最新刊期
卷 ， 期 4 ， 2009
- 摘要：The concept of Shared Risk Link Group（SRLG） is introduced into WDM optical networks,requiring that the work path and the protection path should not exist in one and same SRLG.This article proposes an SRLG constraint-based dynamic shared path protection algorithm that satisfies the Dynamic Link Weight Configuration（DLWC） of K pairs services,called.K-DLWC algorithm.The key to this algorithm lies in the use of the concept of routing options,which can be used to synthetically cope with such key issues as SRLG constraints and local optimization in calculating the work path and the protection path.关键词：SRLG;shared path protection;K-DLWC;local optimization
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发布时间： - 摘要：In IP over WDM networks in an overlay model,effective topological information in the IP layer is further extracted by using the saturated cut algorithm.With this information,the network lightpath setup is optimized so as to reduce the blocking ratio of the entire network.The simulation results show that the blocking ratio is even lower by using the double saturated cut algorithm than that by using the single saturated cut algorithm.关键词：traffic grooming;lightpath;IP over WDM
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发布时间： - 摘要：In this paper,a novel dual SOA-MZI-based packet header and payload separation scheme is proposed on the basis of the existing all-optical packet header and payload separation scheme.The new scheme makes full use of the nonlinearity of SOA-MZI and gives numerical and theoretical analysis of the scheme by using a mathematical model.The results show that the packet header and payload obtain different phase shifts and gains after passing through a separating unit,realizing the effective separation of the packet header and payload.关键词：all-optical packet switching network;header and payload separation;SOA-MZI;packet header extractor
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发布时间： - 摘要：As an important part of ASON control plane,a routing protocol is responsible for link state advertisement and routing calculation.In the actual course of ASON operation,this protocol has some shortages that affect the network scalability,such as occupation of too much DCN bandwidth and excessive synchronization delay of link state database.This article presents an optimization scheme for the routing protocol,including setting a threshold for the flooding routing information and adding database self-updating function to the routing protocol.关键词：ASON;control plane;routing protocol
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发布时间： - 摘要：In transparent networks,the quality of optical signals is degraded owing to physical impairment,thus the impairment-aware-based connection provisioning has become a hot research topic.This paper studies the key issues in this respect in terms of architecture,impairment model and Impairment-aware Routing Wavelength Assignment（IRWA） algorithm,explains the necessity of full use of the intelligentization of optical networks,setting up appropriate impairment model and ensuring the signal quality in routing selection and wavelength assignment by using IRWA algorithm..关键词：transparent network;physical impairment;IRWA
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发布时间： - 摘要：Fiber-optic transmission networks have unique advantages and special vulnerabilities.Their safety has becomes more and more important with the rapid development and extensive applications of the fiber-optic communication technologies.In line with the hierarchical point of view,this paper introduces their safety hierarchical structure,analyses the vulnerabilities of their different layers,types and methods of attack and investigates the relevant safety strategies against the possible safety threat to each layer.关键词：fiber-optic transmission network;vulnerability;safety strategy
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- 120
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发布时间： - 摘要：This paper presents an IEEE 802.3ah-based design scheme for EPON client dedicated chips and realizes the Optical Network Unit（ONU） functions by integrating the FPGA and IP soft core technologies.It describes the hardware structure of the chip,gives the general idea of the IP soft core design,introduces its testing method and verifies the test results from multipleangles.The test results show that the chip fully satisfies the practical application requirements.关键词：EPON;ONU;MPCP;IP soft core
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- 62
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发布时间： - 摘要：This paper first analyzes the advantages and disadvantages of previous peer-to-peer network models and on this basis proposes an improved P2P network model,e.g.discarding messages that have been seen,returning responding messages along the original routes and setting the broadcast radius.Then,it gives a fairly detailed introduction to its functional modules for node management,resource search and download management.Finally,on these bases,it designs and develops a P2P-based Network Management System（NMS）.关键词：peer-to-peer;network model;resource search;NMS
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- 89
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发布时间： - 摘要：This paper analyzes the performance of the queueing system with Fractal Point Process（FPP）-based self-similar traffic as its inputs by simulation of the switch queueing system.The simulation results show that the queue behavior under the self-similar traffic model is far different from that under the conventional exponential traffic model.The results obtained can be used in network traffic modeling,network design,network congestion control and traffic engineering.关键词：self-similar traffic;FPP;queueing system;traffic engineering
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发布时间： - 摘要：A media distribution server is an important module in an IP video surveillance system platform that is in charge of streaming media distribution.Though able to cover the shortage of IPv4 address resource,the IP Network Address Translator（NAT） brings about obstacles in the communications between the users in various private networks or between those in the private and public networks.This article mainly introduces the formation of such obstacles and gives an SIP-based approach for the media distribution server to implement NAT transversal.关键词：IP video surveillance;media distribute server;NAT traversal
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- 56
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发布时间： - 摘要：The IPTV content management system mainly implements the management of the contents provided by IPTV third-party value-added services providers,such as video and text information.This thesis describes the overall design scheme of the system,introduces the function and external interfaces of its principal functional modules,gives its software structure and discusses the software architecture of IPTV content management system,and discusses in detail its programming realization approach.关键词：IPTV;value-added service platform;content management system
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- 114
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发布时间： - 摘要：This paper classifies and describes the typical networking technologies and relevant standards for home networks with an emphasis on the analysis and comparisons on the main bus technologies and the relevant international standards for home networks.It compares and describes three domestic standardization organizations associated with home networks and conducts specific analysis and comparisons between ITopHome and other standards.Finally,it offers a number of suggestions for improvement for home control networks that fit in with the demands for the next generation home networks.关键词：home control network;networking technology;standard
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- 62
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发布时间： - 摘要：This article elaborates the RFID system and the functions of RFID middleware,then proposes a binary tree data filtering algorithm,moves the data filtering function applied in the middleware forward to the reader,thus concluding that in comparison with the data filtering algorithm,this algorithm is even better.Finally it predicts the prospect of the development of RFID middleware.关键词：RFID;middleware;data filtering;reader;binary tree algorithm
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- 185
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发布时间： - 摘要：Supercontinuum broadening has important applications in optical communications.This article numerically investigates by the split-step Fourier method the propagation characteristics and the supercontinuum generation mechanism of femtosecond laser pulses in a Photonic Crystal Fiber（PCF） pumped in different dispersion regions.It is found that the dispersion and strong nonlinearity of the fiber greatly affect the transmission and evolution of the femtosecond pulses in PCF and the supercontinuum broadening.These conclusions are of some reference values to the study on the generation and applications of the supercontinuum.关键词：optical communication;PCF;split-step Fourier method;dispersion;supercontinuum
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- 208
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发布时间： - 摘要：On the basis of the theoretical analysis of the temperature effect of fiber Raman backscattering,this paper investigates in detail the fiber distributed temperature sensor system that is based on anti-Stokes/Stokes scattering optical intensity ratio values and develops a single-mode fiber-based 5 km distributed temperature sensor on the basis of analyzing the requirements of the main devices of the system.The experimental results show that this system can make accurate distributed temperature detection with a temperature resolution ratio of 1℃ and a spatial resolution ratio of 2 m.关键词：distributed sensor;Raman scattering;anti-Stokes scattered light;Stokes scattered light
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- 213
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发布时间： - 摘要：Thanks to its advantages in sensitivity,APD photodetector has found extensive applications in long-haul high-rate digital communication systems.This article systematically describes the key points in the design of the optics and microwave packaging of high-rate APD/TIA detector assemblies,conducts a comprehensive test on the packaged assemblies and analyzes the test results.关键词：APD;APD/TIA photodetector assembly;10 Gbit/s;-3 dB bandwidth;sensitivity
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- 294
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发布时间： - 摘要：The amplification of ultrashort optical pulses in EDFA is numerically studied.The results show that when the initial gap between two adjacent optical pulses is small,they will attract each other and produce new subpulses in the course of amplification,resulting in the worsening of the amplification effects.As the enlargement of the initial gap cannot effectively improve the amplification effect,a new method is proposed to introduce appropriate initial chirps into the input pulses,by which the negative effects brought about by the interactions between the optical pulses are reduced and the pulse amplification quality improved.关键词：fiber-optic communication technology;EDFA;initial chirp;ultrashort optical pulse
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- 85
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发布时间： - 摘要：A novel scheme for an ultrahigh-speed all-optical comparator based on the Four-Wave Mixing（FWM） effects in Semiconductor Optical Amplifiers（SOAs） is proposed,by which can eliminate the pattern effects in SOAs by using the power-constant Polarization-Shift-Keying（PolSK） signal light.By numerical simulation,two input signal power,injection current and the effects of the active region length on the comparator output characteristics are investigated.关键词：all-optical comparator;FWM;PolSK;SOA
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- 105
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发布时间： - 摘要：There exist numerous interferometric methods for absolute distance measurement,but it is difficult to construct compact low-cost measuring systems because of the need of a lot of optical devices for most of them.Featured in simple structure,low cost and high accuracy,the interferometry based on optical feedback self-mixing interference has in recent years attracted extensive attention in the field of measurement.This paper analyzes the theories of laser self-mixing interference and frequency modulation,sets up an absolute distance measurement model and conducts calculations and simulations,the result of which shows that uses can be made of the frequency modulation theory to measure the absolute distance of the targets.关键词：optical feedback;self-mixing interference;absolute distance
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- 248
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发布时间： - 摘要：This paper proposes an experimental research method for the wavelength demultiplexing technology that is based on volume holographic grating in photorefractive LiNbO3 crystal and studies the important factors that affect the grating diffraction efficiency.In this experiment,o-ray optical write in and e-ray readout are used when the write-in beam intensity ratio is nearly 1∶1.The experiment is successfully performed by writing into the grating in the same location with red and green lights successively and then reading out with coupled light.No interferences occur when the included angle between the two gratings is 0.18 °.关键词：wavelength demultiplexing;photorefractive effect;volume holographic grating
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发布时间： - 摘要：This paper derives the upper bounds of the bit error rate of the Pulse Position Modulation（PPM） system after error correction by using linear block code and analyzes the effects of the error correction capability of the error coding and the parameter setting of the PPM resolution on the error performances.Simulation results show that when the numbers of the error corrections are divided exactly by the bit resolution,the PPM system will have higher code modulation performance and higher order error control codes are generally preferable to the PPM system.关键词：optical wireless communication;coded modulation;PPM;BER
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