Communication method and apparatus

Abstract

The present application discloses a communication method and apparatus, in which a radio frequency device receives first time information transmitted over an air interface and second time information transmitted over a fronthaul interface, and the radio frequency device transmits clock offset information, the clock offset information indicating an offset between the first time information and the second time information, and the clock offset information can be applied to fault handling of the fronthaul interface, thereby reducing operation and maintenance costs and improving fault handling efficiency.

Description

[Technical Field]

[0001] TECHNICAL FIELD Embodiments of the present application relate to the field of communication technology, and in particular to a communication method and apparatus. [Background technology]

[0002] In a distributed base station architecture, one baseband unit (BBU) can be remotely connected to multiple radio frequency devices, and a fronthaul interface between each radio frequency device and the BBU can correspond to each transmission path. The BBU can provide a clock source to multiple connected radio frequency devices through the fronthaul interface. If a transmission path fails, for example, if the transmission latency compensation on the transmission path is incorrect, time synchronization between the radio frequency devices may become unsynchronized, which may cause signal interference between the radio frequency devices and abnormal communication services.

[0003] Currently, when a communication service in a distributed base station becomes abnormal, troubleshooting requires personnel to carry test devices and individually check the time of each radio frequency device on-site. This method relies on manual labor and test equipment, resulting in high labor and maintenance costs, long troubleshooting times, and reduced efficiency. Summary of the Invention

[0004] The present application provides a communication method and apparatus to reduce the operation and maintenance costs associated with the fronthaul interface and improve the efficiency of troubleshooting. [Means for solving the problem]

[0005] According to a first aspect, an embodiment of the present application provides a communication method, the method including: a second radio frequency device receiving first time information, where the first time information is time information transmitted over an air interface; and a second radio frequency device transmitting clock offset information, where the clock offset information indicates an offset between the first time information and second time information, and the second time information is time information synchronized over a fronthaul interface.

[0006] In the above design, in addition to synchronizing the time information through the fronthaul interface, the radio frequency device can also receive other time information through an interface other than the fronthaul interface to determine the offset between the two types of time information. Based on the offset between the two types of time information, fault handling is performed on the transmission path corresponding to the fronthaul interface, without the need for manual intervention or additional testing equipment, thereby reducing labor and maintenance costs and improving fault handling efficiency.

[0007] In one possible design, the second radio frequency device receives the first information, the first information indicating the identity of the first device, and the first time information received by the second device is from the first device. Based on this design, the second radio frequency device can determine the origin of the first time information.

[0008] In one possible design, the first device is a first radio frequency device, a satellite device, or a relay device, and the relay device is a device between the second radio frequency device corresponding to the fronthaul interface and the first radio frequency device or the satellite device. For example, the relay device may be a terminal device. Such a design can be adapted to a terrestrial or non-terrestrial communication network scenario and can flexibly implement air interface synchronization.

[0009] In one possible design, the clock offset information is used to determine faults in the transmission path corresponding to the fronthaul interface.

[0010] In one possible design, the clock offset information may further include identification information of the first device. Such a design helps a receiver of the clock offset information to determine that the clock offset information is specifically an offset between the device corresponding to the air interface and the synchronization time information corresponding to the fronthaul interface, thereby facilitating subsequent fault handling and improving fault handling efficiency.

[0011] In one possible design, the first device is time-synchronized with a radio frequency control device corresponding to the fronthaul interface. Such a design can avoid interference with fault determination caused by time asynchronous clock sources and lock the fault determination to the transmission path corresponding to the fronthaul interface, thereby improving the efficiency and accuracy of the fault determination.

[0012] In one possible design, the first time information is transmitted on uplink resources. In this design, the first device may be considered a terminal of the second radio frequency device. The first time information is transmitted using configured uplink resources, and no new determination or configuration is required, thereby reducing the complexity of the solution.

[0013] In one possible design, the second radio frequency device can further receive second information, where the second information indicates the identity of the second device, so that the second radio frequency device transmits the clock offset information to the second device. In this design, to facilitate implementation of the method, the indication information is used to configure the receiver of the clock offset information. For example, the second device is a radio frequency control device corresponding to the fronthaul interface, or a switch device or network management device corresponding to the fronthaul interface. In other words, it will be understood that any implementation of the second device can be used for fault handling and can be flexibly adapted to multiple scenarios.

[0014] According to a second aspect, an embodiment of the present application provides a communication method, the method including: a step of receiving clock offset information by a second device, where the clock offset information indicates an offset between first time information and second time information, the first time information being time information transmitted through an air interface, and the second time information being time information synchronized through a fronthaul interface; and a step of determining, by the second device, based on the clock offset information, whether a fault exists on a transmission path corresponding to the fronthaul interface.

[0015] In one possible design, the second device may further send the clock offset information to the network management device.

[0016] In one possible design, the first time information is from a first device, and the clock offset information includes an identification of the first device.

[0017] In one possible design, the first device is a first radio frequency device, a satellite device, or a relay device, and the relay device is a device between a second radio frequency device corresponding to the fronthaul interface and the first radio frequency device or the satellite device.

[0018] In one possible design, the first device is time-synchronized with a radio frequency control device corresponding to the fronthaul interface.

[0019] In one possible design, the second device is a radio frequency control device corresponding to the fronthaul interface, or a switch device or a network management device corresponding to the fronthaul interface.

[0020] According to a third aspect, an embodiment of the present application provides a communication device. The communication device may be a second radio frequency device, or may be a device, module, chip, etc. within the second radio frequency device, or may be a device that can be used in a manner consistent with the second radio frequency device. In one design, the communication device may include modules that correspond one-to-one to the methods / tasks / steps / operations described in the first aspect. The modules may be implemented by hardware circuits, software, or a combination of hardware circuits and software. In one design, the communication device may include a processing module and a communication module.

[0021] The communication module is configured to receive first time information, the first time information being time information transmitted over an air interface; the processing module is configured to transmit clock offset information over the communication module, the clock offset information indicating an offset between the first time information and the second time information, and the second time information being time information synchronized over a fronthaul interface.

[0022] In one possible design, the communication module is further configured to receive first information, the first information indicating an identity of the first device. The first time information received by the communication module is from the first device.

[0023] In one possible design, the first device is a first radio frequency device, a satellite device, or a relay device, and the relay device is a device between a second radio frequency device corresponding to the fronthaul interface and the first radio frequency device or the satellite device.

[0024] In one possible design, the first device is time-synchronized with a radio frequency control device corresponding to the fronthaul interface.

[0025] In one possible design, the clock offset information is used to determine faults in the transmission path corresponding to the fronthaul interface.

[0026] In one possible design, the first time information is transmitted on an uplink resource.

[0027] In one possible design, the communication module is further configured to receive second information, the second information indicating an identification of the second device, and is further configured to transmit clock offset information to the second device.

[0028] In one possible design, the second device is a radio frequency control device corresponding to the fronthaul interface, or a switch device or a network management device corresponding to the fronthaul interface.

[0029] In one possible design, the clock offset information includes an identification of the first device.

[0030] According to a fourth aspect, an embodiment of the present application provides a communications apparatus. The communications apparatus may be a second device, or may be a device, module, chip, etc. within the second device, or may be an apparatus that can be used in a manner consistent with the second device. In one design, the communications apparatus may include modules that correspond one-to-one to the methods / tasks / steps / operations described in the second aspect. The modules may be implemented by hardware circuits, software, or a combination of hardware circuits and software. In one design, the communications apparatus may include a processing module and a communications module.

[0031] 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 transmitted over an air interface, and the second time information being time information synchronized over a fronthaul interface; The processing module is configured to determine, based on the clock offset information, whether a fault exists on a transmission path corresponding to the fronthaul interface.

[0032] In one possible design, the communication module is further configured to send the clock offset information to a network management device.

[0033] In one possible design, the first time information is from a first device, and the clock offset information includes an identification of the first device.

[0034] In one possible design, the first device is a first radio frequency device, a satellite device, or a relay device, and the relay device is a device between a second radio frequency device corresponding to the fronthaul interface and the first radio frequency device or the satellite device.

[0035] In one possible design, the first device is time-synchronized with a radio frequency control device corresponding to the fronthaul interface.

[0036] In one possible design, the second device is a radio frequency control device corresponding to the fronthaul interface, or a switch device or a network management device corresponding to the fronthaul interface.

[0037] According to a fifth aspect, an embodiment of the present application provides a communication device. The communication device includes a processor configured to perform the method described in the first aspect. The processor is coupled to a memory, the memory configured to store instructions and data, and the method described in the first aspect can 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, 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.

[0038] The communication interface is configured to receive first time information, the first time information being time information transmitted over the air interface; the processor is configured to transmit clock offset information over the communication interface, the clock offset information indicating an offset between the first time information and the second time information, and the second time information being time information synchronized over the fronthaul interface.

[0039] According to a sixth aspect, an embodiment of the present application provides a communication device. The communication device includes 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 can 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.

[0040] 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 transmitted over an air interface, and the second time information being time information synchronized over a fronthaul interface; The processor is configured to determine, based on the clock offset information, whether a fault exists on a transmission path corresponding to the fronthaul interface.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] According to a tenth aspect, an embodiment of the present application further provides a computer-readable storage medium storing a computer program or instructions that, when executed on a computer, enables the computer to perform a method according to the first or second aspect.

[0045] 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 to perform the method according to the first or second aspect, or the chip including circuitry configured to perform the method according to the first or second aspect.

[0046] 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 in performing a method according to the first or second aspect. In one 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 discrete component.

[0047] For the effects of the solutions provided in any one of the second to twelfth aspects, please refer to the corresponding description of the first aspect. [Brief explanation of the drawings]

[0048] [Figure 1] 1 is a diagram of the structure 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 3A] 1 is a diagram of the structure of a distributed base station. [Figure 3B] 1 is a diagram of the structure of a distributed base station. [Figure 3C] FIG. 1 is a diagram of signal interference. [Figure 4A] FIG. 1 is a diagram of the structure of a fronthaul network. [Figure 4B] 1 is a schematic flowchart of a communication method. [Figure 5] FIG. 1 is a diagram illustrating the configuration of a communication device. [Figure 6A] FIG. 1 is a diagram of the structure of radio frequency devices in a distributed base station. [Figure 6B] FIG. 1 is a diagram of the structure of radio frequency devices in a distributed base station. [Figure 6C] FIG. 1 is a diagram of the structure of radio frequency devices in a distributed base station. [Figure 6D] FIG. 1 is a diagram of the structure of radio frequency devices in a distributed base station. [Figure 6E] FIG. 1 is a diagram of the structure of radio frequency devices in a distributed base station. [Figure 7] FIG. 10 is a diagram illustrating the configuration of another communication device. DETAILED DESCRIPTION OF THE INVENTION

[0049] 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.

[0050] In the embodiments of the present application, "at least one (item)" refers to one or more (items). "Multiple (items)" refers to two (items) or three or more (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 can represent the following three cases: when only A exists, when both A and B exist, and when only B exists. The character " / " generally indicates an "or" relationship between related objects. In addition, although terms such as "first" and "second" may be used to describe objects in the embodiments of the present application, it should be understood that these objects should not be limited by these terms. These terms are used merely to distinguish objects from each other.

[0051] In the following description of the embodiments of the present application, the terms "comprises," "having," and any variations thereof are intended to cover non-exclusive inclusions. 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, and may further optionally include other steps or units not listed, or may further optionally 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 represent providing 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 interpreted as being preferred over another method or design solution, or as having more advantages than another method or design solution. To be precise, the use of words such as "example" or "for example" is intended to present a relative concept in a particular manner.

[0052] 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 separate 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 using the core network 200.

[0053] RAN 100 is a 3rd Generation Partnership Project (3 rd cellular systems associated with the Third Generation Partnership Project (3GPP), such as the fourth generation (4 th generation, 4G) or 5th generation (5 thThe RAN 100 may be a 4G (5th generation) mobile communication system, or a future-oriented evolved system (e.g., a 6G mobile communication system). The RAN 100 may alternatively be an open radio access network (open RAN, O-RAN, or ORAN) or a cloud radio access network (CRAN). The RAN 100 may alternatively be a communication system that integrates two or more of the aforementioned systems. 4G mobile communication systems include long term evolution (LTE) systems, and 5G mobile communication systems include new radio (NR) systems.

[0054] 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 node 110 and the terminal 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 the 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 node 110 and the terminal 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.

[0055] The terminal and RAN node are described in detail below.

[0056] (1) Terminal A terminal may alternatively 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 using a RAN. A terminal may include a handheld device with wireless connectivity, another processing device connected to a wireless modem, or an in-vehicle device. A communication device may be a portable, pocket-sized, handheld, computer-integrated, or in-vehicle mobile device. The terminal may 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 by the embodiments of this application.

[0057] (2) RAN node In one possible scenario, a RAN node may alternatively be referred to as an access network device, RAN entity, access node, network device, etc., and forms part of a communication system to assist terminals in implementing wireless access. RAN nodes may also be referred to as base stations (BS), evolved base stations (eNB), access points (AP), transmission reception points (TRP), next generation NodeBs (gNBs), sixth generation (6G) NodeBs, etc. th The RAN node may be a next-generation base station of a 6G (6th generation) mobile communication system, a base station of 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 instead be a server, a wearable device, a vehicle, an in-vehicle device, etc. For example, an access network device in a vehicle-to-everything (V2X) technology may be a road side unit (RSU).

[0058] In another possible scenario, multiple RAN nodes cooperate to help a terminal implement radio access, with each RAN node separately implementing 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 a terminal. For example, the RAN node may be a CU, a DU, a CU-CP, a CU-UP, or an RU.

[0059] In one 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 called a radio frequency unit), for example, included in a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH). The interface between the BBU and the radio frequency device may alternatively be called a fronthaul interface. Additionally, optionally, to implement a fronthaul interface, the DU and RU may be connected using a fronthaul network, and 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. 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 required. 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.

[0060] In different systems, the CU (or CU-CP and CU-UP), DU, or RU may have different names, but it is understood that those skilled in the art can understand the meaning of these names. For example, in an ORAN system, the CU may be alternatively referred to as an O-CU (open CU), the DU may be alternatively referred to as an O-DU, the CU-CP may be alternatively referred to as an O-CU-CP, the CU-UP may be alternatively referred to as an O-CU-UP, and the RU may be alternatively referred to as an O-RU. For ease of explanation, this application uses the CU, CU-CP, CU-UP, DU, and RU as examples for explanation. 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 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 the following: 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 the following: 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 by them. For example, the CU is configured to perform the functions of the PDCP layer and higher protocol layers (e.g., the RRC layer and / or the SDAP layer), and the DU is configured to perform the functions of the protocol layers below the PDCP layer (e.g., the RLC layer, the MAC layer, and / or the PHY layer). As another example, the CU is configured to perform the functions of the protocol layers 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).

[0062] When the CU includes a CU-CP and a CU-UP, the CU-CP is configured to perform the control plane functions of the CU, and the CU-UP is configured to perform the user plane functions of the CU. For example, when the CU is configured to perform the functions of the PDCP layer, the RRC layer, and the SDAP layer, the CU-CP is configured to perform the functions of the RRC layer and the control plane functions of the PDCP layer, and the CU-UP is configured to perform the functions of the SDAP layer and the user plane functions of the PDCP layer.

[0063] The above-described configuration of the CU or DU is merely an example, and the functions of the CU or DU may instead be configured based on requirements. For example, the CU or DU may be configured to have more protocol layer functions, or the 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 in the CU, and the remaining functions of the RLC layer and functions of protocol layers below the RLC layer are configured in the DU. As another example, the division of the functions of the CU or DU may be based on service type or other system requirements. For example, the division may be based on latency. Functions whose processing time must meet low latency requirements are configured in the DU, and functions whose processing time does not need to meet latency requirements are configured in the CU.

[0064] 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 the PHY layer functions as an example, the access network device includes one or more of the following functional modules: 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.

[0065] One or more functional modules may be implemented using software, hardware, or a combination of software and hardware. Physically, the functional modules may be separate or integrated. It will be understood that the aforementioned functional modules are merely examples. The access network device may include more other modules according to design (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), or may not include the functional modules shown in FIG. 2B (e.g., not include a digital BF module).

[0066] The functions of the DU and RU may be configured in multiple ways based on the design.

[0067] For example, the DU may be configured to perform baseband functions, and the RU may be configured to perform intermediate radio frequency functions. As another example, the DU may be configured to perform upper layer functions of the PHY layer, and the RU may be configured to perform lower layer functions of the PHY layer, or to perform lower layer functions and radio frequency functions. The upper layer functions of the PHY layer may include a portion of the PHY layer functions, which are closer to the MAC layer. The lower layer functions of the PHY layer may include another portion of the PHY layer functions, which are closer to the intermediate radio frequency side.

[0068] 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.

[0069] 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 split 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.

[0070] As shown in FIG. 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 (Cat for short) of eCPRI. FIG. 2D provides six examples of eCPRI represented by Cat A, B, C, D, E, and F (or may be represented as Option A to F, Option 1 to 6, or another scheme). It will be understood that there may be other division schemes between the DU and the RU, i.e., there may be other categories of eCPRI.

[0071] Using eCPRI Cat A as an example, for downlink transmission, layer mapping is used as the division. The DU is configured to perform layer mapping and one or more previous functions (i.e., one or more of coding, rate matching, scrambling, modulation, and layer mapping), and other functions after layer mapping (e.g., RE mapping, digital BF, or IFFT / CP addition) are transferred to the RU for implementation. For uplink transmission, RE demapping is used as the 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), and other functions after demapping (e.g., one or more of digital BF or FFT / CP removal) are transferred to the RU for implementation.

[0072] Similarly, eCPRI Cat B, Cat C, Cat D, Cat E, and Cat F 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 the various types of eCPRI segmentation points, please refer to Figure 2D and will not be described in detail one by one. For example, in the case of eCPRI Cat B, 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.

[0073] The eCPRI splitting scheme may be symmetric for uplink and downlink, for example, eCPRI Cat B and Cat C shown in Figure 2D, or the eCPRI splitting scheme may be asymmetric for uplink and downlink, for example, eCPRI Cat A, Cat D, Cat E, and Cat F shown in Figure 2D, but is not limited thereto. Optionally, different splitting schemes may be configured for different channels or different channel groups for uplink and / or downlink, i.e., different categories of eCPRI are configured. One group of channels may include one or more channels.

[0074] In one possible design, the DU is located in the BBU, the RU is located in the RRU / AAU / RRH, a processing unit in the BBU configured to perform baseband functions is referred to as a baseband high (BBH) unit, and a processing unit in the RRU / AAU / RRH configured to perform baseband functions is referred to as a baseband low (BBL) unit.

[0075] The embodiments of the present application relate to a synchronization processing technology for a fronthaul interface. A fronthaul interface between a BBU and a radio frequency device is used as an example. In an optional implementation, the BBU may be directly connected to at least one of multiple radio frequency devices using a transmission medium such as an optical cable or an electrical cable, and the fronthaul interface between the BBU and each radio frequency device corresponds to each transmission path. As shown in FIG. 3A , a 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 using separate optical fibers. In another optional implementation, the BBU and the radio frequency devices may instead be connected to each other using a fronthaul network including one or more switch devices. Such a fronthaul network may instead be referred to as fronthaul networking. A single radio frequency device may be connected to the BBU using one-hop or multi-hop switch devices. The switch devices connected between each radio frequency device and the BBU may be different. Alternatively, it will be understood that the fronthaul interface between each radio frequency device and the BBU corresponds to each transmission path, and each transmission path passes through each switch device. For example, as shown in FIG. 3B , a 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 is connected to a switch device in the fronthaul network using optical fiber, and the two radio frequency devices are connected to the switch device in the fronthaul network using optical fiber. The first radio frequency device is connected to the BBU using switch device 1 and switch device 2 in the fronthaul network, and the second radio frequency device is connected to the BBU using switch device 3 in the fronthaul network.3A and 3B 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 FIG. 3B may be further connected to an additional network management device, which may manage switch devices in the fronthaul network. For distinction, in FIG. 3B, the network management device connected to the BBU using the backhaul interface is labeled network management device 1, and the additional network management device connected to the fronthaul network is labeled network management device 2.

[0076] The BBU provides a clock source to multiple connected radio frequency devices through the 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, to keep all devices in a communication network running at the same rate, signals appear at the same average rate at corresponding valid times or periods. For example, a radio frequency device maintaining clock synchronization with a BBU can be understood as the radio frequency device's local clock tracking a clock source (i.e., the BBU's clock) to achieve frequency synchronization, and the transmit / receive clocks of the radio frequency device and the BBU being synchronized. Time synchronization, also known as phase synchronization, means that the signal frequency and phase 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 a clock source (i.e., the BBU's clock) to achieve phase synchronization.

[0077] As shown in FIG. 3A or 3B, the transmission paths corresponding to the fronthaul interfaces between the BBU and each radio frequency device are separate. Therefore, if there is an abnormality in the transmission path, for example, if a transmission latency compensation error occurs in the transmission path, the time synchronization between the radio frequency device corresponding to the transmission path and the BBU becomes incorrect. The uplink / downlink transmission of the radio frequency device causes signal interference with the uplink / downlink transmission of another radio frequency device time-synchronized with the BBU, resulting in a communication service abnormality. An unsynchronized radio frequency device may instead be described as a faulty radio frequency device, and a synchronized radio frequency device may include a normal radio frequency device in the base station to which the faulty radio frequency device belongs or a radio frequency device in a base station nearby the base station to which the faulty radio frequency device belongs. As shown in FIG. 3C, "D" represents downlink transmission, and "U" represents uplink transmission. In uplink and downlink transmissions, there is a clock offset between the faulty radio frequency device and another synchronized radio frequency device, such as a normal radio frequency device in a local station or a radio frequency device in a nearby station. The clock offset may alternatively be referred to as a phase offset. A faulty radio frequency device will cause signal interference to the uplink / downlink transmissions of synchronized radio frequency devices, such as other radio frequency devices in the same base station or radio frequency devices in nearby base stations, resulting in abnormal communication services.

[0078] Currently, when a communication service abnormality occurs in a distributed base station, an operator must carry test devices, such as time test equipment or a sweep oscillator, to the site to detect the clock of the radio frequency device. For example, if it is determined that the clock offset between the clock of the radio frequency device and the expected clock does not meet the requirements, the radio frequency device may be disconnected from the BBU, and troubleshooting is performed on the transmission path corresponding to the fronthaul interface between the radio frequency device and the BBU. If a fault exists, the fault is repaired so that the clock offset between the clock of the radio frequency device and the expected clock meets the requirements, and then the radio frequency device is reconnected to the network to restore the related communication service. This design relies on manual labor and test equipment, resulting in high labor and maintenance costs, long troubleshooting time, and reduced efficiency.

[0079] In light of this, one embodiment of the present application provides a communication method. In addition to synchronizing time information through a fronthaul interface, a radio frequency device can also receive other time information through an interface other than the fronthaul interface and determine the offset between the two types of time information. This communication method is applied to the aforementioned distributed base station, and based on the offset between the two types of time information, fault handling is performed on the transmission path corresponding to the fronthaul interface, including processing operations such as fault determination (or troubleshooting), fault isolation, and fault recovery. Since there is no need to carry test equipment, operation and maintenance costs can be reduced and fault handling efficiency can be improved.

[0080] From the perspective of a radio frequency device, the aforementioned BBU may instead be described as a radio frequency control device. One end of the fronthaul interface is a radio frequency control device, and the other end is a radio frequency device. The radio frequency control device and the radio frequency device may instead be named according to the communication protocol of the fronthaul interface. The radio frequency control device and the radio frequency device may be directly connected using optical fiber, or indirectly connected using a one-hop or multi-hop switch device in the fronthaul network. For example, as shown in FIG. 4A, 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, CU, or BBU, and the radio frequency device may be an RU, RRU, AAU, or RRH.

[0081] In the following, the communication method provided in this embodiment of the present application will be described in detail using the fronthaul interface between the radio frequency control device and the second radio frequency device as an example.

[0082] As shown in FIG. 4B, the communication method mainly includes the following steps:

[0083] S401: A radio frequency control device transmits first information to a second radio frequency device.

[0084] The first information is used to trigger the second radio frequency device to receive the first time information over the air interface. Optionally, the first information indicates an identification of the first device. The second radio frequency device can determine, based on the first information, that the first time information from the first device is received over the air interface.

[0085] In this application, "transmitting information (e.g., first information) to a device (e.g., a second radio frequency device)" may be understood as the destination of the information being the device. "Transmitting information (e.g., first information) to a device (e.g., a second radio frequency device)" may include transmitting information directly or indirectly to the device. Necessary processing such as format change or frequency conversion may be performed on the information between the source and destination of the information transmission, but the destination can understand valid information from the source. Similar descriptions in this application may be understood in the same way, and will not be described in detail here.

[0086] In this application, "receiving information through the air interface, for example, receiving first time information" may be understood as information being transmitted through the air interface. "receiving information through the air interface, for example, receiving first time information" may include receiving information directly or indirectly. Necessary processing such as format conversion or frequency conversion may be performed on the information between the source and destination of the information transmission, but the destination can understand valid information from the source. Similar descriptions in this application may be understood in the same way, and will not be described in detail here.

[0087] In this application, "receiving information from a device (e.g., a first device)" or "receiving information from a device (e.g., a first device)" may be understood as meaning that the source of the information is the device. "receiving information from a device (e.g., a first device)" or "receiving information from a device (e.g., a first device)" may include receiving information directly or indirectly from the device. Necessary processing such as format conversion or frequency conversion may be performed on the information between the source and destination of the information transmission, but the destination can understand valid information from the source. Similar descriptions in this application can be understood in the same way, and will not be described in detail here.

[0088] For example, the first device may be a first radio frequency device, and the first information indicates identification information of the first radio frequency device. The first radio frequency device and the second radio frequency device are connected to the same radio frequency control device. A transmission path corresponding to a fronthaul interface between the first radio frequency device and the radio frequency control device is different from a transmission path corresponding to a fronthaul interface between the second radio frequency device and the radio frequency control device. The first radio frequency device and the second radio frequency device belong to the same distributed base station, or the first radio frequency device belongs to a base station nearby the distributed base station to which the second radio frequency device belongs. Optionally, the nearby base station and the distributed base station to which the second radio frequency device belongs have the same frequency.

[0089] For example, the first device may be a satellite device, and the first information indicates identification information of the satellite device. Optionally, the external clock source referenced by the radio frequency control device may be provided by the satellite device, or the external clock source referenced by the radio frequency control device may maintain time synchronization with the clock source provided by the satellite device.

[0090] As another example, the first device may be a relay device. In one optional implementation, the relay device may be a device between the second radio frequency device and the first radio frequency device, for example, a terminal device that performs uplink / downlink transmission with the first radio frequency device and the second radio frequency device. In the downlink transmission, the terminal device can receive the first time information from the first radio frequency device. In the uplink transmission, the terminal device can transfer the first time information to the second radio frequency device. Similarly, in another optional implementation, the relay device may be a device between the second radio frequency device and a satellite device, for example, a terminal device or a receiver that can receive information from the satellite device.

[0091] Optionally, the first device and a radio frequency control device connected to the second radio frequency device are time-synchronized. The second radio frequency device is connected to the radio frequency control device through a fronthaul interface. Therefore, it will also be understood that the first device is time-synchronized with the radio frequency control device corresponding to the fronthaul interface.

[0092] In addition, optionally, it may be predetermined that the second radio frequency device receives the first time information through the air interface, and it is predetermined that the source of the first time information is the first device, and the first device is one of the first radio frequency device, a satellite device, or a relay device. In a scenario where the predetermined method is used, S401 may not be performed, i.e., S401 is an optional step and is shown using dashed lines in Figure 4B.

[0093] S402: A second radio frequency device receives first time information from a first device through an air interface.

[0094] The first time information includes a first absolute time, which may be accurate to a time unit such as a year, month, day, hour, minute, second, millisecond, microsecond, or nanosecond. For example, the first absolute time may be accurate to within one second, and the first absolute time is 06:30:30:10 on December 1, 2022. As another example, the first absolute time may be accurate to the second, and the first absolute time is 06:30:30 on December 1, 2022. Optionally, the first absolute time may be understood with reference to time in the Coordinated Universal Time (UTC) system. If the first absolute time is accurate to the second, the first time information further includes information used to determine a time phase to within one second. The first time information may alternatively be described as first clock synchronization information, air interface synchronization information, air interface synchronization phase information, or another name.

[0095] In this embodiment of the present application, an example in which the first absolute time is accurate to the second is used to describe how the second radio frequency device receives the first time information.

[0096] When the first device is the first radio frequency device or a device between the first radio frequency device and the second radio frequency device, receiving the first time information by the second radio frequency device may include receiving, by the second radio frequency device, a system information (SIB) message from the first radio frequency device through an air interface, where the SIB message may be SIB9 and the SIB message carries a first absolute time; receiving, by the second radio frequency device, a radio signal from the first radio frequency device through the air interface; and determining a time phase within one second based on radio frame boundary pulse information corresponding to the radio signal. Optionally, the radio frame boundary pulse information may be instead described as time scale information, and the first absolute time may be understood as absolute time information corresponding to the time scale information.

[0097] For example, if the first device is a first radio frequency device, the first radio frequency device can transmit the first time information using downlink transmission resources, and a receiving module capable of receiving the downlink signal is provided on the second radio frequency device, or the second radio frequency device itself functions as a terminal device of the first radio frequency device to receive the first time information. If the first device is a first radio frequency device, the second radio frequency device can also pre-configure designated uplink transmission resources for receiving the first time information. In other words, the first radio frequency device functions as a terminal device of the second radio frequency device and transmits the first time information using the designated uplink transmission resources. If the first device is a device between the first radio frequency device and the second radio frequency device, the first device may be a terminal device capable of communicating with the first radio frequency device and the second radio frequency device.

[0098] If the first device is a satellite device or a device between the satellite device and the second radio frequency device, receiving the first time information by the second radio frequency device may include receiving a time of day (ToD) message from the satellite device over the air interface, where the ToD message carries a first absolute time, and receiving a satellite signal, such as a 1 pulse per second (pps) clock signal, from the satellite device over the air interface, where the second radio frequency device can determine the time phase within 1 second based on the 1 pps clock signal.

[0099] S403: The second radio frequency device determines clock offset information based on the first time information and the second time information.

[0100] The second time information is time information synchronized by the second radio frequency device from the fronthaul interface. For example, the radio frequency control device provides a clock source to the second radio frequency device through the fronthaul interface, and the radio frequency control device and the second radio frequency device exchange related synchronization packets through the fronthaul interface according to a synchronization protocol such as the Institute of Electrical and Electronics Engineers (IEEE) 1588 protocol (e.g., 1588 v2) or the IEEE 1588 protocol combined with the synchronous Ethernet (SyncE) protocol to perform time synchronization.

[0101] The second time information may include time information of a local clock synchronized by the second radio frequency device according to the aforementioned protocol, such as a second absolute time accurate to the second and a time phase within one second. Optionally, the second time information may be described as second clock synchronization phase information, local station clock synchronization phase information, or another name instead. This is not limited in this embodiment of the present application.

[0102] In addition, it will be understood that in the IEEE 1588 protocol, the clock source provided by the radio frequency control device may alternatively be described as a master clock, and the local clock of the second radio frequency device may alternatively be described as a slave clock. The IEEE 1588 protocol may alternatively be referred to as the precision time protocol (PTP). In the PTP protocol combined with the SyncE protocol, the master clock may alternatively be described as a SyncE+PTP master clock, and the slave clock may alternatively be described as a SyncE+PTP slave clock. The clock offset information indicates an offset between the first time information and the second time information. Corresponding to the description of S402, it will be understood that the offset between the first time information and the second time information includes two parts: an offset between the first absolute time and the second absolute time, and an offset between the time phase determined over the air interface to within one second and the time phase of the local clock to within one 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 the time phase determined over the air interface to within one second and the time phase of the local clock to within one second can be calculated using a phase discrimination function. For example, the phase discrimination function is implemented as a phase discriminator, where the phase discriminator is a component, functional circuit, or software component that can discriminate the phase difference between two input signals. The second radio frequency device inputs radio frame boundary pulse information (or pulse / second information) obtained based on the air interface and the time phase of the local clock to the phase discriminator, and the output of the phase discriminator is the offset between the time phase determined over the air interface to within one second and the time phase of the local clock to within one second. Alternatively, the second radio frequency device inputs the time phase determined over the air interface to within one second and the time phase of the local clock to a phase discriminator, and the output of the phase discriminator is the offset between the time phase determined over the air interface to within one second and the time phase of the local clock to within one second.

[0104] S404: The second radio frequency device transmits clock offset information to the second device.

[0105] Optionally, the second device may be a radio frequency control device connected to the second radio frequency device, and the second radio frequency device may transmit the clock offset information to the radio frequency control device through the fronthaul interface. Alternatively, in the distributed base station shown in FIG. 3B , the second device may be a switch device corresponding to the fronthaul interface, and the second radio frequency device may transmit the clock offset information to the switch device through the fronthaul interface. In addition, the second device may instead be a network management device, such as network management device 1 or network management device 2 shown in FIG. 3B . When transmitting the clock offset information to network management device 1, the second radio frequency device may transmit the clock offset information to the radio frequency control device through the fronthaul interface, and the radio frequency control device transmits the clock offset information to network management device 1 through the backhaul interface. When transmitting the clock offset information to network management device 2, the second radio frequency device may transmit the clock offset information to the switch device corresponding to the fronthaul interface through the fronthaul interface, and the switch device transmits the clock offset information to network management device 2 to which it is connected.

[0106] Optionally, the second device may be determined in a predetermined manner to be a radio frequency control device, or one of a switch device and a network management device corresponding to the fronthaul interface. Alternatively, the second device may be indicated by the radio frequency control device or the network management device. For example, before S404 is executed, S4041 may be further executed: the radio frequency control device sends second information to the second radio frequency device, and the second information indicates identification information of the second device.

[0107] Optionally, the second radio frequency device may further transmit identification information of the first device to the second device when transmitting the clock offset information to the second device. Based on this design, the second device can quickly determine the device for calculating the clock offset by the second radio frequency device, thereby improving the efficiency of performing fault handling on the transmission path corresponding to the fronthaul interface by the second device.

[0108] S405: The second device determines, based on the clock offset information, whether a fault exists on the transmission path corresponding to the fronthaul interface.

[0109] For example, if the clock offset information is greater than a predetermined clock offset information threshold, the second device can determine that a fault exists on the transmission path corresponding to the fronthaul interface. The existence of a fault on the transmission path corresponding to the fronthaul interface can include a fault in the interface on the radio frequency control device corresponding to the fronthaul interface, a fault in a node on the transmission path, such as a switch device in the fronthaul network, a transmission latency compensation error on the transmission path, a fault in the fronthaul interface, or a fault in the second radio frequency device corresponding to the fronthaul interface. Furthermore, the second device can employ a fault isolation scheme, for example, disconnecting the second radio frequency device from the radio frequency control device to avoid signal interference of the second radio frequency device with another normal radio frequency device, such as the first radio frequency device. The second device can further instruct a fault recovery policy, and the second radio frequency device can reconnect to the radio frequency control device when the fault on the transmission path corresponding to the fronthaul interface is recovered.

[0110] As another example, if the clock offset information is less than or equal to a predetermined clock offset information threshold, the second device can determine that no fault exists on the transmission path corresponding to the fronthaul interface, and there is no need to perform processing tasks such as fault isolation and recovery.

[0111] In the aforementioned scheme provided in this embodiment of the present application, multiple clock sources are introduced for one radio frequency device, and fault determination and handling are performed on the fronthaul interface corresponding to the radio frequency device based on the clock offsets of the multiple clock sources, without the need for manual intervention or additional testing equipment, thereby reducing work and maintenance costs and improving fault handling efficiency.

[0112] It should be understood that the communication method provided in this embodiment of the present application may also be used to deal with a fault corresponding to a fronthaul interface in another scenario, for example, to troubleshoot a fronthaul interface between a distributed unit (DU) and a radio unit (RU) in an O-RAN system. A DU in an O-RAN system can provide a clock source to an RU, and the DU corresponds to a BBU or radio frequency control device of the aforementioned distributed base station, and the RU corresponds to a radio frequency device of the aforementioned distributed base station. In addition, the DU may alternatively be referred to as an O-DU, and the RU may alternatively be referred to as an O-RU. This is not limited to this embodiment of the present application.

[0113] Based on the same idea, please refer to FIG. 5 . One embodiment of the present application provides a communication device 500. The communication device 500 includes a processing module 501 and a communication module 502. The communication device 500 may be a first device, or may be a device applied to a first device or used in a manner consistent with the first device and capable of implementing a method executed on the first device side. The communication device 500 may be a second device, or may be a device applied to a second device or used in a manner consistent with the second device and capable of implementing a method executed on the second device side. The communication device 500 may be a radio frequency device, or may be a device applied to a radio frequency device or used in a manner consistent with the radio frequency device and capable of implementing a method executed on the radio frequency device side. The communication device 500 may be a radio frequency control device, or may be a device applied to a radio frequency control device or used in a manner consistent with the radio frequency control device and capable of implementing a method executed on the radio frequency control device side.

[0114] The communications module may alternatively be referred to as a transceiver module, transceiver, transceiver device, transceiver apparatus, etc. The processing module may alternatively be referred to as a processor, processing board, processing unit, processing device, etc. Optionally, the processing module may control the communications module to perform transmitting and receiving operations of the first device, the second device, the second radio frequency device, or the radio frequency controlled device in the manner described above.

[0115] It should be noted that the communication module and / or the processing module may be implemented using virtual modules. For example, the processing module may be implemented using a software functional unit or a virtual device, and the communication module may be implemented using a software function or a virtual device. Alternatively, the processing module or the communication module may be implemented using an entity device. For example, if the device is implemented 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.

[0116] The division into modules in this embodiment of the present application is an example, and is merely a division into logical functions, and may be divided differently in actual implementation. In addition, the functional modules in the example embodiment of the present application may be integrated into one processor, each functional module may exist physically alone, or two or more functional modules may be integrated into one module. The integrated modules may be implemented in the form of hardware or in the form of software functional modules.

[0117] In an embodiment of the present application, for example, the functions of the processing modules and / or communication modules in the first device, the second device, the second radio frequency device, and the radio frequency control device are further divided. As shown in Figure 6A, the communication module in the radio frequency control device (shown using an eCPRI module as an example in the figure) corresponds to a fronthaul interface and is configured to exchange synchronization packets corresponding to the IEEE 1588 protocol and the SyncE protocol with the first radio frequency device or the second radio frequency device. The eCPRI of the radio frequency control device transmits synchronization packets provided by a SyncE+PTP master clock and receives packets fed back by a SyncE+PTP slave clock from the fronthaul interface.

[0118] The communication module of the radio frequency device includes a first communication interface corresponding to the air interface and a second communication interface corresponding to the fronthaul interface. The processing module of the radio frequency device includes an air interface synchronization processing unit and a clock offset calculation unit. The first communication interface may be integrated on the air interface synchronization processing unit.

[0119] The air interface synchronization processing unit receives first time information transmitted by the first device through the first communication interface, analyzes the first time information, and outputs a first absolute time and radio frame boundary pulse information (or pulses per second signal). The second communication interface exchanges synchronization packets corresponding to the IEEE 1588 protocol and the SyncE protocol with the radio frequency control device. For example, the second communication interface is implemented using eCPRI. The eCPRI in the radio frequency device forwards the received synchronization packets to the SyncE+PTP slave clock and outputs the packets fed back by the SyncE+PTP slave clock to the fronthaul interface. After interaction and synchronization via the IEEE 1588 protocol and the SyncE protocol, the SyncE+PTP slave clock outputs the second absolute time and the time phase of the local clock within one second.

[0120] The output of the air interface synchronization processing unit is used as one input to a clock offset calculation unit, and the second absolute time and the time phase within one second of the local clock are used as the other input to the clock offset calculation unit. The clock offset calculation unit can directly calculate the offset between the first absolute time and the second absolute time, and use a phase discriminator to calculate the offset between the time phase within one second determined over the air interface and the time phase within one second of the local clock.

[0121] Optionally, when the second device is a radio frequency control device, as shown in FIG. 6A, the processing module in the radio frequency control device includes a time synchronization performance monitoring unit. The eCPRI in the radio frequency control device is further configured to receive clock offset information transmitted by the second 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 handling on the transmission path corresponding to the fronthaul interface based on the clock offset information. It will be understood that the time synchronization performance monitoring unit may instead be deployed in the second device of another implementation, for example, in a switch device or a network management device corresponding to the fronthaul interface. Details will not be described in this embodiment of the present application.

[0122] Optionally, as shown in Figure 6B, when the first device is a first radio frequency device, the air interface synchronization processing unit may be implemented using a UE module, and the UE module has the function of performing air interface-based time-frequency synchronization. The UE module accesses the first radio frequency device, and an antenna on the UE module (i.e., the aforementioned first communication interface) receives, from the air interface, a radio signal transmitted by the first radio frequency device using a downlink transmission resource, so as to determine radio frame boundary pulse information corresponding to the radio signal.

[0123] As shown in FIG. 6C, when the first device is the first radio frequency device, the air interface synchronization processing unit may instead be implemented using an in-band time-frequency synchronization module. The in-band time-frequency synchronization module performs a function similar to that of a UE module synchronized to a base station by monitoring a synchronization channel of a neighboring station. For example, in a time division duplex (TDD) mode, a portion of the uplink transmission resources (e.g., uplink slots) between the terminal and the base station is allocated for air interface synchronization. Specifically, the in-band time-frequency synchronization module uses an antenna (i.e., a first communication interface) deployed by the in-band time-frequency synchronization module to monitor and receive radio signals transmitted by the first radio frequency device to the terminal device through the air interface based on a portion of the uplink transmission resources between the second radio frequency device and the terminal device. This is similar to the time and frequency synchronization function between the terminal and the base station, and performs time synchronization between the in-band time-frequency synchronization module and the first radio frequency device. The in-band time-frequency synchronization module can then output the first absolute time and / or radio frame boundary pulse information corresponding to the radio signal.

[0124] As shown in FIG. 6D , when the first device is a satellite device, the air interface synchronization processing unit may include a global navigation satellite system (GNSS) receiver. The first communication interface is implemented using an antenna. The GNSS receiver receives and outputs a 1 pps clock signal and a ToD message transmitted by the satellite device using the antenna. The air interface synchronization processing unit may include a time service logic unit. The output of the GNSS receiver is used as an input to the time service logic unit. The time service logic unit can further determine a time phase to within 1 second based on the 1 pps clock signal and determine a first absolute time from the ToD message. The time service logic unit outputs the first absolute time and the time phase to within 1 second to the clock offset calculation unit.

[0125] As shown in FIG. 6E, the first device is a device between the satellite device and the second radio frequency device, for example, a GNSS externally connected to the second radio frequency device. The air interface synchronization processing unit may include a time service logic unit, and the first communication interface is implemented using a GNSS interface. Correspondingly, the GNSS includes a GNSS interface, a GNSS receiver, and a GNSS antenna. To support the transmission of 1 pps clock signals and ToD messages, the GNSS interface in the second radio frequency device is electrically connected to the GNSS interface in the GNSS using 1 pss+ToD. In addition, for the functions of the time service logic unit and the clock offset calculation unit, please refer to the description of FIG. 6D for understanding. Details will not be described in this embodiment of the present application.

[0126] Based on the same technical concept, an embodiment of the present application further provides a communication device 700. For example, the communication device 700 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 discrete device.

[0127] The communications device 700 may include at least one processor 710. Optionally, the processor 710 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 700 may further include at least one memory 720.

[0128] The processor 710 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 logic block diagrams disclosed in the embodiments of the present application. The general-purpose processor may be a microprocessor or any conventional processor. For example, the processor 710 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 software programs, and process data of the software programs. When the communication device 700 is applied to the second radio frequency device described above, in one design, the processor 710 may include the program 113 (which may alternatively be referred to as code or instructions), and the program 113 may be executable on the processor 710, such that the communication device 700 executes the method of the second radio frequency device described above. In another possible design, the communication apparatus 700 includes circuitry (not shown in FIG. 7) configured to perform functions of the second radio frequency device in the following embodiments. Optionally, the processor 710 may further store data.

[0129] The memory 720 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 other medium that can be configured to carry or store program code in the form of instructions or data structures and that can be accessed by a computer, but is not limited to this. The memory in the embodiments of the present application may instead be a circuit or any other device capable of performing a storage function and configured to store programs and / or data. For example, the memory 720 may store the program 114 (which may alternatively be referred to as code or instructions), and the program 114 may be executed on the processor 710, such that the communication device 700 performs the method described in the previous method embodiment.

[0130] Optionally, the processor 710 may include an AI module 117 and / or the memory 720 may include an artificial intelligence (AI) module 118. The AI ​​module is configured to perform AI-related functions. The AI ​​module may be implemented 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.

[0131] The communications device 700 may further include a transceiver 730 and / or an antenna 740. The transceiver 730 may alternatively be referred to as a transceiver unit, a transceiver machine, a transceiver circuit, a transceiver, etc., and is configured to perform transceiver functions of the communications device. For example, the transceiver 730 may be a transceiver machine, a circuit, a bus, a module, a pin, or another type of communications interface. If the communications device 700 is a chip-type device or circuit, the transceiver 730 in the device 700 may alternatively be an input / output circuit that can input information (also referred to as receiving information) and output information (also referred to as transmitting information). Optionally, if the communications device 700 includes an antenna 740, the transceiver 730 is configured to perform transceiver functions of the communications device using the antenna 740.

[0132] The coupling in this embodiment of the present application may be an indirect coupling or communication connection between devices, units, or modules, which may take an electrical, mechanical, or other form, and is used for exchanging information between the devices, units, or modules. The processor 710 may operate in cooperation with the memory 720, the transceiver 730, and / or the antenna 740. The specific connection medium between the processor 710, the memory 720, the transceiver 730, and / or the antenna 740 is not limited in this embodiment of the present application. For example, the processor 710, the memory 720, and the transceiver 730 are connected to each other 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.

[0133] Based on the above example, an embodiment of the present application further provides a communication system including a first device, a radio frequency control device, a radio frequency device, and a second device, which can implement the communication method provided in the example shown in Figure 4B.

[0134] The technical solutions provided in this embodiment of the present application may be fully or partially implemented by 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 a part 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 apparatus. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, optical fiber, or digital subscriber line (DSL)) or wireless (e.g., infrared, radio wave, or microwave) methods. The 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 integrates 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.

[0135] 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 may be cross-referenced between apparatus examples and method examples.

[0136] It is apparent that those skilled in the art can make various modifications and changes to the embodiments without departing from the scope of the embodiments of the present application. Thus, if these modifications and changes fall within the scope of the claims of the embodiments of the present application and their equivalent technologies, the embodiments of the present application are also intended to include these modifications and changes. [Explanation of symbols]

[0137] 100 Wireless Access Network 110 RAN nodes 110a Base Stations, RAN Nodes, Network Elements 110b RAN nodes, network elements 113 Programs 114 Programs 117 AI Module 118 AI modules 120 Terminal, Network Element 120a~120j Terminals, network elements 200 Core Network 300 Internet 500 Communication Equipment 501 Processing Module 502 communication module 700 Communication Equipment 710 processor 720 memory 730 Transceiver 740 Antenna 1000 Communication Systems

Claims

1. 1. A communication method comprising: receiving first time information, the first time information being time information transmitted over an air interface; transmitting clock offset information, the clock offset information indicating an offset between the first time information and second time information, the second time information being time information synchronized via a fronthaul interface; A method comprising:

2. The step of receiving the first time information includes: receiving first information, the first information indicating an identification of a first device; receiving the first time information, the first time information being from the first device; 2. The method of claim 1, comprising:

3. 3. The method of claim 2, wherein the first device is a first radio frequency device, a satellite device, or a relay device, and the relay device is a device between a second radio frequency device corresponding to the fronthaul interface and the first radio frequency device or the satellite device.

4. The method of claim 2 or 3, wherein the first device is time-synchronized with a radio frequency control device corresponding to the fronthaul interface.

5. The method according to claim 3 or 4, wherein the clock offset information is used to determine whether a transmission path corresponding to the fronthaul interface has a fault.

6. The method according to claim 1 , wherein the first time information is transmitted on an uplink resource.

7. The step of transmitting the clock offset information includes: receiving second information, the second information indicating an identity of a second device; transmitting the clock offset information to the second device; 7. The method of any one of claims 1 to 6, comprising:

8. The method of claim 7 , wherein the second device is a radio frequency control device corresponding to the fronthaul interface, or a switch device or a network management device corresponding to the fronthaul interface.

9. The method of claim 1 , wherein the clock offset information includes the identification information of the first device.

10. 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 transmitted over an air interface, and the second time information being time information synchronized over a fronthaul interface; determining whether a fault exists on a transmission path corresponding to the fronthaul interface based on the clock offset information; A method comprising:

11. transmitting the clock offset information to a network management device.

11. The method of claim 10, further comprising:

12. 12. The method of claim 10, wherein the first time information is from a first device, and the clock offset information includes identification information of the first device.

13. 13. The method of claim 12, wherein the first device is a first radio frequency device, a satellite device, or a relay device, and the relay device is a device between a second radio frequency device corresponding to the fronthaul interface and the first radio frequency device or the satellite device.

14. The method of claim 12 or 13, wherein the first device is time-synchronized with a radio frequency control device corresponding to the fronthaul interface.

15. 10. A communications device configured to perform a method according to any one of claims 1 to 9.

16. 15. A communications device configured to perform a method according to any one of claims 10 to 14.

17. A communications device comprising a processor, the processor coupled to a memory, the processor configured to perform the method of any one of claims 1 to 9.

18. A communications device comprising a processor, the processor coupled to a memory, the processor configured to perform the method of any one of claims 10 to 14.

19. A communication system comprising a communication device according to claim 15 or 17 and a communication device according to claim 16 or 18.

20. 15. 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 9 or any one of claims 10 to 14.

21. 15. A computer program product comprising instructions which, when executed on a computer, enable the computer to carry out the method of any one of claims 1 to 9 or any one of claims 10 to 14.

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