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综述多媒体远程教育系统的三种建设方案 被引量:4
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作者 王心 沈琴 《西部广播电视》 2003年第9期20-24,共5页
先对多媒体远程教育系统进行简要介绍 ,然后讨论系统的 3种建设方案 ,分别分析了基于Web方式、基于Web方式 +卫星数字网方式、基于Web方式 +专网方式的系统 ,最后对这 3种方案进行了详细的比较 。
关键词 多媒体远程教育系统 WEB 卫星数字网 专网 建设方案
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Time synchronization in communication networks based on the Beidou foundation enhancement system 被引量:7
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作者 LIU Hui ZHANG RuFei +1 位作者 LIU JingNan ZHANG Ming 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2016年第1期9-15,共7页
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
关键词 Beidou satellite navigation system precision timing time synchronization Beidou foundation enhancement system communication network time synchronization
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