Method and device for controlling operation of mobile relay

Abstract

The present disclosure relates to a technique for controlling the operation of a mobile relay in a mobile communication system, and provides a method and apparatus for controlling the operation of a mobile relay by a source donor base station, the method comprising: a step of transmitting a handover request message to a target donor base station; a step of receiving, from the target donor base station, a handover response message including radio resource configuration information for the mobile relay and / or the terminal served by the mobile relay; and a step of controlling the radio resource configuration information indication to at least one of the mobile relay and the terminal.

Description

Technical Field

[0001] The present disclosure relates to a technology for controlling the operation of a mobile relay in a mobile communication system. Background Art

[0002] In wireless communication systems, relay technology has been used for the purpose of extending cell coverage by utilizing additional network nodes.

[0003] Therefore, the relay technology applicable to the existing LTE technology supports data transfer in the IP packet level of the relay node, and is configured so that only one relay node transfers the IP packet between the terminal and the base station.

[0004] That is, the relay technology applicable to the existing LTE technology only provides a single-hop relay function in order to provide simple services, and most of the configurations are instructed by static OAM (Operations, administration and management), so multi-hop relay cannot be configured.

[0005] In addition, when it is desired to support multi-hop relay through the existing LTE technology, it is not possible to differentiate and process data through multiple relay nodes, and there is a problem of increased delay in signaling and data processing in the upper layer of the IP layer.

[0006] To solve this problem, research is underway on technologies for configuring multiple hops and accurately transmitting user data to base stations. NR is also conducting research on IAB (Integrated Access and Backhaul) technology.

[0007] In particular, a variety of IAB nodes are being studied recently, and a mobile relay technology using a mobile IAB node is being studied. In this case, a mobility support technology may be required, which is different from the existing fixed IAB node. Summary of the invention

[0008] Problems to be solved by the invention

[0009] The present disclosure is directed to providing a technology for controlling a mobile relay operation in a mobile communication system.

[0010] Solutions for solving problems

[0011] On the one hand, this embodiment can provide a method for a source donor base station to control the operation of a mobile relay, including: the step of sending a switching request message to a target donor base station; the step of receiving a switching response message from the target donor base station containing wireless resource configuration information for the mobile relay and at least one of the terminals served by the mobile relay; and the step of controlling the wireless resource configuration information to be indicated to at least one of the mobile relay and the terminal.

[0012] On the other hand, the present embodiment may provide a method for a target donor base station to control the operation of a mobile relay, comprising: a step of receiving a switching request message from a source donor base station; and a step of sending a switching response message containing wireless resource configuration information for the mobile relay and at least one of the terminals served by the mobile relay to the source donor base station, wherein the wireless resource configuration information is indicated to at least one of the mobile relay and the terminal through the source donor base station.

[0013] On the other hand, this embodiment can provide a source donor base station device, which is a source donor base station for controlling the operation of a mobile relay, including: a sending unit, which sends a switching request message to a target donor base station; a receiving unit, which receives a switching response message from the target donor base station containing wireless resource configuration information for the mobile relay and at least one of the terminals served by the mobile relay; and a control unit, which controls the wireless resource configuration information to be indicated to at least one of the mobile relay and the terminal.

[0014] On the other hand, this embodiment can provide a target donor base station device, which is a target donor base station for controlling the operation of a mobile relay, including: a receiving unit, which receives a switching request message from a source donor base station; and a sending unit, which sends a switching response message to the source donor base station, which includes wireless resource configuration information for the mobile relay and at least one of the terminals served by the mobile relay, wherein the wireless resource configuration information is indicated to at least one of the mobile relay and the terminal through the source donor base station.

[0015] Effects of the Invention

[0016] The present disclosure has the effect of providing a specific technology for controlling the operation of a mobile relay in a mobile communication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a diagram that simply shows the structure of an NR wireless communication system that is applicable to this embodiment.

[0018] Figure 2 This is a diagram used to illustrate the frame structure in the NR system to which this embodiment is applicable.

[0019] Figure 3 This is a diagram for explaining a resource grid supporting a wireless access technology to which this embodiment is applicable.

[0020] Figure 4 This is a diagram for explaining a bandwidth portion supporting a wireless access technology to which this embodiment is applicable.

[0021] Figure 5 The figure exemplarily shows a synchronization signal block in a wireless access technology to which the present embodiment is applicable.

[0022] Figure 6 This is a diagram for explaining a random access procedure in a wireless access technology to which this embodiment is applicable.

[0023] Figure 7 This is a diagram for explaining CORESET.

[0024] Figure 8 is a diagram showing one example of the IAB structure according to the present embodiment.

[0025] Fig. 9 1 is a diagram for explaining the relationship between a parent node and child nodes of an IAB node according to the present embodiment.

[0026] Fig.10 is a diagram for explaining the operation of a source donor base station according to one embodiment.

[0027] Fig.11 is a diagram for explaining the operation of a target donor base station according to one embodiment.

[0028] Fig.12 is a diagram of an example of an F1-U protocol stack.

[0029] Fig.13 is a diagram exemplarily showing a protocol stack for terminal access using mobile relay.

[0030] Fig.14 is a diagram showing an example of a BAP data PDU format.

[0031] Fig.15 is a diagram showing an example of an Inter IAB-donor-CU topology adaptation procedure.

[0032] Fig.16 is a diagram showing an example of a protocol structure in mobile relay handover.

[0033] Fig.17 is a diagram showing another example of a protocol structure in mobile relay handover.

[0034] Fig.18 is a diagram showing still another example of a protocol structure in mobile relay handover.

[0035] Fig.19 is a diagram showing the structure of a source donor base station according to one embodiment.

[0036] Fig. 20 is a diagram showing a structure of a target donor base station according to one embodiment. DETAILED DESCRIPTION

[0037] Hereinafter, some embodiments of the present disclosure are described in detail with reference to the exemplary drawings. When assigning figure marks to each figure component, the same symbols may be assigned to the same components as much as possible even if they are displayed in different figures. In addition, when describing the present embodiment, if it is considered that the specific description of the relevant known structure or function will obscure the gist of the technical idea, its detailed description may be omitted. In the present specification, when "including", "having", "formed as", etc. are mentioned, unless "only" is used, it means that other parts may be added. In the case of representing a component in the singular, the plural case may be included unless there is a particularly clear record.

[0038] In addition, when describing the components of the present disclosure, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, order, sequence, or quantity of the component is not limited by the terms.

[0039] In the description of the positional relationship of components, if it is recorded that two or more components are "connected", "combined" or "accessed", the two or more components may be directly "connected", "combined" or "accessed", but it should be understood that other components may be "interposed" into the two or more components to thereby be "connected", "combined" or "accessed". Among them, other components may also be included in one or more of the two or more components that are "connected", "combined" or "accessed" to each other.

[0040] In the description of the time flow relationship related to components, operating methods or manufacturing methods, when the time sequence or process sequence is described by, for example, "after", "subsequently", "next", "before", etc., discontinuous situations may also be included unless "immediately" or "directly" is used.

[0041] On the other hand, when referring to the numerical value of a component or its corresponding information (e.g., grade, etc.), even if there is no separate explicit record, the numerical value or its corresponding information should be interpreted as including the error range that may arise from various factors (e.g., process factors, internal or external impact, noise, etc.).

[0042] The wireless communication system in this specification refers to a system that uses wireless resources to provide various communication services such as voice and data packets. The system may include: a terminal, a base station or a core network.

[0043] The present embodiment disclosed below may be applicable to wireless communication systems using a variety of wireless access technologies. For example, the present embodiment may be applicable to a variety of wireless access technologies, such as: code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA) or non-orthogonal multiple access (NOMA). In addition, wireless access technology not only means a specific access technology, but also means various generations of communication technologies specified by various communication protocol organizations, such as: 3GPP, 3GPP2, WiFi, Bluetooth, IEEE, ITU, etc. For example, CDMA can be implemented by wireless technologies such as: universal terrestrial radio access (UTRA) or CDMA2000. TDMA can be implemented through wireless technologies such as global system for mobile communications (GSM) / general packet radio service (GPRS) / enhanced data rates for GSM evolution (EDGE). OFDMA can be implemented through wireless technologies such as Institute of electrical and electronics engineers (IEEE) 802.11 (Wi-Fi, wireless LAN), IEEE 802.16 (WiMAX, Worldwide Interoperability for Microwave Access), IEEE 802-20, E-UTRA (evolved UTRA), etc. IEEE 802.16m, as an evolution of IEEE 802.16e, provides backward compatibility with systems based on IEEE 802.16e. UTRA is part of the universal mobile telecommunications system (UMTS).The 3rd generation partnership project (3GPP) long term evolution (LTE) as a part of evolved UMTS (Evolved UMTS, E-UMTS) using evolved-UMTSterrestrial radio access (E-UTRA), adopts OFDMA in the downlink and SC-FDMA in the uplink. As described above, the present embodiment can be applied to currently disclosed or commercialized wireless access technologies, and can also be applied to wireless access technologies that are currently being developed or will be developed in the future.

[0044] On the other hand, the terminal in this specification, as a comprehensive concept, refers to a device including a wireless communication module that communicates with a base station in a wireless communication system, and should be interpreted as not only including user equipment (UE) in Wideband Code Division Multiple Access (WCDMA), LTE, New Air Interface (NR), High Speed ​​Packet Access (HSPA) and IMT-2020 (5G or New Radio), but also including mobile stations (MS), user terminals (UT), subscriber stations (SS), wireless devices (wireless devices) in GSM, etc. In addition, the terminal can be a user portable device such as a smartphone according to the usage form, and in the vehicle to everything (V2X) communication system, it can also mean a vehicle, a device including a wireless communication module in the vehicle, etc. In addition, in a machine type communication (Machine Type Communication) system, it can also mean an MTC terminal equipped with a communication module to perform mechanical type communication, a machine to machine (Machine to machine, M2M) terminal, and an ultra-reliable low-latency communication (Ultra-Reliable Low-Latency Communications, URLLC) terminal, etc.

[0045] The base station or cell in this specification refers to a terminal that communicates with the terminal in terms of the network, which means covering a variety of coverage areas, such as: Node-B, evolved Node-B (eNB), gNB (gNode-B), Low Power Node (LPN), Sector, Site, various forms of antennas, Base Transceiver System (BTS), Access Point, Point (e.g., Transmission Point, Reception Point, Transmission / Reception Point), Relay Node, Extra Large Cell, Macro Cell, Micro Cell, Micro Cell, Femto Cell, Remote Radio Head (RRH), Radio Unit (RU), Small Cell, etc. In addition, the cell may mean a Bandwidth Part (BWP) in the frequency domain. For example, the serving cell may mean the Activation BWP of the terminal.

[0046] Since there are base stations controlling more than one cell in the various cells listed above, the base station can be interpreted in two ways. It can indicate: (1) the device itself, which provides a very large cell, macro cell, micro cell, pico cell, micro-micro cell or small cell related to the wireless area; or, (2) the wireless area itself. In case (1), all devices that interact so that the devices providing the specified wireless area are controlled by the same object or that configure the wireless area through collaboration are indicated as base stations. According to the configuration method of the wireless area, an embodiment of the base station is: point, transmission / reception point, transmission point, reception point, etc. In case (2), from the perspective of the user terminal or the standpoint of the adjacent base station, the wireless area itself that receives or sends signals can also be indicated as a base station.

[0047] In this specification, a cell may refer to a coverage component carrier having a signal transmitted from a transmission / reception point or a coverage component carrier of a signal transmitted from a transmission / reception point or a transmission / reception point itself.

[0048] Uplink (UL, or uplink) means a way of sending / receiving data from a terminal to a base station, and downlink (DL, or downlink) means a way of sending / receiving data from a base station to a terminal. Downlink may mean communication or a communication path from multiple transmission / reception points to a terminal, and uplink may mean communication or a communication path from a terminal to multiple transmission / reception points. At this time, in the downlink, the transmitter may be part of the multiple transmission / reception points, and the receiver may be part of the terminal. In addition, in the uplink, the transmitter may be part of the terminal, and the receiver may be part of the multiple transmission / reception points.

[0049] The uplink and downlink transmit / receive control information through control channels such as the Physical Downlink Control Channel (PDCCH) and the Physical Uplink Control Channel (PUCCH); transmit / receive data through data channels such as the Physical Downlink Shared Channel (PDSCH) and the Physical Uplink Shared Channel (PUSCH). In the following, the situation where signals are transmitted / received through channels such as PUCCH, PUSCH, PDCCH and PDSCH is also marked as "transmitting / receiving PUCCH, PUSCH, PDCCH and PDSCH".

[0050] For a clearer explanation, the following describes the technical concept mainly based on the 3GPP LTE / LTE-A / NR (New RAT) communication system, but the technical features are not limited to this communication system.

[0051] In 3GPP, after studying the fourth-generation mobile information system (4th-Generation, 4G) communication technology, the fifth-generation mobile information system (5th-Generation, 5G) communication technology that meets the requirements of the next-generation wireless access technology of ITU-R is being developed. Specifically, 3GPP develops new NR communication technology through 5G communication technology, which is different from LTE-A pro and 4G communication technology that improves LTE-Advanced technology in a manner that meets the requirements of ITU-R. LTE-A pro and NR both mean 5G communication technology. In the following, unless a specific communication technology is specifically mentioned, 5G communication technology will be explained with NR as the center.

[0052] The operation scenarios in NR add satellite, automotive and new vertical considerations to the existing 4G LTE scenarios, and define multiple operation scenarios. In terms of services, it supports enhanced mobile broadband (eMBB) scenarios; massive machine communication (mMTC) scenarios, which have high terminal density and are deployed over a wide range and require low data rate and asynchronous access; ultra-reliable and low latency communication (URLLC) scenarios, which require high responsiveness and reliability and can support high-speed mobility.

[0053] In order to meet these scenarios, NR discloses a wireless communication system that applies new waveform and frame structure technology, low latency technology, ultra-high frequency band (mmWave) support technology, and forward compatible technology. In particular, in the NR system, in order to provide forward compatibility, a variety of technical changes are proposed in terms of flexibility. The main technical features of NR will be described below with reference to the accompanying drawings.

[0054] <Normal NR system>

[0055] Figure 1 This is a diagram simply showing the structure of the NR system applicable to this embodiment.

[0056] Reference Figure 1, the NR system is divided into 5GC (5G Core Network) and NR-RAN (New Radio Radio Access Network) parts. NG-RAN (Next Generation Radio Access Network) consists of gNB and ng-eNB that provide the user plane (SDAP (Service Data Adaptation Protocol) / PDCP (Packet Data Convergence Protocol) / RLC (Radio Link Control) / MAC (Medium Access Control) / PHY (Physical Layer)) and the control plane (RRC) protocol termination for the UE (User Equipment). gNBs are interconnected with each other or gNB and ng-eNB are interconnected through the Xn interface. gNB and ng-eNB are respectively connected to 5GC through the NG interface. 5GC may include: Access and Mobility Management Function (AMF), which is responsible for the control plane such as terminal access and mobility control functions; and User Plane Function (UPF), which is responsible for user data control functions. NR supports both frequency bands below 6 GHz (FR1, Frequency Range 1) and above 6 GHz (FR2, Frequency Range 2).

[0057] gNB means a base station that provides the NR user plane and control plane protocol termination to the terminal, and ng-eNB means a base station that provides the E-UTRA user plane and control plane protocol termination to the terminal. The base station described in this specification should be understood to cover the meanings of gNB and ng-eNB, and can also be used according to the need to distinguish gNB or ng-eNB for calling.

[0058] <Waveform, Parameter Set, and Frame Structure in NR>

[0059] In NR, for downlink transmission, the CP-OFDM (Cyclic prefix Orthogonal Frequency Division Multiplexing) waveform with a cyclic prefix is used, and for uplink transmission, CP-OFDM or DFT-s-OFDM (Discrete Fourier Transform Spread Orthogonal Frequency Division Multiplexing) is used. OFDM technology is easy to combine with Multiple Input Multiple Output (MIMO), and its advantages are high frequency efficiency and the ability to use a low-complexity receiver.

[0060] On the other hand, in NR, since the requirements for data speed, delay speed, coverage, etc. of the above three scenarios are different, it is necessary to effectively meet the requirements of each scenario by the frequency band that constitutes any NR system. To this end, a technology for effectively multiplexing wireless resources based on different multiple numerologies is proposed.

[0061] Specifically, the NR transmission parameter set is determined based on the sub-carrier spacing and CP (Cyclic prefix), as shown in Table 1 below. Taking 15kHz as the benchmark, the μ value is used as an exponential value of 2 and changes in an exponential form.

[0062]

Table 1

[0063]

[0064] As shown in Table 1 above, according to the subcarrier spacing, the parameter set of NR can be divided into 5 types. This is different from the subcarrier spacing of LTE, one of the 4G communication technologies, which is fixed at 15kHz. Specifically, the subcarrier spacing used for data transmission in NR is 15kHz, 30kHz, 60kHz and 120kHz, and the subcarrier spacing used for synchronization signal transmission is 15kHz, 30kHz, 120kHz and 240kHz. In addition, the extended CP is only applicable to 60kHz subcarrier spacing. On the other hand, a frame with a length of 10ms is defined in the frame structure in NR, and the above frame consists of 10 subframes with the same length of 1ms. A frame can be divided into half frames of 5ms, each half frame includes 5 subframes. In the case of 15kHz subcarrier spacing, a subframe consists of a slot, and each slot consists of 14 OFDM symbols.

[0065] Figure 2 This is a diagram used to illustrate the frame structure in the NR system to which this embodiment is applicable.

[0066] Reference Figure 2In the case of normal CP, the time slot is fixedly composed of 14 OFDM symbols, but in the time domain of the time slot, the length can vary according to the subcarrier spacing. For example, in the case of a parameter set with a 15kHz subcarrier spacing, the length of the time slot is 1ms, which is the same as the length of the subframe. Different from this, in the case of a parameter set with a 30kHz subcarrier spacing, although the time slot consists of 14 OFDM symbols, the length is 0.5ms, and two time slots can be contained in one subframe. That is, subframes and frames are defined by a fixed time length, while the time slot is defined by the number of symbols, and the time length can vary according to the subcarrier spacing.

[0067] In addition, the basic unit of scheduling in NR is defined as a time slot. In order to reduce the transmission delay in the wireless interval, mini time slots (or sub-time slots or non-slot based scheduling) are also introduced. If a wide subcarrier spacing is used, the length of a time slot will be inversely shortened, so the transmission delay in the wireless interval can be reduced. Mini time slots (or sub-time slots) are used to effectively support URLLC scenarios and can be scheduled in units of 2, 4, or 7 symbols.

[0068] In addition, unlike LTE, NR defines uplink and downlink resource allocation as symbol levels within a time slot. In order to reduce HARQ (hybrid automatic repeat request) delay, a time slot structure is defined in which HARQ ACK / NACK (hybrid automatic repeat request-acknowledgement / negative) can be directly sent within the transmission time slot, and this time slot structure is named self-contained structure for explanation.

[0069] NR is designed to support a total of 256 time slot formats, of which 62 time slot formats are used for 3GPP Rel-15. In addition, through the combination of various time slots, a common frame structure that constitutes an FDD or TDD frame is supported. For example, a time slot structure in which all symbols of the time slot are set to the downlink and a time slot structure in which all symbols are set to the uplink, as well as a time slot structure in which downlink symbols and uplink symbols are combined. In addition, NR supports data transmission to be scheduled in more than one time slot. Therefore, the base station can use the Slot Format Indicator (SFI) to inform the terminal whether the time slot is a downlink time slot, an uplink time slot or a flexible time slot. The base station can use SFI to indicate the table index formed by terminal-specific (UE-specific) RRC signaling to indicate the time slot format, or it can be dynamically indicated through downlink control information (DCI) or statically or quasi-statically indicated through RRC.

[0070] <Physical Resources in NR>

[0071] Regarding the physical resources in NR, antenna ports, resource grids, resource elements, resource blocks, bandwidth parts, etc. can be considered.

[0072] An antenna port is defined such that the channel carrying symbols on the antenna port can be inferred from the channel carrying other symbols on the same antenna port. If the large-scale properties of the channel carrying symbols on one antenna port can be inferred from the channel carrying symbols on another antenna port, then the two antenna ports are considered to have a QC / QCL (quasico-located or quasico-location) relationship. Among them, the large-scale properties include more than one of the following: Delay spread, Doppler spread, Frequency shift, Average received power, and Received Timing.

[0073] Figure 3 It is a diagram for explaining the resource grid of the radio access technology applicable to support this embodiment.

[0074] Refer to Figure 3 , Since NR supports multiple parameter sets in the same carrier, resource grids can exist according to each parameter set. In addition, resource grids can exist according to antenna ports, subcarrier spacings, and transmission directions.

[0075] A resource block consists of 12 subcarriers and is defined only in the frequency domain. In addition, a resource element consists of one OFDM symbol and one subcarrier. Therefore, as Figure 3 shown, the size of a resource block can vary according to the subcarrier spacing. In addition, NR defines "Point A" which serves as a common reference point for the resource block grid, and common resource blocks, physical resource blocks, virtual resource blocks, etc.

[0076] Figure 4 It is a diagram for explaining the bandwidth part of the radio access technology applicable to support this embodiment.

[0077] In NR, different from LTE where the carrier bandwidth is fixed at 20 MHz, the maximum carrier bandwidth for each subcarrier spacing is set to 50 MHz to 400 MHz. Therefore, it is not assumed that all terminals use these carrier bandwidths. Thus, in NR, as Figure 4 shown, a bandwidth part (BWP) can be specified within the carrier bandwidth for use by the terminal. In addition, the bandwidth part is associated with a parameter set, consists of a subset of consecutive common resource blocks, and can be dynamically activated according to time. The terminal is configured to have up to 4 bandwidth parts for the uplink and downlink respectively, and transmits / receives data using the activated bandwidth part within a specified time.

[0078] In the case of paired spectrum, the uplink and downlink bandwidth parts are set independently. In the case of unpaired spectrum, to prevent unnecessary frequency re-tuning between downlink and uplink operations, the downlink and uplink bandwidth parts are paired and set to share the center frequency.

[0079] <Initial Access in NR>

[0080] In NR, in order for the terminal to access the base station and communicate, it performs cell search and random access procedures.

[0081] Cell search is a process that uses the synchronization signal block (SSB, Synchronization Signal Block) transmitted by the base station to synchronize the terminal with the cell of the above base station, obtain the physical layer cell ID, and obtain system information.

[0082] Figure 5 is a diagram exemplarily showing the synchronization signal block in the radio access technology to which this embodiment is applicable.

[0083] Referring to Figure 5 , the SSB consists of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) that respectively occupy 1 symbol and 127 subcarriers, and a PBCH that occupies 3 OFDM symbols and 240 subcarriers.

[0084] The terminal receives the SSB by monitoring the SSB in the time and frequency domains.

[0085] SSB can be transmitted up to 64 times within 5ms. Most SSBs are transmitted in different transmission beams within 5ms. If the terminal uses a specific beam for transmission as a reference, it is assumed that SSB is transmitted once every 20ms and detection is performed. Within 5ms, the number of beams available for SSB transmission increases as the frequency band increases. For example, up to 4 SSB beams can be transmitted below 3GHz, up to 8 beams can be used in the frequency band from 3GHz to 6GHz, and up to 64 different beams can be used to transmit SSB in the frequency band above 6GHz.

[0086] Two SSBs are included in one time slot, and the starting symbol and the number of repetitions in the time slot are determined as follows based on the subcarrier spacing.

[0087] On the other hand, unlike the existing LTE SS, SSB is not transmitted at the center frequency of the carrier bandwidth. That is, SSB can be transmitted at a place other than the center of the system frequency band, and when broadband operation is supported, multiple SSBs can be transmitted in the frequency domain. As a result, the terminal uses a synchronization raster as a candidate frequency position for monitoring SSB to monitor SSB. In NR, the carrier raster and the synchronization raster are redefined as the center frequency position of the channel for initial access, and the synchronization raster is set to a wider frequency interval than the carrier raster, so that the terminal can support fast SSB search.

[0088] The terminal can obtain the MIB (Master Information Block) through the PBCH of the SSB. The MIB (Master Information Block) includes the minimum information of the remaining minimum system information (RMSI) broadcast by the terminal for receiving the network. In addition, the PBCH may include: the position information of the first DM-RS symbol in the time domain, the information used by the terminal to monitor SIB1 (for example, SIB1 parameter set information, information related to SIB1 CORESET, search space information, and PDCCH-related parameter information, etc.), the offset information between the common resource block and the SSB (the absolute position of the SSB in the carrier is transmitted through SIB1), etc. Among them, the SIB1 parameter set information is also applicable to some messages used in the random access process for accessing the base station after the terminal completes the cell search process. For example, the parameter set information of SIB1 can be applicable to at least one of messages 1 to 4 used for the random access process.

[0089] The above-mentioned RMSI may mean SIB1 (System Information Block 1), which is broadcast periodically (for example, 160ms) in the cell. SIB1 includes the information required for the terminal to perform the initial random access process, and is periodically transmitted through PDSCH. In order to receive SIB1, the terminal needs to receive parameter set information for SIB1 transmission and control resource set (Control Resource Set, CORESET) information for SIB1 scheduling through PBCH. The terminal uses SI-RNTI in CORESET to confirm the scheduling information for SIB1, and obtains SIB1 on PDSCH according to the scheduling information. Other SIBs except SIB1 can be transmitted periodically or according to the requirements of the terminal.

[0090] Figure 6 This is a diagram for explaining a random access procedure in a wireless access technology to which this embodiment is applicable.

[0091] Reference Figure 6 , when the cell search is completed, the terminal transmits a random access preamble for random access to the base station. The random access preamble is transmitted via PRACH. Specifically, the random access preamble is transmitted to the base station via PRACH consisting of continuous radio resources in a specific time slot that is repeated periodically. Generally, when the terminal initially accesses a cell, a contention-based random access procedure is performed, and when random access is performed for beam failure recovery (BFR, Beam Failure Recovery), a non-contention-based random access procedure is performed.

[0092] The terminal receives a random access response to the transmitted random access preamble. The random access response may include: a random access preamble identifier (ID), an uplink grant (UL Grant) (uplink radio resources), a temporary C-RNTI (Temporary Cell-Radio Network Temporary Identifier), and a time alignment command (TAC). Since a random access response may include random access response information for more than one terminal, a random access preamble identifier may be included to notify which terminal the included UL Grant, temporary C-RNTI, and TAC are valid for. The random access preamble identifier may be the identifier of the random access preamble received by the base station. The TAC may be included as information for the terminal to adjust uplink synchronization. The random access response may be indicated by a random access identifier on the PDCCH, i.e., a random access radio network temporary identifier (RA-RNTI).

[0093] The terminal that receives a valid random access response processes the information contained in the random access response and performs a transmission scheduled to the base station. For example, the terminal applies the TAC and stores the temporary C-RNTI. Additionally, the data stored in the terminal buffer or newly generated data is transmitted to the base station using the UL Grant. In this case, information capable of identifying the terminal should be included.

[0094] Finally, the terminal receives a downlink message for contention resolution.

[0095] <CORESET in NR>

[0096] The downlink control channel in NR is transmitted by a CORESET (Control Resource Set) with a length of 1 to 3 symbols and transmits uplink / downlink scheduling information and a slot format index (SFI), transmit power control (TPC) information, etc.

[0097] As mentioned above, in order to ensure the flexibility of the system, the concept of CORESET is introduced in NR. CORESET (Control Resource Set) refers to the time-frequency resources (i.e., time-frequency resources) used for downlink control signals. The terminal can use more than one search space in the CORESET time-frequency resources to decode control channel candidates. A QCL (Quasi CoLocation) assumption is set for each CORESET, the purpose of which is to notify the characteristics of the simulated beam direction in addition to the characteristics based on the existing QCL assumptions: delay spread, Doppler spread, Doppler shift, and average delay.

[0098] Figure 7 This is a diagram for explaining CORESET.

[0099] Reference Figure 7 , CORESET can exist in multiple forms within the carrier bandwidth in a time slot. In the time domain, a CORESET can consist of up to 3 OFDM symbols. In addition, a CORESET is defined as a multiple of up to six resource blocks of the carrier bandwidth in the frequency domain.

[0100] The first CORESET is part of the initial bandwidth component and is indicated by the MIB to receive additional configuration information and system information from the network. After establishing a connection with the base station, the terminal can receive and configure more than one CORESET information through RRC signaling.

[0101] In this specification, frequency, frame, subframe, resource, resource block, region, frequency band, subband, control channel, data channel, synchronization signal, various reference signals, various signals or various messages related to NR (New Radio) may be interpreted as the meaning used in the past or present or multiple meanings used in the future.

[0102] The present disclosure proposes various embodiments regarding access control of a mobile relay and a technology for controlling a mobile relay when a terminal served by the mobile relay moves together.

[0103] IAB (Integrated Access and Backhaul)

[0104] The IAB node is capable of wireless relaying on NG-RAN. The relaying node, referred to as IAB-node, supports access and backhauling via NR. The terminating node of NR backhauling on network side is referred to as the IAB-donor, which represents a gNB with additional functionality to support IAB.

[0105] Figure 8 is a diagram showing one example of the IAB structure according to the present embodiment. Fig. 9 1 is a diagram for explaining the relationship between a parent node and child nodes of an IAB node according to the present embodiment.

[0106] Reference Figure 8 , the IAB node supports the stand alone mode 800 and the non-stand alone mode 810. In addition, Fig. 9As shown, the IAB-donor supports the gNB-DU functionality defined in 3GPP TS 38.401, namely, terminating the NR access interface (NR Uu) to the terminal and the next-hop IAB-node, and terminating the F1 protocol to the gNB-CU functionality of the IAB-node (The IAB-node supports gNB-DU functionality, as defined inTS 38.401, to terminate the NR access interface to UEs and next-hop IAB-nodes, and to terminate the F1 protocol to the gNB-CU functionality, as defined in TS38.401, on the IAB-donor). The IAB-node DU may be referred to as IAB-DU (The IAB-node DU is also referred to as IAB-DU). The IAB-node supports a portion of the UE functionality referred to as IAB-MT (In addition to the gNB-DU functionality, the IAB-node also supports a subset of the UE functionality referred to as IAB-MT, which includes, eg, physical layer, layer-2, RRC and NAS functionality toconnect to the gNB-DU of another IAB-node or the IAB-donor, to connect to the gNB-CU on the IAB-donor, and to the core network).

[0107] On the other hand, 3GPP approved the project of standardized NR IAB structure and protocol-based mobile relay in the previous version. The project is used to support the scenario of mobile IAB node installed in vehicles, which provides 5G coverage / capacity improvement for onboard and / or surrounding terminals.

[0108] The mobile IAB node supports in-band and out-of-band backhaul. The mobile IAB node does not have a descendant IAB node. That is, the mobile IAB node only serves the terminal.

[0109] However, existing IAB technologies basically assume operation at a fixed location for a period of time. For example, the IAB node is located at a fixed (stationary) location. IAB node migration between donor nodes does not support the usual IAB node switching in which the migrated IAB node is disconnected from the source donor node and connected to the target donor node to send and receive data. Therefore, there is a problem that it is difficult to efficiently support control and user data transmission according to the movement of the mobile IAB. In addition, during the mobile IAB topology adjustment process, the switching of the terminal served by the mobile IAB cannot be provided at the same time. In addition, there is a problem that divided access control cannot be provided for mobile relays.

[0110] As described above, the existing IAB technology is difficult to efficiently support control and user data transmission according to IAB mobility, and when the IAB moves, the terminal served by the IAB cannot be switched at the same time. In addition, there is a problem that divided access control cannot be provided for mobile relay.

[0111] The present embodiment proposed to solve these problems aims to provide a method and apparatus for effective access control and mobility control of a mobile relay.

[0112] For ease of explanation, the following description is centered on the relay / IAB node control method based on NR technology. However, this is only for ease of explanation, and this embodiment can also be applied to any relay based on wireless access technology (for example, 6G, LTE, etc.).

[0113] This embodiment includes information elements and operation contents specified in the NR / 5GS specification (e.g., stage 2 specification: TS 38.300, MAC specification: TS 38.321, NR RRC specification: TS 38.331, system structure specification: TS23.501, etc.). Even if the definition of the information element and the related terminal operation content are not included in this specification, the embodiment may also include the related content specified in the standard specification as a known technology.

[0114] Any function described below is defined as a separate terminal capability (UE radio capability or UE core network capability), and can be transmitted by the terminal to the base station / core network object (e.g., AMF / SMF) through the above signaling. Alternatively, any function is combined / combined and defined as the above terminal capability, and can be transmitted to the base station / core network object through the above signaling according to the terminal.

[0115] For any function or any combination of functions described below, the base station may transmit / indicate information indicating the permission / support / configuration of the above function / combination of functions to the terminal through an RRC message (e.g., a dedicated RRC message or system information). For example, the above function / combination of functions may be indicated to the terminal before or while the above function / combination of functions is configured / applied.

[0116] The functions described below can be performed independently. The functions described below can be implemented in any combination / combination, which can obviously be included in the scope of the present disclosure. For example, more than one function can be applied at the same time, or in any order.

[0117] For the sake of convenience, the mobile IAB node is labeled as a mobile relay. This is for the sake of convenience and can be changed to any other name.

[0118] Fig.10 is a diagram for explaining the operation of a source donor base station according to one embodiment.

[0119] refer to Fig.10 , the method for a source donor base station to control the operation of a mobile relay may include: a step S1010 of sending a handover request message to a target donor base station.

[0120] For example, the source donor base station may determine whether to switch the mobile relay or the terminal of the mobile relay service. The source donor base station may send a switching request message for requesting switching to the target donor base station as the switching object of the mobile relay or the terminal of the mobile relay service. The switching request message may be an RRC message.

[0121] The handover request message may include information required for the mobile relay or the terminal served by the mobile relay to handover to the target donor base station.

[0122] As an example, the handover request message may include an RRC container with information required by the target side to prepare for the handover (eg, a Handover preparation message).

[0123] As another example, the handover request message may include at least one of handover indication information of the mobile relay, indication information of a cell being served by the mobile relay, and terminal context information for a terminal served by the mobile relay.

[0124] As another example, the switching indication information of the mobile relay may include at least one of the switching indication information of the mobile terminal (Mobile Terminal, MT) of the mobile relay and the migration indication information of the distributed unit (Distributed Unit, DU) of the mobile relay. Alternatively, the cell indication information that the mobile relay is providing services may include at least one of the cell indication information that the DU (Distributed Unit) of the mobile relay is providing services and the cell indication information provided by the mobile relay.

[0125] As another example, the handover request message may include BAP address information of the mobile relay, transport network layer (TNL) address information (e.g., IP address information for the mobile relay and / or uplink / downlink Transport-layer-address / IP-address for mobile relay-user plane-traffic / F1-U traffic, GTP-TEID(s)), and one or more of the mobile relay identifier.

[0126] For example, the handover indication information of the mobile relay may include information for indicating that the handover is a handover for the mobile relay. Thus, the target donor base station / IAB-donor-CU may recognize that the handover is a handover for the mobile relay and process it.

[0127] In addition, the handover request message may include information and requests required in the handover process of the mobile relay or the terminal served by the mobile relay as described in the following specific embodiments.

[0128] The method for a source donor base station to control an operation of a mobile relay may include a step S1020 of receiving a handover response message including wireless resource configuration information for at least one of the mobile relay and a terminal served by the mobile relay from a target donor base station.

[0129] For example, the target donor base station may respond to the handover request message and perform acceptance control on the handover request. For the handover request according to the handover request message, the target donor base station may send a handover response message to the source donor base station. The target donor base station may provide an RRC configuration as part of the handover response message.

[0130] As an example, the handover response message may include one or more of the BAP address information, default backhaul RLC channel information, default BAP routing ID, uplink / downlink TNL address information, and mobile relay identifier for the mobile relay connected to the target donor base station. This information can be used as information for mapping F1-C and / or F1-U and / or non-F1 traffic (through the target path) to the target donor base station.

[0131] As another example, the handover response message may include wireless resource configuration information for at least one of the mobile relay and the terminal served by the mobile relay. The wireless resource configuration information may include at least one of BAP address information for the mobile relay, default backhaul RLC channel information, default BAP routing ID, uplink / downlink TNL address information, and a mobile relay identifier.

[0132] As yet another example, the wireless resource configuration information may also include time-based event condition information for triggering conditional handover of a terminal served by the mobile relay.

[0133] The information included in the above handover response message may be included in an RRC container and transmitted to the source donor base station.

[0134] The method for the source donor base station to control the operation of the mobile relay may include: step S1030 of controlling the wireless resource configuration information to be indicated to at least one of the mobile relay and the terminal.

[0135] For example, the source donor base station may send the RRC container received from the target donor base station to at least one of the mobile relay and the terminal to transfer the radio resource configuration information.

[0136] The radio resource configuration information may be sent to the mobile relay via an RRC connection reconfiguration message. When the mobile relay receives the RRC connection reconfiguration message, it may perform a random access procedure to the target donor base station to perform a handover process.

[0137] On the other hand, the terminal served by the mobile relay may be configured to skip the random access procedure when performing handover. That is, even if the mobile relay performs the random access procedure for handover to the target donor base station, the terminal served by the mobile relay may not perform the random access procedure.

[0138] On the other hand, the mobile relay may broadcast mobile relay support information for cell reselection of the terminal. For example, the mobile relay may periodically or aperiodically send system information including cell information provided by the mobile relay, information required to connect to the mobile relay, etc.

[0139] Through this operation, the switching operation of the mobile relay can be performed, and the operation of the terminal served by the mobile relay can be supported uninterruptedly.

[0140] The above operation is described again from the perspective of the target donor base station.

[0141] Fig.11 is a diagram for explaining the operation of a target donor base station according to one embodiment.

[0142] refer to Fig.11 , the method for the target donor base station to control the operation of the mobile relay may include: a step S1110 of receiving a handover request message from a source donor base station.

[0143] For example, the source donor base station may determine whether to switch the mobile relay or the terminal of the mobile relay service. The target donor base station may receive a switching request message for requesting switching from the target donor base station that is the switching target of the mobile relay or the terminal of the mobile relay service. The switching request message may be an RRC message.

[0144] The handover request message may include information required for the mobile relay or the terminal served by the mobile relay to handover to the target donor base station.

[0145] As an example, the handover request message may include an RRC container with information required by the target side to prepare for the handover (eg, a Handover preparation message).

[0146] As another example, the handover request message may include at least one of handover indication information of the mobile relay, indication information of a cell being served by the mobile relay, and terminal context information for a terminal served by the mobile relay.

[0147] As another example, the switching indication information of the mobile relay may include at least one of the MT (Mobile Terminal) switching indication information of the mobile relay and the DU (Distributed Unit) migration indication information of the mobile relay. Alternatively, the cell indication information that the mobile relay is providing services may include at least one of the cell indication information that the DU (Distributed Unit) of the mobile relay is providing services and the cell indication information provided by the mobile relay.

[0148] As another example, the handover request message may include BAP address information of the mobile relay, TNL address information (e.g., IP address information for the mobile relay and / or uplink / downlink Transport-layer-address / IP-address for mobile relay-user plane-traffic / F1-U traffic, GTP-TEID(s)), and one or more of the mobile relay identifier.

[0149] For example, the handover indication information of the mobile relay may include information for indicating that the handover is a handover for the mobile relay. Thus, the target donor base station / IAB-donor-CU may recognize that the handover is a handover for the mobile relay and process it.

[0150] In addition, the handover request message may include information and requests required in the handover process of the mobile relay or the terminal served by the mobile relay as described in the following specific embodiments.

[0151] The method for the target donor base station to control the operation of the mobile relay may include the step S1120 of sending a handover response message including radio resource configuration information for at least one of the mobile relay and the terminal served by the mobile relay to the source donor base station.

[0152] For example, the target donor base station may respond to the handover request message and perform acceptance control on the handover request. For the handover request according to the handover request message, the target donor base station may send a handover response message to the source donor base station. The target donor base station may provide an RRC configuration as part of the handover response message.

[0153] As an example, the handover response message may include one or more of the BAP address information, default backhaul RLC channel information, default BAP routing ID, uplink / downlink TNL address information, and mobile relay identifier for the mobile relay connected to the target donor base station. This information can be used as information for mapping F1-C and / or F1-U and / or non-F1 traffic (through the target path) to the target donor base station.

[0154] As another example, the handover response message may include wireless resource configuration information for at least one of the mobile relay and the terminal served by the mobile relay. The wireless resource configuration information may include at least one of BAP address information for the mobile relay, default backhaul RLC channel information, default BAP routing ID, uplink / downlink TNL address information, and a mobile relay identifier.

[0155] As yet another example, the wireless resource configuration information may also include time-based event condition information for triggering conditional handover of a terminal served by the mobile relay.

[0156] The information included in the handover response message may be included in an RRC container and transmitted to the source donor base station. That is, the radio resource configuration information may be indicated to at least one of the mobile relay and the terminal through the source donor base station.

[0157] For example, the source donor base station may send the RRC container received from the target donor base station to at least one of the mobile relay and the terminal to transfer the radio resource configuration information.

[0158] The radio resource configuration information may be sent to the mobile relay via an RRC connection reconfiguration message. When the mobile relay receives the RRC connection reconfiguration message, it may perform a random access procedure to the target donor base station to perform a handover process.

[0159] On the other hand, the terminal served by the mobile relay may be configured to skip the random access procedure when performing handover. That is, even if the mobile relay performs the random access procedure for handover to the target donor base station, the terminal served by the mobile relay may not perform the random access procedure.

[0160] On the other hand, the mobile relay may broadcast mobile relay support information for cell reselection of the terminal. For example, the mobile relay may periodically or aperiodically send system information including cell information provided by the mobile relay, information required to connect to the mobile relay, etc.

[0161] Through this operation, the switching operation of the mobile relay can be performed, and the operation of the terminal served by the mobile relay can be supported uninterruptedly.

[0162] The following will be divided into a specific embodiment of the mobile relay access control operation and a specific embodiment of the mobile relay handover operation for more detailed description. The operations described below can be performed by the above-mentioned source donor base station, target donor base station, and mobile relay.

[0163] Mobile relay access control

[0164] It is necessary for the mobile relay to distinguish the cell supporting the mobile relay and access the base station / donor base station supporting this function. In order to reduce complexity, preferably, the mobile relay is configured as a single hop. To this end, it is necessary to prohibit other mobile relays or IAB-MTs from accessing the cell provided by the mobile relay.

[0165] To this end, mobile relay support information may be defined and broadcasted through system information (e.g., SIB1). And / or information indicating a cell provided by a mobile relay may be defined and broadcasted through system information (e.g., SIB1). The information may be provided per public land mobile network (PLMN) and / or per non-public network (NPN).

[0166] For example, mobile relay support information can be defined and broadcast through system information (e.g., SIB1). If the terminal is a mobile relay (or mobile relay MT / UE), and / or the information (e.g., mobile relay support information) is not provided for the selected PLMN, and / or it is not a registered PLMN, and / or it is not a PLMN in the equivalent PLMN list, and / or it is not a selected standalone non-public network (SNPN), and / or it is not a registered SNPN, then the cell can be considered to be barred. If this information / field exists, the cell supports mobile relay. And, the cell can be considered as a candidate for cell (re)selection for mobile relay. If this information / field does not exist, the cell does not support mobile relay. And / or the cell is prohibited for mobile relay. This information can be defined as information that is distinguished from the information (iab-support) used to indicate IAB support according to the prior art and broadcast.

[0167] For another example, information indicating a cell provided by a mobile relay may be defined and broadcasted through system information.

[0168] If the terminal is a mobile relay (or a mobile relay MT / UE or IAB-MT), and / or the information (e.g., information indicating a cell provided by a mobile relay) is provided for the selected PLMN, and / or it is not a registered PLMN, and / or it is not a PLMN in the equivalent PLMN list, and / or it is not a selected SNPN, and / or it is not a registered SNPN, then the cell may be considered barred. If this information / field exists, it indicates that the cell is a cell provided by a mobile relay. Furthermore, the cell may not be considered as a candidate for cell (re)selection for a mobile relay (or a mobile relay MT / UE or IAB-MT). The cell is barred for mobile relay.

[0169] If this information / field is not present, the cell is not a cell provided by the mobile relay. The cell may be considered as a candidate for cell (re)selection for the mobile relay.

[0170] For another example, in order to configure the mobile relay as a single hop, the mobile relay can prevent the information (iab-support) used to indicate IAB support from being broadcast in the cell to which the mobile relay provides access / service. The information used to indicate IAB support indicates IAB support and the cell status for IAB. If this information / field exists, the cell supports IAB. And, the cell can be considered as a candidate for cell (re)selection of the IAB node. Therefore, in order to prevent a descendant IAB node from accessing the mobile relay, the cell provided by the mobile relay can prevent the information used to indicate IAB support from being included in the system information for broadcasting.

[0171] If the terminal is a mobile relay (or mobile relay MT / UE), and / or provides this information (e.g., IAB-support) for the selected PLMN, and / or is not a registered PLMN, and / or is not a PLMN in the equivalent PLMN list, and / or is not a selected SNPN, and / or is not a registered SNPN, then the cell may be considered barred. If this information / field exists, it indicates that the cell is an IAB-supported cell. And, the cell may not be considered as a candidate for cell (re)selection for the mobile relay (or mobile relay MT / UE). The cell is barred for mobile relay.

[0172] If this information / field is not present, the cell is not a cell provided by the mobile relay. The cell may be considered as a candidate for cell (re)selection for the mobile relay.

[0173] For another example, the mobile relay may include IAB-DU (Integrated access and backhaul Mobile Terminal) / IAB-MT (Integrated access and backhaul Distributed Unit) functions. Therefore, preferably, access control is performed like an IAB having a base station function.

[0174] As an example, the mobile relay (or mobile relay MT / UE) may ignore the cell-barring or cell-reservation indication information included in the cell system information broadcast.

[0175] The mobile relay (or mobile relay MT / UE) can ignore the cell barring (cellBarred: (IE type: "barred" or "not barred")), cell reservation (cellReservedForOperatorUse: (IE type: "reserved" or "not reserved"), cellReservedForOtherUse: (IE type: "true"), cellReservedForFutureUse: (IE type: "true")) indication information contained in the cell system information broadcast.

[0176] As another example, the mobile relay (or mobile relay MT / UE) may ignore the intraFreqReselection indication information. For example, it may be processed in a manner set to allow intraFreqReselection. This information indicates information for controlling cell selection / reselection when the highest ranked cell is prohibited or processed as prohibited.

[0177] As another example, for a mobile relay (mobile relay MT / UE), the Unified Access Control defined in TS38.331 may not be applicable.

[0178] For another example, a mobile relay may include IAB-DU / IAB-MT functions for relaying. However, compared with the prior art IAB for temporary network deployment, single-hop relay for in-vehicle terminals is used as the main use case. Therefore, in a mobile relay, the number of terminals served by the mobile relay may not be greater than the prior art IAB. On the contrary, the number of mobile relays connected to a specific donor base station may be quite large. Therefore, it is preferable to consider that the mobile relay is closer to the terminal than the base station and perform access control.

[0179] The mobile relay can process the cell status or cell reservation indication information in the same way as the ordinary terminal. The mobile relay (or mobile relay MT / UE) can process one or more of the cell barring (cellBarred: (IEtype: "barred" or "not barred")), cell reservation (cellReservedForOperatorUse: (IE type: "reserved" or "not reserved"), cellReservedForOtherUse: (IE type: "true"), cellReservedForFutureUse: (IE type: "true")) indication information contained in the cell system information broadcast in the same way as the ordinary terminal.

[0180] As an example, when the terminal is a mobile relay and / or the cell status is indicated as "not barred" and / or "not reserved" for operator use and / or not "true" for other use and / or not "true" for future use, the terminal may consider the cell as a candidate cell during the cell (re)selection procedure (When cell status is indicated as "not barred" and "not reserved" for operator use and not "true" for other use and not "true" for future use, UEs shall treat this cell as candidate during the cell selection and cell reselection procedures).

[0181] As another example, when the terminal is a mobile relay and / or the cell status is indicated as "true" for future use, the terminal may consider the cell to be barred (When cell status is indicated as "true" for future use, UE shall treat this cell as if cell status is "barred").

[0182] As another example, when the terminal is a mobile relay, and / or the cell status is indicated as "not barred" and "reserved" for operator use for any PLMN / SNPN and not "true" for other use and not "true" for future use, the cell may be considered as a candidate cell during the cell (re)selection procedure even if the mobile relay is indicated as the field cellReservedForOperatorUse for that PLMN set to "reserved". Alternatively, when the terminal is a mobile relay and the cell status is indicated as "not barred" and "reserved" for operator use for any PLMN / SNPN and not "true" for other use and not "true" for future use, if the mobile relay is indicated as the field cellReservedForOperatorUse for that PLMN set to "reserved", the cell may be considered barred (may operate as the cell is barred).

[0183] As another example, the mobile relay may process the intraFreqReselection indication information in the same manner as a normal terminal. For example, if the intraFreqReselection information / field is set to not be allowed, the mobile relay may not reselect other cells as prohibited cells on the same frequency. These cells may be excluded as candidates for cell selection / reselection within a certain time (e.g., 300 seconds).

[0184] As another example, unified access control (Unified Access Control) can be applied to mobile relays (mobile relay MT / UE). Unified access control can be applied when the mobile relay performs an IAB-node integration procedure, for example, when performing an IAB-MT (Integrated access and backhaul Mobile Terminal) setup (setup) of a mobile relay. As another example, when the mobile relay performs an RRC connection setup / establishment procedure, standardized access categories for processing mobile relays can be specified / defined / differentiated. The mobile relay can map the request type to more than one access identifier and one access category. And it can be indicated to the lower layer (e.g., access layer (AS) (RRC)). The lower layer (RRC) of the terminal performs an access barcode check on its request based on the determined access identifier and access category. The NAS / upper layer of the mobile relay can map the access attempt of the terminal to a specific access category and indicate it to the RRC. As another example, access control for access attempts for mobile relays can be performed by specifying more than one of the standardized access category (Reserved standardized Access Categories) numbers. As another example, for a terminal with mobile relay capability, a terminal stored / indicated / configured as a mobile relay terminal capability through joining information, and a terminal authenticated as a mobile relay through NAS signaling, access control for access attempts of the terminal can be performed by specifying one or more of the numbers of the Reserved standardized Access Categories. As another example, access control can be allocated by specifying one or more of the values ​​11-31 reserved as the standardized access categories.

[0185] As another example, access control may be performed for a mobile relay by specifying one or more of the standardized access identifier numbers. For example, one of the values ​​3-10 reserved as standardized access identifiers may be assigned to a mobile relay / a terminal configured with mobile relay capabilities / a terminal configured for mobile relay services. A universal user identity module (USIM) file (of the terminal) may indicate that the terminal is configured with the access identifier. When the terminal is located within a home public land mobile network (HPLMN) or in an equivalent public land mobile network (EPLMN), the contents of the USIM file may be used to determine the applicability of the access identifier.

[0186] To determine whether the access identifier is valid, the terminal may use the indicator bit of the 5GS network support IE. The indicator bit of the 5GS network support IE may be included in the REGISTRATIONACCEPT message and indicated to the terminal. As another example, an operation-defined access category or an operation-defined access identifier number may be used to perform access control for access attempts of mobile relays.

[0187] On the other hand, the terminal served by the mobile relay can also perform unified access control. Therefore, for the relay of data of the mobile relay terminal, the mobile relay does not need to perform unified access control.

[0188] Fig.12 This is a diagram of an example of the F1-U protocol stack. Fig.12 , the protocol structure used to transmit user plane data can be seen through the IAB node. In the wireless backhaul, the IP layer is transported through the BAP (Backhaul Adaptation Protocol) layer that can route multiple hops. Thus, the existing IAB assumes a multi-hop-based structure and therefore needs to support complex routing.

[0189] To reduce complexity, a mobile relay may be provided through a single-hop structure. For example, a mobile relay may not have a descendant IAB node. The mobile relay may directly communicate with an IAB-donor (or base station / donor base station / gNB-CU. For ease of explanation, the IAB-donor is marked as the donor base station. This is just for the sake of explanation. Fig.12 The mobile relay and the donor base station can be configured without an intermediate IAB node (e.g., Fig.12 in IAB-node1).

[0190] Fig.13 is a diagram exemplarily showing a protocol stack for terminal access using mobile relay.

[0191] For example, user plane data between the terminal and the donor base station can be sent and received through the F1-U / GTP-U tunnel associated with the terminal and the DRB (DRB-ID / RB-ID / LogicalChannelID).

[0192] For another example, the user plane data between the terminal and the donor base station can be sent and received by including one or more index / identification information / (multiple) address information of the terminal (UE-ID / C-RNTI / base station terminal identifier), the DRB (DRB-ID / RB-ID / Logical ChannelID), and the mobile relay (mobile relay identifier / base station identifier / Global-NG-RAN-Node-ID) in the BAP header. Thus, user data can be associated with the backhaul RLC channel / backhaul RLC bearer for sending and receiving in the absence of an F1-U / GTP-U tunnel. The mobile relay can associate the PDCP-PDU / RLC-SDU / RLC-PDU received from the terminal with the backhaul RLC channel / backhaul RLC bearer between the mobile relay and the donor base station for sending and receiving. The mobile relay can associate the RLC-SDU / BAP-PDU / BAP-SDU received from the donor base station with the RLC channel / RLC bearer between the terminal and the mobile relay for sending and receiving.

[0193] The information used to configure it can be configured by indicating it to the mobile relay through an F1AP message or an RRC message. The information used to identify the above terminal can be information allocated by the mobile relay to identify the terminal. Alternatively, the information used to identify the terminal can be information allocated by the donor base station to identify the terminal. The information used to identify the terminal can be included in the RRC setup information, RRC reconfiguration information, and RRC reestablishment information.

[0194] An adaptation protocol (eg, BAP or an adaptation protocol distinguished from BAP for supporting mobile relay) may include one or more of the terminal identifier, the DRB identifier of the terminal, and an identifier of a mobile relay providing access / service to the terminal in a corresponding adaptation protocol header.

[0195] Fig.14 is a diagram showing an example of the BAP data PDU format. Fig.14 For example, when the BAP PDU format is used, the (multiple) R fields may be used / changed to indicate differentiation from the existing format. And one or more of the terminal identifier, the DRB identifier of the terminal, and the mobile relay identifier providing access to the terminal may be included in the corresponding adaptation protocol header.

[0196] For the sake of explanation, the following is based on Fig.13The present invention will explain the method for switching the mobile relay / topology adjustment and / or the switching method of the (multiple) terminals served by the mobile relay. This is for the convenience of explanation, and the change of the use of the adaptation protocol header in the state without the F1-U / GTP-U tunnel is also included in the scope of the present disclosure.

[0197] One or more terminals are carried in a vehicle equipped with a mobile relay. When the vehicle moves, the installed mobile relay and the terminals served by the mobile relay can move together. To support the mobility of the mobile relay, a switching / migration / topology adaptation procedure can be provided for the mobile relay and / or a switching procedure can be provided for the terminal(s) served by the mobile relay.

[0198] For example, the MT of the mobile relay may perform a mobile relay MT handover, which performs a change in the wireless backhaul / cell serving the mobile relay MT. The DU of the mobile relay or a terminal served by the DU of the mobile relay may perform a mobile relay DU migration that changes the donor base station / CU.

[0199] Below, the switching / migration / topology adjustment of the mobile relay represents the switching of the Mobile-IAB-MT provided by the mobile relay and / or the migration of the Mobile-IAB-DU provided by the mobile relay. Through the switching of the Mobile-IAB-MT, the parent node serving the Mobile-IAB-MT (or the wireless backhaul / cell provided by the parent node) is changed. The donor base station / CU (for example, source donor base station / CU->target donor base station / CU) that manages / controls / configures the wireless resources of the Mobile-IAB-MT can be changed as the switching of the Mobile-IAB-MT is performed. The DU of the mobile relay or the donor base station / CU of the terminal served by the DU of the mobile relay (for example, source donor base station / CU->target donor base station / CU) can be changed by the migration of the Mobile-IAB-DU. During the migration process of the Mobile-IAB-DU, in order to perform the switching of the terminal served by the mobile relay, the mobile relay can configure / generate two logical mobile relay DUs that are associated with the source donor base station / CU and the target donor base station / CU respectively.

[0200] During the migration of Mobile-IAB-DU, the (multiple) terminals served by a Mobile-IAB-DU provided by the mobile relay can be switched to another Mobile-IAB-DU provided by the mobile relay. During the migration of Mobile-IAB-DU, the (multiple) terminals served by a cell provided by a Mobile-IAB-DU provided by the mobile relay can be switched to another cell provided by the Mobile-IAB-DU. The switching of Mobile-IAB-MT and the migration of Mobile-IAB-DU can be performed in association. The switching of Mobile-IAB-MT and the migration of Mobile-IAB-DU can also be performed independently.

[0201] Mobility control for mobile relays and terminals served by mobile relays

[0202] Fig.15 is a diagram showing an example of an Inter IAB-donor-CU topology adaptation procedure.

[0203] Reference Fig.15 , shows an example of a procedure for providing topology adjustment by switching mobile relays through different donor base stations / IAB-donor-CUs. For ease of explanation, the procedure is described in a base station separation structure in which the base station / donor base station is configured by CU / IAB-donor-CU and DU / IAB-donor-DU. However, this is for ease of explanation, and the case where the CU / IAB-donor-CU and DU / IAB-donor-DU contained in the base station / donor base station are embodied as a single node / logical entity / physical entity is obviously also included in the scope of the present disclosure.

[0204] The mobile relay can switch the RRC connection and / or data radio bearer used for the mobile relay's own signaling and data traffic. The RRC connection and / or data radio bearer of the mobile relay can be changed from the previous donor base station / IAB-donor-CU / IAB-donor-DU / parent node to a new donor base station / IAB-donor-CU / IAB-donor-DU / parent node. The RRC connection and / or data radio bearer used for the signaling and data traffic generated by the mobile relay MT itself can be changed from the previous donor base station / IAB-donor-CU / IAB-donor-DU / parent node to a new donor base station / IAB-donor-CU / IAB-donor-DU / parent node. The F1-U data traffic generated by the terminal served by the mobile relay DU can be changed from the previous donor base station / IAB-donor-CU / parent node to the new donor base station / IAB-donor-CU / parent node.

[0205] For ease of explanation, the previous donor base station / IAB-donor-CU / IAB-donor-DU / parent node is marked as the source donor base station / IAB-donor-CU / IAB-donor-DU / parent node, and the new donor base station / IAB-donor-CU / IAB-donor-DU / parent node is marked as the target donor base station / IAB-donor-CU / IAB-donor-DU / parent node.

[0206] Reference Fig.15 Each step is explained.

[0207] 1. The source donor base station / IAB-donor-CU transmits a handover request message to the target donor base station / IAB-donor-CU.

[0208] The handover request message may include an RRC container (e.g., a Handoverpreparation message) with information required by the target side to prepare for the handover. The handover request message or RRC container may include BAP address information of the mobile relay, default backhaul RLC channel information, default BAP routing ID, uplink / downlink TNL address information (e.g., IP address information for the mobile relay and / or uplink / downlink Transport-layer-address / IP-address, GTP-TEID(s) for the mobile relay-user plane-traffic / F1-U traffic) and one or more of the mobile relay identifier. This information can be used as information for mapping and transmitting the data traffic (e.g., F1-U) of the terminal served by the mobile relay, the F1-C of the mobile relay DU, and the non-F1 traffic of the mobile relay MT. For example, the F1-C / F1-U traffic of the mobile relay DU and the non-F1 traffic of the mobile relay MT can be transmitted from the mobile relay to the source donor base station / IAB-donor-CU.

[0209] The handover request message may include information indicating that the handover is for a mobile relay (or information indicating support for a mobile relay). For example, it may include information indicating that the terminal is authenticated as a mobile relay (mobile relay MT). The information may be received from a core network node. For another example, it may include information indicating that the handover is for a mobile relay DU migration. The target donor base station / IAB-donor-CU may identify and process that the handover is for a mobile relay.

[0210] The handover request message may include information for supporting / providing / indicating mobility for the terminal served by the mobile relay (for example, a terminal accessing the mobile relay and being in an RRC connected state). This will be described later. For example, when handover / topology adjustment of the mobile relay is performed, processing for providing service continuity for the terminal served by the mobile relay may be performed simultaneously or in association (for example, the mobile relay provides a PCI change of the cell, the handover / cell change / RRC reconstruction of the terminal served by the cell is processed according to the PCI change, and the PDCP recovery or PDCP reconstruction of the terminal served by the mobile relay is processed according to the backhaul link change / handover between the mobile relay and the donor base station).

[0211] 2. The target donor base station / IAB-donor-CU may perform acceptance control. For example, when information indicating that the handover is for mobile relay (or information indicating support for mobile relay) is included, the target donor base station / IAB-donor-CU may control / refuse not to handover to a cell that does not support mobile relay.

[0212] The target donor base station / IAB-donor-CU may send a handover request confirmation / response message to the source donor base station / IAB-donor-CU. The RRC configuration may be provided as part of the handover request confirmation / response message. The handover request confirmation / response message or the RRC configuration may include one or more of the BAP address information, default backhaul RLC channel information, default BAP routing ID, uplink / downlink TNL address information, and mobile relay identifier for the mobile relay connected to the target donor base station / IAB-donor-CU. This information may be used as information for mapping F1-C and / or F1-U and / or non-F1 traffic (via the target path) to the target donor base station / IAB-donor-CU.

[0213] For example, the BAP address information, default backhaul RLC channel information, and default BAP configuration information configured on the mobile relay MT can be used to send the F1-C / F1-U traffic of the mobile relay DU and the non-F1 traffic of the mobile relay MT to the target donor base station / IAB-donor-CU. If the mobile relay provides more than one DU for mobile relay DU migration, the BAP address information, default backhaul RLC channel information, and default BAP configuration information configured on the mobile relay MT can be used to send the F1-C / F1-U traffic of the more than one mobile relay DU and the non-F1 traffic of the mobile relay MT to the donor base station / IAB-donor-CU. If the DU is not reconfigured by F1AP after the default backhaul RLC channel information and the default BAP route ID configuration information are configured, the mobile relay selects the route and the BAP route ID according to the default backhaul RLC channel information and the default BAP route ID configuration information.

[0214] The handover request confirmation / response message may include information for supporting / providing / indicating mobility for the terminal served by the mobile relay (e.g., a terminal accessing the mobile relay and being in an RRC connected state). This will be described later. For example, it may include information for supporting processing for providing service continuity for the terminal served by the mobile relay when performing handover / topology adjustment of the mobile relay (e.g., the mobile relay provides a PCI change of the cell, handles the handover / cell change / RRC reconstruction of the terminal served by the cell according to the PCI change, and handles the PDCP recovery or PDCP reconstruction of the terminal served by the mobile relay according to the backhaul link change / handover between the mobile relay and the donor base station).

[0215] The source donor base station / IAB-donor-CU may include / encapsulate the RRC message(s) / RRC container(s) in a downlink RRC message transfer (Transfer) message and send it to the source IAB-donor-DU.

[0216] When supporting processing for providing service continuity for terminals served by the mobile relay in the case of performing switching / topology adjustment of the mobile relay (for example, the mobile relay provides PCI change of the cell, handles switching / cell change / RRC reconstruction of the terminal served by the cell according to the PCI change, handles PDCP recovery or PDCP reconstruction of the terminal served by the mobile relay according to the backhaul link change / switching between the mobile relay and the donor base station), the source donor base station / IAB-donor-CU can include / encapsulate (multiple) of the RRC messages / (multiple) RRC containers in a downlink RRC message transfer (Transfer) message for the terminal served by the mobile relay and send it to the mobile relay (or mobile relay DU).

[0217] 3. The source donor base station / IAB-donor-CU / IAB-donor-DU may send the received RRC reconfiguration message to the mobile relay.

[0218] 4. The mobile relay may perform a random access procedure to the target donor base station / IAB-donor-DU.

[0219] 5. The mobile relay may send an RRC reconfiguration complete message to the target donor base station / IAB-donor-DU / IAB-donor-CU. The target IAB-donor-DU may include / encapsulate the RRC message in an uplink RRC message transfer message and send it to the target donor base station / IAB-donor-CU.

[0220] 6. The target donor base station / IAB-donor-CU may perform a PATH SWITCH procedure with the core network (e.g., AMF). The target donor base station / IAB-donor-CU may send a PATH SWITCH REQUEST message to the AMF. The target donor base station / IAB-donor-CU may receive a PATH SWITCH REQUESTACKNOWLEDGE message from the AMF. The path switching procedure may indicate a path change of a data radio bearer for the mobile relay's own data traffic. (e.g., the data transmission path from the core network to the source donor base station is changed to a data transmission path from the core network to the target donor base station)

[0221] 7. The target donor base station / IAB-donor-CU may send a terminal context release request message to the source donor base station / IAB-donor-CU.

[0222] The source donor base station / IAB-donor-CU may send an F1AP message for instructing the terminal context release to the source IAB-donor-DU.

[0223] The source IAB-donor-DU may release the context of the mobile relay and may send a message indicating completion of the terminal context release to the source donor base station / IAB-donor-CU.

[0224] The source donor base station / IAB-donor-CU / IAB-donor-DU may release the backhaul RLC channel and the BAP layer routing entry on the source path between the mobile relay and the source donor base station / IAB-donor-CU / IAB-donor-DU.

[0225] When the switching of the mobile relay MT is completed, the source donor CU can know the switching of the mobile relay MT from the target donor CU. After the switching of the mobile relay MT is completed, the source donor CU can send the information of the target donor CU for the mobile relay MT to the donor CU of the mobile relay DU (for example, if no DU migration occurs, it is sent to the source donor CU, if both occur, it is sent to the target donor CU).

[0226] For another example, during a handover / topology adjustment procedure for a mobile relay, (when the mobile relay receives an RRCreconfiguration message) the cell provided by the source donor base station / IAB-gNB-CU may not be disconnected (detached) (or the radio link / connection between the mobile relay and the source donor base station / IAB-gNB-CU is maintained) and connected to the cell provided by the target donor base station / IAB-gNB-CU. When the mobile relay receives an explicit release indication from the target donor base station / IAB-gNB-CU (or from the source donor base station / IAB-gNB-CU), the source donor base station / IAB-gNB-CU resources and configuration may be released, and the source donor base station / IAB-gNB-CU and uplink / downlink transmission / reception may be stopped. The mobile relay may continue the source donor base station / IAB-gNB-CU and uplink / downlink transmission / reception before receiving an explicit release indication. The source donor base station / IAB-gNB-CU (or RRC) may suspend subsequent handover / topology adjustment before the cell provided by the source donor base station / IAB-gNB-CU is released.

[0227] The explicit release indication here can be indicated by the RRC reconfiguration message or F1AP message through the indication information. When receiving the indication information, the mobile relay can perform one or more of the source MAC reset, source MAC configuration release, RLC entity release, return RLC entity release, PDCP release, physical channel configuration release, BAP entity release, (BAP routing ID, BAP address, BAPpath id) release (configured by the source path or source donor base station / IAB-gNB-CU) and uplink / downlink TNL information release (configured by the source path or source donor base station / IAB-gNB-CU) in the cell provided by the source donor base station.

[0228] Alternatively, when the handover command for the mobile relay includes information indicating that the handover of the terminal served by the mobile relay is performed together, if the RRC reconfiguration message (with reconfiguration with sync) is received, the mobile relay can perform one or more of source MAC reset, source MAC configuration release, RLC entity release, return RLC entity release, PDCP release, physical channel configuration release, BAP entity release, BAP routing entry (BAP routing ID, BAP address, BAP path id) release (configured by the source path or source donor base station / IAB-gNB-CU), and uplink / downlink TNL information release (configured by the source path or source donor base station / IAB-gNB-CU).

[0229] According to the movement / cell change / handover / topology adjustment of the mobile relay, the service cell provided by the mobile relay can move. The PCI conflict problem may occur in the moving cell. For example, when two cells with the same PCI become adjacent cells, PCI-collision / PCI-confusion may occur. This may cause synchronization signal conflict, wireless link failure, handover failure, contention in RACH attempts, etc. If inherent PCIs are allocated to each cell in a specific area, such problems may not occur. The donor base station / IAB-donor-CU can detect / predict / estimate PCI-collision / PCI-confusion / RACH-contention.

[0230] The mobile relay may change the PCI information and / or PRACH configuration information of the cell being served by the mobile relay. The mobile relay may change the system information of the cell being served by the mobile relay through system information update.

[0231] For example, at any time point, the mobile relay can change the PCI information and / or PRACH configuration information of the cell being served. The donor base station serving the mobile relay can know the global cell ID (CGI: Cell Global ID) and physical cell ID (PCI: Physical cell id) information of the cell provided by the donor base station, the cell provided by the mobile relay, and the cell provided by the neighboring base station.

[0232] As an example, the donor base station manages the Neighbour Cell Relation Table (NCRT) through the automatic Neighbour Cell Relation (ANR) function. The Neighbour Detection Function (NDF) in the ANR can find neighbors through the terminal's measurement report and add them to the NCRT. The donor base station can know the target cell identified by the source cell.

[0233] As another example, the donor base station can receive report information related to the random access procedure through the RACH report of the terminal. The donor base station can receive content related to the radio link failure through the RLF report of the terminal. Through this information, the mobile relay / donor base station / terminal can know the cell information of the source cell or the neighboring cell, as well as the RACH / PRACH configuration and related failure information in the cell.

[0234] For another example, when a PCI / RACH conflict is detected / predicted / estimated, the mobile relay may send one or more of the CGI for the cell provided by the mobile relay, the current PCI / system information that needs to be changed, the PCI / system information to be changed, the PRACH configuration information that has been changed / to be changed, the information for requesting / indicating / notifying the change of PCI information / PRACH configuration / system information, and the detected RACH failure information to the donor base station. The donor base station may indicate the change of the PCI / PRACH configuration / system information of the cell provided by the mobile relay. Examples of PRACH configurations here may include one or more of the information included in rach-ConfigCommon in Section 9.3.1.140 of TS 38.473 or Section 6.3.2 of TS 38.331.

[0235] For another example, when detecting / predicting / estimating a PCI / RACH conflict, the donor base station may send one or more of the following information to the mobile relay: CGI, current PCI / PCI-set that needs to be changed, PCI / PCI-set / available-PCI-lists / system information to be changed / changeable / recommended, PRACH configuration information of neighboring cells, and recommended PRACH configuration information. The mobile relay may consider the received information when adjusting the PCI / PRACH configuration / system information of the cell providing service. When the mobile relay receives the message and / or changes the PCI / PRACH configuration / system information of the cell provided by the mobile relay, it may send a confirmation / response / notification message to it. The message may include one or more of the CGI, current PCI that needs to be changed, PCI / system information that has been changed / to be changed, and PRACH configuration information that has been changed / to be changed.

[0236] For another example, when a mobile relay performs handover / topology adjustment on the mobile relay through different donor base stations / IAB-donor-CUs, the PCI / system information for the cell being served by the mobile relay may be changed (simultaneously or in association).

[0237] The source donor base station / IAB-donor-CU and / or the target donor base station / IAB-donor-CU may detect / predict / estimate PCI / RACH conflicts for cells served by the mobile relay being handed over / topology adjusted during handover / topology adjustment.

[0238] As an example, the switching request message includes: information for indicating that the terminal that will perform the switching is a mobile relay, identification information of the cell that the mobile relay is providing service (e.g., CGI, PCI), any cell configuration information for the cell (e.g., RACH / PRACH configuration information), information for indicating whether the cell is a cell provided by the mobile relay, information for indicating / requesting a change in any configuration information for the cell (e.g., PCI, system information), and one or more pieces of information for indicating / requesting a change in any configuration information for the cell (e.g., PCI, system information) that is performed simultaneously (or in association with) the switching / topology adjustment of the mobile relay.

[0239] As another example, when one or more of the above-mentioned information is received from the source donor base station / IAB-donor-CU and / or when a PCI / RACH conflict is detected / predicted / estimated in the target donor base station / IAB-donor-CU, the source donor base station / IAB-donor-CU or the target donor base station / IAB-donor-CU can generate / determine a configuration for indicating / processing / dealing with it.

[0240] As another example, the target donor base station / IAB-donor-CU may perform admission control on the handover by detecting / predicting / estimating PCI / RACH conflicts. Alternatively, the target donor base station / IAB-donor-CU detects / predicts / estimates PCI / RACH conflicts and, if necessary, transmits one or more of the following information in any step of the handover procedure: CGI for the cell served by the mobile relay, current PCI / PCI-set to be changed, PCI / PCI-set to be changed / changeable / recommended, available-PCI-lists / system information, PRACH configuration information of the neighboring cells, and recommended PRACH configuration information.

[0241] For example, a handover request confirmation / response message (or a handover preparation failure message) may include one or more of the following information: the CGI for the cell served by the mobile relay, the current PCI / PCI-set that needs to be changed, the PCI / PCI-set / available-PCI-lists / system information to be changed / changeable / recommended, the PRACH configuration information of the neighboring cell, and the recommended PRACH configuration information. The corresponding arbitrary information may be provided per cell (e.g., CGI). Alternatively, it may also be provided as common information to the mobile relay (e.g., or a DU in the mobile relay).

[0242] As another example, a mobile relay may change the PCI information of a cell being served by the mobile relay. The mobile relay may broadcast information for indicating / notifying / notifying / pre-announcement of a PCI change / cell change (or switching of a terminal served by a mobile relay) of the cell through system information. The system information may include one or more of the following information: the CGI of the cell served by the mobile relay, the current PCI to be changed, the PCI to be changed, and PCI change / cell change timing information. The PCI change / cell change timing may indicate the time / moment / time point or time range / duration (start time + offset / duration / elapsed time or start time + end time) at which the PCI change is expected / planned / expected / started / triggered / applicable (or the cell is going to stop serving).

[0243] For example, the time / time range / duration may be indicated as absolute time / UTC (Coordinated Universal Time, time InfoUTC) and / or offset / duration / elapsed time. (For example, the field counts the number of UTC seconds in units of 10 milliseconds since 00:00:00 on January 1, 1900 in the Gregorian calendar (between midnight on Sunday, December 31, 1899 and midnight on Monday, January 1, 1900).) As another example, the time / time range / duration may be indicated by a starting SFN, a starting subframe number, a starting timeslot offset, an offset / duration / elapsed time (ms, number of timeslots). As another example, the time may be indicated as an offset / duration / elapsed time (ms, number of timeslots) at which the expected / planned / expected / start / trigger / adaptation of the cell change is performed at a specific reference time (e.g., a reference SFN, a reference subframe number, a reference timeslot offset, or a reference UTC).

[0244] As another example, the donor base station / IAB-donor-CU / mobile relay may notify / indicate PCI changes / cell changes and / or the above-mentioned system information changes and / or related system information changes through a paging message. For example, a short message (Short message) sent through DCI using P-RNTI may be used to notify / indicate it. The paging message may include information for indicating it. The terminal receiving the message may perform handover / RRC reconstruction to the cell with the changed PCI. The terminal may send confirmation information for receiving the message to the mobile relay. The confirmation information may be provided through any L1 (e.g., any L1 signaling such as UCI, HARQ ACK) / L2 (e.g., any L2 signaling such as MSG1, MAC CE, RLC ACK) / L3 (e.g., RRC message) signaling.

[0245] As another example, the mobile relay may notify / indicate the PCI change / cell change and / or the above-mentioned system information change and / or related system information change through a terminal-specific RRC dedicated message (eg, an RRC reconfiguration message).

[0246] As another example, the target donor base station / IAB-donor-CU may notify / indicate to the mobile relay via an F1 interface application protocol (F1application protocol, F1AP) message the PCI change / cell change and / or the above-mentioned system information change and / or related system information change for the cell provided with service by the mobile relay. The F1AP message may be transmitted via a non-UE-related F1AP message.

[0247] For another example, the PCI of the cell being served by the mobile relay may change with the movement / cell change / switching / topology adjustment of the mobile relay. The mobile relay may change the PCI / system information of the cell being served by the mobile relay through system information update, etc. Therefore, the RRC inactive terminal may perform a RAN notification area update in the cell being served by the mobile relay. The RRC inactive terminal will be configured by the RAN notification area information with one or more of the cell list configured by the RAN area and the RAN area codes list configured by the RAN area. The RRC inactive terminal will initiate a RAN notification area update when it does not belong to the RAN notification area of ​​the configured service cell. If there are many RRC inactive terminals in the cell served by the mobile relay, it may cause a signaling load. During the PCI change, in order to switch the RRC connected terminal served by the mobile relay, such a signaling load is not desirable in the presence of considerable signaling.

[0248] As an example of solving this problem, the target donor base station / IAB-donor-CU or the source donor base station / IAB-donor-CU may indicate, through a mobile relay, information for performing a RAN notification area update at a random or indicated waiting time / backoff time / offset (dispersed) to a terminal served by the mobile relay. The terminal may initiate an RRC connection restart procedure according to the random or indicated waiting time / backoff time / offset.

[0249] The handover request information according to the prior art explicitly disclosed in TS 38.423XnAP protocol includes target cell information required for configuring a handover command for a terminal (eg, RRC reconfiguration with sync), the terminal identification information, and the terminal context information. Specifically, it includes: source base station terminal XnAP identifier (source NG-RAN node UE XnAP ID reference), target cell global identifier (Target CGI: Cell Global ID), globally unique AMF identifier (Globally UniqueAMF Identifier, GUAMI), UE history information (UE History Information), global NG-RAN node ID (Global NG-RAN Node ID) contained in the terminal context reference, S-NG-RAN node UE XnAP ID (S-NG-RANnode UE XnAP ID) and AMF UE NGAP ID contained in the terminal context information (NG-C UE associated Signalling reference), IP address of AMF associated with the stream control transmission protocol (SCTP) (signaling TNL related address on the source NG-C side), terminal security capabilities (UE Security Capabilities), AS security information, Index to RAT / Frequency Selection Priority, UE Aggregate Maximum Bit Rate (UE Aggregate Maximum Bit Rate). Rate), PDU session information to be established (PDU session resources to be established list (PDU Session Resources To Be Setup List)), HandoverPreparationInformation message (RRC context), Location Reporting Information (location reporting information), Mobility Restriction List (mobility restriction list).

[0250] For example, during a handover / topology adjustment procedure for a mobile relay, when the cell provided by the source donor base station / IAB-gNB-CU is disconnected (or the radio link / connection between the mobile relay and the source donor base station / IAB-gNB-CU is cut off or released) (when the mobile relay receives an RRCreconfiguration message), and only the cell provided by the target donor base station / IAB-gNB-CU is connected, the source donor base station / IAB-gNB-CU may need to send or share the terminal context of the (multiple) terminals served by the mobile relay in the source donor base station / IAB-gNB-CU to the target donor base station / IAB-gNB-CU.

[0251] For another example, during the switching / topology adjustment procedure of the mobile relay, (when the mobile relay receives the RRCreconfiguration message), the cell provided by the source donor base station / IAB-gNB-CU can be continuously opened (or the wireless link / connection between the mobile relay and the source donor base station / IAB-gNB-CU is maintained) and connected to the cell provided by the target donor base station / IAB-gNB-CU, the source donor base station / IAB-gNB-CU may need to send or share the terminal context of (multiple) terminals served by the mobile relay in the source donor base station / IAB-gNB-CU to the target donor base station / IAB-gNB-CU.

[0252] Through the XnAP message, the source donor base station / IAB-gNB-CU can send the terminal context of the (multiple) terminals served by the mobile relay in the source donor base station / IAB-gNB-CU to the target donor base station / IAB-gNB-CU. Or the donor base station / IAB-gNB-CU can request and extract the information from the source donor base station / IAB-gNB-CU.

[0253] The XnAP message, for example, a handover request message (or an RRC container included in a handover request message, for ease of explanation, the handover request message is taken as an example for explanation, but the use of any XnAP message (for example, a terminal context extraction message) is obviously also included in the scope of the present invention) may include: for one or more terminals served by a mobile relay, for each terminal, a source base station terminal XnAP identifier (Source NG-RAN node UE XnAP ID reference), a target cell global identifier (Target CGI: Cell Global ID), a GUAMI (Globally Unique AMFIdentifier), UE History Information, a Global NG-RAN NodeID included in the terminal context reference, an S-NG-RAN node UE XnAP ID, and an AMF UE NGAP ID (NG-C UEassociated Signalling reference) included in the terminal context information, an IP address of an SCTP-associated AMF (signaling TNL-related address on the source NG-C side), terminal security capabilities (UE Security Capabilities), AS security information, an Index to RAT / Frequency Selection Priority, and a UE Aggregate Maximum Bit Rate, PDU Session Resources To Be Setup List, HandoverPreparationInformation message (RRC context), Location Reporting Information, Mobility Restriction List. The target cell global identifier may use a cell identifier provided by a mobile relay.

[0254] During, during, or in conjunction with, or in association with the mobility / cell change / switching / topology adjustment of a mobile relay, it may be necessary to switch (multiple) terminals served by the mobile relay.

[0255] For example, when the mobile relay is switched / topology adjusted through different donor base stations / IAB-donor-CUs, it may cause a change in the PCI / system information of the cell being served by the mobile relay. Therefore, it may be necessary to switch the (multiple) terminals served by the mobile relay.

[0256] For another example, when the mobile relay switches / topology adjusts the mobile relay through different donor base stations / IAB-donor-CUs, the wireless backhaul link between the mobile relay and the source donor base station is changed to a wireless backhaul link between the mobile relay and the target donor base station. When the wireless backhaul link is changed, packet / PDU loss may occur in the wireless link. For a wireless bearer with a return RLC channel operating in RLC AM mode, when the wireless backhaul link is changed, the RLC entity is reset, making it difficult to perform lossless transmission. To compensate for this problem, it may be necessary to switch the (multiple) terminals served by the mobile relay. Alternatively, it may be necessary to resend the lost packets / PDUs.

[0257] The switching / topology adjustment of the mobile relay and the switching of more than one terminal served by the mobile relay may be performed simultaneously or in association.

[0258] For example, when handover / topology adjustment of a mobile relay is performed, the handover can be performed by adapting each handover procedure together to each terminal served by the mobile relay.

[0259] As an example, in Fig.15 In step 1, when the source donor base station / IAB-donor-CU sends a switching request message for the mobile relay to the target donor base station / IAB-donor-CU, a switching request message for each terminal served by the mobile relay may be sent together. The switching request message for the mobile relay sent by the source donor base station / IAB-donor-CU to the target donor base station / IAB-donor-CU may include sending a switching request message for each terminal served by the mobile relay. When determining the switching of the mobile relay, the source donor base station / IAB-donor-CU may determine the switching of the (multiple) terminals / terminal groups served by the mobile relay and / or the retransmission of lost packets together.

[0260] As another example, in Fig.15In step 1, if the source donor base station / IAB-donor-CU sends a handover request message for the mobile relay to the target donor base station / IAB-donor-CU, the target donor base station / IAB-donor-CU can determine whether it is necessary to switch the (multiple) terminals / terminal groups served by the mobile relay and / or resend the lost packets when performing the handover of the mobile relay. The case where it is determined that the PCI needs to be changed can be an example. The target donor base station / IAB-donor-CU can include information indicating it in a handover request confirmation / response message or a handover preparation failure message and send it to the source donor base station / IAB-donor-CU. The source donor base station / IAB-donor-CU can receive (multiple) handover request confirmation / response messages for it by sending (multiple) handover request messages for each terminal served by the mobile relay to the target donor base station / IAB-donor-CU.

[0261] As another example, when the source donor base station / IAB-donor-CU sends an RRC reconfiguration message for handover of a mobile relay, the RRC reconfiguration message(s) for each terminal served by the mobile relay may be sent together with the RRC reconfiguration message for handover of the mobile relay. For example, an RRC container carrying an RRC reconfiguration message for handover of the mobile relay and an RRC container carrying an RRC reconfiguration message(s) for each terminal served by the mobile relay may be sent to the mobile relay via the source IAB-donor-DU.

[0262] Alternatively, when the source donor base station / IAB-donor-CU sends an RRC reconfiguration message for switching the mobile relay, the RRC reconfiguration message for switching the mobile relay may include (multiple) RRC reconfiguration messages for each terminal served by the mobile relay for transmission. For example, the RRC reconfiguration message for switching the mobile relay may include (multiple) RRC reconfiguration messages for each terminal served by the mobile relay as each information element. Alternatively, at a specific time point when the source donor base station / IAB-donor-CU sends an RRC reconfiguration message for switching the mobile relay, such as before, during, or after the transmission, the (multiple) RRC reconfiguration message for each terminal served by the mobile relay may be sent to the mobile relay. For example, before the source donor base station / IAB-donor-CU sends an RRC reconfiguration message for switching the mobile relay, (multiple) RRC reconfiguration messages for each terminal served by the mobile relay may be sent to the mobile relay.

[0263] As another example, when the mobile relay sends an RRC reconfiguration complete message to the target donor base station / IAB-donor-CU and completes the RRC switching procedure, the (multiple) RRC reconfiguration complete message for each terminal served by the mobile relay can be sent together with the RRC reconfiguration complete message for the mobile relay. For example, an RRC container carrying an RRC reconfiguration complete message for the mobile relay and an RRC container carrying (multiple) RRC reconfiguration complete messages for each terminal served by the mobile relay can be sent to the target donor base station / IAB-donor-CU via the target IAB-donor-DU.

[0264] Alternatively, when the mobile relay sends an RRC reconfiguration complete message to the target donor base station / IAB-donor-CU, the RRC reconfiguration complete message for the mobile relay may include (multiple) RRC reconfiguration complete messages for each terminal served by the mobile relay for transmission. For example, the RRC reconfiguration complete message for the mobile relay may include (multiple) RRC reconfiguration complete messages for each terminal served by the mobile relay as each information element.

[0265] Alternatively, the mobile relay may receive (multiple) RRC reconfiguration complete messages for each terminal served by the mobile relay before sending the RRC reconfiguration complete message to the target donor base station / IAB-donor-CU.

[0266] As another example, when the target donor base station / IAB-donor-CU sends a PATH SWITCH request message to the core network (e.g., AMF / SMF) for path change of the mobile relay's own data traffic, (multiple) PATH SWITCH request messages for each terminal served by the mobile relay may be sent together. Alternatively, the target donor base station / IAB-donor-CU may include (multiple) PATH SWITCH request messages for each terminal served by the mobile relay in the PATH SWITCH request message for path change of the mobile relay's own data traffic. Alternatively, the target donor base station / IAB-donor-CU may receive (multiple) RRC reconfiguration completion messages for each terminal served by the mobile relay before sending a PATH SWITCH request message to the core network (e.g., AMF) for path change of the mobile relay's own data traffic.

[0267] As another example, when the core network (e.g., AMF / SMF) sends a PATH SWITCH request confirmation / response message for a mobile relay to the target donor base station / IAB-donor-CU, (multiple) PATH SWITCH request confirmation / response messages for each terminal served by the mobile relay may be sent together. Alternatively, (multiple) PATH SWITCH request confirmation / response messages for each terminal served by the mobile relay may be included in the PATH SWITCH request confirmation / response message for a mobile relay sent by the core network (e.g., AMF / SMF) to the target donor base station / IAB-donor-CU. Alternatively, (multiple) PATH SWITCH request messages for each terminal served by the mobile relay may be received before the core network (e.g., AMF / SMF) sends a PATH SWITCH request confirmation / response message for a mobile relay to the target donor base station / IAB-donor-CU.

[0268] As another example, when the target donor base station / IAB-donor-CU sends a UE Context release message for mobile relay to the source donor base station / IAB-donor-CU, (multiple) UE Context release messages for each terminal served by the mobile relay may be sent together. Alternatively, the UE Context release message for mobile relay sent by the target donor base station / IAB-donor-CU to the source donor base station / IAB-donor-CU may include (multiple) UE Context release messages for each terminal served by the mobile relay. Alternatively, before the target donor base station / IAB-donor-CU sends a UE Context release message for mobile relay to the source donor base station / IAB-donor-CU, (multiple) PATH SWITCH request confirmation / response messages for each terminal served by the mobile relay may be received.

[0269] For another example, when performing switching / topology adjustment of a mobile relay, (group) switching may be performed on one or more terminals served by the mobile relay (or all terminals, a terminal set, or a terminal group, or a terminal group. For ease of explanation, more than one terminal is used below, but this is for ease of explanation and may mean all terminals served by the mobile relay, a specific terminal group served by a cell provided by the mobile relay, terminals with a specific configuration (e.g., AM RLC) / function / feature / capability, etc.) Any multiple terminals. Switching / topology adjustment of a mobile relay and (group) switching for one or more terminals served by a mobile relay may be performed through a switching procedure. Mobility / switching may be supported for both the mobile relay and the terminals served by the mobile relay.

[0270] As an example, a group handover request message for indicating a handover / topology adjustment of a mobile relay and / or a (grouped) handover resource preparation request for more than one terminal served by the mobile relay may be defined. For ease of explanation, it is labeled as a group handover request message below. This is for ease of explanation and may be replaced by any name. This message may be defined separately from a handover request message for requesting resource preparation for handover of a terminal.

[0271] As another example, information for indicating handover / topology adjustment of a mobile relay and / or a (grouped) handover resource preparation request for one or more terminals served by the mobile relay may be defined and included in the handover request message.

[0272] As another example, the above-mentioned group switching request message or the switching request message including information for indicating group switching may include the source base station node terminal XnAP ID for the mobile relay and the terminal context information for the mobile relay; for more than one terminal served by the mobile relay, the source base station node terminal XnAP ID for each terminal and the terminal context information for each terminal.

[0273] As another example, when the target donor base station / IAB-donor-CU does not accept at least one PDU session resource for the terminal in one or more terminals served by the mobile relay, or a failure occurs during the handover preparation, the target donor base station / IAB-donor-CU can pass the source base station node terminal XnAP ID and the corresponding cause for the terminal to the source donor base station / IAB-donor-CU. For example, this information can be sent via a group handover request confirmation / response message or a handover request confirmation / response message. Alternatively, it can be sent via a separate handover preparation failure message for the terminal. The source donor base station / IAB-donor-CU can handover the terminal to a neighboring cell of the cell provided by the target donor base station / IAB-donor-CU, or a neighboring cell of the cell provided by the mobile relay.

[0274] As another example, the target donor base station / IAB-donor-CU may send a group switching request confirmation / response message for the above-mentioned group switching request message or a switching request message including information for indicating group switching, or a switching request confirmation / response message including information for notifying about resources prepared for group switching. The group switching request confirmation / response message or the switching request confirmation / response message including information for notifying about resources prepared for group switching may include: the source base station node terminal XnAP ID, the target base station node terminal XnAP ID, the accepted PDU session resource list, and the switching command / RRC reconfiguration message for the mobile relay; and / or for more than one (multiple) terminals served by the mobile relay, the source base station node terminal XnAP ID, the target base station node terminal XnAP ID, the accepted PDU session resource list, and the switching command / RRC reconfiguration message for each terminal.

[0275] As another example, for one or more of the source base station node terminal XnAP ID, the target base station node terminal XnAP ID, and the accepted PDU session resource list, index information for mapping them may be defined and used. The message may include the information.

[0276] As another example, information for identifying a terminal group served by the mobile relay may be defined and used. The message may include this information.

[0277] As another example, when the source donor base station / IAB-donor-CU sends an RRC reconfiguration message for switching a mobile relay, for more than one terminal served by the mobile relay, (multiple) RRC reconfiguration messages for each terminal can be sent together with the RRC reconfiguration message for switching the mobile relay. For example, an RRC container carrying an RRC reconfiguration message for switching the mobile relay and (multiple) RRC containers carrying (multiple) RRC reconfiguration messages for each terminal served by the mobile relay can be sent to the mobile relay via the source IAB-donor-DU.

[0278] Alternatively, when the source donor base station / IAB-donor-CU sends an RRC reconfiguration message for switching a mobile relay, for more than one terminal served by the mobile relay, the (multiple) RRC reconfiguration message for each terminal may be included in the RRC reconfiguration message for switching the mobile relay and sent. For example, the RRC reconfiguration message for switching the mobile relay may include (multiple) RRC reconfiguration messages for each terminal served by the mobile relay as each information element. Alternatively, at a specific time point when the source donor base station / IAB-donor-CU sends an RRC reconfiguration message for switching the mobile relay, such as before, during, or after sending, the (multiple) RRC reconfiguration message for each terminal served by the mobile relay may be sent to the mobile relay. For example, before the source donor base station / IAB-donor-CU sends an RRC reconfiguration message for switching the mobile relay, for more than one terminal served by the mobile relay, (multiple) RRC reconfiguration messages for each terminal may be sent to the mobile relay.

[0279] As another example, a handover configuration for one or more terminals served by a mobile relay (or included in the common configuration information of the wireless resource configuration for handover, or included in one or more information elements in reconfiguration with sync, t304, cell common configuration information (spCellConfigCommon / ServingCellConfigCommon)) can be broadcast to the terminal via system information. Terminals supporting this capability can obtain the system information. The handover configuration for one or more terminals served by a mobile relay can be generated / sent in a manner that does not include the common configuration information (e.g., t304, cell common configuration information) included in the wireless resource configuration for handover received via the above-mentioned system information.

[0280] As another example, when the mobile relay sends an RRC reconfiguration complete message to the target donor base station / IAB-donor-CU and completes the RRC switching procedure, for more than one terminal served by the mobile relay, (multiple) RRC reconfiguration complete messages for each terminal can be sent together with the RRC reconfiguration complete message for the mobile relay. For example, an RRC container carrying an RRC reconfiguration complete message for the mobile relay and (multiple) RRC containers carrying (multiple) RRC reconfiguration complete messages for each terminal for more than one terminal served by the mobile relay can be sent to the target donor base station / IAB-donor-CU via the target IAB-donor-DU.

[0281] Alternatively, when the mobile relay sends an RRC reconfiguration complete message to the target donor base station / IAB-donor-CU, for one or more terminals served by the mobile relay, the RRC reconfiguration complete message for the mobile relay may include (multiple) RRC reconfiguration complete messages for each terminal for transmission. For example, for one or more terminals served by the mobile relay, the RRC reconfiguration complete message for the mobile relay may include (multiple) RRC reconfiguration complete messages for each terminal as each information element.

[0282] Alternatively, the mobile relay may receive (multiple) RRC reconfiguration complete messages for each terminal for more than one terminal served by the mobile relay before sending the RRC reconfiguration complete message to the target donor base station / IAB-donor-CU.

[0283] As another example, a group path change request message may be defined for indicating a data traffic path change of a mobile relay (e.g., a data traffic path change for changing a downlink terminal point of an NG-U transport bearer to a new terminal point) and / or a (packetized) data traffic path change request for one or more terminals served by a mobile relay. Alternatively, information for indicating a data traffic path change of a mobile relay and / or a (packetized) data traffic path change request for one or more terminals served by a mobile relay may be defined and included in a path change request (PathSwitch Request) message. The path change request message may include a group path change request message or information for indicating a data traffic path change of a mobile relay and / or a (packetized) data traffic path change request for one or more terminals served by a mobile relay. The path change request message may include the base station node terminal NGAP ID, the AMF terminal NGAP ID, and the PDU session resource list switched in the downlink for the mobile relay; and / or for more than one terminal served by the mobile relay, the base station node terminal NGAP ID, the AMF terminal NGAP ID, and the PDU session resource list switched in the downlink for each terminal.

[0284] As another example, the target donor base station / IAB-donor-CU may receive (multiple) RRC reconfiguration completion messages for each terminal served by the mobile relay before sending a group path change request message or a path change request message including information indicating a data traffic path change of the mobile relay and / or a (grouped) data traffic path change request for one or more terminals served by the mobile relay.

[0285] As another example, a group path change request confirmation / response message for indicating that the path change notifying the mobile relay is successfully completed and / or a path change request confirmation / response (grouped) for one or more terminals served by the mobile relay may be defined. Alternatively, information for indicating the path change request confirmation / response of the mobile relay and / or the path change request confirmation / response (grouped) for one or more terminals served by the mobile relay may be defined and included in the path change request confirmation / response (Path Switch RequestAcknowledge) message. A group path change request confirmation / response message or a path change request confirmation / response message including information for indicating a path change request confirmation / response of a mobile relay and / or a (grouped) path change request confirmation / response for one or more terminals served by a mobile relay may include a base station node terminal NGAP ID, an AMF terminal NGAP ID, and a list of PDU session resources switched in a downlink for the mobile relay; and / or for one or more terminals served by the mobile relay, a base station node terminal NGAP ID, an AMF terminal NGAP ID, and a list of PDU session resources switched in a downlink for each terminal.

[0286] As another example, for one or more of the base station node terminal NGAP ID, the AMF terminal NGAP ID, and the PDU session resource list switched in the downlink, index information for mapping them may be defined and used. As another example, information for identifying the terminal group served by the mobile relay may be defined and used. The message may include this information.

[0287] As another example, in order to make the target donor base station / IAB-donor-CU indicate to the source donor base station / IAB-donor-CU to release the resources of the mobile relay, and / or in order to make the target donor base station / IAB-donor-CU indicate to the source donor base station / IAB-donor-CU to release the (grouped) resources for more than one terminal served by the mobile relay, a group terminal context release message can be defined. Alternatively, information for indicating the release of resources of the mobile relay and / or the release of (grouped) resources for more than one terminal served by the mobile relay can be defined and included in the terminal context release message. The group terminal context release message or the terminal context release message including information for indicating the release of resources of the mobile relay and / or the release of (grouped) resources for more than one terminal served by the mobile relay may include the source base station node terminal XnAP ID and the target base station node terminal XnAP ID for the mobile relay; and / or for more than one terminal served by the mobile relay, the source base station node terminal XnAP ID and the target base station node terminal XnAPID for each terminal. As another example, for one or more of the source base station node terminal XnAP ID and the target base station node terminal XnAP ID, index information for mapping them can be defined and used. As another example, information for identifying the terminal group served by the mobile relay can be defined and used. The message can include this information.

[0288] Other embodiments according to the present disclosure are described below.

[0289] During handover / topology adjustment of the mobile relay, one or more terminals served by the mobile relay may maintain an RRC connection and transmit and receive data through a cell provided by the mobile relay.

[0290] For example, when the mobile relay performs a switching / topology adjustment procedure for any cell provided by the mobile relay without changing the PCI, the wireless connection can be maintained and data can be sent and received on the wireless interface (Uu) between the terminal served by the mobile relay and the mobile relay. However, as the wireless backhaul link between the mobile relay and the source donor base station is changed to the wireless backhaul link between the mobile relay and the target donor base station, packet / PDU loss may occur in the wireless link. Therefore, for (multiple) terminals configured by wireless bearers operating in RLC AM mode, losses may occur in the wireless / wireless backhaul interval. In order to improve this problem, during the switching / topology adjustment of the mobile relay, the target donor base station / IAB-donor-CU (or the source donor base station / IAB-donor-CU) can indicate one of PDCP data recovery and PDCP entity re-establishment for the (multiple) terminals served by the mobile relay if a wireless bearer with RLC AM mode is configured in the terminal. For example, it can be Fig.15 Indicate it in step 2, step 3, or any step in the process.

[0291] When the terminal receives information indicating the resumption of PDCP data, it may perform retransmission of all the PDCP Data PDUs previously submitted to the AM RLC entities in ascending order of the associated COUNT values ​​for which the successful delivery has not been confirmed by lower layers. Here, the AM RLC entity may be in a state of reestablishment, release, establishment after release, reconfiguration, and maintaining the previous configuration.

[0292] When the terminal receives information indicating the re-establishment of the PDCP entity, it may, before the PDCP entity re-establishment, perform retransmission or transmission of all the PDCP SDUs already associated with PDCP SNs in ascending order of the COUNT values ​​associated to the PDCP SDU in accordance with the ascending order of the COUNT values ​​associated with the PDCP SDU.

[0293] The donor base station / IAB-donor-CU may indicate it to the terminal through a mobile relay using a dedicated RRC message (e.g., an RRC reconfiguration message). For example, for a legacy terminal that does not support this function, a dedicated RRC message may be used for indication. For example, the donor base station / IAB-donor-CU may indicate it to the terminal through a mobile relay using system information. For example, for a terminal that supports this function, system information may be used for indication. The transmission of system information through a mobile relay may be indicated by using any method described in this specification.

[0294] For another example, when a mobile relay performs a PCI change and a handover / topology adjustment procedure for any cell provided by the mobile relay, the terminal served by the mobile relay must perform a cell change / handover (reconfiguration with sync) operation. For example, if the T304 timer is started, the target cell starts downlink synchronization, random access starts, the broadcast control channel (BCCH) configuration specified in TS38.331 9.1.1.1 is applied to the target cell, the MIB is obtained, an RLC entity with the same configuration as the source cell group is established in the target cell group for each SRB, a logical channel with the same configuration as the source cell group is established, a new terminal identifier (newUE-Identity) value is applied as C-RNTI in the target cell group, MAC is reset, the lower layer is configured (the lower layer is configured according to the received spCellConfigCommon, and if included in the received reconfigurationWithSync, the lower layer is configured according to other fields not previously covered, such as DRB configuration), the terminal has available logged measurements (logged measurement), available connection establishment failures, available connection restart failures, available radio link failures, and available handover failures. At least one of the following operations needs to be performed: include the available logged measurements (logged measurement) in the RRC reconfiguration complete message. The information contained in the available connection establishment failure measurement, available connection restart failure, available wireless link failure, and available switching failure is partially applicable to the CSI reporting configuration, the scheduling request configuration, and the sounding RS configuration that do not require the UE to know the SFN of the respective target SpCell, if any. The (multiple) terminals served by the mobile relay need to perform cell change / switching operations according to the PCI change, but the basic wireless channel state between the (multiple) terminals and the mobile relay does not change much. Therefore, the terminal served by the mobile relay may not need to perform or simplify the execution of one or more of the above-mentioned cell change / switching (reconfiguration with sync) operations.If the operation includes starting the T304 timer, starting downlink synchronization of the target cell, starting random access, applying the BCCH configuration specified in TS38.331 9.1.1.1 to the target cell, obtaining the MIB, establishing an RLC entity with the same configuration as the source cell group for each SRB in the target cell group, establishing a logical channel with the same configuration as the source cell group, applying a new terminal identifier (newUE-Identity) value as C-RNTI in the target cell group, MAC reset, lower layer configuration, available logged measurement of the terminal, available connection establishment failure, available connection restart failure, available radio link failure, and available handover failure, then the information contained in the available logged measurement, available connection establishment failure, available connection restart failure, available radio link failure, and available handover failure can be included in the RRC reconfiguration completion message, and some of the CSI report configuration, scheduling request configuration, and detection RS configuration that do not require the terminal to know the SFN of the target cell are partially applicable.

[0295] As an example of supporting this, when a terminal served by a mobile relay performs a cell change / switching based on a PCI change, or performs a switching based on a switching / topology adjustment of the mobile relay, information indicating a simplified operation can be defined and indicated to the terminal(s).

[0296] For example, when a terminal served by a mobile relay performs a cell change / switching according to a PCI change, or performs a switching according to a switching / topology adjustment of the mobile relay, there is no need to indicate and apply a new terminal identifier for use as the C-RNTI. The same C-RNTI can be used in the source cell and the target cell. If the donor base station / IAB-CU does not change, the existing SRB can be used directly without establishing an RLC entity and logical channel for the SRB, and there is no need to include log measurement or failure information in the RRC reconfiguration completion message. When receiving the indication information, the terminal can perform a cell change / switching in a cell provided by the mobile relay without performing one or more of the above-mentioned cell change / switching (reconfiguration with sync) operations.

[0297] As another example, for each DRB, the terminal may perform one or more of the following: establishing / reconfiguring / maintaining an RLC entity with the same configuration as the source cell group in the target cell group, establishing / reconfiguring / maintaining a logical channel with the same configuration as the source cell group, establishing / reconfiguring / maintaining a PDCP entity with the same configuration as the source cell group in the target cell group, and establishing / reconfiguring / maintaining an SDAP entity with the same configuration as the source cell group.

[0298] It can be indicated to the (multiple) terminals by information used to indicate it. As another example, for any radio resource configuration parameter configured in the source cell group, the terminal can establish / set / reconfigure / maintain the terminal so that the target cell group has the same configuration as the source cell group. For example, in addition to the parameters for synchronization and random access procedures, for any configuration for sending and receiving data through the control channel / data channel, the same configuration as the source cell group can be maintained to restart data sending and receiving. It can be indicated to the (multiple) terminals by information used to indicate it. The indication information can be indicated by each indication information according to each parameter using the same configuration as the source cell. Alternatively, more than one parameter can be indicated by one indication information.

[0299] For example, the base station does not need to allocate RACH resources to the terminal. Therefore, the base station may include one or more of the timing adjustment indication information, the pre-configured uplink grant, and the beam indication information in the RRC reconfiguration message or the handover command. If the terminal does not receive the configured uplink grant, it may receive the uplink grant through the PDCCH of the target cell. The terminal may use the uplink grant to send the RRC reconfiguration completion information to the base station.

[0300] The mobile relay (mobile relay DU) serving the terminal may share and use one or more of the cell group configuration, RLC configuration, logical channel configuration, and C-RNTI for the source cell as the same configuration as the cell group configuration, RLC configuration, logical channel configuration, and C-RNTI for the target cell. Alternatively, the mobile relay (mobile relay DU) serving the terminal may share and use one or more of the cell group configuration, RLC configuration, logical channel configuration, and C-RNTI for the terminal of the mobile relay DU providing the source cell as the same configuration as the cell group configuration, RLC configuration, logical channel configuration, and C-RNTI for the terminal of the mobile relay DU providing the target cell. The source cell and the target cell provided by the mobile relay may be provided by one mobile relay DU within one mobile relay, or by different mobile relay DUs within one mobile relay. For example, the source cell may be provided by one mobile relay DU, and the target cell may be provided by another mobile relay DU that is distinguished from the mobile relay DU.

[0301] As another example, the mobile relay may suspend the RRC connection, RRC configuration parameters, and the cell / MCG transmission configured in the source cell group during handover / topology adjustment of the mobile relay, during a specific operation / step of handover / topology adjustment of the mobile relay, or during the target cell synchronization and random access process of the mobile relay. Alternatively, the terminal may suspend the RRC connection, RRC configuration parameters, and the cell / MCG transmission configured in the source cell group during handover / topology adjustment of the mobile relay, during a specific operation / step of handover / topology adjustment of the mobile relay, or during the synchronization and random access steps of the terminal.

[0302] When synchronizing with the target cell and successfully completing random access, the RRC connection, RRC configuration parameters, and the cell / MCG transmission can be restarted to send and receive data. The (multiple) terminals can be indicated by information used to indicate it. As another example, the terminal can suspend the RRC connection, RRC configuration parameters, and the cell / MCG transmission configured in the source cell group during synchronization with the PCI cell changed by mobile relay. When synchronizing with the cell with PCI change and sending an RRC reconfiguration completion message, the RRC connection, RRC configuration parameters, and the cell / MCG transmission can be restarted to send and receive data. The (multiple) terminals can be indicated by information used to indicate it.

[0303] As another example, for any of the above indication information, the donor base station / IAB-donor-CU may use a dedicated RRC message (e.g., an RRC reconfiguration message) to indicate it to the terminal through a mobile relay. For example, for a Legacy terminal that does not support this function, a dedicated RRC message may be used for indication. As another example, the donor base station / IAB-donor-CU may use system information to indicate it to the terminal through a mobile relay. For example, for a terminal that supports this function, system information may be used for indication. The transmission of system information through a mobile relay may be indicated by using any method described in this specification.

[0304] As another example, when or before a cell provided by a mobile relay starts / executes / applies a PCI change, the mobile relay may send information indicating that a PCI change has been started / executed / applied to a donor base station / IAB-donor-CU serving the mobile relay.

[0305] During the PCI change and / or the switching / topology adjustment of the mobile relay, executing the switching procedure for multiple terminals served by the mobile relay by sending switching commands to individual terminals in a short period of time may cause a considerable signaling load. Some terminals may not be able to switch at the appropriate time. As a result, a radio link failure / switching failure may occur / detected at the terminal. The terminal can start the RRC reconstruction procedure. In order to restore the RRC connection, time is required for radio link failure / switching failure detection, cell selection, RRC reconstruction signaling, etc. In order to reduce this service interruption, the donor base station / IAB-donor-CU can configure conditional switching or conditional RRC connection reconstruction for (multiple) terminals served by the mobile relay, and allow the terminal to start / execute conditional switching or RRC reconstruction when the corresponding conditions are met.

[0306] For example, the donor base station / IAB-donor-CU may configure in the terminal an indication / help information for triggering conditional switching / conditional RRC reconstruction / RRC reconstruction for (multiple) terminals served by the mobile relay. The indication / help information may include one or more of the PCI of the cell to be changed, the conditional switching trigger condition / event, the conditional switching configuration, the (conditional) RRC reconstruction trigger condition / event, and the PCI change / cell change / switching timing information. The conditional switching configuration and the PCI change / cell change timing information may be provided according to any embodiment included in the present invention.

[0307] For example, the help information can be indicated to the terminal via RRC dedicated information. Alternatively, the help information can be indicated to the terminal via system information. As another example, the conditional switching trigger condition / event or (conditional) RRC reconstruction trigger condition / event can be a time-based trigger condition using PCI change timing information or cell change timing information. The time-based trigger condition using PCI change / cell change timing can be configured together with the measurement-based trigger condition (e.g., conditional switching (CHO) A3 / A4 / A5). Alternatively, the time-based trigger condition using PCI change / cell change timing can be configured without a measurement-based trigger condition (e.g., CHO A3 / A4 / A5). If the PCI change / cell change time is configured by a specific absolute time / moment / time point, there is no need to configure the measurement-based trigger condition at the same time. As another example, it can be defined that the A2 event can be used as a trigger condition for conditional switching or conditional RRC reconstruction.

[0308] In the prior art, only A3 / A4 / A5 are used as measurement-based trigger conditions / events for conditional switching. However, the PCI change can be perceived by the A2 event (Event A2: Serving becomes worse than threshold) in which the measurement value of the serving cell is lower than a specific threshold. Therefore, the A2 event can be additionally defined as a trigger condition for conditional switching or conditional RRC reconstruction. For example, a conditional event (condEventA2) can be defined in the conditional trigger configuration (CondTriggerConfig) information element. The conditional event information element may include a2-threshld, hysteresis, and timeToTrigger information as detailed information elements. As another example, a time-based trigger condition using PCI change / cell change timing can be configured together with any radio link failure criteria. For example, it can be configured together with any radio link failure criteria such as the expiry of a radio problem timer started after indication of radio problems from the physical layer, RLCfailure, etc. Alternatively, when any radio link failure criteria is met, conditional switching / conditional RRC reconstruction / RRC reconstruction can be initiated. As another example, the candidate cell configuration for conditional switching / conditional RRC reconstruction / RRC reconstruction can be configured with a changed PCI value. As another example, when conditional switching / conditional RRC reconstruction / RRC reconstruction is initiated / executed, a cell using the indicated PCI value is selected by the terminal, then conditional switching / conditional RRC reconstruction / RRC reconstruction can be initiated / executed. The terminal can apply a stored conditional switching configuration (e.g., condRRCReconfig) associated with the selected cell. As another example, a conditional switching configuration can be provided according to any embodiment included in the present invention.

[0309] For another example, accurate time control may be required when the PCI is changed / the cell is changed. Before the switching time point, (all) terminals (or RRC connected state terminals) served by the mobile relay must perform the transmission of confirmation messages for conditional switching / conditional RRC reconstruction / handover command reception and / or RRC message reception. Before the switching time point, specific operations for switching (e.g., target cell synchronization, target cell random access procedure) may not be started. Specific operations for switching may be started after the switching time point.

[0310] For another example, in the prior art, when a handover failure occurs when a terminal performs a handover, the terminal includes the PCI, C-RNTI and shortMAC-I / MAC-I of the source PCell in an RRC reestablishment request message and sends it. The base station that receives the message uses the PCI and C-RNTI of the source PCell to identify the terminal. When the terminal fails to switch during the PCI change process, if the PCI of the cell provided by the mobile relay changes, so that the PCI before the change is deleted / released / cancelled, the base station cannot detect / extract the context for the terminal and reestablish / maintain the RRC connection. Therefore, when the PCI changes, it is necessary to maintain information about the change details. As another example, with the change of PCI, when a handover failure occurs when the terminal performs a handover, the terminal can include one or more of the PCI, C-RNTI, and shortMAC-I / MAC-I of the target PCell in an RRC reestablishment request message and send it. Alternatively, one or more of the PCI, C-RNTI, shortMAC-I / MAC-I of the target PCell and the PCI, C-RNTI, shortMAC-I / MAC-I of the source PCell may be included in the RRC reestablishment request message and sent.

[0311] During handover / topology adjustment of the mobile relay and / or handover of (multiple) terminals served by the mobile relay, service continuity should be provided / supported for the terminals served by the mobile relay. For example, for radio bearers using RLC-AM, lossless delivery should be supported. Alternatively, handover operations for the terminal should be supported to minimize service interruption.

[0312] Figures 16 to 18 is a diagram showing various examples of protocol structures in mobile relay handover. For example, Figures 16 to 18 Represents an example of a protocol structure for user plane data transmission for a terminal served by a mobile relay during and / or after a handover / topology adjustment of a mobile relay. Fig.16 , Fig.17 and Fig.18 More than one structure can also be used Fig.16 , Fig.17 and Fig.18 A structure in .

[0313] As described above, the data radio bearer (DRB) of the terminal served by the mobile relay can be established / connected / configured in association with the F1-U protocol (F1-U GTP-U tunnel) between the mobile relay and the donor base station / IAB-donor-CU.

[0314] For example, during the switching / topology adjustment of the mobile relay and / or the switching of (multiple) terminals served by the mobile relay, in order to associate the data radio bearer (DRB) carrying the user data of the terminal served by the mobile relay, the F1-U / GTP-U tunnel between the mobile relay and the source donor base station / IAB-donor-CU can be maintained. Even after the switching / topology adjustment of the mobile relay is completed, the user data of the terminal served by the mobile relay can be sent and received through the F1-U protocol / GTP-U tunnel. The user plane traffic of the terminal served by the mobile relay can be delivered from the source donor base station / IAB-donor-CU to the core network.

[0315] Through the switching / topology adjustment of the mobile relay and / or the switching of (multiple) terminals served by the mobile relay, the donor base station / IAB-donor-CU serving the mobile relay is changed from the source donor base station / IAB-donor-CU to the target donor base station / IAB-donor-CU. The source donor base station / IAB-donor-CU may also continue to maintain the terminal context for the terminal served by the mobile relay. And / or the target donor base station / IAB-donor-CU may continue to maintain the terminal context for the terminal served by the mobile relay.

[0316] As an example, the uplink user plane data of the terminal served by the mobile relay can be mapped / associated in the mobile relay and sent to the source donor base station / IAB-donor-CU through the target donor base station / IAB-donor-CU. For example, although the handover is performed on the mobile relay MT, the migration of the mobile relay DU is not performed (or, when the source cell and the target cell provided by the mobile relay are provided by a mobile relay DU within a mobile relay, and the mobile relay DU is configured by the source donor base station / IAB-donor-CU), the F1-U corresponding to the uplink user plane data of the terminal and the F1-C corresponding to the uplink control plane data of the terminal can be mapped / associated in the mobile relay and sent to the source donor base station / IAB-donor-CU through the target donor base station / IAB-donor-CU. Before the mobile relay DU, for the (source) mobile relay DU configured / controlled by the source donor base station / IAB-donor-CU, the default return RLC channel information, default BAP routing ID, and uplink / downlink TNL address information for F1-U, F1-C traffic processing by the (source) mobile relay DU are configured to send data to the source donor base station / IAB-donor-CU.

[0317] like Fig.16As shown, the uplink user plane data of the terminal served in the mobile relay can be mapped to the GTP-U tunnel between the mobile relay and the source donor base station / IAB-donor-CU and transmitted. For example, the transmission path of the user plane data of the terminal served by the mobile relay can be sent and received by switching the path from 'terminal <-> source donor base station <-> core network' to 'terminal <-> target donor base station <-> source donor base station <-> core network'. Through the migration of the mobile IAB-DU, the terminal connected to the mobile IAB node can switch from the cell provided by the DU associated with the source CU having an F1AP (source cell) to the cell provided by the DU associated with the target CU having an F1AP (target cell). As in the embodiments described above, the switching of the mobile IAB-MT and the migration of the mobile IAB-DU can be performed in association or independently. At this stage, there is no need for a path switching procedure between the base station and the core network.

[0318] The BAP entity of the mobile relay (e.g., the transmission part of the BAP entity) can receive BAP SDUs from the upper layer (e.g., GTP-U / UDP / IP). In addition, the uplink user plane tunnel information to be established can be used in the mobile relay received from the source donor base station / IAB-donor-CU (or from the target donor base station / IAB-donor-CU through the source donor base station / IAB-donor-CU, or from the target donor base station / IAB-donor-CU) to determine the BAP address and Path ID, and append the BAPPDU header to create BAP Data PDUs. The source donor base station / IAB-donor-CU or the target donor base station / IAB-donor-CU can indicate the uplink user plane tunnel information to be established / modified to the mobile relay through an F1AP / RRC message. The uplink user plane tunnel information to be established / modified indicated to the mobile relay can be associated with one or more of the source base station terminal XnAP identifier, the target base station terminal XnAP identifier, the user plane DRB / RLC channel ID, the uplink user plane TNL address (GTP tunnel, Transport-layer-address / IP-address, GTP-TEID) and the return information of the terminal served by the mobile relay. Here, the return information may include the BAP routing ID and the next-hop BAP address containing the BAP address and Path ID of the target IAB-donor / IAB-donor-DU.

[0319] One or more information included in the uplink user plane tunnel information to be established / modified can be sent and received between the source donor base station / IAB-donor-CU and the target donor base station / IAB-donor-CU. As an example, the source donor base station / IAB-donor-CU can include one or more information included in the uplink user plane tunnel information to be established / modified (e.g., source base station terminal XnAP identifier, user plane DRB-ID / RLC channel ID / LCID of the terminal served by the mobile relay, uplink user plane TNL address) in the XnAP message and send it to the target donor base station / IAB-donor-CU. As another example, the target donor base station / IAB-donor-CU can include one or more information included in the uplink user plane tunnel information to be established / modified (e.g., target base station terminal XnAP identifier, target IAB-donor / IAB-donor-DU BAP routing ID) in the XnAP message and send it to the source donor base station / IAB-donor-CU.

[0320] The source donor base station / IAB-donor-CU or the target donor base station / IAB-donor-CU may send the uplink user plane tunnel information to be established / to be modified to the mobile relay via an F1AP / RRC message. For example, the source donor base station / IAB-donor-CU may send the uplink user plane tunnel information to be established / to be modified to the source mobile relay DU via an F1AP message. The target donor base station / IAB-donor-CU may send the uplink user plane tunnel information to be established / to be modified to the target mobile relay DU / MT via an F1AP message. The target donor base station / IAB-donor-CU may send the uplink user plane tunnel information to be established / to be modified to the mobile relay MT via an RRC message.

[0321] The mobile relay or source donor base station / IAB-donor-CU can indicate the downlink user plane tunnel information to be established / modified to the target donor base station / IAB-donor-CU through F1AP / XnAP / RRC messages. The downlink user plane tunnel information to be established / modified indicated to the target donor base station / IAB-donor-CU can be associated with the source base station terminal XnAP identifier, the target base station terminal XnAP identifier, the user plane DRB-ID / RLC channel ID / LCID, and the downlink user plane TNL address (GTP tunnel, Transport-layer-address / IP-adress, GTP-TEID) of the terminal served by the mobile relay.

[0322] In order to switch the transmission path of the user plane data of the terminal served by the mobile relay from 'terminal <-> source donor base station <-> core network' to 'terminal <-> target donor base station <-> source donor base station <-> core network' for transmission and reception, the source donor base station / IAB-donor-CU and the target donor base station / IAB-donor-CU may exchange one or more information included in the uplink user plane tunnel information to be established / modified and one or more information included in the downlink user plane tunnel information to be established / modified by coordinating. For example, it may include Fig.15 The handover request message and the handover request confirmation / response message in step 1 and step 2 are sent and received. Fig.15 After step 7, it can be included in any XnAP message for switching the transmission path and sent and received. Or, in the case of conditional switching / RRC reconstruction, after the conditional switching is configured in the terminal, it can be included in any XnAP message for switching the transmission path and sent and received.

[0323] The source donor base station / IAB-donor-CU or the target donor base station / IAB-donor-CU may send the uplink user plane tunnel information to be established / modified and the downlink user plane tunnel information to be established / modified to the mobile relay via the F1AP / RRC message.

[0324] When the mobile relay receives the F1AP / RRC message including the above information, the BAP routing ID of the target donor base station / IAB-donor / IAB-donor-DU can be included in the BAP header and BAP data PDUs can be created. Alternatively, when the mobile relay receives the F1AP / RRC message including the above information, a BAP header rewriting operation can be performed. For example, the mobile relay can convert the BAP routing ID (BAP address, BAP Path ID) of the source donor base station / IAB-donor / IAB-donor-DU into the BAP routing ID of the source donor base station / IAB-donor / IAB-donor-DU in the header of the BAP data PDU. The rewriting operation can be performed in any step explicitly recorded in this specification or by any indication information. To this end, information for indicating the rewriting of the F1AP / RRC message BAP header and / or configuration information therefor (e.g., source BAP routing ID, target BAP routing ID) can be included.

[0325] For another example, during the switching / topology adjustment of the mobile relay and / or the switching of (multiple) terminals served by the mobile relay, in order to associate the data radio bearer (DRB) carrying the user data of the terminal served by the mobile relay, the F1-U / GTP-U tunnel between the mobile relay and the target donor base station / IAB-donor-CU / IAB-donor-DU and / or the FU / GTP-U tunnel between the target donor base station / IAB-donor-CU and the source donor base station / IAB-donor-CU / IAB-donor-DU can be set / established / modified. The user plane traffic of the terminal served by the mobile relay can be delivered from the source donor base station / IAB-donor-CU to the core network. At this stage, no path switching procedure between the base station and the core network is required.

[0326] Through the switching / topology adjustment of the mobile relay and / or the switching of (multiple) terminals served by the mobile relay, the donor base station / IAB-donor-CU serving the mobile relay is changed from the source donor base station / IAB-donor-CU to the target donor base station / IAB-donor-CU. The source donor base station / IAB-donor-CU may also continue to maintain the terminal context for the terminal served by the mobile relay. And / or the target donor base station / IAB-donor-CU may also continue to maintain the terminal context for the terminal served by the mobile relay.

[0327] As an example, the uplink user plane data of the terminal served by the mobile relay can be mapped / associated in the mobile relay and sent to the source donor base station / IAB-donor-CU through the target donor base station / IAB-donor-CU. For example, although the handover is performed on the mobile relay MT, the migration of the mobile relay DU is not performed (or, when the source cell and the target cell provided by the mobile relay are provided by a mobile relay DU within a mobile relay, and the mobile relay DU is configured by the source donor base station / IAB-donor-CU), the F1-U corresponding to the uplink user plane data of the terminal and the F1-C corresponding to the uplink control plane data of the terminal can be mapped / associated in the mobile relay and sent to the source donor base station / IAB-donor-CU through the target donor base station / IAB-donor-CU. Before the mobile relay DU, for the (source) mobile relay DU configured / controlled by the source donor base station / IAB-donor-CU, the default return RLC channel information, default BAP routing ID, and uplink / downlink TNL address information for F1-U, F1-C traffic processing by the (source) mobile relay DU are configured to send data to the source donor base station / IAB-donor-CU.

[0328] like Fig.17 As shown, the uplink user plane data of the terminal served in the mobile relay can be mapped to the F1-U tunnel / GTP-U tunnel between the mobile relay and the source donor base station / IAB-donor-CU, and the F1-U tunnel / GTP-U tunnel between the target donor base station / IAB-donor-CU and the source donor base station / IAB-donor-CU and transmitted. For example, the transmission path of the user plane data of the terminal served by the mobile relay can be sent and received by switching the path from 'terminal <-> source donor base station <-> core network' to 'terminal <-> target donor base station <-> source donor base station <-> core network'. Through the migration of the mobile IAB-DU, the terminal connected to the mobile IAB node can switch from the cell provided by the DU associated with the source CU with F1AP (source cell) to the cell provided by the DU associated with the target CU with F1AP (target cell). As described in the above embodiment, the switching of the mobile IAB-MT and the migration of the mobile IAB-DU can be performed in association or independently.

[0329] The BAP entity of the mobile relay (e.g., the transmission part of the BAP entity) can receive BAP SDUs from the upper layer (e.g., GTP-U / UDP / IP). In addition, the uplink user plane tunnel information to be established can be used in the mobile relay received from the source donor base station / IAB-donor-CU (or from the target donor base station / IAB-donor-CU through the source donor base station / IAB-donor-CU, or from the target donor base station / IAB-donor-CU) to determine the BAP address and Path ID, and append the BAPPDU header to create BAP Data PDUs. The source donor base station / IAB-donor-CU or the target donor base station / IAB-donor-CU can indicate the uplink user plane tunnel information to be established / modified to the mobile relay through an F1AP / RRC message. The uplink user plane tunnel information to be established / modified indicated to the mobile relay can be associated with one or more of the source base station terminal XnAP identifier, the target base station terminal XnAP identifier, the user plane DRB / RLC channel ID, the uplink user plane TNL address (GTP tunnel, Transport-layer-address / IP-address, GTP-TEID) and the return information of the terminal served by the mobile relay. Here, the return information may include the BAP routing ID and the next-hop BAP address containing the BAP address and Path ID of the target IAB-donor / IAB-donor-DU.

[0330] One or more information included in the uplink user plane tunnel information to be established / to be modified can be sent and received between the source donor base station / IAB-donor-CU and the target donor base station / IAB-donor-CU. As an example, the source donor base station / IAB-donor-CU can include one or more information included in the uplink user plane tunnel information to be established / to be modified (for example, the source base station terminal XnAP identifier, the user plane DRB-ID / RLC channel ID / LCID of the terminal served by the mobile relay, the uplink user plane TNL address of the target donor base station / IAB-donor-CU / IAB-donor-DU, and the uplink user plane TNL address of the source donor base station / IAB-donor-CU / IAB-donor-DU) in the XnAP message and send it to the target donor base station / IAB-donor-CU. As another example, the target donor base station / IAB-donor-CU can include one or more information included in the uplink user plane tunnel information to be established / modified (for example, the source base station terminal XnAP identifier, the target base station terminal XnAP identifier, the target IAB-donor / IAB-donor-DU BAP routing ID) in the XnAP message and send it to the source donor base station / IAB-donor-CU.

[0331] The source donor base station / IAB-donor-CU or the target donor base station / IAB-donor-CU may send the uplink user plane tunnel information to be established / to be modified to the mobile relay via an F1AP / RRC message. For example, the source donor base station / IAB-donor-CU may send the uplink user plane tunnel information to be established / to be modified to the source mobile relay DU via an F1AP message. The target donor base station / IAB-donor-CU may send the uplink user plane tunnel information to be established / to be modified to the target mobile relay DU / MT via an F1AP message. The target donor base station / IAB-donor-CU may send the uplink user plane tunnel information to be established / to be modified to the mobile relay MT via an RRC message.

[0332] The mobile relay or source donor base station / IAB-donor-CU can indicate the downlink user plane tunnel information to be established / modified to the target donor base station / IAB-donor-CU through F1AP / XnAP / RRC messages. The downlink user plane tunnel information to be established / modified to the target donor base station / IAB-donor-CU can be associated with the source base station terminal XnAP identifier, the target base station terminal XnAP identifier, the user plane DRB-ID / RLC channel ID / LCID of the terminal served by the mobile relay, the downlink user plane TNL address (GTP tunnel, Transport-layer-address / IP-adress, GTP-TEID) of the mobile relay, and the downlink user plane TNL address of the target donor base station / IAB-donor-CU.

[0333] In order to switch the transmission path of the user plane data of the terminal served by the mobile relay from 'terminal <-> source donor base station <-> core network' to 'terminal <-> target donor base station <-> source donor base station <-> core network' for transmission and reception, the source donor base station / IAB-donor-CU and the target donor base station / IAB-donor-CU may exchange one or more information included in the uplink user plane tunnel information to be established / modified and one or more information included in the downlink user plane tunnel information to be established / modified by coordinating. For example, it may include Fig.15 The handover request message and the handover request confirmation / response message in step 1 and step 2 are sent and received. Fig.15 After step 7, it can be included in any XnAP message for switching the transmission path and sent and received. Or, in the case of conditional switching / RRC reconstruction, after the conditional switching is configured in the terminal, it can be included in any XnAP message for switching the transmission path and sent and received.

[0334] The source donor base station / IAB-donor-CU or the target donor base station / IAB-donor-CU may send the uplink user plane tunnel information to be established / to be modified and the downlink user plane tunnel information to be established / to be modified to the mobile relay via an F1AP / RRC message. The source donor base station / IAB-donor-CU may send the uplink user plane tunnel information to be established / to be modified and the downlink user plane tunnel information to be established / to be modified to the target donor base station / IAB-donor-CU via an XnAP message.

[0335] When the mobile relay receives the F1AP / RRC message including the above information, the BAP routing ID of the target donor base station / IAB-donor / IAB-donor-DU can be included in the BAP header and BAP data PDUs can be created. Alternatively, when the mobile relay receives the F1AP / RRC message including the above information, a BAP header rewriting operation can be performed. For example, the mobile relay can convert the BAP routing ID (BAP address, BAP Path ID) of the source donor base station / IAB-donor / IAB-donor-DU into the BAP routing ID of the source donor base station / IAB-donor / IAB-donor-DU in the header of the BAP data PDU. The rewriting operation can be performed in any step explicitly recorded in this specification or by any indication information. To this end, information for indicating the rewriting of the F1AP / RRC message BAP header and / or configuration information therefor (e.g., source BAP routing ID, target BAP routing ID) can be included.

[0336] For another example, during the switching / topology adjustment of the mobile relay and / or the switching of (multiple) terminals served by the mobile relay, in order to associate the data radio bearer (DRB) carrying the user data of the terminal served by the mobile relay, the F1-U / GTP-U tunnel between the mobile relay and the target donor base station / IAB-donor-CU / IAB-donor-DU can be set / established / modified. The user plane traffic of the terminal served by the mobile relay can be delivered from the target donor base station / IAB-donor-CU to the core network.

[0337] Through the switching / topology adjustment of the mobile relay and / or the switching of (multiple) terminals served by the mobile relay, the donor base station / IAB-donor-CU serving the mobile relay is changed from the source donor base station / IAB-donor-CU to the target donor base station / IAB-donor-CU. The terminal context for the terminal served by the mobile relay can be released at the source donor base station / IAB-donor-CU through the message (e.g., terminal context release message). And / or the terminal context for the terminal served by the mobile relay can be maintained at the target donor base station / IAB-donor-CU.

[0338] As an example, uplink user plane data of a terminal served by a mobile relay may be mapped / associated in the mobile relay and sent to the core network via the target donor base station / IAB-donor-CU. Fig.18As shown, the uplink user plane data of the terminal served in the mobile relay can be mapped to the F1-U tunnel / GTP-U tunnel between the mobile relay and the target donor base station / IAB-donor-CU and transmitted. For example, the transmission path of the user plane data of the terminal served by the mobile relay can be sent and received by switching the path from 'terminal <-> source donor base station <-> core network' to 'terminal <-> target donor base station <-> core network'.

[0339] The BAP entity of the mobile relay (e.g., the transmission part of the BAP entity) can receive BAP SDUs from the upper layer (e.g., GTP-U / UDP / IP). In addition, the uplink user plane tunnel information to be established can be used in the mobile relay received from the source donor base station / IAB-donor-CU (or from the target donor base station / IAB-donor-CU through the source donor base station / IAB-donor-CU, or from the target donor base station / IAB-donor-CU) to determine the BAP address and Path ID, and append the BAPPDU header to create BAP Data PDUs. The source donor base station / IAB-donor-CU or the target donor base station / IAB-donor-CU can indicate the uplink user plane tunnel information to be established / modified to the mobile relay through an F1AP / RRC message. The uplink user plane tunnel information to be established / modified indicated to the mobile relay can be associated with one or more of the source base station terminal XnAP identifier, the target base station terminal XnAP identifier, the user plane DRB / RLC channel ID, the uplink user plane TNL address (GTP tunnel, Transport-layer-address / IP-address, GTP-TEID) and the return information of the terminal served by the mobile relay. Here, the return information may include the BAP routing ID and the next-hop BAP address containing the BAP address and Path ID of the target IAB-donor / IAB-donor-DU.

[0340] One or more information included in the uplink user plane tunnel information to be established / to be modified can be sent and received between the source donor base station / IAB-donor-CU and the target donor base station / IAB-donor-CU. As an example, the source donor base station / IAB-donor-CU can include one or more information included in the uplink user plane tunnel information to be established / to be modified (for example, the source base station terminal XnAP identifier, the user plane DRB-ID / RLC channel ID / LCID of the terminal served by the mobile relay, and the uplink user plane TNL address of the target donor base station / IAB-donor-CU / IAB-donor-DU) in the XnAP message and send it to the target donor base station / IAB-donor-CU. As another example, the target donor base station / IAB-donor-CU can include one or more information included in the uplink user plane tunnel information to be established / modified (for example, the source base station terminal XnAP identifier, the target base station terminal XnAP identifier, the target IAB-donor / IAB-donor-DU BAP routing ID) in the XnAP message and send it to the source donor base station / IAB-donor-CU.

[0341] The source donor base station / IAB-donor-CU or the target donor base station / IAB-donor-CU may send the uplink user plane tunnel information to be established / to be modified to the mobile relay via an F1AP / RRC message. For example, the source donor base station / IAB-donor-CU may send the uplink user plane tunnel information to be established / to be modified to the source mobile relay DU via an F1AP message. The target donor base station / IAB-donor-CU may send the uplink user plane tunnel information to be established / to be modified to the target mobile relay DU / MT via an F1AP message. The target donor base station / IAB-donor-CU may send the uplink user plane tunnel information to be established / to be modified to the mobile relay MT via an RRC message.

[0342] The mobile relay or source donor base station / IAB-donor-CU can indicate the downlink user plane tunnel information to be established / modified to the target donor base station / IAB-donor-CU through F1AP / XnAP / RRC messages. The downlink user plane tunnel information to be established / modified indicated to the target donor base station / IAB-donor-CU can be associated with the source base station terminal XnAP identifier, the target base station terminal XnAP identifier, the user plane DRB-ID / RLC channel ID / LCID, and the downlink user plane TNL address (GTP tunnel, Transport-layer-address / IP-adress, GTP-TEID) of the terminal served by the mobile relay.

[0343] In order to switch the path from 'terminal <-> source donor base station <-> core network' to 'terminal <-> target donor base station <-> core network' for transmission and reception of user plane data of the terminal served by the mobile relay, the source donor base station / IAB-donor-CU and the target donor base station / IAB-donor-CU may exchange one or more information included in the uplink user plane tunnel information to be established / modified and one or more information included in the downlink user plane tunnel information to be established / modified by coordinating. For example, Fig.15 The handover request message and the handover request confirmation / response message in step 1 and step 2 are sent and received. Fig.15 After step 7, it can be included in any XnAP message for switching the transmission path and sent and received. Or, in the case of conditional switching / RRC reconstruction, after the conditional switching is configured in the terminal, it can be included in any XnAP message for switching the transmission path and sent and received.

[0344] The source donor base station / IAB-donor-CU or the target donor base station / IAB-donor-CU may send the uplink user plane tunnel information to be established / to be modified and the downlink user plane tunnel information to be established / to be modified to the mobile relay via an F1AP / RRC message. The source donor base station / IAB-donor-CU may send the uplink user plane tunnel information to be established / to be modified and the downlink user plane tunnel information to be established / to be modified to the target donor base station / IAB-donor-CU via an XnAP message.

[0345] When the mobile relay receives the F1AP / RRC message including the above information, the BAP routing ID of the target donor base station / IAB-donor / IAB-donor-DU can be included in the BAP header and BAP data PDUs can be created. Alternatively, when the mobile relay receives the F1AP / RRC message including the above information, a BAP header rewriting operation can be performed. For example, the mobile relay can convert the BAP routing ID (BAP address, BAP Path ID) of the source donor base station / IAB-donor / IAB-donor-DU into the BAP routing ID of the source donor base station / IAB-donor / IAB-donor-DU in the header of the BAP data PDU. The rewriting operation can be performed in any step explicitly recorded in this specification or by any indication information. To this end, information for indicating the rewriting of the F1AP / RRC message BAP header and / or configuration information therefor (e.g., source BAP routing ID, target BAP routing ID) can be included.

[0346] For another example, in order to support F1-C traffic between a mobile relay and a donor base station / IAB-donor-CU or F1-C traffic including control messages of terminals served by the mobile relay or user plane data transmission of terminals served by the mobile relay, the target donor base station / IAB-donor-CU may configure one or more of the following information on the target path between the mobile relay and the target IAB-donor-DU / IAB-donor-CU: gNB-CU UE F1AP ID, gNB-DU UE F1AP ID, user plane DRB-ID / RLC channel ID / LCID, downlink user plane TNL address of the mobile relay, uplink TNL address of the target donor base station / IAB-donor-CU, backhaul RLC channel (backhaul RLC channel ID), BAP routing entry (BAP routing ID, BAP address, BAPpath id), downlink mapping information on the target IAB-donor-DU for the target path of the mobile relay (e.g., (multiple) TNL address information of the mobile relay for F1-C traffic / user plane traffic).

[0347] The target IAB-donor-DU / IAB-donor-CU may configure / indicate this information to the mobile relay via F1AP / RRC messages.

[0348] For another example, for (multiple) terminals served by a mobile relay, the mobile relay may allocate new TNL address information different from the TNL address used by the source donor base station / IAB-donor-CU to each user plane F1-U / GTP-U tunnel associated with each DBR, and pass it to the source donor base station / IAB-donor-CU. The source donor base station / IAB-donor-CU may pass the received information to the target donor base station / IAB-donor-CU. The target donor base station / IAB-donor-CU may respond to the source donor base station / IAB-donor-CU by including the terminal identifier to be switched, the DRB identifier / RLC identifier / LCID, the backhaul RLC channel identifier, the uplink TNL address for user plane traffic, and the downlink TNL address. Using the new TNL address information of the mobile relay, the F1-U connection between the mobile relay and the source donor base station / IAB-donor-CU may be switched to the F1-U connection between the mobile relay and the target donor base station / IAB-donor-CU. The user plane traffic of the terminal served by the mobile relay can be delivered to the core network from the target donor base station / IAB-donor-CU. The source donor base station / IAB-donor-CU can provide updated uplink backhaul information (backhaul routing ID) to the mobile relay based on the uplink backhaul information (backhaul routing ID) received from the target donor base station / IAB-donor-CU.

[0349] The above operations can be performed in Fig.15 Any step included in or in Fig.15 Before or after any step included in Fig.15 For the convenience of explanation, the operation may be described at a specific step or before or after a specific step. However, this is for the convenience of explanation. Fig.15 In any step included in or Fig.15 Before or after any step in Fig.15 It is obvious that performing operations after any steps included in is also included in the scope of the present disclosure.

[0350] As described above, the present disclosure can provide effective access control and mobility control for mobile relays.

[0351] The following will explain again how to implement the reference Figures 1 to 18 The structures of a part or all of the source donor base station and the target donor base station of each embodiment will be described.

[0352] Fig.19 is a diagram showing the structure of a source donor base station according to one embodiment.

[0353] Reference Fig.19, a source donor base station 1900 for controlling the operation of a mobile relay may include: a sending unit 1920, sending a switching request message to a target donor base station; a receiving unit 1930, receiving a switching response message containing wireless resource configuration information for at least one of the mobile relay and the terminal served by the mobile relay from the target donor base station; and a control unit 1910, controlling the wireless resource configuration information to be indicated to at least one of the mobile relay and the terminal.

[0354] For example, the control unit 1910 may determine whether to switch the mobile relay or the terminal of the mobile relay service. The sending unit 1920 may send a switching request message for requesting switching to the target donor base station as the switching object of the mobile relay or the terminal of the mobile relay service. The switching request message may be an RRC message.

[0355] The handover request message may include information required for the mobile relay or the terminal served by the mobile relay to handover to the target donor base station.

[0356] As an example, the handover request message may include an RRC container with information required by the target side to prepare for the handover (eg, a Handover preparation message).

[0357] As another example, the handover request message may include at least one of handover indication information of the mobile relay, indication information of a cell being served by the mobile relay, and terminal context information for a terminal served by the mobile relay.

[0358] As another example, the switching indication information of the mobile relay may include at least one of the MT (Mobile Terminal) switching indication information of the mobile relay and the DU (Distributed Unit) migration indication information of the mobile relay. Alternatively, the cell indication information that the mobile relay is providing services may include at least one of the cell indication information that the DU (Distributed Unit) of the mobile relay is providing services and the cell indication information provided by the mobile relay.

[0359] As another example, the handover request message may include BAP address information of the mobile relay, TNL address information (e.g., IP address information for the mobile relay and / or uplink / downlink Transport-layer-address / IP-address for mobile relay-user plane-traffic / F1-U traffic, GTP-TEID(s)), and one or more of the mobile relay identifier.

[0360] For example, the handover indication information of the mobile relay may include information for indicating that the handover is a handover for the mobile relay. Thus, the target donor base station / IAB-donor-CU may recognize that the handover is a handover for the mobile relay and process it.

[0361] In addition, the target donor base station may respond to the handover request message and perform acceptance control on the handover request. For the handover request according to the handover request message, the target donor base station may send a handover response message to the source donor base station. The target donor base station may provide an RRC configuration as part of the handover response message.

[0362] As an example, the handover response message may include one or more of the BAP address information, default backhaul RLC channel information, default BAP routing ID, uplink / downlink TNL address information, and mobile relay identifier for the mobile relay connected to the target donor base station. This information can be used as information for mapping F1-C and / or F1-U and / or non-F1 traffic (through the target path) to the target donor base station.

[0363] As another example, the handover response message may include wireless resource configuration information for at least one of the mobile relay and the terminal served by the mobile relay. The wireless resource configuration information may include at least one of BAP address information for the mobile relay, default backhaul RLC channel information, default BAP routing ID, uplink / downlink TNL address information, and a mobile relay identifier.

[0364] As another example, the radio resource configuration information may also include time-based event condition information for triggering conditional handover of a terminal served by the mobile relay. The information included in the handover response message may be included in an RRC container and delivered to the source donor base station.

[0365] For example, the sending unit 1920 may send the RRC container received from the target donor base station to at least one of the mobile relay and the terminal to transfer the radio resource configuration information.

[0366] The radio resource configuration information may be sent to the mobile relay via an RRC connection reconfiguration message. When the mobile relay receives the RRC connection reconfiguration message, it may perform a random access procedure to the target donor base station to perform a handover process.

[0367] On the other hand, the terminal served by the mobile relay may be configured to skip the random access procedure when performing handover. That is, even if the mobile relay performs the random access procedure for handover to the target donor base station, the terminal served by the mobile relay may not perform the random access procedure.

[0368] On the other hand, the mobile relay may broadcast mobile relay support information for cell reselection of the terminal. For example, the mobile relay may periodically or aperiodically send system information including cell information provided by the mobile relay, information required to connect to the mobile relay, etc.

[0369] Furthermore, the control unit 1910 controls the operation of the overall source donor base station 1900 to perform the control operation according to the mobile relay required for the present embodiment described above.

[0370] The sending unit 1920 and the receiving unit 1930 are used to send and receive signals or messages and data required to execute the above-mentioned embodiment with the terminal and the target donor base station.

[0371] Fig. 20 is a diagram showing a structure of a target donor base station according to one embodiment.

[0372] Reference Fig. 20 , the target donor base station 2000 for controlling the operation of the mobile relay may include: a receiving unit 2030 for receiving a handover request message from a source donor base station; and a sending unit 2020 for sending a handover response message including wireless resource configuration information for at least one of the mobile relay and the terminal served by the mobile relay to the source donor base station. The wireless resource configuration information may be indicated to at least one of the mobile relay and the terminal by the source donor base station.

[0373] For example, the source donor base station may determine whether to switch the mobile relay or the terminal of the mobile relay service. The receiving unit 2030 may receive a handover request message for requesting handover from the target donor base station that is the handover target of the mobile relay or the terminal of the mobile relay service. The handover request message may be an RRC message.

[0374] The handover request message may include information required for the mobile relay or the terminal served by the mobile relay to handover to the target donor base station.

[0375] As an example, the handover request message may include an RRC container with information required by the target side to prepare for the handover (eg, a Handover preparation message).

[0376] As another example, the handover request message may include at least one of handover indication information of the mobile relay, indication information of a cell being served by the mobile relay, and terminal context information for a terminal served by the mobile relay.

[0377] As another example, the switching indication information of the mobile relay may include at least one of the MT (Mobile Terminal) switching indication information of the mobile relay and the DU (Distributed Unit) migration indication information of the mobile relay. Alternatively, the cell indication information that the mobile relay is providing services may include at least one of the cell indication information that the DU (Distributed Unit) of the mobile relay is providing services and the cell indication information provided by the mobile relay.

[0378] As another example, the handover request message may include BAP address information of the mobile relay, TNL address information (e.g., IP address information for the mobile relay and / or uplink / downlink Transport-layer-address / IP-address for mobile relay-user plane-traffic / F1-U traffic, GTP-TEID(s)), and one or more of the mobile relay identifier.

[0379] For example, the handover indication information of the mobile relay may include information for indicating that the handover is a handover for the mobile relay. Thus, the target donor base station / IAB-donor-CU may recognize that the handover is a handover for the mobile relay and process it.

[0380] In addition, the control unit 2010 may perform acceptance control on the handover request in response to the handover request message. The sending unit 2020 may send a handover response message to the source donor base station in response to the handover request message. The sending unit 2020 may provide an RRC configuration as part of the handover response message.

[0381] As an example, the handover response message may include one or more of the BAP address information, default backhaul RLC channel information, default BAP routing ID, uplink / downlink TNL address information, and mobile relay identifier for the mobile relay connected to the target donor base station. This information can be used as information for mapping F1-C and / or F1-U and / or non-F1 traffic (through the target path) to the target donor base station.

[0382] As another example, the handover response message may include wireless resource configuration information for at least one of the mobile relay and the terminal served by the mobile relay. The wireless resource configuration information may include at least one of BAP address information for the mobile relay, default backhaul RLC channel information, default BAP routing ID, uplink / downlink TNL address information, and a mobile relay identifier.

[0383] As yet another example, the wireless resource configuration information may also include time-based event condition information for triggering conditional handover of a terminal served by the mobile relay.

[0384] The information included in the handover response message may be included in an RRC container and transmitted to the source donor base station. That is, the radio resource configuration information may be indicated to at least one of the mobile relay and the terminal through the source donor base station.

[0385] For example, the source donor base station may send the RRC container received from the target donor base station to at least one of the mobile relay and the terminal to transfer the radio resource configuration information.

[0386] The radio resource configuration information may be sent to the mobile relay via an RRC connection reconfiguration message. When the mobile relay receives the RRC connection reconfiguration message, it may perform a random access procedure to the target donor base station to perform a handover process.

[0387] On the other hand, the terminal served by the mobile relay may be configured to skip the random access procedure when performing handover. That is, even if the mobile relay performs the random access procedure for handover to the target donor base station, the terminal served by the mobile relay may not perform the random access procedure.

[0388] On the other hand, the mobile relay may broadcast mobile relay support information for cell reselection of the terminal. For example, the mobile relay may periodically or aperiodically send system information including cell information provided by the mobile relay, information required to connect to the mobile relay, etc.

[0389] Furthermore, the control section 2010 controls the operation of the overall target donor base station 2000 to perform the control operation according to the mobile relay required for the present embodiment described above.

[0390] The sending unit 2020 and the receiving unit 2030 are used to send and receive signals or messages and data required to execute the above-mentioned embodiment with the terminal and the source donor base station.

[0391] The above embodiment may be supported by a standard document disclosed in at least one of IEEE 802, 3GPP and 3GPP2 as wireless access systems. That is, in this embodiment, steps, configurations, and parts that are not described in order to clearly reveal the technical concept may be supported by the above standard documents. In addition, all terms disclosed in this specification may be interpreted by the above standard documents.

[0392] The above-mentioned embodiment can be implemented by various means. For example, the embodiment can be implemented by hardware, firmware, software or a combination thereof.

[0393] In the case of hardware implementation, the method according to the present embodiment can be implemented by one or more ASICs (Application Specific Integrated Circuits), DSPs (Digital Signal Processors), DSPDs (Digital Signal Processing Devices), PLDs (Programmable Logic Devices), FPGAs (Field Programmable Gate Arrays), processors, controllers, microcontrollers or microprocessors, etc.

[0394] In the case of implementation by firmware or software, the method according to this embodiment can be implemented in the form of a device, process or function that performs the functions or operations described above. The software code can be stored in a storage unit and driven by a processor. The storage unit is located inside or outside the processor and can exchange data with the processor through a variety of known devices.

[0395] In addition, the above-mentioned terms such as "system", "processor", "controller", "component", "module", "interface", "model" or "unit" may generally refer to physical hardware related to a computer, a combination of hardware and software, software or running software. For example, the aforementioned components may be processes driven by a processor, processors, controllers, control processors, individuals, execution threads, programs and / or computers, but are not limited to these. For example, an application running in a controller or processor and the controller or processor may become components. More than one component may be located in a process and / or execution thread, and a component may be located in one device (such as a system, a computing device, etc.) or distributed in two or more devices.

[0396] The above description is only an exemplary description of the technical idea of ​​the present disclosure, and technicians in the field of the present disclosure can make various modifications and changes without departing from the essential features of the technical idea. In addition, the present embodiment is to illustrate the technical idea of ​​the present disclosure rather than to limit it, and therefore, the scope of the technical idea is not limited by these embodiments. The scope of protection of the present disclosure should be interpreted in accordance with the following claims, and all technical ideas within the equivalent scope thereof should be interpreted as included in the scope of rights of the present disclosure.

[0397] CROSS-REFERENCE TO RELATED APPLICATIONS

[0398] This patent application claims the priority of patent application No. 10-2022-0081684 filed in South Korea on July 4, 2022 and patent application No. 10-2023-0083426 filed in South Korea on June 28, 2023 under Section 119(a) of the United States Patent Act (35 U.S.C. §119(a)), and the entire contents of which are incorporated as references into this patent application. At the same time, this patent application also claims priority for countries other than the United States for the same reasons as above, and the entire contents of which are incorporated as references into this patent application.

Claims

1. A method for a source donor base station to control the operation of a mobile relay, comprising: The step of sending a handover request message to a target donor base station; a step of receiving, from the target donor base station, a handover response message including radio resource configuration information for at least one of a mobile relay and a terminal served by the mobile relay; as well as The step of controlling the wireless resource configuration information to be indicated to at least one of the mobile relay and the terminal.

2. The method according to claim 1, wherein: The handover request message includes at least one of handover indication information of the mobile relay, indication information of a cell being served by the mobile relay, and terminal context information of a terminal served by the mobile relay.

3. The method according to claim 2, wherein: The switching indication information of the mobile relay includes at least one of MT switching indication information of the mobile relay and DU migration indication information of the mobile relay, and the cell indication information being served by the mobile relay includes at least one of cell indication information being served by the DU of the mobile relay and cell indication information provided by the mobile relay.

4. The method according to claim 1, wherein: The terminal served by the mobile relay is arranged to skip a random access procedure when performing the handover.

5. The method according to claim 1, wherein: The radio resource configuration information includes time-based event condition information for triggering conditional handover of a terminal served by the mobile relay.

6. The method according to claim 1, wherein: The mobile relay broadcasts mobile relay support information used for cell reselection of the terminal.

7. A method for a target donor base station to control the operation of a mobile relay, comprising: The step of receiving a handover request message from a source donor base station; as well as The step of sending a handover response message including radio resource configuration information for at least one of a mobile relay and a terminal served by the mobile relay to the source donor base station, The wireless resource configuration information is indicated to at least one of the mobile relay and the terminal through the source donor base station.

8. The method according to claim 7, wherein: The handover request message includes at least one of handover indication information of the mobile relay, indication information of a cell being served by the mobile relay, and terminal context information of a terminal served by the mobile relay.

9. The method according to claim 8, wherein: The switching indication information of the mobile relay includes at least one of MT switching indication information of the mobile relay and DU migration indication information of the mobile relay, and the cell indication information being served by the mobile relay includes at least one of cell indication information being served by the DU of the mobile relay and cell indication information provided by the mobile relay.

10. The method according to claim 7, wherein: The terminal served by the mobile relay is arranged to skip a random access procedure when performing the handover.

11. The method according to claim 7, wherein: The radio resource configuration information includes time-based event condition information for triggering conditional handover of a terminal served by the mobile relay.

12. The method according to claim 7, wherein: The mobile relay broadcasts mobile relay support information used for cell reselection of the terminal.

13. A source donor base station for controlling the operation of a mobile relay, comprising: A sending unit, sending a handover request message to a target donor base station; a receiving unit, receiving, from the target donor base station, a handover response message including radio resource configuration information for at least one of a mobile relay and a terminal served by the mobile relay; as well as The control unit controls the wireless resource configuration information to be indicated to at least one of the mobile relay and the terminal.

14. The source donor base station according to claim 13, wherein: The handover request message includes at least one of handover indication information of the mobile relay, indication information of a cell being served by the mobile relay, and terminal context information of a terminal served by the mobile relay.

15. The source donor base station according to claim 14, wherein: The switching indication information of the mobile relay includes at least one of MT switching indication information of the mobile relay and DU migration indication information of the mobile relay, and the cell indication information being served by the mobile relay includes at least one of cell indication information being served by the DU of the mobile relay and cell indication information provided by the mobile relay.

16. The source donor base station according to claim 13, wherein: The terminal served by the mobile relay is arranged to skip a random access procedure when performing the handover.

17. The source donor base station according to claim 13, wherein: The radio resource configuration information includes time-based event condition information for triggering conditional handover of a terminal served by the mobile relay.

18. The source donor base station according to claim 13, wherein: The mobile relay broadcasts mobile relay support information used for cell reselection of the terminal.

Images