Orientador: Aldário Chrestani Bordonalli / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-19T04:17:28Z (GMT). No. of bitstreams: 1 Angeli_BrunoCesardeCamargo_M.pdf: 2392306 bytes, checksum: 7046f845a80632fba962680003dddf24 (MD5) Previous issue date: 2011 / Resumo: Devido ao grande volume de trafego causado pelo aumento exponencial do numero de usuários na Internet e o surgimento continuo de novas aplicações de banda larga, redes de alta capacidade são necessárias para suportar a grande demanda de trafego. Dentre os diferentes tipos de redes de acesso, as redes ópticas passivas são consideradas uma das alternativas mais promissoras para conexão de ultima milha, devido ao seu baixo custo e a eficiência de seus recursos, o que a torna uma das principais soluções para a demanda por banda de transmissão. Para acomodar o alto numero de assinantes, a transmissão em modo de rajada e utilizada, sendo o tratamento e a recepção desta natureza de transmissão um dos pontos mais críticos de concepção do sistema. Dentro deste contexto, este trabalho apresenta o estudo e projeto de um receptor operando em modo de rajada para ser usado em redes ópticas passivas de próxima geração, devendo este suportar uma taxa de transmissão de ate 2,5 Gbit/s. Os passos de desenvolvimento do protótipo são descritos e seu desempenho avaliado em termos das recomendações propostas pelo órgão ITU-T / Abstract: Due to the increasing volume of traffic caused by the exponential growth of the number of Internet users and the continuous arrival of new broadband applications, high-capacity networks are necessary to handle large traffic demand. Among the different types of access networks, passive optical networks are considered one of the most promising alternatives for the last mile connection, due to its low cost and resource efficiency, making it one of the main solutions to the demand for bandwidth transmission. To accommodate a large number of subscribers, burst mode transmission is used. Thus, the reception and processing of this type of transmission becomes one of the most critical system design issues. Within this context, this work presents the study and design of a receiver operating in burst mode to be used in next generation passive optical networks, supporting transmission rates up to 2.5 Gbit/s. The prototype development stages are described and the receiver performance evaluated in terms of the recommendations proposed by the ITU-T / Mestrado / Telecomunicações e Telemática / Mestre em Engenharia Elétrica

The objective of the proposed research is to develop multiwavelength lasers as cost-efficient sources for broadband optical access networks. Todays telecommunications networks have widely adopted optical fiber as the backbone transmission medium. Optical fiber systems are promising candidates for the broadband access networks to offer high-speed and future-proof services. To harness the available bandwidth in fiber and to meet the ever-growing bandwidth demand, wavelength division multiplexing (WDM) techniques have been investigated. There have been intense research activities for the creation of new low-cost laser sources for such emerging applications. In this context, multiwavelength fiber ring lasers have been significantly investigated as they present many advantages, including simple structure, low-cost, and selectable multiwavelength operation. We propose a new laser system architecture that emits alternate multiwavelength picosecond pulses operating at room temperature. Optical signal generation is based on a single active component, an unbalanced Mach-Zehnder interferometer, inserted in an actively mode-locked erbium-doped fiber ring laser to provide both intensity modulation and wavelength-selective filtering. Time and frequency controls of the light emission are reached by inserting an additional modulator and a periodic filter in the cavity. This approach focuses on the application of multiwavelength lasers as sources for WDM passive optical networks.

The idea of a Media Frame network (MFN) was proposed very recently for solving the explosively growing demand for end-to-end large file transfers. This networking method combines the advantage of high transmission speed from optical networks and flexibility and fast header parsing from electronic networks. The MFN is based on very large data units or media frames (MF) compared to IP packets. Due to the logical continuity, transporting data in a media frame network largely reduces the power consumption in the intermediate nodes and routers. Currently the backbone of media frame network has been studied. The remaining challenge is to devise a system solving the problem of transporting MFs through access networks (i.e., the last mile) connecting customers to the backbone networks. To our knowledge, no other research activity regarding this challenge has been reported. If this challenge is overcome and if the overall concept is accepted, the MFN could be a very important step in the evolution of the Internet. This thesis focuses mainly on the access network. For the first time, a solution is proposed to establish the ability to transport media frames over a standard PON (e.g. Passive Optical Network) architecture. Because of the unique properties of the media frame network, the physical layer model and transport protocols must be rebuilt. Referring to the ITU-T G.987 recommendations, the physical layer is built based on the XGPON specification. In this thesis, the initialization protocols, bandwidth allocation plan, OLT-ONU (OLT: Optical Line Terminal, e.g. central office. ONU: Optical Network Unit, e.g. customer side box) negotiation protocols are designed. Different schemes for each protocol are proposed, with simulation support based on Omnet++. For the transmission of a 7GB file on average, different transparency degrees under different traffic conditions are compared, and the tradeoffs among essential factors are investigated. / Graduate

The increasing bandwidth demands in access networks motivates network operators, networking devices manufacturers, and standardization institutions to search for new approaches for access networks. These approaches should support higher bandwidth, longer distance between end user and network operator, and less energy consumption. Ethernet Passive Optical Network (EPON) is a favorable choice for broadband access networks. EPONs support transmission rates up to 10 Gbps. EPONs also support distance between end users and central office up to 20 Km. Moreover, optical networks have the least energy consumption among all types of networks. In this dissertation, we focus on reducing delay and saving energy in EPONs. Reducing delay is essential for delay-sensitive traffic, while minimizing energy consumption is an environmental necessity and also reduces the network operating costs. We identify five challenges, namely excess bandwidth allocation, frame delineation, congestion resolution, large round trip time delay in long-reach EPONs (LR-EPONs), and energy saving. We provide a Dynamic Bandwidth Allocation (DBA) approach for each challenge. We also propose a novel scheme that combines the features of the proposed approaches in one highly performing scheme. Our approach is to design novel DBA protocols that can further reduce the delay and be simultaneously simple and fair. We also present a dynamic bandwidth allocation scheme for Green EPONs taking into consideration maximizing energy saving under target delay constraints. Regarding excess bandwidth allocation, we develop an effective DBA scheme called Delayed Excess Scheduling (DES). DES achieves significant delay and jitter reduction and is more suitable for industrial deployment due to its simplicity. Utilizing DES in hybrid TDM/WDM EPONs (TWDM-EPONs) is also investigated. We also study eliminating the wasted bandwidth due to frame delineation. We develop an interactive DBA scheme, Efficient Grant Sizing Interleaved Polling (EGSIP), to compensate the unutilized bandwidth due to frame delineation. Our solution achieves delay reduction ratio up to 90% at high load. We also develop a Congestion Aware Limited Time (CALT) DBA scheme to detect and resolve temporary congestion in EPONs. CALT smartly adapts the optical networking unit (ONU) maximum transmission window according to the detected congestion level. Numerical results show that CALT is more robust at high load compared to other related published schemes. Regarding LR-EPONs, the main concern is large round trip delay mitigation. We address two problems, namely bandwidth over-granting in Multi-Thread Polling (MTP) and on-the-fly void filling. We combine, with some modifications, EGSIP and DES to resolve bandwidth over-granting in MTP. We also manage to adaptively tune MTP active running threads along with the offered load. Regarding on-the-fly void filling, Our approach, Parallel Void Thread (PVT), achieves large delay reduction for delay-sensitive traffic. PVT is designed as a plus function to DBA and can be combined with almost all DBA schemes proposed before. The powerful feature of our proposed solutions is integrability. We integrate our solutions together and form a multi-feature, robust, fairly simple, and well performing DBA scheme over LR-TWDM-EPONs. Our final contribution is about energy saving under target delay constraints. We tackle the problem of downstream based sleep time sizing and scheduling under required delay constraints. Simulation results show that our approach adheres to delay constraints and achieves almost ideal energy saving ratio at the same time.

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.

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.

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.

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

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.

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.