Clock synchronization method, device and system

Abstract

The embodiments of the present application provide a clock synchronization method, an apparatus and a system. The method includes a first device acquiring a first time difference and a second time difference. The first time difference is a time difference between the first device and a satellite, and the first time difference is determined based on a first pulse signal and information about the satellite. The second time difference is a time difference between the second device and a satellite, and the second time difference is derived from the second device. The first device and the second device belong to the same access network device. The first device acquires clock synchronization information of the first device based on the first time difference and the second time difference. According to the aforementioned method, the first device can eliminate a part of the common error in satellite transmission based on the calculation of the first time difference and the second time difference, and improve the accuracy of the clock synchronization. In addition, the method can be applied within the access network, so that the clock synchronization can be implemented without relying on the backhaul network.

Description

[Technical Field]

[0001] This application claims priority to Chinese Patent Application No. 202111664972.7, entitled "Clock Synchronization Method, Apparatus and System," filed with the State Intellectual Property Office of China on December 31, 2021. This Chinese patent application is incorporated herein by reference in its entirety.

[0002] The present application relates to the field of communications, and in particular to a clock synchronization method, apparatus and system. [Background technology]

[0003] The Global Navigation Satellite System (GNSS) is a navigation system for positioning. GNSS is a system that can provide users with full-time space-based radio navigation and positioning at any location on the Earth's surface or in near-Earth space. In communication systems, GNSS technology can be used for clock synchronization. GNSS receivers are deployed in access network devices within the communication systems. The access network devices acquire information about satellites by using the GNSS receiver and correct their local clocks based on the information about the satellites. However, there is an error in the local clock that is corrected using this method. Summary of the Invention

[0004] This application describes a clock synchronization method, apparatus and system.

[0005] According to a first aspect, an embodiment of the present application provides a clock synchronization method. The method is performed by a first device. The method includes the first device acquiring a first time difference and a second time difference. The first time difference is a time difference between the first device and a satellite. The first time difference is determined based on a first pulse signal and information about the satellite. The second time difference is a time difference between the second device and the satellite, and the second time difference is derived from the second device. The first device and the second device belong to the same access network device. The first device acquires clock synchronization information between the first device and the second device based on the first time difference and the second time difference. According to the above solution, the first device can remove a portion of common errors in satellite transmission based on the calculation of the first time difference and the second time difference, thereby further improving the accuracy of the clock synchronization information. In addition, clock synchronization can be implemented in this method without relying on a backhaul network.

[0006] For example, the first device obtaining clock synchronization information between the first device and the second device based on the first time difference and the second time difference can be understood as the first device adjusting the local clock of the first device based on the first time difference and the second time difference, and using the local clock as clock synchronization information between the first device and the second device to obtain the clock synchronization information of the first device. Finally, the clock synchronization information is used to adjust the local clock of the second device to maintain it consistent with the local clock of the first device. The above description is also applicable to the method provided in another aspect of the present application. Details will not be described again.

[0007] In a possible implementation, the first device transmits clock synchronization information to the second device, which may also be understood as the second device being synchronized with the first device or tracking the first device, ultimately maintaining the clock information of the second device consistent with the clock information of the first device.

[0008] In a possible implementation, the first device is a radio device controller in an access network device, and the second device is a radio device in the access network device. The radio device controller may also be referred to as a radio device controller, a radio controller, a radio control unit, or may have another name. This is not limited in the present application. Specifically, the radio device controller may be a baseband unit. Specifically, the radio device controller may be any device having the same or similar functions as a baseband unit. The radio device may also be referred to as a radio device, a radio device, or a radio unit, or may have another name. This is not limited in the present application. Specifically, the radio device may be an active antenna unit or a remote radio unit. Specifically, the radio device controller may be any device having the same or similar functions as an active antenna unit or a remote radio unit. The above description is also applicable to methods provided in other aspects of the present application. Details will not be described again.

[0009] In a possible implementation, the first device and the second device belonging to the same access network device includes both the first device and the second device being wireless devices within the access network device.

[0010] In a possible implementation, the first pulse signal is a pulse-per-second signal. The pulse-per-second signal may be a one-pulse-per-second signal representing a one-second time signal of a satellite. The above description is also applicable to the method provided in another aspect of the present application. The details will not be described again.

[0011] In a possible implementation, the information about the satellite includes a satellite identifier and may further include at least one of satellite time information, satellite status information, and satellite ephemeris data information. The satellite identifier identifies the satellite. Specifically, the first device may determine a specific satellite based on the identifier. The satellite time information, satellite status information, and satellite ephemeris data information are all used to calculate the first time difference. The above description is also applicable to methods provided in other aspects of the present application. Details will not be described again.

[0012] In one possible implementation, the first device obtaining clock synchronization information of the first device based on the first time difference and the second time difference includes the first device calculating a third time difference based on the first time difference and the second time difference, the first device determining an average relative phase frequency difference based on the third time difference, and the first device adjusting local clock information of the first device based on the average relative phase frequency difference.

[0013] In one possible implementation, determining the first time difference based on the first pulse signal and the information about the satellites includes receiving, by the first device, the first pulse signal and the information about the satellites from a first satellite receiver, and determining the first time difference based on the first pulse signal and the information about the satellites.

[0014] According to a second aspect, an embodiment of the present application provides a clock synchronization method. The method is performed by a second device. The method includes the second device transmitting a second time difference to a first device. The second time difference is determined based on a second pulse signal and information about a satellite. The second time difference is a time difference between the second device and the satellite. The first device and the second device belong to the same access network device. The second device receives clock synchronization information from the first device. The second device obtains local clock information for the second device based on the clock synchronization information. According to the above solution, the second device is synchronized with the first device to maintain the clocks of different devices in the first access network device in agreement, and the method reduces requirements for stability and latency characteristics of a network system in which the first device and the second device are located. This further reduces the dependency of clock synchronization on the network system.

[0015] For example, the clock synchronization information is clock synchronization information between a first device and a second device.

[0016] In one possible implementation, the second device acquires the second time difference. Specifically, the second device determines the second time difference based on the second pulse signal and information about the satellite. In another possible implementation, the first device and the second device belonging to the same access network device include the first device being a wireless device controller in the access network device and the second device being a wireless device in the access network device.

[0017] In a possible implementation, the first device and the second device belonging to the same access network device includes both the first device and the second device being wireless devices within the access network device.

[0018] In a possible implementation, the second pulse signal is a pulse per second signal.

[0019] In a possible implementation, the information about the satellite includes a satellite identifier and may further include at least one of satellite time information, satellite status information, and satellite ephemeris data information.

[0020] In one possible implementation, the second device obtaining the second time difference, the second time difference being determined based on the second pulse signal and the information about the satellites, includes the second device receiving the second pulse signal and the information about the satellites from a second satellite receiver, and the second device determining the second time difference based on the second pulse signal and the information about the satellites.

[0021] According to a third aspect, an embodiment of the present application provides a clock synchronization method. The method is performed by a first device. The method includes the first device receiving a first time difference from a second device. The first time difference is a time difference between the second device and a satellite. The first device receives a second time difference from a third device. The second time difference is a time difference between the third device and a satellite. The first device, the second device, and the third device belong to the same access network device. The first device obtains clock synchronization information among the first device, the second device, and the third device based on the first time difference and the second time difference.

[0022] In a possible implementation, the method further includes the first device transmitting clock synchronization information to the second device and the third device.

[0023] In a possible implementation, the first device, the second device, and the third device belonging to the same access network device includes the first device being a wireless device controller in the access network device, and the second device and the third device being wireless devices in the access network device.

[0024] In a possible implementation, the first device receives information about the satellite from the second device, the information about the satellite including a satellite identifier and may further include at least one of satellite time information, satellite status information, and satellite ephemeris data information.

[0025] According to a fourth aspect, an embodiment of the present application provides a clock synchronization method. The method includes a first device acquiring a first time difference and a second device acquiring a second time difference. The second device transmits the second time difference to the first device. The first device acquires clock synchronization information between the first device and the second device based on the first time difference and the second time difference. The second device receives the clock synchronization information from the first device. The second device acquires local clock information of the second device based on the clock synchronization information.

[0026] For the beneficial effects and possible implementations of this aspect, please refer to the descriptions of the first and second aspects, and the details will not be described again.

[0027] According to a fifth aspect, a second device acquires a first time difference, and a third device acquires a second time difference. The second device transmits the first time difference to the first device, and the third device transmits the second time difference to the first device. The first device acquires clock synchronization information among the first device, the second device, and the third device based on the first time difference and the second time difference. The first device transmits the clock synchronization information to the second device and the third device. The second device acquires local clock information of the second device based on the clock synchronization information. The third device acquires local clock information of the third device based on the clock synchronization information.

[0028] For the beneficial effects and possible implementations of this aspect, please refer to the descriptions of the second and third aspects, and the details will not be described again.

[0029] According to a sixth aspect, an embodiment of the present application provides a communications device including a processor, the processor being configured to read a program from a memory and execute the program to implement a method according to the first aspect or any one of its possible implementations, or to implement a method according to the second aspect or any one of its possible implementations, or to implement a method according to the third aspect or any one of its possible implementations.

[0030] According to a seventh aspect, an embodiment of the present application provides a communication system including a first device and a second device, wherein the first device may perform a method according to the first aspect or any one of its possible implementations, or may perform a method according to the third aspect or any one of its possible implementations, or the second device may perform a method according to the second aspect or any one of its possible implementations.

[0031] In a possible communication system, the communication system further includes a third device, which may perform the method according to the second aspect or any one of the possible implementations of the second aspect.

[0032] According to an eighth aspect, an embodiment of the present application provides a computer program product comprising instructions, which, when executed on a computer, enable the computer to perform a method according to the first aspect or any one of its possible implementations, or a method according to the second aspect or any one of its possible implementations, or to implement a method according to the third aspect or any one of its possible implementations, or to implement a method according to the fourth aspect or any one of its possible implementations, or to implement a method according to the fifth aspect or any one of its possible implementations.

[0033] According to a ninth aspect, an embodiment of the present application provides a computer-readable storage medium. The computer-readable storage medium stores instructions that, when executed on a computer, enable a processor to perform a method according to the first aspect or any one of its possible implementations, or a method according to the second aspect or any one of its possible implementations, or to implement a method according to the third aspect or any one of its possible implementations, or to implement a method according to the fourth aspect or any one of its possible implementations, or to implement a method according to the fifth aspect or any one of its possible implementations. [Brief explanation of the drawings]

[0034] [Figure 1] 1 is a schematic diagram of a network architecture to which an embodiment of the present application is applicable;

[0035] [Figure 2A] 1 is a schematic diagram of a clock synchronization method to which an embodiment of the present application is applicable;

[0036] [Figure 2B] FIG. 1 is a schematic diagram of another clock synchronization method to which an embodiment of the present application is applicable;

[0037] [Figure 3] 1 is a schematic diagram of a clock synchronization method according to an embodiment of the present application;

[0038] [Figure 4] FIG. 1 is a schematic diagram of another clock synchronization method according to an embodiment of the present application;

[0039] [Figure 5] FIG. 1 is a schematic diagram of a clock synchronization system architecture according to an embodiment of the present application.

[0040] [Figure 6] FIG. 10 is a schematic diagram of yet another clock synchronization method according to an embodiment of the present application;

[0041] [Figure 7] FIG. 2 is a schematic diagram of another clock synchronization system architecture according to an embodiment of the present application;

[0042] [Figure 8] FIG. 10 is a schematic diagram of yet another clock synchronization method according to an embodiment of the present application;

[0043] [Figure 9] FIG. 10 is a schematic diagram of yet another clock synchronization method according to an embodiment of the present application;

[0044] [Figure 10] FIG. 1 is a schematic diagram of yet another clock synchronization system architecture according to an embodiment of the present application;

[0045] [Figure 11A] FIG. 10 is a schematic diagram of yet another clock synchronization method according to an embodiment of the present application; [Figure 11B] FIG. 10 is a schematic diagram of yet another clock synchronization method according to an embodiment of the present application;

[0046] [Figure 12] 1 is a schematic diagram of a communication device according to an embodiment of the present application;

[0047] [Figure 13] 1 is a schematic diagram of another communication device according to an embodiment of the present application; DETAILED DESCRIPTION OF THE INVENTION

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following describes the embodiments in more detail with reference to the accompanying drawings. The technical solutions in the embodiments of the present application may be applied to various communication systems, such as long-term evolution (LTE) systems, LTE frequency division duplex (FDD) systems, and LTE time division duplex (TDD) systems, fifth-generation (5G) mobile communication systems, new radio (NR) systems, or future communication systems or other similar communication systems. The network architectures and service scenarios described in the present application are intended to more clearly explain the technical solutions in the present application, but do not constitute limitations on the technical solutions provided in the present application. Those skilled in the art may recognize that with the evolution of network architectures and the emergence of new service scenarios, the technical solutions provided in the present application may also be applied to similar technical problems.

[0049] 1 is an architecture diagram of a communication system to which the present application is applicable. The system shows an access network, a backhaul network, and a core network. The core network is a network including multiple functional network elements. The multiple functional network elements are configured to manage user requirements and provide different types of communication services to users. For the core network, please refer to the description in the 3rd Generation Partnership Project (3GPP).

[0050] An access network may be referred to as a Radio Access Network (RAN). The RAN is configured to implement radio-related functions. Nodes in the RAN may also be referred to as access network devices or base stations and are configured to connect terminal devices to the wireless network. The access network device may be a base station, an evolved NodeB (eNodeB) in an LTE system or an LTE-Advanced (LTE-Advanced, LTE-A) system, a next-generation NodeB (gNB) in a 5G communication system, a transmission reception point (TRP), a baseband unit (BBU), a Wi-Fi access point (AP), a base station in a future mobile communication system, or an access node in a Wi-Fi system. Alternatively, the radio access network device may be a module or unit that completes some functions of a base station. For example, the radio access network device may be a central unit (CU) or a distributed unit (DU). The specific technologies and specific device configurations used by the radio access network devices are not limited in the embodiments of the present application. For example, in a network structure, the radio access network devices may be a CU node, a DU node, or an access network device including a CU node and a DU node. Specifically, the CU node is configured to support protocols such as radio resource control (RRC), packet data convergence protocol (PDCP), and service data adaptation protocol (SDAP).The DU node is configured to support a radio link control (RLC) layer protocol, a media access control (MAC) layer protocol, and a physical layer protocol. For ease of explanation, the radio access network device will be referred to as RAN for short in the following.

[0051] A backhaul network is configured to connect an access network and a core network, and provides the function of transmitting information between the access network and the core network.

[0052] As shown in FIG. 1 , the access network may include a wireless device controller, a fronthaul network, and a wireless device. The wireless device controller may also be referred to as a radio equipment controller, a radio controller, a radio control unit, or may have another name. This is not limited in this application. The wireless device controller may be a unit or module configured to process baseband signals. Specifically, the wireless device controller may be a baseband unit. Specifically, the wireless device controller may be any device having the same or similar functions as those of a baseband unit, such as a baseband unit (BBU). The wireless device may also be referred to as a wireless device, a radio device, or a radio unit, or may have another name. This is not limited in this application. The wireless device may be a unit or module configured to process radio frequency signals. Specifically, the wireless device may be an active antenna unit or a remote radio unit. Specifically, the radio device may be any device having the same or similar functions as an active antenna unit or a remote radio unit, for example, a remote radio unit (RRU) or an active antenna unit (AAU). This is not limited in this application. The fronthaul network is a network between the radio device controller and the radio device. The radio device controller and the radio device may be connected by using optical fiber or by using another connecting line. This is not limited in this application.The fronthaul network may use a Common Public Radio Interface (CPRI) protocol, an Enhanced Common Public Radio Interface (eCPRI) protocol, or another type of protocol. In this application, an example in which the wireless device controller included in the base station device is a BBU and the wireless device is an AAU is used for explanation. The above description is also applicable to the methods provided in other aspects of the present application. Details will not be described again.

[0053] The Global Navigation Satellite System (GNSS) is a navigation system for positioning. GNSS is a system that can provide users with full-time space-based radio navigation and positioning at any location on the Earth's surface or in near-Earth space. GNSS has a time-serving function, which can also be understood as a clock calibration function or clock synchronization function. In this application, clock synchronization will be used later as an example for explanation. For example, GNSS is used for clock synchronization in an access network. A GNSS receiver is deployed in the access network, and the GNSS receiver receives satellite navigation information from satellites. The access network obtains the satellite navigation information by using the GNSS receiver, determines the error between the access network's local clock and the satellite's clock based on the satellite navigation information, and further adjusts the local clock based on the error. Finally, clock synchronization is implemented.

[0054] In particular, for the clock synchronization method implemented by the access network by using GNSS, please refer to the description shown in Figures 2A and 2B.

[0055] FIG. 2A is used as an example. This figure illustrates a GNSS-based clock synchronization method. As shown in this figure, a GNSS receiver is deployed on the BBU side in an access network. Similar to the previous method, the GNSS receiver acquires satellite navigation information from satellites. After acquiring the satellite navigation information from the GNSS receiver, the BBU determines the error between the BBU's local clock and the satellite's clock based on the satellite navigation information, and finally adjusts the BBU's local clock based on the error. The adjusted local clock can be regarded as a system clock. Then, in a possible implementation, the BBU can transfer the system clock to the AAU to implement clock synchronization of the communication system by referring to the precision clock synchronization protocol standard for network measurement and control systems, i.e., the Institute of Electrical and Electronics Engineers (IEEE) 1588 protocol.

[0056] FIG. 2B is used as an example. This figure illustrates another GNSS-based clock synchronization method. As shown in this figure, a GNSS receiver is deployed on the AAU side in the access network. Similar to the previous method, the GNSS receiver acquires satellite navigation information from satellites. After acquiring the satellite navigation information from the GNSS receiver, the AAU transmits the satellite navigation information to the BBU. The BBU calculates the time difference between the satellite clock and the local clock of the AAU based on a comparison between the satellite clock in the satellite navigation information and the local clock, and then corrects the local clock of the BBU based on the time difference to obtain a more accurate time point. The corrected time point is used as the system clock of the communication system in which the base station device of the BBU is located. The BBU then transmits the system clock to the AAU using the precision clock synchronization protocol standard for network measurement and control systems, i.e., the IEEE 1588 protocol, so that the wireless network is maintained in sync with the clock associated with the transmission.

[0057] The above two methods of acquiring the system clock using GNSS can meet the basic service requirements of existing communication systems, that is, the error relative to Coordinated Universal Time (UTC) can be controlled to approximately 1.5 microseconds (μs). However, this method cannot meet services with high requirements for time error, such as inter-location coordination services. The errors in this method can be caused by atmospheric environmental factors, satellite system errors, multipath errors caused by object reflections when the satellite reaches the ground, or other errors.

[0058] Based on the above problem, the present application provides a clock synchronization method.

[0059] 3 is a schematic diagram of a clock synchronization method to which the present application is applicable. The method shown in FIG. 3 can be performed by a first device and a second device. The first device and the second device belong to the same access network device. The access network device may be the access network device in the network architecture shown in FIG. 1.

[0060] In a possible implementation, the first device in this method may be a wireless device controller in an access network device, and the second device may be a wireless device in the access network device.

[0061] In another possible implementation, both the first device and the second device in this method are wireless devices within an access network device.

[0062] The method may include the following steps:

[0063] Step 301: A first device obtains a first time difference.

[0064] For example, the first time difference is a time difference between the first device and a satellite. The first device determines the first time difference based on the first pulse signal and information about the satellite.

[0065] In a possible implementation, the first device determining the first time difference based on the first pulse signal and information about the satellites includes the first device receiving the first pulse signal and information about the satellites from a first satellite receiver, and the first device determining the first time difference based on the first pulse signal and information about the satellites.

[0066] In a possible implementation, the first pulse signal is a pulse-per-second signal. The pulse-per-second signal may be a 1 pulse per second (PPS) signal. For example, the first device receives information about satellites from a satellite receiver of the first device and generates a 1 PPS signal based on the information about the satellites.

[0067] In a possible implementation, the information about the satellite includes a satellite identifier and may further include at least one of satellite time information, satellite status information, and satellite ephemeris data information. The satellite identifier identifies the satellite. Specifically, the first device and the second device may determine the specific satellite about which the information is about based on the identifier. The satellite time information, satellite status information, and satellite ephemeris data information are all used to calculate the first time difference and the second time difference.

[0068] Step 302: The second device obtains a second time difference.

[0069] For example, the second time difference is a time difference between the second device and a satellite, and the second time difference is determined by the second device based on the second pulse signal and information about the satellite.

[0070] Similarly, the second pulse signal may be a pulse per second signal, see the pulse per second signal section above.

[0071] In one possible implementation, the second device obtaining the second time difference and determining the second time difference based on the second pulse signal and the information about the satellites includes the second device receiving the second pulse signal and the information about the satellites from a second satellite receiver, and the second device determining the second time difference based on the second pulse signal and the information about the satellites.

[0072] It should be understood that step 301 may be performed simultaneously with step 302, may be performed before step 302, or may be performed after step 302.

[0073] Step 303: The second device transmits the second time difference to the first device.

[0074] Thus, the first device receives a second time difference from the second device.

[0075] Step 304: The first device obtains clock synchronization information between the first device and the second device based on the first time difference and the second time difference.

[0076] For example, a first device obtaining clock synchronization information between the first device and the second device based on the first time difference and the second time difference may be understood as the first device adjusting a local clock of the first device based on the first time difference and the second time difference and using the local clock as clock synchronization information between the first device and the second device. Finally, the clock synchronization information is used to adjust the local clock of the second device, so that the local clock of the second device is maintained consistent with the local clock of the first device.

[0077] In one possible implementation, the first device obtaining clock synchronization information of the first device based on the first time difference and the second time difference includes the first device calculating a third time difference based on the first time difference and the second time difference, the first device determining an average relative phase frequency difference based on the third time difference, and the first device adjusting local clock information of the first device based on the average relative phase frequency difference.

[0078] Step 305: The first device sends clock synchronization information to the second device.

[0079] In response, the second device receives clock synchronization information from the first device.

[0080] For example, the second device may obtain clock synchronization information from the first device by using a fronthaul network.

[0081] Step 306: The second device obtains local clock information of the second device based on the clock synchronization information of the first device.

[0082] It should be understood that at this stage, the second device maintains its local clock information to match the clock information in the clock synchronization information, i.e., the second device obtains a piece of time information from the clock synchronization information and adjusts the local clock of the second device to the time information.

[0083] Steps 305 and 306 may also be understood as the second device being synchronized with the first device, or the second device tracking the first device, and ultimately maintaining the clock information of the second device consistent with the clock information of the first device.

[0084] According to the method shown in Figure 3, the first device may remove a portion of the common error in satellite transmission based on calculation of the first time difference and the second time difference to improve the accuracy of the clock synchronization information. In addition, this method may be applied within the access network, so that the clock synchronization can be implemented without relying on the backhaul network.

[0085] 4 is a schematic diagram of another clock synchronization method to which the present application is applicable. The method shown in FIG. 4 can be performed by a first device, a second device, and a third device. The first device, the second device, and the third device belong to the same access network device. The access network device may be the access network device in FIG. 1. In the method shown in this figure, the first device may be a radio device controller in the access network device, and the second device and the third device may be radio devices in the access network device. The method may include the following steps:

[0086] Step 401: The second device obtains a first time difference.

[0087] For example, the first time difference is a time difference between the second device and the satellite, and the first time difference is determined by the second device based on the first pulse signal and information about the satellite. In a possible implementation, the first device receives the first pulse signal and information about the satellite from the first satellite receiver, and the first device determines the first time difference based on the first pulse signal and information about the satellite. For the first pulse-per-second signal, see the description of the first pulse-per-second signal in FIG. 3.

[0088] The information about the satellite may include a satellite identifier, which may identify the satellite. In other words, the satellite identifier may be used to distinguish a particular satellite about which the information is about. In addition, the information about the satellite may further include at least one of satellite time information, satellite status information, and satellite ephemeris data information. The satellite time information, satellite status information, and satellite ephemeris data information are all used to calculate the first time difference and the second time difference.

[0089] Step 402: The third device obtains the second time difference.

[0090] The second time difference is a time difference between the third device and the satellite, and the second time difference is determined by the third device based on the second pulse signal and information about the satellite. In a possible implementation, the third device receives the second pulse signal and information about the satellite from the second satellite receiver, and the third device determines the first time difference based on the second pulse signal and information about the satellite. For the second pulse-per-second signal, see the description of the second pulse-per-second signal in FIG. 3.

[0091] The execution order of step 401 and step 402 is not limited in this application.

[0092] Step 403: The second device transmits the first time difference to the first device.

[0093] In response, the first device receives a first time difference from the second device.

[0094] In a possible implementation, the first device further receives information about the satellites from the second device.

[0095] Step 404: The third device transmits the second time difference to the first device.

[0096] In response, the first device receives a first time difference from the third device.

[0097] In a possible implementation, the first device further receives information about the satellite from the third device. Specifically, the first device may determine, based on the information about the satellite received from the third device and the information about the satellite received from the second device, that the first time difference is the time difference between the satellite and the second device, and the second time difference is the time difference between the satellite and the third device. In this manner, it can be ensured that the time differences provided by the second device and the third device are the time difference between the second device and the satellite, and the time difference between the third device and the satellite, respectively.

[0098] The order of execution of steps 403 and 404 is not limited in this application.

[0099] Step 405: The first device obtains clock synchronization information among the first device, the second device and the third device based on the first time difference and the second time difference.

[0100] For this step, see the description of step 304 in FIG.

[0101] Step 406: The first device sends clock synchronization information to the second device.

[0102] Step 407: The first device sends clock synchronization information to the third device.

[0103] For steps 406 and 407, please refer to the description of step 305 in FIG.

[0104] The order of execution of steps 406 and 407 is not limited in this application.

[0105] Step 408: The second device obtains local clock information of the second device based on the clock synchronization information.

[0106] Step 409: The third device obtains the local clock information of the third device based on the clock synchronization information.

[0107] For steps 408 and 409, please refer to the description of step 306 in FIG.

[0108] The order of execution of steps 408 and 409 is not limited in this application.

[0109] According to the method shown in Figure 4, the first device may remove a portion of the common error in satellite transmission based on the calculation of the first time difference and the second time difference to further improve the accuracy of the clock synchronization information. In addition, this method may be applied within the access network, so that the clock synchronization can be implemented without relying on the backhaul network.

[0110] For ease of explanation, the wireless device controller in the access network device referred to hereinafter in this application will be described by taking a baseband unit as an example. The baseband unit will be abbreviated as BBU. The wireless device in the base station device will be described by taking an active antenna unit as an example. The active antenna unit will be abbreviated as AAU. The satellite receiver will be abbreviated as GNSS.

[0111] For example, two GNSSs, namely, GNSS1 and GNSS2, are deployed in a clock synchronization network architecture. Figure 5 is a schematic diagram of a clock synchronization system structure. As shown in Figure 5, GNSS1 is deployed on the BBU side, and GNSS2 is deployed on the AAU side. In addition, the BBU and the AAU belong to the same access network device. Specifically, during deployment, GNSS1 may be connected to the BBU side through a feeder, and GNSS2 may be connected to the AAU side through a feeder. Based on the system architecture shown in Figure 5, Figure 6 is a schematic interaction flowchart of a clock synchronization method according to an embodiment of the present application. With reference to the method shown in Figure 3, the method may include the following steps:

[0112] Step 601: A satellite transmits satellite information to GNSS1 and GNSS2.

[0113] In response to this, GNSS1 receives satellite information from the satellite, and GNSS2 receives satellite information from the satellite.

[0114] It can be seen that the satellites transmit satellite information to both GNSS1 and GNSS2, i.e. GNSS1 and GNSS2 track the same satellites.

[0115] For example, the satellite information may include time information, status information, and ephemeris information. The time information may include UTC time information of the satellite, which represents the time of the satellite. For the satellite information, see the description of the information about the satellite in FIG. 3.

[0116] Step 602: GNSS1 transmits pulse signal 1 and satellite information to the BBU.

[0117] For the pulse signal 1 in this method, please refer to the description of the first pulse signal in Figure 3. For the BBU, please refer to the description of the first device in Figure 3.

[0118] For example, pulse signal 1 may be a pulse signal of GNSS 1, and the pulse signal may be a 1 PPS signal. Pulse signal 1 may represent satellite clock information. The clock information includes phase information and frequency information of the satellite clock. The phase information and frequency information may be used for clock synchronization.

[0119] Specifically, the GNSS 1 transmits the pulse signal 1 to a phase determination unit (not shown) of the BBU and transmits the satellite information to a processing unit (not shown) of the BBU. For example, the processing unit may be a satellite data processing unit. In other words, the processing unit is configured to process the satellite information.

[0120] Step 603: The BBU determines the time difference 1 based on the pulse signal 1 and the satellite information.

[0121] For this step, see the description of the first device in step 301 of Figure 3. For time difference 1 in this method, see the description of the first time difference in Figure 3.

[0122] Specifically, the phase discrimination unit of the BBU obtains pulse signal a of the BBU's local clock and performs phase discrimination on pulse signal a and pulse signal 1 to obtain the clock phase difference between the BBU and the satellite. Pulse signal a and pulse signal 1 may be the same type of pulse signal. Next, the processing unit of the BBU obtains the clock phase difference between the BBU and the satellite from the phase discrimination unit of the BBU. Next, the processing unit of the BBU calculates time difference 1 between the BBU and the satellite based on the clock phase difference between the BBU and the satellite and the satellite information. Specifically, the processing unit of the BBU calculates time difference 1 between the BBU and the satellite based on the clock phase difference between the BBU and the satellite and the status information, ephemeris information, and time information in the satellite information.

[0123] Step 604: GNSS2 transmits pulse signal 2 and satellite information to AAU.

[0124] For the AAU in this method, please refer to the description of the second device in Figure 3. For the pulse signal 2 in this method, please refer to the description of the second pulse signal in Figure 3.

[0125] Specifically, the GNSS 2 transmits the pulse signal 2 to a phase determination unit (not shown) of the AAU and transmits the satellite information to a processing unit (not shown) of the AAU. For example, the processing unit may be a satellite data processing unit. In other words, the processing unit is configured to process the satellite information.

[0126] Step 605: The AAU determines a time difference 2 based on the pulse signal 2 and the satellite information.

[0127] For this step, see the description of the second device in step 301 of Figure 3. For time difference 2 in this method, see the description of the second time difference in step 301 of Figure 3.

[0128] Specifically, the phase discrimination unit of the AAU obtains pulse signal b of the local clock of the AAU and performs phase discrimination on pulse signal b and pulse signal 2 to obtain the clock phase difference between the AAU and the satellite. Similarly, pulse signal b and pulse signal 2 are the same type of signal. Next, the processing unit of the AAU obtains the clock phase difference between the AAU and the satellite from the phase discrimination unit of the AAU. Next, the processing unit of the AAU calculates the time difference 2 between the AAU and the satellite based on the clock phase difference between the AAU and the satellite and the satellite information.

[0129] Step 606: The AAU sends the time difference 2 to the BBU.

[0130] For this step, see the description of step 302 in FIG.

[0131] It should be understood that the execution of steps 602 and 603 is independent of the execution of steps 604 through 606, but ultimately steps 602 and 603, and steps 604 through 606, are all executed before step 607.

[0132] Step 607: The BBU determines a time difference 3 based on the time difference 1 and the time difference 2.

[0133] For example, the BBU calculates the difference between time difference 1 and time difference 2 to obtain time difference 3. Specifically, this step is performed by the processing unit of the BBU.

[0134] For time difference 3, please refer to the description of the third time difference in the method shown in FIG.

[0135] Step 608: The BBU obtains the average relative frequency deviation 1.

[0136] Steps 601 to 607 may be repeated at least once to obtain at least two time differences 3. The at least two time differences may be different. In other words, the BBU obtains time differences 31, ..., and time difference 3n, where n is a positive integer greater than 2. Not all of the time differences 31, ..., and time differences 3n are necessarily different from each other. The BBU obtains an average relative frequency shift 1 through calculation based on the at least two time differences 3. For the average relative frequency shift 1, please refer to the description of the average relative phase frequency difference in the method shown in FIG. 3.

[0137] Step 609: The BBU corrects the local clock of the BBU based on the average relative frequency deviation 1.

[0138] For example, the average relative frequency deviation is used as input information for a data processing unit of the BBU and is used by the BBU to correct the local clock of the BBU.

[0139] For steps 607 to 609, please refer to the description of step 303 in FIG.

[0140] Step 610: The AAU obtains the local clock of the BBU as the system clock.

[0141] For this step, please refer to the description of steps 304 and 305 in the method shown in FIG.

[0142] For example, the AAU may acquire the local clock of the BBU from the BBU by using the fronthaul network. It should be understood that the local clock of the BBU acquired by the AAU at this stage is the local clock of the BBU acquired through the correction in step 609. The AAU updates the information about the local clock of the BBU to the local clock of the AAU, that is, the AAU uses the local clock of the BBU as the system clock. Specifically, the interface unit of the AAU acquires the local clock of the BBU from the BBU by using the fronthaul network and sends the local clock of the BBU to the data processing unit of the AAU. After acquiring the local clock of the BBU, the data processing unit of the AAU corrects the time of the local clock module of the AAU.

[0143] It should be understood that the local clock of the BBU may be considered as a base station system clock that is obtained by synchronizing the standard and reference clock sources of the access network device in which the BBU is located.

[0144] According to the method described in this embodiment, a wireless device in an access network device performs clock synchronization with a wireless device control unit. This not only can further eliminate some errors in satellite information transmission, but also can improve the reliability of clock synchronization. It should be understood that the method described in this embodiment of the present application is merely an example. In a specific implementation, multiple GNSSs may be deployed on the AAU side, or one GNSS may be deployed on each of multiple AAUs. During actual deployment, the accuracy of information about satellites acquired by different GNSSs varies. Therefore, the BBU may select an optimal time difference calculated by the AAU, i.e., a time difference calculated with the best accuracy by the AAU based on the information about the satellites, and perform clock synchronization based on this time difference. Therefore, the effect of improving the accuracy of the system clock of the base station may be achieved. In addition, multiple GNSSs may be deployed on the AAU side, or a method in which multiple GNSSs are deployed on multiple AAUs may be used, which ensures that at least one GNSS receiver on the AAU side is operational, further improving the reliability and stability of clock synchronization.

[0145] For example, two GNSSs, i.e., GNSS1 and GNSS2, are deployed in a clock synchronization network architecture. Figure 7 is a schematic diagram of the clock synchronization system architecture. As shown in Figure 7, GNSS1 is deployed on the AAU1 side, and GNSS2 is deployed on the AAU2 side. In addition, AAU1 and AAU2 belong to the same access network device. Specifically, during deployment, these two GNSSs may be connected to the AAU sides where these GNSSs are deployed through feeders. Based on the system architecture shown in Figure 7 and with reference to the method shown in Figure 4, Figure 8 is a schematic interaction flowchart of a clock synchronization method according to an embodiment of the present application. The method may include the following steps:

[0146] Step 801: A satellite transmits satellite information to GNSS1 and GNSS2.

[0147] For satellite information, please refer to the description of information about satellites in the method shown in FIG.

[0148] For this step, see the description of step 601 in FIG.

[0149] Step 802: GNSS1 transmits pulse signal 3 and satellite information to AAU1.

[0150] For AAU1, please refer to the description of the second device in the method shown in FIG.

[0151] For pulse signal 3 in this step, please refer to the description of the first pulse signal in step 401 of the method shown in FIG. 4 and the description of pulse signal 1 in step 602 of the method shown in FIG.

[0152] Step 803: The AAU 1 determines the time difference 4 based on the pulse signal 3 and the satellite information.

[0153] For this step, see the description of the operation of the second device in step 401 of the method shown in Figure 4 and the description of the operation of the BBU in step 603 of Figure 6. For time difference 4, see the description of the first time difference in the method shown in Figure 4.

[0154] Step 804: AAU1 sends time difference 4 to BBU.

[0155] For this step, please refer to the description of the operation of the second device in step 402 of the method shown in Figure 4. For the BBU, please refer to the description of the first device in Figure 4.

[0156] Step 805: The GNSS2 transmits the pulse signal 4 and the satellite information to the AAU2.

[0157] For pulse signal 4 at this stage, please refer to the description of the second pulse signal at step 401 of the method shown in FIG. 4 and the description of pulse signal 2 at step 604 of FIG.

[0158] For AAU2, please refer to the description of the third device in step 401 of the method shown in FIG.

[0159] Step 806: The AAU 2 determines the time difference 5 based on the pulse signal 4 and the satellite information.

[0160] For this step, please refer to the description of the operation of the third device in step 401 of the method shown in FIG. 4 and the description of the operation of the AAU in step 605 of FIG.

[0161] For time difference 5, see the explanation of the second time difference in FIG.

[0162] Step 807: AAU2 sends the time difference 5 to the BBU.

[0163] For this step, please refer to the description of the operation of the third device in step 402 of the method shown in FIG.

[0164] It should be understood that the execution of steps 802 through 804 is independent of the execution of steps 805 through 807, but that both steps 802 through 804 and steps 805 through 807 should be completed before step 808.

[0165] Step 808: The BBU determines a time difference 6 based on the time difference 4 and the time difference 5.

[0166] Step 809: The BBU obtains the average relative frequency shift 2.

[0167] Step 810: The BBU corrects the local clock of the BBU based on the average relative frequency deviation 2 .

[0168] For steps 808 to 810, please refer to the description of the operation of the first device in step 403 in FIG. 4 and the description of the operation of the BBU in steps 607 to 609 in FIG.

[0169] Step 811: AAU1 and AAU2 obtain the local clock of the BBU as the system clock.

[0170] For AAU1 and AAU2 at this stage, please refer to the description of the operation of the second device and the third device at steps 404 and 405 of the method shown in Figure 4, and the description of the operation of the AAUs at step 610 of Figure 6.

[0171] Please refer to the explanation in FIG. 6 for the beneficial effects of the implementation method shown in this figure.

[0172] It should be understood that the method shown in this embodiment of the present application is merely an example. In a specific implementation, multiple GNSSs may be deployed on the AAU side, or multiple GNSSs may be separately deployed in at least three AAUs, thereby achieving the effect of improving the accuracy of the system clock of the base station. In addition, the method in which multiple GNSSs are deployed on the AAU side or multiple GNSSs are deployed on at least three AAU sides can be used to implement the effect of mutual backup between multiple GNSSs, thereby improving the reliability and stability of the time serving performed in this method.

[0173] In addition, the operation of the BBU in the method shown in Figure 8 can alternatively be performed by AAU3. Specifically, there are three AAUs, AAU1, AAU2, and AAU3, in the access network device. AAU3 obtains the time difference between AAU1 and the satellite from AAU1 and AAU2, obtains the time difference between AAU2 and the satellite, and corrects its local clock based on the time difference between AAU1 and the satellite and the time difference between AAU2 and the satellite. After AAU3 corrects its local clock, AAU1 and AAU2 are synchronized with AAU3. Finally, clock synchronization of the communication system is implemented.

[0174] Based on the system architecture shown in Figure 7, Figure 9 is a schematic interaction flowchart of another clock synchronization method according to an embodiment of the present application. Specifically, the method may include the following steps:

[0175] Step 901: A satellite transmits satellite information to GNSS1 and GNSS2.

[0176] For this step, see the description of step 601 in FIG.

[0177] Step 902: GNSS1 transmits pulse signal 5 and satellite information to AAU1.

[0178] For the pulse signal 5 in this step, please refer to the description of the pulse signal 1 in step 602 of FIG.

[0179] Step 903: The AAU 1 determines the time difference 7 based on the pulse signal 5 and the satellite information.

[0180] For time difference 7, see the explanation for time difference 1 in step 603 of FIG.

[0181] Step 904: AAU1 transmits time difference 7 to AAU2.

[0182] Step 905: The GNSS2 transmits the pulse signal 6 and the satellite information to the AAU2.

[0183] For the pulse signal 6 in this step, please refer to the description of the pulse signal 1 in step 602 of FIG.

[0184] Step 906: The AAU 2 determines the time difference 8 based on the pulse signal 6 and the satellite information.

[0185] For time difference 8, see the explanation for time difference 1 in step 603 of FIG.

[0186] Step 907: AAU2 transmits the time difference 8 to AAU1.

[0187] It should be understood that the execution of steps 902 through 904 is independent of the execution of steps 905 through 907, but steps 902 through 904 and steps 905 through 907 should be completed before step 908.

[0188] Step 908: AAU1 determines time difference 9 based on time difference 7 and time difference 8.

[0189] Step 909: AAU1 obtains the average relative frequency shift 3.

[0190] Step 910: AAU1 corrects its local clock based on the average relative frequency deviation 3.

[0191] For steps 908 to 910, please refer to the description of the BBU's operation in steps 607 to 609 in FIG.

[0192] Step 911: AAU2 determines time difference 9 based on time difference 7 and time difference 8.

[0193] Step 912: AAU2 obtains the average relative frequency shift3.

[0194] Step 913: AAU2 corrects its local clock based on the average relative frequency deviation 3.

[0195] For steps 911 to 913, please refer to the description of the BBU's operation in steps 607 to 609 in FIG.

[0196] It should be understood that the execution of steps 908 through 910 is independent of the execution of steps 911 through 913. Any one of steps 908 through 910 need not be executed before any one of steps 911 through 913.

[0197] In other words, in the method shown in Fig. 9, AAU1 and AAU2 do not need to rely on the BBU to perform clock synchronization. For the beneficial effects of Fig. 9, please refer to the description in the previous method. The details will not be described again.

[0198] Figure 10 is a schematic diagram of yet another system architecture to which the present application is applicable. The difference between the architectures shown in Figure 10 and Figure 7 is that a method in which clock synchronization is performed based on multiple satellites is applicable to the architecture shown in Figure 10. Based on the system architecture shown in Figure 10, Figures 11A and 11B are schematic interaction flowcharts of yet another clock synchronization method according to an embodiment of the present application. Specifically, this method may include the following steps:

[0199] Step 1101: Satellite 1 transmits satellite information of satellite 1 to GNSS 1 and GNSS 2.

[0200] Step 1102: Satellite 2 transmits its satellite information to GNSS1 and GNSS2.

[0201] For steps 1101 and 1102, please refer to the description of step 601 in FIG.

[0202] The execution order of step 1101 and step 1102 is not limited in this application.

[0203] Step 1103: GNSS1 transmits pulse signal 7 and satellite information of satellite 1 to AAU1.

[0204] For the pulse signal 7 at this stage, please refer to the description of the pulse signal 1 at step 602 in Fig. 6. For the satellite information of satellite 1, please refer to the description of the satellite information in Fig. 6.

[0205] Step 1104: AAU1 determines the time difference 10 based on the pulse signal 7 and the satellite information of satellite 1.

[0206] For time difference 10, please refer to the explanation of time difference 1 in step 603 of FIG.

[0207] Step 1105: GNSS2 transmits pulse signal 8 and satellite information of satellite 1 to AAU2.

[0208] For the pulse signal 8 in this step, please refer to the description of the pulse signal 1 in step 602 of FIG.

[0209] Step 1106: The AAU 2 determines the time difference 11 based on the pulse signal 8 and the satellite information of the satellite 1.

[0210] For time difference 11, see the explanation for time difference 1 in step 603 of FIG.

[0211] Step 1107: AAU2 transmits the time difference 11 to AAU1.

[0212] Step 1108: AAU1 determines time difference 12 based on time difference 10 and time difference 11.

[0213] Step 1109: AAU1 obtains the average relative frequency shift 4.

[0214] Step 1110: AAU1 corrects its local clock based on the average relative frequency deviation 4.

[0215] For steps 1108 to 1110, please refer to the description of the BBU's operation in steps 607 to 6009 in FIG.

[0216] It should be understood that the execution of steps 1103 and 1104 is independent of the execution of steps 1105 through 1107, but steps 1103 and 1104, and steps 1105 through 1107 should be completed before step 1108.

[0217] Step 1111: GNSS2 transmits pulse signal 10 and satellite information of satellite 2 to AAU2.

[0218] For the pulse signal 10 at this stage, please refer to the description of the pulse signal 1 at step 602 in Fig. 6. For the satellite information of satellite 2, please refer to the description of the satellite information in Fig. 6.

[0219] Step 1112: AAU2 determines the time difference 13 based on the pulse signal 10 and the satellite information of satellite 2.

[0220] For time difference 13, see the explanation of time difference 1 in step 603 of FIG.

[0221] Step 1113: GNSS1 transmits pulse signal 9 and satellite information of satellite 2 to AAU1.

[0222] For the pulse signal 9 in this step, please refer to the description of the pulse signal 1 in step 602 of FIG.

[0223] Step 1114: The AAU2 determines the time difference 14 based on the pulse signal 9 and the satellite information of the satellite 2.

[0224] For time difference 14, see the explanation of time difference 1 in step 603 of FIG.

[0225] Step 1115: AAU1 transmits the time difference 14 to AAU2.

[0226] It should be understood that the execution of steps 1111 and 1112 is independent of the execution of steps 1113 through 1115, and that steps 1111 and 1112, and steps 1113 through 1115, should be completed before step 1116.

[0227] Step 1116: AAU2 determines time difference 15 based on time difference 13 and time difference 14.

[0228] Step 1117: AAU2 obtains the average relative frequency shift 5.

[0229] Step 1118: AAU2 corrects its local clock based on the average relative frequency deviation 5.

[0230] For steps 1116 to 1118, please refer to the description of the BBU's operation in steps 607 to 609 in FIG.

[0231] It should be understood that the execution of steps 1103 through 1110 is independent of the execution of steps 11111 through 1118.

[0232] In this embodiment, AAU1 and AAU2 may correct their respective local clocks by referencing different satellites. In other words, AAU1 may choose to correct its local clock by referencing satellite 1, and AAU2 may choose to correct its local clock by referencing satellite 2. In addition, AAU1 may independently select different satellites for clock synchronization without having to rely on the BBU to perform clock synchronization.

[0233] Please refer to the explanation in FIG. 6 for the beneficial effects of the implementation method shown in this figure.

[0234] Accordingly, an embodiment of the present application further provides a communication device. The communication device may be any one of the first device, second device, third device, BBU, AAU, AAU1, AAU2, and AAU3 in the above-described method embodiments, a device including the functions of any one of the first device, second device, third device, BBU, AAU, AAU1, AAU2, and AAU3, or a component whose functions are similar to those of any one of the first device, second device, third device, BBU, AAU, AAU1, AAU2, and AAU3. To implement the above-described functions, it can be understood that the communication device includes corresponding hardware structures and / or software modules for performing each function. With reference to the units and algorithm steps in the examples described in the embodiments disclosed herein, those skilled in the art will easily recognize that the present application can be implemented in the form of hardware or a combination of hardware and computer software. Whether a specific function is implemented by hardware or hardware driven by computer software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement each described function for a particular application, but such implementation should not be considered as going beyond the scope of this application.

[0235] FIG. 12 is a schematic diagram of a communication device according to an embodiment of the present application.

[0236] The communication device includes a processing module 1201, a receiving module 1202, and a transmitting module 1203. The processing module 1201 is configured to implement data processing by the communication device. The receiving module 1202 is configured to receive content between the communication device and another unit or network element. The transmitting module 1203 is configured to receive content between the communication device and another unit or network element. It should be understood that the processing module 1201 in this embodiment of the present application may be implemented by a processor or a processor-related circuit component (also referred to as a processing circuit), and the receiving module 1202 may be implemented by a receiver or a receiver-related circuit component. The transmitting module 1203 may be implemented by a transmitter or a transmitter-related circuit component.

[0237] For example, a communications apparatus may be a communications device, or may be a chip used within a communications device, or another combined device or component having the functionality of such a communications device.

[0238] For example, the communication device may be the first device or BBU in any one of Figures 3 to 6, AAU1 or AAU2 in any one of Figures 7 to 9, or AAU1 or AAU2 in any of Figures 10, 11A, and 11B.

[0239] When the communication device is the first device or BBU in any one of FIGS. 3 to 6, the AAU1 or AAU2 in any one of FIGS. 7 to 9, or the AAU1 or AAU2 in any one of FIGS. 10, 11A, and 11B, the processing module 1201 is configured to acquire a first time difference (e.g., step 301, step 603, step 903, step 1104, and step 1112). The first time difference is a time difference between the first device and a satellite. The first time difference is determined based on the first pulse signal and information about the satellite. The receiving module 1202 is configured to acquire a second time difference (e.g., step 302, step 606, step 907, step 1107, and step 1115). The second time difference is a time difference between the second device and a satellite. The second time difference is obtained from the second device. The first device and the second device belong to the same access network device. The processing module 1201 is further configured to obtain clock synchronization information between the first device and the second device based on the first time difference and the second time difference (e.g., step 303, steps 607 to 609, steps 908 to 910, steps 1108 to 1110, and steps 1116 to 1118).

[0240] In addition, the aforementioned modules may be further configured to support other processes of the techniques described herein. For beneficial effects, please refer to the above description. The details will not be described again here.

[0241] For example, the communication device may be the second device, the third device, AAU1, or AAU2 in any one of Figures 3 to 11A and 11B.

[0242] If the communication device is the second device, the third device, AAU1, or AAU2 in any one of FIGS. 3 to 11A and 11B, the transmitting module 1203 is configured to transmit the second time difference to the first device (e.g., steps 302, 402, 606, 807, 907, 1107, and 1115). The first device and the second device belong to the same access network device. The second time difference is determined based on the second pulse signal and information about the satellite. The second time difference is the time difference between the second device and the satellite. The receiving module 1202 is configured to receive clock synchronization information from the first device (e.g., steps 304, 404, 610, and 811). The processing module 1201 is configured to obtain local clock information of the second device based on the clock synchronization information (e.g., steps 305, 405, 610, and 811).

[0243] In addition, the aforementioned modules may be further configured to support other processes of the techniques described herein. For beneficial effects, please refer to the above description. The details will not be described again here.

[0244] For example, the communication device may be the first device or the BBU in any one of FIG. 4, FIG. 7 or FIG.

[0245] When the communication device is the first device or the BBU in any one of FIG. 4, FIG. 7, or FIG. 8, the receiving module 1202 is configured to receive from the second device a first time difference, which is a time difference between the second device and the satellite; and receive from the third device a second time difference, which is a time difference between the third device and the satellite (e.g., step 402, step 804, and step 807). The first device, the second device, and the third device belong to the same access network device. The processing module 1201 is configured to obtain clock synchronization information between the first device, the second device, and the third device based on the first time difference and the second time difference (e.g., step 403, and steps 808 to 810).

[0246] In addition, the aforementioned modules may be further configured to support other processes of the techniques described herein. For beneficial effects, please refer to the above description. The details will not be described again here.

[0247] FIG. 13 is a schematic diagram of another communication device according to an embodiment of the present application. The communication device includes a processor 1301, a communication interface 1302, and a memory 1303. The processor 1301, the communication interface 1302, and the memory 1303 may be connected to each other through a bus 1304. The bus 1304 may be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus 1304 may be classified into an address bus, a data bus, a control bus, etc. For ease of representation, the bus is represented by only one line in FIG. 13, but this does not indicate the presence of only one bus or one type of bus. The processor 1301 may be a central processing unit (CPU), a network processor (NP), or a combination of a CPU and an NP. The processor may further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a combination thereof. The PLD may be a complex programmable logic device (CPLD), a field programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof. The memory 1303 may be volatile or non-volatile memory, or may include both volatile and non-volatile memory.Non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM) or flash memory. Volatile memory may be random access memory (RAM) used as an external cache.

[0248] The processor 1301 is configured to implement the data processing operations of the communication device. The communication interface 1302 is configured to implement the receiving and transmitting operations of the communication device.

[0249] For example, the communication device may be the first device or BBU in any one of Figures 3 to 6, AAU1 or AAU2 in any one of Figures 7 to 9, or AAU1 or AAU2 in any of Figures 10, 11A, and 11B.

[0250] When the communication device is the first device or BBU in any one of FIGS. 3 to 6, the AAU1 or AAU2 in any one of FIGS. 7 to 9, or the AAU1 or AAU2 in any one of FIGS. 10, 11A, and 11B, the processor 1301 is configured to acquire a first time difference (e.g., steps 301, 603, 903, 1104, and 1112). The first time difference is a time difference between the first device and a satellite. The first time difference is determined based on the first pulse signal and information about the satellite. The communication interface 1302 is configured to acquire a second time difference (e.g., steps 302, 606, 907, 1107, and 1115). The second time difference is a time difference between the second device and a satellite. The second time difference is obtained from the second device. The first device and the second device belong to the same access network device. The processor 1301 is further configured to obtain clock synchronization information between the first device and the second device based on the first time difference and the second time difference (e.g., step 303, steps 607 to 609, steps 908 to 910, steps 1108 to 1110, and steps 1116 to 1118).

[0251] In addition, the aforementioned modules may be further configured to support other processes of the techniques described herein. For beneficial effects, please refer to the above description. The details will not be described again here.

[0252] For example, the communication device may be the second device, the third device, AAU1, or AAU2 in any one of Figures 3 to 11A and 11B.

[0253] If the communication device is the second device, the third device, AAU1, or AAU2 in any one of FIGS. 3 to 11A and 11B, the communication interface 1302 is configured to transmit the second time difference to the first device (e.g., steps 302, 402, 606, 807, 907, 1107, and 1115). The first device and the second device belong to the same access network device. The second time difference is determined based on the second pulse signal and information about the satellite. The second time difference is the time difference between the second device and the satellite. The communication interface 1302 is configured to receive clock synchronization information from the first device (e.g., steps 304, 404, 610, and 811). The processor 1301 is configured to obtain local clock information of the second device based on the clock synchronization information (e.g., steps 305, 405, 610, and 811).

[0254] In addition, the aforementioned modules may be further configured to support other processes of the techniques described herein. For beneficial effects, please refer to the above description. The details will not be described again here.

[0255] For example, the communication device may be the first device or the BBU in any one of FIG. 4, FIG. 7 or FIG.

[0256] When the communication device is the first device or the BBU in any one of FIG. 4, FIG. 7, or FIG. 8, the communication interface 1302 is configured to receive from the second device a first time difference, which is a time difference between the second device and the satellite; and receive from the third device a second time difference, which is a time difference between the third device and the satellite (e.g., step 402, step 804, and step 807). The first device, the second device, and the third device belong to the same access network device. The processor 1301 is configured to obtain clock synchronization information between the first device, the second device, and the third device based on the first time difference and the second time difference (e.g., step 403, and steps 808 to 810).

[0257] In addition, the aforementioned modules may be further configured to support other processes of the techniques described herein. For beneficial effects, please refer to the above description. The details will not be described again here.

[0258] An embodiment of the present application provides a communication system including a first communication device and a second communication device. The first communication device executes the method performed by the first device, AAU1, AAU2, and BBU in the embodiment shown in any one of Figures 3 to 11A and 11B. The second communication device executes the method performed by the second device, AAU, AAU1, and AAU2 in the embodiment shown in any one of Figures 3 to 11A and 11B.

[0259] In a possible design, the communication system further includes a third communication device, which performs the operations of the third device in FIG. 4 or AAU2 in FIG.

[0260] An embodiment of the present application further provides a computer-readable storage medium. The computer-readable storage medium stores a computer program. When the computer program is executed by a computer, the computer may perform the method performed by the first device, the second device, the third device, AAU1, AAU2, and BBU in the embodiments shown in any one of Figures 3 to 11A and 11B, or the computer may perform the method performed by the first device, the second device, the third device, AAU1, AAU2, and BBU in the embodiments shown in any one of Figures 3 to 11A and 11B.

[0261] An embodiment of the present application further provides a computer program product. The computer program product is configured to store a computer program. When the computer program is executed by a computer, the computer may perform the method performed by the first device, the second device, the third device, AAU1, AAU2, and BBU in the embodiment shown in any one of Figures 3 to 11A and 11B, or the computer may perform the method performed by the first device, the second device, the third device, AAU1, AAU2, and BBU in the embodiment shown in any one of Figures 3 to 11A and 11B.

[0262] The present application further provides a chip including a processor. The processor is configured to read and execute a computer program stored in a memory to perform corresponding operations and / or steps in the clock synchronization method provided herein, performed by the first device, the second device, the third device, AAU1, AAU2, and the BBU. Optionally, the chip further includes a memory. The memory and the processor are connected through circuits or wires. The processor is configured to read and execute the computer program in the memory. Optionally, the memory may alternatively be memory located outside the chip. Furthermore, optionally, the chip further includes a communication interface. The processor is connected to the memory and the communication interface. The communication interface is configured to receive processed data and / or information. The processor obtains the data and / or information from the communication interface and processes the data and / or information. The communication interface may be an input / output interface, an interface circuit, an output circuit, an input circuit, a pin, or related circuitry on the chip. Alternatively, the processor may be embodied as a processing circuit or a logic circuit.

[0263] The chip may alternatively be replaced by a chip system, the details of which will not be described again here.

[0264] As used herein, the terms "include" and "have" and any variations thereof are intended to cover a non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to the steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent in such process, method, product, or device.

[0265] In combination with the examples described in the embodiments disclosed herein, those skilled in the art can recognize that the units and algorithm steps can be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed by hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement each described function for a specific application, but such implementation should not be considered as going beyond the scope of this application.

[0266] For the sake of convenience and simplicity, it can be clearly understood by those skilled in the art that the detailed operation processes of the aforementioned systems, devices and units should be referred to the corresponding processes in the aforementioned method embodiments, and the details will not be described again here.

[0267] It should be understood that in some embodiments provided herein, the disclosed systems, devices, and methods may be implemented in other manners. For example, the described device embodiments are merely examples. For example, the division into multiple units is merely a logical division of function, and other divisions may be used in actual implementation. For example, multiple units or components may be combined or integrated into another system, or some functions may be omitted or not performed. In addition, the shown or described mutual couplings or direct couplings or communication connections may be implemented using some interfaces. Indirect couplings or communication connections between these devices or units may be implemented in electronic, mechanical, or other forms.

[0268] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, specifically, may be located in one place or distributed over multiple network units. Some or all of these units may be selected according to actual conditions to achieve the objectives of the solution of the present embodiment.

[0269] Additionally, the functional units in the embodiments of the present application may be integrated into one processing unit, each of which may exist physically alone, or two or more units may be integrated into one unit.

[0270] When these functions are implemented in the form of software functional units and sold or used as independent products, these functions may be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the present application may be essentially implemented in the form of a software product, or a portion that contributes to the prior art may contribute to the prior art, or some of these technical solutions may be implemented in the form of a software product. A computer software product is stored in a storage medium and includes a plurality of instructions for instructing a computer device (which may be a personal computer, a server, a network device, etc.) to perform all or some of the steps of the methods described in the embodiments of the present application. The storage medium includes any medium that can store program code, such as a USB flash drive, a removable hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0271] Additionally, terms such as "first" and "second" in this specification, claims, and accompanying drawings are intended to distinguish between different objects, but not to describe a particular order. Additionally, terms such as "include" and "have," and any other variations thereof, are intended to include a non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, but may, optionally, further include other unlisted steps or units, or may, optionally, further include other steps or units inherent to such process, method, product, or device.

[0272] Although the present application has been described with reference to specific features and embodiments thereof, it is apparent that various modifications and combinations may be made to the present application without departing from the spirit and scope of the present application. Accordingly, this specification and the accompanying drawings are merely exemplary descriptions of the present application as defined in the appended claims, and any or all modifications, variations, combinations, or equivalents within the scope of the present application are to be considered. It is apparent that a person skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. In this case, if the modifications and variations made to the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include these modifications and variations.

[0273] The above description is merely a specific implementation of the present application and is not intended to limit the scope of protection of the present application. Any modifications or replacements that can be easily thought of by those skilled in the art within the technical scope disclosed in the present application shall be included in the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the scope of protection of the claims. 。 [Other possible items] [Item 1] 1. A clock synchronization method, comprising: acquiring, by a first device, a first time difference and a second time difference, wherein the first time difference is a time difference between the first device and a satellite, the first time difference being determined based on a first pulse signal and information about the satellite, and the second time difference is a time difference between a second device and the satellite, the second time difference being derived from the second device, and the first device and the second device belong to the same access network device; and obtaining, by the first device, clock synchronization information between the first device and the second device based on the first time difference and the second time difference; A method comprising: [Item 2] Item 10. The method of item 1, further comprising transmitting the clock synchronization information by the first device to the second device. [Item 3] The first device and the second device belong to the same access network device, The first device is a wireless device controller in the access network device, and the second device is a wireless device in the access network device. Including, The method according to item 1 or 2. [Item 4] The first device and the second device belong to the same access network device, Both the first device and the second device are wireless devices within the access network device. Including, The method according to item 1 or 2. [Item 5] 5. The method of any one of items 1 to 4, wherein the first pulse signal is a pulse per second signal. [Item 6] 6. The method of any one of items 1 to 5, wherein the information about the satellite includes an identifier of the satellite and further includes at least one of time information of the satellite, status information of the satellite, and ephemeris data information of the satellite. [Item 7] The step of obtaining, by the first device, clock synchronization information of the first device based on the first time difference and the second time difference includes: calculating, by the first device, a third time difference based on the first time difference and the second time difference; determining, by the first device, an average relative phase frequency difference based on the third time difference; and adjusting, by the first device, local clock information of the first device based on the average relative phase frequency difference. having 7. The method according to any one of items 1 to 6. [Item 8] determining the first time difference based on a first pulse signal and information about the satellite; receiving, by the first device, the first pulse signal and the information about the satellite from a first satellite receiver; and determining, by the first device, the first time difference based on the first pulse signal and the information about the satellite. Including, 8. The method according to any one of items 1 to 7. [Item 9] 1. A clock synchronization method, comprising: transmitting, by a second device, a second time difference to the first device, wherein the second time difference is determined based on a second pulse signal and information about a satellite, the second time difference being a time difference between the second device and the satellite, and the first device and the second device belong to the same access network device; receiving, by the second device, clock synchronization information from the first device; and obtaining, by the second device, local clock information of the second device based on the clock synchronization information; A method comprising: [Item 10] The first device and the second device belong to the same access network device, The first device is a wireless device controller in the access network device, and the second device is a wireless device in the access network device. Including, Item 9. The method according to item 9. [Item 11] The first device and the second device belong to the same access network device, Both the first device and the second device are wireless devices within the access network device. Including, Item 9. The method according to item 9. [Item 12] 12. The method of any one of items 9 to 11, wherein the second pulse signal is a pulse per second signal. [Item 13] 13. The method of any one of items 9 to 12, wherein the information about the satellite includes an identifier of the satellite, and the information about the satellite further includes at least one of time information of the satellite, status information of the satellite, and ephemeris data information of the satellite. [Item 14] obtaining, by a second device, a second time difference, wherein the second time difference is determined based on a second pulse signal and information about the satellite; receiving, by the second device, the second pulse signal and the information about the satellite from a second satellite receiver; and determining, by the second device, the second time difference based on the second pulse signal and the information about the satellite. Including, 14. The method according to any one of items 9 to 13. [Item 15] 1. A clock synchronization method, comprising: receiving, by the first device, a first time difference from the second device, wherein the first time difference is a time difference between the second device and a satellite; receiving, by the first device, a second time difference from a third device, wherein the second time difference is a time difference between the third device and the satellite, and the first device, the second device, and the third device belong to the same access network device; and obtaining, by the first device, clock synchronization information among the first device, the second device, and the third device based on the first time difference and the second time difference; A method comprising: [Item 16] transmitting, by the first device, the clock synchronization information to the second device and the third device; Item 16. The method of item 15, further comprising: [Item 17] The first device, the second device, and the third device belong to the same access network device, The first device is a wireless device controller in the access network device, and the second device and the third device are wireless devices in the access network device. Including, 17. The method according to item 15 or 16. [Item 18] 18. The method of any one of items 15 to 17, wherein the first device receives information about the satellite from the second device, the information about the satellite including an identifier of the satellite, and the information about the satellite further including at least one of time information of the satellite, status information of the satellite, and ephemeris data information of the satellite. [Item 19] A communication device, a receiving module configured to obtain a second time difference, wherein the second time difference is a time difference between a second device and a satellite, and the second time difference is provided from the second device; and a processing module configured to acquire a first time difference, where the first time difference is a time difference between the communication device and the satellite, the first time difference being determined based on a first pulse signal and information about the satellite, and the communication device and the second device belong to the same access network device; and the processing module is further configured to acquire clock synchronization information between the first device and the second device based on the first time difference and the second time difference. A communication device comprising: [Item 20] a transmitting module configured to transmit the clock synchronization information to the second device. 20. The communication device of item 19, further comprising: [Item 21] 21. The communication device of claim 19, wherein the processing device is configured to calculate a third time difference based on the first time difference and the second time difference; further configured to determine an average relative phase frequency difference based on the third time difference; and further configured to adjust local clock information of the communication device based on the average relative phase frequency difference. [Item 22] the receiving module is configured to receive the first pulse signal and the information about the satellite from a first satellite receiver; and The processing module is configured to determine the first time difference based on the first pulse signal and the information about the satellite. 22. A communication device according to any one of items 19 to 21. [Item 23] a transmitting module configured to transmit a second time difference to a first device, wherein the second time difference is determined based on a second pulse signal and information about a satellite, the second time difference being a time difference between the second device and the satellite, and the first device and the second device belong to the same access network device; a receiving module configured to receive clock synchronization information from the first device; and a processing module configured to obtain local clock information of the second device based on the clock synchronization information. A communication device comprising: [Item 24] the receiving module is configured to receive the second pulse signal and the information about the satellite from a second satellite receiver; and The processing module is configured to determine the second time difference based on the second pulse signal and the information about the satellite. Item 24. The communication device according to item 23. [Item 25] a receiving module configured to receive a first time difference from a second device, where the first time difference is a time difference between the second device and a satellite; and a receiving module configured to receive a second time difference from a third device, where the second time difference is a time difference between the third device and the satellite, and the first device, the second device, and the third device belong to the same access network device; and a processing module configured to obtain clock synchronization information among the first device, the second device, and the third device based on the first time difference and the second time difference. A communication device comprising: [Item 26] a transmitting module configured to transmit the clock synchronization information to the second device and the third device; Item 26. The communication device of item 25, further comprising: [Item 27] A communication system comprising a first device and a second device, wherein the first device performs the method described in any one of items 1 to 8 or the method described in any one of items 15 to 18, and the second device performs the method described in any one of items 9 to 14. [Item 28] A computer program product comprising instructions, which when executed on a computer, enable the computer to perform the method according to any one of items 1 to 8, items 9 to 14 or items 15 to 18. [Item 29] A computer-readable storage medium storing instructions that, when executed on a computer, enable a processor to perform the method of any one of items 1 to 8, items 9 to 14, or items 15 to 18. [Item 30] A chip comprising a processor and an interface circuit, the interface circuit coupled to the processor, the processor configured to execute a computer program or instructions to perform the method of any one of items 1 to 8, items 9 to 14, or items 15 to 18. [Item 31] 19. A communication device configured to perform the method of any one of items 1 to 8, items 9 to 14 or items 15 to 18. [Item 32] A communication device comprising a processor and a memory, wherein the memory stores a computer program, and when the processor reads and executes the computer program stored in the memory, the communication device is capable of executing the method described in any one of items 1 to 8, items 9 to 14, or items 15 to 18.

Claims

1. 1. A clock synchronization method, comprising: acquiring, by a first device, a first time difference and a second time difference, wherein the first time difference is a time difference between the first device and a satellite, the first time difference being determined based on a first pulse signal and information about the satellite, and the second time difference is a time difference between a second device and the satellite, the second time difference being derived from the second device, and the first device and the second device belong to the same access network device; and obtaining, by the first device, clock synchronization information between the first device and the second device based on the first time difference and the second time difference; A method comprising:

2. The method of claim 1 , further comprising transmitting, by the first device, the clock synchronization information to the second device.

3. The first device and the second device belong to the same access network device, The first device is a wireless device controller in the access network device, and the second device is a wireless device in the access network device. Including, The method according to claim 1 or 2.

4. The first device and the second device belong to the same access network device, Both the first device and the second device are wireless devices within the access network device. Including, The method according to claim 1 or 2.

5. The method of claim 1 or 2, wherein the first pulse signal is a pulse per second signal.

6. The method of claim 1 or 2, wherein the information about the satellite includes an identifier of the satellite, and further includes at least one of time information of the satellite, status information of the satellite, and ephemeris data information of the satellite.

7. The step of obtaining, by the first device, clock synchronization information between the first device and the second device based on the first time difference and the second time difference includes: calculating, by the first device, a third time difference based on the first time difference and the second time difference; determining, by the first device, an average relative phase frequency difference based on the third time difference; and adjusting, by the first device, local clock information of the first device based on the average relative phase frequency difference. having The method according to claim 1 or 2.

8. The step of acquiring the first time difference and the second time difference by the first device is repeatedly performed; the step of calculating, by the first device, a third time difference based on the first time difference and the second time difference includes calculating, by the first device, a plurality of third time differences based on the repeatedly obtained first time difference and second time difference; determining, by the first device, an average relative phase frequency difference based on the third time differences, comprises determining, by the first device, the average relative phase frequency difference based on the plurality of third time differences. The method of claim 7.

9. The first time difference is determined based on a first pulse signal and information about the satellite, receiving, by the first device, the first pulse signal and the information about the satellite from a first satellite receiver; and determining, by the first device, the first time difference based on the first pulse signal and the information about the satellite. Including, The method according to claim 1 or 2.

10. 1. A clock synchronization method, comprising: transmitting, by a second device, a second time difference to the first device, wherein the second time difference is determined based on a second pulse signal and information about a satellite, the second time difference being a time difference between the second device and the satellite, and the first device and the second device belong to the same access network device; receiving, by the second device, clock synchronization information from the first device; and obtaining, by the second device, local clock information of the second device based on the clock synchronization information; A method comprising:

11. The first device and the second device belong to the same access network device, The first device is a wireless device controller in the access network device, and the second device is a wireless device in the access network device. Including, The method of claim 10.

12. The first device and the second device belong to the same access network device, Both the first device and the second device are wireless devices within the access network device. Including, The method of claim 10.

13. 13. The method of any one of claims 10 to 12, wherein the second pulse signal is a pulse per second signal.

14. 13. The method of claim 10, wherein the information about the satellite includes an identifier of the satellite, and the information about the satellite further includes at least one of time information of the satellite, status information of the satellite, and ephemeris data information of the satellite.

15. The step of transmitting, by the second device, a second time difference to the first device, wherein the second time difference is determined based on the second pulse signal and information about the satellite, further comprises: receiving, by the second device, the second pulse signal and the information about the satellite from a second satellite receiver; and determining, by the second device, the second time difference based on the second pulse signal and the information about the satellite. Including, 13. The method according to any one of claims 10 to 12.

16. A step of repeatedly acquiring the second time difference by the second device. Furthermore, the step of transmitting, by the second device, the second time difference to the first device includes transmitting, by the second device, the repeatedly obtained second time difference to the first device; the step of receiving clock synchronization information from the first device by the second device includes the step of receiving, by the second device from the first device, local clock information of the first device as the clock synchronization information; the local clock information of the first device is adjusted based on an average relative phase frequency difference determined by the first device based on a plurality of third time differences, the plurality of third time differences being calculated by the first device based on first time differences repeatedly acquired by the first device and second time differences repeatedly acquired by the second device and received from the second device, the first time difference being a time difference between the first device and the satellite, and the first time difference being determined based on a first pulse signal and information about the satellite; 13. The method according to any one of claims 10 to 12.

17. A communication system comprising a first device and a second device, wherein the first device performs the method of claim 1 or 2, and the second device performs the method of any one of claims 10 to 12.

18. 13. A computer program comprising instructions, which when executed on a computer, enable the computer to carry out the method of claim 1 or 2 or any one of claims 10 to 12.

19. A computer-readable storage medium storing instructions which, when executed on a computer, enable a processor to carry out the method of claim 1 or 2 or any one of claims 10 to 12.

20. A communication device, the first device, configured to perform the method of claim 1 or 2.

21. A communication device, the second device, configured to perform the method described in any one of claims 10 to 12.

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