Delayed delivery of reconfiguration information in Integrated Access and Backhaul (IAB) networks

Abstract

One method of wireless communication by an Integrated Access and Backhaul (IAB) donor involves sending a configuration message to a first IAB node via a first distributed unit of the IAB donor on a source path. The method also instructs the first IAB node to delay delivering the configuration message to a second node. The method then migrates at least a portion of the communication to the first IAB node from the source path to the destination path via a second distributed unit. Another method of wireless communication is performed by a first Integrated Access and Backhaul (IAB) node. This method receives a first configuration message on a source path to the first IAB donor via a first distributed unit of the first IAB donor. The method also delays delivering the first configuration message to a second node until a trigger occurs.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Patent Application No. 17 / 317,814, filed May 11, 2021, entitled “DELAYED DELIVERY OF RECONFIGURATION MESSAGE IN INTEGRATED ACCESS AND BACKHAUL (IAB) NETWORK,” which claims the benefit of U.S. Provisional Patent Application No. 63 / 023,714, filed May 12, 2020, entitled “DELAYED DELIVERY OF RECONFIGURATION MESSAGE IN INTEGRATED ACCESS AND BACKHAUL (IAB) NETWORK,” which is hereby expressly incorporated in its entirety by reference. Technical Field

[0003] In general, aspects of this disclosure relate to wireless communications, and more specifically, aspects of this disclosure relate to techniques and apparatus for delayed delivery of reconfiguration information in integrated access and backhaul (IAB) networks. Background Art

[0004] Wireless communication systems are widely deployed to provide a variety of telecommunications services such as telephone, video, data, messaging, and broadcasting. Typical wireless communication systems employ multiple access technologies that enable communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple access technologies include Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single Carrier Frequency Division Multiple Access (SC-FDMA) systems, Time Division Synchronous Code Division Multiple Access (TD-SCDMA) systems, and Long Term Evolution (LTE). LTE / Improved LTE is an enhanced set of the Universal Mobile Telecommunications System (UMTS) mobile standard released by the 3rd Generation Partnership Project (3GPP).

[0005] A wireless communication network may include multiple base stations (BSs) capable of supporting communication for multiple user equipments (UEs). UEs can communicate with base stations (BSs) via downlinks and uplinks. A downlink (or forward link) refers to the communication link from the BS to the UE, while an uplink (or reverse link) refers to the communication link from the UE to the BS. As will be described in more detail, a BS may be referred to as a Node B, gNB, Access Point (AP), Radio Headend, Transmit / Receive Point (TRP), New Radio (NR) BS, 5G Node B, etc.

[0006] The above multiple access technologies have been adopted in various telecommunications standards to provide a common protocol that enables different user equipment to communicate at the city, country, region, and even global levels. New Radio (NR) (which may also be referred to as 5G) is an enhancement set of the LTE mobile standard released by the 3rd Generation Partnership Project (3GPP). NR is designed to better integrate with other open standards by improving spectrum efficiency, reducing costs, improving service, utilizing new spectrum, and using Orthogonal Frequency Division Multiplexing (OFDM) with Cyclic Prefix (CP) (CP-OFDM) on the downlink (DL) and CP-OFDM and / or SC-FDM (e.g., also known as Discrete Fourier Transform Spread Spectrum OFDM (DFT-s-OFDM)) on the uplink (UL), thereby better supporting mobile broadband internet access, and supporting beamforming, multiple-input multiple-output (MIMO) antenna technologies and carrier aggregation. Summary of the Invention

[0007] This disclosure is set forth in the independent claims. Some aspects of this disclosure are described in the dependent claims.

[0008] According to one aspect of this disclosure, a method for wireless communication by an Integrated Access and Backhaul (IAB) donor transmits a configuration message on a source path having a first IAB node via a first distributed unit of the IAB donor. The method further instructs the first IAB node to delay delivering the configuration message to a second node. The method then migrates at least a portion of the communication to the first IAB node from the source path to a destination path via a second distributed unit.

[0009] In another aspect, a wireless communication method is performed by a first Integrated Access and Backhaul (IAB) network node. The method receives a first configuration message on a source path having the first IAB donor via a first distributed unit of the first IAB donor. The method also delays the delivery of the first configuration message to a second node until a trigger occurs, at which point the message is delivered.

[0010] In another aspect of this disclosure, an apparatus for wireless communication by an Integrated Access and Backhaul (IAB) donor includes a processor and a memory coupled to the processor. Instructions stored in the memory, when executed by the processor, are operable to cause the apparatus to transmit a configuration message on a source path having a first IAB node via a first distributed unit of the IAB donor. The apparatus may also instruct the first IAB node to delay delivery of the configuration message to a second node. The apparatus may also migrate at least a portion of communication to the first IAB node from the source path to a destination path via a second distributed unit.

[0011] In another aspect of this disclosure, an apparatus for wireless communication by a first Integrated Access and Backhaul (IAB) network node includes a processor and a memory coupled to the processor. Instructions stored in the memory, when executed by the processor, are operable to cause the apparatus to receive a first configuration message on a source path having the first IAB donor via a first distributed unit of the first IAB donor. The apparatus may also delay delivery of the first configuration message to a second node. The apparatus may also deliver the first configuration message to the second node in response to a trigger.

[0012] In another aspect of this disclosure, an Integrated Access and Backhaul (IAB) donor for wireless communication includes: a unit for transmitting configuration messages on a source path having a first IAB node via a first distributed unit of the IAB donor. The IAB donor further includes: a unit for instructing the first IAB node to delay delivering the configuration messages to a second node. The IAB donor also includes: a unit for migrating at least a portion of communication to the first IAB node from the source path to a destination path via a second distributed unit.

[0013] In another aspect of this disclosure, a first Integrated Access and Backhaul (IAB) network node for wireless communication includes: a unit for receiving a first configuration message on a source path having the first IAB donor via a first distributed unit of a first IAB donor. The IAB node further includes: a unit for delaying the delivery of the first configuration message to a second node until a trigger occurs, at which time the message is delivered.

[0014] In another aspect of this disclosure, a non-transitory computer-readable medium having program code recorded thereon is disclosed. The program code is executed by an Integrated Access and Backhaul (IAB) donor and includes program code for performing the following operations: transmitting a configuration message on a source path having a first IAB node via a first distributed unit of the IAB donor. The IAB donor also includes program code for performing the following operations: instructing the first IAB node to delay delivering the configuration message to a second node. The IAB donor also includes program code for performing the following operations: migrating at least a portion of communication to the first IAB node from the source path to a destination path via a second distributed unit.

[0015] In another aspect of this disclosure, a non-transitory computer-readable medium having program code recorded thereon is disclosed. The program code is executed by a first Integrated Access and Backhaul (IAB) network node and includes program code for receiving a first configuration message on a source path having the first IAB donor via a first distributed unit of the first IAB donor. The IAB node also includes program code for delaying the delivery of the first configuration message to a second node until a trigger occurs at which time the message is delivered.

[0016] In general, the aspects include methods, apparatus, systems, computer program products, non-transitory computer-readable media, user equipment, base stations, wireless communication equipment, and processing systems as fully described with reference to the accompanying drawings and description and as shown by reference to the accompanying drawings and description.

[0017] The foregoing has provided a fairly broad overview of the features and technical advantages of examples according to this disclosure in order to better understand the following detailed description. Additional features and advantages will be described below. The disclosed concepts and specific examples can be readily used as the basis for modifying or designing other structures for achieving the same purpose as this disclosure. Such equivalent constructions do not depart from the scope of the appended claims. The characteristics of the disclosed concepts (both their organization and manner of operation) and their associated advantages will be better understood when considered in conjunction with the accompanying drawings, based on the following description. Each drawing in the accompanying drawings is provided for illustrative and descriptive purposes and is not intended to define a limitation of the claims. Attached Figure Description

[0018] To gain a full understanding of the features of this disclosure, a particular description can be obtained by referring to various aspects, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only certain aspects of this disclosure and are therefore not intended to limit its scope, as other equally valid aspects may be permitted by this description. The same reference numerals in different drawings may identify the same or similar elements.

[0019] Figure 1 This is a block diagram that conceptually illustrates an example of a wireless communication network according to various aspects of this disclosure.

[0020] Figure 2 This is a block diagram conceptually illustrating an example of a base station communicating with a user equipment (UE) in a wireless communication network according to various aspects of this disclosure.

[0021] Figure 3 This is a block diagram illustrating an integrated access and backhaul (IAB) network according to various aspects of this disclosure.

[0022] Figure 4 This illustrates various aspects based on this disclosure. Figure 3 A block diagram showing a more detailed view of the Integrated Access and Backhaul (IAB) network.

[0023] Figure 5 This is a timing diagram illustrating the handover between user equipment (UE) base stations according to various aspects of this disclosure.

[0024] Figure 6 This is a block diagram illustrating delay specifications for the Radio Resource Control (RRC) process according to various aspects of this disclosure.

[0025] Figure 7 This is a block diagram illustrating migration within a switched central unit (CU) according to various aspects of this disclosure.

[0026] Figure 8 This is a timing diagram illustrating the migration within the central unit (CU) via switching, according to various aspects of this disclosure.

[0027] Figure 9 This is a block diagram illustrating migration within a central unit (CU) via a switch with delayed delivery, according to various aspects of this disclosure.

[0028] Figure 10 This is a timing diagram illustrating the migration within a central unit (CU) via a switch with delayed delivery, according to various aspects of this disclosure.

[0029] Figure 11This is a flowchart illustrating an example process performed, for example, by an Integrated Access and Backhaul (IAB) donor, according to various aspects of this disclosure.

[0030] Figure 12 This is a flowchart illustrating example procedures performed, for example, by an Integrated Access and Backhaul (IAB) node, according to various aspects of this disclosure. Detailed Implementation

[0031] The various aspects of this disclosure are described more fully below with reference to the accompanying drawings. However, this disclosure may be embodied in many different forms and should not be construed as limited to any particular structure or function presented throughout this disclosure. Rather, these aspects are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art. Based on the teachings, those skilled in the art will understand that the scope of this disclosure is intended to cover any aspect of this disclosure, whether implemented independently of or in combination with any other aspect of this disclosure. For example, an apparatus or a method may be implemented using any number of the aspects set forth herein. Furthermore, the scope of this disclosure is intended to cover such apparatuses or methods implemented using structures, functions, or structures and functions other than or different from the aspects of this disclosure set forth herein. It should be understood that any aspect of this disclosed disclosure may be embodied by one or more elements of the claims.

[0032] Several aspects of a telecommunications system will now be described with reference to various devices and techniques. These devices and techniques will be described in detail below and illustrated in the accompanying drawings, through various frames, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as “elements”). These elements can be implemented using hardware, software, or a combination thereof. Whether such an element is implemented as hardware or software depends on the specific application and the design constraints imposed on the entire system.

[0033] It should be noted that while terms commonly associated with 5G and later wireless technologies may be used to describe the aspects, the aspects of this disclosure can be applied to communication systems based on other generations (such as and including 3G and / or 4G technologies).

[0034] 5G New Radio (NR) deployments can utilize high frequencies, such as millimeter waves. While high frequencies are promising compared to low frequencies due to their greater bandwidth, they also have shorter ranges. Therefore, a denser base station deployment is mandated for high frequencies. Fiber backhaul links between base stations are expensive, and a denser deployment significantly increases costs. Therefore, utilizing radio links to replace backhaul links is an attractive solution to address the economics of denser base station deployments. Integrated Access and Backhaul (IAB) networks offer one solution, incorporating radio resources as a portion of the backhaul network.

[0035] In topology adaptation, migrating an IAB node to a different Donor Distributed Unit (DU) triggers a secure handshake among descendant nodes. Migration can be for various reasons, such as addressing signal quality degradation (e.g., radio link failure), responding to the movement of a migrating IAB node to a new area, or for load balancing purposes. In conventional approaches, the secure handshake occurs sequentially, which slows down the topology adaptation process and leads to dropped packets and reduced performance.

[0036] According to various aspects of this disclosure, the Centralized Unit (CU) instructs the IAB Node (DU) to delay the delivery of Radio Resource Control (RRC) reconfiguration messages. This delay allows configuration messages to be sent to the IAB Node on the source path rather than the destination path. This delay also allows for concurrent secure handshakes on the destination path.

[0037] Figure 1 This diagram illustrates a network 100 in which various aspects of this disclosure may be implemented. Network 100 may be a 5G or NR network or some other wireless network (such as an LTE network). Wireless network 100 may include multiple BS 110s (shown as BS 110a, BS 110b, BS 110c, and BS 110d) and other network entities. A BS is an entity that communicates with user equipment (UE) and may also be referred to as a base station, NR BS, Node B, gNB, 5G Node B (NB), access point, Transmit / Receive Point (TRP), etc. Each BS can provide communication coverage for a specific geographic area. In 3GPP, the term "cell" may refer to the coverage area of ​​a BS and / or the BS subsystem serving that coverage area, depending on the context in which the term is used.

[0038] A BS can provide communication coverage for macrocells, picocells, femtocells, and / or another type of cell. A macrocell can cover a relatively large geographic area (e.g., a radius of several kilometers) and can allow unrestricted access by UEs with service subscriptions. A picocell can cover a relatively small geographic area and can allow unrestricted access by UEs with service subscriptions. A femtocell can cover a relatively small geographic area (e.g., a residential area) and can allow restricted access by UEs associated with that femtocell (e.g., UEs in a Closed User Group (CSG)). A BS used for macrocells can be referred to as a macro BS. A BS used for picocells can be referred to as a pico BS. A BS used for femtocells can be referred to as a femtocell BS or a home BS. Figure 1 In the example shown, BS 110a can be a macro BS for macro cell 102a, BS 110b can be a pico BS for pico cell 102b, and BS 110c can be a femto BS for femto cell 102c. A BS can support one or more (e.g., three) cells. The terms “eNB,” “base station,” “NR BS,” “gNB,” “TRP,” “AP,” “Node B,” “5G NB,” and “cell” are used interchangeably.

[0039] In some respects, the cell may not be stationary, and the geographical area of ​​the cell may move depending on the location of the mobile BS. In some respects, BSs may interconnect with each other and / or with one or more other BSs or network nodes (not shown) in access network 100 via various types of backhaul interfaces (e.g., direct physical connection, virtual network, and / or similar interfaces using any suitable transport network).

[0040] The wireless network 100 may also include a relay station. A relay station is an entity that can receive data transmissions from an upstream station (e.g., a BS or a UE) and transmit the data transmissions to a downstream station (e.g., a UE or a BS). A relay station can also be a UE capable of relaying transmissions for other UEs. Figure 1 In the example shown, relay station 110d can communicate with macro BS 110a and UE 120d to facilitate communication between BS 110a and UE 120d. A relay station can also be referred to as a relay BS, relay base station, repeater, etc.

[0041] Wireless network 100 can be a heterogeneous network comprising different types of Base Stations (BSs) (e.g., macro BSs, pico BSs, femto BSs, relay BSs, etc.). These different types of BSs can have different transmit power levels, different coverage areas, and different effects on interference in wireless network 100. For example, macro BSs can have high transmit power levels (e.g., 5 to 40 watts), while pico BSs, femto BSs, and relay BSs can have lower transmit power levels (e.g., 0.1 to 2 watts).

[0042] Network controller 130 can be coupled to a group of base stations (BSs) and can provide coordination and control for these BSs. Network controller 130 can communicate with the BSs via backhaul. BSs can also communicate with each other directly or indirectly, for example, via wireless or wired backhaul.

[0043] UE 120 (e.g., 120a, 120b, 120c) may be distributed throughout the wireless network 100, and each UE may be stationary or mobile. UE may also be referred to as an access terminal, terminal, mobile station, user unit, station, etc. UE may be a cellular phone (e.g., a smartphone), personal digital assistant (PDA), wireless modem, wireless communication device, handheld device, laptop computer, cordless phone, wireless local loop (WLL) station, tablet device, camera, gaming device, netbook, smartbook, ultrabook, medical device or apparatus, biometric sensor / device, wearable device (smartwatch, smart clothing, smart glasses, smart wristband, smart jewelry (e.g., smart ring, smart bracelet, etc.)), entertainment device (e.g., music or video device, or satellite radio unit, etc.), vehicle component or sensor, smart meter / sensor, industrial manufacturing equipment, GPS device, or any other suitable device configured to communicate via wireless or wired media.

[0044] Some UEs can be considered Machine-Type Communication (MTC) or Evolved or Enhanced Machine-Type Communication (eMTC) UEs. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc., which can communicate with a base station, another device (e.g., a remote device), or some other entity. Wireless nodes can provide connectivity to or to a network (e.g., a wide area network such as the Internet or cellular networks) via wired or wireless communication links, for example. Some UEs can be considered Internet of Things (IoT) devices, and / or can be implemented as NB-IoT (Narrowband Internet of Things) devices. Some UEs can be considered Customer Premises Equipment (CPE). UE 120 can be included within a housing that houses the components of UE 120, such as processor components, memory components, etc.

[0045] Typically, any number of wireless networks can be deployed in a given geographical area. Each wireless network can support a specific RAT and can operate on one or more frequencies. A RAT can also be referred to as a radio technology, air interface, etc. A frequency can also be referred to as a carrier, channel, etc. Each frequency can support a single RAT in a given geographical area to avoid interference between wireless networks using different RATs. In some cases, NR or 5G RAT networks can be deployed.

[0046] In some aspects, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly using one or more sidelink channels (e.g., without using base station 110 as an intermediary for communication with each other). For example, UE 120 may communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) protocols (e.g., which may include vehicle-to-vehicle (V2V) protocols, vehicle-to-infrastructure (V2I) protocols, mesh networks, etc.). In this case, UE 120 may perform scheduling operations, resource selection operations, and / or other operations described elsewhere as being performed by base station 110. For example, base station 110 may configure UE 120 via downlink control information (DCI), radio resource control (RRC) signaling, media access control-control element (MAC-CE), or via system information (e.g., system information block (SIB)).

[0047] As pointed out above, Figure 1 This is provided as an example. Other examples may differ from the one provided. Figure 1 The example described.

[0048] Figure 2 Base station 110 and UE 120 are shown (they can be...) Figure 1 The block diagram of design 200 (a base station 110 and a UE 120) is shown. Base station 110 may be equipped with T antennas 234a to 234t, and UE 120 may be equipped with R antennas 252a to 252r, wherein generally, T≥1 and R≥1.

[0049] At base station 110, transmitting processor 220 can receive data for one or more UEs from data source 212, select one or more modulation and coding schemes (MCS) for each UE based at least in part on the Channel Quality Indicator (CQI) received from each UE, process (e.g., code and modulate) the data for each UE based at least in part on the MCS selected for each UE, and provide data symbols for all UEs. Reducing the MCS decreases throughput but improves transmission reliability. Transmitting processor 220 can also process system information (e.g., semi-static resource allocation information (SRPI) and other information) and control information (e.g., CQI requests, grants, upper-layer signaling, etc.), and provide overhead symbols and control symbols. Transmitting processor 220 can also generate reference symbols for reference signals (e.g., cell-specific reference signals (CRS)) and synchronization signals (e.g., primary synchronization signal (PSS) and secondary synchronization signal (SSS)). The transmit (TX) multiple-input multiple-output (MIMO) processor 230 can perform spatial processing (e.g., precoding, if applicable) on data symbols, control symbols, overhead symbols, and / or reference symbols, and can provide T output symbol streams to T modulators (MODs) 232a to 232t. Each modulator 232 can (e.g., for OFDM, etc.) process its corresponding output symbol stream to obtain an output sample stream. Each modulator 232 can further process (e.g., convert to analog, amplify, filter, and up-convert) the output sample stream to obtain a downlink signal. The T downlink signals from modulators 232a to 232t can be transmitted via T antennas 234a to 234t respectively. According to the aspects described in more detail below, position coding can be used to generate synchronization signals to transmit additional information.

[0050] At UE 120, antennas 252a to 252r can receive downlink signals from base station 110 and / or other base stations, and can provide the received signals to demodulators (DEMODs) 254a to 254r respectively. Each demodulator 254 can adjust (e.g., filter, amplify, downconvert, and digitize) the received signal to obtain an input sample. Each demodulator 254 can further process the input sample (e.g., for OFDM, etc.) to obtain a received symbol. MIMO detector 256 can obtain the received symbols from all R demodulators 254a to 254r, perform MIMO detection on the received symbols (if applicable), and provide the detected symbols. Receiver processor 258 can process (e.g., demodulate and decode) the detected symbols, provide decoded data for UE 120 to data sink 260, and provide decoded control information and system information to controller / processor 280. The channel processor can determine the Received Reference Signal Power (RSRP), Received Signal Strength Indicator (RSSI), Received Reference Signal Quality (RSRQ), Channel Quality Indicator (CQI), etc. In some aspects, one or more components of the UE 120 may be included in the housing.

[0051] On the uplink, at UE 120, the transmitting processor 264 can receive and process data from data source 262 and control information from controller / processor 280 (e.g., for reports including RSRP, RSSI, RSRQ, CQI, etc.). The transmitting processor 264 can also generate reference symbols for one or more reference signals. Symbols from the transmitting processor 264 can be pre-encoded (if applicable) by the TX MIMO processor 266, further processed by modulators 254a to 254r (e.g., for DFT-s-OFDM, CP-OFDM, etc.), and transmitted to base station 110. At base station 110, uplink signals from UE 120 and other UEs can be received by antenna 234, processed by demodulator 254, detected by MIMO detector 236 (if applicable), and further processed by receiving processor 238 to obtain decoded data and control information transmitted by UE 120. The receiver processor 238 can provide decoded data to the data sink 239 and decoded control information to the controller / processor 240. The scheduler 246 can schedule the UE to transmit data on the downlink and / or uplink. The base station 110 can include a communication unit 244 and communicate with the network controller 130 via the communication unit 244. The network controller 130 can include a communication unit 294, a controller / processor 290, and a memory 292.

[0052] The controller / processor 240 of base station 110, the controller / processor 280 of UE 120 and / or Figure 2 Any other components may perform one or more techniques associated with delayed message delivery, as described in more detail elsewhere herein. For example, the controller / processor 240 of base station 110, the controller / processor 280 of UE 120, and / or Figure 2 Any other component can perform or direct, for example Figure 10-12 The operation of the process and / or other processes as described. Memory 242 and 282 may store data and program code for base station 110 and UE 120, respectively.

[0053] In some aspects, network controller 130 may include units for receiving, transmitting, indicating, migrating, executing, configuring, delaying, delivering, detecting, initiating, and participating. Such units may include combinations of... Figure 2 One or more components of the network controller 130 described.

[0054] As pointed out above, Figure 2 This is provided as an example only. Other examples may differ from those provided. Figure 2 The example described.

[0055] 5G New Radio (NR) deployments can utilize high frequencies, such as millimeter waves. While high frequencies are promising compared to low frequencies due to their greater bandwidth, they also have shorter ranges. Therefore, a denser base station deployment is mandated for high frequencies. Fiber backhaul links between base stations are expensive, and a denser deployment significantly increases costs. Therefore, utilizing radio links to replace backhaul links is an attractive solution to address the economics of denser base station deployments. Integrated Access and Backhaul (IAB) networks offer one solution, incorporating radio resources as a portion of the backhaul network.

[0056] 5G NR technologies (such as millimeter wave (mm wave)) can support access networks between access nodes (ANs, e.g., base stations) and UEs, as well as backhaul networks between ANs. Figure 3This is a block diagram illustrating an Integrated Access and Backhaul (IAB) network 300 according to various aspects of this disclosure. An IAB donor (e.g., 304) is an access node with a wired connection to a core network 302. An IAB node (e.g., 308) is an access node that relays services to and from the donor via one or more hops. UEs (e.g., 306a-f) can communicate with IAB nodes or with IAB donors via access links. The IAB network shares resources between the access network and the backhaul network. In the IAB network, it is desirable to reuse the framework used for the access network as much as possible.

[0057] Figure 4 This illustrates various aspects based on this disclosure. Figure 3 Block diagram 400 shows a more detailed view of the Integrated Access and Backhaul (IAB) network. An IAB donor (e.g., 304) is an enhanced gNB node with the ability to control the IAB network. A Central Unit (CU) is the central entity that controls the entire IAB network through the configuration of the IAB donor (e.g., 304) and IAB nodes (e.g., 408a-d). The CU performs Radio Resource Control (RRC) / Packet Data Convergence Protocol (PDCP) layer functions. A Distributed Unit (DU) of either the IAB donor (e.g., 304) or the IAB node (e.g., 408a-d) is a scheduling unit that schedules the child nodes (e.g., 408a-d) of the IAB donor (e.g., 304) or the IAB node (e.g., 408a-d), respectively. The DU handles Radio Link Control (RLC) / Media Access Control (MAC) / Physical (PHY) layer functions.

[0058] An IAB node (e.g., 408a) is a Layer 2 (L2) relay node that includes mobile terminal (MT) and DU functions. An MT unit is a scheduled unit similar to a user equipment (UE) scheduled by its parent IAB node or IAB donor 304. A DU of an IAB node (e.g., 304) is a scheduling unit that schedules the child nodes of the IAB node.

[0059] Figure 5 This is a timing diagram 500 illustrating the handover between user equipment (UE) base stations according to various aspects of this disclosure. Figure 5This illustrates a simplified handover between UE base stations, from the source base station (currently serving the UE) to the target base station (as the new serving base station). At time 501, the source base station (e.g., source gNB 515) initiates the handover and sends a handover request to the target gNB 520 on the Xn interface. At time 502, the target gNB 520 performs admission control. For example, the target gNB 520 determines whether there are sufficient resources available to serve the UE 510. If so, at time 503, the target gNB 520 provides the source gNB 515 with a new RRC configuration as part of the handover request confirmation message.

[0060] At time 504, the source gNB 515 provides RRC configuration to UE 510 by forwarding the RRCReconfiguration message received in the handover request confirmation message. At time 505, UE 510 moves the RRC connection to the target gNB 520 (e.g., by performing a random access procedure with the target gNB), and at time 506, replies to the target gNB 520 using the RRCReconfigurationComplete message. At time 507, the target gNB 520 sends a UE context release message to UE 510 to notify the source gNB 515 of the successful handover. Therefore, the source gNB 515 can release the resources allocated to UE 510.

[0061] Figure 6 This is a block diagram 600 illustrating delay specifications for a Radio Resource Control (RRC) procedure according to various aspects of this disclosure. For the RRC procedure, the UE (e.g., Figure 3 As shown in 306c), the UE receives the RRC downlink (DL) command at time 601. At time 602, the UE receives the uplink grant for the transmission of the RRC uplink (UL) response that occurs at time 603. According to the 3GPP standard, for RRC reconfiguration, the time from receiving the RRC downlink (DL) command at the UE's physical layer to when the UE should be ready to receive the uplink grant for the UE's response to a network message is limited to 10 ms. This delay may also include time for Transmission Time Interval (TTI) alignment.

[0062] When the UE receives an RRC message implying a handover, the UE will prepare for D starting from the end of the last TTI containing the RRC command. handover A new uplink Physical Random Access Channel (PRACH) transmission begins within time D. handover It can be defined as:

[0063] D handover = RRC process delay + interruption time (Tinterrupt)

[0064] Tinterrupt=Tsearch+TIU+Tprocessing+TΔ+Tmargin ms,

[0065] Where Tsearch is the time specified for searching the target cell, Tprocessing is the time for UE processing, Tmargin is the time for post-processing of the Synchronization Signal Block (SSB), TΔ is the time for fine-tuning tracking and acquiring full timing information of the target cell, and TIU is the interruption uncertainty for acquiring the first available PRACH opportunity in the new cell.

[0066] Figure 7 This is a block diagram 700 illustrating migration within a switched central unit (CU) according to various aspects of this disclosure. Figure 8 This is a timing diagram 800 illustrating the migration within a central unit (CU) via switching, according to various aspects of this disclosure.

[0067] In some aspects of this disclosure, Figure 7 and 8 The example shown could refer to topology adaptation, where an IAB node 706a (more specifically, its MT functional unit) migrates from a source parent node to a target parent node (to match the reference). Figure 5 The handover process for the UE is described in a similar manner. Figure 7 In the example shown, the source parent node 704a and the target parent node 704b are Figure 8 The same IAB donor 704 distributed units D-DU 1 and D-DU 2 are shown. Communication via source D-DU 1 occurs as follows: Figure 7 The source path is shown in the diagram, while communication via the target D-DU 2 occurs on the target path. Figure 7 and 8 An example of migrating an IAB node 706a that is directly connected to a distributed unit of IAB donor 704 is shown. In some examples, the migrating IAB node can be a child IAB node of another (parent) IAB node, which is then directly or indirectly connected to distributed unit D-DU 1 of IAB donor 704. The migration of the child IAB node can then involve migrating (connecting) the MT functional unit of the child IAB node from the source parent IAB node to a target parent IAB node that is directly or indirectly connected to a different distributed unit D-DU 2 of IAB donor 704. In other words, migrating an IAB node can involve reconnecting / switching the MT functional unit of the IAB node directly or indirectly (i.e., via one or more intermediate IAB nodes) to a different DU of IAB donor 704.

[0068] Reference Figure 7 and 8 As seen at time 71, IAB donor 704 initiates reconfiguration with the synchronization process by sending an RRC reconfiguration message to the migrating IAB node 706a. The RRC reconfiguration message for the IAB node MT carries the new IP address for the migrating IAB node 706a. The IP information of the IAB node used by the IAB node's DU can be deduced from the IP prefix owned by the donor DU, making it possible to route services to / from the IAB node via that donor DU. Therefore, if the donor DU changes, such as... Figure 7 As shown, the IP information used for the IAB node will have to be changed. Similarly, if the IAB node is connected to multiple donor DUs, corresponding IP information will be assigned to each donor DU.

[0069] like Figure 7 As can be seen, IAB node 706a migrates from donor distributed unit (D-DU) 1 704a to D-DU 2 704b. Therefore, in this example, the IP address for D-DU 2 704b is provided via an RRC reconfiguration message from IAB donor CU 704c. The RRC reconfiguration may also include an uplink (UL) mapping, indicating the channel used for communication with D-DU 2 704b. At time 71, the initial communication from the IAB donor (e.g., 704a) to the migrating IAB node (e.g., 706a) occurs via the source path. After synchronization, a response (e.g., a complete RRC reconfiguration message) traverses the destination path (also shown at time 71). Note that the handover may take some time. Therefore, time 71 refers to this time period.

[0070] In response to receiving a new IP address in an RRC reconfiguration message, at time 72, a security handshake (e.g., an Internet Key Exchange (IKE) handshake) occurs between the IAB donor (e.g., via target DU 704b) and the migrating IAB node (e.g., 706a). More specifically, the IAB node (e.g., 706a) DU establishes a security association on the target path.

[0071] Example child IAB node (e.g., 706b) may also be affected by the migrated IAB node (e.g., 706a), and therefore, the new path resulting from the migrated IAB node (e.g., 706a) should be known. Therefore, at time 73, the RRC reconfiguration process with the child IAB node (e.g., 706b) occurs. More specifically, the reconfiguration process occurs with the child IAB node (e.g., 706b) MT on the target path. In conventional systems and methods, the security handshake (e.g., IKE handshake) at the parent IAB node (e.g., 706a) DU occurs before the RRC reconfiguration process with the child IAB node (e.g., 706b), as... Figure 7 and 8 As shown in the diagram. Therefore, the security handshake with the migration and child IAB nodes (e.g., 706b) occurs sequentially on the hop. Figure 8 As can be seen, the secure handshake with child IAB node 706b occurs at time 74, which follows the secure handshake with migrating IAB node 706a at time 72. Therefore, in the conventional approach, if a migration occurs (e.g., between time 72 and time 73) when child IAB node (e.g., 706b) or UE 708 attempts to communicate with IAB donor CU (e.g., 704c) via an IP address anchored at target D-DU2 (e.g., 704b), packets configured for communication via D-DU1 (e.g., 704a) are dropped for security reasons.

[0072] According to various aspects of this disclosure, delayed delivery of RRC reconfiguration messages indicates (or may be considered) the availability of the target path to the child IAB node. By delaying the delivery of reconfiguration messages to the child IAB node, the application of security protocols can be delayed. Therefore, security handshakes occur concurrently on the hop. Thus, dropped packets can be reduced. Alternatively, timers can be configured to account for delayed delivery.

[0073] Figure 9 This is a block diagram 900 illustrating migration within a central unit (CU) via a switch with delayed delivery, according to various aspects of this disclosure. Figure 10This is a timing diagram 1000 illustrating migration within a central unit (CU) via a handover with delayed delivery, according to various aspects of this disclosure. A first IAB donor (e.g., 904) (and in some aspects, first IAB donor CU 904c) sends configuration messages to a child IAB node (e.g., 906a) via a first signaling connection to a migration IAB node (e.g., first IAB node 906a) (e.g., via source D-DU 1 904a) and a second signaling connection to a child IAB node (e.g., second IAB node 906b) (e.g., second IAB node 906a) on a first path via the first IAB node (e.g., 906a). The first signaling connection may be a connection from the IAB donor CU 904c (via source D-DU 1 904a) to the MT functional unit of the migration IAB node 906a. The second signaling connection can be a connection from the IAB donor CU 904c (via source D-DU 1 904a) directly (e.g., without intermediate IAB nodes) to the MT functional unit of the child IAB node 906b. To this end, at time 91, the IAB donor (e.g., 904) sends a configuration message to the migrating IAB node (also referred to as the first IAB node) and instructs the migrating IAB node (e.g., 906a) on the first signaling connection (on the source path) to postpone delivering the configuration message to the child IAB node (e.g., 906b). The first IAB donor CU (e.g., 904c) can instruct the migrating IAB node (e.g., 906a) to postpone delivery (or, in the case of a grandchild node or a further removed node) of the configuration message based on (or in some respects, until reception) the first Backhaul Adaptation Protocol (BAP) address, BAP route ID, Backhaul (BH) RLC channel ID, or Logical Channel ID (LCID).

[0074] Migrating an IAB node (e.g., 906a) can retain configuration messages until a release message is triggered at time 93. The first signaling connection can span either the F1-C or RRC interface. The second signaling connection can also span either the F1-C or RRC interface.

[0075] At time 92, before releasing the configuration message to the child IAB node (e.g., 906b), the IAB donor (904a) begins the reconfiguration process with the migrating IAB node (e.g., 906a) for synchronization. After releasing the configuration message to the child IAB node (e.g., 906b) at time 93, at time 94, the migrating IAB node (e.g., 906a) completes the reconfiguration process with the IAB donor (e.g., 904b) by sending an RRC reconfiguration complete message to the IAB donor CU 904c via the target path (e.g., via D-DU 2 904b). Although at... Figure 10It is not shown in the diagram, but it should be noted that the sending of the RRC reconfiguration completion message can occur before time 93. For example, upon successful handover, the reconfiguration message can be forwarded to the child IAB node (e.g., 906b) or UE 908.

[0076] Due to the delay, the IAB donor (e.g., 904b) and the migrating IAB node (e.g., 906a) can perform a security handshake at time 95, which can occur concurrently with the security handshake between the IAB donor (e.g., 904b) and the child IAB node (e.g., 906b) at time 96. It is important to note that the two handshakes are not time-dependent; therefore, the security handshakes can occur concurrently. After the security handshake, at time 97, the child IAB node (e.g., 906b) sends an RRC reconfiguration complete message to the IAB donor (e.g., 904). Although... Figure 10 It is not shown in the diagram, but an RRC reconfiguration complete message can be sent between time 95 and time 96.

[0077] It is worth noting that, as referenced Figure 10 As described, the reconfiguration message was delivered to the parent (migration node) at time 91 using the F1 connection on the source path. Therefore, forwarding the reconfiguration message to the child IAB node (e.g., 906b) at time 93 does not depend on re-establishing the F1 connection on the target path (e.g., the forwarding of the reconfiguration message does not depend on the security handshake between the IAB donor (e.g., 904b) and the migration IAB node at time 95, which performs the security handshake to redirect the F1 to the target path). Furthermore, releasing the configuration message to the child IAB node (e.g., 906b) at time 93 and the security handshake at time 94 are also independent, as they correspond to the configurations of different nodes (e.g., the child IAB node (e.g., 906b) and the migration IAB node (e.g., 906a)). Therefore, according to various aspects of this disclosure, there is no limitation regarding the order in which the procedures are performed at times 93, 94, or 95.

[0078] In one example, a security handshake at time 95 can be initiated before the process of releasing the configuration message to the child IAB node (e.g., 906b) at time 93 is executed. However, there is no restriction that the security handshake between the IAB donor (e.g., 904b) and the child IAB node (e.g., 906b) at time 96 occurs after the security handshake between the IAB donor (e.g., 904b) and the migrating IAB node (e.g., 906a) at time 95. For example, migrating the IAB node (e.g., 906a) could be ten hops from the IAB donor (e.g., 904b). Therefore, if a security handshake has already begun at time 95, the two-way security handshake at time 95 may take some time to complete. Therefore, the process of releasing the configuration message to the child IAB node (e.g., 906b) at time 93 can occur and trigger a security handshake between the IAB donor (e.g., 904b) and the child IAB node (e.g., 906b) at time 96. The two security handshakes at time 95 and time 96 can continue independently until completion.

[0079] In contrast, Figure 8 In order to deliver the reconfiguration message at time 73, F1 must establish and operate towards the parent (migration node). This also means that the security handshake between the IAB donor (e.g., via target DU 704b) and the migration IAB node (e.g., 706a) at time 72 occurs before the process at time 73, because F1 is running on Internet Protocol Security (IPSec). Therefore, the reconfiguration process at the child IAB node (e.g., 706b) at time 73 depends on the security handshake between the IAB donor (704b) and the migration IAB node (706a) at time 72. Therefore, the security handshake with the child IAB node 706b at time 74 (which uses the new configuration provided at time 73) also depends on the security handshake at time 72. Therefore, the processes at times 72 and 74 are sequential and cannot be executed concurrently.

[0080] Configuration messages destined for a child IAB node (e.g., 906b) can be RRC reconfiguration messages with or without synchronization. The configuration message may carry IP information and Backhaul Adaptation Protocol (BAP) address information for the second IAB node (e.g., the child IAB node), as well as uplink mapping and routing information. In the case of inter-CU migration (not shown), the configuration message may carry a reconfiguration message for the second donor CU (not shown).

[0081] The delivery of a configuration message can trigger multiple procedures at a sub-IAB node (e.g., 906b). For example, the configuration message can trigger a random access procedure, a security handshake, migration of a second signaling connection toward the donor CU (e.g., 904c) to a second path (such as a target path via D-DU 2 904b), and migration of a data tunnel that terminates at the sub-IAB node (e.g., 906b) toward the donor CU (e.g., 904c) to a second path. Furthermore, the message can trigger the establishment of an F1-C connection, including the establishment of an SCTP (Flow Control Transport Protocol) connection and the addition of a path to an existing SCTP connection. It can also trigger the establishment of an F1-U data tunnel.

[0082] Although this description refers to a "child" IAB node, it also anticipates grandchild nodes or other nodes. Similarly, this description refers to the MT as the destination, but configuration messages can also be destined for the UE.

[0083] The release configuration message can be triggered by the donor CU (e.g., 904c) on the first signaling connection. The instruction or configuration used for triggering can be initiated by the parent of the migrating IAB node (e.g., via Media Access Control-Control Element (MAC-CE) or Downlink Control Information (DCI)).

[0084] The command or configuration used for triggering can be UE / MT specific or more general. If the trigger or the corresponding trigger information is UE / MT specific, the trigger information releases the configuration message for that specific UE / MT. Alternatively, for general trigger information, the released configuration message is associated with multiple UE / MTs (e.g., all child nodes of a migrated IAB node).

[0085] According to this disclosure, various types of triggers are anticipated. Triggers can be absolute time, elapsed time, relative time to the timing of a RACH detected by the migrating IAB node (e.g., 906a), a function configured by a RACH detected by the first IAB node, or the execution of a reconfiguration with synchronization. In other aspects, a trigger can be the reception of an RRC reconfiguration message. For example, a trigger may occur when the migrating IAB node (e.g., 906a) receives a reconfiguration message carrying new IP information, BAP address information, or a reconfiguration with synchronization. The migrating IAB node (e.g., 906a) infers that a second path to the first donor CU (e.g., 904c) (or, in the case of inter-CU migration, to the second donor CU) is now available. The same applies to the child IAB node (e.g., 906b), thus the migrating IAB node (e.g., 906a) releases the configuration message.

[0086] In other respects, triggering is based on receiving an indication from the parent of the migrating IAB node (e.g., via MAC-CE or DCI). Triggering can also be in response to detecting a change in a First System Information Block (SIB1) message broadcast by the parent of the migrating IAB node. The SIB1 message carries a cell identifier, such as the NR Cell Global Identity (NCGI). Therefore, triggering can be detecting a change in the parent's cell ID.

[0087] The conditions for measuring the PCI (Physical Cell ID) broadcast by the parent of an IAB node (e.g., a migrated IAB node) can also be triggered. For example, the parent of an IAB node (e.g., a migrated IAB node) may change its broadcast PCI after migrating to a different CU. In this case, what might trigger the handover at the IAB node (e.g., the migrated IAB node) and the release of any messages it retains is the ability to detect the new PCI. Therefore, the IAB node (e.g., the migrated IAB node) performs measurements on the old PCI and the new PCI on the signal broadcast by the parent node. The triggering condition could be that the IAB node (e.g., the migrated IAB node) measures a channel quality metric (e.g., RSRP (Reference Signal Received Power)) measured by the IAB node on the new PCI, which has exceeded a threshold, or that the difference between the measurements corresponding to the new PCI and the old PCI has exceeded a threshold.

[0088] The trigger can be a switchover or migration of the migrating IAB node (e.g., 906a) DU, the opposite of the parent DU. In this case, after the migrating IAB node (e.g., 906a) changes its NR Global Cell Identity (NGCI) carried in the SIB1 message broadcast by the migrating IAB node DU, the migrating IAB node (e.g., 906a) releases its configuration message.

[0089] In other aspects of this disclosure, the trigger can be the execution of a secure handshake for inter-CU operations. For example, an IAB node (e.g., a migrating IAB node) can release configuration messages only after obtaining a backhaul connection to the second CU. Other examples of triggers for inter-CU procedures include establishing an F1-C connection or establishing an F1-U data tunnel. For both intra-CU and inter-CU scenarios, the trigger can be an indication on the first signaling connection.

[0090] In various aspects of this disclosure, the migrating IAB node (e.g., 906a) can acknowledge the donor CU's instruction on the first signaling connection. In other aspects, the migrating IAB node (e.g., 906a) can acknowledge the release of the configuration message on the first signaling connection to the donor CU (e.g., 904c). In yet another aspect, the migrating IAB node (e.g., 906a) can instruct the child IAB node (e.g., 906b) to release a second configuration message while delivering the original configuration message.

[0091] According to various aspects of this disclosure, the donor CU (e.g., 904c) (or the parent of the migrating IAB node) can instruct the migrating IAB node (e.g., 906a) to discard configuration messages (or via Media Access Control-Control Element (MAC-CE) or Downlink Control Information (DCI)) on the first signaling connection. The instruction to discard can occur in response to a failed handover at the upstream node. For example, if the migration of the migrating IAB node (e.g., 906a) fails, the migration of the child IAB node (e.g., 906b) can be cancelled. In other words, no security handshake occurs on the target path because no target path is established.

[0092] The first or second donor CU (in the case of inter-CU procedures) may configure timer extensions at the donor CU. Timer extensions may be band-dependent, for example, FR1 (frequency range one (below 6 GHz) or FR2 (frequency range two mm wave)). In other aspects, the first or second donor CU may configure timer extensions at the child IAB node to prevent reconfiguration failure, connection rebuilding, or connection release at the child IAB node (or UE 908). In some aspects, the first or second donor CU may instruct the child IAB node (e.g., 906b) or the destination UE 908 to prevent reconfiguration failure, connection rebuilding, or connection release at the child IAB node (or UE 908). For example, the child IAB node MT is allowed to send an RRC reconfiguration complete message after performing a secure handshake. Finally, upon releasing the configuration message, the migration IAB node (e.g., 906a), the child IAB node (e.g., 906b), or any intermediate node on the first path may initiate a concurrent procedure (e.g., a secure handshake) toward the first or second donor CU.

[0093] In some aspects, the child IAB node can send an RRC reconfiguration complete message to the IAB donor (e.g., 904) at time 97 within the original (regular) timer, either before or along with the security handshake between the IAB donor (e.g., 904b) and the child IAB node (e.g., 906b) at time 96. Therefore, timer extensions at the child IAB node can be omitted. If the security handshake between the IAB donor (e.g., 904b) and the migrating IAB node (e.g., 906a) has not yet been performed at time 95, the response message can be buffered at the parent and forwarded later. However, this does not prevent the security handshake from being performed concurrently at times 95 and 96.

[0094] As pointed out above, Figure 3-10 This is provided as an example. Other examples may differ from the one provided. Figure 3-10 The example described.

[0095] Figure 11 This is a flowchart illustrating an example process 1100 performed, for example, at an Integrated Access and Backhaul (IAB) donor, according to various aspects of this disclosure. Example process 1100 is an example of delayed delivery of reconfiguration messages in an Integrated Access and Backhaul (IAB) network.

[0096] like Figure 11 As shown, in some aspects, process 1100 may include: sending a configuration message (block 1102) via a first distributed unit of the IAB donor on a source path having a first IAB node. For example, the IAB donor (e.g., using communication unit 294, controller / processor 290, and / or memory 292) may send the configuration message. Furthermore, as referenced... Figure 9 and 10 As described, at time 91, the IAB donor (e.g., 904c) sends a configuration message to the migrating IAB node (also referred to as the first IAB node).

[0097] like Figure 11 As shown, in some aspects, process 1100 may include instructing a first IAB node to delay delivering a configuration message to a second node (block 1104). For example, an IAB donor (e.g., using communication unit 294, controller / processor 290, and / or memory 292) may instruct the first IAB node to delay delivery. Additionally, as referenced... Figure 9 and 10 As described, the configuration message to the migrating IAB node (also referred to as the first IAB node) instructs the migrating IAB node (e.g., 906a) on the first signaling connection (on the source path) to postpone delivering the configuration message to the child IAB node (e.g., 906b).

[0098] like Figure 11 As shown, in some aspects, process 1100 may include migrating at least a portion of communication to the first IAB node from the source path to the destination path via a second distributed unit (block 1106). For example, an IAB donor (e.g., using communication unit 294, controller / processor 290, and / or memory 292) may migrate at least a portion of the communication. Furthermore, as referenced... Figure 9 and 10As described, after releasing a configuration message to the child IAB node (e.g., 906b) at time 93, the migrating IAB node (e.g., 906a) completes the reconfiguration process with the IAB donor (e.g., 904) by sending an RRC reconfiguration complete message to the IAB donor CU 904c via the target path at time 94. The delivery of the configuration message may trigger a random access procedure, a secure handshake, migration of the second signaling connection toward the donor CU (e.g., 904c) to the second path, and migration of the data tunnel that terminates at the child IAB node (e.g., 906b) toward the donor CU (e.g., 904c) to the second path.

[0099] Figure 12 This is a flowchart illustrating an example process 1200 performed, for example, at a first Integrated Access and Backhaul (IAB) network node, according to various aspects of this disclosure. Example process 1200 is an example of delayed delivery of reconfiguration messages in an Integrated Access and Backhaul (IAB) network.

[0100] like Figure 12 As shown, in some aspects, process 1200 may include: receiving a first configuration message (block 1202) via a first distributed unit of the first IAB donor on the source path to the first IAB donor. For example, an IAB node (e.g., using communication unit 294, controller / processor 290, and / or memory 292) may receive the first configuration message. See also... Figure 9 and 10 As described, the migrating IAB node (also referred to as the IAB node, e.g., 906a) receives the first configuration message from the first IAB donor (e.g., 904a) at time 91 via the source path (e.g., the first signaling connection).

[0101] like Figure 12 As shown, in some aspects, process 1200 may include delaying the delivery of the first configuration message to the second node (block 1204). For example, the IAB node (e.g., using communication unit 294, controller / processor 290, and / or memory 292) may delay delivery. See reference... Figure 9 and 10As described, the migrating IAB node (e.g., 906a) can retain configuration messages until they are triggered as release messages at time 93. In some aspects, the trigger for releasing the configuration message can be configured by the donor CU (e.g., 904c) on the first signaling connection. The instruction or configuration for triggering can be initiated by the parent of the migrating IAB node (e.g., via Media Access Control-Control Element (MAC-CE) or Downlink Control Information (DCI)). Furthermore, in some aspects, the trigger can be an absolute time, an elapsed time, a relative time to the RACH timing detected by the migrating IAB node (e.g., 906a), a function configured by the RACH detected by the migrating IAB node, or an execution with synchronous reconfiguration.

[0102] In some respects, the trigger can be the reception of an RRC reconfiguration message. For example, see reference... Figure 9 As described, this may be triggered when the migrating IAB node (e.g., 906a) receives a reconfiguration message carrying new IP information, BAP address information, or a synchronized reconfiguration. The migrating IAB node (e.g., 906a) infers that a second path to the first donor CU (e.g., 904c) (or, in the case of inter-CU migration, to the second donor CU) is now available. The same applies to the child IAB node (e.g., 906b), thus the migrating IAB node (e.g., 906a) releases the configuration message.

[0103] In another example, the trigger is based on receiving an indication from the parent of the migrating IAB node (e.g., via MAC-CE or DCI). The trigger can also be in response to detecting a change in a First System Information Block (SIB1) message broadcast by the parent of the migrating IAB node. The SIB1 message carries a cell identifier, such as the NR Cell Global Identity (NCGI). Therefore, the trigger could be detecting a change in the parent's cell ID.

[0104] like Figure 12 As shown, in some aspects, process 1200 may include: delivering a first configuration message to a second node in response to a trigger (block 1206). For example, an IAB node (e.g., using communication unit 294, controller / processor 290, and / or memory 292) may deliver the first configuration message. Furthermore, as referenced... Figure 9 and 10 As described, the migration IAB node 906a releases a configuration message to the child IAB node (e.g., 906b) at time 93.

[0105] Implementation examples are provided in the following numbered clauses.

[0106] 1. A method for performing IAB node migration at an Integrated Access and Backhaul (IAB) donor, comprising:

[0107] The first distributed unit of the IAB donor sends a configuration message to the first IAB node on the source path; and

[0108] The first IAB node is instructed to delay delivering the configuration message to the second node.

[0109] 2. The method according to Clause 1, wherein the configuration message includes a Radio Resource Control (RRC) message that provides an uplink (UL) mapping or Internet Protocol (IP) address for the first IAB node to communicate with the target donor.

[0110] 3. The method according to any one of Clauses 1-2 further includes: migrating at least a portion of the communication to the first IAB node from the source path to a target path for the first IAB node via a second distributed unit.

[0111] 4. The method according to any one of clauses 1-3 further includes:

[0112] Perform a first security handshake with the first IAB node; and

[0113] A second security handshake is performed with the second node, wherein the second distributed unit is part of the IAB donor.

[0114] 5. The method according to any one of Clauses 1-4, wherein the second security handshake is performed concurrently with the first security handshake.

[0115] 6. The method according to any one of clauses 1-5, wherein the configuration message originates from the first donor central unit (CU) and carries a reconfiguration message of the second donor central unit.

[0116] 7. The method according to any one of Clauses 1-6, wherein indicating the delay of delivery of the first IAB node comprises: indicating the delay of the configuration message based on the Backhaul Adaptation Protocol (BAP) address, BAP route ID, Backhaul Radio Link Control (RLC) channel ID, or logical channel ID.

[0117] 8. The method according to any one of Clauses 1-7 further includes: configuring a trigger to release the configuration message.

[0118] 9. The method according to any one of Clauses 1-8, wherein configuring the trigger includes: configuring for a specific child node.

[0119] 10. The method according to any one of Clauses 1-8, wherein configuring the trigger includes: configuring for all child nodes.

[0120] 11. The method according to any one of clauses 1-10, wherein the triggering includes an absolute time, a duration, a relative time to the timing of a random access channel (RACH) detected by the first IAB node, or a function of the RACH configuration detected by the first IAB node.

[0121] 12. The method according to any one of clauses 1-11 further includes: receiving confirmation of the instruction.

[0122] 13. The method according to any one of clauses 1-12 further includes: upon receiving the confirmation, sending the configuration message to the first IAB node or the upstream node of the source path.

[0123] 14. The method according to any one of clauses 1-13 further includes: receiving confirmation of the release of the configuration message.

[0124] 15. The method according to any one of clauses 1-14 further includes: instructing the first IAB node to discard the configuration message in response to a failure to migrate the first IAB node or an upstream IAB node of the source path.

[0125] 16. The method according to any one of Clauses 1-15 further includes: instructing the second node to prevent reconfiguration failure, connection reconstruction, or connection release.

[0126] 17. A method for performing IAB node migration at a first Integrated Access and Backhaul (IAB) network node, comprising:

[0127] The first distributed unit, via the first IAB donor, receives the first configuration message on the source path having the first IAB donor;

[0128] Delaying the delivery of the first configuration message to the second node; and

[0129] In response to a trigger, the first configuration message is delivered to the second node.

[0130] 18. The method according to Clause 17, wherein the triggering includes: receiving a reconfiguration message carrying Internet Protocol (IP) information or uplink (UL) mapping.

[0131] 19. The method according to Clause 17, wherein the triggering includes: receiving an indication from the parent of the first IAB node for releasing the first configuration message.

[0132] 20. The method according to any one of clauses 17-19, wherein the triggering includes: detecting a change in the cell ID of the parent of the first IAB node.

[0133] 21. The method according to any one of clauses 17-20, wherein the detection occurs based on a condition of a measurement of a System Information Block (SIB) message broadcast by the parent of the first IAB node or a cell ID broadcast by the parent of the first IAB node.

[0134] 22. The method according to Clause 17, wherein the triggering includes a migration of the distributed unit (DU) of the first IAB node, the migration including a change in a System Information Block (SIB) message broadcast by the DU of the first IAB node.

[0135] 23. The method according to Clause 17, wherein the triggering includes: performing a security handshake on the target path via a second distributed unit of the first IAB node.

[0136] 24. The method according to Clause 23, wherein the execution of the secure handshake includes: establishing an F1-C connection or establishing an F1-U data tunnel.

[0137] 25. The method according to Clause 17, wherein the triggering includes: performing a synchronous reconfiguration based on the first configuration message from or forwarded by the first IAB donor.

[0138] 26. The method according to any one of clauses 23-25, wherein the execution of the synchronous reconfiguration includes a switching process.

[0139] 27. The method according to any one of clauses 17-26 further includes: receiving the trigger on the source path.

[0140] 28. The method according to any one of clauses 17-27 further includes: instructing the sub-IAB node to release the second configuration message in response to delivering the first configuration message.

[0141] 29. The method according to any one of Clauses 17-28 further comprises:

[0142] Instruct the child IAB node to discard the second configuration message retained at the child node; and

[0143] In response to delivering the first configuration message to the second node, a concurrent process is initiated toward the first IAB donor, the concurrent process including a security handshake.

[0144] 30. The method according to any one of clauses 17-29 further includes: in response to delivering the first configuration message to the second node, participating in a concurrent process with the second node or another node in a path including the first IAB donor node or the second IAB donor node towards the first IAB donor node or the second IAB donor node.

[0145] 31. An apparatus for wireless communication by an Integrated Access and Backhaul (IAB) donor, comprising:

[0146] processor,

[0147] Memory coupled to the processor; and

[0148] Instructions, which are stored in the memory and operable when executed by the processor, to cause the device to perform the following operations:

[0149] The configuration message is sent via the first distributed unit of the IAB donor on the source path with the first IAB node;

[0150] Instructing the first IAB node to delay delivering the configuration message to the second node; and

[0151] At least a portion of the communication to the first IAB node is migrated from the source path to the target path via the second distributed unit.

[0152] 32. The apparatus according to clause 31, wherein the processor causes the apparatus to perform the following operations:

[0153] Perform a first security handshake with the first IAB node; and

[0154] A second security handshake is performed with the second node, wherein the second distributed unit is part of the IAB donor.

[0155] 33. The apparatus according to any one of clauses 31-32, wherein the processor causes the second security handshake to be performed concurrently with the first security handshake.

[0156] 34. The apparatus according to any one of clauses 31-33, wherein the configuration message originates from the first donor central unit (CU) and carries a reconfiguration message of the second donor central unit.

[0157] 35. The apparatus according to any one of clauses 31-34, wherein the processor causes the apparatus to indicate the delay of the configuration message based on a Backhaul Adaptation Protocol (BAP) address, a BAP route ID, a Backhaul Radio Link Control (RLC) channel ID, or a logical channel ID.

[0158] 36. The apparatus according to any one of clauses 31-35, wherein the processor causes the apparatus to perform the following operation: configuration trigger to release the configuration message.

[0159] 37. The apparatus according to any one of clauses 31-36, wherein the processor causes the apparatus to configure the trigger for a specific child node.

[0160] 38. The apparatus according to any one of clauses 31-37, wherein the processor causes the apparatus to perform the following operation: configure the trigger for all child nodes.

[0161] 39. The apparatus according to any one of clauses 31-38, wherein the triggering comprises an absolute time, a duration, a relative time to the timing of a random access channel (RACH) detected by the first IAB node, or a function of the RACH configuration detected by the first IAB node.

[0162] 40. The apparatus according to any one of clauses 31-39, wherein the processor causes the apparatus to perform the following operation: receiving a reconfiguration message carrying IP (Internet Protocol) information or a default uplink (UL) mapping.

[0163] 41. The apparatus according to any one of clauses 31-40, wherein the processor causes the apparatus to configure the trigger via the source path.

[0164] 42. The apparatus according to any one of clauses 31-41, wherein the processor causes the apparatus to perform the following operation: receiving confirmation of the instruction.

[0165] 43. The apparatus according to any one of clauses 31-42, wherein the processor causes the apparatus to perform the following operation: upon receiving the acknowledgment, sending the configuration message to the first IAB node or another node in a path including the first IAB node and the second node.

[0166] 44. The apparatus according to any one of clauses 31-43, wherein the processor causes the apparatus to perform the following operation: receive an acknowledgment of the release of the configuration message.

[0167] 45. The apparatus according to any one of clauses 31-44, wherein the processor causes the apparatus to: instruct the first IAB node to discard the configuration message in response to a failure of the migration at the first IAB node or an upstream node of the source path.

[0168] 46. ​​The apparatus according to any one of clauses 31-45, wherein the processor causes the apparatus to perform the following operation: instruct the second node to prevent reconfiguration failure, connection reconstruction, or connection release.

[0169] 47. The apparatus according to any one of clauses 31-46, wherein the first IAB node includes a first IAB node, and the second node includes a second IAB node.

[0170] 48. An apparatus for wireless communication by an Integrated Access and Backhaul (IAB) donor, comprising:

[0171] processor,

[0172] Memory coupled to the processor; and

[0173] Instructions, which are stored in the memory and operable when executed by the processor, to cause the device to perform the following operations:

[0174] The first distributed unit, via the first IAB donor, receives the first configuration message on the source path having the first IAB donor;

[0175] Delaying the delivery of the first configuration message to the second node; and

[0176] In response to a trigger, the first configuration message is delivered to the second node.

[0177] 49. The apparatus according to clause 48, wherein the processor causes the apparatus to configure the trigger via downlink control information (DCI) or media access control-control element (MAC-CE).

[0178] 50. The apparatus according to any one of clauses 48-49, wherein the processor causes the apparatus to receive an instruction from the parent of the first IAB node via downlink control information (DCI) or media access control-control element (MAC-CE).

[0179] 51. The apparatus according to any one of clauses 48-50, wherein the processor causes the apparatus to perform the following operation: detect a change in the cell ID of the parent of the first IAB node.

[0180] 52. The apparatus according to any one of clauses 48-51, wherein the detection occurs based on a measurement of a System Information Block (SIB) message broadcast by the parent of the first IAB node or a cell ID broadcast by the parent of the first IAB node.

[0181] 53. The apparatus according to any one of clauses 48-52, wherein the triggering includes a switch of the distributed unit (DU) of the first IAB node, the switch including a change in a System Information Block (SIB) message broadcast by the DU of the first IAB node.

[0182] 54. The apparatus according to any one of clauses 48-52, wherein the triggering comprises: performing a security handshake on the target path via a second distributed unit of the first IAB node.

[0183] 55. The apparatus according to any one of clauses 48-54, wherein the execution of the security handshake comprises: establishing an F1-C connection or establishing an F1-U data tunnel.

[0184] 56. The apparatus according to any one of clauses 48-55, wherein the processor causes the apparatus to perform a synchronous reconfiguration based on the first configuration message from or forwarded by the first IAB donor.

[0185] 57. The apparatus according to any one of clauses 48-56, wherein the processor causes the apparatus to perform the synchronous reconfiguration including a switching process.

[0186] 58. The apparatus according to any one of clauses 48-57, wherein the processor causes the apparatus to perform the following operation: receiving the trigger on the source path.

[0187] 59. The apparatus according to any one of clauses 48-58, wherein the processor causes the apparatus to perform the following operation: in response to delivering the first configuration message, instructing the sub-IAB node to release the second configuration message.

[0188] 60. The apparatus according to any one of clauses 48-59, wherein the processor causes the apparatus to perform the following operation: instructing a child IAB node to discard a second configuration message held at the child node.

[0189] 61. The apparatus according to any one of clauses 48-60, wherein the processor causes the apparatus to perform the following operation: in response to delivering the first configuration message to the second node, initiate a concurrent process toward the first IAB donor.

[0190] 62. The apparatus according to any one of clauses 48-61, wherein the concurrent process includes a security handshake.

[0191] 63. The apparatus according to any one of clauses 48-62, wherein the processor causes the apparatus to perform the following operation: in response to delivering the first configuration message to the second node, participating in a concurrent process with the second node or another node in a path including the first IAB donor node or the second IAB donor node toward the first IAB donor node or the second IAB donor node.

[0192] The foregoing disclosure provides explanations and descriptions, but is not intended to be exhaustive or to limit the aspects to the precise form disclosed. Modifications and variations may be made based on the foregoing disclosure, or modifications and variations may be derived from practice in the aspects.

[0193] As used herein, the term "component" is intended to be interpreted broadly as hardware, firmware, and / or a combination of hardware and software. As used herein, a processor is implemented using hardware, firmware, and / or a combination of hardware and software.

[0194] The threshold is used to describe several aspects. As used, depending on the context, satisfying the threshold can refer to a value greater than the threshold, greater than or equal to the threshold, less than the threshold, less than or equal to the threshold, equal to the threshold, not equal to the threshold, etc.

[0195] It will be apparent that the described systems and / or methods can be implemented in various forms of hardware, firmware, and / or combinations of hardware and software. The specific control hardware or software code used to implement these systems and / or methods is not intended to limit any aspect. Therefore, while the operation and behavior of the systems and / or methods are described without reference to specific software code, it is to be understood that the software and hardware can be designed to implement the systems and / or methods, at least in part, based on the description.

[0196] Even if a specific combination of features is recited in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of the aspects. In fact, many of these features can be combined in ways that are not specifically recited in the claims and / or specifically disclosed in the specification. While each dependent claim listed below may directly depend on only one claim, the disclosure of each aspect includes a combination of each dependent claim with every other claim in the claim set. The phrase “at least one of” in the list of items refers to any combination of those items, including single members. For example, “at least one of a, b, or c” is intended to cover a, b, c, ab, ac, bc, and abc, as well as any combination of multiples of the same element (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc, or any other ordering of a, b, and c).

[0197] None of the elements, actions, or instructions used should be interpreted as critical or necessary unless explicitly stated otherwise. Furthermore, as used, the articles “a” and “an” are intended to include one or more items and may be used interchangeably with “one or more.” Additionally, as used, the terms “set” and “group” are intended to include one or more items (e.g., related items, unrelated items, combinations of related and unrelated items, etc.) and may be used interchangeably with “one or more.” The phrase “only one” or similar language is used when only one item is anticipated. Furthermore, as used, the terms “has,” “have,” “having,” and / or similar terms are intended to be open-ended terms. Additionally, unless explicitly stated otherwise, the phrase “based on” is intended to mean “at least partially based on.”

Claims

1. A method for performing IAB node migration at an Integrated Access and Backhaul (IAB) donor, comprising: The first distributed unit of the IAB donor sends a configuration message to the first IAB node on the source path; as well as The first IAB node is instructed to delay delivering the configuration message to the second node.

2. The method according to claim 1, wherein, The configuration message includes a Radio Resource Control (RRC) message that provides an uplink (UL) mapping or Internet Protocol (IP) address for the first IAB node to communicate with the target donor.

3. The method according to claim 1, further comprising: At least a portion of the communication to the first IAB node is migrated from the source path to the target path for the first IAB node via the second distributed unit.

4. The method according to claim 3, further comprising: Perform a first security handshake with the first IAB node; as well as A second security handshake is performed with the second node, wherein the second distributed unit is part of the IAB donor.

5. The method according to claim 4, wherein, The second security handshake is performed concurrently with the first security handshake.

6. The method according to claim 1, wherein, The configuration message originates from the first donor central unit (CU) and carries a reconfiguration message for the second donor central unit.

7. The method according to claim 1, wherein, Indicating a delay in delivery of the first IAB node includes indicating the delay of the configuration message based on the Backhaul Adaptation Protocol (BAP) address, BAP route ID, Backhaul Radio Link Control (RLC) channel ID, or logical channel ID.

8. The method according to claim 1, further comprising: The configuration triggers the release of the configuration message.

9. The method according to claim 8, wherein, Configuring the trigger includes configuring it for a specific child node.

10. The method according to claim 8, wherein, Configuring the trigger includes configuring it for all child nodes.

11. The method according to claim 8, wherein, The triggering includes absolute time, duration, relative time to the timing of the Random Access Channel (RACH) detected by the first IAB node, or a function of the RACH configuration detected by the first IAB node.

12. The method according to claim 1, further comprising: Receive confirmation of the instruction.

13. The method of claim 12, further comprising: Upon receiving the confirmation, the configuration message is sent to the first IAB node or the upstream node of the source path.

14. The method according to claim 1, further comprising: Receive confirmation of the release of the configuration message.

15. The method according to claim 1, further comprising: In response to a failure to migrate the first IAB node or the upstream IAB node of the source path, the first IAB node is instructed to discard the configuration message.

16. The method according to claim 1, further comprising: Instruct the second node to configure a timer to prevent reconfiguration failures, connection rebuilds, or connection releases.

17. A method for performing IAB node migration at a first Integrated Access and Backhaul (IAB) network node, comprising: The first distributed unit, via the first IAB donor, receives the first configuration message on the source path having the first IAB donor; Delay delivering the first configuration message to the second node; as well as In response to a trigger, the first configuration message is delivered to the second node.

18. The method according to claim 17, wherein, The triggering includes receiving a reconfiguration message carrying Internet Protocol (IP) information or uplink (UL) mapping.

19. The method of claim 17, wherein, The triggering includes receiving an indication from the parent of the first IAB node to release the first configuration message.

20. The method of claim 17, wherein, The triggering includes: detecting a change in the cell ID of the parent of the first IAB node.

21. The method according to claim 20, wherein, The detection occurs based on a condition measured by either a System Information Block (SIB) message broadcast by the parent of the first IAB node or a cell ID broadcast by the parent of the first IAB node.

22. The method according to claim 17, wherein, The triggering includes the migration of the distributed unit (DU) of the first IAB node, the migration including changes to the system information block (SIB) messages broadcast by the DU of the first IAB node.

23. The method according to claim 17, wherein, The triggering includes: performing a security handshake on the target path via the second distributed unit of the first IAB node.

24. The method according to claim 23, wherein, The execution of the secure handshake includes: establishing an F1-C connection or establishing an F1-U data tunnel.

25. The method according to claim 17, wherein, The triggering includes performing a synchronous reconfiguration based on the first configuration message from or forwarded by the first IAB donor.

26. The method of claim 25, wherein, The execution of the synchronous reconfiguration includes a switching process.

27. The method of claim 17, further comprising: The trigger is received on the source path.

28. The method of claim 17, further comprising: In response to delivering the first configuration message, instruct the child IAB node to release the second configuration message.

29. The method of claim 17, further comprising: Instruct the child IAB node to discard the second configuration message retained at the child node; as well as In response to delivering the first configuration message to the second node, a concurrent process is initiated toward the first IAB donor, the concurrent process including a security handshake.

30. The method of claim 17, further comprising: In response to delivering the first configuration message to the second node, a concurrent process is initiated towards the first IAB donor or the second IAB donor node with the second node or another node in a path that includes the first IAB node and the second node.

31. An apparatus for wireless communication by an Integrated Access and Backhaul (IAB) donor, comprising: processor, Memory coupled to the processor; as well as Instructions, which are stored in the memory and operable when executed by the processor, to cause the device to perform the following operations: The configuration message is sent via the first distributed unit of the IAB donor on the source path with the first IAB node; Instruct the first IAB node to delay delivering the configuration message to the second node; as well as At least a portion of the communication to the first IAB node is migrated from the source path to the target path via the second distributed unit.

32. The apparatus according to claim 31, wherein, The processor causes the device to perform the following operations: Perform a first security handshake with the first IAB node; and A second security handshake is performed with the second node, wherein the second distributed unit is part of the IAB donor.

33. The apparatus according to claim 32, wherein, The processor enables the second security handshake to be performed at least partially concurrently with the first security handshake.

34. The apparatus according to claim 31, wherein, The configuration message originates from the first donor central unit (CU) and carries a reconfiguration message for the second donor central unit.

35. The apparatus according to claim 31, wherein, The processor causes the device to indicate the delay of the configuration message based on the Backhaul Adaptation Protocol (BAP) address, BAP route ID, Backhaul Radio Link Control (RLC) channel ID, or logical channel ID.

36. The apparatus according to claim 31, wherein, The processor causes the device to perform the following operation: configure a trigger to release the configuration message.

37. The apparatus according to claim 36, wherein, The processor causes the device to perform the following operation: configure the trigger for a specific child node.

38. The apparatus according to claim 37, wherein, The processor causes the device to perform the following operation: configure the trigger for all child nodes.

39. The apparatus according to claim 37, wherein, The triggering includes absolute time, duration, relative time to the timing of the Random Access Channel (RACH) detected by the first IAB node, or a function of the RACH configuration detected by the first IAB node.

40. The apparatus according to claim 37, wherein, The processor causes the device to perform the following operation: receive a reconfiguration message carrying IP (Internet Protocol) information or a default uplink (UL) mapping.

41. The apparatus according to claim 37, wherein, The processor causes the device to perform the following operation: configure the trigger via the source path.

42. The apparatus according to claim 31, wherein, The processor causes the device to perform the following operation: receive confirmation of the instruction.

43. The apparatus according to claim 42, wherein, The processor causes the device to perform the following operation: upon receiving the confirmation, send the configuration message to the first IAB node or another node in a path that includes the first IAB node and the second node.

44. The apparatus according to claim 31, wherein, The processor causes the device to perform the following operation: receive confirmation of the release of the configuration message.

45. The apparatus according to claim 31, wherein, The processor causes the device to perform the following operation: in response to a failure of the migration at the first IAB node or at an upstream node of the source path, instruct the first IAB node to discard the configuration message.

46. ​​The apparatus according to claim 31, wherein, The processor causes the device to perform the following operations: instruct the second node to prevent reconfiguration failure, connection reconstruction, or connection release.

47. The apparatus according to claim 31, wherein, The first IAB node includes a first IAB node, and the second node includes a second IAB node.

48. An apparatus for wireless communication by an Integrated Access and Backhaul (IAB) donor, comprising: processor, Memory coupled to the processor; as well as Instructions, which are stored in the memory and operable when executed by the processor, to cause the device to perform the following operations: The first distributed unit, via the first IAB donor, receives the first configuration message on the source path having the first IAB donor; Delay delivering the first configuration message to the second node; as well as In response to a trigger, the first configuration message is delivered to the second node.

49. The apparatus according to claim 48, wherein, The processor causes the device to configure the trigger via downlink control information (DCI) or media access control-control element (MAC-CE).

50. The apparatus according to claim 49, wherein, The processor causes the device to receive an instruction from the parent of the first IAB node via downlink control information (DCI) or media access control-control element (MAC-CE).

51. The apparatus according to claim 48, wherein, The processor causes the device to perform the following operation: detect changes in the cell ID of the parent of the first IAB node.

52. The apparatus according to claim 51, wherein, The detection occurs based on a measurement of a System Information Block (SIB) message broadcast by the parent of the first IAB node or a cell ID broadcast by the parent of the first IAB node.

53. The apparatus according to claim 48, wherein, The triggering includes a switch of the distributed unit (DU) of the first IAB node, the switch including a change in the system information block (SIB) message broadcast by the DU of the first IAB node.

54. The apparatus according to claim 48, wherein, The triggering includes: performing a security handshake on the target path via the second distributed unit of the first IAB node.

55. The apparatus according to claim 54, wherein, The execution of the security handshake includes: establishing an F1-C connection or establishing an F1-U data tunnel.

56. The apparatus according to claim 48, wherein, The processor causes the device to perform a synchronous reconfiguration based on the first configuration message from or forwarded by the first IAB donor.

57. The apparatus according to claim 56, wherein, The processor causes the device to perform the following operations: execute the synchronous reconfiguration, including a switching process.

58. The apparatus according to claim 48, wherein, The processor causes the device to perform the following operation: receive the trigger on the source path.

59. The apparatus according to claim 48, wherein, The processor causes the device to perform the following operation: in response to delivering the first configuration message, instructing the sub-IAB node to release the second configuration message.

60. The apparatus according to claim 48, wherein, The processor causes the device to perform the following operation: instruct the child IAB node to discard the second configuration message held at the child node.

61. The apparatus according to claim 48, wherein, The processor causes the device to perform the following operation: in response to delivering the first configuration message to the second node, initiate a concurrent process toward the first IAB donor.

62. The apparatus according to claim 61, wherein, The concurrent process includes a secure handshake.

63. The apparatus according to claim 48, wherein, The processor causes the device to perform the following operation: in response to delivering the first configuration message to the second node, participate in a concurrent process with the second node or another node in a path that includes the first IAB donor node or the second IAB donor node.

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