Optical phase transfer via fiber optics is the most effective method for optical frequency standard comparison on the scale below thousands of kilometers.However,the monotonic phase discrimination range of conventiona...Optical phase transfer via fiber optics is the most effective method for optical frequency standard comparison on the scale below thousands of kilometers.However,the monotonic phase discrimination range of conventional optical phase-locked loops is limited,and link delays restrict the control bandwidth,which makes it a challenge to achieve a continuously reliable optical link.This paper presents an event-timing-based phase detection method that overcomes the monotonic phase discrimination range limitation of conventional phase-locked loops through dual-edge timestamp recording,achieving an optical phase measurement resolution on the order of 10 attoseconds.With such a technique,we established a 7-segment-cascaded optical link over 1402km of commercial fiber while sharing dense wavelength division multiplexing(DWDM)channels with live telecom traffic.The system maintained continuous operation for 11.7 days without phase cycle slips despite encountering 15 km aerial fiber noise up to 21000 rad^(2)·Hz^(−1)·km^(−1)at 1 Hz.Relative instabilities of the link are 3.7×10^(−15)at 1 s and 3.9×10^(−20)at 100000 s.展开更多
In this afticle, three uopt problems on the developlnent and plabong of Beijing metropolis are expounded (1) Having analyzed the process of urbanlzation dunng 45 years, the autihor divides it into three Stages :city e...In this afticle, three uopt problems on the developlnent and plabong of Beijing metropolis are expounded (1) Having analyzed the process of urbanlzation dunng 45 years, the autihor divides it into three Stages :city expansion, qrban sprawl and fonmation of centnpotal urban nngr. Then a rank-number-size law is pLif fotward to predict the development and allocation of satellite towns (2) Having looked back on the change of urban transpoftation nforork, the atlthor points out its merits and demerits.According to the increases of traffic flow, improving measures for the urban road systems are demonstrated. (3) Having reviewed the llistory of commercial distnbution and referred to previous lnodels, the author roprds the spatial structure of business as a combined network from central place and idealized stnucture of lnetropolitan area. The trade and service orgaluzation in n1ain urban area and peripheral zone can be planned with defferent ways. The atlthor predicts a rational network of commerce and service of Beijing with a strong BCD Which is accepted by some trade authorities展开更多
Electcoms, the largest professional trunking network operator in Malaysia, has launched a network based on ZTE’s Global Open Trunking Architecture (GoTa). The launch, in Kuala Lumpur, Malaysia,
ZTE Corporation, a leading global provider of telecommunications equipment and network solutions, announced on November 23, 2010 that it has successfully completed the world＇s first large-scale commercial GPON-based ...ZTE Corporation, a leading global provider of telecommunications equipment and network solutions, announced on November 23, 2010 that it has successfully completed the world＇s first large-scale commercial GPON-based mobile backhaul network for TELKOM Indonesia, a full-service telecom operator in Indonesia. The project is the first such large-scale commercialization of GPON backhaul technology,展开更多
ZTE Corporation announced on January 18, 2010 that it has successfully constructed and launched the world＇s first commercial Evolution Data Optimized （EV-DO） Rev.B network. Together with Smart Telecom, one of Indon...ZTE Corporation announced on January 18, 2010 that it has successfully constructed and launched the world＇s first commercial Evolution Data Optimized （EV-DO） Rev.B network. Together with Smart Telecom, one of Indonesia＇ s CDMA telecommunication service providers, and Qualcomm, the leading developer and innovator of advanced wireless technologies and data solutions, the network has been launched in Bali, Indonesia recently.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2020YFC2200103)the Shandong Provincial Natural Science Foundation(Grant Nos.ZR2022LLZ006 and ZR2022LLZ011)+1 种基金the Innovation Program for Quantum Science and Technology(Grant Nos.2021ZD0300904 and 2021ZD0300903)the Key R&D Plan of Shandong Province(Grant No.2023CXPT105)。
文摘Optical phase transfer via fiber optics is the most effective method for optical frequency standard comparison on the scale below thousands of kilometers.However,the monotonic phase discrimination range of conventional optical phase-locked loops is limited,and link delays restrict the control bandwidth,which makes it a challenge to achieve a continuously reliable optical link.This paper presents an event-timing-based phase detection method that overcomes the monotonic phase discrimination range limitation of conventional phase-locked loops through dual-edge timestamp recording,achieving an optical phase measurement resolution on the order of 10 attoseconds.With such a technique,we established a 7-segment-cascaded optical link over 1402km of commercial fiber while sharing dense wavelength division multiplexing(DWDM)channels with live telecom traffic.The system maintained continuous operation for 11.7 days without phase cycle slips despite encountering 15 km aerial fiber noise up to 21000 rad^(2)·Hz^(−1)·km^(−1)at 1 Hz.Relative instabilities of the link are 3.7×10^(−15)at 1 s and 3.9×10^(−20)at 100000 s.
文摘In this afticle, three uopt problems on the developlnent and plabong of Beijing metropolis are expounded (1) Having analyzed the process of urbanlzation dunng 45 years, the autihor divides it into three Stages :city expansion, qrban sprawl and fonmation of centnpotal urban nngr. Then a rank-number-size law is pLif fotward to predict the development and allocation of satellite towns (2) Having looked back on the change of urban transpoftation nforork, the atlthor points out its merits and demerits.According to the increases of traffic flow, improving measures for the urban road systems are demonstrated. (3) Having reviewed the llistory of commercial distnbution and referred to previous lnodels, the author roprds the spatial structure of business as a combined network from central place and idealized stnucture of lnetropolitan area. The trade and service orgaluzation in n1ain urban area and peripheral zone can be planned with defferent ways. The atlthor predicts a rational network of commerce and service of Beijing with a strong BCD Which is accepted by some trade authorities
文摘Electcoms, the largest professional trunking network operator in Malaysia, has launched a network based on ZTE’s Global Open Trunking Architecture (GoTa). The launch, in Kuala Lumpur, Malaysia,
文摘ZTE Corporation, a leading global provider of telecommunications equipment and network solutions, announced on November 23, 2010 that it has successfully completed the world＇s first large-scale commercial GPON-based mobile backhaul network for TELKOM Indonesia, a full-service telecom operator in Indonesia. The project is the first such large-scale commercialization of GPON backhaul technology,
文摘ZTE Corporation announced on January 18, 2010 that it has successfully constructed and launched the world＇s first commercial Evolution Data Optimized （EV-DO） Rev.B network. Together with Smart Telecom, one of Indonesia＇ s CDMA telecommunication service providers, and Qualcomm, the leading developer and innovator of advanced wireless technologies and data solutions, the network has been launched in Bali, Indonesia recently.
