A Survey on OFDM-Based Elastic Core Optical Networking <s> I <s> Using discrete multi-tone modulation with up to 64-QAM mapping, 24-Gb/s transmission is experimentally demonstrated over 730 m of MMF by direct modulation of an 850-nm VCSEL and direct detection with a MMF receiver. <s> BIB001 </s> A Survey on OFDM-Based Elastic Core Optical Networking <s> I <s> This paper presents an analysis of the energy consumption in a number of optical switch fabric architectures for optical packet-switched applications and compares them to electronic switch fabrics. Optical packet switching does not appear to offer any substantial power consumption advantages over electronic packet switching. Therefore, there is no compelling case for optical packet switching. <s> BIB002 </s> A Survey on OFDM-Based Elastic Core Optical Networking <s> I <s> We discuss the scalability challenges facing the optical networks. Using the architecture based on spectrum-sliced elastic optical path network (SLICE), we demonstrate how the networking functionality can be effectively shifted to the optical domain. <s> BIB003 </s> A Survey on OFDM-Based Elastic Core Optical Networking <s> I <s> The first book on optical OFDM by the leading pioneers in the field. The only book to cover error correction codes for optical OFDM. It gives applications of OFDM to free-space communications, optical access networks, and metro and log haul transports show optical OFDM can be implemented. It contains introductions to signal processing for optical engineers and optical communication fundamentals for wireless engineers. This book gives a coherent and comprehensive introduction to the fundamentals of OFDM signal processing, with a distinctive focus on its broad range of applications. It evaluates the architecture, design and performance of a number of OFDM variations, discusses coded OFDM, and gives a detailed study of error correction codes for access networks, 100 Gb/s Ethernet and future optical networks. The emerging applications of optical OFDM, including single-mode fiber transmission, multimode fiber transmission, free space optical systems, and optical access networks are examined, with particular attention paid to passive optical networks, radio-over-fiber, WiMAX and UWB communications. Written by two of the leading contributors to the field, this book will be a unique reference for optical communications engineers and scientists. Students, technical managers and telecom executives seeking to understand this new technology for future-generation optical networks will find the book invaluable. William Shieh is an associate professor and reader in the electrical and electronic engineering department, The University of Melbourne, Australia. He received his M.S. degree in electrical engineering and Ph.D. degree in physics both from University of Southern California. Ivan Djordjevic is an Assistant Professor of Electrical and Computer Engineering at the University of Arizona, Tucson, where he directs the Optical Communications Systems Laboratory (OCSL). His current research interests include optical networks, error control coding, constrained coding, coded modulation, turbo equalization, OFDM applications, and quantum error correction. 'This wonderful book is the first one to address the rapidly emerging optical OFDM field. Written by two leading researchers in the field, the book is structured to comprehensively cover any optical OFDM aspect one could possibly think of, from the most fundamental to the most specialized. The book adopts a coherent line of presentation, while striking a thoughtful balance between the various topics, gradually developing the optical-physics and communication-theoretic concepts required for deep comprehension of the topic, eventually treating the multiple optical OFDM methods, variations and applications. In my view, this book will remain relevant for many years to come, and will be increasingly accessed by graduate students, accomplished researchers as well as telecommunication engineers and managers keen to attain a perspective on the emerging role of OFDM in the evolution of photonic networks' - Prof. Moshe Nazarathy, EE Dept., Technion, Israel Institute of Technology. <s> BIB004 </s> A Survey on OFDM-Based Elastic Core Optical Networking <s> I <s> The transport network paradigm is moving toward next-generation networks that aim at IP convergence, while architectures and technologies are diversifying. Video technologies including ultrahigh-definition TV (more than 33 M pixels) continue to advance, and future communication networks will become video-centric. The inefficiencies of current IP technologies, in particular, the energy consumption and throughput limitations of IP routers, will become pressing problems. Harnessing the full power of light will resolve these problems and spur the creation of future video-centric networks. Extension of optical layer technologies and coordination with new transport protocols will be critical; hierarchical optical path technologies and optical circuit/path switching will play key roles. Recent technical advances in these fields are presented. <s> BIB005 </s> A Survey on OFDM-Based Elastic Core Optical Networking <s> I <s> The sustained growth of data traffic volume calls for an introduction of an efficient and scalable transport platform for links of 100 Gb/s and beyond in the future optical network. In this article, after briefly reviewing the existing major technology options, we propose a novel, spectrum- efficient, and scalable optical transport network architecture called SLICE. The SLICE architecture enables sub-wavelength, superwavelength, and multiple-rate data traffic accommodation in a highly spectrum-efficient manner, thereby providing a fractional bandwidth service. Dynamic bandwidth variation of elastic optical paths provides network operators with new business opportunities offering cost-effective and highly available connectivity services through time-dependent bandwidth sharing, energy-efficient network operation, and highly survivable restoration with bandwidth squeezing. We also discuss an optical orthogonal frequency-division multiplexing-based flexible-rate transponder and a bandwidth-variable wavelength cross-connect as the enabling technologies of SLICE concept. Finally, we present the performance evaluation and technical challenges that arise in this new network architecture. <s> BIB006 </s> A Survey on OFDM-Based Elastic Core Optical Networking <s> I <s> A practical scheme to perform the fast Fourier transform in the optical domain is introduced. Optical real-time FFT signal processing is performed at speeds far beyond the limits of electronic digital processing, and with negligible energy consumption. To illustrate the power of the method we demonstrate an optical 400 Gbit/s OFDM receiver. It performs an optical real-time FFT on the consolidated OFDM data stream, thereby demultiplexing the signal into lower bit rate subcarrier tributaries, which can then be processed electronically. <s> BIB007 </s> A Survey on OFDM-Based Elastic Core Optical Networking <s> I <s> Orthogonal Frequency Division Multiplexing (OFDM) systems are widely used in the standards for digital audio/video broadcasting, WiFi and WiMax. Being a frequency-domain approach to communications, OFDM has important advantages in dealing with the frequency-selective nature of high data rate wireless communication channels. As the needs for operating with higher data rates become more pressing, OFDM systems have emerged as an effective physical-layer solution. This short monograph is intended as a tutorial which highlights the deleterious aspects of the wireless channel and presents why OFDM is a good choice as a modulation that can transmit at high data rates. The system-level approach we shall pursue will also point out the disadvantages of OFDM systems especially in the context of peak to average ratio, and carrier frequency synchronization. Finally, simulation of OFDM systems will be given due prominence. Simple MATLAB programs are provided for bit error rate simulation using a discrete-time OFDM representation. Software is also provided to simulate the effects of inter-block-interference, inter-carrier-interference and signal clipping on the error rate performance. Different components of the OFDM system are described, and detailed implementation notes are provided for the programs. The program can be downloaded here. Table of Contents: Introduction / Modeling Wireless Channels / Baseband OFDM System / Carrier Frequency Offset / Peak to Average Power Ratio / Simulation of the Performance of OFDM Systems / Conclusions <s> BIB008 </s> A Survey on OFDM-Based Elastic Core Optical Networking <s> I <s> At current growth rates, Internet traffic will increase by a factor of one thousand in roughly 20 years. It will be challenging for transmission and routing/switching systems to keep pace with this level of growth without requiring prohibitively large increases in network cost and power consumption. We present a high-level vision for addressing these challenges based on both technological and architectural advancements. <s> BIB009
N RECENT years, Internet traffic in the core network has been doubling almost every two years, and predictions indicate that it will continue to exhibit exponential growth due to emerging applications such as high-definition and real-time video communications BIB009 BIB003 . As a result of this rapid increase in traffic demands, large-capacity and costeffective optical fiber transmission systems are required for realizing future optical networks. So far, Wavelength-Division Multiplexing (WDM) systems with up to BIB007 Gb/s capacity per channel have been deployed in backbone networks, while 100 Gb/s interfaces are now commercially available and 100 Gb/s deployment are expected soon. Moreover, it is foreseen that optical networks will be required to support Tb/s class transmission in the near future BIB003 BIB004 . However, scaling to the growing traffic demands is challenging for conventional optical transmission technology as it suffers from the electrical bandwidth bottleneck limitation, and the physical impairments become more severe as the transmission speed increases BIB004 . On the other hand, emerging Internet applications such as Internet Protocol television (IPTV), video on demand, and cloud and grid computing applications demonstrate unpredictable changes in bandwidth and geographical traffic patterns BIB005 . This calls for a more data-rate flexible, agile, reconfigurable, and resource-efficient optical network, while the fixed and coarse granularity of current WDM technology will restrict the optical network to stranded bandwidth provisioning, inefficient capacity utilization, and high cost. To meet the needs of the future Internet, the optical transmission and networking technologies are moving forward to a more efficient, flexible, and scalable direction. Solutions such as optical packet switching (OPS) and optical burst switching (OBS) that meet these requirements have been studied in the past few years, but cannot be considered as a near-term solution due to their immaturity BIB002 . Recently, OFDM (Orthogonal Frequency-Division Multiplexing) has been considered a promising candidate for future high-speed optical transmission technology. OFDM is a multicarrier transmission technology that transmits a high-speed data stream by splitting it into multiple parallel low-speed data channels. OFDM first emerged as a leading physicallayer technology in wireless communications, as it provides an effective solution to inter-symbol interference (ISI) caused by the delay spread of wireless channels. It is now widely adopted in broadband wireless and wireline networking standards, such as 802.11a/g Wi-Fi, 802. BIB001 WiMAX, LTE (LongTerm Evolution), DAB and DVB (Digital Audio and Video Broadcasting), and DSL (Digital Subscriber Loop) around the world BIB004 . Because of the great success of OFDM in wireless and wireline systems, it is currently being considered for optical transmission and networking. With the intrinsic flexibility and scalability characteristics of optical OFDM technology (which will be described in Section IV-A in more detail), a novel elastic optical network architecture, possessing the capability to manage signals with different data rate and variable bandwidth, can be built to meet the requirements of future optical networks BIB006 . BIB008 In this paper, we present a comprehensive survey of OFDMbased optical high-speed transmission and networking technologies, with a specific focus on core optical network scenarios. We start with basic OFDM principles in Section II, and introduce various kinds of optical OFDM transmission schemes and technologies in Section III. Next, we address the OFDM-based elastic optical network, detailing its architecture and enabling technologies in Section IV. Finally, we present our concluding remarks in Section V.