TIME SYNCHRONIZATION METHOD AND DEVICE

• US 20200136737A1
• Filed: 12/30/2019
• Published: 04/30/2020
• Est. Priority Date: 06/30/2017
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: WANG, Jinhui, LIU, Song, NIU, Hongwei, QI, Yunlei
• Granted Patent: US 11,343,007 B2
• Time in Patent Office: Days
• CPC Class Codes: H04J 3/06 Synchronising arrangements for television systems H04N5/04; bit-synchronisation H04L7/00
• CPC Class Codes: H04J 3/0655 using timestamps
• CPC Class Codes: H04J 3/0667 Bidirectional timestamps, e.g. NTP or PTP for compensation of clock drift and for compensation of propagation delays arrangements for monitoring round trip delays in packet switching networks H04L43/0864
• CPC Class Codes: H04J 3/067 Details of the timestamp structure
• CPC Class Codes: H04J 3/0673 using intermediate nodes, e.g. modification of a received timestamp before further transmission to the next packet node, e.g. including internal delay time or residence time into the packet

Abstract

A time synchronization method includes receiving, by a receive-end device, a first timestamp and a first header signal sent by a transmit-end device, where the first timestamp indicates a first moment at which a first channel medium conversion module sends the first header signal, and a second moment at which the receive-end device receives the first header signal. The method further includes sending a second header signal to the transmit-end device, where a third moment at which the receive-end device sends the second header signal. The method further includes receiving a fourth timestamp sent by the transmit-end device, where the fourth timestamp indicates a fourth moment at which the transmit-end device receives the second header signal. The method further includes synchronizing time with the transmit-end device based on the first moment, the second moment, the third moment, and the fourth moment.

Claims

1. A time synchronization method, comprising:

receiving, by a receive-end device, a first timestamp sent by a transmit-end device, and receiving a first header signal sent by the transmit-end device, wherein the first header signal is sent by a first channel medium conversion module in the transmit-end device, the first timestamp indicates a first moment at which the first channel medium conversion module sends the first header signal, and a second moment at which the receive-end device receives the first header signal;

sending, by the receive-end device, a second header signal to the transmit-end device, wherein the second header signal is sent by a second channel medium conversion module in the receive-end device, and a third moment at which the receive-end device sends the second header signal;

receiving, by the receive-end device, a fourth timestamp sent by the transmit-end device, wherein the fourth timestamp indicates a fourth moment at which the transmit-end device receives the second header signal; and

synchronizing, by the receive-end device, time with the transmit-end device based on the first moment, the second moment, the third moment, and the fourth moment.

2. The time synchronization method according to claim 1, wherein

the first moment includes a moment at which a first stamping module in the transmit-end device receives a first trigger signal sent by the first channel medium conversion module,

the second moment includes a moment at which a second stamping module in the receive-end device receives a second trigger signal sent by the second channel medium conversion module,

the third moment includes a moment at which the second stamping module receives a third trigger signal sent by the second channel medium conversion module, and

the fourth moment includes a moment at which the first stamping module receives a fourth trigger signal sent by the first channel medium conversion module.

3. The method according to claim 2, wherein the first header signal is received by the second channel medium conversion module, and after the second channel medium conversion module receives the first header signal sent by the first channel medium conversion module, the method further comprises:

sending, by the second channel medium conversion module, the second trigger signal to the second stamping module;

generating, by the second stamping module, a second timestamp when the second stamping module receives the second trigger signal, and

sending the second timestamp to a processor in the receive-end device, wherein the second timestamp indicates the second moment.

4. The method according to claim 2, wherein after the second channel medium conversion module sends the second header signal to the first channel medium conversion module, the method further comprises:

sending, by the second channel medium conversion module, the third trigger signal to the second stamping module;

generating, by the second stamping module, a third timestamp when the second stamping module receives the third trigger signal, and

sending the third timestamp to the processor in the receive-end device, wherein the third timestamp indicates the third moment.

5. A time synchronization method, comprising:

sending, by a transmit-end device, a first timestamp to a receive-end device, and sending a first header signal to the receive-end device, wherein the first header signal is sent by a first channel medium conversion module in the transmit-end device, the first timestamp indicates a first moment at which the first channel medium conversion module sends the first header signal, and a second moment at which the receive-end device receives the first header signal;

receiving, by the transmit-end device, a second header signal sent by the receive-end device, wherein the second header signal is sent by a second channel medium conversion module in the receive-end device, a third moment at which the receive-end device sends the second header signal, and a fourth moment at which the transmit-end device receives the second header signal; and

sending, by the transmit-end device, a fourth timestamp to the receive-end device, so that the receive-end device can synchronize time with the transmit-end device based on the first moment, the second moment, the third moment, and the fourth moment, wherein the fourth timestamp indicates the fourth moment.

6. The time synchronization method according to claim 5, wherein

the first moment includes a moment at which a first stamping module in the transmit-end device receives a first trigger signal sent by the first channel medium conversion module,

the second moment includes a moment at which a second stamping module in the receive-end device receives a second trigger signal sent by the second channel medium conversion module,

the third moment includes a moment at which the second stamping module receives a third trigger signal sent by the second channel medium conversion module, and

the fourth moment includes a moment at which the first stamping module receives a fourth trigger signal sent by the first channel medium conversion module.

7. The method according to claim 6, wherein after the first channel medium conversion module sends the first header signal to the second channel medium conversion module, the method further comprises:

sending, by the first channel medium conversion module, the first trigger signal to the first stamping module;

generating, by the first stamping module, the first timestamp when the first stamping module receives the first trigger signal, and

sending the first timestamp to a processor in the transmit-end device.

8. The method according to claim 6, wherein the second header signal is received by the first channel medium conversion module, and after the first channel medium conversion module receives the second header signal sent by the second channel medium conversion module, the method further comprises:

sending, by the first channel medium conversion module, the fourth trigger signal to the first stamping module;

generating, by the first stamping module, the fourth timestamp when the first stamping module receives the fourth trigger signal, and

sending the fourth timestamp to the processor in the transmit-end device.

9. The method according to claim 6, wherein the sending, by the transmit-end device, the first timestamp to the receive-end device comprises:

sending, after receiving the first timestamp sent by the first stamping module, a synchronization message to the receive-end device by the first channel medium conversion module, wherein the synchronization message carries the first timestamp.

10. The method according to claim 6, wherein the sending, by the transmit-end device, the fourth timestamp to the receive-end device comprises:

sending, after receiving the fourth timestamp sent by the first stamping module, a delay response message to the receive-end device by the first channel medium conversion module, wherein the delay response message carries the fourth timestamp.

11. A receive-end device, comprising:

a processor; and

a second channel medium conversion module configured to;

receive a first timestamp sent by a transmit-end device and receive a first header signal sent by the transmit-end device, wherein the first header signal is sent by a first channel medium conversion module in the transmit-end device, the first timestamp indicates a first moment at which the first channel medium conversion module sends the first header signal, and a second moment at which the receive-end device receives the first header signal;

send a second header signal to the transmit-end device, wherein a third moment at which the second channel medium conversion module sends the second header signal; and

receive a fourth timestamp sent by the transmit-end device, wherein the fourth timestamp indicates a fourth moment at which the transmit-end device receives the second header signal; and

the processor is configured to synchronize time with the transmit-end device based on the first moment, the second moment, the third moment, and the fourth moment.

12. The receive-end device according to claim 11, wherein the receive-end device further comprises:

a second stamping module, wherein

the first moment includes a moment at which a first stamping module in the transmit-end device receives a first trigger signal sent by the first channel medium conversion module,

the second moment includes a moment at which the second stamping module in the receive-end device receives a second trigger signal sent by the second channel medium conversion module,

the third moment includes a moment at which the second stamping module receives a third trigger signal sent by the second channel medium conversion module, and

the fourth moment includes a moment at which the first stamping module receives a fourth trigger signal sent by the first channel medium conversion module.

13. The receive-end device according to claim 12, wherein after the second channel medium conversion module receives the first header signal sent by the first channel medium conversion module, the second channel medium conversion module is further configured to send the second trigger signal to the second stamping module;

and

the second stamping module is configured to generate a second timestamp when receiving the second trigger signal, and send the second timestamp to the processor, wherein the second timestamp indicates the second moment.

14. The receive-end device according to claim 12, wherein after the second channel medium conversion module sends the second header signal to the first channel medium conversion module, the second channel medium conversion module is further configured to send the third trigger signal to the second stamping module;

and

the second stamping module is further configured to generate a third timestamp when receiving the third trigger signal, and send the third timestamp to the processor, wherein the third timestamp indicates the third moment.

15. A transmit-end device, comprising:

a processor; and

a first channel medium conversion module configured to;

send a first timestamp to a receive-end device and send a first header signal to the receive-end device, wherein the first header signal is sent by the first channel medium conversion module in the transmit-end device, the first timestamp indicates a first moment at which the first channel medium conversion module sends the first header signal, and a second moment at which the receive-end device receives the first header signal;

receive a second header signal sent by the receive-end device, wherein the second header signal is sent by a second channel medium conversion module in the receive-end device, a third moment at which the receive-end device sends the second header signal, and a fourth moment at which the transmit-end device receives the second header signal; and

send a fourth timestamp to the receive-end device, so that the receive-end device can synchronize time with the transmit-end device based on the first moment, the second moment, the third moment, and the fourth moment, wherein the fourth timestamp indicates the fourth moment; and

the processor is configured to communicate with the first channel medium conversion module.

16. The transmit-end device according to claim 15, wherein the transmit-end device further comprises:

a first stamping module, wherein

the first moment includes a moment at which the first stamping module receives a first trigger signal sent by the first channel medium conversion module,

the second moment includes a moment at which a second stamping module in the receive-end device receives a second trigger signal sent by the second channel medium conversion module,

the third moment includes a moment at which the second stamping module receives a third trigger signal sent by the second channel medium conversion module, and

the fourth moment includes a moment at which the first stamping module receives a fourth trigger signal sent by the first channel medium conversion module.

17. The transmit-end device according to claim 16, wherein after the first channel medium conversion module sends the first header signal to the second channel medium conversion module, the first channel medium conversion module is further configured to send the first trigger signal to the first stamping module;

and

the first stamping module is configured to generate the first timestamp when receiving the first trigger signal, and send the first timestamp to the processor in the transmit-end device.

18. The transmit-end device according to claim 16, wherein the first channel medium conversion module is further configured to send the fourth trigger signal to the first stamping module after receiving the second header signal sent by the second channel medium conversion module;

and

the first stamping module is further configured to generate the fourth timestamp when receiving the fourth trigger signal, and send the fourth timestamp to the processor in the transmit-end device.

19. The transmit-end device according to claim 16, wherein the first channel medium conversion module is configured to send the first timestamp to the receive-end device comprises:

the processor in the transmit-end device is further configured to send, after receiving the first timestamp sent by the first stamping module, a synchronization message to the receive-end device by using the first channel medium conversion module, wherein the synchronization message carries the first timestamp.

20. The transmit-end device according to claim 16, wherein the first channel medium conversion module is further configured to send a fourth timestamp to the receive-end device comprises:

the processor in the transmit-end device is further configured to send, after receiving the fourth timestamp sent by the first stamping module, a delay response message to the receive-end device by using the first channel medium conversion module, wherein the delay response message carries the fourth timestamp.