最新刊期
      卷 ， 期 3 ， 2007
      • Jiang Lijun,Shi Lei,Li Xuepeng,Jia Peng,Li Jian,Gu Wanyi
        Issue 3, Pages: 1-3(2007) DOI: 10.13756/j.gtxyj.2007.03.001
        摘要：As one of the most important signaling protocols in ASON,RSVP-TE is widely used.Its reliability and survivability have a direct impact on the reliability of ASON.In this paper,the reliability mechanism of RSVP-TE and the "Soft-Refresh" mechanism in support of RSVP-TE survivability are specifically analyzed,two types of basic failures,signaling channel failure and control plane node failure,that affect signaling survivability described and their appropriate recovery mechanisms studied in depth.  
        关键词：ASON;RSVP-TE;reliability;survivability   
        2
        |
        129
        |
        4
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 27515577 false
        发布时间：
      • Bi Hui,Li Tangjun,Liu Xiangchun,Wang Muguang
        Issue 3, Pages: 4-6(2007) DOI: 10.13756/j.gtxyj.2007.03.002
        摘要：In this paper,a number of modern nonlinear optimization algorithms are briefly introduced.On the basis of the structures of the two-stage Polarization Controller（PC） and the time delay line cascaded compensator,global optimization is realized to maximize the Degree of Polarization（DOP） by using the Genetic Algorithm（GA） as the feedback control algorithm in the Polarization Mode Dispersion（PMD） compensation.Theoretical analysis is made of the second-order PMD compensation and a complete set of control structure designed with TMS320C6711DSK as the core hardware.  
        关键词：GA;PMD;DOP;DSP   
        2
        |
        78
        |
        2
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 27515531 false
        发布时间：
      • Fan Zifu,Wan Xiaoyu
        Issue 3, Pages: 7-9(2007) DOI: 10.13756/j.gtxyj.2007.03.003
        摘要：As indicated by the current trend of development,T-MPLS will gradually become a new transport mechanism.This paper introduces the Pseudo Wire Emulation Edge-to-Edge（PWE3） model,analyzes the encapsulation mechanism of T-MPLS signals and brings forward the interworking model for the PW-based T-MPLS layer networks and the Ethernet,on the basis of which it discusses the PW-based interworking process of the Ethernet in detail in connection with the T-MPLS signal encapsulation mechanism.  
        关键词：Pseudo Wire（PW）;Transport MPLS（T-MPLS）;Ethernet;interworking model   
        3
        |
        97
        |
        1
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 27515397 false
        发布时间：
      • Zhao Huaigang
        Issue 3, Pages: 10-12(2007) DOI: 10.13756/j.gtxyj.2007.03.004
        摘要：On the basis of the causes of fiber dispersion and its effects on optical transmission systems,this article introduces some dispersion compensation technologies with the focus on the most commonly used dispersion compensation fiber（DCF） technology.It continues to describe the applications of these technologies in practical projects and explain the calculation of the size of the compensation modules,their allocations and placements in projects and arrive at some valuable conclusions for practical dispersion compensation systems.  
        关键词：fiber dispersion;dispersion compensation module;dispersion compensation fiber   
        3
        |
        432
        |
        9
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 27515563 false
        发布时间：
      • Wu Huan
        Issue 3, Pages: 13-15(2007) DOI: 10.13756/j.gtxyj.2007.03.005
        摘要：Dynamic Bandwidth Allocation（DBA） of the upstream bandwidth is crucial in EPON systems.In this paper,a service priority-based dynamic polling with adaptive cycle scheme is introduced.It ensures the real-time transmission of high priority services and provides basic bandwidths to the low-and medium-priority services with the efficiency and fairness of the dynamic bandwidth allocation guaranteed.The specific implementation of the scheme is described by formula deduction and the feasibility of the new DBA scheme is theoretically proved.  
        关键词：Ethernet over PON（EPON）;DBA;service priority;weight parameter   
        2
        |
        175
        |
        1
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 27515502 false
        发布时间：
      • Zhang Zhongquan,Xie Guoyi,Dang Qiulei
        Issue 3, Pages: 16-19(2007) DOI: 10.13756/j.gtxyj.2007.03.006
        摘要：A novel QoS-ensured dynamic EPON uplink bandwidth allocation algorithm is proposed,which determines the bandwidth allocation weight among the ONUs according to Diff-serv model and the Service Level Agreement（SLA） and assigns different priorities according to different QoS of the data,thus both ensuring bandwidth allocation to and QoS of each ONU and satisfying the requirements of the high-priority services.In addition,appropriate control message formats in Multi-Point Control Protocol（MPCP） for EPON are presented.  
        关键词：EPON;SLA;QoS;dynamic bandwidth allocation;MPCP   
        2
        |
        167
        |
        2
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 27515372 false
        发布时间：
      • Di Yanhai
        Issue 3, Pages: 20-22(2007) DOI: 10.13756/j.gtxyj.2007.03.007
        摘要：Metro Ethernet is currently the major domain of telecom operators in the construction of metro optical transport networks.This paper begins with the description of the basic concepts and technical characteristics of four types of Ethernet services in MSTP as well as the main differences between them.Based on practical projects,it continues to discuss their different modes of networking,ways of realization and applications.The ideas advanced in the paper may be used as some reference for the current metro Ethernet construction in China  
        关键词：MSTP;Ethernet service;networking technology   
        2
        |
        173
        |
        28
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 27515570 false
        发布时间：
      • Xiao Yingying,Luo Xuheng,Yang Yi,Lv Peng
        Issue 3, Pages: 23-27(2007) DOI: 10.13756/j.gtxyj.2007.03.008
        摘要：In connection with the current construction of electric power fiber-optic communication networks and the development of fiberoptic network technologies,this paper explains the main protection and restoration techniques and applications of SDH networks and the protection modes that can be applied in network interconnection.In view of the coordination of multilayer networks,it explores the survivability coordination of SDH-based multilayer networks,providing a useful reference for the practical applications of network topology and the optimization of network structure.  
        关键词：electric power;fiber-optic communication;network survivability;protection;restoration   
        2
        |
        177
        |
        8
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 27515384 false
        发布时间：
      • Huang Ping,Wan Zhikun
        Issue 3, Pages: 28-31(2007) DOI: 10.13756/j.gtxyj.2007.03.009
        摘要：The presentation of such resource search algorithms for structural peer-to-peer（P2P） architecture as Chord,CAN,and Pastry has changed the flooding resource search mode for unstructured P2P architecture and reduced the P2P resource search information flow,thus enhancing the system scalability.However,these algorithms fail to take into consideration of the effects of the practical physical distances between peers on the search path lengths.In this article,a structural search algorithm,called CGC（Combination of Grapes and CBT） based on peer ability and territory is proposed,which combines the advantages of CBT and Grapes and gives full account of the peer regions and capability,thus constructing a P2P system with short search path and compatible peer ability.  
        关键词：P2P;Chord;CBT;CGC   
        2
        |
        130
        |
        6
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 27515491 false
        发布时间：
      • Huang Yimin,Wu Gongxing,Yu Zhengfeng
        Issue 3, Pages: 32-34(2007) DOI: 10.13756/j.gtxyj.2007.03.010
        摘要：Sharing the same frequency band in the upstream and downstream directions,HomePNA 3.0 over coax network supports both SMAC（synchronous MAC） and AMAC（asynchronous MAC） work modes.To ensure the QoS characteristic of video,voice,data and other services in HomePNA network,this paper brings up a new Dynamic Bandwidth Allocation（DBA） algorithm,i.e.bandwidth for upstream high priority services are reserved by SLA（Service-Level Agreement） and low priority services based on the incoming flow statistics.The model setup and simulation results have proved that this algorithm is effective and suitable for the QoS implementation!of the HomePNA network.  
        关键词：HomePNA;Hybrid Fiber-Coax（HFC）;DBA;flow;statistics   
        2
        |
        50
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 27515452 false
        发布时间：
      • Wang Chengyi,Gao Ren
        Issue 3, Pages: 35-38(2007) DOI: 10.13756/j.gtxyj.2007.03.011
        摘要：This thesis briefly analyses the typical architecture of the conventional intelligent home network.In view of the practical needs of the users and the features of the next generation network technology,specially,IPv6,it presents the architecture of the open intelligent home network based on the coordination of the centralized and independent control modes and focuses on discussing its main problems and the appropriate solutions.  
        关键词：open intelligent home network;home gateway;centralized control;independent control   
        2
        |
        125
        |
        3
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 27515464 false
        发布时间：
      • Song Shuyan1,Wu Jun2
        Issue 3, Pages: 39-41(2007) DOI: 10.13756/j.gtxyj.2007.03.012
        摘要：Home gateway is a key device in digital home networks.In this paper,the relevant specifications of the Open Service Gateway Initiative（OSGi） are first introduced.Then a study is made of the model of home gateway and an OSGi-based home gateway is designed.Finally specific applications of the home network services are discussed.  
        关键词：home gateway;OSGI;bundle   
        2
        |
        190
        |
        1
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 27515510 false
        发布时间：
      • Ren Xiukun,Geng Xin,Hu Hanying
        Issue 3, Pages: 42-44(2007) DOI: 10.13756/j.gtxyj.2007.03.013
        摘要：On the basis of the P-CCPCH synchronization principle and the existing synchronization methods,a novel P-CCPCH synchronization method based on the modulated phase and the carrier frequency offset of SYNCDL is proposed.By using this method,the lessened acquisition probability arising from the carrier frequency offset can be easily improved.The simulation results show that this method is well resistant to carrier frequency offset,high in detection probability,small in computational burden,easy to operate and easy to implement.  
        关键词：relative phase method;absolute phase method;channel estimation;carrier frequency offset   
        2
        |
        110
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 27515431 false
        发布时间：
      • Tang Bingshu1,Qin Jiaqian3,Shen Tinggen2
        Issue 3, Pages: 45-47(2007) DOI: 10.13756/j.gtxyj.2007.03.014
        摘要：The interrelations between the fundamental mode effective area and the structural parameters of TIR-PCF with six-fold rotation symmetry at 1.55 μm are numerically studied by multipole method.The results indicate that the fundamental mode effective area has smaller effect on the number of the air-hole layers,but bigger effect on the air-hole diameter,hole space and relative hole diameter.When the number of the air-hole layers and the hole pitch are fixed,the larger the hole diameter,the smaller the fundamental mode effective area.Similarly when the number of the air-hole layers and the hole diameter are fixed,the larger the hole pitch and the fundamental mode effective area.Furthermore,the fundamental mode effective area increases with the magnification when the number of the air-hole layers and the relative hole diameter are fixed.  
        关键词：C6v TIR-PCF;multipole method;fundamental mode effective area;structural parameter   
        2
        |
        75
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 27515414 false
        发布时间：
      • Shi Mingquan,Ning Tigang
        Issue 3, Pages: 48-50(2007) DOI: 10.13756/j.gtxyj.2007.03.015
        摘要：On the basis of the rate equation model of the 3-energy-level-system fiber lasers,this paper focuses on the effects of the reflection coefficient of the input mirror R1,the reflection coefficient of the output mirror R2 and the pump power on the optimum length of the cladding fiber lasers L with a numerical emulator,producing a significant result for the study on cladding-pumped fiber lasers.  
        关键词：cladding-pumped fiber lasers;optimum fiber length;reflection coefficient;pump power   
        2
        |
        132
        |
        1
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 27515546 false
        发布时间：
      • Liu Yuxi1,Zhang Xiaoxia1,Li Ying1,Pang Ying2
        Issue 3, Pages: 51-53(2007) DOI: 10.13756/j.gtxyj.2007.03.016
        摘要：The properties of Er3+∶Yb3+ co-doped phosphate glass waveguide pumped by LD are systematically investigated and the rate equations of its quasi-three-energy-level system set up and solved under the steady state.The characteristics of the output power of 980nm laser diode in pumping are analyzed by numerical simulation.The results show that Er3+∶Yb3+ co-doped phosphate waveguide lasers with high fairly high output power and slope efficiency and relatively low threshold power can be achieved on optimized analyses.  
        关键词：phosphate glass;waveguide laser;steady state   
        2
        |
        92
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 27515519 false
        发布时间：
      • Lin Zhihang,Yuan Xiuhua,Hu Jin
        Issue 3, Pages: 54-57(2007) DOI: 10.13756/j.gtxyj.2007.03.017
        摘要：Because of the imperfections of Conventional Peak Detection（CPD） technique,Spectrum Correlation（SC） and Digital Filter（DF） techniques are proposed,which can be applied to improve the detection precision of the wavelength shift in Fiber Bragg Grating（FBG） sensor systems.Numerical simulations are performed of the wavelength shift detections by CPD,SC and DF（CHEBY and IDEAL） respectively and the experimental results have verified the correctness of the theoretical analysis,which has proved that SC can be used to improve the precision of wavelength shift demodulation and detection up to that by Ideal Low Pass Filter（IDEAL） technique.  
        关键词：FBG;spectrum correlation;conventional peak detection;digital filter;demodulation   
        2
        |
        105
        |
        1
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 27515608 false
        发布时间：
      • Zhang Qian,Qiao Xueguang,Fu Haiwei
        Issue 3, Pages: 58-61(2007) DOI: 10.13756/j.gtxyj.2007.03.018
        摘要：Fiber-optic flowmeter is a new type of flowmeter based on optical signals.When optical signals are transported in optical fibers,their intensity,phase,wavelength and other parameters are changed due to the effects of the flow,the size of which can be determined by measuring the relative changes of the signals.This paper describes the operating principles and features of several types of fiber-optic flowmeters,makes comparative analysis of their merits and demerits and proposes appropriate improvement schemes.  
        关键词：optical fiber;flowmeter;fiber Bragg grating;sensor   
        3
        |
        568
        |
        6
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 27515475 false
        发布时间：
      • Zhang Sen,Liu Menghua,Wang Zhen,Zhou Qi
        Issue 3, Pages: 62-65(2007) DOI: 10.13756/j.gtxyj.2007.03.019
        摘要：This paper first introduces the advantages of fiber-optic sensors as compared with other sensors and the basic principles of the sensing and light-transmitting fiber-optic sensors.Then,it describes the applications of intensity modulation fiber-optic sensor,interferometric fiberoptic sensor,fiber-optic grating and fiber-optic acoustic emission sensor.Finally,it presents the problems in and the orientation of development of fiberoptic sensing technology in China.  
        关键词：fiber-optic sensing technology;interferometric fiber-optic sensor;intensity modulated fiber-optic sensor   
        7
        |
        4591
        |
        3
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 27515596 false
        发布时间：
      • Wei Kanglin,Gao Xiaoxin
        Issue 3, Pages: 66-70(2007) DOI: 10.13756/j.gtxyj.2007.03.020
        摘要：In order to implement dynamic bias voltage compensation for the thermal drift of APD gain,high precision A/D and D/A circuits are designed.Millivolt-grade bias voltage control precision and 0.2℃ sampling precision are attainable for APD.On the basis of the fiberoptic sensing system,the linear relationship between the bias voltage and temperature of APD gain and the bias voltage compensation formula for the thermal drift errors of the gain are acquired by using the data collection and processing technology when the APD gain is stable,so the sensing system can be used to make real-time compensation for the thermal drift of the gain with a precision high enough to satisfy the requirement of the system.  
        关键词：APD;thermal drift;dynamic compensation;Rayleigh curve   
        2
        |
        365
        |
        3
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 27515442 false
        发布时间：
      0