Method and apparatus of implementing time synchronization

• US 9,357,515 B2
• Filed: 07/25/2013
• Issued: 05/31/2016
• Est. Priority Date: 01/26/2011
• 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: Feng, Liexun, He, Yong
• Primary Examiner(s): Phillips, Hassan
• Assistant Examiner(s): Jones, Prenell
• Application Number:
  US13/950,650
• Publication Number:
  US 20130308626A1
• Time in Patent Office: 1,041 Days
• US Class Current: 1/1
• CPC Class Codes: H04B 10/25 Arrangements specific to fibre transmission
• CPC Class Codes: H04B 10/25753 Distribution optical network, e.g. between a base station and a plurality of remote units
• CPC Class Codes: H04J 14/0204 Broadcast and select arrangements, e.g. with an optical splitter at the input before adding or dropping
• CPC Class Codes: H04J 3/0638 Clock or time synchronisation among nodes; Internode synchronisation synchronization for ring networks H04L12/422; data switching networks with synchronous transmission H04L12/43
• 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: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 88/085 Access point devices with remote components

Abstract

The present invention discloses a method of time synchronization and a base station system. The base station system includes a main unit, at least one radio unit, and a transmission medium adapted to transmit information between the main unit and the at least one radio unit. The base station system further includes a clock synchronization server configured close to the side of the at least one radio unit or integrated with the at least one radio unit. The clock synchronization server is adapted to transmit synchronization data to the main unit through the transmission medium, so that the main unit performs configuration processing according to the synchronization data to implement time synchronization with the clock synchronization server.

Claims

1. A base station system, comprising:

a main unit,

at least one radio unit,

an optical fiber configured to transmit information between the main unit and the at least one radio unit,

a clock synchronization server configured to transmit a first synchronization data from the clock synchronization server to the main unit through the optical fiber, wherein

the main unit is configured to perform configuration processing according to the first synchronization data to implement time synchronization with the clock synchronization server,

the clock synchronization server is configured close to a side of the at least one radio unit or integrated with the at least one radio unit,

the base station system further comprises a first optical adapter module coupled to the at least one radio unit and the clock synchronization server,

the first optical adapter module includes a first optical fiber interface coupled to the optical fiber,

the first optical adapter module is configured to converge the first synchronization data and a first service data from the at least one radio unit, and transmit the converged first synchronization data and first service data through the first optical fiber interface, and

the first optical adapter module is configured close to the side of the at least one radio unit or integrated with the at least one radio unit.

2. The base station system according to claim 1, wherein

the base station system further comprises a second optical adapter module,

the second optical adapter module is coupled to the main unit and configured close to a side of the main unit or integrated with the main unit,

the second optical adapter module comprises a second optical fiber interface, and

the second optical fiber interface and the first optical fiber interface of the first optical adapter module are connected through the optical fiber.

3. The base station system according to claim 2, wherein the second optical adapter module is configured to

receive the converged first synchronization data and first service data through the second optical fiber interface,

split the converged first synchronization data and first service data and

transmit the split first synchronization data and the split first service data to the main unit.

4. The base station system according to claim 3, wherein

the second optical adapter module is further configured to converge a second synchronization data and a second service data from the main unit, and

transmit the converged second synchronization data and second service data through the second optical fiber interface.

5. The base station system according to claim 4, wherein

the main unit comprises at least one baseband unit (BBU),

the at least one BBU comprises a baseband radio frequency interface and a synchronization interface coupled to the second optical adapter module,

the baseband radio frequency interface is configured to transmit the second service data and receive the first service data, and

the synchronization interface is configured to transmit the second synchronization data, and receive the first synchronization data.

6. The base station system according to claim 5, wherein

the at least one baseband unit BBU comprises at least two BBUs,

the main unit further comprises at least one transfer switch coupled between the second optical adapter module and the at least two BBUs, and

the at least one transfer switch is configured to transmit the first synchronization data to the at least two BBUs from the clock synchronization server, and receive the second synchronization data from the at least two BBUs.

7. The base station system according to claim 2, wherein the first optical adapter module and the second optical adapter module are optical add-drop multiplexers (OADMs).

8. The base station system according to claim 1, wherein the first optical adapter module is an OADM.

9. The base station system according to claim 1, wherein the clock synchronization server is a server of an IEEE 1588 protocol.

10. The base station system according to claim 1, wherein the clock synchronization server comprises a receiving module configured to receive a synchronization reference signal from a satellite system.

11. A method of time synchronization in a base station system, comprising:

transmitting, by a clock synchronization server in the base station system, a first synchronization data to a main unit in the base station system through a an optical fiber between the clock synchronization server and the main unit, wherein the clock synchronization server is configured close to a side of the at least one radio unit in the base station system or integrated with the at least one radio unit; and

performing, by the main unit, configuration processing according to the first synchronization data to implement time synchronization with the clock synchronization server;

transmitting, by the at least one radio unit, a first service data to the main unit through the optical fiber;

wherein the first service data and the first synchronization data are transmitted to a first optical adapter module coupled to the at least one radio unit and the clock synchronization server, and converged by the first optical adapter module; and

wherein the converged first service data and first synchronization data are transmitted by the first optical adapter module through the optical fiber.

12. The method according to claim 11, wherein the converged first service data and the first synchronization data are transmitted by the first optical adapter module to a second optical adapter module through the optical fiber, and wherein the second optical adapter module is coupled to the main unit.

13. The method according to claim 12, wherein the converged first service data and first synchronization data is split by the second optical adapter module, and the split first synchronization data and the split first service data is transmitted to the main unit by the second optical adapter module.

14. The method according to claim 12, wherein a second synchronization data and a second service data from the main unit is converged by the second optical adapter module, and the converged second synchronization data and second service data is transmitted by the second optical adapter module through the optical fiber.

15. The method according to claim 11, wherein the main unit comprises at least one baseband unit, BBU.

16. The method according to claim 11, wherein the first optical adapter module is an optical add-drop multiplexer, OADM.

17. The method according claim 11, wherein the clock synchronization server comprises a receiving module configured to receive a synchronization reference signal from a satellite system to implement time synchronization with the satellite system.