最新刊期
卷 ， 期 6 ， 2009
- 摘要：A load-balancing routing mechanism based on BFP-Tree approach is proposed in this paper,which first counts up the use frequency of all the nodes,then chooses the most often used path and performs routing selection for the traffic request according to the principle that the statistical variance of the number of the used wavelengths for each link in the network is the minimum.Simulation results show that this mechanism is superior to the BFP-Tree routing mechanism in both blocking probability and transmission delay.关键词：all-optical network;load balance;routing mechanisms;path
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发布时间： - 摘要：In this paper,the architecture of the Automatically Switched Optical Network（ASON） and its survivability mechanism are introduced,the implementation process of its survivability briefly described in a design scheme,several main ways of protection and restoration compared and analyzed and presents the application strategy for its survivability,which is of major importance for its design and planning.关键词：ASON;control plane;survivability mechanisms;protection and restoration;strategy
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- 107
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发布时间： - 摘要：Optical networks with only a portion of their nodes capable of supporting multicast are called sparse splitting optical networks.In consideration of network performance and cost,optical networks are usually configured in a sparse light-splitting state.The multicast routing in these networks mainly aims at requesting to find appropriate light-trees or light-forests for the multipoint transmission of multicast traffic.This paper focuses on analyzing and summarizing the multicast routing mechanism and the relevant algorithms in current sparse splitting optical networks on the basis of integrated classification and forecasting the future work.关键词：WDM;sparse light-splitting;multicast;routing mechanism
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发布时间： - 摘要：EPON has been widely deployed on the globe and Optical Line Terminal（OLT） is its core element.As a shared point-to-multipoint network,its security is subject to menace,so the protection of OLT is of great importance to the entire EPON.In this paper,anti-attack methods for EPON OLT are introduced,with an emphasis on the important roles of switching chips in these methods.Examples are given to explain how the EPON units are protected.关键词：EPON;virtual local area network;address resolution protocol;MAC
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发布时间： - 摘要：WDM-PON is commonly believed to be a representative technology for the future broadband access as it enables point-to-point connection and provides each user with a pair of dedicated wavelengths.The key to WDM-PON is adopting low-cost "colorless" ONU,thus avoiding the cost increases in installation,operation and maintenance resulted from wavelength selection devices.This paper presents and briefly analyzes three approaches for colorless ONU implementation for WDM-PON and points out that colorless ONU is an ideal solution for WDM-ONU construction.关键词：WDM-PON;spectral slicing;injection locking;colorless ONU
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- 647
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发布时间： - 摘要：This paper first introduces the structure of the network management system of GPON and then analyses the functions of the subagent ONUs in these systems,focusing on the classified alarms in the these units in the management and control processes.On this basis,it devises the solutions for the alarm management and completes the design of the SUF alarm process for ONU management control modules.关键词：GPON;network management;alarm management
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发布时间： - 摘要：This paper briefly introduces the present status of the applications of Automatically Switched Optical Network（ASON） equipment,structure,mode of construction,types of service,flow direction and existing problems of the electric power optical communication networks,points out that ASONs are applicable to the backbone networks and MAN and explains the evolution strategy for the ASON-based electric power communication networks in terms of network planning,way of evolution,the interworking between ASON and the traditional optical networks and issues that need attention in the evolution process.关键词：ASON;SDH;electric power communication network;evolution
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- 114
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发布时间： - 摘要：This paper presents a high-resolution distributed fiber temperature sensing system based on spontaneous Raman scattering,which detects the density of the backscattering light and the varied temperature along the sensing fiber on the basis of the relationship between the reflected light density and temperature.In this paper,we discuss in detail the operating principle of system,set up a sensing system and perform a series of temperature sensing experiments.The results show that the system temperature resolution reaches 0.1℃ and its spatial resolution is 1 m.关键词：distributed;temperature;fiber;sensing;Raman scattering
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- 308
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发布时间： - 摘要：As a novel carrier-level Ethernet technology,the Provider Link State Bridge（PLSB）technology can be used to address the issue of PBT’s point to multi-point forwarding limitations.This paper first introduces the forwarding mechanism of PLSB,and then analyzes the cause of temporal loop that might be produced when building forwarding trees,on the basis of which,a loop mitigation called Reverse Path Forwarding Check（RPFC） is presented.关键词：PLSB;loop mitigation;RPFC
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发布时间： - 摘要：As one of the hotspot technologies in current study,Optical Orthogonal Frequency Division Multiplexing（O-OFDM） is applied to enhance the optical network capability to counteract such effects as chromatic dispersion and polarization mode dispersion,thus improving their performances.This paper explains the principle of the technology,reviews its current applications in optical backbone transmission networks and optical access networks and forecasts the trend of its development and prospects of its applications.关键词：O-OFDM;optical transmission network;optical access network
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- 348
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发布时间： - 摘要：As an integrated transmission access system specially designed for subways,Open Transport Network（OTN） is at present widely adopted in subway communication networks.This paper introduces its feature,composition,functions,structure and frame structure and analyzes its operating principle as a private subway communication system,offering the theoretical basis for its operation and maintenance.关键词：OTN;subway;communication
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- 132
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发布时间： - 摘要：IPTV service is gradually moving towards the stage of practical operation and has become the mainstream broadband service of service telecom operators.For its long-term and ordered growth,it is urgently necessary to build a billing system that is appropriate for IPTV value-added service.This paper describes the general structure of a billing system based on the IPTV value-added service platform and explains the definition of the interface between the IPTV business operation platform and the Service Provider（SP） system,on the basis of which,it analyzes in detail its billing-related functional requirements.Finally,it presents an implementation scheme for the interface.关键词：IPTV;billing system;SP;interface
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- 63
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发布时间： - 摘要：In this paper,the properties of a new type of Total Internal Reflection Photonic Crystal Fiber（TIR-PCF） with two small elliptic air holes in the core are studies by using the Full Vectorial Effective Index Method（FVEIM）.The numerical results show that the difference between the refractive index in the core and the equivalent refractive index in the cladding increases with the wavelength,that the relative aperture of the air holes in the fixed cladding and the degeneracy of two orthonormal polarized modes of the PCF fundamental mode is removed,presenting a modal high birefringence,and that the modal birefringence increase and the total PCF dispersion curve becomes flattened with the increase of the ellipticity of the air holes.关键词：TIR-PCF;FVEIM;dispersion;model birefringence
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- 185
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发布时间： - 摘要：In this paper,the development of a TFF-based flat-top tunable optical filter with 50 GHz channel spacing is introduced,the principle for the angle-tuned interference filter discussed and the design of an ultra-narrow band film stack optimized.The module performance is fully tested,which proves that 96 ITU-T channels can be optionally dropped in the range of 40 nm wavelength,thus providing a dynamic low-cost high-performance wavelength selection scheme for intelligent optical networks.关键词：angle-tuned filter;ultra-narrow band;film stack design;flat top
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- 117
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发布时间： - 摘要：This paper analyzes the principle of F-P cavity-based MEMS Tunable Optical Filter（TOF）,deduces and tests the relationship between its wavelength and voltage/temperature,presents the wavelength hybrid control technology by temperature and voltage and realizes tunable optical filters within the range of 1 5301 560 nm.关键词：F-P cavity;MEMS;temperature control;wavelength control
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- 119
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发布时间： - 摘要：Conventional dispersion compensators cannot satisfy the requirement of 40 Gbit/s DWDM systems for accurate control of the dispersion and neither can they do anything about the remnant dispersion or the dispersion variations caused by circumstances.A Tunable Dispersion Compensator（TDC） can adjust the dispersion compensations automatically in line with the system dispersion variations,achieving the ideal compensation effects.In this paper,several dynamic dispersion compensation schemes are presented,compared and analyzed.关键词：TDC;FBG;VIPA;PLC
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- 196
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发布时间： - 摘要：A high-speed Erbium-Doped Fiber Amplifier（EDFA） test system is developed to improve the productivity of EDFA.In this system,multiple test instruments are controlled by one PC with detailed test reports produced.Experimental results prove that this system has fairly high test accuracy and can meet the test needs of different users.关键词：EDFA;high-speed test;auto-testing;test accuracy
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- 106
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发布时间： - 摘要：This paper analyzes the energy transfer process between the Er3+ and Tm3+ ions of Er-Tm co-doped tellurite fiber amplifiers pumped at 980 nm,sets up the rate and power propagation equations and obtains by simulation the law of variations of its amplification gain with the fiber length and pump power.The simulation results show that the amplifier can obtain a flat gain of as high as 50 dB at 1 4401 540 nm by optimizing the fiber length and pump power.关键词：fiber communication;Er-Tm co-doped tellurite fiber amplifier;rate and power propagation equations
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- 110
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发布时间： - 摘要：On the basis of combining multi-wavelength pumps and cascaded optical fibers,the paper optimizes the pump wavelength,power and the length of two sections of fibers by using the genetic algorithm and simulates the 100-channel WDM system by using the numerical method and obtains about 0.069 5 dB gain flatness with a gain value of 13.15 dB.Furthermore,it analyzes the variations of the optical pump power and signal power with the fiber length.关键词：Raman Fiber Amplifiers（RFA）;gain flatness;multi-wavelength pump;cascaded fiber;genetic algorithm
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- 57
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发布时间： - 摘要：Continuous Phase Modulation（CPM） is widely used in wireless communications,especially in military communications,due to its high power and spectrum utility,but the complexity of its demodulation exponentially grows with the partial response length and the modulation parameters.This paper proposes a reduced-state noncoherent sequence detection algorithm for CPM,remarkably decreases the number of the matched filters by the orthogonalizing process,reduces the states of viterbi decoding by the state combination and finally detects the signal with decision feedback.关键词：CPM;noncoherent sequence detection;matched filter
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- 83
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发布时间： - 摘要：On the basis of the study of S&C and Park algorithms,this paper proposes an improved training-sequence-based OFDM synchronization algorithm,in which only one training sequence is used.By using this algorithm,the plateau in timing synchronization is eliminated by multiplying the training sequence by difference sequence in time domain and the integer-carrier frequency offset estimated by the self-correlation of the training sequence between the receiver and transmitter in frequency domain.It is much better than the S&C algorithm in timing synchronization and carrier frequency offset correction.关键词：OFDM;synchronization;training sequence
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