最新刊期
卷 ， 期 2 ， 2013
- 摘要：The research on the standard for the next generation PON,especially for Multi-Wavelength-PON（MW-PON） has become a hotspot in the development of future access networks.This paper first describes its unique approach of stacking multiple wavelengths in the optical layer so as to increase the access capacity of the conventional Optical Distribution Network（ODN） systems.Then it analyzes its logic functions,e.g.wavelength assignment,tuning,resource management and channel performance monitoring.Finally,it investigates the functional entities of Optical Line Terminal（OLT） ports and Optical Network Unit（ONU） equipment,and such key technologies as normal ONU activation,TDM/TDMA activation,and rogue ONU behavior mitigation mechanism.
- 4
- |
- 83
- |
- 1
发布时间： - 摘要：The green energy saving of optical networks is a hot topic of current research and the power aware RWA algorithm as an effective power saving method for service assignment attracts extensive attention.However,the relevant existing research results ignore the role of wavelength converters can play in optical network power saving.This paper presents a novel power aware RWA algorithm,i.e.Load-Based Cost enhanced with Wavelength Conversion（LBC-WC）,aiming at using wavelength converters to concentrate more lightpaths in fewer fibers.It conducts simulation based on wavelength switch optical network with sparsely deployed wavelength converters and the results indicate that this algorithm can significantly reduce the number of fibers used in networks,effectively raise the fiber utilization rate and improve the network energy efficiency.关键词：Route Wavelength Assignment（RWA）;power aware;wavelength converters
- 2
- |
- 105
- |
- 1
发布时间： - 摘要：In order to find a feasible Optical Line Protection（OLP） solution to 40 Gbit/s transmission systems,this paper analyzes such challenges to its protection as dispersion compensation,optical power compensation and system OSNR with the focus on its dispersion compensation solutions,describes a specific case and verifies the feasibility of this solution.关键词：40 Gbit/s system;OLP;dispersion compensation;multi-wavelength TDCM;DCF
- 2
- |
- 40
- |
- 1
发布时间： - 摘要：In view of the long time taken in using the classical p-cycle capacity assignment algorithms,this paper presents a fast heuristic one.Which constructs the p-cycle by taking the improvement of the protection efficiency of the p-cycle as the standard for its expansion and then carries out capacity assignment.As it is not necessary to construct in advance a candidate cycle,it can reduce redundancy and calculation time.The results of simulation on the basis of the pan-European COST239 network topology show that this algorithm can raise the network resource utilization ratio and greatly cut down the running time.关键词：optical network;protection;survivability;P-cycle;capacity assignment
- 2
- |
- 54
- |
- 2
发布时间： - 摘要：In order to recover tributary clock signals from Optical Time Division Multiplexing（OTDM） signals and demultiplex them,and realize the interface between high speed optical signals and relatively lower speed electronic signals,we for the first time demonstrate an experimental scheme on the basis of a commercially available Mach-Zehnder Modulator（MZM） and Polarization Modulator（PolM）-cascaded Optoelectronic Oscillator（OEO） for tributary clock recovering and demultiplexing.Using this improved OEO,we recover 40 GHz electrical clock from 2×40 GBaud/s optical signals in the OTDM DQPSK modulation format.The phase noise of this clock reaches-98.62 dBc/Hz at 10 kHz frequency offset,almost equivalent to that of the microwave source（Agilent Technologies,E8267D）.Simultaneously,we use this OEO to demultiplex the functions of two tributary signals,i.e.demultiplexing 160 Gbit/s PRBS OTDM signals into two high quality 80 Gbit/s tributary signals.关键词：OEO;OTDM;clock recovery;demultiplexing
- 2
- |
- 141
- |
- 2
发布时间： - 摘要：In view of the deficiency of the conventional algorithms in distinguishing service requirements,this paper proposes an improved shared path protection algorithm supporting differentiated service levels in optical networks.This algorithm can dynamically select working paths for different levels of service and realize sharing of protecting paths.It does not only meet the reliability requirements of different levels of services,but also decreases the recovery time of high-level services.关键词：optical network;service level differentiation;shared path protection;link load
- 2
- |
- 100
- |
- 11
发布时间： - 摘要：For eliminating congestion in Optical Burst Switching（OBS） networks,an improved Traffic Engineering（TE） mechanism based on the extension of the link state broadcast messages is proposed and the setup mechanism of LSP and the transmission process of BDP are analyzed.Simulation results demonstrate that this mechanism effectively reduces the network packet loss rate and realizes the rational distribution of the traffic.关键词：OBS;link state broadcast message;TE
- 2
- |
- 41
- |
- 1
发布时间： - 摘要：In order to meet the demand of dual leaky bucket models for traffic flow,this paper proposes a bandwidth demand research program based on statistical network calculus theory.Making use of the advantages of the statistical network calculus in analyzing traffic delay performance,this program establishes a statistical model for the bandwidth demand of the dual leaky bucket model traffic flow on the basis of the relationship between delay and bandwidth and conducts in-depth research and analysis on traffic bandwidth demand.Numerical analysis results show that this program is effective and superior and has much value of reference for rational allocation of network bandwidth resource.关键词：statistical network calculus;dual leaky bucket model;bandwidth demand
- 2
- |
- 75
- |
- 2
发布时间： - 摘要：Optical budget control is a key issue to FTTH-based Optical Distribution Network（ODN） construction.On the basis of a few practical projects,this paper analyzes the composition of the existing ODN optical power attenuation and the measures for improvement,presents the guiding principle in project design for reducing ODN optical attenuation and the key points in construction and describes the implementation of the relevant specifications in actual projects and the test results.Finally,it analyzes the differences between the theoretical calculations of the ODN optical attenuation and the practical test results,providing valuable experience for future operators in FTTH project construction.关键词：FTTH;ODN;optical budget control;construction
- 2
- |
- 63
- |
- 7
发布时间： - 摘要：This paper introduces a pragmatic Bit-Interleaved Coded Modulation（BICM）algorithm on the basis of（2,1,7） convolutional code.First,it numerically simulates this algorithm,proving that the hard-decision feedback iterative decoding of BICM（BICM-ID） algorithm is superior to the Trellis Coded Modulation（TCM）in Rayleigh channels.Then,it applies BICM-ID in SW data links and analyzes such factors as interleaving length,symbol mapping and number of iterations on BICM-ID performances.Finally,it implements this algorithm by using DSP and gives the decoding time for different code rates and data amount,the results of which indicate that the decoding time satisfy the real time requirements of the data links.关键词：iterative decoding;BICM;SW data link
- 2
- |
- 52
- |
- 0
发布时间： - 摘要：<正>日前,工业和信息化部发布了《关于公布国家级信息化和工业化深度融合示范企业（2012年）名单的通知》,授予218家企业为"国家级两化深度融合示范企业"。烽火通信作为信息通信行业代表上榜。
- 2
- |
- 20
- |
- 0
发布时间： - 摘要：To numerically investigate the adjustment of the fundamental mode characteristics of PBG-PCF with six-fold rotation symmetry（C6v） by the central air fiber core radius,full vector plane wave and multipole method are used to calculate the bandgap structures of this kind of fibers and the effective refractive rate of any possible fundamental modes with different central air fiber core radiuses,from which the fundamental mode dispersion,nonlinearity and confinement loss are analyzed.The numerical results demonstrate that the greater the central air fiber core radius,the greater the dispersion,and the dispersions at high wavelengths oscillate and vary near zero dispersion with the incident wavelength,that the nonlinear coefficient at a specific wavelength increases with the increase of the central air fiber core radius,and that the fundamental mode confinement loss as a whole decreases with the increase of the incident wavelength,displaying oscillating behavior at certain air core radiuses.关键词：C6v PBG-PCF;multipole method;central air fiber core radius;fundamental mode characteristics
- 2
- |
- 42
- |
- 0
发布时间： - 摘要：Fault warning and diagnosis for electric power optical fiber cables have a tremendous impact on the power dispatch.On the basis of the analysis of the causes of cable faults and the existing detection methods,this paper proposes a scheme,in which it realizes remote monitoring for electric power optical fiber cables by using an Optical Time Domain Reflector（OTDR）.It designs an OTDR-based remote monitoring system,compiles the related software for host computer and the lower device,i.e.OTDR and then performs laboratory tests.The results indicate that this system can implement remote operation and two-way communication between the host computer and OTDR and perform accurate fault detection and location.关键词：electric power optical fiber cable;OTDR;remote monitoring;fault detection
- 2
- |
- 164
- |
- 3
发布时间： - 摘要：In view of the requirements of coherent optical communication systems for narrow linewidth tunable lasers,this paper presents and develops an external cavity tunable laser using the MEMS technology and analyzes the influence of component parameters in the external cavity on the laser performance.The packaged device has a compact dimension conforming to OIF-MSA-ITLA-01.2,a tuning range of 40 nm in the C-band,a narrow linewidth of less than 100 kHz and output power of larger than 13 dBm.It tests this device in a 100 Gbit/s PM-QPSK system using the developed laser as the intrinsic source and the results show that this laser is ideal candidate for narrow-linewidth tunable source in high-rate coherent optical communication systems.关键词：external cavity semiconductor laser;ITLA;MEMS;linewidth;coherent optical communication
- 7
- |
- 455
- |
- 3
发布时间： - 摘要：This paper analyzes the Four Wave Mixing（FWM） phenomenon between pump and noise in the application of Fiber Raman Amplifiers（FRA） in Non-Zero Dispersion Shifted Fibers（NZ-DSF） and deduces the position where the fourth beam of light appears and proves it in experiments.On this basis,it suggests that when FRA are applied in NZ-DSF,the pump wavelength should be far away from the zero dispersion shift point,so as to avoid the production of FWM effects.关键词：nonlinear optics;FWM;phase matching;FRA
- 3
- |
- 113
- |
- 0
发布时间： - 摘要：In respect to the optical fiber coupling-fixing technology for and temperature characteristics of high power pump source subassemblies in EDFA,this paper introduces the internal structure and main technical indexes of the high power 980 nm LD-FBG subassembly and focuses on reporting the low temperature glass welding/coupling/fixing technology and its temperature characteristics and compares low temperature glass welding with laser welding in a table.The temperature test results show that the maximum peak wavelength variation of the said subassembly with a Thermoelectric Cooler（TEC） is less than 0.1 nm and its maximum optical power variation less than 0.3 dB in the temperature range of-20+75 ℃.关键词：LD-FBG subassembly;low temperature glass welding;coupling and fixing technology
- 5
- |
- 70
- |
- 0
发布时间： - 摘要：As fire accidents in electrical power systems are often caused by device or cable heating,on-line temperature monitoring is an important guarantee for the system security and stability.This paper designs and realizes a high-rate,high precision and low-cost distributed FBG temperature monitoring system suitable for project applications and verifies the temperature response characteristics of the ceramic-packaged FBG sensors.The results show that there is a good linear relationship between the reflective wavelength and temperature of the sensor and a long-term monitoring of the high voltage switchgears shows that this system is highly accurate and fairly stable,appropriate for temperature monitoring in power systems.关键词：temperature monitoring;FBG;electrical temperature monitoring system;high voltage switchgear
- 3
- |
- 150
- |
- 3
发布时间： - 摘要：Microwave frequency measurement system is aimed at enhancing the intercepting and bugging capabilities in the electronic and anti-reconnaissance warfare.In this paper,simulation software Optisystem is used to set up an intensity modulation-based measurement system.With the coaxial cable as the medium for RF signal transmission,the relationship between the output dc voltage and the frequency to magnitude response of the coaxial cable is obtained in accordance with its discrete characteristics and the half periodic oscillation characteristics of the output voltage.In the simulation,measurement range of 012 GHz and measurement error of about 0.6 GHz are realized,which is basically in agreement with the system design requirements.关键词：frequency measurement;microwave photon;intensity modulation;coaxial cable
- 2
- |
- 258
- |
- 1
发布时间： - 摘要：The adaptive techniques for links are usually performed within the layers,often resulting in the optimization of local performance,but not of the entire system.This paper first presents a cross-layer design scheme for LTE systems by using two adaptive transmission techniques,i.e.Adaptive Modulation and Coding（AMC） at the physical layer and Hybrid Automatic Retransmission Request（HARQ） at the Medium Access Control（MAC） sublayer.Then,it analyzes the relationship between the cross-layer coupling parameters and the system performance and gives a detailed derivation process and a concrete expression.Finally,it formulates the cross-layer optimization under the constraints of the average time delay and packet error rate.Simulation results indicate that the proposed cross-layer design can further improve the average spectral efficiency and select the optimum maximum number of HARQ and way of AMC in line with the channel quality so as to maximize the average spectral efficiency under the specified Quality-of-Service（QoS） requirements.关键词：cross-layer design;AMC;HARQ;spectral efficiency
- 3
- |
- 153
- |
- 6
发布时间： - 摘要：As the classical multi-user scheduling algorithms are biased toward channel conditions or fairness,this paper presents a practical Maximum Carrier to Interference ratio（Max C / I） algorithm and a practical Proportional Fair（PF） scheduling algorithm.These two algorithms take the channel condition,user service requirements and throughput as factors of the scheduling metrics.Simulation results show that they can take into account both the user-bearer QoS requirements and spectral efficiency and achieve the balance between throughput and fairness.
- 2
- |
- 144
- |
- 6
发布时间： - 摘要：Noises in the Ultraviolet（UV） communication system bring about significant interference in signal transmission.In order to improve the system performance,this paper designs a module to sample the noises in the system,including Photomultiplier Tube（PMT）,dark current noise,PCB hot noise,Electromagnetic Interference（EMI） noise and noises induced by power source and analyze their characteristics in time and frequency domains and their effects on the system performance.To overcome the disadvantages of analog filters,it develops a digital filter at the receiver end by using FPGA to suppress the noise.The experimental results show that this digital filter improves the Signal to Noise Ratio（SNR） by 37 dB.关键词：UV communication;noise;digital filter;FPGA
- 2
- |
- 206
- |
- 9
发布时间：
- Postal code：430205
- Technical support is provided by Beijing Founder electronics co., LTD 鄂ICP备2022010197
鄂公网安备 42011202002092号 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
- Total Visits：75845
0