最新刊期
卷 ， 期 5 ， 2014
- 摘要：Fiber-optic communication network has stepped into a new era of 100Gbit/s（or above）systems and strides rapidly toward the rate of 400Gbit/s/1Tbit/s systems.Currently,in most 400Gbit/s/1Tbit/s tests,the feasible Optical OFDM（OOFDM）-based high-rate transmission schemes include the Coherent Optical OFDM（CO-OFDM）,All-Optical OFDM（AOOFDM）and hybrid electro-optical OFDM.This paper comparatively analyzes the transmitter and receiver structures of the above mentioned three types of systems and summarizes their performance advantages and disadvantages in high-rate fiber-optic transmissions and the focal point in the next step researches.关键词：O-OFDM;AO-OFDM;CO-OFDM;hybrid electro-optical OFDM;high-rate transmission system
- 3
- |
- 100
- |
- 2
发布时间： - 摘要：Routing is the key factor for building light paths in ASON.In view of the security problems in the routing process,this paper designs a NS-2-based secure routing simulation platform SRSP-NA by constructing the corresponding ASON simulation module and security module with OpenSSL on the NS-2 simulation platform.This simulation platform can be applied to the simulation of the security policy at the routing level.Then,it verifies its effectiveness by comparing against the OSPF-TE routing protocol that has a security mechanism.关键词：ASON;security routing;simulation platform;Network Simulator（NS）
- 2
- |
- 63
- |
- 5
发布时间： - 摘要：In this paper,apacket reassembly circuit is designed to transmit the continuous data stream reorganized in a topdown design approach from the incised discrete data streams in the Optical Transport Network（OTN）switching.The packet data reassembly is completed at the packet request,resolving the problem of the remained bytes in the reassembly process.This circuit is realized using the hardware description language and its functions are simulated and its logics synthesized.Simulation results indicate that it satisfies the design requirements and can implement data packet reassembly.关键词：OTN;reassembly;data packet
- 2
- |
- 43
- |
- 1
发布时间： - 摘要：The Software-Defined Optical Network（SDON）is the latest trend and orientation of the development of optical networks.In order to further improve its intelligentization and dynamic support to traffics,it becomes increasingly important to predict the longer-term traffic flow on the basis of the short-term traffic flow behavior.This article proposes a Bayesian Modelbased Traffic Prediction（BM-TP）scheme,which makes full use of the model to make long-term prediction of SDON traffic flow.Simulation results verify the accuracy and effectiveness of this scheme.关键词：SDON;Bayesian model;traffic flow prediction
- 2
- |
- 88
- |
- 0
发布时间： - 摘要：This paper first presents a Deep Packet Inspection（DPI）-based smart gateway service QoS guarantee and bandwidth speeding-up scheme.Then it elaborates the DPI status of the smart gateway,by which it identifies the high-priority user services,realizes QoS guarantee by adopting an absolute priority strategy;timely finds out user bandwidth bottles using the bandwidth detection mechanism of DPI;realizes real-time bandwidth speeding-up in cooperation with the portal push function of the smart gateway and the telecommunication operator platform and elevates telecommunication user experience perspective by implementing high priority-user service guarantee and real-time bandwidth speeding-up.关键词：smart gateway（router）;DPI;service priority;bandwidth speeding-up
- 2
- |
- 88
- |
- 7
发布时间： - 摘要：There commonly exist dynamic variations in current MPLS-TP-based optical networks,which cannot be fully aware of the diversified demands for upper-level services.To solve this problem,this article proposes a multi-dimensional perceptionbased signaling mechanism,which makes full use of the service perception technology and network awareness technology in order to realize the network supporting capability for upper-level service diversification.Simulation results verify the effectiveness of this mechanism as it reduces the collision rate and time delay in service connection establishment and enhances the efficient matching between the light-path allotment and service requirements.关键词：MPLS-TP;optical network;service awareness;network awareness
- 2
- |
- 39
- |
- 1
发布时间： - 摘要：To break the bottleneck of slow routing lookup in packet forwarding on a multi-core processor platform,this paper presents a parallel routing lookup algorithm based on the divided multi-branch trie.This algorithm divides a multi-branched trie into several subtrees according to the number of processor cores,and each of them becomes a separate multi-branched trie.In the subtrees,it abolishes prefix lookup and composes a large intermediate node and adopts fixed-step query between the intermediate nodes,within which it uses the binary tries for expression.The experimental results show that this algorithm is characteristic of small number of memory access,fast looking-up speed,small memory space occupation and small update overhead and furthermore,it is applicable to both IPv4 and IPv6addresses.关键词：parallel routing lookup algorithm;trie;multi-core processor;prefix match
- 2
- |
- 62
- |
- 0
发布时间： - 摘要：Network availability is one of the important indexes of the Service Level Agreement（SLA）in the field of telecommunications and its improvement is a realistic issue for Internet Service Providers（ISP）and also a hot topic of research in the academic circles at home and abroad.On the basis of the existing researches on Wavelength Division Multiplexing（WDM）networks,this paper develops an heuristic algorithm using Java language and presents an M∶Nprotecting technology-based availability analysis model.The results show that this technology can enhance the network availability to a great extent and the link protecting technology can achieve still higher availability at the expense of consuming the reserved network resource than the path protecting technology.关键词：availability;link;path;service connection;protecting technology
- 2
- |
- 34
- |
- 0
发布时间： - 摘要：The network facilities virtualization technology emerges in response to the current demand for simplifying network structure and improving networking reliability.This technology works by linking up multiple switchboards to constitute a stronger one for unified management and applications.This text outlines the concept,principle and features of the N∶1virtualization technology in the switching platform,and selectively analyses the working process of the synchronization mechanism in the virtualized system.The relevant test results verify that it performs well,implements the required functions and improves the facilities reliability关键词：virtualization;synchronization;switching platform
- 5
- |
- 24
- |
- 1
发布时间： - 摘要：A Nonlinear Schrodinger（NLS）equation-based theoretical analysis method for the parameter estimation of optical communication devices is proposed and validated.In this method,a light pulse with width of over 5ps as an example is derived and analyzed and two innovative parameters of nonlinear power and dispersion width obtained.They are simulated with reference in WDM+TDM-PON systems,supporting the total bandwidths with uplink/downlink as 160/170Gbit/s and obtaining the optimum output power value corresponding to the theoretical BER of 10-50.Simulation results verify the feasibility of this analysis method,which provides a valuable reference for device parameter settings.关键词：NLS equation;dispersion;self-phase modulation;BER
- 4
- |
- 35
- |
- 0
发布时间： - 摘要：In order to identify the relationship between fiber unit strain and fiber composite submarine cable strain so as to accurately measure the submarine cable strain distribution by using the distributed optical fiber sensing technology,this paper conducts mathematical modeling for and simulation of the said relationship.It first establishes the mathematical model on the basis of analyzing the submarine cable structure and the finite element model by rationally simplifying the submarine cable structure.Then it conducts the linear stretching numerical calculation and compares the calculation results and mathematical model.The results show that the they are in agreement,in other work,the fiber unit strain is linear with the submarine cable strain and smaller than the latter,which means we can use fiber unit strain to calculate the submarine cable strain and provide a theoretical basis for monitoring the state of submarine cables on the basis of distributed optical fiber strain measurements.关键词：optical fiber composite submarine cable;mathematical modeling;twisted structure;finite element simulation
- 3
- |
- 239
- |
- 1
发布时间： - 摘要：In view of the damaged authentication of the electric power cable data in the process of power cable state detection and data acquisition arising from false negatives or negatives,this paper conducts a research on the data correction technology.In this research,it gives a prediction model for the sensor data stream by using the linear regression method and presents an automatic adjusting strategy for automatically adjusting the model when the prediction error exceeds the preset threshold value,thus improving the quality of power cable sensing data and reducing the incidence rate of defects in optical fiber detection.关键词：power cable;distributed optical fiber;quality of data
- 2
- |
- 92
- |
- 1
发布时间： - 摘要：This paper introduces the principle of testing fiber strain by using the Brillion scattering.In view of the deficiency of the BOTDR technology in monitoring fiber micro-strains,it presents a Support Vector Regression（SVR）-based method for Optical Power Ground Wire（OPGW）strain analysis.In this method,it builds a model for the frequency shift variations of fiber sections under different tensile forces,maps the vector to high-dimensional space using the kernel function and makes regression analysis by using the SVR method.Experimental results prove the effectiveness of this algorithm and demonstrate its huge potential in OPGW anomaly detection.关键词：OPGW;SVR;Brilliouin scattering;BOTDR;kernel function
- 2
- |
- 61
- |
- 0
发布时间： - 摘要：To further expand the Free Spectrum Range（FSR）and increase the Qfactor of microwave photonic filters,this paper conducts researches on an Infinite Impulse Response（IIR）filter cascaded respectively with a Finite Impulse Response（FIR）filter and an IIR filter.Then,it analyzes the filtering characteristics of these two cascaded structures and derives the corresponding transfer functions.In the former case,the FSR and the Qfactor are 2n times that of the IIR filter and in the latter case,the FSR is the least common multiple of that of each IIR filter.It simulates and verifies the frequency response characteristics of the two structures using the Matlab,and experimentally verifies the cascaded characteristics of an IIR filter with an IIR filter.The cascading of an IIR with an IIR is expected to realize single-passband filtesrs in a wide frequency range.关键词：microwave photonic;filter;optical signal processing;semiconductor optical amplifier
- 2
- |
- 135
- |
- 3
发布时间： - 摘要：With the daily increasing demands for the applications of low-cost colorless optical transmitter modules in WDMPON,hybrid integrated miniaturized external cavity tunable lasers are receiving more and more attention for their simple implementation process,high signal quality,wide tuning range and other excellent features,On the basis of investigating and analyzing the factors affecting their modulation characteristics,this paper experimentally develops specifically structured miniaturized external cavity tunable lasers and analyzes their characteristics,obtaining some valuable conclusions concerning the impacts of laser resonator cavity length on modulation bandwidth and provides theoretical support to the device development at the later stages.关键词：miniaturized colorless optical transmitter module;external cavity tunable laser;modulation bandwidth
- 5
- |
- 129
- |
- 1
发布时间： - 摘要：On the basis of the design of low-loss terahertz photonic crystal fibers,this paper designs,on the basis of the optical design software Zemax,a Topas COC terahertz single-lens with focal length of 24.80 mm,thickness of 2mm and effective aperture of 6.25 mm,which effectively improves the coupling between the terahertz beam and waveguide by as high as 75.01%.It analyzes the impacts of the docking system error between the terahertz waveguide and coupling system on the coupling efficiency using Zemax and Matlab and gives the coupling efficiency variation curves when lateral and angular deviations exist.The study results provide a theoretical basis for terahertz transmission technology.关键词：terahertz wave;photonic crystal fiber;single-lens coupling;Zemax softwares
- 2
- |
- 110
- |
- 1
发布时间： - 摘要：Coherent receivers that are composed of a 90°optical hybrid and Photo Diodes（PD）are core components of coherent optical communication systems.Currently,the key to the development of coherent receivers is to realize their cost-effectiveness by improving their integration level.This paper,fabricates two types of 90°optical hybrids using a low-cost polymer Planar Lightwave Circuit（PLC）and integrates it with four back-illuminated III-V PD via a 45°reflecting mirror.Experimental results indicate that they both have good performances and high integration level.关键词：high-order coded modulation;DQPSK;90°optical hybrid;integrated optics
- 2
- |
- 89
- |
- 3
发布时间： - 摘要：On basis of comparing and analyzing the different modes of laser external modulation,this paper focuses on the principle and control methods of Acousto-Optic Modulation（AOM）devices.Then it presents three controllable ones and compares and verifies them respectively.It adopts the TTL level（3.5V/0.2V）control method to modulate and encode the digital signals via FPGA by way of 2FSK and load the modulated signals on to laser light by AOM,which realizes 115.2kbit/s digital communication after free space transmission and the carrier of this laser external modulation communication system reaches about 0.7MHz.关键词：AOM;laser communication;FPGA;FSK
- 3
- |
- 274
- |
- 8
发布时间： - 摘要：Noises brings about obvious interferences with signals in Ultraviolet（UV）communication systems.For the purpose of improving the system communication quality,this paper implements an improved Low-Density Parity-Check（LDPC）codec algorithm and simulates its Non-Line-Of-Sight（NLOS）performances on a UV channel model.It conducts experiments on a LDPC（960,480）and RS（18,10）codec test bed.The experimental result shows that under the conditions of given power and10-6 bit error rate,the reliable communication range increases by only 42% with RS relative to uncoded systems,but by 100%with LPDC,thus effectively improving the communication performance.关键词：UV communication;LDPC code;RS code;NLOS;BER
- 2
- |
- 65
- |
- 1
发布时间： - 摘要：For Rayleigh fading channels with inaccurate timing,vehicle moving,inter-User Equipment（UE）interference and innate frequency offset at the receiver/transmitter sides,this paper proposes a novel method suitable for the frequency offset estimation at multi-UE base station side of LTE systems.It first estimates the size of frequency domain broadening generated by window function.Then it analyzes the size and scope of the frequency offset interferences brought about by band-adjacent UE and designs to eliminate these interferences.Finally,it estimates the frequency offset by utilizing the relationship between the frequency offset and the cross-correlation function.The link simulation results show that this method reduces the inter-UE interferences and overcome the influences resulted from multipath effects and inaccurate timing to a great extent,achieving superior frequency offset estimation fitting and block error rate performance to those in various conventional methods.关键词：frequency offset estimation;inter-UE interference;multipath effect;inaccurate timing
- 2
- |
- 40
- |
- 3
发布时间： - 摘要：<正>日前,在日内瓦举行的国际电联第13研究组全会上,由武汉邮科院提出并主导制定的"深度包解析的框架"获得国际电联批准,正式成为代号为ITU-T Y.2771的国际标准。这是武汉邮科院继2012年在全球首次提出互联网业务感知和内容识别国际标准Y.2770之后又一重大突破。目前全球互联网用户数超过27亿,中国用户已突破6亿,对于如此庞大的用户量和网络流量,其自身主要指标和特征如何感知、诊断和测量是摆在各国面前急需解决的难题。武汉邮科院从2004年开始在ITUT SG13研究组提出互联网业务感知和内容识别课题立项,2008年提出主体架构文稿,2012年在迪拜世界
- 3
- |
- 18
- |
- 0
发布时间： - 摘要：<正>2014年6月11日,烽火通信的"研制出中国第一根中空带隙光子晶体光纤"、"弯曲不敏感光纤技术水平全国第一"和"国内第一个实现棒纤装备自主化"等三项成果获评首届武汉制造业中的全国第一。为了展示武汉制造业的实力,宣传武汉优秀制造业的形象,促进武汉市工业倍增计划的实施,2013年武汉市工业总会、武汉质量协会、长江日报社三家联合发起了在全市制造业开展推介武汉制造业中的全国第一的活动。烽火通信等62家企业申报了102个项目。经过层层筛选和多轮专家评议,最后确立了21家企业
- 4
- |
- 28
- |
- 0
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