This paper presents the design and implementation of access controller used for Ethernet passive optical network ( EPON). As a first step to develop an ASIC product, the entire system is designed on a field programm...This paper presents the design and implementation of access controller used for Ethernet passive optical network ( EPON). As a first step to develop an ASIC product, the entire system is designed on a field programmable gate array (FPGA) with an embedded CPU. To reduce working frequency of the FPGA, the byte-to-word conversion is proposed. Propagation delays are equalized by ranging procedure so as to avoid data collision. Implementations of synchronization, classification, as well as Linux porting are illustrated in detail. The interface between the FPGA and CPU are also presented. Experimental results show that the proposed system can properly function in a relatively low cost FPGA.展开更多
Latency sensitive services have attracted much attention lately and imposedstringent requirements on the access network design. Passive optical networks (PONs) providea potential long-term solution for the underlying ...Latency sensitive services have attracted much attention lately and imposedstringent requirements on the access network design. Passive optical networks (PONs) providea potential long-term solution for the underlying transport network supporting theseservices. This paper discusses latency limitations in PON and recent progress in PONstandardization to improve latency. Experimental results of a low latency PON system arepresented as a proof of concept.展开更多
Dynamic bandwidth allocation(DBA) is an open and hot topic in the Ethernet passive optical network(EPON) ,which is regarded as one of the best choices for next-generation access networks. However,most proposed DBA...Dynamic bandwidth allocation(DBA) is an open and hot topic in the Ethernet passive optical network(EPON) ,which is regarded as one of the best choices for next-generation access networks. However,most proposed DBA schemes ignore the quality of service(QoS) guarantee on maximum delay and delay jitter for the real-time traffic and the downstream bandwidth utilization under light upstream load in EPON. In this paper,a new DBA scheme,QoS guaranteed adaptive downstream bandwidth utilization(QoS-ADBU),is proposed. This scheme can provide better QoS assurance by determining the maximum transmission cycle time according to the maximum acceptable packet delay and delay jitter for real-time traffic. Besides,the downstream utilization can also be improved by adapting the polling frequency to downstream traffic load.展开更多
The Ethernet passive optical network(EPON) is the next generation of broad-band network technique.A crucial issue in EPONs is the sharing of uplink bandwidth among optical network units(ONUs).This article provides a n...The Ethernet passive optical network(EPON) is the next generation of broad-band network technique.A crucial issue in EPONs is the sharing of uplink bandwidth among optical network units(ONUs).This article provides a novel dynamic bandwidth allocation algorithm,i.e.threshold dynamic bandwidth allocation(TDBA),which is based on adaptive threshold,to increase resource utilization.The algorithm uses ONU data-transmitting rate to adjust optical line terminal(OLT) receiving data threshold from an ONU.Simulation results show that this algorithm can decrease average packet delay and increase network throughput in a 10G EPON system.展开更多
1. IntroductionA large number of networks for realizing first and second order transfer functions using a currentconveyor have been reported in the literature. Especially, the networks that can offer highinput impedan...1. IntroductionA large number of networks for realizing first and second order transfer functions using a currentconveyor have been reported in the literature. Especially, the networks that can offer highinput impedance attract attention, for high input impedance has the advantage that the networksmay be used in cascade without requiring impedance matching device. In the Higashimura and展开更多
The problem of passivity analysis is investigated for uncertain stochastic neural networks with discrete interval and distributed time-varying delays.The parameter uncertainties are assumed to be norm bounded and the ...The problem of passivity analysis is investigated for uncertain stochastic neural networks with discrete interval and distributed time-varying delays.The parameter uncertainties are assumed to be norm bounded and the delay is assumed to be time-varying and belongs to a given interval,which means that the lower and upper bounds of interval time-varying delays are available.By constructing proper Lyapunov-Krasovskii functional and employing a combination of the free-weighting matrix method and stochastic analysis technique,new delay-dependent passivity conditions are derived in terms of linear matrix inequalities(LMIs).Finally,numerical examples are given to show the less conservatism of the proposed conditions.展开更多
An optical network is a type of data communication network built with optical fibre technology. It utilizes optical fibre cables as the primary communication medium for converting data and passing data as light pulses...An optical network is a type of data communication network built with optical fibre technology. It utilizes optical fibre cables as the primary communication medium for converting data and passing data as light pulses between sender and receiver nodes. The major issue in optical networking is disjoints that occur in the network. A polynomial time algorithm Wavelength Division Multiplexing-Passive Optical Networking (WDM-PON) computes disjoints of an optical network and reduces the count of disjoints that occur in the network by separating Optical Network Units (ONU) into several virtual point-to-point connections. The Arrayed Waveguide Grating (AWG) filter is included in WDM-PON to avoid the traffic in the network thereby increasing the bandwidth capacity. In case of a failure or disjoint Ant Colony Optimization (ACO) algorithm is used to find the optimized shortest path for re-routing. For enhanced security, modified Rivert Shamir Adleman (RSA) algorithm encrypts the message during communication between the nodes. The efficiency is found to be improved in terms of delay in packet delivery, longer optical reach, optimized shortest path, packet error rate.展开更多
Elman networks' dynamical modeling capability is discussed in this paper firstly.According to Elman networks' unique structure,a weight training algorithm is designed and a nonlinear adaptive controller is con...Elman networks' dynamical modeling capability is discussed in this paper firstly.According to Elman networks' unique structure,a weight training algorithm is designed and a nonlinear adaptive controller is constructed.Without the PE presumption,neural networks controller's closed loop properties are studied and the whole Elman networks' passivity is demonstrated.展开更多
A dual optical time domain reflectometry (OTDR) system, which employs two different continuous waves at the optical line terminal and a pair of fiber Bragg gratings at the end of each optical network unit, is propos...A dual optical time domain reflectometry (OTDR) system, which employs two different continuous waves at the optical line terminal and a pair of fiber Bragg gratings at the end of each optical network unit, is proposed in a time-division multiplexing passive optical network (PON). The proposed scheme accomplishes the fiber fault monitoring by comparing the different wavelength's testing curves. Complete complementary code is utilized to measure multiple wavelength signals simultaneously with only one receiver and to improve the dynamic range of this system. The PON system consisting of 20 km feeding fiber and a 1:16 splitter is investigated by the experiments. The experimental results show that the faulty branch can be successfully identified by using our scheme. What is more, we also demonstrate that our scheme can be applied to the multi-stage PON.展开更多
Cyclic polling-based dynamic wavelength and bandwidth allocation algorithm supporting differentiated classes of services in wavelength division multiplexing (WDM) passive optical networks (PONs) is proposed. In th...Cyclic polling-based dynamic wavelength and bandwidth allocation algorithm supporting differentiated classes of services in wavelength division multiplexing (WDM) passive optical networks (PONs) is proposed. In this algorithm, the optical line terminal (OLT) polls for optical network unit (ONU) requests to transmit data in a cyclic manner. Services are categorized into three classes: expedited forward (EF) priority, assured forwarding (AF) priority, and best effort (BE) priority. The OLT assigns bandwidth for different priorities with different strategies. Simulation results show that the proposed algorithm saves a lot of downstream bandwidth under low load and does not show the light-load penalty compared with the simultaneous and interleaved polling schemes.展开更多
The passive optical network(PON)technology has been drastically improved in recent years.In spite of using the optical technology,the utilization of the entire bandwidth is a very challenging task.The main categories ...The passive optical network(PON)technology has been drastically improved in recent years.In spite of using the optical technology,the utilization of the entire bandwidth is a very challenging task.The main categories of PON are the Ethernet passive optical network(EPON)and gigabit passive optical network(GPON).These two networks use the dynamic bandwidth allocation(DBA)algorithm to attain the maximum usage of bandwidth,which is provided in the network dynamically according to the need of the customers with the support of the service level agreement(SLA).This paper will provide a clear review about the DBA algorithm of both technologies as well as the comparison。展开更多
In this paper, the 40-Gbps orthogonal frequency division multiple access(OFDMA) technology enabled by subcarrier allocation in the form of integrated architecture for the intra-cell is proposed in the downlink transmi...In this paper, the 40-Gbps orthogonal frequency division multiple access(OFDMA) technology enabled by subcarrier allocation in the form of integrated architecture for the intra-cell is proposed in the downlink transmission passive broadband optical access system. The data-carrying subcarriers in the inverse fast Fourier transform/fast Fourier transform(IFFT/FFT) size of1 024 points are successfully divided into three sub-channels,in which each sub-channel has 256 useful subcarriers, by using adaptive dynamic bandwidth allocation(DBA). Taking the inherent advantages of M-ary quadrature amplitude modulation(MQAM)modulation mechanism into account, the performance of the absolutely identical MQAM format over the different sub-channels for the downstream OFDMA-passive optical network(PON) is investigated based on the intensity modulation direct detection(IMDD) system by simulations. The results show that three parallel4 QAM or 16 QAM or 64 QAM OFDMA data, which are transmitted over three sub-channels, is more suitable for different sub-channel allocations, respectively. In addition, comparing with single port4/16/64 QAM OFDM over the same access system, the receiver sensitivity economizes – 0.6 d Bm, 0.6 d Bm, 4.6 d Bm at the bit error rate(BER) value of 10-3 respectively.展开更多
As a promising solution to efficiently achieving fiber to the home (FTTH), Ethernet passive optical network (EPON) is currently improved to provide intercommunication among customers, together with normal traffic ...As a promising solution to efficiently achieving fiber to the home (FTTH), Ethernet passive optical network (EPON) is currently improved to provide intercommunication among customers, together with normal traffic delivery, via optical local area network emulation. It is a new research direction and expected to enhance the normal EPON performances. The purpose of this article is to review the state-of -the-art solutions to emulating optical local area networks (OLANs) over EPON. We discuss the major problems involved, e.g., network architecture, control mechanisms, and other potential enhancements. We also outline areas for future researches.展开更多
Nonlinearity impairments and distortions have been bothering the bandwidth constrained passive optical network(PON)system for a long time and limiting the develop-ment of capacity in the PON system.Unlike other works ...Nonlinearity impairments and distortions have been bothering the bandwidth constrained passive optical network(PON)system for a long time and limiting the develop-ment of capacity in the PON system.Unlike other works concentrating on the exploration of the complex equalization algorithm,we investigate the potential of constellation shap-ing joint support vector machine(SVM)classification scheme.At the transmitter side,the 8 quadrature amplitude modulation(8QAM)constellation is shaped into three designs to mitigate the influence of noise and distortions in the PON channel.On the receiver side,simple multi-class linear SVM classifiers are utilized to replace complex equalization methods.Simulation results show that with the bandwidth of 25 GHz and overall bitrate of 50 Gbit/s,at 10 dBm input optical power of a 20 km standard single mode fiber(SSMF),and under a hard-decision forward error correction(FEC)threshold,transmission can be realized by employing Circular(4,4)shaped 8QAM joint SVM classifier at the maximal power budget of 37.5 dB.展开更多
We demonstrated a unified two-band broadband light source based on erbium-doped fiber. The proposed scheme generates high output power at both bands and saves doped-fiber and pump lasers.
We demonstrate that an asynchronous CSMA/CD protocol with an optical loop-back star coupler can achieve high upstream channel utilizatbn in an Ethernet PON, readily supporting a large installed base of Ethernet 10Base...We demonstrate that an asynchronous CSMA/CD protocol with an optical loop-back star coupler can achieve high upstream channel utilizatbn in an Ethernet PON, readily supporting a large installed base of Ethernet 10BaseT and 100BaseT interfaces.展开更多
In this paper, we propose a new structure of a centralized-light-source wavelength division multiplexed passive op- tical network (WDM-PON) utilizing inverse-duobinary-return-to-zero (inverse-duobinary-RZ) downstr...In this paper, we propose a new structure of a centralized-light-source wavelength division multiplexed passive op- tical network (WDM-PON) utilizing inverse-duobinary-return-to-zero (inverse-duobinary-RZ) downstream and DPSK up- stream. It reuses downstream light for the upstream modulation, which retrenches lasers assembled at each optical network unit (ONU), and ultimately cuts down the cost of ONUs a great deal. Meanwhile, a 50-km-reach WDM-PON experiment with 10-Gb/s inverse-duobinary-RZ downstream and 6-Gb/s DPSK upstream is demonstrated here. It is revealed to be a novel cost-effective alternative for the next generation access network.展开更多
This paper proposed a novel variable optical splitter, of which the splitting ratio can be dynamically adjusted according to different wavelengths. A novel intelligent passive optical network (PON) system based on t...This paper proposed a novel variable optical splitter, of which the splitting ratio can be dynamically adjusted according to different wavelengths. A novel intelligent passive optical network (PON) system based on this splitter was also presented. Experimental results demonstrated that the insertion loss can be reduced corresponding to the decrease of the splitting ratio.展开更多
Real-time video streaming using ultra-wideband(UWB) technology is experimentally demonstrated along long-reach passive optical networks(LR-PONs) with different wired and wireless reaches. Experimental tests using exte...Real-time video streaming using ultra-wideband(UWB) technology is experimentally demonstrated along long-reach passive optical networks(LR-PONs) with different wired and wireless reaches. Experimental tests using external and direct modulation with UWB wireless radiation in the 10- and 60-GHz bands are performed. An ultra-bendable fiber is also considered for a last-mile distribution. The video quality at the output of the optical fiber infrastructure of the LR-PON is assessed using the error vector magnitude(EVM), and the link quality indicator(LQI) is used as a figure of merit after wireless radiation. An EVM below –17 dB is achieved for both externally and directly modulated LR-PONs comprising up to 125 km of optical fiber. EVM improvement is observed for longer LR-PONs when directly modulated lasers(DMLs) are used because of the amplitude gain provided by the combined effect of dispersion and DML's chirp. Compared with optical back-to-back operation, the LQI level degrades to the maximum around 20% for LR-PONs ranging between 75 and 125 km of fiber reach and with a wireless coverage of 2 m in the 10-GHz UWB band. The same level of LQI degradation is observed using the 60-GHz UWB band with a LR-PON integrating 101 km of access network, a last-mile distribution using ultra-bendable fiber, and a 5.2-m wireless link.展开更多
Future high-speed mobile communication systems require low latency and high capacity networks.Coherent wavelength division multiplexing(WDM)passive optical network(PON)scheme is expected to play a vital role in these ...Future high-speed mobile communication systems require low latency and high capacity networks.Coherent wavelength division multiplexing(WDM)passive optical network(PON)scheme is expected to play a vital role in these systems.In this paper,coherent WDM-PON scheme based on dual-polarization 16-quadrature amplitude modulation(DP-16 QAM)transceiver has been investigated.The aim of this scheme is to build a 2 Tbit/s(125 Gbit/s/λ×16 wavelengths)network that will be used in the construction of the transport architecture of fifth generation(5 G)and beyond 5 G(B5 G)cellular networks either in mobile front haul(MFH)or mobile back haul(MBH).The results indicate that the proposed scheme is very adequate for both 5 G and B5 G cellular networks requirements.展开更多
基金Project supported by Science Foundation of Shanghai Municipal Commission of Science and Technology (Grant No .04dz12045)
文摘This paper presents the design and implementation of access controller used for Ethernet passive optical network ( EPON). As a first step to develop an ASIC product, the entire system is designed on a field programmable gate array (FPGA) with an embedded CPU. To reduce working frequency of the FPGA, the byte-to-word conversion is proposed. Propagation delays are equalized by ranging procedure so as to avoid data collision. Implementations of synchronization, classification, as well as Linux porting are illustrated in detail. The interface between the FPGA and CPU are also presented. Experimental results show that the proposed system can properly function in a relatively low cost FPGA.
文摘Latency sensitive services have attracted much attention lately and imposedstringent requirements on the access network design. Passive optical networks (PONs) providea potential long-term solution for the underlying transport network supporting theseservices. This paper discusses latency limitations in PON and recent progress in PONstandardization to improve latency. Experimental results of a low latency PON system arepresented as a proof of concept.
基金supported by the Tianjin Enterprise Innovation Fund under Grant No. 08ZXCXGX17500
文摘Dynamic bandwidth allocation(DBA) is an open and hot topic in the Ethernet passive optical network(EPON) ,which is regarded as one of the best choices for next-generation access networks. However,most proposed DBA schemes ignore the quality of service(QoS) guarantee on maximum delay and delay jitter for the real-time traffic and the downstream bandwidth utilization under light upstream load in EPON. In this paper,a new DBA scheme,QoS guaranteed adaptive downstream bandwidth utilization(QoS-ADBU),is proposed. This scheme can provide better QoS assurance by determining the maximum transmission cycle time according to the maximum acceptable packet delay and delay jitter for real-time traffic. Besides,the downstream utilization can also be improved by adapting the polling frequency to downstream traffic load.
文摘The Ethernet passive optical network(EPON) is the next generation of broad-band network technique.A crucial issue in EPONs is the sharing of uplink bandwidth among optical network units(ONUs).This article provides a novel dynamic bandwidth allocation algorithm,i.e.threshold dynamic bandwidth allocation(TDBA),which is based on adaptive threshold,to increase resource utilization.The algorithm uses ONU data-transmitting rate to adjust optical line terminal(OLT) receiving data threshold from an ONU.Simulation results show that this algorithm can decrease average packet delay and increase network throughput in a 10G EPON system.
文摘1. IntroductionA large number of networks for realizing first and second order transfer functions using a currentconveyor have been reported in the literature. Especially, the networks that can offer highinput impedance attract attention, for high input impedance has the advantage that the networksmay be used in cascade without requiring impedance matching device. In the Higashimura and
基金supported by Department of Science and Technology,New Delhi,India(SR/S4/MS:485/07)
文摘The problem of passivity analysis is investigated for uncertain stochastic neural networks with discrete interval and distributed time-varying delays.The parameter uncertainties are assumed to be norm bounded and the delay is assumed to be time-varying and belongs to a given interval,which means that the lower and upper bounds of interval time-varying delays are available.By constructing proper Lyapunov-Krasovskii functional and employing a combination of the free-weighting matrix method and stochastic analysis technique,new delay-dependent passivity conditions are derived in terms of linear matrix inequalities(LMIs).Finally,numerical examples are given to show the less conservatism of the proposed conditions.
文摘An optical network is a type of data communication network built with optical fibre technology. It utilizes optical fibre cables as the primary communication medium for converting data and passing data as light pulses between sender and receiver nodes. The major issue in optical networking is disjoints that occur in the network. A polynomial time algorithm Wavelength Division Multiplexing-Passive Optical Networking (WDM-PON) computes disjoints of an optical network and reduces the count of disjoints that occur in the network by separating Optical Network Units (ONU) into several virtual point-to-point connections. The Arrayed Waveguide Grating (AWG) filter is included in WDM-PON to avoid the traffic in the network thereby increasing the bandwidth capacity. In case of a failure or disjoint Ant Colony Optimization (ACO) algorithm is used to find the optimized shortest path for re-routing. For enhanced security, modified Rivert Shamir Adleman (RSA) algorithm encrypts the message during communication between the nodes. The efficiency is found to be improved in terms of delay in packet delivery, longer optical reach, optimized shortest path, packet error rate.
基金This research was supported by the National863Project Foundation(863- 51 1 - 945- 0 1 0 ),Tianjin Nat-ural Science Foundation
文摘Elman networks' dynamical modeling capability is discussed in this paper firstly.According to Elman networks' unique structure,a weight training algorithm is designed and a nonlinear adaptive controller is constructed.Without the PE presumption,neural networks controller's closed loop properties are studied and the whole Elman networks' passivity is demonstrated.
基金supported by the National 863Program of China(No.2015AA017002)the Research Foundation of Wuhan Science and Technology Bureau(No.2015010303010141)+1 种基金the Open Foundation of State Key Laboratory of Optical Communication Technologies and Networks(W.R.I.)the Accelink Technologies Company Ltd
文摘A dual optical time domain reflectometry (OTDR) system, which employs two different continuous waves at the optical line terminal and a pair of fiber Bragg gratings at the end of each optical network unit, is proposed in a time-division multiplexing passive optical network (PON). The proposed scheme accomplishes the fiber fault monitoring by comparing the different wavelength's testing curves. Complete complementary code is utilized to measure multiple wavelength signals simultaneously with only one receiver and to improve the dynamic range of this system. The PON system consisting of 20 km feeding fiber and a 1:16 splitter is investigated by the experiments. The experimental results show that the faulty branch can be successfully identified by using our scheme. What is more, we also demonstrate that our scheme can be applied to the multi-stage PON.
基金supported by the National "973" Program of China (No. 2007CB310705)the National Natural Science Foundation of China (Nos. 60772024, 60711140087)+3 种基金the National "863" Program of China (No. 2007AA01Z255)the Program for Changjiang Scholars and Innovative Research Team in University (No. IRT0609)the International Science and Technology Cooperation Project of China (No. 2006DFA11040)the 111 Project of China (No. B07005).
文摘Cyclic polling-based dynamic wavelength and bandwidth allocation algorithm supporting differentiated classes of services in wavelength division multiplexing (WDM) passive optical networks (PONs) is proposed. In this algorithm, the optical line terminal (OLT) polls for optical network unit (ONU) requests to transmit data in a cyclic manner. Services are categorized into three classes: expedited forward (EF) priority, assured forwarding (AF) priority, and best effort (BE) priority. The OLT assigns bandwidth for different priorities with different strategies. Simulation results show that the proposed algorithm saves a lot of downstream bandwidth under low load and does not show the light-load penalty compared with the simultaneous and interleaved polling schemes.
文摘The passive optical network(PON)technology has been drastically improved in recent years.In spite of using the optical technology,the utilization of the entire bandwidth is a very challenging task.The main categories of PON are the Ethernet passive optical network(EPON)and gigabit passive optical network(GPON).These two networks use the dynamic bandwidth allocation(DBA)algorithm to attain the maximum usage of bandwidth,which is provided in the network dynamically according to the need of the customers with the support of the service level agreement(SLA).This paper will provide a clear review about the DBA algorithm of both technologies as well as the comparison。
基金supported by the National Natural Science Foundation of China(61771082 61801065+3 种基金 61871062)the China Scholarship Council(201908500139)the Science and Technology Research Program of Chongqing Municipal Education Commission(KJQN201800615KJQN201800609)
文摘In this paper, the 40-Gbps orthogonal frequency division multiple access(OFDMA) technology enabled by subcarrier allocation in the form of integrated architecture for the intra-cell is proposed in the downlink transmission passive broadband optical access system. The data-carrying subcarriers in the inverse fast Fourier transform/fast Fourier transform(IFFT/FFT) size of1 024 points are successfully divided into three sub-channels,in which each sub-channel has 256 useful subcarriers, by using adaptive dynamic bandwidth allocation(DBA). Taking the inherent advantages of M-ary quadrature amplitude modulation(MQAM)modulation mechanism into account, the performance of the absolutely identical MQAM format over the different sub-channels for the downstream OFDMA-passive optical network(PON) is investigated based on the intensity modulation direct detection(IMDD) system by simulations. The results show that three parallel4 QAM or 16 QAM or 64 QAM OFDMA data, which are transmitted over three sub-channels, is more suitable for different sub-channel allocations, respectively. In addition, comparing with single port4/16/64 QAM OFDM over the same access system, the receiver sensitivity economizes – 0.6 d Bm, 0.6 d Bm, 4.6 d Bm at the bit error rate(BER) value of 10-3 respectively.
基金the National Science Fund for Distinguished Young Scholars(Grant No.60725104)the National Basic Research Program of China(Grant No.2007CB310706)+2 种基金the National High Technology Research and Development Program of China(Grant Nos.2007AA01Z246 and 2007AA01Z227)the National Natural Science Foundation of China(Grant No.60672045)the Research Fund for the Doctoral Program of Higher Education(Grant No.20060614018)
文摘As a promising solution to efficiently achieving fiber to the home (FTTH), Ethernet passive optical network (EPON) is currently improved to provide intercommunication among customers, together with normal traffic delivery, via optical local area network emulation. It is a new research direction and expected to enhance the normal EPON performances. The purpose of this article is to review the state-of -the-art solutions to emulating optical local area networks (OLANs) over EPON. We discuss the major problems involved, e.g., network architecture, control mechanisms, and other potential enhancements. We also outline areas for future researches.
文摘Nonlinearity impairments and distortions have been bothering the bandwidth constrained passive optical network(PON)system for a long time and limiting the develop-ment of capacity in the PON system.Unlike other works concentrating on the exploration of the complex equalization algorithm,we investigate the potential of constellation shap-ing joint support vector machine(SVM)classification scheme.At the transmitter side,the 8 quadrature amplitude modulation(8QAM)constellation is shaped into three designs to mitigate the influence of noise and distortions in the PON channel.On the receiver side,simple multi-class linear SVM classifiers are utilized to replace complex equalization methods.Simulation results show that with the bandwidth of 25 GHz and overall bitrate of 50 Gbit/s,at 10 dBm input optical power of a 20 km standard single mode fiber(SSMF),and under a hard-decision forward error correction(FEC)threshold,transmission can be realized by employing Circular(4,4)shaped 8QAM joint SVM classifier at the maximal power budget of 37.5 dB.
文摘We demonstrated a unified two-band broadband light source based on erbium-doped fiber. The proposed scheme generates high output power at both bands and saves doped-fiber and pump lasers.
文摘We demonstrate that an asynchronous CSMA/CD protocol with an optical loop-back star coupler can achieve high upstream channel utilizatbn in an Ethernet PON, readily supporting a large installed base of Ethernet 10BaseT and 100BaseT interfaces.
基金Project supported by the National Natural Science Foundation of China (Grant No. 61271192)the National Basic Research Program of China (Grant No. 2013CB329204)the National High Technology Research and Development Program of China (Grant No. 2013AA013401)
文摘In this paper, we propose a new structure of a centralized-light-source wavelength division multiplexed passive op- tical network (WDM-PON) utilizing inverse-duobinary-return-to-zero (inverse-duobinary-RZ) downstream and DPSK up- stream. It reuses downstream light for the upstream modulation, which retrenches lasers assembled at each optical network unit (ONU), and ultimately cuts down the cost of ONUs a great deal. Meanwhile, a 50-km-reach WDM-PON experiment with 10-Gb/s inverse-duobinary-RZ downstream and 6-Gb/s DPSK upstream is demonstrated here. It is revealed to be a novel cost-effective alternative for the next generation access network.
文摘This paper proposed a novel variable optical splitter, of which the splitting ratio can be dynamically adjusted according to different wavelengths. A novel intelligent passive optical network (PON) system based on this splitter was also presented. Experimental results demonstrated that the insertion loss can be reduced corresponding to the decrease of the splitting ratio.
基金supported by the Fundao para a Ciência e a Tecnologia from Portugal under projects PEst-OE/EEI/LA0008/2013 and TURBO-PTDC/EEATEL/104358/2008by the European FIVER-FP7-ICT-2009-4-249142 project
文摘Real-time video streaming using ultra-wideband(UWB) technology is experimentally demonstrated along long-reach passive optical networks(LR-PONs) with different wired and wireless reaches. Experimental tests using external and direct modulation with UWB wireless radiation in the 10- and 60-GHz bands are performed. An ultra-bendable fiber is also considered for a last-mile distribution. The video quality at the output of the optical fiber infrastructure of the LR-PON is assessed using the error vector magnitude(EVM), and the link quality indicator(LQI) is used as a figure of merit after wireless radiation. An EVM below –17 dB is achieved for both externally and directly modulated LR-PONs comprising up to 125 km of optical fiber. EVM improvement is observed for longer LR-PONs when directly modulated lasers(DMLs) are used because of the amplitude gain provided by the combined effect of dispersion and DML's chirp. Compared with optical back-to-back operation, the LQI level degrades to the maximum around 20% for LR-PONs ranging between 75 and 125 km of fiber reach and with a wireless coverage of 2 m in the 10-GHz UWB band. The same level of LQI degradation is observed using the 60-GHz UWB band with a LR-PON integrating 101 km of access network, a last-mile distribution using ultra-bendable fiber, and a 5.2-m wireless link.
基金the Alexander von Humboldt Foundation for their support。
文摘Future high-speed mobile communication systems require low latency and high capacity networks.Coherent wavelength division multiplexing(WDM)passive optical network(PON)scheme is expected to play a vital role in these systems.In this paper,coherent WDM-PON scheme based on dual-polarization 16-quadrature amplitude modulation(DP-16 QAM)transceiver has been investigated.The aim of this scheme is to build a 2 Tbit/s(125 Gbit/s/λ×16 wavelengths)network that will be used in the construction of the transport architecture of fifth generation(5 G)and beyond 5 G(B5 G)cellular networks either in mobile front haul(MFH)or mobile back haul(MBH).The results indicate that the proposed scheme is very adequate for both 5 G and B5 G cellular networks requirements.