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Enhancement of laser phase noise to intensity noise conversion by fiber nonlinearity and its impact on the intensity modulation system performance

Enhancement of laser phase noise to intensity noise conversi...

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Conference on all-optical communication systems - architecture, control, and network issues III

作者： Morgado, JAP Cartaxo, AVT Instituto Superior Tecnico (Portugal)

ISBN: (纸本)0819426636

Laser phase noise conversion to intensity noise due to fiber dispersion may impose severe degradation in intensity modulation and direct detection (IM-DD) system performance. In this paper, we investigate theoretically and numerically the influence of fiber nonlinearity on the conversion of phase noise to intensity noise at fiber output. Excellent agreement of noise characteristics between simulations results obtained from an accurate solution of the noise driven laser rate equations and theoretical predictions has been achieved. Results reveal that due to the fiber nonlinearity a significant enhancement of magnitude of the relative intensity noise (RIN) spectrum as well as its broadening is observed in the anomalous dispersion regime while a magnitude reduction and narrowing of the spectrum is observed in the normal regime. The system penalty due to RIN at the fiber output in IM-DD transmission systems using external modulator is assessed, The maximum transmission distance imposed by RIN for 1dB of power penalty is presented for various optical power at fiber input in gigabit-per-second transmission systems. It is shown that in the anomalous dispersion regime the RIN enhancement due to the fiber nonlinearity can impose a significant impairment in IM-DD transmission systems through the phase modulation to IM conversion enhancement.

关键词： optical communication intensity noise phase noise fibre dispersion fibre nonlinearity power penalty bit error rate intensity modulation semiconductor laser external modulator

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Autonomic Intelligent Cyber-Sensor to Support Industrial control network Awareness

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IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS 2014年第2期10卷 1647-1658页

作者： Vollmer, Todd Manic, Milos Linda, Ondrej Idaho Natl Lab Idaho Falls ID 83415 USA Univ Idaho Idaho Falls ID 83402 USA Expedia Inc Bellevue WA 98004 USA

The proliferation of digital devices in a networked industrial ecosystem, along with an exponential growth in complexity and scope, has resulted in elevated security concerns and management complexity issues. This paper describes a novel architecture utilizing concepts of autonomic computing and a simple object access protocol (SOAP)-based interface to metadata access points (IF-MAP) external communication layer to create a network security sensor. This approach simplifies integration of legacy software and supports a secure, scalable, and self-managed framework. The contribution of this paper is twofold: 1) A flexible two-level communication layer based on autonomic computing and service oriented architecture is detailed and 2) three complementary modules that dynamically reconfigure in response to a changing environment are presented. One module utilizes clustering and fuzzy logic to monitor traffic for abnormal behavior. Another module passively monitors network traffic and deploys deceptive virtual network hosts. These components of the sensor system were implemented in C++ and PERL and utilize a common internal D-Bus communication mechanism. A proof of concept prototype was deployed on a mixed-use test network showing the possible real-world applicability. In testing, 45 of the 46 network attached devices were recognized and 10 of the 12 emulated devices were created with specific operating system and port configurations. In addition, the anomaly detection algorithm achieved a 99.9% recognition rate. all output from the modules were correctly distributed using the common communication structure.

关键词： Autonomic computing control systems industrial ecosystems service-oriented architecture network security

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DESIGN issues FOR INTERACTIVE TELEVISION systems

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COMPUTER 1995年第5期28卷 25-39页

作者： FURHT, B KALRA, D KITSON, FL RODRIGUEZ, AA Wall, WE HEWLETT PACKARD CORP DEPT VISUAL COMPPALO ALTOCA 94304

The day is soon coming when we can enjoy interactive services in our own homes, including video-on-demand, home shopping, multimedia libraries, and electronic versions of magazines. Infrastructure and content providers, such as cable TV and telephone companies, are aware that these interactive services can be profitably delivered, although not on current TV systems and architectures. Recently, alliances among entertainment, cable, phone, and computer companies have formed to design wide-area multimedia infrastructures built on improved network technologies and computing and compression techniques. An architecture that can support on-demand, interactive TV applications is a hierarchical configuration of multimedia servers and network switches. In such a system, multimedia data must be compressed, stored, retrieved, and transmitted over the network to its destination, then decompressed and synchronized for playback at the receiving site. For shared access to multimedia data, multimedia servers control large volumes of continuous data, data storage devices, and the networks and communications that deliver the data to and from the subscribers in real time. The set-top box (STB), located at the subscriber premises, is the bridge between the subscriber's display devices, peripherals, and input devices (such as a hand-held infrared remote controller) and a communication channel that connects to the information infrastructure of service providers through a network consisting of switches and transmission medium. The transmission medium can be a coaxial cable or a fiber-optic channel. Wireless technology is also being investigated for delivering data to subscribers. The authors discuss architectures for video-on-demand now being tested separately by Bell Atlantic and GTE;candidate networks (cable, telephone, Internet, and combined cable/telephone);and access technologies (such as hybrid fiber coax, asymmetric digital subscriber line, high-speed digital subscriber line, and Sy

关键词： Multimedia systems Cable TV optical fiber cables Hybrid fiber coaxial cables network servers Coaxial cables Asynchronous transfer mode Switches Computer architecture Telephony

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Cooperative networks for the future wireless world

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IEEE communicationS MAGAZINE 2004年第9期42卷 70-79页

作者： Politis, C Oda, T Dixit, S Schieder, A Lach, HY Smirnov, MI Uskela, S Tafazolli, R Univ Surrey Guildford GU2 5XH Surrey England Nippon Ericsson KK Tokyo Japan Nokia Res Ctr Burlington MA USA Erisson Eurolab GmbH Dusseldorf Germany Motorola Labs Toulouse France Fraunhofer FOKUS Berlin Germany Nokia Tampere Finland

Beyond-3G (B3G) systems have been envisaged as an evolution and convpartial derivativeergence of mobile/wireless communication systems and IP technologies to offer a multitude of services over a variety of access technologies. To fulfill the vision, it is necessary to understand the requirements with respect to the support of heterogeneity in network accesses, communication services, mobility, user devices, and so on. Besides, it is equally important to promote the necessary research in networking technology by providing a guiding framework of research areas and technical issues with priority. The new architectures and technologies will have to address the fundamental assumptions and requirements that govern the design. all these issues are being tackled by the Cooperative network working group (CoNet) of WWRF;the group is working on a series of white papers outlining B3G visions and roadmap, architectural principles, research challenges, and candidate approaches. This article outlines the CoNet concept, architectural principles, and guidelines for research into cooperative networks assuming that the B3G systems will be built over generic IP networking technologies. The article also presents the key research challenges, research framework, and major network components and technologies. The key points are that the system should be layered on demand, encourage reuse of independent modularized functional blocks, support multiple services and service creation, ensure consistent end-to-end connectivity across different access technologies, and cooperate in terms of network control, operations, and maintenance. The architecture shall include the endpoints of communications as part of the communications system, and should provide a secure and trusted environment in which network functions are performed;the network should self-organize dynamically. Additionally, the article presents the IST WSI architecture proposed to CoNet as reference model along with some approaches to

关键词： Mobile radio mobility management Mobile communication Multimedia communication Technology management Multimedia systems Quality of service communication system security Broadcast technology Ad hoc networks Environmental management

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VISION FOR RESIDENTIAL BROAD-BAND SERVICES - ATM-TO-THE-HOME

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IEEE network 1995年第5期9卷 14-28页

作者： KWOK, T Microsoft Corp Redmond WA US

The arrival of asynchronous transfer mode (ATM) networks has enabled a wide range of new interactive multimedia applications for the residential market. The article presents a vision for supporting universal residential broadband services based on an ATM-to-the-home (ATTH) network architecture. This network architecture applies to the various residential access network (RAN) architectures being deployed today, such as hybrid fiber/coax (HFC), fiber-to-the-curb (FTTC), fiber-to-the-home (FTTH), and asymmetric digital subscriber loop (ADSL) technologies. The article addresses today's residential networks and applications, to understand why a switched broadband residential network is required to support residential broadband services. After exploring residential broadband application requirements, a new class of service is proposed to support a very important class of residential broadband applications that has been not addressed. Then, the technical and strategic motivations for using the ATTH architecture are discussed in detail. A universal model for residential broadband network architecture based on ATTH is described, which is shown to apply to various RAN architectures. Finally, it discusses the signaling requirements of residential broadband services and explain why the ATM multiconnection per-call model is much more efficient than the digital stored media command and control (DSM-CC) session control protocol approach for the ATTH architecture.< >

关键词： Application software Cable TV optical fiber subscriber loops TV broadcasting Broadband communication Asynchronous transfer mode communication cables Video on demand Radio access networks Hybrid fiber coaxial cables

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THE DESIGN OF A EUROPEAN optical network

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JOURNAL OF LIGHTWAVE TECHNOLOGY 1995年第5期13卷 817-828页

作者： OMAHONY, MJ SIMEONIDOU, D YU, A ZHOU, J Dept. of Electron. Syst. Eng. Essex Univ. Colchester UK Center for Network Research Department of Electronic Systems Engineering University of Essex Colchester UK

This paper presents a number of design issues under consideration in the development of an all-optical network linking major centers in Europe. The proposed network is characterized by spanning a large geographical area, the diameter is in excess of 3000 km, but with a relatively small number of nodes (20). The study combines aspects of two optical network projects funded by the European Commission: COST 239-Ultra-High Capacity optical Transmission networks and RACE 2028: Multi-Wavelength Transport network. The network uses multiwavelength technology and combines wavelength selection and space switching to achieve signal routing. One of the objectives of the study is to understand the extent to which transparency can be achieved in such a large network. For example the effect of using amplifiers to achieve transparency is to provide extremely long fiber paths in which non-linear effects may become significant and effectively limit the number of wavelengths that can be employed;this limit may be at conflict with the number of wavelengths required from a traffic viewpoint. The paper therefore considers capacity requirements, transmission limitations and node and network architecture issues. It is concluded that partitioning of the network may be necessary to maximize transparency and suggestions are made as to how this might be achieved.

关键词： optical design optical fiber networks Space technology all-optical networks Joining processes Europe Costs Fiber nonlinear optics Nonlinear optics Wavelength routing

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X-NEST: A Scalable, Flexible, and High-Performance network architecture for Distributed Machine Learning

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JOURNAL OF LIGHTWAVE TECHNOLOGY 2021年第13期39卷 4247-4254页

作者： Lu, Yunfeng Gu, Huaxi Yu, Xiaoshan Li, Peng Xidian Univ State Key Lab Integrated Serv Networks Xian 710071 Peoples R China State Key Lab Math Engn & Adv Comp Wuxi 214125 Jiangsu Peoples R China

In a large-scale distributed machine learning system, the interconnection network between computing devices has an important impact on performance in the training of neural network models. The current expansion of training data and model size has led to a rapid increase in the number of computing devices used in distributed machine learning systems, which places higher demands on network scalability. In addition, the synchronization algorithms used for data exchange between computing devices have different communication topologies, and traditional electrical networks have difficulty matching them due to their fixed network topology. Neural network models and model partitioning methods can also affect the amount of communication between devices, but the overprovisioned bandwidth of traditional electric networks incurs unnecessary costs. To address these issues, we propose a scalable, flexible, and high-performance network architecture called X-NEST. The flexibility of optical switching devices allows X-NEST to dynamically change its topology and the number of links between devices according to traffic pattern variations, thereby improving network performance and resource utilization. Although changes in the connection relationships between devices depend on the controller, the simple and flexible control plane of X-NEST can quickly respond to network communication requirements. Extensive analytical simulations using different traffic patterns demonstrate that X-NEST copes well with the communication characteristics of various synchronization algorithms.

关键词： Synchronization optical switches Microswitches Topology network topology Micromechanical devices Parallel processing Data centers machine learning optical interconnects topology

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The MainStreetXpress core services node - A versatile ATM switch architecture for the full service network

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IEEE JOURNAL ON SELECTED AREAS IN communicationS 1997年第5期15卷 795-806页

作者： Rathgeb, EP Fischer, W Hinterberger, C Wallmeier, E WilleFier, R SIEMENS AG DEPT SEMICONDD-81359 MUNICHGERMANY SIEMENS AG RES LABSD-81359 MUNICHGERMANY

Switching systems based on the ATM principle have outgrown the experimental stage, and are already used today in private and corporate networks, as well as in public wide area networks to provide regular service, ATM has the inherent ability to provide a common basis for transmission and switching functionality in both local and wide area networks. With the potential to support all services available today as well as those envisaged for the future, ATM holds a strong promise for network operators and end customers, To fully exploit this potential, ATM switch architectures are required which provide versatility and modularity in supporting services and protocols, independent scalability of data throughput and control performance over a wide range, and also reliability features adaptable to the respective application scenario, This paper describes in some detail how the MainStreetXpress core services node, which has evolved from the prototype described earlier [5] to a mature central office ATM switch, addresses these issues and provides a future-proof architecture incorporating all of the features required in the B-ISDN era.

关键词： asynchronous transfer mode broad-band communication redundancy switching systems

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A survey of pricing for integrated service networks

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COMPUTER communicationS 2001年第18期24卷 1808-1818页

作者： Chang, XJ Petr, DW Univ Kansas ITTC Lawrence KS 66045 USA

Advances in technology have greatly increased the demand for a single integrated service network that can provide multiple service classes for different user requirements. For such a multiple-service network, congestion control is one of the key issues to be addressed. However, without an appropriate mechanism to encourage end users to use the network properly, over-utilization and congestion are unavoidable. For this problem, it is widely accepted that pricing is a proper tool to manage congestion, encourage network growth, and allocate resource to users in a fair manner. However, how to charge for the traffic and at what price is still under study. In this paper, we first briefly review the state of the art and technological growth of congestion control for integrated service networks (ISN). Subsequently, we present a summary of the recent developments on various pricing policies and different charging and billing schemes that have been proposed for ATM and Internet Differentiated Services. Some architecture and implementation issues are also discussed. Finally, some future trends are identified. (C) 2001 Elsevier Science B.V. all rights reserved.

关键词： Voice/data communication systems

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NEURAL-network IMPLEMENTATION USING SELF-LENSING MEDIA

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APPLIED OPTICS 1995年第20期34卷 4129-4135页

作者： SKINNER, SR BEHRMAN, EC CRUZCABRERA, AA STECK, JE WICHITA STATE UNIV DEPT PHYSWICHITAKS 67260 WICHITA STATE UNIV DEPT MECH ENGNWICHITAKS 67260

An all-optical implementation of a feed-forward artificial neural network is presented that uses self-lensing materials in which the index of refraction is irradiance dependent. Many of these types of material have ultrafast response times and permit both weighted connections and nonlinear neuron processing to be implemented with only thin material layers separated by free space. Both neuron processing and weighted interconnections emerge directly from the physical optics of the device. One creates virtual neurons and their connections simply by applying patterns of irradiance to thin layers of the nonlinear media. This is a result of a variation of the refractive-index profile of the self-lensing nonlinear media in response to the applied irradiance. An optical-backpropagation training method for this network is presented. The optical backpropagation is a training method that can be implemented potentially within the same optical device as the forward calculations, although several issues crucial to this possibility remain to be addressed. Such a network was numerically simulated and trained to solve many benchmark classification problems, and some of these results are presented. To demonstrate the feasibility of building such a network, we also describe experimental work in the construction of an optical network trained to perform a logic KNOR function. This network, as a proof of concept, uses a relatively slow thermal nonlinear material with similar to 1-s response time.

关键词： Neural networks optical network architecture optical networks optical systems Physical optics Spatial light modulators

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