User equipment backup method and equipment thereof

Abstract

A wireless communication method for a first wireless terminal is disclosed. The method includes determining that a takeover event occurs, transmitting service data to the wireless network node in response to the occurring takeover event, where the service data is configured to be transmitted via the second wireless terminal, where the first wireless terminal is configured as a backup terminal of the second wireless terminal.

Description

Technical Field

[0001] This document focuses primarily on wireless communication, especially 5G communication or next-generation wireless communication. Background Technology

[0002] As an integral part of the Industry 4.0 architecture, wireless communication systems are crucial tools for providing timely and reliable message sending and receiving services. Typical industry use cases demand ultra-high reliability from wireless communication systems. Within 3GPP (3rd Generation Partnership Project), several mechanisms have been introduced to ensure high reliability in 5G wireless communication systems. Figure 1 A schematic diagram of repetitive transmission based on DC / CA (dual connectivity / carrier aggregation) is shown to ensure high reliability in 5G wireless communication systems. Figure 1 In this process, transmissions on component carrier CC1 are handled as DC / CA-based repetitive transmissions (e.g., transmissions on component carriers CC2 / CC3 / CC4) to ensure high reliability of Uu transmissions (i.e., transmissions between UE (User Equipment) and RAN (Radio Access Network) nodes 1 / 2). Furthermore, the N3 / N9 interface also supports redundant transmissions (e.g., transmissions on tunnel 2). Additionally, extra / redundant user plane paths (e.g., the UE-RAN node 2-UPF2-DN (Data Network) path) are supported to improve the equipment reliability of RAN nodes and UPF (User Plane Functions).

[0003] However, Figure 1 The duplicate transmissions and / or redundant paths shown may reduce resource efficiency. Specifically, duplicate transmissions and / or redundant paths require dual UE power resources, radio resources, transport resources, and processing resources. Furthermore, network capacity may also be affected / reduced. On the other hand, Figure 1 The system shown relies on only one terminal (i.e., UE) to receive / transmit service data. If the UE is damaged due to accident, aging, or hardware / software failure, data from that UE will be lost, potentially reducing the reliability of the wireless communication system. Therefore, while considering UE reliability, a more resource-efficient, high-reliability mechanism can be anticipated. Summary of the Invention

[0004] This document relates to methods, systems, and devices for backup mechanisms, and in particular to systems and devices for backup mechanisms with high reliability.

[0005] This invention relates to a wireless communication method for a first wireless terminal. The method includes: Confirming the occurrence of a takeover event, and In response to a takeover event, service data is transmitted to the wireless network node, wherein the service data is configured to be transmitted via a second wireless terminal. The first wireless terminal is configured as a backup terminal for the second wireless terminal.

[0006] Various embodiments can preferably achieve the following features: Preferably, in response to the occurrence of the takeover event, transmitting the service data to the wireless network node includes: In response to the takeover event, the service data is transmitted to the wireless network node in a buffer, wherein if the service data's discard timer expires, the service data in the buffer is discarded.

[0007] Preferably, in response to the occurrence of the takeover event, transmitting the service data to the wireless network node includes: Receive feedback information from the second wireless terminal, the feedback information indicating successful transmission of the service data, and In response to the takeover event, the service data is transmitted to the wireless network node after the last successful transmission indicated by the feedback information.

[0008] Preferably, in response to the occurrence of the takeover event, transmitting the service data to the wireless network node includes: A status report is received from the wireless network node, the status report indicating the reception status of the service data, and In response to the takeover event, service data associated with the unacknowledged successful reception status and service data that has not yet been transmitted are transmitted to the wireless network node.

[0009] Preferably, the wireless communication method further includes: From the second wireless terminal or the wireless network node, receive Protocol Data Unit (PDU) session configuration and Data Radio Bearer (DRB) configuration for transmitting the service data, and Maintain at least one virtual PDU session based on the received PDU session configuration. Maintain at least one virtual DRB based on the received DRB configuration. The at least one virtual PDU session and the at least one virtual DRB are configured to transmit the service data in the event of the takeover event.

[0010] Preferably, the wireless communication method further includes: From the wireless network node, receive at least one low-layer configuration of a DRB, the DRB being configured to transmit the service data, and Based on the aforementioned low-level configuration, at least one virtual DRB is activated to transmit the service data.

[0011] Preferably, the lower-layer configuration includes at least one of a logical channel configuration, a media access control layer configuration, or a physical layer configuration.

[0012] Preferably, at least one first DRB between the wireless network node and the first wireless terminal and at least one second DRB between the wireless network node and the second wireless terminal are configured with different logical channel identifiers.

[0013] Preferably, the wireless communication method further includes: The wireless network node transmits auxiliary information associated with being a backup terminal, the backup terminal being configured to transmit service data configured to be transmitted by the at least one master terminal in the event of at least one takeover event associated with at least one master terminal, wherein the auxiliary information includes at least one of willingness to be a backup terminal, interest in being a backup terminal, or indication of capability to be a backup terminal.

[0014] Preferably, the capability indication includes at least one of the following: backup terminal capability, power limitation, radio capability, uplink aggregated maximum bit rate (AMBR), downlink AMBR, terminal AMBR, at least one quality of service (QoS) parameter, or the maximum number of primary terminals.

[0015] Preferably, the wireless communication method further includes: The information of the second wireless terminal is received from the wireless network node, wherein the information of the second wireless terminal includes at least one of the following: terminal identifier, aggregated maximum bit rate, or at least one quality of service (QoS) parameter.

[0016] Preferably, the wireless communication method further includes at least one of the following: receiving a first discovery message for the backup terminal from the second wireless terminal, wherein the first discovery message includes an indication to search for the backup terminal.

[0017] Preferably, the wireless communication method further includes transmitting a second discovery message to the second wireless terminal for use as a backup terminal, wherein the second discovery message includes at least one of the following: As an instruction for the backup terminal, The terminal identifier configured for the backup terminal. Serving cell identifier, The distance between the second wireless terminal and the backup terminal, or Link quality of the interface between the backup terminal and the wireless network node.

[0018] Preferably, the takeover event includes at least one of the following: determining that the second wireless terminal is being taken over; receiving a takeover instruction for the second wireless terminal from the wireless network node; detecting a link failure associated with the second wireless terminal; failing to receive a link activation instruction from the second wireless terminal; receiving a takeover instruction for the second wireless terminal from the second wireless terminal; receiving service data from the terminal device of the second wireless terminal, the service data being configured to be transmitted via the second wireless terminal, or transmitting the takeover instruction for the second wireless terminal to the terminal device of the second wireless terminal or the wireless network node.

[0019] This invention relates to a wireless communication method for a wireless network node. The method includes: Service data is received from a first wireless terminal, which is configured as a backup terminal for a second wireless terminal, and the service data is configured to be transmitted via the second wireless terminal.

[0020] Various embodiments can preferably achieve the following features: Preferably, the wireless communication method further includes: transmitting a status report to the first wireless terminal, the status report indicating the reception status of the service data.

[0021] Preferably, the wireless communication method further includes: transmitting a low-level configuration of at least one DRB to the first wireless terminal, the DRB being configured to transmit the service data.

[0022] Preferably, the lower-layer configuration includes at least one of a logical channel configuration, a media access control layer configuration, or a physical layer configuration.

[0023] Preferably, at least one first DRB between the wireless network node and the first wireless terminal and at least one second DRB between the wireless network node and the second wireless terminal are configured with different logical channel identifiers.

[0024] Preferably, the wireless communication method further includes: transmitting the service data to the core network via at least one first PDU session of the first wireless terminal.

[0025] Preferably, the wireless communication method further includes: transmitting the service data to the core network via at least one second PDU session of the second wireless terminal.

[0026] Preferably, the wireless communication method further includes: transmitting the PDU session configuration and DRB configuration of the second wireless terminal to the first wireless terminal.

[0027] Preferably, the wireless communication method further includes: transmitting the service data to the core network via at least one third PDU session, wherein the at least one third PDU session is shared by the first wireless terminal and the second wireless terminal.

[0028] Preferably, the wireless communication method further includes: From the core network, a PDU session resource establishment request for at least one third PDU session for the second wireless terminal is received, wherein the PDU session resource establishment request includes at least one of the following: an indication of at least one third PDU session shared by the first wireless terminal and the second wireless terminal, or a terminal identifier of the first wireless terminal.

[0029] Preferably, the terminal identifier of the first wireless terminal includes at least one of the following: an identifier for identifying the first wireless terminal in access and mobility management functions, an identifier for identifying the first wireless terminal in the wireless network node, or an identifier for identifying the first wireless terminal in the core network.

[0030] Preferably, the wireless communication method further includes: From the first wireless terminal, auxiliary information associated with being a backup terminal is received, the backup terminal being configured to transmit service data configured to be transmitted by the at least one master terminal in the event of at least one takeover event associated with at least one master terminal, wherein the auxiliary information includes at least one of willingness to be a backup terminal, interest in being a backup terminal, or indication of capability to be a backup terminal.

[0031] Preferably, the capability indication includes at least one of the following: backup terminal capability, power limitation, radio capability, uplink aggregated maximum bit rate (AMBR), downlink AMBR, terminal AMBR, at least one QoS parameter, or the maximum number of primary terminals.

[0032] Preferably, the wireless communication method further includes: transmitting information of the second wireless terminal to the first wireless terminal, wherein the information of the second wireless terminal includes at least one of the following: terminal identifier, aggregated maximum bit rate, or at least one quality of service (QoS) parameter.

[0033] Preferably, the wireless communication method further includes: From the second wireless terminal, receive a request for a backup terminal or at least one candidate backup terminal from the backup terminal candidate list, and The backup terminal configuration associated with the first wireless terminal is transmitted to the second wireless terminal.

[0034] Preferably, the backup terminal candidate list includes at least one of the following: a backup terminal identifier for each backup terminal candidate, a serving cell identifier for each backup terminal candidate, the distance between the second wireless terminal and each backup terminal candidate, the link quality between the wireless network node and each backup terminal candidate, or the capability information of each backup terminal candidate.

[0035] Preferably, the wireless communication method further includes: receiving backup authorization from the access and mobility management function for the first wireless terminal and / or the second wireless terminal. Preferably, the backup authorization includes at least one of the following: authorization that allows the first wireless terminal to act as a backup terminal, or authorization that allows the second wireless terminal to use the backup terminal.

[0036] Preferably, the wireless communication method further includes: transmitting backup association information to the access and mobility management function, the backup association information indicating the association between the first wireless terminal and the second wireless terminal.

[0037] Preferably, the wireless communication method further includes: transmitting to the first wireless terminal an instruction to take over the second wireless terminal.

[0038] Preferably, the wireless communication method further includes: detecting a link failure associated with the second wireless terminal.

[0039] Preferably, the wireless communication method further includes: determining that the link quality between the second wireless terminal and the wireless network node is below a threshold.

[0040] Preferably, the wireless communication method further includes: receiving a takeover instruction from the first wireless terminal or from the second wireless terminal to take over the second wireless terminal.

[0041] This invention relates to a wireless communication method for a second wireless terminal. The method includes: To the wireless network node, transmit a request for a backup terminal or at least one of the backup terminal candidate lists, and The backup terminal configuration associated with the first wireless terminal is received from the wireless network node.

[0042] Various embodiments can preferably achieve the following features: Preferably, the wireless communication method further includes: transmitting feedback information to the first wireless terminal, the feedback information indicating successful transmission of service data, the service data being configured to be transmitted via the second wireless terminal.

[0043] Preferably, the wireless communication method further includes: transmitting a protocol data unit (PDU) session configuration and a data radio bearer (DRB) configuration for transmitting service data to the first wireless terminal, wherein the service data is configured to be transmitted via the second wireless terminal.

[0044] Preferably, at least one first DRB between the wireless network node and the first wireless terminal and at least one second DRB between the wireless network node and the second wireless terminal are configured with different logical channel identifiers.

[0045] Preferably, the backup terminal candidate list includes at least one of the following: a backup terminal identifier for each backup terminal candidate, a serving cell identifier for each backup terminal candidate, the distance between the second wireless terminal and each backup terminal candidate, the link quality between the wireless network node and each backup terminal candidate, or the capability information of each backup terminal candidate.

[0046] Preferably, the wireless communication method further includes: transmitting a first discovery message for the backup terminal to the first wireless terminal, wherein the first discovery message includes an indication to search for the backup terminal.

[0047] Preferably, the wireless communication method further includes: The first wireless terminal receives a second discovery message as a backup terminal, wherein the second discovery information includes at least one of the following: an indication of a backup terminal, a terminal identifier configured for the backup terminal, a serving cell identifier, the distance between the second wireless terminal and the backup terminal, or the link quality of the interface between the backup terminal and the wireless network node.

[0048] Preferably, the wireless communication method further includes: stopping the transmission of a link activation indication to the first wireless terminal, the link activation indication being configured to be transmitted to the first wireless terminal periodically.

[0049] Preferably, the wireless communication method further includes: transmitting a takeover instruction to the first wireless terminal and / or the wireless network node to take over the second wireless terminal.

[0050] Preferably, the wireless communication method further includes: detecting a link failure associated with the interface between the second wireless terminal and the wireless network node.

[0051] Preferably, the wireless communication method further includes: determining that the link quality of the first link between the wireless network node and the second wireless terminal is lower than a first threshold.

[0052] Preferably, the wireless communication method further includes: determining that the link quality of the second link between the terminal device and the second wireless terminal is lower than a second threshold.

[0053] This invention relates to a first terminal. The first terminal includes: The processor is configured to determine when a takeover event occurs, and A communication unit is configured to transmit service data to a wireless network node in response to a takeover event, wherein the service data is configured to be transmitted via a second wireless terminal, wherein the first wireless terminal is configured as a backup terminal of the second wireless terminal.

[0054] Various embodiments may preferably achieve the following features: Preferably, the processor is also configured to perform any of the above-described wireless communication methods.

[0055] This invention relates to a wireless network node. The wireless network node includes: A communication unit is configured to receive service data from a first wireless terminal, the first wireless terminal being configured as a backup terminal for a second wireless terminal, the service data being configured to be transmitted via the second wireless terminal.

[0056] Various embodiments may preferably achieve the following features: Preferably, the wireless network node further includes a processor configured to perform any of the above-described wireless communication methods.

[0057] This invention relates to a second wireless terminal. The second wireless terminal includes: The communication unit is configured to: transmit a request for a backup terminal or at least one of a backup terminal candidate list to a wireless network node, and receive a backup terminal configuration associated with the first wireless terminal from the wireless network node.

[0058] Various embodiments may preferably achieve the following features: Preferably, the second wireless terminal further includes a processor configured to perform any of the above-described wireless communication methods.

[0059] The present invention relates to a computer program product comprising computer-readable program medium code stored thereon, the code causing the processor to implement the wireless communication method described in any of the above methods when executed by a processor.

[0060] The exemplary embodiments disclosed herein are intended to provide features that will become apparent from the following description and in conjunction with the accompanying drawings. Exemplary systems, methods, apparatuses, and computer program products are disclosed herein according to various embodiments. However, it should be understood that these embodiments are presented by way of example and not limitation, and that various modifications can be made to the disclosed embodiments while remaining within the scope of the invention, as will be apparent to those skilled in the art who read this invention.

[0061] Therefore, this disclosure is not limited to the exemplary embodiments and applications described and illustrated herein. Furthermore, the specific order and / or hierarchy of steps in the methods disclosed herein are merely exemplary methods. Based on design preferences, the specific order or hierarchy of steps in the disclosed methods or processes may be rearranged while remaining within the scope of this disclosure. Therefore, those skilled in the art will understand that the methods and techniques disclosed herein present various steps or actions in an exemplary order, and unless otherwise expressly stated, the invention is not limited to the specific order or hierarchy presented.

[0062] This invention is specifically described by the independent claims. Preferred embodiments are defined in the dependent claims. In the following description, although many features may be specified as optional, it should be acknowledged that all features included in the independent claims should not be considered optional.

[0063] The above and other aspects and their implementations are described in more detail in the accompanying drawings, description and claims. Attached Figure Description

[0064] Figure 1 A schematic diagram of repetitive transmission based on DC / CA is shown.

[0065] Figure 2 A schematic diagram of UE backup according to an embodiment of the present disclosure is shown.

[0066] Figure 3 A schematic diagram of UE backup according to an embodiment of the present disclosure is shown.

[0067] Figure 4 A schematic diagram of UE backup for multiple UEs according to an embodiment of the present disclosure is shown.

[0068] Figure 5 A schematic diagram of data transmission for UE backup according to an embodiment of the present disclosure is shown.

[0069] Figure 6 A schematic diagram of UE backup according to an embodiment of the present disclosure is shown.

[0070] Figure 7 An example of a schematic diagram of a wireless terminal according to an embodiment of the present disclosure is shown.

[0071] Figure 8 An example of a schematic diagram of a wireless network node according to an embodiment of the present disclosure is shown.

[0072] Figure 9 A flowchart of a method according to an embodiment of this disclosure is shown.

[0073] Figure 10 A flowchart of a method according to an embodiment of this disclosure is shown.

[0074] Figure 11 A flowchart of a method according to an embodiment of this disclosure is shown.

[0075] Figure 12 A flowchart of a method according to an embodiment of this disclosure is shown.

[0076] Figure 13 A flowchart of a method according to an embodiment of this disclosure is shown.

[0077] Figure 14 A flowchart of a method according to an embodiment of this disclosure is shown.

[0078] Figure 15 A flowchart of a method according to an embodiment of this disclosure is shown. Detailed Implementation

[0079] In this disclosure, the terms “info” or “Info” may refer to information.

[0080] In this disclosure, multiple terminals can be deployed as backups of another terminal (i.e., UE backups) and used to receive duplicate content to ensure reliability and resolve UE reliability issues. Figure 2 A schematic diagram of UE backup according to an embodiment of this disclosure is shown. Figure 2 In this scenario, UE2 is deployed as a backup for UE1. In one embodiment, UE2 may or may not have its own services. The link between UE1 / UE2 and its corresponding terminal device / PLC (Programmable Logic Controller) can be a wired connection or a wireless connection (e.g., short-range communication such as Wi-Fi / Bluetooth / D2D / PC5 / SL). In one embodiment, UE1 and UE2 are responsible for different services. In another embodiment, the associated backup UE (e.g., UE2) only takes over the services of the primary UE (e.g., UE1) when the primary UE fails (e.g., UE failure or link failure). In this case, only a set of wireless resources, transmission resources, and processing resources are needed. Therefore, resource efficiency is improved. To achieve such an efficient UE backup scheme, certain aspects need to be considered, such as how to configure / identify backup UE associations, rapid fault detection, and low-latency and lossless takeover mechanisms.

[0081] In this disclosure, UE1 may refer to the primary UE, and vice versa.

[0082] In this disclosure, UE2 may refer to the backup UE of the primary UE, and vice versa.

[0083] Backup UE association In one embodiment, in order to use / enable Figure 2 In the UE backup scheme, a UE can have / configure a backup UE. That is, a UE can obtain the association between itself and its backup UE. The UEs / nodes involved may also need to know this association.

[0084] The following scenarios / examples can be considered for configuring the association of backup UEs: 1) In one embodiment, the association of the backup UE can be configured by the gNB (e.g., BS (base station), RAN (radio access network), or RAN node).

[0085] In one embodiment, the primary UE may send a backup UE request or high reliability requirement or capability to the gNB. Alternatively, the primary UE may send a list of candidate backup UEs to the gNB. For each candidate backup UE, the list may include at least one of the following: backup UE ID (identifier), serving cell ID of the backup UE, distance between the backup UE and the primary UE, Uu link quality of the backup UE, or capability of the backup UE. The gNB may accordingly configure the backup UE as the primary UE. For each configured backup UE, the corresponding configuration may include at least one of the backup UE ID or a valid time interval (e.g., the backup UE is associated with being valid within that time interval). If the link between the primary UE and the backup UE is via a PC5 interface / SL (side link), the primary UE may reuse the SL discovery procedure to discover candidate backup UEs. In one embodiment, the discovery message transmitted by the primary UE may include an indication / interest / high reliability requirement / capability of a found backup UE. In one embodiment, the discovery message transmitted by the backup UE may include at least one of the following: an indication of the backup UE's willingness / interest / capability, the UE ID for backup, serving cell ID, distance between the UE and the peer UE, or Uu link quality.

[0086] In one embodiment, a backup UE (candidate) may indicate its willingness / interest / capability to act as a backup UE to the gNB. If the gNB configures the backup (UE) (candidate) as a backup UE of the primary UE, the gNB notifies the backup UE (candidate) of the primary UE's primary UE information. The primary UE information may include UE ID, AMBR (Aggregate Maximum Bit Rate), or QoS (Quality of Service) parameters (e.g., a QoS profile for each QoS flow, including at least one of PQI (PC5 QoS Identifier), resource type, priority, PDB (Packet Delay Budget), PER (Packet Error Rate), average window, or maximum data burst size).

[0087] The capabilities of a backup / primary UE may also include at least one of the following: the ability to act as a backup UE, the functionality of using a backup UE, power limitations, radio capabilities, UL / DL / UE AMBR, QoS parameters (allowing Uu communication), the maximum number of primary UEs that can be served, or the maximum number of backup UEs that can be used / configured.

[0088] In one embodiment, the UE ID of the primary UE / backup UE can be one of the following: C-RNTI, S-TMSI, L2 ID, or other ID newly assigned by gNB or 5GC (5G core).

[0089] In one embodiment, to configure a backup UE association, the gNB can obtain / need / own / acquire a backup authorization for a specific UE from the AMF. The backup authorization may include at least one of the following: (indicating) authorization to use the backup UE (as the primary UE), or (indicating) authorization to be / be used as a backup UE. Furthermore, if the 5GC assigns a UE ID to the backup UE, the gNB can obtain the UE ID of the given UE from the AMF. Additionally, if the UE has a backup UE association in its subscription information within the 5GC, the gNB can obtain the backup UE association from the AMF. Alternatively, when / if the gNB determines a backup UE association, it can send the information to the AMF.

[0090] In one embodiment, the primary UE can send backup UE associations to its terminal device / PLC.

[0091] In one embodiment, the primary UE can send information about its terminal device / PLC to the backup UE.

[0092] 2) In one embodiment, the association of the backup UE may be included in the subscription information in 5GC.

[0093] During registration or service request, the 5GC can send backup UE associations to the UE via NAS messages. For example, for the primary UE, the backup UE association may include at least one of the following: a list of possible / permitted backup UEs, the UE ID of each backup UE, or the capabilities of each backup UE. For the backup UE, the backup UE association may include at least one of the following: a list of possible / permitted primary UEs, the UE ID of each primary UE, or the capabilities of each primary UE. Additionally, the 5GC can send backup UE associations to the gNB.

[0094] 3) In one embodiment, the backup UE association is fixed and pre-configured. For example, the backup UE is considered a dedicated backup module for UE1. When a link / communication failure of UE1 is detected, the backup UE uses UE1's identity and configuration to re-establish the RRC connection with the gNB. In one embodiment, the RRC re-establishment request message includes an additional indication that it is the backup UE.

[0095] Note that the primary UE and the backup UE can be each other's backup UE. As an alternative or supplement, UE3 can be a backup UE of UE2. That is, UE2 is the primary UE of UE3.

[0096] Rapid Fault Detection In one embodiment, a fast fault detection mechanism can be designed for the primary UE so that the backup UE can take over the primary UE's service in a timely manner. Two scenarios can be considered for this fast fault detection mechanism.

[0097] 1) The gNB detects / obtains fault information and instructs the backup UE to take over the services of the primary UE.

[0098] In one embodiment, if the Uu link quality between the gNB and the primary UE deteriorates (e.g., falls below a threshold), or if a Uu RLF (radio link failure) occurs, or if the primary UE fails, the gNB is able to detect / determine these failures or changes in link quality.

[0099] In one embodiment, if the link quality between the primary UE and its terminal device / PLC deteriorates (e.g., falls below a threshold) or a link failure occurs between the primary UE and its device / PLC, the primary UE sends an indication to the gNB. In this embodiment, the gNB can be configured with a link quality threshold for the primary UE, where the threshold is used to determine whether the link quality between the primary UE and its terminal device / PLC has deteriorated.

[0100] In one embodiment, when / if the gNB receives an indication from the primary UE (e.g., the link quality between the primary UE and its terminal equipment / PLC deteriorates (e.g., below a threshold) and / or a link failure), or the gNB detects / determines a link problem itself (e.g., the Uu link quality between the gNB and UE1 deteriorates (e.g., below a threshold) or a Uu RLF occurs or the primary UE fails), the gNB notifies the backup UE to take over the primary UE's service and configures the backup UE with the necessary configuration to transmit the primary UE's service data to the network.

[0101] 2) The backup UE detects / obtains fault information and (autonomously) decides to take over the services of the primary UE.

[0102] In one embodiment, the primary UE sends an indication to the backup UE when / if the following occurs: - Detect / determine a deterioration in link quality on the Uu RLF or Uu interface (i.e., the interface between the primary UE and gNB), or - Detect / determine link failure or deterioration of link quality between the main UE and its terminal equipment / PLC.

[0103] In one embodiment, a novel link keep-alive / fault detection mechanism is proposed for the primary UE and the backup UE. For example, the primary UE can periodically send dedicated signals (e.g., empty data packets) to the backup UE to indicate that the path / link in which the primary UE resides (e.g., the Uu link between UE1 and gNB and / or the link between UE1 and its terminal device / PLC) is functioning normally. If / when the primary UE detects any interface fault or the link quality becomes worse than a threshold, the primary UE stops sending dedicated signals to the backup UE. In an embodiment where the primary UE fails, the primary UE is unable to send dedicated signals.

[0104] If the backup UE does not receive dedicated signals as expected / normally, or receives an indication from the primary UE (e.g., link quality deterioration (e.g., below a threshold) and / or link failure between the primary UE and its terminal equipment / PLC), the backup UE considers / determines that the primary UE's link / path is faulty and may decide to take over the service (e.g., service from the primary UE's terminal equipment / PLC). Furthermore, the backup UE may send an indication to the gNB (instructing the backup UE to take over the primary UE's service) and obtain the configuration required to send service data to the network / gNB.

[0105] In one embodiment, when / if the primary UE detects a deterioration in the Uu RLF or Uu link quality, the primary UE can send an indication to its terminal device / PLC. When the terminal device / PLC detects a link failure or deterioration in link quality to UE1, or receives a link failure indication from UE1, the terminal device / PLC can initiate a link connection to the backup UE and / or send a link / path indication to the backup UE. The backup UE can then decide to take over the services associated with the terminal device / PLC of UE1.

[0106] Low latency and seamless takeover mechanism In one embodiment, when / if a link failure of the primary UE is detected / determined or an instruction to take over the primary UE's services is received from the gNB, the backup UE takes over the services of the primary UE (e.g., services from the primary UE's device / PLC). To ensure no impact on service continuity, the process of taking over the primary UE's services may need to be completed in a very short time and without data loss.

[0107] In one embodiment, service data from the terminal device / PLC of the primary UE can be transmitted to both the primary UE and the backup UE. In this embodiment, the primary UE is the only UE that transmits the received data to the network. In abnormal conditions (e.g., Figure 2 The anomaly shown indicates that a link failure was detected in the primary UE (or an instruction to take over the primary UE's services was received from the gNB), and the backup UE takes over the primary UE, such as... Figure 3 As shown, service data is continuously transmitted to the network. Note that in abnormal conditions, the terminal device / PLC of UE1 may not transmit service data to UE1.

[0108] In one embodiment, when / if the backup UE takes over the service of the primary UE (whether the gNB instructs the backup UE to take over the primary UE or the backup UE decides to take over the primary UE voluntarily), the backup UE needs to know the origin of the data packets / data to be transmitted to the network. To achieve this, the following approach can be considered: 1) The primary UE provides the backup UE with PDU session configurations (e.g., QoS rules / packet filter sets) and corresponding DRB configurations (e.g., SDAP (Service Data Adaptation Protocol), PDCP (Packet Data Convergence Protocol), and RLC (Radio Link Control) configurations) obtained from the 5GC / gNB. Specifically, the primary UE provides the backup UE with QoS rule packet filter sets in the PDU session configuration, enabling the backup UE to operate on the same principle as the primary UE 1 and filter packets into QoS flows. Furthermore, UE1 provides UE2 with DRB configurations (e.g., SDAP, PDCP, and RLC configurations) so that UE2 has the same mapping between QoS flows and DRBs as UE1. In this case, UE2 can maintain the same inactive / virtual PDU session and DRBs as UE1, and maintain the same PDCP SN (Sequence Number) and RLC SN for the same packets as UE1. Note that without these DRB logical channel / MAC / PHY configurations, UE2 will not transmit data through the Uu interface before taking over UE1's service.

[0109] In one embodiment, UE2 discards data packets based on a PDCP drop timer. In this embodiment, when / if it takes over the service of UE1, UE2 can transmit all data packets in the PDCP buffer in ascending order.

[0110] In one embodiment, when UE1 receives RLC feedback from the gNB, it forwards the RLC feedback to UE2. When UE2 takes over UE1's service, it either transmits data packets starting from the first packet that was not acknowledged as successfully delivered by a lower layer, or it retransmits all packets that were not acknowledged as successfully delivered by a higher layer in ascending order and begins transmitting packets that were not transmitted by UE1. Furthermore, when instructing UE2 to take over UE1's service, the gNB may also instruct UE2 to perform PDCP reconstruction or PDCP data recovery on these DRBs.

[0111] In one embodiment, if / when instructing UE2 to take over the service of UE1, the gNB can send a PDCP status report of UE1's uplink data to UE2. In this embodiment, UE2 (re)transmits data to the gNB based on the PDCP status report. For example, UE2 first retransmits data packets for which the PDCP status report has not been acknowledged as successfully delivered, and then transmits data packets that UE1 did not transmit in the buffer.

[0112] In one embodiment, if / when taking over the service of UE1, UE2 needs to obtain the logical channel / MAC / PHY configuration of these DRBs from the gNB in ​​order to activate the DRBs and transmit data on the DRBs.

[0113] 2) UE1 maintains a receive buffer on the Rx (receive) side for data received from the terminal device / PLC, and a transmit buffer on the Tx (transmit) side for the Uu interface. If a data packet is successfully transmitted on the Uu interface (e.g., receiving an RLC acknowledgment (message) of the packet from the gNB), the Tx side notifies the Rx side and removes the data packet from the receive buffer. UE2 is a backup for data received from UE1's terminal device / PLC, maintaining the same receive buffer as UE1. UE1 periodically sends the status of its receive buffer to UE2 to update the receive buffer accordingly (e.g., discarding data packets in the buffer accordingly). When / if UE2 takes over UE1, UE2 transmits data / data packets from its receive buffer.

[0114] In both approaches, if backup UE2 is considered a dedicated backup module for UE1, then when a failure of UE1 is detected, backup UE2 uses UE1's identity and configuration to perform RRC connection reconstruction with the gNB. In one embodiment, the RRC reconstruction request message includes an additional indication that it is a backup UE. If backup UE2 is a single UE, and if UE2 does not have its own data / service and / or only serves as a backup UE for UE1 (not serving other UEs), then UE2 can remain in an RRC (Radio Resource Control) connected state.

[0115] If UE2 has its own service (e.g., terminal device / PLC) and / or UE2 also acts as a backup UE for another UE (e.g., UE3), as described in the above embodiments, UE2 can obtain the PDU session (QoS rules / packet filter set) / DRB (SDAP / PDCP / RLC) configurations of UE1 and UE3. UE2 maintains the PDU sessions / DRBs of UE1, UE3, and itself, respectively. Figure 4 As shown. When / if UE2 takes over UE1 and / or UE3, the gNB provides UE2 with the corresponding logical channel / MAC / PHY configuration for the relevant DRB.

[0116] For DRBs from different UEs, the same DRB ID can be configured. To allow the gNB to identify DRBs from different UEs, the gNB configures different LCIDs (Logical Channel IDs) for DRBs with the same DRB ID. For example, in... Figure 4In this configuration, the gNB configures LCID1 and LCID2 for UE1's DRB1 and DRB2 respectively. For UE2's DRB1 and DRB2, the gNB configures LCID3 and LCID4 respectively. Similarly, the gNB configures LCID5 and LCID6 for UE3's DRB1 and DRB2 respectively. When / if a data packet is received through the logical channel of LCID2, the gNB can identify that the data is for UE1's DRB2. When a data packet is received through the logical channel of LCID4, the gNB can identify that the data is for UE2's DRB2.

[0117] Low latency and seamless takeover mechanism After UE2 transmits data from UE1's terminal device / PLC to gNB, gNB may have three options for transmitting data to 5GC, such as... Figure 5 As shown: 1) The gNB transmits service data to the 5GC via the original PDU session of UE1. (Note that the data is not transmitted on the DRB of UE1 via Uu).

[0118] In this scenario, the gNB needs to know the relationship between UE2's DRB and UE1's DRB / PDU session, and deliver packets from UE2's DRB to the correct PDU session for UE1.

[0119] In one embodiment, UE1 may provide the backup UE with the PDU session configuration (QoS rules / packet filter set) and corresponding DRB configuration (SDAP, PDCP, and RLC configuration) obtained from the 5GC / gNB. Alternatively, when the gNB configures the DRB configuration of UE1, the gNB may also send at least a portion of the DRB configuration (SDAP / PDCP / RLC configuration) of UE1 and NAS messages for the PDU session configuration of UE1 to the backup UE.

[0120] After obtaining the relevant information, UE2 can maintain the same inactive / virtual PDU session and DRB as UE1. Therefore, the gNB is aware of the relationship between UE2's DRB and UE1's DRB / PDU session.

[0121] 2) gNB transmits service data to 5GC via the PDU session owned by UE2.

[0122] When / if UE2 receives service data from UE1's terminal equipment / PLC, UE2 initiates a service request procedure. The 5GC / AMF initiates the establishment of a PDU session for UE2. In this case, the 5GC establishes a PDU session for UE2, but no data is transmitted before UE2 takes over the service from UE1. To improve resource efficiency, when / if the AMF initiates the establishment of a PDU session for UE2 to the gNB, the AMF can instruct the PDU session to be deactivated. When / if the gNB receives a notification from the AMF that a PDU session for UE2 has been established, it can configure the corresponding DRB for UE2 via the Uu interface. The DRB configuration can include only SDAP / PDCP / RLC configuration. UE2 establishes the PDU session and DRB, but does not transmit data through the Uu interface. Since the service data transmitted from UE1's terminal equipment / PLC to UE1 and UE2 is actually the same, the PDU session configuration and DRB configuration of UE1 and UE2 can be the same, thus maintaining the same PDCP SN and RLC SN for the same data packet at both UE1 and UE2. Based on the above-described low-latency and seamless takeover mechanism, UE2 is able to know the data packets to be transmitted when / if it takes over the service of UE1.

[0123] When / if it is decided that UE2 will take over the service of UE1, the gNB provides UE2 with the logical channel / MAC / PHY configuration of the relevant DRB. Furthermore, the gNB may instruct the AMF to activate the corresponding PDU session for UE2. For example, the gNB may include / transmit an activation indication in UE2's PDU session resource modification indication message.

[0124] In one embodiment, when / if a service request is received from UE1, 5GC knows the backup UE association of UE1 and initiates the establishment of a PDU session for UE1 and the establishment of a PDU session for UE2 (with the same configuration).

[0125] 3) gNB transmits service data to 5GC via a shared PDU session between UE1 and UE2.

[0126] The 5GC (e.g., AMF) can know the backup UE associated with UE1 (e.g., the backup UE of UE1 is UE2). When / if a PDU session establishment for UE1 is initiated, the 5GC can instruct that the PDU session be shared by UE1 and UE2. Specifically, when / if the AMF sends a PDU session resource establishment request for UE1 to the gNB, the AMF can also include at least one of the following information in the message: an indication of a shared PDU session or the backup UE ID (e.g., at least one of UE2's AMF UE NGAP ID / RAN UE NGAP ID / 5G-S-TMSI).

[0127] Furthermore, when / if UE2 takes over the service of UE1, the gNB sends a PDU session resource modification indication message for UE1 to the AMF to change the PDU session / shared PDU session associated with UE1 to one associated with UE2 (e.g., replacing UE1's AMF UE NGAP ID and RAN UE NGAP identifier with UE2's AMF UE NGAP ID and RAN UE NGAP identifier in the PDU session resource modification indication message). To allow the AMF to know / distinguish that it is a backup UE associated with UE1's PDU session / shared PDU session, the message may also include at least one of the following: primary UE information (e.g., UE1's AMF UE NGAP ID / RAN UE NGAP ID / 5G-S-TMSI), a shared PDU session indication, or a backup UE indication.

[0128] Low latency and seamless takeover mechanism In one embodiment, UE1's terminal device / PLC can maintain a control plane connection with UE2 only and / or not transmit service data to the backup UE under normal conditions. Under abnormal conditions (e.g., a link failure related to UE1 is detected or a takeover instruction is received from the gNB), UE2 takes over UE1 to receive service data from UE1's terminal device / PLC and continuously transmits the service data to the network, such as... Figure 6 As shown.

[0129] As described in the above embodiments, the terminal device / PLC of UE1 or UE2 can obtain information associated with the backup UE, and the terminal device / PLC of UE1 or UE2 can also initiate a link connection between the terminal devices / PLCs of UE1 and UE2. Since the terminal devices / PLCs of UE1 and UE2 maintain a link connection without data transmission, it is necessary to consider how to maintain the link connection in this situation.

[0130] In one embodiment, the terminal device and / or backup UE may periodically send empty data packets to each other to maintain the link connection.

[0131] As an alternative or supplement, if the link connection between the terminal devices / PLCs of UE1 and UE2 is a side link / PC5 interface, an SL inactive state can be introduced.

[0132] In one embodiment, the terminal device needs to know when to transmit service data to backup UE2. In one approach, if the terminal device detects / determines that UE1 has failed or experienced a link failure, or that the link quality to UE1 is below a threshold, or receives a notification from UE1, the terminal device begins transmitting service data to UE2. Specifically, the terminal device first (re)transmits data packets that UE1 has not yet acknowledged as successfully delivered, and then transmits / receives data packets from higher layers in a buffer. Notifications from UE1 may include at least one of a backup indication (indicating data transmission to the backup UE), a Uu RLF, or an indication that the Uu link quality is below a threshold. In another approach, when / if UE2 decides or is configured to take over UE1 (e.g., see the embodiments in the "Fast Failure Detection" section), UE2 instructs / commands the terminal device to begin transmitting data to UE2.

[0133] Figure 7 This is a schematic diagram relating to a wireless terminal 70 according to an embodiment of the present disclosure. The wireless terminal 70 may be a user equipment (UE), mobile phone, laptop computer, tablet computer, e-book reader, or portable computer system, and is not limited thereto. The wireless terminal 70 may include a processor 700 such as a microprocessor or application-specific integrated circuit (ASIC), a storage unit 710, and a communication unit 720. The storage unit 710 may be any data storage device storing program code 712 accessed and executed by the processor 700. Embodiments of the storage unit 710 include, but are not limited to, a user identity module (SIM), read-only memory (ROM), flash memory, random access memory (RAM), hard disk, and optical data storage devices. The communication unit 720 may be a transceiver for transmitting and receiving signals (e.g., messages or data packets) based on the processing results of the processor 700. In one embodiment, the communication unit 720 communicates via… Figure 7 At least one antenna 722 shown transmits and receives signals.

[0134] In one embodiment, the storage unit 710 and the program code 712 may be omitted, and the processor 700 may include a storage unit with stored program code.

[0135] The processor 700 can implement any of the steps in the exemplary embodiments on the wireless terminal 70, for example, by executing program code 712.

[0136] The communication unit 720 may be a transceiver. Alternatively or as a supplement, the communication unit 720 may be combined with a transmission unit and a receiving unit configured to transmit signals to and receive signals from a wireless network node (e.g., a base station), respectively.

[0137] Figure 8This diagram relates to a wireless network node 80 according to an embodiment of the present disclosure. The wireless network node 80 may be a satellite, base station (BS), network entity, mobility management entity (MME), serving gateway (S-GW), packet data network (PDN) gateway (P-GW), radio access network (RAN) node, next-generation RAN (NG-RAN) node, gNB, eNB, gNB central unit (gNBCU), gNB distributed unit (gNB-DU), data network, core network, or radio network controller (RNC), and is not limited thereto. Furthermore, the wireless network node 80 may include (execute) at least one network function, such as access and mobility management function (AMF), session management function (SMF), user location function (UPF), policy control function (PCF), application function (AF), etc. The wireless network node 80 may include a processor 800 such as a microprocessor or ASIC, a storage unit 810, and a communication unit 820. The storage unit 810 may be any data storage device storing program code 812 accessed and executed by the processor 800. Examples of storage units 810 include, but are not limited to, SIM, ROM, flash memory, RAM, hard disk, and optical data storage devices. The communication unit 820 can be a transceiver used to transmit and receive signals (e.g., messages or packets) based on the processing results of the processor 800. In one example, the communication unit 820 is connected via... Figure 8 At least one antenna 822 shown transmits and receives signals.

[0138] In one embodiment, the storage unit 810 and the program code 812 may be omitted. The processor 800 may include a storage unit containing stored program code.

[0139] The processor 800 can implement any of the steps described in the exemplary embodiments on the wireless network node 80, for example, by executing program code 812.

[0140] The communication unit 820 may be a transceiver. Alternatively or as a supplement, the communication unit 820 may be combined with a transmission unit and a receiving unit configured to transmit signals to and receive signals from a wireless terminal (e.g., a user equipment or another wireless network node).

[0141] Figure 9 A flowchart of a method according to an embodiment of this disclosure is shown. Figure 9 The method shown can be used in a first wireless terminal (e.g., Figure 2 The backup UE or UE2 in the system includes the following steps: Step 901: Determine if a takeover event has occurred.

[0142] Step 902: In response to a takeover event, transmit service data to the wireless network node, wherein the service data is configured to be transmitted via a second wireless terminal.

[0143] exist Figure 9 In this configuration, the first wireless terminal is configured as the second wireless terminal (e.g., Figure 2 The first radio terminal is the back-end terminal (i.e., the backup UE) of the primary UE or UE1. In other words, the first radio terminal is configured to take over the service of the second radio terminal if / when a takeover event occurs. Specifically, if / when a takeover event is determined to have occurred, the first radio terminal is configured to transmit service data to a radio network node (e.g., BS, gNB, RAN (node), or UPF or DN), where the transmitted service data was originally configured to be transmitted by the second radio terminal. Since the first radio terminal can use the same transmission resources to transmit service data, resource utilization efficiency is improved. Furthermore, the reliability of the system is also improved because multiple radio terminals are used to support the service.

[0144] In one embodiment, if a takeover event occurs, the first wireless terminal transmits service data in a buffer. In this embodiment, if the service data discard timer expires, the service data in the buffer is discarded. In other words, if the second wireless terminal is taken over and / or a takeover event occurs, the first wireless terminal transmits service data for the period prior to taking over the second wireless terminal.

[0145] In one embodiment, a first wireless terminal receives feedback information from a second wireless terminal, indicating that service data was successfully transmitted. Based on the feedback information, the first wireless terminal, in response to a takeover event, transmits service data after the last successful transmission indicated by the feedback information.

[0146] In one embodiment, a first wireless terminal receives a status report from a wireless network node, the status report indicating the reception status of service data. Based on the status report, the first wireless terminal confirms which service data has been successfully received by the wireless network node. In response to a takeover event, the first wireless terminal transmits service data that has not yet been successfully received by the wireless network node.

[0147] In one embodiment, the first wireless terminal receives PDU session configuration and DRB configuration for transmitting service data, or receives PDU session configuration and DRB settings from the second wireless terminal. The PDU session configuration and DRB configuration can be received from the second wireless terminal or a wireless network node. Based on the received PDU session configuration and DRB configuration, the first wireless terminal maintains a virtual PDU session and a virtual DRB. Note that the virtual PDU session and virtual DRB are configured to transmit the service data of the second wireless terminal after / if a takeover event occurs. Before a takeover event occurs, the first wireless terminal does not transmit service data.

[0148] In one embodiment, a first wireless terminal receives a low-level configuration (e.g., configuration of at least one of the logical channel MAC layer or PHY layer) of a DRB (e.g., a DRB of a second wireless terminal), and the DRB is configured to transmit service data. Based on the received low-level configuration, the first wireless terminal activates at least one virtual DRB to transmit service data.

[0149] In one embodiment, to allow the wireless network node to distinguish the DRB from the first and second wireless terminals, the DRBs from different wireless terminals are configured with different LCIDs (e.g., see...). Figure 4 ).

[0150] In one embodiment, the first wireless terminal transmits auxiliary information associated with being a backup terminal to the other wireless terminal. As described above, the backup terminal is configured to transmit service data, which is configured to be transmitted by the primary terminal, upon the occurrence of a takeover event associated with the primary terminal. The auxiliary information includes at least one of a willingness to be a backup terminal, an interest in being a backup terminal, or an indication of a backup terminal's capabilities.

[0151] In one embodiment, the capability indication includes at least one of the following: the ability to act as a backup terminal, power limitations, radio capabilities, uplink AMBR, downlink AMBR, terminal AMBR, QoS parameters, or the maximum number of primary terminals.

[0152] In one embodiment, the first wireless terminal receives information from the second wireless terminal from the wireless network node to confirm which terminal is configured as the primary terminal. The information of the second wireless terminal may include at least one of terminal ID, AMBR, or QoS parameters.

[0153] In one embodiment, the first wireless terminal can receive a first discovery message from the second wireless terminal. The first discovery message is used to search for backup terminals. For example, the first discovery message may include an instruction to search for backup terminals.

[0154] In one embodiment, the first wireless terminal may transmit a second discovery message to the second wireless terminal. The second discovery message is used to indicate the willingness / interest / capability to act as a backup terminal. For example, the second discovery message may include at least one of the following: indication of acting as a backup terminal, a terminal ID configured for the backup terminal, a serving cell ID, the distance between the second wireless terminal (the primary terminal) and the backup terminal, or the link quality of the interface between the backup terminal and the wireless network node.

[0155] In one embodiment, a takeover event includes at least one of the following: - Confirm takeover of the second wireless terminal. - Receive takeover instructions from the wireless network node to take over the second wireless terminal. - Detect link failures related to the second wireless terminal. - Failed to receive link activation indication from the second wireless terminal. - Receive takeover instructions from the second wireless terminal. - Receive service data configured to be transmitted via the second wireless terminal from the terminal device of the second wireless terminal, or - Transmit a takeover instruction to the terminal device or wireless network node of the second wireless terminal.

[0156] Figure 10 A flowchart of a method according to an embodiment of this disclosure is shown. Figure 10 The method shown can be used on wireless network nodes (such as BS or RAN (nodes)) and includes the following steps: Step 1001: Receive service data from the first wireless terminal, the service data being configured to be transmitted via the second wireless terminal.

[0157] In this embodiment, the first wireless terminal is configured as a backup terminal for the second wireless terminal (e.g., the primary terminal). In response to a takeover event, the first wireless terminal takes over the services of the second wireless terminal. In this case, the wireless network node receives service data configured to be transmitted via the second wireless terminal from the first wireless terminal.

[0158] In one embodiment, a wireless network node transmits a status report to a first wireless terminal. The status report indicates the reception status of service data, informing the first wireless terminal of the reception status of service data transmitted by the second wireless terminal, and / or allowing the first wireless terminal to know which service data should be transmitted after the first wireless terminal takes over the second wireless terminal.

[0159] In one embodiment, a wireless network node transmits a low-level configuration of at least one DRB, which is configured to transmit service data to a first wireless terminal to activate a virtual DRB maintained by the first wireless terminal, and / or enable / allow / activate the first wireless terminal to transmit service data.

[0160] In one embodiment, the lower-layer configuration includes at least one of logical channel configuration, MAC layer configuration, or PHY layer configuration.

[0161] In one embodiment, the wireless network node configures different LCIDs for the DRBs of different terminals (e.g., see...). Figure 4 This is to distinguish the DRBs of different terminals (e.g., primary terminal and backup terminal).

[0162] In one embodiment, the wireless network node is configured to transmit service data, received from a first wireless terminal and transmitted via a second wireless terminal, to a CN (e.g., a UPF). These transmissions may be in the following states: - The first PDU session of the first wireless terminal; - A second PDU session of a second wireless terminal; or - A third PDU session shared by the first wireless terminal and the second wireless terminal.

[0163] In one embodiment, a wireless network node can transmit the PDU session configuration and DRB configuration of a second wireless terminal to a first wireless terminal.

[0164] In one embodiment, the wireless network node can receive a PDU session resource establishment request for a third PDU session of a second wireless terminal from the CN. The PDU session resource establishment request includes at least one of an indication of a third PDU session shared by the first and second wireless terminals, or the terminal ID of the first wireless terminal.

[0165] In one embodiment, the terminal ID of the first wireless terminal includes at least one of the following: an ID for identifying the first wireless terminal in the AMF, an identifier for identifying the first wireless terminal in the wireless network node, or an identifier for identifying the first wireless terminal in the CN.

[0166] In one embodiment, a wireless network node may receive auxiliary information associated with being a backup terminal (in terms of willingness / interest / capability). The auxiliary information includes at least one of willingness to be a backup terminal, interest in being a backup terminal, or a capability indication as a backup terminal. For example, a capability indication may include at least one of the following: backup terminal capability, power limitations, radio capabilities, uplink AMBR, downlink AMBR, terminal AMBR, QoS parameters, or the maximum number of primary terminals.

[0167] In one embodiment, the wireless network node transmits information about the second wireless terminal (e.g., backup UE association) to the first wireless terminal. For example, the information about the second wireless terminal includes at least one of terminal ID, AMBR, or QoS parameters.

[0168] In one embodiment, the wireless network node can receive 1) a request for a backup terminal and / or 2) a list of backup terminal candidates from the second wireless terminal. Therefore, the wireless network node can configure a backup terminal for the second wireless terminal. In this embodiment, the wireless network node can transmit the backup terminal configuration associated with the first wireless terminal to the second wireless terminal to notify the second wireless terminal that the first wireless terminal has been configured as a backup terminal for the second wireless terminal.

[0169] In one embodiment, the backup terminal candidate list includes at least one of the following: the backup terminal ID of each backup terminal candidate, the serving cell ID of each backup terminal candidate, the distance between the second wireless terminal and each backup terminal candidate, the link quality between the wireless network node and each backup terminal candidate, or the capability information of each backup terminal candidate.

[0170] In one embodiment, a wireless network node may receive backup authorization from a CN (e.g., an AMF), wherein the backup authorization can be used for a first wireless terminal and / or a second wireless terminal. Specifically, the backup authorization may include: - Authorization to allow the first wireless terminal to act as a backup terminal, or - Authorize a second wireless terminal to use the backup terminal.

[0171] In one embodiment, a wireless network node may transmit backup association information to a CN (e.g., an AMF) that indicates the association between a first wireless terminal and a second wireless terminal (i.e., indicating that the first wireless terminal is a backup terminal of the second wireless terminal, or indicating that the second wireless terminal is the master terminal of the first wireless terminal).

[0172] In one embodiment, the wireless network node transmits an instruction to the first wireless terminal to take over the second wireless terminal. For example, the wireless network node may transmit the instruction if / when the following occurs: - Detect link failures associated with the second wireless terminal. - Determine that the link quality between the second wireless terminal and the wireless network node is below a threshold, or - Receive takeover instructions from the first wireless terminal or from the second wireless terminal.

[0173] Note that the instruction to take over the second wireless terminal received from the second wireless terminal may indicate a link failure (e.g., between the second wireless terminal and its terminal equipment / PLC), or indicate a deterioration in the link quality between the second wireless terminal and its terminal equipment / PCL (e.g., below a threshold).

[0174] Figure 11 A flowchart of a method according to an embodiment of this disclosure is shown. Figure 11 The method shown can be used in a second wireless terminal (e.g., Figure 2 (The main UE or UE1 in the system), and includes the following steps: Step 1101: Transmit a request for backup terminals and / or a list of backup terminal candidates to the wireless network node.

[0175] Step 1102: Receive the backup terminal configuration associated with the first wireless terminal from the wireless network node.

[0176] exist Figure 11 In this configuration, the second wireless terminal requests a backup terminal by sensing a request (message) from the wireless network node for a backup terminal and / or a request for a candidate list of backup terminals. The second wireless terminal can receive backup terminal configuration from the wireless network node, whereby the backup terminal configuration indicates its association with the first wireless terminal. That is, the first wireless terminal is configured as a backup terminal for the second wireless terminal, and the association / configuration between the first and second wireless terminals is communicated to the second wireless terminal.

[0177] In one embodiment where the first wireless terminal is configured as a backup terminal for the second wireless terminal, the second wireless terminal transmits feedback information indicating successful transmission of service data, which is configured to be transmitted via the second wireless terminal to notify the first wireless terminal of the transmission result of the service data.

[0178] In one embodiment, the second wireless terminal transmits PDU session configuration and DRB configuration for transmitting service data.

[0179] In one embodiment, the DRB of the first wireless terminal and the DRB of the second wireless terminal may be configured with different LCIDs (and the same DRB ID).

[0180] In one embodiment, the backup terminal candidate list includes at least one of the following: the backup terminal ID of each backup terminal candidate, the serving cell ID of each backup terminal candidate, the distance between the second wireless terminal and each backup terminal candidate, the link quality between the wireless network node and each backup terminal candidate, or the capability information of each backup terminal candidate.

[0181] In one embodiment, the second wireless terminal transmits a first discovery message to the first wireless terminal, wherein the first discovery message is used to (request) a backup terminal. For example, the first discovery message includes an instruction to search for a backup terminal.

[0182] In one embodiment, the second wireless terminal receives a second discovery message from the first wireless terminal, wherein the second discovery information indicates the willingness / interest / capability to act as a backup terminal. For example, the second discovery message includes at least one of the following: an indication of acting as a backup terminal, a terminal ID configured for the backup terminal, a serving cell ID, the distance between the second wireless terminal and the backup terminal, or the link quality of the interface between the backup terminal and the wireless network node.

[0183] In one embodiment, the second wireless terminal may periodically transmit a link activation indication to the first wireless terminal. If / when a link failure is detected or it is determined that the link quality between the second wireless terminal and the wireless network node / terminal device / PLC has deteriorated (e.g., below a threshold), the second wireless terminal stops transmitting the link activation indication.

[0184] In one embodiment, the second wireless terminal may transmit a takeover instruction to the wireless network node and / or the first wireless terminal. The takeover instruction may be transmitted when / if the second wireless terminal detects a link failure or determines that the link quality between the second wireless terminal and the wireless network node / terminal device / PLC has deteriorated (e.g., below a threshold).

[0185] Figure 12 A flowchart of a method according to an embodiment of this disclosure is shown. Figure 12 The method shown can be used in terminal devices (such as PLCs) and includes the following steps: Step 1201: Transmit the service data to the second wireless terminal, and configure the service data to be transmitted by the second wireless terminal.

[0186] Step 1202: If a takeover event occurs, stop transmitting service data configured to be transmitted by the second wireless terminal to the second wireless terminal; and start transmitting service data configured to be transmitted by the second wireless terminal to the first wireless terminal.

[0187] exist Figure 12 In this configuration, the terminal device is configured to transmit service data to a second wireless terminal. In response to a takeover event (i.e., if a takeover event occurs), the terminal device stops transmitting service data to the second wireless terminal and begins transmitting service data to the first wireless terminal (i.e., the backup terminal of the second wireless terminal).

[0188] In one embodiment, a takeover event includes at least one of the following: - Detect link failures related to the second wireless terminal, or - Receive a takeover instruction from the first wireless terminal to take over the services of the second wireless terminal from the first wireless terminal or the second wireless terminal.

[0189] In one embodiment, the terminal device receives backup association information from the second wireless terminal, wherein the backup association information indicates that the first wireless terminal is a backup terminal of the second wireless terminal and / or the first wireless terminal is configured to take over the second wireless terminal when a takeover event occurs.

[0190] Figure 13 A flowchart of a method according to an embodiment of this disclosure is shown. Figure 13 The method shown can be used in a first wireless terminal (e.g., a UE or a backup UE) and includes the following steps: Step 1301: Transmit auxiliary information related to being a backup terminal to the wireless network node.

[0191] exist Figure 13 In this embodiment, the first wireless terminal transmits auxiliary information associated with being a backup terminal to the wireless network node to help the wireless network node decide to allocate / configure the backup terminal. In this embodiment, the backup terminal can be defined as a terminal used to transmit service data configured to be transmitted by at least one primary terminal when at least one takeover event associated with at least one primary terminal occurs.

[0192] In one embodiment, the auxiliary information includes at least one of the following: willingness to act as a backup terminal, interest in acting as a backup terminal, or indication of ability to act as a backup terminal.

[0193] In one embodiment, the capability indication includes at least one of the following: the capability to act as a backup terminal, power limitations, radio capabilities, uplink AMBR, downlink AMBR, terminal AMBR, at least one QoS parameter, or the maximum number of primary terminals.

[0194] In one embodiment, a first wireless terminal receives information from a second wireless terminal from a wireless network node. The information of the second wireless terminal includes at least one of a terminal ID, an AMBR, or at least one QoS parameter.

[0195] In one embodiment, the first wireless terminal receives information from the second wireless terminal from the wireless network node to confirm which terminal is configured as the primary terminal. The information of the second wireless terminal may include at least one of terminal ID, AMBR, or QoS parameters.

[0196] In one embodiment, the first wireless terminal can receive a first discovery message from the second wireless terminal. The first discovery message is used to search for backup terminals. For example, the first discovery message may include an instruction to search for backup terminals.

[0197] In one embodiment, the first wireless terminal may transmit a second discovery message to the second wireless terminal. The second discovery message is used to indicate the willingness / interest / capability to act as a backup terminal. For example, the second discovery message may include at least one of the following: indication of acting as a backup terminal, a terminal ID configured for the backup terminal, a serving cell ID, the distance between the second wireless terminal (the primary terminal) and the backup terminal, or the link quality of the interface between the backup terminal and the wireless network node.

[0198] Figure 14 A flowchart of a method according to an embodiment of this disclosure is shown. Figure 14 The method shown can be used in a first wireless terminal (e.g., a UE or a backup UE) and includes the following steps: Step 1401: Detect a takeover event associated with the second wireless terminal.

[0199] Step 1402: If a takeover event is detected, service data is transmitted to the wireless network node, and the service data is configured to be transmitted via a second wireless terminal.

[0200] exist Figure 14 In this configuration, a first wireless terminal is configured as a backup terminal for a second wireless terminal and is also configured to detect / determine a takeover event associated with the second wireless terminal. When a takeover event is detected, the first wireless terminal takes over from the second wireless terminal and transmits the service data configured to be transmitted via the second wireless terminal to the wireless network node.

[0201] In one embodiment, a takeover event includes at least one of the following: - Confirm takeover of the second wireless terminal. - Receive takeover instructions from the wireless network node to take over the second wireless terminal. - Detect link failures related to the second wireless terminal. - Failed to receive link activation indication from the second wireless terminal. - Receive takeover instructions from the second wireless terminal to take over the services of the second wireless terminal. - Receive service data configured to be transmitted via the second wireless terminal from the terminal device of the second wireless terminal, or - Transmit a takeover instruction to the terminal device or wireless network node of the second wireless terminal.

[0202] Figure 15 A flowchart of a method according to an embodiment of this disclosure is shown. Figure 15 The method shown can be used on wireless network nodes (such as BS or RAN (nodes)) and includes the following steps: Step 1501: Receive service data from the first wireless terminal, the service data being configured to be transmitted via the second wireless terminal.

[0203] Step 1502: Transmit service data to CN via at least one of the first PDU session of the first wireless terminal, the second PDU session of the second wireless terminal, or a third PDU session shared by the first and second wireless terminals.

[0204] exist Figure 15 In this configuration, the first wireless terminal is configured as a backup terminal for the second wireless terminal. If / when a takeover event occurs, the first wireless terminal takes over from the second wireless terminal to continuously transmit the service data of the second wireless terminal. The wireless network node can transmit service data configured to be transmitted via the second wireless terminal and received from the first wireless terminal via at least one of the following: - The first PDU session of the first wireless terminal; - A second PDU session of a second wireless terminal; or - A third PDU session shared by the first wireless terminal and the second wireless terminal.

[0205] In one embodiment, a wireless network node can transmit the PDU session configuration and DRB configuration of a second wireless terminal to a first wireless terminal.

[0206] In one embodiment, the wireless network node can receive a PDU session resource establishment request for a third PDU session of a second wireless terminal from the CN. The PDU session resource establishment request includes at least one of an indication of a third PDU session shared by the first and second wireless terminals, or the terminal ID of the first wireless terminal.

[0207] In one embodiment, the terminal ID of the first wireless terminal includes at least one of an ID for identifying the first wireless terminal in the AMF, an identifier for identifying the first wireless terminal in the wireless network node, or an identifier for identifying the first wireless terminal in the CN.

[0208] While various embodiments of the invention have been described above, it should be understood that they are merely examples and not limitations. Similarly, various accompanying drawings are provided to depict exemplary architectures or configurations, which are intended to enable those skilled in the art to understand the exemplary features and functions of the invention. However, those skilled in the art will understand that the invention is not limited to the illustrated exemplary architectures or configurations, but can be implemented using various alternative architectures and configurations. Furthermore, as those skilled in the art will understand, one or more features of one embodiment may be combined with one or more features of another embodiment described herein. Therefore, the breadth and scope of the invention should not be limited by any of the exemplary embodiments described above.

[0209] It should also be understood that any reference to elements using names such as "first," "second," etc., in this document generally does not restrict the number or order of these elements. Rather, these names can be used as a convenient means of distinguishing two or more elements or instances of elements in this document. Therefore, mentioning the first and second elements does not imply that only two elements can be used, nor does it imply that the first element must precede the second element in some way.

[0210] Furthermore, those skilled in the art will understand that information and signals can be represented using any of a variety of different techniques and skills. For example, data, instructions, commands, information, signals, bits, and symbols that may be referenced in the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0211] Those skilled in the art will further understand that any of the various illustrative logic blocks, units, processors, devices, circuits, methods, and functions described in connection with the aspects disclosed herein can be implemented by electronic hardware (e.g., digital implementation, analog implementation, or a combination of both), firmware, various forms of program or design code containing instructions (which may be referred to herein as "software" or "software unit" for convenience), or any combination of these technologies.

[0212] To clearly illustrate this interchangeability of hardware, firmware, and software, various illustrative components, blocks, units, circuits, and steps have been generally described above according to their functions. Whether this function is implemented as hardware, firmware, or software, or a combination of these technologies, depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art can implement the described functions in various ways for each specific application, but such implementation decisions will not depart from the scope of the invention. According to various embodiments, processors, devices, components, circuits, structures, machines, units, etc., can be configured to perform one or more functions described herein. The term "configured as" or "configured for" as used herein with respect to a specified operation or function refers to a processor, device, component, circuit, structure, machine, unit, etc., physically constructed, programmed, and / or arranged to perform the specified operation or function.

[0213] Furthermore, those skilled in the art will understand that the various exemplary logic blocks, cells, devices, components, and circuits described herein can be implemented within or executed by an integrated circuit (IC), which may include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, or any combination thereof. Logic blocks, cells, and circuits may also include antennas and / or transceivers for communicating with various components within a network or device. A general-purpose processor may be a microprocessor, but may also be any conventional processor, controller, or state machine. A processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, or any other suitable configuration performing the functions described herein. If implemented in software, these functions may be stored as one or more instructions or code on a computer-readable medium. Therefore, the steps of the methods or algorithms disclosed herein can be implemented as software stored on a computer-readable medium.

[0214] Computer-readable media include computer storage media and communication media, including any medium capable of transferring computer programs or code from one place to another. Storage media can be any available medium that is accessible to a computer. By way of example and not limitation, such computer-readable media can include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and is accessible to a computer.

[0215] In this document, the term "unit" as used herein refers to software, firmware, hardware, and any combination of these elements used to perform the relevant functions described herein. Furthermore, for the purposes of discussion, various units are described as discrete units; however, as will be apparent to those skilled in the art, two or more units can be combined to form a single unit that performs the relevant functions according to embodiments of the invention.

[0216] Furthermore, in embodiments of the present invention, memory or other memory and communication components may be employed. It should be understood that, for clarity, the foregoing description has referenced various functional units and processors in describing embodiments of the present invention. However, it will be apparent that any suitable functional distribution among different functional units, processing logic elements, or domains may be used without diminishing the invention. For example, functions shown to be performed by separate processing logic elements or controllers may be performed by the same processing logic unit or controller. Therefore, references to specific functional units are merely references to suitable means of providing said functionality, and not references to strict logical or physical structures or organizations.

[0217] Various modifications to the embodiments described herein will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments without departing from the scope of the claims. Therefore, the invention is not intended to be limited to the embodiments shown herein, but should be given the widest scope consistent with the novel features and principles disclosed herein, as set forth in the following claims.

Claims

1. A wireless communication method for a first wireless terminal, the method comprising: Confirming the occurrence of a takeover event, and In response to a takeover event, service data is transmitted to the wireless network node, wherein the service data is configured to be transmitted via a second wireless terminal. The first wireless terminal is configured as a backup terminal for the second wireless terminal.

2. The wireless communication method according to claim 1, wherein, In response to the aforementioned takeover event, the service data is transmitted to the wireless network node, including: In response to the aforementioned takeover event, the service data is transmitted to the wireless network node from the buffer. Specifically, if the service data discard timer expires, the service data in the buffer is discarded.

3. The wireless communication method according to claim 1, wherein, In response to the aforementioned takeover event, the service data is transmitted to the wireless network node, including: Receive feedback information from the second wireless terminal, the feedback information indicating successful transmission of the service data, and In response to the takeover event, the service data is transmitted to the wireless network node after the last successful transmission indicated by the feedback information.

4. The wireless communication method according to claim 1, wherein, In response to the aforementioned takeover event, the service data is transmitted to the wireless network node, including: A status report is received from the wireless network node, the status report indicating the reception status of the service data, and In response to the takeover event, service data associated with the unacknowledged successful reception status and service data that has not yet been transmitted are transmitted to the wireless network node.

5. The wireless communication method according to any one of claims 1 to 4, further comprising: From the second wireless terminal or the wireless network node, receive Protocol Data Unit (PDU) session configuration and Data Radio Bearer (DRB) configuration for transmitting the service data, and Maintain at least one virtual PDU session based on the received PDU session configuration. Maintain at least one virtual DRB based on the received DRB configuration. The at least one virtual PDU session and the at least one virtual DRB are configured to transmit the service data in the event of the takeover event.

6. The wireless communication method according to claim 5, further comprising: From the wireless network node, receive at least one low-layer configuration of a DRB, the DRB being configured to transmit the service data, and Based on the low-level configuration, the at least one virtual DRB is activated to transmit the service data.

7. The wireless communication method according to claim 6, wherein, The lower-layer configuration includes at least one of logical channel configuration, media access control layer configuration, or physical layer configuration.

8. The wireless communication method according to any one of claims 1 to 7, wherein, At least one first DRB between the wireless network node and the first wireless terminal, and at least one second DRB between the wireless network node and the second wireless terminal, are configured with different logical channel identifiers.

9. The wireless communication method according to any one of claims 1 to 8, further comprising: The wireless network node transmits auxiliary information associated with it as a backup terminal, the backup terminal being configured to transmit service data configured to be transmitted by the at least one master terminal in the event of at least one takeover event associated with at least one master terminal. The auxiliary information includes at least one of the following: willingness to serve as a backup terminal, interest in serving as a backup terminal, or indication of the ability to serve as a backup terminal.

10. The wireless communication method according to claim 9, wherein, The capability indication includes at least one of the following: The backup terminal's capabilities, power limits, radio capabilities, uplink aggregation maximum bit rate AMBR, downlink AMBR, terminal AMBR, at least one QoS parameter, or the maximum number of primary terminals.

11. The wireless communication method according to any one of claims 1 to 10, further comprising: Receive information from the second wireless terminal from the wireless network node. The information of the second wireless terminal includes at least one of the following: terminal identifier, aggregated maximum bit rate, or at least one quality of service (QoS) parameter.

12. The wireless communication method according to any one of claims 1 to 11, further comprising at least one of the following: From the second wireless terminal, a first discovery message for the backup terminal is received, wherein... The first discovery message includes an instruction to search the backup terminal, or The second wireless terminal is transmitted a second discovery message for use as a backup terminal, wherein the second discovery message includes at least one of the following: As an instruction for the backup terminal, The terminal identifier configured for the backup terminal. Serving cell identifier, The distance between the second wireless terminal and the backup terminal, or Link quality of the interface between the backup terminal and the wireless network node.

13. The wireless communication method according to any one of claims 1 to 12, wherein, The takeover event includes at least one of the following: Confirm takeover of the second wireless terminal. Receive a takeover instruction from the wireless network node to take over the second wireless terminal. Detect link failures associated with the second wireless terminal. Unable to receive link activation indication from the second wireless terminal Receive a takeover instruction from the second wireless terminal. Receive service data from the terminal device of the second wireless terminal, the service data being configured to be transmitted via the second wireless terminal, or Transmit a takeover instruction to the terminal device of the second wireless terminal or the wireless network node.

14. A wireless communication method for a wireless network node, the method comprising: Service data is received from a first wireless terminal, which is configured as a backup terminal for a second wireless terminal, and the service data is configured to be transmitted via the second wireless terminal.

15. The wireless communication method according to claim 14, further comprising: A status report is transmitted to the first wireless terminal, the status report indicating the reception status of the service data.

16. The wireless communication method according to claim 14 or 15, further comprising: The first wireless terminal is transmitted with a low-level configuration of at least one DRB, the DRB being configured to transmit the service data.

17. The wireless communication method according to claim 16, wherein, The lower-layer configuration includes at least one of logical channel configuration, media access control layer configuration, or physical layer configuration.

18. The wireless communication method according to any one of claims 14 to 17, wherein, At least one first DRB between the wireless network node and the first wireless terminal, and at least one second DRB between the wireless network node and the second wireless terminal, are configured with different logical channel identifiers.

19. The wireless communication method according to any one of claims 14 to 18, further comprising: The service data is transmitted to the core network via at least one first PDU session of the first wireless terminal.

20. The wireless communication method according to any one of claims 14 to 19, further comprising: The service data is transmitted to the core network via at least one second PDU session of the second wireless terminal.

21. The wireless communication method according to claim 20, further comprising: The PDU session configuration and DRB configuration of the second wireless terminal are transmitted to the first wireless terminal.

22. The wireless communication method according to any one of claims 14 to 21, further comprising: The service data is transmitted to the core network via at least one third PDU session, which is shared by the first wireless terminal and the second wireless terminal.

23. The wireless communication method according to claim 22, further comprising: From the core network, a PDU session resource establishment request is received for at least one third PDU session of the second wireless terminal. The PDU session resource establishment request includes at least one of the following: an indication of at least one third PDU session shared by the first wireless terminal and the second wireless terminal, or the terminal identifier of the first wireless terminal.

24. The wireless communication method according to claim 23, wherein, The terminal identifier of the first wireless terminal includes at least one of the following: an identifier for identifying the first wireless terminal in access and mobility management functions, an identifier for identifying the first wireless terminal in the wireless network node, or an identifier for identifying the first wireless terminal in the core network.

25. The wireless communication method according to any one of claims 14 to 24, further comprising: From the first wireless terminal, auxiliary information associated with a backup terminal is received, the backup terminal being configured to transmit service data configured to be transmitted by the at least one master terminal in the event of at least one takeover event associated with at least one master terminal. The auxiliary information includes at least one of the following: willingness to serve as a backup terminal, interest in serving as a backup terminal, or indication of the ability to serve as a backup terminal.

26. The wireless communication method according to claim 25, wherein, The capability indication includes at least one of the following: The backup terminal's capabilities, power limits, radio capabilities, uplink aggregation maximum bit rate AMBR, downlink AMBR, terminal AMBR, at least one QoS parameter, or the maximum number of primary terminals.

27. The wireless communication method according to any one of claims 14 to 26, further comprising: Transmit the information of the second wireless terminal to the first wireless terminal. The information of the second wireless terminal includes at least one of the following: terminal identifier, aggregated maximum bit rate, or at least one quality of service (QoS) parameter.

28. The wireless communication method according to any one of claims 14 to 27, further comprising: From the second wireless terminal, receive a request for a backup terminal or at least one candidate backup terminal from the backup terminal candidate list, and The backup terminal configuration associated with the first wireless terminal is transmitted to the second wireless terminal.

29. The wireless communication method according to claim 28, wherein, The backup terminal candidate list includes at least one of the following: The backup terminal identifier for each candidate backup terminal. Each backup terminal can be assigned a serving cell identifier. The distance between the second wireless terminal and each backup terminal candidate The link quality between the wireless network node and each backup terminal candidate, or Capability information for each backup terminal candidate.

30. The wireless communication method according to any one of claims 14 to 29, further comprising: From the access and mobility management function, receive backup authorization from the first wireless terminal and / or the second wireless terminal. The backup authorization includes at least one of the following: Authorization to allow the first wireless terminal to act as a backup terminal, or The second wireless terminal is authorized to use the backup terminal's authorization.

31. The wireless communication method according to any one of claims 14 to 30, further comprising: The backup association information is transmitted to the access and mobility management function, the backup association information indicating the association between the first wireless terminal and the second wireless terminal.

32. The wireless communication method according to any one of claims 14 to 31, further comprising: The instruction to take over the second wireless terminal is transmitted to the first wireless terminal.

33. The wireless communication method according to claim 32, further comprising at least one of the following: Detect link failures associated with the second wireless terminal. It is determined that the link quality between the second wireless terminal and the wireless network node is below a threshold, or Receive a takeover instruction from the first wireless terminal or from the second wireless terminal to take over the second wireless terminal.

34. A wireless communication method for a second wireless terminal, the method comprising: To the wireless network node, transmit a request for a backup terminal or at least one of the backup terminal candidate lists, and The backup terminal configuration associated with the first wireless terminal is received from the wireless network node.

35. The wireless communication method according to claim 34, further comprising: Feedback information is transmitted to the first wireless terminal, the feedback information indicating successful transmission of service data, the service data being configured to be transmitted via the second wireless terminal.

36. The wireless communication method according to claim 34 or 35, further comprising: The first wireless terminal is provided with a transmission protocol data unit (PDU) session configuration and a data radio bearer (DRB) configuration for transmitting service data, wherein the service data is configured to be transmitted via the second wireless terminal.

37. The wireless communication method according to any one of claims 34 to 36, wherein, At least one first DRB between the wireless network node and the first wireless terminal, and at least one second DRB between the wireless network node and the second wireless terminal, are configured with different logical channel identifiers.

38. The wireless communication method according to any one of claims 34 to 37, wherein, The backup terminal candidate list includes at least one of the following: The backup terminal identifier for each candidate backup terminal. Each backup terminal can be assigned a serving cell identifier. The distance between the second wireless terminal and each backup terminal candidate The link quality between the wireless network node and each backup terminal candidate, or Capability information for each backup terminal candidate.

39. The wireless communication method according to any one of claims 34 to 38, further comprising at least one of the following: A first discovery message for the backup terminal is transmitted to the first wireless terminal, wherein... The first discovery message includes an instruction to search the backup terminal, or From the first wireless terminal, a second discovery message is received as a backup terminal, wherein the second discovery message includes at least one of the following: As an instruction for the backup terminal, The terminal identifier configured for the backup terminal. Serving cell identifier, The distance between the second wireless terminal and the backup terminal, or Link quality of the interface between the backup terminal and the wireless network node.

40. The wireless communication method according to any one of claims 34 to 39, further comprising: Stop transmitting link activation indications to the first wireless terminal, the link activation indications being configured to be transmitted periodically to the first wireless terminal, or Transmit a takeover instruction to the first wireless terminal and / or the wireless network node to take over the second wireless terminal.

41. The wireless communication method according to claim 40, further comprising: Detect link failures associated with the interface between the second wireless terminal and the wireless network node. It is determined that the link quality of the first link between the wireless network node and the second wireless terminal is lower than a first threshold, or It is determined that the link quality of the second link between the terminal device and the second wireless terminal is lower than a second threshold.

42. A first wireless terminal, comprising: The processor is configured to determine when a takeover event occurs, and A communication unit is configured to transmit service data to a wireless network node in response to a takeover event, wherein the service data is configured to be transmitted via a second wireless terminal. The first wireless terminal is configured as a backup terminal for the second wireless terminal.

43. The first wireless terminal according to claim 42, wherein, The processor is also configured to perform the wireless communication method according to any one of claims 2 to 13.

44. A wireless network node, comprising: A communication unit is configured to receive service data from a first wireless terminal, the first wireless terminal being configured as a backup terminal for a second wireless terminal, the service data being configured to be transmitted via the second wireless terminal.

45. The wireless network node of claim 44, further comprising a processor configured to perform the wireless communication method of any one of claims 15 to 33.

46. ​​A second wireless terminal, comprising: The communication unit is configured as follows: To the wireless network node, transmit a request for a backup terminal or at least one of the backup terminal candidate lists, and The backup terminal configuration associated with the first wireless terminal is received from the wireless network node.

47. The second wireless terminal according to claim 46, further comprising a processor configured to perform the wireless communication method according to any one of claims 35 to 41.

48. A computer program product comprising computer-readable program medium code stored thereon, the code causing the processor to implement the wireless communication method of any one of claims 1 to 41 when executed by a processor.

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