Communication method and apparatus

Abstract

This application discloses a communication method and apparatus. A switch device or radio frequency device in a fronthaul network monitors clock offset information between first time information and second time information, where the first time information is time information synchronized via a fronthaul interface corresponding to a first baseband unit, and the second time information is time information synchronized via a fronthaul interface corresponding to a second baseband unit. The clock offset information is used to assist in fault handling of the baseband units, thereby reducing operation and maintenance costs and improving fault handling efficiency.

Description

[Technical Field]

[0001] The present application relates to the field of communication technologies, and more particularly to communication methods and devices. [Background technology]

[0002] In a distributed base station architecture, one radio frequency device may establish communication connections to multiple base band units (BBUs), but the radio frequency device maintains time synchronization with only one of the multiple BBUs. If the multiple BBUs are not time-synchronized, signal interference may be generated in communications between the radio frequency device and the multiple BBUs, resulting in abnormal communication services.

[0003] Currently, when an abnormality occurs in the communication service of a distributed base station, workers must carry test devices and individually check the times of different BBUs on-site to troubleshoot the problem. This approach relies on manual operation and test equipment, resulting in high operation and maintenance costs, long troubleshooting times, and low efficiency. Summary of the Invention

[0004] The present application provides a communication method and apparatus for reducing operation and maintenance costs associated with BBUs in a fronthaul network and improving fault handling efficiency.

[0005] According to a first aspect, an embodiment of the present application provides a communication method. The method may include: a first device acquiring first time information and second time information, and transmitting clock offset information. The clock offset information indicates an offset between the first time information and the second time information, the first time information being time information synchronized via a fronthaul interface corresponding to a first baseband unit, and the second time information being time information synchronized via a fronthaul interface corresponding to a second baseband unit.

[0006] In the above design, when multiple BBUs access the same fronthaul network, the clock offset between the synchronized time information is determined via the clock sources of different BBUs. Fault handling is performed for the associated BBU based on the clock offset. This eliminates the need to manually transport test devices, thereby reducing operation and maintenance costs and improving fault handling efficiency.

[0007] In a possible design, before transmitting the clock offset information, the first device may further determine that the first baseband unit is a master clock device based on the first time information and the second time information. Optionally, the master clock device may alternatively be referred to as a primary BBU.

[0008] In a possible design, the second baseband unit may be a non-master clock device (also called a non-primary BBU), or the second baseband unit may be any one of multiple non-master clock devices. In this design, a clock offset between one or more non-primary BBUs and the primary BBU may be monitored.

[0009] In a possible design, the first device may transmit clock offset information to the second device, and the clock offset information may be used to determine a fault of the second baseband unit. The second device may be the second baseband unit or a network management device, so that fault processing for the baseband unit can be flexibly implemented by using different devices.

[0010] In a possible design, the first device may further transmit first information to the first baseband unit, where the first information may indicate one or more of: that the first baseband unit is a master clock device; and that a clock offset between the first baseband unit and the master clock device is zero. Based on such a design, the first baseband unit may determine that the first baseband unit is a master clock device.

[0011] In a possible design, the first device may be a radio frequency device or a switch device in a fronthaul network, and the radio frequency device communicates with the first baseband unit and the second baseband unit.

[0012] In a possible design, when the first device is a switch device in a fronthaul network, the switch device may further provide a clock source to the radio frequency device based on the first time information, and the radio frequency device communicates with the first baseband unit and the second baseband unit. Such a design can implement synchronization between the radio frequency device and the first baseband unit.

[0013] In a possible design, the first baseband unit is time-synchronized with a first external clock reference source, and the second baseband unit is time-synchronized with a second external clock reference source, and the first external clock reference source and the second external clock reference source may be the same or different. In other words, the method provided in this embodiment of the present application can be applied to a scenario in which the baseband units are out of sync because the external clock reference sources are out of sync, and can also be applied to a scenario in which the external clock reference sources are the same but the baseband units are out of sync because jumps occur.

[0014] According to a second aspect, an embodiment of the present application provides a communication method, which may include: a second device receiving clock offset information, the clock offset information indicating an offset between first time information and second time information, the first time information being time information synchronized via a fronthaul interface corresponding to a first baseband unit, and the second time information being time information synchronized via a fronthaul interface corresponding to a second baseband unit; and the second device determining, based on the clock offset information, whether a fault exists in the second baseband unit.

[0015] In a possible design, the second device may be a radio frequency device or a switch device in a fronthaul network.

[0016] In a possible design, the first baseband unit may be a master clock device (or called a primary BBU).

[0017] In a possible design, the second baseband unit may be a non-master clock device (also called a non-primary BBU), or the second baseband unit may be any one of multiple non-master clock devices.

[0018] In a possible design, the first baseband unit is time-synchronized with a first external clock reference source, and the second baseband unit is time-synchronized with a second external clock reference source, and the first external clock reference source and the second external clock reference source may be the same or different.

[0019] According to a third aspect, an embodiment of the present application provides a communication device. The communication device may be a first device, or may be a device, module, chip, etc. within the first device, or may be a device that can be used in conjunction with the first device. In design, the communication device may include modules that correspond one-to-one to the methods / operations / steps / actions described in the first aspect. The modules may be implemented by hardware circuits, software, or a combination of hardware circuits and software. In design, the communication device may include a processing module and a communication module.

[0020] The communication module is configured to obtain first time information and second time information, where the first time information is time information synchronized via a fronthaul interface corresponding to a first baseband unit and the second time information is time information synchronized via a fronthaul interface corresponding to a second baseband unit; and send clock offset information, where the clock offset information indicates an offset between the first time information and the second time information.

[0021] The processing module is configured to control the communication module to perform the acquisition or transmission operation.

[0022] In a possible design, the processing module is further configured to determine, based on the first time information and the second time information, that the first baseband unit is a master clock device. Optionally, the master clock device may alternatively be referred to as a primary BBU.

[0023] In a possible design, the second baseband unit may be a non-master clock device (also called a non-primary BBU), or the second baseband unit may be any one of multiple non-master clock devices.

[0024] In one possible design, the communication module may be configured to transmit the clock offset information to a second device, where the clock offset information is used to determine a fault in the second baseband unit. The second device may be the second baseband unit or a network management device.

[0025] In a possible design, the communication module may be further configured to send first information to the first baseband unit, the first information indicating one or more of: that the first baseband unit is a master clock device; and that a clock offset between the first baseband unit and the master clock device is zero. Based on such a design, the first baseband unit may determine that the first baseband unit is the master clock device.

[0026] In a possible design, the first device may be a radio frequency device or a switch device in a fronthaul network, and the radio frequency device communicates with the first baseband unit and the second baseband unit.

[0027] In a possible design, when the first device is a switch device in a fronthaul network, the processing module is further configured to provide a clock source to the radio frequency device based on the first time information, and the radio frequency device communicates with the first baseband unit and the second baseband unit.

[0028] In a possible design, the first baseband unit is time-synchronized with a first external clock reference source, and the second baseband unit is time-synchronized with a second external clock reference source, and the first external clock reference source and the second external clock reference source are the same or different.

[0029] According to a fourth aspect, an embodiment of the present application provides a communication device. The communication device may be a second device, or may be a device, module, chip, etc. within the second device, or may be a device that can be used in conjunction with the second device. In design, the communication device may include modules that correspond one-to-one to the methods / operations / steps / actions described in the second aspect. The modules may be implemented by hardware circuits, software, or a combination of hardware circuits and software. In design, the communication device may include a processing module and a communication module.

[0030] The communication module is configured to receive clock offset information, the clock offset information indicating an offset between first time information and second time information, the first time information being time information synchronized via a fronthaul interface corresponding to a first baseband unit, and the second time information being time information synchronized via a fronthaul interface corresponding to a second baseband unit, and the processing module is configured to determine whether a fault exists in the second baseband unit based on the clock offset information.

[0031] In a possible design, the second device may be a radio frequency device or a switch device in a fronthaul network.

[0032] In a possible design, the first baseband unit may be a master clock device (or called a primary BBU).

[0033] In a possible design, the second baseband unit may be a non-master clock device (also called a non-primary BBU), or the second baseband unit may be any one of multiple non-master clock devices.

[0034] In a possible design, the first baseband unit is time-synchronized with a first external clock reference source, and the second baseband unit is time-synchronized with a second external clock reference source, and the first external clock reference source and the second external clock reference source may be the same or different.

[0035] According to a fifth aspect, an embodiment of the present application provides a communication device. The communication device may include a processor configured to perform the method described in the first aspect. The processor is coupled to a memory, the memory being configured to store instructions and data, and the method described in the first aspect may be performed when the processor executes the instructions stored in the memory. Optionally, the communication device may further include a memory. The communication device may further include a communication interface, the communication interface being used by the device to communicate with another device. For example, the communication interface may be a transceiver, a circuit, a bus, a module, a pin, or another type of communication interface.

[0036] The communication interface is configured to obtain first time information and second time information, where the first time information is time information synchronized via a fronthaul interface corresponding to a first baseband unit and the second time information is time information synchronized via a fronthaul interface corresponding to a second baseband unit, and to transmit clock offset information, where the clock offset information indicates an offset between the first time information and the second time information.

[0037] The processor is configured to control the communication interface to perform the obtain or transmit operation.

[0038] According to a sixth aspect, an embodiment of the present application provides a communication device. The communication device may include a processor configured to perform the method described in the second aspect. The processor is coupled to a memory. The memory is configured to store instructions and data. When the processor executes the instructions stored in the memory, the method according to the second aspect may be performed. Optionally, the communication device may further include a memory. The communication device may further include a communication interface, which is used by the device to communicate with another device. For example, the communication interface may be a transceiver, a circuit, a bus, a module, a pin, or another type of communication interface.

[0039] The communication interface is configured to receive clock offset information, the clock offset information indicating an offset between first time information and second time information, the first time information being time information synchronized via a fronthaul interface corresponding to the first baseband unit, and the second time information being time information synchronized via a fronthaul interface corresponding to the second baseband unit, and the processor is configured to determine whether a fault exists in the second baseband unit based on the clock offset information.

[0040] According to a seventh aspect, an embodiment of the present application provides a communication system including a communication device according to the third or fifth aspect and a communication device according to the fourth or sixth aspect.

[0041] According to an eighth aspect, an embodiment of the present application further provides a computer program, which, when run on a computer, enables the computer to perform the method according to the first or second aspect.

[0042] According to a ninth aspect, an embodiment of the present application further provides a computer program product comprising instructions, which when executed on a computer, enable the computer to perform a method according to the first or second aspect.

[0043] According to a tenth aspect, an embodiment of the present application further provides a computer-readable storage medium storing a computer program or instructions, which, when executed on a computer, enables the computer to perform the method according to the first or second aspect.

[0044] According to an eleventh aspect, an embodiment of the present application further provides a chip, the chip being configured to read a computer program stored in a memory and to perform a method according to the first or second aspect, or the chip including circuitry configured to perform a method according to the first or second aspect.

[0045] According to a twelfth aspect, an embodiment of the present application further provides a chip system. The chip system includes a processor configured to support an apparatus for performing a method according to the first or second aspect. In a possible design, the chip system further includes a memory configured to store programs and data required by the apparatus. The chip system may include a chip, or may include a chip and another separate component.

[0046] For the effects of the solutions provided in any one of the second to twelfth aspects, please refer to the corresponding explanation in the first aspect. [Brief explanation of the drawings]

[0047] [Figure 1] FIG. 1 is a structural diagram of a communication system. [Figure 2A] FIG. 1 is a diagram of a radio access network RAN. [Figure 2B]FIG. 2 is a diagram of functional modules of an access network device. [Figure 2C] FIG. 1 is a diagram of the division of the physical layer into functional modules. [Figure 2D] FIG. 2 is another diagram of the division of the physical layer into functional modules. [Figure 3] FIG. 1 is a structural diagram of a fronthaul network. [Figure 4A] FIG. 1 is a structural diagram of a distributed base station. [Figure 4B] FIG. 1 is a structural diagram of a distributed base station. [Figure 5A] FIG. 1 is a structural diagram of a distributed base station. [Figure 5B] FIG. 1 is a structural diagram of a distributed base station. [Figure 5C] FIG. 1 is a structural diagram of a distributed base station. [Figure 6] 1 is a schematic flowchart of a communication method. [Figure 7] 1 is a schematic flowchart of a communication method. [Figure 8] FIG. 1 is a structural diagram of a communication device. [Figure 9A] FIG. 1 is a structural diagram of a distributed base station. [Figure 9B] FIG. 1 is a structural diagram of a distributed base station. [Figure 10] FIG. 10 is a structural diagram of another communication device. DETAILED DESCRIPTION OF THE INVENTION

[0048] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the following further describes the embodiments of the present application in detail with reference to the accompanying drawings.

[0049] In the embodiments of the present application, at least one (item) refers to one or more (items). "Multiple (items)" means two (items) or more than two (items). The term "and / or" describes an association relationship for describing related objects and indicates that three relationships may exist. For example, A and / or B may represent the following three cases: only A exists, both A and B exist, and only B exists. The character " / " typically indicates an "or" relationship between related objects. In addition, terms such as "first" and "second" may be used to describe objects in the embodiments of the present application, but it should be understood that these objects should not be limited by these terms. These terms are used simply to distinguish objects from each other.

[0050] The terms "comprise," "have," and any variations thereof in the following description of the embodiments of the present application are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or device comprising a series of steps or units is not limited to the listed steps or units, but may optionally further include other unlisted steps or units, or may optionally further include other inherent steps or units of the process, method, product, or device. It should be noted that in the embodiments of the present application, the words "exemplary" or "for example" are used to indicate an example, illustration, or explanation. Any method or design solution described as an "example" or "for example" in the embodiments of the present application should not be described as being more preferred or having more advantages than another method or design solution. Rather, the use of words such as "example" or "for example" is intended to present a relative concept in a particular way.

[0051] The techniques provided in the embodiments of the present application may be applied to various communication systems. FIG. 1 is a diagram of a possible, non-limiting communication system. As shown in FIG. 1, the communication system 1000 includes a radio access network (RAN) 100 and a core network (CN) 200. The RAN 100 includes at least one RAN node (e.g., 110a and 110b in FIG. 1 , collectively referred to as 110) and at least one terminal (e.g., 120a to 120j in FIG. 1 , collectively referred to as 120). The RAN 100 may also include another RAN node, such as a wireless relay device and / or a wireless backhaul device (not shown in FIG. 1 ). The terminal 120 is connected to the RAN node 110 in a wireless manner. The RAN node 110 is connected to the core network 200 in a wireless or wired manner. The RAN node 110 is configured to help the terminal implement wireless access. The core network devices in the core network 200 and the RAN nodes 110 in the RAN 100 may be different physical devices or may be the same physical device that integrates the logical functions of the core network and the radio access network. Optionally, the RAN nodes 110 may be further connected to the Internet 300 or may be connected to the Internet 300 by using the core network 200.

[0052] RAN100 is a 3rd Generation Partnership Project (3 rd Generation Partnership Project (3GPP), e.g., 4th Generation (4 th generation, 4G) or fifth generation (5 thThe RAN 100 may be a cellular system related to a 4G (5th generation) mobile communication system, or a future-oriented evolved system (e.g., a 6G mobile communication system). Alternatively, the RAN 100 may be an open radio access network (OpenRAN, O-RAN, or ORAN) or a cloud radio access network (CRAN). Alternatively, the RAN 100 may be a communication system that integrates two or more of the aforementioned systems. The 4G mobile communication system includes a long term evolution (LTE) system, and the 5G mobile communication system includes a new radio (NR) system.

[0053] The multiple RAN nodes 110 in the communication system 1000 may be nodes of the same category or different categories. In some scenarios, the roles of the RAN nodes 110 and the terminals 120 are relative to each other. For example, the network element 120i in FIG. 1 may be a helicopter or an unmanned aerial vehicle and may be configured as a mobile base station. To a terminal 120j that accesses the RAN 100 using the network element 120i, the network element 120i is a base station. However, to the base station 110a, the network element 120i is a terminal. Both the RAN nodes 110 and the terminals 120 may be referred to as communication devices. For example, the network elements 110a and 110b in FIG. 1 may be understood as communication devices having base station functionality, and the network elements 120a-120j may be understood as communication devices having terminal functionality.

[0054] The terminal and RAN node are described in detail below.

[0055] (1) Terminal

[0056] Alternatively, a terminal may be referred to as a terminal device, user equipment (UE), mobile station, mobile terminal, etc. A terminal may be a user-side entity configured to receive or transmit signals. A terminal may communicate with one or more core networks by using a RAN. A terminal includes a handheld device with wireless connectivity, another processing device connected to a wireless modem, an in-vehicle device, etc. A communication device may be a portable, pocket-sized, handheld, computer-integrated, or vehicle-mounted mobile device. The terminal can be widely applied to various scenarios, such as cellular communication, device-to-device (D2D), vehicle-to-everything (V2X) communication, end-to-end P2P, machine-to-machine (M2M), machine-type communication (MTC), internet of things (IOT), virtual reality (VR), augmented reality (AR), industrial control, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wearable, smart transportation, smart city, mobile phone, tablet computer, computer with wireless transceiver function, wearable device, vehicle, unmanned aerial vehicle, helicopter, aircraft, ship, robot, robot arm, and smart home device. The device form of the terminal is not limited in the embodiments of the present application.

[0057] (2) RAN node

[0058] In possible scenarios, the RAN node may alternatively be referred to as an access network device, RAN entity, access node, network device, etc., and may form part of a communication system and help terminals implement wireless access. The RAN node may be a base station (BS), evolved base station (eNB), access point (AP), transmission reception point (TRP), next generation NodeB (gNB), sixth generation (6G) NodeB (6G), etc. th The RAN node may be a next-generation base station in a 6G (6th generation) mobile communication system, a base station in a future mobile communication system, etc. The RAN node may be a macro base station (e.g., 110a in FIG. 1 ), a micro base station or an indoor station (e.g., 110b in FIG. 1 ), a relay node or a donor node, or a radio controller in a CRAN scenario. Optionally, the RAN node may alternatively be a server, a wearable device, a vehicle, a vehicle-mounted device, etc. For example, an access network device in a vehicle-to-everything (V2X) technology may be a road side unit (RSU).

[0059] In another possible scenario, multiple RAN nodes cooperate to help a terminal implement radio access, and different RAN nodes separately implement some functions of an access network device. Figure 2A is a diagram of a radio access network (RAN). As shown in Figure 2A, the access network device includes a central unit (CU), a distributed unit (DU), and a radio unit (RU). The CU may be connected to a core network and one or more DUs. One DU may be connected to one or more RUs, and the interface between the DU and the RU may be called a fronthaul interface (FH). Optionally, the CU may have some functions of the core network, and the CU includes a CU control plane (CP) and a CU user plane (UP). The RU is configured to transmit signals to or receive signals from terminals. For example, the RAN node may be a CU, a DU, a CU-CP, a CU-UP, or an RU.

[0060] It can be understood that in different systems, the CU (or CU-CP and CU-UP), DU, or RU may alternatively have different names, but those skilled in the art can understand the meaning of the names. For example, in an ORAN system, the CU may alternatively be called an O-CU (open CU), the DU may alternatively be called an O-DU, the CU-CP may alternatively be called an O-CU-CP, the CU-UP may alternatively be called an O-CU-UP, and the RU may alternatively be called an O-RU. For ease of explanation, the CU, CU-CP, CU-UP, DU, and RU are used as examples for explanation in this application. Any one of the CU (or CU-CP or CU-UP), DU, and RU in this application may be implemented by using a software module, a hardware module, or a combination of a software module and a hardware module.

[0061] (3) Dividing access network devices into power modules

[0062] Communications between the access network device and the terminal conform to a specific protocol layer structure. The protocol layers may include a control plane protocol layer and a user plane protocol layer. For example, the control plane protocol layer may include at least one of a radio resource control (RRC) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, a media access control (MAC) layer, a physical (PHY) layer, etc. The user plane protocol layer may include at least one of a service data adaptation protocol (SDAP) layer, a PDCP layer, an RLC layer, a MAC layer, a physical layer, etc. The CU and DU may be configured based on the protocol layer functions of the wireless network implemented thereby. For example, the CU is configured to implement the functions of the PDCP layer and upper protocol layers (e.g., the RRC layer and / or the SDAP layer), and the DU is configured to implement the functions of the protocol layers below the PDCP layer (e.g., the RLC layer, the MAC layer, and / or the PHY layer). In another example, the CU is configured to perform the functions of a protocol layer above the PDCP layer (e.g., the RRC layer and / or the SDAP layer), and the DU is configured to perform the functions of the PDCP layer and lower protocol layers (e.g., the RLC layer, the MAC layer, and / or the PHY layer).

[0063] When a CU includes a CU-CP and a CU-UP, the CU-CP is configured to perform control plane functions of the CU, and the CU-UP is configured to perform user plane functions of the CU. For example, when a CU is configured to perform functions of a PDCP layer, an RRC layer, and an SDAP layer, the CU-CP is configured to perform functions of the RRC layer and control plane functions of the PDCP layer, and the CU-UP is configured to perform functions of the SDAP layer and user plane functions of the PDCP layer.

[0064] The above-described configuration of a CU or DU is merely an example, and the functions of a CU or DU may alternatively be configured based on requirements. For example, a CU or DU may be configured to have more protocol layer functions, or a CU or DU may be configured to have some processing functions of protocol layers. For example, some functions of the RLC layer and functions of protocol layers above the RLC layer are configured on the CU, and the remaining functions of the RLC layer and functions of protocol layers below the RLC layer are configured on the DU. In another example, the division of functions into CU or DU may be performed based on service type or other system requirements. For example, the division may be performed based on latency. Functions whose processing time must meet low latency requirements are configured on the DU, and functions whose processing time does not need to meet latency requirements are configured on the CU.

[0065] Optionally, the DU and RU may cooperate to jointly perform PHY layer functions. As shown in Figure 2B, the access network device includes one or more functional modules configured to perform signal processing. Using physical layer functions as an example, the access network device includes one or more functional modules of encoding, rate matching, scrambling, modulation, layer mapping, precoding, resource element (RE) mapping, digital beamforming (BF), inverse fast Fourier transformation (IFFT) / cyclic prefix (CP) addition, decoding, de-rate matching, descrambling, demodulation, inverse discrete Fourier transformation (IDFT), channel equalization (or channel estimation), RE demapping, digital BF, and fast Fourier transform (FFT) / CP removal, digital to analog (DA) conversion, analog BF, analog to digital (AD) conversion, or analog BF.

[0066] One or more functional modules may be implemented by using software, hardware, or a combination of software and hardware. Physically, the functional modules may be separate or integrated. It may be understood that the aforementioned functional modules are merely examples. The access network device may include more other modules (e.g., a scheduling module, a power control module, a hybrid automatic repeat request (HARQ) module, a flow control module, a mobility management module, or an artificial intelligence (AI) module) according to the design, or may not include the functional modules shown in FIG. 2B (e.g., not include a digital BF module).

[0067] The functions of the DU and RU can be configured in multiple ways based on the design.

[0068] For example, the DU is configured to perform baseband functions, and the RU is configured to perform intermediate radio frequency functions. In another example, the DU is configured to perform higher layer functions of the PHY layer, and the RU is configured to perform lower layer functions of the PHY layer, or lower layer functions and radio frequency functions. The higher layer functions of the physical layer may include part of the physical layer functions, this part of the functions being closer to the MAC layer. The lower layer functions of the physical layer may include another part of the physical layer functions, this part of the functions being closer to the intermediate radio frequency side.

[0069] There is a fronthaul interface between the DU and the RU. For example, the communication protocol of the fronthaul interface may be, but is not limited to, a common public radio interface (CPRI) interface protocol, an enhanced common public radio interface (eCPRI) interface protocol, etc. Different fronthaul interfaces correspond to DUs and RUs with different functions.

[0070] As shown in Figure 2C, when the fronthaul interface between the DU and the RU is CPRI, the PHY functions shown in Figure 2B are divided into baseband and radio frequency functions, with the DU configured to perform one or more of the baseband functions and the RU configured to perform one or more of the radio frequency functions.

[0071] As shown in Figure 2D, when the fronthaul interface between the DU and the RU is eCPRI, compared to CPRI, some downlink and / or uplink baseband functions are moved from the DU to the RU for implementation. Different division schemes between the DU and the RU correspond to different categories (Cats) of eCPRI. Figure 2D provides six examples of eCPRI represented by Cat A, B, C, D, E, and F (which may alternatively be represented as Options A to F, Options 1 to 6, or other schemes). It can be understood that there may be other division schemes between the DU and the RU, i.e., other categories of eCPRI.

[0072] Using eCPRICatA as an example, in downlink transmission, layer mapping is used as a division. The DU is configured to perform layer mapping and one or more previous functions (i.e., one or more of encoding, rate matching, scrambling, modulation, and layer mapping), as well as another function after layer mapping is moved to the RU for implementation (e.g., RE mapping, digital BF, or IFFT / CP addition). In uplink transmission, RE demapping is used as a division. The DU is configured to perform demapping and one or more previous functions (i.e., one or more of decoding, de-rate matching, descrambling, demodulation, IDFT, channel equalization, and RE demapping), as well as another function after demapping is moved to the RU for implementation (e.g., one or more of digital BF or FFT / CP removal).

[0073] Similarly, eCPRICatB, CatC, CatD, CatE, and CatF correspond to different segmentation schemes between the DU and the RU. The segmentation point and functions before the segmentation point are performed by the DU, and functions after the segmentation point are performed by the RU. For various types of eCPRI segmentation points, please refer to FIG. 2D and will not be described in detail one by one. For example, in eCPRICatB, RE mapping is used as the segmentation for downlink transmission, and RE demapping is used as the segmentation for uplink transmission. For uplink transmission, RE mapping and functions before RE mapping are performed by the DU, and functions after RE mapping and radio frequency functions are performed by the RU. For downlink transmission, RE demapping and functions before RE demapping are performed by the DU, and functions after RE demapping and radio frequency functions are performed by the RU.

[0074] The eCPRI division scheme may be symmetric for the uplink and downlink, e.g., eCPRICatB and CatC shown in Figure 2D, or the eCPRI division scheme may be asymmetric for the uplink and downlink, e.g., eCPRICatA, CatD, CatE, and CatF shown in Figure 2D, but optionally, without limitation, in the uplink and / or downlink, different division schemes may be configured for different channels or different channel groups, i.e., different categories of eCPRI are configured. One group of channels may include one or more channels.

[0075] In a possible implementation, the CU and DU are included in the same network element, for example, a baseband unit (BBU). The RU may be included in a radio frequency device (also referred to as a radio frequency unit), for example, a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH). A processing unit in the BBU configured to perform baseband functions is called a baseband high (BBH) unit, and a processing unit in the RRU / AAU / RRH configured to perform baseband functions is called a baseband low (BBL) unit.

[0076] The BBU and the radio frequency device may be integrated in one cabinet, or the BBU and the radio frequency device may be separated. For example, the BBU is installed in the cabinet and the radio frequency device is deployed at a remote end, for example, where signal coverage is needed. An access network device in which the BBU and the radio frequency device are separated may be understood as a distributed access network device or may be called a distributed base station.

[0077] The interface between the BBU and the radio frequency device may alternatively be referred to as a fronthaul interface. To implement the fronthaul interface, the DU and RU may be connected using a fronthaul network, or the BBU and the radio frequency device may be connected using a fronthaul network. For example, fronthaul networks include, but are not limited to, fiber direct connect and wavelength division networks. From the perspective of the radio frequency device, the BBU may alternatively be described as a radio frequency control device. One end of the fronthaul interface is the radio frequency control device, and the other end is the radio frequency device. Alternatively, the radio frequency control device and the radio frequency device may be named according to the communication protocol of the fronthaul interface. For example, as shown in FIG. 3, if the communication protocol of the fronthaul interface is the eCPRI protocol, the radio frequency control device may be an eCPRI radio equipment control (eREC), and the radio frequency device may be an eCPRI radio equipment (eRE). As another example, in an ORAN system, the radio frequency control device may be a DU, a CU, or a BBU, and the radio frequency device may be an RU, an RRU, an AAU, or an RRH. In this embodiment of the present application, the BBU and the radio frequency device are used as examples for explanation.

[0078] In a distributed base station, one BBU may be connected to multiple radio frequency devices, and fronthaul interfaces between different radio frequency devices and the BBU correspond to different transmission paths. In an optional implementation, the BBU may be directly connected to at least one of the multiple radio frequency devices by using a transmission medium such as an optical fiber (optical cable) or an electrical cable. As shown in FIG. 4A , the distributed base station includes one BBU and two radio frequency devices, i.e., a first radio frequency device and a second radio frequency device. The BBU and the two radio frequency devices may be connected by using different optical fibers. In another optional embodiment, the BBU and the radio frequency devices may alternatively be connected to each other by using a fronthaul network including one or more switch devices. Such a fronthaul network may alternatively be referred to as fronthaul networking. A single radio frequency device may be connected to the BBU by using a one-hop switch device or a multi-hop switch device. The switch devices connected between different radio frequency devices and the BBU may be the same or different. For example, as shown in Figure 4B, the distributed base station includes one BBU and two radio frequency devices, i.e., a first radio frequency device and a second radio frequency device, where the BBU is connected to a switch device in a fronthaul network using optical fiber, and the two radio frequency devices are connected to the switch device in the fronthaul network using optical fiber.

[0079] Based on requirements such as resource multiplexing and reliability, multiple BBUs may sometimes access the same fronthaul network. In other words, one radio frequency device may be connected to multiple BBUs. For example, FIG. 5A shows a distributed base station with one radio frequency device and two BBUs, specifically, BBU1 and BBU2. The radio frequency device may be connected to the two BBUs using different optical fibers. For example, FIG. 5B shows another distributed base station with BBU1, BBU2, and a radio frequency device. BBU1 and BBU2 access a fronthaul network including a switch device, and radio frequency device 1 and radio frequency device 2 also access the fronthaul network. In another example, FIG. 5C shows yet another distributed base station including BBU1, BBU2, radio frequency device 1, and radio frequency device 2. BBU1 and BBU2 access a fronthaul network including a switch device, and radio frequency device 1 and radio frequency device 2 also access the fronthaul network. The fronthaul network includes switch devices 1, 2, 3, and 4. BBU1 is indirectly connected to switch device 3 using switch device 1, BBU2 is indirectly connected to switch device 3 using switch device 2, radio frequency device 1 is indirectly connected to switch device 3 using switch device 4, and radio frequency device 2 is directly connected to switch device 3.

[0080] 4A, 4B, 5A, 5B, and 5C further illustrate that a BBU may be connected to a network management device, and the interface between the network management device and the BBU may be referred to as a backhaul interface. Optionally, the fronthaul network illustrated in FIGS. 4B, 5B, and 5C may be further connected to an additional network management device, and the additional network management device may manage switch devices within the fronthaul network. For differentiation, in FIGS. 4B, 5B, and 5C, the network management device connected to the BBU using the backhaul interface is illustrated as network management device 1, and the additional network management device connected to the fronthaul network is illustrated as network management device 2.

[0081] A BBU provides a clock source to multiple connected radio frequency devices via a fronthaul interface. The radio frequency devices maintain clock or time synchronization with the BBU. Clock synchronization, also known as frequency synchronization, means maintaining a strict, specific relationship between the frequency or phase of signals. For example, signals are displayed at the same average rate with corresponding effective moments or effective time periods, so that all devices in a communication network operate at the same rate. For example, a radio frequency device maintaining clock synchronization with a BBU can be understood as the radio frequency device's local clock tracking the clock source (i.e., the BBU's clock) to achieve frequency synchronization, and the radio frequency device and BBU's clocks transmitting / receiving are synchronized. Time synchronization, also known as phase synchronization, means that the signal frequencies and phases are consistent. For example, a radio frequency device maintaining time synchronization with a BBU can be understood as the radio frequency device's local clock tracking the clock source (i.e., the BBU's clock) to achieve phase synchronization.

[0082] When multiple BBUs are connected to the same fronthaul network, a radio frequency device maintains time synchronization with one BBU among the multiple BBUs. As shown in FIG. 5A, a radio frequency device may select clock source 1 provided by BBU1 or clock source 2 provided by BBU2 to perform time synchronization. As shown in FIG. 5B, a switch device in the fronthaul network may select clock sources provided by the same BBU (e.g., BBU1) to perform time synchronization for all radio frequency devices connected to the fronthaul network, or the switch device in the fronthaul network may select clock source 1 provided by BBU1 to perform time synchronization for radio frequency device 1 and clock source 2 provided by BBU2 to perform time synchronization for radio frequency device 2. As shown in FIG. 5C, the switch device 3 in the fronthaul network may select a clock source provided by the same BBU (e.g., BBU1) for all radio frequency devices connected to the fronthaul network to perform time synchronization, or the switch device 3 in the fronthaul network may select a clock source 1 provided by BBU1 for radio frequency device 1 to perform time synchronization, and may select a clock source 2 provided by BBU2 for radio frequency device 2 to perform time synchronization.

[0083] It can be understood that two BBUs are shown as an example in FIGS. 5A, 5B, and 5C. The multiple BBUs in this embodiment of the present application may alternatively be more than two BBUs. For example, two BBUs are shown as an example in FIGS. 5A, 5B, and 5C. The multiple BBUs in this embodiment of the present application may alternatively be more than two BBUs. For example, two BBUs are shown as an example in FIGS. 5A, 5B, and 5C. The multiple BBUs in this embodiment of the present application may alternatively be more than two BBUs. For example, FIG. 5A may further include BBU3, BBU4, ..., etc. in addition to BBU1 and BBU2. This is not limited to the embodiment of the present application.

[0084] Generally, after Clock Source 1 and Clock Source 2 are synchronized using an external clock reference source, Clock Source 1 and Clock Source 2 are also time-synchronized, or BBU 1 and BBU 2 are time-synchronized, to achieve the synchronization accuracy required by the service. For example, if the difference between the same reference time of Clock Source 1 and Clock Source 2 is within an expected indicator (e.g., ±1100 ns), synchronization between Clock Source 1 and Clock Source 2 can be achieved. The reference time may be Coordinated Universal Time (UTC). In this case, the latency obtained based on the local time for data transmission between the BBU where Clock Source 1 / 2 is located and the corresponding radio frequency device can meet the latency requirements required by the service.

[0085] However, because Clock Source 1 and Clock Source 2 are not the same clock source, an abnormality may occur in which the clock offset exceeds the expected indicator. For example, a jump occurs in the external clock reference source corresponding to Clock Source 2, resulting in the difference (e.g., 100 ms) between Clock Source 2 and the reference time exceeding the expected indicator. In other words, Clock Source 1 and Clock Source 2 are not time-synchronized, or BBU 1 and BBU 2 are not time-synchronized. In this case, when Radio Frequency Device 1, which maintains time synchronization with BBU 1, communicates with BBU 2, the Radio Frequency Device 1 and BBU 2 are not time-synchronized, so the communication latency has an offset and cannot meet the latency requirement required by the service. As a result, the service is abnormal.

[0086] Currently, to address the above service anomalies, technicians must bring test devices, such as time test equipment or sweep generators, to the site to detect the clock source of each BBU. If it is determined that the difference between the BBU's clock source and the reference time exceeds the expected indicator, it may be determined that the BBU's clock source is abnormal. Furthermore, the BBU may be disconnected from the radio frequency device, and fault handling may be performed on the BBU. After the difference between the BBU's clock source and the reference time meets the expected indicator, the BBU may be reconnected to the network and related services may be restored. Such a design relies on manual operation and test devices, resulting in high operation and maintenance costs, long fault handling times, and low efficiency.

[0087] Based on this, an embodiment of the present application provides a communication method. When multiple BBUs access the same fronthaul network, a radio frequency device or a switch device in the fronthaul network can determine the clock offset between the clock sources of the different BBUs. The communication method is applied to the aforementioned distributed base station, and fault processing, including processing operations such as fault determination (or troubleshooting), fault isolation, and fault recovery, is performed on the associated BBUs based on the clock offset between the clock sources of the different BBUs. Since there is no need to manually bring in test devices, operation and maintenance costs can be reduced and fault processing efficiency can be improved.

[0088] In an optional implementation, as shown in FIG. 5A, when a BBU is directly connected to a radio frequency device, the radio frequency device may select a clock source provided by one BBU among the multiple BBUs to determine the time information synchronized through the BBU as the time information of the local clock, and the radio frequency device may calculate a clock offset between the time information synchronized through the remaining BBUs and the time information of the local clock to determine the clock offset between the remaining BBUs and the selected BBU.

[0089] The following describes in detail the procedure of the communication method provided in this manner by using an example in which the first BBU represents the BBU selected by the radio frequency device to provide the clock source, and the second BBU represents any BBU other than the selected BBU among the multiple BBUs. As shown in Figure 6, the communication method mainly includes the following steps:

[0090] S601: A radio frequency device obtains first time information and second time information.

[0091] The first time information is time information synchronized by the radio frequency device from a fronthaul interface corresponding to the first BBU. For example, the first BBU and the radio frequency device exchange related synchronization packets via the fronthaul interface according to a synchronization protocol such as the Institute of Electrical and Electronics Engineers (IEEE) 1588 protocol (such as 1588v2) or the IEEE 1588 protocol combined with the synchronous Ethernet (SyncE) protocol to perform time synchronization. Finally, the radio frequency device may obtain the first time information. For example, the first time information may include a first absolute time accurate to within seconds and a time phase within one second. Optionally, the first time information may alternatively be described as first clock synchronization phase information or another name. This is not limited in this embodiment of the present application.

[0092] It can be understood that in the IEEE1588 protocol, the clock source provided by the first BBU can alternatively be described as a first master clock. Correspondingly, a first slave clock corresponding to the first master clock is located in the radio frequency device, and the first time information can be understood as the time information of the first slave clock. The IEEE1588 protocol can alternatively be referred to as precision time protocol (PTP). In the PTP protocol combined with the SyncE protocol, the first master clock can alternatively be described as a first SyncE+PTP master clock, and the first slave clock can alternatively be described as a first SyncE+PTP slave clock.

[0093] Similarly, the second time information is time information synchronized by the radio frequency device from the fronthaul interface corresponding to the second BBU. For example, the second BBU and the radio frequency device exchange related synchronization packets via the fronthaul interface according to the IEEE 1588 protocol (such as 1588v2) or the IEEE 1588 protocol combined with the synchronous Ethernet SyncE protocol to perform time synchronization. Finally, the radio frequency device may obtain the second time information. For example, the second time information may include a second absolute time accurate to within seconds and a time phase within one second. Optionally, the second time information may alternatively be described as second clock synchronization phase information or another name. This is not limited in this embodiment of the present application.

[0094] It may be understood that in the IEEE 1588 protocol, the clock source provided by the second BBU may alternatively be described as a second master clock. Correspondingly, a second slave clock corresponding to the second master clock is located in the radio frequency device, and the second time information may be understood as the time information of the second slave clock. The IEEE 1588 protocol may alternatively be referred to as precision time protocol (PTP). In the PTP protocol combined with the SyncE protocol, the second master clock may alternatively be described as a second SyncE+PTP master clock, and the second slave clock may alternatively be described as a second SyncE+PTP slave clock.

[0095] Optionally, the first BBU is time-synchronized with a first external clock reference source, specifically, the clock source provided by the first BBU (also referred to as a first master clock) is synchronized with the first external clock reference source. The second BBU is time-synchronized with a second external reference source, specifically, the clock source provided by the second BBU (also referred to as a second master clock) is synchronized with the second external clock reference source. The first external clock reference source and the second external clock reference source may be the same or different. For example, the external clock reference source in this embodiment of the present application may be a global navigation satellite system (GNSS) clock or a 1588V2 PTP clock.

[0096] The radio frequency device in this embodiment of the present application represents a general concept. For example, when there are multiple radio frequency devices accessing the same fronthaul network, the radio frequency device described in this embodiment of the present application may be any one of the multiple radio frequency devices.

[0097] S602: The radio frequency device determines, based on the first time information and the second time information, that the first BBU is a master clock device.

[0098] Optionally, the radio frequency device may select one time information from the time information separately synchronized via multiple BBUs as the time information of the local clock of the radio frequency device according to a best master clock algorithm (BMCA). The BBU corresponding to the selected time information may be referred to as a master clock device or a primary BBU. Alternatively, the local clock of the radio frequency device may be described as a system clock of the radio frequency device or another name. This is not limited in this embodiment of the present application.

[0099] For example, corresponding to the solution described in S601, when the radio frequency device uses the first time information synchronized through the first BBU according to the BMCA algorithm as the time information of the local clock of the radio frequency device, the radio frequency device may determine the first BBU as the master clock device. Optionally, when the radio frequency device performs time synchronization with the first BBU according to the IEEE1588 protocol, it may also be understood that the radio frequency device determines the first slave clock as the local clock of the radio frequency device according to the BMCA algorithm.

[0100] Furthermore, optionally, the first BBU may be configured as a master clock device in a predetermined manner. In this case, the radio frequency device may not need to perform S602. In other words, S602 is an optional step, and S602 is indicated by a dashed line in FIG. 6.

[0101] S603: The radio frequency device sends clock offset information to the second BBU.

[0102] The clock offset information indicates an offset between the first time information and the second time information. Optionally, corresponding to the description of S601, the offset between the first time information and the second time information may include two parts: an offset between the first absolute time and the second absolute time, and an offset between time phases within 1 second.

[0103] For example, the first absolute time is denoted as t1, the second absolute time is denoted as t2, and the offset between the first absolute time and the second absolute time is the difference between t1 and t2. The offset between time phases within one second can be calculated by using a phase identification function. For example, the phase identification function is implemented as a phase identifier, where the phase identifier is a component, functional circuit, or software component that can identify the phase difference between two input signals. The radio frequency device inputs the time phase within one second contained in the first time information and the time phase within one second contained in the second time information to the phase identifier, and the output of the phase identifier is the offset between the time phase within one second contained in the first time information and the time phase within one second contained in the second time information.

[0104] Corresponding to the radio frequency device selecting the first BBU as the primary BBU, the second BBU being a non-primary BBU, and the first time information synchronized via the first BBU being used as the time information of the local clock of the radio frequency device, the clock offset information may also be understood as an offset between the time information synchronized via the non-primary BBU and the time information of the local clock, or a clock offset between the non-primary BBU and the radio frequency device.

[0105] Correspondingly, the second BBU receiving the clock offset information from the radio frequency device may alternatively be described as the second BBU receiving the clock offset information from the radio frequency device.

[0106] In this application, "sending information (e.g., clock offset information) to a device (e.g., a second BBU)" may be understood as meaning that the destination end of the information is the device. "sending information (e.g., clock offset information) to a device (e.g., a second BBU)" may include directly or indirectly sending information to the device. Necessary processing, such as format change or frequency conversion, may be performed on the information between the source end and the destination end of the information transmission, but the destination end may understand the valid information from the source end. Similar descriptions in this application may be understood in the same way, and details will not be described here.

[0107] In this application, "receiving information from a device (e.g., a first radio frequency device)" or "receiving information from a device (e.g., a first radio frequency device)" may be understood to mean that the source end of the information is the device. "receiving information from a device (e.g., a first radio frequency device)" or "receiving information from a device (e.g., a first radio frequency device)" may include directly or indirectly receiving information from the device. Necessary processing, such as format change or frequency conversion, may be performed on the information between the source end and the destination end of the information transmission, but the destination end may understand the valid information from the source end. Similar descriptions in this application may be understood in the same way, and details will not be described here.

[0108] S604: The second BBU determines whether a fault exists in the second BBU based on the clock offset information.

[0109] For example, if the clock offset information is greater than a preset clock offset information threshold, the second BBU may determine that a fault exists in the second BBU. In this case, the second BBU may use a fault isolation method, such as disconnecting from the radio frequency device, to avoid interference caused by communication between the second BBU and the radio frequency device with communication between other devices, such as communication between the radio frequency device and the first BBU. The second BBU may further report the abnormality to an administrator or a system, and corresponding fault handling, such as troubleshooting, fault isolation, and fault recovery, may be performed manually or automatically by the system. When the second BBU recovers from the fault, the second BBU may re-establish a connection to the radio frequency device to access the radio frequency device.

[0110] In another example, if the clock offset information is equal to or less than a preset clock offset information threshold, the second BBU may determine that no fault exists in the second BBU, and there is no need to perform an abnormality report or the like.

[0111] Additionally, optionally, the radio frequency device may alternatively transmit the clock offset information to a network management device, for example, a network management device corresponding to a backhaul interface, for example, the network management device in FIG. 5A. In this embodiment of the present application, there may be two or more BBUs connected to the same radio frequency device. As described above, the second BBU is any BBU among the remaining BBUs other than the master clock device (first BBU), and the network management device receives clock offset information between each BBU of the remaining BBUs and the master clock device. Alternatively, it is described that the network management device may receive clock offset information corresponding to each of the remaining BBUs. If possible, the clock offset information corresponding to most of the remaining BBUs (e.g., more than a specified percentage) is greater than a preset clock offset information threshold. In this case, the network management device may further determine whether the first BBU is faulty and perform corresponding fault processing.

[0112] For the first BBU used as the master clock device, the radio frequency device may not report clock offset information. Alternatively, optionally, as shown in FIG. 6, the radio frequency device may further perform S605.

[0113] S605: The radio frequency device sends first information to the first BBU.

[0114] The first information may indicate one or more of: that the first BBU is a master clock device; and that a clock offset between the first BBU and the master clock device is zero. The first BBU may determine, based on the first information, that the first BBU is the master clock device.

[0115] In the above-described scheme provided in this embodiment of the present application, the radio frequency device can automatically acquire the clock offset between the non-primary BBU and the radio frequency device. This helps to quickly implement measures such as fault isolation and avoid service abnormalities caused by clock desynchronization between the BBU and the radio frequency device. Furthermore, manual operation and additional test equipment are not required, reducing operation and maintenance costs and improving fault handling efficiency.

[0116] In another optional embodiment, when a BBU is indirectly connected to a radio frequency device by using a switch device in a fronthaul network, the switch device (e.g., the switch device in FIG. 5B or the switch device 3 in FIG. 5C) may select time information of a clock source provided by one BBU among the multiple BBUs, for example, may determine the time information synchronized via the BBU as the time information of the local clock of the switch device. The switch device may calculate a clock offset between the time information synchronized via the remaining BBUs and the time information of the local clock to determine the clock offset between the remaining BBUs and the selected BBU.

[0117] The following describes in detail the procedure of the communication method provided in this manner by using an example in which the first BBU represents the BBU selected by the switch device to provide the clock source, and the second BBU represents any BBU other than the selected BBU among the multiple BBUs. As shown in Figure 7, the communication method mainly includes the following steps:

[0118] S701: A switch device in a fronthaul network obtains first time information and second time information.

[0119] The first time information is time information synchronized by the switch device from a fronthaul interface corresponding to the first BBU. For example, the first BBU and the switch device exchange related synchronization packets via the fronthaul interface according to the IEEE 1588 protocol (such as 1588v2) or the IEEE 1588 protocol combined with the SyncE protocol to perform time synchronization. Finally, the switch device may obtain the first time information. For example, the first time information may include a first absolute time accurate to within seconds and a time phase within one second. Optionally, the first time information may alternatively be described as first clock synchronization phase information or another name. This is not limited in this embodiment of the present application.

[0120] It may be understood that in the IEEE 1588 protocol, the clock source provided by the first BBU may alternatively be described as a first master clock. Correspondingly, a first slave clock corresponding to the first master clock may be disposed in the switch device, and the first time information may be understood as the time information of the first slave clock. The IEEE 1588 protocol may alternatively be referred to as precision time protocol (PTP). In the PTP protocol combined with the SyncE protocol, the first master clock may alternatively be described as a first SyncE+PTP master clock, and the first slave clock may alternatively be described as a first SyncE+PTP slave clock.

[0121] Similarly, the second time information is time information synchronized by the switch device from the fronthaul interface corresponding to the second BBU. For example, the second BBU and the switch device exchange related synchronization packets via the fronthaul interface according to the IEEE 1588 protocol (such as 1588v2) or the IEEE 1588 protocol combined with the synchronous Ethernet SyncE protocol to perform time synchronization. Finally, the switch device may obtain the second time information. For example, the second time information may include a second absolute time accurate to within seconds and a time phase within one second. Optionally, the second time information may alternatively be described as second clock synchronization phase information or another name. This is not limited in this embodiment of the present application.

[0122] It may be understood that in the IEEE 1588 protocol, the clock source provided by the second BBU may alternatively be described as a second master clock. Correspondingly, a second slave clock corresponding to the second master clock may be disposed in the switch device, and the second time information may be understood as the time information of the second slave clock. The IEEE 1588 protocol may alternatively be referred to as precision time protocol (PTP). In the PTP protocol combined with the SyncE protocol, the second master clock may alternatively be described as a second SyncE+PTP master clock, and the second slave clock may alternatively be described as a second SyncE+PTP slave clock.

[0123] Optionally, the first BBU is time-synchronized with a first external clock reference source, specifically, the clock source provided by the first BBU (also referred to as a first master clock) is synchronized with the first external clock reference source. The second BBU is time-synchronized with a second external reference source, specifically, the clock source provided by the second BBU (also referred to as a second master clock) is synchronized with the second external clock reference source. The first external clock reference source and the second external clock reference source may be the same or different. For example, the external clock reference source in this embodiment of the present application may be a GNSS clock or a 1588V2 PTP clock.

[0124] S702: The switch device determines, based on the first time information and the second time information, that the first BBU is the master clock device.

[0125] Optionally, the switch device may select one piece of time information from the time information separately synchronized via multiple BBUs as the time information of the local clock of the switch device according to the BMCA algorithm. The BBU corresponding to the selected time information may be referred to as a master clock device or a primary BBU.

[0126] For example, in accordance with the solution described in S701, when the switch device uses the first time information synchronized through the first BBU according to the BMCA as the time information of the local clock of the switch device, the switch device may determine the first BBU as the master clock device. Optionally, it may also be understood that when the switch device performs time synchronization with the first BBU according to the IEEE1588 protocol, the switch device determines the first slave clock as the local clock of the switch device according to the BMCA. Optionally, the local clock of the switch device may alternatively be described as the system clock of the switch device or another name. This is not limited in this embodiment of the present application.

[0127] Furthermore, optionally, the first BBU may be configured as a master clock device in a predetermined manner. In this case, the switch device may not need to perform S702. In other words, S702 is an optional step, and S702 is indicated by a dashed line in FIG. 7.

[0128] S703: The switch device provides a clock source to the radio frequency device based on the first time information.

[0129] The radio frequency device communicates with the first BBU and the second BBU.

[0130] Corresponding to the description of S702, when the switch device uses the first time information as the time information of the local clock of the switch device according to the BMCA, the switch device may provide a clock source to the radio frequency device based on the first time information to implement synchronization between the radio frequency device and the first BBU. For example, the switch device and the radio frequency device exchange related synchronization packets via the fronthaul interface according to a synchronization protocol such as the IEEE 1588 protocol (e.g., 1588v2) or the IEEE 1588 protocol combined with the synchronous Ethernet SyncE protocol to perform time synchronization. Finally, the radio frequency device may obtain synchronized third time information through the switch device. For example, the third time information may include a third absolute time accurate to within seconds and a time phase within one second. Optionally, the third time information may alternatively be described as third clock synchronization phase information or another name. This is not limited in this embodiment of the present application.

[0131] In the IEEE1588 protocol, for a radio frequency device, the local clock of the switch device can be regarded as a master clock that provides a clock source for the radio frequency device. For distinction, in this embodiment of the present application, the master clock that provides a clock source for the radio frequency device is hereinafter referred to as a third master clock.

[0132] A third slave clock corresponding to the third master clock may be located in a radio frequency device, and the third time information may be understood as the time information of the third slave clock. The IEEE 1588 protocol may alternatively be referred to as precision time protocol (PTP). In the PTP protocol combined with the SyncE protocol, the third master clock may alternatively be described as a third SyncE+PTP master clock, and the third slave clock may alternatively be described as a third SyncE+PTP slave clock.

[0133] S704: The switch device sends the clock offset information to the second BBU.

[0134] For the implementation of this step, please refer to S603, and the details will not be described in this embodiment of the present application.

[0135] Further, optionally, the switch device may alternatively transmit the clock offset information to the network management device. The network management device may be a network management device corresponding to a backhaul interface, for example, network management device 1 in FIG. 5B / FIG. 5C, or may be a network management device corresponding to a fronthaul network, for example, network management device 2 in FIG. 5B / FIG. 5C. In this embodiment of the present application, there may be two or more BBUs connected to the same radio frequency device. As described above, the second BBU is any BBU among the remaining BBUs other than the master clock device (first BBU), and the network management device receives clock offset information between each BBU of the remaining BBUs and the master clock device. Alternatively, it is described that the network management device may receive clock offset information corresponding to each of the remaining BBUs. If possible, the clock offset information corresponding to most of the remaining BBUs (e.g., more than a specified percentage) is greater than a preset clock offset information threshold. In this case, the network management device may further determine whether the first BBU is faulty and perform corresponding fault processing.

[0136] S705: The second BBU determines whether a fault exists in the second BBU based on the clock offset information.

[0137] For the implementation of this step, please refer to S604, and the details will not be described in this embodiment of the present application.

[0138] For the first BBU used as the master clock device, the switch device may not report clock offset information. Alternatively, optionally, as shown in FIG. 7, the switch device may further perform S706.

[0139] S706: The switch device sends the first information to the first BBU.

[0140] For the implementation of this step, please refer to S605, and the details will not be described in this embodiment of the present application.

[0141] The above-described scheme provided in this embodiment of the present application is applied to fronthaul networking scenarios, so that synchronization problems between multiple BBUs and radio frequency devices can be automatically monitored, and measures such as fault isolation can be quickly implemented to avoid service abnormalities caused by clock asynchronization. Furthermore, manual operation and additional test equipment are not required, reducing operation and maintenance costs and improving fault handling efficiency.

[0142] It may be understood that the communication method provided in this embodiment of the present application may further be used for fault handling corresponding to a fronthaul interface in another scenario, for example, used for fault handling for a distributed unit (DU) on a fronthaul interface between a DU and a radio unit (RU) in an O-RAN system.

[0143] Based on the same idea, please refer to FIG. 8 . An embodiment of the present application provides a communication device 800. The communication device 800 includes a processing module 801 and a communication module 802. The communication device 800 may be a BBU, a device applied to a BBU, or a device used in conjunction with a BBU and capable of implementing a method performed on the BBU side. Alternatively, the communication device 800 may be a switch device, a device applied to a switch device, or a device used in conjunction with a switch device and capable of implementing a method performed on the switch device side. Alternatively, the communication device 800 may be a radio frequency device, a device applied to a radio frequency device, or a device used in conjunction with a radio frequency device and capable of implementing a method performed on the radio frequency device side.

[0144] The communication module may alternatively be referred to as a transceiver module, a transceiver, a transceiver device, a transceiver apparatus, etc. The processing module may alternatively be referred to as a processor, a processing board, a processing unit, a processing device, etc. Optionally, the processing module may control the communication module to perform transmit and receive operations of the BBU, switch device, or radio frequency device in the manner described above.

[0145] It should be noted that the communication module and / or the processing module may be implemented by using a virtual module. For example, the processing module may be implemented by using a software functional unit or a virtual device, and the communication module may be implemented by using a software function or a virtual device. Alternatively, the processing module and / or the communication module may be implemented by using an entity device. For example, if the device is implemented by using a chip / chip circuit, the communication module may be an input / output circuit and / or a communication interface, performing input operations (corresponding to the aforementioned receiving operations) and output operations (corresponding to the aforementioned transmitting operations). The processing module is an integrated processor, a microprocessor, or an integrated circuit.

[0146] The division into modules in this embodiment of the present application is merely an example, and is merely a division into logical functions, and other divisions may be used in actual implementation. In addition, the functional modules in the example embodiment of the present application may be integrated into one processor, and each functional module may exist physically alone, or two or more functional modules may be integrated into one module. The integrated module may be implemented in the form of hardware or in the form of a software functional module.

[0147] In this embodiment of the present application, the functionality of the processing and / or communication modules within the BBU, switch device, or radio frequency device is further divided.

[0148] A communication module (illustrated by using eCPRI as an example in FIG. 9A or 9B ) in the first BBU or the second BBU corresponds to a fronthaul interface and is configured to exchange synchronization packets corresponding to the IEEE1588 protocol and the SYNCE protocol with a switch device or a radio frequency device. The eCPRI of the first BBU transmits synchronization packets provided by a first SyncE+PTP master clock and receives packets fed back by a first SyncE+PTP slave clock from the fronthaul interface. The eCPRI of the second BBU transmits synchronization packets provided by a second SyncE+PTP master clock and receives packets fed back by a second SyncE+PTP slave clock from the fronthaul interface.

[0149] The processing module in the first BBU or the second BBU includes a time synchronization performance monitoring unit. Corresponding to the above embodiment, the eCPRI in the second BBU is further configured to receive clock offset information transmitted by the switch device or the radio frequency device and transmit the clock offset information to the time synchronization performance monitoring unit. The time synchronization performance monitoring unit is configured to perform fault processing on the second BBU based on the clock offset information. It can be understood that the time synchronization performance monitoring unit can alternatively be located in another device, for example, a network management device corresponding to a fronthaul network or a network management device corresponding to a backhaul interface. Details will not be described in this embodiment of the present application.

[0150] FIG. 9A shows the internal structure of the first BBU, the second BBU, and the radio frequency device in the solution described in FIG. 6. The first BBU, the second BBU, and the radio frequency device exchange synchronization packets corresponding to the IEEE 1588 protocol and the SyncE protocol. The communication module in the radio frequency device includes a first communication interface for communicating with the first BBU and a second communication interface for communicating with the second BBU. The second communication interface exchanges synchronization packets corresponding to the IEEE 1588 protocol and the SyncE protocol with the radio frequency device. The first communication interface is implemented by using a first eCPRI. The first eCPRI in the radio frequency device forwards the received synchronization packets to the first SyncE+PTP slave clock and outputs the feedback packets from the first SyncE+PTP slave clock to the fronthaul interface. After interaction and synchronization according to the IEEE 1588 protocol and the SyncE protocol, the first SyncE+PTP slave clock outputs first time information. The second communication interface is implemented by using a second eCPRI. The second eCPRI in the radio frequency device forwards the received synchronization packets to a second SyncE+PTP slave clock and outputs the feedback packets from the second SyncE+PTP slave clock to the fronthaul interface. After interaction and synchronization according to the IEEE1588 protocol and the SyncE protocol, the second SyncE+PTP slave clock outputs second time information.

[0151] The processing module in the radio frequency device includes a BCMA source selection unit and a clock offset calculation unit. The BCMA source selection unit is configured to select one of the first SyncE+PTP slave clock and the second SyncE+PTP slave clock as the local clock. Figure 9A shows the BCMA source selection unit selecting the first SyncE+PTP slave clock as the local clock.

[0152] Furthermore, the time information of the local clock (i.e., the first time information) is used as one input to a clock offset calculation unit, and the second time information is used as another input to the clock offset calculation unit. The clock offset calculation unit may directly calculate an offset between the first absolute time included in the first time information and the second absolute time included in the second time information. In addition, the clock offset calculation unit uses a phase identifier to determine an offset between the time phase included in the first time information to within one second and the time phase included in the second time information to within one second. The second eCPRI of the radio frequency device reports the clock offset information, i.e., the offset between the first time information and the second time information, to the second BBU.

[0153] 9B shows the internal structures of the first BBU, the second BBU, the switch device, and the radio frequency device in the solution described in FIG. 7. The first BBU, the second BBU, and the switch device exchange synchronization packets corresponding to the IEEE 1588 protocol and the SyncE protocol. The communication module in the switch device includes a first communication interface (also referred to as a first transmission interface) that communicates with the first BBU and a second communication interface (also referred to as a second transmission interface) that communicates with the second BBU. The second communication interface exchanges synchronization packets corresponding to the IEEE 1588 protocol and the SyncE protocol with the radio frequency device. The first communication interface in the switch device forwards the received synchronization packets to the first SyncE+PTP slave clock and transmits packets fed back by the first SyncE+PTP slave clock to the eCPRI of the first BBU. After interaction and synchronization according to the IEEE1588 protocol and the SyncE protocol, the first SyncE+PTP slave clock outputs first time information. The second communication interface in the switch device forwards the received synchronization packet to the second SyncE+PTP slave clock and transmits the packet fed back by the second SyncE+PTP slave clock to the eCPRI of the second BBU. After interaction and synchronization according to the IEEE1588 protocol and the SyncE protocol, the second SyncE+PTP slave clock outputs second time information.

[0154] The processing module in the switch device includes a BCMA source selection unit and a clock offset calculation unit. The BCMA source selection unit is configured to select one of the first SyncE+PTP slave clock and the second SyncE+PTP slave clock as the system clock. Figure 9B shows the BCMA source selection unit selecting the first SyncE+PTP slave clock as the system clock.

[0155] Furthermore, the time information of the system clock (i.e., the first time information) is used as one input to a clock offset calculation unit, and the second time information is used as another input to the clock offset calculation unit. The clock offset calculation unit may directly calculate an offset between the first absolute time included in the first time information and the second absolute time included in the second time information. In addition, the clock offset calculation unit uses a phase identifier to determine an offset between a time phase within one second included in the first time information and a time phase within one second included in the second time information. The second communication interface of the switch device reports the clock offset information, i.e., the offset between the first time information and the second time information, to the second BBU.

[0156] Furthermore, the communication module of the switch device may further include a third communication interface. After the switch device determines the system clock, the system clock may be used as a third SyncE+PTP master clock corresponding to the radio frequency device. The third communication interface exchanges synchronization packets corresponding to the IEEE1588 protocol and the SyncE protocol with the radio frequency device. The communication module (e.g., implemented using eCPRI) in the radio frequency device forwards the received synchronization packets to the third SyncE+PTP slave clock and transmits packets fed back by the third SyncE+PTP slave clock to the third communication interface of the switch device. After interaction and synchronization according to the IEEE1588 protocol and the SyncE protocol, the third SyncE+PTP slave clock in the radio frequency device may output third time information.

[0157] It can be understood that there may be one or more radio frequency devices in Figure 9B. The switch device may select the same master clock source or different master clock sources for different radio frequency devices. Figure 9B shows only one radio frequency device as an example.

[0158] Based on the same technical concept, an embodiment of the present application further provides a communication device 1000. For example, the communication device 1000 may be a chip or a chip system. Optionally, in this embodiment of the present application, the chip system may include a chip, or may include a chip and another individual device.

[0159] The communications device 1000 may include at least one processor 1010. Optionally, the processor 1010 is coupled to a memory. The memory may be located within the device. Alternatively, the memory may be integrated with the processor. Alternatively, the memory may be located external to the device. For example, the communications device 1000 may further include at least one memory 1020.

[0160] The processor 1010 may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or another programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, and may implement or execute the methods, steps, and logical block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor or any conventional processor, etc. For example, the processor 1010 may be a baseband processor or a central processing unit. The baseband processor may be configured to process communication protocols and communication data. The central processing unit may be configured to control a communication device (e.g., a radio frequency control device, a radio frequency device, a RAN node, a terminal, or a chip), execute a software program, and process data of the software program.

[0161] The communication device 1000 is applied to the radio frequency device described above. In one design, the processor 1010 may include a program 113 (which may alternatively be referred to as code or instructions). The program 113 may be executed on the processor 1010 to cause the communication device 1000 to perform a method on the radio frequency device side in the above-described embodiments. In another possible design, the communication device 1000 includes a circuit (not shown in FIG. 10 ), and the circuit is configured to implement a function on the radio frequency device side in the above-described embodiments. Optionally, the processor 1010 may further store data.

[0162] The communication device 1000 is applied to the aforementioned switch device. In a design, the processor 1010 may include a program 113 (which may alternatively be referred to as code or instructions). The program 113 may be executed on the processor 1010 to cause the communication device 1000 to perform a method on the switch device side in the aforementioned embodiment. In another possible design, the communication device 1000 includes a circuit (not shown in FIG. 10 ), and the circuit is configured to implement a function on the switch device side in the aforementioned embodiment. Optionally, the processor 1010 may further store data.

[0163] The communication device 1000 is applied to a BBU (e.g., a first BBU or a second BBU). In a design, the processor 1010 may include a program 113 (which may alternatively be referred to as code or instructions), which may be executed on the processor 1010 to cause the communication device 1000 to perform a method on the BBU side in the aforementioned embodiments. In another possible design, the communication device 1000 includes a circuit (not shown in FIG. 10 ), which is configured to implement a function on the BBU side in the aforementioned embodiments. Optionally, the processor 1010 may further store data.

[0164] The memory 1020 may be a non-volatile memory, such as a hard disk drive (HDD) or a solid-state drive (SSD), or a volatile memory, such as a random access memory (RAM). The memory may be any medium that can be used to carry or store program code, such as instructions or data structures, and that can be accessed by a computer, but is not limited to such a medium. The memory in the embodiments of the present application may alternatively be a circuit or any other device capable of implementing a memory function and configured to store programs and / or data. For example, the memory 1020 may store a program 114 (which may alternatively be referred to as code or instructions) that executes on the processor 1010 to cause the communication device 1000 to perform the methods described in the preceding method embodiments.

[0165] Optionally, the processor 1010 may further include an artificial intelligence (AI) module 1110, and / or the memory 1020 may further include an AI module 118. The AI ​​module is configured to implement AI-related functions. The AI ​​module may be implemented by using software, hardware, or a combination of software and hardware. For example, the AI ​​module may include a radio access network intelligent controller (RAN intelligent controller, RIC) module. For example, the AI ​​module may be a near real-time RIC or a non-real-time RIC.

[0166] The communication device 1000 may further include a transceiver 1030 and / or an antenna 1040. Alternatively, the transceiver 1030 may be referred to as a transceiver unit, a transceiver machine, a transceiver circuit, a transceiver, etc., and is configured to implement transceiver functions of the communication device. For example, the transceiver 1030 may be a transceiver machine, a circuit, a bus, a module, a pin, or another type of communication interface. If the communication device 1000 is a chip-type device or circuit, the transceiver 1030 in the communication device 1000 may alternatively be an input / output circuit and may input information (or be referred to as receiving information) and output information (or be referred to as transmitting information). Optionally, if the communication device 1000 includes an antenna 1040, the transceiver 1030 is configured to implement transceiver functions of the communication device by using the antenna 1040.

[0167] The coupling in this embodiment of the present application may be an electrical, mechanical, or other form of indirect coupling or communication connection between devices, units, or modules, used for exchanging information between the devices, units, or modules. The processor 1010 may operate in cooperation with one or more of the memory 1020, the transceiver 1030, and the antenna 1040. The specific connection medium between the processor 1010, the memory 1020, the transceiver 1030, and / or the antenna 1040 is not limited in this embodiment of the present application. For example, the processor 1010, the memory 1020, and the transceiver 1030 are connected to each other by using a bus. The bus may be a peripheral component interconnect (PCI) bus, an extended industry standard architecture (EISA) bus, etc. The bus may be categorized into an address bus, a data bus, a control bus, etc.

[0168] Based on the above example, an embodiment of the present application further provides a communication system, including at least one BBU and at least one radio frequency device, which can implement the communication method provided in the example shown in FIG.

[0169] An embodiment of the present application further provides a communication system including at least one BBU, a switch device in a fronthaul network, and at least one radio frequency device, wherein the communication system may implement the communication method provided in the example shown in FIG.

[0170] The technical solutions provided in this embodiment of the present application may be fully or partially implemented through software, hardware, firmware, or any combination thereof. When implementing an embodiment using software, all or a part of the embodiment 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 some of the procedures or functions according to the embodiment of the present application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, a network management device, or another 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 via wired (e.g., coaxial cable, optical fiber, or digital subscriber line (DSL)) or wireless (e.g., infrared, radio, or microwave) methods. A computer-readable storage medium may be any available medium that can be accessed by a computer, or a data storage device such as a server or data center that consolidates one or more available media. The available medium may be magnetic media (e.g., floppy disks, hard disks, or magnetic tapes), optical media (e.g., digital video discs (DVDs)), semiconductor media, etc.

[0171] In the embodiments of the present application, examples may be cross-referenced, provided that there is no logical contradiction. For example, methods and / or terms in method embodiments may be cross-referenced, functions and / or terms in apparatus embodiments may be cross-referenced, and functions and / or terms between apparatus examples and method examples may be cross-referenced.

[0172] It is apparent that those skilled in the art can make various modifications and variations to the embodiments without departing from the scope of the embodiments of the present application. Thus, the embodiments of the present application are also intended to cover these modifications and variations, provided that they fall within the scope of the claims of the embodiments of the present application and their equivalent technologies.

Claims

1. 1. A communication method comprising: Obtaining first time information and second time information, where the first time information is time information synchronized via a fronthaul interface corresponding to a first baseband unit, and the second time information is time information synchronized via a fronthaul interface corresponding to a second baseband unit; transmitting clock offset information, the clock offset information indicating an offset between the first time information and the second time information; A method comprising:

2. before transmitting the clock offset information, 2. The method of claim 1, further comprising: determining, based on the first time information and the second time information, that the first baseband unit is a master clock device.

3. 3. The method of claim 1, further comprising providing a clock source to a radio frequency device based on the first time information, the radio frequency device communicating with the first baseband unit and the second baseband unit.

4. transmitting the clock offset information 4. The method according to claim 1, further comprising transmitting the clock offset information to the second baseband unit, wherein the clock offset information is used to determine a fault in the second baseband unit.

5. transmitting first information to the first baseband unit, the first information comprising: the first baseband unit is a master clock device; and The clock offset between the first baseband unit and the master clock device is zero.

5. The method of claim 1, further comprising indicating one or more of:

6. 6. The method according to claim 1, wherein the first baseband unit is time-synchronized with a first external clock reference source and the second baseband unit is time-synchronized with a second external clock reference source, and the first external clock reference source and the second external clock reference source are the same or different.

7. 1. A communication method comprising: receiving clock offset information, the clock offset information indicating an offset between first time information and second time information, the first time information being time information synchronized via a fronthaul interface corresponding to a first baseband unit, and the second time information being time information synchronized via a fronthaul interface corresponding to a second baseband unit; determining whether a fault exists in the second baseband unit based on the clock offset information; The method further comprising:

8. 8. The method of claim 7, wherein the first baseband unit is a master clock device.

9. 9. The method according to claim 7 or 8, wherein the first baseband unit is time-synchronized with a first external clock reference source, and the second baseband unit is time-synchronized with a second external clock reference source, and the first external clock reference source and the second external clock reference source are the same or different.

10. A communication device configured to perform the method of any one of claims 1 to 6.

11. A communication device configured to perform the method of any one of claims 7 to 9.

12. 7. A communication device comprising a processor, the processor being coupled to a memory, the processor being configured to invoke computer program instructions stored in the memory to perform the method of any one of claims 1 to 6.

13. 10. A communications device comprising a processor, the processor being coupled to a memory, the processor being configured to invoke computer program instructions stored in the memory to perform the method of any one of claims 7 to 9.

14. A communication system comprising: a communication device according to claim 10 or 12; and a communication device according to claim 11 or 13.

15. 10. A computer-readable storage medium storing instructions that, when executed on a computer, enable the computer to perform the method of any one of claims 1 to 6 or any one of claims 7 to 9.

16. 10. A computer program product comprising instructions, which when executed on a computer, enable the computer to carry out the method according to any one of claims 1 to 6 or any one of claims 7 to 9.

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