最新刊期
卷 ， 期 5 ， 2016
- 摘要：In this paper,we propose an optimal cost model for IP/MPLS-over-EON.Based on the model,two path segmentation routing schemes are presented:the adaptive and the heuristic.The construction cost of the IP/MPLS-over-EON based on these two schemes are investigated.The adaptive scheme enumerates every intermediate node of a path one by one to choose the path-segment point,in which an IP router will be placed and the path will have the minimum cost.The heuristic scheme implements path segmentation by setting a specific distance.When the distance is reached,a router will be placed for path segmentation.Numerical results demonstrate that when compared with the scheme of no path segmentation,the routing scheme of path segmentation can lower the total network cost effectively for medium and high load traffic profiles.It is because that for medium and high load traffic profiles,more traffic need to and can be groomed in intermediate nodes with IP routers being placed in intermediate nodes.关键词：Elastic Optical Networks（EON）;CAPEX;path segmentation;optimal design
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发布时间： - 摘要：In order to achieve effective transmission of optical signals,the basic principle of different dispersion compensation methods（dispersion compensation fiber and fiber Brag grating）is studied.A single-channel transmission system based on RZ modulation format by Optisystem is designed and two dispersion compensation schemes（pre-compensation,post-compensation）of DCF and FBG is studied.In this paper,the intermediate dispersion compensation method based on FBG is proposed.Simulation results show that the Qvalue of the system is higher than the other two methods when use the FBG intermediate dispersion compensation.The intermediate cascaded FBG module is further proposed as a dispersion compensation device of WDM system.The simulation model in Optisystem is established.Simulation results show that this method can maintain good compensation effect even if the transmission distance is long.关键词：dispersion compensation fiber;fiber Brag grating;intermediate dispersion compensation;Optisystem software
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Polarization Manipulation Algorithm for Random Number Generation in Dual Mach-Zehnder Interferometer
摘要：Random number generation algorithm based on correlation between two channels is adopted.The proposed method eliminates the phase shift in dual Mach-Zehnder（M-Z）fiber sensing system through manipulating the polarization of the input,and improves the correlation of the signals.The feasibility of the generation algorithm and three corresponding parameters are theoretically analyzed.The experimental results indicate that most area of the Poincare sphere can be swept in 5 min.Meanwhile,the optimal position of the polarization can be searched in 3min.Subsequently,the correlation of the signals is improved with a correlation coefficient of 0.9.关键词：dual M-Z interferometer;correlation coefficient;random number generation algorithm;polarization manipulation- 3
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发布时间： - 摘要：Applying router virtualization technology into SDN can not only forward traditional telecom traffic in SDN but also solve the problem of insufficient support of current SDN in fields of routing functions.In SDN controller,we can extend south interface to manage and control virtual router,and convert flow table and route table.Then we can control the data forwarding function of virtual router or Openflow switch.This method can make up the deficiencies of routing function in the current SDN controller,and achieve compatibility forwarding function of SDN traffic and traditional telecommunications traffic.This paper proposes a designing method and system of SDN platform based on the study of forwarding function of virtual router and SDN controller,which can realize basic routing functions.The system analysis result shows that the platform has features of excellent versatility,flexibility,and simple combining with cloud computing technologies.关键词：SDN;virtual router;Openflow protocols
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发布时间： - 摘要：Telecom carriers urgently hope to relieve the competition pressure via fixed-mobile convergent network.In order to deal with the challenges in the fixed-mobile convergence related with bandwidth,survivability and cost,China Unicom has promoted G.metro standard in ITU-T.Based on the requirements of G.metro,an architecture of fixed-mobile convergent access network is proposed.It achieves sharing of resources based on NFV,and balances the differences between the fixed and mobile accesses based on the combination of WDM loop and PON,while keeping the requirements of simplicity and low cost.关键词：WDM;access;fixed-mobile convergence;NFV
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发布时间： - 摘要：Focusing on the RWA problem in optical transmission network,we proposed a RWA optimization algorithm based on ant colony algorithm framework.The way of choosing a request from requests zone is introduced,which would improve optimization ability of the algorithm.In addition,the way of updating pheromone and searching routes in ACO algorithm are also improved.This method can effectively reduce the network traffic congestion.Finally,we conduct a simulation to demonstrate the proposed method in a grid network and a province electric power communication network.关键词：ACO;pheromone;congestion rate;RWA;electric power communication network
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发布时间： - 摘要：Absolute Polar Duty-Cycle Division Multiplexing（APDCDM）is a novel multiplexing technology used to reduce the signals’ voltage level in Duty-Cycle Division Multiplexing（DCDM）system.In order to further reduce the number of voltage levels,a novel coding technique called Improved-APDCDM（I-APDCDM）is proposed.The principle of I-APDCDM is first introduced.An optical fiber transmission system based on I-APDCDM is then designed by joint simulation of Optisystem and MATLAB.The effects of transmission distance and extinction ratio of modulator are analyzed.The simulation results show that,comparing with APDCDM,the number of voltage levels of system is reduced by 1and the power of transmitted signal is reduced by A2 Ts/24.Therefore,the I-APDCDM not only reduces the number of voltage levels but also significantly improves the system performance.关键词：fiber optic transmission system;bipolar signal;DCDM;alternative signal;voltage level
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发布时间： - 摘要：The conventional encoding method of Low Density Parity Check（LDPC）Code often cannot put the girth and nonsingularity of check matrices into consideration at the same time,which has negative effects on the performances of encoding and decoding,and increases the decoding complexity.A low complexity method to construct check matrices is presented.A matrix with properties of girth of 10,column weight of 2,nonsingularity,and approximate lower triangular is generated by constructing the sub-matrix Aand sub-matrix Bstep by step.Due to these features,some advantages such as better decoding performance,more suitable for partial response channels,lower encoding and decoding complexity are shown.The simulation result shows that the proposed coding scheme has lower complexity than the code with girth of 10.It also presents better decoding performance than common code with girth of 6in AWGN channels after Belief Propagation（BP）decoding algorithm.关键词：LDPC code;high girth;low complexity;approximate lower triangular;nonsingularity
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发布时间： - 摘要：The laser intensity distribution in the optical fiber is one of the key parts in the research of laser illumination.In this paper,light transmission at the optical beam radius of 15μm,30μm,50μm in single-mode,dual-mode and multi-mode optical fiber in the two-uniform structure are investigated through simulation by optical software OptiBPM.The fiber core diameter size is set at 100μm,120μm,150μm,180μm,respectively.The simulation results show that for the multi-mode of highpower semiconductor laser,the most uniform of light intensity at the exit end of the optical fiber is achieved when the width of the laser beam is equal to fiber core diameter.关键词：fiber beam combiner;semiconductor lasers;white laser light
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发布时间： - 摘要：To solve the distance limitation of Passive Optical Network（PON）,a PON fiber multiplexing and reach extending method is first introduced.The relevant key technologies,such as aggregating and reach extending of PON signals are then analyzed.The technology can increase PON’s transmission distance and capacity,Finally we introduce two application scenarios based on this technology.关键词：PON;multiplexing and reach extending;GMP;AMP
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发布时间： - 摘要：To solve the insufficiency problem of the opening laboratory equipment management in universities,an intelligent equipment management system on Internet of things is designed in this paper.A server system is constructed in this system by using ASP.NET,C# and other technology on the software platform of SQL Server 2005 and Visual Studio 2012.The intelligent perception of equipment is achieved by using low-power Bluetooth technology,RFID radio frequency identification technology,and gateway communication technology and so on.The system can automatically discover the equipment,report and record their status.Meanwhile,it can provide services such as reserving,borrowing,returning equipment,automatically.Also it can manage and control the intelligent scheduling,which improves the utilization of the equipment and saves manpower,material and time resources.关键词：device management;intelligent perception;bluetooth;RFID;gateway
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Finite Element Analysis for Bending Degree of Fiber Composite Submarine Cable by Optical Unit Strain
摘要：The finite element bending model of fiber composite submarine cable is established in this paper.By meshing and applying load,the paper obtains the stress and strain data of copper and lead alloy.The whole bending process of submarine cable bending is analyzed in detail.In addition,the paper uses the least square method to establish the relationship between the optical unit strain and the copper and lead alloy stress.The result shows that the same cross-sectional structure at the same outer stress have the same equal and opposite directions under the same bending angular velocity and different bending radius conditions.The change of structure stress has similar trends when it bending with different radius.The investigation provides a theoretical reference for use of distributed optical fiber sensing technology in detection of submarine cable bending state.关键词：submarine cable;bending;strain;finite element- 3
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发布时间： - 摘要：Macrobending loss of single-mode fibers is analyzed theoretically and measured experimentally in the paper.Simulations of macrobending loss for Corning SMF28single-mode optical fiber are conducted based on the formulas proposed by D.Marcuse,H.Renner and L.Faustini,respectively.The measurement and simulation results are compared.The results show that the simulation results based on D.Marcuse’s equation cannot predict the macrobending loss oscillation phenomenon,while the simulation results based on H.Renner’s can predict this phenomenon with largest relative error of 57.8% between simulation and experimental results.Meanwhile,the simulation results based on L.Faustini’s formula can predict this phenomenon with largest relative error of only 19.6%.Therefore,the equation presented by L.Faustini can be considered as an accurate formula to calculate macrobending loss of coated single-mode fibers.关键词：single-mode fibers;macrobending loss;coating;bend radius;wavelength
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发布时间： - 摘要：This paper studies optical properties of few-mode fibers with non-uniform refractive index profile,namely:the Ushape refractive index few-mode fiber and the bending two-mode and four-mode fiber.Finite element method is used to analyze the modal profile of these few-mode fibers.The U-shape refractive index few-mode fiber can support LP11 mode and suppress LP01 mode with a proper pump at 1 550 nm.The two-mode fiber and four-mode fiber can only support LP01 and LP11mode with a bending radius of 4cm and 2cm,respectively.Two-mode and four-mode Fiber Bragg Gratings（FBG）are also studied theoretically and experimentally.As to the two-mode FBG,LP11 mode distribution with a two-lobe shape is measured experimentally near a transmission wavelength of 1 549.79 nm.As to the four-mode FBG,the number of reflection peak wavelength is decreased with a lower bending radius.关键词：few-mode fiber;cylindrical vector beam;non-uniform refractive index;few-mode fiber Bragg grating;transmission spectrum
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发布时间： - 摘要：Based on the rigorous coupled wave theory and equivalent medium theory,a Si-based GaN guided-mode resonance filter with the operation wavelength ranging from 1 300 to 1 400 nm was studied.The effects of the grating period and incident angle on the reflective spectra of the filter were analyzed under strong modulation and weak modulation condition.Also,the sensitivity of the reflection spectrum under different grating period and incident angle was studied.According to the sensitivity of the reflection spectrum to the incident angle of the grating period in the strong modulation condition,an angle adjustable Sibased GaN guided-mode resonance filter was proposed.The incident angle of the grating is tuned by a MEMS electrostatic comb drive to control the output of the different resonance wavelength.The simulation results demonstrate that the incident angle could be tuned from 0.5to 5.7!and the corresponding wavelength could be tuned from 1 319 to 1 352 nm with the FWHM less than 2.2nm.关键词：guide-mode resonance;GaN;the angle modulation;micro-electro-mechanical system
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发布时间： - 摘要：In order to further improve the performance of positive feedback surface plasmas（R-SPP）in the asymmetric waveguide structure,we design a new type of planar asymmetric structure of waveguide in this paper.We study the oscillation characteristics of the propagation distance function under certain value of incident angle and wavelength.The analysis shows that long-distance transmission SPP mode can be achieved by changing the angle of incidence at the certain value of the thickness of the core.It is shown that 5to 50 !m propagation distance can be achieved under the incident wavelength of 7001 500 nm range.It is noted that the traditional SPP propagation distance is limited to be about 2 !m.However,the design of the structure can increase the maximum transmission distance up to 50 !m.The results have certain theoretical and practical significances in the application of new photonic device based on SPP.关键词：positive feedback surface plasmas;asymmetric waveguide;SPP mode
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发布时间： - 摘要：In this paper,we cascade two symmetrical slow tapers in a single-mode fiber and remove the coating between two tapers,which achieve a Mach-Zehnder（M-Z）interferometer.The cladding is act as a sensing arm,which is sensitive to the refractive index in the outside world.Through the analysis of the optical field evolution of taper region,mode field radius will reach maximum value of 14.8!m when fiber taper has a radius of 25!m.When taper waist radius is 12.5!m,transition region is 5 mm,and taper region interval is 131 mm,the effect of coupling and waving is best.The sensing arm can detect alcohol concentration in the range of 0100%,which has a good linear relationship between refractive index and wavelength offset with detection sensitivity of-120nm/RIU.The sensor has advantages of low insertion loss,stable performance and strong anti-interference capacity,which can be applied to areas such as distillery and water quality monitoring.关键词：fiber optics;interferometer;symmetrical slow taper;sensor;refractive index
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发布时间： - 摘要：This paper introduces the structure of second-order Distributed Raman Amplifier（DRA）and the effective noise figure of DRA.Based on previous work,the relationship of the second order DRA’s noise characteristic and the injection ratio of first order and second order pump is investigated both in experiment and theory.It is found that when the amplifier gain is approximately constant,the greater the injection ratio of second order pump can be achieved with smaller effective noise figure.Therefore,through the appropriate adjustment of the first order and second order pump power,it can make the amplifier work on the smaller noise condition.The noise performance of the whole system can also be improved.关键词：second order distributed Raman amplifier;gain;effective noise figure
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发布时间： - 摘要：In order to further improve the performance of gas sensing,this paper apply ring-down cavity technology in gas sensing field.The theoretical and experimental analysis results show that the use of ring-down cavity technology can significantly improve the sensitivity of gas detection,which can realize the gas concentration detection limit at 10-3.The designed sensor system has much faster response time than spectrometer peak ratio method.The method of time of ring-down signal feedback can improve the sensitivity and detect the gas peak change at the same time.关键词：ring-down cavity;gas sensor;detection limit
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发布时间： - 摘要：The graphene-based passively Q-switched erbium-doped fiber laser is reported.The laser adopts ring cavity configuration,and the Q-switcher is the self-made graphene absorber.Stable Q-switcher pulse train occurs at about 0.8mW incident pump power and the pulse repetition rate is 31 kHz.The maximum average output power of 13.8mW is obtained when pump power rise to 460 mW with corresponding pulse width of 800 ns,repetition rate of 77 kHz,and central wavelength of1 558 nm.Furthermore,we also explain the phenomenon that the repetition rate,average output power and incident pump power having approximate linear relationship.关键词：graphene;Erbium-doped fiber;saturable absorber;passively Q-switched
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发布时间： - 摘要：The influence of noise on the signal is small between the Base Band Unit and the Remote Radio Unit（BBU-RRU）in downlink and need a lot of space for storage.The sparseness of frequency domain of OFDM signal meets the requirement of the compressed sensing theory.Based on the above issues,this paper realizes OFDM signal reconstruction under different signal-tonoise ratios by using the compressed sensing theory.The simulation results show that this method can save nearly five times storage space of signal.Reconstruction signal has different damage rate and bit error rate under different signal-to-noise ratio,which meets the demand of communication system in the practical situation.关键词：OFDM signal;compressed sensing;sparsity;damage rate;bit error rate
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发布时间： - 摘要：To solve the problem that the nodes updating the location information and respond to requests which increases the control packet overhead in existing content routing based on location aware for mobile Ad hoc networks,an Efficient Publish/subscribe Routing based on Location aware for Mobile Ad hoc networks（EPRLM）is proposed.Combining information update based on NFZ area mechanism and piggybacking mechanism of join reply packet,EPRLM analyzes the location information and update on time to reduce the control packet forwarding appropriately in the process of publishing content.关键词：mobile Ad hoc networks;publish/subscribe;content routing;location aware
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