Method and apparatus for operating mobile integrated access and backhaul node in next generation mobile communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate in which a network can identify the mobility of an IAB node and indicate a procedure according to the mobility of the respective node. A method performed by a first node in a wireless communication system includes transmitting system information including an indicator indicating that a mobile integrated access and backhaul (IAB) node is supported, receiving a radio resource control (RRC) setup request message from the node, transmitting the RRC setup message to the node, and receiving, from the node, an RRC setup completion message including information indicating that the node is a mobile IAB node.

Description

Technical Field

[0001] The present disclosure relates generally to the operation of an Integrated Access and Backhaul (IAB) node in a mobile communication system, and more particularly to a method of handling mobility of an IAB node. Background Art

[0002] 5G mobile communication technology defines a wide frequency band, making high transmission rates and new services possible, and can be implemented not only in "below 6 GHz" frequency bands such as 3.5 GHz, but also in "above 6 GHz" frequency bands (including 28 GHz and 39 GHz) called millimeter waves. In addition, 6G mobile communication technology (called super 5G system) is also considered to be implemented in terahertz (THz) frequency bands (for example, 95 GHz to 3 THz frequency bands) to achieve a transmission rate 50 times faster than 5G mobile communication technology and an ultra-low latency of only one-tenth of 5G mobile communication technology.

[0003] At the beginning of the development of 5G mobile communication technology, in order to support services and to meet performance requirements related to enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC) and massive machine type communication (mMTC), standardization of the following items has been ongoing: beamforming and massive MIMO for reducing radio wave path loss and increasing radio wave transmission distance in millimeter waves, dynamic operation for efficiently utilizing millimeter wave resources and time slot formats to support parameter sets (for example, operating multiple subcarrier spacings), initial access technology for supporting multi-beam transmission and broadband, definition and operation of BWP (bandwidth part), new channel coding methods such as LDPC (low-density parity check) codes for large-scale data transmission and polarization codes for highly reliable transmission of control information, L2 preprocessing, and network slicing for providing dedicated networks dedicated to specific services.

[0004] Currently, discussions are underway on how to improve and enhance the performance of initial 5G mobile communications technology for the services it will support, and physical layer standardization has been carried out for the following technologies: V2X (vehicle-to-everything), which is used to assist autonomous vehicles in making driving decisions and improve user convenience based on information about the vehicle's location and status transmitted by the vehicle; NR-U (New Radio Unlicensed), which is designed to enable system operation to comply with various regulatory requirements for unlicensed frequency bands; NR UE power saving; non-terrestrial network (NTN), where the UE communicates directly with satellites to provide coverage in areas where it is unable to communicate with terrestrial networks; and positioning.

[0005] Moreover, standardization in air interface architecture / protocols has been carried out for technologies such as: Industrial Internet of Things (IIoT), supporting new services through interworking and integration with other industries; IAB (Integrated Access and Backhaul), providing nodes for network service area expansion through integrated support of wireless backhaul links and access links; mobility enhancement, including conditional handover and DAPS (Dual Active Protocol Stack) handover; and two-step random access, which is used to simplify the random access process (two-step RACH for NR). In terms of system architecture / services, 5G baseline architecture (e.g., service-based architecture or service-based interface) is also being standardized to combine network function virtualization (NFV) and software-defined network (SDN) technologies, as well as mobile edge computing (MEC) for receiving services based on UE location.

[0006] As 5G mobile communication systems are commercialized, an exponentially increasing number of networked devices will be connected to the communication network, and therefore it is expected that it will be necessary to enhance the functions and performance of 5G mobile communication systems and the integrated operation of networked devices. To this end, new research is planned in the following areas: effective support for extended reality (XR) such as AR (augmented reality), VR (virtual reality), and MR (mixed reality); improving 5G performance and reducing complexity using artificial intelligence (AI) and machine learning (ML); AI service support; metadata service support; and drone communication.

[0007] Furthermore, this development of 5G mobile communication systems will serve as the basis for the development of new waveforms for providing terahertz band coverage for 6G mobile communication technology, multi-antenna transmission technologies such as full-dimensional MIMO (FD-MIMO), array antennas, and massive antennas, metamaterial-based lenses and antennas for improving the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using OAM (orbital angular momentum), and RIS (reconfigurable smart surface), as well as full-duplex technology for improving the frequency efficiency of 6G mobile communication technology and improving system networks; AI-based communication technology that utilizes satellites and AI (artificial intelligence) from the design stage and internalizes end-to-end AI support functions to achieve system optimization; and next-generation distributed computing technology that utilizes ultra-high-performance communication and computing resources to enable services with a complexity that exceeds the limits of UE operating capabilities.

[0008] With the development of the above-mentioned wireless communication systems, various services can be provided, and thus a scheme for efficiently providing these services is required. Summary of the invention

[0009] Technical issues

[0010] The present disclosure is to address at least the above-mentioned problems and / or disadvantages and to provide at least the advantages described below.

[0011] One aspect of the present disclosure is to provide a network and method thereof, wherein, when an IAB node has mobility, corresponding characteristics of the IAB node are identified, and operations are performed according to the identified characteristics.

[0012] Another aspect of the present disclosure is to provide a network and method thereof, in which mobility of an IAB node can be identified and a process according to the mobility of the IAB node can be indicated.

[0013] Technical Solution

[0014] According to one aspect of the present disclosure, a method performed by a first node in a wireless communication system is provided. The method includes sending system information, the system information including an indicator indicating that a mobile integrated access and backhaul (IAB) node is supported; receiving a radio resource control (RRC) setup request message from a node; sending an RRC setup message to the node; and receiving an RRC setup complete message from the node including information indicating that the node is the mobile IAB node.

[0015] According to another aspect of the present disclosure, a method performed by a node in a wireless communication system includes: receiving system information from a first node, the system information including an indicator indicating support for a mobile integrated access and backhaul (IAB) node; sending a radio resource control (RRC) establishment request message to the first node; receiving an RRC establishment message from the first node; and sending an RRC establishment completion message to the first node including information indicating that the node is the mobile IAB node.

[0016] According to another aspect of the present disclosure, a first node for a wireless communication system is provided. The first node includes a transceiver; and at least one processor, the at least one processor being configured to: send system information including an indicator indicating support for a mobile integrated access and backhaul (IAB) node via the transceiver, receive a radio resource control (RRC) establishment request message from a node via the transceiver, send an RRC establishment message to the node via the transceiver, and receive an RRC establishment completion message including information indicating that the node is the mobile IAB node from the node via the transceiver.

[0017] According to another aspect of the present disclosure, a node for a wireless communication system is provided. The node includes a transceiver; and at least one processor, the at least one processor being configured to: receive system information including an indicator indicating that a mobile integrated access and backhaul (IAB) node is supported from a first node via the transceiver, send a radio resource control (RRC) establishment request message to the first node via the transceiver, receive an RRC establishment message from the first node via the transceiver, and send an RRC establishment completion message including information indicating that the node is the mobile IAB node to the first node via the transceiver.

[0018] Beneficial effects of the present invention

[0019] According to an embodiment of the present disclosure, a network and method thereof are provided in which mobility of an IAB node can be identified and a process according to the mobility of the IAB node can be indicated. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The above and other aspects, features and advantages of certain embodiments of the present disclosure will become more apparent through the following description in conjunction with the accompanying drawings.

[0021] Figure 1 A conventional Long Term Evolution (LTE) system is shown.

[0022] Figure 2 The wireless protocol structure in the conventional LTE system is shown.

[0023] Figure 3 A next generation mobile communication system according to an embodiment is shown.

[0024] Figure 4 A radio protocol structure of a next generation mobile communication system according to an embodiment is shown.

[0025] Figure 5 A terminal according to an embodiment is shown.

[0026] Figure 6 An NR base station (BS) according to an embodiment is shown.

[0027] Figure 7 is a signal flow diagram illustrating initial access of a mobile IAB node according to an embodiment.

[0028] Figure 8 8 is a signal flow chart showing a method of instructing a co-located distributed unit (DU) of a mobile IAB node 800 to use an independent logical DU according to an embodiment.

[0029] Fig. 9is a signal flow chart illustrating a method of controlling a mobile IAB node as a last hop node according to an embodiment.

[0030] Fig.10 is a signal flow diagram illustrating a method of limiting measurement reporting events of an access terminal of a mobile IAB node according to an embodiment.

[0031] Fig.11 is a signal flow diagram illustrating a method of indicating a complete migration or a partial migration during migration of a mobile IAB node according to an embodiment. Specific embodiments

[0032] Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description of the present disclosure, when it is determined that the description may make the subject matter of the present disclosure unnecessarily unclear, the detailed description of the known functions or configurations contained herein will be omitted. The terms to be described below are defined in consideration of the functions in the present disclosure and may differ depending on the user, the user's intention or custom. Therefore, the definition of the terms should be based on the content of the entire specification.

[0033] In the following description, for the convenience of description, the terms such as identifying access nodes, referring to network entities, referring to messages, referring to interfaces between network entities, referring to various identification information, etc. are exemplarily used. Therefore, the present disclosure is not limited to the specific terms used below, and other terms referring to subjects with equivalent technical meanings may be used.

[0034] In the following description, a BS is an entity that allocates resources to a terminal and may be at least one of a gNode B, an eNode B, a Node B, a wireless access unit, a BS controller, or a node on a network. A terminal may include a UE, a mobile station (MS), a cellular phone, a smart phone, a computer, or a multimedia system capable of performing a communication function.

[0035] In this document, "downlink (DL)" refers to a radio link through which a BS sends a signal to a terminal, and "uplink (UL)" refers to a radio link through which a signal is sent to a BS. In addition, an LTE or LTE-Advanced (LTE-A) system may be described as an example, but embodiments of the present disclosure may also be applied to other communication systems with similar technical backgrounds or channel types. Examples of such communication systems may include 5G mobile communication technologies (e.g., 5G and NR) developed outside of LTE-A, and in the following description, "5G" may be a concept covering existing LTE, LTE-A, or other similar services.

[0036] In addition, based on the determination of those skilled in the art, the embodiments of the present disclosure can also be applied to other communication systems through some modifications without significantly departing from the scope of the present disclosure.In this article, it should be understood that each block of the flowchart illustration and the combination of the blocks in the flowchart illustration can be implemented by computer program instructions.

[0037] These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device create a device for implementing the functions specified in one or more flowchart blocks. These computer program instructions can also be stored in a computer-usable or computer-readable memory, which can instruct the computer or other programmable data processing device to operate in a specific manner so that the instructions stored in the computer-usable or computer-readable memory produce an article of manufacture including instructions for implementing the functions specified in one or more flowchart blocks. The computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more flowchart blocks.

[0038] Furthermore, each block of the flowchart illustrations may represent a module, segment, or portion of code, which includes one or more executable instructions for implementing the specified logical function(s).

[0039] In some alternative implementations, the functions noted in the blocks may occur out of order. For example, two blocks shown in succession may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order, depending on the functionality involved.

[0040] As used herein, the term "unit" may refer to a software element or a hardware element that performs a predetermined function, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC). However, a "unit" does not always have to be limited to software or hardware. A "unit" may be constructed to be stored in an addressable storage medium, or may be constructed to execute one or more processors. Therefore, a "unit" may include software elements, object-oriented software elements, class elements or task elements, processes, functions, attributes, programs, subroutines, program code segments, drivers, firmware, microcodes, circuits, data, databases, data structures, tables, arrays, and parameters. The elements and functions that a "unit" provides may be combined into a smaller number of elements or "units", or may be divided into a larger number of elements or "units". In addition, these elements and "units" may be implemented to reproduce one or more central processing units (CPUs) in a device or a secure multimedia card. In addition, a "unit" may include one or more processors.

[0041] In the following description, for ease of description, the embodiments of the present disclosure will be described using terms and names defined in the 5GS and NR standards, which are the latest standards specified by the Third Generation Partnership Project (3GPP) LTE. However, the present disclosure is not limited by these terms and names, and can be applied to systems that conform to other standards in the same manner. For example, the present disclosure can be applicable to 3GPP 5GS / NR.

[0042] Figure 1 A conventional LTE system is shown.

[0043] Reference Figure 1 , the wireless access network of the LTE system may include next generation BSs (evolved Node Bs (ENBs), Node Bs or BSs) 1-05, 1-10, 1-15 and 1-20, a mobility management entity (MME) 1-25 and a serving gateway (S-GW) 1-30. A user terminal (e.g., UE or terminal) 1-35 may access an external network through the ENBs 1-05 to 1-20 and the S-GW 1-30.

[0044] The ENBs 1-05 to 1-20 may correspond to Node Bs of a Universal Mobile Telecommunications Service (UMTS) system. The ENBs 1-05 to 1-20 may be connected to the UEs 1-35 through wireless channels and perform more complex functions than Node Bs of the prior art. In an LTE system, user traffic including real-time services such as Voice over Internet Protocol (VoIP) over IP may be provided with services through shared channels. Therefore, a device for collecting and scheduling status information such as a buffer status, an available transmission power status, and a channel status of a UE may be required, and the ENBs 1-05 to 1-20 may be used as such a device.

[0045] One ENB can control multiple cells. For example, in order to achieve a transmission rate of 100 Mbps, the LTE system can use orthogonal frequency division multiplexing (OFDM) as a wireless access technology within a bandwidth of 20 MHz. In addition, an adaptive modulation and coding (AMC) scheme that determines the modulation scheme and channel coding rate can be applied according to the channel state of the UE 1-35. The S-GW 1-30 is a device for providing data bearers, and generates or removes data bearers under the control of the MME 1-25. The MME 1-25 is a device for managing the mobility of the UE 1-35 and performing various control functions, and can be connected to multiple ENBs 1-05 to 1-20.

[0046] Figure 2 The wireless protocol structure in the conventional LTE system is shown.

[0047] Reference Figure 2 In the wireless protocol of the LTE system, the UE and ENB may include packet data convergence protocol (PDCP) 2-05 and 2-40, radio link control (RLC) 2-10 and 2-35, and medium access control (MAC) 2-15 and 2-30, respectively. PDCP 2-05 and 2-40 may compress / reconstruct IP headers. The functions of PDCP 2-05 and 2-40 include the following:

[0048] -Header compression and decompression function (Header compression and decompression: Robust Header Compression (ROHC) only)

[0049] -User data transmission function (transmission of user data)

[0050] - In-sequence delivery function (in-sequence delivery of upper layer packet data units (PDUs) during PDCP re-establishment in RLC Acknowledged Mode (AM))

[0051] - Re-sequence functionality (for split bearers in Dual Connectivity (DC) (supports RLC AM only): PDCP PDU routing for transmission and PDCP PDU re-ordering for reception)

[0052] - Duplicate detection function (duplicate detection of lower layer service data units (SDUs) during PDCP reestablishment of RLC AM)

[0053] - Retransmission functionality (retransmit PDCP SDU at handover and, for split bearers in DC, retransmit PDCP PDU during PDCP data recovery for RLC AM)

[0054] -Encryption and decryption functions (encryption and decryption)

[0055] -Timer-based SDU removal function (timer-based SDU discard in UL)

[0056] RLC 2-10 and 2-35 can reconfigure PDCP PDU to an appropriate size and perform automatic repeat request (ARQ) operations. The functions of RLC 2-10 and 2-35 include the following:

[0057] -Data transmission function (transmission of upper layer PDU)

[0058] -ARQ function (error correction through ARQ (only for AM data transmission))

[0059] - Concatenation, segmentation and reassembly function (concatenation, segmentation and reassembly of RLC SDU (only for Unacknowledged Mode (UM) and AM data transmission))

[0060] - Re-segmentation function (resegmentation of RLC data PDU (only for AM data transmission))

[0061] - Reordering function (reordering of RLC data PDUs (only for UM and AM data transmission))

[0062] - Duplicate detection function (Duplicate detection (only for UM and AM data transmission))

[0063] - Error detection function (protocol error detection (for AM data transmission only))

[0064] -RLC SDU deletion function (RLC SDU discard (only for UM and AM data transmission))

[0065] -RLC reestablishment function (RLC reestablishment)

[0066] MAC 2-15 and 2-30 can be connected with various RLC layer devices included in one UE, and multiplex RLC PDU to MAC PDU and demultiplex RLC PDU from MAC PDU. The functions of MAC 2-15 and 2-30 include the following:

[0067] - Mapping function (mapping between logical channels and transmission channels)

[0068] - Multiplexing and demultiplexing functions (multiplexing / demultiplexing MAC SDUs belonging to one or more different logical channels into transport blocks (TBs) transmitted to or from the PHY on transport channels)

[0069] -Scheduling information reporting function (Scheduling information reporting)

[0070] -Hybrid Automatic Repeat Request (HARQ) function (error correction through HARQ)

[0071] -Logical channel priority control function (priority processing between logical channels of a UE)

[0072] -UE priority control function (prioritization between UEs through dynamic scheduling)

[0073] -Multimedia Broadcast Multicast Service (MBMS) service identification function (MBMS service identification)

[0074] -Transmission format selection function (transmission format selection)

[0075] -Filling function (fill)

[0076] PHY 2-20 and 2-25 can perform operations of channel coding and modulating upper layer data to generate OFDM symbols and transmit the OFDM symbols through a wireless channel, or demodulating and channel decoding OFDM symbols received through a wireless channel and transmitting the demodulated and channel-decoded OFDM symbols to an upper layer.

[0077] Figure 3 A next generation mobile communication system is shown.

[0078] Reference Figure 3 , the wireless access network of the next generation mobile communication system (e.g., NR or 5G) may include a next generation BS (e.g., NR Node B, NR gNB, or NR NB) 3-10 and an NR core network (CN) 3-05. The NR UE or terminal 3-15 accesses the external network through the NR gNB 3-10 and the NR CN 3-05.

[0079] Figure 3 The NR gNB 3-10 may correspond to the eNB in ​​the LTE system. The NR gNB may be connected to the NR UE 3-15 through a wireless channel and may provide better services than a conventional Node B. In the next generation mobile communication system, all user traffic may be served through a shared channel. Therefore, a device for collecting and scheduling status information of the buffer status, available transmission power status, and channel status of the UE may be required, and the NR gNB 3-10 may be used as the device. One NR-gNB may typically control multiple cells.

[0080] The next generation mobile communication system may have a bandwidth wider than the maximum bandwidth of the prior art in order to achieve ultra-high-speed data transmission compared with the prior art LTE, and may apply OFDM through wireless access technology, and may also apply beamforming technology.

[0081] In addition, an AMC scheme that determines a modulation scheme and a channel coding rate can be applied according to the channel state of the NR UE 3-15. The NR CN 3-05 can perform functions of supporting mobility, configuring bearers, and configuring quality of service (QoS). The NR CN 3-05 is a device for managing the mobility of the NR UE 3-05 and performing various control functions, and can be connected to multiple NRgNBs.

[0082] In addition, the next generation mobile communication system can be connected to the LTE system, and the NR CN 3-05 can be connected to the MME 3-25 through a network interface. The MME 3-25 can be connected to the eNB 3-30 which is the LTE BS.

[0083] Figure 4 A radio protocol structure of a next generation mobile communication system according to an embodiment is shown.

[0084] Reference Figure 4 , UE and NR gNB include NR Service Data Application Protocol (SDAP) 4-01 and 4-45, NR PDCP 4-05 and 4-40, NR RLC 4-10 and 4-35, NR MAC 4-15 and 4-30, and NR PHY 4-20 and 4-25 in the radio protocol of the next generation mobile communication system.

[0085] The capabilities of NR SDAP 4-01 and 4-45 may include the following:

[0086] -User data transmission function (transmission of user plane data)

[0087] - Functionality for mapping QoS flows and data bearers for UL and DL (mapping between QoS flows and data radio bearers (DRBs) for both DL and UL)

[0088] - Function of marking QoS flow identifier (ID) of UL and DL (marking QoS flow ID in both DL data packets and UL data packets)

[0089] - Function to map the reflective QoS flow of UL SDAP PDU to data bearer (Mapping of reflective QoS flow of UL SDAP PDU to DRB)

[0090] For SDAP layer devices, the UE can receive configuration of whether to use the header of the SDAP layer device or the function of the SDAP layer device for each PDCP layer device, each bearer or each logical channel through an RRC message. When the SDAP header is configured, the 1-bit indication of the non-access stratum (NAS) reflected QoS and the 1-bit indication of the access stratum (AS) reflected QoS of the SDAP header can indicate that the UE updates or reconfigures the mapping of QoS flows and data bearers in UL and DL. The SDAP header may include QoS flow ID information indicating QoS. QoS information can be used as data processing priority or scheduling information to support seamless services.

[0091] The functions of NR PDCP 4-05 and 4-40 may include the following:

[0092] -Header compression and decompression function (Header compression and decompression: ROHC only)

[0093] -User data transmission function (transmission of user data)

[0094] - Sequential delivery function (sequential delivery of upper layer PDU)

[0095] - Out-of-sequence delivery function (out-of-sequence delivery of upper layer PDU)

[0096] - Reordering function (for reordering of received PDCP PDUs)

[0097] - Duplicate detection function (duplicate detection of lower layer SDU)

[0098] -Retransmission function (retransmission of PDCP SDU)

[0099] -Encryption and decryption functions (encryption and decryption)

[0100] -Timer-based SDU removal function (timer-based SDU discard in UL)

[0101] In the above description, the reordering function of the NR PDCP device is a function of sequentially reordering the PDCP PDUs received from the lower layer based on the PDCP sequence number (SN). The reordering function of the NR PDCP device may include a function of sequentially transmitting the reordered data to the upper layer, a function of directly sending the reordered data regardless of the sequence, a function of recording the PDCP PDUs lost due to the reordering, a function of reporting the status of the lost PDCP PDUs to the transmitting side, and a function of requesting the retransmission of the lost PDCP PDP.

[0102] The functions of NR RLC 4-10 and 4-35 may include the following:

[0103] -Data transmission function (transmission of upper layer PDU)

[0104] - Sequential delivery function (sequential delivery of upper layer PDU)

[0105] - Out-of-sequence delivery function (out-of-sequence delivery of upper layer PDU)

[0106] -ARQ function (error correction through ARQ)

[0107] - Concatenation, segmentation and reassembly functions (concatenation, segmentation and reassembly of RLC SDU)

[0108] - Re-segmentation function (resegmentation of RLC data PDU)

[0109] - Reordering function (reordering of RLC data PDU)

[0110] -Duplicate detection function (duplicate detection)

[0111] -Error detection function (protocol error detection)

[0112] -RLC SDU deletion function (RLC SDU discard)

[0113] -RLC reestablishment function (RLC reestablishment)

[0114] In the above description, the sequential delivery function (sequential delivery) of the NR RLC device is a function of sequentially transmitting RLC SDUs received from a lower layer to an upper layer, and may include a function of reassembling and sending RLC SDUs when an original RLC SDU is divided into multiple RLC SDUs and then received.

[0115] The in-sequence delivery function (in-sequence delivery) of the NR RLC device may include a function of reordering the received RLC PDU based on the RLC SN, a function of recording the RLC PDU lost due to reordering, a function of reporting the status of the lost RLC PDU to the transmitting side, and a function of requesting retransmission of the lost RLC PDU.

[0116] When there is a lost RLC SDU, the in-sequence delivery function (in-sequence delivery) of the NR RLC device may include a function of sequentially transmitting only the RLC SDU preceding the lost RLC SDU to the upper layer.

[0117] The sequential delivery function (sequential delivery) of the NR RLC device may include: if a predetermined timer expires when there is a lost RLC SDU, a function of sequentially transmitting all RLC SDUs received before the timer starts to the upper layer.

[0118] The sequential delivery function (sequential delivery) of the NR RLC device may include: if a predetermined timer expires when there is a lost RLC SDU, a function of sequentially transmitting all RLC SDUs received up to that point in time to the upper layer.

[0119] The NR RLC device can process the RLC PDUs sequentially in the order in which they are received, and can transmit the RLC PDUs to the NR PDCP device regardless of the order of the SNs (out-of-order delivery).

[0120] In the case of segmentation, the NR RLC device can receive segments stored in the buffer or to be received in the future, reconfigure the segments into one RLC PDU, process the RLC PDU, and then send it to the PDCP device.

[0121] The NR RLC layer may not include the cascading function, and this function may be performed by the NR MAC layer, or may be replaced by the multiplexing function of the NR MAC layer.

[0122] In the above description, the non-sequential delivery function (out-of-order delivery) of the NR RLC device is a function of directly transmitting the RLC SDU received from the lower layer to the upper layer regardless of the order of the RLC SDU. When an original RLC SDU is divided into multiple RLC SDUs and then received, the non-sequential delivery function of the NR RLC device may include a function of reassembling and sending the RLC PDU. The non-sequential delivery function (out-of-order delivery) of the NR RLC device may include a function of storing the RLC SN or PDCP SN of the received RLC PDU, reordering the RLC PDU, and recording the lost RLC PDU.

[0123] NR MAC 4-15 and 4-30 may be connected to a plurality of NR RLC layer devices configured in one UE, and the functions of NR MAC 4-15 and 4-30 may include the following functions:

[0124] - Mapping function (mapping between logical channels and transmission channels)

[0125] -Multiplexing and demultiplexing functions (multiplexing / demultiplexing of MAC SDU)

[0126] -Scheduling information reporting function (Scheduling information reporting)

[0127] -HARQ function (error correction through HARQ)

[0128] -Logical channel priority control function (priority processing between logical channels of a UE)

[0129] -UE priority control function (prioritization between UEs through dynamic scheduling)

[0130] -MBMS service identification function (MBMS service identification)

[0131] -Transmission format selection function (transmission format selection)

[0132] -Filling function (fill)

[0133] The NR PHY layers 4-20 and 4-25 may perform operations for channel coding and modulating upper layer data to generate OFDM symbols and transmit the OFDM symbols through a wireless channel, or demodulating and channel decoding OFDM symbols received through a wireless channel and transmitting the demodulated and channel-decoded OFDM symbols to an upper layer.

[0134] Figure 5 A terminal according to an embodiment is shown.

[0135] Reference Figure 5 , a terminal (eg, UE) includes a radio frequency (RF) processor 5-10, a baseband processor 5-20, a memory 5-30, and a controller 5-40.

[0136] The RF processor 5-10 performs functions of sending and receiving signals via a wireless channel, such as converting or amplifying the frequency band of the signal. That is, the RF processor 5-10 up-converts the baseband signal provided by the baseband processor 5-20 into an RF band signal, transmits the RF band signal through an antenna, and then down-converts the RF band signal received by the antenna into a baseband signal. For example, the RF processor 5-10 may include a transmitting filter, a receiving filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), etc. Although Figure 5 Only one antenna is shown, but the UE may include multiple antennas. The RF processor 5-10 may include multiple RF chains. The RF processor 5-10 may perform beamforming. For beamforming, the RF processor 5-10 may control the phase and magnitude of each signal sent / received through multiple antennas or antenna elements. The RF processor 5-10 may perform MIMO and receive multiple layers when performing MIMO operations.

[0137] The baseband processor 5-20 performs the conversion function between the baseband signal and the bit stream according to the physical layer standard of the system. For example, in data transmission, the baseband processor 5-20 generates complex symbols by encoding and modulating the transmission bit stream. In addition, in data reception, the baseband processor 5-20 reconstructs the received bit stream by demodulating and decoding the baseband signal provided from the RF processor 5-10. For example, in the OFDM scheme, when transmitting data, the baseband processor 5-20 generates complex symbols by encoding and modulating the transmission bit stream, maps the complex symbols to subcarriers, and then configures the OFDM symbols by inverse fast Fourier transform (IFFT) operation and cyclic prefix (CP) insertion. In addition, in data reception, the baseband processor 5-20 divides the baseband signal provided from the RF processor 5-10 in units of OFDM symbols, reconstructs the signal mapped to the subcarrier by fast Fourier transform (FFT) operation, and then reconstructs the received bit stream by demodulation and decoding.

[0138] The baseband processor 5-20 and the RF processor 5-10 send and receive signals as described above. Therefore, each of the baseband processor 5-20 and the RF processor 5-10 can be referred to as a transmitter, a receiver, a transceiver, or a communication unit. In addition, at least one of the baseband processor 5-20 and the RF processor 5-10 may include multiple communication modules to support a variety of different wireless access technologies. At least one of the baseband processor 5-20 and the RF processor 5-10 may include different communication modules to process signals in different frequency bands. For example, different wireless access technologies may include wireless local area networks (LANs) (e.g., IEEE802.11), cellular networks (e.g., LTE), etc. In addition, different frequency bands may include ultra-high frequency (SHF) (e.g., 2.NRHz, NRHz) bands and millimeter (mm) wave (e.g., 60GHz) bands.

[0139] The memory 5-30 stores data such as basic programs, applications, configuration information, etc. for the operation of the UE. Specifically, the memory 5-30 may store information related to a second access node that performs wireless communication by using a second radio access technology. The memory 5-30 provides stored data according to a request from the controller 5-40.

[0140] The controller 5-40 controls the overall operation of the UE. For example, the controller 5-40 sends and receives signals through the baseband processor 5-20 and the RF processor 5-10. In addition, the controller 5-40 records data in the memory 5-30 and reads the data. To this end, the controller 5-40 may include at least one processor, namely a multi-link processor 5-42. For example, the controller 5-40 may include a communication processor that performs communication control and an application processor (AP) that controls an upper layer (e.g., an application).

[0141] Figure 6 An NR BS according to an embodiment is shown.

[0142] Reference Figure 6 , the BS includes an RF processor 6-10, a baseband processor 6-20, a backhaul communicator 6-30, a memory 6-40, and a controller 6-50.

[0143] The RF processor 6-10 performs functions of sending and receiving signals via a wireless channel, such as converting or amplifying the frequency band of a signal. That is, the RF processor 6-10 up-converts the baseband signal provided by the baseband processor 6-20 into an RF band signal, then transmits the converted signal through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processor 6-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc. Although Figure 6 Only one antenna is shown, but the first access node may include multiple antennas. The RF processing unit 6-10 may include multiple RF chains. The RF processor 6-10 may perform beamforming. For beamforming, the RF processor 6-10 may control the phase and magnitude of each signal sent and received through multiple antennas or antenna elements. The RF processor 6-10 may perform DL MIMO operations by sending one or more layers.

[0144] The baseband processor 6-20 performs the function of performing conversion between the baseband signal and the bit stream according to the physical layer standard of the first wireless access technology. For example, in data transmission, the baseband processor 6-20 generates complex symbols by encoding and modulating the transmission bit stream. In addition, in data reception, the baseband processor 6-20 reconstructs the received bit stream by demodulating and decoding the baseband signal provided from the RF processor 6-10. For example, according to the OFDM scheme, in data transmission, the baseband processor 6-20 generates complex symbols by encoding and modulating the transmission bit stream, maps the complex symbols to subcarriers, and then configures OFDM symbols by IFFT operation and CP insertion. In addition, in data reception, the baseband processor 6-20 divides the baseband signal provided from the RF processor 6-10 in units of OFDM symbols, recovers the signal mapped with subcarriers by FFT operation, and then reconstructs the received bit stream by demodulation and decoding. The baseband processor 6-20 and the RF processor 6-10 send and receive signals as described above. Therefore, each of the baseband processor 6-20 and the RF processor 6-10 may be referred to as a transmitter, a receiver, a transceiver, a communication unit, or a wireless communication unit.

[0145] The backhaul communicator 6-30 provides an interface for communicating with other nodes in the network. The backhaul communicator 6-30 converts a bit stream to be transmitted from the master BS to other nodes (eg, secondary BS or CN) into a physical signal, and converts a physical signal received from other nodes into a bit stream.

[0146] The memory 6-40 stores data such as basic programs, applications, configuration information, etc. for the operation of the master BS. Specifically, the memory 6-40 may store information about bearers allocated to the accessed UE, measurement results reported from the accessed UE, etc. In addition, the memory 6-40 may store information as a reference for determining whether to provide or stop multiple connections to the UE. The memory 6-40 provides the stored data according to a request from the controller 6-50.

[0147] The controller 6-50 controls the overall operation of the BS. For example, the controller 6-50 sends and receives signals through the baseband processor 6-20 and the RF processor 6-10 or through the backhaul communicator 6-30. In addition, the controller 6-50 records data in the memory 6-40 and reads data. To this end, the controller 6-50 may include at least one processor, namely, a multi-link processor 6-52.

[0148] According to an embodiment of the present disclosure, an IAB node may know whether the IAB node itself is a mobile IAB node. Here, it is assumed that the IAB node already knows whether it is a mobile IAB node. In addition, each IAB node broadcasts an indication indicating whether the donor node or the central unit (CU) of the donor node to which it and / or its DU is anchored supports mobile IAB nodes connected thereto. For example, when each IAB node supports mobile IAB nodes, the cell of the co-located DU may broadcast a corresponding 1-bit indication in a master information block (MIB) or a system information block (SIB, e.g., SIB1). The 1-bit indication may indicate whether mobile IAB nodes are supported or not.

[0149] The cell may broadcast an indication indicating support for the mobile IAB node through SIB1. In addition, the mobile IAB node newly accessing the network may only consider the cell that sends the indication indicating support for the mobile IAB node as an accessible cell during cell selection / reselection.

[0150] The mobile IAB node that has received the indication can select a corresponding cell for its own connection during the RRC connection establishment process after the connection, and can perform an operation of notifying the network that the mobile IAB node is a mobile IAB node. Through the corresponding operation, the network (e.g., the cell) can recognize that the mobile IAB node is trying to access and can perform an operation of controlling the mobile IAB node.

[0151] When a mobile IAB node is accessing the network, it can indicate the mobile IAB node to its donor node. There are several candidate ways to indicate the mobile IAB node to the network. (Assumption: the traditional cell (re)selection of the IAB node procedure is reused for initial access)

[0152] - Through RRC:

[0153] ■RRCSetupRequest message: This is possible. 1-bit new indication of mobile IAB node

[0154] ■RRCSetupComplete: Most likely message. 1-bit new indication of mobile IAB node, with enumeration {True}, or Boolean {True or False}, or legacy field iab-NodeIndication extended with enumeration {True, Mobile}

[0155] ■UEAssistanceInformation: Less likely due to possible delays. The indication format is the same as in the RRCSetupRequest case

[0156] ■IABOtherInformation: Less likely due to possible delays. The indication format is the same as in the RRCSetupRequest case

[0157] - Via L1

[0158] ■Send a mobile IAB node dedicated random access preamble (RAP) to the gNB. Upon reception, the gNB will know the mobile IAB node and / or use a dedicated rach opportunity (RO) or resource to be used.

[0159] The mobile IAB node may inform the network that it is a mobile IAB node by the following method.

[0160] Option 1-1: Use dedicated random access configuration information.

[0161] Option 1-2. Use start / frequency resource information for random access and / or dedicated random access opportunities

[0162] The dedicated RA preamble and / or dedicated random access opportunity may be configured from the SIB of the cell desired to be accessed. When the mobile IAB node that has received the configuration performs random access when attempting to access the corresponding cell, the mobile IAB node may attempt to access by using the received RAP and / or the received RO. The DU of the parent node may identify the entity accessing using the dedicated RAP or RO as a mobile IAB node.

[0163] Option 1-3. Access may be performed using general random access (RA) configuration information. Alternatively, even if option 1-1 / option 1-2 is still used, the mobile IAB node may notify the network that it is a mobile IAB node in a different method during the process after RA. The method includes the following method.

[0164] Option 1-3-1. In case of 4-step RACH, message 3 or 2-step RACH, a mobile IAB node specific logical channel ID (LCID) may be included in the LCID indicating a UL RRC message included in the UL MAC CE sent in message A, such as an RRCSetupRequest message, and then sent.

[0165] Option 1-3-2: The indication of the mobile IAB node may be included in the RRCSetupRequest message.

[0166] Option 1-3-3: An indication of the mobile IAB node may be included in the RRCSetupComplete message.

[0167] Option 2. After the RRC connection is established, an indication of the mobile IAB node may be included and sent to the network via a UEAssistanceInformation message or an IAB OtherInformation message.

[0168] Figure 7 is a signal flow diagram illustrating initial access of a mobile IAB node according to an embodiment.

[0169] Reference Figure 7 In step S725, the already running parent IAB node (or donor) 710 uses (based on) MIB or SIB1 to broadcast an indication of supporting mobile IAB nodes in its DU cell. Since the mobile IAB node support indication can also refer to the support of conventional fixed IAB nodes, based on this indication, the fixed IAB node can also be regarded as an accessible cell during cell selection / reselection. In addition, random access resource / preamble configuration information for mobile IAB node access can be sent in the SIB.

[0170] When receiving the dedicated RA information, the mobile IAB node 700 attempts access by using option 1-1 and / or option 1-2 in step S730. When the mobile IAB node 700 receives the dedicated RA information and performs access by using option 1-1 / 1-2 or performs access by using general RA, the mobile IAB node 700 receives a random access response (RAR) from the parent IAB node (or donor) 710 in step S735.

[0171] In step S745, the mobile IAB node 700 sends an RRCSetupRequest through the UL resources included in the corresponding RAR. To this end, the mobile IAB node 700 notifies the network that it is a mobile IAB node by using option 1-3-1 or option 1-3-2 in step S740. For example, as described above, the mobile IAB node 700 may include a mobile IAB node-specific LCID in the LCID indicating the RRCSetupRequest message and send the mobile IAB node-specific LCID by using option 1-3-1, or may include an indication indicating a mobile IAB node in the RRCSetupRequest message by using option 1-3-2.

[0172] Regardless of whether the above option is used, the mobile IAB node 700 receives the RRCSetup message (RRC setup message) in step S745. The mobile IAB node 700 may apply the configuration information included in the RRCSetup message. Thereafter, when the above option is not used, the mobile IAB node 700 notifies the network that it is a mobile IAB node by using option 1-3-3 in step S750. For example, based on option 1-3-3, the mobile IAB node 700 may include an indication indicating the mobile IAB node in the RRCSetupComplete message and send the indication.

[0173] After the RRC connection establishment is completed through RRCSetupComplete transmission in step S750, in step S755, the parent node 710 notifies the entity connected to the CU 720 of the donor node through the F1-AP message, uplinkRRCTransfer (uplink RRC transfer message) or a message corresponding thereto that the entity is a mobile IAB node. For example, based on any one of the above embodiments, the parent node 710 that has received an indication indicating the mobile IAB node from the mobile IAB node 700 can notify the CU 720 of the donor node of the mobile IAB node.

[0174] In step S760, the parent IAB node 710 sends an RRCReconfiguration message to the mobile IAB node 700. In addition, in step S765, the mobile IAB node 700 sends an RRCReconfigurationComplete message to the parent IAB node 710.

[0175] When the above options are not used, in step S770, the mobile IAB node 700 can use option 2 to inform the network that it is a mobile IAB node. In this case, the parent IAB node 710 can indicate that it is a mobile IAB node in an F1-AP message, uplinkRRCTransfer, or a message corresponding thereto after receiving the message used in option 2, and send the message to the donor CU 720.

[0176] After indicating that it is a mobile IAB node, the donor CU 720 may instruct or request the mobile IAB node 700 to perform an operation applied only to the mobile IAB node 700 .

[0177] Figure 8 is a signal flow diagram illustrating a method of instructing a co-located DU of a mobile IAB node to use a separate logical DU according to an embodiment.

[0178] Reference Figure 8 , when configuring and operating cells while maintaining separate physical resources, an independent logical DU is required. When a mobile IAB node performs a handover, it may be necessary to use such a separated physical resource cell. Before performing a handover, for example, from an access point, a separate resource cell may be operated while knowing that it is a mobile IAB node. After determining the handover, re-dividing the resources of the cell operated in the existing single DU to operate the new cell may cause the terminal connected to the IAB node to be disconnected.

[0179] In this case, after the mobile IAB node 800 notifies the source donor 810 that the mobile IAB node 800 is a mobile IAB node in a connected state in step S830, the source donor 810 determines to use an independent logical DU in step S840. In addition, the source donor 810 may issue a corresponding instruction.

[0180] In step S845, the source donor 810 instructs the mobile IAB node 800 to use an independent logical DU and a configuration to be used in the corresponding logical DU through an F1-AP message. As configuration information, a physical cell ID (PCI) and / or NR cell global ID (CGI) (NCGI) information associated with the current source donor 810 may be sent. In addition, an indication of whether the target logical DU uses hard-partitioned physical resources or shared physical resources may be included.

[0181] In step S850, the mobile IAB node 800 having received the information operates a cell to which the configuration information given in the co-located DU is applied.

[0182] The donor node may determine to use separate logical DUs in the IAB node, where each logical DU may share or have separate physical resources to run different units simultaneously. In addition, the donor node may indicate the use of separate logical DUs and configure the DU information to run a cell including a PCI / NCGI associated with the donor node. The signaling may be sent over the F1 interface. When the mobile IAB node receives the information of the configuration of the logical DU and the cell, it may configure the co-located DU to run the configured cell.

[0183] Fig. 9 is a signal flow chart illustrating a method of controlling a mobile IAB node as a last hop node according to an embodiment.

[0184] Reference Fig. 9 , when the mobile IAB node 900 accommodates a child IAB node below the node, due to mobility, it takes time to relay the control signal related to mobility, resulting in a data transmission / reception interruption time of the terminal connected to the child node. Therefore, the source donor 910 may not want to accept the connected mobile IAB node as the last node, such as a child node of the node. To this end, when the source donor 910 identifies from the mobile IAB node 900 that it is a mobile IAB node in connection mode (for example, when the source donor 910 receives an indication from the mobile IAB node in step S930 that it is a mobile IAB node 900 in contact mode), the source donor 910 determines in step S940 to limit the mobile IAB node 900 to only one hop. In addition, the source donor 910 may send an IAB support bit and / or an indication of the mobile IAB node support indication for disabling the co-located DU broadcast of the mobile IAB node to the co-located DU of the mobile IAB node. In step S950, the command is sent as an F1-AP message DUConfigurationUpdate or a message corresponding thereto.

[0185] Upon receiving the above message, in step S960, the mobile IAB node 900 stops broadcasting the IAB support bit and / or the mobile IAB node support indication sent in its DU.

[0186] The donor node may instruct the DU of the mobile IAB node to turn off the IAB support bit in SIB1 to maintain the single-hop topology.

[0187] Fig.10 is a signal flow diagram illustrating a method of limiting measurement reporting events of an access terminal of a mobile IAB node according to an embodiment.

[0188] Reference Fig.10, according to the movement of the IAB node, the terminal connected to the mobile IAB node may often experience changes in the strength of the neighboring cells. However, when the strength of the actually connected serving cell does not change significantly, and only the neighboring cells often change, the BS may not play a big role after receiving the measurement report. For example, when the strength of the serving cell is good, there is no need to command the corresponding terminal to switch. However, when the command is configured, the measurement report on the change of the neighboring cell may be frequently sent to the source donor 1030, and the frequent reports of multiple terminals may eventually become a waste of radio resources. In order to avoid this situation, when the source donor 1030 finds that the connected entity is a mobile IAB node in step S1035, in step S1040, the terminals 1000 and 1010 connected to the corresponding mobile IAB node 1020 are restricted from performing measurement reports based on changes in only neighboring cells. The measurement report based on changes in only neighboring cells can be an event based only on the absolute value of the channel state, such as events A1, A2 and A4, such as events other than A3 / A5.

[0189] After the source donor 1030 identifies that it is a mobile IAB node, for each terminal that has configured an event based only on absolute values ​​through the F1-AP message DownlinkRRCInformation, a configuration for deleting the corresponding measurement configuration, such as the measurement object, the reporting configuration, and the measurement ID including the combination of the two, can be included in the RRCReconfiguartion and sent in step S1045.

[0190] Upon receiving the corresponding F1-AP message, the mobile IAB node 1020 forwards the included RRCReconfiguration message to the terminals 1000 and 1010 in steps S1050 and S1065.

[0191] Upon receiving the message, each of the terminals 1000 and 1010 deletes the measurement report configuration based on the corresponding absolute value. In addition, in steps S1050 and 1070, the terminals 1000 and 1010 send an RRCReconfigurationcomplete message to the mobile IAB node 1020.

[0192] Configure measurement reporting for its access UEs, thereby releasing events based on absolute signal strength (events A1, 2, 4 or inter-RAT B1, etc.) and retaining only events based on relative strength. This can prevent access UEs from reporting MRs when good neighbor cells are detected.

[0193] Fig.11 is a signal flow diagram illustrating a method of indicating a complete migration or a partial migration during migration of a mobile IAB node according to an embodiment.

[0194] Reference Fig.11 , the inter-donor node migration of Release 17IAB nodes is a partial migration, where the RRC and UP of the mobile terminal (MT) of the migration node are anchored to the target donor node, but the RRC and UP of the remaining access UEs and the F1 interface of the DU of the migration node are anchored to the source donor node. In the case of a mobile IAB node, it may not be possible to anchor to the source node due to continuous physical movement. For this reason, transferring all MTs and DUs of the migration node and the CP and UP of the access UE to the target donor can be called a full migration, and this full migration can be performed.

[0195] The source donor 1110, which has identified that it is a mobile IAB node in connected mode in step S1125, determines to perform a complete migration in step S1130 when determining that a handover is required. In step S1135, the source donor 1110 determines the target donor node 1120 and forwards a HandoverRequest message (handover request message) to the determined corresponding node. In addition to the configuration and context information of the migration node, the HandoverRequest message may also include the configuration and context information of the access UE.

[0196] In addition, the HandoverRequest message may include an indication indicating that the handover is for the mobile IAB node 1100 and / or an indication indicating that the handover is for a full migration. The target donor node 1120 may perform a full migration procedure after receiving the HandoverRequest message.

[0197] In step S1140, the target donor node 1120 performs admission control of the migrating node and the access UE.

[0198] In step S1145, the target donor node 1120 includes the result of performing admission control in the HOReqACk message and forwards the message to the source donor 1110. The configuration information from the corresponding target donor node 1120 may be forwarded to the mobile IAB node 1100 and the access UE.

[0199] Thereafter, the mobile IAB node 1100, which has received a handover (HO) command from the source donor 1110 according to the complete migration process, can access the cell of the parent IAB node of the target donor node 1120, and in step S1150, the access UE accesses the new cell of the mobile IAB node that has been operated using the cell information provided from the target donor.

[0200] Whenever a handover is required for inter-donor CU migration, it is determined whether to perform partial migration or full migration. Regardless of whether the decision is full migration or partial migration, it can include an indication of the mobile IAB node as UE context information, and when the decision is to perform full migration, the indication of full migration for the handover process can be further included in a handover request message (HOReq message) and sent to the target donor node. The target donor node performs the relevant partial or full migration operation.

[0201] The methods according to various embodiments described in the claims or specification of the present disclosure may be implemented by hardware, software, or a combination of hardware and software.

[0202] When these methods are implemented by software, a computer-readable storage medium for storing one or more programs (software modules) may be provided. One or more programs stored in the computer-readable storage medium may be configured to be executed by one or more processors in an electronic device. The at least one program may include instructions for causing an electronic device to perform the method according to the attached claims and / or the various embodiments of the present disclosure disclosed herein.

[0203] Programs (software modules or software) can be stored in non-volatile memory, including random access memory and flash memory, read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), magnetic disk storage devices, compact disk ROM (CD-ROM), digital versatile disk (DVD) or other types of optical storage devices, or magnetic tapes. Alternatively, any combination of some or all of them can form a memory for storing programs. In addition, multiple such memories may be included in an electronic device.

[0204] In addition, the program can be stored in a connectable storage device that can access the electronic device through a communication network such as the Internet, an intranet, a local area network, a wide area network (WLAN), and a storage area network (SAN), or a combination thereof. Such a storage device can access the electronic device through an external port. In addition, a separate storage device on a communication network can access the portable electronic device.

[0205] In the above detailed embodiments of the present disclosure, the elements included in the present disclosure are expressed in the singular or plural, according to the detailed embodiments presented. However, the singular form or plural form is appropriately selected according to the presented situation for ease of description, and the present disclosure is not limited to the elements expressed in the singular or plural. Therefore, the elements expressed in the plural may also include a single element, or the elements expressed in the singular may also include multiple elements.

[0206] Although specific embodiments have been described in the detailed description of the present disclosure, it is apparent that various modifications and changes may be made thereto without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be defined as limited to the embodiments, but should be defined by the appended claims and their equivalents.

Claims

1. A method performed by a first node in a wireless communication system, the method comprising: Sending system information including an indicator indicating support for a mobile integrated access and backhaul IAB node; receiving a radio resource control (RRC) setup request message from a node; Sending an RRC establishment message to the node; as well as An RRC setup complete message is received from the node, the RRC setup complete message including information indicating that the node is the mobile IAB node.

2. The method according to claim 1, further comprising: determining a switch for the node that is sending the second message; as well as A handover request message is sent to the second node, wherein the handover request message includes information indicating that the node is the mobile IAB node.

3. The method according to claim 1, further comprising: Determining to use an independent logical distributed unit DU for the node; as well as A first message is sent to the node, wherein the first message includes information indicating the use of the independent logical DU.

4. The method according to claim 1, further comprising: Determine, for the node, to disable supporting the mobile IAB node; as well as A second message is sent to the node, the second message including information indicating prohibition of sending an indicator indicating support for the mobile IAB node.

5. A method performed by a node in a wireless communication system, the method comprising: receiving system information from a first node, the system information comprising an indicator indicating a node supporting mobile integrated access and backhaul (IAB); Sending a radio resource control (RRC) establishment request message to the first node; receiving an RRC setup message from the first node; as well as An RRC setup complete message is sent to the first node, where the RRC setup complete message includes information indicating that the node is the mobile IAB node.

6. The method according to claim 5, wherein: The switching of the node is determined, and The handover request message including information indicating that the node is the mobile IAB node is sent from the first node to the second node.

7. The method according to claim 5, further comprising: In case the first node determines to use an independent logical distributed unit DU for the node, receiving a first message from the first node, the first message including information indicating to use the independent logical DU; as well as In case that the first node determines to disable supporting the mobile IAB node for the node, a second message is received from the first node, the second message including information indicating prohibition of sending an indicator indicating supporting the mobile IAB node.

8. A first node in a wireless communication system, the first node comprising: Transceiver; as well as at least one processor, the at least one processor being configured to: sending, via the transceiver, system information including an indicator indicating support for a mobile integrated access and backhaul IAB node, receiving a radio resource control (RRC) setup request message from a node via the transceiver, sending, via the transceiver, an RRC setup message to the node, and An RRC setup complete message is received from the node via the transceiver, the RRC setup complete message including information indicating that the node is the mobile IAB node.

9. The first node according to claim 8, wherein: The at least one processor is further configured to: determining a switch to the node that is sending the second message, and A handover request message is sent to a second node via the transceiver, the handover request message including information indicating that the node is the mobile IAB node.

10. The first node according to claim 8, wherein: The at least one processor is further configured to: determining to use an independent logical distributed unit DU for the node, and A first message is sent to the node via the transceiver, the first message including information indicating use of the independent logical DU.

11. The first node according to claim 8, wherein: The at least one processor is further configured to: determining to disable the node from supporting the mobile IAB node, and A second message is transmitted to the node via the transceiver, the second message including information indicating prohibition of transmitting an indicator indicating support for the mobile IAB node.

12. A node in a wireless communication system, the node comprising: Transceiver; as well as at least one processor, the at least one processor being configured to: receiving system information from a first node via the transceiver, the system information including an indicator indicating a node supporting mobile integrated access and backhaul (IAB), sending a radio resource control (RRC) setup request message to the first node via the transceiver, receiving, via the transceiver, an RRC setup message from the first node, and An RRC setup complete message is sent to the first node via the transceiver, the RRC setup complete message including information indicating that the node is the mobile IAB node.

13. The node according to claim 12, wherein: The switching of the node is determined, and The handover request message including information indicating that the node is the mobile IAB node is sent from the first node to the second node.

14. The node according to claim 12, wherein: The at least one processor is further configured to: In case the first node determines to use an independent logical distributed unit DU for the node, a first message is received from the first node via the transceiver, the first message including information indicating to use the independent logical DU.

15. The node according to claim 12, wherein: The at least one processor is further configured to: In case the first node determines to disable support for the mobile IAB node for the node, a second message is received from the first node via the transceiver, the second message including information indicating prohibition of sending an indicator indicating support for the mobile IAB node.

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