Link failure processing method, apparatus, terminal device and storage medium

Abstract

The embodiments of the present application disclose a link failure handling method, an apparatus, a terminal device and a storage medium, which can be applied to a 5G / NR system, and the method includes: a relay terminal device sends a first notification message to a remote terminal device after a link failure occurs, the link failure including at least one of a radio link failure, an expiration of a T310 timer, an expiration of a T312 timer, an SRB1 integrity detection failure, an SRB2 integrity detection failure, an SRB3 integrity detection failure, and a reconfiguration failure. After a link failure occurs, the relay terminal device notifies the remote terminal device, and the remote terminal device performs a corresponding operation according to the notification to handle the link failure of the relay terminal device, so that a reasonable processing manner can be adopted according to the quality of service QoS requirements of the remote terminal device, and unnecessary relay reselection can be avoided, which is helpful in saving resources and avoiding wasteful resource use.

Description

[Technical field]

[0001] The present application relates to the field of communication technologies, and in particular to a link failure handling method, apparatus, terminal device and storage medium. [Background technology]

[0002] In order to support direct communication between User Equipment (UE) and UE, a sidelink communication method is introduced, and the interface between UEs is a PC5 port. Based on the correspondence between the sending UE and the receiving UE, three transmission methods are supported on the sidelink: unicast, multicast and broadcast.

[0003] A UE can communicate with a base station by relaying another UE without directly connecting to the base station, where a UE not connected to a base station is called a remote UE, a UE providing relay function is called a relay UE, and the remote UE and relay UE communicate with each other via a sidelink. When a relay UE communicates with a remote UE, a link failure situation often occurs in the relay UE, which causes the remote UE to be unable to communicate with the base station, but currently there is a lack of an effective means for handling the link failure of the relay UE. Summary of the Invention [Problem to be solved by the invention]

[0004] The embodiments of the present application provide a link failure handling method, apparatus, terminal device and storage medium, which can be applied to a 5G / NR (New Radio) system. After a link failure occurs, a relay terminal device notifies a remote terminal device, and the remote terminal device can know through the notification that a link failure occurs in the corresponding relay terminal device, so that the remote terminal device can perform corresponding operations based on the notification to handle the link failure of the relay terminal device. For example, the remote terminal device can select relay reselection according to the notification, or wait for connection reestablishment of the relay terminal device, so as to adopt a reasonable processing manner according to the service quality QoS requirements of the remote terminal device, and avoid unnecessary relay reselection, which is helpful in saving resources and avoiding wasteful resource usage. [Means for solving the problem]

[0005] In a first aspect, an embodiment of the present application provides a link failure handling method applied to a relay terminal device, the method including: transmitting a first notification message to a remote terminal device in response to a link failure occurring at the intermediate terminal device, where the link failure includes at least: The failures include any one of the following: radio link failure, T310 timer expiration, T312 timer expiration, SRB1 (Signalling Radio Bearers) integrity detection failure, SRB2 integrity detection failure, SRB3 integrity detection failure, and reconfiguration failure.

[0006] In this technical solution, after a link failure occurs, the relay terminal device notifies the remote terminal device, and the remote terminal device can know that a link failure occurs in the corresponding relay terminal device through the notification, so that the remote terminal device can perform corresponding operations based on the notification to handle the link failure of the relay terminal device, for example, the remote terminal device can select relay reselection according to the notification, or wait for the connection reestablishment of the relay terminal device, so as to adopt a reasonable processing manner according to the service quality QoS requirements of the remote terminal device, and avoid unnecessary relay reselection, which is helpful in saving resources and avoiding wasteful resource usage.

[0007] In one embodiment, the step of transmitting the first notification message to the remote terminal device includes the step of determining whether to transmit the first notification message to the remote terminal device based on the reconstructed cell.

[0008] In one alternative embodiment, the step of determining whether to send a first notification message to the remote terminal device based on the reconstructed cell includes the steps of receiving an area range transmitted by a network device, the area range being a cell list or a tracking area list, not sending the first notification message to the remote terminal device in response to the relay terminal device reconstructing a cell within the area range, and sending the first notification message to the remote terminal device in response to the relay terminal device not reconstructing a cell within the area range.

[0009] In this technical solution, by determining whether to send a first notification message to a remote terminal device in a reconstruction cell of a relay terminal device, the sending of unnecessary notifications can be avoided, which is helpful in saving resources and avoiding the use of unnecessary resources.

[0010] In one alternative embodiment, the step of determining whether to send a first notification message to the remote terminal device based on the reconstructed cell includes the steps of: not sending the first notification message to the remote terminal device in response to the cell selected by the relay terminal to be reconstructed being the same as the serving cell before the link failure; and sending the first notification message to the remote terminal device in response to the cell selected by the relay terminal to be reconstructed being different from the serving cell before the link failure.

[0011] In this technical solution, by determining whether to send a first notification message to a remote terminal device based on whether the cell selected by the relay terminal device to be reconstructed is the same as the serving cell before the failure, the sending of unnecessary notifications can be avoided, which is helpful in saving resources and avoiding wasteful resource usage.

[0012] In one embodiment, the step of sending a first notification message to a remote terminal device includes determining to send the first notification message to a remote terminal device based on a configuration of a network device.

[0013] Optionally, the step of deciding to send the first notification message to a remote terminal device based on a setting of the network device includes the steps of receiving first identification information sent by the network device, the first identification information instructing all remote terminal devices to send the first notification message, and determining based on the first identification information whether to send the first notification message to all remote terminal devices connected to the relay terminal device.

[0014] In this technical solution, when a link failure occurs in an intermediate terminal device, the network device determines whether to send a notification to all remote terminal devices based on one identifier sent to the intermediate terminal device, and the one identifier can instruct the intermediate terminal device whether it needs to send a notification to all remote terminal devices, which can improve processing efficiency and help save resources and avoid wasteful use of resources.

[0015] Optionally, the step of deciding to send the first notification message to a remote terminal device based on a setting of the network device includes the steps of receiving a plurality of second identification information transmitted by the network device, each of the second identification information indicating whether or not to send the first notification message to a corresponding remote terminal device, and determining whether or not to send the first notification message to a corresponding remote terminal device based on the plurality of second identification information transmitted by the network device.

[0016] In this technical solution, when a link failure occurs in an intermediate terminal device, the network device determines whether to send a notification to the corresponding remote terminal device based on the multiple identifiers corresponding to the remote terminal devices sent to the intermediate terminal device by the network device, thereby instructing the intermediate terminal device with the multiple identifiers to send a notification with a goal, and can avoid sending unnecessary notifications, which is helpful in saving resources and avoiding wasteful resource usage.

[0017] Optionally, the step of deciding to send the first notification message to a remote terminal device based on a setting of the network device includes the steps of receiving a quality of service requirement sent by the network device, and in response to data of the remote terminal device satisfying the corresponding quality of service requirement, sending the first notification message to the remote terminal device that satisfies the corresponding quality of service requirement, or in response to data of the remote terminal device satisfying the corresponding quality of service requirement, not sending the first notification message to the remote terminal device that satisfies the corresponding quality of service requirement.

[0018] In this technical solution, when a link failure occurs in an intermediate terminal device, the intermediate terminal device determines whether to send a notification to a remote terminal device that meets the corresponding quality of service requirements based on the quality of service requirements sent by the network device and the data of the remote terminal device, and adopts a reasonable processing manner according to the quality of service requirements of the remote terminal device, so as to avoid the intermediate terminal device from sending unnecessary notifications, and also to avoid unnecessary intermediate reselection by the remote terminal device.

[0019] In one embodiment, the first notification message carries support information, the support information including at least one of: whether a process of a secondary cell group (SCG) recovering a master cell group (MCG) has been initiated; whether a reconfiguration target cell is the same cell as the serving cell before the link failure; and a failure cause, the failure cause including at least one of: a radio link failure; expiration of a T310 timer; expiration of a T312 timer; failure to detect integrity of SRB1; failure to detect integrity of SRB2; failure to detect integrity of SRB3; and failure of reconfiguration.

[0020] In one embodiment, the method further includes ceasing transmission of relay discovery messages and / or notifying higher layers of the occurrence of a link failure, which can help conserve resources and avoid unnecessary resource usage.

[0021] In an optional embodiment, the method further includes a step of sending a second notification message to a network device after the RRC connection reestablishment of the relay terminal device is successful, and / or a step of sending a notification of successful RRC connection reestablishment to the remote terminal device, where the second notification message includes remote terminal devices whose connections are currently pending or remote terminal devices that have already been released.

[0022] In an alternative embodiment, the method further comprises the step of sending an RRC connection reestablishment failure notification to the remote terminal device after the RRC connection reestablishment of the relay terminal device has failed.

[0023] In a second aspect, an embodiment of the present application provides another link failure handling method applied to a remote terminal device, the method including: receiving a first notification message sent by an intermediate terminal device, the first notification message being sent by the intermediate terminal device when a link failure occurs, where the link failure includes at least: The failures include any one of a radio link failure, expiration of a T310 timer, expiration of a T312 timer, failure of integrity detection of SRB1, failure of integrity detection of SRB2, failure of integrity detection of SRB3, and failure of reconfiguration.

[0024] In one embodiment, the method further includes a step of determining whether to continue maintaining a connection with the relay terminal device based on assistance information carried in the first notification message, and notifying the relay terminal device of the decision result, where the assistance information includes at least one of: whether a process of an SCG recovering an MCG has been initiated; whether a reconfiguration target cell is the same cell as the serving cell before the link failure; and a failure cause, where the failure cause includes at least one of: a radio link failure; expiration of a T310 timer; expiration of a T312 timer; failure of SRB1 integrity detection; failure of SRB2 integrity detection; failure of SRB3 integrity detection; and failure of reconfiguration.

[0025] In this technical solution, the remote terminal device can know the processing operation after the link failure of the relay terminal device or the cause of the link failure based on the assistance information carried in the notification message sent by the relay terminal device, so that the remote terminal device can adopt a reasonable processing method based on the assistance information to avoid unnecessary relay reselection.

[0026] In one embodiment, the method further comprises the step of ceasing transmission of relay data to the relay terminal device in response to determining to continue maintaining the connection with the relay terminal device.

[0027] In this technical solution, when a remote terminal device determines to continue to maintain a connection with the relay terminal device, it can stop sending relay data to the relay terminal device, which can help save resources and avoid wasteful resource usage.

[0028] In one possible embodiment, the method further includes a step of receiving a notification of successful RRC connection reestablishment of the relay terminal device sent by the relay terminal device, and a step of resuming transmission of relay data to the relay terminal device.

[0029] In this technical solution, when the remote terminal device receives a notification of successful RRC connection reestablishment of the relay terminal device sent by the relay terminal device, the remote terminal device can determine that the RRC connection reestablishment of the relay terminal device is successful, and at this time, can resume transmitting relay data to the relay terminal device, and realize communication with the network device through the relay terminal device, thereby ensuring that the remote terminal device can communicate normally.

[0030] In one possible embodiment, the method further comprises the steps of receiving a notification of failure of the RRC connection reestablishment of the relay terminal device sent by the relay terminal device, disconnecting the connection with the relay terminal device and performing relay reselection and / or triggering connection reestablishment and / or performing cell reselection.

[0031] In this technical solution, when the remote terminal device receives a notification that the RRC connection reestablishment of the relay terminal device has failed sent by the relay terminal device, it knows that the RRC connection reestablishment of the relay terminal device has failed, and at this time, it can select relay reselection, such as disconnecting the connection with the relay remote device and selecting another relay to communicate, or can trigger connection reestablishment to wait for the connection reestablishment of the relay terminal device, or can perform cell reselection, so that the remote terminal device can adopt a reasonable processing manner according to service quality requirements to avoid unnecessary relay reselection.

[0032] In a third aspect, the embodiment of the present application provides a link failure processing device having some or all of the functions of a relay terminal device for implementing the method according to the first aspect. For example, the functions of the link failure processing device may include some or all of the functions of the embodiments of the present application, or may include a function for implementing any of the embodiments of the present application. The functions may be implemented by hardware, or may be realized by hardware executing corresponding software. The hardware or software includes a unit or module corresponding to one or more of the above functions.

[0033] In one embodiment, the structure of the link failure processing device may include: a transceiver module for supporting communication between the link failure processing device and other devices, and a processing module configured to support the link failure processing device to perform corresponding functions in the above method. The link failure processing device may further include a storage module used for coupling with the transceiver module and the processing module, and for storing computer programs and data required by the link failure processing device.

[0034] As examples, the processing module may be a processor, the transceiver module may be a transceiver or a communication interface, and the storage module may be a memory.

[0035] In a fourth aspect, the embodiment of the present application provides another link failure processing device, which has part or all of the functions of the remote terminal device in the example of implementing the method according to the second aspect. For example, the function of the link failure processing device may have the functions of some or all of the embodiments of the present application, or may have the function of implementing any one of the embodiments of the present application alone. The functions may be implemented by hardware, or may be implemented by hardware executing corresponding software. The hardware or software includes units or modules corresponding to one or more of the above functions.

[0036] In one embodiment, the structure of the link failure processing device may include: a transceiver module for supporting communication between the link failure processing device and other devices, and a processing module configured to support the link failure processing device to perform corresponding functions in the above method. The link failure processing device may further include a storage module used for coupling with the transceiver module and the processing module, for storing computer programs and data required for the communication device.

[0037] As examples, the processing module may be a processor, the transceiver module may be a transceiver or a communication interface, and the storage module may be a memory.

[0038] In a fifth aspect, an embodiment of the present application provides a terminal device, comprising a processor, the method according to the first aspect being performed when the processor invokes a computer program in a memory.

[0039] In a sixth aspect, an embodiment of the present application provides a terminal device, comprising a processor, the method according to the second aspect being performed when the processor invokes a computer program in a memory.

[0040] In a seventh aspect, an embodiment of the present application provides a terminal device, comprising a processor and a memory in which a computer program is stored, the processor executing the computer program stored in the memory to cause the terminal device to perform a method according to the first aspect.

[0041] In an eighth aspect, an embodiment of the present application provides a terminal device, comprising a processor and a memory in which a computer program is stored, the processor executing the computer program stored in the memory to cause the terminal device to perform the method according to the second aspect.

[0042] In a ninth aspect, an embodiment of the present application provides a terminal device, comprising a processor and an interface circuit for receiving and transmitting code instructions to the processor, the processor executing the code instructions to cause the terminal device to perform a method according to the first aspect.

[0043] In a tenth aspect, an embodiment of the present application provides a terminal device, the terminal device including a processor and an interface circuit for receiving and transmitting code instructions to the processor, the processor executing the code instructions to cause the terminal device to perform the method according to the second aspect.

[0044] In an eleventh aspect, an embodiment of the present application provides a communication system, the system comprising a link failure processing device according to the third aspect and a link failure processing device according to the fourth aspect, or the system comprising a terminal device according to the fifth aspect and a terminal device according to the sixth aspect, or the system comprising a terminal device according to the seventh aspect and a terminal device according to the eighth aspect, or the system comprising a terminal device according to the ninth aspect and a terminal device according to the tenth aspect.

[0045] In a twelfth aspect, an embodiment of the present invention provides a computer readable storage medium for storing instructions for use in the terminal device, the instructions, when executed, causing the terminal device to perform the method according to the first aspect.

[0046] In a thirteenth aspect, an embodiment of the present invention provides a readable storage medium for storing instructions for use in the network device, the instructions, when executed, causing the network device to perform the method according to the second aspect.

[0047] In a fourteenth aspect, the present application further provides a computer program product comprising a computer program which, when run on a computer, causes the computer to perform the method according to the first aspect above.

[0048] In a fifteenth aspect, the present application further provides a computer program product comprising a computer program which, when run on a computer, causes the computer to perform the method according to the second aspect above.

[0049] In a sixteenth aspect, the present application provides a computer program which, when run on a computer, causes the computer to carry out the method according to the first aspect above.

[0050] In a seventeenth aspect, the present application provides a computer program which, when run on a computer, causes the computer to carry out the method according to the second aspect above. [Brief description of the drawings]

[0051] In order to more clearly describe the technical solutions in the embodiments and background art of the present application, the drawings that need to be used in the embodiments and background art of the present application are described below. [Figure 1] 1 is a schematic diagram of the architecture of a communication system provided in an embodiment of the present application; [Diagram 2] 4 is a flowchart of a link failure handling method provided in an embodiment of the present application; [Diagram 3] 4 is a flowchart of another link failure handling method provided in an embodiment of the present application; [Figure 4] 4 is a flowchart of another link failure handling method provided in an embodiment of the present application; [Diagram 5] 4 is a flowchart of another link failure handling method provided in an embodiment of the present application; [Figure 6] 4 is a flowchart of another link failure handling method provided in an embodiment of the present application; [Figure 7] FIG. 2 is a schematic structural diagram of a link failure processing device provided in an embodiment of the present application; [Figure 8] FIG. 2 is a schematic structural diagram of another link failure processing device provided in an embodiment of the present application; [Figure 9]FIG. 2 is a schematic structural diagram of another link failure processing device provided in an embodiment of the present application; [Figure 10] FIG. 2 is a schematic structural diagram of a further link failure processing device provided in an embodiment of the present application; [Figure 11] FIG. 2 is a schematic structural diagram of a terminal device provided in an embodiment of the present application; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0052] Hereinafter, the present application will be described in detail with reference to the drawings, examples of which are illustrated in the drawings, in which the same or similar reference numerals throughout refer to the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the drawings are illustrative and are used to explain the present application, and cannot be understood as limiting the present application.

[0053] In order to provide a better understanding of the link failure handling method disclosed in the embodiment of the present application, a communication system used in the embodiment of the present application will be described below first.

[0054] Referring to FIG. 1, FIG. 1 is a schematic diagram of the architecture of a communication system provided in an embodiment of the present application. The communication system includes, but is not limited to, one network device and multiple terminal devices, where a terminal device not connected to the network device among the multiple terminal devices is called a remote terminal device, a terminal device providing a relay function is called a relay terminal device, and the remote terminal device and the relay terminal device communicate with each other via a sidelink. The number and form of devices shown in FIG. 1 are merely exemplary and do not limit the embodiment of the present application, and may include two or more network devices and two or more terminal devices in actual application. The communication system shown in FIG. 1 is exemplified by including one network device 101, one relay terminal device 102, and one remote terminal device 103.

[0055] It should be noted that the technical solutions of the embodiments of the present application can be applied to various communication systems, such as a long term evolution (LTE) system, a fifth generation (5G) mobile communication system, a 5G new radio (NR) system, or other future new mobile communication systems.

[0056] The network device 101 in the embodiment of the present application is an entity for transmitting or receiving a signal on the network side. For example, the network device 101 may be an evolved base station (eNB), a transmission reception point (TRP), a next generation base station (gNB) in an NR system, a base station in other future mobile communication systems, or an access node in a wireless fidelity (WiFi) system. The embodiment of the present application does not limit the specific technology and the specific device form adopted in the network device. The network device provided in the embodiment of the present application may be composed of a central unit (CU) and a distributed unit (DU), where the CU may be called a control unit. Using the CU-DU structure, the protocol layer of the network device, for example, a base station, can be divided, and some protocol layer functions are arranged in the CU and centrally controlled, and the remaining part or all of the protocol layer functions are distributed to the DU, and the DU is centrally controlled by the CU.

[0057] The terminal devices in the embodiment of the present application (the relay terminal device 102 and the remote terminal device 103 as described above) are entities that transmit or receive signals on the user side, such as a mobile phone. The terminal devices may be called terminal devices (terminals), user equipment (UE), mobile stations (MS), mobile terminals (MT), etc. The terminal devices may be automobiles with communication capabilities, smart cars, mobile phones, wearable devices, tablets (Pads), computers with wireless transmission and reception capabilities, virtual reality (VR) terminal devices, augmented reality (AR) terminal devices, wireless terminal devices in industrial control, wireless terminal devices in self-driving, wireless terminal devices in remote medical surgery, wireless terminal devices in smart grids, wireless terminal devices in transportation safety, wireless terminal devices in smart cities, wireless terminal devices in smart homes, etc. The embodiments of the present application are not limited to a specific technology adopted in the terminal device and a specific device form.

[0058] It should be understood that the communication system described in the embodiment of the present application is for more clearly illustrating the technical solution of the embodiment of the present application, and does not limit the technical solution provided in the embodiment of the present application. Those skilled in the art will understand that with the evolution of system architecture and the emergence of new business scenarios, the technical solution provided in the embodiment of the present application can be similarly applied to similar technical problems.

[0059] The link failure handling method, apparatus, terminal device and storage medium provided in the present application are introduced in detail below with reference to the accompanying drawings.

[0060] Referring to Fig. 2, Fig. 2 is a flow chart of a link failure handling method provided in an embodiment of the present application. It should be noted that the link failure handling method in the embodiment of the present application can be applied to a relay terminal device. As shown in Fig. 2, the link failure handling method includes, but is not limited to, the following steps:

[0061] In step S201, in response to a link failure occurring in the intermediate terminal device, a first notification message is sent to the remote terminal device.

[0062] In an embodiment of the present application, the link failure may include, but is not limited to, any one of a radio link failure, expiration of a T310 timer, expiration of a T312 timer, failure of integrity detection of SRB1, failure of integrity detection of SRB2, failure of integrity detection of SRB3, and failure of reconfiguration.

[0063] In addition, in the 3GPP RAN2 conference discussion, many companies proposed to introduce a fast radio link failure (RLF) restart mechanism based on the T312 timer in LTE Rel-12 to further reduce business interruptions and handover failures caused by radio link failures in the NR system and the LTE system. In the LTE system, the operation of the T312 timer is as shown in Table 1. The introduction of T312 allows the terminal device to declare radio link failure earlier, thereby starting the Radio Resource Control (RRC) connection reestablishment process earlier, effectively shortening the business interruption time. If the T310 timer is running, it indicates that the downlink link quality of the terminal device at this time is not good, and the measurement report trigger (e.g., A3 event) is likely to explain that the terminal device has already found a suitable target cell, and the network device sends a handover command to the terminal device based on the measurement result of the terminal device. However, due to the downlink link quality problem at this time, the terminal device is likely unable to receive the handover command from the network device, which causes the radio link to fail. If the T312 timer is not introduced, the terminal device needs to wait until T310 expires and then trigger RRC connection reestablishment to resume the RRC connection. In order to shorten the business interruption event of the terminal device, after the T312 timer is introduced, RRC connection reestablishment can be triggered when T312 expires, so as to declare a radio link failure earlier and assist the terminal device to start the RRC connection reestablishment process earlier.

[0064] [Table 1]

[0065] Therefore, in the embodiment of the present application, the relay terminal device can determine whether a link failure occurs by monitoring whether a radio link failure occurs, or monitoring whether a T310 timer expires, or monitoring whether a T312 timer expires, or monitoring whether a detection of the integrity of SRB1, SRB2, or SRB3 fails, or monitoring whether a reconfiguration fails. When the relay terminal device determines that a link failure has been sent, it notifies the remote terminal device. That is, when any of the above situations that may cause the above link failure occurs, the relay terminal device sends the first notification information to the remote terminal device. For ease of understanding, a specific example is given below.

[0066] Example 1 When a radio link failure occurs in the intermediate terminal device, it sends a first notification message to the remote terminal device.

[0067] For example, the network device sends a handover command to the relay terminal device based on the measurement result of the relay terminal device, but the relay terminal device is likely to be unable to receive the handover command of the network device due to downlink link quality problems at this time, which leads to radio link failure. At this time, the relay terminal device sends a first notification message to the remote terminal device, i.e., notifies the remote terminal device, so that the remote terminal device can know that a radio link failure has occurred in the corresponding relay terminal device through the notification, and the remote terminal device can perform corresponding operations based on the notification to handle the radio link failure of the relay terminal device. For example, the remote terminal device can select relay reselection according to the notification, or wait for the connection reestablishment of the relay terminal device, so that a reasonable processing manner can be adopted according to the quality of service QoS requirements of the remote terminal device to avoid unnecessary relay reselection, which helps to save resources and avoid wasteful resource use.

[0068] Example 2 When the T310 timer of the intermediate terminal device expires, it sends a first notification message to the remote terminal device.

[0069] For example, when the relay terminal device performs radio link detection, the start of timer T310 is triggered when the number of consecutively received downlink out of sync indications is equal to N310. If timer T310 expires, it is considered that a radio link failure is detected, and at this time, the relay terminal device sends a first notification message to the remote terminal device.

[0070] Example 3 When the T312 timer of the intermediate terminal device expires, it sends a first notification message to the remote terminal device.

[0071] For example, when a measurement ID for which a T312 timer is set transmits a measurement report, the T312 timer is started at the point in time when the start condition of the T312 timer is satisfied, and if the condition is not triggered and handover is not performed before the T312 timer expires, it is determined that a radio link failure has occurred in the relay terminal device after the T312 timer expires, and at this time, the relay terminal device transmits a first notification message to the remote terminal device.

[0072] Example 4 If the integrity detection of the SRB1 of the intermediate terminal device fails, it sends a first notification message to the remote terminal device.

[0073] Example 5 If the integrity detection of the SRB2 of the intermediate terminal device fails, a first notification message is sent to the remote terminal device.

[0074] Example 6 If the integrity detection of the SRB3 of the intermediate terminal device fails, a first notification message is sent to the remote terminal device.

[0075] That is, if the integrity detection of SRB1 or SRB2 or SRB3 of the relay terminal device fails, RRC reestablishment initialization needs to be triggered, i.e., indicating a link failure of the relay terminal device, and at this time, the relay terminal device sends a first notification message to the remote terminal device.

[0076] Example 7 If the reconfiguration of the intermediate terminal device fails, a first notification message is sent to the remote terminal device.

[0077] For example, if the RRC reconfiguration of a relay terminal device fails, the relay terminal device notifies the remote terminal device, and the remote terminal device can know from the notification that a link failure has occurred in the corresponding relay terminal device.

[0078] In one embodiment, support information may be carried in the first notification message, where in the embodiment of the present application, the support information may include, but is not limited to, any one or more of: whether a process of a secondary cell group (SCG) recovering a master cell group (MCG) has been initiated; whether a reconfiguration target cell is the same cell as the serving cell before the link failure; and failure causes, including any one of: radio link failure; expiration of a T310 timer; expiration of a T312 timer; failure of SRB1 integrity detection; failure of SRB2 integrity detection; failure of SRB3 integrity detection; and failure of reconfiguration.

[0079] By implementing the embodiment of the present application, a remote terminal device can know that a link failure occurs in a corresponding relay terminal device through the notification sent by the relay terminal device, so that the remote terminal device can perform corresponding operations based on the notification to handle the link failure of the relay terminal device. For example, the remote terminal device can select relay reselection according to the notification, or wait for the connection reestablishment of the relay terminal device, so as to adopt a reasonable processing manner according to the quality of service QoS requirements of the remote terminal device, and avoid unnecessary relay reselection, which is helpful in saving resources and avoiding wasteful resource usage.

[0080] Wherein, the relay terminal device can determine whether to notify the remote terminal device according to the reconstructed cell. Optionally, refer to FIG. 3, which is a flowchart of another link failure handling method provided in the embodiment of the present application. Wherein, the link failure handling method of the embodiment of the present application can be applied to the relay terminal device. As shown in FIG. 3, the link failure handling method can include, but is not limited to, the following steps:

[0081] In step S301, in response to a link failure occurring in a relay terminal device, it is determined whether to send a first notification message to a remote terminal device based on a reconstructed cell.

[0082] In the embodiment of the present application, the link failure may include, but is not limited to, any one of radio link failure, T310 timer expiration, T312 timer expiration, SRB1 integrity detection failure, SRB2 integrity detection failure, SRB3 integrity detection failure, and reconfiguration failure. Below, some examples are given to introduce when to send the first notification message to the remote terminal device.

[0083] Example 1 When a radio link failure occurs in the relay terminal device, it determines whether to send a first notification message to the remote terminal device based on the reconstructed cell.

[0084] Example 2 When the T310 timer of the relay terminal device expires, it determines whether to send a first notification message to the remote terminal device based on the reconstructed cell.

[0085] Example 3 When the T312 timer of the relay terminal device expires, it determines whether to send a first notification message to the remote terminal device based on the reconstructed cell.

[0086] Example 4 If the integrity detection of the SRB1 of the relay terminal device fails, it determines whether to send a first notification message to the remote terminal device based on the reconstruction cell.

[0087] Example 5 If the integrity detection of the SRB2 of the relay terminal device fails, it determines whether to send a first notification message to the remote terminal device based on the reconstruction cell.

[0088] Example 6 If the integrity detection of the SRB3 of the relay terminal device fails, it determines whether to send a first notification message to the remote terminal device based on the reconstruction cell.

[0089] Example 7 If the reconfiguration of the intermediate terminal device fails, it is determined whether to send a first notification message to the remote terminal device based on the reconfiguration cell.

[0090] It should be noted that in the embodiment of the present application, after a link failure occurs in the relay terminal device, the relay terminal device starts reestablishment and finally completes the reestablishment in the following two cases: 1. Complete the reestablishment in the original cell; 2. Complete the reestablishment in the adjacent cell. The relay terminal device in the embodiment of the present application determines whether to send a first notification message to the remote terminal device based on the cell selected to be reestablished. Below, two different examples are given to introduce an embodiment in which the relay terminal device determines whether to send a first notification message to the remote terminal device based on the reestablishment cell.

[0091] As an example of a possible embodiment, an embodiment in which the relay terminal device determines whether to send a first notification message to the remote terminal device based on the reconstructed cell is as follows: receiving an area range sent by a network device, where the area range is a cell list or a Tracking Area list (TA), in response to the relay terminal device reconstructing a cell in the area range, not sending a first notification message to the remote terminal device, and in response to the relay terminal device not reconstructing a cell in the area range, sending a first notification message to the remote terminal device.

[0092] For example, a network device (such as a base station) transmits an area range to a relay terminal device. The relay terminal device determines whether to reconstruct a cell in the area range. If the relay terminal device reconstructs a cell in the area range, it does not notify the remote terminal device. If the relay terminal device does not reconstruct a cell in the area range, it notifies the remote terminal device. This can avoid sending unnecessary notifications by determining whether to send a first notification message to the remote terminal device in the reconstruction cell of the relay terminal device, which helps to save resources and avoid wasteful resource usage.

[0093] As an example of another possible embodiment, an embodiment in which the relay terminal device decides whether to send a first notification message to the remote terminal device based on the reconstructed cell is as follows: in response to the cell selected by the relay terminal device to be reconstructed being the same as the serving cell before the link failure, not sending the first notification message to the remote terminal device, and in response to the cell selected by the relay terminal device to be reconstructed being different from the serving cell before the link failure, sending the first notification message to the remote terminal device.

[0094] That is, if the cell selected by the relay terminal device as the cell to be reconstructed is the same as the serving cell before the link failure, the relay terminal device does not notify the remote terminal device, and if the cell selected by the relay terminal device as the cell to be reconstructed is different from the serving cell before the link failure, the relay terminal device notifies the remote terminal device. This allows the determination of whether to send a first notification message to the remote terminal device based on whether the cell selected by the relay terminal device as the cell to be reconstructed is the same as the serving cell before the failure, and can avoid sending unnecessary notifications, which is helpful in saving resources and avoiding the use of wasteful resources.

[0095] If a link failure occurs in the intermediate terminal device, the intermediate terminal device can determine whether to notify the remote terminal device according to the setting of the network device. Optionally, refer to FIG. 4, which is a flowchart of another link failure handling method provided in the embodiment of the present application. It should be noted that the link failure handling method of the embodiment of the present application can be applied to the intermediate terminal device. As shown in FIG. 4, the link failure handling method may include, but is not limited to, the following steps:

[0096] In step S401, in response to a link failure occurring in the intermediate terminal device, it is determined to send a first notification message to the remote terminal device based on a setting of the network device.

[0097] In an embodiment of the present application, the link failure may include, but is not limited to, any one of a radio link failure, expiration of a T310 timer, expiration of a T312 timer, failure of integrity detection of SRB1, failure of integrity detection of SRB2, failure of integrity detection of SRB3, and failure of reconfiguration.

[0098] Below, some examples are given to introduce when to send the first notification message to the remote terminal device.

[0099] Example 1 When a radio link failure occurs in the intermediate terminal device, it is determined to send a first notification message to the remote terminal device based on a configuration of the network device.

[0100] Example 2 When the T310 timer of the intermediate terminal device expires, it determines to send a first notification message to the remote terminal device according to the configuration of the network device.

[0101] Example 3 When the T312 timer of the intermediate terminal device expires, it determines to send a first notification message to the remote terminal device according to the setting of the network device.

[0102] Example 4 If the integrity detection of the SRB1 of the intermediate terminal device fails, determine to send a first notification message to the remote terminal device based on the setting of the network device.

[0103] Example 5 If the integrity detection of the SRB2 of the intermediate terminal device fails, determine to send a first notification message to the remote terminal device based on the setting of the network device.

[0104] Example 6 If the integrity detection of the SRB3 of the intermediate terminal device fails, determine to send a first notification message to the remote terminal device based on the setting of the network device.

[0105] Example 7 If the reconfiguration of the intermediate terminal device fails, determine to send a first notification message to the remote terminal device based on the configuration of the network device.

[0106] It should be noted that in the embodiment of the present application, a network device (such as a base station) sets an identifier, which is used to instruct the relay terminal device whether to send a notification to all remote terminal devices, or to instruct the relay terminal device to which remote terminal device to send a notification. The following examples will describe different embodiments of the step of determining to send a first notification message to a remote terminal device based on the setting of the network device.

[0107] As an example of a possible embodiment, an embodiment in which an intermediate terminal device determines to send a first notification message to a remote terminal device based on a setting of a network device is as follows: receiving first identification information sent by a network device, the first identification information being used to instruct all remote terminal devices to send a first notification message, and determining whether to send the first notification message to all remote terminal devices connected to the intermediate terminal device based on the first identification information.

[0108] For example, a network device (such as a base station) transmits one identifier (i.e., the above-mentioned first identification information) to a relay terminal device. The relay terminal device determines whether to transmit the first notification information to all remote terminal devices connected to the relay terminal device based on the first identification information, that is, the relay terminal device determines whether to transmit notifications to all remote terminal devices based on the identifier transmitted by the network device. Thus, in the technical solution, when a link failure occurs in the relay terminal device, it determines whether to transmit notifications to all remote terminal devices based on the one identifier transmitted by the network device to the relay terminal device, and the one identifier can instruct the relay terminal device whether it needs to transmit notifications to all remote terminal devices, which can improve processing efficiency and help save resources and avoid wasteful resource use.

[0109] As an example of another possible embodiment, an embodiment in which an intermediate terminal device determines to send a first notification message to a remote terminal device based on a setting of a network device is as follows: receive a plurality of second identification information sent by the network device, each of the second identification information is used to indicate whether to send a first notification message to a corresponding remote terminal device, and determine whether to send a first notification message to a corresponding remote terminal device based on the plurality of second identification information sent by the network device.

[0110] For example, the network device sends multiple identifiers (second identification information as described above) corresponding to remote terminal devices to the intermediate terminal device, and each identifier is used to instruct whether to send a notification to the corresponding remote terminal device, and thus the intermediate terminal device determines whether to send a notification to the corresponding remote terminal device based on the multiple identifiers sent by the network device, thereby instructing the intermediate terminal device to send notifications with a goal by the multiple identifiers, and can avoid sending unnecessary notifications, which is helpful in saving resources and avoiding wasteful resource usage.

[0111] As another example of a possible embodiment, an embodiment in which the intermediate terminal device decides to send a first notification message to a remote terminal device based on a setting of the network device is as follows: receive a quality of service requirement sent by the network device, and in response to the data of the remote terminal device satisfying the corresponding quality of service requirement, send a first notification message to the remote terminal device that satisfies the corresponding quality of service requirement, or in response to the data of the remote terminal device satisfying the corresponding quality of service requirement, do not send a first notification message to the remote terminal device that satisfies the corresponding quality of service requirement, where the quality of service can be controlled by a quasi-cooperative positioning indicator (PQI) and a packet delay budget.

[0112] For example, a network device sends a quality of service requirement to a relay terminal device. When the data of a remote terminal device meets the corresponding quality of service requirement, the relay terminal device sends the first notification information to the corresponding remote UE, or when the data of the remote terminal device meets the corresponding quality of service requirement, the relay terminal device does not send the first notification message to the corresponding remote terminal device. Thus, when a link failure occurs in a relay terminal device, the relay terminal device determines whether to send a notification to a remote terminal device that meets the corresponding quality of service requirement according to the quality of service requirement sent by the network device and the data of the remote terminal device, and adopts a reasonable processing manner according to the quality of service requirement of the remote terminal device to avoid the relay terminal device from sending unnecessary notifications, and also avoids unnecessary relay reselection by the remote terminal device.

[0113] In one embodiment, the link failure handling method of the embodiment of the present application further includes: the relay terminal device stops sending relay discovery messages after the link fails; optionally, the relay terminal device notifies an upper layer of the occurrence of link failure after the link fails; the upper layer stops sending relay discovery messages after receiving the notification of link failure, which can help save resources and avoid wasteful resource usage.

[0114] In an optional embodiment, the link failure handling method of the embodiment of the present application further includes: after the RRC connection reestablishment of the relay terminal device is successful, sending a second notification message to the network device, and / or sending a notification of successful RRC connection reestablishment to the remote terminal device, where the second notification message includes the remote terminal device whose connection is currently pending or the remote terminal device that has already been released.

[0115] That is, after the relay terminal device successfully reestablishes the RRC connection, it notifies the network device (such as a base station) of the remote terminal device state, where the notification includes the remote terminal devices currently holding the connection, or the notification includes the remote terminal devices that have already been released, thereby informing the network device which remote terminal devices are holding the connection, or informing the network device which remote terminal devices have already released the connection. Also, for example, after the relay terminal device successfully reestablishes the RRC connection, it sends a notification of successful reestablishment to the remote terminal device, so that the remote terminal device knows that the relay terminal device has successfully reestablished the RRC connection, and resumes sending relay data to the relay terminal device, ensuring normal communication of the remote terminal device.

[0116] Also, for example, after the relay terminal device successfully reestablishes the RRC connection, it sends a second notification message to the network device and sends a notification of successful RRC connection reestablishment to the remote terminal device, so as to inform the network device which remote terminal device is holding the connection, or to inform the network device which remote terminal device has already released the connection, and also to inform the remote terminal device that the relay terminal device has successfully reestablished the RRC connection, so as to resume sending relay data to the relay terminal device, and ensure normal communication of the remote terminal device.

[0117] In an optional embodiment, the link failure handling method of the embodiment of the present application further includes: sending a notification of RRC connection reestablishment failure to the remote terminal device after the RRC connection reestablishment of the relay terminal device fails, so that the remote terminal device can be informed that the RRC connection reestablishment of the relay terminal device fails, and the remote terminal device can disconnect from the relay terminal device and perform relay reselection and / or trigger connection reestablishment and / or perform cell reselection, so that the remote terminal device can adopt a reasonable handling manner according to the service quality requirements to avoid unnecessary relay reselection.

[0118] It should be understood that the above embodiment describes the embodiment of the link failure handling method of the embodiment of the present application from the side of the intermediate terminal device. The embodiment of the present application further provides another link failure handling method, and the embodiment of the link failure handling method will be described below from the side of the remote terminal device. Referring to FIG. 5, FIG. 5 is a flowchart of another link failure handling method provided in the embodiment of the present application. It should be noted that the link failure handling method of the embodiment of the present application can be applied to the remote terminal device. As shown in FIG. 5, the link failure handling method may include, but is not limited to, the following steps:

[0119] In step S501, a first notification message sent by an intermediate terminal device is received, where in the embodiment of the present application, the first notification message is sent by the intermediate terminal device when a link failure occurs.

[0120] That is, when a link failure occurs, the relay terminal device transmits the first notification information to the remote terminal device. The remote terminal device receives the first notification message transmitted by the relay terminal device through Sidelink communication. Here, the link failure may include, but is not limited to, any one of a radio link failure, expiration of a T310 timer, expiration of a T312 timer, failure of SRB1 integrity detection, failure of SRB2 integrity detection, failure of SRB3 integrity detection, and failure of reconfiguration.

[0121] That is, when any of the above situations that may cause a link failure occur, the relay terminal device sends the first notification information to the remote terminal device, and for ease of understanding, a specific example is given below.

[0122] Example 1 When a radio link failure occurs in the intermediate terminal device, it sends a first notification message to the remote terminal device.

[0123] For example, the network device sends a handover command to the relay terminal device based on the measurement result of the relay terminal device, but the relay terminal device is likely to be unable to receive the handover command of the network device due to downlink link quality problems at this time, which leads to radio link failure. At this time, the relay terminal device sends a first notification message to the remote terminal device, i.e., notifies the remote terminal device, so that the remote terminal device can know that a radio link failure has occurred in the corresponding relay terminal device through the notification, and the remote terminal device can perform corresponding operations based on the notification to handle the radio link failure of the relay terminal device. For example, the remote terminal device can select relay reselection according to the notification, or wait for the connection reestablishment of the relay terminal device, so that a reasonable processing manner can be adopted according to the service quality QoS requirements of the remote terminal device to avoid unnecessary relay reselection, which is helpful in saving resources and avoiding wasteful resource use.

[0124] Example 2 When the T310 timer of the intermediate terminal device expires, it sends a first notification message to the remote terminal device.

[0125] For example, when the relay terminal device performs radio link detection, the start of timer T310 is triggered when the number of consecutively received downlink out of sync indications is equal to N310. If timer T310 expires, it is considered that a radio link failure is detected, and at this time, the relay terminal device sends a first notification message to the remote terminal device.

[0126] Example 3 When the T312 timer of the intermediate terminal device expires, it sends a first notification message to the remote terminal device.

[0127] For example, when a measurement ID for which a T312 timer is set transmits a measurement report, the T312 timer is started at the point in time when the start condition of the T312 timer is satisfied, and if the condition is not triggered and handover is not performed before the T312 timer expires, it is determined that a radio link failure has occurred in the relay terminal device after the T312 timer expires, and at this time, the relay terminal device transmits a first notification message to the remote terminal device.

[0128] Example 4 If the integrity detection of the SRB1 of the intermediate terminal device fails, it sends a first notification message to the remote terminal device.

[0129] Example 5 If the integrity detection of the SRB2 of the intermediate terminal device fails, a first notification message is sent to the remote terminal device.

[0130] Example 6 If the integrity detection of the SRB3 of the intermediate terminal device fails, a first notification message is sent to the remote terminal device.

[0131] That is, if the integrity detection of SRB1 or SRB2 or SRB3 of the relay terminal device fails, RRC reestablishment initialization needs to be triggered, i.e., indicating a link failure of the relay terminal device, and at this time, the relay terminal device sends a first notification message to the remote terminal device.

[0132] Example 7 If the reconfiguration of the intermediate terminal device fails, it sends a first notification message to the remote terminal device.

[0133] For example, if the RRC reconfiguration of a relay terminal device fails, the relay terminal device notifies the remote terminal device, and the remote terminal device can know from the notification that a link failure has occurred in the corresponding relay terminal device.

[0134] It should be noted that the relay terminal device can determine whether to notify the remote terminal device based on the reconstructed cell. As an example of a possible embodiment, an embodiment in which the relay terminal device determines whether to send a first notification message to the remote terminal device based on the reconstructed cell is as follows: Receive an area range sent by a network device, where the area range is a cell list or a tracking area list (Tracking Area, TA), in response to the relay terminal device reconstructing a cell in the area range, do not send a first notification message to the remote terminal device, and in response to the relay terminal device not reconstructing a cell in the area range, send a first notification message to the remote terminal device.

[0135] As an example of another possible embodiment, an embodiment in which the relay terminal device decides whether to send a first notification message to the remote terminal device based on the reconstructed cell is as follows: in response to the cell selected by the relay terminal to be reconstructed being the same as the serving cell before the link failure, not sending the first notification message to the remote terminal device, and in response to the cell selected by the relay terminal to be reconstructed being different from the serving cell before the link failure, sending the first notification message to the remote terminal device.

[0136] In addition, when a link failure occurs in the relay terminal device, the relay terminal device can determine whether to notify the remote terminal device based on the setting of the network device. As an example of a possible embodiment, an embodiment in which the relay terminal device determines to send a first notification message to the remote terminal device based on the setting of the network device is as follows: receiving first identification information sent by the network device, the first identification information is used to instruct all remote terminal devices to send a first notification message, and determining whether to send the first notification message to all remote terminal devices connected to the relay terminal device based on the first identification information.

[0137] As an example of another possible embodiment, an embodiment in which an intermediate terminal device determines to send a first notification message to a remote terminal device based on a setting of a network device is as follows: receive a plurality of second identification information sent by the network device, each of the second identification information is used to indicate whether to send a first notification message to a corresponding remote terminal device, and determine whether to send a first notification message to a corresponding remote terminal device based on the plurality of second identification information sent by the network device.

[0138] As another example of a possible embodiment, an embodiment in which the intermediate terminal device decides to send a first notification message to a remote terminal device based on a setting of the network device is as follows: receive a quality of service requirement sent by the network device, and in response to the data of the remote terminal device satisfying the corresponding quality of service requirement, send a first notification message to the remote terminal device that satisfies the corresponding quality of service requirement, or in response to the data of the remote terminal device satisfying the corresponding quality of service requirement, do not send a first notification message to the remote terminal device that satisfies the corresponding quality of service requirement, where the quality of service can be controlled by a quasi-cooperative positioning indicator (PQI) and a packet delay budget.

[0139] By implementing the embodiment of the present application, when the remote terminal device receives the first notification information sent by the relay terminal device after a link failure occurs, the remote terminal device can timely know that a link failure has occurred in the relay terminal device, so that the remote terminal device can timely adopt a reasonable processing method to ensure normal communication of the remote terminal device, and further avoid unnecessary relay reselection of the remote terminal device.

[0140] In addition, the assistance information may be carried in the first notification message sent by the relay terminal device to the remote terminal device. In this way, after the remote terminal device receives the first notification message, it determines whether to continue to maintain the connection with the relay terminal device. Optionally, refer to FIG. 6, which is a flowchart of another link failure handling method provided in an embodiment of the present application. In addition, the link failure handling method of the embodiment of the present application can be applied to the remote terminal device. As shown in FIG. 6, the link failure handling method may include, but is not limited to, the following steps:

[0141] In step S601, a first notification message sent by a relay terminal device is received. The first notification message is sent by the relay terminal device when a link failure occurs, where the link failure includes at least: The failures include any one of a radio link failure, expiration of a T310 timer, expiration of a T312 timer, failure of integrity detection of SRB1, failure of integrity detection of SRB2, failure of integrity detection of SRB3, and failure of reconfiguration.

[0142] In the embodiments of the present application, step S601 can be realized by using any of the methods in each embodiment of the present application, and the embodiments of the present application are not limited thereto, and detailed description thereof will be omitted.

[0143] In step S602, it is determined whether to continue to maintain the connection with the relay terminal device based on the assistance information carried in the first notification message, and the determination result is notified to the relay terminal device.

[0144] In some embodiments of the present application, the assistance information may include, but is not limited to, any one or more of: whether the process of the SCG recovering the MCG has been initiated, whether the reestablishment target cell is the same cell as the serving cell before the link failure, and failure causes, where the failure causes include any one of: radio link failure, expiration of the T310 timer, expiration of the T312 timer, failure of SRB1 integrity detection, failure of SRB2 integrity detection, failure of SRB3 integrity detection, and reconfiguration failure.

[0145] In an embodiment of the present application, after a remote terminal device receives a first notification message sent by a relay terminal device after a link failure occurs, in response to a determination to continue to maintain a connection with the relay terminal device based on the assistance information carried in the first notification message, the remote terminal terminal maintains the connection with the relay terminal device, and when the remote terminal terminal determines to maintain the connection, notifies the relay terminal device to inform the relay terminal device that the remote terminal device is suspending the connection with the relay terminal device. In response to a determination to disconnect the connection with the relay terminal device based on the assistance information carried in the first notification message, the remote terminal terminal disconnects the connection with the relay terminal device, and when the remote terminal terminal disconnects the connection with the relay terminal device, notifies the relay terminal device to inform the relay terminal device that the remote terminal device has disconnected the connection with the relay terminal device.

[0146] By implementing the embodiment of the present application, the remote terminal device can know the processing operation after the link failure of the relay terminal device or the cause of the link failure based on the assistance information carried in the notification message sent by the relay terminal device, so that the remote terminal device can adopt a rational processing method based on the assistance information to avoid unnecessary relay reselection.

[0147] In one embodiment, the link failure handling method of the embodiment of the present application further includes: when the remote terminal device determines to continue to maintain the connection with the relay terminal device, stopping sending relay data to the relay terminal device. In this technical solution, when the remote terminal device determines to continue to maintain the connection with the relay terminal device, it can stop sending relay data to the relay terminal device, which can help save resources and avoid wasteful resource usage.

[0148] In one possible embodiment, the link failure handling method of the embodiment of the present application further includes: the remote terminal device receives a notification of the success of the RRC connection reestablishment of the relay terminal device sent by the relay terminal device, and resumes sending relay data to the relay terminal device. In this technical solution, when the remote terminal device receives the notification of the success of the RRC connection reestablishment of the relay terminal device sent by the relay terminal device, the relay terminal device can determine that the RRC connection reestablishment is successful, and at this time, can resume sending relay data to the relay terminal device, and can realize communication with the network device through the relay terminal device, thereby ensuring that the remote terminal device can communicate normally.

[0149] In one possible embodiment, the link failure handling method of the embodiment of the present application further includes: a remote terminal device receives a notification of the failure of the RRC connection reestablishment of the relay terminal device sent by the relay terminal device, disconnects the connection with the relay terminal device and performs relay reselection, and / or disconnects the connection with the relay terminal device and triggers connection reestablishment, and / or disconnects the connection with the relay terminal device and performs cell reselection. In this technical solution, when the remote terminal device receives the notification of the failure of the RRC connection reestablishment of the relay terminal device sent by the relay terminal device, it knows that the RRC connection reestablishment of the relay terminal device has failed, and at this time, it can select relay reselection, such as disconnecting the connection with the relay remote device and selecting another relay to communicate, or it can trigger connection reestablishment and perform cell reselection, so that the remote terminal device can adopt a reasonable processing manner according to the service quality requirements to avoid unnecessary relay reselection.

[0150] In the above embodiments provided in the present application, the methods provided in the embodiments are introduced from the perspective of the relay terminal device and the remote terminal device, respectively. In order to realize each function in the method provided in the above embodiments, the relay terminal device and the remote terminal device may include a hardware structure and a software module, and each of the above functions can be realized in the form of a hardware structure, a software module, or a hardware structure plus a software module. Some of the above functions can be implemented in the form of a hardware structure, a software module, or a hardware structure plus a software module.

[0151] 7, there is shown a schematic structural diagram of a link failure processing device 70 provided in an embodiment of the present application. It should be noted that the link failure processing device 70 may be a terminal device (a relay terminal device in the embodiment of the method as described above), may be a device in the terminal device, or may be a device that can be used in conjunction with the terminal device.

[0152] 7 may include a transceiver module 701. The transceiver module 701 may include a transmitting module for realizing a transmitting function and / or a receiving module for realizing a receiving function, and the transmitting function and / or the receiving function can be realized by the transceiver module 701.

[0153] In an embodiment of the present application, the transceiver module 701 sends a first notification message to the remote terminal device in response to a link failure occurring in the relay terminal device, where the link failure includes at least one of a radio link failure, expiration of a T310 timer, expiration of a T312 timer, failure of integrity detection of SRB1, failure of integrity detection of SRB2, failure of integrity detection of SRB3, and failure of reconfiguration.

[0154] In one embodiment, the embodiment in which the transceiver module 701 sends the first notification message to the remote terminal device may be to determine whether to send the first notification message to the remote terminal device based on the reconstructed cell.

[0155] In one possible embodiment, an embodiment in which the transceiver module 701 determines whether to send a first notification message to a remote terminal device based on a reconstructed cell is as follows: receive an area range sent by a network device, which is a cell list or a tracking area list, and in response to the relay terminal device reconstructing a cell within the area range, do not send a first notification message to the remote terminal device, and in response to the relay terminal device not reconstructing a cell within the area range, send a first notification message to the remote terminal device.

[0156] In one possible embodiment, the embodiment in which the transceiver module 701 determines whether to send a first notification message to the remote terminal device based on the reconstructed cell is as follows: in response to the cell selected by the relay terminal to be reconstructed being the same as the serving cell before the link failure, not sending the first notification message to the remote terminal device, and in response to the cell selected by the relay terminal to be reconstructed being different from the serving cell before the link failure, sending the first notification message to the remote terminal device.

[0157] In one embodiment, the embodiment in which the transceiver module 701 sends the first notification message to the remote terminal device may be to determine to send the first notification message to the remote terminal device based on the setting of the network device.

[0158] In one possible embodiment, the embodiment in which the transceiver module 701 determines to send a first notification message to a remote terminal device based on the setting of the network device is as follows: receive first identification information sent by the network device, where the first identification information is used to instruct all remote terminal devices to send a first notification message, and determine whether to send the first notification message to all remote terminal devices connected to the relay terminal device based on the first identification information.

[0159] In another possible embodiment, the embodiment in which the transceiver module 701 determines to send a first notification message to a remote terminal device based on the setting of the network device is as follows: receive a plurality of second identification information sent by the network device, each second identification information is used to indicate whether to send a first notification message to a corresponding remote terminal device, and determine whether to send a first notification message to a corresponding remote terminal device based on the plurality of second identification information sent by the network device.

[0160] In another possible embodiment, the embodiment in which the transceiver module 701 determines to send a first notification message to a remote terminal device based on the setting of the network device is as follows: receive a quality of service requirement sent by the network device, and in response to the data of the remote terminal device satisfying the corresponding quality of service requirement, send a first notification message to the remote terminal device that satisfies the corresponding quality of service requirement, or in response to the data of the remote terminal device satisfying the corresponding quality of service requirement, do not send a first notification message to the remote terminal device that satisfies the corresponding quality of service requirement.

[0161] In one embodiment, assistance information is carried in the first notification message, and the assistance information includes at least one or more of whether a process of a secondary cell group (SCG) recovering a master cell group (MCG) has been initiated, whether the reconfiguration target cell is the same cell as the serving cell before the link failure, and a failure cause, and the failure cause includes at least one of a radio link failure, expiration of a T310 timer, expiration of a T312 timer, failure of integrity detection of SRB1, failure of integrity detection of SRB2, failure of integrity detection of SRB3, and failure of reconfiguration.

[0162] In one possible embodiment, as shown in Fig. 8, the link failure processing device 80 may further include a processing module 802, where the processing module 802 stops sending relay discovery messages and / or notifies the occurrence of link failure to an upper layer after a link failure occurs in a relay terminal device, where 801 in Fig. 8 and 701 in Fig. 7 have the same function and structure.

[0163] In one possible embodiment, the transceiver module further sends a second notification message to the network device after the RRC connection reestablishment of the relay terminal device is successful, and / or sends a notification of successful RRC connection reestablishment to the remote terminal device, where the second notification message includes the remote terminal device whose connection is currently pending or the remote terminal device that has already been released.

[0164] In one possible embodiment, the transceiver module further sends a notification of RRC connection reestablishment failure to the remote terminal device after the RRC connection reestablishment of the relay terminal device fails.

[0165] Regarding the apparatus in the above embodiment, the specific manner in which each module therein performs operations has been described in detail in the embodiment related to the method, so detailed description thereof will be omitted here.

[0166] 9, there is shown a schematic structural diagram of another link failure processing device 90 provided in an embodiment of the present application. It should be noted that the link failure processing device 90 may be a terminal device (a remote terminal device in the embodiment of the method as described above), may be a device in the terminal device, or may be a device used in conjunction with the terminal device.

[0167] 9 may include a transceiver module 901. The transceiver module 901 may include a transmitting module for realizing a transmitting function and / or a receiving module for realizing a receiving function, and the transmitting function and / or the receiving function can be realized by the transceiver module 901.

[0168] In an embodiment of the present application, the transceiver module 901 receives a first notification message sent by a relay terminal device, and the first notification message is sent by the relay terminal device when a link failure occurs, where the link failure includes at least one of a radio link failure, expiration of a T310 timer, expiration of a T312 timer, failure of SRB1 integrity detection, failure of SRB2 integrity detection, failure of SRB3 integrity detection, and failure of reconfiguration.

[0169] In an embodiment, as shown in FIG. 10, the link failure processing device 100 may further include a processing module 1002. The processing module 1001 determines whether to continue to maintain a connection with the relay terminal device based on the assistance information carried in the first notification message. The transceiver module 1001 further notifies the relay terminal device of the determination result, where the assistance information includes at least one of: whether the process of the SCG recovering the MCG is initiated; whether the reconfiguration target cell is the same cell as the serving cell before the link failure; and failure causes, where the failure causes include at least one of: radio link failure; expiration of the T310 timer; expiration of the T312 timer; failure of SRB1 integrity detection; failure of SRB2 integrity detection; failure of SRB3 integrity detection; and failure of reconfiguration. Here, 1001 in FIG. 10 and 901 in FIG. 9 have the same function and structure.

[0170] In one embodiment, the processing module 1002 is further configured to stop transmitting relay data to the relay terminal device in response to determining to continue maintaining the connection with the relay terminal device.

[0171] In one possible embodiment, the transceiver module 1001 further receives a notification of successful RRC connection reestablishment of the relay terminal device sent by the relay terminal device, and resumes sending relay data to the relay terminal device.

[0172] In one possible embodiment, the transceiver module 1001 further receives a notification sent by the relay terminal device that the RRC connection reestablishment of the relay terminal device has failed, and the processing module 1002 further disconnects the connection with the relay terminal device and performs relay reselection and / or triggers connection reestablishment and / or performs cell reselection.

[0173] Regarding the apparatus in the above embodiment, the specific manner in which each module therein performs operations has been described in detail in the embodiment related to the method, so detailed description thereof will be omitted.

[0174] Referring to Fig. 11, Fig. 11 is a schematic structural diagram of a terminal device 1100 provided in an embodiment of the present application. The terminal device 1100 may be a terminal device (an intermediate terminal device in the above-mentioned method embodiment), or may be a remote terminal device in the above-mentioned method embodiment, or may be a chip, chip system, or processor, etc., that supports the terminal device to realize the above-mentioned method. The terminal device can be used to realize the method described in the above-mentioned method embodiment, and the description in the above-mentioned method embodiment can be referred to in detail.

[0175] The terminal device 1100 may include one or more processors 1101. The processor 1101 may be a general-purpose processor or a dedicated processor, etc. For example, it may be a baseband processor or a central processing unit. The baseband processor may be used to process communication protocols and communication data, and the central processing unit may be used to control a communication device (e.g., a base station, a baseband chip, a terminal device, a terminal device chip, a DU or a CU, etc.), execute a computer program, and process data of the computer program.

[0176] Optionally, the terminal device 1100 may further include one or more memories 1102 capable of storing computer programs 1104, and the processor 1101 executes the computer programs 1104 to cause the terminal device 1100 to perform the methods described in the above method embodiments. Optionally, the memory 1102 may further store data. The terminal device 1100 and the memory 1102 may be provided separately or integrated together.

[0177] Optionally, the terminal device 1100 may further include a transceiver 1105 and an antenna 1106. The transceiver 1105 may be referred to as a transmitting / receiving unit, a transceiver, or a transmitting / receiving circuit, etc., and is used to realize a transmitting / receiving function. The transceiver 1105 may include a receiver and a transmitter, and the receiver may be referred to as a receiver or a receiving circuit, etc., and is used to realize a receiving function, and the transmitter may be referred to as a transmitter or a transmitting circuit, and is used to realize a transmitting function.

[0178] Optionally, the terminal device 1100 may further include one or more interface circuits 1107. The interface circuit 1107 is used to receive and transmit code instructions to the processor 1101. The processor 1101 executes the code instructions to cause the terminal device 1100 to perform the methods described in the above method embodiments.

[0179] The terminal device 1100 is a relay terminal device in the embodiment of the method, and the transceiver 1105 is used to perform step S201 of Fig. 2, step S301 of Fig. 3, and step S401 of Fig. 4. The processor 1101 is used to perform the step of stopping the transmission of a relay discovery message after a link failure occurs, and / or the step of notifying an upper layer of the occurrence of the link failure.

[0180] The terminal device 1100 is a remote terminal device in the embodiment of the method, and the transceiver 1105 is used to execute step S501 of Fig. 5, execute step S601 of Fig. 6, execute a step of receiving a notification of successful RRC connection reestablishment of the relay terminal device sent by the relay terminal device and resuming transmission of relay data to the relay terminal device, and execute a step of receiving a notification of failed RRC connection reestablishment of the relay terminal device sent by the relay terminal device. The processor 1101 is used to execute step S602 of Fig. 6, execute a step of stopping transmission of relay data to the relay terminal device in response to determining to continue maintaining the connection with the relay terminal device, disconnect the connection with the relay terminal device, perform relay reselection, and / or trigger connection reestablishment, and / or perform cell reselection.

[0181] In one embodiment, the processor 1101 may include a transceiver for implementing the receiving and transmitting functions. For example, the transceiver may be a transmitting and receiving circuit, an interface, or an interface circuit. The transmitting and receiving circuit, the interface, or the interface circuit for implementing the receiving and transmitting functions may be separate or integrated together. The transmitting and receiving circuit, the interface, or the interface circuit may be used to read and write code / data, or the transmitting and receiving circuit, the interface, or the interface circuit may be used to transmit or convey signals.

[0182] In one embodiment, the processor 1101 may store a computer program 1103, which, when run on the processor 1101, can cause the terminal device 1101 to execute the method described in the above method examples. The computer program 1103 may be solidified in the processor 1101, in which case the processor 1101 may be realized by hardware.

[0183] In one embodiment, the terminal device 1101 may include circuitry capable of implementing the functions of transmitting or receiving or communicating in the embodiments of the method. The processors and transceivers described herein may be implemented in an integrated circuit (IC), an analog IC, a radio frequency integrated circuit (RFIC), a mixed signal IC, an application specific integrated circuit (ASIC), a printed circuit board (PCB), an electronic device, etc. The processors and transceivers may be fabricated in a variety of IC processing technologies, such as complementary metal oxide semiconductor (CMOS), nMetal-oxide-semiconductor (NMOS), pMetal-oxide-semiconductor (PMOS), bipolar junction transistor (BJT), bipolar CMOS (BiCMOS), silicon germanium (SiGe), gallium arsenide (GaAs), etc.

[0184] The terminal device described in the above embodiments may be a network device or a terminal device (for example, a relay terminal device or a remote terminal device in the embodiment of the method), but the scope of the terminal device described in the present application is not limited thereto, and the structure of the terminal device is not limited to that shown in FIG. 11. The terminal device may be an independent device or a part of a larger device. For example, the terminal device may be any of the following (1) to (6). (1) A standalone integrated circuit IC or chip, or a chip system or subsystem; (2) A set having one or more ICs (optionally, the set of ICs may include a storage member for storing data, computer programs, etc.) (3) ASICs such as modems (4) Modules embedded within other devices; (5) Receivers, terminal devices, smart terminal devices, mobile phones, wireless devices, handsets, mobile units, in-vehicle devices, network devices, cloud devices, artificial intelligence devices, etc. (6) Others.

[0185] Those skilled in the art can further understand that the various illustrative logical blocks and steps listed in the embodiments of the present application can be implemented by electronic hardware, computer software, or a combination of both. Whether such functions are implemented by hardware or software depends on the specific application and the design requirements of the entire system. Those skilled in the art can implement the functions using various methods for each specific application, but such implementation should not be understood as exceeding the protection scope of the embodiments of the present application.

[0186] An embodiment of the present application further provides a link failure processing system, which includes a link failure processing device as a relay terminal device in the method embodiment in the embodiments of Figures 7 and 8 and a link failure processing device as a remote terminal device in the method embodiment in the embodiments of Figures 9 and 10, or the system includes a terminal device as a relay terminal device in the method embodiment in the embodiment of Figure 11 and a terminal device as a remote terminal device in the method embodiment.

[0187] The present application further provides a readable storage medium having instructions stored thereon which, when executed by a computer, effectuate the functionality of any of the method embodiments described above.

[0188] The present application further provides a computer program product, which, when executed by a computer, implements the functionality of any of the method embodiments described above.

[0189] In the above embodiments, the whole or part may be realized by software, hardware, firmware, or any combination thereof. When realized using software, the whole or part may be realized in the form of a computer program product. The computer program product includes one or more computer programs. When the computer programs are loaded and executed on a computer, all or part of the flow or function described in the embodiments of the present application is generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer program may be stored in a computer-readable storage medium or may be transmitted from one computer-readable storage medium to another, for example, the computer program may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wire (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium may be any available medium accessible by a computer, or one or more data storage devices such as a server, data center, etc., in which one or more available media are integrated. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a high density digital video disc (DVD)), or a semiconductor medium (e.g., a solid state disk (SSD)).

[0190] Those skilled in the art will understand that the various numbers such as first, second, etc. in the present application are distinguished for the convenience of description, and do not limit the scope of the embodiments of the present application, nor do they represent a sequential order.

[0191] At least one of the present application may be described as one or more, and more may be two, three, four or even more, and is not limited in the present application. In the embodiments of the present application, for one type of technical feature, the technical features of this type of technical feature are classified as "first", "second", "third", "A", "B", "C" and "D", etc., and there is no chronological or dimensional order between the technical features described as "first", "second", "third", "A", "B", "C" and "D".

[0192] The correspondence shown in each table of the present application may be set or may be predefined. The values ​​of the information in each table are merely examples and may be set to other values, and are not limited in the present application. When setting the correspondence between the information and each parameter, it is not necessary to set all the correspondences shown in each table. For example, the correspondence shown in a certain row in the table of the present application may not be set. Also, for example, based on the above table, deformation and adjustment such as division and combination may be performed. In each of the above tables, other names that the communication device can understand can be used as the names of the parameters shown in the title, and other values ​​or display methods that the communication device can understand can be used as the values ​​or display methods of the parameters. In realizing each of the above tables, other data structures can be used, such as arrays, queues, containers, stacks, linear tables, pointers, link tables, trees, graphs, structures, classes, heaps, hash tables, or hash tables.

[0193] Predefined in this application may be understood as defined, predefined, stored, pre-stored, pre-negotiated, pre-set, solidified, or pre-baked.

[0194] Those skilled in the art will recognize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in a hardware manner or a software manner depends on the specific application and design conditions of the technical solution. Experts may use different methods for each specific application to implement the described functions, but such implementation should not be interpreted as going beyond the scope of the present invention.

[0195] Those skilled in the art will understand that for convenience and conciseness of explanation, the specific operating processes of the above-described systems, devices and units may refer to the corresponding processes in the method embodiments, and detailed descriptions thereof are omitted here.

[0196] The above description is merely a specific embodiment of the present application, and the scope of protection of the present application is not limited thereto, and a person skilled in the art can easily imagine modifications or replacements within the technical scope disclosed in the present application, all of which should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A link failure handling method, the method being applied to a relay terminal device, the method comprising: a step of transmitting a first notification message to a remote terminal device in response to a link failure occurring in the relay terminal device, the first notification message being used by the remote terminal device to determine whether to continue to maintain a connection with the relay terminal device based on assistance information carried in the first notification message, and to notify the relay terminal device of a decision result, the decision result including the remote terminal device releasing the connection with the relay terminal device; The link failure includes at least any one of the following: radio link failure, expiry of a T310 timer, expiry of a T312 timer, failure of integrity detection of a signaling radio bearer (SRB) 1, failure of integrity detection of an SRB2, failure of integrity detection of an SRB3, and failure of a radio resource control (RRC) reconfiguration.

23. A method for handling link failures comprising:

2. The connection between the remote terminal device and the relay terminal device is an RRC connection.

2. The method of claim 1, wherein the link failure processing method is a method for processing a link failure.

3. The step of sending a first notification message to the remote terminal device includes: determining whether to send a first notification message to the remote terminal device based on the reconstructed cell; 2. The method of claim 1, wherein the link failure processing method is a method for processing a link failure.

4. determining whether to send a first notification message to the remote terminal device based on the reconstructed cell, receiving an area range transmitted by a network device, the area range being a cell list or a tracking area list; in response to the relay terminal device reconstructing a cell within the area range, not transmitting the first notification message to the remote terminal device; sending the first notification message to the remote terminal device in response to the relay terminal device not reconstructing a cell within the area range; or or determining whether to send a first notification message to the remote terminal device based on the reconstructed cell, in response to the cell selected by the relay terminal device to reestablish the link being the same as the serving cell before the link failure, not sending the first notification message to the remote terminal device; and transmitting the first notification message to the remote terminal device in response to the cell selected by the relay terminal device to reestablish the link being different from a serving cell before the link failure.

4. The method of claim 3, wherein the link failure processing method is a method for processing a link failure.

5. The step of sending a first notification message to the remote terminal device includes: determining, based on a configuration of a network device, to send the first notification message to a remote terminal device; 2. The method of claim 1, wherein the link failure processing method is a method for processing a link failure.

6. determining, based on a configuration of the network device, to send the first notification message to a remote terminal device, receiving first identification information sent by the network device, the first identification information instructing all remote terminal devices to send the first notification message; determining whether to send the first notification message to all remote terminal devices connected to the relay terminal device based on the first identification information; 6. The method of claim 5, wherein the link failure processing method is a method for processing a link failure.

7. determining, based on a configuration of the network device, to send the first notification message to a remote terminal device, receiving a plurality of second identification information transmitted by the network device, each of the second identification information instructing a corresponding remote terminal device whether to transmit the first notification message; and determining whether to send the first notification message to a corresponding remote terminal device based on the plurality of second identification information sent by the network device.

6. The method of claim 5, wherein the link failure processing method is a method for processing a link failure.

8. determining, based on a configuration of the network device, to send the first notification message to a remote terminal device, receiving quality of service requirements transmitted by the network device; in response to the data of a remote terminal device satisfying a corresponding quality of service requirement, transmitting the first notification message to the remote terminal device satisfying the corresponding quality of service requirement; or in response to the data of a remote terminal device satisfying a corresponding quality of service requirement, not transmitting the first notification message to the remote terminal device satisfying the corresponding quality of service requirement.

6. The method of claim 5, wherein the link failure processing method is a method for processing a link failure.

9. The support information includes at least Whether the process of the secondary cell group (SCG) recovering the master cell group (MCG) link has been initiated; Whether a reestablishment target cell is the same cell as the serving cell before the link failure; and any one or more of the following causes of failure: The failure cause includes at least one of a radio link failure, expiration of a T310 timer, expiration of a T312 timer, failure of SRB1 integrity detection, failure of SRB2 integrity detection, failure of SRB3 integrity detection, and failure of RRC reconfiguration.

2. The method of claim 1, wherein the link failure processing method is a method for processing a link failure.

10. Stopping the transmission of relay discovery messages; and / or further comprising the step of notifying an upper layer of the occurrence of a link failure.

2. The method of claim 1, wherein the link failure processing method is a method for processing a link failure.

11. The method further includes the steps of: sending a second notification message to a network device after the RRC connection reestablishment of the relay terminal device is successful; and / or sending a notification of successful RRC connection reestablishment to the remote terminal device, in which the second notification message includes identification information of a remote terminal device whose connection is currently pending or identification information of a remote terminal device that has already been released; or or After the RRC connection reestablishment of the relay terminal device fails, the relay terminal device further includes a step of sending a notification of the failure of the RRC connection reestablishment to the remote terminal device.

2. The method of claim 1, wherein the link failure processing method is a method for processing a link failure.

12. 1. A link failure handling method, the method being applied to a remote terminal device, the method comprising: receiving a first notification message sent by a relay terminal device, the first notification message being sent by the relay terminal device when a link failure occurs; The link failure includes at least any one of a radio link failure, expiration of a T310 timer, expiration of a T312 timer, a signaling radio bearer (SRB) 1 integrity detection failure, an SRB2 integrity detection failure, an SRB3 integrity detection failure, and a radio resource control (RRC) reconfiguration failure; determining whether to continue to maintain a connection with the relay terminal device based on the assistance information carried in the first notification message, and notifying the relay terminal device of a decision result, the decision result including that the remote terminal device releases the connection with the relay terminal device; 23. A method for handling link failures comprising:

13. The support information includes at least Whether the process of the secondary cell group (SCG) recovering the master cell group (MCG) link has been initiated; Whether a reestablishment target cell is the same cell as the serving cell before the link failure; and any one or more of the following causes of failure: The failure cause includes at least one of a radio link failure, expiration of a T310 timer, expiration of a T312 timer, failure of SRB1 integrity detection, failure of SRB2 integrity detection, failure of SRB3 integrity detection, and failure of RRC reconfiguration. The method of claim 12, wherein the link failure handling method is 14. The connection between the remote terminal device and the relay terminal device is an RRC connection. The method of claim 12, wherein the link failure handling method is

15. and in response to determining to continue to maintain the connection with the relay terminal device, stopping transmission of relay data to the relay terminal device. The method of claim 13, wherein the link failure handling method is

16. receiving a notification of successful RRC connection reestablishment of the relay terminal device sent by the relay terminal device; and resuming transmission of relay data to the relay terminal device. The method of claim 15, wherein the link failure handling method is

17. receiving a notification that the RRC connection reestablishment of the relay terminal device has failed, the notification being sent by the relay terminal device; Disconnecting the relay terminal device and performing relay reselection; and / or Triggering a connection re-establishment, and / or and performing cell reselection. The method of claim 13, wherein the link failure handling method is

18. A link failure processing device, the device being applied to a relay terminal device, the device comprising: a transceiver module for transmitting a first notification message to a remote terminal device in response to a link failure occurring in the relay terminal device, the first notification message being used by the remote terminal device to determine whether to continue to maintain a connection with the relay terminal device based on assistance information carried in the first notification message, and to notify the relay terminal device of the determination result, the determination result including the remote terminal device releasing the connection with the relay terminal device; The link failure includes at least any one of the following: radio link failure, expiry of a T310 timer, expiry of a T312 timer, failure of integrity detection of a signaling radio bearer (SRB) 1, failure of integrity detection of an SRB2, failure of integrity detection of an SRB3, and failure of a radio resource control (RRC) reconfiguration.

23. A link failure processing device comprising:

19. A link failure processing apparatus, the apparatus being applied to a remote terminal device, the apparatus comprising: A transceiver module for receiving a first notification message sent by a relay terminal device, the first notification message being sent by the relay terminal device when a link failure occurs; The link failure includes at least any one of a radio link failure, expiration of a T310 timer, expiration of a T312 timer, a signaling radio bearer (SRB) 1 integrity detection failure, an SRB2 integrity detection failure, an SRB3 integrity detection failure, and a radio resource control (RRC) reconfiguration failure; a processing module for determining whether to continue to maintain a connection with the relay terminal device based on assistance information carried in the first notification message; The transceiver module further notifies the relay terminal device of a decision result, the decision result including that the remote terminal device releases the connection with the relay terminal device.

23. A link failure processing device comprising:

20. a processor and a memory in which a computer program is stored, the processor executing the computer program stored in the memory to cause the terminal device to perform the method according to any one of claims 1 to 11; A terminal device comprising:

21. a processor and a memory in which a computer program is stored, the processor executing the computer program stored in the memory to cause the terminal device to perform the method according to any one of claims 12 to 17; A terminal device comprising:

22. A computer-readable storage medium for storing instructions, comprising: When the instructions are executed, the method according to any one of claims 1 to 11 is performed. A computer-readable storage medium comprising:

23. A computer-readable storage medium for storing instructions, comprising: When the instructions are executed, the method according to any one of claims 12 to 17 is performed. A computer-readable storage medium comprising:

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