for use in a passive optical network (PON) upstream burst-mode transmitter (BM-Tx) using low cost complementary metal oxide semiconductors (CMOS) technology. The maturation of CMOS technology has lead to aggressive scaling of device sizes which has made it an increasingly attractive technology for high speed analog design. CMOS provides high levels of integration as it is the industry standard for digital circuits, analog and digital systems can share one substrate reducing costs. Additionally CMOS is a more cost effective solution than traditional expensive high speed analog substrates. A 2.5 Gbps LDS fabricated in 0.18 um CMOS technology is presented. The LDS uses a two stage per-amplifier. Stage one consists of a cascode differential pair with a source follower voltage buffer, while stage two consists of a shunt inductively peaked differential pair using active inductors. A differential pair composed of large transistors is used in an open drain configuration for the output stage. Measurements of S-parameters are presented which accurately agree with simulations. Electrical eye diagram measurements are presented which demonstrate the LDS is able to provide a modulation current of 14.6-58 mA. 10%-90% approximate rise/fall times of 230/260 ps was obtained for a modulation current of 58 mA. Power consumption of the core was determined to be 68.5 mW, while the chip consumed an area of 0.8 mm x 0.7 mm including pads. A 10 Gbps LDS fabricated in 0.18 um CMOS technology is also presented. The LDS uses a cascode differential pair for the output stage. The per-amplifier for this design consists of a differential pair and utilizes spiral inductors for series inductive peaking between the per-amplifier and output stage. Measurements of S-parameters are presented which accurately agree with simulations. Electrical eye diagram measurements are presented which demonstrate the LDS is able to provide a modulation current of 22.6-62 mA. 10%-90% rise/fall time of 87 ps and 75 ps are respectively obtained while operating at maximum modulation current. The core of the LDS consumes a power of 287 mW, while the chip consumed an area of 0.79 mm x 0.7mm. The measured electrical eye diagrams for the 2.5 Gbps and the 10 Gbps meet the timing requirements for the GPON standard. Further work is needed to investigate whether or not the timing requirements would still be met once the CMOS chips are integrated with commercial laser diodes. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2010-09-24 10:43:33.418
4

Open Access Fiber to the Home Networking

Timmerman, Roger E. 01 December 2009 (has links) (PDF)
The concept of open-access networks appeals to communities that want to invest in and improve their access to modern telecommunications services. By investing in, or building their own open-access telecommunications networks, communities can create an environment where several telecommunications service providers can co-exist on a common open-access infrastructure. This model promotes innovation and competition among several smaller service providers rather than having a monopoly or oligopoly from those companies that can afford the investment of infrastructure in the community. This research provides an analysis of two large open-access fiber-to-the-home networks in Utah to determine a set of recommendations and best-practices for other communities that are considering building their own community networks. The networks analyzed in this research are the Utah Telecommunications Open Infrastructure Agency (UTOPIA) and the Provo City network (iProvo).
5

On Understanding the Internet Via Edge Measurement

Sargent, Matthew 04 September 2015 (has links)
No description available.
6

Εφαρμογή μοντέλων διείσδυσης ευρυζωνικής πρόσβασης σε αστικές – ημιαστικές περιοχές

Μουντζούρης, Νικόλαος 05 February 2015 (has links)
Η παρούσα διπλωματική εργασία αναφέρεται στην πρόβλεψη της διείσδυσης της FTTH (Fiber To The Home) τεχνολογίας στο σύνολο των αστικών και ημιαστικών περιοχών της Βόρειου Αμερικής. Η εν λόγω πρόβλεψη γίνεται με την χρήση μοντέλων διείσδυσης και μοντέλων ARIMA, ενώ γίνεται και σύγκριση με το αποτέλεσμα τροποποιημένων γενετικών αλγόριθμων, καθώς και με πραγματικές τιμές. Βασικός στόχος είναι να προβλέψουμε όσο το δυνατόν καλύτερα πώς θα συμπεριφερθεί η διείσδυση της συγκεκριμένης ευρυζωνικής υπηρεσίας στο εγγύς μέλλον. Γίνεται επίσης εκτενής αναφορά στα δίκτυα πρόσβασης, την αρχιτεκτονική των δικτύων, στις ευρυζωνικές υπηρεσίες και στις ευρυζωνικές τεχνολογίες πρόσβασης που υπάρχουν στις μέρες μας, καθώς και στα μοντέλα με τα οποία μπορεί να γίνει πρόβλεψη, με χρήση παρελθοντικών τιμών. / This dissertation concerns the provision FTTH (Fiber To The Home) penetration in urban and suburban areas of North America. This prediction is a result of the use of diffusion models, Arima Models, while the results of those models are compared with the results of modified genetic algorithms and real data. The main objective is to predict as better, as possible, the conduct of penetration, of a spesific broadband service in the near future. Another part of this dissertation, is an extensive reference to access networks, network architecture and broadband services and broadband access technologies that exist today,as well as, to models that prediction can be achieved, with the use of past values.
7

Návrh, realizace a měření pasivní optické sítě / Design, implementation and measurement of passive optical network

Kužela, Jan January 2017 (has links)
The aim of this thesis is to formulate the design of optical access network in designated area. The design is focused on the physical network layer and it covers optical fibers, cable protectors and links, optical hubs, racks and active components. The thesis also docu- ments network architecture, the configuration of active components and provides results from monitoring of selected network segments. The thesis consists of the theoretical part and practical part. In the theoretical part, there is an introduction to optical networks, their configurations (FTTH, FTTB, FTTC, FTTN), relevant networking standards and technologies. The practical part of the thesis covers design proposal of a network located in Slavičín. The design reuses infrastructure and technologies of existing network. The proposed design follows FTTH architecture which has benefits of low maintenance cost and it also fulfills GPON standard.
8

Metodika měření optických sítí FTTH / Methodology for FTTH optical network measurement

Gajdoš, Jaroslav January 2009 (has links)
The main topic of this master thesis is a FTTH measurement methodology of optical networks and its specific features 9 compared with other measurement methodologies. Also, the use of the FTTH measurement methodology: an example of measurements of a passive network with splitter 1:8 and analysis of the results of these experimental measurements. The first part of the thesis concerns itself with the description of optical networks and characteristics and features of the FTTH networks. A detailed description of the passive optical networks is provided: e.g. the optical network unit ONU, the optical line termination OLT, and, most importantly, the passive optical splitter. The wavelength division multiplex 9 WDM 9 which is used in passive optical networks is also described in detail. The chapter on measurement methodologies focuses in detail and provides many examples of currently used measurement methodologies of these networks. The best results are currently achieved with the OTDR methodology. The second part of the thesis concentrates on the description of the measurement of a passive optical network with splitter 1:8 using the methods described in previous chapters. As conclusion, a detailed analysis, assessment of the results and their usefulness when put into practice is provided.
9

Socio-economic Impact of Fiber to the Home in Sweden

Xiong, Ziyi January 2013 (has links)
Fiber-to-the-Home (FTTH) has been talked about since the introduction of fiberin the 1970s. It is nowadays shaping up to be the foundation of our newdigital society, bringing economic prosperity and a multitude of business,social, and entertainment opportunities to its users. The increased consumerdemand for high-speed network accessibility is being taken more and moreseriously and a fiber-based network is able to cope with these growing demandsdue to its wide bandwidth and reliability. Today there is a practical need forquantitative analysis regarding the socio-economic impacts of fiber-basedaccess networks. This analysis could be used as an indicator/reference for allthe stakeholder entities as they consider future investments anddevelopments. Sweden is a suitable target country for this analysis since ithas adopted fiber for some years and the benefits that FTTH has brought seemto already be tangible. The primary value of this thesis lies ininvestigation of its quantified evidence of the socio-economic impacts of FTTHdeployment in Sweden. This has been achieved based on data from the SwedishPost and Telecommunications Authority (PTS), Statistics Sweden (SCB), previousrelated studies, and information collected on-line from operators involved inthe fiber market, along with empirical analysis based on multivariateregression models. The results of the study show that fiber penetrationhas had a significant impact on the population’s evolution, specially the netamount of migration into a municipality, which indicates the attractiveness ofmunicipalities per se. It is therefore reasonable to suggest that localgovernment and local authorities take fiber deployment into consideration, ifthey want to attract people to stay for further local development. The studyalso analyzed the competition in fiber-based open networks and the prices ofsubscribing for 10/10 Mbps symmetrical Internet Service. Study findingsrevealed that networks with multiple competing service providers have a widerrange of services and a lower price: the more ISPs competing in a fibernetwork, the lower consumer prices. Specifically, for each new serviceprovider present in the network, there will be 5 SEK per month decrease of theaverage price of the Internet services, and an approximately 7 SEK per monthreduction in the lowest price. Nevertheless, a number of socio-economicimpacts remain unquantifiable as of the current time and due to the limitedavailable data. It is recommended to incorporate more socio-economic effectsin future research in order to draw a more complete picture for all theinterested sectors, and to supplement the data with recent figures for 2012and 2013. / Fiber till hemmet (Fiber-to-the-Home, FTTH) har talats om sedan fiberintroducerades på 1970-talet. Det håller numera på att bli grunden för vårtnya digitala samhälle, och bidra till ekonomiskt välstånd och medföra en mängdaffärsmässiga, sociala och underhållningsmässiga möjligheter tillslutanvändare. Den ökade efterfrågan på höghastighetsnät tas mer och mer påallvar och ett fiberbaserat nät kan hantera dessa ökade krav på grund av dessbreda bandbredd och tillförlitlighet. Idag finns ett praktiskt behov avkvantitativ analys av de socioekonomiska effekterna av fiberbaseradeaccessnät. Denna analys kan användas som en indikator och referens för allaintressenter när de överväger framtida investeringar. Sverige är ett lämpligtmålland för denna analys eftersom den har antagit fiber i några år och defördelar som FTTH har fört verkar redan vara synliga. Det huvudsakligavärdet av denna avhandling ligger i utredningen av kvantifierade bevis för desocioekonomiska effekterna av FTTH utbyggnad i Sverige. Detta har uppnåtts pågrundval av uppgifter från den Post- och telestyrelsen (PTS), Statistiskacentralbyrån (SCB), tidigare liknande studier och information som samlats inpå nätet från aktörer inom fiber, tillsammans med empirisk analys baserad påmultivariate regressionsmodeller. Resultatet visat att fiber har haft enbetydande inverkan på befolkningens utveckling, speciellt netto in- ochutflyttning till en kommun, vilket indikerar attraktionskraft kommunerna isig. Det är därför rimligt att föreslå att kommunerna och de lokalamyndigheterna överväger fiber driftsättning på allvar om de vill lockainvånare att stanna för ytterligare lokal utveckling. Studien analyserar ocksåkonkurrensen på fiberbaserade öppna nät och priserna på 10/10 Mbps symmetriskInternet-tjänst. Resultaten visar att nätverk med flera konkurrerandetjänsteleverantörer har ett bredare utbud av tjänster och ett lägre pris: jufler Internetleverantörer i ett fibernät, desto lägre konsumentpriser. Merspecifikt, för varje ny tjänsteleverantör som finns i nätverket, minskar detgenomsnittliga priset med 5 kronor per månad, och det lägsta priset med cirka7 kronor per månad. Ändå förblir ett antal socioekonomiska effekteromätbara på grund av begränsade tillgängliga data. Rekommendationen är attinförliva fler socioekonomiska effekter i framtida forskning för att dra enmer komplett bild för alla berörda sektorer, och att komplettera data medfärska siffror för 2012 och 2013.
10

Dynamic bandwidth allocation MAC protocols for gigabit-capable passive optical networks

Chang, Ching-Hung January 2008 (has links)
The research initiatives addressed in this thesis are geared towards improving the performance of passive optical networks (PONs) through the development of advanced dynamic bandwidth allocation (DBA) protocols. In particular, the aim of the research undertaken is to enhance the quality of service (QoS) offered by standard PONs by means of providing subscribers with service level agreement (SLA) to fulfil applications and associated bandwidth requirements on demand. To accomplish the research objectives, a novel service and bandwidth focused DBA protocol is developed for standard time division multiplexing (TDM), gigabit-capable PONs (GPONs) by flexibly assigning a guaranteed minimum bandwidth to each optical network unit (ONU),terminated at subscribers premises. Modelling and simulation of the developed algorithms have displayed a tenfold enhancement in network performance, showing a superior performance to other published DBA protocols, in terms of mean packet delay. To accomplish protocol optimisation, the ONU upstream transmission properties of TDM-PONs have been further analysed and subsequently the ONU data transfer order in each communication cycle has been dynamically configured to increase the network upstream throughput by overlapping the upstream transmission period with parts of the bandwidth request-allocation process between OLT and ONUs. In addition, with the objective of extending the application of the developed protocol to long-reach PONs by means of reducing the augmented propagation delays due to the network’s extensive reach, the concept of virtual communication cycles has been incorporated into the optimised DBA algorithm. This approach demonstrates comparable transmission efficiency in the context of subscriber throughput and packet delay as in a standard PON but at much longer distances from the network exchange. To overcome the inevitably limited communication capacity of single wavelength TDM protocols and with the transportation of the ever increasing, time-sensitive, multi-media services in mind, a novel multi-wavelength DBA protocol is then developed to be applied to a wavelength division multiplexing–PON. With this protocol, both the downstream and upstream network capacity is dynamically adjusted according to subscribers’ service level and bandwidth demand in each polling cycle as opposed to a fixed upstream network capacity in TDM-PONs. It therefore also demonstrates improved upstream transmission efficiency.

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