Download or read book Optical Fiber Telecommunications VIB written by Keang-Po Ho and published by Elsevier Inc. Chapters. This book was released on 2013-05-11 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mode coupling is a key to overcoming challenges in mode-division-multiplexed transmission systems in multimode fiber. This chapter provides an in-depth description of mode coupling, including its physical origins, its effect on modal dispersion (MD) and mode-dependent loss or gain (MDL), and the resulting impact on system performance and implementation complexity. Strong mode coupling reduces the group delay spread from MD, minimizing the complexity of digital signal processing used for compensating MD and separating multiplexed signals. Likewise, strong mode coupling reduces the variations of MDL arising from transmission fibers and inline optical amplifiers, maximizing average channel capacity. When combined with MD, strong mode coupling creates frequency diversity, which reduces the probability of outage caused by MDL and enables the outage capacity to approach the average capacity. The statistics of strongly coupled MD and MDL depend only on the number of modes and the variances of MD or MDL, and can be derived from the eigenvalue distributions of certain random matrices.

Download or read book Optical Fiber Telecommunications VIB written by Y.C. Chung and published by Elsevier Inc. Chapters. This book was released on 2013-05-11 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wavelength-division-multiplexed passive optical network (WDM PON) has long been considered as an ultimate solution for the future optical access network capable of providing practically unlimited bandwidth to each subscriber. On the other hand, it is still considered to be too expensive for the massive deployment. To solve this problem and meet the ever-increasing demand for bandwidth, there have been numerous efforts to improve the competitiveness of WDM PON. This chapter reviews the current status and future direction of these WDM PON technologies. We first review various colorless light sources, which are critical for the cost-effective implementation of the optical network units (ONUs), and several representative network architectures proposed for WDM PONs. We then review the recent research activities for the realization of high-speed (>10Gb/s) and long-reach WDM PONs. Various fault-monitoring and protection techniques are also reviewed as they can be increasingly important in the future high-capacity WDM PONs.

Download or read book Optical Fiber Telecommunications VIB written by Charles H. Cox and published by Elsevier Inc. Chapters. This book was released on 2013-05-11 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: The transmission of multi-band radio signals through optical fibers has drawn great attention recently for its potential in cellular backhaul networks, mobile cloud computing, and wireless local-area networks. As wireless services and technologies evolve to multi-gigabit radio access networks, their speed is increased but the wireless coverage of a single access point is inevitably reduced dramatically. As a result, the importance of >10GHz radio-over-fiber techniques has been emphasized for the capability of expanding wireless coverage feasibility, and in the meantime reducing system complexity and operation expenditure, especially in the high-speed millimeter-wave regime. In this chapter, we introduce the radio-over-fiber technique and its challenge of handling optical millimeter-wave generation, transmission, and converged multi-band system. By exploring real-world, system implementation and characterization, the unique features and versatile applications of radio-over-fiber technologies are investigated and reviewed to reach next-generation converged optical and wireless access networks.

Download or read book Optical Fiber Telecommunications VIB written by Tiejun J. Xia and published by Elsevier Inc. Chapters. This book was released on 2013-05-11 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: This chapter provides a global network service provider’s view on the technology development and product commercialization of 100-Gb/s for optical transport networks. Optical channel capacity has been growing over the past four decades to address traffic demand growth and will continue this trend for the foreseeable future to meet the ever-increasing bandwidth requirements. In this chapter, optical channels are re-classified into three basic design types. Commercial 100-Gb/s channel development experienced all three types of channel designs before eventually settling on the single carrier PM-QPSK format with coherent detection, which appears to be the optimal design in the industry. A series of 100-Gb/s channel related field trials were performed in service providers’ networks to validate the technical merits as well as business advantages of this new capacity standard before its deployment. Introduction of the 100-Gb/s channel brings new opportunities to boost fiber capacity, accommodate increases in client interface speed rates, lower transmission latency, simplify network management, and speed up the realization of next generation optical add/drop functions.

Download or read book Optical Fiber Telecommunications VIB written by Loukas Paraschis and published by Elsevier Inc. Chapters. This book was released on 2013-05-11 with total page 29 pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasingly important role of Internet-based, “cloud” service delivery is motivating the evolution of the Internet to a flatter hierarchy of more densely interconnecting networks that shall cost-effectively scale to Zettabytes of bandwidth with improved operational efficiency, under increased traffic variability, and forecast unpredictability. This chapter reviews the implications of this evolution in its underlying metro regional and core transport network architectures, and evaluates the most important innovations in photonics, optical transport, routing, and traffic engineering technologies enabling it. Most notably, 1) a new generation of coherent DWDM systems with more than 2 b/s/Hz spectral efficiency is scaling the existing fiber infrastructure, albeit at a significantly higher proportion, typically more than 50%, of the total transport network cost, while 2) the convergence of IP/MPLS with flexible DWDM promises the most cost-efficient transport evolution, in open architectures that combine advancements in photonics, routing, multi-layer control-plane and management coordination, with interoperability, to improve operation, automate provisioning and restoration, and may optimize network utilization.

Download or read book Optical Fiber Telecommunications VIB written by Peter J. Winzer and published by Elsevier Inc. Chapters. This book was released on 2013-05-11 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: At the beginning of an exciting new era in optical communications, we review fundamentals as well as practical experimental aspects of MIMO-SDM: we discuss the importance of selectively addressing all modes of a coupled-mode SDM channel at transmitter and receiver in order to achieve reliable capacity gains and show that reasonable levels of mode-dependent loss (MDL) are acceptable without much loss of channel capacity. We then introduce MIMO-DSP techniques as an extension of familiar algorithms used in polarization-division multiplexed (PDM) digital coherent receivers and discuss their functionality and scalability. Finally, we review the design of mode multiplexers (MMUXs) that allow for the mapping of the individual transmission signals onto an orthogonal basis of waveguide mode, and discuss their performance in experimental demonstrations.

Download or read book Optical Fiber Telecommunications VIB written by Ivan B. Djordjevic and published by Elsevier Inc. Chapters. This book was released on 2013-05-11 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: This chapter represents an overview of advanced coding techniques for optical communication. Topics include: codes on graphs, coded modulation, rate-adaptive coded modulation, and turbo equalization. The main objectives of this chapter are: (i) to describe different classes of codes on graphs of interest for optical communications, (ii) to describe how to combine multilevel modulation and channel coding, (iii) to describe how to perform equalization and soft-decoding jointly, and (iv) to demonstrate efficiency of joint de-modulation, decoding, and equalization in dealing with various channel impairments simultaneously. Codes on graphs of interest for next-generation FEC for high-speed optical transport include turbo codes, turbo-product codes and low-density parity-check (LDPC) codes. We describe both binary and nonbinary LDPC codes, their design and decoding algorithms. We also discuss an FPGA implementation of decoders for binary LDPC codes. We demonstrate that an LDPC-coded turbo equalizer is an excellent candidate to simultaneously mitigate uncompensated chromatic dispersion, PMD, fiber nonlinearities and I/Q-imbalance. For completeness of presentation, we also provide the information capacity study of optical channels with memory.

Download or read book Optical Fiber Telecommunications VIB written by Jian Wang and published by Elsevier Inc. Chapters. This book was released on 2013-05-11 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this chapter, we provide a comprehensive review of multimode communications using OAM. The fundamentals of OAM are introduced first followed by the techniques for OAM generation, multiplexing/demultiplexing, and detection. We then present recent research efforts to free-space communication links and fiber-based transmission links using OAM multiplexing together with optical signal processing using OAM (data exchange, add/drop, multicasting, monitoring, and compensation). Future challenges of OAM communications are discussed at the end.

Download or read book Optical Fiber Telecommunications VIB written by Gee-Kung Chang and published by Elsevier Inc. Chapters. This book was released on 2013-05-11 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radio-over-fiber (RoF) link technology has been developed to support multiple wireless signals over optical fiber applications such as mobile backhaul networks and WLANs. Given that conventional wireless networks use packet-switch links between the central office and remote base stations, the cost and complexity of the high-speed wireless networks for data and video transmission increase exponentially while the area of effective coverage decreases. These wireless systems become more inefficient as the data rates and the carrier frequencies required for delivering multi-gigabit wireless services climb higher. However, radio-over-fiber link systems utilizing lightwave to carry multiple analog RF signals through optical fibers can greatly extend the cellular sizes while transparent to the bit rates, modulation formats, and protocols. As a result, the complexity of wireless system to deliver multi-band, multi-gigabit wireless services can be simplified by taking advantages of microwave photonics in optical wireless network design and system integration. The end-to-end RoF systems, from the generation schemes of 1–100 GHz optical wireless signals in the central office to the design of transceivers for base stations and radio access units, are reviewed and investigated in this chapter. Various radio-over-fiber link technologies and the optical wireless interface specifications required to build a converged multi-service, gigabit wireless access network are introduced. The system impairment and its mitigation of radio-over-fiber link transmission will be investigated and analyzed.

Download or read book Optical Fiber Telecommunications VIB written by René-Jean Essiambre and published by Elsevier Inc. Chapters. This book was released on 2013-05-11 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: This chapter starts by providing some statistics on traffic demand in optical networks and the capacity scaling over time of commercial optical communication systems. Next there is a brief review of the basic results of information theory. We then describe the stochastic nonlinear Schrödinger equation (SNSE), the equation that governs nonlinear propagation in SMFs. This is followed by calculations of nonlinear capacity limit estimates for the SSMF, and advanced fibers with improved transmission characteristics are then presented along with an analytical formula of nonlinear capacity. We then introduce a set of coupled partial differential equations (PDEs) describing nonlinear propagation of polarization-division multiplexed (PDM) signals in SMFs along with nonlinear capacity estimates for these systems. This followed by a focus on multimode fibers (MMFs) and multicore fibers (MCFs). The rest of the chapter then focuses on nonlinear effects in MMFs and MCFs, with an emphasis on MMFs and FMFs. The chapter concludes by reporting experimental observations of two important effects involving nonlinear effects between spatial modes: inter-modal cross-phase modulation (IM-XPM) and inter-modal four-wave mixing (IM-FWM).

Download or read book Optical Fiber Telecommunications VIB written by Vincent W.S. Chan and published by Elsevier Inc. Chapters. This book was released on 2013-05-11 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: Present-day networks are being challenged by dramatic increases in data rate demands of emerging applications. New network architectures for streaming/routing large “elephant” transactions will be needed for cost and power efficiencies. This chapter examines a number of possible optical network transport mechanisms: optical packet switching, burst switching, and flow switching and describes the necessary physical layer, routing, and transport layers architectures for these transport mechanisms. Performance comparisons are made based on capacity utilization, scalability, costs, and power consumption. A global-reach network architecture, incorporating optical flow switching, will provide significant lower cost and power consumption for large transactions. This transport mechanism will necessitate physical, media access control, routing, and transport layers and control plane architecture changes over the current Internet architecture and must co-exist with traditional TCP/IP electronic packet switching transport in the same optical network. Scalability in network management and control and session scheduling is identified as the most important driver in the architecture construct. The physical architecture coupled with a matched media access control protocol can help slow down the control plane and still can operate the network with highly dynamic sessions and at high efficiency which is critical for low cost and low power operations. For intra-data center networks when the network bandwidth is not as challenged as a wide area network some form of burst switching can be advantageous if fast light-weight protocols are needed albeit the network must be used at light occupancy for low collision probabilities.

Download or read book Optical Fiber Telecommunications VIB written by Xi Chen and published by Elsevier Inc. Chapters. This book was released on 2013-05-11 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this chapter, we present an overview of multicarrier transmission and its application to optical communication. Specifically, we first introduce the historical perspectives in the development of optical multicarrier technologies. We then present different variants of optical multicarrier transmission. We also highlight the problem of fiber nonlinearity in optical multicarrier transmission systems and present an analysis of fiber capacity under nonlinear impairments. Furthermore, we discuss applications of multicarrier techniques to long-haul systems, access networks, and free-space optical communication systems. Finally, we summarize with some possible research directions in implementing multicarrier technologies in optical transmission.

Download or read book Optical Fiber Telecommunications VIB written by Kristin Rauschenbach and published by Elsevier Inc. Chapters. This book was released on 2013-05-11 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rapidly increasing network demand based on unpredictable services has driven research into methods to provide intelligent provisioning, efficient restoration and recovery from failures, and effective management schemes that reduce the amount of “hands-on” activity to plan and run the network. Integrating the service-oriented IP layer together with the efficient transport capabilities of the optical layer is a cornerstone of this research. Converged IP-optical networks are being demonstrated in large multi-carrier and multi-vendor venues. Research is continuing on making this convergence more efficient, flexible, and scalable. In this chapter, we review the current key technologies that contribute to the convergence of IP and optical networks, describing control and management plane technologies, techniques and standards in some detail. We also illustrate current research challenges, and discuss future directions for research.

Download or read book Optical Fiber Telecommunications VIB written by Polina Bayvel and published by Elsevier Inc. Chapters. This book was released on 2013-05-11 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: The key question of current optical communications research is: how to maximize both capacity and transmission distance in future optical transmission networks by using spectrally-efficient modulation formats with coherent detection, and how can digital signal processing aid in this quest? There is a clear trade-off between spectral efficiency and transmission distance, since the more spectrally-efficient modulation formats are also more susceptible to optical fiber nonlinearities. This chapter illustrates the application of nonlinear backpropagation to mitigate for both linear and nonlinear transmission impairments for a range of modulation formats, at varying symbol-rates and wavelength spacings, and also by varying the signal bandwidth which is backpropagated. The basics of coherent receiver structure and DSP algorithms for chromatic dispersion compensation, equalization and phase recovery of PDM-BPSK, PS-QPSK, PDM-QPSK, PDM-8PSK, PDM-8QAM, and PDM-16QAM are reviewed and the effectiveness of the nonlinearity compensating DSP based on digital backpropagation is explored. This chapter includes a comprehensive literature review of the key experimental demonstrations of nonlinearity-compensating DSP.

Download or read book Optical Fiber Telecommunications VIB written by S. Chandrasekhar and published by Elsevier Inc. Chapters. This book was released on 2013-05-11 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical superchannel transmission has recently attracted much research and development effort, aiming to increase the capacity and cost-effectiveness of wavelength-division multiplexing (WDM) systems. The use of superchannels avoids the electronic bottleneck via optical parallelism, and provides high per-channel data rate and better spectral utilization, especially in transparent mesh optical networks. This chapter reviews recent advances in the generation, detection, and transmission of optical superchannels with channel data rates on the order of Terabits/s. Multiplexing schemes such as optical orthogonal-frequency-division-multiplexing (O-OFDM) and Nyquist WDM are described, in conjunction with modulation schemes such as OFDM and Nyquist-filtered single-carrier modulation. Superchannel transmission performance is discussed. Finally, networking implications brought by the use of superchannels, such as flexible-grid WDM, are also discussed.

Download or read book Optical Fiber Telecommunications VIB written by Frank Effenberger and published by Elsevier Inc. Chapters. This book was released on 2013-05-11 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: This chapter aims to describe the current state of the PON technology, including both “state-of-the-art” systems that are currently under research in the laboratory and “standardized” systems that have been or soon will be described as an industry norm. A short introduction to the PON topic will be given, to set the scene and provide the basic motivation for why PON is so important to fiber access. Then, each of the major technologies will be reviewed, including TDM, Video overlay, WDM, FDM, and Hybrid multiplexing. The focus of each review will be at a system level and will not dive into the details (those will be handled via references to published works). Rather, the intention is to present the wide view of the whole range, so as to compare and contrast them.

Download or read book Optical Fiber Telecommunications VIB written by Vincent O’Byrne and published by Elsevier Inc. Chapters. This book was released on 2013-05-11 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since the early 2000s Fiber-to-the-X, where X has many meanings to different operators, has taken off across the world and is seen as the main method to meet the continued growth in broadband needs of the residential and business customers. In this chapter we review the various architectures employed by operators across the world together with technologies that have been deployed to date and the new technologies that are under consideration for the future in order to meet their customers’ residential and business needs.