In this thesis, I proposed a novel framework of all-optical failure restoration which jointly determines network monitoring plane and spare capacity allocation in the presence of either static or dynamic traffic. The proposed framework aims to enable a general shared protection scheme to achieve near optimal capacity efficiency as in Failure Dependent Protection(FDP) while subject to an ultra-fast, all-optical, and deterministic failure restoration process. Simply put, Local Unambiguous Failure Localization(L-UFL) and FDP are the two building blocks for the proposed restoration framework. Under L-UFL, by properly allocating a set of Monitoring Trails (m-trails), a set of nodes can unambiguously identify every possible Shared Risk Link Group (SRLG) failure merely based on its locally collected Loss of Light(LOL) signals. Two heuristics are proposed to solve L-UFL, one of which exclusively deploys Supervisory Lightpaths (S-LPs) while the other jointly considers S-LPs and Working Lightpaths (W-LPs) for suppressing monitoring resource consumption. Thanks to the ``Enhanced Min Wavelength Max Information principle'', an entropy based utility function, m-trail global-sharing and other techniques, the proposed heuristics exhibit satisfactory performance in minimizing the number of m-trails, Wavelength Channel(WL) consumption and the running time of the algorithm. Based on the heuristics for L-UFL, two algorithms, namely MPJD and DJH, are proposed for the novel signaling-free restoration framework to deal with static and dynamic traffic respectively. MPJD is developed to determine the Protection Lightpaths (P-LPs) and m-trails given the pre-computed W-LPs while DJH jointly implements a generic dynamic survivable routing scheme based on FDP with an m-trail deployment scheme. For both algorithms, m-trail deployment is guided by the Necessary Monitoring Requirement (NMR) defined at each node for achieving signaling-free restoration. Extensive simulation is conducted to verify the performance of the proposed heuristics in terms of WL consumption, number of m-trails, monitoring requirement, blocking probability and running time. In conclusion, the proposed restoration framework can achieve all-optical and signaling-free restoration with the help of L-UFL, while maintaining high capacity efficiency as in FDP based survivable routing. The proposed heuristics achieve satisfactory performance as verified by the simulation results.

In this thesis, I proposed a novel framework of all-optical failure restoration which jointly determines network monitoring plane and spare capacity allocation in the presence of either static or dynamic traffic. The proposed framework aims to enable a general shared protection scheme to achieve near optimal capacity efficiency as in Failure Dependent Protection(FDP) while subject to an ultra-fast, all-optical, and deterministic failure restoration process. Simply put, Local Unambiguous Failure Localization(L-UFL) and FDP are the two building blocks for the proposed restoration framework. Under L-UFL, by properly allocating a set of Monitoring Trails (m-trails), a set of nodes can unambiguously identify every possible Shared Risk Link Group (SRLG) failure merely based on its locally collected Loss of Light(LOL) signals. Two heuristics are proposed to solve L-UFL, one of which exclusively deploys Supervisory Lightpaths (S-LPs) while the other jointly considers S-LPs and Working Lightpaths (W-LPs) for suppressing monitoring resource consumption. Thanks to the ``Enhanced Min Wavelength Max Information principle'', an entropy based utility function, m-trail global-sharing and other techniques, the proposed heuristics exhibit satisfactory performance in minimizing the number of m-trails, Wavelength Channel(WL) consumption and the running time of the algorithm. Based on the heuristics for L-UFL, two algorithms, namely MPJD and DJH, are proposed for the novel signaling-free restoration framework to deal with static and dynamic traffic respectively. MPJD is developed to determine the Protection Lightpaths (P-LPs) and m-trails given the pre-computed W-LPs while DJH jointly implements a generic dynamic survivable routing scheme based on FDP with an m-trail deployment scheme. For both algorithms, m-trail deployment is guided by the Necessary Monitoring Requirement (NMR) defined at each node for achieving signaling-free restoration. Extensive simulation is conducted to verify the performance of the proposed heuristics in terms of WL consumption, number of m-trails, monitoring requirement, blocking probability and running time. In conclusion, the proposed restoration framework can achieve all-optical and signaling-free restoration with the help of L-UFL, while maintaining high capacity efficiency as in FDP based survivable routing. The proposed heuristics achieve satisfactory performance as verified by the simulation results.

The emerging passive optical network (PON) requires the burst mode clock and data recovery (BM-CDR) for the successful data detection, with a strict requirement in the locking time. Two innovative BM-CDR schemes are proposed, modeled, simulated, and analyzed. They simplify the circuit design and reduce the chip size and the power consumption by utilizing the characteristics of the optical components in the upstream fiber link. One scheme utilizes the phenomenon of the clock tone generation by the fiber dispersion. The other scheme utilizes the nonlinear relaxation oscillation of the directly modulated laser (DML) to generate the clock tone. The phenomenon of the clock tone generation by the DML relaxation oscillation is discovered for the first time. Both schemes do not incur extra cost, additional optical components or electrical circuit blocks. In both schemes, the BM clock recovery (CR) circuitry is based on the injection locked oscillator (ILO). Its behavior in the BM-CR application with the input of the distorted non-return-to-zero (NRZ) data is simulated at the system level for the first time. The BM-CR circuitry is designed and fabricated in a standard 0.18 !lm CMOS technology to experimentally demonstrate the two schemes operating at the bit rate close to 10 Gbps. / The emerging passive optical network (PON) requires the burst mode clock and data recovery (BM-CDR) for the successful data detection, with a strict requirement in the locking time. Two innovative BM-CDR schemes are proposed, modeled, simulated, and analyzed. They simplify the circuit design and reduce the chip size and the power consumption by utilizing the characteristics of the optical components in the upstream fiber link. One scheme utilizes the phenomenon of the clock tone generation by the fiber dispersion. The other scheme utilizes the nonlinear relaxation oscillation of the directly modulated laser (DML) to generate the clock tone. The phenomenon of the clock tone generation by the DML relaxation oscillation is discovered for the first time. Both schemes do not incur extra cost, additional optical components or electrical circuit blocks. In both schemes, the BM clock recovery (CR) circuitry is based on the injection locked oscillator (ILO). Its behavior in the BM-CR application with the input of the distorted non-return-to-zero (NRZ) data is simulated at the system level for the first time. The BM-CR circuitry is designed and fabricated in a standard 0.18 !lm CMOS technology to experimentally demonstrate the two schemes operating at the bit rate close to 10 Gbps. / Thesis / Doctor of Philosophy (PhD)

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

Optical fibre communications are now widely used in many applications, including local area computer networks. I postulate that many future optical LANs will be required to operate with limited optical power budgets for a variety of reasons, including increased system complexity and link speed, low cost components and minimal increases in transmit power. Some developers will wish to run links with reduced power budget margins, and the received data in these systems will be more susceptible to errors than has been the case previously. The errors observed in optical systems are investigated using the particular case of Gigabit Ethernet on fibre as an example. Gigabit Ethernet is one of three popular optical local area interconnects which use 8B/10B line coding, along with Fibre Channel and Infiniband, and is widely deployed. This line encoding is also used by packet switched optical LANs currently under development. A probabilistic analysis follows the effects of a single channel error in a frame, through the line coding scheme and the MAC layer frame error detection mechanisms. Empirical data is used to enhance this original analysis, making it directly relevant to deployed systems. Experiments using Gigabit Ethernet on fibre with reduced power levels at the receiver to simulate the effect of limited power margins are described. It is found that channel bit error rate and packet loss rate have only a weakly deterministic relationship, due to interactions between a number of non-uniform error characteristics at various network sub-layers. Some data payloads suffer from high bit error rates and low packet loss rates, compared to others with lower bit error rates and yet higher packet losses. Experiments using real Internet traffic contribute to the development of a novel model linking packet loss, the payload damage rate, and channel bit error rate. The observed error behaviours at various points in the physical and data link layers are detailed. These include data-dependent channel errors; this error hot- spotting is in contrast to the failure modes observed in a copper-based system. It is also found that both multiple channel errors within a single code-group, and multiple error instances within a frame, occur more frequently than might be expected. The overall effects of these error characteristics on the ability of cyclic redundancy checks (CRCs) to detect errors, and on the performance of higher layers in the network, is considered. This dissertation contributes to the discussion of layer interactions, which may lead to un-foreseen performance issues at higher levels of the network stack, and extends it by considering the physical and data link layers for a common form of optical link. The increased risk of errors in future optical networks, and my findings for 8B/10B encoded optical links, demonstrate the need for a cross-layer understanding of error characteristics in such systems. The development of these new networks should take error performance into account in light of the particular requirements of the application in question.

International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / To deliver high bandwidth, a ubiquitous inter-/intra-building cable plant consisting of single mode and multimode fiber as well as twisted pair copper is required. The selection of the "glue" to transport and interconnect distributed LANs with central facility resources over a pervasive cable plant is the focus of this paper. A description of the traditional problems that must be overcome to provide very high bandwidth beyond the narrow confines of a computer center is given. The applicability of Asynchronous Transfer Mode (ATM) switching (interconnection) and Synchronous Optical NETwork (SONET) (transport) for high bandwidth delivery is described using the environment and requirements of Sandia National Laboratories. Other methods for distributing high data rates are compared and contrasted. Sandia is implementing a standards based foundation utilizing a pervasive single mode fiber cable plant, SONET transport, and ATM switching to meet the goals of gigabit networking.

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.

Due to the advances in content distribution and data center technologies, the traffic inside metropolitan area network (MAN) becomes more and more distributed. The current MAN architecture that only plays the role of bridge becomes insufficient to handle such new traffic patterns. Hence, the demand for a new MAN architecture is inevitable. It is expected to be both efficient and cost-effective. In this thesis, we proposed Optical Buffer Ring (OBR) as the solution of next generation MAN. It combines both OBS's low end-to-end delay and RPR's low loss rate. And compared to more advanced network architectures based on optical packet switching, OBR is of lower cost and thus more feasible in the near future. To evaluate the performance of OBR, we conducted simulation study over large set of parameters. According to the results, the performance of OBR indeed coincides with our expectation. Furthermore, OBR scales better than both OBS and RPR in that the end-to-end delay of OBR decreases as network size increases while the loss rate increases little with network size. Index Terms¡ÐMAN, WDM, OBS, OBR, RPR, HORNET, LightRing, Diffserv, optical packet switching.

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.