The development of Internet brings a great challenge to the survivability of the supporting distributed intelligent optical networks. The emergence of Active-Fault-Alarm (AFA) technology makes it possible for the syst...The development of Internet brings a great challenge to the survivability of the supporting distributed intelligent optical networks. The emergence of Active-Fault-Alarm (AFA) technology makes it possible for the system to be aware of the incoming or possible fault in advance and to provide possibility to develop a more active restoration mechanism. On this base, an Active Segment Pre-Restoration (ASPR) mechanism for distributed optical network is proposed. ASPR allows establishing a Segment Pre-Restoration Path (SPR-Path) as a work path, which is initiated by the local node, in advance of potential fault occuring and keeps the SPR-Path only during the low-quality or fault period. Simulation results show that the ASPR mechanism has better restoration performance compared with that of Active Restoration (AR) scheme.展开更多
Using a series of quantum correlated photon pairs, we propose a theoretical scheme for any-to-any multi-user quantum key distribution network based on differential phase shift. The differential phase shift and the dif...Using a series of quantum correlated photon pairs, we propose a theoretical scheme for any-to-any multi-user quantum key distribution network based on differential phase shift. The differential phase shift and the different detection time slots ensure the security of our scheme against eavesdropping. We discuss the security under the intercept-resend attack and the source replacement attack.展开更多
Dispersive optics quantum key distribution(DO-QKD)based on energy-time entangled photon pairs is an important QKD scheme.In DO-QKD,the arrival time of photons is used in key generation and security analysis,which woul...Dispersive optics quantum key distribution(DO-QKD)based on energy-time entangled photon pairs is an important QKD scheme.In DO-QKD,the arrival time of photons is used in key generation and security analysis,which would be greatly affected by fiber dispersion.In this work,we establish a theoretical model of the entanglement-based DO-QKD system,considering the protocol,physical processes(such as fiber transmission and single-photon detection),and the analysis of security tests.Based on this theoretical model,we investigate the influence of chromatic dispersion introduced by transmission fibers on the performance of DO-QKD.By analyzing the benefits and costs of dispersion compensation,the system performance under G.652 and G.655 optical fibers are shown,respectively.The results show that dispersion compensation is unnecessary for DO-QKD systems in campus networks and even metro networks.Whereas,it is still required in DO-QKD systems with longer fiber transmission distances.展开更多
详细阐述了光分配网络(Optical Distribution Network,ODN)在智慧城市中的应用前景和面临的挑战。通过对其在智能交通、能源管理、公共服务、安防与应急响应等领域应用的深入分析,结合对建设成本、网络维护、融合现有网络以及数据安全...详细阐述了光分配网络(Optical Distribution Network,ODN)在智慧城市中的应用前景和面临的挑战。通过对其在智能交通、能源管理、公共服务、安防与应急响应等领域应用的深入分析,结合对建设成本、网络维护、融合现有网络以及数据安全等方面挑战的探讨,为ODN网络在智慧城市的有效部署和持续发展提供全面视角。展开更多
We propose and experimentally validate an optical true time delay beamforming scheme with straightforward integration into hybrid optical/millimeter（mm）-wave access networks. In the proposed approach, the most compl...We propose and experimentally validate an optical true time delay beamforming scheme with straightforward integration into hybrid optical/millimeter（mm）-wave access networks. In the proposed approach, the most complex functions, including the beamforming network, are implemented in a central office, reducing the complexity and cost of remote antenna units. Different cores in a multi-core fiber are used to distribute the modulated signals to high-speed photodetectors acting as heterodyne mixers. The mm-wave carrier frequency is fixed to 50 GHz（VBand）, thereby imposing a progressive delay between antenna elements of a few picoseconds. That true time delay is achieved with an accuracy lower than 1 ps and low phase noise.展开更多
文章分析了当前校园网建设面临的挑战,回顾了校园网的建设背景和现状,提出主流的组网方案,并对比了它们的优缺点。在方案设计部分,推荐基于全光网架构进行组网,并详细阐述核心交换机、出口网关设备、光线路终端(Optical Line Terminal,O...文章分析了当前校园网建设面临的挑战,回顾了校园网的建设背景和现状,提出主流的组网方案,并对比了它们的优缺点。在方案设计部分,推荐基于全光网架构进行组网,并详细阐述核心交换机、出口网关设备、光线路终端(Optical Line Terminal,OLT)、光分配网(Optical Distribution Network,ODN)、光网络单元(Optical Network Unit,ONU)以及无线接入点(Access Point,AP)的具体设计方案。展开更多
城市光纤化将大力推进城市系统物联化和互联化的发展,民用航空机场一般采用光纤入户(FTTH)作为光网覆盖的解决方案。要建设高效率低成本的FTTH光缆网络,其组网理念、产品选择以及施工方式需综合考虑。以杭州萧山国际机场国际航站楼综合...城市光纤化将大力推进城市系统物联化和互联化的发展,民用航空机场一般采用光纤入户(FTTH)作为光网覆盖的解决方案。要建设高效率低成本的FTTH光缆网络,其组网理念、产品选择以及施工方式需综合考虑。以杭州萧山国际机场国际航站楼综合布线系统为背景,给出了光分配网络ODN(optical distribution network)的设计规划、选材和施工等关注的重点,对光分配网络建设进行了研究。展开更多
基金supported in part by National High Technical Research and Development Program of China (863 Program)under Grant No.2009AA01z255, 2009AA01A345National Key Basic Research Program of China (973 Program) under Grant No.2007CB310705+1 种基金National Natural Science Foundation of China under Grant No. 60932004Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No.200800130001
文摘The development of Internet brings a great challenge to the survivability of the supporting distributed intelligent optical networks. The emergence of Active-Fault-Alarm (AFA) technology makes it possible for the system to be aware of the incoming or possible fault in advance and to provide possibility to develop a more active restoration mechanism. On this base, an Active Segment Pre-Restoration (ASPR) mechanism for distributed optical network is proposed. ASPR allows establishing a Segment Pre-Restoration Path (SPR-Path) as a work path, which is initiated by the local node, in advance of potential fault occuring and keeps the SPR-Path only during the low-quality or fault period. Simulation results show that the ASPR mechanism has better restoration performance compared with that of Active Restoration (AR) scheme.
基金Supported by the National Key Basic Research Programme of China under Grant No 2006CB921106, the National Natural Science Foundation of China under Grant Nos 10325521 and 60433050, and the SRFDP Programme of the Ministry of Education of China, and the Key Project of the Ministry of Education of China under Grant No 306020.
文摘Using a series of quantum correlated photon pairs, we propose a theoretical scheme for any-to-any multi-user quantum key distribution network based on differential phase shift. The differential phase shift and the different detection time slots ensure the security of our scheme against eavesdropping. We discuss the security under the intercept-resend attack and the source replacement attack.
基金the National Key R&D Program of China under Grants No.2017YFA0303704 and No.2018YFB2200400Natural Science Foundation of Beijing under Grant No.Z180012National Natural Science Foundation of China under Grants No.61875101 and No.91750206.
文摘Dispersive optics quantum key distribution(DO-QKD)based on energy-time entangled photon pairs is an important QKD scheme.In DO-QKD,the arrival time of photons is used in key generation and security analysis,which would be greatly affected by fiber dispersion.In this work,we establish a theoretical model of the entanglement-based DO-QKD system,considering the protocol,physical processes(such as fiber transmission and single-photon detection),and the analysis of security tests.Based on this theoretical model,we investigate the influence of chromatic dispersion introduced by transmission fibers on the performance of DO-QKD.By analyzing the benefits and costs of dispersion compensation,the system performance under G.652 and G.655 optical fibers are shown,respectively.The results show that dispersion compensation is unnecessary for DO-QKD systems in campus networks and even metro networks.Whereas,it is still required in DO-QKD systems with longer fiber transmission distances.
文摘详细阐述了光分配网络(Optical Distribution Network,ODN)在智慧城市中的应用前景和面临的挑战。通过对其在智能交通、能源管理、公共服务、安防与应急响应等领域应用的深入分析,结合对建设成本、网络维护、融合现有网络以及数据安全等方面挑战的探讨,为ODN网络在智慧城市的有效部署和持续发展提供全面视角。
基金founded by H2020 ITN CELTA under Grant No.675683 of Call:H2020-MSCA-ITN-2015
文摘We propose and experimentally validate an optical true time delay beamforming scheme with straightforward integration into hybrid optical/millimeter（mm）-wave access networks. In the proposed approach, the most complex functions, including the beamforming network, are implemented in a central office, reducing the complexity and cost of remote antenna units. Different cores in a multi-core fiber are used to distribute the modulated signals to high-speed photodetectors acting as heterodyne mixers. The mm-wave carrier frequency is fixed to 50 GHz（VBand）, thereby imposing a progressive delay between antenna elements of a few picoseconds. That true time delay is achieved with an accuracy lower than 1 ps and low phase noise.
文摘文章分析了当前校园网建设面临的挑战,回顾了校园网的建设背景和现状,提出主流的组网方案,并对比了它们的优缺点。在方案设计部分,推荐基于全光网架构进行组网,并详细阐述核心交换机、出口网关设备、光线路终端(Optical Line Terminal,OLT)、光分配网(Optical Distribution Network,ODN)、光网络单元(Optical Network Unit,ONU)以及无线接入点(Access Point,AP)的具体设计方案。
文摘城市光纤化将大力推进城市系统物联化和互联化的发展,民用航空机场一般采用光纤入户(FTTH)作为光网覆盖的解决方案。要建设高效率低成本的FTTH光缆网络,其组网理念、产品选择以及施工方式需综合考虑。以杭州萧山国际机场国际航站楼综合布线系统为背景,给出了光分配网络ODN(optical distribution network)的设计规划、选材和施工等关注的重点,对光分配网络建设进行了研究。
