A method and apparatus for information transmission

Abstract

The application provides a method and device for information transmission. The method comprises: a first network device sending a first message to a second network device, the first message being used for requesting to switch a terminal device from a first cell to a second cell, the first cell belonging to the first network device, and the second cell belonging to the second network device; the first network device receiving a response message of the first message from the second network device, the response message comprising reference time information; and the first network device sending the reference time information to the terminal device. The embodiment of the application can help to avoid the influence of the service performance of the terminal device caused by the sending delay of the reference time in the switching process.

Description

Technical Field

[0001] This application relates to the field of communications, and more specifically, to a method and apparatus for information transmission. Background Technology

[0002] In the traditional handover (HO) procedure of mobile communication systems, mobility management of connected terminal devices is controlled by network devices. Specifically, the network device instructs the terminal device which cell to hand over to and how to perform the handover by sending a handover message. Upon receiving the handover message, the terminal device accesses the target cell based on the information contained within it. Therefore, successful transmission of the handover message is a necessary condition for a successful handover under the traditional handover mechanism.

[0003] Currently, terminal devices can only request reference time after completing the handover process and establishing a connection with the target base station. For certain services of the terminal device, if these services are still in operation during the handover process, the delay in sending the reference time will affect the performance of these services. Summary of the Invention

[0004] This application provides a method and apparatus for information transmission, which helps to avoid the impact on the service performance of terminal equipment due to the transmission delay of reference time during the handover process.

[0005] In a first aspect, an information transmission method is provided, the method comprising: a first network device sending a first message to a second network device, the first message being used to request a terminal device to switch from a first cell to a second cell, the first cell belonging to the first network device and the second cell belonging to the second network device; the first network device receiving a response message from the second network device to the first message, the response message including reference time information; and the first network device sending the reference time information to the terminal device.

[0006] In this embodiment of the application, the second network device can send reference time information to the first network device during the handover process, and the first network device can then send it to the terminal device. In this way, the terminal device can obtain the reference time information during the handover process, which helps to avoid the impact of the reference time transmission delay on the service performance of the terminal device.

[0007] In some possible implementations, if there is an interface between the first network device and the second network device, the first message is a handover request message.

[0008] In some possible implementations, if there is no interface between the first network device and the second network device, then the first network device can send the first message, which is a handover request message, to the core network device. After receiving the handover request message, the core network device can send a handover request message to the second network device.

[0009] In conjunction with the first aspect, in some implementations of the first aspect, the reference time information includes information about the reference time and information about the reference point corresponding to the reference time.

[0010] In this embodiment of the application, the reference time information sent by the second network device includes reference time information and reference point information corresponding to the reference time. This helps the terminal device determine the reference time based on the reference point, thereby helping the terminal device to accurately obtain the reference time.

[0011] In conjunction with the first aspect, in some implementations of the first aspect, the first message includes information about the type of reference time, and the reference time information is the reference time information corresponding to the type of reference time. The method further includes: the first network device receiving a second message sent by the terminal device, the second message being used to request the reference time information, and the second message including information about the type of reference time.

[0012] In this embodiment of the application, by carrying information about the type of reference time in the first message, the second network device can obtain the type of the requested reference time. The second network device can send the corresponding reference time information to the first network device according to the type of reference time, which helps to save the signaling overhead of the second network device.

[0013] In conjunction with the first aspect, in some implementations of the first aspect, the first network device sending the reference time information to the terminal device includes: the first network device sending a System Message Block (SIB) to the terminal device via unicast, the SIB including the reference time information.

[0014] In this embodiment of the application, when the first network device sends reference time information to the terminal device, it can carry the reference time information in the SIB and send it to the terminal device via unicast. This helps the terminal device to know the reference time during the handover process, thereby helping to avoid the impact of the reference time transmission delay on the service performance of the terminal device.

[0015] In conjunction with the first aspect, in certain implementations of the first aspect, the reference time information includes first time information and second time information, wherein the first network device sends the reference time information to the terminal device by: the first network device sending an SIB to the terminal device via unicast, the SIB including the first time information; and the first network device sending an RRC message to the terminal device, the RRC message including the second time information.

[0016] In conjunction with the first aspect, in some implementations of the first aspect, the RRC message is a downlink information transfer message.

[0017] In this embodiment, when the first network device sends reference time information to the terminal device, it can carry the first time information in the SIB and send it to the terminal device via unicast; and carry the second time information in the RRC message and send it to the terminal device. This helps to avoid the impact of reference time transmission delay on the service performance of the terminal device, while requiring minimal changes to the standard.

[0018] In some possible implementations, the first time information is Coordinated Universal Time (UTC) time information; the second time information is the time information of the wireless network (e.g., 5G time).

[0019] In conjunction with the first aspect, in some implementations of the first aspect, the first network device sending the reference time information to the terminal device includes: the first network device sending an SIB to the terminal device via broadcast, the SIB including the reference time information.

[0020] In this embodiment, when the first network device sends reference time information to the terminal device, it can carry the reference time information in the SIB and send it to the terminal device via broadcast. When sending the reference time information via broadcast, the reference point information does not need to be carried in the reference time information. The terminal device can implicitly know the reference point corresponding to the reference time in the reference time information, which helps to save the signaling overhead of the first network device.

[0021] In conjunction with the first aspect, in some implementations of the first aspect, the response message is a switch request confirmation message or a switch requirement confirmation message.

[0022] In this embodiment of the application, the second network device may carry reference time information in the handover request confirmation message or handover requirement confirmation message sent to the first network device, which helps to save the signaling overhead of the second network device.

[0023] In conjunction with the first aspect, in some implementations of the first aspect, the response message is a handover request confirmation message, in which the reference time information sent by the first network device to the terminal device is carried; or, the response message is a handover requirement confirmation message, in which the reference time information sent by the first network device to the terminal device is carried.

[0024] In this embodiment, the first network device can directly transmit the handover request confirmation message or handover requirement confirmation message received from the second network device to the terminal device. This saves the first network device the processing time for the handover request confirmation message or handover requirement confirmation message.

[0025] In a second aspect, a method for information transmission is provided, the method comprising: a first network device receiving a first message sent by a second network device, the first message being used to request a terminal device to switch from a first cell to a second cell, the first cell belonging to the second network device and the second cell belonging to the first network device; the first network device sending a response message to the second network device regarding the first message, the response message including reference time information.

[0026] In this embodiment of the application, the second network device can send reference time information to the first network device during the handover process, and the first network device can then send it to the terminal device. In this way, the terminal device can obtain the reference time information during the handover process, which helps to avoid the impact of the reference time transmission delay on the service performance of the terminal device.

[0027] In conjunction with the second aspect, in some implementations of the second aspect, the reference time information includes information about the reference time and information about the reference point corresponding to the reference time.

[0028] In this embodiment of the application, the reference time information sent by the second network device includes reference time information and reference point information corresponding to the reference time. This helps the terminal device determine the reference time based on the reference point, thereby helping the terminal device to accurately obtain the reference time.

[0029] In conjunction with the second aspect, in some implementations of the second aspect, the first message includes information about the type of reference time, which is the reference time information corresponding to the type of reference time.

[0030] In this embodiment of the application, by carrying information about the type of reference time in the first message, the second network device can obtain the type of the requested reference time. The second network device can send the corresponding reference time information to the first network device according to the type of reference time, which helps to save the signaling overhead of the second network device.

[0031] In conjunction with the second aspect, in some implementations of the second aspect, the response message is a switch request confirmation message or a switch requirement confirmation message.

[0032] In this embodiment of the application, the second network device may carry reference time information in the handover request confirmation message or handover requirement confirmation message sent to the first network device, which helps to save the signaling overhead of the second network device.

[0033] Thirdly, an information transmission method is provided, the method comprising: a centralized unit (CU) sending a first message to a distributed unit (DU), the first message being used to request reference time information, the reference time information including UTC time information; and the CU receiving the reference time information sent by the DU.

[0034] In this embodiment, the CU can request UTC time information from the DU, and the DU sends reference time information including UTC time information to the CU, thereby the CU sends the reference time information to the terminal device. This allows the terminal device to obtain UTC time information.

[0035] In conjunction with the third aspect, in some implementations of the third aspect, the first message also includes information about the type of reference time, which is the reference time information corresponding to the type of reference time.

[0036] In this embodiment of the application, by carrying information about the type of reference time in the first message, the DU can obtain the type of the requested reference time. The DU can then send the corresponding reference time information to the CU based on the type of reference time, which helps to save the DU's signaling overhead.

[0037] In conjunction with the third aspect, in some implementations of the third aspect, the protocol layer functions of the CU are at least one of the functions of the radio resource control protocol layer, the service data adaptation layer, and the packet data convergence protocol layer; and / or the protocol layer functions of the DU are at least one of the functions of the radio link control protocol layer, the media access control layer, and the physical layer.

[0038] In conjunction with the third aspect, in some implementations of the third aspect, the reference time information also includes the time information of the wireless network.

[0039] In conjunction with the third aspect, in some implementations of the third aspect, the first message further includes the first indication information and the second indication information, wherein the first indication information is used to instruct the DU to send the UTC time information to the CU according to a first cycle, or the first indication information is used to instruct the DU to send the UTC time information to the CU after receiving the first request message sent by the CU; the second indication information is used to instruct the DU to send the wireless network time information to the CU according to a second cycle, or the second indication information is used to instruct the DU to send the wireless network time information to the CU after receiving the second request message sent by the CU.

[0040] In this embodiment, the CU can instruct the DU to send reference time information to the CU using different reporting methods. For different types of reference times, the DU can report them in different ways. This helps to improve the flexibility of the DU when reporting reference time information.

[0041] In conjunction with the third aspect, in some implementations of the third aspect, the first message further includes the first indication information, wherein the first indication information is used to instruct the DU to send the UTC time information and the wireless network time information to the CU according to the third cycle, or the first indication information is used to instruct the DU to send the UTC time information and the wireless network time information to the CU after receiving the third request message sent by the CU.

[0042] In this embodiment of the application, the CU can instruct the DU to send reference time information to the CU in a unified reporting manner.

[0043] Fourthly, an information transmission method is provided, the method comprising: a distributed unit (DU) receiving a first message sent by a centralized unit (CU), the first message being used to request reference time information, the reference time information including UTC time information; and the DU sending the reference time information to the CU.

[0044] In this embodiment, the CU can request UTC time information from the DU, and the DU sends reference time information, including the UTC time information, to the CU, which then sends the reference time information to the terminal device. This allows the terminal device to obtain the UTC time information.

[0045] In conjunction with the fourth aspect, in some implementations of the fourth aspect, the first message also includes information about the type of reference time, which is the reference time information corresponding to the type of reference time.

[0046] In this embodiment of the application, by carrying information about the type of reference time in the first message, the DU can obtain the type of the requested reference time. The DU can then send the corresponding reference time information to the CU based on the type of reference time, which helps to save the DU's signaling overhead.

[0047] In conjunction with the fourth aspect, in some implementations of the fourth aspect, the protocol layer functions of the CU are at least one of the functions of the radio resource control protocol layer, the service data adaptation layer, and the packet data convergence protocol layer; and / or the protocol layer functions of the DU are at least one of the functions of the radio link control protocol layer, the media access control layer, and the physical layer.

[0048] Fifthly, a method for information transmission is provided, the method comprising: a terminal device sending a first message to a network device, the first message being used to request a System Message Block (SIB), the SIB including reference time information; the terminal device receiving reference time information and reference point information corresponding to the reference time sent by the network device.

[0049] In this embodiment of the application, the terminal device can obtain the reference time sent by the network device and the reference point information corresponding to the reference time when requesting SIB, which helps the terminal device to accurately obtain the reference time based on the reference point.

[0050] In conjunction with the fifth aspect, in some implementations of the fifth aspect, the first message also includes information about the type of the reference time, which is the reference time information corresponding to the type of the reference time.

[0051] In this embodiment of the application, by carrying information about the type of reference time in the first message, the network device can obtain the type of the requested reference time. The network device can then send the corresponding reference time information to the terminal device according to the type of reference time, which helps to save the signaling overhead of the network device.

[0052] In conjunction with the fifth aspect, in some implementations of the fifth aspect, the terminal device receiving information about the reference time and the reference point corresponding to the reference time sent by the network device includes: the terminal device receiving the SIB sent by the network device via unicast, the SIB including information about the reference time and information about the reference point corresponding to the reference time.

[0053] In conjunction with the fifth aspect, in some implementations of the fifth aspect, the reference time information includes first time information and second time information. The terminal device receiving the reference time and the reference point information corresponding to the reference time sent by the network device includes: the terminal device receiving the SIB sent by the network device via unicast, the SIB including the first time information and the reference point information corresponding to the first time; and the terminal device receiving the RRC message sent by the network device, the RRC message including the second time information and the reference point information corresponding to the second time.

[0054] In conjunction with the fifth aspect, in some implementations of the fifth aspect, the RRC message is a downlink information transfer message.

[0055] In this embodiment, when a network device sends reference time information to a terminal device, it can carry the first time information in the SIB and send it to the terminal device via unicast; and carry the second time information in an RRC message and send it to the terminal device. This requires minimal modification to the standard.

[0056] In some possible implementations, the first time information is Coordinated Universal Time (UTC) time information; the second time information is the time information of the wireless network (e.g., 5G time).

[0057] In conjunction with the fifth aspect, in some implementations of the fifth aspect, the terminal device receiving information about the reference time and the reference point corresponding to the reference time sent by the network device includes: the terminal device receiving the SIB sent by the network device via broadcast, the SIB including the reference time and the reference point corresponding to the reference time.

[0058] In this embodiment, when a network device sends reference time information to a terminal device, it can carry the reference time information in the SIB and send it to the terminal device via broadcast. When sending reference time information via broadcast, the reference point information does not need to be carried in the reference time information. The terminal device can implicitly know the reference point corresponding to the reference time in the reference time information, which helps to save the signaling overhead of the network device.

[0059] In a sixth aspect, an information transmission apparatus is provided, the apparatus comprising units or means for performing the steps of the first to fourth aspects above.

[0060] In a seventh aspect, an information transmission apparatus is provided, the apparatus including units or means for performing the steps of the fifth aspect above or each of the steps of the fifth aspect.

[0061] Eighthly, an information transmission apparatus is provided, the apparatus including at least one processor and a memory, the at least one processor being used to perform the methods provided in the first to fourth aspects above.

[0062] Ninthly, an information transmission apparatus is provided, the apparatus including at least one processor and a memory, the at least one processor being configured to perform the method provided in the fifth aspect above.

[0063] In a tenth aspect, a terminal device is provided, which includes the apparatus provided in the seventh aspect above, or the terminal includes the apparatus provided in the ninth aspect above.

[0064] In the eleventh aspect, a network device is provided, the terminal device including the apparatus provided in the sixth aspect above, or the terminal including the apparatus provided in the eighth aspect above.

[0065] In a twelfth aspect, a program is provided that, when executed by a processor, performs a method provided by any one of the first to fifth aspects.

[0066] In a thirteenth aspect, this application provides a program product, such as a computer-readable storage medium, including the program of the twelfth aspect. Attached Figure Description

[0067] Figure 1 This is a schematic diagram of the communication system provided in an embodiment of this application.

[0068] Figure 2 This is a schematic diagram of a network architecture provided in an embodiment of this application.

[0069] Figure 3 This is a schematic diagram of another network architecture provided in the embodiments of this application.

[0070] Figure 4 It is a schematic flowchart illustrating the process of a terminal device switching from a source network device to a target network device.

[0071] Figure 5 This is a schematic flowchart of the information transmission method provided in the embodiments of this application.

[0072] Figure 6 This is a diagram illustrating how terminal devices determine reference time.

[0073] Figure 7 This is another illustrative flowchart of the information transmission method provided in the embodiments of this application.

[0074] Figure 8 This is another illustrative flowchart of the information transmission method provided in the embodiments of this application.

[0075] Figure 9 This is a schematic block diagram of an information transmission device provided in an embodiment of this application.

[0076] Figure 10 This is another schematic block diagram of the information transmission apparatus provided in the embodiments of this application.

[0077] Figure 11 This is another schematic block diagram of the information transmission apparatus provided in the embodiments of this application.

[0078] Figure 12 This is another schematic block diagram of the information transmission apparatus provided in the embodiments of this application.

[0079] Figure 13 This is another schematic block diagram of the information transmission apparatus provided in the embodiments of this application.

[0080] Figure 1 Figure 4 is a schematic diagram of the structure of the terminal device provided in the embodiment of this application.

[0081] Figure 1 Figure 5 is a schematic diagram of the structure of the network device provided in the embodiments of this application. Detailed Implementation

[0082] The following is an explanation of some of the terms used in this application:

[0083] 1) A terminal, also known as user equipment (UE), mobile station (MS), or mobile terminal (MT), is a device that provides voice / data connectivity to a user. Examples include handheld devices with wireless connectivity or in-vehicle devices. Currently, some examples of terminals include: mobile phones, tablets, laptops, PDAs, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, wireless terminals in self-driving, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, and wireless terminals in smart homes.

[0084] 2) Network devices are devices within a wireless network, such as radio access network (RAN) nodes that connect terminals to the wireless network. Examples of RAN nodes include: gNB, transmission reception point (TRP), evolved Node B (eNB), radio network controller (RNC), Node B (NB), base station controller (BSC), base transceiver station (BTS), home base station (e.g., home-evolved Node B, or home Node B, HNB), baseband unit (BBU), and wireless fidelity (Wi-Fi) access point (AP). In a network architecture, network devices may include centralized unit (CU) nodes, distributed unit (DU) nodes, or RAN devices comprising both CU and DU nodes.

[0085] The technical solutions of this application embodiment can be applied to various communication systems, such as: Global System for Mobile Communication (GSM) system, Code Division Multiple Access (CDMA) system, Wideband Code Division Multiple Access (WCDMA) system, General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, LTE Frequency Division Duplex (FDD) system, LTE Time Division Duplex (TDD) system, Universal Mobile Telecommunication System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication system, 5G system, or New Radio (NR), etc.

[0086] Before introducing the embodiments of this application, let's first briefly introduce a few concepts related to the embodiments of this application.

[0087] Coordinated Universal Time, also known as World Standard Time or Coordinated International Time, is commonly abbreviated as UTC due to the different abbreviations in English (CUT) and French (TUC).

[0088] Figure 1 This is a schematic diagram of a communication system 100 provided in an embodiment of this application, as shown below. Figure 1 As shown, terminal 130 connects to a wireless network to access services from an external network (e.g., the Internet) or to communicate with other terminals. The wireless network includes a RAN 110 and a core network (CN) 120, where RAN 110 connects terminal 130 to the wireless network, and CN 120 manages the terminal and provides a gateway for communication with the external network.

[0089] It should be understood that the data transmission method provided in this application can be applied to wireless communication systems, for example, Figure 1 The wireless communication system 100 shown is provided. Two communication devices within the wireless communication system have a wireless communication connection, and one of these two communication devices can correspond to… Figure 1 The terminal 130 shown, for example, can be... Figure 1 Terminal 130 in the middle can also be a chip configured in terminal 130; the other communication device of the two communication devices can correspond to Figure 1 The RAN110 shown, for example, can be... Figure 1 RAN110 in the context can also be a chip configured in RAN110.

[0090] The embodiments of this application will be described in detail below using the interaction process between a terminal and a network device as an example, without loss of generality. It is understood that any terminal in a wireless communication system can communicate with one or more network devices having a wireless communication connection using the same method. This application does not limit this.

[0091] It should be understood that, for Figure 1 The communication system shown may include network devices. Figure 1 In RAN1 10, the terminal can be Figure 1 Terminal 130 in the middle.

[0092] Figure 2 This is a schematic diagram of a network architecture provided in an embodiment of this application, such as... Figure 2As shown, this network architecture includes CN (Network Address Translation) equipment and RAN (Radio Address Translation) equipment. The RAN equipment includes a baseband unit and a radio frequency (RF) unit. The baseband unit can be implemented by a single node or multiple nodes. The RF unit can be implemented independently from the baseband unit, integrated into the same physical device, or partially remote and partially integrated with the baseband unit. For example, in an LTE communication system, the eNB (eNB) acting as the RAN equipment includes a baseband unit and an RF unit. The RF unit can be deployed remotely relative to the baseband unit; for example, a remote radio unit (RRU) can be deployed remotely relative to the BBU (Baseband Unit).

[0093] Communication between RAN devices and terminals follows a specific protocol layer structure. For example, the control plane protocol layer structure may include the functions of the RRC layer, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, Media Access Control (MAC) layer, and physical layer. The user plane protocol layer structure may include the functions of the PDCP layer, RLC layer, MAC layer, and physical layer; in one implementation, a Service Data Adaptation Protocol (SDAP) layer may also be included above the PDCP layer.

[0094] The functionality of these protocol layers can be implemented by a single node or by multiple nodes; for example, in one evolutionary architecture, the RAN equipment may include centralized units (CUs) and distributed units (DUs), with multiple DUs being centrally controlled by a single CU. Figure 3 As shown, CU and DU can be divided according to the protocol layer of the wireless network. For example, the functions of the PDCP layer and above are set in the CU, and the functions of the protocol layers below PDCP, such as the RLC layer and MAC layer, are set in the DU.

[0095] This layered protocol division is merely an example; it can also be applied to other protocol layers. For instance, at the RLC layer, functions of the RLC layer and above could be placed in the CU, while functions of lower-level protocol layers could be placed in the DU. Alternatively, it could be done within a specific protocol layer, for example, placing some functions of the RLC layer and functions of higher-level protocol layers in the CU, while placing the remaining functions of the RLC layer and functions of lower-level protocol layers in the DU. Furthermore, it can be divided in other ways, such as by latency, placing functions whose processing time needs to meet latency requirements in the DU, and functions that do not need to meet that latency requirement in the CU.

[0096] Furthermore, the radio frequency device can be moved remotely and not placed in the DU, or it can be integrated into the DU, or it can be partially moved remotely and partially integrated into the DU, without any restrictions.

[0097] Please continue to refer to this. Figure 3 , Figure 3 This illustration shows a schematic diagram of another network architecture provided in an embodiment of this application, relative to... Figure 2 The architecture shown can also separate the control plane (CP) and user plane (UP) of the CU and implement them as different entities, namely the control plane CU entity (CU-CP entity) and the user plane CU entity (CU-UP entity).

[0098] In the above network architecture, signaling generated by the CU can be sent to the terminal via the DU, or signaling generated by the terminal can be received by the DU and then sent to the CU. The DU can directly encapsulate the signaling through the protocol layer and transmit it to the terminal or CU without parsing it. In the following embodiments, if such signaling transmission between the CU and the terminal is involved, the DU's sending or receiving of signaling includes this scenario. For example, RRC or PDCP layer signaling will eventually be processed into physical layer data and sent to the terminal, or it may be transformed from received physical layer data. In this architecture, the RRC or PDCP layer signaling can be considered to be sent by the DU, or by the DU and the radio frequency.

[0099] In the above embodiments, the CU is classified as a network device on the RAN side. Alternatively, the CU can also be classified as a network device on the CN side, without any limitation.

[0100] The apparatus in the following embodiments of this application, depending on the function it performs, can be located in a terminal or a network device. When the above CU-DU structure is adopted, the network device can be a CU node, or a DU node, or a network device including both CU nodes and DU nodes.

[0101] Figure 4 This refers to the process of a terminal device switching from a source network device to a target network device. In the traditional handover process of mobile communication systems, the mobility management of a terminal device in the connected state is controlled by the network device. That is, the network device instructs the terminal device which cell to switch to and how to perform the handover by sending handover messages. Figure 4 As shown, specifically, after receiving the handover message, the terminal device accesses the target cell according to the content contained in the handover message. Therefore, the successful transmission of the handover message is a necessary condition for a successful handover under the traditional handover mechanism. This handover process includes:

[0102] S101, the source network device sends the first RRC reconfiguration message to the terminal device.

[0103] Optionally, the RRC reconfiguration message includes parameters such as the measurement object, report configuration, and measurement identifier.

[0104] S102, after the terminal device performs the measurement based on the RRC reconfiguration message, it sends the measurement result to the source network device.

[0105] Terminal devices can measure a series of cells based on RRC reconfiguration messages, generate reports, and report various events to the source network devices, such as the signal strength of the current serving cell being lower than the threshold and the signal strength of the target cell being higher than the threshold.

[0106] S103, the source network device determines whether a handover to the terminal device is required.

[0107] After receiving the report from the terminal device, the source base station will decide whether the terminal device needs to switch. If it needs to switch, the source network device will send a switch request message to the target network device.

[0108] S104, if the source network device determines that the terminal device needs to be switched, the source network device sends a switch request to the target network device.

[0109] S105, the target network device decides whether to allow the terminal device to access based on its own number of connections and other factors. If allowed, it sends a handover confirmation message to the source network device.

[0110] Optionally, the handover confirmation message may include parameters such as the new cell radio network temporary identifier (C-RNTI) and the target base station's security-related algorithms.

[0111] S106, the source network device sends a second RRC reconfiguration message (or a handover command) to the terminal device.

[0112] After receiving the handover confirmation message from the target network device, the source network device sends a second RRC reconfiguration message (or handover command) to the terminal device. The second RRC reconfiguration message contains information from the handover confirmation message in S105, making the source network device layer transparent. Specifically, the handover command in the NR system includes relevant information about the target cell and the configuration parameters required for the terminal device to access the target cell. For example, the handover command includes information about the target cell (e.g., the physical cell identifier (PCI) and the corresponding frequency information (e.g., the frequency point of the target cell; specifically, the content of the frequency information in the NR system can be found in the detailed description of FrequencyInfoDL IE in protocol TS38331-f51)), the C-RNTI allocated to the terminal device by the target cell, and the random access channel (RACH) resource information required to access the target cell (e.g., dedicated RACH resources and / or public RACH resources).

[0113] S107, The terminal device initiates random access to the target network device.

[0114] In the current handover process, the terminal device disconnects from the source network device, resulting in a brief interruption when sending and receiving data before successfully accessing the target network device. For Ultra-Reliable and Low-Latency Communications (URLLC) services, if the URLLC service is still running during the handover process, the terminal device will only receive the reference time (e.g., UTC time) information from the target network device after successfully accessing it. This delay in reference time transmission can negatively impact the performance of the URLLC service. In this embodiment, by having the target network device send the reference time information earlier during the handover process, the impact of the reference time transmission delay on the performance of the URLLC service during the handover process can be reduced.

[0115] Figure 5 A schematic flowchart of an information transmission method 200 provided in an embodiment of this application is shown. Figure 5 As shown, the method 200 includes:

[0116] S201, the first network device sends a first message to the second network device, and the second network device receives the first message sent by the first network device. The first message is used to request the terminal device to switch from the first cell to the second cell, wherein the first cell belongs to the first network device and the second cell belongs to the second network device.

[0117] For example, the first network device can be Figure 4 The source network device in the middle, the second network device can be Figure 4 The target network device.

[0118] Optionally, when there is an Xn interface between the first network device and the second network device, the first network device can initiate an Xn handover. The first message can be a handover request message, which is sent directly from the first network device to the second network device.

[0119] Optionally, when there is no NG interface between the first network device and the second network device, the first network device can initiate an NG handover, and the first message can be a handover required message. The first network device can send the first message to the core network device, and the core network device can send message a to the second network device (this message a can be the same as or different from the first message).

[0120] For example, the first network device sends a handover request message to the core network device, and the core network device sends a handover request message to the second network device.

[0121] Optionally, the first message may include, but is not limited to, one or more of the following:

[0122] (1) Context information of the terminal device, including the security capabilities of the terminal device, such as the encryption and integrity protection algorithms supported by the terminal device.

[0123] (2) Reference time request information is used to instruct the second network device to send reference time information.

[0124] Optionally, the reference time information includes at least one of the following:

[0125] (2a) System Information Block (SIB) indication information, used to indicate the SIB information requested by the terminal device. For example, it can be the SIB number, such as SIB9, used to indicate that the terminal device requests the first network device to send SIB9.

[0126] (2b) Reference time type information, used to indicate the type of reference time requested by the terminal device. For example, if the reference time type is UTC time, it is used to indicate that the terminal device requests the second network device to send UTC time information; or wireless network time, it is used to indicate that the terminal device requests the base station to send wireless network time information; or UTC time and wireless network time, it is used to indicate that the terminal device requests the second network device to send UTC time and wireless network time.

[0127] Optionally, the method 200 further includes: the terminal device sending a second message to a first network device, the first network device receiving the second message sent by the terminal device, the second message including information about the type of reference time.

[0128] It should be understood that, in the embodiments of this application, the time of the wireless network can be the third generation partner program (3GPP). rd 3GPP (Generation Partnership Project) timeline, 5G mobile communication technology (5G) th The time (e.g., 5G or 6G time) of generation mobile networks are used for synchronization within the 5G or 6G system, such as synchronization between 5G or 6G network devices and terminal devices. This application does not limit this in any way.

[0129] (2c) First period information, used to indicate the transmission period of SIB information requested by the terminal device, for example in the form of radio frame or system frame, or in the form of milliseconds, minutes, slots, etc.

[0130] (2d) Second period information, used to indicate the transmission period of reference time information, for example in the form of wireless frames or system frames, or in the form of milliseconds, minutes, time slots, etc.

[0131] (2e) Transmission method information, used to indicate the transmission method of the SIB information and / or reference time information requested by the terminal device, such as unicast or broadcast. The transmission method information may be the transmission method preferred by the terminal device and is sent to the first network device as auxiliary information. The specific transmission method is subject to the decision of the first network device.

[0132] Optionally, before sending the first message to the second network device, the first network device receives the measurement results sent by the terminal device. Based on the measurement results, the first network device decides to switch itself from the first cell to the second cell.

[0133] S202, the second network device sends a response message to the first network device regarding the first message, and the first network device receives the response message from the second network device, which includes reference time information.

[0134] Optionally, when there is an Xn interface between the first network device and the second network device, the first network device can initiate an Xn handover, and the response message can be a handover request acknowledge message, which is sent directly from the second network device to the first network device.

[0135] Optionally, when there is no NG interface between the first network device and the second network device, the first network device can initiate an NG handover, and the response message can be a handover request acknowledge message. The second network device can send this response message to the core network device, which then sends message b to the first network device (this message b may be the same as or different from the response message, but both include reference time information).

[0136] For example, the second network device can send a handover request confirmation message to the core network device, and the core network device can send a handover request confirmation message (handover command) to the first network device.

[0137] Optionally, the reference time information includes the information of reference time and the information of the reference point corresponding to the reference time.

[0138] For example, the reference time includes UTC time, and the information of the UTC time includes, but is not limited to, one or more of the following:

[0139] (1) UTC time, for example, in 10ms granularity.

[0140] (2) UTC time reference point, used to indicate the reference point corresponding to the UTC time, that is, the UTC time corresponding to the reference point is the UTC time.

[0141] It should be understood that in the embodiments of this application, the reference point can be the boundary of a time unit, and the time unit can be a slot, a mini-slot, a slot after multiple slots are aggregated, a radio frame, or a system frame, etc., and this application is not limited to these.

[0142] For example, this reference point could be the start or end position of a radio frame corresponding to a certain system frame number (SFN). The terminal device can determine the reference time using this reference point. Figure 6 As shown, the terminal device can receive the reference time information within a certain time slot of SFN=x-3. The reference time information contains the reference time information and the reference point SFN=x information. Then the terminal device can determine the time corresponding to the end position of the system frame of SFN=x as the reference time.

[0143] (3) The deviation between UTC time and local time.

[0144] (4) Deviation between global positioning system (GPS) time and UTC time.

[0145] For example, the reference time includes the time of the wireless network (hereinafter, 5G time will be used as an example), and the information of this 5G time includes, but is not limited to, one or more of the following:

[0146] (1) 5G time, for example, with a granularity of 10ns.

[0147] (2) 5G time reference point, used to indicate the reference point corresponding to 5G time, that is, the 5G time corresponding to the reference point is the 5G time.

[0148] (3) Time type, used to indicate whether 5G time is local clock or GPS time.

[0149] For example, the reference time information may also include the aforementioned UTC time information and 5G time information.

[0150] S203, the first network device sends reference time information to the terminal device, and the terminal device receives the reference time information sent by the first network device.

[0151] Optionally, the first network device sends reference time information to the terminal device, including: the first network device sending a System Message Block (SIB) to the terminal device via unicast, wherein the SIB includes the reference time information.

[0152] For example, if the reference time information includes UTC time information or wireless network time information, then the SIB can include two cells, one of which can indicate the reference time and the other cell can indicate the reference point corresponding to the reference cell.

[0153] For example, if the reference time information includes UTC time information and wireless network time information (e.g., 5G time information), then the SIB can include four information cells, one of which can indicate UTC time, another information cell can indicate the reference point corresponding to UTC time; one information cell indicates the wireless network time, and another information cell can indicate the reference point corresponding to the wireless network time.

[0154] Alternatively, the SIB can include three cells: one cell indicating UTC time, another cell indicating the wireless network time, and a third cell indicating the reference point corresponding to both the UTC and wireless network times. In other words, the reference point corresponding to the wireless network time can be used as the reference point for the UTC time.

[0155] Optionally, the first network device may not carry reference point information when unicasting the SIB, but instead indicate the UTC time reference point implicitly. For example, the first network device can use the boundary of the system information (SI) window containing the UTC time SIB broadcast as the reference point for that UTC time. In this case, the first network device does not need to carry the UTC time reference point when unicasting the SIB. When the terminal device receives the SIB sent by the first network device via unicast, it can use the boundary of the SI window as the UTC time reference point, thereby helping to save signaling overhead for the network device.

[0156] Optionally, the first network device may also send a first RRC message to the terminal device via unicast, the first RRC message including reference time information.

[0157] Optionally, the first RRC message may be an RRC reconfiguration, RRC setup, RRC resume, or downlink information transfer, etc., and the specific first RRC message is not limited here.

[0158] Optionally, the reference time information includes first time information and second time information. The first network device sends the reference time information to the terminal device, including: the first network device sending an SIB to the terminal device via unicast, the SIB including the first time information; the first RRC message including the SIB, for example, using a dedicated information element (IE) to send the SIB; and the first network device sending a second RRC message to the terminal device, the second RRC message including the second time information.

[0159] Optionally, the first time information is UTC time information, and the second time information is wireless network time information.

[0160] Optionally, the second RRC message can be an RRC reconfiguration message, an RRC setup message, an RRC resume message, or a downlink information transfer (DL information transfer) message, etc. The specific second RRC message is not limited here.

[0161] In this embodiment of the application, the first network device can carry UTC time information in the first RRC message or the SIB contained in the first RRC message, and carry wireless network time information in the second RRC message. In this way, only one information element needs to be added to the SIB to indicate the reference point corresponding to the UTC time, which requires minimal modification to the standard.

[0162] Optionally, the first network device sends reference time information to the terminal device, including: the first network device broadcasting an SIB to the terminal device, the SIB including reference time information.

[0163] It should be understood that when the first network device sends an SIB to the terminal device via broadcast, the reference time information in the SIB may not include the reference point information corresponding to the reference time.

[0164] Since the first network device can send an SIB within an SI window when broadcasting it to the terminal device, the terminal device can determine the reference point corresponding to the reference time by using the SI window containing the SIB when it receives the SIB broadcast from the first network device.

[0165] Optionally, the first network device sends reference time information to the terminal device, including:

[0166] The first network device sends a handover request confirmation message to the terminal device, carrying an RRC container. This RRC container contains the reference time information; or...

[0167] The first network device sends a handover request confirmation message to the terminal device, which includes an RRC container containing the reference time information.

[0168] After receiving a handover request confirmation message or a handover requirement confirmation message from the second network device, the first network device can pass through the RRC container in the handover request confirmation message or the handover requirement confirmation message to the terminal device.

[0169] In this embodiment of the application, the terminal device can request reference time information from the network device during the handover preparation phase, so as to enable the target network device to send the reference time information in advance, thereby reducing the impact of handover delay on the transmission of reference time information during the handover process.

[0170] Figure 7 A schematic flowchart of an information transmission method 300 provided in an embodiment of this application is shown. Figure 7 As shown, the method 300 includes:

[0171] S301, the terminal device sends a third message to the network device, and the network device receives the third message sent by the terminal device. The third message is used to request a reference time.

[0172] Optionally, the third message can be an RRC message, which may be a dedicated system message request (SIB request), user equipment assistance information (UE assistance information), an RRC setup request (RRC setup request), an RRC resume request (RRC resume request), etc. In this embodiment of the application, no limitation is made on the RRC message.

[0173] Optionally, the third message may include, but is not limited to, one or more of the following:

[0174] (1) SIB indication information, used to indicate the SIB information requested by the terminal device. For example, it can be an SIB number, such as SIB9, used to indicate that the terminal device requests the network device to send SIB9.

[0175] (2) Reference time type information, used to indicate the type of reference time requested by the terminal device. For example, it could be UTC time and / or wireless network time.

[0176] One possible approach is for the terminal device to display information about the type of reference time in the third message. For example, the type of reference time could be indicated by a specific information cell in the third message. Exemplarily, the reference time type information could take one of the following values: {1, 2, 3}. Where 1 indicates that the terminal device is requesting UTC time; 2 indicates that the terminal device is requesting the wireless network time; and 3 indicates that the terminal device is requesting both UTC time and the wireless network time.

[0177] Another possible approach is for the terminal device to indicate the type of reference time via a specific element in the third message when requesting only UTC time or only the wireless network time. For example, the reference time type information could take one of the following values: {1, 2}. Here, 1 indicates that the terminal device is requesting UTC time; 2 indicates that the terminal device is requesting the wireless network time. If the terminal device does not indicate the type of reference time via a specific element in the third message, then the terminal device implicitly indicates that it is requesting both UTC time and the wireless network time.

[0178] It should be understood that the above value selection methods are merely illustrative and are not limited in any way in the embodiments of this application.

[0179] Another possible approach is for the terminal device to implicitly carry information about the type of reference time. For example, different reference time information can be requested through different third messages. For instance, if the third message is a dedicated system message request message, the terminal device implicitly indicates that it is requesting UTC time; if the third message is UE assistance information, the terminal device implicitly indicates that it is requesting the radio network time. This eliminates the need to indicate the type of reference time in a specific information element within the third message, thus saving signaling overhead on the terminal device.

[0180] (3) First period information, used to indicate the transmission period of SIB information requested by the terminal device, for example in the form of wireless frames or system frames, or in the form of milliseconds, minutes, time slots, etc.

[0181] (4) Second period information, used to indicate the transmission period of reference time information, such as in the form of wireless frames or system frames, or in the form of milliseconds, minutes, time slots, etc.

[0182] (5) Transmission method information, used to indicate the transmission method of the SIB information and / or reference time information requested by the terminal device, such as unicast or broadcast. The transmission method information may be the transmission method preferred by the terminal device, and the specific transmission method is subject to the decision of the network device.

[0183] S302, the network device sends a fourth message to the terminal device, and the terminal device receives the fourth message sent by the network device, which includes reference time information.

[0184] Optionally, the reference time information includes information about the reference time and information about the reference point corresponding to the reference time.

[0185] It should be understood that the information carried in the reference time information can be referred to in the description of reference time information in S202 above, and for the sake of brevity, it will not be repeated here.

[0186] It should also be understood that the method by which network devices send the fourth message to terminal devices can be referred to the description in S203 above, and will not be repeated here for the sake of brevity.

[0187] Existing technologies only support connected terminal devices requesting SIBs via on-demand system information (OSI) messages. Furthermore, network devices do not carry the reference point corresponding to the UTC time when unicasting the SIB. Therefore, terminal devices cannot accurately obtain the UTC time when receiving the SIB sent by the network device via unicast. In this embodiment, the network device can carry the reference point corresponding to the UTC time in the fourth message, thereby enabling the terminal device to accurately obtain the UTC time from the SIB.

[0188] It should be understood that method 300 can be combined with method 200. For example, in S201, before the first network device sends the first message to the second network device, the first network device can first receive the third message sent by the terminal device and send a fourth message to the terminal device, so that the terminal device can obtain the reference time information sent by the first network device. Subsequently, the terminal device can also obtain the reference time information sent by the second network device through S203.

[0189] Figure 8 A schematic flowchart of an information transmission method 400 provided in an embodiment of this application is shown. Figure 8 As shown, the method 400 includes:

[0190] S40 1, The centralized unit CU sends a fifth message to the distributed unit DU. The DU receives the fifth message sent by the CU. The fifth message is used to request reference time information, which includes UTC time.

[0191] Optionally, the fifth message can be a reference time information reporting control message, or any message transmitted on the CU and DU interfaces; there is no limitation here.

[0192] Optionally, the fifth message may include one or more of the following:

[0193] (1) Reporting request type, including periodic reporting or on-demand reporting. For example, if it is periodic reporting, the reporting request type includes a period value to indicate the period size of the periodic reporting, such as in radio frames. For example, if it is on-demand reporting, the DU only reports the reference time information to the CU after receiving a request from the CU.

[0194] (2) Information on the type of reference time, used to indicate the type of reference time requested by the CU. For example, the type of reference time is UTC time, used to indicate that the type of reference time sent by the CU to the DU is UTC time; for example, the type of reference time is wireless network time, used to indicate that the type of reference time sent by the CU to the DU is wireless network time; for example, the type of reference time is both UTC and wireless network time, used to indicate that the type of reference time sent by the CU to the DU is both UTC and wireless network time.

[0195] One possible approach is for the CU to display information about the type of reference time in the fifth message. For example, the type of reference time could be indicated by a specific cell in the fifth message. Exemplarily, the type of reference time information could take one of the following values: {1, 2, 3}. Where 1 indicates that the CU is requesting UTC time; 2 indicates that the CU is requesting the wireless network time; and 3 indicates that the CU is requesting both UTC time and the wireless network time.

[0196] Another possible approach is that the CU can indicate the type of reference time through a cell in the fifth message when requesting only UTC time or only wireless network time. For example, the reference time type information can take one of the following values: {1, 2}. Where 1 indicates that the CU is requesting UTC time; 2 indicates that the CU is requesting wireless network time. If the CU does not indicate the type of reference time through a cell in the fifth message, then the CU implicitly indicates that it is requesting both UTC time and wireless network time.

[0197] It should be understood that the above value selection methods are merely illustrative and are not limited in any way in the embodiments of this application.

[0198] Optionally, if the CU requests the UTC time and the wireless network time from the DU, then the fifth message includes indication information i1 and indication information i2, wherein indication information i1 is used to instruct the DU to send the UTC time information to the CU according to the first cycle, or indication information i1 is used to instruct the DU to send the UTC time information to the CU after receiving the first request message sent by the CU;

[0199] Instruction information i2 is used to instruct the DU to send wireless network time information to the CU according to the second cycle, or, instruction information i2 is used to instruct the DU to send wireless network time information to the CU after receiving the second request message sent by the CU.

[0200] Optionally, if the CU requests UTC time and wireless network time from the DU, then the fifth message includes indication information i3, which instructs the DU to send UTC time information and wireless network time information to the CU according to the third cycle. Alternatively, indication information i3 instructs the DU to send UTC time information and wireless network time information to the CU after receiving the third request message sent by the CU.

[0201] Optionally, if the reference time information requested by the CU from the DU includes UTC time information, then the fifth message may also be used to request one or more of the following information:

[0202] (1) Daylight saving time (DST): The time is advanced by one hour by the state in order to save energy. In high latitude regions such as Europe, New Zealand, and Canada, daylight saving time is implemented in the summer (usually starting from the summer solstice).

[0203] (2) Leap seconds: This indicates the time difference between GPS time and UTC time. For example, after receiving the UTC time and the leap seconds, the terminal device can derive the GPS time based on these two pieces of information.

[0204] (3) Local time offset (LTC): This indicates the difference between local time and UTC time. For example, after receiving UTC time and LTC, the terminal device can derive the local time based on these two pieces of information.

[0205] S402, the DU sends a sixth message to the CU, and the CU receives the sixth message sent by the DU. The sixth message includes reference time information.

[0206] Optionally, the sixth piece of information may be a reference time information report message, or any message transmitted on the CU and DU interfaces, without limitation here.

[0207] Optionally, if the sixth message sent by the DU to the CU includes information on UTC time and wireless network time (taking 5G time as an example), then the DU can use the same reference point to indicate both the UTC time and the wireless network time. The sixth message may include UTC time, for example, with a granularity of 10ms; 5G time, for example, with a granularity of 10ns; a reference point, used to indicate the reference point corresponding to the UTC time and the wireless network time; and a time type, used to indicate whether the 5G time is local clock or GPS time.

[0208] Optionally, if the sixth message sent by the DU to the CU includes UTC time information and wireless network time information, then...

[0209] UTC time information includes UTC time, for example, in 10ms increments; the reference point corresponding to the UTC time, used to indicate the reference point at which the UTC time is located; the deviation between the UTC time and the local time; and the deviation between the GPS time and the UTC time.

[0210] The 5G time information includes the 5G time itself, for example, in 10ns increments; the reference point corresponding to the 5G time; and the time type, which indicates whether the 5G time is a local clock or GPS time.

[0211] Currently, the DU can only report 5G time information. However, the clock types of UTC and 5G time information may differ. For example, when the clock type of 5G time is a local clock, the CU cannot deduce the UTC time from the 5G time information, and therefore cannot obtain accurate UTC time information. This embodiment adds a UTC time reporting process, enabling the CU to obtain both UTC time and / or 5G time.

[0212] It should be understood that method 400 described above can be combined with method 200 or method 300. For example, when combined with method 300, the CU can receive a fourth message from the terminal device, which requests UTC time information and 5G time information. The CU can then request the UTC time information and 5G time information from the DU. After obtaining the UTC time information and 5G time information from the DU, the CU can send the UTC time information and 5G time information to the terminal device.

[0213] For example, when combined with method 200, the CU of the target network device receives a first message sent by the source network device, which requests UTC time information and 5G time information. The CU of the target network device can then request the UTC time information and 5G time information from the DU of the target network device. After obtaining the UTC time information and 5G time information, the CU of the target network device can send the UTC time information and 5G time information back to the source network device.

[0214] The above text combined Figures 1 to 8 The method of information transmission according to the embodiments of this application is described in detail below, in conjunction with Figures 9 to 15 This application describes in detail the information transmission apparatus, terminal device, and network device according to embodiments of the present application.

[0215] This application also provides apparatus for implementing any of the above methods. For example, an apparatus is provided, including units (or means) for implementing the various steps performed by the terminal device in any of the above methods. Furthermore, another apparatus is provided, including units (or means) for implementing the various steps performed by the network device in any of the above methods.

[0216] Figure 9 A schematic block diagram of an information transmission apparatus 500 provided in an embodiment of this application is shown, such as... Figure 9 As shown, the data transmission device 500 may include a first transmitting unit 510, a first receiving unit 520, and a second transmitting unit 530.

[0217] In one possible implementation, the information transmission device 500 can be the first network device in the method 200 described above, or it can be a chip configured in the first network device.

[0218] Specifically, the first sending unit 510 is used to send a first message to the second network device, the first message being used to request the terminal device to switch from the first cell to the second cell, the first cell belonging to the device 500 and the second cell belonging to the second network device;

[0219] The first receiving unit 520 is used to receive a response message from the second network device to the first message, the response message including reference time information;

[0220] The second sending unit 530 is used to send the reference time information to the terminal device.

[0221] In this embodiment of the application, the second network device can send reference time information to the first network device during the handover process, and the first network device can then send it to the terminal device. In this way, the terminal device can obtain the reference time information during the handover process, which helps to avoid the impact of the reference time transmission delay on the service performance of the terminal device.

[0222] It should be understood that the method by which the device sends the first message to the second network device may differ from the method by which the device sends the reference time information to the terminal device. For example, the device may transmit the first message to the second network device via a wired connection; or the device may transmit the reference time information to the terminal device via an air interface.

[0223] Optionally, the reference time information includes information about the reference time and information about the reference point corresponding to the reference time.

[0224] In this embodiment of the application, the reference time information sent by the second network device includes reference time information and reference point information corresponding to the reference time. This helps the terminal device determine the reference time based on the reference point, thereby helping the terminal device to accurately obtain the reference time.

[0225] Optionally, the first message includes information about the type of reference time, wherein the reference time information is the reference time information corresponding to the type of reference time, and the device further includes:

[0226] The second receiving unit is configured to receive a second message sent by the terminal device, the second message being used to request the reference time information, and the second message including information about the type of the reference time.

[0227] In this embodiment of the application, by carrying information about the type of reference time in the first message, the second network device can obtain the type of the requested reference time. The second network device can send the corresponding reference time information to the first network device according to the type of reference time, which helps to save the signaling overhead of the second network device.

[0228] Optionally, the second transmitting unit 530 is specifically used for:

[0229] The system message block (SIB) is sent to the terminal device via unicast, and the SIB includes the reference time information.

[0230] In this embodiment of the application, when the first network device sends reference time information to the terminal device, it can carry the reference time information in the SIB and send it to the terminal device via unicast. This helps the terminal device to know the reference time during the handover process, thereby helping to avoid the impact of the reference time transmission delay on the service performance of the terminal device.

[0231] Optionally, the reference time information includes first time information and second time information, and the second sending unit 530 is specifically used for:

[0232] The SIB, which includes the first-time information, is sent to the terminal device via unicast; and

[0233] An RRC message is sent to the terminal device, the RRC message including the second time information.

[0234] In this embodiment, when the first network device sends reference time information to the terminal device, it can carry the first time information in the SIB and send it to the terminal device via unicast; and carry the second time information in the RRC message and send it to the terminal device. This helps to avoid the impact of reference time transmission delay on the service performance of the terminal device, while requiring minimal changes to the standard.

[0235] In some possible implementations, the first time information is Coordinated Universal Time (UTC) time information; the second time information is the time information of the wireless network (e.g., 5G time).

[0236] Optionally, the RRC message is a downlink information transfer message.

[0237] Optionally, the second transmitting unit 530 is specifically used for:

[0238] The SIB, which includes the reference time information, is sent to the terminal device via broadcast.

[0239] In this embodiment, when the first network device sends reference time information to the terminal device, it can carry the reference time information in the SIB and send it to the terminal device via broadcast. When sending the reference time information via broadcast, the reference point information does not need to be carried in the reference time information. The terminal device can implicitly know the reference point corresponding to the reference time in the reference time information, which helps to save the signaling overhead of the first network device.

[0240] Optionally, the response message may be a switch request confirmation message or a switch requirement confirmation message.

[0241] In this embodiment of the application, the second network device may carry reference time information in the handover request confirmation message or handover requirement confirmation message sent to the first network device, which helps to save the signaling overhead of the second network device.

[0242] Optionally, the response message is a handover request confirmation message, in which the reference time information sent by the first network device to the terminal device is carried; or, the response message is a handover requirement confirmation message, in which the reference time information sent by the first network device to the terminal device is carried.

[0243] In this embodiment, the first network device can directly transmit the handover request confirmation message or handover requirement confirmation message received from the second network device to the terminal device. This saves the first network device the processing time for the handover request confirmation message or handover requirement confirmation message.

[0244] Figure 10 A schematic block diagram of an information transmission apparatus 600 provided in an embodiment of this application is shown, such as... Figure 10 As shown, the information transmission device 600 may include a third receiving unit 610 and a third sending unit 620.

[0245] In one possible implementation, the information transmission device 600 can be the second network device in the method 200 described above, or it can be a chip configured in the second network device.

[0246] Specifically, the third receiving unit 610 is used to receive a first message sent by the second network device, the first message being used to request the terminal device to switch from the first cell to the second cell, the first cell belonging to the second network device, and the second cell belonging to the device 600;

[0247] The third sending unit 620 is used to send a response message to the first message to the second network device, the response message including reference time information.

[0248] Optionally, the reference time information includes information about the reference time and information about the reference point corresponding to the reference time.

[0249] Optionally, the first message includes information about the type of reference time, which is the reference time information corresponding to the type of reference time.

[0250] Optionally, the response message may be a switch request confirmation message or a switch requirement confirmation message.

[0251] Figure 11 A schematic block diagram of an information transmission apparatus 700 provided in an embodiment of this application is shown, such as... Figure 11 As shown, the information transmission device 700 may include a fourth transmitting unit 710 and a fourth receiving unit 720.

[0252] In one possible implementation, the information transmission device 700 can be the CU in the method 400 described above, or it can be a chip configured in the CU.

[0253] Specifically, the fourth sending unit 710 sends a first message to the distributed unit DU, the first message being used to request reference time information, the reference time information including UTC time information;

[0254] The fourth receiving unit 720 is used to receive the reference time information sent by the DU.

[0255] In this embodiment, the CU can request UTC time information from the DU, and the DU sends reference time information including UTC time information to the CU, thereby the CU sends the reference time information to the terminal device. This allows the terminal device to obtain UTC time information.

[0256] Optionally, the first message may also include information about the type of reference time, which is the reference time information corresponding to the type of reference time.

[0257] In this embodiment of the application, by carrying information about the type of reference time in the first message, the DU can obtain the type of the requested reference time. The DU can then send the corresponding reference time information to the CU based on the type of reference time, which helps to save the DU's signaling overhead.

[0258] Optionally, the protocol layer functions of the device 700 include at least one of the following: radio resource control protocol layer, service data adaptation layer, and packet data convergence protocol layer; and / or

[0259] The DU has at least one of the following protocol layer functions: radio link control protocol layer, media access control layer, and physical layer functions.

[0260] Optionally, the reference time information may also include the time information of the wireless network.

[0261] Optionally, the first message may also include the first instruction information and the second instruction information, wherein,

[0262] The first indication information is used to instruct the DU to send the UTC time information to the device 700 according to the first cycle, or the first indication information is used to instruct the DU to send the UTC time information to the device 700 after receiving the first request message sent by the device 700;

[0263] The second instruction information is used to instruct the DU to send the time information of the wireless network to the device 700 according to the second cycle, or the second instruction information is used to instruct the DU to send the time information of the wireless network to the device 700 after receiving the second request message sent by the device 700.

[0264] Optionally, the first message may also include the first instruction information, wherein,

[0265] The first indication information is used to instruct the DU to send the UTC time information and the wireless network time information to the device 700 according to the third cycle, or the first indication information is used to instruct the DU to send the UTC time information and the wireless network time information to the device 700 after receiving the third request message sent by the device 700.

[0266] Figure 12 A schematic block diagram of an information transmission apparatus 800 provided in an embodiment of this application is shown, such as... Figure 12 As shown, the information transmission device 800 may include a fifth receiving unit 810 and a fifth sending unit 820.

[0267] In one possible implementation, the information transmission device 800 can be the DU in the method 400 described above, or it can be a chip configured in the DU.

[0268] Specifically, the fifth receiving unit 810 receives a first message sent by the centralized unit CU, the first message being used to request reference time information, the reference time information including UTC time information;

[0269] The fifth transmitting unit 820 is used to transmit the reference time information to the CU.

[0270] Optionally, the first message may also include information about the type of reference time, which is the reference time information corresponding to the type of reference time.

[0271] Optionally, the CU has at least one of the following protocol layer functions: radio resource control protocol layer, service data adaptation layer, and packet data convergence protocol layer; and / or the device 800 has at least one of the following protocol layer functions: radio link control protocol layer, media access control layer, and physical layer.

[0272] Figure 13 A schematic block diagram of an information transmission apparatus 900 provided in an embodiment of this application is shown, such as... Figure 13 As shown, the information transmission device 900 may include a sixth transmitting unit 910 and a sixth receiving unit 920.

[0273] In one possible implementation, the information transmission device 900 can be the terminal device in methods 200 to 400 described above, or it can be a chip configured in the terminal device.

[0274] The sixth sending unit 910 is used to send a first message to the network device, the first message being used to request a system message block (SIB), the SIB including reference time information;

[0275] The sixth receiving unit 920 is used to receive information about the reference time sent by the network device and information about the reference point corresponding to the reference time.

[0276] In this embodiment of the application, the terminal device can obtain the reference time sent by the network device and the reference point information corresponding to the reference time when requesting SIB, which helps the terminal device to accurately obtain the reference time based on the reference point.

[0277] Optionally, the first message may also include information about the type of the reference time, which is the reference time information corresponding to the type of reference time.

[0278] In this embodiment of the application, by carrying information about the type of reference time in the first message, the network device can obtain the type of the requested reference time. The network device can then send the corresponding reference time information to the terminal device according to the type of reference time, which helps to save the signaling overhead of the network device.

[0279] Optionally, the sixth receiving unit 920 is specifically used for:

[0280] Receive the SIB sent by the network device via unicast. The SIB includes information about the reference time and information about the reference point corresponding to the reference time.

[0281] Optionally, the reference time information includes first time information and second time information, and the sixth receiving unit 920 is specifically used for:

[0282] Receive the SIB transmitted by the network device via unicast, the SIB including information about the first time and information about the reference point corresponding to the first time; and

[0283] Receive an RRC message sent by the network device, the RRC message including the second time information and the reference point information corresponding to the second time.

[0284] Optionally, the RRC message is a downlink information transfer message.

[0285] Optionally, the sixth receiving unit 920 is specifically used for:

[0286] Receive the SIB broadcast by the network device, which includes the reference time and information about the reference point corresponding to the reference time.

[0287] It should be understood that the division of units in the above device is merely a logical functional division. In actual implementation, they can be fully or partially integrated into a single physical entity, or they can be physically separated. Furthermore, all units in the device can be implemented entirely through software calls from processing elements; all units can be implemented entirely in hardware; or some units can be implemented through software calls from processing elements, and some units can be implemented in hardware. For example, each unit can be a separately established processing element, or it can be integrated into a chip within the device. Alternatively, it can be stored as a program in memory, called and executed by a processing element of the device. Moreover, these units can be fully or partially integrated together, or implemented independently. The processing element mentioned here can also be called a processor, which can be an integrated circuit with signal processing capabilities. In the implementation process, each step of the above method or each of the above units can be implemented through integrated logic circuits in the processor element or through software calls from processing elements.

[0288] In one example, a unit in any of the above devices can be one or more integrated circuits configured to implement the methods described above, such as: one or more application-specific integrated circuits (ASICs), or one or more digital signal processors (DSPs), or one or more field-programmable gate arrays (FPGAs), or a combination of at least two of these forms of integrated circuits. As another example, when a unit in the device can be implemented in the form of a processing element scheduler, the processing element can be a general-purpose processor, such as a central processing unit (CPU) or other processor capable of calling programs. Furthermore, these units can be integrated together to implement a system-on-a-chip (SOC).

[0289] The receiving unit described above is an interface circuit of the device, used to receive signals from other devices. For example, when the device is implemented as a chip, the receiving unit is an interface circuit for the chip to receive signals from other chips or devices. The transmitting unit described above is an interface circuit of the device, used to transmit signals to other devices. For example, when the device is implemented as a chip, the transmitting unit is an interface circuit for the chip to transmit signals to other chips or devices.

[0290] Figure 1 Figure 4 shows a schematic diagram of a terminal device provided in an embodiment of this application. It can be the terminal device in the above embodiments, used to implement the operations of the terminal device in the above embodiments. Figure 1 As shown in Figure 4, the terminal device includes: an antenna 1010, a radio frequency (RF) section 1020, and a signal processing section 1030. The antenna 1010 is connected to the RF section 1020. In the downlink direction, the RF section 1020 receives information sent by the network device through the antenna 1010 and sends the information to the signal processing section 1030 for processing. In the uplink direction, the signal processing section 1030 processes the information from the terminal device and sends it to the RF section 1020. The RF section 1020 processes the information from the terminal device and then sends it to the network device through the antenna 1010.

[0291] The signal processing section 1030 may include a modem subsystem for processing data at various communication protocol layers; it may also include a central processing subsystem for processing the terminal device's operating system and application layers; furthermore, it may include other subsystems, such as a multimedia subsystem and a peripheral subsystem, wherein the multimedia subsystem controls the terminal device's camera, screen display, etc., and the peripheral subsystem enables connection with other devices. The modem subsystem may be a separately configured chip. Optionally, the aforementioned devices for the terminal device may be located within this modem subsystem.

[0292] The modem subsystem may include one or more processing elements 1031, such as a main control CPU and other integrated circuits. Furthermore, the modem subsystem may also include a storage element 1032 and an interface circuit 1033. The storage element 1032 is used to store data and programs, but the program used to execute the methods performed by the terminal device in the above methods may not be stored in the storage element 1032, but rather in a memory outside the modem subsystem, which loads and uses it when needed. The interface circuit 1033 is used to communicate with other subsystems. The above-described means for the terminal device may be located in the modem subsystem, which can be implemented by a chip. The chip includes at least one processing element and an interface circuit, wherein the processing element is used to execute the various steps of any of the methods executed by the terminal device, and the interface circuit is used to communicate with other devices. In one implementation, the unit of the terminal device that implements the various steps of the above methods can be implemented in the form of a processing element scheduler. For example, the means for the terminal device includes a processing element and a storage element, and the processing element calls the program stored in the storage element to execute the method executed by the terminal device in the above method embodiments. Storage elements can be storage elements located on the same chip as processing elements, i.e., on-chip storage elements.

[0293] In another implementation, the program used to execute the method performed by the terminal device in the above method can be located on a storage element on a different chip than the processing element, i.e., an off-chip storage element. In this case, the processing element calls or loads the program from the off-chip storage element onto the on-chip storage element to call and execute the method executed by the terminal device in the above method embodiments.

[0294] In another implementation, the units in the terminal device that implement the steps of the above methods can be configured as one or more processing elements located on the modem subsystem. These processing elements can be integrated circuits, such as one or more ASICs, one or more DSPs, one or more FPGAs, or combinations of these types of integrated circuits. These integrated circuits can be integrated together to form a chip.

[0295] The units implementing each step of the above method in the terminal device can be integrated together and implemented in the form of a System-on-Chip (SoC). This SoC chip is used to implement the above method. The chip can integrate at least one processing element and a storage element, with the processing element calling a stored program in the storage element to implement the method executed by the terminal device; alternatively, the chip can integrate at least one integrated circuit to implement the method executed by the terminal device; or, a combination of the above implementation methods can be used, with the function of some units implemented by the processing element calling a program, and the function of some units implemented by the integrated circuit.

[0296] As can be seen, the above-described apparatus for a terminal device may include at least one processing element and an interface circuit, wherein the at least one processing element is used to execute any of the methods provided by the terminal device in the above-described method embodiments. The processing element may execute part or all of the steps executed by the terminal device in a first manner: that is, by calling a program stored in a storage element; or in a second manner: that is, by combining instructions with the integrated logic circuits of the hardware in the processor element; of course, it may also combine the first and second methods to execute part or all of the steps executed by the terminal device.

[0297] The processing element here is as described above and can be a general-purpose processor, such as a CPU, or one or more integrated circuits configured to implement the above methods, such as one or more ASICs, or one or more microprocessors (DSPs), or one or more FPGAs, or a combination of at least two of these integrated circuit forms.

[0298] A storage element can be a single memory or a collective term for multiple storage elements.

[0299] Figure 15 This is a schematic diagram of the structure of a network device provided in an embodiment of this application. It is used to implement the operation of the network devices in the above embodiments (e.g., the first or second network device in method 200, the network device in method 300, and the CU or DU in method 400). Figure 15 As shown, the network device includes: an antenna 1101, a radio frequency (RF) device 1102, and a baseband device 1103. The antenna 1101 is connected to the RF device 1102. In the uplink direction, the RF device 1102 receives information sent by the terminal device through the antenna 1101 and transmits the information to the baseband device 1103 for processing. In the downlink direction, the baseband device 1103 processes the information from the terminal device and transmits it to the RF device 1102. The RF device 1102 processes the information from the terminal device and then transmits it to the terminal device through the antenna 1101.

[0300] The baseband device 1103 may include one or more processing elements 11031, such as a main control CPU and other integrated circuits. Furthermore, the baseband device 1103 may also include a storage element 11032 and an interface 11033. The storage element 11032 is used to store programs and data; the interface 11033 is used to interact with the radio frequency device 1102, and this interface is, for example, a Common Public Radio Interface (CPRI). The above-described means for network devices may be located in the baseband device 1103. For example, the above-described means for network devices may be a chip on the baseband device 1103, which includes at least one processing element and an interface circuit. The processing element is used to execute the various steps of any of the methods executed by the network device, and the interface circuit is used to communicate with other devices. In one implementation, the unit of the network device that implements the various steps of the above methods can be implemented in the form of a processing element scheduler. For example, the means for network devices includes a processing element and a storage element, and the processing element calls the program stored in the storage element to execute the method executed by the network device in the above method embodiments. Storage elements can be storage elements located on the same chip as the processing elements, i.e., on-chip storage elements, or storage elements located on different chips than the processing elements, i.e., off-chip storage elements.

[0301] In another implementation, the units in the network device that implement the steps of the above methods can be configured as one or more processing elements located on the baseband device. These processing elements can be integrated circuits, such as one or more ASICs, one or more DSPs, one or more FPGAs, or combinations of these types of integrated circuits. These integrated circuits can be integrated together to form a chip.

[0302] The units implementing the various steps of the above methods in a network device can be integrated together and implemented in the form of a System-on-Chip (SoC). For example, a baseband device includes this SoC chip for implementing the above methods. This chip can integrate at least one processing element and a storage element, with the processing element calling a stored program from the storage element to implement the methods executed by the network device. Alternatively, the chip can integrate at least one integrated circuit for implementing the methods executed by the network device. Alternatively, a combination of the above implementation methods can be used, with some unit functions implemented by the processing element calling a program, and some unit functions implemented by an integrated circuit.

[0303] As can be seen, the above-described apparatus for a network device may include at least one processing element and an interface circuit, wherein the at least one processing element is used to execute any of the methods provided by the network device in the above method embodiments. The processing element may execute part or all of the steps executed by the network device in a first manner: that is, by calling a program stored in a storage element; or in a second manner: that is, by combining instructions with the integrated logic circuits of the hardware in the processor element; of course, it may also combine the first and second methods to execute part or all of the steps executed by the network device.

[0304] The processing element here is as described above and can be a general-purpose processor, such as a CPU, or one or more integrated circuits configured to implement the above methods, such as one or more ASICs, or one or more microprocessors (DSPs), or one or more FPGAs, or a combination of at least two of these integrated circuit forms.

[0305] A storage element can be a single memory or a collective term for multiple storage elements.

[0306] The terminal devices and network devices in the above-described device embodiments can completely correspond to the terminal devices or network devices in the method embodiments, with corresponding modules or units performing the corresponding steps. For example, when the device is implemented as a chip, the receiving unit can be an interface circuit of the chip for receiving signals from other chips or devices. The above-described transmitting unit is an interface circuit of the device used to transmit signals to other devices. For example, when the device is implemented as a chip, the transmitting unit is an interface circuit of the chip for transmitting signals to other chips or devices.

[0307] This application also provides a communication system, which includes: the aforementioned terminal device, and / or the aforementioned network device.

[0308] In the embodiments of this application, it should be noted that the method embodiments described above can be applied to a processor or implemented by a processor. The processor may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method embodiments can be completed by integrated logic circuits in the processor's hardware or by instructions in software form. The processor described above can be a general-purpose processor, DSP, ASIC, FPGA, or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor, etc. The steps of the methods disclosed in the embodiments of this application can be directly embodied as being executed by a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above methods.

[0309] It is understood that the memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory used in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0310] It should be understood that the phrase "one embodiment" or "an embodiment" mentioned in the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of this application. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does 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 should be understood that in the various embodiments of this application, the sequence number of the above-described processes 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 the embodiments of this application.

[0311] The terms "first," "second," etc., appearing in this application are merely for distinguishing different objects; they do not inherently limit the actual order or function of the objects they modify. Expressions such as "exemplary," "example," "for example," "optional design," or "a design" appearing in this application are used only to indicate exemplification, illustration, or description. Any embodiment or design scheme described as "exemplary," "example," "for example," "optional design," or "a design" in this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of these terms is intended to present the relevant concepts in a concrete manner.

[0312] The terms "uplink" and "downlink" appearing in this application are used to describe the direction of data / information transmission in specific scenarios. For example, the "uplink" direction generally refers to the direction of data / information transmission from the terminal device to the network side, or the direction of transmission from the distributed unit to the centralized unit. The "downlink" direction generally refers to the direction of data / information transmission from the network side to the terminal device, or the direction of transmission from the centralized unit to the distributed unit. It can be understood that "uplink" and "downlink" are only used to describe the direction of data / information transmission, and the specific starting and ending devices of the data / information transmission are not limited.

[0313] In this application, various objects such as messages / information / devices / network elements / systems / apparatus / actions / operations / processes / concepts may be named. It is understood that these specific names do not constitute a limitation on the relevant objects. The names may be changed depending on the scenario, context, or usage habits. The understanding of the technical meaning of the technical terms in this application should be mainly determined from their functions and technical effects embodied / performed in the technical solution.

[0314] The architecture of CU and DU in this embodiment is not limited to 5G NR gNB, but can also be applied to scenarios where LTE base stations are divided into CU and DU; CU can be further divided into CP and UP. Optionally, when it is an LTE base station, the protocol layer does not include the SDAP layer.

[0315] Furthermore, the terms "system" and "network" are often used interchangeably in this paper. The term "and / or" in this paper merely describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / " in this paper generally indicates that the preceding and following related objects have an "or" relationship.

[0316] The network architecture and business scenarios described in the embodiments of this application are for the purpose of enabling readers to clearly understand the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions provided in the embodiments of this application. As those skilled in the art will know, with the evolution of network architecture and the emergence of new business scenarios, the technical solutions provided in the embodiments of this application are also applicable to similar technical problems.

[0317] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented, in whole or in part, as a computer program product. The computer program product may include one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic disk), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0318] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software 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.

[0319] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0320] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of 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 system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0321] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0322] In addition, 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.

[0323] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An information transmission method, characterized in that, include: A first network device sends a first message to a second network device. The first message is used to request the terminal device to switch from a first cell to a second cell. The first cell belongs to the first network device, and the second cell belongs to the second network device. The first network device receives a response message from the second network device in response to the first message, the response message including reference time information; The first network device sends the reference time information to the terminal device; The reference time information includes reference time information and reference point information corresponding to the reference time. The first message includes reference time type information. The reference time information is the reference time information corresponding to the reference time type. The reference time type includes Coordinated Universal Time (UTC) and / or wireless network time. The method further includes: The first network device receives a second message sent by the terminal device. The second message is used to request the reference time information and includes information about the type of the reference time.

2. The method according to claim 1, characterized in that, The first network device sends the reference time information to the terminal device, including: The first network device sends a System Message Block (SIB) to the terminal device via unicast, and the SIB includes the reference time information.

3. The method according to claim 1 or 2, characterized in that, The reference time information includes first time information and second time information, wherein the first network device sends the reference time information to the terminal device, including: The first network device sends an SIB to the terminal device via unicast, the SIB including the first time information; and The first network device sends an RRC message to the terminal device, the RRC message including the second time information.

4. The method according to claim 3, characterized in that, The RRC message is a downlink information transfer message.

5. The method according to claim 1, characterized in that, The first network device sends the reference time information to the terminal device, including: The first network device sends an SIB to the terminal device via broadcast, the SIB including the reference time information.

6. The method according to claim 1, characterized in that, The response message is either a switch request confirmation message or a switch requirement confirmation message.

7. The method according to claim 6, characterized in that, The response message is a handover request confirmation message, in which the reference time information sent by the first network device to the terminal device is carried; or... The response message is a handover request confirmation message, in which the reference time information sent by the first network device to the terminal device is carried.

8. A method for information transmission, characterized in that, include: The first network device receives a first message sent by the second network device. The first message is used to request the terminal device to be switched from the first cell to the second cell. The first cell belongs to the second network device, and the second cell belongs to the first network device. The first network device sends a response message to the second network device in response to the first message, the response message including reference time information; The reference time information includes reference time information and reference point information corresponding to the reference time. The first message includes reference time type information. The reference time information is the reference time information corresponding to the reference time type. The reference time type includes UTC time and / or wireless network time.

9. The method according to claim 8, characterized in that, The response message is either a switch request confirmation message or a switch requirement confirmation message.

10. An information transmission method, characterized in that, include: The centralized unit (CU) sends a first message to the distributed unit (DU), the first message being used to request reference time information, the reference time information including UTC time information; The CU receives the reference time information sent by the DU; The first message also includes information about the type of reference time, which is the reference time information corresponding to the type of reference time, including UTC time and / or wireless network time.

11. The method according to claim 10, characterized in that, The CU has at least one of the following protocol layer functions: radio resource control protocol layer, service data adaptation layer, and packet data convergence protocol layer; and / or The DU has at least one of the following protocol layer functions: radio link control protocol layer, media access control layer, and physical layer functions.

12. The method according to claim 10 or 11, characterized in that, The reference time information also includes the time information of the wireless network.

13. The method according to claim 12, characterized in that, The first message also includes first indication information and second indication information, wherein, The first indication information is used to instruct the DU to send the UTC time information to the CU according to a first cycle, or the first indication information is used to instruct the DU to send the UTC time information to the CU after receiving the first request message sent by the CU; The second indication information is used to instruct the DU to send the time information of the wireless network to the CU according to the second period, or the second indication information is used to instruct the DU to send the time information of the wireless network to the CU after receiving the second request message sent by the CU.

14. The method according to claim 12, characterized in that, The first message also includes first indication information, wherein, The first indication information is used to instruct the DU to send the UTC time information and the wireless network time information to the CU according to the third cycle, or the first indication information is used to instruct the DU to send the UTC time information and the wireless network time information to the CU after receiving the third request message sent by the CU.

15. An information transmission method, characterized in that, include: The distributed unit (DU) receives a first message sent by the centralized unit (CU), the first message being used to request reference time information, the reference time information including UTC time information; The DU sends the reference time information to the CU; The first message also includes information about the type of reference time, which is the reference time information corresponding to the type of reference time, including UTC time and / or wireless network time.

16. The method according to claim 15, characterized in that, The CU has at least one of the following protocol layer functions: radio resource control protocol layer, service data adaptation layer, and packet data convergence protocol layer; and / or The DU has at least one of the following protocol layer functions: radio link control protocol layer, media access control layer, and physical layer functions.

17. A method for transmitting information, characterized in that, The method includes: The terminal device sends a first message to the network device. The first message is used to request a System Message Block (SIB), and the SIB includes reference time information. The terminal device receives reference time information and reference point information corresponding to the reference time sent by the network device; The first message also includes information about the type of the reference time, which is the reference time information corresponding to the type of reference time, including UTC time and / or wireless network time.

18. The method according to claim 17, characterized in that, The terminal device receives information from the network device regarding the reference time and the reference point corresponding to the reference time, including: The terminal device receives the SIB sent by the network device via unicast. The SIB includes information about the reference time and information about the reference point corresponding to the reference time.

19. The method according to claim 17, characterized in that, The reference time information includes first time information and second time information. The terminal device receives the reference time and the reference point corresponding to the reference time sent by the network device, including: The terminal device receives the SIB transmitted by the network device via unicast, the SIB including information about the first time and information about the reference point corresponding to the first time; and The terminal device receives an RRC message sent by the network device. The RRC message includes information about the second time and information about the reference point corresponding to the second time.

20. The method according to claim 19, characterized in that, The RRC message is a downlink information transfer message.

21. The method according to claim 17, characterized in that, The terminal device receives information from the network device regarding the reference time and the reference point corresponding to the reference time, including: The terminal device receives the SIB broadcast by the network device. The SIB includes the reference time and information about the reference point corresponding to the reference time.

22. An information transmission device, characterized in that, Includes units for performing the various steps of the method as described in any one of claims 1-16.

23. An information transmission device, characterized in that, Includes units for performing the various steps of the method as described in any one of claims 17-21.

24. An information transmission device, characterized in that, It includes at least one processor and interface circuitry, wherein the at least one processor is used to perform the method as described in any one of claims 1-16.

25. An information transmission device, characterized in that, It includes at least one processor and interface circuitry, wherein the at least one processor is used to perform the method as described in any one of claims 17-21.

26. A terminal device, characterized in that, Includes the apparatus as described in claim 23 or 25.

27. A network device, characterized in that, Includes the apparatus as described in claim 22 or 24.

28. A readable storage medium, characterized in that, Includes a program or instructions that, when run on a computer, execute the method as described in any one of claims 1-21.

29. A computer program product, characterized in that, Includes a program or instructions that, when run on a computer, execute the method as described in any one of claims 1-21.

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