ZTE Corporation has completed test for the high-precision time source device based on the principle of satellite common view in National Time Service Center (NTSC), Chinese Academy of Sciences (CAS).
The time source test based on common view technology is the first that achieves the time precision of +/-10ns. The completion of this test marks that ZTE has introduced the satellite common view technology from scientific research on astronomical navigation to communication industry application for the first time, boosting Internet of Everything (IoE) in 5G.
Performed in NTSC in Lintong, Xi’an, this test adopts two time source devices (CVTS) self-developed by ZTE based on satellite common view to verify the remote time comparison performance of CVTS, and the difference between the output time and UTC.
The test result shows that when providing the two time source devices with time service in ultra-long-distance condition, the direct time difference between the 1PPS signals output by the two independently running devices is less than 10ns.
However, the precision of the currently widely used time server PRTC-A is around +/-100ns, while the precision of ePRTC-A and ePRTC-B under research by ITU-T are +/-30ns and +/-40ns, respectively.
Common view is one of the major methods of long-distance clock comparison in the world and a primary technological means for International Atomic Time. Satellite common view can eliminate the impacts of satellite clock and most impacts of path latency. It improves the measurement precision of clock difference between two sites, realizing high-precision time comparison. The comparison imprecision can be largely reduced to several nanoseconds.
With reference to the standard Coordinated Universal Time (UTC) of National Time Service Center (NTSC), the test uses a time interval counter to measure the difference between 1PPS signals output by the time source and UTC (NTSC). The test result is in compliance with the expectation.
ZTE’s time source based on common view technology achieves +/-10ns time precision and provides applications that require different precision, such as 5G, indoor location and Internet of Things with different solutions. Moreover, common view technology enables a new flexible networking mode for large-scale ultra-high-precision time synchronization networks.
ZTE will continue to lead 5G transport technology innovations to boost rapid development of the 5G industry chain.