A communication method and device

Abstract

The application relates to a communication method and device. A remote device receives configuration information from a first access network device, which is used for configuring a measurement frequency on a sidelink and configuring cell information or air interface frequency information. The remote device measures a first type of relay device according to the configuration information, the first type of relay device being a relay device working on the measurement frequency and having camped on or being able to camp on a cell corresponding to the cell information, or being a relay device working on the measurement frequency and having camped on or being able to camp on a cell on a frequency corresponding to the air interface frequency information. The remote device sends a measurement result to the first access network device to determine a communication path of the remote device. The first access network device can obtain frequency information of a cell where a relay terminal device is located, so that a more suitable relay terminal device can be selected when the relay terminal device is selected for the remote device.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202111562237.5, filed on December 20, 2021, entitled "A Communication Method and Device", the entire contents of which are incorporated herein by reference; and to Chinese Patent Application No. 202210022645.X, filed on January 10, 2022, entitled "A Communication Method and Device", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of communication technology, and in particular to a communication method and device. Background Technology

[0004] When a user equipment (UE) is far from a network device—for example, if the UE is outside the network device's coverage area, at the edge of the network device's coverage, or if the link quality between the UE and the network device is poor—this UE can communicate with the network device through another UE. In other words, another UE can provide relay services to this UE, enabling it to communicate with the network device. The UE that communicates with the network device through another UE is called a remote UE, and the UE that provides relay services to the remote UE is called a relay UE.

[0005] When a remote UE connects to the network via a relay UE, the remote UE can determine whether it can continue operating as a remote. To do this, the remote UE can measure the cell where the relay UE is operating or camped, and make a judgment based on the measurement results. To measure the cell where the relay UE is operating or camped, it is first necessary to determine the cell where the relay UE is operating or camped. Specifically, the remote UE can blindly search on various frequency points, searching for the corresponding cell based on the known physical cell identity (PCI) of the cells where the relay UE is operating or camped. After determining a cell, the remote UE reads the system information block 1 (SIB1) of that cell to determine whether the new radio cell identity (NCI) broadcast by SIB1 is the same as the NCI obtained from the relay UE. If the two NCIs are the same, the remote UE can determine that the cell is the cell where the relay UE is operating or camped; otherwise, the remote UE needs to continue searching.

[0006] It is evident that the current time required for a remote UE to find a cell where a relay UE is working or camped is relatively long, and the power consumption is relatively high because it needs to blindly search on multiple frequency points. Summary of the Invention

[0007] This application provides a communication method and device for reducing the power consumption of a remote UE.

[0008] In a first aspect, a first communication method is provided, which can be executed by a terminal device, or by a larger device including the terminal device, or by a chip system or other functional module capable of implementing the functions of the terminal device, such as being disposed within the terminal device. The method includes: obtaining frequency information of a first cell, the first cell being the cell where a first relay device is located; determining the first cell based on the frequency information and an identifier of the first cell; and measuring the first cell to determine whether the terminal device can act as a remote device in the first cell.

[0009] In this embodiment, the terminal device can obtain the frequency information of the cell where the first relay device is located. Based on this frequency information and the cell's identifier, the terminal device can determine the cell without blindly searching multiple frequency points, thus reducing the time required to find the cell. Furthermore, reducing the blind frequency search process also saves power consumption for the terminal device.

[0010] In conjunction with the first aspect, in a first optional implementation of the first aspect, the identifier of the first cell includes the PCI and / or the NCI of the first cell. There may be multiple identifiers for the first cell, and this application embodiment does not impose any limitations.

[0011] In conjunction with the first aspect or the first optional implementation of the first aspect, in the second optional implementation of the first aspect, obtaining the frequency information of the first cell includes: receiving a first message from the first relay device, the first message including or indicating the frequency information of the first cell. The first relay device sends the first message, so that the terminal device can receive the first message without the terminal device sending a message to the first relay device, thereby reducing signaling overhead. For example, the first relay device can send the first message by broadcasting or unicasting.

[0012] In conjunction with the first aspect or the first optional implementation of the first aspect, in the third optional implementation of the first aspect, obtaining the frequency information of the first cell includes: sending a second message to the first relay device, the second message being used to inquire about the frequency information of the cell where the first relay device is located, or to inquire whether the first relay device has camped on a cell at a first frequency, wherein the first cell is a cell at the first frequency; and receiving a first message from the first relay device, the first message including or indicating the frequency information of the first cell, or the first message indicating that the first relay device has camped on a cell at the first frequency. The terminal device can send the second message, and for example, a relay device (e.g., the first relay device) that meets the conditions queried by the second message can reply to the message, thereby enabling the filtering of relay devices, reducing the need for the terminal device to measure relay devices that do not meet the conditions, and saving power consumption of the terminal device.

[0013] In conjunction with the second or third optional implementation of the first aspect, in the fourth optional implementation of the first aspect, the first message is a discovery message, a PC5 RRC message, or an RRC message from the serving access network device of the first relay device. For example, if the first message is a discovery message, the terminal device can receive the first message before establishing a connection with the first relay device, which can improve the efficiency of the terminal device in obtaining the frequency of the first cell. Alternatively, if the first message is a PC5 RRC message, the terminal device can receive the first message after establishing a connection with the first relay device, and the sending of the first message can be more targeted. Or, if the first message comes from the serving access network device of the first relay device, it is equivalent to the frequency information of the first cell also being informed to the terminal device by the network, thus the way the terminal device obtains the frequency information of the first cell is more flexible.

[0014] In a fifth optional embodiment of the first aspect, combining any of the second to fourth optional embodiments of the first aspect, the first message further includes the identifier of the first cell. For example, the identifier of the first cell may be carried in the first message and sent together, allowing the terminal device to obtain the frequency information and identifier of the first cell with a single message, thus saving signaling overhead. Alternatively, the identifier of the first cell may not be included in the first message but may be sent to the terminal device through other messages, such as those from the first relay device or the serving access network device of the first relay device, etc., without specific limitations.

[0015] In a sixth optional embodiment of the first aspect, combining any of the second to fifth optional embodiments of the first aspect, the first message further includes first information indicating that the first cell is not in an access-blocked state. This first information allows the terminal device to determine as early as possible whether access to the first cell is permitted, thereby minimizing the probability of accessing an unsuitable cell.

[0016] In a seventh optional embodiment of the first aspect, combining any of the second to sixth optional embodiments of the first aspect, the first message further includes second information, which indicates whether searching for an accessible cell is allowed at the frequency of the first cell when the first cell is in an access-prohibited state. For example, if other cells at the frequency of the first cell may have high load, or other cells at the frequency of the first cell may be in an access-prohibited state, then the second information can indicate that searching for an accessible cell at the frequency of the first cell is not allowed. This can reduce the invalid search process of the terminal device and save the power consumption of the terminal device.

[0017] In conjunction with any of the first optional embodiments of the first aspect or the first to seventh optional embodiments of the first aspect, in the eighth optional embodiment of the first aspect, the method further includes: after establishing a connection with the first relay device, receiving the PCI of the first cell from the first relay device; or, sending a first request message to an access network device and receiving the PCI of the first cell from the access network device, wherein the first request message is used to request establishing a connection with the access network device. The terminal device may obtain the PCI of the first cell in various ways, such as receiving it from the first relay device, or it may also receive it from an access network device, such as an access network device that the terminal device is registered or operates on, or it may be an access network device that the first relay device is registered or operates on (e.g., the serving access network device of the first relay device).

[0018] Firstly, a first communication method is provided, which can be executed by a terminal device, a larger device including the terminal device, or a chip system or other functional module capable of implementing the functions of the terminal device, such as being disposed within the terminal device. For example, the terminal device may be a relay device, such as a first relay device. The method includes: sending frequency information of a first cell to the terminal device, the frequency information of the first cell being used to determine whether the terminal device can act as a remote device in the first cell, where the first cell is the cell where the first relay device is located.

[0019] In conjunction with the first aspect, in a first optional implementation of the first aspect, sending frequency information of the first cell to the terminal device includes: sending a first message to the terminal device, the first message including the frequency information of the first cell.

[0020] In conjunction with the first aspect, in a second optional implementation of the first aspect, sending frequency information of the first cell to the terminal device includes: receiving a second message from the terminal device, the second message being used to inquire about the frequency information of the cell where the first relay device is located, or to inquire whether the first relay device has camped on a cell of the first frequency, wherein the first cell is a cell of the first frequency; sending a first message to the terminal device, the first message including the frequency information of the first cell, or the first message being used to indicate that the first relay device has camped on a cell of the first frequency.

[0021] In conjunction with the first optional implementation of the first aspect or the second optional implementation of the first aspect, in the third optional implementation of the first aspect, the first message is: a discovery message, or a PC5 RRC message, or an RRC message from the serving access network device of the first relay device.

[0022] In conjunction with any of the first to third optional embodiments of the first aspect, in a fourth optional embodiment of the first aspect, the first message further includes an identifier of the first cell, wherein the identifier of the first cell includes the PCI or NCI of the first cell.

[0023] In a fifth optional implementation of the first aspect, in conjunction with any of the first to fourth optional implementations of the first aspect, the first message further includes first information indicating that the first cell is not in a blocked access state.

[0024] In conjunction with any of the first to fifth optional implementations of the first aspect, in the sixth optional implementation of the first aspect, the first message further includes second information, which is used to indicate whether it is allowed to search for an accessible cell at the frequency of the first cell when the first cell is in an access-deprived state.

[0025] In conjunction with any of the first optional implementations of the first aspect or the first to sixth optional implementations of the first aspect, in the seventh optional implementation of the first aspect, the method further includes: sending the PCI of the first cell to the terminal device after establishing a connection with the terminal device.

[0026] For the technical effects of the second aspect or various alternative implementation methods, please refer to the introduction of the technical effects of the first aspect or corresponding implementation methods.

[0027] Thirdly, a third communication method is provided, which can be executed by a terminal device, a larger device including the terminal device, or a chip system or other functional module capable of implementing the functions of the terminal device, for example, being located within the terminal device. The terminal device is, for example, a remote device. The method includes: receiving configuration information from a first access network device, the configuration information being used to configure measurement frequencies on the sidelink and to configure cell information or air interface frequency information; performing measurements on a first type of relay device according to the configuration information, the first type of relay device being a relay device operating on the measurement frequency and already camped or capable of camping on the cell corresponding to the cell information, or a relay device operating on the measurement frequency and already camped or capable of camping on the cell at the frequency corresponding to the air interface frequency information; and sending measurement results to the first access network device, the measurement results being used to determine the communication path of the remote device.

[0028] In this embodiment, the first access network device can obtain the frequency information of the cell where the relay terminal device is located, thereby enabling it to select a more suitable relay terminal device when choosing a relay terminal device for the remote device. For example, the first access network device can select a relay terminal device that operates at a higher frequency on the air interface for the remote device, thereby increasing the data rate of the remote device. In addition, the remote device can communicate through a single-connection communication path or through a multi-connection communication path, improving the communication flexibility of the remote device and also helping to improve the throughput of the remote device.

[0029] In conjunction with the third aspect, in a first optional implementation of the third aspect, the method further includes: receiving a fourth message from a first relay device, the fourth message including information about a first frequency, wherein the first frequency is the frequency of the cell where the first relay device is located, or the frequency of a cell that the first relay device can camp on. In this manner, the information about the first frequency can be obtained from the message received from the relay terminal device without the remote device sending a message to the relay terminal device, thus reducing signaling overhead.

[0030] In conjunction with the first optional implementation of the third aspect, in the second optional implementation of the third aspect, the fourth message is a discovery message or a PC5 RRC message. The fourth message may be, for example, a discovery message, or a PC5 RRC message, or it may be other types of messages; this application embodiment does not limit this.

[0031] In conjunction with the first optional implementation of the third aspect or the second optional implementation of the third aspect, in the third optional implementation of the third aspect, measuring the first type of relay device according to the configuration information includes: if the first frequency belongs to the frequency corresponding to the air interface frequency information configured in the configuration information, or the cell corresponding to the cell information configured in the configuration information belongs to the first frequency, measuring or reporting the measurement on the first relay device. If the configuration information configures air interface frequency information, then if the first frequency belongs to the frequency corresponding to the air interface frequency information configured in the configuration information, it indicates that the first relay device is the object to be measured; or, if the configuration information configures cell information, then if the cell corresponding to the cell information configured in the configuration information belongs to the first frequency (or, in other words, the cell operates at the first frequency), it also indicates that the first relay device is the object to be measured. Essentially, the remote device can measure the object configured in the configuration information to reduce invalid measurement processes by the remote device.

[0032] In conjunction with the third aspect, in a fourth optional implementation of the third aspect, the method further includes: sending a fifth message to the first relay device, the fifth message being used to query the frequency information of the cell where the first relay device is located, or to query the frequency information of the cell that the first relay device can camp on, or to query whether the first relay device has camped on or can camp on a cell at a second frequency, the second frequency belonging to the frequency corresponding to the air interface frequency information configured in the configuration information; receiving a sixth message from the first relay device, the sixth message including information about the second frequency, or the sixth message indicating that the first relay device has camped on or can camp on a cell at the second frequency. In this manner, the remote device can first send a message to the first relay device, for example, the message sent by the remote device is called the fifth message. After receiving the fifth message, the first relay device can send a message to the remote device, for example, called the sixth message, and the remote device can perform measurements based on the sixth message. Since the fifth message queries the relevant information, it is more beneficial for the remote device to locate suitable relay terminal devices for measurement.

[0033] In a fifth optional embodiment of the third aspect, in conjunction with any of the first to fourth optional embodiments of the third aspect, the method further includes: receiving an RRC reconfiguration message from the first access network device, the RRC reconfiguration message being used to instruct the remote device to switch to a second cell, or to instruct the remote device to switch to a first relay device, or to instruct the remote device to add the second cell as a secondary cell, or to instruct the remote device to add a path for communication with the network through the first relay device, wherein the first relay device is one of the first type of relay devices. Through this RRC reconfiguration message, a new communication path can be indicated to the remote device.

[0034] In conjunction with the fifth optional implementation of the third aspect, in the sixth optional implementation of the third aspect, the RRC reconfiguration message further includes the PCI of the cell where the first relay device is located. For example, the second access network device can send the stored PCI of the cell where the first relay device is located to the first access network device, and the first access network device can then pass the PCI to the remote device. This provides one way for the remote device to obtain the PCI of the cell where the first relay device is located.

[0035] In conjunction with the fifth or sixth optional implementation of the third aspect, in the seventh optional implementation of the third aspect, the RRC reconfiguration message further includes frequency information of the cell where the first relay device is located. For example, the second access network device can send the frequency information of the cell where the first relay device is located to the first access network device, and the first access network device can then transmit the frequency information to a remote device. This provides one way for a remote device to obtain the frequency information of the cell where the first relay device is located.

[0036] In conjunction with the fifth optional implementation of the third aspect, in the eighth optional implementation of the third aspect, the method further includes: after establishing a connection with the first relay device, receiving the PCI of the cell where the first relay device is located from the first relay device. The remote device may obtain the PCI of the cell where the first relay device is located in two ways: one is through an access network device (e.g., the first access network device), and the other is through the first relay device. These two methods can be used individually or in combination.

[0037] In a ninth optional embodiment of the third aspect, combining any of the fifth to eighth optional embodiments of the third aspect, the method further includes: after establishing a connection with the first relay device, sending first indication information to the first relay device, the first indication information being used to instruct the first relay device to reselect to the cell corresponding to the cell information configured in the configuration information, or to reselect to the cell at the frequency corresponding to the air interface frequency information configured in the configuration information. If the first relay device is only capable of camping on the cell corresponding to the configuration information, but is not currently camping on the cell corresponding to the configuration information, then the remote device can send the first indication information to the first relay device to instruct the first relay device to reselect to the cell corresponding to the configuration information, so that the first relay device can normally provide relay services to the remote device.

[0038] In conjunction with any of the optional embodiments of the third aspect or the first to ninth optional embodiments of the third aspect, in the tenth optional embodiment of the third aspect, receiving configuration information from the first access network device includes: receiving configuration information from the first access network device via a second relay device. For example, a remote device may initially connect to the first access network device via the second relay device, then the configuration information sent by the first access network device can be sent to the remote device via the second relay device.

[0039] Fourthly, a fourth communication method is provided, which can be executed by a terminal device, a larger device including the terminal device, or a chip system or other functional module capable of implementing the functions of the terminal device, for example, being disposed within the terminal device. The terminal device is, for example, a first relay device. The method includes: sending information of a third frequency to a remote device, the third frequency being the frequency of the cell where the first relay device is located, or the frequency of a cell where the first relay device can camp, the third frequency information being used to determine the communication path of the remote device.

[0040] For the technical effects of the fourth aspect, please refer to the introduction of the technical effects of the third aspect or the corresponding implementation method.

[0041] Fifthly, a fifth communication method is provided, which can be executed by a first access network device, or by a larger device including the first access network device, or by a chip system or other functional module capable of implementing the functions of the first access network device, such as being disposed within the first access network device. The first access network device is, for example, a base station. The method includes: sending configuration information to a remote device, the configuration information being used to configure the measurement frequency on the sidelink and to configure cell information or air interface frequency information that a relay device operating on the measurement frequency needs to camp or operate on; receiving measurement results from the remote device; and determining the communication path of the remote device based on the measurement results.

[0042] For details regarding the technical effects of the fifth aspect, please refer to the description of the technical effects of the third aspect or the corresponding implementation method.

[0043] A sixth aspect provides a sixth communication method, which can be executed by a first access network device, or by a larger device including the first access network device, or by a chip system or other functional module capable of implementing the functions of the first access network device, such as being disposed within the first access network device. The first access network device is, for example, a base station. The method includes: sending a handover request message to a second access network device, the handover request message being used to inquire whether to accept a remote device accessing the network through a first relay device under the second access network device, or the handover request message being used to inquire whether to accept a remote device accessing a second cell under the second access network device; receiving a handover request response from the second access network device, the handover request response being used to indicate whether to accept the remote device accessing the network through the first relay device, or to indicate whether to accept the remote device accessing the second cell, wherein the handover request response further includes frequency information of the cell where the first relay device has camped or is capable of camping.

[0044] For details regarding the technical effects of the sixth aspect, please refer to the description of the technical effects of the third aspect or the corresponding implementation method.

[0045] A seventh aspect provides a seventh communication method, which can be executed by a second access network device, or by a larger device including the second access network device, or by a chip system or other functional module capable of implementing the functions of the second access network device, for example, being disposed within the second access network device. The second access network device is, for example, a base station. The method includes: receiving a handover request message from a first access network device, the handover request message being used to inquire whether to accept a remote device accessing the network through a first relay device under the second access network device, or the handover request message being used to inquire whether to accept a remote device accessing a second cell under the second access network device; sending a handover request response to the first access network device, the handover request response being used to indicate whether to accept the remote device accessing the network through the first relay device, or to indicate whether to accept the remote device accessing the second cell, wherein the handover request response further includes frequency information of the cell where the first relay device has camped or is capable of camping.

[0046] For details regarding the technical effects of the seventh aspect, please refer to the description of the technical effects of the third aspect or the corresponding implementation method.

[0047] Eighthly, an eighth communication method is provided, which can be executed by a terminal device, a larger device including the terminal device, or a chip system or other functional module capable of implementing the functions of the terminal device, for example, being disposed within the terminal device. The terminal device is, for example, a remote device. The method includes: receiving configuration information from an access network device, the configuration information being used to configure a first type of measurement object and a second type of measurement object, wherein the communication path of the remote device corresponding to the first type of measurement object is different from the communication path corresponding to the first type of measurement object; measuring the first type of measurement object according to the configuration information; and measuring the second type of measurement object if the measurement result of the first type of measurement object does not meet a first condition.

[0048] In this embodiment, although the access network device can be configured with two types of measurement objects, the remote device determines which measurement object to measure based on a first condition. Therefore, the remote device may not need to measure both measurement objects simultaneously, saving power consumption. Furthermore, the access network device does not need to configure the measurement object separately; the remote device can decide which measurement object to measure, thus reducing measurement latency.

[0049] A ninth aspect provides a ninth communication method, which can be executed by a terminal device, a larger device including the terminal device, or a chip system or other functional module capable of implementing the functions of the terminal device, such as being disposed within the terminal device. The terminal device is, for example, a remote device. The method includes: receiving configuration information from an access network device, the configuration information being used to configure measurement events, the measurement events including a measurement result of a first type of measurement object being less than a first threshold, and a measurement result of a second type of measurement object being greater than or equal to a second threshold, wherein the communication path of the remote device corresponding to the first type of measurement object is different from the communication path corresponding to the first type of measurement object; measuring the first type of measurement object and the second type of measurement object; and sending the measurement results of the first type of measurement object and / or the second type of measurement object to the access network device according to the measurement events.

[0050] In this embodiment, the access network device can filter the preferred measurement results to be reported through the configured measurement events. The remote device can send the measurement results to the access network device according to the measurement events, so that the sent measurement results are more in line with the needs of the access network device, reducing redundant reporting by the remote device and saving transmission overhead.

[0051] A tenth aspect provides a tenth communication method, which can be executed by a terminal device, a larger device including the terminal device, or a chip system or other functional module capable of implementing the functions of the terminal device, for example, being disposed within the terminal device. The terminal device is, for example, a remote device. The method includes: receiving configuration information from an access network device, the configuration information being used to configure a first measurement event, a second measurement event, and a third measurement event, wherein the first measurement event includes a measurement result of a first type of measurement object whose value is less than a first threshold, the second measurement event includes a measurement result of a second type of measurement object whose value is greater than or equal to a second threshold, and the third measurement event includes a measurement result of the first type of measurement object whose value is greater than or equal to the first threshold, wherein the communication path of the remote device corresponding to the first type of measurement object is different from the communication path corresponding to the first type of measurement object; measuring the first type of measurement object and the second type of measurement object; and sending the measurement results of the first type of measurement object and / or the second type of measurement object to the access network device according to the first measurement event, the second measurement event, and the third measurement event.

[0052] In this embodiment, the access network device can filter the preferred measurement results to be reported through the configured measurement events. The remote device can send the measurement results to the access network device according to the measurement events, so that the sent measurement results are more in line with the needs of the access network device, reducing redundant reporting by the remote device and saving transmission overhead.

[0053] Eleventhly, a communication device is provided. The communication device can be a terminal device, a remote device, or a first relay device as described in any one of the first to tenth aspects. The communication device possesses the functions of the aforementioned terminal device, remote device, or first relay device. The communication device is, for example, a terminal device, a remote device, or a first relay device, or a functional module within a remote device or first relay device, such as a baseband device or a chip system. In one optional implementation, the communication device includes a baseband device and a radio frequency device. In another optional implementation, the communication device includes a processing unit (sometimes also called a processing module) and a transceiver unit (sometimes also called a transceiver module). The transceiver unit is capable of performing both transmitting and receiving functions. When the transceiver unit performs the transmitting function, it can be called a transmitting unit (sometimes also called a transmitting module), and when the transceiver unit performs the receiving function, it can be called a receiving unit (sometimes also called a receiving module). The transmitting unit and the receiving unit can be the same functional module, which is called the transceiver unit. This functional module can realize the transmitting and receiving functions; or, the transmitting unit and the receiving unit can be different functional modules, and the transceiver unit is a general term for these functional modules.

[0054] In one alternative implementation, the communication device further includes a storage unit, and the processing unit is configured to couple with the storage unit and execute programs or instructions in the storage unit to enable the communication device to perform the functions of a terminal device, a remote device, or a first relay device as described in any one of the first to tenth aspects above.

[0055] In a twelfth aspect, a communication device is provided. The communication device may be a first access network device or a second access network device as described in any one of the first to tenth aspects. The communication device possesses the functions of the first or second access network device. The communication device may be, for example, a first or second access network device, or a functional module within a first or second access network device, such as a baseband device or a chip system. In one optional implementation, the communication device includes a baseband device and a radio frequency device. In another optional implementation, the communication device includes a processing unit (sometimes also called a processing module) and a transceiver unit (sometimes also called a transceiver module). For details on the implementation of the transceiver unit, please refer to the description in the eleventh aspect.

[0056] In one alternative implementation, the communication device further includes a storage unit, and the processing unit is configured to couple with the storage unit and execute programs or instructions in the storage unit to enable the communication device to perform the functions of the first access network device or the second access network device as described in any one of the first to tenth aspects above.

[0057] In a thirteenth aspect, a computer-readable storage medium is provided for storing a computer program or instructions that, when executed, cause the methods performed by the terminal device, remote device, first relay device, first access network device, or second access network device in the foregoing aspects to be implemented.

[0058] In a fourteenth aspect, a computer program product containing instructions is provided that, when run on a computer, enables the methods described in the above aspects to be implemented.

[0059] In a fifteenth aspect, an apparatus is provided comprising one or more units for performing the method described in any embodiment of the present application.

[0060] In a sixteenth aspect, a communication system is provided, comprising a communication device as described in the twelfth aspect for implementing the functions of a first access network device, and a communication device as described in the twelfth aspect for implementing the functions of a second access network device.

[0061] Optionally, the communication system may also include the communication means described in the eleventh aspect for implementing the functions of the remote device.

[0062] Optionally, the communication system may further include the communication means described in the eleventh aspect for implementing the functions of the first relay device.

[0063] In a seventeenth aspect, a communication system is provided, comprising the communication apparatus described in the eleventh aspect for implementing the functions of a terminal device or a remote device, and the communication apparatus described in the twelfth aspect for implementing the functions of a first relay device. Attached Figure Description

[0064] Figure 1 This is a schematic diagram illustrating an application scenario according to an embodiment of this application;

[0065] Figures 2-6 Flowcharts of several communication methods provided in the embodiments of this application;

[0066] Figure 7 A schematic diagram of an apparatus provided in an embodiment of this application;

[0067] Figure 8 This is a schematic diagram of another device provided in an embodiment of this application. Detailed Implementation

[0068] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the embodiments of this application will be further described in detail below with reference to the accompanying drawings.

[0069] The following explanations of some terms or concepts used in the embodiments of this application are provided to facilitate understanding by those skilled in the art.

[0070] In this embodiment, the terminal device is a device with wireless transceiver capabilities, which can be a fixed device, a mobile device, a handheld device (e.g., a mobile phone), a wearable device, an in-vehicle device, or a wireless device (e.g., a communication module, a modem, or a chip system, etc.) built into the aforementioned devices. The terminal device is used to connect people, objects, machines, etc., and can be widely used in various scenarios, including but not limited to the following: cellular communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) communication, machine-to-machine / machine-type communications (M2M / MTC) communication, Internet of Things (IoT), virtual reality (VR), augmented reality (AR), industrial control, self-driving, remote medical care, smart grid, smart furniture, smart office, smart wearables, smart transportation, smart city, drones, robots, and other scenarios. The terminal device may sometimes be referred to as user equipment (UE), terminal, access station, UE station, remote station, wireless communication equipment, or user device, etc. For ease of description, the terminal device in this application embodiment will be described using UE as an example.

[0071] The network devices in this application embodiment may include, for example, access network devices and / or core network devices. The access network devices are devices with wireless transceiver capabilities, used to communicate with the terminal devices. The access network devices include, but are not limited to, base stations (base transceiver stations, BTS, Node B, eNodeB / eNB, or gNodeB / gNB), transmission reception points (TRPs), base stations evolved from the 3rd generation partnership project (3GPP), access nodes in Wi-Fi systems, wireless relay nodes, wireless backhaul nodes, etc. The base stations may be: macro base stations, micro base stations, pico base stations, small cells, relay stations, etc. Multiple base stations can support networks using the same access technology or networks using different access technologies. A base station may contain one or more co-located or non-co-located transmission and reception points. The access network equipment can also be a radio controller, centralized unit (CU), and / or distributed unit (DU) in a cloud radio access network (CRAN) scenario. The access network equipment can also be a server, etc. For example, in vehicle-to-everything (V2X) technology, the access network equipment can be a roadside unit (RSU). The following description uses a base station as an example. A base station can communicate with a terminal device, or it can communicate with a terminal device through a relay station. A terminal device can communicate with multiple base stations in different access technologies. The core network equipment is used to implement functions such as mobility management, data processing, session management, policy and billing. The names of the equipment implementing core network functions may differ in systems using different access technologies; this application does not limit this. Taking a 5G system as an example, the core network equipment includes: access and mobility management function (AMF), session management function (SMF), policy control function (PCF), or user plane function (UPF), etc.

[0072] In this application embodiment, the communication device used to implement the network device function can be a network device itself, or it can be a device capable of supporting the network device in implementing that function, such as a chip system. This device can be installed within the network device. In the technical solutions provided in this application embodiment, the example of a network device being used to implement the network device function is used to describe the technical solutions provided in this application embodiment.

[0073] In this application embodiment, the number of nouns, unless otherwise specified, refers to "singular nouns or plural nouns," that is, "one or more." "At least one" means one or more, and "more than one" means two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, or B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the related objects before and after are in an "or" relationship. For example, A / B means: A or B. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c means: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0074] The ordinal numbers such as "first" and "second" mentioned in the embodiments of this application are used to distinguish multiple objects and are not used to limit the size, content, order, timing, priority, or importance of the multiple objects. For example, the first cell and the second cell can be the same cell or different cells, and such names do not indicate differences in the location, coverage area, corresponding access network equipment, priority, or importance of the two cells. In addition, the numbering of steps in the various embodiments described in this application is only to distinguish different steps and is not used to limit the order of steps. For example, S201 may occur before S202, or may occur after S202, or may occur simultaneously with S202.

[0075] When a UE camps on a cell, it can be determined whether it can function as a remote UE within that cell. This can be achieved by assessing the cell's signal strength. For example, the UE can determine whether it can receive and / or send discovery messages on the sidelink (SL) based on certain threshold rules, further aiding in determining whether access stratum (AS) thresholds are met. For instance, based on base station configuration (such as system information configuration), if the UE's signal quality in the cell is below a threshold (e.g., the highest threshold for remote UEs (threshHighRemote)) minus an offset, the UE is considered eligible to function as a remote UE in that cell; conversely, if the signal quality is above a threshold (e.g., threshHighRemote), the UE is considered not eligible to function as a remote UE in that cell. This offset could be, for example, hystMaxRemote.

[0076] If a remote UE can function as a remote UE in its current camping cell, it can find and connect to a relay UE, allowing the remote UE to camp in that cell. The relay UE's cell can be either its camping cell or its serving cell. For a remote UE camping in the relay UE's cell, it can obtain the NCI (Network Cell Identity) of that cell via a discovery message from the relay UE. The NCI is a unique cell ID within a public land mobile network (PLMN). The high-order bits of the NCI indicate a unique gNB ID within the PLMN, while the low-order bits indicate the cell ID under that gNB ID. Currently, the remote UE can also obtain the PCI (Position Identity) of the relay UE's cell. The PCI is a unique cell ID under the Uu frequency band where the relay UE camps or operates.

[0077] Once a remote UE finds a relay UE and establishes a connection, the remote UE can determine whether it can continue operating as a remote UE. To do this, the remote UE can measure the cell where the relay UE is operating or camping, and make a judgment based on the measurement results. To measure the cell where the relay UE is operating or camping, it is first necessary to determine the cell where the relay UE is operating or camping. Specifically, the remote UE can blindly search on various frequency points, searching for the corresponding cell based on the known PCI of the cells where the relay UE is operating or camping. After determining a cell, the remote UE reads the SIB1 of that cell and determines whether the NCI broadcast by SIB1 is the same as the NCI obtained from the relay UE. If the two NCIs are the same, the remote UE can determine that the cell is the cell where the relay UE is operating or camping; otherwise, the remote UE needs to continue searching.

[0078] It is evident that the current time required for a remote UE to find a cell where a relay UE is working or camped is relatively long, and the power consumption is relatively high because it needs to blindly search on multiple frequency points.

[0079] Therefore, the technical solution of this application embodiment is provided. In this application embodiment, the terminal device can obtain the frequency information of the cell where the first relay device is located, and thus determine the cell based on the frequency information and the cell's PCI, without blindly searching on multiple frequency points, reducing the process of blindly searching frequency points and saving the time required to find the cell. Moreover, by reducing the process of blindly searching frequency points, the power consumption of the terminal device is also saved.

[0080] The technical solutions provided in this application can be applied to fourth-generation (4G) mobile communication technology systems, such as long-term evolution (LTE) systems, or to 5G systems, such as new radio (NR) systems, or to next-generation mobile communication systems or other similar communication systems, without any specific limitations.

[0081] This application relates to a UE-to-network relay mechanism, which can be used to improve cellular network coverage. Its topology is as follows: Figure 1 As shown, Figure 1This can also be considered a communication network architecture used in the embodiments of this application. The relay UE is within the coverage area of ​​the radio access network (RAN) node (which can be understood as a cellular base station) of the cellular network; that is, the relay UE can communicate directly with the RAN through the Uu interface. The remote UE can communicate with the relay UE through the PC5 interface, sending data from the remote UE to the relay UE. Then, the relay UE forwards the data from the remote UE to the RAN and the core network through the Uu interface, interacting with the data network (DN) through the core network. Alternatively, data from the DN to be sent to the remote UE arrives at the core network, which sends the data to the RAN. The RAN then sends the data to the relay UE through the Uu interface, and the relay UE forwards the data to the remote UE through the PC5 interface. Figure 1 In this context, the core network is taken as an example, specifically the 5G core network (5Gcore, 5GC).

[0082] To better illustrate the embodiments of this application, the methods provided by the embodiments of this application are described below with reference to the accompanying drawings. In the accompanying drawings corresponding to the various embodiments of this application, all optional steps are represented by dashed lines. For ease of description, the various embodiments of this application use UE as an example for the terminal device, remote UE as an example for the remote device, and relay UE as an example for the relay device (for example, the first relay device is represented by the first relay UE). The methods provided by the various embodiments of this application can be applied to... Figure 1 The network architecture shown, for example, the remote UE or UE involved in the various embodiments of this application, is... Figure 1 The remote UE in this application refers to the access network device or the second access network device involved in the various embodiments of this application. Figure 1 In the context of the RAN, the relay UE or the first relay UE involved in the various embodiments of this application is... Figure 1 The relay UE in the application. Additionally, in various embodiments of this application, the air interface is, for example, a Uu interface.

[0083] This application provides a first communication method, please refer to [link to relevant documentation]. Figure 2 Here is a flowchart of the method.

[0084] S201, The UE determines that it can function as a remote UE.

[0085] For example, the UE can perform measurements on a second cell and obtain the measurement results. The second cell is either the UE's current serving cell or the cell where the UE is currently camped. Additionally, the UE can read the system information of the second cell and determine whether it can act as a remote UE based on a first threshold and offset provided in the system information. For example, if the measurement result is lower than the difference between the first threshold and the offset, the UE can act as a remote UE and can begin searching for a relay UE; for example, the UE can execute S202. However, if the measurement result is higher than or equal to the difference between the first threshold and the offset, the UE may or may not be a remote UE, and subsequent steps are unnecessary.

[0086] S201 is an optional step. For example, the UE may not need to execute S201, but can directly execute S202.

[0087] S202. The UE obtains the frequency information of the first cell. The first cell is the cell where the first relay UE is located. The cell where the first relay UE is located may be, for example, the serving cell or primary cell (PCell) of the first relay UE (e.g., the first relay UE is in a connected state of radio resource control (RRC), or the cell where the first relay UE is camped (e.g., the first relay UE is in an idle state of RRC or an inactive state of RRC). When the UE searches for a relay UE, it may involve information exchange with multiple relay UEs. This embodiment of the application uses the interaction between the UE and the first relay UE as an example for illustration.

[0088] Optionally, the UE may obtain the frequency information of the first cell in two ways, which will be described separately below. Since the following text involves the UE and the first relay UE, for ease of distinction, the UE will be temporarily referred to as the remote UE in the descriptions of the following steps. However, this remote UE has not actually connected to the network through the first relay UE; it only expects to connect to the network through the first relay UE.

[0089] 1. The first method.

[0090] In the first method, the relay UE sends a message, which can be called the first message. The first message may include the frequency information of the first cell, or it may indicate the frequency information of the first cell even if it doesn't explicitly include it. After receiving the first message, the remote UE can determine the frequency information of the first cell. This frequency information may include, for example, the absolute radio frequency channel number (ARFCN) or band of the first cell.

[0091] The first message can be a discovery message, a PC5 RRC message, or an RRC message from the serving access network device of the first relay UE. This is equivalent to the serving access network device sending the first message to the remote UE through the first relay UE. If the first message is a discovery message, the remote UE can receive it after establishing a connection with the first relay UE, or it can receive it before establishing a connection, which helps the remote UE obtain the frequency information of the first cell as quickly as possible. Optionally, if the first message is a discovery message, the first relay UE can send it via broadcast or unicast.

[0092] If the first message is a PC5 RRC message, the remote UE can receive the first message from the first relay UE after establishing a connection with the first relay UE. The first relay UE can send the first message via broadcast or unicast.

[0093] If the first message comes from the serving access network device of the first relay UE, then the remote UE can receive the first message from the first relay UE after establishing a connection with the first relay UE, and both the remote UE and the first relay UE may be in RRC connection state.

[0094] Optionally, the first message may also include the identifier of the first cell, which may include, for example, the NCI and / or PCI of the first cell. That is, the identifier of the first cell and the frequency information of the first cell may be sent in a single message. Alternatively, the first message may not include the identifier of the first cell. For example, the remote UE obtains the identifier of the first cell through a message other than the first message, such as a discovery message, a PC5 RRC message, or an RRC message from the serving access network device of the first relay UE. This message may be of the same type as the first message (e.g., both are discovery messages) or may be different (e.g., this message is a PC5 RRC message, and the first message is a discovery message).

[0095] Optionally, the first message may also include first information, which may indicate whether the first cell is in an access-barred state or not. The first information could be, for example, cell bar information. If the first cell is in a cell bar state, it indicates that the first cell is in an access-barred state; if the first cell is not in a cell bar state, it indicates that the first cell is not in an access-barred state. If the first cell is in an access-barred state, the remote UE should, in principle, not access the first cell; if the first cell is not in an access-barred state, the remote UE can access the first cell. By using the first information, the remote UE can determine as early as possible whether access to the first cell is permitted, thereby minimizing the probability of accessing an unsuitable cell.

[0096] Alternatively, the first information may not be included in the first message, but may be sent to the remote UE through other messages. This message may be, for example, a discovery message, a PC5 RRC message, or an RRC message from the serving access network device of the first relay UE. This message may be of the same type as the first message (e.g., both are discovery messages), or it may be different (e.g., this message is a discovery message, and the first message is a PC5 RRC message).

[0097] If the first message includes first information, it may optionally also include second information. The second information may indicate whether searching for an accessible cell at the frequency of the first cell is permitted when the first cell is in an access-deprived state. Alternatively, the second information may indicate whether searching for an accessible cell at the same frequency as the first cell is permitted when the first cell is in an access-deprived state. The second information may be, for example, intraFreqReselection (IFRI), or other information. For instance, if the second information indicates that searching for an accessible cell at the frequency of the first cell is permitted when the first cell is in an access-deprived state (e.g., the second information is an IFRI indicating "allow"), then if the first information indicates that the first cell is in an access-deprived state, the remote UE can continue searching for other cells at the frequency of the first cell to determine whether other cells are accessible. If the second information indicates that searching for accessible cells is not allowed at the frequency of the first cell when the first cell is in an access-prohibited state (e.g., the second information is an IFR indicating "not allow"), then if the first information indicates that the first cell is in an access-prohibited state, the remote UE cannot search for other cells at the frequency of the first cell. In this case, the remote UE can end the cell search process, or the remote UE can search for cells at other frequencies. For example, if other cells at the frequency of the first cell may have high load, or other cells at the frequency of the first cell may be in a cell bar state, then the second information can indicate that searching for accessible cells at the frequency of the first cell is not allowed. This can reduce the invalid search process of the remote UE and save the power consumption of the remote UE.

[0098] Alternatively, the second information may not be included in the first message, but may be sent to the remote UE via another message. This message could be a discovery message, a PC5 RRC message, or an RRC message from the serving access network device of the first relay UE. This message may be of the same type as the first message (e.g., both are discovery messages), or it may be different (e.g., this message is a discovery message, and the first message is a PC5 RRC message). Furthermore, the message including the first information and the message including the second information may be the same message or different messages.

[0099] 2. The second method.

[0100] In the second approach, the remote UE can first send a message to the relay UE, which can be called the second message. After receiving the second message, the relay UE can send a message to the remote UE, which can be called the first message. The first message may include the frequency information of the first cell, or although it may not include the frequency information of the first cell, it may indicate the frequency information of the first cell. After receiving the first message, the remote UE can determine the frequency information of the first cell. The frequency information of the first cell may be, for example, the ARFCN or band information of the first cell.

[0101] The second message may be a discovery message, a PC5 RRC message, or an RRC message sent to the serving access network device of the first relay UE. The second message may be of the same type as the first message (e.g., both are discovery messages) or different (e.g., the second message is a discovery message, and the first message is a PC5 RRC message). If the second message is a discovery message, the remote UE can send it after establishing a connection with the first relay UE, or it can send it before establishing a connection with the first relay UE, which helps the remote UE obtain the frequency information of the first cell as quickly as possible. Optionally, if the second message is a discovery message, the remote UE can send it via broadcast or unicast.

[0102] If the second message is a PC5 RRC message, the remote UE can send the second message to the first relay UE after establishing a connection with the first relay UE. The first relay UE can send the first message via broadcast or unicast.

[0103] If the second message is sent to the serving access network device of the first relay UE, then the remote UE can send the second message to the first relay UE after establishing a connection with the first relay UE, and both the remote UE and the first relay UE may be in RRC connection state.

[0104] Optionally, the second message includes the identifier of the cell in which the remote UE is working or camped, such as referred to as the second cell, and the identifier of the second cell includes, for example, the NCI and / or PCI of the second cell.

[0105] Alternatively, the second message may include query information, which can be used to inquire (or query, or request) the air interface frequency at which the first relay UE operates or camps, or to inquire (or query, or request) whether the first relay UE operates or camps on a certain air interface frequency (or, to inquire whether the first relay UE operates or camps on a cell at a certain air interface frequency), for example, the air interface frequency being the first frequency. If the query information is used to inquire about the air interface frequency at which the first relay UE operates or camps, then the query information may not include specific air interface frequency information, but only inquire about the air interface frequency at which the first relay UE operates or camps. After receiving the query information, the first relay UE can indicate (or include) the frequency information at which the first relay UE operates or camps through a first message sent to the remote UE. For example, the first message may include or indicate the frequency information of the first cell, which is the cell at which the first relay UE operates or camps.

[0106] Alternatively, if the query information is used to inquire whether the first relay UE is operational or camped on a first frequency, the query information may include information about the first frequency. This first frequency might be, for example, the air interface frequency on which the relay UE, which the remote UE expects to serve, is operational or camped. The first frequency information might include, for example, ARFCN or band information. After receiving the query information, if the first relay UE is operational or camped on the first frequency—for example, if the frequency corresponds to the ARFCN, or if the frequency belongs to the band—then the first relay UE can send a first message to the remote UE. In this case, the first message may include or indicate the frequency information of the cell in which the first relay UE operates or camps; alternatively, the first message may not include or indicate the frequency information of the cell in which the first relay UE operates or camps. For example, the first message may indicate that the first relay UE is camped on a first frequency, or indicate that the first relay UE is camped on a cell at the first frequency. For instance, the first message can indicate this using only one bit, thus saving the overhead of the first message. It is also possible that the frequency in which the first relay UE operates or camps is not the first frequency. In this case, the first relay UE may not send a message to the remote UE (e.g., not send the first message), or the first relay UE may send a message to the remote UE that includes or indicates the frequency information of the cell in which the first relay UE operates or camps, or indicates that the first relay UE is not camped on the first frequency.

[0107] Alternatively, the first frequency information may not include ARFCN or band information, but may include other information. For example, if a remote UE wants to find a relay UE camped at a high frequency on the air interface to improve its data rate, the first frequency information included in the query message could be a frequency threshold, with air interface frequencies above this threshold considered as meeting the condition. After receiving the query message, if the first relay UE operates or camps at the first frequency, for example, if the frequency of the first relay UE's operation or camping is higher than the frequency threshold, the first relay UE can send a first message to the remote UE. In this case, the first message may include or indicate the frequency information of the cell in which the first relay UE operates or camps; or, the first message may not include or indicate the frequency information of the cell in which the first relay UE operates or camps. For example, the first message may indicate that the first relay UE is camped at the first frequency, or indicate that the first relay UE is camped at a cell at the first frequency. For example, the first message can indicate this with just one bit, thus saving the overhead of the first message. It is also possible that the frequency at which the first relay UE operates or camps is not the first frequency. In this case, the first relay UE may not send a message to the remote UE (e.g., not send the first message), or the first relay UE may send a message to the remote UE that includes or indicates the frequency information of the cell in which the first relay UE operates or camps, or indicates that the first relay UE is not camping on the first frequency.

[0108] Optionally, if the first relay UE is a release 17 UE, and if the second message includes the NCI of the second cell, then if the first relay UE determines that the NCI of the second cell is the same as the NCI of the first cell, the first relay UE can determine the content of the first message or determine whether to send the first message according to the above method; however, if the first relay UE determines that the NCI of the second cell is different from the NCI of the second cell, then the first relay UE may not send a message to the remote UE (e.g., not send the first message). This is because a different NCI may indicate that the access network equipment corresponding to the first cell is different from the access network equipment corresponding to the second cell. Release 17 requires that in the case of co-location, a UE can switch from a direct connection path with the access network equipment to an indirect connection path accessed through the relay UE. Therefore, if the NCI of the second cell is different from the NCI of the second cell, it indicates that the remote UE and the first relay UE are under different access network equipment, and the remote UE cannot access through the first relay UE. Therefore, in this case, the first relay UE does not need to reply to the remote UE.

[0109] Regarding the implementation method of the first message, such as the type of the first message or the content it includes (e.g., it may include the identifier of the first cell, the first information, or one or more of the second information), please refer to the introduction above.

[0110] The remote UE can obtain the frequency information of the first cell through either of the two methods described above. Alternatively, the remote UE can obtain the frequency information of the first cell through other methods besides those described above, and this application embodiment does not impose any restrictions.

[0111] S203. The remote UE establishes a connection with the first relay UE. The connection established between the remote UE and the first relay UE can be a sideline connection.

[0112] The remote UE may have performed an interaction process similar to S202 with multiple relay UEs. In S203, the remote UE can establish a connection with some or all of the multiple relay UEs. This embodiment of the application takes the establishment of a connection between the remote UE and the first relay UE as an example.

[0113] If the remote UE obtains the first information, and if the first information indicates that the first cell is not in an access-blocked state, then S203 and subsequent steps can be executed. If the first information indicates that the first cell is in an access-blocked state, then the remote UE does not need to execute S203 and subsequent steps; for example, the remote UE can re-search for cells and reselect a relay UE. If the remote UE needs to re-search for cells, and the remote UE has obtained the second information, then if the second information indicates that searching for accessible cells at the frequency of the first cell is allowed when the first cell is in an access-blocked state, then the remote UE can continue searching for cells at the frequency of the first cell. However, if the second information indicates that searching for accessible cells at the frequency of the first cell is not allowed when the first cell is in an access-blocked state, then the remote UE can choose not to search for cells at the frequency of the first cell; for example, the remote UE can search for cells at frequencies other than that frequency, or the remote UE can stop the search process and end the procedure. If the remote UE searches for cells at frequencies other than this frequency, and if the remote UE identifies a relay UE during the search process, the remote UE needs to determine whether the frequency of the cell in which the relay UE is operating or camped is the frequency of the first cell. If the frequency of the cell in which the relay UE is operating or camped is the frequency of the first cell, the remote UE needs to abandon the relay UE.

[0114] S203 is an optional step; the remote UE may not establish a connection with the first relay UE. Furthermore, S203 may occur after S202 or before S202.

[0115] Optionally, the remote UE can also obtain the PCI of the first cell. For example, after establishing a connection with the remote UE, the first relay UE can send the PCI of the first cell to the remote UE. Alternatively, after establishing a connection with the first relay UE, the remote UE may also wish to establish a connection with the access network device corresponding to the first cell. In this case, the remote UE can send an RRC establishment request message to the access network device. After receiving the RRC establishment request message, the access network device can send an RRC establishment response message to the remote UE, which may include the PCI of the first cell.

[0116] As mentioned earlier, the first message may include the identifier of the first cell, which may include the PCI of the first cell. This scheme does not conflict with the scheme here where the remote UE obtains the PCI of the first cell. For example, the remote UE may receive the PCI of the first cell multiple times. Alternatively, the identifier of the first cell included in the first message mentioned earlier may also be the NCI of the first cell, in which case the remote UE can also obtain the PCI of the first cell.

[0117] S204. The remote UE determines the first cell based on the frequency information and identifier of the first cell. This can also be understood as the remote UE searching for or finding the first cell.

[0118] For example, if the identifier of the first cell is its PCI, the remote UE searches at the frequency corresponding to the frequency information of the first cell, and may find one or more cells. Based on the PCI of the first cell, the remote UE can uniquely identify one cell from these cells. Optionally, after identifying the cell, the remote UE can also read system information such as SIB1 within that cell, determine the NCI of the cell based on SIB1, and compare the NCI of this cell with the NCI of the first cell. If they match, the remote UE can identify this cell as the first cell.

[0119] Alternatively, if the identifier of the first cell is the NCI of the first cell, then the remote UE searches at the frequency corresponding to the frequency information of the first cell, for example, searching for one or more cells. The remote UE can read system information such as SIB1 in each searched cell, determine the NCI of each cell based on SIB1, and compare the read NCI with the NCI of the first cell. If the NCI of a certain cell matches the NCI of the first cell, then the remote UE can determine that cell is the first cell.

[0120] As can be seen, the remote UE can obtain the frequency information of the first cell where the first relay UE is located. Based on this frequency information and the identifier of the first cell, it can determine the first cell without blindly searching multiple frequency points, thus reducing the time required for cell location. Furthermore, reducing the blind frequency search process also saves power consumption for the remote UE.

[0121] S205, remote UE performs measurements on the first cell.

[0122] For example, a remote UE receives a downlink reference signal in the first cell. This downlink reference signal may be, for example, a synchronization signal and physical broadcast channel block (SSB) or a channel state information-reference signal (CSI-RS). Measuring this downlink reference signal by the remote UE can be considered as measuring the first cell.

[0123] S206. The remote UE determines whether it can function as a remote UE in the first cell based on the measurement results. Alternatively, the remote UE determines whether it can access the first cell via a relay UE based on the measurement results. Alternatively, the remote UE determines whether it can function as a remote UE based on the measurement results.

[0124] For example, a remote UE assesses the access layer (AS layer) status by determining whether it can receive or send discovery messages on the sidelink based on whether threshold conditions are met. For instance, if the measurement result for the first cell (serving cell, primary cell, or camped cell) is lower than threshold A (e.g., threshHighRemote) minus the offset, the remote UE is deemed to meet the threshold condition and can function as a remote UE in the first cell; conversely, if the measurement result for the first cell (serving cell, primary cell, or camped cell) is higher than threshold A, the remote UE is deemed not to meet the threshold condition and does not meet the conditions for functioning as a remote UE in the first cell. The offset, for example, is hystMaxRemote.

[0125] If the remote UE can function as a remote UE in the first cell, it can connect to the first cell through the first relay UE. However, if the measurement result is higher than threshold A, the remote UE can directly access the first cell with better signal quality, and therefore the remote UE can access the first cell by directly connecting to the access network equipment.

[0126] Optionally, S206 can occur after the remote UE detects poor signal on the sidelink and triggers relay reselection. For example, if the remote UE finds that the sidelink quality (e.g., RSRP) is less than a certain threshold B, it triggers relay reselection. After the remote UE reselects to the first relay UE, it triggers the remote UE to measure and determine the serving cell or camping cell of the reselected first relay UE. Optionally, when the sidelink quality (e.g., RSRP) between the remote UE and the first relay UE is greater than a certain threshold, the remote UE may not measure and determine the serving cell or camping cell of the first relay UE, thereby saving power consumption.

[0127] Alternatively, S206 can also occur after the remote UE discovers that the signal quality (e.g., RSRP) on the sidelink is worse than a threshold C. For example, if the remote UE discovers that the sidelink quality (e.g., RSRP) is less than a certain threshold C, relay reselection may not be triggered, but the remote UE can still measure and determine the serving cell or camping cell of the currently connected first relay UE. Optionally, when the sidelink quality (e.g., RSRP) between the remote UE and the first relay UE is greater than a certain threshold, the remote UE may choose not to measure and determine the serving cell or camping cell of the relay UE, thereby saving power consumption.

[0128] In this embodiment, the UE can obtain the frequency information of the cell where the relay UE is located. Based on this frequency information and the cell's identifier, the UE can determine the cell without blindly searching multiple frequency points, reducing the blind search process and saving time required to find the cell. Furthermore, reducing the blind search process also saves UE power consumption. Additionally, the UE can obtain first information, or both first and second information, thereby reducing invalid search processes and further saving power.

[0129] Currently, when a remote UE is served in RRC connected mode, the remote UE may move or experience link obstruction, leading to a deterioration in the connection quality between the remote UE and the access network device, and service quality cannot be guaranteed. In this situation, the access network device can switch the remote UE from a direct link to the access network device to an indirect link connected via a relay UE. This switching process is also called path switching. For example, when the Uu interface connection quality between the remote UE and the access network device deteriorates, the access network device can configure measurement objects for the remote UE. These measurement objects can include Uu interface measurement objects and SL measurement objects. Uu interface measurement objects, for example, include the frequencies of the Uu interface, which the remote UE can measure. SL measurement objects, for example, include the frequencies of the SL interface, which the remote UE can measure relay UEs operating on these frequencies on the sidelink. After completing the measurement, the remote UE can send the measurement results to the access network device, which can include the Uu interface measurement results and the SL measurement results. Access network equipment can determine whether the remote UE is undergoing cell handover or switching from a direct link to an indirect link based on the measurement results.

[0130] When a remote UE sends SL measurement results to the access network device, it may also send the ID of the serving cell of the relay UE being measured. The access network device can identify the serving cell based on this ID. However, if the serving cell is not provided by the access network device, the access network device cannot determine the frequency of the serving cell. Generally, the serving cell of the relay UE is a high-frequency cell of FR2 (i.e., a frequency greater than 6GHz), such as a serving cell frequency of 28GHz or a serving cell operating on band n257. After the remote UE switches to this relay UE, because the serving cell of the relay UE has a larger bandwidth (usually 400MHz), the relay UE can obtain a higher data rate. Therefore, for remote UEs with high traffic, it is generally desirable to connect to a relay UE with a higher frequency in its serving cell. For example, if the access network device determines that a remote UE is switching to an indirect link based on measurement results, it can identify a relay UE. However, since the frequency of the serving cell for some relay UEs is unknown to the access network device, it may simply select a relay UE randomly, and the selected relay UE may be serving a low-frequency cell. Therefore, under the current scheme, the data rate of the relay UE selected by the access network device cannot be guaranteed for the remote UE.

[0131] Another scenario is when a remote UE is served in RRC connected mode. Because the remote UE has high service demands, such as users needing to watch high-definition video, a direct air interface connection or transmission via only a relay is insufficient to provide a good service quality. Therefore, the remote UE also needs to find a relay UE that can provide a higher data rate.

[0132] Therefore, this application provides a second communication method. In this method, the access network device can configure cell information or air interface frequency information that the relay UE needs to meet for the remote UE. This allows the access network device to clearly identify the cell information or air interface frequency information of the relay UE measured by the remote UE. When selecting a relay UE for the remote UE, the access network device can prioritize selecting relay UEs that meet the conditions, such as selecting relay UEs with higher frequencies in their respective cells, thereby improving the data rate of the remote UE. Please refer to... Figure 3 Here is a flowchart of the method.

[0133] S300: The remote UE sends auxiliary information to the first access network device. Correspondingly, the first access network device receives the auxiliary information from the remote UE. This auxiliary information may indicate that the remote UE wishes to add a relay path, for example, if the remote UE system wants to improve data rate or reliability, it may wish to add a relay path; or, the auxiliary information may indicate that the remote UE wishes to switch to a relay path, for example, if the remote UE wishes to reduce power consumption, it may wish to switch to a relay path.

[0134] Step S300 is optional. Step S300 can occur before the remote UE finds the first relay UE, or it can occur after the first relay UE has been found.

[0135] S301. The first access network device sends configuration information to the remote UE. Correspondingly, the remote UE receives configuration information from the first access network device. The first access network device is, for example, the serving access network device of the remote UE (e.g., the remote UE is in RRC connected state), or the access network device to which the remote UE is camped (e.g., the remote UE is in RRC idle state or RRC inactive state). The first access network device can send configuration information to the remote UE directly or through other relay devices, and correspondingly, the remote UE can receive configuration information from the first access network device directly or through other relay devices. Because this embodiment may involve the remote UE changing its communication path, the first access network device can also be referred to as the source access network device.

[0136] This configuration information can be used to configure SL measurement objects (MOs), which include, for example, measurement frequencies on the SL. One SL measurement object can be considered as one SL measurement frequency, and this configuration information can be used to configure one or more SL measurement objects. The measurement frequency on the SL refers to the frequency at which a remote UE can measure a relay UE operating on the sidelink. Optionally, this configuration information can also be used to configure cell information or Uu interface frequency information (or air interface frequency information). The cell information includes, for example, the cell that the relay UE operating on the SL measurement object needs to work in or camp on, and the air interface frequency information includes, for example, the frequency of the cell that the relay UE operating on the SL measurement object needs to work in or camp on. Specifically, if a UE is in RRC connected state, then the UE is considered to be working in the cell it currently resides in, i.e., the serving cell of the UE; while if a UE is in RRC idle state or RRC inactive state, then the UE is considered to be camping in the cell it currently resides in. Optionally, cell information may include, for example, the cell identifier, which may include, for example, the cell's PCI and / or NCI, or may also include other identifiers of the cell; air interface frequency information may include, for example, ARFCN or band information, etc.

[0137] The remote UE can filter the relay UEs to be measured based on this configuration information. For example, if the configuration information specifies the SL measurement object and cell information, then the relay UEs that the remote UE needs to measure include those operating on the SL measurement object on the sidelink and that are already camped (or active) or able to camp (or able to work) on the cell corresponding to the cell information. For example, if the SL measurement object configured in this configuration information includes frequency f1, and the cell information configured in this configuration information includes cell c1, then the remote UE can perform measurements on the relay UE operating on frequency f1 on the sidelink and that are already camped (or active) or able to camp (or able to work) on cell c1 on the Uu interface. As another example, if the configuration information specifies the SL measurement object and air interface frequency information, then the relay UEs that the remote UE needs to measure include those operating on the SL measurement object on the sidelink and that are already camped (or active) or able to camp (or able to work) on the cell at the frequency corresponding to the air interface frequency information. For example, if the SL measurement object configured in this configuration information includes frequency f1, and the air interface frequency information configured in this configuration information includes frequency f2, then the remote UE can perform measurements on a relay UE that is operating on frequency f1 and is camped (or already working) or able to camp (or able to work) on frequency f2 in the Uu interface.

[0138] Alternatively, this configuration information can also configure the air interface measurement object (or Uu interface measurement object). The air interface measurement object may include, for example, air interface frequency information, or air interface frequency information and cell information. For distinction, the cell information included in the SL measurement object configured in this configuration information can be called the first cell information, the air interface frequency information included in the SL measurement object can be called the first air interface frequency information, the cell information included in the air interface measurement object configured in this configuration information can be called the second cell information, and the air interface frequency information included in the air interface measurement object can be called the second air interface frequency information. It is important to note that the first cell information and the first air interface frequency information are not used for measurement by the remote UE. That is, the remote UE does not need to measure the first cell information or the first air interface frequency information on the air interface. The first cell information and the first air interface frequency information are used by the remote UE to filter relay UEs that need to be measured, or to filter relay UEs that need to send measurement reports to the first access network device. However, the second cell information and the second air interface frequency information are used for remote UE to perform measurements. That is, the remote UE can perform measurements on the air interface of the cell corresponding to the second cell information or the cell at the frequency corresponding to the second air interface frequency information.

[0139] For the first access network device, the communication path of the remote UE can be determined based on this configuration information. For example, the communication path determined by the first access network device for the remote UE can be a single-connection path, such as a path where the remote UE is directly connected to the access network device, which could be the first access network device or another access network device. In this case, the remote UE may or may not need to perform a cell handover. Alternatively, the single-connection path could be a path where the remote UE connects to the network through a relay UE, and the remote UE connects to the access network device where the relay UE is located, which could be the first access network device or another access network device. Alternatively, the communication path determined by the first access network device for the remote UE may also be a dual-connection or multi-connection path. Taking a dual-connection path as an example, the dual-connection path may include two paths on the air interface for the remote UE to connect to two cells respectively. These two cells may correspond to the same access network device or different access network devices. Alternatively, the dual-connection path may include a path for the remote UE to connect to a cell on the air interface, and a path for it to connect to the network through a relay UE. The cell and the cell where the relay UE is located may be the same cell or different cells. If these two cells are different cells, they may correspond to the same access network device or different access network devices. Alternatively, the dual-connection path may include paths for the remote UE to connect to the network through two relay UEs respectively. The cells where these two relay UEs are located may be the same cell or different cells. If these two cells are different cells, they may correspond to the same access network device or different access network devices.

[0140] The first access network device needs to determine the communication path of the remote UE based on the configuration information, which can be achieved in the following ways, as described in S302 to S304.

[0141] S302. The remote UE performs measurements on the first type of relay UE based on the configuration information. Alternatively, S302 can be replaced with: The remote UE determines the first type of relay UE based on the configuration information and performs measurements on the first type of relay UE.

[0142] The first type of relay UE is determined based on configuration information. For example, if the configuration information specifies the SL measurement object and the first cell information, then the first type of relay UE can include relay UEs that operate on the SL measurement object and are camped (or have already worked) or are capable of camping (or are capable of working) in the cell corresponding to the first cell information. For example, if the SL measurement object configured in the configuration information includes frequency f1, and the first cell information configured in the configuration information includes cell c1, then the first type of relay UE can include relay UEs that operate on frequency f1 in the side-channel and are camped (or have already worked) or are capable of camping (or are capable of working) in cell c1 on the Uu interface. If a relay UE meets one or more of the following conditions, then the relay UE does not belong to the first type of relay UE: the side-channel operating frequency of the relay UE is not the SL measurement object; the relay UE is not working on the Uu interface and is not camped in the cell corresponding to the first cell information; or, the relay UE cannot work on the Uu interface and cannot camp in the cell corresponding to the first cell information.

[0143] Alternatively, if the configuration information configures the SL measurement object and the first air interface frequency information, then the first type of relay UE can include a relay UE that operates on the SL measurement object and is camped (or already operational) or capable of camping (or capable of operational) in a cell at the frequency corresponding to the first air interface frequency information. For example, if the SL measurement object configured in the configuration information includes frequency f1, and the air interface frequency information configured in the configuration information includes frequency f2, then the first type of relay UE can include a relay UE that operates on frequency f1 in the side-by-side and is camped (or already operational) or capable of camping (or capable of operational) in a cell at frequency f2 on the Uu interface. If a relay UE meets one or more of the following conditions, then the relay UE does not belong to the first type of relay UE: the side-by-side operating frequency of the relay UE is not the SL measurement object; the relay UE is neither operational on the Uu interface nor camped in a cell at the frequency corresponding to the first air interface frequency information; or, the relay UE cannot operate on the Uu interface and cannot camp in a cell at the frequency corresponding to the first air interface frequency information.

[0144] After the remote UE identifies the first type of relay UE, it can perform measurements on this first type of relay UE. It's important to note that the remote UE may only measure the first type of relay UE, omitting measurements for other relay UEs; alternatively, the remote UE may measure other relay UEs in addition to the first type. This application's embodiments primarily describe the process of the remote UE measuring the first type of relay UE. If the remote UE also needs to measure other relay UEs, the measurement process is similar.

[0145] For a remote UE to measure a relay UE, it needs to receive messages from the relay UE to complete the measurement based on the received messages. Optionally, the measurement process of the remote UE can be implemented in different ways, which will be described below. In the following description, the measurement process of a remote UE to a relay UE (e.g., referred to as the first relay UE) will be used as an example.

[0146] 1. The first method.

[0147] In the first approach, the first relay UE can send a message, for example, referred to as the fourth message, as shown in S302a. Optionally, the fourth message may include information about a first frequency, such as the frequency of the cell where the first relay UE resides, or the frequency of the cell where the first relay UE can operate or camp. This "first frequency" can also be referred to as the "third frequency." Optionally, the first frequency information may include, for example, ARFCN or band information. Additionally, the fourth message may optionally include the identifier of the first relay UE, such as the NCI and / or PCI of the first relay UE.

[0148] In various embodiments of this application, if a UE is in RRC connected state, the cell where the UE is located is, for example, the serving cell of the UE, or the cell where the UE is working; or, if a UE is in RRC inactive state or RRC idle state, the cell where the UE is located is, for example, the cell where the UE is camped. That is, "working cell" or "serving cell" corresponds to a UE in RRC connected state; "camped cell" corresponds to a UE in RRC inactive state or RRC idle state.

[0149] The fourth message could be a discovery message, or a PC5 RRC message, etc. For information on these messages, please refer to [link / reference needed]. Figure 2The illustrated embodiment. In S302a, taking the fourth message as a discovery message and including information about the first frequency as an example.

[0150] If the remote UE only measures the first type of relay UE and does not measure other types of relay UE, then the remote UE can determine whether the first relay UE belongs to the first type of relay UE based on the configuration information. For example, if the configuration information configures the first air interface frequency information, and the first frequency belongs to the frequency corresponding to the first air interface frequency information, then the first relay UE belongs to the first type of relay UE, and the remote UE can perform measurements on the first relay UE. However, if the first frequency does not belong to the frequency corresponding to the first air interface frequency information, then the first relay UE does not belong to the first type of relay UE, and the remote UE may not perform measurements on the first relay UE. As another example, if the configuration information configures the first cell information, and the frequency of the first cell belongs to the first frequency (e.g., the frequency of the first cell is the first frequency, or the frequency of the first cell is included in the first frequency (e.g., the first frequency is a band)), then the first relay UE belongs to the first type of relay UE, and the remote UE can perform measurements on the first relay UE. However, if the frequency of the first cell belongs to the first frequency, then the first relay UE does not belong to the first type of relay UE, and the remote UE may not perform measurements on the first relay UE. If the remote UE needs to measure the first relay UE, optionally, the remote UE can perform the measurement of the first relay UE by measuring the fourth message. For example, the remote UE can measure the reference signal receiving power (RSRP) or reference signal receiving quality (RSRQ) of the fourth message.

[0151] Alternatively, if the remote UE can measure other types of relay UEs in addition to the first type of relay UE, then the remote UE can measure the first relay UE regardless of whether the first frequency belongs to or does not belong to the frequency corresponding to the first air interface frequency information, or regardless of whether the frequency of the first cell belongs to or does not belong to the first frequency.

[0152] 2. The second method.

[0153] In the second approach, the remote UE can first send a message to the first relay UE, for example, this message can be called the fifth message. After receiving the fifth message, the first relay UE can send a message to the remote UE, for example, called the sixth message, and the remote UE can perform measurements based on the sixth message. See S302b and S302c for details.

[0154] The fifth message can be used to query (or request) the frequency information of the cell where the first relay UE is located, or to query (or request) the frequency information of the cell where the first relay UE can work or camp, or to query (or request) whether the first relay UE has camped or can camp on a cell under the second frequency. Wherein, if the fifth message is used to query whether the first relay UE has camped or can camp on a cell under the second frequency, then the first relay UE is considered to have met the conditions queried by the fifth message if it has camped on a cell under the second frequency, or although it is not currently camped on a cell, it can camp on a cell under the second frequency, or it is currently working on a cell under the second frequency, or although it is not currently working on a cell, it can work on a cell under the second frequency. The second frequency is, for example, the frequency corresponding to the first air interface frequency information. If the first air interface frequency information is configured with multiple frequencies, the second frequency can include all or some of these frequencies. For example, the "second frequency" here can also be called the "third frequency".

[0155] Specifically, if the fifth message inquires whether the first relay UE is capable of operating or camping on a cell at a certain frequency, it indicates an inquiry into the first relay UE's capabilities. Even if the first relay UE is not currently operating or camping on that frequency, as long as the first relay UE possesses the capability to operate or camp on that frequency, the condition for the fifth message's inquiry is considered met. Alternatively, if the first relay UE is currently operating or camping on that frequency, the condition for the fifth message's inquiry is also considered met. However, if the fifth message inquires whether the first relay UE is operating or camping on a cell at a certain frequency, it indicates an inquiry into the cell the first relay UE is currently in. If the first relay UE is currently operating or camping on that frequency, the condition for the fifth message's inquiry is considered met. If the first relay UE is not currently operating or camping on that frequency, even if the first relay UE possesses the capability to operate or camp on that frequency, the condition for the fifth message's inquiry is not met.

[0156] If the fifth message is used to query the frequency information of the cell where the first relay UE is located, or to query the frequency information of the cell in which the first relay UE can work or camp, then the fifth message may not include specific frequency information. The remote UE can wait for the reply from the first relay UE, which can save the transmission overhead of the fifth message.

[0157] Alternatively, if the fifth message is used to inquire whether the first relay UE is already camped or can camp on a cell in the second frequency, the fifth message may include information about the second frequency, such as ARFCN or band information.

[0158] For the first relay UE, if the fifth message is used to query the frequency information of the cell where the first relay UE is located, the sixth message may include the frequency information of the cell where the first relay UE is currently working or camped.

[0159] Alternatively, if the fifth message is used to query the frequency information of the cell in which the first relay UE can work or camp, the sixth message may include the frequency information of the cell in which the first relay UE can work or camp.

[0160] Alternatively, if the fifth message is used to inquire whether the first relay UE is already camped or can camp on a cell of the second frequency, then the first relay UE may or may not meet the conditions inquired by the fifth message. If the first relay UE is already camped, is operational, can camp, or can operate on a cell of the second frequency, then the first relay UE meets the conditions inquired by the fifth message, and the sixth message may include information about the second frequency; or, the sixth message may also be used to indicate whether the first relay UE is currently camped or can camp on a cell of the second frequency. For example, the sixth message may use a single bit to indicate this, and if the value of the bit is "1", it indicates that the first relay UE is currently camped or can camp on a cell of the second frequency. If the first relay UE is currently not camped, not operating, unable to camp, and unable to operate in a cell at the second frequency, then the first relay UE does not meet the conditions for the fifth message query. In this case, the first relay UE can still send a sixth message to the remote UE. The sixth message may include, for example, the frequency of the cell that the first relay UE is camped on or can camp on, or it may indicate that the first relay UE is not camped on and cannot camp on a cell at the second frequency. For example, the sixth message may use a single bit to indicate this; if the value of this bit is "0", it indicates that the first relay UE is neither camped on nor can camp on a cell at the second frequency. Alternatively, if the first relay UE is currently not camped, not operating, unable to camp, and unable to operate in a cell at the second frequency, then the first relay UE does not meet the conditions for the fifth message query. In this case, the first relay UE may not send a sixth message to the remote UE, and the remote UE will not need to perform measurements on the first relay UE. This method saves signaling overhead and also saves the power consumption of the remote UE.

[0161] If the sixth message includes frequency information of the cell where the first relay UE is currently working or camped, or if the sixth message includes frequency information of the cell where the first relay UE can work or camp, then the frequency corresponding to the frequency information included in the sixth message may belong to the frequency corresponding to the first air interface frequency information, in which case the first relay UE belongs to the first type of relay UE; or, the frequency corresponding to the frequency information included in the sixth message may not belong to the frequency corresponding to the first air interface frequency information, in which case the first relay UE does not belong to the first type of relay UE. The remote UE can only measure the first type of relay UE. If the first relay UE belongs to the first type of relay UE, the remote UE can measure it; if the first relay UE does not belong to the first type of relay UE, the remote UE may not measure it; or, the remote UE can measure other relay UEs in addition to measuring the first type of relay UE, regardless of whether the first relay UE belongs to the first type of relay UE.

[0162] In S302b, the fifth message is a discovery message and includes information about the second frequency, as an example. In S302c, the sixth message is a discovery message and includes frequency information of the cell corresponding to the first relay UE, as an example. The cell corresponding to the first relay UE is, for example, the cell where the first relay UE is currently working or camped, or the cell where the first relay UE can work or camp.

[0163] S303. The remote UE sends the measurement result to the first access network device. Correspondingly, the first access network device receives the measurement result from the remote UE. This measurement result may be, for example, a measurement report, or it can be understood that the measurement result is included in a measurement report. The measurement result can be used to determine the communication path of the remote UE; for example, the first access network device can determine the communication path of the remote UE based on the measurement result.

[0164] Specifically, if the remote UE only measures the first type of relay UE and not other types of relay UE, the measurement result can include the measurement results of the first type of relay UE but not the measurement results of other relay UEs; or, if the remote UE measures other relay UEs in addition to the first type of relay UE, the measurement result still only includes the measurement results of the first type of relay UE and not the measurement results of other relay UEs. That is, even if the remote UE measures multiple types of relay UEs, when sending the measurement results to the first access network device, the remote UE can only send the measurement results of the first type of relay UE, so that the measurement results reported by the remote UE meet the requirements of the first access network device and save transmission overhead.

[0165] Optionally, in addition to sending the measurement results to the first access network device, the remote UE may also send one or more of the following information to the first access network device: the identifier of the relay UE corresponding to the measurement results, the identifier of the cell where the relay UE is located, or the frequency of the relay UE on the Uu interface (e.g., the frequency of the cell where the relay UE is located).

[0166] Optionally, if the remote UE also measures the air interface measurement object, the measurement result may also include the air interface measurement result, such as the cell measurement result.

[0167] For example, a remote UE can send an RRC message to the first access network device. The measurement results can be included in the RRC message. One or more of the following information can also be included in the RRC message: the identifier of the relay UE, the identifier of the cell where the relay UE is located, or the frequency of the relay UE on the Uu interface.

[0168] S304. The first access network device determines the communication path of the remote UE based on the measurement results.

[0169] For example, based on the measurement results, the first access network device can determine whether the communication path of the remote UE is switched to connect to the network through a relay UE or switched to another cell. That is, the communication path determined by the first access network device for the remote UE is a single-connection path. For example, if the measurement results show that the air interface measurement results are better, the first access network device may determine that the communication path of the remote UE is switched to connect to the network through a relay UE; or, if the measurement results show that the SL measurement results are better, the first access network device may determine that the communication path of the remote UE is switched to connect to the network through a relay UE, which is, for example, a relay UE with better measurement results, determined by the first access network device based on the measurement results.

[0170] Optionally, regardless of whether the determined communication path of the remote UE is a handover to another cell or a handover to the network via a relay UE, the first access network device can send a handover request message to the second access network device. This handover request message is, for example, a handover request. If the communication path of the remote UE is a handover to another cell, the second access network device is the access network device corresponding to that cell, for example, the second cell. The handover request message can be used to inquire (or query, or request) whether to accept the remote UE's access to the second cell under the second access network device. If the communication path of the remote UE is a handover to the network via a relay UE, taking the relay UE as an example (e.g., the first relay UE), the second access network device is the access network device corresponding to the cell where the relay UE is working or camped. The handover request message can be used to inquire (or query, or request) whether to accept the remote UE's connection to the network via the first relay UE under the second access network device. Optionally, the handover request message may also include the frequency to which the remote UE is expected to switch and / or the expected quality of service (QoS) information, wherein the frequency to which the remote UE is expected to switch is, for example, the frequency of the second cell or the frequency of the cell where the first relay UE is located.

[0171] After receiving the handover request message, the second access network device can send a handover request response to the first access network device. This handover request response is, for example, a HO response. If the handover request message is used to inquire whether to accept the remote UE's access to the second cell under the second access network device, and if the second access network device can accept the remote UE's access to the second cell under the second access network device, then the HO response is, for example, a HO affirmative response (ACK), to indicate that the second access network device accepts the remote UE's access to the second cell under the second access network device; and if the second access network device cannot accept the remote UE's access to the second cell under the second access network device, then the HO response is, for example, a HO negative response (NACK), to indicate that the second access network device does not accept the remote UE's access to the second cell under the second access network device. Alternatively, if the handover request message is used to inquire whether to accept the remote UE connecting to the network through the first relay UE under the second access network device, and if the second access network device can accept the remote UE connecting to the network through the first relay UE under the second access network device, then the HO response is, for example, HO ACK, to indicate that the second access network device accepts the remote UE connecting to the network through the first relay UE under the second access network device; or, if the second access network device cannot accept the remote UE connecting to the network through the first relay UE under the second access network device, then the HO response is, for example, HO NACK, to indicate that the second access network device does not accept the remote UE connecting to the network through the first relay UE under the second access network device.

[0172] If the handover request response is HO ACK, and HO ACK is used to instruct the second access network device to accept the remote UE connecting to the network through the first relay UE under the second access network device, then optionally, the handover request response may also include the frequency information of the cell where the first relay UE is located, and / or include the PCI of the cell where the first relay UE is located. For the first access network device, if the first air interface frequency information is configured for the remote UE in S301, the first access network device can verify whether the frequency corresponding to the frequency information of the cell where the first relay UE is located belongs to the frequency corresponding to the first air interface frequency information. If it belongs, the remote UE can connect to the network through the first relay UE; if it does not belong, it may be necessary to reselect the relay UE or redetermine the communication path of the remote UE.

[0173] For example, if the handover request response is HO ACK, and HO ACK is used to instruct the second access network device to accept the remote UE connecting to the network through the first relay UE under the second access network device, one possibility is that the handover request response includes the frequency information of the cell where the first relay UE is located or the cell it can camp on, and / or includes the ID of the cell where the first relay UE is located, such as PCI / NCI, while other messages before this do not include the frequency information of the cell where the relay UE is located, nor the frequency information of the cell where the relay UE can camp (for example, the configuration information in S301 does not configure the first cell information and the first air interface frequency information; the fourth message does not include the first frequency information, that is, it does not include the frequency information of the cell where the first relay UE is located; the fifth message neither asks for the frequency information of the cell where the first relay UE is located, nor asks for the frequency information of the cell where the first relay UE can work or camp, nor asks whether the first relay UE has camped or can camp on a cell under the second frequency); in addition, the remote UE may not send relay to the access network device in S303. If the UE's frequency information is not included in the Uu interface, then the first access network device may have selected the first relay UE without knowing the frequency of the cell where the first relay UE resides. The handover request response includes the frequency information of the cell where the first relay UE resides. The first access network device can determine whether this frequency information is the operating or camped frequency of the relay UE that the remote UE is expected to connect to. If so, the first access network device can determine that the first relay UE is available, and the remote UE can connect to the network through the first relay UE; otherwise, the first access network device can reselect the remote UE or re-determine the communication path for the remote UE. In this way, it is not necessary to include frequency information in multiple messages, which helps to save signaling overhead.

[0174] Alternatively, the first access network device can determine, based on measurement results, that the communication path for the remote UE includes adding a path to connect to the network through a relay UE, or adding a direct path (e.g., adding a secondary cell for carrier aggregation (CA) / dual connectivity (DC)). That is, in addition to the current path, the communication path for the remote UE can include additional paths. In other words, the communication path determined by the first access network device for the remote UE is a dual-connectivity or multi-connectivity path. For example, if the quality of the remote UE's current path is good, but the first access network device also wants to increase the remote UE's data rate, it can set a multi-connectivity path for the remote UE. Or, if the quality of the remote UE's current path is poor, and the remote UE urgently needs to find a new path, the first access network device can set a single-connectivity path for the remote UE, enabling the remote UE to connect to the network as quickly as possible. This application embodiment uses dual connectivity as an example.

[0175] Regardless of whether the first access network device is adding a secondary cell or a relay for a remote UE, it can also send a handover request message to the second access network device. Similarly, the second access network device can also send a handover request message to the first access network device. This process can be referred to the above description.

[0176] Optionally, if the first access network device and the second access network device are the same access network device, the above-mentioned handover request message and handover request response process need not be executed.

[0177] Alternatively, if the remote UE is adding a new communication path instead of switching communication paths through this embodiment of the application, for example, if the first access network device is adding a secondary cell or a relay for the remote UE, then the aforementioned handover request message and handover request response process does not need to be executed. Optionally, the first access network device may also execute a negotiation process with the second access network device, the process of which is similar to the handover request message and handover request response.

[0178] S305. The first access network device sends an RRC reconfiguration message to the remote UE. Correspondingly, the remote UE receives the RRC reconfiguration message from the first access network device.

[0179] If the communication path determined by the first access network device for the remote UE is to switch to the second cell under the second access network device, then the RRC reconfiguration message can instruct the remote UE to switch to the second cell; or, if the communication path determined by the first access network device for the remote UE is to switch to connect to the network through the first relay UE under the second access network device, then the RRC reconfiguration message can instruct the remote UE to switch to the first relay UE; or, if the communication path determined by the first access network device for the remote UE is to add the second cell under the second access network device as a secondary cell, then the RRC reconfiguration message can instruct the remote UE to add the second cell as a secondary cell; or, if the communication path determined by the first access network device for the remote UE is to add a path to connect to the network through the first relay UE under the second access network device, then the RRC reconfiguration message can instruct the remote UE to add a path to connect to the network through the first relay UE.

[0180] If the RRC reconfiguration message instructs the remote UE to hand over to the first relay UE, or instructs the remote UE to add a path to connect to the network through the first relay UE, then optionally, the RRC reconfiguration message may include one or more of the following: the identifier of the first relay UE, the identifier of the cell where the first relay UE resides, or the cell-radio network temporary identifier (C-RNTI) of the first relay UE. The identifier of the cell where the first relay UE resides may include, for example, the cell's NCI and / or PCI. For example, if the handover request response includes the PCI of the cell where the first relay UE resides, then optionally, the RRC reconfiguration message including the PCI of the cell where the first relay UE resides is equivalent to the second access network device storing the PCI of the cell where the first relay UE resides and passing it to the remote UE.

[0181] S306. The remote UE establishes a connection with the first relay UE, for example, the connection is a unicast connection.

[0182] If the RRC reconfiguration message instructs the remote UE to switch to the first relay UE, or instructs the remote UE to add a path to connect to the network through the first relay UE, then the remote UE can execute S306 and subsequent steps. However, if the RRC reconfiguration message instructs the remote UE to switch to the second cell, or instructs the remote UE to add the second cell as a secondary cell, then the remote UE does not need to execute S306 and subsequent steps; for example, the remote UE can access the second cell. This application's embodiments mainly describe the case of a remote UE switching to or adding a first relay UE.

[0183] Additionally, if the remote UE has already established a connection with the first relay UE, then S306 need not be executed.

[0184] Optionally, after the remote UE establishes a connection with the first relay UE, the first relay UE can send the PCI of the cell where the first relay UE resides to the remote UE. In this case, the RRC reconfiguration message in S305 may or may not include the PCI of the cell where the first relay UE resides. That is, the remote UE can obtain the PCI of the cell where the first relay UE resides in various ways, such as by the first relay UE sending it to the remote UE, or by the access network device (e.g., the second access network device) sending it to the remote UE.

[0185] The first relay UE may only be able to camp on the cell configured in the configuration information, but is not currently camped on that cell; or the first relay UE may only be able to camp on a cell at the frequency configured in the configuration information, but is not currently camped on a cell at that frequency. Therefore, optionally, after establishing a connection with the first relay UE, the remote UE can also send a first indication message to the first relay UE. The first indication message is used to instruct the first relay UE to reselect to the cell corresponding to the cell information configured in the configuration information, or to reselect to the cell at the frequency corresponding to the air interface frequency information configured in the configuration information. The first relay UE can reselect to the corresponding cell according to the first indication message, thereby providing relay services to the remote UE.

[0186] S307. The second access network device sends an RRC reconfiguration message to the first relay UE. Correspondingly, the first relay UE receives the RRC reconfiguration message from the second access network device. For distinction, the RRC reconfiguration message in S305 can also be referred to as the first RRC reconfiguration message, and the RRC reconfiguration message in S307 can be referred to as the second RRC reconfiguration message.

[0187] The second RRC reconfiguration message can be used to configure the first relay UE, enabling the remote UE to connect to the network through the first relay UE.

[0188] Optionally, if the first access network device and the second access network device are the same access network device, then S307 can also be replaced by the first access network device sending an RRC reconfiguration message to the first relay UE, and correspondingly, the first relay UE receiving the RRC reconfiguration message from the first access network device.

[0189] S308: The first relay UE sends an RRC reconfiguration complete message to the second access network device. Correspondingly, the second access network device receives the RRC reconfiguration complete message from the first relay UE. After configuring according to the second RRC reconfiguration message, the first relay UE can execute S308. S307 and S308 represent the information exchange between the first relay UE and the access network device after the first relay UE enters the RRC connected state.

[0190] Optionally, if the first access network device and the second access network device are the same access network device, then S308 can also be replaced by the first relay UE sending an RRC reconfiguration complete message to the first access network device, and correspondingly, the first access network device receiving the RRC reconfiguration complete message from the first relay UE. For example, the RRC reconfiguration complete message in S308 can be referred to as the second RRC reconfiguration complete message.

[0191] S309. The remote UE sends an RRC reconfiguration complete message. For example, the remote UE sends this RRC reconfiguration complete message to the first relay UE, which receives it from the remote UE. Then, the first relay UE sends the RRC reconfiguration complete message to the second access network device, which receives it from the first relay UE. For example, the RRC reconfiguration complete message in S309 can be referred to as the first RRC reconfiguration complete message.

[0192] For example, when the path of the first relay UE is the path added by the first access network device for the remote UE, after the first relay UE successfully establishes a connection with the second access network device (e.g., the first relay UE successfully accesses the second network device, or timer T300 stops, or timer T301 stops, or the first relay UE enters the RRC connection state), the remote UE can send a first RRC reconfiguration completion message to the first access network device after receiving the instruction from the first relay UE.

[0193] Optionally, if the first access network device and the second access network device are the same access network device, then in S309, the remote UE sends a first RRC reconfiguration complete message to the first relay UE, and the first relay UE receives the first RRC reconfiguration complete message from the remote UE; then, the first relay UE sends the first RRC reconfiguration complete message to the first access network device, and the first access network device receives the first RRC reconfiguration message from the first relay UE. Alternatively, the remote UE also sends the first RRC reconfiguration complete message to the first access network device after receiving the message that the first relay has successfully accessed.

[0194] After the remote UE establishes a connection with the first relay UE, if the first relay UE is in an RRC idle state or an RRC inactive state, optionally, upon receiving the first RRC reconfiguration complete message from the remote UE, the first relay UE can trigger the entry into the RRC connected state and access the second access network device, or the second access network device can be referred to as the target network device. Therefore, in S309, the remote UE sends the first RRC reconfiguration complete message to the first relay UE. This step can occur before or after S307.

[0195] If the first relay UE does not parse the first RRC reconfiguration complete message from the remote UE, then there may be multiple ways to trigger the first relay UE to enter the RRC connected state.

[0196] Since the first relay UE knows the configuration of the first RRC reconfiguration completion message in the PC5 radio link control (RLC) (e.g., the PC5 RLC is configured as the default PC5 RLC, or configured by the remote UE via a PC5 RRC message), the first relay UE can determine whether it needs to trigger entry into the RRC connected state based on whether a specific PC5 LCID is present or based on data packets received on the SL RLC bearer, i.e., based on whether the logical channel ID (LCID) of the RRC reconfiguration completion message was sent or data packets received on the SL RLC bearer. For example, when the first relay UE is in the RRC idle state, if the first relay UE receives any message from the remote UE via SL-RLC1 (sideline RLC1, used to transmit the RLC channel of the remote UE's SRB1 on the sideline link) L2 U2N (UE to Network), the RRC layer of the first relay UE can initiate an RRC connection establishment procedure to enter the RRC connected state. For example, when the first relay UE is in the RRC inactive state, if the first relay UE receives any message from the L2 U2N remote UE transmitted through SL-RLC1 (sideline RLC1, the RLC channel for transmitting the remote UE's SRB1 on the sideline link), the RRC layer of the first relay UE can initiate an RRC connection recovery process to enter the RRC connected state.

[0197] However, since the first relay UE does not send the message to the RRC layer of the first relay UE for parsing after receiving it on the SL-RLC, the RRC layer of the first relay UE needs the lower layer of the first relay UE to inform the SL-RLC whether the data packet has been received.

[0198] One possible approach is that if the RRC layer of the first relay UE determines that the first relay UE is in an RRC idle state or an RRC inactive state, and receives an indication from the MAC or RLC layer that a data packet has been received at a specific LCID, then the RRC layer can determine that the conditions for the first relay UE to enter the RRC connected state are met. In this case, the RRC layer can inform the first relay UE's non-access stratum (NAS) that it needs to enter the RRC connected state. The NAS then issues an instruction to the RRC layer to trigger the RRC layer to initiate an RRC connection establishment process or an RRC connection recovery process to enter the RRC connected state.

[0199] For example, when the MAC layer receives a MAC service data unit (SDU) with source L2 ID = X and LCID = 1 (the LCID is the LCID of the logical channel carrying the first RRC reconfiguration completion message), if this MAC SDU is the first MAC SDU received on the logical channel with source L2 ID = X and LCID = 1, the MAC layer determines whether it has received data with source L2 ID = X and LCID = 0 (the LCID is the ID of the logical channel carrying the RRC connection establishment request message or the RRC connection recovery request message) before this. If it has not received any data, it sends an indication to the RRC layer to indicate that the MAC layer has received a data packet at the specific LCID.

[0200] For example, when the RLC bearer (e.g., SL-RLC1) corresponding to LCID=1 (LCID carrying the RRC reconfiguration completion message) receives an RLC protocol data unit (PDU), if this RLC PDU is the first RLC PDU received on the RLC bearer, the RLC layer can send an indication to the RRC layer to indicate that the RLC layer has received a data packet at a specific LCID.

[0201] Another possible approach is that if the RRC layer of the first relay UE determines that the relay UE is in an inactive RRC state and receives an indication from the MAC or RLC layer that a data packet has been received at a specific LCID, then the conditions for the first relay UE to enter the RRC connected state are met. In this case, the RRC layer can initiate an RRC connection recovery process to trigger entry into the RRC connected state.

[0202] For example, when the MAC layer receives a MAC SDU with source L2 ID = X and LCID = 1 (LCID carrying an RRC reconfiguration completion message), if this MAC SDU is the first MAC SDU received on the logical channel with source L2 ID = X and LCID = 1, the MAC layer determines whether it has received data with source L2 ID = X and LCID = 0 (carrying an RRC connection establishment request message or an RRC connection recovery request message) before this. If it has not received such data, it sends an indication to the RRC layer to indicate that the MAC layer has received a data packet at a specific LCID.

[0203] For example, when the RLC bearer (e.g., SL-RLC1) corresponding to LCID=1 (LCID carrying the RRC reconfiguration completion message) receives an RLC PDU, if the RLC PDU is the first RLC PDU received on the RLC bearer, the RLC layer can send an indication to the RRC layer to indicate that the RLC layer has received a data packet at a specific LCID.

[0204] The process by which the RRC layer of the first relay UE determines whether to enter the RRC connected state can also be applied to relay UEs in the RRC idle state or RRC inactive state. For example, after receiving a connection establishment request message from a remote UE in the RRC idle state or a connection restoration request message from a remote UE in the inactive state, the UE in the RRC idle state or RRC inactive state can determine whether to enter the RRC connected state according to the method described above.

[0205] At this point, the remote UE can connect to the network through the first relay UE. If the remote UE is switching to this path, it needs to disconnect its original communication path; for example, the remote UE needs to release its connection with the first access network device. However, if the remote UE has added this path, it does not need to disconnect its original communication path. For example, the remote UE can connect directly to the first access network device or connect to the network through the first relay UE, thereby improving the throughput of the remote UE.

[0206] S305 to S309 are all optional steps.

[0207] In this embodiment, the first access network device can obtain the frequency information of the cell where the relay UE is located, thereby selecting a more suitable relay UE when choosing a relay UE for the remote UE. For example, the first access network device can select a relay UE that operates at a higher frequency on the air interface, thereby increasing the data rate of the remote UE. In addition, the remote UE can communicate through a single-connection communication path or through a multi-connection communication path, which improves the communication flexibility of the remote UE and also helps to improve the throughput of the remote UE.

[0208] exist Figure 3The illustrated embodiment involves the measurement process of the remote UE. For example, the remote UE can measure objects on the Uu port and also measure objects on the PC5 port (or, in other words, SL objects). If the remote UE starts both measurement processes simultaneously, the power consumption is relatively high. If the access network device only configures the remote UE to perform one of the measurement processes, and the measurement results obtained by the remote UE may not meet the reporting conditions, or although they meet the reporting conditions, the measurement results may be poor, then the access network device may need to configure the remote UE to perform the other measurement process, which results in a large measurement latency. Therefore, this application provides a third communication method in which the remote UE can perform measurements according to a corresponding strategy, avoiding both excessive power consumption due to the need to start two measurement processes simultaneously and excessive measurement latency due to only being able to perform one measurement process. Please refer to... Figure 4 Here is a flowchart of the method.

[0209] S400: The remote UE sends auxiliary information to the first access network device. Correspondingly, the first access network device receives the auxiliary information from the remote UE.

[0210] S400 is an optional step. For more information about S400, such as an introduction to this auxiliary information, please refer to [link / reference needed]. Figure 3 S300 in the illustrated embodiment.

[0211] S401. The access network device sends configuration information to the remote UE. Correspondingly, the remote UE receives the configuration information from the access network device.

[0212] This configuration information can be used to configure measurement objects. For example, it can configure a first type of measurement object and a second type of measurement object. The communication path for the remote UE corresponding to the first type of measurement object is different from the communication path for the second type of measurement object. For example, the first type of measurement object is a Uu interface measurement object (or an air interface measurement object), and the second type of measurement object is an SL interface measurement object (or a PC5 interface measurement object); or, for another example, the second type of measurement object is a Uu interface measurement object, and the first type of measurement object is an SL interface measurement object. In this case, the communication path for the remote UE corresponding to the Uu interface measurement object is the Uu interface communication path, and the communication path for the SL interface measurement object is the SL path. Therefore, the communication paths for the remote UE corresponding to these two types of measurement objects are different.

[0213] The SL measurement object may include, for example, the SL measurement frequency, and the air interface measurement object may include, for example, the air interface measurement frequency (or include the air interface measurement frequency and cell information; this embodiment uses the air interface measurement frequency as an example). The configuration information can configure one or more SL measurement objects, or it can configure one or more air interface measurement objects. Optionally, the SL measurement object can be associated with the air interface measurement object. For example, an air interface measurement frequency configured in the configuration information can be associated with some or all of the SL measurement frequencies configured in the configuration information. Associating an air interface measurement frequency with an SL measurement frequency means that the relay UE to be measured needs to operate or camp on that air interface measurement frequency on the Uu interface, and the relay UE needs to operate on that SL measurement frequency on the PC5 interface.

[0214] Alternatively, the configuration information may also include a first threshold, such as a threshold corresponding to the first type of measurement object, or a threshold corresponding to the measurement result of the first type of measurement object.

[0215] S402, The remote UE performs measurements on the first type of measurement object based on this configuration information.

[0216] For example, this configuration information configures M first-type measurement objects and N second-type measurement objects, where M and N are both positive integers. If the first-type measurement object is, for example, an air interface measurement object, then the remote UE can perform measurements on the M air interface measurement objects configured in this configuration information; or, if the first-type measurement object is, for example, an SL measurement object, then the remote UE can perform measurements on the N SL measurement objects configured in this configuration information.

[0217] S403. If the measurement result of the first type of measurement object does not meet the first condition, then the remote UE performs measurement on the second type of measurement object, or in other words, the remote UE starts measuring the second type of measurement object. Alternatively, if the measurement result of the first type of measurement object meets the first condition, then the remote UE may not perform measurement on the second type of measurement object, or in other words, the remote UE may not start measuring the second type of measurement object.

[0218] Among them, Figure 4S402 and S403 both cover the first relay UE. This only indicates that the remote UE measures the relay UE; it does not mean that the first relay UE is included in both the measurement process of the first type of measurement object and the measurement process of the second type of measurement object. It can be understood that the first relay UE may be included in both the measurement process of the first type of measurement object and the measurement process of the second type of measurement object; or, the first relay UE may be included in the measurement process of the first type of measurement object but not in the measurement process of the second type of measurement object; or, the first relay UE may be included in the measurement process of the second type of measurement object but not in the measurement process of the first type of measurement object.

[0219] There may be different ways to determine whether the measurement results of the first type of measurement object meet the first condition. For example, one method is to consider the measurement results of the first type of measurement object as not meeting the first condition if none of the measurement results of the M measurement objects configured in the configuration information meet the first condition; conversely, if any one of the measurement results of the M measurement objects meets the first condition, the measurement results of the first type of measurement object are considered to meet the first condition. In this case, the remote UE can start measuring N second type of measurement objects. Essentially, the remote UE can determine whether to start the measurement process for the second type of measurement object only after all M measurement objects have been measured.

[0220] Alternatively, another method is to measure and judge each of the M measurement objects separately. For example, if the measurement result of one of the M measurement objects (e.g., the measurement result of the first measurement object) satisfies the first condition, then the measurement result of the first type of measurement object is considered to satisfy the first condition, and the remote UE can continue to measure the next measurement object among the M measurement objects, for example, the second measurement object. If the measurement result of the first measurement object does not satisfy the first condition, then the measurement result of the first type of measurement object is considered to not satisfy the first condition. At this time, the remote UE can start measuring the second type of measurement objects. The second type of measurement objects measured by the remote UE at this time may be, for example, K second type of measurement objects that are related to the first measurement object. For NK second type of measurement objects, the remote UE may temporarily not measure them, where K is a positive integer less than or equal to N. For example, after measuring the K second type of measurement objects, the remote UE can measure the next measurement object among the M measurement objects again, such as the second measurement object, and determine whether the measurement result of the second measurement object satisfies the first condition, and so on. In other words, the remote UE makes a judgment on each first-type measurement object to determine whether to start the measurement of the second-type measurement object corresponding to that first-type measurement object.

[0221] For example, the first type of measurement object is the air interface measurement object, the second type of measurement object is the SL measurement object, M measurement objects represent M air interface frequencies, and N measurement objects represent N SL frequencies. The remote UE can measure cells at the first air interface frequency among the M air interface frequencies. If the measurement result of any cell at the first air interface frequency meets the first condition, the remote UE considers the measurement result of the first air interface frequency to meet the first condition and can continue measuring the next air interface frequency (e.g., the second air interface frequency) among the M air interface frequencies. However, if the measurement results of all measurable cells at the first air interface frequency do not meet the first condition, the remote UE considers the measurement result of the first air interface frequency to not meet the first condition. The remote UE can then measure the SL frequencies associated with the first air interface frequency among the N SL frequencies, that is, measure the relay UEs operating on these SL frequencies on the sidelink. After measuring these SL frequencies, the remote UE can start measuring the next air interface frequency (e.g., the second air interface frequency) among the M air interface frequencies, and so on.

[0222] For example, the first type of measurement object is the SL measurement object, the second type of measurement object is the air interface measurement object, M measurement objects are M SL frequencies, and N measurement objects are N air interface frequencies. The remote UE can measure the SL frequencies associated with the first air interface frequency among the M air interface frequencies. These SL frequencies are, for example, called the first SL frequencies, which may include one or more SL frequencies. If the measurement result of any relay UE under the first SL frequency meets the first condition, the remote UE considers the measurement result of the first SL frequency to meet the first condition and can continue to measure the SL frequencies associated with the next air interface frequency (e.g., the second air interface frequency) among the M air interface frequencies; however, if the measurement results of all relay UEs that can be measured under the first SL frequency do not meet the first condition, the remote UE considers the measurement result of the first SL frequency to not meet the first condition, and the remote UE can perform measurements under the first air interface frequency, that is, measure the cell under the first air interface frequency. After measuring the first air interface frequency, the remote UE can then begin measuring the SL frequency associated with the next air interface frequency (e.g., the second air interface frequency) among the M air interface frequencies, and so on.

[0223] Optionally, the measurement result of a first type of measurement object may satisfy a first condition, such as whether the value of the measurement result is less than a first threshold. If the value of the measurement result is less than the first threshold, the measurement result is considered not to satisfy the first condition; if the value of the measurement result is greater than or equal to the first threshold, the measurement result is considered to satisfy the first condition. Alternatively, the first condition may have other implementation methods, which are not limited.

[0224] It is important to note that even the measurement results of a single Class I measurement object may include one or more measurement results. For example, if the Class I measurement object is an air interface measurement object, and the Class I measurement object is, for instance, an air interface frequency, the measurement results of the Class I measurement object may include the measurement results of one or more cells at that air interface frequency. In other words, the measurement results of the Class I measurement object may include one or more measurement results. Therefore, if any one of the one or more measurement results of the Class I measurement object satisfies the first condition (e.g., the value of that measurement result is greater than or equal to the first threshold), the measurement results of the Class I measurement object are considered to satisfy the first condition. Conversely, if none of the one or more measurement results of the Class I measurement object satisfy the first condition (e.g., the value of each of the multiple measurement results is less than the first threshold), the measurement results of the Class I measurement object are considered to not satisfy the first condition.

[0225] For example, if the first type of measurement object is an SL measurement object, such as an SL frequency, then the measurement results of that SL frequency may also include the measurement results of one or more relay UEs operating on that SL frequency. That is, the measurement results of that SL frequency may also include one or more measurement results. Therefore, if any one of the one or more measurement results of that SL frequency satisfies the first condition, then the measurement results of that SL frequency are considered to satisfy the first condition; conversely, if none of the one or more measurement results of that SL frequency satisfy the first condition, then the measurement results of that SL frequency are considered to not satisfy the first condition.

[0226] As mentioned above, if the measurement results of the first type of measurement object meet the first condition, the remote UE may not measure the second type of measurement object; however, if the measurement results of the first type of measurement object do not meet the first condition, the remote UE may measure the second type of measurement object.

[0227] S404. The remote UE sends the measurement result to the access network device. Correspondingly, the access network device receives the measurement result from the remote UE.

[0228] If the remote UE has not initiated the measurement process for the second type of measurement object, the measurement results obtained by the remote UE include the measurement results for the first type of measurement object, and the measurement results sent by the remote UE to the access network device also include the measurement results for the first type of measurement object. Alternatively, if the remote UE has initiated the measurement process for the second type of object, the measurement results obtained by the remote UE may include the measurement results for both the first and second types of measurement objects, and the measurement results sent by the remote UE to the access network device may include the measurement results for the first type of measurement object and / or the measurement results for the second type of measurement object. The remote UE determines whether to send the measurement results to the access network device based on whether the measurement event has been triggered, and the measurement results may include all or part of the measurement results obtained by the remote UE.

[0229] S405: The access network device determines the communication path of the remote UE based on the measurement results. S405 may involve a second access network device; therefore, the access network device executing S401 to S405 can also be referred to as the first access network device.

[0230] For more information about S405, please refer to [link / reference]. Figure 3 S304 in the illustrated embodiment.

[0231] S406. The first access network device sends an RRC reconfiguration message to the remote UE. Correspondingly, the remote UE receives the RRC reconfiguration message from the first access network device.

[0232] For more information about S406, please refer to [link / reference]. Figure 3 S305 in the illustrated embodiment.

[0233] S407. The remote UE establishes a connection with the first relay UE, for example, the connection is a unicast connection.

[0234] For more information about the S407, please refer to [link / reference]. Figure 3 S306 in the illustrated embodiment.

[0235] S408. The second access network device sends an RRC reconfiguration message to the first relay UE. Correspondingly, the first relay UE receives the RRC reconfiguration message from the second access network device. For distinction, the RRC reconfiguration message in S406 can also be referred to as the first RRC reconfiguration message, and the RRC reconfiguration message in S408 can be referred to as the second RRC reconfiguration message.

[0236] The second RRC reconfiguration message can be used to configure the first relay UE, enabling the remote UE to connect to the network through the first relay UE.

[0237] S409: The first relay UE sends a second RRC reconfiguration completion message to the second access network device. Correspondingly, the second access network device receives the second RRC reconfiguration completion message from the first relay UE. After configuring according to the second RRC reconfiguration message, the first relay UE can execute S409. S408 and S409 represent the information exchange between the first relay UE and the access network device after the first relay UE enters the RRC connected state.

[0238] S410. The remote UE sends a first RRC reconfiguration complete message. For example, the remote UE sends the first RRC reconfiguration message to the first relay UE, and the first relay UE receives the first RRC reconfiguration complete message from the remote UE; then, the first relay UE sends the first RRC reconfiguration complete message to the second access network device, and the second access network device receives the first RRC reconfiguration message from the first relay UE.

[0239] For example, when the path of the first relay UE is the path added by the first access network device for the remote UE, after the connection between the first relay UE and the second access network device is successfully established (for example, the first relay UE successfully accesses the second network device, or timer T300 stops or timer T301 stops, or the first relay UE enters the RRC connection state), the remote UE can send a first RRC reconfiguration completion message to the first access network device after receiving the instruction from the first relay UE.

[0240] Similarly, the first access network device and the second access network device may be different access network devices or the same access network device. If they are the same access network device, the implementation methods of S408 to S410 can be referred to Figure 3 S307 to S309 in the illustrated embodiment.

[0241] S404 to S410 are all optional steps.

[0242] In this embodiment, although the access network device can be configured with two measurement objects, the remote UE determines which measurement object to measure based on a first condition. Therefore, the remote UE may not need to measure both measurement objects simultaneously, saving power consumption. Furthermore, the access network device does not need to configure the measurement object separately; the remote UE can decide which measurement object to measure, thus reducing measurement latency.

[0243] For access network equipment, the choice of communication path for the remote UE may be predetermined. For example, the access network equipment may prefer a direct connection path to the remote UE, or it may prefer a path connected via a relay UE. However, when the remote UE sends measurement results to the access network equipment, it may send two types of measurement results (Uu interface measurement results and SL measurement results). For the access network equipment, some measurement results may be redundant, wasting transmission overhead. Therefore, this application provides a fourth communication method. Through this method, the remote UE can send measurement results to the access network equipment in a targeted manner, making the sent measurement results more in line with the requirements of the access network equipment and saving transmission overhead. Please refer to... Figure 5 Here is a flowchart of the method.

[0244] S500: The remote UE sends auxiliary information to the first access network device. Correspondingly, the first access network device receives the auxiliary information from the remote UE.

[0245] S500 is an optional step. For more information about S500, such as an explanation of auxiliary information, please refer to [link / reference needed]. Figure 3 S300 in the illustrated embodiment.

[0246] S501. The access network device sends configuration information to the remote UE. Correspondingly, the remote UE receives the configuration information from the access network device.

[0247] This configuration information allows you to configure measurement events. For example, the measurement events configured in this information include: the measurement result of a first type of measurement object is less than a first threshold, and the measurement result of a second type of measurement object is greater than or equal to a second threshold. Essentially, this configuration information configures a measurement event; when this measurement event is triggered, the remote UE sends the measurement result under this event to the access network device.

[0248] For example, the measurement events configured in this configuration information may include multiple measurement events, such as a first measurement event, a second measurement event, and a third measurement event. The first measurement event includes the measurement result of a first type of measurement object being less than a first threshold; the second measurement event includes the measurement result of a second type of measurement object being greater than or equal to a second threshold; and the third measurement event includes the measurement result of a first type of measurement object being greater than or equal to a first threshold. In other words, this configuration information can configure multiple measurement events, and for any measurement result satisfying any one of these events, a measurement time is triggered, and the remote UE can send the result to the access network device. That is, when a first measurement event is configured for a first measurement object, if the measurement result of the first measurement object is less than a first threshold, the measurement event is triggered, and the remote UE can report the measurement result to the access network device. The first measurement object belongs to the first type of measurement object. When a second measurement event is configured for a second measurement object, if the measurement result of the second measurement object is greater than or equal to a second threshold, the measurement event is triggered, and the remote UE can send the measurement result to the access network device. The second measurement object belongs to the second type of measurement object. When a third measurement event is configured for a third measurement object, if the measurement result of the third measurement object is greater than or equal to a first threshold, the measurement event is triggered, and the remote UE can send the measurement result to the access network device. The third measurement object belongs to the first type of measurement object.

[0249] Optionally, this configuration information can also configure measurement objects. For example, this configuration information can configure a first type of measurement object and a second type of measurement object. The first type of measurement object configured in this configuration information may include, for example, M measurement objects, and the second type of measurement object configured in this configuration information may include, for example, N measurement objects. Furthermore, the first type of measurement object and the second type of measurement object can also have an association relationship. For more information on this part, please refer to... Figure 4 S401 in the illustrated embodiment.

[0250] S502, remote UE performs measurements on the first type of measurement object and the second type of measurement object.

[0251] For example, if the configuration information specifies M measurement objects and N measurement objects, then the remote UE can measure the M measurement objects and the N measurement objects.

[0252] S503. The remote UE sends measurement results to the access network device according to the measurement events configured in the configuration information. Correspondingly, the access network device receives the measurement results from the remote UE. These measurement results may include, for example, measurement results of the first type of measurement object and / or measurement results of the second type of measurement object.

[0253] 1. This configuration information specifies a measurement event where the measurement result of a first type of measurement object is less than a first threshold, and the measurement result of a second type of measurement object is greater than or equal to a second threshold. The first and / or second thresholds are, for example, predefined by a protocol or configured by the access network device.

[0254] The remote UE can assess the obtained measurement results to determine whether to send the measurement results to the access network device, or which measurement results to send to the access network device. For example, if the measurement result of the first type of measurement object is less than a first threshold, and the measurement result of the second type of measurement object is greater than or equal to the second threshold, then the measurement result of the second type of measurement object is better, while the measurement result of the first type of measurement object is worse. Even if the measurement result of the first type of measurement object is sent to the access network device, the possibility that the access network device can select the communication path corresponding to the first type of measurement object for the remote UE is relatively small. Therefore, the remote UE can send the measurement result of the second type of measurement object to the access network device instead of sending the measurement result of the first type of measurement object.

[0255] Alternatively, if the measurement result of the first type of measurement object is greater than or equal to the first threshold, the measurement result of the first type of measurement object is better. For example, the communication path corresponding to the first type of measurement object is the communication path that the access network device expects to select for the remote UE. Therefore, regardless of whether the measurement result of the second type of measurement object is greater than or equal to the second threshold, the remote UE can send the measurement result of the first type of measurement object to the access network device without having to send the measurement result of the second type of measurement object.

[0256] Alternatively, if the measurement result of the first type of measurement object is less than the first threshold and the measurement result of the second type of measurement object is less than the second threshold, this indicates that the measurement results of both types of measurement objects are poor. The access network device may not be able to determine the communication path of the remote UE from this. Therefore, the remote UE may not send the measurement results to the access network device, whether it is the measurement result of the first type of measurement object or the measurement result of the second type of measurement object. That is, S503 is not executed.

[0257] Optionally, the first type of measurement object and the second type of measurement object under this measurement condition may not be related, or it may be understood that whether the first type of measurement object and the second type of measurement object under this measurement condition are related is not considered.

[0258] For example, the first type of measurement object configured in this configuration information includes M measurement objects, and the second type of measurement object configured in this configuration information includes N measurement objects. Taking the first type of measurement object as an air interface measurement object and the second type of measurement object as an SL measurement object as an example, then the M measurement objects are M air interface frequencies, and the N measurement objects are N SL frequencies. The measurement results of the M air interface frequencies may include the measurement results of one or more cells under the M air interface frequencies. Among these measurement results, as long as the value of any one measurement result is greater than or equal to a first threshold, the remote UE can send the measurement result to the access network device without sending the measurement results of the second type of measurement object. Alternatively, if the values ​​of all measurement results corresponding to the M air interface frequencies (e.g., all measurement results in the measurement results of the one or more cells) are less than the first threshold, and the measurement result of a relay UE among the N SL frequencies has a value greater than or equal to a second threshold (wherein, the measurement results of the N SL frequencies may include the measurement results of one or more relay UEs operating on the N SL frequencies), the remote UE can send the measurement result of that relay UE to the access network device without sending the measurement results of the first type of measurement object. Alternatively, if the values ​​of all measurement results corresponding to the M air interface frequencies are less than the first threshold, and the values ​​of all measurement results corresponding to the N SL frequencies are less than the second threshold, then the remote UE may not send the measurement results to the access network device.

[0259] Alternatively, the first and second types of measurement objects under this measurement condition may be correlated. That is, the measurement condition may be, for example, that the measurement result of the first type of measurement object is less than a first threshold, and the measurement result of the second type of measurement object that is correlated with the first type of measurement object is greater than or equal to a second threshold.

[0260] For example, if the configuration information specifies M measurement objects as the first type and N measurement objects as the second type, the remote UE can determine each of the M measurement objects separately. Taking the first type of measurement objects as air interface measurement objects and the second type as SL measurement objects as an example, then the M measurement objects represent M air interface frequencies, and the N measurement objects represent N SL frequencies. For the first air interface frequency among the M air interface frequencies, the remote UE can measure one or more cells under the first air interface frequency, thereby obtaining one or more measurement results. Of these measurement results, if any one of them is greater than a first threshold, the remote UE can send that measurement result to the access network device without sending the measurement results for the SL frequency corresponding to the first air interface frequency. If all measurement results for the first air interface frequency are less than or equal to the first threshold, and one measurement result for the SL frequency corresponding to the first air interface frequency is greater than a second threshold, then the remote UE can send the measurement result with the value greater than the second threshold to the access network device without sending the measurement result for the first air interface frequency. Alternatively, if all measurement results for the first air interface frequency are less than or equal to the first threshold, and all measurement results for the SL frequency corresponding to the first air interface frequency are less than or equal to the second threshold, then the remote UE does not need to send the measurement results to the access network device. The remote UE can adopt a similar approach for the other air interface frequencies among the M air interface frequencies.

[0261] For example, taking the first type of measurement object as the SL measurement object and the second type of measurement object as the air interface measurement object, then M measurement objects represent M SL frequencies, and N measurement objects represent N air interface frequencies. For the first air interface frequency among the N air interface frequencies, the remote UE can measure the SL frequencies that are related to the first air interface frequency, that is, measure the relay UEs operating on these SL frequencies, thereby obtaining one or more measurement results. If any measurement result is greater than a first threshold, the remote UE can send that measurement result to the access network device without sending the measurement results for the first air interface frequency. Conversely, if all measurement results for these SL frequencies are less than or equal to the first threshold, and one measurement result for the first air interface frequency is greater than a second threshold, the remote UE can send the measurement result with the value greater than the second threshold to the access network device without sending the measurement results for the SL frequencies corresponding to the first air interface frequency. Alternatively, if all measurement results for these SL frequencies are less than or equal to the first threshold, and all measurement results for the first air interface frequency are less than or equal to the second threshold, the remote UE does not need to send the measurement results to the access network device. A similar approach can be taken for the other air interface frequencies among the N air interface frequencies.

[0262] For example, the measurement event configured for the SL measurement object is that the measurement result of the air interface neighbor cell is less than a first threshold, and the measurement result of the neighbor relay is greater than or equal to a second threshold. The measurement results of M air interface frequencies may include the measurement results of one or more cells under the M air interface frequencies. Among these measurement results, as long as the value of any one measurement result is greater than or equal to the first threshold (i.e., there is a good measurement result of a certain neighbor cell under the M air interface frequencies), the measurement reporting of the SL measurement object will not be triggered, and the remote UE does not need to send the measurement results of the SL measurement object. However, if the measurement results of the M air interface frequencies (e.g., all the measurement results of the one or more cells) are all less than the first threshold, and the measurement result of the neighbor relay measured on the SL measurement object is greater than the second threshold, the remote UE will be triggered to send the measurement results of the SL measurement object to the access network device. That is, the remote UE can send the measurement results of the neighbor relay to the access network device.

[0263] Alternatively, the measurement event configured for the SL measurement object is as follows: the measurement result of a neighboring cell on a certain air interface MO (i.e., a certain frequency) is less than a first threshold, and the measurement result of the neighbor relay is greater than or equal to a second threshold. If the values ​​of all measurement results corresponding to that air interface frequency (e.g., all measurement results from the one or more cells) are less than the first threshold, and the measurement result of a relay UE in the SL frequency measurement results is greater than or equal to the second threshold (wherein, the SL frequency measurement results may include the measurement results of one or more relay UEs operating on the SL frequency in the sideline), a measurement reporting by the remote UE is triggered, and the remote UE can send its measurement result to the access network device. By configuring this measurement event, if the access network device determines that the air interface quality is good, it can avoid configuring the relay path, minimizing the reporting of useless measurement results by the remote UE and saving power for the remote UE.

[0264] For example, the measurement event configured for the air interface measurement object is that the measurement result of the SL measurement object is less than a first threshold, and the measurement result of the neighboring cell on the air interface measurement object is greater than or equal to a second threshold. The measurement results of N SL frequencies may include the measurement results of one or more cells under N SL frequencies. Among these measurement results, as long as the value of any one measurement result is greater than or equal to the first threshold (i.e., there is a better measurement result of a certain neighbor relay under N SL frequencies), the air interface measurement reporting will not be triggered, and the remote UE does not need to send the measurement result of the air interface measurement object. However, if the values ​​of the measurement results of N SL frequencies (e.g., all the measurement results of the one or more relays) are all less than the first threshold, and the result of the neighboring cell measured on the air interface measurement object is greater than or equal to the second threshold, the remote UE will be triggered to send the measurement result of the air interface measurement object to the access network equipment.

[0265] Alternatively, the measurement event configured for the air interface measurement object is as follows: the measurement result of the neighbor relay on a certain SL frequency (i.e., a certain SL frequency) is less than a first threshold, and the measurement result of the air interface neighbor cell is greater than or equal to a second threshold. If the values ​​of all measurement results corresponding to that SL frequency (e.g., all measurement results in the one or more relays) are less than the first threshold, and the measurement results of neighbor cells in the air interface frequency measurement results are greater than or equal to the second threshold (wherein, the air interface frequency measurement results may include the measurement results of one or more cells operating on the air interface frequency), measurement reporting is triggered, and the remote UE can send the air interface frequency measurement results whose values ​​are greater than or equal to the second threshold to the access network device. By configuring this measurement event, if the access network device has determined that the relay path is good, it can avoid configuring the Uu path, thus minimizing the need for the remote UE to report useless measurement results and saving power for the remote UE.

[0266] 2. This configuration information configures multiple measurement events, such as the first measurement event, the second measurement event, and the third measurement event.

[0267] The remote UE can evaluate the obtained measurement results to determine whether to send the measurement results to the access network device, or which measurement results to send to the access network device. For example, if the measurement result of the first type of measurement object is less than a first threshold, the remote UE can send the measurement result to the access network device; if the measurement result of the second type of measurement object is greater than or equal to the second threshold, the remote UE can send the measurement result to the access network device; and if the measurement result of the first type of measurement object is greater than or equal to the first threshold, the remote UE can send the measurement result to the access network device.

[0268] Optionally, in this configuration, the remote UE does not need to consider the correlation between the first and second types of measurement objects; it can simply select the measurement result based on the corresponding measurement event. For example, the first type of measurement objects configured in this information includes M measurement objects, such as M measurement frequencies. Taking M measurement frequencies as an example, where the M measurement frequencies are M air interface frequencies, the remote UE measures one or more cells under the first air interface frequency, obtaining one or more measurement results. Among these measurement results, if any measurement result has a value greater than or equal to a first threshold, the remote UE can send the measurement result with a value greater than or equal to the first threshold to the access network device; and if any measurement result has a value less than the first threshold, the remote UE can also send the measurement result with a value less than the first threshold to the access network device. The remote UE uses the same processing method for the other air interface frequencies among the M air interface frequencies.

[0269] Alternatively, taking the M measurement frequencies as M SL frequencies as an example. For the first SL frequency among the M SL frequencies, the remote UE measures one or more relay UEs operating on the first SL frequency, obtaining one or more measurement results. Among these measurement results, if any measurement result has a value greater than or equal to a first threshold, the remote UE can send the measurement result with a value greater than or equal to the first threshold to the access network device; and if any measurement result has a value less than the first threshold, the remote UE can also send the measurement result with a value less than the first threshold to the access network device. The remote UE uses the same processing method for the other air interface frequencies among the M air interface frequencies.

[0270] For example, the second type of measurement object configured in this configuration information includes N measurement objects, such as N measurement frequencies, taking N air interface frequencies as an example. For the second air interface frequency among the N air interface frequencies, the remote UE measures one or more cells under the second air interface frequency and obtains one or more measurement results. Among these measurement results, if any measurement result has a value greater than or equal to the second threshold, the remote UE can send the measurement result with a value greater than or equal to the second threshold to the access network device, while for measurement results with a value less than the second threshold, the remote UE may not send them to the access network device. The remote UE also uses the same processing method for other air interface frequencies among the M air interface frequencies.

[0271] Alternatively, taking N measurement frequencies as N SL frequencies as an example. For the second SL frequency among the N SL frequencies, the remote UE measures one or more relay UEs operating on the second SL frequency in the sideline, obtaining one or more measurement results. Among these measurement results, if any measurement result has a value greater than or equal to a second threshold, the remote UE can send the measurement result with a value greater than or equal to the second threshold to the access network device; for measurement results with values ​​less than the second threshold, the remote UE may not send them to the access network device. The remote UE uses the same processing method for the other SL frequencies among the M SL frequencies.

[0272] For example, the access network device prioritizes configuring air interface measurement objects for the remote UE. The measurement event configured for the air interface measurement object is that the measurement result of the air interface neighbor cell is less than a first threshold. The measurement results of M air interface frequencies may include the measurement results of one or more cells under the M air interface frequencies. Among these measurement results, as long as the value of any one measurement result is greater than or equal to the first threshold (i.e., there is a good measurement result of a certain neighbor cell under the M air interface frequencies), the air interface measurement reporting will not be triggered, and the remote UE does not need to send the measurement results of the M air interface frequencies. However, if the remote UE does not measure the air interface frequency, or if the value of the measurement result of the remote UE for the M air interface frequencies is less than the first threshold, the measurement reporting of the air interface measurement object will be triggered, and the remote UE will send the measurement result of the air interface measurement object to the access network device. By configuring the aforementioned measurement events, the access network device can promptly obtain information about poor air interface conditions and configure new measurement events for the remote UE in a timely manner. This allows the remote UE to perform timely measurements on the SL (Short Path), shortening the time required to add new communication paths for the remote UE. Optionally, the access network device can configure the SL measurement object and measurement event for the remote UE when poor air interface conditions are determined. For example, the measurement event could be that the measurement result of the neighbor relay measured on the SL measurement object is greater than or equal to a second threshold. For a remote UE, the SL measurement object can be measured. If the measurement result of the relay UE (e.g., the remote UE measuring the SL measurement object may include measuring one or more relay UEs operating on the frequency corresponding to the SL measurement object, and the measurement result may include some or all of them) is greater than a second threshold, a measurement report is triggered, and the remote UE can send the SL measurement result with a value greater than or equal to the second threshold to the access network device. Alternatively, if all the measurement results obtained by the remote UE from measuring the SL measurement object are less than the second threshold, or if the remote UE does not obtain any measurement results, a measurement report is not triggered. By triggering and reporting the SL measurement event, the access network device can further configure the relay path for the remote UE based on the measurement results.

[0273] For example, the access network device prioritizes configuring SL measurement objects for remote UEs. The measurement event configured for the SL measurement object is that the measurement result of the relay UE measured on the SL measurement object is less than a first threshold. The measurement results for each SL frequency may include the measurement results of one or more relay UEs. If any one of these measurement results is greater than or equal to the first threshold (i.e., there is a good measurement result for a relay UE under the SL), the measurement reporting of the SL measurement object will not be triggered, and the remote UE does not need to send the measurement result of the SL measurement object. However, if the remote UE does not measure the SL measurement object, or if the measurement result of the remote UE for the SL measurement object is less than the first threshold (e.g., the measurement results of all relay UEs corresponding to the SL measurement object are less than the first threshold), the measurement reporting of the SL measurement object will be triggered, and the remote UE will send the result of the SL measurement object to the access network device. By configuring the aforementioned measurement events, the access network device can promptly detect poor SL (Service Level) quality and configure new measurement events for the remote UE. This allows the remote UE to perform timely air interface measurements, shortening the time required to add new communication paths. Optionally, the access network device can configure air interface measurement objects and measurement events for the remote UE when poor SL is determined. For example, the measurement event could be that the measurement result of a neighboring cell measured on the air interface measurement object is greater than or equal to a second threshold. For a remote UE, measurements can be performed on the air interface measurement object. If the measurement result of the measured cell (for example, the remote UE's measurement of the air interface measurement object may include measurements of one or more cells at the corresponding air interface frequency, and the measurement result may include all or part of the measurement results) is greater than a second threshold, a measurement report is triggered, and the remote UE can send the air interface measurement result with a value greater than or equal to the second threshold to the access network device. Alternatively, if all the measurement results obtained by the remote UE from measuring the air interface measurement object are less than the second threshold, or if the remote UE does not obtain any measurement results, a measurement report is not triggered. By triggering and reporting air interface measurement events, the access network device can further configure a direct connection path between the remote UE and the network based on the measurement results.

[0274] S504: The access network device determines the communication path of the remote UE based on the measurement results. S504 may involve a second access network device; therefore, the access network device executing S501 to S504 can also be referred to as the first access network device.

[0275] For more information about S504, please refer to [link / reference]. Figure 3 S304 in the illustrated embodiment.

[0276] S505. The first access network device sends an RRC reconfiguration message to the remote UE. Correspondingly, the remote UE receives the RRC reconfiguration message from the first access network device.

[0277] For more information about the S505, please refer to [link / reference]. Figure 3 S305 in the illustrated embodiment.

[0278] S506. The remote UE establishes a connection with the first relay UE, for example, the connection is a unicast connection.

[0279] For more information about S506, please refer to [link / reference]. Figure 3 S306 in the illustrated embodiment.

[0280] S507: The second access network device sends an RRC reconfiguration message to the first relay UE. Correspondingly, the first relay UE receives the RRC reconfiguration message from the second access network device. For distinction, the RRC reconfiguration message in S505 can be referred to as the first RRC reconfiguration message, and the RRC reconfiguration message in S507 can be referred to as the second RRC reconfiguration message.

[0281] The second RRC reconfiguration message can be used to configure the first relay UE, enabling the remote UE to connect to the network through the first relay UE.

[0282] S508: The first relay UE sends a second RRC reconfiguration completion message to the second access network device. Correspondingly, the second access network device receives the second RRC reconfiguration completion message from the first relay UE. After configuring according to the second RRC reconfiguration message, the first relay UE can execute S508. S507 and S508 represent the information exchange between the first relay UE and the access network device after the first relay UE enters the RRC connected state.

[0283] S509. The remote UE sends a first RRC reconfiguration complete message. For example, the remote UE sends the first RRC reconfiguration message to the first relay UE, and the first relay UE receives the first RRC reconfiguration complete message from the remote UE; then, the first relay UE sends the first RRC reconfiguration complete message to the second access network device, and the second access network device receives the first RRC reconfiguration message from the first relay UE.

[0284] For example, when the path of the first relay UE is the path added by the first access network device for the remote UE, after the first relay UE successfully establishes a connection with the second access network device (e.g., the first relay UE successfully accesses the second access network device, or timer T300 stops, or timer T301 stops, or the first relay UE enters the RRC connection state), the remote UE can send a first RRC reconfiguration complete message to the first access network device after receiving the indication from the first relay UE.

[0285] Similarly, the first access network device and the second access network device may be different access network devices or the same access network device. If they are the same access network device, the implementation methods of S507 to S509 can be referred to Figure 3 S307 to S309 in the illustrated embodiment.

[0286] S504 to S509 are all optional steps.

[0287] In this embodiment, the access network device can filter the preferred measurement results to be reported through the configured measurement events. The remote UE can send the measurement results to the access network device according to the measurement events, so that the sent measurement results are more in line with the needs of the access network device, reducing the redundant reporting of the remote UE and saving transmission overhead.

[0288] Currently, before a remote UE adds a relay path or switches to a relay path, the relay UE it seeks may be in an RRC idle or inactive state. When the relay UE selected by the remote UE or the access network device is in an RRC idle or inactive state, the relay UE needs to enter the RRC connected state. A reasonable approach is for the remote UE to send an RRC configuration complete message to the access network device via the relay UE, which then triggers its entry into the RRC connected state upon receiving this message. However, since the relay UE's RRC layer does not parse messages from the remote UE, under the current scheme, the relay UE cannot determine which message is the RRC configuration complete message and may be unable to enter the RRC connected state. Similarly, when a remote UE in RRC idle or RRC inactive state wants to conduct services through a relay UE in RRC idle or RRC inactive state, or when a remote UE wants to initiate connection reconstruction through a relay UE in RRC idle or RRC inactive state, it will send a connection establishment request message or a connection restoration message to the relay UE. This can trigger the relay UE to enter the RRC connected state. However, since the relay UE's RRC layer does not parse messages from the remote UE, under the current scheme, the relay UE cannot know which message is a connection establishment request message or a connection restoration message, or whether it is unable to enter the RRC connected state.

[0289] Therefore, this application provides a sixth communication method. In this method, the relay UE can determine whether it needs to enter the RRC connected state by whether the logical channel receiving messages on the side link or the RLC entity has received the first data packet, thus providing an implementation mechanism for the relay UE to enter the RRC connected state. Please refer to... Figure 6 Here is a flowchart of the method.

[0290] S601a, the remote UE sends an RRC reconfiguration complete message to the relay UE. Correspondingly, the relay UE receives the RRC reconfiguration complete message from the remote UE.

[0291] Since the first relay UE knows the PC5 RLC configuration used to send the RRC reconfiguration complete message (e.g., the PC5 RLC configuration is the default PC5 RLC configuration, or it is configured by the remote UE via PC5 RRC), the first relay UE can determine whether it needs to trigger entry into the RRC connected state based on whether a specific PC5 LCID is present or whether a data packet is received on the SL RLC bearer, or in other words, based on whether a data packet is received on the LCID or SL RLC bearer used to send the RRC reconfiguration complete message. For example, when the first relay UE is in the RRC idle state, if the first relay UE receives any message from the L2 U2N remote UE transmitted via SL-RLC1 (sideline RLC1, the RLC channel used to transmit the remote UE's SRB1 on the sideline link), the RRC layer of the first relay UE can initiate the RRC connection establishment process and enter the RRC connected state. For example, when the first relay UE is in the RRC inactive state, if the first relay UE receives any message from the L2 U2N remote UE transmitted through SL-RLC1 (sideline RLC1, used to transmit the RLC channel of the remote UE's SRB1 on the sideline link), the RRC layer of the first relay UE can initiate the RRC connection recovery process and enter the RRC connected state.

[0292] However, since the first relay UE receives the message on the SL-RLC, the message is not sent to the RRC layer of the first relay UE for parsing. Therefore, the RRC layer of the first relay UE needs the lower layer to inform the SL-RLC whether the data packet has been received.

[0293] One possible approach is that if the RRC layer of the first relay UE determines that the first relay UE is in an RRC idle state or an RRC inactive state, and receives an indication from the MAC layer or RLC layer that a data packet has been received at a specific LCID, then the conditions for the first relay UE to enter the RRC connected state are met. In this case, the RRC layer of the first relay UE can inform the NAS layer of the first relay UE that it needs to enter the RRC connected state. The NAS layer can then issue an instruction to the RRC layer to trigger the RRC layer to initiate an RRC connection establishment or RRC connection recovery process, thus entering the RRC connected state.

[0294] For example, when the MAC layer receives a MAC SDU with source L2 ID = X and LCID = 1 (the LCID of the logical channel carrying the RRC reconfiguration complete message), if this MAC SDU is the first MAC SDU received on the logical channel with source L2 ID = X and LCID = 1, the MAC layer determines whether it has received data with source L2 ID = X and LCID = 0 (the LCID of the logical channel carrying the RRC connection establishment request message or the RRC connection recovery request message) before this. If it has not received such data, the MAC layer may send an indication to the RRC layer to indicate that a data packet was received at a specific LCID.

[0295] For example, when the RLC bearer (e.g., SL-RLC1) corresponding to LCID=1 (the LCID of the logical channel carrying the RRC reconfiguration completion message) receives an RLC PDU, if this RLC PDU is the first RLC PDU received on the RLC bearer, the RLC layer can send an indication to the RRC layer to indicate that a data packet was received at a specific LCID.

[0296] Another possible approach is that if the RRC layer of the first relay UE determines that the relay UE is in an RRC inactive state and receives an indication from the MAC layer or RLC layer that a data packet has been received at a specific LCID, then the conditions for the first relay UE to enter the RRC connected state are met. In this case, the RRC layer can initiate an RRC connection recovery process to trigger entry into the RRC connected state.

[0297] For example, when the MAC layer receives a MAC SDU with source L2 ID = X and LCID = 1 (the LCID of the logical channel carrying the RRC reconfiguration complete message), if this MAC SDU is the first MAC SDU received on the logical channel with source L2 ID = X and LCID = 1, the MAC layer determines whether it has received data with source L2 ID = X and LCID = 0 (the LCID of the logical channel carrying the RRC connection establishment request message or the RRC connection recovery request message) before this. If it has not received any data, the MAC layer can send an indication to the RRC layer to indicate that a data packet was received at a specific LCID.

[0298] For example, when the RLC bearer (e.g., SL-RLC1) corresponding to LCID=1 (the LCID of the logical channel carrying the RRC reconfiguration completion message) receives an RLC PDU, if this RLC PDU is the first RLC PDU received on the RLC bearer, the RLC layer can send an indication to the RRC layer to indicate that a data packet was received at a specific LCID.

[0299] S601b: The remote UE sends an RRC connection establishment request message to the relay UE, and the relay UE receives the RRC connection establishment request message from the remote UE. Alternatively, the remote UE sends an RRC connection restoration message to the relay UE, and the relay UE receives the RRC connection restoration message from the remote UE. Or, the remote UE sends an RRC connection reconstruction request message to the relay UE, and the relay UE receives the RRC connection reconstruction request message from the remote UE.

[0300] Since the first relay UE knows the PC5 RLC configuration used to send RRC connection establishment request messages, connection recovery messages, or connection re-establishment request messages (e.g., the PC5 RLC configuration is the default PC5 RLC configuration), the first relay UE can determine whether it needs to trigger entry into the RRC connected state based on whether a specific PC5 LCID is present or whether a data packet is received on the SL RLC bearer, or in other words, based on whether a data packet is received on the LCID used to send the RRC reconfiguration completion message or on the SL RLC bearer. For example, when the first relay UE is in the RRC idle state, if the first relay UE receives any message from the L2 U2N remote UE transmitted through SL-RLC0 (sideline RLC0, the RLC channel used to transmit the remote UE's SRB0 on ​​the sideline link), the RRC layer of the first relay UE can initiate the RRC connection establishment process and enter the RRC connected state. For example, when the first relay UE is in the RRC inactive state, if the first relay UE receives any message from the L2 U2N remote UE transmitted through SL-RLC0 (sideline RLC0, used to transmit the RLC channel of the remote UE's SRB0 on ​​the sideline link), the RRC layer of the first relay UE can initiate the RRC connection recovery process and enter the RRC connected state.

[0301] However, since the first relay UE does not send the message to its RRC for parsing after receiving it on the SL-RLC, the RRC layer of the first relay UE needs to inform the lower layer whether the data packet has been received.

[0302] One possible approach is that if the RRC layer of the first relay UE determines that the first relay UE is in an RRC idle state or an RRC inactive state, and receives an indication from the MAC layer or RLC layer that a data packet has been received at a specific LCID, then the conditions for the first relay UE to enter the RRC connected state can be met. In this case, the RRC layer can inform the NAS layer of the first relay UE that it needs to enter the RRC connected state, and the NAS layer can then issue an instruction to the RRC layer, triggering the RRC layer to initiate an RRC connection establishment or RRC connection recovery process, thus entering the RRC connected state.

[0303] For example, when the MAC layer receives a MAC SDU with source L2 ID = X and LCID = 0 (the LCID of the logical channel carrying an RRC connection establishment request message, connection recovery message, or connection reconstruction request message), if the MAC SDU is the first MAC SDU received on the logical channel with source L2 ID = X and LCID = 0, the MAC layer can send an indication to the RRC layer to indicate that a data packet was received at a specific LCID.

[0304] For example, when an RLC bearer (e.g., SL-RLC0) corresponding to LCID=0 (the LCID of the logical channel carrying an RRC connection establishment request message, connection recovery message, or connection reconstruction request message) receives an RLC PDU, if the RLCPDU is the first RLC PDU received on the RLC bearer, the RLC layer can send an indication to the RRC layer to indicate that a data packet was received at a specific LCID.

[0305] Another possible approach is that if the RRC layer of the first relay UE determines that the relay UE is in an RRC inactive state and receives an indication from the MAC layer or RLC layer that a data packet has been received at a specific LCID, then the conditions for the first relay UE to enter the RRC connected state can be met. In this case, the RRC layer can initiate an RRC connection recovery process, triggering entry into the RRC connected state.

[0306] For example, when the MAC layer receives a MAC SDU with source L2 ID = X and LCID = 0 (the LCID of the logical channel carrying an RRC connection establishment request message, connection recovery message, or connection reconstruction request message), the MAC layer can send an indication to the RRC layer to indicate that a data packet was received at a specific LCID.

[0307] For example, when an RLC bearer (e.g., SL-RLC0) corresponding to LCID=0 (the LCID of the logical channel carrying an RRC connection establishment request message, connection recovery message, or connection reconstruction request message) receives an RLC PDU, if the RLCPDU is the first RLC PDU received on the RLC bearer, the RLC layer can send an indication to the RRC layer to indicate that a data packet was received at a specific LCID.

[0308] S601a and S601b are two optional implementation methods, and they can be considered to be in an "and / or" relationship.

[0309] S602. The relay UE sends an RRC connection establishment request message to the access network device, and the access network device receives the RRC connection establishment request message sent by the relay UE. Alternatively, the first relay UE sends an RRC connection restoration message to the access network device, and the access network device receives the RRC connection restoration message sent by the relay UE.

[0310] The first relay UE can enter the RRC connection state by executing S602, so that it can provide corresponding services to the remote UE.

[0311] The application provided Figure 2 The embodiments shown to Figure 6 Any two or more embodiments shown can be used in combination, for example, a remote UE according to Figure 3 The illustrated embodiment performs the measurement process, and according to Figure 5 The illustrated embodiment determines the reported measurement results; or the remote UE determines the reported measurement results based on... Figure 4 Measurements were performed according to the embodiments shown, and based on Figure 5 The illustrated embodiment determines the reported measurement results; or the remote UE determines the reported measurement results based on... Figure 3 The illustrated embodiment performs the measurement process according to Figure 4 Measurements were performed according to the illustrated embodiments, and based on Figure 5 The illustrated embodiment determines the reported measurement results, or based on Figures 2-5 Measurements were performed according to the embodiments shown. Figure 6 The scheme enables relay UEs to enter RRC connected state, etc. Alternatively, Figure 2 The embodiments shown to Figure 6 The embodiments shown can also be used separately without being combined.

[0312] Figure 7 A schematic diagram of a communication device according to an embodiment of this application is provided. The communication device 700 may be... Figure 2The embodiments shown to Figure 6 The remote UE or its circuitry in any of the embodiments shown is used to implement the method corresponding to the remote UE in the above method embodiments. Alternatively, the communication device 700 may be... Figure 2 The embodiments shown to Figure 6 The relay UE (e.g., the first relay UE) or its circuitry in any of the embodiments shown is used to implement the method corresponding to the relay UE in the above method embodiments. Alternatively, the communication device 700 may be... Figure 2 The embodiments shown to Figure 6 The access network device or its circuitry in any of the embodiments shown is used to implement the method corresponding to the access network device in the above method embodiments. Alternatively, the communication device 700 may be... Figure 2 The embodiments shown to Figure 5 The first access network device or its circuitry in any of the embodiments shown is used to implement the method corresponding to the first access network device in the above method embodiments. Alternatively, the communication device 700 may be... Figure 2 The embodiments shown to Figure 5 The second access network device or its circuit system described in any of the embodiments shown is used to implement the method corresponding to the second access network device in the above method embodiments. Specific functions can be found in the descriptions of the above method embodiments. For example, one type of circuit system is a chip system.

[0313] The communication device 700 includes at least one processor 701. The processor 701 can be used for internal processing within the device to implement certain control processing functions. Optionally, the processor 701 includes instructions. Optionally, the processor 701 can store data. Optionally, different processors can be independent devices, located in different physical locations, or located on different integrated circuits. Optionally, different processors can be integrated into one or more processors, for example, integrated on one or more integrated circuits.

[0314] Optionally, the communication device 700 includes one or more memories 703 for storing instructions. Optionally, the memories 703 may also store data. The processor and the memories may be separate or integrated together.

[0315] Optionally, the communication device 700 includes a communication line 702 and at least one communication interface 704. Since the memory 703, communication line 702, and communication interface 704 are all optional, therefore... Figure 7All are represented by dashed lines.

[0316] Optionally, the communication device 700 may further include a transceiver and / or an antenna. The transceiver can be used to send information to or receive information from other devices. The transceiver may be referred to as a transceiver unit, transceiver circuit, input / output interface, etc., and is used to realize the transmission and reception functions of the communication device 700 via the antenna. Optionally, the transceiver includes a transmitter and a receiver. For example, the transmitter can be used to generate a radio frequency (RF) signal from a baseband signal, and the receiver can be used to convert the RF signal back into a baseband signal.

[0317] The processor 701 may include a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of programs according to the present application.

[0318] Communication line 702 may include a path for transmitting information between the aforementioned components.

[0319] The communication interface 704 uses any transceiver-like device for communicating with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area network (WLAN), wired access network, etc.

[0320] The memory 703 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or it may be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital versatile optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but is not limited thereto. The memory 703 may exist independently and be connected to the processor 701 via communication line 702. Alternatively, the memory 703 may be integrated with the processor 701.

[0321] The memory 703 stores computer execution instructions for implementing the scheme of this application, and its execution is controlled by the processor 701. The processor 701 executes the computer execution instructions stored in the memory 703, thereby implementing the communication method provided in the above embodiments of this application.

[0322] Optionally, the computer execution instructions in the embodiments of this application may also be referred to as application code, and the embodiments of this application do not specifically limit this.

[0323] In a specific implementation, as one example, the processor 701 may include one or more CPUs, for example... Figure 7 CPU0 and CPU1 in the CPU.

[0324] In a specific implementation, as one example, the communication device 700 may include multiple processors, such as... Figure 7 Processors 701 and 708 are mentioned. Each of these processors can be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. A processor here can refer to one or more devices, circuits, and / or processing cores used to process data (e.g., computer program instructions).

[0325] when Figure 7When the device shown is a chip, such as a chip for an access network device, a UPF chip, an SMF chip, or a terminal device chip, then the chip includes a processor 701 (which may also include a processor 708), a communication line 702, a memory 703, and a communication interface 704. Specifically, the communication interface 704 may be an input interface, pins, or circuits, etc. The memory 703 may be a register, cache, etc. The processor 701 and processor 708 may be a general-purpose CPU, microprocessor, ASIC, or one or more integrated circuits for controlling the execution of a program that controls the communication method of any of the above embodiments.

[0326] In the first implementation, the communication device 700 can be used to implement the method corresponding to the UE in the above-mentioned application embodiments, and the specific functions are described in the above-mentioned embodiments.

[0327] For example, the communication device 700 includes a processor 701, which executes a computer program or instructions to cause the method corresponding to the UE in the above-described embodiments to be executed. For example, the method corresponding to the remote UE (or simply UE) in the above-described embodiments includes: obtaining frequency information of a first cell, wherein the first cell is the cell where the first relay device is located; determining the first cell based on the frequency information of the first cell and the identifier of the first cell; and measuring the first cell to determine whether the terminal device can act as a remote device in the first cell.

[0328] For example, the method corresponding to the first relay UE in the above application embodiment includes: sending frequency information of a first cell to the terminal device, wherein the frequency information of the first cell is used to determine whether the terminal device can act as a remote device in the first cell, and the first cell is the cell where the first relay device is located.

[0329] This application embodiment can divide the device into functional modules according to the above method example. For example, each function can be divided into its own functional modules, or two or more functions can be integrated into one processing module. The integrated modules can be implemented in hardware or as software functional modules. It should be noted that the module division in this application embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods. For example, when dividing the device into functional modules according to each function, Figure 8 A schematic diagram of an apparatus is shown. The apparatus 800 can be an access network device or a terminal device involved in the above-described method embodiments, or it can be a chip in an access network device or a chip in a terminal device. The apparatus 800 includes a transmitting unit 801, a processing unit 802, and a receiving unit 803.

[0330] It should be understood that the device 800 can be used to implement the steps performed by the access network device or the terminal device in the method of the embodiments of this application. The relevant features can be referred to the various embodiments above, and will not be repeated here.

[0331] Optional, Figure 8 The functions / implementation processes of the transmitting unit 801, receiving unit 803, and processing unit 802 can be understood through... Figure 7 The processor 701 and / or processor 708 in the memory 703 call computer execution instructions stored in the memory 703 to implement the function. Alternatively, Figure 8 The function / implementation process of the processing unit 802 in the middle can be achieved through Figure 7 The processor 701 and / or processor 708 in the memory 703 call computer execution instructions stored in the memory 703 to implement the function. Figure 8 The functions / implementation process of the transmitting unit 801 and the receiving unit 803 can be obtained through Figure 7 It is implemented using the 704 communication interface.

[0332] Optionally, when the device 800 is a chip or circuit, the functions / implementation of the transmitting unit 801 and the receiving unit 803 can also be implemented through pins or circuits.

[0333] This application also provides a computer-readable storage medium storing a computer program or instructions that, when executed, implement the methods performed by the access network device or terminal device in the aforementioned method embodiments. Thus, the functions described in the above embodiments can be implemented as software functional units and sold or used as independent products. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to it, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0334] This application also provides a computer program product comprising: computer program code, which, when run on a computer, causes the computer to perform the method executed by the terminal device or access network device in any of the foregoing method embodiments.

[0335] This application also provides a processing apparatus, including a processor and an interface; the processor is used to execute the methods performed by the terminal device or access network device involved in any of the above method embodiments.

[0336] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can 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 can 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 can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid-state disk (SSD)).

[0337] The various illustrative logic units and circuits described in the embodiments of this application can be implemented or operate the described functions using a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination thereof. The general-purpose processor can be a microprocessor; alternatively, it can be any conventional processor, controller, microcontroller, or state machine. The processor can also be implemented using a combination of computing devices, such as a digital signal processor and a microprocessor, multiple microprocessors, one or more microprocessors combined with a digital signal processor core, or any other similar configuration.

[0338] The steps of the methods or algorithms described in the embodiments of this application can be directly embedded in hardware, software units executed by a processor, or a combination of both. The software units can be stored in RAM, flash memory, ROM, erasable programmable read-only memory (EPROM), EEPROM, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium in the art. Exemplarily, the storage medium can be connected to the processor so that the processor can read information from the storage medium and write information to the storage medium. Optionally, the storage medium can also be integrated into the processor. The processor and storage medium can be disposed in an ASIC, which can be disposed in the terminal device. Optionally, the processor and storage medium can also be disposed in different components of the terminal device.

[0339] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0340] Although embodiments of this application have been described in conjunction with specific features and examples, it is obvious that various modifications and combinations can be made thereto without departing from the scope of the embodiments of this application. Accordingly, the embodiments and drawings of this application are merely exemplary illustrations of the embodiments of this application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of the embodiments of this application. Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the scope of the embodiments of this application. Thus, if these modifications and variations of the embodiments of this application fall within the scope of the claims of the embodiments of this application and their equivalents, then the embodiments of this application are also intended to include these modifications and variations.

[0341] Example 1. A communication method applied to a remote device, the method comprising:

[0342] The first access network device receives configuration information, which is used to configure the measurement frequency on the side link and to configure cell information or air interface frequency information.

[0343] According to the configuration information, the first type of relay device is measured. The first type of relay device is a relay device that operates on the measurement frequency and has been or can be stationed in the cell corresponding to the cell information, or a relay device that operates on the measurement frequency and has been or can be stationed in the cell at the frequency corresponding to the air interface frequency information.

[0344] The measurement results are sent to the first access network device, and the measurement results are used to determine the communication path of the remote device.

[0345] Example 2. The method according to Example 1, the method further includes:

[0346] A fourth message is received from the first relay device, the fourth message including information about a first frequency, the first frequency being the frequency of the cell where the first relay device is located, or the frequency of the cell where the first relay device can camp.

[0347] Example 3. According to the method described in Example 2, the fourth message is a discovery message or a PC5 RRC message.

[0348] 4. According to the method described in Embodiment 2 or 3, measuring the first type of relay device based on the configuration information includes:

[0349] If the first frequency belongs to the frequency corresponding to the air interface frequency information configured in the configuration information, or if the cell corresponding to the cell information configured in the configuration information belongs to the first frequency, the first relay device is measured or the measurement is reported.

[0350] Example 5. The method according to Example 1, the method further includes:

[0351] Send a fifth message to the first relay device. The fifth message is used to query the frequency information of the cell where the first relay device is located, or to query the frequency information of the cell that the first relay device can camp on, or to query whether the first relay device has camped on or can camp on a cell under a second frequency, where the second frequency belongs to the frequency corresponding to the air interface frequency information configured in the configuration information.

[0352] The first relay device receives a sixth message, the sixth message including information about the second frequency, or the sixth message indicating that the first relay device has camped or is able to camp on a cell at the second frequency.

[0353] Example 6. The method according to any one of Examples 1 to 5, the method further comprising:

[0354] The remote device receives an RRC reconfiguration message from the first access network device. The RRC reconfiguration message is used to instruct the remote device to switch to the second cell, or to instruct the remote device to switch to the first relay device, or to instruct the remote device to add the second cell as a secondary cell, or to instruct the remote device to add a path for communication with the network through the first relay device. The first relay device is one of the first type of relay devices.

[0355] Example 7. According to the method described in Example 6, the RRC reconfiguration message further includes the PCI of the cell where the first relay device is located.

[0356] Example 8. According to the method described in Example 6 or 7, the RRC reconfiguration message further includes the frequency information of the cell where the first relay device is located.

[0357] Example 9. The method according to Example 6, the method further includes:

[0358] After establishing a connection with the first relay device, the PCI of the cell where the first relay device is located is received from the first relay device.

[0359] Example 10. The method according to any one of Examples 6 to 9, the method further comprising:

[0360] After establishing a connection with the first relay device, a first indication message is sent to the first relay device. The first indication message is used to instruct the first relay device to reselect to the cell corresponding to the cell information configured in the configuration information, or to reselect to the cell under the frequency corresponding to the air interface frequency information configured in the configuration information.

[0361] Example 11. The method described in any one of Examples 1 to 10, receiving configuration information from a first access network device, includes: receiving configuration information from the first access network device through a second relay device.

[0362] Example 12. A communication method applied to a first relay device, the method comprising:

[0363] Send information about a third frequency to a remote device. The third frequency is either the frequency of the cell where the first relay device is located or the frequency of the cell where the first relay device can camp. The information about the third frequency is used to determine the communication path of the remote device.

[0364] Example 13. According to the method described in Example 11, sending information of a third frequency to a remote device includes: sending a fourth message to the remote device, the fourth message including the information of the third frequency.

[0365] Example 14. According to the method described in Example 13, the fourth message is a discovery message or a PC5 RRC message.

[0366] Example 15. The method according to Example 13 or 14, wherein the third frequency is the frequency of the cell in which the first relay device can camp, and the method further includes:

[0367] After establishing a connection with the remote device, the system receives first indication information from the remote device and, based on the first indication information, reselects a cell on the third frequency; or,

[0368] The device receives a second instruction from the first access network device and switches to the cell under the third frequency according to the second instruction.

[0369] Example 16. The method described in Example 12,

[0370] The remote device receives a fifth message, which is used to query the frequency information of the cell where the first relay device is located, or to query the frequency information of the cell that the first relay device can camp on, or to query whether the first relay device has camped on or can camp on a cell under the third frequency.

[0371] Sending information about a third frequency to a remote device includes sending a sixth message to the remote device, the sixth message including information about the third frequency, or the sixth message indicating that the first relay device has camped or is able to camp on a cell under the third frequency.

[0372] Example 17. According to the method described in Example 16, the third frequency is the frequency of the cell where the first relay device can camp, and the method further includes: reselecting to a cell under the third frequency.

[0373] Example 18. The method according to any one of Examples 12 to 17, the method further includes: after establishing a connection with the remote device, sending the PCI of the cell where the first relay device is located to the remote device.

[0374] Example 19. A communication method applied to a first access network device, the method comprising:

[0375] Send configuration information to the remote device. The configuration information is used to configure the measurement frequency on the side link and the cell information or air interface frequency information that the relay device operating on the measurement frequency needs to camp or operate.

[0376] Receive measurement results from the relay device from the remote device;

[0377] The communication path of the remote device is determined based on the measurement results.

[0378] Example 20. The method according to Example 19, the method further includes:

[0379] A handover request message is sent to the second access network device. The handover request message is used to inquire whether to accept the remote device accessing the network through the first relay device under the second access network device, or to inquire whether to accept the remote device accessing the second cell under the second access network device. The first relay device is determined based on the measurement results.

[0380] The handover request response is received from the second access network device. The handover request response is used to indicate whether to accept the remote device to access the network through the first relay device, or to indicate whether to accept the remote device to access the second cell.

[0381] Example 21. According to the method described in Example 20, the handover request response further includes frequency information of the cell where the first relay device has camped or is able to camp.

[0382] Example 22. The method according to Example 21, the method further includes:

[0383] An RRC reconfiguration message is sent to the remote device. The RRC reconfiguration message is used to instruct the remote device to switch to the second cell, or to instruct the remote device to switch to the first relay device, or to instruct the remote device to add the second cell as a secondary cell, or to instruct the remote device to add a path for communication with the network through the first relay device.

[0384] Example 23. According to the method described in Example 22, the RRC reconfiguration message further includes the PCI of the cell where the first relay device is located.

[0385] Example 24. According to the method described in Example 22 or 23, the RRC reconfiguration message further includes the frequency information of the cell where the first relay device is located.

[0386] Example 25. A communication method applied to a first access network device, the method comprising:

[0387] Send a handover request message to the second access network device. The handover request message is used to ask whether to accept the remote device to access the network through the first relay device under the second access network device, or the handover request message is used to ask whether to accept the remote device to access the second cell under the second access network device.

[0388] The second access network device receives a handover request response, which is used to indicate whether to accept the remote device's access to the network through the first relay device, or to indicate whether to accept the remote device's access to the second cell. The handover request response also includes frequency information of the cell where the first relay device has camped or is able to camp.

[0389] Example 26. According to the method described in Example 25, the handover request response further includes the PCI of the cell where the first relay device is located.

[0390] Example 27. The method according to Example 25 or 26, further comprising:

[0391] An RRC reconfiguration message is sent to the remote device. The RRC reconfiguration message is used to instruct the remote device to switch to the second cell, or to instruct the remote device to switch to the first relay device, or to instruct the remote device to add the second cell as a secondary cell, or to instruct the remote device to add a path for communication with the network through the first relay device. The RRC reconfiguration message also includes the PCI of the cell where the first relay device is located.

[0392] Example 28. The method according to any one of Examples 25 to 27, the method further comprising:

[0393] The frequency corresponding to the frequency information of the cell where the first relay device has camped or is able to camp is the air interface operating frequency of the relay device that is expected to serve the remote device.

[0394] Example 29. A communication method applied to a second access network device, the method comprising:

[0395] A handover request message is received from the first access network device. The handover request message is used to inquire whether to accept the remote device to access the network through the first relay device under the second access network device, or the handover request message is used to inquire whether to accept the remote device to access the second cell under the second access network device.

[0396] A handover request response is sent to the first access network device. The handover request response is used to indicate whether to accept the remote device's access to the network through the first relay device, or to indicate whether to accept the remote device's access to the second cell. The handover request response also includes frequency information of the cell where the first relay device has camped or is able to camp.

[0397] Example 30. According to the method described in Example 29, the handover request response further includes the PCI of the cell where the first relay device is located.

[0398] Example 31. A communication method applied to a remote device, the method comprising:

[0399] The remote device receives configuration information from the access network device. The configuration information is used to configure a first type of measurement object and a second type of measurement object. The communication path of the remote device corresponding to the first type of measurement object is different from the communication path corresponding to the first type of measurement object.

[0400] The first type of measurement object is measured according to the configuration information;

[0401] If the measurement result of the first type of measurement object does not meet the first condition, the second type of measurement object is measured.

[0402] Example 32. According to the method described in Example 31, the first type of measurement object includes M measurement objects, and the second type of measurement object includes N measurement objects, where M and N are both positive integers; wherein, the measurement result of the first type of measurement object does not satisfy the first condition, including:

[0403] The measurement results of the M measurement objects are all less than the first threshold; or,

[0404] The measurement result of the first measurement object among the M measurement objects is less than the first threshold.

[0405] Example 33. According to the method described in Example 32, if the measurement result of the first type of measurement object does not meet the first condition, including that the value of the measurement result of the first measurement object among the M measurement objects is less than a first threshold, then, the second type of measurement object is measured, including:

[0406] Measurements are performed on K of the N measurement objects, where the K measurement objects are related to the first measurement object, and K is a positive integer less than or equal to N.

[0407] Example 34. The method according to any one of Examples 31 to 33, the method further includes: if the measurement result of the first type of measurement object meets the first condition, the second type of measurement object is not measured.

[0408] Example 35. A communication method applied to a remote device, the method comprising:

[0409] The remote device receives configuration information from the access network device. The configuration information is used to configure measurement events. The measurement events include the measurement result of a first type of measurement object being less than a first threshold, and the measurement result of a second type of measurement object being greater than or equal to a second threshold. The communication path of the remote device corresponding to the first type of measurement object is different from the communication path corresponding to the first type of measurement object.

[0410] Measurements are performed on the first type of measurement object and the second type of measurement object;

[0411] The measurement results of the first type of measurement object and / or the second type of measurement object are sent to the access network device according to the measurement event.

[0412] Example 36. According to the method described in Example 35, sending the measurement results of the first type of measurement object and / or the second type of measurement object to the access network device based on the measurement event includes:

[0413] If the measurement result of the first type of measurement object is less than the first threshold, and the measurement result of the second type of measurement object is greater than or equal to the second threshold, the measurement result of the second type of measurement object is sent to the access network device; or,

[0414] If the measurement result of the first type of measurement object is greater than or equal to the first threshold, the measurement result of the first type of measurement object is sent to the access network device.

[0415] Example 37. The method described according to Example 35 or 36,

[0416] The first type of measurement object is an air interface measurement object, and the second type of measurement object is a side link measurement object; or,

[0417] The first type of measurement object is the measurement object of the side link, and the second type of measurement object is the air interface measurement object.

[0418] Example 38. A communication method applied to a remote device, the method comprising:

[0419] Configuration information is received from the access network device. The configuration information is used to configure a first measurement event, a second measurement event, and a third measurement event. The first measurement event includes a measurement result of a first type of measurement object whose value is less than a first threshold. The second measurement event includes a measurement result of a second type of measurement object whose value is greater than or equal to a second threshold. The third measurement event includes a measurement result of the first type of measurement object whose value is greater than or equal to the first threshold. The communication path of the remote device corresponding to the first type of measurement object is different from the communication path corresponding to the first type of measurement object.

[0420] Measurements are performed on the first type of measurement object and the second type of measurement object;

[0421] The measurement results of the first type of measurement object and / or the second type of measurement object are sent to the access network device according to the first measurement event, the second measurement event and the third measurement event.

[0422] Example 39. According to the method described in Example 38, the measurement results of the first type of measurement object and / or the second type of measurement object are sent to the access network device based on the first measurement event, the second measurement event, and the third measurement event, including one or more of the following:

[0423] If the value of the measurement result of the first type of measurement object is less than the first threshold, the measurement result of the first type of measurement object is sent to the access network device;

[0424] If the measurement result of the first type of measurement object is greater than or equal to the first threshold, the measurement result of the first type of measurement object is sent to the access network device; or,

[0425] If the measurement result of the second type of measurement object is greater than or equal to the second threshold, the measurement result of the second type of measurement object is sent to the access network device.

[0426] Example 40. The method described according to Example 38 or 39,

[0427] The first type of measurement object is an air interface measurement object, and the second type of measurement object is a side link measurement object; or,

[0428] The first type of measurement object is the measurement object of the side link, and the second type of measurement object is the air interface measurement object.

[0429] Example 41. A communication device, comprising:

[0430] One or more processors;

[0431] One or more memory units;

[0432] And one or more computer programs, wherein the one or more computer programs are stored in the one or more memories, the one or more computer programs including instructions that, when executed by one or more processors of the communication device, cause the communication device to perform the method as described in any one of Embodiments 1 to 11, or cause the communication device to perform the method as described in any one of Embodiments 12 to 18, or cause the communication device to perform the method as described in any one of Embodiments 31 to 34, or cause the communication device to perform the method as described in any one of Embodiments 35 to 37, or cause the communication device to perform the method as described in any one of Embodiments 38 to 10.

[0433] Example 42. A communication device, comprising:

[0434] One or more processors;

[0435] One or more memory units;

[0436] And one or more computer programs, wherein the one or more computer programs are stored in the one or more memories, the one or more computer programs including instructions that, when executed by one or more processors of the communication device, cause the communication device to perform the method as described in any one of Embodiments 19 to 24, or cause the communication device to perform the method as described in any one of Embodiments 25 to 28, or cause the communication device to perform the method as described in any one of Embodiments 29 to 30.

[0437] Example 43. A computer-readable storage medium for storing a computer program that, when run on a computer, causes the computer to perform the method as described in any one of Examples 1 to 11, or the method as described in any one of Examples 12 to 18, or the method as described in any one of Examples 31 to 34, or the method as described in any one of Examples 35 to 37, or the method as described in any one of Examples 38 to 10, or the method as described in any one of Examples 19 to 24, or the method as described in any one of Examples 25 to 28, or the method as described in any one of Examples 29 to 30.

[0438] Example 44. A chip comprising one or more processors and a communication interface, wherein the one or more processors are configured to read instructions to execute a method as described in any one of Examples 1 to 11, or a method as described in any one of Examples 12 to 18, or a method as described in any one of Examples 31 to 34, or a method as described in any one of Examples 35 to 37, or a method as described in any one of Examples 38 to 10, or a method as described in any one of Examples 19 to 24, or a method as described in any one of Examples 25 to 28, or a method as described in any one of Examples 29 to 30.

[0439] Example 45. An apparatus comprising units for performing the methods described in any embodiment of this application.

[0440] Example 46. A computer program product comprising a computer program that, when run on a computer, causes the computer to perform the method as described in any one of Examples 1 to 11, or the method as described in any one of Examples 12 to 18, or the method as described in any one of Examples 31 to 34, or the method as described in any one of Examples 35 to 37, or the method as described in any one of Examples 38 to 10, or the method as described in any one of Examples 19 to 24, or the method as described in any one of Examples 25 to 28, or the method as described in any one of Examples 29 to 30.

Claims

1. A communication method, characterized in that, The method includes: (The method is applied to a remote device or a chip within a remote device.) The first access network device receives configuration information, which is used to configure the measurement frequency on the side link and to configure cell information or air interface frequency information. According to the configuration information, the first type of relay device is measured. The first type of relay device is a relay device that operates on the measurement frequency and has been or can be stationed in the cell corresponding to the cell information, or a relay device that operates on the measurement frequency and has been or can be stationed in the cell at the frequency corresponding to the air interface frequency information. The measurement results are sent to the first access network device, and the measurement results are used to determine the communication path of the remote device.

2. The method according to claim 1, characterized in that, The method further includes: A fourth message is received from the first relay device, the fourth message including information about a first frequency, the first frequency being the frequency of the cell where the first relay device is located, or the frequency of the cell where the first relay device can camp.

3. The method according to claim 2, characterized in that, The fourth message is a discovery message or a PC5 RRC message.

4. The method according to claim 2 or 3, characterized in that, Based on the configuration information, measurements are performed on the first type of relay equipment, including: If the first frequency belongs to the frequency corresponding to the air interface frequency information configured in the configuration information, or if the cell corresponding to the cell information configured in the configuration information belongs to the first frequency, the first relay device is measured or the measurement is reported.

5. The method according to claim 1, characterized in that, The method further includes: Send a fifth message to the first relay device. The fifth message is used to query the frequency information of the cell where the first relay device is located, or to query the frequency information of the cell that the first relay device can camp on, or to query whether the first relay device has camped on or can camp on a cell under a second frequency, where the second frequency belongs to the frequency corresponding to the air interface frequency information configured in the configuration information. The first relay device receives a sixth message, the sixth message including information about the second frequency, or the sixth message indicating that the first relay device has camped or is able to camp on a cell at the second frequency.

6. The method according to any one of claims 1 to 5, characterized in that, The method further includes: The remote device receives an RRC reconfiguration message from the first access network device. The RRC reconfiguration message is used to instruct the remote device to switch to the second cell, or to instruct the remote device to switch to the first relay device, or to instruct the remote device to add the second cell as a secondary cell, or to instruct the remote device to add a path for communication with the network through the first relay device. The first relay device is one of the first type of relay devices.

7. The method according to claim 6, characterized in that, The RRC reconfiguration message also includes the PCI of the cell where the first relay device is located.

8. The method according to claim 6 or 7, characterized in that, The RRC reconfiguration message also includes frequency information of the cell where the first relay device is located.

9. The method according to claim 6, characterized in that, The method further includes: After establishing a connection with the first relay device, the PCI of the cell where the first relay device is located is received from the first relay device.

10. The method according to any one of claims 6 to 9, characterized in that, The method further includes: After establishing a connection with the first relay device, a first indication message is sent to the first relay device. The first indication message is used to instruct the first relay device to reselect to the cell corresponding to the cell information configured in the configuration information, or to reselect to the cell under the frequency corresponding to the air interface frequency information configured in the configuration information.

11. The method according to any one of claims 1 to 10, characterized in that, Receive configuration information from the first access network device, including: The configuration information is received from the first access network device through the second relay device.

12. A communication method, characterized in that, The method includes: (1) A chip applied to a first relay device or a chip in a first relay device. Send information about the third frequency of the first cell and the identifier of the first cell to the remote device. The third frequency is the frequency of the cell where the first relay device is located, and the first cell is the cell where the first relay device is located. Alternatively, the third frequency is the frequency of the cell where the first relay device can camp, and the first cell is the cell where the first relay device can camp. The information about the third frequency and the identifier of the first cell are used by the remote device to determine whether it can act as a remote device in the first cell. If the first relay device is in an RRC disconnected state, upon receiving a message from the remote device transmitted via SL RLC1, it initiates an RRC connection recovery process or an RRC connection establishment process to enter the RRC connected state.

13. The method according to claim 12, characterized in that, Sending information on a third frequency to a remote device, including: A fourth message is sent to the remote device, the fourth message including information about the third frequency.

14. The method according to claim 13, characterized in that, The fourth message is a discovery message or a PC5 RRC message.

15. The method according to claim 13 or 14, characterized in that, The third frequency is the frequency of the cell where the first relay device can camp, and the method further includes: After establishing a connection with the remote device, the system receives first indication information from the remote device and, based on the first indication information, reselects a cell on the third frequency; or, The device receives a second instruction from the first access network device and switches to the cell under the third frequency according to the second instruction.

16. The method according to claim 12, characterized in that, The method further includes: The remote device receives a fifth message, which is used to query the frequency information of the cell where the first relay device is located, or to query the frequency information of the cell that the first relay device can camp on, or to query whether the first relay device has camped on or can camp on a cell under the third frequency. Sending information about a third frequency to a remote device includes sending a sixth message to the remote device, the sixth message including information about the third frequency, or the sixth message indicating that the first relay device has camped or is able to camp on a cell under the third frequency.

17. The method according to claim 16, characterized in that, The third frequency is the frequency of the cell where the first relay device can camp, and the method further includes: Reselect to the cell at the third frequency.

18. The method according to any one of claims 12 to 17, characterized in that, The method further includes: After establishing a connection with the remote device, the PCI of the cell where the first relay device is located is sent to the remote device.

19. A communication device, characterized in that, The device is a remote device or a chip within a remote device, and the device includes: The receiving unit is configured to receive configuration information from the first access network device, the configuration information being used to configure the measurement frequency on the side link and to configure cell information or air interface frequency information. The processing unit is configured to measure a first type of relay device according to the configuration information. The first type of relay device is a relay device that operates on the measurement frequency and has been or can be stationed in the cell corresponding to the cell information, or a relay device that operates on the measurement frequency and has been or can be stationed in the cell at the frequency corresponding to the air interface frequency information. The sending unit is configured to send measurement results to the first access network device, the measurement results being used to determine the communication path of the remote device.

20. The apparatus according to claim 19, characterized in that, The receiving unit is further configured to: A fourth message is received from the first relay device, the fourth message including information about a first frequency, the first frequency being the frequency of the cell where the first relay device is located, or the frequency of the cell where the first relay device can camp.

21. The apparatus according to claim 20, characterized in that, The fourth message is a discovery message or a PC5 RRC message.

22. The apparatus according to claim 20 or 21, characterized in that, The processing unit is specifically configured as follows: If the first frequency belongs to the frequency corresponding to the air interface frequency information configured in the configuration information, or if the cell corresponding to the cell information configured in the configuration information belongs to the first frequency, the first relay device is measured or the measurement is reported.

23. The apparatus according to claim 19, characterized in that, The transmitting unit is further configured to: Send a fifth message to the first relay device. The fifth message is used to query the frequency information of the cell where the first relay device is located, or to query the frequency information of the cell that the first relay device can camp on, or to query whether the first relay device has camped on or can camp on a cell under a second frequency, where the second frequency belongs to the frequency corresponding to the air interface frequency information configured in the configuration information. The first relay device receives a sixth message, the sixth message including information about the second frequency, or the sixth message indicating that the first relay device has camped or is able to camp on a cell at the second frequency.

24. The apparatus according to any one of claims 19 to 23, characterized in that, The receiving unit is further configured to: The remote device receives an RRC reconfiguration message from the first access network device. The RRC reconfiguration message is used to instruct the remote device to switch to the second cell, or to instruct the remote device to switch to the first relay device, or to instruct the remote device to add the second cell as a secondary cell, or to instruct the remote device to add a path for communication with the network through the first relay device. The first relay device is one of the first type of relay devices.

25. The apparatus according to claim 24, characterized in that, The RRC reconfiguration message also includes the PCI of the cell where the first relay device is located.

26. The apparatus according to claim 24 or 25, characterized in that, The RRC reconfiguration message also includes frequency information of the cell where the first relay device is located.

27. The apparatus according to claim 24, characterized in that, The receiving unit is further configured to: After establishing a connection with the first relay device, the PCI of the cell where the first relay device is located is received from the first relay device.

28. The apparatus according to any one of claims 24 to 27, characterized in that, The transmitting unit is further configured to: After establishing a connection with the first relay device, a first indication message is sent to the first relay device. The first indication message is used to instruct the first relay device to reselect to the cell corresponding to the cell information configured in the configuration information, or to reselect to the cell under the frequency corresponding to the air interface frequency information configured in the configuration information.

29. The apparatus according to any one of claims 19 to 28, characterized in that, Receive configuration information from the first access network device, including: The configuration information is received from the first access network device through the second relay device.

30. A communication device, characterized in that, The device is a first relay device or a chip in a first relay device, and the device includes: The transmitting unit transmits information about the third frequency of the first cell and the identifier of the first cell to the remote device. The third frequency is the frequency of the cell where the first relay device is located, and the first cell is the cell where the first relay device is located. Alternatively, the third frequency is the frequency of the cell where the first relay device can camp, and the first cell is the cell where the first relay device can camp. The information about the third frequency and the identifier of the first cell are used by the remote device to determine whether it can act as a remote device in the first cell. If the first relay device is in an RRC disconnected state, upon receiving a message from the remote device transmitted via SL RLC1, the processing unit initiates an RRC connection recovery process or an RRC connection establishment process to enter the RRC connected state.

31. The apparatus according to claim 30, characterized in that, The sending unit is specifically configured to include: A fourth message is sent to the remote device, the fourth message including information about the third frequency.

32. The apparatus according to claim 31, characterized in that, The fourth message is a discovery message or a PC5 RRC message.

33. The apparatus according to claim 31 or 32, characterized in that, The third frequency is the frequency of the cell where the first relay device can camp. The device further includes a receiving unit, which is configured to: After establishing a connection with the remote device, the system receives first indication information from the remote device and, based on the first indication information, reselects a cell on the third frequency; or, The device receives a second instruction from the first access network device and switches to the cell under the third frequency according to the second instruction.

34. The apparatus according to claim 30, characterized in that, The device further includes: The receiving unit is configured to receive a fifth message from the remote device. The fifth message is used to query the frequency information of the cell where the first relay device is located, or to query the frequency information of the cell that the first relay device can camp on, or to query whether the first relay device has camped on or can camp on a cell under the third frequency. The sending unit is specifically configured to send a sixth message to the remote device, the sixth message including information about the third frequency, or the sixth message indicating that the first relay device has camped or is able to camp in a cell under the third frequency.

35. The apparatus according to claim 34, characterized in that, The third frequency is the frequency of the cell where the first relay device can camp, and the processing unit is further configured to: Reselect to the cell at the third frequency.

36. The apparatus according to any one of claims 30 to 35, characterized in that, The transmitting unit is further configured to: After establishing a connection with the remote device, the PCI of the cell where the first relay device is located is sent to the remote device.

37. A communication device, characterized in that, include: One or more processors; One or more memory units; And one or more computer programs, wherein the one or more computer programs are stored in the one or more memories, the one or more computer programs including instructions that, when executed by one or more processors of the communication device, cause the communication device to perform the method as claimed in any one of claims 1 to 11, or cause the communication device to perform the method as claimed in any one of claims 12 to 18.

38. A computer-readable storage medium, characterized in that, The computer-readable storage medium is used to store a computer program that, when run on a computer, causes the computer to perform the method as described in any one of claims 1 to 11, or causes the computer to perform the method as described in any one of claims 12 to 18.

39. A chip, characterized in that, It includes one or more processors and a communication interface, wherein the one or more processors are configured to read instructions to perform the method as described in any one of claims 1 to 11, or to perform the method as described in any one of claims 12 to 18.

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