WO2016000142A1 - Clock synchronization method, system and related device - Google Patents

Abstract

A clock synchronization method, system and related device, satisfying synchronization requirements between small cell stations, the method comprising: a small cell station determines whether the small cell station is of a first station type or a second station type; if the small cell station is of the first station type, then the clock synchronizes via an external synchronization source; if the small cell station is of the second station type, then the clock synchronizes via a station of the first station type.

Description

 Clock synchronization method, system and related device

Technical field

 The present invention relates to the field of communications technologies, and in particular, to a clock synchronization method, system, and related apparatus.

Background technique

 At present, in order to meet the rapidly growing traffic demand, a large number of base stations can be densely deployed in some indoor or outdoor hotspot areas based on the traditional macro base station cellular network. Taking a small cell (small cell) as an example, in order to ensure normal data transmission between the macro base station and each small base station and between the small base stations, between the small base stations and the small base stations and the macro base stations Need to achieve clock synchronization. Generally, considering a deployment scenario, cost, and implementation complexity, in a densely deployed group of small base stations, network synchronization can be achieved through network listening, that is, some small base stations or macro base stations are synchronized through the outside world. The synchronization signals provided by the source (such as Global Navigation Satellite System (GNSS), IEEE 1588 Ethernet clock synchronization, etc.) obtain clock synchronization, and provide synchronization signals for other small base stations as synchronization sources so that other d and base stations can also implement Clock synchronization. A small base station that obtains clock synchronization through other base stations is referred to as a target base station, a small base station that provides synchronization information for other base stations is referred to as a source base station, and a plurality of small base stations densely deployed in a geographical area are referred to as a cluster ( Cluster ), the clock synchronization needs to be implemented between multiple small base stations included in the cluster. In addition, in order to identify the synchronization status of each small base station, the synchronization level of the small base station may be further defined.

 If each small base station in the cluster can receive the signal sent by the macro base station, all the small base stations in the cluster can select the strongest macro base station as the source base station, and at this time, each target base station listens to the source base station. The quality of the channel experienced by the synchronization signal is better. For example, the signal interference noise ratio (SINR) is higher than -8 dB, that is, the maximum synchronization level of the target base station in the cluster is 1.

 However, in this case, there may be multiple synchronization sources (that is, multiple source base stations) for one cluster. Due to the transmission time deviation between different source base stations and the propagation delay of different source base stations reaching different target base stations, an additional timing estimation error is caused to the clock synchronization between the target base stations, thereby causing different small base stations in the same cluster. The clock synchronization requirement cannot be met.

Summary of the invention Embodiments of the present invention provide a clock synchronization method, system, and related apparatus, which can satisfy clock synchronization requirements between small base stations.

 In a first aspect, the present invention provides a clock synchronization method, which may include:

 The small base station determines that the small base station is the first type of base station or the second type of base station, and when it is determined that the small base station is the first type of base station, the clock synchronization is implemented by the external synchronization source, and if it is determined that the small base station is the second type of base station, A type of base station implements clock synchronization.

 In a first possible implementation manner of the first aspect, the small base station determines that the small base station is the first type of base station or the second type of base station, and specifically includes: the small base station determines the small base station according to the preset selection criterion of the first type of base station. a first type of base station or a second type of base station; wherein the selection criteria of the first type of base station include: determining a small base station equipped with a global navigation satellite system (GNSS) as a first type of base station; and/or, acquiring a clock through the wired network The synchronized small base station is determined to be the first type of base station; and/or the small base station determined to be reliable for clock synchronization is determined to be the first type of base station; and/or the strength of the signal receiving the macro base station is satisfied to be small The base station is determined to be the first type of base station.

 With reference to the first aspect, or the first possible implementation manner of the first aspect, in a second possible implementation manner, determining that the small base station is the second type of base station, performing clock synchronization by using the first type of base station, specifically including The small base station determines that the small base station is the second type of base station; the small base station determines that the other small base stations connected thereto are the first type of base station or the second type of base station through information interaction, and if other small base stations connected thereto are determined to be the first type of base station Then, clock synchronization is implemented by any of the other small base stations connected thereto.

 In conjunction with the second possible implementation of the first aspect, in a third possible implementation manner, the small base station determines, by using the information exchange, the other small base stations connected to the first base station or the second type of base station, including: The small base station determines the type of the interactive information according to the preset selection criteria of the first type of base station; the small base station interacts with other small base stations, extra-cluster macro base stations or network controllers connected thereto according to the type of the interactive information. The small base station determines, according to the interaction information, that the other small base stations connected thereto are the first type of base station or the second type of base station, wherein the other small base stations connected thereto include: other small base stations except the small base station in the cluster, and network control The management manages or moves the management entity for operations.

With reference to the third possible implementation manner of the first aspect, in a fourth possible implementation, the selection criteria of the preset first type of base station are configured according to the following manner, including: receiving configuration information of the network controller, The selection criteria of the first type of base station are configured; or, the receiving and the small base station are wired The configuration information of the macro base station to which the interface and/or the wireless interface are connected is configured to configure a selection criterion of the first type of base station; or, the small base station itself is configured by the factory.

 With reference to the third possible implementation manner of the first aspect, in a fifth possible implementation manner, the selection criterion of the first type of base station includes: determining a small base station that is equipped with a global navigation satellite system (GNSS) as the first type of base station; And/or determining, as a first type of base station, a small base station that acquires clock synchronization through a wired network; and/or determining a small base station determined to be reliable for clock synchronization as a first type of base station; and/or, receiving a macro base station The small base station whose strength of the signal satisfies the preset condition is determined as the first type of base station.

 With the fifth possible implementation of the first aspect, in a sixth possible implementation, the clock synchronization is implemented by using an external synchronization source, which includes: directly acquiring a clock synchronization signal through the GNSS for clock synchronization, or acquiring through a wired network. The clock synchronization signal is clock-synchronized, or the clock synchronization signal is obtained by the reliable base station for clock synchronization, or the clock synchronization signal is obtained by the received signal sent by the macro base station for clock synchronization; the clock synchronization is implemented by the first type of base station, The method includes: acquiring clock synchronization signals by the first type of base station for clock synchronization.

 With reference to the sixth possible implementation of the first aspect, in a seventh possible implementation, the signal of the macro base station includes a primary synchronization signal PSS, a secondary synchronization signal SSS, and a reference signal, where the reference signal includes: a cell-specific reference signal CRS And one or more of a channel state information reference signal CSI-RS, a multimedia broadcast multicast service single frequency network reference signal MBSFN RS, a positioning reference signal PRS, and a discovery reference signal Discovery reference signal.

 With the seventh possible implementation of the first aspect, in an eighth possible implementation, the clock synchronization signal is obtained by using the received signal sent by the macro base station to perform clock synchronization, including: obtaining coarse by using PSS and/or SSS Synchronization; obtaining fine synchronization by reference signal;

 After obtaining the fine synchronization by using the reference signal, the method further includes: providing the indication information to the second type of base station by using the backhaul link or the air interface signaling, so that the second type of base station determines the synchronization status of the first type of base station according to the indication information, and passes the first The class base station obtains the clock synchronization signal; or, by using the backhaul link or the air interface signaling, provides the indication information and the preset validity time to the second type of base station, so that the second type of base station determines the synchronization state of the first type of base station according to the indication information, and The clock synchronization signal is acquired within the preset effective time or is in the network listening state or in the data not transmitting state.

With reference to the fifth possible implementation manner of the first aspect, in a ninth possible implementation manner, the small base station determines, according to a preset selection criterion of the first type of base station, a type of information to be exchanged, including: A type of base station selection criterion is to determine a base station with a GNSS as a first type of base station, and the type of information that the small base station determines to interact includes: a cell identifier cell ID of the small base station and synchronization state information indicating whether the small base station is installed with the GNSS; Alternatively, if the first type of base station selection criterion is to determine the base station that obtains clock synchronization through the wired network as the first type of base station, the type of information that the small base station determines to interact includes: the cell ID of the small base station and whether the small base station is wired. The network obtains the synchronized synchronization state information; or, if the first type of base station selection criterion is to determine the base station that is determined to be reliable for clock synchronization as the first type of base station, the type of information that the small base station determines to interact includes: the cell ID of the small base station and Synchronization status information indicating whether the clock synchronization of the small base station is reliable.

 With reference to the fifth possible implementation manner of the first aspect, in a tenth possible implementation manner, the small base station determines, according to a preset selection criterion of the first type of base station, a type of information to be exchanged, including: The base station selection criterion is that the base station that determines the strength of the signal of the macro base station that meets the preset condition is determined as the first type of base station, and the information type that the small base station determines to interact includes: the cell ID of the small base station, and the received signal strength exceeds the first The cell ID of the macro base station corresponding to the macro base station signal of the preset threshold, and the size of the macro base station signal whose received signal strength exceeds the first preset threshold.

 With reference to the tenth possible implementation manner of the first aspect, in the eleventh possible implementation manner, if the first type of base station selection criterion is that the base station that receives the strength of the signal received by the macro base station meets the preset condition, the base station determines A type of base station, the small base station obtains the type of information to be exchanged according to the following manner: the small base station acquires the neighboring cell list information, detects the cell lD of the macro base station from the neighboring cell list information, and the small base station indicates the indication in the received neighboring cell list information. The strength of the signal sent by all other small base stations is detected, and the detection result is obtained. From the detection result, the size of the macro base station signal whose received signal strength exceeds the first preset threshold is determined, and the cell ID of the macro base station is obtained. And determining a cell ID of the macro base station corresponding to the macro base station signal whose signal strength exceeds the first preset threshold.

With reference to the tenth possible implementation manner of the first aspect, in the twelfth possible implementation, if the first type of base station selection criterion is that the base station that receives the strength of the signal received by the macro base station meets the preset condition, the base station determines A type of base station, the small base station obtains the type of information to be exchanged based on the following manner: the small base station acquires the neighboring cell list information, detects the cell lD of the macro base station from the neighboring cell list information, and the small base station indicates the cell ID of the received macro base station. The strength of the signal sent by the macro base station is detected, and the detection result is obtained. From the detection result, the size of the macro base station signal whose received signal strength exceeds the first preset threshold is determined, and the macro base station corresponding to the macro base station signal is determined. Cell ID. With reference to the first possible implementation manner or the fifth possible implementation manner of the first aspect, in the thirteenth possible implementation manner, the small base station that receives the strength of the signal of the macro base station that meets the preset condition is determined as The first type of base station includes: determining, by the small base station that receives the macro base station, the signal strength of the small base station as the first type of base station; or determining, by the small base station that receives the macro base station, the signal strength that exceeds the second preset threshold is a candidate a first type of base station; determining, according to the candidate first type of base station, a number of candidate first type of base stations whose signal strength received from the same macro base station exceeds a third preset threshold; and the number of candidate first type of base stations is correspondingly the most The macro base station determines the source base station that provides clock synchronization for the first type of base station, and determines the candidate first type base station that receives the signal strength exceeding the third predetermined threshold from the macro base station as the first type of base station.

 With reference to the first aspect, the first to thirteenth possible implementation manners of the first aspect, in the fourteenth possible implementation manner, if the method further includes: receiving configuration information of the network controller Configuring a maximum synchronization level N allowed in the cluster, N is a positive integer; or receiving configuration information of a macro base station connected to the small base station via a wired interface and/or a wireless interface, and the maximum synchronization level N allowed in the cluster is performed. Configuration; or, through the small base station itself factory configuration.

 In a second aspect, the present invention provides a clock synchronization method, which may include:

 The identity information of each small base station is configured as a first type of base station or a second type of base station, so that each small base station performs clock synchronization according to the identity information, where the first type of base station directly implements clock synchronization through an external synchronization source, and the second type of base station is not. Clock synchronization is achieved directly through an external synchronization source.

 In a first possible implementation manner of the second aspect, configuring the identity information of each small base station to be the first type of base station or the second type of base station, the method includes: configuring, by the network controller, each of the preset first type of base station selection criteria The identity information of the small base station is a first type of base station or a second type of base station, and the network controller is an operation management maintenance or mobility management entity; or the macro base station configures identity information of each small base station according to a preset first type of base station selection criterion. For the first type of base station or the second type of base station, the macro base station is connected to each small base station via a wired interface and/or a wireless interface.

 With reference to the first possible implementation manner of the second aspect, in a second possible implementation manner, the first type of base station selection criterion includes: selecting one or more of the small base stations connected to the network controller or the macro base station The small base stations are determined to be the first type of base stations.

 In a third aspect, the present invention provides a small base station, which may include:

 a determining unit, configured to determine that the small base station is a first type of base station or a second type of base station;

a processing unit, configured to: when the determining unit determines that the small base station is the first type of base station, The source implements clock synchronization. If it is determined that the small base station is the second type of base station, clock synchronization is implemented by the first type of base station.

 In a first possible implementation manner of the third aspect, the determining unit is configured to determine, according to the preset selection criterion of the first type of base station, that the small base station is the first type of base station or the second type of base station; The selection criteria of the class base station include: determining the small base station equipped with the global navigation satellite system GNSS as the first type of base station; and/or determining the small base station acquiring the clock synchronization through the wired network as the first type of base station; and/or, The small base station determined to be reliable for clock synchronization is determined as the first type of base station; and/or the small base station that receives the strength of the signal of the macro base station that satisfies the preset condition is determined as the first type of base station.

 With reference to the third aspect, or a possible implementation manner of the third aspect, in a second possible implementation manner, the processing unit is further configured to: when the determining unit determines that the small base station is the second type of base station, And determining that the other small base stations connected to the small base station are the first type of base station or the second type of base station, and if the other small base stations connected to the small base station are determined to be the first type of base stations, the other small base stations connected to the small base station are used. A small base station implements clock synchronization.

 With the second possible implementation of the third aspect, in a third possible implementation, the processing unit includes: a first processing sub-unit, configured to determine an interaction according to a preset selection criterion of the first type of base station a type of information; a second processing sub-unit, configured to interact with other small base stations, macro base stations, or network controllers connected to the small base station according to the type of information exchanged, to obtain interaction information; and a third processing sub-unit, configured to: According to the interaction information, the other small base stations connected to the small base station are determined to be the first type of base station or the second type of base station, where the other small base stations connected to the small base station include: other small base stations except the small base station in the cluster; Manage administrative or mobile management entities for operations management.

With reference to the third possible implementation manner of the third aspect, in a fourth possible implementation manner, the selection criterion of the first type of base station includes: determining a small base station that is equipped with a global navigation satellite system (GNSS) as the first type of base station; And/or determining, as a first type of base station, a small base station that acquires clock synchronization through a wired network; and/or determining a small base station determined to be reliable for clock synchronization as a first type of base station; and/or, receiving a macro base station The small base station whose strength meets the preset condition is determined to be the first type of base station, wherein the signal of the macro base station includes a primary synchronization signal PSS, a secondary synchronization signal SSS, and a reference signal, and the reference signal includes: a cell-specific reference signal CRS, a channel state One or more of the information reference signal CSI-RS, the multimedia broadcast multicast service single frequency network reference signal MBSFN RS, the positioning reference signal PRS, and the discovery reference signal Discovery reference signal. With the fourth possible implementation manner of the third aspect, in a fifth possible implementation manner, clock synchronization is implemented by using an external synchronization source, which includes: directly acquiring a clock synchronization signal by using GNSS for clock synchronization, or acquiring through a wired network. The clock synchronization signal is clock-synchronized, or the clock synchronization signal is obtained by the reliable base station for clock synchronization, or the clock synchronization signal is obtained by the received signal sent by the macro base station for clock synchronization; the clock synchronization is implemented by the first type of base station, The method includes: acquiring clock synchronization signals by using the first type of base station to perform clock synchronization; wherein, obtaining clock synchronization signals by using the signals sent by the macro base station to perform clock synchronization, including: acquiring coarse synchronization through PSS and/or SSS; acquiring by reference signals Fine synchronization; providing indication information to the second type of base station by using a backhaul link or air interface signaling, so that the second type of base station determines the synchronization status of the first type of base station according to the indication information, and acquires the time synchronization clock synchronization signal by using the first type of base station. Or through the backhaul link Or the air interface signaling provides the indication information and the preset validity time to the second type of base station, so that the second type of base station determines the synchronization status of the first type of base station according to the indication information, and acquires a clock synchronization signal or is in the network within a preset effective time. Listening state or being in a data not sending state.

 With reference to the fourth possible implementation manner of the third aspect, or the fifth possible implementation manner, in a sixth possible implementation manner, the first processing sub-unit is configured to: if the first type of base station selection criterion is to be installed The base station of the GNSS is determined to be the first type of base station, and the type of information that the small base station determines to interact includes: a cell identifier cell ID of the small base station and synchronization state information indicating whether the small base station is installed with the GNSS; or, if the first type of base station selects the criterion The determining, by the small base station, the type of the information to be exchanged includes: a cell ID of the small base station and synchronization state information indicating whether the small base station acquires synchronization through the wired network; or If the first type of base station selection criterion is to determine the base station that is determined to be reliable for clock synchronization as the first type of base station, the type of information that the small base station determines to interact includes: the cell ID of the small base station and whether the clock synchronization of the small base station is reliable. Synchronization status information; or, if the first type of base station selection criterion is strong for the signal to be received by the macro base station The base station that meets the preset condition is determined to be the first type of base station, and the type of information that the small base station determines to interact includes: a cell ID of the small base station, and a macro base station corresponding to the macro base station signal whose received signal strength exceeds the first preset threshold. The cell ID, and the size of the macro base station signal whose received signal strength exceeds the first preset threshold.

With reference to the sixth possible implementation manner of the third aspect, in a seventh possible implementation, the small base station that receives the strength of the signal of the macro base station that meets the preset condition is determined to be the first type of base station, including: The small base station with the highest signal strength of the obtained macro base station is determined to be the first type of base station; or, it will receive The small base station that exceeds the second preset threshold value of the macro base station is determined as the candidate first type base station; and based on the candidate first type base station, determines that the signal strength received from the same macro base station exceeds the third preset threshold The number of candidate first-class base stations is determined; the macro base station corresponding to the maximum number of candidate first-class base stations is determined as a source base station that provides clock synchronization to the first-type base station, and the received signal strength from the macro base station exceeds a third preset width. The candidate first type of base station of the value is determined to be the first type of base station.

 With reference to the third aspect, or any one of the first to the seventh aspects of the third aspect, in the eighth possible implementation, the small base station further includes: a configuration unit, configured to receive the network controller The configuration information is configured to configure a maximum synchronization level N allowed in the cluster, where N is a positive integer; or, receiving configuration information of a macro base station connected to the small base station via a wired interface and/or a wireless interface, and a maximum synchronization level allowed in the cluster N is configured; or, it is configured by the small base station itself.

 In a fourth aspect, the present invention provides a clock synchronization apparatus, which may include:

 The configuration unit is configured to configure the identity information of each small base station to be a first type of base station or a second type of base station, so that each small base station performs clock synchronization according to the identity information, where the first type of base station directly implements clock synchronization by using an external synchronization source. The second type of base station is a base station that does not directly synchronize clocks through an external synchronization source.

 In a first possible implementation manner of the fourth aspect, the method further includes: if the clock synchronization device is a network controller, the configuration unit is configured to configure identity information of each small base station according to the preset first type of base station selection criterion For the first type of base station or the second type of base station, the network controller is an operation management maintenance or mobility management entity; if the clock synchronization device is a macro base station, the configuration unit is configured to configure each according to a preset first type of base station selection criterion The identity information of the small base station is a first type of base station or a second type of base station, and the macro base station is connected to each small base station via a wired interface and/or a wireless interface.

 With reference to the first possible implementation manner of the fourth aspect, in a second possible implementation manner, the first type of base station selection criterion includes: selecting one or more of the base stations connected to the network controller or the macro base station The small base station is determined to be the first type of base station.

 With reference to the fourth aspect, the first possible implementation manner of the fourth aspect, or the second possible implementation manner, in a third possible implementation manner, the configuration unit is further configured to send configuration information to the small base station, so that The base station configures the maximum synchronization level N allowed in the cluster according to the configuration information, where N is a positive integer.

In a fifth aspect, the present invention provides a clock synchronization system, which may include: Any small base station, and any of the clock synchronization devices as provided in the fourth aspect.

 It can be seen from the above technical solutions that the clock synchronization method, system and related device provided by the embodiments of the present invention have the following advantages: in the embodiment of the present invention, the small base station can determine that it is the first type of base station or the second type of base station, when determining When the small base station is the first type of base station, the clock synchronization is implemented by the external synchronization source. If it is determined that the small base station is the second type of base station, the clock synchronization is implemented by the first type of base station, so that clock synchronization can be satisfied between each d and the base station. demand. DRAWINGS

 In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the present invention, Those skilled in the art can obtain other drawings according to these drawings without paying any creative work.

 1 is a schematic flowchart of a clock synchronization method according to an embodiment of the present invention;

 2 is a schematic structural diagram of a small base station according to an embodiment of the present invention;

 3 is another schematic structural diagram of a small base station according to an embodiment of the present invention;

 4 is a schematic structural diagram of a clock synchronization apparatus according to an embodiment of the present invention;

 FIG. 5 is a schematic structural diagram of a clock synchronization system according to an embodiment of the present invention; FIG.

 FIG. 6 is another schematic structural diagram of a small base station according to an embodiment of the present invention.

detailed description

 Embodiments of the present invention provide a clock synchronization method, system, and related apparatus, which can satisfy clock synchronization requirements between small base stations.

 The technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. The embodiments are merely a part of the embodiments of the invention, and not all of the embodiments. All other embodiments obtained by a person skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

The terms "first", "second", "third", "fourth", etc. (if present) in the specification and claims of the present invention and the above figures are used to distinguish similar objects without being used for Describe a specific order or order. It should be understood that the data used in this way can be interchanged where appropriate, so here The described embodiments of the invention can be implemented, for example, in a sequence other than those illustrated or described herein. In addition, the terms "comprises" and "comprises" and "comprises" and "includes" or "includes" or "comprises" or "comprises" or "comprises" Those steps or units may include other steps or units not explicitly listed or inherent to such processes, methods, products or devices.

 The detailed description will be respectively made below through specific embodiments. The method is applied to the LTE/LTE-A wireless communication system as an example for analysis and description, and does not constitute a limitation of the present invention.

 The embodiment of the present invention provides a clock synchronization method, where the execution entity of the clock synchronization method may be a small cell (small cell), and the small base station may be any small base station.

 A clock synchronization method may specifically include: the small base station determines that the small base station is the first type of base station or the second type of base station, and when it is determined that the small base station is the first type of base station, the clock synchronization is implemented by using an external synchronization source, if it is determined to be small The base station is a second type of base station, and clock synchronization is implemented by the first type of base station.

 Referring to FIG. 1, FIG. 1 is a schematic flowchart of a clock synchronization method according to an embodiment of the present invention. For example, the method may include the following steps:

 Step 101: The small base station confirms its identity information, where the identity information of the small base station includes: a first type of base station or a second type of base station;

 It is easy to understand that in a macro base station (also referred to as a macro cell) cellular network, a large number of small cells (small cells, or small base stations) are densely deployed in some indoor or outdoor hotspot areas, wherein the form of the small base station can be Including: Metro cell, Micro cell, Pico cell, Femto cell, and Wireless LAN using Wi-Fi (Wireless Fidelity) technology (WLAN) , Wireless Local Area Networks ) and so on. The small base station has the characteristics of low transmission power and small coverage.

 In the embodiment of the present invention, the identity information of the small base station is classified into two types, that is, the first type base station and the second type base station. The first type of base station is a small base station that implements clock synchronization through an external synchronization source, and the second type of base station is a small base station that does not directly synchronize clocks through an external synchronization source, that is, the second type of base station can implement clock synchronization through the first type of base station. Small base station.

After the small base station confirms its identity information, it can perform small base stations according to its own identity information. The clock is synchronized, as shown in step 102.

 Step 102: The small base station performs clock synchronization according to its own identity information. When the small base station is the first type of base station, the clock synchronization is implemented by using the external synchronization source. When the small base station is the second type of base station, the small base station is implemented by the first type of base station. Clock synchronization.

 It should be noted that, in the present invention, a plurality of small base stations densely deployed in a geographical area are referred to as a cluster.

(cluster), the macro base station and the small base station in the cluster have a wired or wireless interface.

 It should be understood that, in order to ensure normal data transmission between the macro base station and each small base station and each small base station, a clock needs to be implemented between each small base station included in the cluster, and between the small base station and the macro base station in the cluster. Synchronize.

 For example, network synchronization can be implemented by network listening, that is, the small base station that is itself the first type of base station obtains clock synchronization through the synchronization signal provided by the external synchronization source, and provides synchronization signals for other small base stations as a synchronization source. This allows other small base stations to also implement clock synchronization.

 The external synchronization source may specifically include: a macro base station, a Global Navigation Satellite System (GNSS), and a wired network clock synchronization method (for example, IEEE 1588 Ethernet clock synchronization). In practical applications, GNSS may include Global Positioning System (GPS), Beidou satellite navigation system, and the like. The embodiment of the present invention analyzes and describes the method by using the external synchronization source as a macro base station or a GPS as an example, and does not constitute a limitation of the present invention.

 The clock synchronization is implemented between the small base stations and the small base station and the macro base station, which can further enhance the inter-cell interference cancellation technology, the coordinated multi-point technology between the base stations, the carrier aggregation technology, the small base station fast discovery technology, and the single uplink. Implementation of dual link technology and advanced receiver technology for RF links. Moreover, if the small base station and the macro base station use the Time Division Duplex (TDD) mode, the clock synchronization can avoid uplink and downlink interference between the small base stations and between the small base station and the macro base station.

 Clock synchronization includes frequency synchronization and time synchronization. Specifically, the frequency synchronization between each small base station and between the small base station and the macro base station means that the output frequency error of each small base station is within a set threshold; between the small base stations, and the small base station and the Acer base Time synchronization between stations means that the deviation between the transmission timings of the small base stations is within the set threshold, or the deviation between the transmission timings of the small base stations and the macro base stations is within the set threshold.

It can be seen from the above that the small base station confirms its own identity information, and if it is the first type of base station, it passes through the outside world. The step source implements clock synchronization. If the second type of base station is used, clock synchronization is implemented by the first type of base station, so that the clock synchronization source of the small base station in the cluster has the same timing reference point and/or frequency reference point, and Ensure that the small base station listens to the synchronization signal (such as the Network Listening Reference Signal, NLRS) with a good SINR, so that different small base stations in the same cluster, and between the small base station and the macro base station are satisfied. Clock synchronization requirements. Further, it should be understood that a small base station that obtains clock synchronization by other small base stations or macro base stations is referred to as a target base station, and a small base station or macro base station that provides synchronization signals for other small base stations is referred to as a source base station. The target base station obtains clock synchronization through the source base station, and the source base station provides a synchronization signal to the target base station so that the target base station acquires clock synchronization according to the synchronization signal. It should be understood that the first type of base station may be the source base station or the target base station, and the second type of base station is the target base station.

 The first type of base station and the second type of base station maintain clock synchronization with the source base station using a predefined network listening pattern. The network listening pattern refers to at least one of a time domain resource, a frequency domain resource, and a sequence resource used by the target base station to perform network monitoring when the source base station acquires clock synchronization, or may also be used by the source base station to send the NLRS. At least one of the time domain resource, the frequency domain resource, and the sequence resource, in the clock synchronization method, if the small base station determines that the identity information is the first type of base station, the clock synchronization may be implemented by using a GNSS or a wired clock synchronization method. Alternatively, the preset network listening pattern may be used to maintain clock synchronization with the source base station, or the information of the source base station may be determined by interaction with the source base station, and the network listening pattern and the source base station may be used to maintain clock synchronization. The information interaction here may be through wired information interaction or wireless information interaction. If the small base station determines that the identity information of the second base station is the second type of base station, and determines that the other small base stations connected thereto are the first type of base stations through information interaction, any one of the other small base stations that are connected to the small base station and determined to be the first type of base station The small base station may notify the small base station of the NLRS format in an interactive manner, so that the small base station determines the network listening pattern of the small base station according to the NLRS format, and then uses the determined network listening pattern and the source base station (ie, notifies the small base station of the NLRS format) And the small base station connected to the small base station) keeps clock synchronization.

 Further, in the foregoing step 101, the small base station determines that the small base station is the first type of base station or the second type of base station, and the method may include: determining, by the small base station, the small base station as the first type of base station according to the preset selection criterion of the first type of base station. Or a second type of base station.

The selection criteria for the first type of base station may include: GNSS to be installed with the global navigation satellite system The small base station is determined to be the first type of base station; and/or the small base station that acquires clock synchronization through the wired network is determined to be the first type of base station; and/or the small base station determined to be reliable for clock synchronization is determined as the first type of base station And/or, the small base station that receives the strength of the signal of the macro base station that satisfies the preset condition is determined as the first type of base station.

 In some embodiments, when the selection criterion of the preset first type of base station is: when the small base station equipped with the global navigation satellite system GNSS is determined as the first type of base station, then when the small base station is equipped with the GNSS, the small The base station determines that the small base station is a first type of base station.

 When the selection criterion of the preset first type of base station is: when the small base station that acquires clock synchronization through the wired network is determined to be the first type of base station, when the small base station acquires clock synchronization through the wired network, the small base station determines that the small base station is The first type of base station.

 When the selection criterion of the preset first type of base station is: determining that the small base station that is reliable for clock synchronization is determined to be the first type of base station, when the small base station determines that the clock synchronization is reliable, the small base station determines that the small base station is the first Class base station.

 When the selection criterion of the preset first type of base station is: when the small base station that receives the strength of the signal of the macro base station meets the preset condition is determined as the first type of base station, the small base station selects according to the preset first type of base station. The criterion, the determining that the small base station is the first type of base station or the second type of base station, may include: the small base station interacts with the macro base station, so that the macro base station sends the acknowledgement information to the small base station, where the acknowledgement information carries the small base station to receive the Whether the strength of the macro base station signal satisfies the message of the preset condition. The small base station can determine that the small base station is the first type of base station or the second type of base station according to the received confirmation information. In addition, the small base station may also interact with the network controller, so that the network controller sends the acknowledgement information to the small base station, where the acknowledgement information carries a message that the base station receives the macro base station signal strength to meet the preset condition.

Specifically, if the macro base station determines the small base station with the highest signal strength of the received macro base station as the first type of base station, the small base station may be determined to be the first type of base station or the second type of base station by: small base station and macro base station Interacting, so that the macro base station receives the strength of the macro base station signal for the small base station, and the strength of the other small base station receiving the signal by the macro base station to receive the macro base station signal, to determine whether the small base station receives the macro base. The signal strength of the station is the largest, and the determination message carrying the determination result is sent to the small base station, so that the small base station determines that it is the first type of base station or the second type of base station. When the small base station interacts with the network controller, the macro base station may receive the strength of the macro base station signal of the small base station, and sort the strength of the macro base station signal received by the other small base station receiving the signal by the macro base station, and The sorting result is sent to the network controller, and the network controller determines whether the small base station receives the macro base station with the highest signal strength, and the network controller sends the determination message carrying the determination result to the small base station, so that the small base station determines itself. It is a first type of base station or a second type of base station. Let me repeat.

 Further, in the foregoing step 102, when it is determined that the small base station is the second type of base station, the clock synchronization is implemented by the first type of base station, which may be implemented by:

 Step 1021: The small base station determines that the small base station is the second type of base station;

 Step 1022: The small base station determines, by using information interaction, that the other small base stations connected thereto are the first type of base station or the second type of base station, and if other small base stations connected thereto are determined to be the first type of base stations, pass through other small base stations connected thereto. Any of the small base stations implements clock synchronization.

 Further, in step 1022, the small base station determines, by using the information exchange, the other small base stations connected to the first base station or the second type of base station, which may include:

 Step 1022-1: The small base station determines, according to a preset selection criterion of the first type of base station, a type of information to be exchanged;

 Step 1022-2: The small base station interacts with other small base stations, macro base stations, or network controllers connected thereto according to the type of the information to be exchanged, to obtain interaction information.

 For example, information can be exchanged by means of backhaul or air interface signaling. Step 1022-3: The small base station determines, according to the interaction information, that the other small base stations connected thereto are the first type of base station or the second type of base station, and the other small base stations connected thereto include: other small base stations except the small base station in the cluster, The network controller maintains or manages the entity for operational management.

 It should be noted that, in step 1022-2, the small base station may interact with any one or more of the other small base stations, the macro base station, and the network controller connected thereto according to the type of the interactive information. Interactive information. Step 1022-2 is a preferred embodiment and does not constitute a limitation of the present invention.

 The selection criteria for the first type of base station in step 1022-1 may be configured based on any of the following modes:

Manner 1: The network controller sends configuration information to each small base station, so that each small base station configures a selection criterion of the first type of base station according to the configuration information. Specifically, the network controller configures each deployed small base station in the cluster according to the first type of base station selection criterion, where the network controller is a functional entity that manages and maintains the small base station, and the 1" column can be OAM (Operation Administration and Maintenance), or Mobility Management Entity (MME).

 Manner 2: The macro base station connected to each small base station via a wired interface and/or a wireless interface sends configuration information to each small base station, so that each small base station configures a selection criterion of the first type of base station according to the configuration information.

 Specifically, for example, when the macro base station and the cluster belong to the same operator, the macro base station may configure the selection criteria of the first type of base station in the cluster by means of air interface signaling or by means of a backhaul link. Give each small base station in the cluster.

 The third method is configured by the small base station itself, for example, by the factory to implement the configuration. It should be noted that if the small base stations in the cluster belong to different operators, the same configuration content needs to be used by different operators, so that the configurations of the small base stations in the cluster are consistent. For example, different operators have the same selection criteria for the first type of base stations in the cluster.

 When the selection criterion of the first type of base station is configured in the method, in step 1022-1, the small base station determines the type of the information to be exchanged according to the preset selection criterion of the first type of base station, which may be: Interacting with the network controller, so that the small base station receives the indication information sent by the network controller to determine the type of information exchanged.

 When the selection criterion of the first type of base station is configured in the second mode, in step 1022-1, the small base station determines the type of the interaction information according to the preset selection criterion of the first type of base station, which may be: And interacting with the macro base station, so that the small base station receives the indication information sent by the macro base station to determine the type of the interactive information.

 When the selection criterion of the first type of base station is configured in the third mode, in step 1022-1, the small base station determines the type of the information to be exchanged according to the selection criterion of the preset first type of base station, which may be specifically configured by the small base station. Self-factory configuration, confirm the type of information exchanged.

 In some embodiments, the selection criteria for the first type of base station in step 1022-1 comprises: determining the small base station equipped with the global navigation satellite system GNSS as the first type of base station;

And/or determining, as the first type of base station, the small base station that acquires clock synchronization through the wired network; and/or determining the small base station determined to be reliable for clock synchronization as the first type of base station; And/or determining, by the small base station that receives the strength of the signal of the macro base station that meets the preset condition, as the first type of base station.

 The following is a detailed description of the implementation of the first type of base station using the following four different selection criteria:

 The first type of base station selection criterion is: the small base station equipped with the GNSS GNSS is determined as the first type of base station, and correspondingly, step 1022 may specifically include:

 Step a. The small base station determines, according to the preset selection criteria of the first type of base station, the type of the information to be exchanged: the cell ID of the small base station, and the synchronization status information indicating whether the small base station is installed with the GNSS;

 Step b: The small base station interacts with other small base stations, macro base stations or network controllers connected thereto according to the type of information determined in step a;

 For example, information can be exchanged by means of backhaul or air interface signaling. If the small base station interacts with the network controller or the macro base station, the small base station determines, according to the received indication information sent by the network controller or the macro base station, other small base stations connected thereto as the first type of base station or the second type of base station; The base station interacts with other small base stations connected thereto, and determines, according to the interaction information obtained by the interaction and the selection criterion of the preset first type of base station, that the other small base stations connected thereto are the first type of base station or the second type of base station.

Step _c : The small base station determines, according to the interaction information, that the other small base stations connected thereto are the first type of base station or the second type of base station;

 Specifically, the small base station can know whether the small base station itself installs the GNSS (for example, GPS) by using the type of the information of the interaction in the step b, and can know whether the GPS is installed in other small base stations connected to the small base station, and thus can determine the small The identity information of the base station can also determine the identity information of other small base stations connected to the small base station. If the small base station is equipped with GPS, the small base station is the first type of base station, and if other small base stations connected to the small base station are installed with GPS, the other small base stations connected to the small base station are the first type of base station.

 Step d: If the small base station determines that the other small base stations connected thereto are the first type of base stations, the clock synchronization is implemented by obtaining a clock synchronization signal of any small base station determined to be the first type of base station connected thereto.

Criterion 2: When the first class of base station selection criteria is: A small base that will acquire clock synchronization through a wired network. The station is determined to be the first type of base station, and correspondingly, the step 1022 may specifically include:

 Step a. The small base station determines, according to the preset selection criteria of the first type of base station, the type of the information to be exchanged: the cell ID of the small base station, and the synchronization state information indicating whether the small base station is synchronized through the wired network;

 Step b: The small base station interacts with other small base stations, macro base stations or network controllers connected thereto according to the type of information determined in step a;

 For example, information can be exchanged by means of backhaul or air interface signaling. If the small base station interacts with the network controller or the macro base station, the small base station determines, according to the received indication information sent by the network controller or the macro base station, other small base stations connected thereto as the first type of base station or the second type of base station; The base station interacts with other small base stations connected thereto, and determines, according to the interaction information obtained by the interaction and the selection criterion of the preset first type of base station, that the other small base stations connected thereto are the first type of base station or the second type of base station.

Step _c : The small base station determines, according to the interaction information, that the other small base stations connected thereto are the first type of base station or the second type of base station;

 Specifically, the small base station can learn whether the small base station acquires the synchronized synchronization state information through the wired network by using the type of the information of the interaction in the step b, and can learn whether other small base stations connected to the small base station acquire synchronization through the wired network. The synchronization status information can further determine the identity information of the small base station, and can also determine the identity information of other small base stations connected to the small base station. If the small base station acquires synchronization through the wired network, the small base station is the first type of base station, and if the other small base stations connected to the small base station acquire synchronization through the wired network, the other small base stations connected to the small base station are the first type of base stations. .

 Step d: If the small base station determines that the other small base stations connected thereto are the first type of base stations, the clock synchronization is implemented by obtaining a clock synchronization signal of any small base station connected thereto.

 The third criterion is that the first type of base station selection criterion is: determining the small base station that is determined to be reliable for clock synchronization as the first type of base station, and correspondingly, step 1022 may specifically include:

 It should be understood that the clock synchronization of the small base station considering the relative clock synchronization relationship with other small base stations is considered to be reliable, and the clock synchronization of the small base station which does not consider the relative clock synchronization relationship with other small base stations is considered to be unreliable. For example, a small base station deployed in isolation, whose clock synchronization can be considered unreliable.

The definition of whether the clock synchronization is reliable can also be: it will be able to directly connect to the source through the external synchronization or between The small base station that obtains the clock information through the external synchronization source is considered to be a small base station with reliable clock synchronization, wherein the clock information is directly obtained through the external synchronization source, which means that the small base station can directly from the GNSS, such as GPS, Beidou satellite navigation system, or The wired network (for example, the IEEE1588 clock synchronization protocol and the Ethernet clock synchronization protocol) acquires clock information; the indirect acquisition of the clock information by the external synchronization source means that the small base station obtains the clock information of the external synchronization source through other small base stations or macro base stations, for example, small The base station A obtains the clock synchronization directly through the external synchronization source, and the small base station B acquires the clock synchronization through the small base station A. Then, the clock synchronization of the small base station B belongs to the synchronization information obtained by the external synchronization source indirectly, that is, it can also be considered as reliable.

 The definition of whether the clock synchronization is reliable or not can also be that the clock synchronization of the synchronized small base station is considered to be reliable, and the clock synchronization of the unsynchronized (or out of synchronization) small base station is considered to be unreliable.

 The definition of whether the clock synchronization is reliable or not can also be: The clock synchronization of the small base station directly or indirectly through the GNSS and the wired network is considered to be reliable, and the clock synchronization of the small base station that is not directly or indirectly passed through the GNSS or the wired network is considered to be unreliable. For example, any of the small base stations deployed in isolation or one cluster of small base stations deployed in isolation.

 The definition of whether the clock synchronization is reliable may also be: The clock synchronization of the small base station whose clock source is GNSS, the wired network, and the synchronization small base station is considered to be reliable; otherwise, it is considered to be unreliable, for example, the isolated deployment d, the base station Or any one of the clusters of small base stations deployed in isolation, the base station.

 Whether the clock synchronization is reliable or not can be defined according to other rules. For example, it can also be defined as: Any small base station that satisfies any of the above definitions of "clock synchronization unreliable" is considered to be unreliable; or as long as any of the above is satisfied A small base station with the definition of "clock synchronization reliable" is considered to be reliable. The above embodiments are not intended to limit the invention.

 Step a: The small base station determines, according to the preset selection criterion of the first type of base station, the type of the information to be exchanged: a cell ID of the small base station, and synchronization state information indicating whether the clock synchronization of the small base station is reliable; Step b, the small base station according to The type of the interactive information determined in step a, interacting with other small base stations, macro base stations or network controllers connected thereto;

If the small base station interacts with the network controller or the macro base station, the small base station determines, according to the received indication information sent by the network controller or the macro base station, other small base stations connected thereto as the first type of base station or the second type of base station; The base station interacts with other small base stations connected thereto, and determines, according to the interaction information obtained by the interaction and the selection criterion of the preset first type of base station, that the other small base stations connected thereto are the first Class base station or second type base station.

Step _c : The small base station determines, according to the interaction information, that the other small base stations connected thereto are the first type of base station or the second type of base station;

 Specifically, the small base station can know whether the small base station itself is clock synchronous and reliable, and can know that the clock synchronization of other small base stations connected to the small base station is reliable, and thus can determine the identity information of the small base station. The identity information of other small base stations connected to the small base station can be determined. If the clock synchronization of the small base station is reliable, the small base station is the first type of base station. If the clock synchronization of other small base stations connected to the small base station is reliable, the other small base stations connected to the small base station are the first type of base station.

 Step d: If the small base station determines that the other small base stations connected thereto are the first type of base stations, the clock synchronization is implemented by obtaining a clock synchronization signal of any small base station connected thereto.

 The fourth criterion is: when the first type of base station selection criterion is: the small base station that receives the strength of the signal received by the macro base station meets the preset condition, and determines that the first type of base station acquires the clock synchronization signal of any small base station connected thereto to implement clock synchronization. :

 Step a: The small base station determines, according to the preset selection criterion of the first type of base station, the type of the information to be exchanged: the cell ID of the small base station, and the macro base station signal whose received signal strength exceeds the first preset threshold. a cell ID of the macro base station, and a size of the macro base station signal whose received signal strength exceeds the first preset threshold;

 Step b: The small base station interacts with other small base stations, macro base stations or network controllers connected thereto according to the type of information determined in step a;

 If the small base station interacts with the network controller or the macro base station, the small base station determines, according to the received indication information sent by the network controller or the macro base station, other small base stations connected thereto as the first type of base station or the second type of base station; The base station interacts with other small base stations connected thereto, and determines, according to the interaction information obtained by the interaction and the selection criterion of the preset first type of base station, that the other small base stations connected thereto are the first type of base station or the second type of base station.

 Step c: The small base station determines, according to the interaction information, that the other small base stations connected thereto are the first type of base station or the second type of base station;

Specifically, the small base station can learn the strength of the signal received by the small base station from the macro base station by using the type of the information of the interaction of the step b, and can also know the strength of the signal received by the other small base station connected to the small base station from the macro base station. In turn, the identity information of the small base station can be determined, and the small base station can also be determined to be connected. Identity information of other small base stations. If the strength of the signal received by the small base station of the macro base station exceeds the first preset threshold, the small base station is the first type of base station, and if the strength of the signal received by the other small base station connected to the small base station exceeds the first preset For the threshold, the other small base stations connected to the small base station are the first type of base stations.

 Step d: If the small base station determines that the other small base stations connected thereto are the first type of base stations, the clock synchronization is implemented by obtaining a clock synchronization signal of any small base station connected thereto.

 It should be noted that, in the fourth criterion, the strength of the signal received by the macro base station may be the strength of the signal transmitted by the macro base station detected by the small base station. The signals of the macro base station include: a primary synchronization signal PSS (PSS, Primary synchronization signal), a secondary synchronization signal (SSS, Secondary synchronization signal), a cell specific reference signal (CRS), and a channel state information reference signal ( CSI-RS, Channel state information reference signal, Multimedia broadcast multicast service single frequency network reference signal (MBSFN RS, Multimedia broadcast multicast service single frequency network reference signal), Positioning reference signal (PRS), and discovery reference signal One or more of ( Discovery reference signal ). The signal strength of the macro base station may be represented by the energy or power of the signal of the macro base station, or the reference signal received power (RSRP, Reference signal received power) or the reference signal measured by using the signal of the macro base station. Receive quality (RSRQ, Reference signal received quality) is reflected.

 Further, acquiring clock synchronization by using the signal sent by the received macro base station may specifically include: acquiring coarse synchronization by using PSS and/or SSS;

 Fine synchronization is obtained by reference signals.

 It should be understood that the first type of base station may not provide the synchronization signal for the second type of base station before acquiring the clock synchronization, and the small base stations in the cluster may not serve the user equipment before the clock synchronization is implemented. In addition, when the second type of base station acquires clock synchronization through the first type of base station, the interference experienced by the second type of base station during network listening should be reduced as much as possible. Specifically, it may include:

 One implementation manner is that after obtaining fine synchronization through the reference signal, the method further includes:

Providing indication information to the second type of base station by using a backhaul link or air interface signaling, so that the second type of base station determines the synchronization status of the first type of base station according to the indication information, and acquires time synchronization by using the first type of base station; Yes, after obtaining fine synchronization through the reference signal, it also includes: Providing the indication information and the preset effective time to the second type of base station by using the backhaul link or the air interface signaling, so that the second type of base station determines the synchronization status of the first type of base station according to the indication information, and acquires the time synchronization within the preset effective time. Either in the network listening state or in the data not sending state.

 The preset effective time is set to indicate that all the second type of base stations are synchronized with the clock of the first type of base station within the valid time, or are in a network listening state, or are in a data non-transmitting state. Then, it is ensured that the second type of base station acquires the synchronization signal from the first type of base station after acquiring the synchronization of the first type of base station, and ensures that the second type of base station maintains the initial clock synchronization with the first type of base station, and the other The second type of base station does not transmit signals, thereby reducing interference.

 Further, in criterion four, for all other small base stations indicated in the neighboring cell list information, the small base station can obtain the type of the interactive information based on the following method:

 Step A: The small base station acquires neighboring cell list information, and detects a cell ID of the macro base station from the neighboring cell list information.

 Step A2: The small base station detects the strength of the signal sent by all other small base stations indicated in the neighboring cell list information, and obtains the detection result.

 The detection result may be: the strength of the received signal, such as signal energy, signal power, reference signal received power, or reference signal received quality.

 Step A3: Determine, according to the detection result, a size of the macro base station signal whose received signal strength exceeds the first preset threshold, and determine, from the cell ID of the macro base station, that the signal strength exceeds the first preset threshold The cell ID of the macro base station corresponding to the macro base station signal.

 In addition, for the macro base station indicated by the cell ID of the macro base station, the type of the interactive information can also be obtained by the following method:

 Step Bl, the small base station acquires the neighboring cell list information, and detects the cell ID of the macro base station from the neighboring cell list information;

 Step B2: The small base station detects the strength of the signal sent by the macro base station that receives the cell ID indication of the macro base station, and obtains the detection result.

 Step B3: Determine, from the detection result, a size of the macro base station signal whose received signal strength exceeds the first preset threshold, and a cell ID of the macro base station corresponding to the macro base station signal.

It should be noted that, in the fourth criterion, the macro base station connected to the first type of base station in the cluster via the wired interface and/or the wireless interface may be one or more, for example, specifically: First, if the macro base station connected to the first type of base station in the cluster via the wired interface and/or the wireless interface is one, then the small base station that satisfies the preset condition that the strength of the signal received by the macro base station meets the preset condition is determined as the first The class base station may specifically include: determining, as the first type of base station, the small base station that receives the received signal strength of the macro base station.

 That is to say, all small base stations can be sorted according to the strength of the received macro base station signal, and the small base station with the strongest receiving macro base station signal is determined as the first type of base station of the cluster. For example, a cluster includes a small base station 1, a small base station 2, a small base station 3, a small base station 4, and a small base station 5. If the strength of the received macro base station signal is from strong to weak, the order is: small base station 1 > small base station 2 > small Base station 3 > small base station 4 > small base station 5, then it can be determined that the small base station 1 is the first type of base station of the cluster.

 Second, if a plurality of macro base stations connected to the first type of base station in the cluster via the wired interface and/or the wireless interface are configured, the small base station that satisfies the preset condition that the strength of the signal received by the macro base station meets the preset condition is determined to be the first A type of base station may specifically include:

 Determining, by the small base station that receives the macro base station signal strength that exceeds the second preset threshold, as the candidate first type base station; and determining, based on the candidate first type of base station, that the signal strength received from the same macro base station exceeds the third preset width The number of candidate first-class base stations is determined; the macro base station corresponding to the maximum number of candidate first-class base stations is determined as a source base station that provides clock synchronization to the first-type base station, and the received signal strength from the macro base station exceeds the third pre- The candidate first type base station with the set value is determined to be the first type of base station.

 For example, a cluster includes a small base station 1, a small base station 2, a small base station 3, a small base station 4, and a small base station 5, wherein the signal strength received by the small base station 1, the small base station 3, and the small base station 4 from the macro base station 1 is second. Above the preset threshold, the signal strength received by the small base station 2 and the small base station 5 from the macro base station 2 is above the second preset threshold. Then, through information interaction, each small base station can learn the above information and determine The small base stations 1, 2, 3, 4, and 5 are all candidate first type base stations. Since the macro base station 1 corresponds to three candidate first type base stations, it is determined that the macro base station 1 provides a clock synchronization signal for the first type of base stations in the cluster. If the source base station determines that the small base station 1, the small base station 3, and the small base station 4 receive the signal strength from the macro base station 1 exceeding the third predetermined threshold, determining that the small base station 1, the small base station 3, and the small base station 4 are the cluster The first type of base station. Therefore, no matter how the selection criterion of the first type of base station is specifically set, whether the first type of base station in the cluster is one or more, since the macro base station that provides the clock synchronization signal for the first type of base station is the same, the first one is guaranteed. The timing error between class base stations is controllable.

In some embodiments, the timing error between the first type of base stations can be guaranteed by Controlled:

 The transmission timing of the macro base station corresponding to each of the first type of base stations can be mutually exchanged between the first type of base stations, so that different first type of base stations can perform clock synchronization adjustment based on the same clock synchronization reference point equivalently; or The transmission timing difference between the plurality of macro base stations simultaneously detected by each of the first type of base stations may be exchanged between the first type of base stations, so that different first type of base stations can be equivalently based on the same clock synchronization reference point. Clock synchronization adjustment.

 Specifically, for example, a cluster includes a small base station 1, a small base station 2, a small base station 3, a small base station 4, a small base station 5, a small base station 1 from a macro base station 1, a small base station 2, a macro base station 2, and a small base station 3 from an Acer base. The signal strengths received by the station 3 and the small base station 4 from the macro base station 4 and the small base station 5 from the macro base station 5 exceed the second predetermined threshold. Then, according to the selection criteria of the first type of base station, the small base stations 1, 2, 3, 4, 5 can be used as the first type of base station in the cluster, each small base station can calculate the transmission timing of the corresponding macro base station, and the transmission timing difference of different macro base stations, and then configure one of the small base stations as a clock synchronization. At the reference point, the small base stations can realize clock synchronization between the small base stations by mutually interacting with the transmission timing difference of different macro base stations or the transmission timing of the macro base station. For example, the small base station 1 can simultaneously detect the signals of the macro base station 1 and the macro base station 2 and adjust its own clock synchronization according to the clock synchronization of the macro base station 1, and can calculate the transmission timings t1 and t2 of the macro base station 1 and the macro base station 2, thereby The transmission timing difference t1 - t2 of the macro base station 1 and the macro base station 2 can be calculated, and the small base station 2 can detect the signal of the macro base station 2 and adjust its own clock synchronization according to the clock synchronization of the macro base station 2, and then pass through the small base station 1 and The transmission timing difference t1 - t2 between the macro base station 1 and the macro base station 2 that interacts between the small base stations 2 can calculate the transmission timing difference between the small base station 2 and the macro base station 1, and thus can adjust itself according to the transmission timing of the macro base station 1. Clock synchronization. This is equivalent to both the small base station 1 and the small base station 2 adjusting their own clock synchronization in accordance with the transmission timing of the macro base station 1. In brief, by configuring the clock synchronization reference point in the cluster and the difference in the transmission timing of different macro base stations between the small base stations, the small base stations in the cluster can adjust their transmission timing according to the same clock synchronization reference point, thereby In addition, it ensures that the timing error between the first type of base stations is controllable, thereby ensuring that the clock synchronization in the cluster can meet the demand.

 It can be understood that the method of implementing clock synchronization by the above criterion 1, criterion 2 or criterion 3 can also be selected according to the above.

It should be noted that if there are multiple first-class base stations in the same cluster, the second type of base station can maintain clock synchronization with the first-type base station with the highest received signal strength of the macro base station, and can also receive and receive. The first type of base station whose signal strength is above a certain threshold maintains clock synchronization.

 Further, if the small base stations in the cluster complete the initial synchronization and the synchronization tracking, a newly deployed small base station appears in the cluster. One implementation manner is that the first type of base station in the cluster is not considered to be replaced: for example, new The deployed small base station can obtain clock synchronization by using any small base station in the cluster as the source base station before serving the user equipment. Any one of the small base stations referred to herein may be the newly added slave base station receiving the most signal. The strongly corresponding small base station may also be a small base station whose received signal strength is above a certain threshold. Then, the network listening pattern is used to implement synchronization tracking with the source base station. The network listening pattern is obtained in the same manner as above, and is not described here.

 Another implementation manner is to consider replacing the first type of base station in the cluster. For example, the newly deployed small base station can still obtain clock synchronization by using any small base station in the cluster as the source base station before serving the user equipment. Any one of the small base stations referred to herein may be a newly added small base station corresponding to the strongest received signal from the macro base station, or may be a small base station whose received signal strength is above a certain threshold, and then according to the cluster within the cluster. The selection criteria of the first type of base station, the newly deployed small base station can exchange its own identity information to other small base stations in the cluster through backhaul or air interface signaling, and other small base stations can also exchange their identity information to the newly deployed small base station. In order to determine whether it is necessary to replace the first type of base station in the cluster. For example, if it is found that the newly deployed small base station receives the measurement result of the macro base station, it may choose to replace the first type of base station in the cluster as the newly deployed small base station. For example, if the source base station corresponding to the first type of base station of the cluster is a macro base station, and the newly deployed small base station is installed with GPS, the cluster may also replace the first type of base station in the cluster as the newly deployed small base station.

If the first type of base station in the cluster is replaced, the network synchronization listening device needs to be replaced, considering that the initial synchronization has been completed. In order to unify the operation in the cluster, for the cluster that has been synchronized, a time window may be set for the backhaul interaction between the small base stations in the cluster and/or the replacement of the first type of base station and the network listening pattern, that is, only in this time window. Therefore, the necessary information is exchanged between each small base station, the first type of base station is replaced, and the network is listening to the patchem. Alternatively, each small base station considers replacing the above information at the same time boundary. In addition, since the clock synchronization error is accumulated as the synchronization level increases, in order to meet the synchronization requirement, based on the configuration of the first type of base station, the maximum synchronization level N allowed in the cluster can also be configured, and N is positive. Integer. Specifically, the network controller can be connected to the small base station via a wired interface. The macro base station connected to the radio interface, or the manner in which the small base station itself is factory set, configures the maximum synchronization level N allowed in the cluster.

 For example, the configuration information of the network controller may be received, and the maximum synchronization level N allowed in the cluster is configured, where N is a positive integer;

 Or, receiving configuration information of a macro base station connected to the small base station via a wired interface and/or a wireless interface, and configuring a maximum synchronization level N allowed in the cluster;

 Or, through the small base station itself factory configuration.

 It can be understood that the synchronization level of the small base station that implements clock synchronization by the external synchronization source other than the macro base station is 0 ( stratum-0 ), and the synchronization level of the small base station that implements clock synchronization by the macro base station is 1 ( stratum-1 ) The synchronization level of other small base stations synchronized by the small base station with synchronization level 1 is 2, the synchronization level of other small base stations synchronized by the small base station with synchronization level 2 is 3, and so on.

 Specifically, configuring the maximum synchronization level N allowed in the cluster may include:

 When the maximum synchronization level N is configured to be 2, the first type of base station in the cluster performs clock synchronization through the macro base station, and the second type of base station performs clock synchronization through the first type of base station;

 When the maximum synchronization level N is set to 1, the first type of base station in the cluster performs clock synchronization through an external synchronization source other than the macro base station, and the second type of base station performs clock synchronization through the first type of base station.

 It should be noted that any small base station may be both a target base station and a source base station, for example, a small base station 1 with a synchronization level of 1, a target base station that is an external synchronization source, and a source base station of the small base station 2 with a synchronization level of 2. . In addition, an embodiment of the present invention further provides a clock synchronization method, where an execution body may be a clock synchronization device, and the clock synchronization device is an entity having a control function for a small base station, for example, the clock synchronization device may be a network controller or The macro base station, the present invention is described in detail by taking the clock synchronization device as a network controller or a macro base station as an example, and does not constitute a limitation of the present invention.

 The network controller or the macro base station configures the identity information of each small base station to be a first type of base station or a second type of base station, so that each small base station performs clock synchronization according to the identity information, wherein the first type of base station directly implements clock synchronization through an external synchronization source. The second type of base station does not directly synchronize clocks through an external synchronization source.

Specifically, the network controller is an operation management maintenance or mobility management entity, and the macro base station is connected to the wired interface. And/or a wireless interface is connected to each small base station. It should be noted that the macro base station and each small base station belong to the same operator.

 In one embodiment, the network controller or macro base station arbitrarily selects one or more small base stations connected to the network controller or macro base station to determine the first type of base station. When there are multiple base stations of the first type, the centralized controller or the macro base station needs to ensure that the clock synchronization reference points between the first type of base stations are the same.

 It should be noted that the specific implementation of the embodiment of the present invention can be referred to the foregoing embodiment, and details are not described herein again.

A small base station 200 based on the above clock synchronization method is provided. The meaning of the noun is the same as that in the above clock synchronization method. For specific implementation details, refer to the description in the method embodiment.

 Please refer to 2, FIG. 2 is a schematic structural diagram of a small base station. A small base station 200 may include: a determining unit 201 and a processing unit 202. For example, the small base station may be as follows:

 a determining unit 201, configured to determine that the small base station is a first type of base station or a second type of base station;

 The processing unit 202 is configured to: when the determining unit determines that the small base station is the first type of base station, implement clock synchronization by using an external synchronization source, and if it is determined that the small base station is the second type of base station, implement clock synchronization by using the first type of base station.

 In some embodiments, the processing unit 201 is further configured to: when the determining unit 202 determines that the small base station is the second type of base station, determine, by using information interaction, that the other small base stations connected to the small base station are the first type of base station or the second The class base station, if it is determined that the other small base stations connected to the small base station are the first type of base stations, implement clock synchronization through any one of the other small base stations connected to the small base station.

 In some embodiments, the processing unit 201 includes: a first processing subunit 2011, a second processing subunit 2012, and a third processing subunit 2013. For example, please refer to FIG. 3. FIG. 3 is another structural diagram of the small base station. Specifically, it can be as follows:

 The first processing subunit 2011 is configured to determine, according to a preset selection criterion of the first type of base station, a type of information to be exchanged;

 The second processing subunit 2012 is configured to interact with another small base station, a macro base station, or a network controller connected to the small base station according to the type of the information to be exchanged, to obtain interaction information;

The third processing sub-unit 2013 is configured to determine, according to the interaction information, that the other small base stations connected to the small base station are the first type of base station or the second type of base station, where the other small base stations connected to the small base station include: Other small base stations outside; the network controller is an operation management maintenance or mobility management entity. In some embodiments, the selection criteria for the first type of base station include:

 Determining a small base station equipped with a Global Navigation Satellite System GNSS as a first type of base station;

 And/or, determining, as a first type of base station, a small base station that acquires clock synchronization through a wired network; and/or determining, as a first type of base station, a small base station determined to be reliable in clock synchronization;

 And/or, the small base station that receives the strength of the signal of the macro base station that satisfies the preset condition is determined as the first type of base station.

 The signal of the macro base station includes a primary synchronization signal PSS, a secondary synchronization signal SSS, and a reference signal, and the reference signal includes: a cell-specific reference signal CRS, a channel state information reference signal CSI-RS, and a multimedia broadcast multicast service single-frequency network reference signal MBSFN. One or more of RS, positioning reference signal PRS, and discovery reference signal Discovery reference signal.

 Correspondingly, in some embodiments, clock synchronization is implemented by using an external synchronization source, specifically: acquiring clock synchronization signals directly by GNSS for clock synchronization, or acquiring clock synchronization signals through a wired network for clock synchronization, or reliably by clock synchronization. The base station acquires a clock synchronization signal for clock synchronization, or obtains a clock synchronization signal for clock synchronization through a signal sent by the received macro base station; and implements clock synchronization by using the first type of base station, which specifically includes: acquiring a clock synchronization signal by using the first type of base station to perform clock synchronization Synchronize.

 In some embodiments, the clock synchronization signal is acquired by the received signal sent by the macro base station to perform clock synchronization, which specifically includes:

 Get coarse synchronization through PSS and / or SSS;

 Fine synchronization is obtained by reference signals.

 The first type of base station may not provide the synchronization signal for the second type of base station before the clock synchronization is obtained, and the small base stations in the cluster may not serve the user equipment before the clock synchronization is implemented. In addition, when the second type of base station acquires clock synchronization through the first type of base station, the interference experienced by the second type of base station during network listening should be reduced as much as possible. Specifically, it may include:

 One implementation manner is that after obtaining fine synchronization through the reference signal, the method further includes:

 Providing indication information to the second type of base station by using a backhaul link or air interface signaling, so that the second type of base station determines the synchronization status of the first type of base station according to the indication information, and acquires time synchronization by using the first type of base station; Yes, after obtaining fine synchronization through the reference signal, it also includes:

Providing indication information and a preset effective time to the second type of base station through a backhaul link or air interface signaling, The second type of base station determines the synchronization status of the first type of base station according to the indication information, and acquires time synchronization or is in a network listening state or in a data non-transmitting state within a preset effective time.

 The preset effective time is set to indicate that all the second type of base stations are synchronized with the clock of the first type of base station within the valid time, or are in a network listening state, or are in a data non-transmitting state. Then, it is ensured that the second type of base station acquires the synchronization signal from the first type of base station after acquiring the synchronization of the first type of base station, and ensures that the second type of base station maintains the initial clock synchronization with the first type of base station, and the other The second type of base station does not transmit signals, thereby reducing interference.

 In some embodiments, the first processing sub-unit 2011 may determine the type of information that the small base station and other small base stations connected to the small base station need to interact according to the selection criteria of the first type of base station. For example, the method may include:

 If the first type of base station selection criterion is to determine the base station with the GNSS as the first type of base station, the type of information that the small base station determines to interact includes: the cell identifier cell ID of the small base station and the synchronization status indicating whether the small base station is installed with the GNSS. Information

 If the first type of base station selection criterion is to determine the base station that acquires clock synchronization through the wired network as the first type of base station, the type of information that the small base station determines to interact includes: the cell ID of the small base station and whether the small base station is allowed to obtain through the wired network. Synchronized synchronization status information;

 If the first type of base station selection criterion is to determine the base station that is determined to be reliable for clock synchronization as the first type of base station, the type of information that the small base station determines to interact includes: a cell ID of the small base station and a synchronization indicating whether the clock synchronization of the small base station is reliable. status information;

 If the first type of base station selection criterion is that the base station that receives the strength of the signal received by the macro base station meets the preset condition is determined as the first type of base station, the information type that the small base station determines to interact includes: the cell ID of the small base station, and the received signal. And a cell ID of the macro base station corresponding to the macro base station signal whose strength exceeds the first preset threshold, and a size of the macro base station signal whose received signal strength exceeds the first preset threshold.

 In some embodiments, the small base station that receives the strength of the signal of the macro base station that meets the preset condition is determined as the first type of base station, and includes:

 Determining the small base station with the highest signal strength of the received macro base station as the first type of base station;

Or determining, by the small base station that receives the macro base station that the signal strength exceeds the second preset threshold, as the candidate first type base station; and determining, according to the candidate first type of base station, that the signal strength received from the same macro base station exceeds the third pre- The number of candidate first-class base stations with a wide value; the macro corresponding to the number of candidate first-class base stations The base station determines the source base station that provides clock synchronization for the first type of base station, and determines the candidate first type base station that receives the signal strength from the macro base station exceeding the third predetermined threshold as the first type of base station.

 In some embodiments, in order to meet the synchronization requirement, based on the configuration of the first type of base station, the maximum synchronization level N allowed in the cluster may also be configured, where N is a positive integer. Referring to FIG. 3, the small base station may further include:

 The configuration unit 203 is configured to receive configuration information of the network controller, and configure a maximum synchronization level N allowed in the cluster, where N is a positive integer;

 Or, receiving configuration information of a macro base station connected to the small base station via a wired interface and/or a wireless interface, and configuring a maximum synchronization level N allowed in the cluster;

 Or, through the small base station itself factory configuration.

 It can be seen that, in the embodiment of the present invention, the small base station can determine that it is the first type of base station or the second type of base station. When it is determined that the small base station is the first type of base station, the clock synchronization is implemented by using an external synchronization source, if it is determined that the small base station is In the second type of base station, clock synchronization is implemented by the first type of base station, so that clock synchronization requirements are met between the small base stations. In order to facilitate the implementation of the clock synchronization method provided by the embodiment of the present invention, an embodiment of the present invention further provides an apparatus based on the above clock synchronization method. The meaning of the noun is the same as that in the above clock synchronization method. For specific implementation details, refer to the description in the method embodiment.

 Please refer to FIG. 4. FIG. 4 is a schematic structural diagram of a clock synchronization device. A clock synchronization apparatus 300 may include: a configuration unit 301, configured to configure identity information of each small base station to be a first type of base station or a second type of base station, so that each small base station performs clock synchronization according to the identity information, where The class base station directly implements clock synchronization through an external synchronization source, and the second type of base station does not directly synchronize the base station through the external synchronization source.

 It should be noted that the clock synchronization device may be a network controller or a macro base station, or other entities having control functions for the small base station, and other entities and small base stations have a wireless and/or wired interface. For example, if a small base station in a cluster can control or determine the identity information of other small base stations in the cluster, the small base station in the cluster can be considered as an entity having control functions for other small base stations in the cluster.

 The present invention is described in detail by taking the clock synchronization device as a network controller or a macro base station as an example. For example, the method may include:

If the clock synchronization device is a network controller, the configuration unit 301 is configured to use the first class according to the preset The base station selection criterion is configured to configure identity information of each small base station as a first type of base station or a second type of base station, where the network controller is an operation management maintenance or a mobility management entity;

 If the clock synchronization device is a macro base station, the configuration unit 301 is configured to configure, according to the preset first type of base station selection criteria, the identity information of each small base station as a first type of base station or a second type of base station, and the macro base station passes the wired interface and / or the wireless interface is connected to each small base station.

 It is easy to understand that the first type of base station selection criterion includes: arbitrarily selecting one or more small base stations to be determined as the first type of base stations in the base station connected to the network controller or the macro base station.

 Further, in order to meet the synchronization requirement, based on the configuration of the first type of base station, the maximum synchronization level N allowed in the cluster may also be configured, where N is a positive integer. Specifically, the configuration unit 301 is further configured to send configuration information to the small base station, so that the small base station configures the maximum synchronization level N allowed in the cluster according to the configuration information, where N is a positive integer. In addition, in order to facilitate the implementation of the clock synchronization method provided by the embodiment of the present invention, the embodiment of the present invention further provides a system based on the foregoing clock synchronization method. The meaning of the noun is the same as that in the above clock synchronization method. For specific implementation details, refer to the description in the method embodiment.

 Please refer to FIG. 5, which is a schematic structural diagram of a clock synchronization system. A clock synchronization system 400 may include: any of the above-described small base stations 200 and any of the above-described clock synchronization devices 300. For the specific implementation, refer to the foregoing embodiment, and details are not described herein again. Please refer to FIG. 6. FIG. 6 is a schematic diagram of another structure of a small base station 200 according to an embodiment of the present invention. The small base station 200 may include at least one processor 401 (for example, a CPU, Central Processing Unit), at least one network interface or the like. A communication interface, a memory 402, and at least one communication bus are used to effect connection communication between the devices. The processor 401 is configured to execute an executable module, such as a computer program, stored in the memory. The memory 402 may include a high speed random access memory (RAM), and may also include a non-volatile memory such as at least one disk memory. The communication connection between the system gateway and at least one other network element is implemented by at least one network interface (which may be wired or wireless), and may use an Internet, a wide area network, a local area network, a metropolitan area network, or the like.

As shown in FIG. 6, in some embodiments, program instructions are stored in the memory 402, and the program instructions may be executed by the processor 401. The processor 401 specifically performs the following steps: Determining that the small base station is the first type of base station or the second type of base station. When it is determined that the small base station is the first type of base station, the clock synchronization is implemented by the external synchronization source. If it is determined that the small base station is the second type of base station, the first type is adopted. The base station implements clock synchronization.

 In the above embodiments, the descriptions of the various embodiments are different, and the details are not described in the specific embodiments. For details, refer to related descriptions of other embodiments. In the several embodiments provided herein, it should be understood that the disclosed systems, devices, and methods may be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored, or not executed. Alternatively, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in electrical, mechanical or other form. The components displayed by the unit may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the objectives of the solution of the embodiment.

 In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a standalone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present invention may contribute to the prior art or all or part of the technical solution may be embodied in the form of a software product stored in a storage medium. A number of instructions are included to cause a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The foregoing storage medium includes: a U disk, a removable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and the like, which can store program codes. . The foregoing detailed description of a clock synchronization method, system and related apparatus provided by the present invention is only for assisting in understanding the method of the present invention and its core idea; and at the same time, it is implemented by those skilled in the art according to the present invention. The scope of the present invention is not limited by the scope of the present invention.

Claims

Rights request

 A clock synchronization method, comprising:

 The small base station determines that the small base station is the first type of base station or the second type of base station. When it is determined that the small base station is the first type of base station, the clock synchronization is implemented by using an external synchronization source, and if the small base station is determined to be the second The class base station implements clock synchronization through the first type of base station.

 The method according to claim 1, wherein the small base station determines that the small base station is a first type of base station or a second type of base station, and specifically includes: the small base station according to the preset selection of the first type of base station a criterion for determining that the small base station is a first type of base station or a second type of base station;

 The selection criteria of the first type of base station include:

 Determining a small base station equipped with a Global Navigation Satellite System GNSS as a first type of base station;

 And/or, determining, as a first type of base station, a small base station that acquires clock synchronization through a wired network; and/or determining, as a first type of base station, a small base station determined to be reliable in clock synchronization;

 And/or, the small base station that receives the strength of the signal of the macro base station that satisfies the preset condition is determined as the first type of base station.

 The method according to claim 1 or 2, wherein the determining that the small base station is a second type of base station, the clock synchronization is implemented by the first type of base station, specifically:

 The small base station determines that the small base station is a second type of base station;

 The small base station determines that the other small base stations connected thereto are the first type of base station or the second type of base station through information exchange, and if other small base stations connected thereto are determined to be the first type of base stations, pass through the other small base stations connected thereto Any small base station implements clock synchronization.

 The method according to claim 3, wherein the small base station determines that the other small base stations connected thereto are the first type of base station or the second type of base station, and the following includes:

 'J. The base station determines the type of the information to be exchanged according to the preset selection criteria of the first type of base station; the small base station according to the type of the information to be exchanged, and other small base stations, extra-cluster macro base stations or network controllers connected thereto Interact and get interactive information;

 The small base station determines, according to the interaction information, that the other small base stations connected thereto are the first type of base station or the second type of base station, where the other small base stations connected thereto include: other small base stations in the cluster except the small base station The network controller is an operation management maintenance or mobility management entity.

The method according to claim 4, wherein the preset first type of base station Selection criteria are configured based on the following methods, including:

 Receiving configuration information of the network controller, configuring a selection criterion of the first type of base station; or receiving configuration information of the macro base station connected to the small base station via a wired interface and/or a wireless interface, to the first type of base station Select criteria for configuration;

 Alternatively, the small base station is configured by itself.

 The method according to claim 4, wherein the selection criteria of the first type of base station comprise:

 Determining a small base station equipped with a Global Navigation Satellite System GNSS as a first type of base station;

 And/or, determining, as a first type of base station, a small base station that acquires clock synchronization through a wired network; and/or determining, as a first type of base station, a small base station determined to be reliable in clock synchronization;

 And/or, the small base station that receives the strength of the signal of the macro base station that satisfies the preset condition is determined as the first type of base station.

 7. The method of claim 6 wherein:

 The clock synchronization is implemented by using the external synchronization source, and the method includes: acquiring, by the GNSS, a clock synchronization signal for clock synchronization, or acquiring a clock synchronization signal by the wired network for clock synchronization, or obtaining the reliable base station by using the clock synchronization. Synchronizing the clock synchronization signal, or acquiring a clock synchronization signal by using the received signal sent by the macro base station to perform clock synchronization;

 The clock synchronization is implemented by the first type of base station, and the method includes: acquiring clock synchronization signals by using the first type of base station to perform clock synchronization.

 The method according to claim 7, wherein the signal of the macro base station comprises a primary synchronization signal PSS, a secondary synchronization signal SSS, and a reference signal, where the reference signal comprises: a cell-specific reference signal CRS, channel state information One or more of a reference signal CSI-RS, a multimedia broadcast multicast service single frequency network reference signal MBSFN RS, a positioning reference signal PRS, and a discovery reference signal Discovery reference signal.

 The method according to claim 8, wherein the obtaining a clock synchronization signal by using the received signal sent by the macro base station to perform clock synchronization includes:

 Obtaining coarse synchronization through the PSS and/or the SSS;

 Obtaining fine synchronization by using the reference signal;

After obtaining the fine synchronization by using the reference signal, the method further includes: Providing the indication information to the second type of base station by using the backhaul link or the air interface signaling, so that the second type of base station determines the synchronization status of the first type of base station according to the indication information, and acquires clock synchronization by using the first type of base station. signal;

 Or providing the indication information and the preset validity time to the second type of base station by using the backhaul link or the air interface signaling, so that the second type of base station determines the synchronization status of the first type of base station according to the indication information, and The clock synchronization signal is acquired within the preset valid time or is in the network listening state or in the data not transmitting state.

 The method according to claim 6, wherein the small base station determines the type of the information to be exchanged according to the selection criteria of the preset first type of base station, including:

 If the first type of base station selection criterion is to determine the base station with the GNSS as the first type of base station, the type of information that the small base station determines to interact with includes: a cell identifier of the small base station, a cell ID, and an indication of whether the small base station is The synchronization status information of the GNSS is installed;

 Or, if the first type of base station selection criterion is that the base station that acquires clock synchronization through the wired network is determined to be the first type of base station, the type of information that the small base station determines to interact with: the cell ID of the small base station and the indication Whether the small base station acquires synchronized synchronization status information through the wired network;

 Or, if the first type of base station selection criterion is to determine the base station that is determined to be reliable for clock synchronization as the first type of base station, the type of information that the small base station determines to interact with: the cell ID of the small base station and the indication of the small Whether the clock synchronization of the base station is reliable or not.

 The method according to claim 6, wherein the small base station determines the type of the interactive information according to the selection criteria of the preset first type of base station, including:

 If the first type of base station selection criterion is that the base station that receives the strength of the signal of the macro base station meets the preset condition is determined as the first type of base station, the information type of the small base station determining the interaction includes: the cell of the small base station The ID, the cell ID of the macro base station corresponding to the macro base station signal whose received signal strength exceeds the first preset threshold, and the size of the macro base station signal whose received signal strength exceeds the first preset threshold.

 The method according to claim 11, wherein if the first type of base station selection criterion is that the base station that receives the strength of the signal of the macro base station meets a preset condition is determined as the first type of base station, The small base station obtains the type of information exchanged in the following manner:

The small base station acquires neighboring cell list information, and detects a macro from the neighboring cell list information. The cell ID of the base station;

 The small base station detects the strength of the signal sent by all other small base stations indicated in the neighboring cell list information, and obtains a detection result;

 Determining, from the detection result, a size of the macro base station signal whose received signal strength exceeds the first preset threshold, and determining, from the cell ID of the macro base station, that the signal strength exceeds the first preset threshold The macro base station signal corresponds to the cell ID of the macro base station.

 The method according to claim 11, wherein if the first type of base station selection criterion is that the base station that receives the strength of the signal of the macro base station meets a preset condition is determined as the first type of base station, The small base station obtains the type of information exchanged in the following manner:

 The small base station acquires neighboring cell list information, and detects a cell ID of the macro base station from the neighboring cell list information;

 The small base station detects the strength of the signal sent by the macro base station that receives the cell ID indicated by the macro base station, and obtains a detection result;

 From the detection result, the size of the macro base station signal whose received signal strength exceeds the first preset threshold is determined, and the cell ID of the macro base station corresponding to the macro base station signal.

 The method according to claim 2 or 6, wherein the determining, by the small base station that the strength of the signal of the macro base station that meets the preset condition is the first type of the base station, includes:

 Determining, by the small base station, the signal strength of the received macro base station is the first type of base station; or determining, by the small base station that receives the macro base station, the signal strength exceeding the second predetermined threshold is the candidate first type base station;

 Determining, according to the candidate first type of base station, the number of candidate first type of base stations whose signal strength received from the same macro base station exceeds a third preset threshold;

 Determining, by the macro base station corresponding to the number of the candidate first type of base stations, a source base station that provides clock synchronization to the first type of base station, and receiving, from the macro base station, a candidate first class whose signal strength exceeds a third preset threshold The base station is determined to be the first type of base station.

 The method according to any one of claims 1 to 14, wherein, for a cluster, the method further comprises: receiving configuration information of the network controller, and configuring a maximum synchronization level N allowed in the cluster. , the N is a positive integer;

Or receiving a macro base station connected to the small base station via a wired interface and/or a wireless interface Set the information, the maximum synchronization level N allowed in the cluster is configured;

 Alternatively, the small base station is configured by itself.

 16. A clock synchronization method, comprising:

 Configuring the identity information of each small base station to be a first type of base station or a second type of base station, so that each small base station performs clock synchronization according to the identity information, where the first type of base station directly implements clock synchronization through an external synchronization source. The second type of base station does not directly implement clock synchronization through an external synchronization source.

 The method according to claim 16, wherein the configuring the identity information of each small base station to be the first type of base station or the second type of base station comprises:

 The network controller configures the identity information of each small base station as a first type of base station or a second type of base station according to a preset first type of base station selection criterion, where the network controller is an operation management maintenance or a mobility management entity;

 Alternatively, the macro base station configures the identity information of each small base station as a first type of base station or a second type of base station according to a preset first type of base station selection criterion, and the macro base station is connected to each small base station via a wired interface and/or a wireless interface. connection.

 The method according to claim 17, wherein the first type of base station selection criteria comprises:

 In the small base station connected to the network controller or the macro base station, one or more small base stations are arbitrarily selected to be determined as the first type of base station.

 19. A small base station, comprising:

 a determining unit, configured to determine that the small base station is a first type of base station or a second type of base station;

 a processing unit, configured to: when the determining unit determines that the small base station is a first type of base station, implement clock synchronization by using an external synchronization source, and if it is determined that the small base station is a second type of base station, pass the first type of base station. Implement clock synchronization.

 20. The small base station according to claim 19, wherein

 The determining unit is specifically configured to determine, according to a preset selection criterion of the first type of base station, that the small base station is a first type of base station or a second type of base station;

 The selection criteria of the first type of base station include:

 Determining a small base station equipped with a Global Navigation Satellite System GNSS as a first type of base station;

And/or, determining, by the wired network, a small base station that acquires clock synchronization as the first type of base station; And/or determining, as a first type of base station, a small base station determined to be reliable for clock synchronization;

 And/or, the small base station that receives the strength of the signal of the macro base station that satisfies the preset condition is determined as the first type of base station.

 The small base station according to claim 19 or 20, further comprising: the processing unit, configured to: when the determining unit determines that the small base station is a second type of base station, determine by information interaction The other small base stations connected to the small base station are the first type of base station or the second type of base station. If it is determined that the other small base stations connected to the small base station are the first type of base stations, the other small base stations connected to the small base station are used. A small base station implements clock synchronization.

 The small base station according to claim 21, further comprising:

 The processing unit includes: a first processing subunit, configured to determine a type of information to be exchanged according to a preset selection criterion of the first type of base station;

 a second processing sub-unit, configured to interact with another small base station, a macro base station, or a network controller connected to the small base station according to the type of the information to be exchanged, to obtain interaction information;

 a third processing subunit, configured to determine, according to the interaction information, that the other small base stations connected to the small base station are the first type of base station or the second type of base station, where the other small base stations connected to the small base station include: Other small base stations other than the small base station; the network controller is an operation management maintenance or mobility management entity.

 The small base station according to claim 22, wherein the selection criteria of the first type of base station comprise:

 Determining a small base station equipped with a Global Navigation Satellite System GNSS as a first type of base station;

 And/or, determining, as a first type of base station, a small base station that acquires clock synchronization through a wired network; and/or determining, as a first type of base station, a small base station determined to be reliable in clock synchronization;

 And/or determining, by the small base station that the strength of the signal of the macro base station that meets the preset condition is a first type of base station, where the signal of the macro base station includes a primary synchronization signal PSS, a secondary synchronization signal SSS, and a reference signal, where The reference signal includes: one or more of a cell-specific reference signal CRS, a channel state information reference signal CSI-RS, a multimedia broadcast multicast service single-frequency network reference signal MBSFN RS, a positioning reference signal PRS, and a discovery reference signal Discovery reference signal Kind.

 The small base station according to claim 23, further comprising:

The clock synchronization is implemented by using an external synchronization source, and specifically includes: directly acquiring by using the GNSS The clock synchronization signal is clock-synchronized, or the clock synchronization signal is acquired by the wired network for clock synchronization, or the clock synchronization reliable base station acquires a clock synchronization signal for clock synchronization, or receives the received signal sent by the macro base station. Acquiring a clock synchronization signal for clock synchronization;

 The clock synchronization is implemented by the first type of base station, and the method includes: acquiring clock synchronization signals by the first type of base station to perform clock synchronization;

 The obtaining a clock synchronization signal by using the signal sent by the received macro base station to perform clock synchronization includes:

 Obtaining coarse synchronization through the PSS and/or the SSS;

 Obtaining fine synchronization by using the reference signal;

 Providing indication information to the second type of base station by using the backhaul link or the air interface signaling, so that the second type of base station determines the synchronization status of the first type of base station according to the indication information, and acquires time synchronization by using the first type of base station. Clock synchronization signal; or

 Providing the indication information and the preset validity time to the second type of base station by using the backhaul link or the air interface signaling, so that the second type of base station determines the synchronization status of the first type of base station according to the indication information, and is in the preset The clock synchronization signal is obtained within the valid time or is in the network listening state or in the data not transmitting state.

 The small base station according to claim 23 or 24, further comprising: a first processing subunit, configured to: if the first type of base station selection criterion is to determine the base station with the GNSS as the first class The base station, the type of information that the small base station determines to interact with, includes: a cell identifier cell ID of the small base station, and synchronization state information indicating whether the small base station is installed with the GNSS;

 Or, if the first type of base station selection criterion is that the base station that acquires clock synchronization through the wired network is determined to be the first type of base station, the type of information that the small base station determines to interact with: the cell ID of the small base station and the indication Whether the small base station acquires synchronized synchronization status information through the wired network;

 Or, if the first type of base station selection criterion is to determine the base station that is determined to be reliable for clock synchronization as the first type of base station, the type of information that the small base station determines to interact with: the cell ID of the small base station and the indication of the small Whether the clock synchronization of the base station is reliable or not;

Or, if the first type of base station selection criterion is that the base station that receives the strength of the signal of the macro base station meets the preset condition is determined as the first type of base station, the information type that the small base station determines to interact includes: the small base station Corresponding to the cell ID and the macro base station signal whose received signal strength exceeds the first preset threshold The cell ID of the macro base station and the size of the macro base station signal whose received signal strength exceeds the first preset threshold.

 The small base station according to claim 25, further comprising:

 Determining, by the small base station that receives the strength of the signal of the macro base station that meets the preset condition, as the first type of base station, includes:

 Determining, by the small base station, the signal strength of the received macro base station is the first type of base station; or determining, by the small base station that receives the macro base station, the signal strength exceeding the second predetermined threshold is the candidate first type base station;

 Determining, according to the candidate first type of base station, the number of candidate first type of base stations whose signal strength received from the same macro base station exceeds a third preset threshold;

 Determining, by the macro base station corresponding to the number of the candidate first type of base stations, a source base station that provides clock synchronization to the first type of base station, and receiving, from the macro base station, a candidate first class whose signal strength exceeds a third preset threshold The base station is determined to be the first type of base station.

 The small base station according to any one of claims 19 to 26, further comprising: a configuration unit, configured to receive configuration information of the network controller, and the maximum synchronization level allowed in the cluster

N is configured, where N is a positive integer;

 Or receiving configuration information of a macro base station connected to the small base station via a wired interface and/or a wireless interface, and configuring a maximum synchronization level N allowed in the cluster;

 Alternatively, the small base station is configured by itself.

 28. A clock synchronization apparatus, comprising:

 a configuration unit, configured to configure the identity information of each small base station to be a first type of base station or a second type of base station, so that each small base station performs clock synchronization according to the identity information, where the first type of base station directly passes an external synchronization source The clock synchronization is implemented, and the second type of base station does not directly implement the clock synchronization of the base station through the external synchronization source.

 The clock synchronization device according to claim 28, further comprising: if the clock synchronization device is a network controller, the configuration unit is configured to select a criterion according to a preset first type of base station, The identity information of each small base station is configured as a first type of base station or a second type of base station, where the network controller is an operation management maintenance or mobility management entity;

If the clock synchronization device is a macro base station, the configuration unit is configured to be based on the preset first class The base station selection criterion is that the identity information of each small base station is configured as a first type of base station or a second type of base station, and the macro base station is connected to each d and the base station via a wired interface and/or a wireless interface.

 The apparatus according to claim 29, wherein the first type of base station selection criteria comprises:

 Among the base stations connected to the network controller or the macro base station, one or more small base stations are arbitrarily selected to be determined as the first type of base stations.

 31. Apparatus according to any of claims 28-30, characterized in that

 The configuration unit is further configured to send configuration information to the small base station, so that the small base station configures a maximum synchronization level N allowed in the cluster according to the configuration information, where the N is a positive integer.

 32. A clock synchronization system, comprising:

 A small base station according to any one of claims 19 to 27, and a clock synchronizing apparatus as claimed in any one of claims 28 to 31.