Communication networks rely on time synchronization information generated by base station equipment(either the Global Navigation Satellite System receiver or rubidium atomic clock) to enable wireless networking and co...Communication networks rely on time synchronization information generated by base station equipment(either the Global Navigation Satellite System receiver or rubidium atomic clock) to enable wireless networking and communications. Meanwhile, the time synchronization among base stations depends on the Network Time Protocol. With the development of mobile communication systems, the corresponding time synchronization accuracy has increased as well. In this case, the use of sparsely distributed-high-precision synchronization points to synchronize time for an entire network with high precision is a key problem and is the foundation of the enhanced network communication. The current receiver equipment for China's digital synchronous network typically includes dedicated multi-channel GPS receivers for communication; however, with the development of GPS by the USA, network security has been destabilized and reliability is low. Nonetheless, network time synchronization based on Beidou satellite navigation system timing devices is an inevitable development trend for China's digital communications network with the establishment of the independently developed BDS, especially the implementation and improvement of the Beidou foundation enhancement system.展开更多
Precision time synchronization underpins a wide array of modern technologies,from relativistic geodesy to distributed quantum networks.Quantum two-way time transfer(QTWTT),which harnesses the tight temporal correlatio...Precision time synchronization underpins a wide array of modern technologies,from relativistic geodesy to distributed quantum networks.Quantum two-way time transfer(QTWTT),which harnesses the tight temporal correlations of energy-time entangled photon pairs,has achieved remarkable sub-picosecond stability[1]while offering intrinsic security against timing attacks[2].Yet,the quantum nocloning theorem—prohibiting the amplification of quantum states—imposes a fundamental barrier to extending QTWTT over long distances due to inevitable signal loss in fiber-optic channels[3].In a recent study published in Science China Physics,Mechanics&Astronomy,a cascaded Q-TWTT architecture is presented that bypasses this challenge by using relay stations to generate and distribute entangled photon pairs[4].展开更多
文摘Communication networks rely on time synchronization information generated by base station equipment(either the Global Navigation Satellite System receiver or rubidium atomic clock) to enable wireless networking and communications. Meanwhile, the time synchronization among base stations depends on the Network Time Protocol. With the development of mobile communication systems, the corresponding time synchronization accuracy has increased as well. In this case, the use of sparsely distributed-high-precision synchronization points to synchronize time for an entire network with high precision is a key problem and is the foundation of the enhanced network communication. The current receiver equipment for China's digital synchronous network typically includes dedicated multi-channel GPS receivers for communication; however, with the development of GPS by the USA, network security has been destabilized and reliability is low. Nonetheless, network time synchronization based on Beidou satellite navigation system timing devices is an inevitable development trend for China's digital communications network with the establishment of the independently developed BDS, especially the implementation and improvement of the Beidou foundation enhancement system.
文摘Precision time synchronization underpins a wide array of modern technologies,from relativistic geodesy to distributed quantum networks.Quantum two-way time transfer(QTWTT),which harnesses the tight temporal correlations of energy-time entangled photon pairs,has achieved remarkable sub-picosecond stability[1]while offering intrinsic security against timing attacks[2].Yet,the quantum nocloning theorem—prohibiting the amplification of quantum states—imposes a fundamental barrier to extending QTWTT over long distances due to inevitable signal loss in fiber-optic channels[3].In a recent study published in Science China Physics,Mechanics&Astronomy,a cascaded Q-TWTT architecture is presented that bypasses this challenge by using relay stations to generate and distribute entangled photon pairs[4].
