CN116981044A

CN116981044A - Clock synchronization system and method for expanding small base station to be compatible with multiple clock sources

Info

Publication number: CN116981044A
Application number: CN202311227195.9A
Authority: CN
Inventors: 朱锦璐; 郑永亮; 曹毅清
Original assignee: Shenzhen Jiaxian Communication Technology Co ltd
Current assignee: Shenzhen Jiaxian Communication Technology Co ltd
Priority date: 2023-09-22
Filing date: 2023-09-22
Publication date: 2023-10-31
Anticipated expiration: 2043-09-22
Also published as: CN116981044B

Abstract

The application discloses a clock synchronization system and a method for an extended small base station compatible with various clock sources, comprising a BU, EU, GNSS clock source, an RS422 clock source and RUs, wherein the BUs are in communication connection with EUs, and the EUs are in communication connection with a plurality of RUs; the clock module is arranged on the BU, and is used for carrying out clock synchronization with the PTP clock source and transmitting time information to the EU; the method comprises the steps that a clock source selection module, a clock analysis module and a time service holding module are deployed in EU, the clock selection module is used for selecting a clock source and transmitting time information to the clock analysis module, the clock analysis module extracts the time information and transmits the time information to the time service holding module after analyzing according to clock messages of the type of the clock source, and the time service holding module is used for holding a clock when the clock source is lost and outputting the time information to a phase-locked loop to serve as a clock source of a base station system. The application enables the base station to switch among the GNSS clock source, the ptp clock source and the 422 clock source, thereby improving the stability and reliability of the base station clock synchronization system.

Description

Clock synchronization system and method for expanding small base station to be compatible with multiple clock sources

Technical Field

The application belongs to the technical field of 5G communication, and particularly relates to a clock synchronization system and method for an extended small base station compatible with multiple clock sources.

Background

The current base station clock synchronization system only supports a single clock source, such as GNSS only, and GNSS signals are weak in certain environments, such as underground mines, underground garages and urban canyons, and GNSS receivers in the scenes cannot provide stable clock sources for the base station, so that normal operation of the base station is affected. If only the PTP clock source is supported, some current network environments are not connected with the PTP clock source and the PTP node, so that the BBU cannot realize clock synchronization by using PTP, and the normal operation of the base station is also affected.

The time synchronization between the extended small base stations is the basis for the smooth development of wireless communication services, which requires that the base stations can acquire stable clock signals and realize clock synchronization no matter what environment the base stations are deployed in.

Disclosure of Invention

The embodiment of the application provides a clock synchronization system and a clock synchronization method compatible with various clock sources, so that a base station can be switched among a GNSS clock source, a ptp clock source and a 422 clock source, and the stability and the reliability of the clock synchronization system of the base station are improved.

In a first aspect, an embodiment of the present application provides a clock synchronization system compatible with multiple clock sources by an extended small base station, where the clock synchronization system includes a BU, EU, GNSS clock source, an RS422 clock source, and an RU, where the BU is in communication connection with EU, and the EU is in communication connection with multiple RU;

the clock module is arranged on the BU and is used for carrying out clock synchronization with the PTP clock source and transmitting time information to the EU;

a clock source selection module, a clock analysis module and a time service maintaining module are deployed in EU,

the clock selection module is used for selecting a clock source and transmitting time information to the clock analysis module,

the clock analysis module extracts time information and transmits the time information to the time service maintaining module after analyzing according to the clock message of the type of the clock source,

the time service maintaining module is used for maintaining the clock when the clock source is lost and outputting time information to the phase-locked loop as the clock source of the whole base station system.

The clock module is connected with the PTP server.

The GNSS clock source is in communication connection with the clock selection module through a GNSS receiver, the RS422 clock source is in communication connection with the clock selection module, and the GNSS receiver is embedded in EU and is used for receiving and resolving GNSS messages; the clock source of the GNSS clock source is the global satellite navigation system, support GPS, BDS, GLONASS and GALILEO.

The clock selection module, the clock analysis module and the clock holding module are sequentially connected in a communication way to transmit information and data.

In a second aspect, the present application also provides a clock synchronization method for an extended small base station compatible with multiple clock sources, including the following steps: when the clock source selection module selects the GNSS clock source, the clock analysis module analyzes the GNSS message, extracts time information, and sends the time information to the time service maintaining module, so that clock information is provided for the RU and the BU.

Preferably, when the GNSS signal is weak or lost, the GNSS receiver switches the clock source to the PTP clock source, and then the clock selection module on the EU selects the PTP clock source, the clock module on the BU analyzes and synchronizes with the PTP server, the PTP server is used as the master clock, the BU is used as the slave clock, the clock module of the BU outputs the time information to the clock selection module, and the clock analysis module of the EU analyzes and sends the time information to the time service maintaining module.

Preferably, when there is no stable GPS signal and PTP clock source, an RS422 clock source is selected, and when the clock source selecting module selects the RS422 clock source, the EU receives a time message from the RS422 port, and the clock analyzing module analyzes and sends the time message to the time service maintaining module.

Preferably, the clock source switching can be realized manually or automatically, the real-time uploading data is weighted-average and the cloud server is uploaded to perform real-time calculation and replacement threshold switching, the threshold updating is obtained by an autonomous algorithm, the device autonomously selects the threshold of each clock source, and the priority of clock source selection is GNSS clock source > PTP clock source > RS422 clock source.

In a third aspect, a computer-readable storage medium stores a computer program, x86 and arm architecture BBU, which when executed by a processor implements a method according to the second aspect.

Compared with the prior art, the embodiment of the application has the beneficial effects that:

1) The base station can use three types of clock sources, so that the adaptability and clock stability of the small base station are improved.

2) Stability only for extended small base station communication, compatibility with a variety of clock sources: the scheme supports GNSS, PTP and RS422 clock sources, and can meet clock synchronization requirements of base stations in different scenes.

3) The clock synchronization system is stable: by adopting the multi-source clock synchronization scheme, the stability and the reliability of the system can be ensured when the clock source selection fails.

4) Support automatic selection: according to the scheme, the automatic clock source selection can be set, so that manual intervention is reduced, and the degree of automation of the system is improved.

5) The expandability is strong: according to the scheme, clock sources can be added or deleted as required, and the expansibility is strong.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments or the description of the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic view of an overall structure according to an embodiment of the present application;

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth such as the particular system architecture, techniques, etc., in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

It should be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It should also be understood that the term "and/or" as used in the present specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.

As used in the present description and the appended claims, the term "if" may be interpreted as "when..once" or "in response to a determination" or "in response to detection" depending on the context. Similarly, the phrase "if a determination" or "if a [ described condition or event ] is detected" may be interpreted in the context of meaning "upon determination" or "in response to determination" or "upon detection of a [ described condition or event ]" or "in response to detection of a [ described condition or event ]".

Furthermore, the terms "first," "second," "third," and the like in the description of the present specification and in the appended claims, are used for distinguishing between descriptions and not necessarily for indicating or implying a relative importance.

Reference in the specification to "one embodiment" or "some embodiments" or the like means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," and the like in the specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments" unless expressly specified otherwise. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless expressly specified otherwise.

Clock synchronization is an important issue in micro-service architecture. Since each service is independent, clock synchronization between them becomes difficult. If the times of the two services are not synchronized, they cannot properly coordinate their operations. In addition, because the services in the micro-service architecture are distributed, clock synchronization also needs to take into account network delays and data transmission in some cases.

To address these issues, some algorithms and protocols for clock synchronization may be used, such as using GPS satellite positioning technology to achieve accurate clock synchronization, or some specialized clock synchronization protocols, such as Coordinated Universal Time (Coct) or Network Time Protocol (NTP), etc.

Communication protocols are another important issue in micro-service architecture. Because the services in the micro-service architecture are distributed, a reliable, efficient communication protocol is needed to enable communication between the services. Common communication protocols include HTTP, TCP/IP, coordinated Universal Time (Coct), and the like.

Network architecture is an important issue in micro-service architecture. Because the services in the micro-service architecture are distributed, an efficient, reliable network architecture is needed to enable communication between the services. Common network architectures include high performance networks, distributed networks, and the like.

Wherein EU, BBU, RRU, RS, GNSS are common technical abbreviations of the communication industry. English is adopted for brevity.

In one possible implementation, as shown in fig. 1, the present embodiment provides a clock synchronization system in which an extended small base station is compatible with multiple clock sources, including: the clock module is arranged in the BU and used for carrying out clock synchronization with the ptp clock source and transmitting time information to the EU; the system comprises a clock source selection module, a clock analysis module and a time service holding module, wherein the clock source selection module, the clock analysis module and the time service holding module are deployed in EU and are used for selecting a clock source and transmitting time information to the clock analysis module, the clock analysis module analyzes different clock messages according to different clock sources, extracts the time information and transmits the time information to the time service holding module, and the time service holding module is used for holding a clock when the clock source is lost and outputting the time information to a phase-locked loop to serve as a clock source of the whole base station system.

In this solution, the GNSS clock source is used only for the extended small cell by default, the clock source of the GNSS clock source is the global satellite navigation system, support GPS, BDS, GLONASS and GALILEO, EU is embedded in the GNSS receiver for receiving and decoding GNSS messages,

when the clock source selection module selects the GNSS clock source, the clock analysis module analyzes the GNSS message, extracts time information, and sends the time information to the time service maintaining module, so that clock information is provided for the RU unit and the BU unit.

When the base station is deployed in the scenes of underground mines, underground garages, urban canyons and the like,

when the GNSS signal is weak or lost, the GNSS receiver acquires stable clock information, the clock source is switched to the PTP clock source, at this time, the clock selection module on the EU can select the PTP clock source, in this case, the clock module on the BU analyzes and synchronizes with the PTP server in clock, the PTP server serves as a master clock, the BU serves as a slave clock, the clock module of the BU outputs time information to the clock selection module, and the clock analysis module of the EU analyzes and transmits the time information to the time service maintaining module.

When there is no stable GPS signal and PTP clock source,

the RS422 clock source can also be selected, typically from another base station that is closer. When the clock source selection module selects the RS422 clock source, the EU receives the time message from the RS422 port, and the clock analysis module analyzes the time information and sends the time information to the time service maintaining module.

The clock source can be manually switched on the man-machine interaction interface, EU can be set to automatically select the clock source, the GNSS clock source is used by default, when the GNSS clock source signal is bad, the PTP clock source is automatically switched, when the PTP clock source is not available, whether the RS422 port has the clock signal or not is detected, and if the PTP clock source and the RS422 clock source are not available, the GNSS clock source is used by default.

The clock selection adopts the following rule to limit priority selection, and automatic control is realized through software.

a. When selecting a clock source, logic is added to detect the signal quality of the clock source in real time.

b. If neither the PTP clock source nor the RS422 clock source exists, whether the RS422 port has a clock signal or not needs to be detected, and the detection result is used as a basis for selecting the clock source.

Regarding parameter criteria for which GNSS clock signals are not good,

a. a threshold value of GNSS clock source signal quality is defined below which the automatic switching to the PTP clock source occurs.

b. An option of GNSS clock source signal quality, such as "low quality" may be added when the clock source is selected, and if "low quality" is selected, the switch to PTP clock source is automatic.

c. An option of RS422 clock source signal quality, such as "low quality", may be added when both the RS422 clock source and the RS422 port are selected. If neither the RS422 clock source nor the RS422 port is available, detecting whether the RS422 port has a clock signal or not, and taking the detection result as the basis for selecting the clock source.

Defining a threshold from historical data: the quality of the GNSS clock sources may be evaluated from historical data, such as recording the signal strength of each clock source, and then calculating a signal quality score for each clock source from these data. If the score of a certain clock source is below a set threshold, it may be set as a default clock source.

The threshold is defined according to the requirements and limitations of the system. For example, if the system needs to select a clock source at high precision timing and high reliability, a higher high precision timing threshold may be set to ensure stability of the system. The threshold is defined in terms of laboratory test results: tests can be performed in the laboratory to evaluate the signal strength of each clock source and record this data. The signal quality score for each clock source can then be calculated from this data. Low quality/medium quality/high quality is defined.

If the score of a certain clock source is above a set threshold, it may be set as the default GNSS clock source. In laboratory testing, algorithms and test conditions may be continually improved to improve the accuracy of test results. And uploading data in real time for weighted average, and obtaining the threshold value update by an autonomous algorithm to enable the equipment to select the threshold value of each clock source. The threshold of "low quality", "medium quality" or "high quality" is selected. The threshold a for each clock source may be dynamically updated according to the user's selection. To enable autonomous selection of clock types.

The scheme enables the extended small base station to use three types of clock sources, and improves the adaptability and clock stability of the base station. The method has wide applicability and can support BBU of x86 and arm architecture.

In another embodiment, the specific implementation includes:

1. the clock synchronization module comprises a plurality of clock sources, such as BU, EU, GNSS, RS and the like, and a clock selection module for selecting the clock sources and transmitting time information to the time service maintaining module.

2. And the clock analysis module is used for analyzing the clock message of the clock source and extracting time information.

3. And the time service maintaining module is used for maintaining the clock when the clock source is lost and outputting time information to the phase-locked loop as the clock source of the whole base station system.

4. And the communication protocol module comprises a clock module which is connected with the PTP server and is used for carrying out clock synchronization with the PTP server.

5. The network architecture module comprises a plurality of clock sources, such as BU, EU, GNSS, RS and 422, a selection module, a clock analysis module and a time service maintaining module, and is used for realizing clock synchronization.

The modules communicate through a communication protocol to realize clock synchronization and time information transfer. In a specific implementation manner, when the clock selection module selects the GNSS clock source, the clock analysis module analyzes according to the GNSS message, extracts time information, and sends the time information to the time service maintaining module, so as to provide clock information for the RU and the BU. When the GNSS signal is weak or lost, the GNSS receiver can acquire stable clock information, at the moment, the clock source is switched to the PTP clock source, then the clock selection module on the EU can select the PTP clock source, the clock module on the BU analyzes and synchronizes the clock with the PTP server, the PTP server serves as a master clock, the BU serves as a slave clock, the clock module of the BU outputs time information to the clock selection module, and the clock analysis module of the EU analyzes and transmits the time information to the time service maintaining module. The clock source switching can be realized manually or automatically, the real-time uploading data is weighted and averaged, the cloud server is uploaded to perform real-time calculation and replacement threshold switching, the threshold updating is obtained by an autonomous algorithm, the equipment autonomously selects the threshold of each clock source, and the priority of clock source selection is GNSS clock source > PTP clock source > RS422 clock source.

In the foregoing embodiments, the descriptions of the embodiments are emphasized, and in part, not described or illustrated in any particular embodiment, reference is made to the related descriptions of other embodiments.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus/network device and method may be implemented in other manners. For example, the apparatus/network device embodiments described above are merely illustrative, e.g., the division of the modules or units is merely a logical functional division, and there may be additional divisions in actual implementation, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection via interfaces, devices or units, which may be in electrical, mechanical or other forms.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

The above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application.

Claims

1. The clock synchronization system compatible with a plurality of clock sources of the extended small base station is characterized by comprising a BU, EU, GNSS clock source, an RS422 clock source and RUs, wherein the BUs are in communication connection with EUs, and the EUs are in communication connection with a plurality of RUs;

2. The system of claim 1, wherein the clock module is coupled to the PTP server.

3. The clock synchronization system of claim 1, wherein the extended small base station is compatible with multiple clock sources, and further comprising: the GNSS clock source is in communication connection with the clock selection module through a GNSS receiver, the RS422 clock source is in communication connection with the clock selection module, and the GNSS receiver is embedded in EU and is used for receiving and resolving GNSS messages; the clock source of the GNSS clock source is the global satellite navigation system, support GPS, BDS, GLONASS and GALILEO.

4. The clock synchronization system of claim 1, wherein the extended small base station is compatible with multiple clock sources, and further comprising: the clock selection module, the clock analysis module and the clock holding module are sequentially connected in a communication mode and transmit information and data.

5. A clock synchronization method for an extended small base station compatible with multiple clock sources is characterized by comprising the following steps: when the clock source selection module selects the GNSS clock source, the clock analysis module analyzes the GNSS message, extracts time information, and sends the time information to the time service maintaining module, so that clock information is provided for the RU and the BU.

6. The method for synchronizing clocks of multiple clock sources compatible with an extended small base station as set forth in claim 5, wherein when the GNSS signal is weak or lost, the GNSS receiver switches the clock source to the PTP clock source when the GNSS receiver acquires stable clock information, and further the clock selection module on the EU selects the PTP clock source, the clock module on the BU analyzes and synchronizes clocks with the PTP server, the PTP server serves as a master clock, the BU serves as a slave clock, the clock module of the BU outputs time information to the clock selection module, and the clock analysis module of the EU analyzes and transmits the time information to the time service maintaining module.

7. The method for synchronizing clocks of multiple clock sources compatible with an extended small base station according to claim 5, wherein when there is no stable GPS signal and PTP clock source, an RS422 clock source is selected, the clock source is a base station RU with a shorter distance, when the RS422 clock source is selected by the clock source selecting module, the EU receives a time message from an RS422 port, and the clock analyzing module analyzes and transmits the time message to the time service maintaining module.

8. The method for synchronizing clocks of multiple clock sources compatible with an extended small base station according to claim 5, wherein the switching of the clock sources can be realized manually or automatically, the real-time uploading data is weighted-averaged, the cloud server is uploaded to perform real-time calculation and replacement threshold switching, the threshold updating is obtained by an autonomous algorithm, the device autonomously selects the threshold of each clock source, and the priority of clock source selection is GNSS clock source > PTP clock source > RS422 clock source.

9. A computer readable storage medium storing a computer program, BBU of x86 and arm architecture, which when executed by a processor implements the method according to any one of claims 5 to 8.