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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.
11

Návrh a simulace optické přístupové sítě typu PON / Design and simulation of passive optical network PON

Mikauš, Jiří January 2012 (has links)
The aim of master's thesis was to demonstrate chosen PON network in simulation software OPNET Modeler. The work deals with passive optical networks. In particular, solutions that are based on the transmission of Ethernet frames. EPON and 10GEPON standards are described in theoretical section. EPON Standard was introduced already in 2004. Newer 10GEOPN is back compatible, which is ideal as a suitable solution for modern network with a high data rates demands. The practical part describes process of developing network nodes for passive optical network. EPON model was developed in simulation tool, that demonstrates basic features of the standard IEEE 802.3ah. The simulation results are demonstrated in last section.
12

Um novo esquema de proteção para redes PON TDM

Carvalho, Maurício Moderno de 06 August 2008 (has links)
Made available in DSpace on 2016-03-15T19:38:10Z (GMT). No. of bitstreams: 1 Mauricio Moderno de Carvalho.pdf: 2212181 bytes, checksum: 274e2da279304668d738afe9e3483c45 (MD5) Previous issue date: 2008-08-06 / Fundo Mackenzie de Pesquisa / By adopting a ring topology and optical switches we propose a novel protection mechanism for time division multiplexed passive optical network (TDM-PON) that provides resilience against multiple network fails. Some protection schemes have been proposed in order to give resilience for passive optical network (PON) as defined at ITU-T Recommendation G983.1. However that recommendation defines the optical distribution network (ODN) and equipment duplication to protect it against multiple points of fail. We propose a ring topology with dual fibers paths capable to protect the network by switching these lines individually according to the local alarms detected by each optical network unit (ONU). According to our proposal neither equipment nor network should be duplicated to provide survivability to the system. / Adotando uma topologia em anel e chaves ópticas, estamos propondo um novo mecanismo de proteção para redes ópticas passivas TDM (Time Division Multiplexed) que possibilita a proteção da rede contra múltiplos pontos de falha. Muitos esquemas de proteção foram propostos para dar confiabilidade para as redes ópticas passivas como definido pela recomendação ITUT G.983.1. Para permitir proteção contra múltiplos pontos de falhas a recomendação ITU-T define a duplicação da rede óptica (ODN) e equipamento. Apresentamos, então, uma topologia em anel com dois caminhos ópticos distintos protegendo a rede pela comutação individual destas linhas de acordo com a detecção de alarmes locais por cada Optical Network Unit (ONU). Conforme nossa proposta, nem o equipamento ou a rede precisam ser duplicadas para prover proteção do sistema.
13

Projeto e dimensionamento de redes ópticas passivas (PONs) / Project and dimensioning of passive optical networks (PONs)

Takeuti, Paulo 01 August 2005 (has links)
Redes ópticas passivas são redes de acesso que utilizam fibras ópticas interligadas na topologia estrela e na configuração ponto-multiponto, sendo constituídas apenas por componentes ópticos passivos entre o terminal de linha óptica (optical line terminal - OLT) e a unidade de rede óptica (optical network unit - ONU). Como estratégia de evolução tecnológica, podem ser utilizadas para aproveitar a base instalada de cabos de cobre e cabos coaxiais na rede de acesso, servindo como cabo alimentador para uso das tecnologias digital subscriber line (DSL), cable modem e local multipoint distribution system (LMDS), e, no futuro, para disponibilizar a fibra óptica até às instalações do usuário. O principal mérito da arquitetura das redes ópticas passivas está na redução dos custos de implantação e de manutenção, pela ampliação da largura de banda disponível sem a necessidade de aumento no número de componentes ópticos ativos na rede, como lasers e amplificadores ópticos. Neste contexto, este trabalho define as redes ópticas passivas, apresenta o histórico de seu desenvolvimento, seu princípio de funcionamento e suas aplicações como forma de acesso a serviços de banda larga, identifica fornecedores visando à implementação de um teste de campo e discute as perspectivas para o futuro dessa tecnologia / Passive optical networks (PONs) are access networks which use interconnected optical fibers configured in a point to multipoint star topology having only passive optical components between the optical line terminal (OLT) and the optical network unit (ONU). As a strategy for technological evolution they can be used to take advantage of copper and coax base cables installed in the access network, serving as a feeder cable for the use of DSL, cable modem and LMDS technologies, in order to allow optical fibers to reach customers' facilities. The main merit of the passive optical networks architecture consists on the cost reduction involved on its implantation and maintenance, offering bandwidth enlargement without increasing the number of active optical components, such as lasers and optical amplifiers, in the network. In this context, this text defines PONs, presents its development history, operation principle and their applications as a way to provide broadband access services, identifies suppliers for field test implementation and discusses the perspectives for the future
14

Projeto e dimensionamento de redes ópticas passivas (PONs) / Project and dimensioning of passive optical networks (PONs)

Paulo Takeuti 01 August 2005 (has links)
Redes ópticas passivas são redes de acesso que utilizam fibras ópticas interligadas na topologia estrela e na configuração ponto-multiponto, sendo constituídas apenas por componentes ópticos passivos entre o terminal de linha óptica (optical line terminal - OLT) e a unidade de rede óptica (optical network unit - ONU). Como estratégia de evolução tecnológica, podem ser utilizadas para aproveitar a base instalada de cabos de cobre e cabos coaxiais na rede de acesso, servindo como cabo alimentador para uso das tecnologias digital subscriber line (DSL), cable modem e local multipoint distribution system (LMDS), e, no futuro, para disponibilizar a fibra óptica até às instalações do usuário. O principal mérito da arquitetura das redes ópticas passivas está na redução dos custos de implantação e de manutenção, pela ampliação da largura de banda disponível sem a necessidade de aumento no número de componentes ópticos ativos na rede, como lasers e amplificadores ópticos. Neste contexto, este trabalho define as redes ópticas passivas, apresenta o histórico de seu desenvolvimento, seu princípio de funcionamento e suas aplicações como forma de acesso a serviços de banda larga, identifica fornecedores visando à implementação de um teste de campo e discute as perspectivas para o futuro dessa tecnologia / Passive optical networks (PONs) are access networks which use interconnected optical fibers configured in a point to multipoint star topology having only passive optical components between the optical line terminal (OLT) and the optical network unit (ONU). As a strategy for technological evolution they can be used to take advantage of copper and coax base cables installed in the access network, serving as a feeder cable for the use of DSL, cable modem and LMDS technologies, in order to allow optical fibers to reach customers' facilities. The main merit of the passive optical networks architecture consists on the cost reduction involved on its implantation and maintenance, offering bandwidth enlargement without increasing the number of active optical components, such as lasers and optical amplifiers, in the network. In this context, this text defines PONs, presents its development history, operation principle and their applications as a way to provide broadband access services, identifies suppliers for field test implementation and discusses the perspectives for the future
15

Návrh, výstavba a měření optických přístupových sítí / Design, development and measurement of optical access networks

Ambrož, Jan January 2011 (has links)
The work deals with the possibilities of realization of optical access networks. They are introduced to FTTx optical access, including their specifications and differences. The document was largely devoted to passive and active optical networks. These two different technological approaches are explained and compared. Are presented technical solutions of routes - traditional options for laying underground or into the air, but also as an alternative microtubing. Mentioned are also the active network technology. The work also included the issue of measurement of optical access networks. They are illuminated important transmission parameters and methods for their measurement. The whole work is directed to the full FTTH network design according to the standard GEPON. In designing the use of theoretical information contained in each chapter. It does the form of technical documentation in accordance with the procedures used in practice, contains drawings, specific technical solutions and a detailed budget price. The design was verified by attenuation of balance. Finally there are the results of simulations of the proposed network in OptiSystem7.
16

Traffic and performance evaluation for optical networks : an investigation into modelling and characterisation of traffic flows and performance analysis and engineering for optical network architectures

Mouchos, Charalampos January 2009 (has links)
The convergence of multiservice heterogeneous networks and ever increasing Internet applications, like peer to peer networking and the increased number of users and services, demand a more efficient bandwidth allocation in optical networks. In this context, new architectures and protocols are needed in conjuction with cost effective quantitative methodologies in order to provide an insight into the performance aspects of the next and future generation Internets. This thesis reports an investigation, based on efficient simulation methodologies, in order to assess existing high performance algorithms and to propose new ones. The analysis of the traffic characteristics of an OC-192 link (9953.28 Mbps) is initially conducted, a requirement due to the discovery of self-similar long-range dependent properties in network traffic, and the suitability of the GE distribution for modelling interarrival times of bursty traffic in short time scales is presented. Consequently, using a heuristic approach, the self-similar properties of the GE/G/∞ are being presented, providing a method to generate self-similar traffic that takes into consideration burstiness in small time scales. A description of the state of the art in optical networking providing a deeper insight into the current technologies, protocols and architectures in the field, which creates the motivation for more research into the promising switching technique of 'Optical Burst Switching' (OBS). An investigation into the performance impact of various burst assembly strategies on an OBS edge node's mean buffer length is conducted. Realistic traffic characteristics are considered based on the analysis of the OC-192 backbone traffic traces. In addition the effect of burstiness in the small time scales on mean assembly time and burst size distribution is investigated. A new Dynamic OBS Offset Allocation Protocol is devised and favourable comparisons are carried out between the proposed OBS protocol and the Just Enough Time (JET) protocol, in terms of mean queue length, blocking and throughput. Finally the research focuses on simulation methodologies employed throughout the thesis using the Graphics Processing Unit (GPU) on a commercial NVidia GeForce 8800 GTX, which was initially designed for gaming computers. Parallel generators of Optical Bursts are implemented and simulated in 'Compute Unified Device Architecture' (CUDA) and compared with simulations run on general-purpose CPU proving the GPU to be a cost-effective platform which can significantly speed-up calculations in order to make simulations of more complex and demanding networks easier to develop.
17

Future Extensions to Passive Optical Access Networks

Radziwilowicz, Robert 30 April 2012 (has links)
Rapid changes in population distribution across Canada and the introduction of new telecommunication services to the consumer market have resulted in a number of significant challenges for existing network infrastructure. Fast growing populations in metropolitan regions require high density access networks to meet the growing need for bandwidth that results. Furthermore, new services such as high definition TV, online gaming and real-time video teleconferencing are becoming increasingly popular among consumers. These services require higher bandwidth to be available to end users. Changes in the Canadian economy will soon lead to a transition in Canadian industry from manufacturing to services and exploration of natural resources. This will create opportunities for new industrial development and growth in northern regions. Expanding industrialization towards northern Canada will require deployment of reliable telecommunication infrastructure. The combination of open source software, Linux operating system and Personal Computer (PC) based hardware platform is proposed to become the foundation for low cost and flexible technology that will provide transition towards all-optical infrastructures. An innovative prototype of a low-cost optical gigabit Ethernet switch is presented and its benchmark results are discussed. Scalability of the switch and its future applications in optical networks are studied. A prototype of a software based data encapsulation system was designed and implemented in a PC based platform, and its performance was evaluated using real data that was captured in commercial LAN. Semiconductor optical amplifiers (SOA) are studied as a building block in next generation switching devices for all-optical access networks. A prototype of an SOA-based low-cost optical switching device with implemented FPGA based controlling mechanism is presented and its characteristics are discussed. SOA is also studied as an energy efficient optical amplifier that can be deployed in end user facilities. The presented results provide proof of concept of a low cost flexible platform that can be used to design and build network devices to facilitate the transition of existing telecommunication networks towards next generation optical access infrastructure.
18

Design and Analysis of Green Mission-Critical Fiber-Wireless Broadband Access Networks

Dhaini, Ahmad R. 09 September 2011 (has links)
In recent years, the ever-increasing environmental friendliness concern has made energy efficiency in telecom networks as an important theme in their operations. Meanwhile, mission-critical (MC) services and systems (such as healthcare, police, and firefighting) have been acquiring special attention from telecom designers and operators. The currently deployed MC network technologies are indigent in terms of bandwidth capacity, and thus they are not able to support the emerging MC multimedia applications. Therefore in this thesis, we first explore the possibility of provisioning the MC services over the integration of fiber-wireless (FiWi) technologies, which has been considered as a promising candidate for the deployment of high-speed and mobile broadband access networks. We then investigate the energy efficiency problem in the FiWi integration, which consists of WiMAX in the wireless plane, and of Ethernet Passive Optical Network (EPON) - the most popular variant of the next-generation PON (NG-PON) technology, in the optical plane. In WiMAX, the energy saving protocol has been extensively investigated and standardized. Conversely, it has been recently studied in NG-PON, which currently consumes the least power among all the high-speed access networks. However, NG-PON has notably matured in the past few years and is envisioned to massively evolve in the near future. This trend will increase the power requirements of NG-PON and make it no longer coveted. Therefore we address the energy efficiency problem in NG-PON. For each of our contributions, we conduct extensive simulations to demonstrate the effectiveness and advantages of the proposed solutions.
19

Performance evaluation of optical packet switching technology : access control, resource allocation and QoS management for metropolitan and access networks

Nguyen, Tuan Dung 09 November 2010 (has links) (PDF)
The rapid growth in client application demands, in terms of bandwidth and (QoS), has motivated the deployment of the optical technology at Metro Access and Metro Core Networks. More diverse and more intelligent optic devices are required for efficiently management of huge capacity in the network. The explosion in demand for network bandwidth is mainly due to the growth in data traffic whose nature is also becoming more and more complex. In general, most of service-based traffics are transported in networks which are now being dominated by the optical switching technology. Nevertheless, such technology has some drawbacks such as inflexible and non-scalable properties. (OPS), which offers significant benefits in terms of both network efficiency and control scalability, may overcome these limitations. This has motivated the orientation from optical circuit switching to optical packet switching in the future network infrastructure. In reality, optical packet switching ring (OPSR) networks, which combine the packet switching technology with the well-known advantages of ring topology such as fast service restoration in cases of failure and high gain of statistical traffic multiplexing over the ring, appear to be the technology of choice for the next generation of Metro Area Networks. A new OPSR architecture which is based on the all-optical infrastructure that offers intelligent features with lower cost while maximizing processing time and is now considering being replaced existing opto-electronic architectures such as Resilient Packet Ring, have been presented in the scope of the dissertation. The key element of such network is Packet Optical Add/Drop Multiplexer (POADM) which is implemented inside a ring node, allowing the node to exploit the optical transparency. This dissertation hence focuses on the performance evaluation of the new generation of OPSR network. In this dissertation, we have investigated the performance analysis (in terms of packet delay and queue-length distribution of access nodes) of an optical synchronous bus-based metropolitan network supporting fixed-size packets. We have modeled each access node by an embedded discrete time Markov chain (EDTMC). The solution of the EDTMC allows us to compute the approximate probability that access nodes on the bus "see" free slots in the transit line. Using a recursive analysis technique, we approximately outline the mean waiting time of client packets coming from the upper layer as well as an approximate queue-length distribution of local buffers at access nodes in two cases: with and without QoS guarantees. To characterize the performance of an asynchronous OPSR network, we have evaluated the impact of Optical fixed-Size Packet Creation on the network performance without and with different quality of services (QoS) requirements. Performance analysis of such systems has allowed us to identify a reasonable combination of some parameters (timeslot duration, timer expiration values, profile of client traffic and network load) which may be able to improve the bandwidth utilization of the network for a given traffic matrix. The most important point that we have mentioned in the dissertation is the comparison of two architectural approaches: Variable Length - Optical Packet Format (VL-OPF) model supporting empty packets versus Fixed Length - Optical Packet Format (FL-OPF) model. In addition to CoS-Upgrade Mechanism (CUM) which is proposed to improve the filling ratio of the optical container, we have proposed a novel mechanism named Dynamic CoS-Upgrade Mechanism (DCUM) where timers are dynamically changed according to the state of the local buffer of network nodes and the traffic circulating in the network, in order to create containers with a high filling ratio while limiting the time needed for their creation.
20

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

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