Time transmitting method

Abstract

Being applicable to occasion of requiring accurate, reliable time information, the method possesses features of high precision, good safety and long transmission distance. The method includes steps: (1) time server at upper stage outputs signal of time code; (2) converting signal of time code to data signal transmitted on digital data dedicated line; (3) digital data is transmitted on digital datadedicated line; (4) transmitted data signals are converted to signal of time code again, and received by time server at lower stage; (5) processing signal of time code received by time server at lower stage, and outputting diversified types of time signal. Not connected to IP network, the time server at upper stage without limitation in transmission distance outputs signal of time code in one wayonly so as to eliminate hidden trouble in safety. Through phase-lock and time delay compensation process, time server at lower stage outputs time in precision in microsecond or Nano second level.

Description

technical field [0001] The present invention relates to a method for time transfer, more specifically, a method for high-precision time transfer between offices or within an office. Background technique [0002] Accurate and reliable time is widely used in the fields of satellite, communication and aerospace. For some applications, an error of one ten-thousandth of a second will also have a serious impact. For example, the CDMA mobile phone system requires the absolute time difference between base station equipment <10us. The billing system used in the communication network can reduce the error of billing information and provide the basis for settlement between different operators' networks. Time Synchronization The ultimate time source is the global satellite positioning system (such as GPS). After obtaining the standard time from a time source (such as the global satellite positioning system), the time information needs to be sent to various devices that need time syn...

AI Technical Summary

Problems solved by technology

The networking method of this scheme is simple, but there are the following disadvantages: 1. Because the time information is transmitted in the IP network, the security of the NTP server is not high, it is not easy to isolate the network, and the time server is vulnerable to attack; The route is not fixed, so the delay is not fixed. When the scope of the IP network is large, it often affects the accuracy of the time; 3. The time accuracy of the NTP transmission time is low, which cannot meet the needs of higher accuracy. Usually, the general wide area network The precision of NTP is 100ms-1000ms, the precision of NTP of network metropolitan area network is 10ms-100ms, the precision of NTP of local area network is 1ms-10ms

4. In this networking mode, the secondary time server cannot provide high-precision DCLS, IRIG-B and 1PPS format signals

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