Method and device for updating data transmission during transition between donors - Patents.com

Abstract

The present disclosure describes a method, system, and device for informing at least one downstream device of a transitioning integrated access backhaul node (IAB-node) about an inter-donor transition status of the transitioning IAB-node undergoing transition from a source IAB-donor to a target IAB-donor. The method includes receiving, by a receiving device, a radio resource control (RRC) message transmitted from the IAB-donor. The RRC message includes an information element indicating an inter-donor transition status of the transitioning IAB-node. The method further includes transmitting, by the receiving device, a Packet Data Convergence Protocol (PDCP) status report to the target IAB-donor in response to the information element indicating successful inter-donor transition.

Description

[Technical field]

[0001] The present disclosure is directed generally to wireless communications. More particularly, the present disclosure relates to methods and devices for updating data transmissions during transitions between donors. [Background technology]

[0002] Wireless communication technologies are moving the world towards an increasingly connected and networked society. Compared to Long Term Evolution (LTE), Fifth Generation (5G) New Radio (NR) technology has a much wider spectrum, including, for example, millimeter wave (mm wave) frequency bands. With the development of multiple input multiple output (MIMO) and / or multiple beam systems, 5G NR may offer much higher speeds and much lower latency.

[0003] 5G NR may include an Integrated Access Backhaul (IAB) implementation. An IAB implementation may include one or more IAB-donors and multiple connecting IAB-nodes. Currently, there are issues and / or problems associated with updating data transmissions of downstream devices, especially when one IAB node transitions from one IAB-donor to another IAB-donor.

[0004] The present disclosure may address at least some of the problems / issues associated with existing systems to improve performance of wireless communications. Summary of the Invention [Means for solving the problem]

[0005] This document relates to methods, systems, and devices for wireless communication, and more particularly, to methods, systems, and devices for updating data transmission for downstream devices of a transitioning Integrated Access Backhaul Node (IAB-node) during transition between donors.

[0006] In one embodiment, the present disclosure describes a method for wireless communication, the method including receiving, by a receiving device, a radio resource control (RRC) message transmitted from a transmitting device, the RRC message comprising: IAB-Donor Transition Related Information and the transmitting device comprises one of the subsets, the subset comprising at least one of a target Node B (gNB), a target gNB central unit (gNB-CU), a source gNB, and a source gNB-CU.

[0007] In another embodiment, the present disclosure describes a method for wireless communication, the method including receiving, by a receiving device, a medium access control (MAC) control element (CE) MAC CE transmitted from a transmitting device, the MAC CE comprising: IAB-Donor Transition Related Information The first information indicates

[0008] In another embodiment, the present disclosure describes a method for wireless communication, the method including transmitting, by a first IAB-node as a transmitting device, a Backhaul Adaptation Protocol (BAP) control protocol data unit (PDU) to a second IAB-node, the BAP control PDU comprising: IAB-Donor Transition Related Information The first information indicates

[0009] In another embodiment, the present disclosure describes a method for wireless communication, the method comprising: a first IAB-node as a transmitting device, adapted for backhaul to a second IAB-node; transmitting a protocol (BAP) control protocol data unit (PDU), the BAP control PDU comprising: IAB-Donor Transition Related Information The first information indicates

[0010] In some other embodiments, an apparatus for wireless communication may include a memory storing instructions and processing circuitry in communication with the memory, the processing circuitry being configured, when the instructions are executed, to perform the methods described above.

[0011] In some other embodiments, a device for wireless communication may include a memory storing instructions and processing circuitry in communication with the memory, the processing circuitry being configured, when the instructions are executed, to perform the methods described above.

[0012] In some other embodiments, a computer readable medium comprises instructions that, when executed by a computer, cause the computer to perform the above-described methods.

[0013] These and other aspects and implementations are described in more detail in the drawings, description, and claims. The present invention provides, for example, the following: (Item 1) 1. A method for wireless communication, the method comprising: receiving, by the receiving device, a radio resource control (RRC) message transmitted from the transmitting device; The RRC message is IAB-Donor Transition Related Information and the transmission device comprises one of a subset, the subset comprising at least one of a target Node B (gNB), a target gNB central unit (gNB-CU), a source gNB, and a source gNB-CU. method. (Item 2) 2. The method of claim 1, further comprising: the first information further indicating one of a subset, the subset comprising at least one of: at least one upstream integrated access backhaul node (IAB-node) of the receiving device causing an inter-donor transition from a source IAB-donor to a target IAB-donor; a success status of the inter-donor transition; an ongoing status of the inter-donor transition; a failure status of the inter-donor transition; a start status of the inter-donor transition; and an instruction to trigger the receiving device to perform a Packet Data Convergence Protocol (PDCP) status reporting procedure. (Item 3) and triggering the receiving device to send one or more Packet Data Convergence Protocol (PDCP) status reports to the target IAB-donor in response to the first information indicating a successful status of the inter-donor transition; 3. The method of claim 2, wherein the PDCP status report corresponds to a Radio Link Control-Acknowledged Mode (RLC-AM) bearer that is configured to be requested to transmit the PDCP status report in the uplink. (Item 4) and in response to the first information indicating triggering the receiving device to perform the Packet Data Convergence Protocol (PDCP) status reporting procedure, triggering the receiving device to send one or more Packet Data Convergence Protocol (PDCP) status reports to the target IAB-donor; 3. The method of claim 2, wherein the PDCP status report corresponds to a Radio Link Control-Acknowledged Mode (RLC-AM) bearer that is configured to be requested to transmit the PDCP status report in the uplink. (Item 5) 3. The method of claim 2, further comprising: in response to the first information indicating the ongoing status of the inter-donor transition or the start status of the inter-donor transition, the receiving device stopping data transmission of all radio bearers. (Item 6) 3. The method of claim 2, further comprising the receiving device stopping or canceling behavior associated with the inter-donor transition in response to the first information indicating the failed status of the inter-donor transition. (Item 7) 2. The method of claim 1, wherein the receiving device comprises at least one user equipment (UE) connected to a transition IAB-node. (Item 8) 2. The method of claim 1, wherein the receiving device comprises at least one user equipment (UE) connected to a downstream IAB-node of the transition IAB-node. (Item 9) The receiving device is configured to receive at least one downstream IAB -The method according to item 1, comprising a node. (Item 10) 1. A method for wireless communication, the method comprising: receiving, by the receiving device, a medium access control (MAC) control element (CE) transmitted from the transmitting device; The MAC CE is IAB-Donor Transition Related Information and providing first information indicative of (Item 11) the transmitting device comprises one of a subset of devices, the subset of devices comprising at least one of a transition IAB-node, a target parent IAB-node of the transition IAB-node, a child IAB-node of a downstream IAB-node of the transition IAB-node; 11. The method of claim 10, wherein the receiving device comprises at least one of a user equipment (UE) and a child IAB-node connected to the transmitting device. (Item 12) 11. The method of claim 10, wherein the first information further comprises one of a subset, the subset comprising at least one of: at least one upstream integrated access backhaul node (IAB-node) of the receiving device causing an inter-donor transition from a source IAB-donor to a target IAB-donor; a success status of the inter-donor transition; an ongoing status of the inter-donor transition; a start status of the inter-donor transition; a failure status of the inter-donor transition; and an instruction to trigger the receiving device to perform a Packet Data Convergence Protocol (PDCP) status reporting procedure. (Item 13) and triggering the receiving device to send one or more Packet Data Convergence Protocol (PDCP) status reports to the target IAB-donor in response to the first information indicating the successful status of the inter-donor transition; Item 13. The method of item 12, wherein the PDCP status report corresponds to a Radio Link Control-Acknowledged Mode (RLC-AM) bearer configured to be requested to transmit the PDCP status report in an uplink. (Item 14) and in response to the first information indicating triggering the receiving device to perform the Packet Data Convergence Protocol (PDCP) status reporting procedure, triggering the receiving device to send one or more Packet Data Convergence Protocol (PDCP) status reports to the target IAB-donor; Item 13. The method of item 12, wherein the PDCP status report corresponds to a Radio Link Control-Acknowledged Mode (RLC-AM) bearer configured to be requested to transmit the PDCP status report in an uplink. (Item 15) 13. The method of claim 12, further comprising: in response to the first information indicating the ongoing status of the inter-donor transition or the start status of the inter-donor transition, the receiving device stopping data transmission of all radio bearers. (Item 16) Item 13. The method of item 12, further comprising, in response to the first information indicating a failure of a transition between donors, the receiving device assuming that a radio link failure has occurred on the link over which the MAC CE is received. (Item 17) The trigger for the transmitting device to transmit the MAC CE includes satisfying one of a subset of conditions, the subset of conditions being the following conditions: The transmitting device is a transition IAB-node, and a handover command is sent from the target donor CU to the receiving a message; the transmitting device is a transition IAB-node and undergoes a donor-to-donor transition; the transmitting device is a transition IAB-node and successfully establishes a connection with a target upstream device; the transmitting device is a transition IAB-node and fails to connect with a target upstream device, the target upstream device comprising one of a target IAB-donor and a target parent IAB-node of the transition IAB-node; the transmitting device being a child IAB-node and receiving the MAC CE from a parent IAB-node of the child IAB-node; the transmitting device being a transition IAB-node; the transmitting device is a parent IAB-node of the transition IAB-node and successfully establishes a connection with the transition IAB-node; receiving an RRC message from a target donor CU by the transmitting device, the RRC message comprising an indication that at least one upstream IAB-node of the device receiving the RRC message is to cause an inter-donor transition; Item 11. The method of item 10, further comprising at least one of: (Item 18) 1. A method for wireless communication, the method comprising: transmitting, by a first IAB-node as a transmitting device, a Backhaul Adaptation Protocol (BAP) control protocol data unit (PDU) to a second IAB-node; The BAP control PDU is IAB-Donor Transition Related Information and providing first information indicative of (Item 19) 1. A method for wireless communication, the method comprising: transmitting, by a first IAB-node as a transmitting device, a Backhaul Adaptation Protocol (BAP) control protocol data unit (PDU) to a second IAB-node; The BAP control PDU is IAB-Donor Transition Related Informationand providing first information indicative of (Item 20) the first IAB-node comprises one of a subset of IAB-nodes, the subset of IAB-nodes comprising at least one of a transition IAB-node, a target parent IAB-node of the transition IAB-node, and a child IAB-node of a downstream IAB-node of the transition IAB-node; 20. A method according to any of items 18-19, wherein the second IAB-node comprises at least one of the child IAB-nodes of the first IAB-node. (Item 21) 20. The method of any of items 18-19, wherein the first information further comprises one of a subset, the subset comprising at least one of: at least one upstream IAB-node of the first IAB-node causing an inter-donor transition from a source IAB-donor to a target IAB-donor; a success status of the inter-donor transition; an ongoing status of the inter-donor transition; a start status of the inter-donor transition; a failure status of the inter-donor transition; and an instruction to trigger a receiving device to perform a Packet Data Convergence Protocol (PDCP) status reporting procedure. (Item 22) In response to the first information, the second IAB-node transmits the first information to a third device. 23. The method of claim 21, further comprising: transmitting a MAC CE indicating information, the third device comprising at least one child device of the second IAB-node. and triggering the third device to send one or more Packet Data Convergence Protocol (PDCP) status reports to the target IAB-donor in response to the first information indicating the successful status of the inter-donor transition; 23. The method of claim 22, wherein the PDCP status report corresponds to a Radio Link Control-Acknowledged Mode (RLC-AM) bearer that is configured to be requested to transmit the PDCP status report in the uplink. (Item 24) and triggering the third device to transmit one or more Packet Data Convergence Protocol (PDCP) status reports to the target IAB-donor in response to the first information indicating triggering the receiving device to perform the Packet Data Convergence Protocol (PDCP) status reporting procedure; 23. The method of claim 22, wherein the PDCP status report corresponds to a Radio Link Control-Acknowledged Mode (RLC-AM) bearer that is configured to be requested to transmit the PDCP status report in the uplink. (Item 25) 22. The method of claim 21, further comprising: in response to the first information indicating the ongoing status of the inter-donor transition or the starting status of the inter-donor transition, the second IAB-node stopping data transmission for all radio bearers. (Item 26) 22. The method of claim 21, further comprising: in response to the first information indicating the successful status of the inter-donor transition, the second IAB-node resuming data transmission for all radio bearers. (Item 27) 22. The method of claim 21, further comprising, in response to the first information indicating the failed status of the inter-donor transition, the second IAB-node considering that a radio link failure has occurred on the link over which the BAP control PDU is received. (Item 28) 23. The method of claim 22, further comprising: in response to the first information indicating the ongoing status of the inter-donor transition or the start status of the inter-donor transition, the third device stopping data transmission of all radio bearers. (Item 29) 23. The method of claim 22, further comprising, in response to the first information indicating the failed status of the transition between the donors, the third device determining that a radio link failure has occurred on the link over which the BAP control PDU is received. (Item 30) The trigger for the transmitting device to transmit the BAP control PDU includes satisfying one of a subset of conditions, the subset of conditions being the following conditions: the transmitting device is a transition IAB-node and receives a handover command from a target donor CU; the transmitting device is a transition IAB-node and undergoes a donor-to-donor transition; the transmitting device is a transition IAB-node and successfully establishes a connection with a target upstream device; the transmitting device is a transition IAB-node and fails to connect with a target upstream device, the target upstream device comprising one of a target IAB-donor and a target parent IAB-node of the transition IAB-node; The transmission device is a child IAB-node, and the transmission device is a parent IAB-node of the child IAB-node. receiving the BAP control PDU from the the transmitting device is a parent IAB-node of the transition IAB-node and successfully establishes a connection with the transition IAB-node; receiving an RRC message from a target donor CU by the transmitting device, the RRC message comprising an indication that at least one upstream IAB-node of the device receiving the RRC message causes an inter-donor transition; 20. The method of any of items 18-19, further comprising at least one of: (Item 31) A wireless communication device comprising a processor and a memory, the processor configured to read code from the memory and implement a method according to any one of items 1-30. (Item 32) A computer program product comprising computer readable program medium code stored thereon, the code, when executed by a processor, causing the processor to implement a method according to any of items 1-30. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 illustrates an embodiment of a wireless communication system that includes an integrated access backhaul (IAB) system. [Diagram 2] FIG. 2 shows an example of an IAB-donor or an IAB-node. [Diagram 3] FIG. 3 shows an example of a user equipment. [Figure 4] Figure 4 shows a schematic diagram of the transition IAB-node in donor-to-donor transition. [Diagram 5] FIG. 5 illustrates a flow diagram of a method for wireless communication. [Figure 6] FIG. 6 illustrates an example logic flow of the method for wireless communication in FIG. [Figure 7A] FIG. 7A illustrates a flow diagram of another method for wireless communication. [Figure 7B] FIG. 7B shows an example of a medium access control (MAC) control element (CE). [Figure 7C] FIG. 7C shows example dedicated logical channel identifier (LCID) values. [Figure 8] FIG. 8 illustrates an example logic flow of the method for wireless communication in FIG. 7A. [Figure 9A] FIG. 9A illustrates a flow diagram of another method for wireless communication. [Figure 9B]FIG. 9B illustrates several examples of configuration formats for a Backhaul Adaptation Protocol (BAP) control protocol data unit (PDU). [Figure 9C] FIG. 9C illustrates an example of a Backhaul Adaptation Protocol (BAP) control protocol data unit (PDU). [Figure 9D] FIG. 9D illustrates another example of a Backhaul Adaptation Protocol (BAP) control protocol data unit (PDU). [Figure 9E] FIG. 9E illustrates an example of a dedicated Radio Link Failure (RLF) indication type value. [Figure 10] FIG. 10 illustrates another example logic flow of the method for wireless communication in FIG. 9A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The present disclosure will now be described in detail hereinafter with reference to the accompanying drawings which form a part hereof and which show, by way of illustration, specific examples of embodiments. It should be noted, however, that the present disclosure may be embodied in a variety of different forms, and thus, the subject matter directed or claimed is not intended to be construed as limited to any of the embodiments which will be described below.

[0016] Throughout this specification and claims, terms may have subtle meanings that are suggested or implied in the context beyond those explicitly stated. Similarly, the phrases "in one embodiment" or "in some embodiments" as used herein do not necessarily refer to the same embodiment, and the phrases "in another embodiment" or "in other embodiments" as used herein do not necessarily refer to different embodiments. The phrases "in one implementation" or "in some implementations" as used herein do not necessarily refer to the same implementation, and the phrases "in another implementation" or "in other implementations" as used herein do not necessarily refer to different implementations. For example, it is intended that the claimed subject matter includes, in whole or in part, a combination of example embodiments or implementations.

[0017] Generally, terminology may be understood, at least in part, from usage in context. For example, terms such as "and," "or," or "and / or" as used herein may include various meanings that may depend, at least in part, on the context in which such terms are used. Typically, "or," when used to relate a list such as A, B, or C, is intended to mean A, B, and C, which are used herein in an inclusive sense, and A, B, or C, which are used herein in an exclusive sense. In addition, the terms "one or more" or "at least one" as used herein may be used, at least in part, to describe any feature, structure, or characteristic in a singular sense, or may be used to describe a combination of features, structures, or characteristics in a plural sense, depending at least in part on the context. Similarly, again, terms such as "a," "an," or "the" may be understood to convey a singular use or to convey a plural use, depending at least in part on the context. In addition, the terms "based on" or "determined by" may be understood as not necessarily intended to convey an exclusive set of factors, but instead may allow for the existence of additional factors not necessarily explicitly described, again depending at least in part on the context.

[0018] The present disclosure describes methods and devices for updating data transmission for downstream devices of a transitioning Integrated Access Backhaul Node (IAB-node) during transition between donors.

[0019] Next-generation (NG) or fifth-generation (5G) wireless communications may offer a variety of capabilities from downloading at high speeds to supporting real-time low-latency communications. Compared to long-term evolution (LTE), 5G new radio (NR) technology has a much wider spectrum, including, for example, millimeter-wave (mm-wave) frequency bands. With the development of multiple-input multiple-output (MIMO) and / or multiple beam systems, 5G NR may offer much higher speeds and much lower latency. 5G NR may include the development of an integrated access backhaul (IAB) implementation. An IAB implementation may include one or more IAB-donors and multiple connecting IAB-nodes. An IAB implementation may communicate between one or more IAB-donors and one or more IAB-nodes via wireless backhaul and relay links. An IAB implementation may provide flexible NR cell configurations and increase cell density without increasing the density of IAB-donors.

[0020] An IAB system may include one or more IAB-donors and one or more IAB-nodes, which collectively provide wireless connectivity services to one or more user equipments (UEs) (e.g., smartphones). The IAB-donors and IAB-nodes may be wireless network base stations, including NG Radio Access Network (NG-RAN) base stations, which may include Node Bs (NBs, e.g., gNBs) in a mobile communication context. The IAB-donors may provide access backhaul to one or more child IAB-nodes, and the IAB-donors may connect to a core network via wired communication. In one implementation, the core network may include a 5G core network (5GC). In another implementation, the wired communication may include fiber transmission communication. The IAB-nodes may include a wireless access link and a wireless backhaul link. The wireless access link may be used for communication between the UE and the IAB-node. The wireless backhaul link may be used for communication between an IAB-node and an IAB-donor, and / or between one IAB-node and another IAB-node. Thus, the IAB-node does not need a wired communication network for data backhaul. In some implementations, the IAB-node does not include a wired communication network for data backhaul, so that the IAB-node is more flexible, easier to implement, and reduces the burden of implementing a wired communication network. The access link and the backhaul link may use a transmission band with the same frequency (known as in-band relaying) or may use a transmission band with different frequencies (known as out-of-band relaying).

[0021] 1, the IAB-donor 130 may provide access backhaul 140 to one or more connecting IAB-nodes (152 and 154). The IAB-donor 130 may connect to a core network 110 via wired communication 120. In one implementation, the core network 110 may include a 5G core network (5GC). In another implementation, the wired communication 120 may include fiber transmission communication.

[0022] An IAB-donor may provide wireless connectivity to one or more user equipment (UE). A UE may be a mobile device, such as a smartphone or a mobile communication module located in a vehicle. For example, the IAB-donor 130 may provide wireless connectivity 160 to a UE 172.

[0023] Similarly, without limitation, a child IAB-node may provide wireless connectivity to one or more UEs. For example, IAB-node 152 may provide wireless connectivity 160 to UE 174.

[0024] Similarly, without limitation, a child IAB-node may provide access backhaul to one or more downstream IAB-nodes. For example, IAB-node 154 may provide access backhaul 140 to downstream IAB-node 156 and downstream IAB-node 157. From the perspective of IAB-node 154, IAB-node 156 may be referred to as a child IAB-node of IAB-node 154, and IAB-node 157 may be referred to as a grandchild IAB-node of IAB-node 154.

[0025] Similarly, without limitation, grandchild IAB-node 157 may also provide access backhaul to one or more connecting grandchild IAB-nodes and / or provide wireless connectivity to one or more UEs (e.g., UE 178).

[0026] In one implementation, the IAB system 100 may include another IAB-donor 135. The IAB-donor 135 may also connect to a core network (e.g., 5GC) 110 via wired communication 120. The IAB-donor 135 may provide access backhaul 140 to one or more connecting IAB-nodes 158, which may provide wireless connectivity 160 to one or more UEs 176.

[0027] An IAB-node 156 currently connected to an IAB-donor 130 via an IAB-node 154 may transition to an IAB-donor 135. This may be referred to as an inter-donor transition, and the IAB-node 156 may be referred to as a transitioning IAB-node. Currently, there are issues and / or problems associated with updating data transmissions for downstream devices (IAB-nodes or UEs) during and / or after an inter-donor transition.

[0028] In an embodiment involving a NR system, after an inter-gNB transition, the target gNB may retransmit a portion of the data packets to ensure continuity of communication services to the UE. To minimize that portion of the data packets, the UE may send a Packet Data Convergence Protocol (PDCP) status report to the target gNB. The PDCP status report may inform the target gNB of the condition (e.g., failure or success condition) of the data packets received by the UE, so that the target gNB may determine which data packets are selected for retransmission or transmission. In current systems, the UE's transmit PDCP status report may be triggered by PDCP data recovery and / or PDCP re-establishment. In an implementation involving both PDCP re-establishment and PDCP data recovery, the UE may need to retransmit PDCP protocol data units (PDUs) or PDCP service data units (SDUs) that have not been acknowledged by the lower layer (e.g., the Radio Link Control (RLC) layer).

[0029] In one implementation involving PDCP re-establishment, the UE may send a PDCP status report during inter-gNB transition by the following procedure: The target gNB may send a radio resource control (RRC) message via the source gNB. The RRC message may be configured inside an RRC container of the source gNB and the UE; the RRC message may also include a reestablishPDCP information element. The reestablishPDCP information element may trigger the UE to trigger the PDCP re-establishment procedure and send a PDCP status reporter. The UE may send a PDCP status report to the target gNB after the connection between the UE and the target gNB is successfully established.

[0030] In an IAB system, in order to avoid unnecessary retransmission of data packets and ensure service continuity, the UE may report a PDCP status report. However, some problems / issues arise. One of the problems / issues may include that after the transition IAB-node establishes a connection between the IAB-node and the target gNB-CU, the UE connecting with the transition IAB-node may need to be triggered to send a PDCP status report to the target IAB-donor. The triggering event may include one of a PDCP data recovery procedure and a PDCP re-establishment procedure. This may lead to retransmission of data packets that arrive at the IAB-donor CU but may be on the source path during the transition of the transition IAB-node, which may then waste network resources and result in poor performance.

[0031] The present disclosure describes embodiments of a method and device for updating configuration information for a transition IAB-node and / or at least one of the transition IAB-node's downstream devices during the transition IAB-node's inter-donor transition, addressing at least some of the problems discussed above. In an embodiment, the downstream IAB-node and / or the corresponding UE may send a PDCP status report to the target IAB-node without undergoing either a PDCP data recovery or a PDCP re-establishment process.

[0032] FIG. 2 illustrates an exemplary wireless communication base station 200. The wireless communication base station 200 may be an exemplary implementation of at least one of the IAB-donors (130 and 135) and IAB-nodes (152, 154, 156, and 158) in FIG. 1. The base station 200 may include wireless transmission / reception (Tx / Rx) circuitry 208 for transmitting / receiving communications with one or more UEs and / or one or more other base stations. The base station may also include network interface circuitry 209 for allowing the base station to communicate with other base stations and / or core networks, e.g., optical or wired interconnects, Ethernet, and / or other data transmission media / protocols. The base station 200 may optionally include an input / output (I / O) interface 206 for communicating with an operator, etc.

[0033] The base station may also include system circuitry 204. System circuitry 204 may include a processor 221 and / or memory 222. Memory 222 may include an operating system 224, instructions 226, and parameters 228. Instructions 226 may be configured for one or more of processors 124 to perform functions of the base station. Parameters 228 may include parameters to support execution of instructions 226. For example, the parameters may include network protocol settings, bandwidth parameters, radio frequency mapping assignments, and / or other parameters.

[0034] FIG. 3 illustrates an exemplary user equipment (UE) 300. The UE 300 may be a mobile device, such as a smartphone or a mobile communications module disposed in a vehicle. The UE 300 may be an exemplary implementation of at least one of the UEs (172, 174, and 176) in FIG. 1. The UE 300 may include a communication interface 302, system circuitry 304, an input / output interface (I / O) 306, display circuitry 308, and storage 309. The display circuitry may include a user interface 310. The system circuitry 304 may include any combination of hardware, software, firmware, or other logic / circuitry. The system circuitry 304 may be implemented, for example, with one or more system-on-chips (SoCs), application specific integrated circuits (ASICs), discrete analog and digital circuits, and other circuitry. The system circuitry 304 may be part of an implementation of any desired functionality in the UE 300. In that regard, system circuitry 304 may include logic that facilitates, by way of example, decoding and playing music and video, e.g., MP3, MP4, MPEG, AVI, FLAC, AC3, or WAV decoding and playback; launching applications; receiving user input; storing and terminating application data; establishing, maintaining, and terminating cellular calls or data connections, for Internet connectivity, by way of example; establishing, maintaining, and terminating wireless network connections, Bluetooth connections, or other connections; and displaying associated information on user interface 310. User interface 310 and input / output (I / O) interface 306 may include a graphical user interface, a touch-sensitive display, tactile feedback or other tactile output, voice or facial recognition input, buttons, switches, speakers, and other user interface elements.Additional examples of I / O interface 306 may include microphones, video, still cameras, temperature sensors, vibration sensors, rotation and orientation sensors, headset and microphone input / output jacks, universal serial bus (USB) connectors, memory card slots, radiation sensors (e.g., IR sensors), and other types of inputs.

[0035] 3, the communication interface 302 may include radio frequency (RF) transmit (Tx) and receive (Rx) circuitry 316 that handles transmission and reception of signals through one or more antennas 314. The communication interface 302 may include one or more transceivers. The transceivers may be wireless transceivers that include modulation / demodulation circuitry, digital-to-analog converters (DACs), shaping tables, analog-to-digital converters (ADCs), filters, wave shapers, filters, preamplifiers, power amplifiers, and / or other logic to transmit and receive through one or more antennas or (for some devices) through a physical (e.g., wired) medium. The transmitted and received signals may conform to any of a diverse array of formats, protocols, modulations (e.g., QPSK, 16-QAM, 64-QAM, or 256-QAM), frequency channels, bit rates, and encodings. As one specific example, the communication interface 302 may include a transceiver supporting transmission and reception under 2G, 3G, BT, WiFi, Universal Mobile Telecommunications System (UMTS), High Speed ​​Packet Access (HSPA)+, 4G / Long Term Evolution (LTE), and 5G standards. However, the techniques described below are applicable to other wireless communication technologies, whether originating from Third Generation Partnership Project (3GPP), the Global System for Mobile Communications (GSM) Association, 3GPP2, IEEE, or other collaborative or standardization bodies.

[0036] 3, the system circuitry 304 may include one or more processors 321 and memory 322. The memory 322 stores, for example, an operating system 324, instructions 326, and parameters 328. The processor 321 is configured to execute the instructions 326 to perform desired functionality for the UE 300. The parameters 328 may provide and define configuration and operate options for the instructions 326. The memory 322 may also store any BT, WiFi, 3G, 4G, 5G, or other data that the UE 300 may transmit or receive through the communication interface 302. In various implementations, system power for the UE 300 may be supplied by a power storage device, such as a battery or a converter.

[0037] The present disclosure describes several embodiments of methods and devices for updating data transmission for at least one downstream device of a transition integrated access backhaul node (IAB-node) during transition between donors, which may be implemented partially or fully on the wireless network base station and / or user equipment described above in FIGS. 2 and 3.

[0038] Referring to FIG. 4, an IAB system 400 may include one or more IAB-donors (410 and 420). An IAB-node 450 currently connected to an IAB-donor 410 via an IAB-node 430 may transition to an IAB-donor 420 via an IAB-node 440. This may be referred to as a transition between donors. The IAB-node 450 may be a transition IAB-node, the IAB-donor 410 may be a source IAB-donor, the IAB-node 430 may be a source parent IAB-node, the IAB-donor 420 may be a target IAB-donor, and the IAB-node 440 may be a target parent IAB-node.

[0039] In some embodiments, for one IAB-node, there may be one or more upstream IAB-nodes 492, which may collectively connect the IAB-node to a corresponding IAB-donor; there may also be one or more downstream devices 494 connecting to the IAB-node, which may include one or more downstream IAB-nodes and / or one or more downstream UEs.

[0040] In some embodiments, the transition IAB-node 450 may connect to an IAB-donor via one or more IAB-nodes, which may collectively be referred to as parent IAB-nodes.

[0041] The source IAB-donor 410 may include a central unit (CU) 412 and a distributed unit (DU) 414, and the source IAB-donor CU 412 may communicate with the source IAB-donor DU 414. The source parent IAB-node 430, which communicates with the source IAB-donor 410, may include a mobile termination (MT) 432 and a distributed unit (DU) 434. The target IAB-donor 420 may include a CU 422 and a DU 424, and the target IAB-donor CU 422 may communicate with the target IAB-donor DU 424. The target IAB-node 440, which communicates with the target IAB-donor 420, may include an MT 442 and a DU 444.

[0042] Prior to the donor-to-donor migration, the transition IAB-node 450 may communicate with the source parent IAB-node 430. The transition IAB-node 450 may include an MT 452 and a DU 454. In one implementation, the transition IAB-node 450 may communicate with a UE 470. In another implementation, the transition IAB-node 450 may communicate with a child IAB-node 460. The child IAB-node 460 may include an MT 462 and a DU 464. In one implementation, the child IAB-node 460 may communicate with a UE 472.

[0043] 4, a transition IAB-node 450 may change its attachment point from a source parent IAB-node 430 connecting to a source IAB-donor 410 to a target IAB-node 440 connecting to a target IAB-donor 420. In one implementation, a handover (HO) process may occur during the transition between donors, which may be an inter-CU HO scenario. The transition IAB-node DU 454 may communicate with the target IAB-donor CU 422 via an F1-AP message 482.

[0044] 5, the present disclosure describes various embodiments of a method 500 of using a radio resource control (RRC) message to inform at least one downstream device of a transition integrated access backhaul node (IAB-node) that the transition IAB-node is causing an inter-donor transition from a source IAB-donor to a target IAB-donor. The method may solve problems / issues associated with requesting PDCP data recovery and / or PDCP re-establishment for a receiving device to trigger a transmit PDCP status report.

[0045] Method 500 may include some or all of the following steps: step 510: receiving a radio resource control (RRC) message sent from a target IAB-donor central unit (CU) by at least one downstream device of the transition IAB-node, the RRC message comprising an information element (IE) indicating that the transition IAB-node is causing a transition between donors; step 520: sending, by the at least one downstream device, a packet data convergence protocol (PDCP) status report to the target IAB-donor in response to the IE further indicating successful transition between donors or a trigger for the receiving device to perform a packet data convergence protocol (PDCP) status reporting procedure, the PDCP status report corresponding to a radio link control acknowledged mode (RLC-AM) bearer configured to be enabled to send the PDCP status report in the uplink.

[0046] The method 500 may optionally, and additionally or alternatively, include, in step 530: resuming data transmission of the radio bearer by at least one downstream device in response to the IE further indicating successful transition between donors.

[0047] The method 500 may optionally, and additionally or alternatively, include, step 540: in response to the first information further indicating an ongoing status of the inter-donor transition or a start status of the inter-donor transition, the receiving device stopping data transmission for all radio bearers.

[0048] The method 500 may optionally, and additionally or alternatively, include, step 550: in response to the first information further indicating a failed status of the inter-donor migration, the receiving device stopping or canceling behavior associated with the inter-donor migration.

[0049] In one implementation, the RRC message may be an RRC Reconfiguration message.

[0050] In one implementation, the IE may indicate the status of the transfer between donors. In one implementation, the IE may include a value of either TRUE or FALSE. In another implementation, the IE may only include a value of TRUE.

[0051] In one implementation, a TRUE value of the IE in the RRC message may indicate successful transition between donors, while in another implementation, a TRUE value of the IE may indicate triggering at least one downstream device to transmit a PDCP status report corresponding to a Radio Link Control-acknowledged mode (RLC-AM) bearer that is configured to be enabled to transmit PDCP status reports in the uplink.

[0052] In one implementation, a FALSE value in the RRC message may indicate a failure to transition between donors, while in another implementation, a FALSE value in the IE may indicate not to trigger the receiver to transmit PDCP status reports corresponding to RLC-AM bearers that are configured to be enabled to transmit PDCP status reports in the uplink.

[0053] 6 illustrates a logical flow of a method 600 of using RRC messages to update data transmission for at least one downstream device of the transition IAB-node during donor-to-donor transition from source IAB-donor to target IAB-donor. In another implementation, FIG. 6 illustrates a logical flow of a method 600 of using RRC messages to inform at least one downstream device of the transition IAB-node that the transition IAB-node is effecting a donor-to-donor transition from source IAB-donor to target IAB-donor.

[0054] 6, after the inter-donor transition, the target IAB-donor CU 680 may send an RRC message to the IAB-node MT 682. In one implementation, the IAB-node may include the transition IAB-node. In another implementation, the IAB-node may include a downstream IAB-node of the transition IAB-node.

[0055] 6, during the transition between donors, the target IAB-donor CU 680 may send an RRC message to the UE 684. In one implementation, the UE 684 may include a UE connecting to the transition IAB-node. In another implementation, the UE 684 may include a UE connecting to a downstream IAB-node of the transition IAB-node.

[0056] 6, in response to the received RRC message including an IE indicating successful inter-donor transition, the IAB-node MT 682 may send a Packet Data Convergence Protocol (PDCP) status report to the target IAB-donor. The PDCP status report may correspond to a Radio Link Control Acknowledged Mode (RLC-AM) bearer that is configured to be enabled to send PDCP status reports in the uplink.

[0057] 6, in response to the received RRC message including an IE indicating successful inter-donor transition, the UE 684 may send a PDCP status report to the target IAB-donor. The PDCP status report may correspond to a Radio Link Control-acknowledged mode (RLC-AM) bearer that is configured to be enabled to send PDCP status reports in the uplink.

[0058] 7A, the present disclosure describes various embodiments of a method 700 of using a medium access control (MAC) control element (CE) to inform at least one downstream device of a transition integrated access backhaul node (IAB-node) that the transition IAB-node is causing an inter-donor transition from a source IAB-donor to a target IAB-donor. The method may solve problems / issues associated with requesting PDCP data recovery and / or PDCP re-establishment for a receiving device to trigger a transmit PDCP status report.

[0059] The method 700 may include some or all of the following steps:

[0060] Step 710: Sending, by the IAB-node DU, a Medium Access Control (MAC) Control Element (CE) to at least one downstream device of the IAB-node, where the MAC CE indicates that the transition IAB-node will effect a transition between donors;

[0061] Step 720: When the receiving device is a UE and the IE further indicates a successful inter-donor transition or a trigger for a PDCP status reporting procedure, or a trigger for the receiving device to perform a PDCP status reporting procedure, the UE sends a PDCP status report to the target IAB-donor, where the PDCP status report corresponds to a radio link control acknowledged mode (RLC-AM) bearer that is configured to be enabled to send the PDCP status report in the uplink;

[0062] Step 730: When the receiving device is an IAB-node, the IAB-node sends a MAC CE to its child IAB-nodes and / or its connected UEs;

[0063] Step 740: In response to the received MAC CE indicating successful transition between donors, the UE may resume data transmission on the radio bearer;

[0064] Step 750: When the IE further indicates an ongoing status of inter-donor transition or an initiation status of inter-donor transition, the receiving device (e.g., IAB-node or UE) stops data transmission for all radio bearers;

[0065] Step 760: When the IE further indicates an inter-donor transition failure status, the receiving device (eg, IAB-node or UE) assumes that a radio link failure has occurred on the link over which the MAC CE is received.

[0066] In one implementation, referring to FIG. 7B, the MAC CE is identified by a MAC subheader 750 that includes a logical channel ID (LCID) 755. In another implementation, the LCID may include a reserved value that does not have a conflict with other values. For example, referring to FIG. 7C, the LCID value 782 may correspond to an index 780 into the LCID value. For the LCID shown in FIG. 7B, the LCID may have 6 binary bits, the value of the LCID for the downlink-shared channel (DL-SCH) may include a reserved range 784 of 33 to 44 (inclusive), and the PDCP status only report 785 may include a value of 44. In another implementation, the MAC CE may have a fixed size of zero bits for its load.

[0067] 8 illustrates a logical flow of a method 800 of using a MAC CE to update data transmission for at least one downstream device of a transition IAB-node during donor-to-donor transition from a source IAB-donor to a target IAB-donor. In another implementation, FIG. 8 illustrates a logical flow of a method 600 of using a MAC CE to inform at least one downstream device of a transition IAB-node that the transition IAB-node is effecting a donor-to-donor transition from a source IAB-donor to a target IAB-donor.

[0068] Referring to step 810 in FIG. 8, during transition between donors, IAB-node DU 881 may send a MAC CE to child IAB-node MT 682 if one of the following conditions is met:

[0069] In one implementation, the IAB-node may include a transition IAB-node, and the conditions may include the transition IAB-node successfully establishing, failing to establish, or in the process of establishing a connection with an upstream device. The upstream device may include one of the target IAB-donor and target parent IAB-node of the transition IAB-node.

[0070] In another implementation, the IAB-node may include the target parent IAB-node of the transition IAB-node; the conditions may include the transition IAB-node successfully establishing a connection with the target parent IAB-node of the transition IAB-node, or failing to establish it, or being in the process of establishing it, or starting to establish it.

[0071] In another implementation, the IAB-node may include a child IAB-node; the condition may include whether the child IAB-node receives a MAC CE from a parent IAB-node of the child IAB-node.

[0072] In another implementation, the conditions may include the transition IAB-node, and the preset conditions may include the transition IAB-node receiving a Radio Resource Control (RRC) message sent from the target IAB-donor CU, and the received RRC message comprising an information element (IE) indicating information related to transition between transition donors.

[0073] 8, during transition between donors, if conditions are met, the IAB-node DU 881 may send a MAC CE to the UE 884. The UE 884 connects to the IAB-node.

[0074] 8, optionally, and additionally in response to a received MAC CE indicating successful inter-donor transition or a trigger for the receiving device to perform a Packet Data Convergence Protocol (PDCP) status reporting procedure, the IAB-node 882 may transmit a PDCP status report to the target IAB-donor 880. The PDCP status report may correspond to a Radio Link Control Acknowledged Mode (RLC-AM) bearer that is configured to be enabled to transmit PDCP status reports in the uplink.

[0075] Referring to step 835 in FIG. 8, in response to the received MAC CE, the IAB-node 882 may transmit a MAC CE to one or more downstream IAB-nodes and / or UEs of the IAB-node 882.

[0076] 8, in response to a received MAC CE indicating successful inter-donor transition or a trigger for the receiving device to perform a Packet Data Convergence Protocol (PDCP) status reporting procedure, the UE 884 may send a PDCP status report to the target IAB-donor 880. The PDCP status report may correspond to an RLC-AM bearer that is configured to be enabled to send PDCP status reports in the uplink.

[0077] Referring to step 840 in FIG. 8, in response to the received MAC CE indicating successful transition between donors, the UE 884 may resume data transmission for the radio bearer.

[0078] Referring to steps 835 and 840 in FIG. 8, in response to the received MAC CE indicating an ongoing status of inter-donor transition or a start status of inter-donor transition, the receiving device (IAB-node 882 or UE 884) may stop data transmission for all radio bearers.

[0079] Referring to steps 835 and 840 in FIG. 8, in response to the received MAC CE indicating a failed status of the inter-donor transition, the receiving device (IAB-node 882, or UE 884) may assume that a radio link failure has occurred on the link over which the MAC CE is received.

[0080] With reference to FIG. 9A, the present disclosure describes various embodiments of a method 900 of using a backhaul adaptation protocol (BAP) control protocol data unit (PDU) to inform at least one downstream device of a transition integrated access backhaul node (IAB-node) of information related to transition inter-donor transition in which the transition IAB-node transitions from a source IAB-donor to a target IAB-donor. The method may solve problems / issues associated with requesting PDCP data recovery and / or PDCP re-establishment for a receiving device to trigger a sending PDCP status report. The information related to the inter-donor transition in the BAP control PDU further includes an instruction for at least one of the upstream IAB nodes of the first IAB-node to cause an inter-donor transition from a source IAB-donor to a target IAB-donor, or a successful status of the inter-donor transition, or an ongoing status of the inter-donor transition, or a start status of the inter-donor transition, or a failure status of the inter-donor transition, or an instruction to trigger the receiving device to perform a procedure of Packet Data Convergence Protocol (PDCP) status reporting.

[0081] Method 900 may include some or all of the following steps: step 910: transmitting a BAP control PDU by the IAB-node DU to at least one downstream IAB-node of the IAB-node; step 920: when the receiving IAB-node receives a BAP control indicating information related to the transition between PDU transition donors, the receiving IAB-node transmits a BAP control PDU to its child IAB-node, and / or. Step 930: When the receiving IAB-node receives a BAP control PDU indicating successful inter-donor transition or a trigger for the receiving device to perform a PDCP status reporting procedure, the receiving IAB-node sends a PDCP status report to the target IAB-donor and / or resumes data transmission for the radio bearers; Step 940: When the receiving IAB-node receives a BAP control PDU indicating an ongoing status of inter-donor transition or a start status of inter-donor transition, the receiving IAB-node may stop data transmission for all radio bearers; Step 950: When the receiving IAB-node receives a BAP control PDU indicating a failed status of inter-donor transition, the receiving IAB-node may assume that a radio link failure has occurred on the link on which the BAP control PDU is received.

[0082] 9B, the BAP control PDU may include a dedicated information element (IE) in any one of three configuration formats 950, 952, and 954. In one implementation, the IE may be called OnlyPDCPStatusReportInitialization.

[0083] In one implementation, the IE may indicate the status of the transfer between donors. In one implementation, the IE may include a value of either TRUE or FALSE. In another implementation, the IE may only include a value of TRUE.

[0084] In one implementation, a TRUE value of the IE in the BAP control PDU may indicate successful transition between donors, while in another implementation, a TRUE value of the IE may indicate triggering at least one downstream device to transmit a PDCP status report corresponding to a Radio Link Control-acknowledged mode (RLC-AM) bearer that is configured to be enabled to transmit PDCP status reports in the uplink.

[0085] In one implementation, a FALSE value of the IE in the BAP control PDU may indicate a failure of the inter-donor transition, while in another implementation, a FALSE value of the IE may indicate that a radio link failure has occurred on the link over which the BAP control PDU is received.

[0086] 9C and 9D, in some embodiments, the BAP control PDU may include assigning a dedicated value to one already existing information element. The dedicated value may include a reserved value that does not have a conflict with other values.

[0087] In one implementation, referring to FIG. 9C, PDU type 961 may be used and a new dedicated value may be assigned to the PDU type. In one implementation, the dedicated value for the PDU type in the BAP control PDU may indicate a trigger for downstream nodes to perform PDCP status reporting or a status of transition between donors selected from any subset of the set including success status, failure status, ongoing status, and starting status. In another implementation, the dedicated value for the PDU type in the BAP control PDU may indicate a trigger for at least one downstream device to transmit a PDCP status report corresponding to a radio link control acknowledged mode (RLC-AM) bearer that is configured to be enabled to transmit PDCP status reports in the uplink.

[0088] In another implementation, referring to Figure 9D, a radio link failure (RLF) indication type 971 may be used and a new dedicated value may be assigned to the RLF indication type. For example, in Figures 9D and 9E, the RLF indication type may have 2 binary bits, the binary value of the RLF indication type may include a reserved range 984 of 00 to 11, inclusive, and by way of example and not limitation, a dedicated value 985 indicating the status of the transition between donors or a trigger for downstream nodes to implement may include a binary value of 11.

[0089] 10 illustrates a logical flow of a method 1000 of using a BAP control PDU to update data transmission for at least one downstream device of a transition IAB-node during a donor-to-donor transition from a source IAB-donor to a target IAB-donor. In another implementation, FIG. 10 illustrates a logical flow of a method 1000 of using a BAP control PDU to inform at least one downstream device of a transition IAB-node that the transition IAB-node is effecting a donor-to-donor transition from a source IAB-donor to a target IAB-donor.

[0090] Referring to step 1010 in FIG. 10, during transition between donors, the IAB-node DU 1081 may send a BAP control PDU to the child IAB-node MT 1082 if the following conditions are met:

[0091] In one implementation, the IAB-node may include a transition IAB-node, and the condition may include whether the transition IAB-node succeeds in establishing a connection with an upstream device. The upstream device may include one of the target IAB-donor and target parent IAB-node of the transition IAB-node.

[0092] In another implementation, the IAB-node may include a target parent IAB-node of the transition IAB-node, and the condition may include whether the transition IAB-node successfully establishes a connection with the target parent IAB-node of the transition IAB-node.

[0093] In another implementation, the IAB node may include a child IAB-node, and the condition may include whether the child IAB-node receives a BAP control PDU from a parent IAB-node of the child IAB-node.

[0094] In another implementation, optionally and alternatively, the IAB-node 1081 in FIG. 10 may include a transition IAB-node, and the preset conditions may include the transition IAB-node receiving a radio resource control (RRC) message sent from the target IAB-donor CU, and the received RRC message comprising an information element (IE) indicating information related to transition between transition donors.

[0095] Referring to step 1020 in FIG. 10, in response to the received BAP control PDU, the child IAB-node 1082 may transmit a BAP control PDU to one or more downstream IAB-nodes of the child IAB-node 1082.

[0096] Optionally, and additionally or alternatively, referring to step 1030 in Figure 10, in response to the received BAP control PDU, the child IAB-node 1082 may transmit a MAC CE to one or more downstream IAB-nodes and / or UEs of the child IAB-node 1082. The MAC CE may be of any embodiment, as discussed above.

[0097] Optionally, and additionally or alternatively, referring to step 1040 in Figure 10, in response to the received BAP control PDU indicating a successful status of the inter-donor transition or a trigger for downstream nodes to perform a PDCP status report, the IAB-node 1082 may send a PDCP status report to the target IAB-donor 1080. The PDCP status report may correspond to a radio link control acknowledged mode (RLC-AM) bearer that is configured to be enabled to send PDCP status reports in the uplink.

[0098] Optionally, and additionally or alternatively, referring to step 1050 in FIG. 10, in response to the received BAP control PDU indication, the child IAB-node 1082 may resume data transmission for the radio bearer.

[0099] Optionally, and in addition or alternatively, referring to step 1060 in FIG. 10, in response to the received BAP control PDU indicating an ongoing status of inter-donor transition or a start status of inter-donor transition, the child IAB-node 1082 may stop data transmission for all radio bearers.

[0100] Optionally, and additionally or alternatively, referring to step 1070 in FIG. 10, in response to a received BAP control PDU indicating a failed status of the inter-donor transition, the child IAB-node 1082 may assume that a radio link failure has occurred on the link over which the BAP control PDU was received.

[0101] The present disclosure describes a method, an apparatus, and a computer-readable medium for wireless communication. The present disclosure addressed issues with updating data transmission of one or more downstream integrated access backhaul (IAB) nodes during transition between donors. The method, the device, and the computer-readable medium described in the present disclosure may facilitate performance of wireless communication by using an RRC message, or using a MAC CE, or using a BAP control PDU to inform at least one downstream device of the transition IAB-node during transition between donors, thus improving transition efficiency and overall wireless network performance. The method, the device, and the computer-readable medium described in the present disclosure may improve the overall efficiency of the wireless communication system.

[0102] References to features, advantages, or similar language throughout this specification do not imply that all of the features and advantages that may be realized using the solution should or are included in any single implementation thereof. Rather, language referring to features and advantages is to be understood to mean that the specific features, advantages, or characteristics described in connection with an embodiment are included in at least one embodiment of the solution. Thus, discussions of features and advantages and similar language throughout this specification may, but do not necessarily, refer to the same embodiment.

[0103] Furthermore, the described features, advantages, and characteristics of the solution may be combined in any suitable manner in one or more embodiments. Those skilled in the art will recognize in light of the description herein that the solution may be practiced without one or more of the specific features or advantages of a particular embodiment. In other cases, additional features and advantages may be recognized in an embodiment that may not be present in all embodiments of the solution.

Claims

1. 1. A method for wireless communication, comprising: The method includes receiving, by a receiving device, a radio resource control (RRC) message transmitted from a transmitting device; The RRC message comprises first information indicating IAB-donor transition related information, the transmitting device comprises one of a subset, the subset comprising at least one of a target Node B (gNB), a target gNB central unit (gNB-CU), a source gNB, and a source gNB-CU; the first information further indicates one of a subset, the subset comprising at least one of a successful status of inter-donor transition, an ongoing status of the inter-donor transition, a failed status of the inter-donor transition, a start status of the inter-donor transition, and information indicating triggering the receiving device to perform a Packet Data Convergence Protocol (PDCP) status reporting procedure.

2. In response to the first information indicating a successful status of the inter-donor transition, the receiving device triggers sending one or more Packet Data Convergence Protocol (PDCP) status reports to the target IAB-donor; 2. The method of claim 1, wherein a PDCP status report corresponds to a Radio Link Control-acknowledged mode (RLC-AM) bearer that is configured to be required to transmit the PDCP status report in an uplink.

3. In response to the first information indicating triggering the receiving device to perform the Packet Data Convergence Protocol (PDCP) status reporting procedure, the receiving device triggers sending one or more Packet Data Convergence Protocol (PDCP) status reports to a target IAB-donor; 2. The method of claim 1, wherein a PDCP status report corresponds to a Radio Link Control-acknowledged mode (RLC-AM) bearer that is configured to be required to transmit the PDCP status report in an uplink.

4. 2. The method of claim 1, wherein in response to the first information indicating the ongoing status of the inter-donor transition or the starting status of the inter-donor transition, the receiving device stops data transmission for all radio bearers.

5. The method of claim 1 , wherein in response to the first information indicating the failed status of the inter-donor transition, the receiving device stops or cancels a behavior associated with the inter-donor transition.

6. The method of claim 1 , wherein the receiving device comprises at least one user equipment (UE) connecting to a transition IAB-node.

7. The method of claim 1 , wherein the receiving device comprises at least one user equipment (UE) connecting to a downstream IAB-node of a transition IAB-node.

8. The method of claim 1 , wherein the receiving device comprises at least one downstream IAB-node of a transition IAB-node.

9. An apparatus, comprising: A memory storing instructions; a processor in communication with the memory; Equipped with When the processor executes the instructions, the processor is configured to cause the apparatus to receive a radio resource control (RRC) message transmitted from a transmitting device; The RRC message comprises first information indicating IAB-donor transition related information, the transmitting device comprises one of a subset, the subset comprising at least one of a target Node B (gNB), a target gNB central unit (gNB-CU), a source gNB, and a source gNB-CU; the first information further indicates one of a subset, the subset comprising at least one of a successful status of inter-donor migration, an ongoing status of the inter-donor migration, a failed status of the inter-donor migration, a start status of the inter-donor migration, and information indicating triggering the device to perform a Packet Data Convergence Protocol (PDCP) status reporting procedure.

10. In response to the first information indicating a successful status of the inter-donor transition, the device triggers sending one or more Packet Data Convergence Protocol (PDCP) status reports to the target IAB-donor; 10. The apparatus of claim 9, wherein the PDCP status report corresponds to a Radio Link Control-acknowledged mode (RLC-AM) bearer configured to be required to transmit the PDCP status report in an uplink.

11. in response to the first information indicating triggering the device to perform the Packet Data Convergence Protocol (PDCP) status reporting procedure, the device triggers sending one or more Packet Data Convergence Protocol (PDCP) status reports to a target IAB-donor; 10. The apparatus of claim 9, wherein the PDCP status report corresponds to a Radio Link Control-acknowledged mode (RLC-AM) bearer configured to be required to transmit the PDCP status report in an uplink.

12. 10. The apparatus of claim 9, in response to the first information indicating the ongoing status of the inter-donor transition or the starting status of the inter-donor transition, the apparatus stops data transmission for all radio bearers.

13. The apparatus of claim 9 , wherein in response to the first information indicating the failed status of the inter-donor transition, the apparatus stops or cancels behavior associated with the inter-donor transition.

14. The apparatus of claim 9, wherein the apparatus comprises at least one user equipment (UE) connecting to a transition IAB-node.

15. The apparatus of claim 9, comprising at least one user equipment (UE) connecting to a downstream IAB-node of a transition IAB-node.

16. The apparatus of claim 9 , wherein the apparatus comprises at least one downstream IAB-node of a transition IAB-node.

17. A computer-readable storage medium storing a program, the program being configured, when executed by a processor in an apparatus, to cause the processor to receive a radio resource control (RRC) message transmitted from a transmission device; The RRC message comprises first information indicating IAB-donor transition related information, the transmitting device comprises one of a subset, the subset comprising at least one of a target Node B (gNB), a target gNB central unit (gNB-CU), a source gNB, and a source gNB-CU; The computer-readable storage medium, wherein the first information further indicates one of a subset, the subset comprising at least one of a successful status of inter-donor migration, an ongoing status of the inter-donor migration, a failed status of the inter-donor migration, a start status of the inter-donor migration, and information indicating triggering the device to perform a Packet Data Convergence Protocol (PDCP) status reporting procedure.

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