Wavelength assignment for parallel FFT communication pattern on linear arrays by lattice embedding

©2005 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.Fast Fourier Transform(FFT) represents a common communication pattern shared by a large class of scientific and engineering problems and wavelength assignment is a key issue to increase efficiency and reduce cost in Wavelength Division Multiplexing (WDM) optical networks. In this paper, we propose a new scheme for the wavelength assignment of parallel FFT communication pattern on WDM linear arrays. By lattice embedding, the number of wavelengths required to realize parallel FFT communication pattern on WDM linear arrays significantly improves the known result. Our proposed embedding method also provides a new approach to the hypercube layout problem considering connections dimension by dimension rather than all connections as in the traditional approach.Yawen Chen, Hong She

A survey on OFDM-based elastic core optical networking

Orthogonal frequency-division multiplexing (OFDM) is a modulation technology that has been widely adopted in many new and emerging broadband wireless and wireline communication systems. Due to its capability to transmit a high-speed data stream using multiple spectral-overlapped lower-speed subcarriers, OFDM technology offers superior advantages of high spectrum efficiency, robustness against inter-carrier and inter-symbol interference, adaptability to server channel conditions, etc. In recent years, there have been intensive studies on optical OFDM (O-OFDM) transmission technologies, and it is considered a promising technology for future ultra-high-speed optical transmission. Based on O-OFDM technology, a novel elastic optical network architecture with immense flexibility and scalability in spectrum allocation and data rate accommodation could be built to support diverse services and the rapid growth of Internet traffic in the future. In this paper, we present a comprehensive survey on OFDM-based elastic optical network technologies, including basic principles of OFDM, O-OFDM technologies, the architectures of OFDM-based elastic core optical networks, and related key enabling technologies. The main advantages and issues of OFDM-based elastic core optical networks that are under research are also discussed

OpTree: An Efficient Algorithm for All-gather Operation in Optical Interconnect Systems

All-gather collective communication is one of the most important communication primitives in parallel and distributed computation, which plays an essential role in many HPC applications such as distributed Deep Learning (DL) with model and hybrid parallelism. To solve the communication bottleneck of All-gather, optical interconnection network can provide unprecedented high bandwidth and reliability for data transfer among the distributed nodes. However, most traditional All-gather algorithms are designed for electrical interconnection, which cannot fit well for optical interconnect systems, resulting in poor performance. This paper proposes an efficient scheme, called OpTree, for All-gather operation on optical interconnect systems. OpTree derives an optimal $m$-ary tree corresponding to the optimal number of communication stages, achieving minimum communication time. We further analyze and compare the communication steps of OpTree with existing All-gather algorithms. Theoretical results exhibit that OpTree requires much less number of communication steps than existing All-gather algorithms on optical interconnect systems. Simulation results show that OpTree can reduce communication time by 72.21%, 94.30%, and 88.58%, respectively, compared with three existing All-gather schemes, WRHT, Ring, and NE.Comment: This paper is under review at a conferenc

Software Defined Applications in Cellular and Optical Networks

abstract: Small wireless cells have the potential to overcome bottlenecks in wireless access through the sharing of spectrum resources. A novel access backhaul network architecture based on a Smart Gateway (Sm-GW) between the small cell base stations, e.g., LTE eNBs, and the conventional backhaul gateways, e.g., LTE Servicing/Packet Gateways (S/P-GWs) has been introduced to address the bottleneck. The Sm-GW flexibly schedules uplink transmissions for the eNBs. Based on software defined networking (SDN) a management mechanism that allows multiple operator to flexibly inter-operate via multiple Sm-GWs with a multitude of small cells has been proposed. This dissertation also comprehensively survey the studies that examine the SDN paradigm in optical networks. Along with the PHY functional split improvements, the performance of Distributed Converged Cable Access Platform (DCCAP) in the cable architectures especially for the Remote-PHY and Remote-MACPHY nodes has been evaluated. In the PHY functional split, in addition to the re-use of infrastructure with a common FFT module for multiple technologies, a novel cross functional split interaction to cache the repetitive QAM symbols across time at the remote node to reduce the transmission rate requirement of the fronthaul link has been proposed.Dissertation/ThesisDoctoral Dissertation Electrical Engineering 201

Nanoscale Semiconductor Materials and Devices Employing Hybrid 1D and 2D Structures for Tunable Electronic and Photonic Applications

Das, Suprem R. Ph.D., Purdue University, December 2013. Nanoscale Semiconductor Materials and Devices employing Hybrid 1D and 2D structures for Tunable Electronic and Photonic Applications. Major Professor: Dr. David B. Janes. Continued miniaturization of microelectronic devices over past decades has brought the device feature size towards the physical limit. Likewise, enormous `waste energy\u27 in the form of self-heating in almost all of the electronic and optoelectronic devices needs an `energy-efficient low power\u27 and `high performance\u27 material as well as device with alternate geometry. III-V semiconductors are proven to be one of the alternate systems of materials for various applications including CMOS devices, low power and high performance transistor devices, power transistors, as well as thermoelectric applications. InSb, being the bulk semiconductor with lowest bandgap, highest mobility, low effective mass, and highest spin–orbit coupling has potential of providing numerous novel applications. Also, InSb in nanowire form has not been explored in many aspects. First part of this thesis explores the possibility of growing InSb nanowires using solution based electrodeposition technique followed by field effect transistor studies. InSb nanowires have recently shown very promising magneto-transport properties at low temperatures and with magnetic field due to its high spin orbit coupling. This thesis demonstrates initial low temperature device studies on hybrid devices with InSb channel and superconducting electrodes (aluminum). In the last section of InSb nanowire studies, the thesis explores hierarchial branched nanowires with different diameters that demonstrate near unity optical absorption in UV–VIS regime and wavelength dependent absorption in near infrared (NIR) regime. A photonic coupling model was developed to explain the phenomena. The unique photonic properties of the structurally tailored branched nanowire arrays could be used to devise new types of photonic, optoelectronics and/or photovoltaic devices. The second half of the thesis explores another class of hybrid material structure involving 2D semiconductor/semimetal ‘Graphene’ and 1D silver nanowires. While the ultimate goal was to push the limit of ‘transparent and flexible technology’ the thesis, also critically explores the physics of percolation doping to beat the conduction–transparency bottleneck. The thesis demonstrates theory of ‘co-percolation’ involving two individual networks in which the invidual\u27s weakness is circumvented by the other. This study not only applies to the particular system chosen but also could be readily applied to any large scale 2D–1D nanoscale systems such as layered semiconductors, topological insulators and nanowires

Enabling Technology in Optical Fiber Communications: From Device, System to Networking

This book explores the enabling technology in optical fiber communications. It focuses on the state-of-the-art advances from fundamental theories, devices, and subsystems to networking applications as well as future perspectives of optical fiber communications. The topics cover include integrated photonics, fiber optics, fiber and free-space optical communications, and optical networking

Modern Applications in Optics and Photonics: From Sensing and Analytics to Communication

Optics and photonics are among the key technologies of the 21st century, and offer potential for novel applications in areas such as sensing and spectroscopy, analytics, monitoring, biomedical imaging/diagnostics, and optical communication technology. The high degree of control over light fields, together with the capabilities of modern processing and integration technology, enables new optical measurement systems with enhanced functionality and sensitivity. They are attractive for a range of applications that were previously inaccessible. This Special Issue aims to provide an overview of some of the most advanced application areas in optics and photonics and indicate the broad potential for the future