Method, Apparatus and System for Checking Clock Information - Patent application

Abstract

The present application provides a method, an apparatus and a system for checking clock information, and relates to the field of communication technology. In the present application, a baseband unit obtains information provided by a radio frequency unit to help determine whether the clock information provided by a time serving unit is available, thereby helping to avoid service interference caused by using inaccurate clock information and improve the reliability of system clock synchronization.

Description

[Technical field]

[0001] The present application relates to the field of communication technologies, and in particular to a method, apparatus and system for checking clock information. [Background technology]

[0002] Time serving units are nowadays installed in many communication systems, which are configured to provide clock information based on received satellite signals, so that the communication systems perform clock synchronization based on the clock information.

[0003] Due to interference from sources such as pseudolites, the information determined by the time serving unit based on the received signal may not be accurate. Thus, inaccurate clock information may affect the service. So that it doesn't happen, It is necessary to check whether the clock information provided by the time serving unit is available. Summary of the Invention

[0004] The embodiment of the present application is a method for preventing inaccurate clock information from affecting services. So that it doesn't happen, A method, apparatus and system for checking clock information is provided. The technical solutions are given as follows:

[0005] According to a first aspect, there is provided a method for checking clock information, the method comprising: Using The method includes obtaining first information, obtaining information regarding at least one radio frequency unit of the communication system, and determining, based on the information regarding the at least one radio frequency unit and the first information, whether clock information provided by a time serving unit is available.

[0006] In the above method, the baseband unit obtains information provided by the radio frequency unit to help determine whether the clock information provided by the time serving unit is available, thereby helping to avoid service interference caused by using inaccurate clock information and improve the reliability of system clock synchronization.

[0007] Optionally, the information on the radio frequency unit is geographical location information of the radio frequency unit, and the first information is geographical location information obtained by the time serving unit based on a signal received by the time serving unit.

[0008] In the above optional scheme, the location of the radio frequency unit is equivalent to the known reference location. If the location determined by the time serving unit is inaccurate due to interference with the time serving unit, the deviation between the location determined by the time serving unit and the known reference location will be excessively large. Therefore, whether the clock information provided by the time serving unit is available is determined based on the geographic location provided by the radio frequency unit and the geographic location provided by the time serving unit, which helps to improve the accuracy of the determination result.

[0009] Optionally, the information on the radio frequency unit is clock information of the radio frequency unit, and the first information is clock information obtained by the time serving unit based on a signal received by the time serving unit.

[0010] In the above optional scheme, the clock of the time serving unit is equivalent to a reliable clock. If the location determined by the time serving unit is inaccurate due to interference with the time serving unit, the deviation between the time determined by the time serving unit and the reliable clock will be excessively large. Therefore, whether the clock information provided by the time serving unit is available is determined based on the clock provided by the radio frequency unit and the clock provided by the time serving unit, which helps to improve the accuracy of the determination result.

[0011] Optionally, the clock information of the radio frequency unit or the clock information provided by the time serving unit The following, i.e. The information includes at least one of time information, frequency information, or phase information.

[0012] The above optional schemes help support various scenarios, such as time synchronization, frequency synchronization, and phase synchronization, improving flexibility.

[0013] Optionally, determining whether the clock information provided by the time serving unit is available based on the information about the at least one radio frequency unit and the first information includes obtaining at least one deviation based on the information about the at least one radio frequency unit and the first information, and determining whether the clock information provided by the time serving unit is available based on the at least one deviation and a threshold value.

[0014] Optionally, determining whether the clock information provided by the time serving unit is available based on the information on the at least one radio frequency unit and the first information comprises determining whether the clock information provided by the time serving unit is available based on at least one deviation Each ofdetermining that the clock information provided by the time serving unit is unavailable based on the fact that one of the at least one deviations is greater than the threshold; determining that the clock information provided by the time serving unit is unavailable based on the fact that one of the at least one deviations is greater than the threshold; Specific determining that the clock information provided by the time serving unit is unavailable based on the fact that the ratio reaches or exceeds a threshold value among at least one deviation; Specific determining that clock information provided by a time serving unit is unavailable based on the fact that a quantity is reached or This includes combinations thereof.

[0015] In the above optional scheme, the information provided by multiple radio frequency units is considered comprehensively. Even if the information provided by a certain radio frequency unit is inaccurate, the accuracy of the decision result can be guaranteed by using the information provided by another radio frequency unit. Therefore, the fault tolerance ability is improved.

[0016] Optionally, the deviation is The following, i.e. The at least one of the following may be included: spatial distance, time difference, frequency deviation, or phase deviation.

[0017] In the above optional manner, the determining is performed with respect to multiple dimensions, such as space, time, frequency, and phase, and thus the reference information for determining is richer and more comprehensive, which helps to improve the accuracy of the determining result.

[0018] Optionally, a time serving unit of the communication system Using Obtaining the first information includes any one of receiving the first information output by the time serving unit, or determining the first information based on the information output by the time serving unit. orThis includes combinations thereof.

[0019] Optionally, obtaining information regarding the at least one radio frequency unit of the communication system comprises: Receiving information regarding the at least one radio frequency unit from the at least one radio frequency unit or receiving information regarding the at least one radio frequency unit from a network management device Any one of or This includes combinations thereof.

[0020] Optionally, after determining whether clock information provided by a time serving unit is available based on the information about the at least one radio frequency unit and the first information, the method further comprises: using the clock information provided by the time serving unit if the clock information is available; and using the clock information provided by a unit other than the time serving unit if the clock information is unavailable. The key Either using clock information provided by the source, or entering a clock holdover mode if clock information is unavailable. or It further includes combinations thereof.

[0021] In the above optional scheme, when it is determined that the clock information of the time serving unit is unavailable, another element is used as the clock source or enters a clock holdover mode to avoid service interference caused by tracking of an inaccurate clock source.

[0022] Optionally, the radio frequency unit and the time serving unit are located in the same base station.

[0023] The above optional scheme supports a scenario in which the baseband unit determines whether a local time serving unit is available based on information provided by the local site's radio frequency unit.

[0024] Optionally, the radio frequency unit and the time serving unit are located in different base stations.

[0025] The above optional schemes may be implemented using information provided by radio frequency units at adjacent or remote sites. Based on , supporting a scenario in which the baseband unit determines whether a local time serving unit is available, application scenarios are more diverse.

[0026] Optionally, the time serving unit is located in the baseband unit, or the time serving unit is located in one of the at least one radio frequency unit.

[0027] The above optional scheme supports a scenario in which the baseband unit determines whether a local time serving unit is available and a scenario in which the baseband unit determines whether a time serving unit in a radio frequency unit is available, and the application scenarios are more diverse.

[0028] Optionally, the method is performed by a baseband unit, or the method is performed by one of the at least one radio frequency unit.

[0029] According to a second aspect, a method for checking clock information, implemented by a radio frequency unit in a communication system, is provided. do. The method includes obtaining information about the radio frequency unit and sending information about the radio frequency unit to a baseband unit in the communication system, the information about the radio frequency unit being used by the baseband unit to determine whether clock information provided by a first time serving unit in the communication system is available.

[0030] Optionally, the information relating to the radio frequency unit is geographic location information of the radio frequency unit.

[0031] Optionally, obtaining information about the radio frequency unit includes obtaining geographic location information of the radio frequency unit pre-stored in the radio frequency unit; Using Obtaining geographic location information of the radio frequency unit, receiving geographic location information of the radio frequency unit from a network management device, or a positioning unit Using obtaining geographic location information of the radio frequency unit. or This includes combinations thereof.

[0032] Optionally, the information relating to the radio frequency unit is clock information of the radio frequency unit.

[0033] Optionally, obtaining information about the radio frequency unit comprises: Using This includes obtaining clock information of the radio frequency unit.

[0034] According to a third aspect, there is provided a communications device, comprising: Time serving unit of a communication system Using a capture module configured to capture first information, an acquisition module, the acquisition module being further configured to acquire information regarding at least one radio frequency unit of the communication system; a determination module configured to determine whether clock information provided by a time serving unit is available based on information about the at least one radio frequency unit and the first information; Includes.

[0035] Optionally, the information relating to the radio frequency unit is geographic location information of the radio frequency unit; The first information is geographic location information obtained by the time serving unit based on a signal received by the time serving unit.

[0036] Optionally, the information relating to the radio frequency unit is clock information of the radio frequency unit; The first information is clock information obtained by the time serving unit based on a signal received by the time serving unit.

[0037] Optionally, the clock information of the radio frequency unit or the clock information provided by the time serving unit The following, i.e. The information includes at least one of time information, frequency information, or phase information.

[0038] Optionally, the decision module: Obtaining at least one deviation based on information about the at least one radio frequency unit and the first information; determining whether the clock information provided by the time serving unit is available based on at least one deviation and a threshold value; The present invention is configured to:

[0039] Optionally, the decision module: At least one deviation Each of determining that the clock information provided by the time serving unit is unavailable based on the fact that determining that the clock information provided by the time serving unit is unavailable based on the fact that one of the at least one deviations is greater than a threshold; At least one deviation is greater than the threshold. Specific determining that the clock information provided by the time serving unit is unavailable based on the fact that the ratio is reached; or At least one deviation is greater than the threshold. Specific Determining that the clock information provided by the time serving unit is unavailable based on the fact that a quantity is reached. Any one of or It is configured to implement any combination thereof.

[0040] Optionally, the deviation is The following, i.e. The at least one of the following may be included: spatial distance, time difference, frequency deviation, or phase deviation.

[0041] Optionally, the acquisition module further comprises: receiving first information output by a time serving unit; or determining first information based on the information output by the time serving unit; Any one of or It is configured to implement any combination thereof.

[0042] Optionally, the acquisition module further comprises: receiving information about the at least one radio frequency unit from the at least one radio frequency unit; or receiving information regarding at least one radio frequency unit from a network management device; Any one of or It is configured to implement any combination thereof.

[0043] Optionally, the apparatus further comprises a processing module, the processing module comprising: using clock information provided by a time serving unit when the clock information is available; Other than the time serving unit when clock information is not available The key using the clock information provided by the Entering clock holdover mode when clock information is unavailable Any one of orIt is configured to implement any combination thereof.

[0044] In some embodiments, the units in the communication device are implemented by using software, and the units in the communication device are program modules. In some other embodiments, the units in the communication device are implemented by using hardware or firmware. For specific details of the communication device provided in the third aspect, please refer to the first aspect or the optional scheme of the first aspect. Details will not be described again in this specification.

[0045] According to a fourth aspect, there is provided a communication device, wherein the communication device is disposed in a radio frequency unit. do. This device is an acquisition module configured to acquire information regarding the radio frequency unit; a transmitting module configured to send information about a radio frequency unit to a baseband unit in a communication system, the information about the radio frequency unit being used by the baseband unit to determine whether clock information provided by a first time serving unit in the communication system is available; Includes.

[0046] Optionally, the information relating to the radio frequency unit is geographic location information of the radio frequency unit.

[0047] Optionally, the acquisition module further comprises: obtaining geographic location information of the radio frequency unit that is pre-stored in the radio frequency unit; Second Time Serving Unit Using Obtaining geographic location information of the radio frequency unit; receiving geographic location information of the radio frequency unit from a network management device; or Positioning Unit UsingObtaining geographic location information of a radio frequency unit Any one of or It is configured to implement any combination thereof.

[0048] Optionally, the information relating to the radio frequency unit is clock information of the radio frequency unit.

[0049] Optionally, the acquisition module further comprises: Using It is configured to obtain clock information of the radio frequency unit.

[0050] In some embodiments, the unit in the communication device is implemented by using software, and the unit in the communication device is a program module. In some other embodiments, the unit in the communication device is implemented by using hardware or firmware. For specific details of the communication device provided in the fourth aspect, please refer to the second aspect or the optional scheme of the second aspect. Details will not be described again in this specification.

[0051] According to a fifth aspect, a communication device is provided, wherein the communication device includes a processor, the processor is coupled to a memory, the memory stores at least one computer program instruction, and the at least one computer program instruction is loaded and executed by the processor, so that the communication device implements the method provided in the first aspect or the optional manner of the first aspect. For specific details of the communication device provided in the fifth aspect, please refer to the first aspect or the optional manner of the first aspect. Details will not be described again in this specification.

[0052] According to a sixth aspect, a communication device is provided, wherein the communication device includes a processor, the processor is coupled to a memory, the memory stores at least one computer program instruction, and the at least one computer program instruction is loaded and executed by the processor, so that the communication device implements the method provided in the second aspect or the optional manner of the second aspect. For specific details of the communication device provided in the sixth aspect, please refer to the second aspect or the optional manner of the second aspect. Details will not be described again in this specification.

[0053] According to a seventh aspect, a computer-readable storage medium is provided. The storage medium stores at least one instruction. When the instruction is executed on a computer, the computer is enabled to perform the method provided in the first aspect or any of the options of the first aspect.

[0054] According to an eighth aspect, a computer-readable storage medium is provided. The storage medium stores at least one instruction. When the instruction is executed on a computer, the computer is enabled to perform the method provided in the second aspect or in any of the optional manners of the second aspect.

[0055] According to a ninth aspect, there is provided a computer program product, comprising one or more computer program instructions, which, when loaded and executed by a computer, enable the computer to perform the method provided in the first aspect or in any optional manner of the first aspect.

[0056] According to a tenth aspect, there is provided a computer program product comprising one or more computer program instructions which, when loaded and executed by a computer, enable the computer to perform the method provided in the second aspect or in any optional manner of the second aspect.

[0057] According to an eleventh aspect, there is provided a chip comprising programmable logic circuitry and / or program instructions, and configured to implement the method provided in the first aspect or any optional manner of the first aspect when the chip is operated.

[0058] According to a twelfth aspect, a chip is provided. do. The chip includes programmable logic circuitry and / or program instructions such that, when the chip operates, the chip is configured to implement the method provided in the second aspect or any optional manner of the second aspect.

[0059] According to a thirteenth aspect, there is provided a communication system, the communication system including a communication device according to the third aspect and a communication device according to the fourth aspect, or the communication system including a communication device according to the fifth aspect and a communication device according to the sixth aspect. [Brief description of the drawings]

[0060] [Figure 1] FIG. 1 is a schematic diagram of a fronthaul network in a distributed base station according to an embodiment of the present application; [Diagram 2] 1 is a schematic diagram of a communication system 10 according to an embodiment of the present application. [Diagram 3] 2 is a flowchart of a method for checking clock information according to an embodiment of the present application. [Figure 4] FIG. 2 is a schematic diagram of an application scenario according to an embodiment of the present application. [Diagram 5] FIG. 2 is a schematic diagram of an application scenario according to an embodiment of the present application. [Figure 6] 2 is a schematic diagram of the effect of mutual interference between base stations according to one embodiment of the present application; [Figure 7] FIG. 2 is a schematic diagram of an application scenario according to an embodiment of the present application. [Figure 8] FIG. 2 is a schematic diagram of an application scenario according to an embodiment of the present application. [Figure 9] FIG. 2 is a schematic diagram of an application scenario according to an embodiment of the present application. [Figure 10] FIG. 2 is a schematic diagram of clock processing performed by a BBU according to an embodiment of the present application. [Figure 11] FIG. 1 is a schematic diagram of writing longitude and latitude information during AAU placement according to one embodiment of the present application. [Figure 12] FIG. 2 is a schematic diagram of a BBU obtaining longitude and latitude information of an AAU from an AAU according to an embodiment of the present application. [Figure 13] FIG. 1 is a schematic diagram of disposing a GNSS receiver in an AAU to obtain location information according to one embodiment of the present application. [Figure 14] FIG. 2 is a schematic diagram of a BBU obtaining longitude and latitude information of an AAU from an AAU according to an embodiment of the present application. [Figure 15] FIG. 2 is a schematic diagram of a BBU obtaining longitude and latitude information of an AAU from an AAU according to an embodiment of the present application. [Figure 16] 1 is a schematic diagram of a structure of a communication device 300 according to an embodiment of the present application. [Figure 17] 4 is a schematic diagram of the structure of a communication device 400 according to an embodiment of the present application. [Figure 18] 5 is a schematic diagram of the structure of a communication device 500 according to an embodiment of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0061] In order to make the objectives, technical solutions and advantages of the present application clearer, the following further describes the implementation of the present application in detail with reference to the accompanying drawings.

[0062] In the following, certain terms and concepts in the embodiments of the present application are explained and described.

[0063] (1)Base station

[0064] A base station is a wireless communication site installed at a fixed location in a cellular mobile communication network. The main function of a base station is to provide wireless coverage and support communication between terminals and a core network. Base stations include, but are not limited to, evolutional Node B (eNB or eNodeB) in Long Term Evolution (LTE), base stations (gNodeB, gNB) in 5G (the fifth generation) networks such as New Radio (NR), etc. The physical structure of a base station mainly includes a baseband unit (BU) and a radio frequency unit (RU).

[0065] (2) Baseband unit

[0066] A BU is a module or device that has baseband signal processing functions and / or RU management functions. Baseband signal processing includes channel coding, multiplexing, modulation, spreading, power limiting on carriers, canceling power limiting, etc. For example, a BU may be a Building Baseband Unit (BBU), a Central Unit (CBU), a Building Baseband Unit (B ... l These include the Distributed Unit (DU), Distributed Unit (CU), etc.

[0067] (3) Radio Frequency Unit

[0068] An RU is a module or device that has the function of processing intermediate frequency signals, radio frequency signals, or intermediate frequency signals and radio frequency signals. For example, an RU is a Remote Radio Unit (RRU) or an Active Antenna Unit (AAU).

[0069] (4) Distributed Base Station (DBS)

[0070] A distributed base station is a base station in which a baseband unit and a radio frequency unit are separately arranged. is The core concept of the distributed base station is to divide the traditional macro base station into two functional modules according to functions. The base station's baseband, main control, transmission, clock and other functions are Modules, i.e. Baseband Unit (commonly called BBU) To The baseband unit is Compact size in flexible Have a configuration The intermediate and radio frequency functions, such as the transceiver and power amplifier, are integrated into a separate radio frequency unit (commonly called the RRU), which is then connected to the antenna. Na The radio frequency unit and the baseband unit are connected through optical fibers to form a distributed base station.

[0071] (5) CU and DU

[0072] In the 5G network, the BBU is evolved into two entities: CU and DU. The CU is mainly configured to perform non-real-time functions, such as upper layer protocol stack processing, such as Packet Data Convergence Protocol (PDCP) layer processing and Radio Resource Control (RRC) layer processing. Optionally, the CU is further configured to perform some functions of core network and edge application services. The DU is mainly configured to perform real-time functions in the BBU, such as Media Access Control (MAC) layer and Radio Link Control (RLC) layer function modules.

[0073] (6) AAU

[0074] In a 5G network, the RRU and the passive antenna are integrated to form an AAU. The AAU is configured to implement the functions of the RRU and the antenna. Optionally, the AAU is further configured to implement some physical layer functions in a BBU.

[0075] (7) Common Public Radio Interface (CPRI)

[0076] CPRI is an interface standard between BBU and RRU, and is used to replace traditional coaxial cable connection. The CPRI protocol gives specifications for the communication interface between Radio Equipment Control (REC) and Radio Equipment (RE) in a cellular wireless network. A typical example of a REC is a BBU, and a typical example of a RE is an RRU. CPRI is an interface standard based on a direct cable connection, uses TDM to implement data multiplexing, requires exclusive transmission bandwidth, and defines three types of data streams: user, control and management, and synchronization. The user plane data stream is used to transmit a quantized IQ modulated signal (where I is in-phase and q is quadrature) of the RRU antenna.

[0077] (8) Enhanced Common Public Radio Interface (enhanced CPRI, eCPRI)

[0078] eCPRI is an interface standard evolved from CPRI. The eCPRI protocol defines a specification for connecting an eCPRI REC (eREC) and an eCPRI RE (eRE) through a fronthaul network. A typical example of an eREC is a BBU, and a typical example of an eRE is an AAU or an RRU. Unlike CPRI, eCPRI is a packet-based interface standard that does not specify the network implementation and can be implemented based on any network, such as Ethernet, Internet Protocol (IP), Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and optical transport network (OTN). Based on the BBU-RRU split mode defined in the 3rd Generation Partnership Project (3GPP), eCPRI provides several split modes. By splitting some or all of the physical layer functions into the RRU, the data transmitted between the BBU and the RRU is changed from an IQ signal on the antenna to a modulation symbol (IID), a coded bit sequence (ID), and even the original data bit (D). Compared with CPRI, eCPRI helps reduce the transmission bandwidth between the baseband unit and the radio frequency unit, and meets the bandwidth requirements of wideband multi-antenna services such as massive multiple-in multiple out (Massive MIMO).

[0079] eCPRI includes a User Plane (U-plane, also called Data Plane) interface, a Synchronization Plane (S-plane) interface, and a Control & Management Plane (C&M plane or C-plane) interface. The User Plane interface is used to transmit IQ data, i.e., sampling data obtained through Orthogonal Frequency Division Multiplexing (OFDM) modulation. The Synchronization Plane is used by the BBU to transmit clock synchronization signals to the RRU. The Control & Management Plane interface is used to transmit Operation Administration and Maintenance (OAM) operation, maintenance, and management data of the BBU to the RRU.

[0080] (9) Fronthaul Interface and Fronthaul Network

[0081] The fronthaul interface refers to a communication interface between a baseband unit and a radio frequency unit. The fronthaul interface includes, but is not limited to, CPRI or eCPRI. Of course, the fronthaul interface can also be another interface evolved from CPRI or eCPRI. The fronthaul network is a connection switching network between the baseband unit and the radio frequency unit. Figure 1 is a schematic diagram of a fronthaul network in a distributed base station defined in the eCPRI protocol. As shown in Figure 1, the fronthaul network is a network between an eREC (i.e., a baseband unit such as a BBU) and an eRE (i.e., a radio frequency unit such as an AAU or an RRU).

[0082] (10) Time serving unit

[0083] A time serving unit is a module or device configured to provide time information based on received signals. Time serving units include, but are not limited to, satellite time serving units, network time serving units based on the Network Time Protocol (NTP), terrestrial radio time serving units, television network time serving units, etc. A satellite time serving unit, also called a satellite clock source, is a unit, e.g., a GNSS receiver, that receives satellite signals and determines time information based on the satellite signals. An NTP-based network time serving unit is a network clock source that receives satellite signals and determines time information based on the satellite signals. On It is a unit that determines time information by exchanging packets with an NTP server. For example, an NTP-based network time serving unit can be a 1588v2 clock processing unit or an NTP client.

[0084] (11) Satellite navigation system (Global Navigation Satellite System, GNSS)

[0085] GNSS is a satellite system that uses spatial positioning and allows a receiver to determine its location and time based on satellite signals. GNSS includes four global satellite systems, including the United States' Global Positioning System (GPS), which is formed by 24 satellites, Russia's Global Positioning System (GLONASS), China's Bei Dou satellite navigation system (BDS), and the European Union's Galileo satellite navigation system (Galileo). In addition, GNSS further includes regional systems and augmentation systems. Regional systems are, for example, Japan's Quasi-Zenith Satellite System (QZSS) and India's Indian Regional Navigation Satellite System (IRNSS). Augmentation systems are, for example, the United States' Wide Area Augmentation System (WAAS).

[0086] The system architecture of GNSS is mainly divided into three parts: space part, ground part, and user part. The space part mainly includes multiple satellites. The ground part mainly includes control stations and monitoring stations. The user part mainly includes GNSS receivers.

[0087] (12) GNSS receiver

[0088] GNSS receivers are also called GNSS time serving receivers. The function of a GNSS receiver is to receive signals from GNSS satellites and use the satellite signals to calculate location and time. The hardware structure of a GNSS receiver includes an antenna, a processor, a memory, an input / output (IO) interface, a frequency converter, a signal channel, etc. GNSS receivers are used for navigation, positioning, time serving, and geodesy purposes. Two typical applications of a GNSS receiver in a base station are time serving and positioning.

[0089] The basic principle of using a GNSS receiver by a base station to implement time serving is as follows: the GNSS receiver is disposed in the base station, which receives radio frequency signals from the GNSS antenna, implements signal processing such as frequency conversion and demodulation, and provides time serving information to the base station, so that the base station implements clock synchronization by using the time serving information provided by the GNSS receiver.

[0090] (13) Clock synchronization

[0091] Clock synchronization is a concept in computer science and engineering that aims to coordinate multiple independent clocks. In fact, even if the times of multiple clocks are adjusted to be the same, the times will still appear as different due to clock drift after a certain period of time. This is because the timing rates of different clocks are slightly different. The difference in clock timing rates creates many problems. Therefore, a clock source must ensure that the timing rates and time deviations of different clocks are within a reasonable range. Retained It needs to be referenced for calibration to ensure that it is accurate.

[0092] (14) Time Division Duplex (TDD)

[0093] The uplink and downlink of a (mobile communication) system use the same frequency band, and the uplink and downlink are transmitted in different slots. Within the frequency band, the time occupied by the uplink and downlink can be adjusted as necessary, and the time occupied by the uplink and downlink is generally divided into several time periods at fixed intervals called slots. A TDD system requires that the base station supports time synchronization.

[0094] (15) Clock holdover mode

[0095] The clock holdover mode is a working mode that can be used when the tracked clock source is abnormal. The basic principle of the clock holdover mode is as follows: When the clock source is found to be abnormal, the last frequency information stored before the clock source is abnormal is used as the timing reference. In this working mode, the clock accuracy is high, but the mode cannot be maintained for a long time.

[0096] Taking the application in a base station as an example, the clock holdover mode is a working mode that the system clock of the base station can use when it recognizes that the reference clock is abnormal. In the clock holdover mode, the base station can normally provide service within the holdover period, but the holdover period depends on the holdover capability of the clock device and the system algorithm capability, for example, 24 hours. After the holdover period expires, the system clock of the base station cannot meet the service requirements, and service interference may occur.

[0097] (16) Pulse Per Second (PPS)

[0098] 1PPS is one pulse per second. It represents the total second moment. The moment is generally represented by the rising edge of the pulses per second.

[0099] (17) Primary Reference Clock (PRC)

[0100] The PRC is a national reference clock that includes a cesium atomic clock and conforms to the G.811 standard.

[0101] (18) Institute of Electrical and Electronics Engineers (IEEE) 1588 Protocol

[0102] IEEE1588 protocol is short for PTP (Precision Timing Protocol). Its full name is IEEE 1588 Precision Clock Synchronization Protocol for Network Measurement and Control Systems. The basic working principle of the protocol is that a synchronization data frame is sent between the master node and the slave node, the sending time and receiving time information of the data frame are recorded, and the time information is added to the data frame. The slave node obtains the time information, calculates the time deviation between the slave node's local clock and the master clock and the transmission delay between the network nodes, corrects the local clock, and synchronizes the local clock with the master clock. IEEE1588 has two versions, IEEE1588v1 and IEEE1588v2. The v1 version is developed for industrial automatic measurement and control systems and is applicable to industrial local area network applications. The v2 version is developed based on the v1 version and is specifically designed for communication networks.

[0103] (19) Synchronous Ethernet (SyncE)

[0104] SyncE is a technology that recovers clock by using a code stream on an Ethernet link. SyncE recovers clock at the transmitting end from a serial data bit stream through an Ethernet physical layer chip. In this way, network clock synchronization is implemented.

[0105] The following describes the system architecture of the communication system provided in one embodiment of the present application by using an example.

[0106] FIG. 2 is a schematic diagram of a communication system 10 according to one embodiment of the present application.

[0107] The communication system 10 is any system that implements communication based on wireless communication technology, such as a cellular mobile network system, a wireless local area network (WLAN) system, or a communication network that integrates WLAN and cellular mobile networks.

[0108] Optionally, the communication system 10 is a 5G network system, such as NR, or a system of a next-generation communication technology developed based on 5G, or the communication system 10 is a 4G system, such as an LTE system. The network standard of the communication system 10 is not limited in this embodiment.

[0109] The following describes the functions of the devices in the communication system shown in Fig. 2 and the connection relationships between different devices in the communication system in the manner shown in Fig. 3. For further details of the devices in the communication system, please refer to the descriptions of the base station, baseband unit, radio frequency unit and time serving unit in the above explanation of the terminology concept.

[0110] As shown in FIG. 2, the communication system 10 includes a baseband unit 101, at least one radio frequency unit 102, and a time serving unit 103.

[0111] The baseband unit 101 is configured to control the communication system to implement clock synchronization. For example, the baseband unit 101 uses the time serving unit 103 as a reference source for clock synchronization of the communication system 10. The baseband unit 101 distributes clock information provided by the time serving unit 103 to each radio frequency unit 102, and each radio frequency unit 102 corrects its local clock according to the clock information sent by the baseband unit 101, thereby implementing clock synchronization of the whole system.

[0112] The time serving unit 103 is configured to determine clock information based on the received signal, and provide the clock information to the baseband unit 101. There are many specific implementations of the time serving unit 103. In the following, implementations 1 to 3 are used as examples for explanation.

[0113] Implementation 1: The time serving unit 103 and the baseband unit 101 are implemented in an integrated manner. In other words, the time serving unit 103 and the baseband unit 101 are integrated into a hardware device. For example, the time serving unit 103 is disposed in the baseband unit 101, and the time serving unit 103 is a functional unit of the baseband unit 101.

[0114] Implementation 2: The time serving unit 103 and the baseband unit 101 are disposed separately. For example, the time serving unit 103 and the baseband unit 101 are connected through a feeder, an optical fiber, or a network, and the time serving unit 103 communicates with the baseband unit through an interface.

[0115] Implementation 3: Some components of the time serving unit 103 are integrated with the baseband unit 101, and other components are arranged separately from the baseband unit 101. For example, the time serving unit 103 includes an antenna and a processor. The antenna of the time serving unit 103 is arranged outside the baseband unit 101, and the processor of the time serving unit 103 is arranged in the baseband unit 101. For example, the processor of the time serving unit 103 is integrated with the processor of the baseband unit 101.

[0116] The radio frequency unit 102 serves as a data source for determining whether the time serving unit 103 is reliable. In particular, the radio frequency unit 102 is arranged to provide information to the baseband unit 101, such that the baseband unit 101 determines, based on the information provided by the radio frequency unit 102, whether the clock information provided by the time serving unit 103 is available.

[0117] The baseband unit 101 and the at least one radio frequency unit 102 are connected through a fronthaul network. The fronthaul network generally refers to the network between the baseband unit 101 and the radio frequency unit 102.

[0118] The baseband unit 101 is connected to at least one radio frequency unit 102. The manner of connection between the baseband unit 101 and the at least one radio frequency unit 102 includes multiple implementations, for example, the baseband unit 101 and the at least one radio frequency unit 102 are connected through a wired network. Optionally, the baseband unit 101 is connected to the at least one radio frequency unit 102 through an optical fiber. Alternatively, the baseband unit 101 and the at least one radio frequency unit 102 are connected through a Passive Optical Network (PON). Alternatively, the baseband unit 101 is connected to the at least one radio frequency unit 102 through a feeder.

[0119] Optionally, the baseband unit 101 is physically directly connected to the at least one radio frequency unit 102. Alternatively, the baseband unit 101 and the at least one radio frequency unit 102 are connected through one or more forwarding devices (e.g., switches or routers).

[0120] It is optional that the time serving unit described in Fig. 2 is disposed in a baseband unit. In this case, the baseband unit optionally uses a local time serving unit as a reference source for system clock synchronization. In some other embodiments, the time serving unit is disposed in a radio frequency unit. In this case, the baseband unit optionally uses a time serving unit in the radio frequency unit as a reference source for system clock synchronization. Furthermore, when the time serving unit is disposed in a radio frequency unit, the time serving unit and the radio frequency unit are optionally disposed separately or integrated together. This is not limited in this embodiment.

[0121] The following describes the method process provided in one embodiment of the present application by using an example.

[0122] Fig. 3 is a flow chart of a method for checking clock information according to an embodiment of the present application. The interacting subjects of the method shown in Fig. 3 include a baseband unit, a radio frequency unit and a time serving unit. The method shown in Fig. 3 includes the following steps S201 to S207.

[0123] A network deployment scenario on which the method shown in Figure 3 is based is optionally shown in Figure 2. For example, referring to Figure 2, the baseband unit in the method shown in Figure 3 is the baseband unit 101 in Figure 2, and the radio frequency unit in the method shown in Figure 3 is the radio frequency unit 102 in Figure 2. The time serving unit in the method shown in Figure 3 is the time serving unit 103 in Figure 2.

[0124] The method illustrated in Figure 3 concerns information provided by a radio frequency unit to a baseband unit and information provided by a time serving unit to the baseband unit. In order to distinguish between information from different sources, "first information" is used to describe the information provided by the time serving unit.

[0125] In the method shown in Fig. 3, the process is explained by using an example in which the baseband unit and the time serving unit are separately arranged. The time serving unit performs S204 and S205, and the baseband unit performs S206 and S207. When the baseband unit and the time serving unit are integrated, S204, S205, S206, and S207 are all implemented by the device integrated by the baseband unit and the time serving unit. For example, when the time serving unit is integrated into the baseband unit, the following S204, S205, S206, and S207 are all implemented in the baseband unit.

[0126] The method shown in FIG. 3 is explained by using an example in which S201 to S203 are performed first, and then S204 to S206 are performed. In some other embodiments, S204 to S206 are performed first, and then S201 to S203 are performed. In some other embodiments, S201 to S203 and S204 to S206 are performed simultaneously. The sequence of S201 to S203 and S204 to S206 is not limited in this embodiment.

[0127] The method shown in FIG. 3 is explained by using an example in which a baseband unit performs S206 and S207. In some other embodiments, a radio frequency unit performs S206 and S207. For example, when a time serving unit is disposed in a radio frequency unit, the time serving unit provides the first information to the radio frequency unit. After the radio frequency unit receives the first information sent by the time serving unit, optionally, the radio frequency unit sends the first information and the information of the radio frequency unit to the baseband unit, and the baseband unit determines whether the clock information of the time serving unit is available based on the two types of information provided by the radio frequency unit. Alternatively, the radio frequency unit determines whether the clock information provided by the time serving unit is available based on the first information and the information about the radio frequency unit, and sends the determination result to the baseband unit.

[0128] Optionally, the method shown in FIG. 3 is applied to the base station. For example, the baseband unit of the base station receives information provided by the radio frequency unit of the local site. Based on , to determine whether a local time serving unit is available. In this scenario, the baseband unit, the radio frequency unit and the time serving unit in the method shown in FIG. 3 are components of the same base station in a communication system. Alternatively, FIG. 3 is implemented by different base stations through dialogue. For example, the baseband unit of a base station may use information provided by a radio frequency unit of an adjacent or remote site. Based on, determine whether a local time serving unit is available. In this scenario, the baseband unit and the radio frequency unit in the method shown in Fig. 3 are components of different base stations. For example, the communication system includes a first base station and a second base station, the baseband unit and the time serving unit are components included in the first base station, and the radio frequency unit is a component included in the second base station.

[0129] S201: The radio frequency unit obtains information about the radio frequency unit.

[0130] The information acquired by the radio frequency unit includes, but is not limited to, geographic location information of the radio frequency unit and / or clock information of the radio frequency unit. In the following, an example is used to describe the type of information acquired by the radio frequency unit and the specific implementation of acquiring the information. For details, please refer to (A) and (B) below.

[0131] (A) Geographic location information of the radio frequency unit

[0132] From an information function point of view, the geographic location information of a radio frequency unit indicates the geographic location of the radio frequency unit.

[0133] From the information form point of view, optionally, the geographical location information of the radio frequency unit includes a longitude of the location of the radio frequency unit and a latitude of the location of the radio frequency unit, where the longitude and latitude indicate the location of the radio frequency unit in the Earth coordinate system. Optionally, the geographical location information of the radio frequency unit further includes an altitude of the radio frequency unit.

[0134] Alternatively, the geographic location information of the radio frequency unit is other information that can represent the geographic location of the radio frequency unit in addition to longitude and latitude. For example, the geographic location information of the radio frequency unit is a three-dimensional point coordinate of the radio frequency unit, for example, a three-dimensional point coordinate of the radio frequency unit in various three-dimensional coordinate systems, such as a geographic coordinate system, a navigation coordinate system, a carrier coordinate system, and an earth coordinate system. In another example, the three-dimensional space is divided into many spatial rasters, and the geographic location information of the radio frequency unit is an identifier of the spatial raster in which the radio frequency unit is located.

[0135] The radio frequency unit acquires geographic location information in a number of implementations. In the following, implementations 1 to 5 are described that may be used when the radio frequency unit acquires geographic location information by using an example.

[0136] Implementation 1: The radio frequency unit pre-stores the geographic location information during the site construction phase, and optionally, the geographic location information is obtained through survey by a network manager by using survey and mapping equipment during survey of the site.

[0137] Implementation 2: The radio frequency unit includes a positioning element, and the radio frequency unit use The positioning element is configured to determine a geographic location of the positioning element by using a GPS receiver. The positioning element in the radio frequency unit is, for example, a GNSS receiver or various wireless positioning elements such as an infrared sensor, an ultrasonic sensor, and a Bluetooth module.

[0138] Implementation 3: The network management device obtains the geographical location information of the radio frequency unit, and the network management device sends the geographical location information of the radio frequency unit to the radio frequency unit. The radio frequency unit receives the geographical location information of the radio frequency unit sent by the network management device.

[0139] Implementation 4: The radio frequency unit obtains the geographic location information of the radio frequency unit through measurement. For example, one or more designated network elements whose locations are known send positioning reference signals to the radio frequency unit. After the radio frequency unit receives the positioning reference signals, the radio frequency unit determines the distance between the radio frequency unit and the designated network elements based on the transmission delay of the positioning reference signals, and then determines the geographic location of the radio frequency unit based on the distance and the location of the designated network elements.

[0140] Implementation 5: The radio frequency unit calls a communication interface provided by the positioning server to request the positioning server to determine the geographic location of the radio frequency unit. The positioning server obtains the geographic location information of the radio frequency unit in response to the request of the radio frequency unit, and sends the geographic location information to the radio frequency unit.

[0141] (B) Radio frequency unit clock information

[0142] The clock information of the radio frequency unit includes, but is not limited to, at least one of time information, frequency information, or phase information. The clock information of the radio frequency unit has many forms. The following describes the forms of the clock information of the radio frequency unit by using examples related to (B-1) to (B-3).

[0143] (B-1) The clock information of the radio frequency unit is a periodic pulse signal.

[0144] Optionally, the clock information of the radio frequency unit is a square wave signal, for example a 1PPS signal. The location of a rising edge or a falling edge in the pulse signal represents a time point. The number of pulses in a time period of the pulse signal indicates the frequency.

[0145] (B-2) The clock information of the radio frequency unit includes a specific value of time, frequency, or phase.

[0146] For example, the time information of the radio frequency unit is a specific value of year, month, day, hour, minute, and second, e.g., 18:20:10 on December 20, 2021. The news is , in seconds Measured In another example, the frequency information of the radio frequency unit is a frequency of a particular value, for example, megahertz, kilohertz, or gigahertz.

[0147] (B-3) The time information of the radio frequency unit is an identifier of a time within a radio frame, for example, a frame number or a subframe number.

[0148] S202: The radio frequency unit sends information about the radio frequency unit to a baseband unit in the communication system.

[0149] In one exemplary embodiment, the radio frequency unit calls the fronthaul interface and sends information about the radio frequency unit to the baseband unit through the fronthaul interface.

[0150] The type of fronthaul interface used to transmit information about the radio frequency unit between the radio frequency unit and the baseband unit described above includes multiple implementations. The following describes the types of fronthaul interfaces that can be used to transmit information about the radio frequency unit between the radio frequency unit and the baseband unit by using examples, with respect to implementations a to d.

[0151] Implementation a: The radio frequency unit sends geographic location information, clock information, and / or other information of the radio frequency unit to the baseband unit through the fronthaul interface of the synchronous plane. The baseband unit receives the geographic location information, clock information, and / or other information of the radio frequency unit through the fronthaul interface of the synchronous plane.

[0152] Implementation b: The radio frequency unit sends the geographic location information, clock information, and / or other information of the radio frequency unit to the baseband unit through the fronthaul interface of the management plane. The baseband unit receives the geographic location information, clock information, and / or other information of the radio frequency unit through the fronthaul interface of the management plane.

[0153] Implementation c: The radio frequency unit sends the geographical location information, clock information, and / or other information of the radio frequency unit to the baseband unit through the fronthaul interface of the control plane. The baseband unit receives the geographical location information, clock information, and / or other information of the radio frequency unit through the fronthaul interface of the control plane.

[0154] Implementation d: The radio frequency unit sends the geographical location information, clock information, and / or other information of the radio frequency unit to the baseband unit through the fronthaul interface of the user plane. The baseband unit receives the geographical location information, clock information, and / or other information of the radio frequency unit through the fronthaul interface of the user plane.

[0155] For a specific implementation in which the radio frequency unit sends information through a fronthaul interface, the following describes technical details by using an example in which the fronthaul interface is eCPRI.

[0156] In a possible implementation, the radio frequency unit generates an eCPRI message based on information about the radio frequency unit and sends the eCPRI message to the baseband unit, the eCPRI message including information about the radio frequency unit.

[0157] In locations where information about radio frequency units is carried in eCPRI messages, in a possible implementation, a new type of Type-Length-Value (TLV) is extended in the eCPRI message to carry information about radio frequency units. The TLV includes a type field, a length field, and a value field. The type field carries type information of the TLV, which indicates that the TLV carries information about radio frequency units. The length field carries length information of the TLV, which indicates the length of the information about radio frequency units in the TLV. octet The Value field conveys information about the radio frequency unit.

[0158] Referring to Scheme 1 to Scheme 4, the following uses an example to describe the type of protocol packet that carries the geographic location information, clock information, and / or other information of the radio frequency unit.

[0159] Scheme 1: 1588 protocol packets (eg, IEEE 1588v2 packets) carry eCPRI messages that include geographic location information, clock information, and / or other information of the radio frequency unit.

[0160] For example, the radio frequency unit generates a 1588v2 packet and sends it to the baseband unit, where the payload field of the 1588v2 packet includes geographic location information, clock information, and / or other information.

[0161] Method 2: SyncE protocol packets, Simple Network Management Protocol (SNMP) packets, Hyper Text Transfer Protocol (HTTP) packets, or Hyper Text Transfer Protocol over Secure Sockets Layer (HSLA) packets. eS The eCPRI (Universal Socket Layer, HTTPS) packets carry eCPRI messages that include geographic location information, clock information, and / or other information of the radio frequency units.

[0162] Scheme 3: A protocol packet dedicated to carrying eCPRI messages is used to carry eCPRI messages that include information about the radio frequency units.

[0163] Method 4: The TCP / IP protocol stack is skipped and the MAC Ethernet frame is used to carry the eCPRI message, which contains information about the radio frequency unit.

[0164] It is optional for the radio frequency unit described above to use the eCPRI fronthaul interface to send information. In some other embodiments, the radio frequency unit uses a fronthaul interface other than eCPRI, for example, an interface evolved from CPRI or eCPRI, to send information, or uses another interface between the radio frequency unit and the baseband unit to send information. The specific fronthaul interface used by the radio frequency unit to send information to the radio frequency unit is not limited in this embodiment. Furthermore, for a specific implementation of sending information by using another fronthaul interface other than eCPRI, please refer to the above description of sending information by using eCPRI.

[0165] The occasions that the radio frequency unit reports information to the baseband unit include multiple cases. The following describes the occasions that the radio frequency unit reports information to the baseband unit by using examples about Case 1 to Case 3.

[0166] Case 1: A radio frequency unit periodically transmits its geographic location information, clock information, and / or other information.

[0167] For example, the radio frequency unit periodically acquires geographic location information, clock information, and / or other information of the radio frequency unit each time, and sends the acquired information to the baseband unit. The length of the time period is set according to requirements, for example, a Transmission Time Interval (TTI).

[0168] Case 2: When receiving signaling from the baseband unit, the radio frequency unit sends out geographic location information, clock information, and / or other information of the radio frequency unit.

[0169] For example, when the baseband unit needs to determine whether clock information is available, the baseband unit generates one signaling and sends it to the radio frequency unit, where the signaling indicates to the radio frequency unit to report the geographical location information, clock information, and / or other information of the radio frequency unit. When the radio frequency unit receives the signaling of the baseband unit, the radio frequency unit obtains the geographical location information, clock information, and / or other information of the radio frequency unit and sends the obtained information to the baseband unit.

[0170] Case 3: The radio frequency unit sends out geographic location information, clock information, and / or other information of the radio frequency unit when transmitting service data.

[0171] For example, when sending service data to a baseband unit, the radio frequency unit encapsulates the service data along with geographical location information, clock information, and / or other information of the radio frequency unit in the same packet and sends the packet containing the service data and information about the radio frequency unit to the baseband unit.

[0172] S203: The baseband unit receives information about the radio frequency unit from the radio frequency unit.

[0173] The above S201 to S203 describe the interaction between the baseband unit and the radio frequency unit. In a scenario where there are multiple radio frequency units, the baseband unit and the multiple radio frequency units can be optionally each performs similar processes as S201 to S203, and thus the baseband unit obtains information about the multiple radio frequency units.

[0174] The above S201 to S203 describe the interaction between the baseband unit and the radio frequency unit to obtain information about the radio frequency unit. Alternatively, the baseband unit obtains information about the radio frequency unit from another device or network element other than the radio frequency unit. The following uses an example for Scheme 1 to Scheme 3.

[0175] Method 1: The network management device obtains geographic location information, clock information, and / or other information of the radio frequency unit, and sends the information about the radio frequency unit to the baseband unit. The baseband unit receives the information about the radio frequency unit from the network management device.

[0176] Method 2: The control plane device or the core network obtains geographic location information, clock information, and / or other information of the radio frequency unit, and sends the information about the radio frequency unit to the baseband unit. The baseband unit receives the information about the radio frequency unit from the control plane device or the core network.

[0177] Method 3: A network administrator configures the geographic location information, clock information, and / or other information of the radio frequency unit in the baseband unit by using a command line, a web interface, or the like.

[0178] S204: The time serving unit determines first information based on the received signal.

[0179] The signals received by the time serving unit include radio signals transmitted by satellites and / or radio signals transmitted by interference sources. For example, the time serving unit is a GPS receiver. In the case where interference does not exist, the signals received by the GPS receiver are radio signals transmitted by GPS satellites. In the case where interference exists, the signals received by the GPS receiver include radio signals transmitted by GPS satellites and / or radio signals transmitted by interference sources. When the interference is severe or the channel quality is insufficient, the GPS receiver may receive radio signals from the interference sources instead of from the GPS satellites. For example, FIG. 2 shows a scenario where both satellites and interference sources exist. When the satellites transmit radio signals, the interference sources also transmit radio signals. Thus, the time serving unit not only receives radio signals transmitted by satellites, but also receives radio signals transmitted by interference sources. The first information is any information that may be determined based on the signals received by the time serving unit.

[0180] Optionally, the first information is of a time serving unit and is geographical location information determined by the time serving unit based on a signal received by the time serving unit. The following describes the geographical location information determined by the time serving unit.

[0181] From the viewpoint of information function, the geographical location information determined by the time serving unit indicates the geographical location of the time serving unit. In other words, the geographical location information determined by the time serving unit is the geographical location information of the time serving unit. For example, the geographical location information determined by the time serving unit indicates the geographical location of the antenna of the time serving unit. For example, referring to FIG. 4, the GNSS receiver in FIG. 4 is an example of a time serving unit, and the point P in FIG. 4 is an example of the location of the antenna of the GNSS receiver, and the geographical location information determined by the time serving unit indicates, for example, the location of the point P.

[0182] From the viewpoint of information form, optionally, the geographical location information determined by the time serving unit includes a longitude of a location of the time serving unit and a latitude of a location of the time serving unit, where the longitude and latitude indicate a location of the time serving unit in the Earth coordinate system. Optionally, the geographical location information determined by the time serving unit further includes an altitude of the time serving unit.

[0183] Alternatively, the geographic location information determined by the time serving unit is other information that can represent the geographic location of the time serving unit in addition to longitude and latitude. For example, the geographic location information determined by the time serving unit is a three-dimensional point coordinate of the time serving unit, for example, a three-dimensional point coordinate of the time serving unit in various three-dimensional coordinate systems such as a geographic coordinate system, a navigation coordinate system, a carrier coordinate system, and an earth coordinate system.

[0184] Optionally, the first information is clock information determined by the time serving unit based on a signal received by the time serving unit. The clock information determined by the time serving unit includes, but is not limited to, at least one of time information, frequency information, or phase information. In terms of information form, optionally, the clock information determined by the time serving unit is a periodic pulse signal (e.g., 1PPS). In another example, the clock information determined by the time serving unit includes a specific value of time, frequency, or phase.

[0185] The geographical location information and the clock information described above have an AND / OR logical relationship. Optionally, the time serving unit determines both the geographical location information and the clock information based on the received signal, and provides both the determined geographical location information and the determined clock information to the baseband unit. For example, the time serving unit includes multiple IO interfaces, and when one IO interface outputs a pulse signal including the clock information, another IO interface outputs the geographical location information. In another example, the time serving unit determines and provides one of the geographical location information and the clock information.

[0186] S205: The time serving unit provides first information to the baseband unit.

[0187] S206: The baseband unit includes a time serving unit. use to obtain the first information.

[0188] The time serving unit provides the first information to the baseband unit in several implementations. In the following, several possible implementations in which the time serving unit provides the first information to the baseband unit for schemes A to C are used as illustrative examples.

[0189] Scheme A: The time serving unit includes an IO interface, and the time serving unit outputs the first information through the IO interface. The baseband unit receives the first information output by the time serving unit from the IO interface.

[0190] Scheme B: The time serving unit includes a network interface, and the time serving unit encapsulates the first information in a packet, where a destination address of the packet is an address of the baseband unit. The time serving unit sends the packet carrying the first information to the baseband unit through the network interface of the time serving unit. The baseband unit receives the packet carrying the first information through the network interface of the baseband unit.

[0191] Method C: The time serving unit stores the first information in a designated memory built in the time serving unit, and provides the storage address of the first information to the baseband unit. The baseband unit accesses the designated memory on the time serving unit based on the storage address of the first information to obtain the first information.

[0192] The above described case in which the time serving unit determines and outputs the first information is an optional manner. In some other embodiments, after the time serving unit outputs the information, the baseband unit determines the first information according to the information output by the time serving unit.

[0193] The information output by the time serving unit is the information output by the time serving unit through an IO interface, a network interface, etc. For example, the information output by the time serving unit and the information provided by the radio frequency unit may have different attributes, dimensions, or formats. The baseband unit first converts the information output by the time serving unit to obtain first information, and then performs a subsequent step based on the first information obtained through calculation. For example, the information output by the time serving unit is clock information, and the information provided by the radio frequency unit is geographical location information. After the baseband unit receives the clock information output by the time serving unit, the baseband unit calculates geographical location information of the time serving unit based on the clock information output by the time serving unit, and then determines whether the clock information provided by the time serving unit is available based on the geographical location information obtained through calculation and the geographical location information provided by the radio frequency unit.

[0194] S207: The baseband unit determines, based on the information about the at least one radio frequency unit and the first information, whether the clock information provided by the time serving unit is available.

[0195] For example, the baseband unit uses information provided by the radio frequency unit as reference information, and based on the information provided by the radio frequency unit, the baseband unit helps to determine whether the information provided by the time serving unit is reliable, and determines whether to use the clock information provided by the time serving unit to perform clock synchronization.

[0196] In some embodiments, the specific process of determining, by the baseband unit, whether the clock information is available includes determining, by the baseband unit, whether to use the clock information provided by the time serving unit based on a deviation between the information provided by the time serving unit and the information provided by the radio frequency unit. In particular, the baseband unit obtains at least one deviation based on the information on the at least one radio frequency unit and the first information provided by the time serving unit, and the baseband unit determines, based on the at least one deviation and a threshold value, whether the clock information provided by the time serving unit is available.

[0197] The deviation is the deviation between the first information provided by the time serving unit to the baseband unit and the information provided by the radio frequency unit to the baseband unit. The threshold is a parameter used to determine whether the deviation is within a proper range. Optionally, the threshold is pre-stored in the baseband unit. With reference to Case 1 and Case 2, the following describes a specific form of the deviation determined by the baseband unit and the threshold used by the baseband unit by using an example.

[0198] Case 1: The information given by the radio frequency unit to the baseband unit is the geographic location information of the radio frequency unit, and the first information given by the time serving unit to the baseband unit is the geographic location information obtained by the time serving unit based on the received signal. The deviation refers to the deviation between the geographic location of the time serving unit and the geographic location of the radio frequency unit, i.e., the spatial distance between the radio frequency unit and the time serving unit. The above threshold is a spatial distance threshold. Optionally, the threshold is the sum of the distance between the radio frequency unit and the baseband unit and the maximum error allowed to occur in the time serving unit. For example, if the radio frequency unit is located at a location 1000 meters away from the baseband unit and a maximum error of 100 meters is allowed when the time serving unit outputs the location, the threshold is 1100 meters.

[0199] Case 2: The information provided by the radio frequency unit to the baseband unit is clock information of the radio frequency unit, and the first information provided by the time serving unit to the baseband unit is clock information obtained by the time serving unit based on the received signal. The deviation is a deviation of the clock of the time serving unit relative to the clock of the radio frequency unit, and the deviation includes at least one of a time difference, a frequency deviation, or a phase deviation. The threshold includes at least one of a spatial distance threshold, a time difference threshold, a frequency deviation threshold, or a phase deviation threshold. The time difference is the difference between the time of the time serving unit and the time of the radio frequency unit. The frequency deviation is the difference between the frequency of the time serving unit and the frequency of the radio frequency unit. The phase deviation is the difference between the phase of the time serving unit and the phase of the radio frequency unit.

[0200] In the following, the principles of making decisions based on geographic location information are described.

[0201] The location of the radio frequency unit is equivalent to a known reference location. If the location determined by the time serving unit is inaccurate due to interference with the time serving unit, the deviation between the location determined by the time serving unit and the known reference location increases. Therefore, whether the time serving unit is reliable can be accurately determined by determining whether the deviation between the location determined by the time serving unit and the location of the radio frequency unit is greater than a threshold value.

[0202] When multiple radio frequency units are deployed, optionally the baseband unit is Each of and the first information to obtain a plurality of deviations. The baseband unit determines whether the time serving unit is available based on the plurality of deviations. In particular, the baseband unit obtains a deviation between the information given by Based on How to implement the determining includes multiple schemes. Referring to scheme 1 to scheme 4, the following describes how the baseband unit: Based on multiple deviations, By using an example At that time Next, a specific method for determining whether a serving unit is available will be described.

[0203] Method 1: The baseband unit determines whether each of a plurality of deviations is greater than a threshold value. If each deviation is greater than the threshold value, the baseband unit determines that the clock information provided by the time serving unit is unavailable. If one of the deviations is equal to or less than the threshold value, the baseband unit determines that the clock information provided by the time serving unit is available. In other words, if the information provided by all the radio frequency units indicates that the information provided by the time serving unit is inappropriate, it is determined that the clock information provided by the time serving unit is unavailable.

[0204] Method 2: The baseband unit is One of them is greater than a threshold value. If one of the deviations is greater than a threshold value, the baseband unit determines that the clock information provided by the time serving unit is unavailable. If each deviation is equal to or less than a threshold value, the baseband unit determines that the clock information provided by the time serving unit is available. In other words, if the information provided by one radio frequency unit indicates that the information provided by the time serving unit is inappropriate, it is determined that the clock information provided by the time serving unit is unavailable.

[0205] Method 3: The baseband unit determines whether each of the multiple deviations is greater than a threshold value. death, Determine the ratio of deviations that are greater than a threshold value among the plurality of deviations. Specific If the ratio is reached, the baseband unit determines that the clock information provided by the time serving unit is unavailable.

[0206] Method 4: The baseband unit determines whether each of the plurality of deviations is greater than a threshold value. death, Determine the quantity of deviations greater than the threshold. Specific If the quantity is reached, the baseband unit determines that the clock information provided by the time serving unit is unavailable.

[0207] In some embodiments, after the baseband unit determines whether the clock information provided by the time serving unit is available, the baseband unit performs different processing actions according to different determination results. With reference to scheme a to scheme c, the following uses an example to describe the processing actions that the baseband unit can perform after determining whether the clock information provided by the time serving unit is available.

[0208] Method a: if the baseband unit determines that the clock information provided by the time serving unit is available, the baseband unit performs clock synchronization by using the clock information provided by the time serving unit. If the baseband unit determines that the clock information provided by the time serving unit is unavailable, the baseband unit stops using the time serving unit as a clock reference source, i.e., stops performing clock synchronization based on the clock information provided by the time serving unit.

[0209] Scheme b: There are multiple candidate time serving units in the communication system, and each time serving unit provides clock information to the baseband unit. By using the above method, if the baseband unit determines that the clock information provided by one of the time serving units is unavailable, the baseband unit determines other time serving units other than the time serving unit as a clock reference source, and performs clock synchronization by using the clock information provided by the other time serving units.

[0210] Method c: When the baseband unit determines that the clock information provided by the time serving unit is unavailable, the baseband unit enters the clock holdover mode. For example, when only one time serving unit exists in the communication system and the baseband unit determines that the clock information provided by the time serving unit is unavailable by using the above method, the baseband unit enters the clock holdover mode. In another example, when multiple candidate time serving units exist in the communication system and the baseband unit determines that the clock information provided by each time serving unit is unavailable by using the above method, the baseband unit enters the clock holdover mode.

[0211] In the method provided in this embodiment, the baseband unit obtains information provided by the radio frequency unit to help determine whether the clock information provided by the time serving unit is available, thereby helping to avoid service interference caused by using inaccurate clock information and improve the reliability of system clock synchronization.

[0212] In the following, an example is used to explain an application scenario of a distributed base station and the embodiment shown in FIG. 3 with respect to some specific examples.

[0213] The distributed base station in the following example is an example of a communication system in the method shown in FIG. 3, and the GNSS receiver in the following example is an example of a time serving unit in the method shown in FIG. 3. The BBU in the following example is an example of a baseband unit in the method shown in FIG. 3. The AAU in the following example is an example of a radio frequency unit in the method shown in FIG. 3. The longitude and latitude information (x1, y1) of the AAU in the following example is an example of geographic location information of the radio frequency unit in the method shown in FIG. 3. The longitude and latitude information (x2, y2) acquired by the GNSS receiver of the BBU in the following example is an example of first information in the method shown in FIG. 3. The straight-line distance L in the following example is an example of deviation in the method shown in FIG. 3.

[0214] The GNSS clock synchronization method is widely used in base stations, and is also called GNSS time serving of base stations. When a distributed base station supports GNSS clock synchronization, the GNSS receiver is generally located at the BBU side. FIG. 4 is a schematic diagram of supporting GNSS clock synchronization by a base station according to an embodiment of the present application. As shown in FIG. 4, the antenna of the GNSS receiver is disposed outside the BBU, the GNSS receiver body is integrated in the BBU, and the antenna of the GNSS receiver is connected to the GNSS receiver body through a feeder. The antenna of the GNSS receiver is configured to receive satellite signals transmitted by four or more satellites, for example, the signal transmitted by satellite A, the signal transmitted by satellite B, the signal transmitted by satellite C, and the signal transmitted by satellite D shown in FIG. 4. The GNSS receiver outputs clock information and location information to the BBU based on the satellite signals received by the antenna, and the BBU uses the clock information output by the GNSS receiver as the PRTC of the base station.

[0215] However, since the satellite signals are in the open and unencrypted, the GNSS receiver is vulnerable to spoofing of satellite signals sent by devices such as pseudolites and not matching the current GNSS satellite system. Figure 5 is a schematic diagram of interference caused by pseudolites to the GNSS clock synchronization of a base station according to one embodiment of the present application. As shown in Figure 5, when receiving satellite signals of the GNSS satellite system, the GNSS receiver also receives the interference signals sent by the pseudolites.

[0216] Spoofing interference to GNSS receivers originates from navigation positioning principles. Because the delay of interference signals generated by interference sources such as pseudolites reaching the GNSS receiver does not match the delay of real GNSS satellite signals reaching the GNSS receiver in the air, the distance detected by the GNSS receiver (where distance is called "pseudo distance" in satellite navigation) will change, and the location information output by the GNSS receiver will not match the real location information. More importantly, when the GNSS receiver of a base station is spoofed, the system time of the base station will not match the system time of other surrounding base stations, resulting in a large clock phase offset between base stations, which is also called clock desynchronization. In TDD wireless networks, clock desynchronization will cause service interference. Figure 6 is a schematic diagram of the service interference of a base station according to one embodiment of the present application. As shown in Figure 6, since the faulty base station is affected by the interference signal, the downlink signal of the faulty base station will be sent out in the uplink slot of a normal base station, and the service of the base station will be severely interfered.

[0217] It can be seen that satellite spoofing interference has great harm to base stations. The spoofing interference is implemented by using signals similar to satellite navigation signals in the air, so that the GNSS receiver obtains false location information and false time information. If the base station can identify that the location information output by the GNSS receiver is false, the base station can switch to another clock reference source other than the GNSS receiver, for example, the clock reference source of the network, or enter a holdover mode when there is no other available reference source, and then track the GNSS reference source after the interference is removed, thereby avoiding the impact on the service.

[0218] However, if a spoof signal exists when a base station is deployed or restarted, it is difficult for the base station to identify whether the GNSS receiver is subject to spoof interference. Thus, service interference occurs when the base station is deployed. Furthermore, during the operation process of the base station, the base station enters a clock holdover mode because the reference source is lost, or the GNSS receiver is subject to spoof interference, or for other reasons. In the clock holdover mode, it is also difficult for the base station to identify whether the GNSS receiver is subject to spoof interference.

[0219] In conclusion, the reason why a base station cannot identify spoof signals during site deployment, restart, or clock holdover mode is because the base station cannot identify whether the current location acquired by the GNSS receiver is correct or not. In other words, the GNSS receiver of the base station does not have an accurate reference location and therefore cannot identify whether the received signal is a spoof interference signal or a normal signal.

[0220] In the following example, in a distributed base station, a GNSS receiver is integrated into a BBU. The AAU reports its precise location to the BBU through a fronthaul network. The BBU uses the precise location of the AAU to determine the distance and change between the location information output by the GNSS receiver and the precise location of the AAU, and determines whether the GNSS is spoofed.

[0221] In the following, a system architecture is described which applies to the following examples.

[0222] The following example applies to a distributed base station architecture. The GNSS receiver is located in the BBU for base station clock synchronization. Figure 7 is a schematic diagram of a system architecture according to one embodiment of the present application. As shown in Figure 7, AAU1, AAU2, AAU3 and BBU are connected through a fronthaul network.

[0223] A fronthaul network generally refers to a connection between a BBU and an AAU or an RRU. For example, a BBU is directly connected to an AAU. Figure 8 is a schematic diagram of a direct connection between a BBU and an AAU through an optical fiber according to an embodiment of the present application. As shown in Figure 8, a BBU is directly connected to AAU1 through an optical fiber, a BBU is directly connected to AAU2 through an optical fiber, and a BBU is directly connected to AAU3 through an optical fiber.

[0224] It is also applicable that the BBU and the AAU are connected to different network management devices. Figure 9 is a schematic diagram of an application example scenario according to one embodiment of the present application. As shown in Figure 9, the BBU is connected to a network management device A, and AAU1, AAU2, and AAU3 are connected to a network management device B. In Figure 9, the solid lines represent physical connections, and the dashed lines represent logical connections.

[0225] The following describes the details of the clock processing in the BBU.

[0226] 10 is a schematic diagram of clock processing performed by a BBU according to an embodiment of the present application. As shown in FIG. 10, the BBU includes a GNSS receiver, a 1588v2 clock processing unit, a base station clock processing unit, and a base station local clock.

[0227] The GNSS receiver provides the satellite clock reference source. As shown in Figure 10, the GNSS receiver body is integrated into the BBU, and the GNSS receiver body is connected to the GNSS antenna through a feeder. The output data of the GNSS receiver includes a 1pps pulse signal used to provide frequency and phase information. In addition, the serial port of the GNSS receiver outputs a data message, where the data message includes information such as year, month, date, hour, minute, second, and longitude and latitude.

[0228] The 1588v2 clock processing unit provides the clock reference source for the network. As shown in Figure 10, the 1588v2 clock processing unit is connected to a clock server through a backhaul network. The clock server periodically sends 1588v2 packets to the 1588v2 clock processing unit. After receiving the 1588v2 packets through the backhaul network, the 1588v2 clock processing unit outputs the SyncE clock and packets based on the timestamp carried in the 1588v2 packets.

[0229] The base station clock processing unit is configured to obtain a satellite clock reference source from the GNSS receiver and a network clock reference source from the 1588v2 clock processing unit, and detect the status of the two types of clock reference sources. If both the satellite clock reference source and the network clock reference source are available, the clock processing unit selects a designated reference source based on a user configuration. If both the satellite clock reference source and the network clock reference source are unavailable, the clock processing unit enters a holdover mode.

[0230] With reference to some specific examples, the following describes how to check the clock information provided by the GNSS receiver on the BBU in a distributed base station scenario by using examples. See Example 1 to Example 3 below.

[0231] Example 1

[0232] In the distributed base station, a GNSS receiver is placed in the BBU for clock synchronization. During or before the installation and placement of the AAU, the accurate longitude and latitude information of the AAU is recorded through the local maintenance interface of the AAU. The longitude and latitude information is obtained from a site survey. Figure 11 is a schematic diagram of writing the longitude and latitude information during AAU placement. As shown in Figure 11, the maintenance terminal stores the longitude and latitude information of the AAU obtained through the survey. The maintenance terminal sends the longitude and latitude information of the AAU to the maintenance interface of the AAU, and the AAU receives the longitude and latitude information of the AAU through the maintenance interface.

[0233] The AAU is located near the BBU. For example, the distance between the AAU and the antenna of the GNSS receiver of the BBU is within 1 km. The BBU and the AAU are directly connected through optical fiber.

[0234] During site deployment, the BBU and the AAU establish a communication link through a fronthaul interface (eCPRI or CPRI). The BBU obtains the longitude and latitude information of the AAU from the AAU. For example, as shown in FIG. 12, the BBU selects AAU1 from AAU1, AAU2, and AAU3 as a reference data source for determining whether the GNSS receiver is reliable, the AAU sends out the longitude and latitude information (x1, y1) stored in the BBU through the fronthaul interface, and the BBU obtains the longitude and latitude information (x1, y1) of the AAU.

[0235] Optionally, the AAU sends the longitude and latitude information to the BBU by using a management packet of the synchronous plane 1588 protocol. For example, when the longitude and latitude information of the AAU is sent by using a management packet (e.g., a management packet in the 1588 protocol), the longitude and latitude information of the AAU and other information acquired by the GNSS receiver are optionally encapsulated in the same management packet. For example, the format of the management packet carrying the longitude and latitude information of the AAU and other information acquired by the GNSS receiver is shown in Table 1.

[0236] [Table 1]

[0237] If the above information is carried between the AAU and the BBU in another packet other than a management packet, the format of the packet carrying the information may not be limited to the fields listed in Table 1.

[0238] The BBU compares the acquired longitude and latitude information (x1,y1) of the AAU with the longitude and latitude information (x2,y2) acquired by the GNSS receiver integrated in the BBU. The BBU then calculates the straight-line distance L between the longitude and latitude information (x1,y1) and the longitude and latitude information (x2,y2). The distance L represents the distance between the precise geographic location of the AAU1 and the geographic location of the GNSS receiver, which is determined by the GNSS receiver.

[0239] If the GNSS receiver is spoofed by a pseudolite, the location information output by the GNSS receiver will deviate significantly. In this case, the distance L will be greater than the appropriate distance (e.g., 1 km). Based on this determination, the BBU considers that the output data of the GNSS receiver is unreliable, and the BBU avoids tracking the inaccurate reference source by selecting another reference source, etc., thereby avoiding service interference.

[0240] In another possible implementation, the BBU comprehensively determines the distance between the survey locations of all AAUs and the locations acquired by the GNSS receiver of the BBU. If the distance between the survey locations of all AAUs and the locations acquired by the GNSS receiver of the BBU is not within a proper range, or the distance between the survey locations of most AAUs and the locations acquired by the GNSS receiver of the BBU is not within a proper range, the BBU considers that the output data of the GNSS receiver is not trustworthy, and the BBU avoids tracking an inaccurate reference source by selecting another reference source, etc., thereby avoiding service interference.

[0241] For example, the BBU obtains longitude and latitude information 1 reported by AAU1, longitude and latitude information 2 reported by AAU2, longitude and latitude information 3 reported by AAU3, and longitude and latitude information 4 output by the GNSS receiver. The BBU then obtains a distance a between the longitude and latitude information 1 and the longitude and latitude information 4, a distance b between the longitude and latitude information 2 and the longitude and latitude information 4, and a distance c between the longitude and latitude information 3 and the longitude and latitude information 4. The BBU then determines whether the distance a is greater than a threshold, whether the distance b is greater than a threshold, and whether the distance c is greater than a threshold, respectively. If two of the distances a, b, and c are greater than a threshold, the BBU determines that the GNSS receiver is interfered with by the longitude and latitude information. Locations reported by multiple AAUs are considered. Even if the locations recorded by some AAUs are inaccurate, the locations given by other AAUs can be used to ensure the accuracy of the decision, thus eliminating the location recording error of a particular AAU and improving the fault tolerance capability.

[0242] After the base station operates normally, the BBU checks the distance L between the location information output by the GNSS receiver and the location information of the AAU. If the distance L jumps, for example, the distance L is more than 1 km, the BBU considers the output data of the GNSS receiver to be unreliable. In this case, the BBU avoids tracking an inaccurate reference source by selecting a reference source other than the GNSS receiver, etc. If no other reference source is available, the base station enters a clock holdover mode to avoid service interference. Alternatively, after the base station operates normally, the BBU comprehensively checks the distances between the survey locations of all AAUs and the locations acquired by the GNSS receiver of the BBU. If all distances are not within the proper range or most of the distances are not within the proper range, the BBU considers the output data of the GNSS receiver to be unreliable, and the BBU avoids tracking an inaccurate reference source by selecting another reference source, etc., thereby avoiding service interference.

[0243] When the base station is in clock holdover mode, after the GNSS spoofing interference event disappears, the BBU checks the distance L between the location information output by the GNSS receiver and the location information of the selected AAU. If the distance L is within a proper range, the BBU considers that the output data of the GNSS receiver is normal, and the BBU resumes tracking the clock reference source, i.e., the GNSS receiver, thereby avoiding out-of-synchronization interference caused by exceeding the holdover capability.

[0244] In another possible implementation, when the base station is in clock holdover mode, after the GNSS spoofing interference event disappears, the BBU comprehensively checks the distances between the survey locations of all AAUs and the locations acquired by the GNSS receiver of the BBU. If all the distances are within the proper range or most of the distances are within the proper range, the BBU considers the output data of the GNSS receiver to be normal, and the BBU resumes tracking the clock reference source, i.e., the GNSS receiver, thereby avoiding the out-of-synchronization interference caused by exceeding the holdover capability.

[0245] The technical effects of Example 1 are described below.

[0246] In the above example 1, the BBU helps determine the location spoofing interference event of the GNSS receiver by using the precise location information of the AAU. When the base station is deployed or restarted, the BBU can identify that the GNSS receiver is subject to location spoofing by using the method of example 1, and the BBU avoids tracking an inaccurate reference source by selecting another reference source, etc., thereby avoiding service interference. When the base station is in clock holdover mode, the BBU can identify that the location spoofing of the GNSS receiver disappears by using the method of example 1. The BBU resumes tracking the clock provided by the GNSS receiver to avoid service interference caused by exceeding the holdover period.

[0247] Example 2

[0248] In a distributed base station, a GNSS receiver is deployed in a BBU for clock synchronization. During AAU deployment, a GNSS receiver is deployed in the AAU to obtain location information of the AAU. In an exemplary scenario, The endA GNSS receiver is integrated into the AAU to enable the BBU to generate a beam pointing to the end. The AAU obtains the precise location of the AAU by using the GNSS receiver and generates a beam based on the precise location of the AAU by using beamforming techniques. In this scenario, not only is the location given by the GNSS receiver in the AAU used to help the AAU to perform beamforming, but also the location given by the GNSS receiver in the AAU is used to help the BBU determine GNSS spoofing interference.

[0249] FIG. 13 is a schematic diagram of placing a GNSS receiver in an AAU to obtain location information.

[0250] The AAU is located near the BBU. For example, the distance between the antenna of the GNSS receiver of the AAU and the antenna of the GNSS receiver of the BBU is within 1 km. The BBU and the AAU are directly connected through optical fiber.

[0251] During site deployment, the BBU and the AAU establish a communication link through a fronthaul interface (eCPRI or CPRI). The AAU obtains the longitude and latitude information (x1,y1) of the AAU from a GNSS receiver connected to the AAU. The BBU obtains the longitude and latitude information of the AAU from the AAU. For example, the BBU selects an AAU from AAU1, AAU2, and AAU3. The AAU obtains the longitude and latitude information (x1,y1) by using the GNSS receiver of the AAU, and sends the longitude and latitude information (x1,y1) to the BBU through the fronthaul interface. The BBU obtains the longitude and latitude information (x1,y1) of the AAU.

[0252] The BBU compares the acquired longitude and latitude information (x1, y1) of the AAU with the longitude and latitude information (x2, y2) acquired by the GNSS receiver integrated in the BBU. The BBU then calculates the straight-line distance L between the longitude and latitude information (x1, y1) and the longitude and latitude information (x2, y2). For example, referring to FIG. 14, the BBU selects AAU3 in FIG. 14 as a reference data source for determining whether the GNSS receiver is reliable. The GNSS receiver A in AAU3 determines the longitude and latitude information (x1, y1) of the GNSS receiver A. The longitude and latitude information (x1, y1) represents the precise geographic location A of the GNSS receiver A, which is equivalent to the precise geographic location of the AAU3. The AAU3 sends the longitude and latitude information (x1, y1) given by the GNSS receiver A to the BBU. GNSS receiver B integrated in the BBU receives the longitude and latitude of GNSS receiver B. information (x2,y2 )of The longitude and latitude information (x2, y2) is determined by the GNSS receiver. B The BBU calculates a straight-line distance L between the longitude and latitude information (x1, y1) and the longitude and latitude information (x2, y2), where distance L represents the distance between the geographic location of GNSS receiver A and the geographic location of GNSS receiver B.

[0253] If the GNSS receiver is spoofed by a pseudolite, the location information output by the GNSS receiver will deviate significantly. In this case, the distance L will be larger than the appropriate distance (e.g., 1 km). Based on this determination, the BBU considers the output of the GNSS receiver to be unreliable, and the BBU avoids tracking the inaccurate reference source by selecting another reference source, thereby avoiding service interference. In another possible implementation, the BBU comprehensively determines the distances between the location information output by the GNSS receivers connected to all AAUs and the location obtained by the GNSS receiver of the BBU. If all distances are not within the appropriate range or the distances of the majority of the AAUs are not within the appropriate range, the BBU considers the output of the GNSS receiver to be unreliable, and the BBU avoids tracking the inaccurate reference source by selecting another reference source, etc., thereby avoiding service interference.

[0254] After the base station operates normally, the BBU checks the distance L between the location information output by the GNSS receiver and the location information output by the GNSS receiver connected to the AAU. If the distance L jumps, for example, the distance L is more than 1 km, the BBU considers the output of the GNSS receiver to be unreliable. In this case, the BBU avoids tracking an inaccurate reference source by selecting a reference source other than the GNSS receiver, etc. If no other reference source is available, the BBU enters a clock holdover mode to avoid service interference. In another possible implementation, the BBU comprehensively checks the distances between the location information output by the GNSS receiver connected to all AAUs and the location information obtained by the GNSS receiver of the BBU. If all the distances are not within the proper range or the distances of most of the AAUs are not within the proper range, the BBU considers the output of the GNSS receiver to be unreliable, and the BBU avoids tracking an inaccurate reference source by selecting another reference source other than the GNSS receiver, etc., thereby avoiding service interference.

[0255] In clock holdover mode, after the GNSS spoofing interference event disappears, the BBU checks the distance L between the location information output by the GNSS receiver and the location information output by the GNSS receiver connected to the AAU. If the distance L is within a proper range, the BBU considers the output of the GNSS receiver to be normal, and the BBU resumes tracking the clock reference source, i.e., the GNSS receiver, thereby avoiding out-of-sync interference caused by exceeding the holdover capability.

[0256] In another possible implementation, in clock holdover mode, after the GNSS spoofing interference event disappears, the BBU comprehensively checks the distances between the location information output by the GNSS receivers connected to all AAUs and the location information acquired by the GNSS receiver of the BBU. If all the distances are within a proper range or the distances of most AAUs are within a proper range, the BBU considers the output data of the GNSS receiver to be normal, and the BBU resumes tracking the clock reference source, i.e., the GNSS receiver, thereby avoiding out-of-synchronization interference caused by exceeding the holdover capability.

[0257] The technical effects of Example 2 are described below.

[0258] In the above example 2, the BBU helps determine the location spoofing interference event of the GNSS receiver by using the location information output by the GNSS receiver connected to the AAU. In this solution, when the GNSS receiver located in the BBU is interfered with but the GNSS receiver located in the AAU is not interfered with, it can be accurately determined whether the GNSS receiver located in the BBU is interfered with. Because the location of the BBU is lower than the location of the AAU, the GNSS receiver of the BBU is more likely to be interfered with than the GNSS receiver located in the AAU located on the tower or rooftop. Therefore, in a practical application, in this solution, it can effectively determine whether the GNSS receiver located in the BBU is interfered with.

[0259] When a base station is deployed or restarted, the BBU can identify that the GNSS receiver is subject to location spoofing by using the method of Example 2, and the BBU avoids tracking an inaccurate reference source by selecting a different reference source, etc., thereby avoiding service interference.

[0260] In clock holdover mode, the BBU can identify that the location spoofing of the GNSS receiver disappears by using the method of example 2, and the BBU resumes tracking the clock provided by the GNSS receiver to avoid service interference caused by exceeding the holdover period.

[0261] Example 3

[0262] Example 3 illustrates a scenario in which the fronthaul network and the backhaul network are connected to different network management devices. In Example 3, optionally, a network administrator inputs the location information of the AAU into the network management device of the fronthaul network, and then the network management device sends the location information of the AAU to the AAU, but does not necessarily input the location information of the AAU to the AAU on-site. The BBU obtains the location information of the AAU from the AAU through the fronthaul network.

[0263] In the distributed base station, a GNSS receiver is disposed in a BBU for clock synchronization. The BBU is connected to a network management device A. The AAUs are respectively connected to a fronthaul network and a network management device B. Figure 15 is a schematic diagram in which the BBUs and the AAUs are respectively connected to different network management devices. As shown in Figure 15, each of AAU1, AAU2, and AAU3 is connected to a network management device B, and each of AAU1, AAU2, and AAU3 is connected to a fronthaul network.

[0264] During installation and configuration of the AAUs, accurate longitude and latitude information of the AAUs is input to the AAUs through network management device B, where the accurate longitude and latitude information of the AAUs is obtained through a site survey. For example, as shown in Figure 15, network management device B sends the longitude and latitude information of AAU1 to AAU1, the longitude and latitude information of AAU2 to AAU2, and the longitude and latitude information of AAU3 to AAU3.

[0265] The AAU is located near the BBU. For example, the distance between the location of the AAU and the location of the antenna of the GNSS receiver of the BBU is within 1 km. When the BBU obtains the location information of the AAU, the AAU sends the location information previously sent by the network management device to the BBU through the fronthaul network. For example, as shown in FIG. 15, AAU1 sends the longitude and latitude information of AAU1 to the BBU through the fronthaul network, AAU2 sends the longitude and latitude information of AAU2 to the BBU through the fronthaul network, and AAU3 sends the longitude and latitude information of AAU3 to the BBU through the fronthaul network.

[0266] During site deployment, the BBU and the AAU establish a communication link through a fronthaul interface (e.g., eCPRI). The BBU obtains the longitude and latitude information of the AAU from the AAU. For example, the BBU selects an AAU from AAU1, AAU2, and AAU3, and the longitude and latitude information of the AAU is (x1, y1).

[0267] The BBU compares the acquired longitude and latitude information (x1, y1) of the AAU with the longitude and latitude information (x2, y2) acquired by the GNSS receiver integrated in the BBU. The BBU then calculates the straight-line distance L between the longitude and latitude information (x1, y1) and the longitude and latitude information (x2, y2). If the GNSS receiver is spoofed by a pseudolite, the location information output by the GNSS receiver will deviate significantly. In this case, the distance L will be greater than the appropriate distance (e.g., 1 km). Based on this determination, the BBU considers that the output data of the GNSS receiver is unreliable, and the BBU avoids tracking an inaccurate reference source by selecting another reference source, etc., thereby avoiding service interference.

[0268] In another possible implementation, the BBU comprehensively determines the distances between the survey locations of all AAUs and the locations acquired by the GNSS receiver of the BBU. If all the distances are not within the proper range or the distances of most of the AAUs are not within the proper range, the BBU considers that the output data of the GNSS receiver is not trustworthy, and the BBU avoids tracking an inaccurate reference source by selecting another reference source, etc., thereby avoiding service interference.

[0269] After the base station operates normally, the BBU checks the distance L between the location information output by the GNSS receiver and the location information of the AAU. If the distance L jumps, for example, the distance L is more than 1 km, the BBU considers the output of the GNSS receiver to be unreliable. In this case, the BBU avoids tracking an inaccurate reference source by selecting a reference source, etc. If no other reference source is available, the BBU enters a clock holdover mode to avoid service interference.

[0270] In another possible implementation, the BBU comprehensively checks the distances between the survey locations of all AAUs and the locations acquired by the GNSS receiver of the BBU. If all the distances are not within the proper range or the distances of most of the AAUs are not within the proper range, the BBU considers that the output data of the GNSS receiver is not trustworthy, and the BBU avoids tracking an inaccurate reference source by selecting another reference source, etc., thereby avoiding service interference.

[0271] When the base station is in clock holdover mode, after the GNSS spoofing interference event disappears, the BBU checks the distance L between the location information output by the GNSS receiver and the location information of the AAU. If the distance L is within a proper range, the BBU considers that the output data of the GNSS receiver is normal, and the BBU resumes tracking the clock reference source, i.e., the GNSS receiver, thereby avoiding out-of-synchronization interference caused by exceeding the holdover capability.

[0272] In another possible implementation, when the base station is in clock holdover mode, after the GNSS spoofing interference event disappears, the BBU comprehensively checks the distances between the survey locations of all AAUs and the locations acquired by the GNSS receiver of the BBU. If all the distances are within the proper range or the distances of most AAUs are within the proper range, the BBU considers the output data of the GNSS receiver to be normal, and the BBU resumes tracking the clock reference source, i.e., the GNSS receiver, thereby avoiding the out-of-synchronization interference caused by exceeding the holdover capability.

[0273] The technical effects of Example 3 are described below.

[0274] In the above example 3, the BBU helps determine the location spoofing interference event of the GNSS receiver by using the precise location information of the AAU. When the base station is deployed or restarted, the BBU can identify that the GNSS receiver is subject to location spoofing by using the method of example 3, and the BBU avoids tracking an inaccurate reference source by selecting another reference source, etc., thereby avoiding service interference.

[0275] When the base station is in clock holdover mode, the BBU can identify that the location spoofing of the GNSS receiver disappears by using the method of Example 3. The BBU resumes tracking the clock provided by the GNSS receiver to avoid service interference caused by exceeding the holdover period.

[0276] Referring to the methods given in Examples 1 to 3 above, in the above examples, in a distributed base station, a GNSS receiver is integrated into a BBU, and the AAU reports an accurate location of the AAU to the BBU through a fronthaul network, and the BBU calculates the distance between the output location of the GNSS receiver integrated into the BBU and the location reported by the AAU, and helps determine whether the GNSS receiver integrated into the BBU is subject to location spoofing based on the distance or distance jump within a suitable range, thereby avoiding interference with the service of the base station.

[0277] In the case of the problem that the GNSS receiver for clock synchronization at the BBU side of the distributed base station does not have an accurate reference location and cannot identify whether the received signal is a spoofing interference signal or a normal signal, the above example provides a technical solution in which the location information of the AAU is used to help the GNSS receiver of the BBU determine whether it is subject to location spoofing. By using this technical solution, the base station can accurately determine whether the GNSS receiver used by the BBU for time serving is subject to location spoofing, thereby avoiding service interference and improving the clock synchronization reliability of the base station.

[0278] The above example is illustrated by using a scenario in which the example is applied in a distributed base station and the location information of the AAU is obtained through a fronthaul network to help determine the location spoofing interference of the GNSS receiver of the BBU. For another similar scenario, see the above example.

[0279] The above example is explained by using an example in which the GNSS receiver used to support clock synchronization of the distributed base station is located on the BBU side. In some other embodiments, the GNSS receiver used to support clock synchronization of the distributed base station is located on the AAU side, and the BBU uses the GNSS receiver in the AAU as a reference source for clock synchronization.

[0280] For example, the GNSS receiver is located in the AAU, and the AAU locally stores the precise location information of the AAU. The AAU obtains the location information output by the GNSS receiver and the location information pre-stored by the AAU to obtain two pieces of location information. In a possible implementation, the AAU sends the two pieces of location information to the BBU. The BBU receives the two pieces of location information from the AAU. The BBU calculates the distance between the two pieces of location information, and determines whether the time serving information provided by the GNSS receiver in the AAU is available based on whether the distance is greater than a threshold. In another possible implementation, the AAU calculates the distance between the two pieces of location information, and the AAU sends the distance to the BBU. The BBU: From AAUReceive the distance, and determine whether the time serving information provided by the GNSS receiver in the AAU is available based on whether the distance is greater than a threshold. In yet another implementation, the AAU calculates the distance between two pieces of location information, and determines whether the time serving information provided by the GNSS receiver in the AAU is available based on whether the distance is greater than a threshold. Optionally, when the AAU determines that the time serving information provided by the GNSS receiver in the AAU is unavailable, the AAU generates a notification message and sends the notification message to the BBU. The notification message indicates that the time serving information provided by the time serving receiver in the AAU is unavailable. The BBU receives the notification message from the AAU, and stops using the time serving information provided by the time serving receiver in the AAU to perform clock synchronization based on the notification message.

[0281] The above listed implementations are all possible implementations in this embodiment. In this embodiment, it is not limited whether the GNSS receiver is located in the BBU or the AAU in the distributed base station, and it is not limited whether the steps in the process from obtaining the location to determining whether the time serving information is available are performed by the BBU or the AAU.

[0282] The above example is explained by using an example in which the GNSS receiver sends geographic location information, such as longitude and latitude information (x2, y2) to the BBU. In some other embodiments, the GNSS receiver sends clock information to the BBU. The BBU calculates the longitude and latitude information (x2, y2) based on the clock information, and determines the distance L based on the calculated longitude and latitude information (x2, y2) and the longitude and latitude information (x1, y1) of the AAU.

[0283] The above example is explained by using an example in which the GNSS receiver used by the base station to perform clock synchronization is integrated into the BBU. In some other embodiments, the GNSS receiver and the BBU are separately disposed, and the GNSS receiver and the BBU exchange information through a network and a corresponding communication interface.

[0284] The above example is explained by using an example in which the BBU obtains location information from the AAU to determine whether the GNSS receiver is trustworthy. In some other embodiments, the BBU obtains time information from the AAU to determine whether the GNSS receiver is trustworthy. For example, a GNSS receiver is integrated into each AAU, and each AAU obtains time information from the GNSS receiver of the AAU and sends the time information to the BBU through a fronthaul network. The BBU performs a majority vote on the time information output by the GNSS receiver in the BBU based on the time information given by multiple AAUs. If the time information output by the GNSS receiver in the BBU is different from the time information of three or more AAUs, the BBU determines that the GNSS receiver of the BBU is not trustworthy. For the format of the time information transmitted between the AAU and the BBU, please refer to the above format of the location information.

[0285] 16 is a schematic diagram of the structure of a communication device 300 according to an embodiment of the present application. The communication device 300 includes: an acquisition module 301 and a determination module 302.

[0286] Optionally, for the application scenario shown in FIG. 2, the communication device 300 shown in FIG. 16 is disposed in the baseband unit 101 of FIG.

[0287] Optionally, with respect to Fig. 3, the communication device 300 shown in Fig. 16 is disposed in the baseband unit of Fig. 3. The communication device 300 shown in Fig. 16 is configured to support the baseband unit to perform steps in the method embodiment shown in Fig. 3. The acquisition module 301 is configured to support the communication device 300 to perform S203 and S206. The determination module 302 is configured to support the communication device 300 to perform S207.

[0288] Optionally, with respect to FIG. 4, the communication device 300 shown in FIG. 16 is disposed in the BBU of FIG.

[0289] Optionally, with respect to FIG. 5, the communication device 300 shown in FIG. 16 is disposed in the BBU of FIG.

[0290] Optionally, with respect to FIG. 7, the communication device 300 shown in FIG. 16 is disposed in the BBU of FIG.

[0291] Optionally, with respect to FIG. 8, the communication device 300 shown in FIG. 16 is disposed in the BBU of FIG.

[0292] Optionally, with respect to FIG. 9, the communication device 300 shown in FIG. 16 is disposed in the BBU of FIG.

[0293] Optionally, with respect to FIG. 10, the communication device 300 shown in FIG. 16 is disposed in the BBU of FIG. 10, for example, in the clock processing unit of the base station of FIG.

[0294] Optionally, with respect to FIG. 12, the communication device 300 shown in FIG. 16 is disposed in the BBU of FIG.

[0295] Optionally, with respect to FIG. 14, the communication device 300 shown in FIG. 16 is disposed in the BBU of FIG.

[0296] Optionally, with respect to FIG. 15, the communication device 300 shown in FIG. 16 is disposed in the BBU of FIG.

[0297] The device embodiment described in FIG. 16 is only an example. For example, the module division is only a logical function division, and may be other divisions in actual implementation. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not implemented. The functional modules in the embodiments of the present application may be integrated into one processing module, or each module may exist physically alone, or two or more modules may be integrated into one module.

[0298] All or part of the modules in the communication device 300 may be implemented by using software, hardware, firmware, or any combination thereof.

[0299] In the case where software is used for implementation, for example, the above-mentioned determination module 302 is implemented by a software function module generated after the processor 501 of FIG. 18 reads the program code 510 stored in the memory 502.

[0300] In the case where hardware is used for implementation, for example, the modules in Fig. 16 are implemented separately by different hardware. For example, the determination module 302 is implemented by a part of the processing resources in the processor 501 in Fig. 18 (for example, one or two cores in a multi-core processor), or the determination module 302 is implemented by a programmable device such as a field-programmable gate array (FPGA) or a coprocessor. The acquisition module 301 is implemented by the network interface 503 and / or the input / output interface 506 in Fig. 18.

[0301] 17 is a schematic diagram of the structure of a communication device 400 according to an embodiment of the present application. The communication device 400 shown in FIG. 17 is configured to support a radio frequency module to implement steps in the above method embodiment. The communication device 400 includes an acquisition module 401 and a transmission module 402.

[0302] Optionally, for the application scenario shown in FIG. 2, the communication device 400 shown in FIG. 17 is the radio frequency module 102 of FIG.

[0303] Optionally, with respect to Fig. 3, the communication device 400 shown in Fig. 17 is the radio frequency module of Fig. 3. The acquisition module 401 is configured to support the communication device 400 to perform S201. The transmission module 402 is configured to support the communication device 400 to perform S202.

[0304] Optionally, with respect to FIG. 5, the communication device 400 shown in FIG. 17 is AAU1, AAU2, or AAU3 of FIG.

[0305] Optionally, with respect to FIG. 7, the communication device 400 shown in FIG. 17 is AAU1, AAU2, or AAU3 in FIG.

[0306] Optionally, with respect to FIG. 8, the communication device 400 shown in FIG. 17 is AAU1, AAU2, or AAU3 of FIG.

[0307] Optionally, with respect to FIG. 9, the communication device 400 shown in FIG. 17 is AAU1, AAU2, or AAU3 of FIG.

[0308] Optionally, with respect to FIG. 11, the communication device 400 shown in FIG. 17 is the AAU of FIG.

[0309] Optionally, with respect to FIG. 12, the communication device 400 shown in FIG. 17 is AAU1, AAU2, or AAU3 of FIG.

[0310] Optionally, with respect to FIG. 13, the communication device 400 shown in FIG. 17 is the AAU of FIG.

[0311] Optionally, with respect to FIG. 14, the communication device 400 shown in FIG. 17 is AAU1, AAU2, or AAU3 of FIG.

[0312] Optionally, with respect to FIG. 15, the communication device 400 shown in FIG. 17 is AAU1, AAU2, or AAU3 of FIG.

[0313] The device embodiment described in FIG. 17 is only an example. For example, the module division is only a logical function division, and may be other divisions in actual implementation. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not implemented. The functional modules in the embodiments of the present application may be integrated into one processing module, or each module may exist physically alone, or two or more modules may be integrated into one module.

[0314] All or part of the modules in the communication device 400 may be implemented by using software, hardware, firmware, or any combination thereof.

[0315] In the case where software is used for implementation, for example, the acquisition module 401 is implemented by a software functional module generated after at least one processor 501 of FIG. 18 reads program code stored in memory 502.

[0316] In the case where hardware is used for implementation, for example, the modules in FIG. 17 are implemented separately by different hardware. For example, the acquisition module 401 is implemented by a portion of the processing resources in at least one processor 501 in FIG. 18 (for example, one core or two cores in a multi-core processor), or the acquisition module 401 is implemented by using a programmable device such as a field-programmable gate array (FPGA) or a coprocessor, or the acquisition module 401 is implemented by using a network interface 503 and / or an input / output interface 506. The transmission module 402 is implemented by the network interface 503 and / or the input / output interface 506 in FIG. 18.

[0317] 18 is a schematic diagram of the structure of a communication device 500 according to an embodiment of the present application. The communication device 500 includes at least one processor 501, a memory 502, and at least one network interface 503.

[0318] Optionally, for the application scenario shown in FIG. 2, the communication device 500 shown in FIG. 18 is the baseband unit 101 or the radio frequency unit 102 in FIG.

[0319] Optionally, with respect to Fig. 3, the communication device 500 shown in Fig. 18 is the baseband unit of Fig. 3. The communication device 500 shown in Fig. 18 is configured to perform the steps performed by the baseband unit in the method embodiment shown in Fig. 3. The network interface 503 is configured to perform S203. The processor 501 is configured to perform S207. Optionally, the network interface 503 is further configured to perform S206, or the input / output interface 506 is configured to perform S206.

[0320] Alternatively, the communication device 500 shown in Fig. 18 is the radio frequency unit of Fig. 3. The communication device 500 shown in Fig. 18 is configured to perform the steps performed by the radio frequency unit in the method embodiment shown in Fig. 3. The network interface 503 is configured to perform S202. Optionally, the network interface 503 is further configured to perform S201, or the input / output interface 506 is configured to perform S201. Alternatively, the processor 501 is configured to perform S201.

[0321] Optionally, with respect to FIG. 4, the communication device 500 shown in FIG. 18 is the BBU of FIG.

[0322] Optionally, with respect to FIG. 5, the communication device 500 shown in FIG. 18 is the BBU, AAU1, AAU2, or AAU3 of FIG.

[0323] Optionally, with respect to FIG. 7, the communication device 500 shown in FIG. 18 is the BBU, AAU1, AAU2, or AAU3 of FIG.

[0324] Optionally, with respect to FIG. 8, the communication device 500 shown in FIG. 18 is the BBU, AAU1, AAU2, or AAU3 of FIG.

[0325] Optionally, with respect to FIG. 9, the communication device 500 shown in FIG. 18 is the BBU, the AAU1, the AAU2, or the AAU3 in FIG.

[0326] Optionally, with respect to FIG. 10, the communication device 500 shown in FIG. 18 is a BBU in FIG. 10, for example a clock processing unit of the base station in FIG.

[0327] Optionally, with respect to FIG. 12, the communication device 500 shown in FIG. 18 is the BBU, AAU1, AAU2, or AAU3 of FIG.

[0328] Optionally, with respect to FIG. 14, the communication device 500 shown in FIG. 18 is the BBU, AAU1, AAU2, or AAU3 of FIG.

[0329] Optionally, with respect to FIG. 15, the communication device 500 shown in FIG. 18 is the BBU, AAU1, AAU2, or AAU3 of FIG.

[0330] The processor 501 may be, for example, a general-purpose central processing unit (CPU), a network processor (NP), a graphics processing unit (GPU), a neural-network processing unit (NPU), a data processing unit (DPU), a microprocessor, or one or more integrated circuits configured to implement the solutions of the present application. For example, the processor 501 may include an Application-Specific Integrated Circuit (ASIC), a Programmable Logic Device (PLD), or a combination thereof. The PLD may be, for example, a Complex Programmable Logic Device (CPLD), a Field-Programmable Gate Array (FPGA), a Generic Array Logic (GAL), or any combination thereof.

[0331] The memory 502 may be, for example, but not limited to, a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, or a random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other compact disc storage device, an optical disc storage device (including a compact disc, a laser disc, an optical disc, a digital versatile disc, a Blu-ray disc, etc.), a magnetic disc storage medium or other magnetic storage device, or any other medium capable of carrying and storing expected program code in the form of instructions or data structures and accessible by a computer. Optionally, the memory 502 exists independently and is connected to the processor 501 by using an internal connection 504. Alternatively, the memory 502 and the processor 501 are optionally integrated together.

[0332] The network interface 503 may be configured to communicate with another device or a communication network using any device, such as a transceiver. The network interface 503 may include, for example, at least one of a wired network interface or a wireless network interface. The wired network interface may be, for example, an Ethernet interface. The Ethernet interface may be, for example, an optical interface, an electrical interface, or a combination thereof. The wireless network interface may be, for example, a wireless local area network (WLAN) interface. k,WLAN) interface, a cellular network interface, or a combination thereof.

[0333] In some embodiments, the processor 501 includes one or more CPUs, such as CPU0 and CPU1 shown in FIG.

[0334] In some embodiments, the communications device 500 optionally includes multiple processors, e.g., processor 501 and processor 505 shown in FIG. 18. Each of these processors may be, for example, a single-core processor (single-CPU) or a multi-core processor (multi-CPU). A processor herein optionally refers to one or more devices, circuits, and / or processing cores configured to process data (e.g., computer program instructions).

[0335] In some embodiments, the communication device 500 further includes an internal connection 504. The processor 501, the memory 502, and the at least one network interface 503 are connected through the internal connection 504. The internal connection 504 includes a path for transferring information between the above components. Optionally, the internal connection 504 is a board or a bus. Optionally, the internal connection 504 is classified as an address bus, a data bus, a control bus, or the like.

[0336] In some embodiments, the communication device 500 further includes an input / output interface 506. The input / output interface 506 is connected to the internal connection 504.

[0337] In some embodiments, the input / output interface 506 is configured to connect to an input device and receive commands or data input by a user using the input device and related to the above method embodiments, such as geographic location information of the radio frequency unit. The input device includes, but is not limited to, a keyboard, a touch screen, a microphone, a mouse, a sensing device, etc.

[0338] In some embodiments, the input / output interface 506 is further configured to connect to an output device. The input / output interface 506 may be used to control the processor by implementing the above method embodiments. 5 01 outputs the intermediate and / or final results generated by 01, for example, whether clock information is available. Output devices include, but are not limited to, displays, printers, projectors, etc.

[0339] Optionally, the processor 501 implements the method in the above embodiment by reading the program code 510 stored in the memory 502, or the processor 501 implements the method in the above embodiment by using the program code stored therein. When the processor 501 implements the method in the above embodiment by reading the program code stored in the memory 502, the memory 502 stores the program code 510 for implementing the above method embodiment provided in the embodiment of the present application.

[0340] For further details about implementing the above functions by the processor 501, please refer to the description in the above method embodiment, and the details will not be described again in this specification.

[0341] The embodiments herein have been described in a progressive manner, and for the same or similar parts of the embodiments, please refer to each other, with each embodiment focusing on the differences from other embodiments.

[0342] A refers to B, which means that A is the same as B or that A is a simple variation of B.

[0343] In the description and claims of the embodiments of this application, the terms "first," "second," etc. are intended to distinguish between different objects, but do not indicate any particular order of the objects, and cannot be understood as indicating or implying relative importance.

[0344] In the embodiments of the present application, unless otherwise specified, "at least one" means one or more, and "multiple" means two or more. For example, multiple radio frequency units refers to two or more radio frequency units.

[0345] All or part of the above embodiments may be implemented by using software, hardware, firmware, or any combination thereof. When software is used to implement the embodiments, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the procedures or functions described in the embodiments of the present application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from a computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website, computer, server, or data center to another website, computer, server, or data center in a wired (e.g., coaxial cable, optical fiber, or digital subscriber line (DSL)) or wireless (e.g., infrared, radio, or microwave) manner. The computer-readable storage medium may be any available medium accessible by a computer or a data storage device, e.g., a server or data center, that integrates one or more available media. Available media include magnetic media (e.g., floppy disks, hard disks, or magnetic tapes), optical media (e.g., DVDs), and semiconductor media (e.g., Solid State Drives). Drive (SSD)), etc.

[0346] The above embodiments are only intended to describe the technical solutions of the present application, and are not intended to limit the present application. Although the present application is described in detail with reference to the above embodiments, those skilled in the art should nevertheless understand that, without departing from the scope of the technical solutions of the embodiments of the present application, modifications may be made to the technical solutions described in the above embodiments, or equivalent substitutions may be made to some technical features thereof.

Claims

1. 1. A method for checking clock information, comprising: Obtaining first information through a time serving unit of a communication system; obtaining information regarding at least one radio frequency unit of the communication system; determining whether the clock information provided by the time serving unit is available based on the information regarding the at least one radio frequency unit and the first information; A method comprising:

2. the information about the radio frequency unit is geographic location information of the radio frequency unit; The method of claim 1 , wherein the first information is geographic location information obtained by the time serving unit based on signals received by the time serving unit.

3. the information about the radio frequency unit is clock information of the radio frequency unit; The method of claim 1 , wherein the first information is clock information obtained by the time serving unit based on a signal received by the time serving unit.

4. The method of claim 3 , wherein the clock information of the radio frequency unit or the clock information provided by the time serving unit includes at least one of time information, frequency information, or phase information.

5. The step of determining whether the clock information provided by the time serving unit is available based on the information on the at least one radio frequency unit and the first information comprises: obtaining at least one deviation based on the information regarding the at least one radio frequency unit and the first information; determining whether the clock information provided by the time serving unit is available based on the at least one deviation and a threshold value; The method of any one of claims 1 to 4, comprising:

6. The step of determining whether the clock information provided by the time serving unit is available based on the information on the at least one radio frequency unit and the first information comprises: determining that the clock information provided by the time serving unit is unavailable based on the fact that each deviation in the at least one deviation is greater than a threshold value; determining that the clock information provided by the time serving unit is unavailable based on the fact that one of the at least one deviations is greater than the threshold value; determining that the clock information provided by the time serving unit is unavailable based on the fact that a deviation in the at least one deviation that is greater than the threshold value reaches a set ratio, or determining that the clock information provided by the time serving unit is unavailable based on the fact that a deviation in the at least one deviation that is greater than the threshold value reaches a set quantity; The method of claim 5, comprising any one of and combinations thereof.

7. The method of claim 5 or 6, wherein the deviation comprises at least one of a spatial distance, a time difference, a frequency deviation, or a phase deviation.

8. The step of obtaining first information through a time serving unit of a communication system includes: receiving the first information output by the time serving unit; or determining the first information based on information output by the time serving unit; The method of claim 1 , comprising any one of the following:

9. The step of obtaining information regarding at least one radio frequency unit of the communication system comprises: receiving said information relating to said at least one radio frequency unit from said at least one radio frequency unit; or receiving said information regarding said at least one radio frequency unit from a network management device; The method of any one of claims 1 to 8, comprising any one of and combinations thereof.

10. After the step of determining whether the clock information provided by the time serving unit is available based on the information on the at least one radio frequency unit and the first information, the method further comprises: using the clock information provided by the time serving unit if the clock information is available; using clock information provided by another element other than the time serving unit if the clock information is unavailable; or entering a clock holdover mode if the clock information is unavailable.

10. The method of claim 1, further comprising any one of the following:

11. The method according to claim 1 , wherein the radio frequency unit and the time serving unit are located in the same base station.

12. The method according to claim 1 , wherein the radio frequency unit and the time serving unit are located in different base stations.

13. said time serving unit being located in a baseband unit; or The method according to claim 1 , wherein the time serving unit is located in one of the at least one radio frequency unit.

14. 1. A method for checking clock information implemented by a radio frequency unit in a communication system, comprising: obtaining information about the radio frequency unit; sending said information about said radio frequency unit to a baseband unit in said communication system, said information about said radio frequency unit being used by said baseband unit to determine whether clock information provided by a first time serving unit in said communication system is available; A method comprising:

15. The method of claim 14 , wherein the information regarding the radio frequency unit is geographic location information of the radio frequency unit.

16. The step of obtaining information about the radio frequency unit comprises: obtaining the geographical location information of the radio frequency unit pre-stored in the radio frequency unit; obtaining the geographic location information of the radio frequency unit through a second time serving unit; receiving the geographical location information of the radio frequency unit from a network management device; or obtaining the geographic location information of the radio frequency unit through a positioning unit; 16. The method of claim 15, comprising any one of and combinations thereof.

17. The method of claim 14 , wherein the information about the radio frequency unit is clock information of the radio frequency unit.

18. The step of obtaining information about the radio frequency unit comprises:

20. The method of claim 17, comprising obtaining the clock information of the radio frequency unit through a second time serving unit.

19. An acquisition module configured to acquire first information through a time serving unit of a communication system, an acquisition module further configured to acquire information regarding at least one radio frequency unit of the communication system; a determination module configured to determine whether the clock information provided by the time serving unit is available based on the information regarding the at least one radio frequency unit and the first information; A communication device comprising:

20. A communication device disposed in a radio frequency unit, comprising: an acquisition module configured to acquire information regarding the radio frequency unit; a transmission module configured to send the information about the radio frequency unit to a baseband unit, the information about the radio frequency unit being used by the baseband unit to determine whether clock information provided by a first time serving unit is available; A communication device comprising:

21. A communications device including a processor, the processor coupled to a memory, the memory storing at least one computer program instruction, the at least one computer program instruction being loaded and executed by the processor, thereby causing the communications device to implement a method according to any one of claims 1 to 13 or claims 14 to 18.

22. A communication system comprising a communication device according to claim 19 and a communication device according to claim 20.

23. A computer readable storage medium storing at least one instruction, which when executed on a computer enables the computer to perform a method according to any one of claims 1 to 13 or claims 14 to 18.

24. A computer program product comprising one or more computer program instructions, which when loaded and executed by a computer, enable the computer to perform the method according to any one of claims 1 to 13 or claims 14 to 18.

Images