Synchronization method and apparatus

Abstract

The present application relates to the technical field of communications, and provides a synchronization method and apparatus. In the method, a terminal can receive a first signal from a wireless access network node, and on the basis of first information, determine at least one of a downlink timing of a second-type signal or an uplink timing of the second-type signal. The first signal is a first-type signal, and the first-type signal is synchronized with a first clock. The second-type signal is synchronized with a second clock. A timing offset between the first-type signal and the second-type signal is a first time difference, and both the downlink timing and the uplink timing are related to the first time difference. That is to say, the terminal can determine the downlink timing and / or the uplink timing on the basis of the first time difference, without performing downlink timing by means of an SSB, or performing uplink timing by means of random access, so that a duration of the terminal performing uplink synchronization and / or downlink synchronization can be shortened, thereby shortening a time delay of the access network node paging the terminal.

Description

Synchronization Method and Device

[0001] This application claims priority to Chinese Patent Application No. 202410504508.9, filed with the State Intellectual Property Office of China on April 24, 2024, entitled "Synchronization Method and Apparatus", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communication technology, and in particular to synchronization methods and apparatus. Background Technology

[0003] With the development of communication technology, the requirements for terminal capabilities in communication networks are becoming increasingly stringent, leading to greater power consumption. To reduce terminal power consumption and improve battery life, a scheme has been proposed for terminals in non-connected states (such as idle or inactive states) to operate in a low-power mode. In low-power mode, the terminal can detect wake-up signals sent by access network nodes and determine whether to exit low-power mode and perform normal data transmission based on the wake-up signal. Specifically, if the wake-up signal does not contain information related to the terminal, the terminal can continue to maintain low-power mode to save power; if the wake-up signal contains information related to the terminal, the terminal can exit low-power mode and perform normal data transmission with the access network node. Before performing normal data transmission, the terminal also needs to receive a synchronization signal block (SSB) for downlink synchronization and initiate random access to complete uplink synchronization. However, the time spent on uplink and downlink synchronization is relatively long, resulting in a longer delay for access network nodes to page the terminal, affecting user experience. Summary of the Invention

[0004] This application provides a synchronization method and apparatus that can shorten the duration of uplink and / or downlink synchronization of terminals, thereby reducing the latency of paging terminals at access network nodes.

[0005] To achieve the above objectives, this application adopts the following technical solution:

[0006] Firstly, a synchronization method is provided that can be executed by a terminal. Here, "terminal" can refer to the terminal itself, or to a processor, circuit, module, logic node, chip, or chip system within the terminal that implements the method.

[0007] The method includes: receiving a first signal from a radio access network node; and determining at least one of a first downlink timing or a first uplink timing based on the first signal. The first signal is a first type of signal, synchronized with a first clock. The first downlink timing is used to determine the time for receiving a second signal from the radio access network node, and the first uplink timing is used to determine the time for sending a third signal to the radio access network node. The second and third signals are second type signals, synchronized with a second clock. The timing deviation between the first type of signal and the second type of signal is a first time difference, and both the first downlink timing and the first uplink timing are related to the first time difference. Optionally, the first time difference can be positive or negative.

[0008] Based on the method provided in the first aspect above, the terminal can determine the first uplink timing and / or the first downlink timing based on the timing deviation between the first type of signal and the second type of signal. Understandably, if the terminal determines the first downlink timing, it does not need to perform downlink synchronization based on the SSB, thus effectively reducing downlink synchronization latency. If the terminal determines the first uplink timing, it does not need to perform uplink synchronization via random access, effectively reducing uplink synchronization latency. In summary, the method provided in the first aspect above can shorten the time for the terminal to perform uplink synchronization and / or downlink synchronization, thereby reducing the latency of paging the terminal by the radio access network node and improving user experience.

[0009] In one possible implementation, the method further includes receiving first information from a wireless access network node for indicating the aforementioned first time difference.

[0010] Based on the above possible implementation methods, the terminal can determine the first time difference based on the first information, and then determine the first uplink timing and / or the first downlink timing based on the first time difference.

[0011] In one possible implementation, the first downlink timing is determined based on the second downlink timing and the first time difference, wherein the second downlink timing is the downlink timing of the first type of signal.

[0012] Based on the above possible implementation methods, the terminal can determine the first downlink timing according to the second downlink timing and the first time difference. For example, when the first time difference is negative, the first downlink timing is delayed by f compared to the second downlink timing, where f is the absolute value of the first time difference; when the first time difference is positive, the first downlink timing is advanced by f compared to the second downlink timing.

[0013] In one possible implementation, the first downlink timing is also related to the propagation delay between the terminal and the radio access network node.

[0014] Based on the above possible implementation methods, the terminal can determine the first downlink timing according to the first time difference and the above propagation delay (hereinafter referred to as D).

[0015] In one possible implementation, the first downlink timing is determined based on the timing of the first clock, the first time difference, and the propagation delay.

[0016] Based on the above possible implementation methods, the terminal can determine the first downlink timing according to the timing of the first clock, the first time difference, and D. For example, when the first time difference is negative, the first downlink timing is delayed by (f+D) compared to the timing of the first clock, where f is the absolute value of the first time difference; when the first time difference is positive, the first downlink timing is advanced by (fD) compared to the timing of the first clock.

[0017] In one possible implementation, the first uplink timing is also related to the propagation delay between the terminal and the radio access network node.

[0018] Based on the above possible implementation methods, the terminal can determine the first uplink timing according to the first time difference and D.

[0019] In one possible implementation, the first uplink timing is determined based on the first downlink timing and D; or, the first uplink timing is determined based on the timing of the first clock, the first time difference, and D.

[0020] Based on the above possible implementations, the terminal can determine the first uplink timing based on the first downlink timing and D. For example, the first uplink timing is achieved by advancing the first downlink timing by (2×D), where 2×D represents 2 multiplied by D. Alternatively, the terminal can determine the first uplink timing based on the timing of the first clock, the first time difference, and D. For example, when the first time difference is negative, the first uplink timing is delayed by (fD) compared to the timing of the first clock, where f is the absolute value of the first time difference; when the first time difference is positive, the first uplink timing is advanced by (f+D) compared to the timing of the first clock.

[0021] In one possible implementation, the first uplink timing is determined based on the second uplink timing and the first time difference, wherein the second uplink timing is the uplink timing of the first type of signal.

[0022] Based on the above possible implementation methods, the terminal can determine the first uplink timing according to the first uplink timing and the first time difference. For example, when the first time difference is negative, the first uplink timing is delayed by f compared to the second uplink timing, where f is the absolute value of the first time difference; when the first time difference is positive, the first uplink timing is advanced by f compared to the second uplink timing.

[0023] In one possible implementation, the method further includes receiving second information from a radio access network node, the second information indicating a timing advance, the timing advance being related to the propagation delay.

[0024] Based on the above possible implementation methods, the terminal can obtain the timing advance based on the second information, determine D based on the timing advance, and then determine the first uplink timing and / or the first downlink timing.

[0025] In one possible implementation, the second information also indicates the effective time of the timing advance, which is used to determine the determination method of the first downlink timing or the determination method of the first uplink timing.

[0026] Based on the above possible implementation methods, the terminal can determine whether the timing advance is valid according to the second information. It is understandable that when the timing advance is valid, the terminal can determine D based on the timing advance, and then determine the first uplink timing and / or the first downlink timing based on D. When the timing advance is invalid, the terminal does not use the timing advance indicated by the second information to determine the first uplink timing and / or the first downlink timing. For example, the terminal completes downlink timing through SSB and uplink timing through random access.

[0027] In one possible implementation, the power consumption of the first type of signal is lower than that of the second type of signal.

[0028] Based on the above possible implementation methods, the power consumption of the terminal can be reduced.

[0029] In one possible implementation, the first clock is the Global Navigation Satellite System clock, and the second clock is the clock of the radio access network node.

[0030] Based on the above possible implementations, since the terminal typically deploys a Global Navigation Satellite System (GNSS) module, it can relatively easily obtain the timing of the first clock. However, the terminal cannot easily obtain the timing of the clock of the radio access network (RAN) node. Therefore, the terminal can first determine the timing of the first clock based on the GNSS module, and then determine the timing of the second clock by combining it with the first time difference.

[0031] Secondly, a synchronization method is provided, which can be executed by a radio access network node. Here, "radio access network node" can refer to the radio access network node itself, or to the processor, circuit, module, logic node, chip, or chip system within the radio access network node that implements the method.

[0032] The method includes: sending a first signal to a terminal. The first signal is a first type of signal, synchronized with a first clock. Subsequently, a second signal may be sent to the terminal, or a third signal may be received from the terminal. The second and third signals are second type signals, synchronized with a second clock. The timing deviation between the first and second type signals is a first time difference, which is related to a first downlink timing and a first uplink timing. The first downlink timing is used to determine the time when the terminal receives the second signal, and the first uplink timing is used to determine the time when the terminal sends the third signal. Optionally, the first time difference can be positive or negative.

[0033] In one possible implementation, the method further includes sending first information to the terminal, the first information being used to indicate a first time difference.

[0034] In one possible implementation, the first downlink timing is determined based on the second downlink timing and the first time difference, wherein the second downlink timing is the downlink timing of the first type of signal.

[0035] In one possible implementation, the first downlink timing is also related to the propagation delay between the terminal and the radio access network node.

[0036] In one possible implementation, the first downlink timing is determined based on the timing of the first clock, the first time difference, and the propagation delay.

[0037] In one possible implementation, the first uplink timing is also related to the propagation delay between the terminal and the radio access network node.

[0038] In one possible implementation, the first uplink timing is determined based on the first downlink timing and the propagation delay; or, the first uplink timing is determined based on the timing of the first clock, the first time difference, and the propagation delay.

[0039] In one possible implementation, the first uplink timing is determined based on the second uplink timing and the first time difference, wherein the second uplink timing is the uplink timing of the first type of signal.

[0040] In one possible implementation, the method further includes sending a second message to the terminal, the second message indicating a timing advance, the timing advance being related to the propagation delay.

[0041] In one possible implementation, the second information also indicates the effective time of the timing advance, which is used to determine the determination method of the first downlink timing or the determination method of the first uplink timing.

[0042] In one possible implementation, the power consumption of the first type of signal is lower than that of the second type of signal.

[0043] In one possible implementation, the first clock is the Global Navigation Satellite System clock, and the second clock is the clock of the radio access network node.

[0044] Thirdly, a communication device is provided for implementing the method described in the first aspect. This communication device can be the terminal described in the first aspect. The communication device includes modules, units, or means corresponding to the method described in the first aspect. These modules, units, or means can be implemented in hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the aforementioned functions.

[0045] In one possible implementation, the communication device may include a processing module and an interface module. The processing module can be used to implement the processing functions in any of the above aspects and their possible implementations. The processing module may be, for example, a processor. The interface module, also called an interface unit, is used to implement the sending and / or receiving functions in any of the above aspects and their possible implementations. The interface module may consist of an interface circuit, a transceiver, a transceiver unit, or a communication interface.

[0046] In one possible implementation, the interface module is configured to receive a first signal from a wireless access network node, the first signal being a first type of signal synchronized with a first clock; the processing module is configured to determine at least one of a first downlink timing or a first uplink timing based on the first signal; wherein the first downlink timing is used to determine the time for receiving a second signal from the wireless access network node, the first uplink timing is used to determine the time for sending a third signal to the wireless access network node, the second signal and the third signal being second type of signal synchronized with a second clock, the timing deviation between the first type of signal and the second type of signal being a first time difference, and both the first downlink timing and the first uplink timing being related to the first time difference.

[0047] In one possible implementation, the interface module is further configured to receive first information from the wireless access network node, the first information indicating the first time difference.

[0048] In one possible implementation, the first downlink timing is determined based on a second downlink timing and the first time difference, wherein the second downlink timing is the downlink timing of the signal of the first type.

[0049] In one possible implementation, the first downlink timing is also related to the propagation delay between the terminal and the radio access network node.

[0050] In one possible implementation, the first downlink timing is determined based on the timing of the first clock, the first time difference, and the propagation delay.

[0051] In one possible implementation, the first uplink timing is also related to the propagation delay between the terminal and the radio access network node.

[0052] In one possible implementation, the first uplink timing is determined based on the first downlink timing and the propagation delay; or, the first uplink timing is determined based on the timing of the first clock, the first time difference, and the propagation delay.

[0053] In one possible implementation, the first uplink timing is determined based on a second uplink timing and the first time difference, wherein the second uplink timing is the uplink timing of the signal of the first type.

[0054] In one possible implementation, the interface module is further configured to receive second information from the radio access network node, the second information indicating a timing advance that is related to the propagation delay.

[0055] In one possible implementation, the second information further indicates the effective time of the timing advance, which is used to determine the determination method of the first downlink timing or the determination method of the first uplink timing.

[0056] In one possible implementation, the first time difference can be positive or negative.

[0057] In one possible implementation, the power consumption of the first type of signal is lower than that of the second type of signal.

[0058] In one possible implementation, the first clock is the Global Navigation Satellite System clock, and the second clock is the clock of the radio access network node.

[0059] Fourthly, a communication device is provided for implementing the method described in the second aspect above. The communication device can be a wireless access network node as described in the second aspect. The communication device includes modules, units, or means corresponding to the method described in the second aspect, which can be implemented in hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the functions described above.

[0060] In one possible implementation, the communication device may include a processing module and an interface module. The processing module can be used to implement the processing functions in any of the above aspects and their possible implementations. The processing module may be, for example, a processor. The interface module, also called an interface unit, is used to implement the sending and / or receiving functions in any of the above aspects and their possible implementations. The interface module may consist of an interface circuit, a transceiver, a transceiver unit, or a communication interface.

[0061] In one possible implementation, the interface module is configured to send a first signal to the terminal, the first signal being a first type of signal synchronized with a first clock; the interface module is also configured to send a second signal to the terminal, or receive a third signal from the terminal; wherein the second signal and the third signal are second type of signals synchronized with a second clock, the timing deviation between the first type of signal and the second type of signal is a first time difference, the first time difference being related to a first downlink timing and a first uplink timing, the first downlink timing being used to determine the time when the terminal receives the second signal, and the first uplink timing being used to determine the time when the terminal sends the third signal.

[0062] In one possible implementation, the interface module is also used to send first information to the terminal, the first information being used to indicate the first time difference.

[0063] In one possible implementation, the first downlink timing is determined based on a second downlink timing and the first time difference, wherein the second downlink timing is the downlink timing of the signal of the first type.

[0064] In one possible implementation, the first downlink timing is also related to the propagation delay between the terminal and the radio access network node.

[0065] In one possible implementation, the first downlink timing is determined based on the timing of the first clock, the first time difference, and the propagation delay.

[0066] In one possible implementation, the first uplink timing is also related to the propagation delay between the terminal and the radio access network node.

[0067] In one possible implementation, the first uplink timing is determined based on the first downlink timing and the propagation delay; or, the first uplink timing is determined based on the timing of the first clock, the first time difference, and the propagation delay.

[0068] In one possible implementation, the first uplink timing is determined based on a second uplink timing and the first time difference, wherein the second uplink timing is the uplink timing of the signal of the first type.

[0069] In one possible implementation, the interface module is further configured to send a second message to the terminal, the second message indicating a timing advance that is related to the propagation delay.

[0070] In one possible implementation, the second information further indicates the effective time of the timing advance, which is used to determine the determination method of the first downlink timing or the determination method of the first uplink timing.

[0071] In one possible implementation, the first time difference can be positive or negative.

[0072] In one possible implementation, the power consumption of the first type of signal is lower than that of the second type of signal.

[0073] In one possible implementation, the first clock is the Global Navigation Satellite System clock, and the second clock is the clock of the radio access network node.

[0074] Fifthly, a communication device is provided, comprising: a processor; configured to cause the communication device to perform the method described in any of the preceding aspects by executing a computer program (or computer-executable instructions) stored in a memory, and / or by means of logic circuitry. The communication device may be a terminal as described in the first aspect; or, the communication device may be a wireless access network node as described in the second aspect. Optionally, the number of processors may be one or more.

[0075] In one possible implementation, the communication device also includes a memory.

[0076] In one possible implementation, the processor and memory are integrated together; or, the memory is independent of the processor.

[0077] In one possible implementation, the communication device further includes a communication interface for communicating with other devices, such as transmitting or receiving data and / or signals. Exemplarily, the communication interface may be a transceiver, circuit, bus, module, or other type of communication interface.

[0078] In one possible implementation, the communication device is a chip or a chip system. Optionally, when the communication device is a chip system, it can be composed of chips or may include chips and other discrete components.

[0079] A sixth aspect provides a communication device, comprising: a processor and an interface circuit; the interface circuit being configured to receive a computer program or instructions and transmit them to the processor; the processor being configured to execute the computer program or instructions to cause the communication device to perform the method described in any of the preceding aspects. The communication device may be a terminal as described in the first aspect; or, the communication device may be a wireless access network node as described in the second aspect. Optionally, the number of processors may be one or more.

[0080] In one possible implementation, the communication device is a chip or a chip system. Optionally, when the communication device is a chip system, it can be composed of chips or may include chips and other discrete components.

[0081] A seventh aspect provides a chip or chip system, comprising: a processor; and a means for causing the chip or chip system to perform the methods described in any of the preceding aspects by executing a computer program (or computer-executable instructions) stored in a memory, and / or by means of logic circuitry. The chip or chip system may be deployed in a terminal as described in the first aspect; or, the chip or chip system may be deployed in a wireless access network node as described in the second aspect.

[0082] Eighthly, a computer-readable storage medium is provided that stores instructions which, when executed on a computer, cause the computer to perform the methods described in any of the preceding aspects.

[0083] Ninthly, a computer program product containing instructions is provided, which, when run on a computer, enables the computer to perform the methods described in any of the preceding aspects.

[0084] In a tenth aspect, a communication system is provided, comprising a terminal for performing the method described in the first aspect and a wireless access network node for performing the method described in the second aspect.

[0085] The technical effects of any possible implementation of aspects two through ten can be found in the first aspect or the technical effects of different possible implementations of aspects one above, and will not be repeated here.

[0086] Understandably, provided that the solutions do not contradict each other, the solutions in the above aspects can be combined. Attached Figure Description

[0087] Figure 1 is a schematic diagram of the communication system architecture provided in this application;

[0088] Figure 2A is a schematic diagram of communication between the terminal provided in this application and the radio access network (RAN) node via a first type of signal and a second type of signal;

[0089] Figure 2B is a schematic diagram of the timing deviation between the first clock and the second clock provided in this application;

[0090] Figure 3 is a schematic diagram of the hardware structure of the communication device provided in this application;

[0091] Figure 4 is a flowchart illustrating the synchronization method provided in this application.

[0092] Figure 5A is a schematic diagram of the first downlink timing provided in this application;

[0093] Figure 5B is a schematic diagram of the first downlink timing provided in this application;

[0094] Figure 5C is a schematic diagram of the first downlink timing provided in this application;

[0095] Figure 5D is a schematic diagram of the first downlink timing provided in this application;

[0096] Figure 6A is a schematic diagram of the first uplink timing provided in this application;

[0097] Figure 6B is a schematic diagram of the first uplink timing provided in this application;

[0098] Figure 6C is a schematic diagram of the first uplink timing provided in this application;

[0099] Figure 6D is a schematic diagram of the first uplink timing provided in this application;

[0100] Figure 7 is a flowchart of the synchronization method provided in this application (II).

[0101] Figure 8 is a schematic diagram of the communication device provided in this application. Detailed Implementation

[0102] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0103] The method provided in this application can be used in various communication systems. For example, the communication system can be a Universal Mobile Telecommunications System (UMTS) system, a Long Term Evolution (LTE) system, a 5th generation (5G) communication system, a Wireless Fidelity (WiFi) system, a 3rd Generation Partnership Project (3GPP) related communication system, a communication system evolving after 5G (such as a 6th generation (6G) communication system), or a system integrating multiple systems, etc., without limitation. Among them, 5G can also be referred to as New Radio (NR). The method provided in this application is described below using the communication system 1000 shown in Figure 1 as an example. Figure 1 is only a schematic diagram and does not constitute a limitation on the applicable scenarios of the technical solution provided in this application.

[0104] Figure 1 shows a schematic diagram of the architecture of the communication system 1000 provided in this application. In Figure 1, the communication system 1000 includes a RAN 100. Optionally, the communication system 1000 may also include at least one of a core network (CN) 200 or an Internet 300. The RAN 100 includes at least one RAN node (as shown in Figure 1, 110a and 110b, collectively referred to as 110) and at least one terminal (as shown in Figure 1, 120a-120j, collectively referred to as 120). The RAN 100 may also include other RAN nodes, such as wireless relay devices and / or wireless backhaul devices (not shown in Figure 1). The terminal 120 is wirelessly connected to the RAN node 110. The RAN node 110 is wirelessly or wiredly connected to the core network 200. The core network equipment in the core network 200 and the RAN node 110 in the RAN 100 can be different physical devices, or they can be the same physical device integrating core network logical functions and wireless access network logical functions.

[0105] RAN 100 can be a 3GPP-related cellular system, such as a 4G or 5G mobile communication system, or a future-oriented evolution system (such as a 6G mobile communication system). RAN 100 can also be an open access network (open RAN, O-RAN, or ORAN), a cloud radio access network (CRAN), or a WiFi system. RAN 100 can also be a communication system that integrates two or more of the above systems.

[0106] RAN node 110, sometimes also referred to as access network equipment, RAN entity, or access node, constitutes part of the communication system and is used to help terminals achieve wireless access. Multiple RAN nodes 110 in the communication system 1000 can be of the same type or different types.

[0107] In one possible scenario, a RAN node can be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB), a next-generation base station in a 6G mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system. A RAN node can be a macro base station (as shown in Figure 1, 110a), a micro base station or indoor station (as shown in Figure 1, 110b), a relay node or donor node, or a radio controller in a CRAN scenario. Optionally, a RAN node can also be a server, wearable device, vehicle, or in-vehicle equipment. For example, the access network equipment in vehicle-to-everything (V2X) technology can be a roadside unit (RSU). In some scenarios, the roles of RAN node 110 and terminal 120 are relative. For example, a helicopter or drone, typically configured as a terminal, can also be configured as a mobile base station, and devices accessing the RAN via the helicopter or drone are configured as terminals.

[0108] In another possible scenario, multiple RAN nodes collaborate to assist the terminal in achieving wireless access, with different RAN nodes each implementing some of the base station's functions. Specifically, RAN nodes can be central units (CUs), distributed units (DUs), or radio units (RUs), etc. For example, a CU can perform the functions of the base station's radio resource control (RRC) layer and packet data convergence protocol (PDCP) layer. A CU can also perform the functions of the service data adaptation protocol (SDAP) layer. A DU can perform the functions of the base station's radio link control (RLC) layer and medium access control (MAC) layer. A DU can also perform some or all of the physical layer functions. An RU can be used to implement radio frequency signal transmission and reception. CUs and DUs can be set up separately or included in the same network element, such as a baseband unit (BBU). The RU can be included in radio frequency equipment or radio frequency units, such as in a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH). Furthermore, the CU can be further divided into the CU-control plane (CP) and the CU-user plane (UP).

[0109] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, in an ORAN system, CU can also be called O-CU (open CU), DU can also be called O-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CU-UP, and RU can also be called O-RU. For ease of description, this application uses CU, CU-CP, CU-UP, DU, and RU as examples. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software and hardware modules.

[0110] The terminal in this application, such as terminal 120, is a device with wireless transceiver capabilities. The terminal can be deployed on land, including indoors, outdoors, handheld, or vehicle-mounted; it can also be deployed on water (such as on ships); and it can be deployed in the air (such as on airplanes, balloons, and satellites). The terminal can also be referred to as a terminal device, which can be user equipment (UE), mobile station (MS), mobile terminal (MT), or a device used to provide voice or data connectivity to users. The UE includes handheld devices with wireless communication capabilities, vehicle-mounted devices (e.g., cars, bicycles, electric vehicles, airplanes, ships, trains, high-speed trains, etc.), wearable devices (e.g., smartwatches, smart bracelets, pedometers, etc.), or computing devices. For example, the UE can be a mobile phone, tablet computer, laptop computer, PDA, mobile internet device (MID), satellite terminal, or computer with wireless transceiver capabilities. UE can also be a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless modem, a point-of-sale (POS) machine, customer-premises equipment (CPE), a smart robot, a robotic arm, workshop equipment, smart home devices (e.g., refrigerators, televisions, air conditioners, electricity meters, etc.), a wireless terminal in industrial control, a wireless terminal in autonomous driving, a wireless terminal in telemedicine, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in intelligent transportation, a wireless terminal in a smart city, a wireless terminal in a smart home, an in-vehicle terminal, a roadside unit (RSU) with terminal functionality, or a flying device (e.g., a smart robot, a hot air balloon, a drone, an airplane), etc. A terminal can also be other devices with terminal functionality; for example, a terminal can be a device that acts as a terminal in device-to-device (D2D) communication.

[0111] By way of example and not limitation, in this application, the terminal can be a wearable device. Wearable devices, also known as wearable smart devices, are a general term for devices that utilize wearable technology to intelligently design and develop everyday wearables, such as glasses, gloves, watches, clothing, and shoes. Wearable devices are portable devices that are worn directly on the body or integrated into a user's clothing or accessories. For example, wearable devices are not merely hardware devices, but also devices that achieve powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include devices that are feature-rich, large in size, and can achieve complete or partial functions without relying on a smartphone, such as smartwatches or smart glasses, as well as devices that focus on only one type of application function and need to be used in conjunction with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0112] In this application, the terminal can be a terminal in an Internet of Things (IoT) system. IoT is an important component of future information technology development, and its main technical feature is connecting objects to networks through communication technologies, thereby realizing an intelligent network of human-machine interconnection and machine-to-machine interconnection. The terminal in this application can be a terminal in machine-type communication (MTC).

[0113] The terminal in this application can be an on-board module, on-board component, on-board chip, on-board unit (OBU), or telematics box (T-BOX) built into a vehicle as one or more components or units. The vehicle can implement the methods of this application through the built-in on-board module, on-board component, on-board chip, on-board unit, or T-BOX. The terminal can also be a complete vehicle device. Therefore, this application can be applied to vehicle networking, such as vehicle-to-everything (V2X), long-term evolution vehicle (LTE-V), and vehicle-to-vehicle (V2V).

[0114] In one possible scenario, the terminal connects to a single RAN node, and both the RAN node to which the terminal connects and the core network to which the RAN node connects use the same network standard. For example, in Figure 1, terminal 120i is connected to RAN node 110a, and RAN node 110a is connected to core network 200. Here, RAN node 110a is a 5G base station, and core network 200 is a 5G core; alternatively, RAN node 110a can be a 6G base station, and core network 200 can be a 6G core.

[0115] In another possible scenario, the terminal connects to multiple RAN nodes, which can be of the same or different standards. Taking dual connectivity (DC) between terminal 120f and RAN nodes 110b and 110a as an example, RAN node 110b is a 5G base station, RAN node 110a is a 6G base station, and core network 200 is a 5G core. RAN node 110b can act as the primary station, and RAN node 110a as the secondary station. Alternatively, RAN node 110b can be a 5G base station, RAN node 110a can be a 6G base station, and core network 200 is a 6G core. RAN node 110a can act as the primary station, and RAN node 110b as the secondary station. Or, both RAN nodes 110b and 110a can be 6G base stations, and core network 200 is a 6G core. One of RAN nodes 110b and 110a can act as the primary station, and the other as the secondary station.

[0116] In this application, the terminal and the RAN node can communicate via a first type of signal and a second type of signal, respectively. The first type of signal and the second type of signal have different waveforms. For example, the first type of signal is a chirp-based signal or an ON-OFF key (OOK) signal. The second type of signal is a signal based on orthogonal frequency division multiplexing (OFDM) or a signal based on discrete fourier transform-spread-OFDM (DFT-S-OFDM), etc.

[0117] To reduce terminal power consumption, the power consumption of Type I signals can be lower than that of Type II signals. In this case, Type I signals can also be referred to as low-power signals, wake-up signals, low-power wake-up signals (LP-WUS), low-power radio (LR) signals, low-power wake-up receiver (LP-WUR) signals, or low-power receiver (LPR) signals, etc. Type II signals can also be referred to as normal signals or main radio (MR) signals, etc. For ease of description, Type I signals will be referred to as Class I signals, and Type II signals as Class II signals.

[0118] Figure 2A illustrates the communication process between the terminal and the RAN node via Type I and Type II signals. After entering an idle state (e.g., Radio Resource Control idle (RRC-idle)) or a connectionless state (e.g., Radio Resource Control inactive (RRC-inactive)), the terminal can detect Type I signals sent by the RAN node. If the detected Type I signal does not carry terminal-related information, such as the terminal's identifier or the identifier of the terminal's group, the terminal continues to detect Type I signals. If the detected Type I signal carries terminal-related information, such as the terminal's identifier, the terminal can use the method provided in this application to determine the uplink timing and / or downlink timing of the Type II signal, and then communicate with the RAN node via the Type II signal. If the Type I signal carries the identifier of the terminal's group, the terminal can detect paging messages sent by the RAN node to determine whether the RAN node is paging it. If the terminal determines that the RAN node is paging it, it can use the method provided in this application to determine the uplink timing of the Type II signal and / or the downlink timing of the Type II signal, and then communicate with the RAN node through the Type II signal.

[0119] Figure 2A illustrates the process of a RAN node sending a Type I signal to a terminal. In practical applications, the terminal can also send Type I signals to the RAN node. For example, when a terminal in an idle or disconnected state needs to send data to the RAN node, it sends a Type I signal. Upon receiving the Type I signal, the RAN node can determine that the terminal needs to transmit uplink data. Subsequently, the terminal can use the method provided in this application to determine the uplink timing and / or downlink timing of the Type II signal, and then communicate with the RAN node through the Type II signal.

[0120] Understandably, in the above example, Type I signals can be signals used by the terminal to communicate with the RAN node when it is in an idle or disconnected state. Type II signals can be signals used by the terminal to communicate with the RAN node when it is in a connected state (such as a radio resource control connected (RRC-connected) state).

[0121] In this application, Class I signals and Class II signals may have different clock synchronizations. For example, Class I signals may be synchronized with a first clock, and Class II signals may be synchronized with a second clock. Synchronization of Class I signals with the first clock can be understood as Class I signals being timed / counted based on the first clock, and synchronization of Class II signals with the second clock can be understood as Class II signals being timed / counted based on the second clock. The first clock and the second clock are different. For example, the first clock may be a non-terrestrial network clock, such as a Global Navigation Satellite System (GNSS) clock. The second clock may be a terrestrial network clock, such as the clock of a RAN node.

[0122] In this application, there may be a timing deviation or an absolute timing deviation (such as the first time difference in the embodiments below) between the first clock and the second clock. For example, for the same time unit, if the first clock is used, the starting time of the time unit is t1; if the second clock is used, the starting time of the time unit is t2. Since t1 and t2 are different, the timing deviation can be positive or negative. Of course, in specific applications, the timing deviation can also be equal to 0, without limitation. It is understood that the time unit in this application is a segment of resources in the time domain. For example, a time unit includes at least one symbol, at least one slot, at least one subframe, or at least one radio frame, etc. It is understood that the unit of the time unit can also be a time unit, such as n milliseconds (ms), n microseconds, or n nanoseconds, where n is a positive number. The starting time of the above-mentioned time unit can also be replaced by the ending time of the time unit.

[0123] For example, taking wireless frame 201 with index 0 as shown in Figure 2B, if the start time of wireless frame 201 is T1 and the end time is T2 for the first clock, and the start time of wireless frame 201 is T3 and the end time is T4 for the second clock, then the timing deviation between the first clock and the second clock is equal to the difference between T3 and T1, or the difference between T4 and T2. For example, the timing deviation between the first clock and the second clock is s as shown in Figure 2B.

[0124] It is understandable that, since Class I signals are synchronized with the first clock and Class II signals are synchronized with the second clock, the timing deviation between the first clock and the second clock can be understood as the timing deviation between Class I signals and Class II signals.

[0125] In this application, the RAN node can simultaneously transmit and receive Type I signals, and simultaneously transmit and receive Type II signals. For the RAN node, Type I and Type II signals can be transmitted / received through the same transceiver or through different transceivers, without restriction. The terminal can simultaneously transmit and receive Type II signals. Furthermore, the terminal can also have the ability to receive Type I signals but not transmit them, or the terminal can simultaneously transmit and receive Type I signals. For the terminal, Type I and Type II signals can be transmitted / received through the same transceiver or through different transceivers, without restriction.

[0126] It is understood that the communication system 1000 shown in Figure 1 is for illustrative purposes only and is not intended to limit the technical solutions of this application. Those skilled in the art should understand that in specific implementations, the communication system 1000 may also include other devices, and the number of RAN nodes and terminals may be determined according to specific needs without limitation.

[0127] Optionally, each network element or device (such as a RAN node or terminal) in Figure 1 of this application may also be referred to as a communication device, which may be a general-purpose device or a special-purpose device. This application does not make any specific limitation on this.

[0128] Optionally, the functions of each network element or device (e.g., RAN node or terminal) in Figure 1 of this application can be implemented by one device, multiple devices working together, or one or more functional modules within a single device. This application does not impose specific limitations on these functions. It is understood that the aforementioned functions can be network elements in hardware devices, software functions running on dedicated hardware, a combination of hardware and software, or virtualization functions instantiated on a platform (e.g., a cloud platform).

[0129] In specific implementations, optionally, each network element or device (e.g., RAN node or terminal) in Figure 1 of this application can adopt the composition structure shown in Figure 3, or include the components shown in Figure 3. Figure 3 shows a schematic diagram of the hardware structure of a communication device applicable to this application. It is understood that the communication device 30 includes means of necessary forms such as modules, units, elements, circuits, or interfaces, to be appropriately configured together to execute the solution provided in this application. For example, the communication device 30 includes one or more processors 301 for implementing the method provided in this application.

[0130] Processor 301 can be a general-purpose processor or a dedicated processor. For example, processor 301 can be a baseband processor or a central processing unit (CPU). The baseband processor can be used to process communication protocols and communication data, while the CPU can be used to control the communication device 30 (such as a RAN node, terminal, or chip), execute software programs, and process data from the software programs. Optionally, in one design, processor 301 may include program 305 (sometimes also referred to as code or instructions), which can be run on processor 301 to cause the communication device 30 to perform the methods described in the embodiments below. In yet another possible design, communication device 30 includes circuitry (not shown in FIG3) for implementing the functions of the RAN node or terminal in the embodiments below.

[0131] Optionally, the communication device 30 may include one or more memories 303. The memory 303 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM), cache, or other type of dynamic storage device capable of storing information and instructions. It may also be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media, or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but is not limited thereto. The memory provided in this application may generally be non-volatile. Optionally, the memory 303 stores a program 307 (sometimes referred to as code or instructions), which can be run on the processor 301 to cause the communication device 30 to perform the methods described in the following method embodiments.

[0132] Optionally, data may also be stored in the processor 301 and / or the memory 303. The processor 301 and the memory 303 may be configured separately or integrated together.

[0133] Optionally, the communication device 30 may also include a transceiver 302 and / or an antenna 304. The transceiver 302 can realize the transmission and reception functions of the communication device 30 through the antenna 304. For example, the transceiver 302 can transmit / receive Class I signals and Class II signals through the antenna 304.

[0134] Optionally, the communication device 30 may also include a transceiver 309 and / or an antenna 310. The transceiver 309 can perform the transmission and reception functions of the communication device 30 through the antenna 310. When the communication device 30 includes both transceivers 302 and 309, one transceiver can be used to transmit / receive Class I signals, and the other can be used to transmit / receive Class II signals. For example, transceiver 309 can transmit / receive Class I signals through the antenna 310; in this case, transceiver 302 is turned off to reduce power consumption. When there is a data transmission requirement, transceiver 302 is turned on to transmit / receive Class II signals through the antenna 304. In this case, transceiver 309 has lower power consumption or energy consumption compared to transceiver 302, while transceiver 302, although having higher power consumption or energy consumption, has better communication performance. In this case, transceiver 309 can be referred to as LR, LP-WUR, or LPR. Transceiver 302 can be referred to as MR.

[0135] Figure 3 shows transceiver 302 and transceiver 309 transmitting / receiving signals through different antennas. In specific applications, transceiver 302 and transceiver 309 can also transmit / receive signals through the same antenna without limitation.

[0136] In specific applications, processor 301 may sometimes be referred to as a processing unit, which controls communication device 30. Transceiver 302 / 309 may sometimes be referred to as transceiver unit, transceiver, transceiver circuit, or transceiver, etc., without limitation.

[0137] It is understood that the composition shown in Figure 3 does not constitute a limitation on the communication device. In addition to the components shown in Figure 3, the communication device may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0138] The method provided in this application will now be described with reference to the accompanying drawings. Each network element in the following embodiments may include the components shown in Figure 3, which will not be elaborated upon further.

[0139] It is understood that the methods described below in this application use RAN nodes and terminals as examples to illustrate the interaction, but this application does not limit the execution entities of the interaction. For example, the RAN node in the methods provided in the embodiments of this application can also be a chip, chip system, or processor that supports the RAN node in implementing the method, or it can be a logical node, logical module, or software that can implement all or part of the functions of the RAN node; the terminal in the methods provided below in this application can also be a chip, chip system, or processor that supports the terminal in implementing the method, or it can be a logical node, logical module, or software that can implement all or part of the functions of the electronic device.

[0140] As shown in Figure 4, a synchronization method provided in this application may include the following steps:

[0141] S401: The RAN node sends a first signal to the terminal. Correspondingly, the terminal receives the first signal from the RAN node.

[0142] Understandably, the aforementioned RAN node can be any RAN node in the communication system 1000 shown in Figure 1, and the terminal can be any terminal in the communication system 1000 shown in Figure 1 that is connected to the RAN node for communication. For example, the aforementioned RAN node is RAN node 110a in Figure 1, and the aforementioned terminal is terminal 120a in Figure 1.

[0143] In this application, the first signal is a Class I signal, which is synchronized with a first clock. Optionally, the first signal is used to wake up the terminal, for example, the first signal carries the terminal's identifier or the identifier of the group to which the terminal belongs. The descriptions of the Class I signal and the first clock can be found in the preceding text and will not be repeated here.

[0144] S402: The terminal determines at least one of a first downlink timing or a first uplink timing based on the first signal.

[0145] In this application, the first downlink timing is the downlink timing of a Class II signal, which can be used to determine the time or moment when the terminal receives a Class II signal (such as a second signal) from the RAN node. The first uplink timing is the uplink timing of a Class II signal, which can be used to determine the time or moment when the terminal sends a Class II signal (such as a third signal) to the RAN node. The Class II signal is synchronized with the second clock. The timing deviation between the first clock and the second clock is the first time difference, or in other words, the timing deviation between the Class I signal and the Class II signal is the first time difference. For a detailed description of the Class II signal, the second clock, and the first time difference, please refer to the corresponding description above; it will not be repeated here.

[0146] It should be understood that the first time difference in this application can also be replaced by a second time difference. The second time difference is the timing deviation between the second clock and the first clock, or the timing deviation between a Class II signal and a Class I signal. This application uses the first time difference as an example to describe the specific process by which the terminal determines the first uplink timing and / or the first downlink timing. It is understood that the principle by which the terminal determines the above timing based on the second time difference is similar to the principle by which the terminal determines the above timing based on the first time difference, and will not be elaborated further.

[0147] One possible design is that both the first downlink timing and the first uplink timing are related to the first time difference. Understandably, in this application, the way the terminal determines the first downlink timing differs from the way the terminal determines the first uplink timing, which will be described separately below.

[0148] 1. Method for determining the timing of the first downlink

[0149] Design 1.1: The first downlink timing is determined based on the second downlink timing and the first time difference.

[0150] In this application, the second downlink timing is the downlink timing of a Class I signal, which can be used to determine the time or moment when the terminal receives a Class I signal from the RAN node.

[0151] Understandably, due to the distance between the RAN node and the terminal, the terminal will not receive the Type I signal immediately after the RAN node sends it, but will receive it after a time delay of D. D is the propagation delay between the terminal and the RAN node. Therefore, the second downlink timing can be determined based on the timing of the first clock and D. For example, the second downlink timing is to delay the timing of the first clock by D. For example, in Figure 5A or Figure 5B, a Type I signal sent by the RAN node at time T1 can be received by the terminal at time T1+D. In summary, after the terminal determines D, it can determine the second downlink timing by combining it with the timing of the first clock.

[0152] Understandably, since the first time difference is the timing deviation between Class I and Class II signals, and the propagation delay of both Class I and Class II signals between the terminal and the RAN node is D, the terminal can directly obtain the first downlink timing based on the second downlink timing and the first time difference. For example, as shown in Figure 5A, if the first time difference is negative (i.e., the timing of the Class I signal is earlier than the timing of the Class II signal), then the first downlink timing is delayed by f compared to the second downlink timing, where f is the absolute value of the first time difference. As another example, as shown in Figure 5B, if the first time difference is positive (i.e., the timing of the Class I signal is later than the timing of the Class II signal), then the first downlink timing is advanced by f compared to the second downlink timing.

[0153] The method by which the terminal determines D is explained below.

[0154] One possible implementation is that D is determined based on the first signal.

[0155] As an example, the terminal can determine D (D equals the difference between the reception time and the transmission time of the first signal) based on the transmission time (which can be an absolute time) and reception time (which can also be an absolute time) of the first signal. The reception time of the first signal can be determined by the terminal based on a first clock. The transmission time of the first signal can be determined by the RAN node based on the first clock and indicated to the terminal. Taking the first clock as a GNSS clock as an example, the terminal can determine the absolute time of receiving the first signal based on the GNSS module deployed on it, and the RAN node can determine the absolute time of transmitting the first signal based on the GNSS module deployed on the RAN node. It should be understood that the transmission time of the first signal can be carried in the first signal or in other messages besides the first signal, such as system messages, without restriction. Optionally, the first signal can be a conventional signal, for example, the first signal is the first SSB carried on the radio frame with index 0.

[0156] As another example, the first signal may carry information about the absolute time of the agreed-upon moment, such as the absolute time corresponding to the start symbol of the first SSB. The terminal can determine D (D equals the difference between the time the terminal received the first SSB and the absolute time of the agreed-upon moment) based on this absolute time and the time when the first SSB was received. Optionally, the first signal carries a system message, which includes the aforementioned information about the absolute time of the agreed-upon moment.

[0157] Optionally, the first signal can directly indicate its transmission time or the absolute time of an agreed-upon moment through information cells. For example, the first signal can carry the information cell ReferenceTimeInfo shown in Table 1, which indicates the transmission time or the absolute time of an agreed-upon moment. Here, refDays represents days, refSeconds represents seconds, refMilliSeconds represents milliseconds, and refTenNanoSeconds represents nanoseconds. Therefore, the terminal can determine that the time indicated by the first signal is equal to: refDays*86400*1000*100000+refSeconds*1000*100000+refMilliSeconds*100000+refTenNanoSeconds. Alternatively, the first signal can indicate its transmission time or the absolute time of an agreed-upon moment by carrying a reference point and a delay. This delay is the delay between the transmission time of the first signal and the reference point, or the delay between the absolute time of the agreed-upon moment and the reference point.

[0158] Table 1

[0159] Another possible implementation is that D is determined based on instructions from the RAN node. For example, the RAN node may communicate with the terminal based on Type I signals, such as performing a random access procedure, and determine a timing advance (TA) for the terminal. This TA is related to D; for example, TA is equal to twice D. The RAN node can also indicate the TA to the terminal. For example, the RAN node may send second information to the terminal to indicate the TA. After receiving the second information, the terminal can determine D based on it. Exemplarily, the second information is a TA command, which may directly include the TA value.

[0160] Optionally, the second information may also indicate the validity period of the TA. For example, the second information may include the validity period of the TA, or the expiration time of the TA's validity period. The validity period of the TA can be used by the terminal to determine the method for determining the first downlink timing, and / or the method for determining the first uplink timing. The process of the terminal determining the method for determining the first downlink timing and the process of the terminal determining the method for determining the first uplink timing will be described after the method shown in Figure 4, and will not be repeated here.

[0161] It should be understood that the validity period of TA can also be indicated to the terminal through information other than the second information, without limitation.

[0162] Optionally, after receiving the TA's validity period indicated by the RAN node, the terminal can start a timer. The timer's duration is set to the remaining validity period of the TA, allowing the terminal to detect whether the TA has expired. For example, if the timer has not expired, the terminal determines that the TA is valid; if the timer expires, the terminal determines that the TA is invalid.

[0163] Understandably, the above TA is determined based on Class I signals, so it can also be called the TA of Class I signals.

[0164] Design 1.2: The first downlink timing is related to D. The process by which the terminal determines D can be referred to the corresponding description in Design 1.1 above, and will not be repeated here.

[0165] Understandably, due to the distance between the RAN node and the terminal, the terminal will not receive the Type II signal immediately after the RAN node sends it, but will receive it after a time interval D. Based on this principle, the first downlink timing can be determined. As mentioned earlier, Type II signals are synchronized with the second clock, so the first downlink timing can be determined based on the timing of the second clock and D. For example, the first downlink timing is the time obtained by delaying the timing of the second clock by D. For example, in Figure 5C or Figure 5D, a Type II signal sent by the RAN node at time T2 of the second clock can be received by the terminal at time T2+D.

[0166] In addition to the methods described above, the first downlink timing can also be determined based on the timing of the first clock, the first time difference, and D. For example, in some scenarios, the terminal cannot obtain the timing of the second clock (e.g., the second clock is the clock of the RAN node), but can obtain the timing of the first clock (e.g., the first clock is the GNSS clock, and the terminal can determine the GNSS timing based on the GNSS module deployed on it). In this case, the first downlink timing can be determined based on the timing of the first clock, the first time difference, and D.

[0167] For example, as shown in Figure 5C, when the first time difference is negative, the first downlink timing is delayed by (f+D) compared to the timing of the first clock, where f is the absolute value of the first time difference. As shown in Figure 5D, when the first time difference is positive, the first downlink timing is advanced by (fD) compared to the timing of the first clock.

[0168] 2. Method for determining the first uplink timing

[0169] Design 2.1: The first uplink timing is determined based on the second uplink timing and the first time difference.

[0170] In this application, the second uplink timing is the uplink timing of a Class I signal, which can be used to determine the time or moment when the terminal sends a Class I signal to the RAN node.

[0171] Understandably, due to the distance between the RAN node and the terminal, for the Class I signal sent by the terminal to reach the RAN node at time T3, the terminal needs to send the Class I signal D earlier than time T3. Therefore, the second uplink timing can be determined based on the timing of the first clock and D. For example, the second uplink timing is to advance the timing of the first clock by D. For example, in Figure 6A or Figure 6B, if the terminal sends a Class I signal at time T4, the RAN node can receive it at time T3. Here, T4 + D = T3. If the second downlink timing is used as the timing reference, since the second downlink timing delays the timing of the first clock by D, the second uplink timing is to advance the second downlink timing by (2 × D). Here, 2 × D means 2 multiplied by D. The process by which the terminal determines D can be referred to the corresponding description in Design 1.1 above, and will not be repeated here.

[0172] Understandably, since the first time difference is the timing deviation between Class I and Class II signals, and the propagation delay of both Class I and Class II signals between the terminal and the RAN node is D, the terminal can directly obtain the first uplink timing based on the second uplink timing and the first time difference. For example, as shown in Figure 6A, if the first time difference is negative (i.e., the timing of Class I signals is earlier than that of Class II signals), then the first uplink timing is delayed by f compared to the second uplink timing, where f is the absolute value of the first time difference. As another example, as shown in Figure 6B, if the first time difference is positive (i.e., the timing of Class I signals is later than that of Class II signals), then the first uplink timing is advanced by f compared to the second uplink timing.

[0173] Design 2.2: The first uplink timing is related to D. The process by which the terminal determines D can be referred to the corresponding description in Design 1.1 above, and will not be repeated here.

[0174] One possible implementation is that the first uplink timing is determined based on the first downlink timing and D. It is understandable that the relationship between the first uplink timing and the first downlink timing is similar to the relationship between the second uplink timing and the second downlink timing; therefore, the first uplink timing is achieved by advancing the first downlink timing by (2×D).

[0175] Another possible implementation is that the first uplink timing is determined based on the timing of the first clock, the first time difference, and D. For example, as shown in Figure 6C, when the first time difference is negative, the first uplink timing advances the timing of the second clock by D. The timing deviation between the timing of the first clock and the timing of the second clock is the first time difference, so the first uplink timing is delayed by (fD) compared to the timing of the first clock, where f is the absolute value of the first time difference. As shown in Figure 6D, when the first time difference is positive, the first uplink timing advances the timing of the second clock by D. The timing deviation between the timing of the first clock and the timing of the second clock is the first time difference, so the first uplink timing is advanced by (f+D) compared to the timing of the first clock. Of course, if the terminal can determine the timing of the second clock, the first uplink timing can be determined based on the timing of the second clock and D.

[0176] S403: RAN nodes and terminals communicate via Class II signals.

[0177] One possible implementation involves the RAN node sending a second signal to the terminal. Correspondingly, the terminal receives the second signal from the RAN node based on a first downlink timing. For example, the terminal can determine the time to receive the second signal based on the first downlink timing and begin receiving or demodulating the second signal from that time.

[0178] One possible implementation is that the terminal sends a third signal to the RAN node based on a first uplink timing. For example, the terminal can determine the time to send the third signal based on the first uplink timing and send the third signal to the RAN node at that time. Accordingly, the RAN node receives the third signal from the terminal.

[0179] Based on the method shown in Figure 4, the terminal can determine the first uplink timing and / or the first downlink timing. Understandably, if the terminal determines the first downlink timing, it can directly receive Type II signals from the RAN node according to the first downlink timing without needing to receive SSBs, or the terminal can receive SSBs to obtain system configuration but does not need to perform downlink synchronization based on the SSBs. In related technologies, the terminal typically requires 3 to 6 SSBs to complete downlink synchronization, taking approximately 50ms to 110ms. However, with the method provided in this application, the terminal does not need to perform downlink synchronization via SSBs, thus effectively reducing downlink synchronization latency. If the terminal determines the first uplink timing, it can directly send Type II signals to the RAN node according to the first uplink timing without initiating random access for uplink synchronization. In related technologies, the random access process requires four interactions between the terminal and the RAN node (e.g., a 4-step random access process; even a 2-step random access process requires at least two interactions between the terminal and the RAN node). However, with the method provided in this application, the terminal does not need to perform uplink synchronization via random access, effectively reducing uplink synchronization latency. In summary, the method shown in Figure 4 can shorten the time for the terminal to perform uplink and / or downlink synchronization, thereby reducing the latency of the RAN node paging the terminal and improving the user experience.

[0180] Optionally, in one possible implementation of the method shown in Figure 4, the RAN node can indicate a first time difference to the terminal so that the terminal can determine a first uplink timing and / or a first downlink timing based on the first time difference. Specifically, as shown in Figure 7, the method shown in Figure 4 may further include the following steps:

[0181] S400: The RAN node sends the first information to the terminal. Correspondingly, the terminal receives the first information from the RAN node.

[0182] In this application, the first information may indicate a first time difference. This application does not limit the unit of the first time difference; for example, the unit of the first time difference may be microsecond, nanosecond, or millisecond.

[0183] As an example, the RAN node directly indicates the first time difference. For instance, the first information includes the first time difference. Or, for another example, the first information includes the absolute value of the first time difference, and also indicates whether the first time difference is positive or negative. For instance, the first information includes the absolute value of the first time difference and a 1-bit indication. If the value of this 1-bit indication is "0", it indicates that the first time difference is negative; if the value of this 1-bit indication is "1", it indicates that the first time difference is positive, and vice versa.

[0184] Optionally, to reduce signaling overhead, the first time difference can be an integer. Furthermore, the first time difference is also related to the subcarrier spacing of Class I (or Class II) signals. For example, a smaller subcarrier spacing indicates a longer duration occupied by the time-domain symbol, thus resulting in a larger first time difference; a larger subcarrier spacing indicates a shorter duration occupied by the time-domain symbol, thus resulting in a smaller first time difference.

[0185] As an example, the RAN node indirectly indicates the first time difference. For instance, the first information includes the time for the RAN node to transmit a Type II signal, determined based on a second clock. The terminal can determine the actual time to receive the Type II signal based on the first clock and the time indicated by the first information to determine the first time difference. Taking the time indicated by the first information as t1 and the actual time for the terminal to receive the Type II signal as t2, then according to the second clock, the time for the terminal to receive the Type II signal is (t1+D), so the first time difference is [t2-(t1+D)].

[0186] Optionally, the initial information can be carried in a system message.

[0187] Understandably, S400 can be executed before S402 so that the terminal can determine the first uplink timing and / or the first downlink timing based on the first time difference in S402. Figure 7 shows S400 executing before S401. In specific applications, S400 can also be executed after S401 and before S402, or simultaneously with S401, without restriction.

[0188] It is understood that the actions of the terminal or RAN node in the above steps can be executed by the processor 301 in the communication device 30 shown in Figure 3, which calls the application code stored in the memory 303. This application does not impose any restrictions on this.

[0189] Understandably, Figure 4 provides a synchronization method that can reduce the latency of uplink synchronization and / or downlink synchronization at the terminal. However, in practical applications, the terminal can also perform uplink and / or downlink synchronization in other ways. Therefore, how the terminal determines the first uplink timing and / or the first downlink timing remains an unresolved issue.

[0190] To address the aforementioned issues, this application also provides a method in which the terminal determines the first uplink timing and / or the first downlink timing based on one or more of the following: the terminal's capabilities, whether the RAN node provides a first time difference, or whether the TA provided by the RAN node is valid. Here, the terminal's capabilities refer to the terminal's ability to transmit and receive Type I signals, or the terminal's ability to receive Type I signals but not transmit them.

[0191] First, we introduce three methods for the terminal to determine the first downlink timing and the first uplink timing. Specifically, they can be shown in Table 2. In Method 1, the terminal can determine the first downlink timing based on the synchronization signal of the Type II signal, such as the SSB. Subsequently, the terminal initiates random access via the Type II signal and receives the TA command for the Type II signal from the RAN node. Based on the TA command, the terminal can obtain the TA of the Type II signal and determine the first uplink timing based on the first downlink timing and the TA of the Type II signal. For example, the first uplink timing is achieved by advancing the first downlink timing by the TA. In Method 2, the terminal can determine the first downlink timing based on the synchronization signal of the Type II signal, such as the SSB. The terminal can also obtain the TA of the Type I signal. For example, if the terminal has the ability to send and receive Type II signals, it can determine D based on the time the RAN node sends the Type I signal and the time it receives the Type I signal, and then determine the aforementioned TA based on D. Alternatively, the terminal can initiate random access via the Type I signal and receive the TA command for the Type I signal from the RAN node to obtain the aforementioned TA. Subsequently, the terminal determines the first uplink timing based on the aforementioned TA and the first downlink timing. For example, the first uplink timing is achieved by advancing the first downlink timing by the TA. Optionally, the aforementioned TA command can also indicate the validity period of the TA. The description of the TA command can be found in the preceding description of the second information, and will not be repeated here. The specific process of Method 3 can be found in the corresponding description in the method shown in Figure 4, and will not be repeated here.

[0192] Table 2

[0193] The following examples, Scenario 1 to Scenario 4, will be used to illustrate this.

[0194] Scenario 1: RAN nodes provide the first time difference.

[0195] For scenario 1, the terminal can determine the first downlink timing and the first uplink timing using method 3 described above. Subsequently, the terminal can receive Type II signals according to the first downlink timing, and / or, the terminal can transmit Type II signals on pre-configured uplink resources according to the first uplink timing. These pre-configured uplink resources can be configured via system messages or RRC messages.

[0196] Optionally, if the terminal supports receiving Type I signals but not transmitting them, the terminal can determine D based on the first signal, and then determine the first downlink timing and the first uplink timing. If the terminal supports both transmitting and receiving Type I signals, the terminal can determine D based on the first signal or based on the second information sent by the RAN node. The process of determining D based on the first signal and the process of determining D based on the second information can be referred to the corresponding description in Design 1.1 above. It is understood that if the second information also indicates the validity period of the TA, then within the validity period of the TA, the terminal determines D based on the second information sent by the RAN node.

[0197] Scenario 2: The RAN node does not provide the first time difference, and the terminal supports sending and receiving Class I signals.

[0198] For scenario 2, the terminal can determine the first downlink timing and the first uplink timing using method 2 described above. Subsequently, the terminal can receive Type II signals according to the first downlink timing, and / or, the terminal can transmit Type II signals on pre-configured uplink resources according to the first uplink timing. These pre-configured uplink resources can be configured via system messages or RRC messages.

[0199] Understandably, if the TA command in Method 2 also indicates the validity period of the TA, then the validity period of the TA has not expired.

[0200] Scenario 3: The RAN node does not provide the first time difference. The terminal supports sending and receiving Class I signals, but the validity period of the TA indicated by the TA command has expired.

[0201] For scenario 3, the terminal can determine the first downlink timing and the first uplink timing using method 1 described above. Subsequently, the terminal can receive Type II signals according to the first downlink timing, and / or, the terminal can transmit Type II signals on pre-configured uplink resources according to the first uplink timing. These pre-configured uplink resources can be configured via system messages or RRC messages.

[0202] Scenario 4: The RAN node does not provide the first time difference. The terminal supports receiving Class I signals, but does not support sending Class I signals.

[0203] For scenario 4, the terminal can determine the first downlink timing and the first uplink timing using method 1 described above. Subsequently, the terminal can receive Type II signals according to the first downlink timing, and / or, the terminal can transmit Type II signals on pre-configured uplink resources according to the first uplink timing. These pre-configured uplink resources can be configured via system messages or RRC messages.

[0204] The various embodiments mentioned above in this application can be combined without contradiction, and no limitation is imposed.

[0205] It should be understood that the applicable scenarios of the method provided in this application are not limited to terrestrial cellular communication scenarios, but may also include non-terrestrial communication scenarios, satellite communication scenarios, high altitude platform station (HAPS) communication scenarios, V2X communication scenarios, integrated access and backhaul (IAB) communication scenarios, reconfigurable intelligent surface (RIS) communication scenarios, etc.

[0206] The above mainly describes the solution provided in this application from the perspective of interaction between various network elements. Correspondingly, this application also provides a communication device, which can be a terminal in the above method embodiments, or a device containing the above terminal, or a component usable in a terminal; or, the communication device can be a RAN node in the above method embodiments, or a device containing the above RAN node, or a component usable in a RAN node. It is understood that the above-mentioned terminal or RAN node, etc., includes hardware structures and / or software modules corresponding to the execution of each function in order to achieve the above functions. Those skilled in the art should readily recognize that, based on the unit and algorithm operations of the various examples described in conjunction with the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed by hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0207] This application can divide the terminal or RAN node into functional modules based on the above method examples. For example, each function can be divided into its own functional module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. It is understood that the module division in this application is illustrative and only represents one logical functional division; other division methods may be used in actual implementation.

[0208] For example, when functional modules are integrated, Figure 8 shows a schematic diagram of a communication device 80. The communication device 80 includes an interface module 801 and a processing module 802. The interface module 801, also called an interface unit, is used to perform transmit and receive operations; for example, it can be an interface circuit, transceiver, or communication interface. The processing module 802, also called a processing unit, is used to perform operations other than transmit and receive operations; for example, it can be a processing circuit or a processor.

[0209] In some embodiments, the communication device 80 may further include a storage module (not shown in FIG8) for storing program instructions and data.

[0210] For example, the communication device 80 is used to implement the functions of a terminal. The communication device 80 is, for example, the terminal described in the embodiment shown in FIG4 or the embodiment shown in FIG7.

[0211] Interface module 801 is used to receive a first signal from the RAN node. The first signal is a first type of signal, and this first type of signal is synchronized with a first clock. For example, interface module 801 can be used to execute S401.

[0212] Processing module 802 is configured to determine at least one of a first downlink timing or a first uplink timing based on a first signal. The first downlink timing is used to determine the time to receive a second signal from the RAN node, and the first uplink timing is used to determine the time to send a third signal to the RAN node. The second and third signals are of a second type, synchronized with a second clock. The timing deviation between the first and second type signals is a first time difference, and both the first downlink timing and the first uplink timing are related to the first time difference. For example, processing module 802 can be used to execute S402.

[0213] When used to implement the functions of a terminal, other functions that the communication device 80 can implement can be referred to the relevant descriptions of the embodiments shown in FIG4 or FIG7, which will not be elaborated further.

[0214] Alternatively, by way of example, the communication device 80 is used to implement the functions of a RAN node. The communication device 80 is, for example, the RAN node described in the embodiment shown in FIG4 or the embodiment shown in FIG7.

[0215] The interface module 801 is used to send a first signal to the terminal. This first signal is a first type of signal, and it is synchronized with a first clock. For example, the interface module 801 can be used to execute S401.

[0216] Interface module 801 is also used to send a second signal to the terminal or receive a third signal from the terminal. The second and third signals are of a second type, synchronized with a second clock. The timing deviation between the first and second type signals is a first time difference, which is related to a first downlink timing and a first uplink timing. The first downlink timing is used to determine the time when the terminal receives the second signal, and the first uplink timing is used to determine the time when the terminal sends the third signal. For example, interface module 801 can also be used to execute S403.

[0217] When used to implement the functions of a RAN node, other functions that the communication device 80 can implement can be referred to the relevant descriptions of the embodiments shown in Figure 4 or Figure 7, which will not be elaborated further.

[0218] In a simplified embodiment, those skilled in the art will recognize that the communication device 80 can take the form shown in FIG3. For example, the processor 301 in FIG3 can invoke computer execution instructions stored in memory 303 to cause the communication device 80 to perform the methods described in the above embodiments.

[0219] For example, the functions / implementation processes of the interface module 801 and processing module 802 in FIG8 can be implemented by the processor 301 in FIG3 calling computer execution instructions stored in memory 303. Alternatively, the functions / implementation processes of the processing module 802 in FIG8 can be implemented by the processor 301 in FIG3 calling computer execution instructions stored in memory 303, and the functions / implementation processes of the interface module 801 in FIG8 can be implemented by the transceiver 302 and / or transceiver 309 in FIG3.

[0220] It is understood that one or more of the above modules or units can be implemented by software, hardware, or a combination of both. When any of the above modules or units are implemented by software, the software exists as computer program instructions and is stored in memory. The processor can be used to execute the program instructions and implement the above method flow. The processor can be built into a system-on-a-chip (SoC) or ASIC, or it can be a separate semiconductor chip. In addition to the core that executes the software instructions for computation or processing, the processor may further include necessary hardware accelerators, such as field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), or logic circuits that implement dedicated logic operations.

[0221] When the above modules or units are implemented in hardware, the hardware can be any one or any combination of a CPU, microprocessor, digital signal processing (DSP) chip, microcontroller unit (MCU), artificial intelligence processor, ASIC, SoC, FPGA, PLD, application-specific digital circuit, hardware accelerator, or non-integrated discrete device, which can run the necessary software or perform the above method flow independently of software.

[0222] Optionally, this application also provides a chip system, including: at least one processor and an interface, wherein the at least one processor is coupled to a memory via the interface, and when the at least one processor executes a computer program or instructions in the memory, the method in any of the above method embodiments is executed. In one possible implementation, the chip system further includes a memory. Optionally, the chip system may be composed of chips or may include chips and other discrete devices; this application does not specifically limit this.

[0223] Optionally, this application also provides a computer-readable storage medium. All or part of the processes in the above method embodiments can be implemented by a computer program instructing related hardware. This program can be stored in the aforementioned computer-readable storage medium. When executed, the program can include the processes described in the above method embodiments. The computer-readable storage medium can be an internal storage unit of the communication device in any of the foregoing embodiments, such as the hard disk or memory of the communication device. The aforementioned computer-readable storage medium can also be an external storage device of the communication device, such as a plug-in hard disk, smart media card (SMC), secure digital (SD) card, flash card, etc., equipped on the communication device. Further, the aforementioned computer-readable storage medium can include both internal storage units and external storage devices of the communication device. The aforementioned computer-readable storage medium is used to store the aforementioned computer program and other programs and data required by the communication device. The aforementioned computer-readable storage medium can also be used to temporarily store data that has been output or will be output.

[0224] Optionally, this application also provides a computer program product. All or part of the processes in the above method embodiments can be executed by a computer program instructing related hardware. This program can be stored in the above computer program product, and when executed, it can include the processes described in the above method embodiments.

[0225] Optionally, this application also provides computer instructions. All or part of the processes in the above method embodiments can be executed by computer instructions instructing related hardware (such as a computer, processor, terminal, or RAN node). The program can be stored in the aforementioned computer-readable storage medium or the aforementioned computer program product.

[0226] Optionally, this application also provides a communication system, including: the RAN node and terminal in the above embodiments.

[0227] Through the description of the above implementation methods, technical personnel in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0228] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules or units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed. Furthermore, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms.

[0229] The units described as separate components may or may not be physically separate. A component shown as a unit can be one or more physical units; that is, it can be located in one place or distributed in multiple different locations. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0230] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0231] It is understood that the message names between various network elements or the names of various parameters in the messages in the above embodiments of this application are just examples, and other names may be used in the specific implementation. This application does not make any specific limitations on this.

[0232] It is understood that in this application, " / " can indicate that the objects before and after it are in an "or" relationship. For example, A / B can mean A or B. "And / or" can be used to describe three relationships between the related objects. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. Here, A and B can be singular or plural. Furthermore, expressions like "at least one of A, B, and C" or "at least one of A, B, or C" are generally used to indicate any of the following: A exists alone; B exists alone; C exists alone; A and B exist simultaneously; A and C exist simultaneously; B and C exist simultaneously; A, B, and C exist simultaneously. The above examples using three elements (A, B, and C) illustrate the optional entries for this item. When the expression contains more elements, its meaning can be obtained according to the aforementioned rules.

[0233] To facilitate the description of the technical solutions of this application, the terms "first" and "second" may be used to distinguish technical features with the same or similar functions. The terms "first" and "second" do not limit the number or execution order, nor do they imply that they are necessarily different. In this application, the terms "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design scheme described as "exemplary" or "for example" should not be construed as being more preferred or advantageous than other embodiments or design schemes. The use of "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner for ease of understanding.

[0234] It is understood that the term "embodiment" used throughout the specification means that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, various embodiments throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It is understood that in the various embodiments of this application, the sequence number of each process does not imply a sequential order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of this application.

[0235] In this application, "simultaneously" can be understood as at the same point in time, within a period of time, or within the same cycle.

[0236] It is understood that in this application, "when," "under the circumstances," "if," and "if" all refer to the corresponding processing that will be carried out under certain objective circumstances, and are not time-limited, nor do they require that there must be a judgment action when implemented, nor do they imply any other limitations.

[0237] It is understood that some optional features in this application can be implemented independently in certain scenarios without relying on other features, such as the current solution upon which they are based, to solve the corresponding technical problems and achieve the corresponding effects. Alternatively, they can be combined with other features as needed in certain scenarios. Correspondingly, the apparatus provided in this application can also implement these features or functions, which will not be elaborated here.

[0238] It is understood that the same step or step with the same function or technical feature in this application can be referenced and learned from each other in different embodiments.

[0239] It is understood that in this application, RAN nodes and / or terminals may perform some or all of the steps in this application. These steps are merely examples, and this application may also perform other steps or variations thereof. Furthermore, the steps may be performed in different orders as presented in this application, and it is possible that not all steps in this application need to be performed.

[0240] The above is only a specific embodiment of the present application, but the scope of protection of this application is not limited to this. Any changes or substitutions within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A synchronization method, characterized in that, The method includes: Receive a first signal from a wireless access network node, the first signal being a first type of signal, and the first type of signal being synchronized with a first clock; Determine at least one of a first downlink timing or a first uplink timing based on the first signal; Wherein, the first downlink timing is used to determine the time to receive the second signal from the radio access network node, the first uplink timing is used to determine the time to send the third signal to the radio access network node, the second signal and the third signal are second type signals, the second type signals are synchronized with the second clock, the timing deviation between the first type signals and the second type signals is the first time difference, and both the first downlink timing and the first uplink timing are related to the first time difference.

2. The method according to claim 1, characterized in that, The method further includes: Receive first information from the wireless access network node, the first information indicating the first time difference.

3. The method according to claim 1 or 2, characterized in that, The first downlink timing is determined based on the second downlink timing and the first time difference, wherein the second downlink timing is the downlink timing of the signal of the first type.

4. The method according to claim 1 or 2, characterized in that, The first downlink timing is also related to the propagation delay between the terminal and the wireless access network node.

5. The method according to claim 4, characterized in that, The first downlink timing is determined based on the timing of the first clock, the first time difference, and the propagation delay.

6. The method according to any one of claims 1-5, characterized in that, The first uplink timing is also related to the propagation delay between the terminal and the wireless access network node.

7. The method according to claim 6, characterized in that, The first uplink timing is determined based on the first downlink timing and the propagation delay; or, The first uplink timing is determined based on the timing of the first clock, the first time difference, and the propagation delay.

8. The method according to any one of claims 1-6, characterized in that, The first uplink timing is determined based on the second uplink timing and the first time difference, wherein the second uplink timing is the uplink timing of the signal of the first type.

9. The method according to any one of claims 4-7, characterized in that, The method further includes: The system receives second information from the wireless access network node, the second information indicating a timing advance, the timing advance being related to the propagation delay.

10. The method according to claim 9, characterized in that, The second information also indicates the effective time of the timing advance, which is used to determine the determination method of the first downlink timing or the determination method of the first uplink timing.

11. The method according to any one of claims 1-10, characterized in that, The first time difference can be positive or negative.

12. The method according to any one of claims 1-11, characterized in that, The power consumption of the first type of signal is lower than that of the second type of signal.

13. The method according to any one of claims 1-12, characterized in that, The first clock is the Global Navigation Satellite System clock, and the second clock is the clock of the wireless access network node.

14. A synchronization method, characterized in that, The method includes: Send a first signal to the terminal. The first signal is a first type of signal and is synchronized with a first clock. Sending a second signal to the terminal, or receiving a third signal from the terminal; wherein the second signal and the third signal are signals of a second type, the second type of signal is synchronized with a second clock, the timing deviation between the first type of signal and the second type of signal is a first time difference, the first time difference is related to a first downlink timing and a first uplink timing, the first downlink timing is used to determine the time when the terminal receives the second signal, and the first uplink timing is used to determine the time when the terminal sends the third signal.

15. The method according to claim 14, characterized in that, The method further includes: Send first information to the terminal, the first information being used to indicate the first time difference.

16. The method according to claim 14 or 15, characterized in that, The first downlink timing is determined based on the second downlink timing and the first time difference, wherein the second downlink timing is the downlink timing of the signal of the first type.

17. The method according to claim 14 or 15, characterized in that, The first downlink timing is also related to the propagation delay between the terminal and the wireless access network node.

18. The method according to claim 17, characterized in that, The first downlink timing is determined based on the timing of the first clock, the first time difference, and the propagation delay.

19. The method according to any one of claims 14-18, characterized in that, The first uplink timing is also related to the propagation delay between the terminal and the wireless access network node.

20. The method according to claim 19, characterized in that, The first uplink timing is determined based on the first downlink timing and the propagation delay; or, The first uplink timing is determined based on the timing of the first clock, the first time difference, and the propagation delay.

21. The method according to any one of claims 14-19, characterized in that, The first uplink timing is determined based on the second uplink timing and the first time difference, wherein the second uplink timing is the uplink timing of the signal of the first type.

22. The method according to any one of claims 17-20, characterized in that, The method further includes: A second message is sent to the terminal, the second message indicating a timing advance, the timing advance being related to the propagation delay.

23. The method according to claim 22, characterized in that, The second information also indicates the effective time of the timing advance, which is used to determine the determination method of the first downlink timing or the determination method of the first uplink timing.

24. The method according to any one of claims 14-23, characterized in that, The first time difference can be positive or negative.

25. The method according to any one of claims 14-24, characterized in that, The power consumption of the first type of signal is lower than that of the second type of signal.

26. The method according to any one of claims 14-25, characterized in that, The first clock is the Global Navigation Satellite System clock, and the second clock is the clock of the radio access network node.

27. A communication device, characterized in that, It includes units or modules for performing the method as described in any one of claims 1 to 13, or includes units or modules for performing the method as described in any one of claims 14 to 26.

28. A communication device, characterized in that, include: A processor coupled to a memory for storing a program or instructions which, when executed by the processor, cause the apparatus to perform the method as claimed in any one of claims 1 to 13, or the method as claimed in any one of claims 14 to 26.

29. A chip, characterized in that, include: A processor and an interface circuit, the interface circuit being configured to receive a computer program or instructions and transmit them to the processor, the processor being configured to execute the computer program or instructions, causing the chip to perform the method as described in any one of claims 1 to 13, or the method as described in any one of claims 14 to 26.

30. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program or instructions are executed, they cause the computer to perform the method as described in any one of claims 1 to 13, or the method as described in any one of claims 14 to 26.

31. A computer program product, said computer program product comprising computer program code, characterized in that, When the computer program code is run on a computer, it causes the computer to implement the method of any one of claims 1 to 13, or the method of any one of claims 14 to 26.

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