Download or read book Investigation of Techniques for Long reach Passive Optical Networks LR PON written by Xiaodan Pang and published by . This book was released on 2010 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Long Reach Passive Optical Networks written by Huan Song and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: With the advances in optical technology, the span of a broadband access network using Passive Optical Network (PON) technology can be increased from today's standard of 20 km to 100 km or higher. Such an extended-reach PON is known as Long-Reach PON (LR-PON). This technology can enable broadband access for a large number of customers in the access/metro area, while decreasing capital and operational expenditures for the network operator. Therefore, it is very desirable to comprehensively investigate this technology for future broadband access. This dissertation is dedicated to the research of architecture, management, and reliability of LR-PON. This dissertation first reviews the evolutionary path of access networks and shows the drivers from technology and business perspectives for high bandwidth and low cost. A variety of research challenges in this field is reviewed, from optical components in the physical layer to the control and management issues in the upper layers. We discuss the requisites for optical sources, optical amplifiers, and optical receivers in optical access networks with high transmission rate (10 Gbps) and large power attenuation (due to large split, transmission over 100 km and beyond, and propagation). We analyze the key topological structures to guarantee physical protection (e.g., tree-and-branch, ring-and-spur). Then, some relevant demonstrations of Long-Reach optical access networks developed worldwide by different research institutes are presented. A major challenge in LR-PON is that the propagation delay (for data as well as control signals) between the telecom central office (CO) and the end user is increased by a very significant amount. Now, traditional PON algorithms for scheduling the upstream transmission, such as dynamic bandwidth allocation (DBA) algorithms, may not be sufficient; actually, they may lead to degraded performance because of the long delay of the CO-to-Users "control loop". This challenge motivates us to propose and study a multi-thread polling algorithm to effectively and fairly distribute the upstream bandwidth dynamically. This algorithm exploits the benefits of having multiple polling processes running simultaneously and enabling users to send bandwidth requests before receiving acknowledgement from the CO. We compare the proposed algorithm with traditional DBA, and show its advantage on average packet delay. With the increased bandwidth requests from the expanding base of users, LR-PON should utilize the network resource (e.g., wavelengths, lasers, etc.) more effectively. We propose a new and efficient protocol to achieve better utilization of tunable lasers, as well as wavelength resources across different user groups in LR-PON. In order to accommodate downstream bursty traffic and provide Quality of Service (QoS) in the user-specified Service-Level Agreements (SLA), the protocol integrates our proposed SLA-aware bandwidth allocation scheme based on flow scheduling. We show the protocol's advantage to support incremental upgrade of bandwidth with increasing user bandwidth requests, and to provide a user with a SLA which guarantees a number of streaming flows with average bandwidth and maximum delay guarantee (e.g., 5 ms), as well as data flows with average bandwidth specifications. Since LR-PON serves a lot more users, a network failure may lead to a huge amount of data loss and negative user experience. Thus, to understand the importance of LR-PON survivability, we propose hardware-accelerated protection schemes for the LR-PON, incorporating the "ring-and-spur" structure to achieve fast protection-switching time, and automatic failure location at the Optical Line Terminal (OLT), which is located at the head end of the optical access network. We design the protection schemes for multiple network environments, e.g., unidirectional transmission vs. bidirectional transmission, and 1+1 protection vs. 1:1 protection. The numerical examples demonstrate that protection paths can be established within a few tens of ms after a failure occurs. This dissertation makes important contributions by studying novel architectures, protocols, and algorithms of LR-PON that will help to improve the next-generation telecom access networks.

Download or read book Energy efficient Long reach Passive Optical Networks written by Lei Shi and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: To bring the high capacity of the optical fiber closer to the end users with affordable costs, passive optical network (PON) was introduced and developed as a promising access network technology over the past decade. Long-reach PON (LR-PON) extends the coverage span of PONs from the traditional 20 km range to 100 km, consolidates the multiple active sites and thus lowers the costs. Besides extending the reach, energy conservation, which is of growing concern today, gives LR-PON a brand new advantage over its competitors. In this dissertation, we focus on the intersection of these two topics, namely Energy-Efficient LR-PON. We present several distinct schemes with the potential for substantial energy savings under practical settings, while not significantly affecting the network's performance. We develop and evaluate novel architectures, protocols, and algorithms for a LR-PON to will help to improve the performance of next-generation telecom access networks. One major component of LR-PON is the optical line terminal (OLT), which is deployed in central offices. Specifically for energy savings in OLT, we propose a centralized network planning approach based on user behaviors. By considering the different network usage behaviors of different kinds of users, we develop an efficient user-assignment scheme in which users with complementary behaviors are assigned to the same network segment to share the bandwidth. This achieves high bandwidth utilization at all times, and reduces the number of wavelengths needed, thus lowing cost and energy usage. Heuristic searches can provide such assignments, and their approximate solutions are very close to the lower bound. We then extend our work to the network operation (i.e., traffic engineering) stage, where an energy-efficient dynamic wavelength allocation scheme is developed on the "ring-and-spur" LR-PON. This scheme enables a wavelength to be dropped dynamically at multiple remote nodes, making it possible for users in different network segments to share downstream capacity in a statistical multiplexing fashion. The wavelength allocation may also be dynamically changed according to the network traffic so that the OLT can efficiently utilize all operational wavelengths. The other major component of LR-PON is the optical network unit (ONU), a remote unit close to the users. We propose a service-level agreement (SLA)-based scheduling scheme, in which the sleep time of an ONU can be adjusted and the ONU can quit sleep mode to send high-priority packets. Our proposal solves the problems of slow transition of power from active mode to sleep mode in an ONU and the relatively large recovery and synchronization time needed during the wakeup process. The tradeoff in energy savings vs. delay performance is evaluated using simulations under practical power-consumption settings. We also study the effects of arrayed-waveguide grating (AWG) and erbium-doped-fiber amplifier (EDFA) on bit-error rate (BER) in LR-PON, and propose both short-term and long-term distance-aware wavelength allocation schemes to balance the BER among ONUs at different distances. Simulation results show that average BER improves and the relative standard deviation decreases.

Download or read book 10GB S Burst Mode Transmission in Long Reach Passive Optical Networks written by Cleitus Antony and published by . This book was released on 2010 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Long reach passive optical networks (PONs) are currently emerging as one of the leading candidates for the next generation of telecommunications access networks, which will provide end customers with future high bandwidth interactive and video-rich services. In order to satisfy future bandwidth demand in an economic fashion it is likely that PON technology will need to evolve dramatically from that which is commercially available today. In particular the reach of these networks will need to increase fivefold to around 100km and the supported data rates will jump by nearly an order of magnitude to around 10Gb/s. In this thesis a hybrid dense wavelength division multiplexed- time division multiple access passive optical network (DWDM-TDMA PON) suitable for use in next generation optical access networks is proposed and studied. In order to implement such challenging architectures new types of high speed, burst mode optical transmission techniques are required, which enable bandwidth sharing between users on the network. This project has developed these new burst mode techniques and sub-systems required to enable these new networks. The main aim of the investigations in this thesis are in overcoming all the physical layer challenges due to 10Gb/s burst mode nature of transmission in these types of networks. A range of investigations, both of a theoretical and experimental nature, such as the dynamics of optical amplifiers, interferometric noise mitigation, suppression of crosstalk from multiple sources, maximum transmission distance, etc., are carried out to optimise the performance of individual components as well as the fully integrated system. The suitability of hybrid DWDM-TDMA architectures as a cost effective solution for use in future optical access networks is verified through full-scale network demonstrations in an experimental long reach PON laboratory test-bed.

Download or read book Physical Layer Monitoring of Passive Optical Networks written by Maged A. Esmail and published by LAP Lambert Academic Publishing. This book was released on 2013 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to enable new services that require high data rates over longer distances, the optical ber substitutes the copper cable step by step in the access network area. Time division multiplexed-Passive optical network (TDM-PON) is a fast emerging architecture that uses only passive components between the customer and the central office. PON operators need a monitoring system for the physical layer to guarantee high service quality. This monitoring system is necessary during the ber installation, final network installation testing, regular operation of the network, and for fault localization. In this book, we present the motivations, requirements and challenges of TDM-PON monitoring. We made an exhaustive review and comparison of the monitoring techniques and systems for TDM-PON, mostly proposed within the last five years. We have discussed the open issues and future research perspectives in physical layer PON monitoring that may target higher performance, lower cost, or scalability to next generation PON architectures. This includes wavelength division multiplexing (WDM), TDM over WDM or long-reach PONs intended to extend the reach from 20 up to 100 km distances and beyond.

Download or read book Long Reach RSOA Based Passive Optical Networks written by Sourav Mondal and published by LAP Lambert Academic Publishing. This book was released on 2014-10-01 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present access services like video on demand, live streaming, online gaming etc. require enormous amount of bandwidth and traditional digital subscriber line technology fails to meet up this requirement. The next generation networks, in particular, hybrid WDM-TDM Long-Reach Passive Optical Networks provide the required bandwidth and reduce the operational expenditure. Laser sources used at the Optical Network Units increase the cost due the extra equipment required for stabilizing the operating wavelength. To overcome this, a centralized source is installed at the Optical Line Terminal and the signal is reflected and intensity-modulated at the ONU, by using a special optical device Reflective Semiconductor Amplifier (RSOA), thus making the end receiver unit "colourless." The analytical model for RSOA has been described in detailed in this book. The primary objective of this enitre work is to examine the feasibility of hybrid WDM-TDM LR-PON physical layer uplink setup consisting of reflective ONUs with due consideration to the BER performance in presence of realistic and non-ideal characteristics of optical and optoelectronic devices used in the setup.

Download or read book Springer Handbook of Optical Networks written by Biswanath Mukherjee and published by Springer Nature. This book was released on 2020-10-15 with total page 1169 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook is an authoritative, comprehensive reference on optical networks, the backbone of today’s communication and information society. The book reviews the many underlying technologies that enable the global optical communications infrastructure, but also explains current research trends targeted towards continued capacity scaling and enhanced networking flexibility in support of an unabated traffic growth fueled by ever-emerging new applications. The book is divided into four parts: Optical Subsystems for Transmission and Switching, Core Networks, Datacenter and Super-Computer Networking, and Optical Access and Wireless Networks. Each chapter is written by world-renown experts that represent academia, industry, and international government and regulatory agencies. Every chapter provides a complete picture of its field, from entry-level information to a snapshot of the respective state-of-the-art technologies to emerging research trends, providing something useful for the novice who wants to get familiar with the field to the expert who wants to get a concise view of future trends.

Download or read book Next Generation FTTH Passive Optical Networks written by Josep Prat and published by Springer. This book was released on 2010-10-19 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fibre-to-the-Home networks constitute a fundamental telecom segment with the required potential to match the huge capacity of transport networks with the new user communication demands. Huge investments in access network infrastructure are expected for the next decade, with many initiatives already launched around the globe recently, driven by the new broadband service demands and the necessity by operators to deploy a future-proof infrastructure in the field. Dense FTTH Passive Optical Networks (PONs) is a cost-efficient way to build fibre access, and international standards (G/E-PON) have been already launched, leading to new set of telecom products for mass deployment. However, these systems only make use of less than 1% of the optical bandwidth; thus, relevant research is taking place to maximize the capacity of these systems, with the latest opto-electronic technologies, demonstrating that the huge bandwidth available through the fibre access can be exploited in a cost-efficient and reliable manner. Next-Generation FTTH Passive Optical Networks gathers and analyzes the most relevant techniques developed recently on technologies for the next generation FTTH networks, trying to answer the question: what’s after G/E-PONs?

Download or read book Passive Optical Networks written by Cedric F. Lam and published by Elsevier. This book was released on 2011-10-10 with total page 369 pages. Available in PDF, EPUB and Kindle. Book excerpt: Passive optical network (PON) technologies have become an important broadband access technology as a result of the growing demand for bandwidth-hungry video-on-demand applications. Written by the leading researchers and industry experts in the field, Passive Optical Networks provides coherent coverage of networking technologies, fiber optic transmission technologies, as well as the electronics involved in PON system development. Features: - An in-depth overview of PON technologies and the potential applications that they enable - Comprehensive review of all major PON standards and architecture evolutions, as well as their pros and cons - Balanced coverage of recent research findings with economic and engineering considerations - Presents system issues of protocols, performance, management and protection - Extensive references to standards and research materials for further studies This book provides an authoritative overview of PON technologies and system requirements and is ideal for engineers and managers in industry, university researchers, and graduate students. - Balances treatment of the optical technologies with systems issues such as protocols, performance, management and protection - Covers latest developments in WDM-PONS, protection switching, dynamic bandwidth allocation - Practical coverage with a chapter on PON applications and deployment - Case studies on implementing PONs

Download or read book Next Generation FTTH Passive Optical Networks written by Josep Prat and published by Springer Science & Business Media. This book was released on 2008-07-16 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fibre-to-the-Home networks constitute a fundamental telecom segment with the required potential to match the huge capacity of transport networks with the new user communication demands. Huge investments in access network infrastructure are expected for the next decade, with many initiatives already launched around the globe recently, driven by the new broadband service demands and the necessity by operators to deploy a future-proof infrastructure in the field. Dense FTTH Passive Optical Networks (PONs) is a cost-efficient way to build fibre access, and international standards (G/E-PON) have been already launched, leading to new set of telecom products for mass deployment. However, these systems only make use of less than 1% of the optical bandwidth; thus, relevant research is taking place to maximize the capacity of these systems, with the latest opto-electronic technologies, demonstrating that the huge bandwidth available through the fibre access can be exploited in a cost-efficient and reliable manner. Next-Generation FTTH Passive Optical Networks gathers and analyzes the most relevant techniques developed recently on technologies for the next generation FTTH networks, trying to answer the question: what’s after G/E-PONs?

Download or read book Reconfigurable Technology for Future Optical Access Networks written by She-Hwa Yen and published by Stanford University. This book was released on 2011 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fiber-based access is recognized as the most promising technology for solving broadband bandwidth bottlenecks. Time division multiplexing passive optical networks (TDM-PONs) that are passive and non-reconfigurable are currently the most widely deployed type of fiber access networks. However, due to their passive nature, TDM-PONs faces several limitations such as inflexible service area coverage, lack of intelligence for control, and inability to counteract security attacks. In order to address the current limitations of optical access networks, we propose reconfigurable technologies for next generation PONs. Two novel reconfigurable technologies are proposed, analyzed, and experimentally evaluated. The first solution is a reconfigurable power-and wavelength- assignment technology based on a novel non-volatile, reconfiguration node. The proposed remote node can reconfigure the network to adapt it to varying degrees of deployment conditions and/or network attacks. Moreover, the proposed remote node incorporates a novel quasi-passive device that does not consume energy once it is reconfigured into a new latching state. Therefore, the proposed remote node has very low energy consumption and does not require local power supply to preserve the passive character of the distribution network. In particular, two novel quasi-passive optical power splitter technologies based on Micro-Electro-Mechanical Systems (MEMS) and transition metal oxide have been designed for the reconfigurable device. A simulation study shows the proposed reconfigurable device would outperform traditional passive splitter in terms of maximum number of supportable users under realistic deployment conditions. The second solution addresses the issue of reconfigurable network consolidation and infrastructure simplification. Current TDM-PONs suffers from limited reach and split-ratio. To enhance the performance in terms of service range and quality of service, reconfigurable network consolidation is a promising solution. It can also simplify the network and reduce cost. We propose the following novel reconfigurable technologies for consolidation and simplification of next generation access networks: (1) Passive reach-extension technology for the drop section of optical access networks; (2) Sleep mode ONUs for energy saving; (3) Centrally managed optical signature that can monitor and protect the upstream link; and (4) Multi-rate burst mode receivers. These reconfigurable technologies can bring the intelligence into optical access networks and improve the efficiency and flexibility for next generation optical access networks.

Download or read book Communications Signal Processing and Systems written by Qilian Liang and published by Springer. This book was released on 2019-06-14 with total page 1228 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together papers from the 2018 International Conference on Communications, Signal Processing, and Systems, which was held in Dalian, China on July 14–16, 2018. Presenting the latest developments and discussing the interactions and links between these multidisciplinary fields, the book spans topics ranging from communications, signal processing and systems. It is aimed at undergraduate and graduate electrical engineering, computer science and mathematics students, researchers and engineers from academia and industry as well as government employees.

Download or read book FTTX Concepts and Applications written by Gerd Keiser and published by John Wiley & Sons. This book was released on 2006-02-06 with total page 313 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents fundamental passive optical network (PON) concepts, providing you with the tools needed to understand, design, and build these new access networks. The logical sequence of topics begins with the underlying principles and components of optical fiber communication technologies used in access networks. Next, the book progresses from descriptions of PON and fiber-to-the-X (FTTX) alternatives to their application to fiber-to-the-premises (FTTP) networks and, lastly, to essential measurement and testing procedures for network installation and maintenance. An Instructor's Manual presenting detailed solutions to all the problems in the book is available from the Wiley editorial department.

Download or read book Issues in Electrical Computer and Optical Engineering 2012 Edition written by and published by ScholarlyEditions. This book was released on 2013-01-10 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Issues in Electrical, Computer, and Optical Engineering: 2012 Edition is a ScholarlyEditions™ eBook that delivers timely, authoritative, and comprehensive information about Electrical Engineering. The editors have built Issues in Electrical, Computer, and Optical Engineering: 2012 Edition on the vast information databases of ScholarlyNews.™ You can expect the information about Electrical Engineering in this eBook to be deeper than what you can access anywhere else, as well as consistently reliable, authoritative, informed, and relevant. The content of Issues in Electrical, Computer, and Optical Engineering: 2012 Edition has been produced by the world’s leading scientists, engineers, analysts, research institutions, and companies. All of the content is from peer-reviewed sources, and all of it is written, assembled, and edited by the editors at ScholarlyEditions™ and available exclusively from us. You now have a source you can cite with authority, confidence, and credibility. More information is available at http://www.ScholarlyEditions.com/.

Download or read book Improved Techniques for Passive Optical Networks written by Douglas Ryan Tourtillott Jorgesen and published by . This book was released on 2010 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: The work in this thesis introduces a variety of techniques that can be used to improve the performance of previous state of the art passive optical networks (PONs). These networks will be of increasing importance as increasing bandwidth demand drives the penetration of optical fiber into access networks. PONs require novel design techniques due to their bidirectional nature and tight cost requirements. In this thesis improvements are proposed in three categories: filtering of bidirectional noise; novel modulation techniques; and use of non-traditional low cost devices (specifically vertical cavity surface emitting lasers (VCSELs)). High pass filtering (HPF) is shown to reduce the impact of bidirectional Rayleigh noise, which is dominant in PONs. It is demonstrated that under certain circumstances Rayleigh noise immunity is improved by up to 10 dB with proper selection of an HPF. A model to predict the effects of baseline wander caused by HPF is developed and experimentally validated. This model is combined with an existing Rayleigh noise model, which is experimentally validated. This model is extended to predict the performance of a bidirectional on-off keyed (OOK) PON and experimentally verified. Three methods are investigated to improve the ONU modulator. First it is shown that transmitter pre-distortion can provide a doubling of the non-equalized datarate of a low modulation bandwidth ONU modulator. Next a four level intensity modulation format is demonstrated. It is shown that while this method is possible, it provides no improvement over OOK modulation. A novel method for modulating the orthogonal phases of an intensity modulated microwave subcarrier, similar to quadrature amplitude modulation (QAM), is demonstrated. Significant performance improvement is realized with this scheme. Finally the use of a VCSEL in PONs is evaluated. It is predicted that using a VCSEL as central office (CO) laser will offer minor benefits and some moderate challenges. Use of a vertical cavity semiconductor optical amplifier (VCSOA) as an ONU modulator is prevented by a dispersive nonlinearity. This nonlinearity leads to bistability. First demonstration of butterfly bistability in a 1550 nm VCSOA and record low power bistability are demonstrated.

Download or read book Optical Switching Networks written by Martin Maier and published by Cambridge University Press. This book was released on 2008-02-11 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical Switching Networks describes all the major switching paradigms developed for modern optical networks, discussing their operation, advantages, disadvantages and implementation. Following a review of the evolution of optical WDM networks, an overview of the future trends out. The latest developments in optical access, local, metropolitan, and wide area networks are covered, including detailed technical descriptions of generalized multiprotocol label switching, waveband switching, photonic slot routing, optical flow, burst and packet switching. The convergence of optical and wireless access networks is also discussed, as are the IEEE 802.17 Resilient Packet Ring and IEEE 802.3ah Ethernet passive optical network standards and their WDM upgraded derivatives. The feasibility, challenges and potential of next-generation optical networks are described in a survey of state-of-the-art optical networking testbeds. Animations showing how the key optical switching techniques work are available via the web, as are lecture slides (www.cambridge.org/9780521868006).

Download or read book Next Generation Passive Optical Networks Based on Orthogonal Frequency Division Multiplexing Techniques written by Francesc Xavier Escayola Elias and published by . This book was released on 2016 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent decades, the industry of communications has acquired huge significance, and nowadays constitutes an essential tool for the society information. Thus, the exponential growth in demand of broadband services and the increasing amount of information to be transmitted have spurred the evolution of the access network infrastructure to effectively meet the user needs in an effective way in terms of costs of both installation and maintenance. Passive optical networks (PON) are currently considered the most efficient and least costly alternative to deploy fiber to the home environment. In order to allow many users simultaneously coexist PONs based on time multiplexing (TDMA) have been developed. Looking ahead, however, it is expected that these techniques do not meet the requirements on access networks. In consequence, other multiple access techniques such as Wavelength Division Multiplexing Access (WDMA) or Orthogonal Frequency Division Multiplexing Access (OFDMA) are currently under study and development for use in the next generation of PONs. Particularly, in recent years OFDM has stood out among the scientific community to be considered a solution with great potential on future implementation of PONs. This is especially true due to the capacity of OFDM to work with multilevel modulations, its high tolerance to chromatic dispersion, and its high flexibility and granularity in terms of bandwidth management. Given the above, the aim of this Thesis is to study deeply the advantages and challenges of implementing the standard OFDM as an access network solution; likewise, it offers solutions to improve its performance. In order to evaluate the main structures and strategies for OFDM-based PON, a comparative analysis of all of them is performed firstly, highlighting their sensitivity levels, maximum range and number of users. A key aspect for network providers is the cost of operation, deployment and maintenance of networks. As a low-cost solution, this Thesis proposes a network model called Statistical-OFDMA-PON based on intensity modulation and direct detection. In addition, dynamic bandwidth management strategies are applied into this model getting an improvement in the power balance which in turn, allows to increase the maximum range and the scalability in number of users. One of the main OFDM problems is the Peak-to-Average Power Ratio (PAPR) which increases with the number of carriers. This thesis proposes a new algorithm based on folding the signal and transmitting auxiliary information in order to compensate the PAPR effect and thus increase the sensitivity of the optical system. On the other hand, OFDMA requires a large number of operations in the digital domain resulting in a high computational effort, which in turn results in an increased cost. For this reason, this Thesis presents a study on the optimization of the required resolution in the Digital-to-Analog / Analog-to-Digital Converters (DAC/ADCs) maintaining the transmission quality. The optimization of the computation time may make the OFDMA-based optical network more attractive for future PONs. Finally, another problem concerning the OFDM optical networks is their sensitivity to Phase Noise (PN). In this regard, this Thesis presents a study of the effect of the laser linewidth and its dependence on signal bandwidth. A mitigation technique based on pilot tones is implemented and the limiting values for the laser linewidth are found to be within the reach of present low-cost light sources.