Method and apparatus for transmitting or receiving data with dual connectivity of iab node in wireless communication system

Abstract

The disclosure provides a method of transmitting and receiving data in a wireless communication system, performed by an integrated access and backhaul (IAB) node. The method can include receiving resource allocation information from an IAB donor node, receiving first resource scheduling information from a first parent IAB node, receiving second resource scheduling information from a second parent IAB node, transmitting data to and receiving data from at least one of the first parent IAB node, the second parent IAB node, a child IAB node, or a user equipment (UE) based on the resource allocation information, the first resource scheduling information, and the second resource scheduling information.

Description

TECHNICAL FIELD

[0001] The disclosure relates to a wireless communication system, and more particularly, to a method and apparatus for transmitting and receiving data by using dual connectivity of an integrated access and backhaul (IAB) node. BACKGROUND

[0002] To meet the increasing demand with respect to wireless data traffic after the commercialization of the fourth generation (4G) communication systems, efforts have been made to develop a fifth generation (5G) or pre-5G communication system. For this reason, the 5G or pre-5G communication system is also called a 'beyond 4G network' or a 'post long term evolution (post-LTE) system'.

[0003] To achieve a high data rate, implementation of a 5G communication system in an ultra-high frequency band (e.g., a 60-gigahertz (GHz) band) is being considered. To reduce a path loss of radio waves and increase a transmission distance of radio waves in the ultra-high frequency band of the 5G communication system, various technologies, such as beamforming, massive multiple-input multiple-output (massive MIMO), full dimensional MIMO (FD-MIMO), array antennas, analog beam-forming, and large-scale antennas, are being studied.

[0004] To improve a system network for the 5G communication system, various technologies, such as evolved small cells, advanced small cells, cloud radio access networks (Cloud-RAN), ultra-dense networks, device-to-device communication (D2D), wireless backhaul, moving networks, cooperative communication, coordinated multi-points (CoMP), and receive interference cancellation, have been developed.

[0005] In addition, for the 5G communication system, advanced coding modulation (ACM) technologies, such as hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM) (FQAM) and sliding window superposition coding (SWSC), and advanced access technologies, such as filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA), have been developed.

[0006] The Internet has evolved from a human-based connection network, where humans create and consume information, to the Internet of Things (IoT), where distributed components such as objects exchange information with each other to process the information. Internet of Everything (IoE) technologies have emerged, in which the IoT technology is combined with, for example, technology for processing big data through connection with a cloud server. To implement the IoT, various technological elements, such as sensing technology, wired / wireless communication and network infrastructure, service interface technology, and security technology, are required, and in recent years, technologies related to sensor networks for connecting objects, Machine-to-Machine (M2M) communication, and Machine Type Communication (MTC) have been studied. In the IoT environment, intelligent Internet technology (IT) services can be provided to collect and analyze data obtained from connected objects to create a new value in a human life. As existing information technology (IT) and various industries converge and combine with each other, IT can be applied to various fields, such as smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, health care, smart home appliances, and advanced medical services.

[0007] Various attempts are being made to apply 5G communication systems to IoT networks. For example, technologies related to sensor networks, M2M communication, and MTC are implemented by using 5G communication techniques such as beamforming, MIMO, and array antennas. Cloud Radio Access Network (Cloud-RAN) as an application of the above-described big data processing technology can be an example of convergence of 5G communication technology and IoT technology.

[0008] Recently, various studies are being conducted to use Integrated Access and Backhaul (IAB), and thus, there is a need to enhance communication services in a dual connectivity environment of an IAB node. SUMMARY

[0009] TECHNICAL SOLUTION

[0010] The disclosure provides a method and apparatus for efficiently providing services in a mobile communication system.

[0011] In more detail, when an Integrated Access and Backhaul (IAB) communication system operates, in which an IAB node is configured for dual connectivity with a plurality of parent IAB nodes on a higher level of the IAB node, data transmission and reception between a distributed unit (DU) of the parent IAB node and a mobile terminal (MT) of the IAB node and data transmission and reception between a DU of the IAB node and an MT of a child IAB node or an access UE on a lower level of the IAB node are mixed, so that it is difficult to satisfy a half duplex constraint at a moment, the disclosure provides various methods of communicating while satisfying the half duplex constraint.

[0012] ADVANTAGEOUS EFFECTS

[0013] According to an embodiment of the disclosure, an apparatus and a method for efficiently providing a service in a wireless communication system are provided. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 A communication system operating an integrated access and backhaul (IAB) node according to an embodiment of the disclosure is illustrated.

[0015] Figure 2 FIG. 1 is a diagram schematically illustrating multiplexing of each of an access link and a backhaul link in a time domain or a frequency domain at an IAB node according to an embodiment of the disclosure.

[0016] Figure 3 FIG. 2 is a diagram illustrating multiplexing of an access link and a backhaul link in a time domain in an IAB communication system according to an embodiment of the disclosure.

[0017] Figure 4 FIG. 3 is a diagram illustrating multiplexing of an access link and a backhaul link in a frequency domain and a spatial domain in an IAB communication system according to an embodiment of the disclosure.

[0018] Figure 5 FIG. 4 is a diagram schematically illustrating an architecture of an IAB node according to an embodiment of the disclosure.

[0019] Figure 6 FIG. 5 is a diagram illustrating a communication system according to an embodiment of the disclosure.

[0020] Figure 7 FIG. 6 is a diagram schematically illustrating a dual connectivity structure of an IAB node according to an embodiment of the disclosure.

[0021] Figure 8 FIG. 7 is a diagram schematically illustrating a dual connectivity structure of an IAB node according to an embodiment of the disclosure.

[0022] Figure 9 FIG. 8 is a diagram schematically illustrating an environment in which real-time coordination can occur according to a dual connectivity structure of an IAB node according to an embodiment of the disclosure.

[0023] Figure 10 FIG. 9 is a flowchart of a method for describing transmitting and receiving data by an IAB node according to an embodiment of the disclosure.

[0024] Figure 11 FIG. 10 is a diagram illustrating a UE apparatus according to an embodiment of the disclosure.

[0025] Figure 12 FIG. 11 is a diagram illustrating a BS apparatus according to an embodiment of the disclosure.

[0026] Figure 13 FIG. 12 is a diagram illustrating an IAB node according to an embodiment of the disclosure. DETAILED DESCRIPTION

[0027] BEST MODE

[0028] According to embodiments of the disclosure, a method of transmitting and receiving data in a wireless communication system, performed by an integrated access and backhaul (IAB) node, can include receiving resource allocation information from an IAB donor node, receiving first resource scheduling information from a first parent IAB node, receiving second resource scheduling information from a second parent IAB node, transmitting and receiving data to and from at least one of the first parent IAB node, the second parent IAB node, a child IAB node, or a user equipment (UE) based on the resource allocation information, the first resource scheduling information, and the second resource scheduling information.

[0029] MODE FOR INVENTION

[0030] Hereinafter, exemplary embodiments of the disclosure will be described more fully with reference to the accompanying drawings, in which like reference numerals refer to like elements throughout. It should be noted, however, that this disclosure may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and fully convey the concept of the disclosure to those skilled in the art, and no aspect of the disclosure is directed to any specific embodiment thereof. Like reference numerals in the drawings denote like elements.

[0031] In the following description of the embodiments, a description of a well-known technology and configuration related to the disclosure is omitted. By omitting unnecessary description, the essence of the disclosure can not be obscured and can be clearly conveyed.

[0032] For the same reason, some components in the drawings are exaggerated, omitted, or schematically shown. Also, the size of each component does not exactly correspond to the actual size of each component. In each drawing, the same or corresponding components are presented as the same reference numerals.

[0033] The advantages and features of the disclosure and the method of accomplishing the same can be understood more readily by reference to the following detailed description of embodiments of the disclosure and the accompanying drawings. The disclosure may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the disclosure to those skilled in the art, and no aspect of the disclosure is directed to any specific embodiment thereof. Accordingly, the scope of the disclosure is defined only by the claims which are to be interpreted in the light of this disclosure. Throughout the specification, like reference numerals denote like elements.

[0034] It should be understood that each block of the flowchart illustrations, and combinations of blocks in the flowchart illustrations, can be implemented by computer program instructions. These program instructions can be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate means for implementing the functions specified in the flowchart block or blocks. These computer program instructions can also be stored in a computer- executable or a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer- executable or computer-readable memory produce an article of manufacture including instructions which implement the functions specified in the flowchart block or blocks. The computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks.

[0035] Also, each block in the flowchart illustrations, and combinations of blocks in the flowchart illustrations, can represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical functions. It should also be noted that in some alternative implementations, the functions noted in the blocks can occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks can sometimes be executed in the reverse order, depending upon the functionality involved.

[0036] The term "unit" used in the present embodiment means a software or hardware component that performs certain tasks, such as Field Programmable Gate Array (FPGA) or Application Specific Integrated Circuit (ASIC). However, the term "unit" does not limit the software or hardware to a certain style of implementation. The "unit" can be configured as software or hardware and / or a combination of software and hardware. Thus, the "unit" can include, for example, components such as software components, object-oriented software components, class components, and task components, processes, functions, attributes, procedures, subroutines, segments of program codes, drivers, firmware, microcodes, circuits, data, databases, data structures, tables, arrays, and variables. The components and the "unit" provided in the functions can be combined into a smaller number of components and "units" or further separated into additional components and "units". In addition, the components and "units" can be implemented to operate one or more central processing units (CPUs) in a device or a secure multimedia card.

[0037] Hereinafter, for convenience of description, terms indicating an access node, terms indicating a network entity, terms indicating a message, terms indicating an interface between network entities, and terms indicating various kinds of identification information used in the following description are exemplified. Accordingly, the disclosure is not limited to the terms to be described below, and other terms indicating objects having the same technical meanings can be used.

[0038] Hereinafter, a base station is an entity that allocates resources to a terminal, and can be at least one of a next generation node B (gNB), an evolved node B (eNB), a node B, a base station (BS), a radio access unit, a BS controller, or a node on a network. A terminal can include a user equipment (UE), a mobile station (MS), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. In addition, the term "terminal (UE)" refers not only to a mobile phone, an NB-IoT device, and a sensor, but also to other wireless communication devices. Obviously, the BS and the terminal are not limited to the examples.

[0039] For convenience of description, in the disclosure, terms and names defined in the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) standard are used. However, the disclosure is not limited to the terms and names, and can be equally applied to systems conforming to other standards.

[0040] According to communication standards such as High Speed Packet Access (HSPA), Long Term Evolution (LTE), or Evolved Universal Terrestrial Radio Access (E-UTRA), LTE-Advanced (LTE-A), LTE-Pro of 3GPP, High Rate Packet Data (HRPD), Ultra Mobile Broadband (UMB) of 3GPP2, and 802.16e of the Institute of Electrical and Electronics Engineers (IEEE), a wireless communication system that provides a voice-based service in an early stage is being developed into a broadband wireless communication system that provides a high-speed and high-quality packet data service.

[0041] As a representative example of a broadband wireless communication system, an LTE system employs Orthogonal Frequency Division Multiplexing (OFDM) for a downlink (DL) and Single Carrier Frequency Division Multiple Access (SC-FDMA) for an uplink (UL). The UL refers to a radio link for transmitting data or control signals from a terminal (e.g., a UE or an MS) to a base station (e.g., an eNB or a BS), and the DL refers to a radio link for transmitting data or control signals from the base station to the terminal. The above-described various access schemes identify data or control information of each user in such a manner that time-frequency resources for carrying the data or control information of each user are allocated and managed not to overlap each other, i.e., to achieve orthogonality thereof.

[0042] As a post-LTE communication system, i.e., a 5G (or new radio (NR)) communication system, needs to support services capable of freely reflecting and simultaneously satisfying various requirements of users, service providers, etc. Services considered for the 5G system include enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), ultra-reliability low-latency communications (URLLC) services, etc.

[0043] The eMBB aims to provide a higher data rate than that supported by the conventional LTE, LTE-A, or LTE-Pro. For example, in the 5G communication system, the eMBB should be able to provide a peak data rate of 20 Gbps in the DL at one BS and a peak data rate of 10 Gbps in the UL. In addition, the 5G communication system must simultaneously provide a peak data rate of the UE and an increased user-perceived data rate. To meet this requirement, transmission / reception techniques including an improved multiple-input multiple-output (MIMO) transmission technique need to be improved. In addition, the data rate required in the 5G communication system can be met by using a frequency bandwidth wider than 20 MHz in a 3 GHz to 6 GHz or 6 GHz or more frequency band, rather than by using a maximum of 20 MHz in the 2 GHz frequency band to transmit a signal of the LTE.

[0044] In addition, the mMTC is considered to support application services such as IoT in the 5G communication system. To efficiently provide the IoT, the mMTC can need to support a large number of terminals in a cell, improve coverage of terminals, improve battery time, reduce the cost of terminals, etc. Because the IoT is connected to various sensors and various devices to provide a communication function, the mMTC should be able to support a large number of terminals (e.g., 1,000,000 terminals / km 2 ). In addition, because a terminal supporting the mMTC can be located in a shadow area that cannot be covered by a cell (e.g., a basement of a building), the terminal can need a wider coverage range than other services provided by the 5G communication system due to the characteristics of the service. The terminal supporting the mMTC should be configured as a low-cost terminal, and can need a very long battery life of 10 to 15 years because it is difficult to frequently replace the battery of the terminal.

[0045] Finally, the URLLC refers to a cellular-based wireless communication service for mission-critical purposes. For example, services for remotely controlled robots or machines, industrial automation, drones, remote health care, emergency alerts, etc. can be considered. Therefore, the URLLC should provide communication providing a very low latency and a very high reliability. For example, a service supporting the URLLC should satisfy an air interface latency of less than 0.5 milliseconds, and at the same time, require a packet error rate of 10 -5Or less. Accordingly, for a service supporting URLLC, the 5G system should provide a smaller transmission time interval (TTI) than other services, and can have a design requirement of allocating a wide resource in a frequency band at the same time in order to secure reliability of a communication link.

[0046] The three services of 5G, eMBB, URLLC, and mMTC, can be multiplexed and transmitted in one system. Here, in order to meet different requirements of services, services can use different transceiving schemes and different transceiving parameters.

[0047] Although LTE, LTE-A, LTE Pro, or 5G (or NR, next generation mobile communication) systems are mentioned as examples in the following description, embodiments of the present disclosure can also be applied to other communication systems having a similar technical background or channel type. Furthermore, embodiments of the present disclosure can also be applied to other communication systems by partial modification based on the determination of one of ordinary skill in the art, without deviating significantly from the scope of the present disclosure. In 5G, when a BS transmits or receives data to or from a UE in a frequency band equal to or greater than 6 GHz, particularly in a millimeter wave (mmWave) frequency band, coverage can be limited due to propagation path attenuation. The coverage limitation can be addressed by densely arranging a plurality of repeaters (or repeater nodes) in a propagation path between the BS and the UE, however, a huge cost of installing optical cables for connecting backhaul between the repeaters can be a problem. Accordingly, instead of installing optical cables between the repeaters, a wideband radio frequency resource available for the mmWave can be used to transmit or receive backhaul data between the repeaters in order to address the cost problem of installing optical cables and more efficiently use the mmWave frequency band.

[0048] A technology of transmitting or receiving backhaul data from a BS using a mmWave and finally transmitting or receiving access data to a UE via a plurality of repeaters as described above is referred to as integrated access and backhaul (IAB), and at this point, a repeater node that transmits or receives data to or from a BS by using a wireless backhaul is referred to as an IAB node. Here, the BS includes a central unit (CU) and a distributed unit (DU), and the IAB node includes a DU and a mobile terminal (MT). The CU can control the DUs of all IAB nodes connected to the BS via a multi-hop.

[0049] The IAB node can use different frequency bands or the same frequency band in order to receive backhaul data from the BS and transmit access data to the UE, and receive access data from the UE and transmit backhaul data to the BS. When the same frequency band is used, the IAB node has a half duplex constraint at an instant. Accordingly, as a method of reducing transmission and reception latency due to the half duplex constraint of the IAB node, the IAB node can perform frequency division multiplexing (FDM) and / or spatial division multiplexing (SDM) on backhaul data (downlink (DL) data from a DU of a parent IAB node to an MT of the IAB node and uplink (UL) data from an MT of a child IAB node to a DU of the IAB node) at the time of reception, and access data from the UE (UL data from the UE to the IAB node).

[0050] In addition, the IAB node for transmission can perform FDM and / or SDM on backhaul data (UL data from the MT of the IAB node to the DU of the parent IAB node and DL data from the DU of the IAB node to the MT of the child IAB node) and access data to the UE (DL data from the IAB node to the UE). Here, when the IAB node is configured to be dual-connected with a plurality of parent IAB nodes on a higher layer of the IAB node, data transmission and reception between the DUs of the parent IAB nodes and the MT of the IAB node and data transmission and reception between the DU of the IAB node and the MT of the child IAB node or the access UE on a lower layer of the IAB node are mixed, so it is difficult to satisfy the half duplex constraint at an instant. The present disclosure can provide a method by which the IAB node is able to operate in an environment in which data transmission and reception are mixed environments to comply with the half duplex constraint. Here, embodiments of the present disclosure will now be described with reference to the accompanying drawings.

[0051] Figure 1 A communication system operating an IAB node according to an embodiment of the present disclosure is illustrated.

[0052] In Figure 1In the middle, the gNB 101 is a public BS (e.g., eNB or gNB), and in the present disclosure, the gNB 101 is referred to as a gNB, eNB, BS, donor BS, or donor IAB. The IAB node #1 111 and the IAB node #2 121 are IAB nodes for performing backhaul link transmission and reception in a millimeter wave band. The UE 1 102 transmits and receives access data to and from the gNB 101 via an access link 103. The IAB node #1 111 transmits and receives backhaul data to and from the gNB 101 via a backhaul link 104. The UE 2 112 transmits and receives access data to and from the IAB node #1 111 via an access link 113. The IAB node #2 121 transmits and receives backhaul data to and from the IAB node #1 111 via a backhaul link 114. Accordingly, the IAB node #1 111 is a higher IAB node of the IAB node #2 121 and is referred to as a parent IAB node, and the IAB node #2 121 is a lower IAB node of the IAB node #1 111 and is referred to as a child IAB node. The UE 3 122 transmits and receives access data to and from the IAB node #2 121 via an access link 123.

[0053] Now, measurements of an IAB node or a donor gNB performed by a UE will be described.

[0054] The UE 2 112 or the UE 3 122 can need coordination between a donor gNB and an IAB node to perform measurements on a neighboring donor gNB or a neighboring donor IAB node that is not serving the IAB node. That is, the donor gNB can match measurement resources of IAB nodes with even hop orders or match measurement resources of IAB nodes with odd hop orders, thereby minimizing waste of resources in which the UE performs measurements on neighboring IAB nodes or IAB BSs. The UE can receive a higher layer signal for measurement of a synchronization signal block (SSB) / physical broadcast channel (PBCH) or a channel state information reference signal (CSI-RS) for measurement of a neighboring IAB node from a serving IAB node or BS. When the UE is configured to perform measurements on a neighboring BS via SSB / PBCH, the UE can be configured to have at least two SSB / PBCH measurement timing configurations (SMTC) for each frequency of measurement resources of IAB nodes with even hop orders or for each frequency of measurement resources of IAB nodes with odd hop orders. Upon receiving the configuration, the UE can perform measurements on IAB nodes with even hop orders in one SMTC and perform measurements on IAB nodes with odd hop orders in another SMTC.

[0055] Next, the measurement of the IAB node performed by another IAB node or a donor gNB will be described.

[0056] Coordination between the donor gNB and the IAB node can be necessary for the IAB node to perform measurement on another neighboring donor gNB or another neighboring IAB node. That is, the donor gNB can match the measurement resource for the IAB node with even hop order or match the measurement resource for the IAB node with odd hop order, thereby minimizing the waste of resources of one IAB node performing measurement on a neighboring IAB node or IAB BS. One IAB node can receive a higher layer signal for measurement of SSB / PBCH or CSI-RS for measurement of a neighboring IAB node from a serving IAB node or BS. When the IAB node is configured to perform measurement on a neighboring BS via SSB / PBCH, the IAB node can be configured to have at least two SMTCs for each frequency of the measurement resource of the IAB node with even hop order or at least two SMTCs for the measurement resource of the IAB node with odd hop order. Upon receiving the configuration, the IAB node can perform measurement on the IAB node with even hop order in one SMTC and perform measurement on the IAB node with odd hop order in another SMTC.

[0057] In the IAB technology proposed in the present disclosure, reference will now be made to Figure 2 , Figure 3 and Figure 4 to describe in detail multiplexing of the backhaul link between the BS and the IAB node or between the IAB nodes and the access link between the BS and the UE or between the IAB node and the UE in the wireless resource.

[0058] Figure 2 is a diagram schematically illustrating multiplexing of the access link and the backhaul link at the IAB node according to an embodiment of the present disclosure. In the upper part of Figure 2 Time domain multiplexing of the access link and the backhaul link at the IAB node is shown. In the lower part of Figure 2 Frequency domain multiplexing of the access link and the backhaul link at the IAB node is shown.

[0059] In Figure 2In the radio resources 201 shown in the upper part, the backhaul link 203 between the gNB and the IAB node or the access link 202 between the IAB node and the UE is time domain multiplexed (TDM). Thus, in the time domain in which the gNB or the IAB node transmits and receives data to and from the UE, data transmission and reception between the gNB and the IAB node is not performed, and in the time domain in which data transmission and reception between the gNB and the IAB node is performed, the gNB or the IAB node does not transmit and receive data to and from the UE.

[0060] Next, in the radio resources 211 shown in the lower part, the backhaul link 213 between the gNB and the IAB node or between the IAB nodes and the access link 212 between the gNB and the UE or between the IAB nodes and the UE are FDMed. Thus, in the time domain in which the gNB or the IAB node transmits and receives data to and from the UE, it is possible to transmit and receive data between the gNB and the IAB node, but only one-way data transmission is possible due to the half duplex constraint of the IAB node. That is, in the time domain in which the IAB node receives data from the UE, the IAB node can receive backhaul data only from another IAB node or the gNB. Also, in the time domain in which the IAB node transmits data to the UE, the IAB node can transmit backhaul data only to another IAB node or the gNB. Figure 2

[0061] Although the TDM and the FDM are described in connection with the upper part of FIG. 2, spatial domain multiplexing (SMD) of the access link and the backhaul link in the spatial domain is also possible. Thus, the access link and the backhaul link can be simultaneously transmitted and received via the SDM, but even with the SDM, data transmission in the same direction is only possible under the half duplex constraint of the IAB node, just as with the FDM in the lower part of FIG. 2. That is, in the time domain in which the IAB node receives data from the UE, the IAB node can receive backhaul data only from another IAB node or the gNB. Also, in the time domain in which the IAB node transmits data to the UE, the IAB node can transmit backhaul data only to another IAB node or the gNB. Figure 2 Figure 2

[0062] When the IAB node performs initial access to the gNB or a higher IAB node, the multiplexing scheme using the TDM, the FDM, and the SDM can be configured by the IAB node transmitting a capability for the multiplexing scheme to the gNB or the higher IAB node, then receiving configuration information from the gNB or the higher IAB node via system information or a radio resource control (RRC) signal, or receiving the configuration information from the gNB or the higher IAB node via the backhaul link after the initial access.

[0063] Figure 3 ​​​This is a diagram illustrating the multiplexing of access links and backhaul links in the time domain in an IAB communication system according to an embodiment of the present disclosure.

[0064] exist Figure 3 The upper part illustrates the communication process between IAB node 302 and its parent node 301, child IAB node 303, and UE 304. The links between the nodes are explained in more detail, with parent node 301 on the backhaul DL link L. P，DL (311) sends a backhaul DL signal to IAB node 302, and IAB node 302 sends a backhaul UL link L P，UL (312) Sends a return UL signal to parent node 301. IAB node 302 accesses DL link L A，DL (316) sends an access DL signal to UE 304, and UE 304 accesses the UL link L. A，UL (315) Sends an access UL signal to IAB node 302. IAB node 302 sends an access UL signal to the backhaul DL link L. C，DL The IAB sub-node 303 sends a backhaul DL signal (313), and the IAB sub-node 303 on the backhaul UL link L C，UL The middle node sends a backhaul UL signal (314) to IAB node 302. In the above symbols, P refers to the backhaul link to the parent node, A refers to the access link to the UE, and C refers to the backhaul link to the child node.

[0065] These link relationships are described relative to IAB node 302, and from the perspective of IAB child node 303, the parent node is IAB node 302, and IAB child node 303 may have another IAB child node at a lower level. Furthermore, from the perspective of parent node 301, the child node is IAB node 302, and parent node 301 may have another IAB parent node at a higher level.

[0066] The aforementioned signals include data and control information, channels for transmitting data and control information, reference signals required for decoding data and control information, or reference signals used for calculating channel information.

[0067] exist Figure 3 The lower part illustrates the process for multiplexing all links in the time domain. In the accompanying figures, the backhaul DL links are arranged in chronological order. P，DL 311. Backhaul DL link L C，DL 313. Access DL link L A，DL 316. Access UL Link L A，UL 315. Backhaul UL Link L C，UL 314 and backhaul UL link L P，UL312 are multiplexed. The order of the links provided in the figure is one example, but any order can be equally applied.

[0068] The links are multiplexed in time domain in time order, therefore, it is obvious that the multiplexing scheme needs the longest time to transmit a signal from a parent node 301 to a child IAB node through an IAB node 302, even to a UE. Therefore, in order to reduce the time delay of transmitting a signal from the parent node 301 to the UE finally, a method of multiplexing a backhaul link or a backhaul link and an access link in a frequency domain or a spatial domain and transmitting the result simultaneously can be considered.

[0069] Figure 4 is a diagram illustrating multiplexing of an access link and a backhaul link in a frequency domain and a spatial domain in an IAB communication system according to an embodiment of the disclosure.

[0070] Reference Figure 4 Now, a method of reducing time latency by multiplexing a backhaul link or a backhaul and an access link in a frequency domain or a spatial domain will be described.

[0071] First, similarly to Figure 3 , in the upper part of Figure 4 , a process in which an IAB node 402 communicates with a parent node 401, a child IAB node 403, and a UE 404 is illustrated. The links between the respective nodes are explained in more detail, the parent node 401 transmits a backhaul DL signal to the IAB node 402 in a backhaul DL link L P，DL (411), and the IAB node 402 transmits a backhaul UL signal to the parent node 401 in a backhaul UL link L P，UL (412). The IAB node 402 transmits an access DL signal to the UE 404 in an access DL link L A，DL (416), and the UE 404 transmits an access UL signal to the IAB node 402 in an access UL link L A，UL (415). The IAB node 402 transmits a backhaul DL signal to the child IAB node 403 in a backhaul DL link L C，DL (413), and the IAB child node 403 transmits a backhaul UL signal to the IAB node 402 in a backhaul UL link L C，UL (414). In the above notation, P refers to a backhaul link to a parent node, A refers to an access link to a UE, and C refers to a backhaul link to a child node.

[0072] These link relations are described with respect to the IAB node 402, and from the perspective of the IAB child 403, the parent is the IAB node 402, and the IAB child 403 can have another IAB child on its lower level. Also, from the perspective of the parent 401, the child is the IAB node 402, and the parent 401 can have another IAB parent on its higher level.

[0073] The above signals include data and control information, channels for transmitting data and control information, reference signals required to decode data and control information, or reference signals for calculating channel information.

[0074] Next, in the lower part of Figure 4 a scheme for multiplexing the above links in the frequency domain or the spatial domain is shown.

[0075] As described above, the IAB node has a half-duplex constraint at an instant, and thus there is a limitation on signals that can be multiplexed in the frequency domain or the spatial domain. For example, when considering the half-duplex constraint of the IAB node 402, the links that can be multiplexed in the time domain in which the IAB node can perform transmission are the backhaul UL link L P，UL 412, the backhaul DL link L C，DL 413, the access DL link L A，DL 416, etc. Thus, when the links are multiplexed in the frequency domain or the spatial domain, the IAB node 402 can transmit all the links in the same time domain as in 421. Also, the links that can be multiplexed in the time domain in which the IAB node can perform reception are the backhaul UL link L P，DL 411, the backhaul DL link L C，UL 414, the access UL link L A，UL 415, etc. Thus, when the links are multiplexed in the frequency domain or the spatial domain, the IAB node 402 can receive all the links in the same time domain as in 422.

[0076] The multiplexing of the links provided in the accompanying drawings is one example, and two of the three links multiplexed in the frequency or spatial domain can be multiplexed.

[0077] The structure of the IAB node will now be described.

[0078] For 5G, various forms of BS structures have been researched that are optimal for service requirements to support various services such as massive transmission, low latency, and high reliability or a large number of machine-to-machine communication devices and to reduce capital expenditure (CAPEX) for installing a communication network. In 4G LTE, in order to reduce CAPEX and efficiently handle interference control, a cloud radio access network (C-RAN) structure has been commercialized in which data processors in a BS and wireless transceivers (or remote radio heads (RRHs)) are separated and the data processors are arranged at a center to be processed and the wireless transceivers are arranged at a cell site. In the C-RAN structure, when the BS data processor transmits baseband digital IQ data to the wireless transceiver, an optical link of a common public radio interface (CPRI) standard is generally used. When data is transmitted to the wireless transceiver, a large amount of data is required. For example, a transmission rate of 614.4 Mbps is required to transmit 10 MHz of Internet protocol (IP) data, and a transmission rate of 1.2 Gbps is required to transmit 20 MHz of IP data. Accordingly, the 5G RAN structure is designed by dividing the BS (gNB) into a CU and a DU to have various structures, thereby reducing a large amount of load of the optical link and applying function split to the CU and the DU. The 3GPP is standardizing many different function split options for the CU and the DU. The function split option is to split a protocol inter-layer or a protocol intra-layer into functions, and there are a total of 8 options from option 1 to option 8, in which option 2 and option 7 are first considered in the current 5G BS structure. Option 2 has an RRC and a packet data convergence protocol (PDCP) layer located in the CU and a radio link control (RLC), a medium access control (MAC), a physical (PHY), and a radio frequency (RF) layer located in the DU. Option 7 has an RRC, a PDCP, an RLC, a MAC, and a higher PHY layer located in the CU and a lower PHY layer located in the DU. Such a function split allows a structure having deployment flexibility to separate and migrate NR network protocols between the CU and the DU. Such a structure results in a flexible hardware implementation, provides a cost-saving solution, and the separated structure between the CU and the DU allows load management and adjustment of real-time performance optimization, allows network function virtualization (NFV) / software-defined network (SDN), and the configurable function split can have an advantage that can be applied to various applications (variable latency in transmission).

[0079] An architecture of an IAB node considering function split will now be described with reference to Figure 5 Figure 5 is a diagram schematically illustrating an architecture of an IAB node according to an embodiment of the disclosure.

[0080] In Figure 5 ​In the middle, the gNB 501 includes a CU and a DU, and the IAB nodes each include an MT and a DU, the MT for transmitting data to and receiving data from a parent node via a backhaul link, and the DU for transmitting data to and receiving data from a child node via a backhaul link. In Figure 5 In the middle, the gNB 501 includes a CU and a DU, and the IAB nodes each include an MT and a DU, the MT for transmitting data to and receiving data from a parent node via a backhaul link, and the DU for transmitting data to and receiving data from a child node via a backhaul link. In

[0081] As Figure 5 indicated, the CU of the gNB 501 not only controls the DU of the gNB 501 but also controls the DUs of all the IAB nodes (i.e., the IAB node #1 502 and the IAB node #2 503 (511 and 512)) wirelessly connected to the gNB 501. The CU can allocate radio resources to the DUs so that the DUs can transmit data to and receive data from the MTs of the IAB nodes on lower layers of the DUs. The allocation of the radio resources can be performed on the DUs by using an F1 application protocol (F1AP) interface and transmitting system information, higher layer signals, or physical signals. Here, the radio resources can be configured by DL time resources, UL time resources, flexible time resources, etc.

[0082] The configuration of the radio resources will now be described in detail based on the IAB node #2 503. The DL time resources are resources in which the DU of the IAB node #2 503 transmits DL control / data and signals to the MTs of the IAB nodes on a lower level (not shown). The UL time resources are resources in which the DU of the IAB node #2 503 receives UL control / data and signals from the MTs of the IAB nodes on a lower level. The flexible time resources are resources that can be used as the DL time resources or the UL time resources by the DU of the IAB node #2 503, and how to use the flexible time resources can be indicated to the MTs of the lower IAB nodes through the DL control signals of the DU of the IAB node #2 503. Upon receiving the DL control signals, the MT determines whether the flexible time resources are for the DL time resources or the UL time resources. When no DL control signals are received, the MT does not perform a transmission or reception operation. That is, the MT does not monitor or decode a DL control channel on the resources or does not measure a signal on the resources. The MT does not perform a transmission or reception operation on the resources. That is, the MT does not monitor or decode a DL control channel in the resources or does not measure a signal on the resources. Two different types (or three different types including time resources that are always unavailable) of the DL time resources, the UL time resources, and the flexible time resources can be indicated from the CU to the DU.

[0083] - The first type is a soft type in which the CU can use the F1AP (interface between the CU and the DU) to configure the DU of the IAB node #2 503 with soft type DL time resources, UL time resources, or flexible time resources. In this case, for the configured soft type resources, the parent IAB node (or the DU of the parent IAB node) of the IAB node #2 502, 503 can explicitly (e.g., by using a DCI format) or implicitly indicate to the IAB node #2 503, child IAB node (or the DU of the child IAB node) whether the resources are available. That is, when a specific resource is indicated to be available, the DU of the IAB node #2 503 can use the resource to transmit and receive data to and from the MT of the lower IAB node. That is, the DU of the IAB node #2 503 can use the resource to perform transmission when the resource is a DL resource or use the resource to perform reception when the resource is a UL resource. When the specific resource is indicated to be unavailable, the IAB node #2 503 can not use the resource for data transmission and reception to and from the MT of the lower IAB node. That is, the DU of the IAB node #2 503 cannot use the resource for transmission or reception.

[0084] The method of indicating the availability of the soft type resource by using the DCI format will now be described in more detail. The DCI format in embodiments can include an availability indicator to indicate the availability of one or more consecutive UL, DL, or flexible symbols.

[0085] The IAB node #2 503 can pre-receive information about at least one of the location of the availability indicator indicating the availability of the DCI format of the IAB node #2, the table indicating the availability of the time resources corresponding to a plurality of slots, or the mapping relationship of the availability indicator together with the cell ID of the DU of the IAB node #2 503 from the CU or the parent IAB node (e.g., the IAB node #1 502) through a higher layer signal in order to receive the DCI format. The value (or indicator) indicating the availability of the consecutive UL symbols, DL symbols, or flexible symbols in one slot and the meaning of the value (or indicator) can be represented as shown in Table 1 below.

[0086] [Table 1]

[0087]

[0088] When the availability indicator is indicated from the parent IAB node to the IAB node #2 503 in the DCI format and the IAB node #2 503 receives the indication, the following method can be considered as a method by which the DU of the IAB node #2 503 interprets the relationship between the DL, UL, or flexible time resources configured for the IAB DU by the CU and the availability.

[0089] The first method is a method in which the IAB DU expects the number of values indicating availability included in the availability indicator of the DCI format to correspond to the number of slots of the soft type including consecutive symbols configured by the CU. According to this method, the IAB DU can determine that availability is applied only to slots of the soft type.

[0090] The second method is a method in which the IAB DU expects the number of values indicating availability included in the availability indicator of the DCI format to correspond to the number of all slots configured by the CU, i.e., the number of all slots having the hard / soft / unavailable (NA) type. In this embodiment, the IAB DU can determine that availability is applied only to slots having the soft type, and availability is not applied to slots having the hard or NA type without the soft type.

[0091] In the first and second methods, the IAB DU can expect the meaning of the values indicating availability to match the DL resource, the UL resource, or the flexible resource. For example, when only the DL soft resource or the DL hard resource exists in the slot, the IAB DU can also expect only the value 1 to be indicated in Table 1 above. Accordingly, among the values in the table, it can not be expected to indicate a value including availability of the UL soft resource.

[0092] Alternatively, the IAB DU can determine that, for at least the flexible resource configured by the CU, in addition to the value indicating that the flexible resource is available, it can be indicated that the DL resource or the UL resource is available. For example, for the flexible soft resource or the flexible hard resource, the DU of the IAB node can expect that it can indicate the value 1 or 2 instead of the value 4 in Table 1. In this case, the DU of the IAB node #2 can determine that the flexible resource can be used as the UL or the DL according to the indication from the parent IAB instead of the determination of the IAB node #2.

[0093] Alternatively, the IAB DU expects that even for any hard / soft or NA resource configured by the CU, the value 0 can be indicated in the above table. In this case, the IAB DU determines that the hard / soft resource that has been configured by the CU is not available, and the resource is considered to be unavailable for the DU of the IAB node #2 to perform data transmission or reception with the MT of a lower IAB node as in the case of the resource type that is always unavailable configured by the CU until it is indicated as available in a later DCI format. When the resource is indicated as available again by the DCI format, the DU of the IAB node #2 can use the resource configured by the CU or received in the DCI format.

[0094] - The second type is a hard type, and the resource is always available between the DU and the MT. That is, regardless of the transmission or reception operation of the MT of the IAB node #2 503, the DU of the IAB node #2 503 can perform transmission when the resource is a DL time resource, and can perform reception when the resource is a UL resource. When the resource is a flexible resource, the IAB DU can determine to perform transmission or reception (corresponding to a DCI format that indicates to the MT of the lower IAB node whether the flexible resource is a DL resource or a UL resource).

[0095] - The third type is a type that is always unused or always unavailable, and the DU of the IAB node #2 can not use the resource to transmit data to the MT and receive data from the MT.

[0096] When the DU receives the DL time resource, the UL time resource, the flexible time resource, or the reserved time resource from the CU in the higher layer signal, the above-described types are received together.

[0097] Next, the DU of the gNB 501 is a public BS, and the DU controls scheduling (521) of the MT of the IAB node #1 502 for data transmission or reception. The DU of the IAB #1 502 is a public BS, and the DU controls scheduling (522) of the MT of the IAB node #2 503 for data transmission or reception.

[0098] The DU can indicate radio resources for data transmission and reception to and from the MT of the lower IAB node based on the radio resources allocated from the CU. The configuration of the radio resources can be transmitted to the MT via system information, a higher layer signal, or a physical signal. Here, the radio resources can be configured by a DL time resource, a UL time resource, a flexible time resource, a reserved time resource, etc. The DL time resource is a resource in which the DU transmits DL control / data and signals to the MT of the lower IAB node. The UL time resource is a resource in which the DU receives UL control / data and signals from the MT of the lower IAB node. The flexible time resource is a resource that can be used as a DL time resource or a UL time resource by the DU, and how to use the flexible time resource can be indicated to the MT of the lower IAB by a DL control signal of the DU. Upon receiving the DL control signal, the MT determines whether the flexible time resource is for a DL time resource or a UL time resource. When the DL control signal is not received, the MT does not perform a transmission or reception operation. That is, the MT does not monitor or decode a DL control channel on the resource or does not measure a signal on the resource.

[0099] The DL control signal is signaled to the MT as a combination of higher layer signal and physical signal, and the MT can determine the slot format in a specific slot by receiving the signaling. The slot format is basically formed to start with a DL symbol, have a flexible symbol in the middle, and end with a UL symbol (i.e., a structure having a D-F-U order). When only the slot format is used, the DU of the IAB node can be able to perform a DL transmission at the start of the slot, but the MT of the IAB node configured by the parent IAB in the same slot format (i.e., a D-F-U structure) cannot perform a UL transmission at the same time (corresponding to slot format indexes 0 to 55 in Table 2 below). Therefore, the slot format formed to start with a UL symbol, have flexible symbols in the middle and at the end of a DL symbol, can be as defined in Table 2 below (corresponding to slot format indexes 56 to 96 in Table 2 below). The slot format defined in Table 2 below can be transmitted to the MT by using the DL control signal, and can be configured for the DU by the CU using the F1AP.

[0100] [Table 2]

[0101]

[0102]

[0103] The reserved time resource is a resource on which the DU cannot transmit data to and receive data from the lower-level MT, so that the MT does not perform a transmission or reception operation on the resource. That is, the MT does not monitor or decode a DL control channel on the resource or does not measure a signal on the resource.

[0104] Therefore, the MT in the IAB node is controlled by the DU in the upper IAB node in order to receive scheduling for data transmission or reception, and the DU in the same IAB node is controlled by the CU of the gNB 501. That is, the MT and the DU in one IAB are controlled by different entities, and thus can not be coordinated in real time.

[0105] Next, Figure 6 is a diagram illustrating a communication system according to an embodiment of the disclosure. Although Figure 6 An example of a system configured by combining a BS using a new radio access technology and an LTE / LTE-A BS is illustrated, but a system configured by combining a BS using a new radio access technology can also exist.

[0106] Referring to Figure 6Small BSs 603, 605, and 607 with relatively small coverage 604, 606, and 608 can be deployed within coverage 602 of macro BS 601. Generally, macro BS 601 is capable of transmitting a signal with a higher transmission power than small BSs 603, 605, or 607, so that coverage 602 of macro BS 601 is greater than coverage 604, 606, or 608 of small BSs 603, 605, or 607. In Figure 6 In an example, the macro BS refers to an LTE / LTE-A system operating in a relatively lower frequency band, and small BSs 603, 605, or 607 refer to a system to which a new radio access technology (NR or 5G) operating in a relatively higher frequency band is applied.

[0107] Macro BS 601 and small BSs 603, 605, and 607 can be connected to each other and there can be a certain degree of backhaul delay according to the connection state. Therefore, it can not be desirable to exchange information susceptible to transmission delay between macro BS 601 and small BSs 603, 605, or 607.

[0108] Although Figure 6 an example shows carrier aggregation between macro BS 601 and small BSs 603, 605, or 607, the disclosure is not limited thereto and can be equally applied to carrier aggregation between BSs located in geographically different locations. For example, in some embodiments, it can be equally applied to carrier aggregation between a macro BS and a macro BS located in different locations or carrier aggregation between small BSs and small BSs located in different locations. Also, there is no limit to the number of carriers. Alternatively, the present disclosure can be applied to carrier aggregation in macro BS 601 and carrier aggregation in small BSs 603, 605, or 607.

[0109] Referring to Figure 6 , macro BS 601 can use frequency f1 for DL signal transmission, and small BSs 603, 605, or 607 can use frequency f2 for DL signal transmission. In this case, macro BS 601 can transmit data or control information to a specific UE 609 on frequency f1, and small BSs 603, 605, or 607 can transmit data or control information to UE 609 on frequency f2. Through the above-described carrier aggregation, a BS to which a new radio access technology supporting a high frequency to an ultra-high frequency band is applied can provide an ultra-high speed data service and an ultra-low latency service, and together with the BS, a BS to which an LTE / LTE-A technology is applied in a relatively low frequency band can support reliable UE mobility.

[0110] Figure 6The configuration shown can be applied not only to DL carrier aggregation but also to UL carrier aggregation. For example, UE 609 can send data or control information to macro BS 601 at frequency f1' for UL signal transmission. Furthermore, UE 609 can send data or control information to small BSs 603, 605, or 607 at frequency f2' for UL signal transmission. f1' can correspond to f1, and f2' can correspond to f2. UL signal transmission from the UE to the macro and small BSs can be performed at different times or at one time. In either case, due to the physical constraints of the power amplifiers in the UE and the propagation constraints on the UE's output power, the total UL transmit power of the UE must remain equal to or less than a certain threshold within a random time period.

[0111] Through such Figure 6 In the environment shown, the operation of UE609, which connects to macro BS 601 and small BS 603, 605, or 607 to perform communication, is called dual connectivity (DC). When the UE performs dual connectivity, the following three configurations are possible.

[0112] According to the first configuration, after the UE performs initial access to the macro BS 601 operating as an LTE / LTE-A system, the UE receives configuration information for data transmission and reception of the macro BS 601 via a higher-layer signal (system or RRC signal). Then, the UE receives configuration information for data transmission and reception of the micro BS 603, 605, or 607 operating as an NR system via the higher-layer signal (system or RRC signal) of the macro BS 601, and the UE performs random access to the micro BS 603, 605, or 607, thus having a dual-connectivity state, where the UE can transmit and receive data to and from both the macro BS 601 and the micro BS 603, 605, or 607. Here, the macro BS 601 operating as an LTE / LTE-A system is included in the primary cell group (MCG), and the micro BS 603, 605, or 607 operating as an NR system is included in the secondary cell group (SCG). When a UE is in dual connectivity, this can be represented as a UE configured with an MCG using E-UTRA radio access (or LTE / LTE-A) and an SCG using NR radio access. Alternatively, the UE can be represented as a UE configured with NR E-UTRA dual connectivity (NE-DC).

[0113] According to a second configuration, after the UE performs initial access to the small BS 603, 605, or 607 operating as an NR system, the UE receives configuration information for data transmission and reception with respect to the small BS 603, 605, or 607 via a higher layer signal (system or RRC signal). Then, the UE receives configuration information for data transmission and reception with respect to the macro BS 601 operating as an LTE / LTE system from the small BS 603, 605, or 607 via a higher layer signal (system or RRC signal) and performs random access to the macro BS 601, thereby having a dual connectivity state in which the UE can transmit and receive data to and from the macro BS 601 and the small BS 603, 605, or 607. Here, the small BS 603, 605, or 607 operating as an NR system is included in the MCG, and the macro BS 601 operating as an LTE system is included in the SCG. When the UE is in the dual connectivity state, this can be expressed as the UE being configured with an MCG using NR radio access and an SCG using E-UTRA radio access (or LTE / LTE-A). Alternatively, the UE can be expressed as being configured with NR-E-UTRA dual connectivity (NE-DC).

[0114] According to a third configuration, after the UE performs initial access to the first BS 601, 603, 605, or 607 operating as an NR system, the UE receives configuration information for data transmission and reception with respect to the first BS via a higher layer signal (system or RRC signal). Then, the UE receives configuration information for data transmission and reception with respect to the second BS 601, 603, 605, or 607 operating as an NR system from the first BS via a higher layer signal (system or RRC signal) and performs random access to the second BS, and thus has a dual connectivity state in which the UE can transmit and receive data to and from the first BS and the second BS. Here, the first BS operating as an NR system is included in the MCG, and the second BS also operating as an NR system is included in the SCG. When the UE is in the dual connectivity state, this can be expressed as the UE being configured with an MCG using NR radio access and an SCG using NR radio access. Alternatively, the UE can be expressed as being configured with NR-NR dual connectivity (NN-DC).

[0115] In the above description, the dual connectivity configuration is described for a specific UE 609, however, the dual connectivity configuration can also be applied to an IAB node 614. The dual connectivity configuration and access procedure of the UE 609 described above can also be applied to dual connectivity of the IAB node 614. Thus, the IAB node 614 can perform dual connectivity to different parent IAB nodes 611 and 612 connected to different donor BSs 601 and 607 via wireless backhaul (615), or to different parent IAB nodes 612 and 613 both connected to one donor BS 601 via wireless backhaul (616), by applying the dual connectivity procedure and method of the UE 609. Referring to Figure 7 and Figure 8 Now, the dual connectivity structure of the IAB node will be described in detail.

[0116] First, referring to Figure 7 Now, a structure in which an IAB node performs dual connectivity to different parent IAB nodes connected to one donor BS via wireless backhaul will be described.

[0117] Figure 7 FIG. 1 is a diagram schematically illustrating a dual connectivity structure of an IAB node according to an embodiment of the disclosure. Figure 7 The dual connectivity structure of the IAB node in FIG. 1 is a structure considering the above-described functional split in the disclosure.

[0118] In Figure 7 In FIG. 1, the gNB 701 includes a CU and a DU, and the IAB nodes each include an MT for transmitting and receiving data to and from a parent node via a backhaul link and a DU for transmitting and receiving data to and from a child node via a backhaul link. In Figure 7 In FIG. 1, the parent IAB node #1 702 is wirelessly connected to the gNB 701 having one hop (711), and the parent IAB node #2 703 is wirelessly connected to the gNB 701 having one hop (712). The IAB node #1 704 performs dual connectivity to different parent IAB nodes #1 702 and #2 703, and is wirelessly connected to the gNB 701 via different parent IAB nodes having two hops.

[0119] Although in Figure 7The CU of the gNB 701 not only controls the DU of the gNB 701 but also controls the DUs of all the IAB nodes, i.e., the parent IAB node #1 702, the parent IAB node #2 703, and the IAB node #1 704 wirelessly connected to the gNB 701, although not shown. The CU can allocate radio resources to the DUs so that the DUs can transmit and receive data to and from the MTs of the IAB nodes on lower layers of the DUs. The allocation of the radio resources can be performed by transmitting system information or higher layer signals or physical signals to the DUs using the F1AP interface. Here, the IAB nodes of the DUs that have received the radio resources use the resources to transmit and receive DL control / data and signals or UL control / data and signals to and from the MTs of the lower child IAB nodes according to resource configurations configured with DL time resources, UL time resources, flexible time resources, resource types, availability, etc., and the indication by the DUs of the higher parent IAB nodes.

[0120] In Figure 7 the IAB node #1 704 is dual-connected with different parent IAB nodes #1 702 and #2 703, and the parent IAB nodes #1 702 and #2 703 are connected to one donor BS 701 via a wireless backhaul. Accordingly, the MT in the IAB node #1 704 is controlled by each of the DUs in the parent IAB nodes 702 or 703 on a higher layer to receive scheduling for data transmission and reception, and the DU of the IAB node #1 704 has to act as a BS for data transmission and reception with respect to the lower IAB nodes and UEs, so that the MT and the DU can not be coordinated in real time.

[0121] Next, reference will be made to Figure 8 A structure in which an IAB node performs dual connectivity to different parent IAB nodes connected to different donor BSs via a wireless backhaul, respectively, will now be described.

[0122] Figure 8 is a diagram schematically illustrating a dual connectivity structure of an IAB node according to an embodiment of the disclosure. Figure 8 The dual connectivity structure of the IAB node in

[0123] In Figure 8 the gNB #1 801 includes a CU and a DU, and the IAB nodes each include an MT for transmitting and receiving data to and from a parent node via a backhaul link and a DU for transmitting and receiving data to and from a child node via a backhaul link. In Figure 8In the middle, the parent IAB node #1 803 is wirelessly connected to the gNB #1 801 (811) with one hop, and the parent IAB node #2 804 is wirelessly connected to the gNB #2 802 (812) with one hop. The IAB node #1 805 performs dual connectivity to the different parent IAB node #1 803 and the parent IAB node #2 804, and is wirelessly connected to the gNB #1 801 and the gNB #2 802 via the different parent IAB nodes with two hops.

[0124] Although not shown in Figure 8 , the CU of the gNB #1 801 can control not only the DU of the gNB #1 801 but also the DUs of any lower IAB nodes (i.e., the parent IAB node #1 803) wirelessly connected to the gNB #1 801, and the CU of the gNB #2 802 can control not only the DU of the gNB #2 804 but also the DUs of any lower IAB nodes (i.e., the parent IAB node #2 804) wirelessly connected to the gNB #2 802. The DU of the IAB node #1 805 wirelessly connected to the gNB #1 801 and the gNB #2 802 can be controlled by the CU of the gNB (e.g., gNB #1) included in the MCG.

[0125] The CU can allocate radio resources to the DU so that the DU can transmit and receive data to and from the MT of the IAB node on a lower layer of the DU. The allocation of the radio resources can be performed by transmitting system information or higher layer signals or physical signals to the DU using the F1AP interface. Here, the IAB node of the DU that has received the radio resources uses the resources according to the resource configuration configured with DL time resources, UL time resources, flexible time resources, resource types, availability, etc., and the indication by the DU of the higher parent IAB node, to transmit and receive DL control / data and signals or UL control / data and signals to and from the MT of the lower child IAB node.

[0126] In Figure 8 , the IAB node #1 805 is dual-connected with the different parent IAB node #1 803 and the parent IAB node #2 804, and the parent IAB node #1 803 and the parent IAB node #2 804 are connected to the different donor BS 801 and 802 via wireless backhaul, respectively. Therefore, since the MT in the IAB node #1 805 is controlled by the DU in the parent IAB node 803 or 804 on a higher layer in order to receive scheduling for data transmission and reception, and the DU of the IAB node #1 805 has to act as a BS for data transmission and reception with respect to the lower IAB nodes and UEs, the MT and the DU can not be like in Figure 7as in the dual connectivity structure of FIG. 9A, are coordinated in real time. It will be referred to Figure 9 Details are described.

[0127] Figure 9 FIG. 9B is a diagram schematically illustrating an environment that can occur in a dual connectivity structure of an IAB node according to an embodiment of the disclosure.

[0128] Figure 9 FIG. 9B shows a case where the IAB node #1 904 is wirelessly connected to different parent IAB nodes through dual connectivity (e.g., where the IAB node #1 904 is wirelessly connected to the parent IAB node #1 902 (913) and wirelessly connected to the parent IAB node #2 903 (916)) according to the description of FIG. 9A. Figure 7 and Figure 8 FIG. 9B shows a case where the IAB node #1 904 is wirelessly connected to different parent IAB nodes through dual connectivity (e.g., where the IAB node #1 904 is wirelessly connected to the parent IAB node #1 902 (913) and wirelessly connected to the parent IAB node #2 903 (916)) according to the description of FIG. 9A. Figure 5 , Figure 7 and Figure 8 FIG. 9B shows a case where the IAB node #1 904 is wirelessly connected to different parent IAB nodes through dual connectivity (e.g., where the IAB node #1 904 is wirelessly connected to the parent IAB node #1 902 (913) and wirelessly connected to the parent IAB node #2 903 (916)) according to the description of FIG. 9A. Figure 7 and Figure 8 FIG. 9B shows a case where the IAB node #1 904 is wirelessly connected to different parent IAB nodes through dual connectivity (e.g., where the IAB node #1 904 is wirelessly connected to the parent IAB node #1 902 (913) and wirelessly connected to the parent IAB node #2 903 (916)) according to the description of FIG. 9A.

[0129] Here, as in 915 and 916 of FIG. 9A, the MT of the IAB node #1 904 can perform DL reception or UL transmission according to the configuration and indication from the parent IAB node #1 902 or the parent IAB node #2 903, and as in 917 of FIG. 9A, the DU of the IAB node #1 904 can perform UL reception or DL transmission according to the configuration and indication to the MT of the lower IAB node. Figure 9 Figure 9 The MT of the IAB node #1 904 determines time resources as DL time resources or UL time resources or flexible time resources based on the configuration and indication from the DU of the parent IAB node #1 902. In addition, the MT of the IAB node #1 904 determines time resources as DL time resources or UL time resources or flexible time resources based on the configuration and indication from the DU of the parent IAB node #2 903. In addition, the DU of the IAB node #1 904 determines time resources as DL time resources or UL time resources or flexible time resources according to the configuration from the CU and determines resources as hard (H), soft (S), or not available (NA) according to the type.

[0130] The MT of the IAB node #1 904 determines time resources as DL time resources or UL time resources or flexible time resources based on the configuration and indication from the DU of the parent IAB node #1 902. In addition, the MT of the IAB node #1 904 determines time resources as DL time resources or UL time resources or flexible time resources based on the configuration and indication from the DU of the parent IAB node #2 903. In addition, the DU of the IAB node #1 904 determines time resources as DL time resources or UL time resources or flexible time resources according to the configuration from the CU and determines resources as hard (H), soft (S), or not available (NA) according to the type.

[0131] ​Afterwards, when the time resource is determined as a DL time resource according to the scheduling from the parent IAB node #1 902 or the parent IAB node #2 903, the MT of the IAB node #1 904 can receive a DL control / data channel and a reference signal, when the time resource is determined as a UL time resource, the MT of the IAB node #1 904 can transmit a UL control / data channel and a reference signal, and can receive a DL control / data channel and a reference signal or transmit a UL control / data channel and a reference signal according to the indication. When the time resource is determined as a flexible time resource. On the other hand, although not shown in Figure 9 , the DU of the IAB node #1 904 can determine the time resource as a DL time resource, a UL time resource, or a flexible time resource according to the indication of the CU to the MT of the lower IAB node, and transmit a UL control / data channel and a reference signal, and thus can receive a UL control / data channel and a reference signal, or can transmit a DL control / data channel and a reference signal. Accordingly, according to the indication and determination of the parent IAB node and the configuration from the CU, the MT and the DU of the IAB node #1 904 each have to determine and perform the transmission and reception of the time resource, and in this case, a situation in which the half duplex constraint of the IAB node cannot be satisfied can occur. Now, the cases 1, 2, and 3 will be described in detail as an example. Figure 9

[0132] In case 1, the MT of the IAB node #1 904 can determine the time resource as a DL time resource according to the indication from the DU of the parent IAB node #1 902 in order to receive a DL control / data channel and a reference signal, at the same time, the MT of the IAB node #1 904 can determine the time resource as a UL time resource according to the indication from the DU of the parent IAB node #2 903 in order to transmit a UL control / data channel and a reference signal, at the same time, the DU of the IAB node #1 904 can determine the time resource as a UL time resource to receive a UL control / data channel and a reference signal. Accordingly, in a case in which the MT of the IAB node #1 904 has to perform reception and transmission with respect to different parent IAB nodes and the DU has to perform reception, the half duplex constraint cannot be satisfied.

[0133] ​In Case 2, the MT of the IAB node #1 904 can determine the time resources as DL time resources to receive DL control / data channels and reference signals according to the indication from the DU of the parent IAB node #1 902, while the MT of the IAB node #1 904 can determine the time resources as UL time resources to transmit UL control / data channels and reference signals according to the indication from the DU of the parent IAB node #2 903, while the DU of the IAB node #1 904 can determine the time resources as DL time resources to transmit DL control / data channels and reference signals. Thus, in the case where the MT of the IAB node #1 904 has to perform reception and transmission with respect to different parent IAB nodes and the DU has to perform transmission, the half duplex constraint cannot be satisfied.

[0134] In Case 3, the MT of the IAB node #1 904 can determine the time resources as UL time resources to transmit UL control / data channels and reference signals according to the indication from the DU of the parent IAB node #1 902, while the MT of the IAB node #1 904 can determine the time resources as DL time resources to receive DL control / data channels and reference signals according to the indication from the DU of the parent IAB node #2 903, while the DU of the IAB node #1 904 can determine the time resources as DL time resources to transmit DL control / data channels and reference signals. Thus, in the case where the MT of the IAB node #1 904 has to perform transmission and reception with respect to different parent IAB nodes and the DU has to perform transmission (or reception), the half duplex constraint cannot be satisfied.

[0135] The disclosure can provide embodiments of a method of satisfying a half duplex constraint of an IAB node while transmitting and receiving data in a backhaul link when transmission and reception of an MT collide with transmission and reception of a DU in the IAB node.

[0136] [Embodiment 1]

[0137] In Embodiment 1, a case is assumed in which transmission and reception of a DU and transmission and reception of an MT of the IAB node #1 904 can collide with each other when following a configuration from a CU or an indication or scheduling from the parent IAB node #1 902 or a parent IAB node #2 903 connected to the IAB node #1 904 through dual connectivity. In Embodiment 1, a procedure for the IAB node #1 904 can be determined according to whether a resource type of the DU of the IAB node #1 904 is hard, soft, or not available (NA).

[0138] When the resource type of the DU of IAB node #1 904 is hard, the DU of IAB node #1 904 can perform both sending and receiving, regardless of the sending and receiving of the MT of IAB node #1 904. That is, when the time resource of the DU of IAB node #1 904 is DL, the DU of IAB node #1 904 can perform sending; when the time resource of the DU of IAB node #1 904 is UL, the DU of IAB node #1 904 can perform receiving; and when the time resource of the DU of IAB node #1 904 is flexible, the DU of IAB node #1 904 can perform either sending or receiving. In this case, sending or receiving from the MT of IAB node #1 904 can only be done from the scheduling of the parent IAB node corresponding to the sending or receiving direction of the DU of IAB node #1 904 (i.e., satisfying the half-duplex constraint). For example, when the DU of IAB node #1 904 performs a transmission, the MT of IAB node #1 904 can perform a UL transmission according to the instruction from the parent IAB node scheduled for UL. Therefore, when the MT of IAB node #1 904 is scheduled for DL, it cannot follow the instruction from the parent IAB node, and the MT of IAB node #1 904 cannot receive DL transmissions.

[0139] When the resource type of the DU of IAB node #1 904 is soft, the DU of IAB node #1 904 can perform transmission or reception when at least one of the following conditions 1, 2, or 3 satisfies the half-duplex constraint. That is, when at least one of conditions 1, 2, or 3 is satisfied, the DU of IAB node #1 904 can perform transmission when its time resources are used for DL, can perform reception when its time resources are used for UL, and can perform transmission or reception when its time resources are flexible.

[0140] (Condition 1) The MT of IAB node #1 904 does not perform transmission or reception simultaneously with the transmission or reception of DU. In other words, Condition 1 corresponds to the case where there is no scheduling of transmission or reception from the parent IAB node while DU is transmitting or receiving.

[0141] (Condition 2) Because the transmission or reception direction of the DU of the IAB node #1 904 corresponds to the transmission or reception direction of the MT of the IAB node #1 904, the half duplex constraint can be maintained so that the transmission or reception direction of the DU of the IAB node #1 904 does not affect the transmission or reception of the MT of the IAB node #1 904. In this case, for example, for the transmission or reception direction of the MT of the IAB node #1 904, the transmission or reception direction scheduled or indicated from the parent IAB node included in the MCG can be considered first, and then when there is no scheduling or indication of data transmission or reception from the parent IAB node included in the MCG, the transmission or reception direction scheduled or indicated from the parent IAB node included in the SCG can be considered.

[0142] (Condition 3) The MT of the IAB node #1 904 receives an indication that the soft resource from at least one parent IAB node is available for the DU of the IAB node #1 904.

[0143] When the resource type of the DU of the IAB node #1 904 is NA, i.e., not available, for the half duplex constraint, the DU of the IAB node #1 904 does not perform transmission or reception. In this case, if the scheduling conflicts between the parent IAB nodes, the MT of the IAB node #1 904 can prioritize the scheduling from the parent IAB node included in the MCG. That is, the MT of the IAB node #1 904 can perform transmission or reception according to the scheduling from the parent IAB node included in the MCG, and when the scheduling from the parent IAB node included in the SCG does not satisfy the half duplex constraint, the scheduling from the SCG can be ignored.

[0144] When the DU of the IAB node #1 904 transmits an SS / PBCH block, transmits a PDCCH for SIB1 transmission, transmits a periodic CSI-RS, or receives a PRACH or an SR on a time resource (i.e., a time resource in which transmission and reception of the DU and transmission and reception of the MT of the IAB node #1 904 can collide with each other), for the case in which the resource type of the DU of the IAB node #1 904 is hard, the IAB node #1 904 can perform the procedure of the IAB node #1 904 regardless of the resource type configured for the DU of the IAB node #1 904.

[0145] [Embodiment 2]

[0146] In Embodiment 2, a case is assumed in which transmission and reception of a DU and transmission and reception of an MT of an IAB node #1 904 can collide with each other when following a configuration from a CU or an indication or scheduling from a parent IAB node #1 902 or a parent IAB node #2 903 connected to the IAB node #1 904 through dual connectivity. In Embodiment 2, based on the direction of resources of a DU of an IAB node #1 904, a procedure for the IAB node #1 904 can be determined according to whether the DU resources are for UL, DL, or flexible. For example, when the direction of resources of a DU of an IAB node #1 904 is DL, an MT of the IAB node #1 904 can perform an indication only from a parent IAB node scheduled by UL transmission to satisfy a half duplex constraint. Accordingly, the MT of the IAB node #1 904 can ignore scheduling from a parent IAB node that cannot satisfy the half duplex constraint.

[0147] [Embodiment 3]

[0148] In Embodiment 3, a case is assumed in which transmission and reception of the DU and transmission and reception of the MT of the IAB node #1 904 can collide with each other when following the configuration from the CU or the indication or scheduling from the parent IAB node #1 902 or the parent IAB node #2 903 connected to the IAB node #1 904 through dual connectivity. In Embodiment 3, based on the direction of resources or scheduling from the parent IAB node belonging to the MCG performing scheduling of the MT of the IAB node #1 904, that is, according to the scheduling or resource configuration and indication from the parent IAB node belonging to the MCG, it can be determined for the procedure of the IAB node #1 904 according to whether the MT resources are for UL, DL, or flexible. For example, the MT of the IAB node #1 904 can perform DL reception to satisfy the half duplex constraint when the direction of resources indicated or configured by the parent IAB node included in the MCG performing scheduling for the MT of the IAB node #1 904 is DL, and can receive data only from the parent IAB node included in the SCG when the direction of resources indicated or configured by the parent IAB node included in the SCG is the direction of resources indicated or configured by the parent IAB node in the SCG. For DL, in this case, the DU of the IAB node #1 904 can perform only UL reception. For example, when the direction of resources indicated or configured by the parent IAB node included in the MCG performing scheduling of the MT of the IAB node #1 904 is for UL, the MT of the IAB node #1 904 can perform UL transmission to satisfy the half duplex constraint, and can transmit data only from the parent IAB node included in the SCG when the direction of resources indicated or configured by the parent IAB node included in the SCG is for UL. In this case, the DU of the IAB node #1 904 can perform only DL transmission. That is, the MT of the IAB node #1 904 can ignore scheduling from the parent IAB node included in the SCG that cannot satisfy the half duplex constraint.

[0149] [Embodiment 4]

[0150] In Embodiment 4, a case is assumed in which transmission and reception of the MT of the IAB node #1 904 can collide with each other when following the configuration from the CU or the indication or scheduling from the parent IAB node #2 903 connected to the IAB node #1 904 through dual connectivity or the parent IAB node #1 902. In this case, a case in which the DU of the IAB node #1 904 does not perform transmission or reception is assumed. When the scheduling received from the parent IAB nodes collide with each other, the MT of the IAB node #1 904 can prioritize the scheduling from the parent IAB nodes included in the MCG. That is, the MT of the IAB node #1 904 can perform transmission or reception according to the scheduling from the parent IAB nodes included in the MCG, and when the scheduling from the parent IAB nodes included in the SCG does not satisfy the half duplex constraint, the scheduling from the SCG can be ignored.

[0151] One or more embodiments can be combined and used, and can be applied to some or all of the present disclosure.

[0152] Figure 10 is a flowchart for describing a method of transmitting and receiving data by an IAB node according to an embodiment of the present disclosure.

[0153] Referring to Figure 10 In operation 1010, the IAB node according to an embodiment of the present disclosure can receive resource allocation information from an IAB donor node.

[0154] In operation 1020, the IAB node according to an embodiment of the present disclosure can receive first resource scheduling information from a first parent IAB node.

[0155] In operation 1030, the IAB node according to an embodiment of the present disclosure can receive second resource scheduling information from a second parent IAB node.

[0156] In operation 1040, the IAB node according to an embodiment of the present disclosure can transmit and receive data to and from at least one of the first parent IAB node, the second parent IAB node, a child IAB node, or a UE (e.g., a UE in a cell) based on the resource allocation information, the first resource scheduling information, and the second resource scheduling information.

[0157] To perform the embodiments of the present disclosure, Figure 11 and Figure 12 Transmitters, receivers, and controllers of a UE and a BS are respectively illustrated. Also, Figure 13 An apparatus of an IAB node is illustrated. Figure 11 to Figure 13A transmission or reception method of a BS (donor BS) performing backhaul link transmission or reception with an IAB node on a millimeter wave, and a transmission or reception method of a UE performing access link transmission or reception with an IAB node when transmitting or receiving a backhaul link or an access link via the IAB node in a 5G communication system corresponding to embodiments of the disclosure, are shown, and in order to perform the methods, a transmitter, a receiver, and a processor of each of the BS, the UE, and the IAB node can operate according to embodiments.

[0158] Figure 11 is a block diagram showing an internal structure of a UE according to an embodiment of the disclosure. Referring to Figure 11 , the UE can include a UE controller 1101, a UE receiver 1102, and a UE transmitter 1103. Although not shown, the UE can further include a memory. However, components of the UE are not limited to the example shown in Figure 11 . For example, the UE can include more components than the above components or less components. In addition, the UE controller 1101, the UE receiver 1102, and the UE transmitter 1103 can be implemented in one chip.

[0159] The UE controller 1101 can control a series of processes to enable the UE to operate according to embodiments of the disclosure. For example, the UE controller 1101 according to embodiments of the disclosure can differently control access link transmission or reception with respect to an IAB node. The UE controller 1101 can control the UE receiver 1102 and the UE transmitter 1103 to receive and transmit information. In addition, the UE controller 1101 can include one or more processors.

[0160] In embodiments of the disclosure, the UE receiver 1102 and the UE transmitter 1103 can be collectively referred to as a transceiver. The transceiver can transmit and receive signals to and from the BS. The signals can include control information and data. To this end, the transceiver can include an RF transmitter for up-converting and amplifying the frequency of a signal to be transmitted, and an RF receiver for low-noise amplification and down-conversion of the frequency of a received signal. In addition, the transceiver can receive a signal on a wireless channel and can output the signal to the UE controller 1101, and can transmit a signal output from the UE controller 1101 on a wireless channel.

[0161] The memory (not shown) can store programs and data required for operations of the UE. Further, the memory can store control information or data included in a signal obtained by the UE. The memory can include a storage medium such as a read-only memory (ROM), a random access memory (RAM), a hard disk, a compact disk ROM (CD-ROM), and a digital versatile disk (DVD), or a combination thereof. Further, the memory can not exist separately, but can be included in the UE controller 1101. Further, the UE controller 1101 can control the components of the UE by executing the programs stored in the memory.

[0162] Figure 12 is a block diagram illustrating an internal structure of a BS according to an embodiment of the disclosure. Referring to Figure 12 , the BS can include a BS controller 1201, a BS receiver 1202, and a BS transmitter 1203. Although not shown, the BS can further include a memory. However, the components of the BS are not limited to the example shown in Figure 12 . For example, the BS can include more components than the above-described components or less components. Further, the BS controller 1201, the BS receiver 1202, and the BS transmitter 1203 can be implemented in one chip.

[0163] The BS controller 1201 can control a series of processes to enable the BS to operate according to an embodiment of the disclosure. For example, the backhaul link transmission or reception and the access link transmission or reception with respect to the IAB node according to an embodiment of the disclosure can be differently controlled. The BS controller 1201 can control the BS receiver 1202 and the BS transmitter 1203 to receive and transmit information. Further, the BS controller 1201 can include one or more processors.

[0164] In an embodiment of the disclosure, the BS receiver 1202 and the BS transmitter 1203 can be collectively referred to as a transceiver. The transceiver can transmit and receive signals to and from the UE. The signals can include control information and data. To this end, the transceiver can include an RF transmitter for up-converting and amplifying the frequency of a signal to be transmitted, and an RF receiver for low-noise amplification and down-conversion of the frequency of a received signal. Further, the transceiver can receive a signal on a wireless channel and can output the signal to the BS controller 1201, and can transmit a signal output from the BS controller 1201 on a wireless channel.

[0165] The memory (not shown) can store programs and data required for operations of the BS. Further, the memory can store control information or data included in a signal obtained by the BS. The memory can include a storage medium such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD, or a combination thereof. Further, the memory can not exist separately, but can be included in the BS controller 1201. Further, the BS controller 1201 can control the components of the BS by executing the programs stored in the memory.

[0166] Figure 13 is a block diagram illustrating an internal structure of an IAB node according to an embodiment of the disclosure. As shown in Figure 13 , the IAB node can include a BS function controller 1301, a BS function receiver 1302, and a BS function transmitter 1303 of the IAB node for performing transmission or reception to a lower IAB node via a backhaul link. Further, the IAB node can include a UE function controller 1311, a UE function receiver 1312, and a UE function transmitter 1313, etc. of the IAB node for performing initial access to a higher IAB node and a donor BS, performing transmission or reception of a higher layer signal before transmission or reception via a backhaul link, and performing transmission or reception to the higher IAB node and the donor BS via the backhaul link. Although not shown, the IAB node can further include a memory. However, the components of the IAB node are not limited to the example shown in Figure 13 . For example, the IAB node can include more components than the above components or less components. Further, each of the components shown in Figure 13 may be implemented in the form of one chip. Further, each of the BS function controller 1301 of the IAB node and the UE function controller 1311 of the IAB node can include one or more processors.

[0167] The BS function controller 1301 of the IAB node can control a series of processes for the IAB node to operate according to embodiments of the disclosure, and for example, can perform the functions of the DU of the IAB node as described above. For example, the BS function controller 1301 can differently control the backhaul link transmission or reception with respect to a lower IAB node and the access link transmission or reception with a UE. In embodiments of the disclosure, the BS function receiver 1302 and the BS function transmitter 1303 can be collectively referred to as a transceiver. The transceiver can transmit and receive signals to and from the lower IAB node and the UE. The signals can include control information and data. To this end, the transceiver can include an RF transmitter for up-converting and amplifying the frequency of a signal to be transmitted, and an RF receiver for low-noise amplification and down-conversion of the frequency of a received signal. Further, the transceiver can receive a signal on a wireless channel and can output the signal to the BS function controller 1301, and can transmit a signal output from the BS function controller 1301 on a wireless channel.

[0168] According to the above-described embodiments of the disclosure, the UE function controller 1311 of the IAB node can control a series of processes for the lower IAB node to operate as a UE for data transmission and reception with respect to a donor BS or a higher IAB node, and for example, can perform the functions of the MT of the IAB node as described above. For example, according to embodiments of the disclosure, the UE function controller 1311 can differently control the backhaul link transmission or reception with respect to a donor BS and a higher IAB node. In embodiments of the disclosure, the UE function receiver 1312 and the UE function transmitter 1313 can be collectively referred to as a transceiver. The transceiver can transmit and receive signals to and from the donor BS and the higher IAB node. The signals can include control information and data. To this end, the transceiver can include an RF transmitter for up-converting and amplifying the frequency of a signal to be transmitted, and an RF receiver for low-noise amplification and down-conversion of the frequency of a received signal. Further, the transceiver can receive a signal on a wireless channel and can output the signal to the UE function controller 1311, and can transmit a signal output from the UE function controller 1311 on a wireless channel.

[0169] The memory (not shown) can store programs and data required for the operation of the IAB node. Further, the memory can store control information or data included in a signal obtained by the IAB node. The memory can include a storage medium such as a ROM, a RAM, a hard disk, a CD-ROM, and a DVD, or a combination of storage media. Further, the memory can not exist separately, but can be included in the BS function controller 1301 of the IAB node and / or the UE function controller 1311 of the IAB node. Further, the BS function controller 1301 of the IAB node and / or the UE function controller 1311 of the IAB node can control the components of the IAB node by executing the programs stored in the memory.

[0170] Meanwhile, the BS function controller 1301 of the IAB node and the UE function controller 1311 of the IAB node included in the IAB node Figure 13 may be integrated to be implemented as an IAB node controller. In this case, the IAB node controller can control the functions of the DU and the MT in the IAB node.

[0171] The method according to the embodiments of the disclosure as described in the claims or the specification can be implemented as hardware, software, or a combination of hardware and software.

[0172] When implemented as software, a computer-readable storage medium storing one or more programs (for example, software modules) can be provided. The one or more programs stored in the computer-readable storage medium are configured to be executed by one or more processors in an electronic device. The one or more programs include instructions instructing the electronic device to execute the method according to the embodiments of the disclosure as described in the claims or the specification.

[0173] The program (for example, software module or software) can be stored in a non-volatile memory including a RAM or a flash memory, a ROM, an electrically erasable programmable read-only memory (EEPROM), a magnetic disc storage device, a CD-ROM, a DVD, another optical storage device, or a magnetic cassette. Alternatively, the program can be stored in a memory including a combination of some or all of the above-mentioned storage media. Further, a plurality of such memories can be included.

[0174] Further, the program can be stored in an attachable storage device accessible through any one or a combination of communication networks such as the Internet, an intranet, a local area network (LAN), a wide area network (WAN), a storage area network (SAN), or the like. Such a storage device can access a device performing the embodiments of the disclosure via an external port. Further, a separate storage device on the communication network can access the electronic device performing the embodiments of the disclosure.

[0175] In the above-described embodiments of the disclosure, components included in the disclosure are expressed in singular or plural form according to the embodiments. However, for the convenience of description, singular or plural form is appropriately selected, and the disclosure is not limited thereto. Thus, components expressed in plural form can also be configured as a single component, and components expressed in singular form can also be configured as plural components. Meanwhile, the embodiments of the disclosure described with reference to the specification and the drawings are merely for the convenience of description and understanding of specific examples of the disclosure, and are not intended to limit the scope of the disclosure. That is, it will be understood by those of ordinary skill in the art that other modifications based on the disclosure are feasible. Furthermore, embodiments can be combined as needed to be implemented. For example, parts of the methods provided by the disclosure can be combined with each other to enable the BS and the UE to operate. Furthermore, the embodiments of the disclosure can be applied to other communication systems, and various modifications of the technical concepts based on the embodiments are feasible.

Claims

1. A method of transmitting and receiving data in a wireless communication system, performed by an integrated access and backhaul, IAB, node, the method comprising: receiving first resource configuration information from a first parent IAB node in a master cell group, MCG; receiving second resource configuration information from a second parent IAB node in a secondary cell group, SCG; identifying whether there is simultaneous transmission and reception in the MCG and the SCG based on the first resource configuration information and the second resource configuration information; and in case that there is simultaneous transmission and reception in the MCG and the SCG and the IAB node cannot simultaneously transmit and receive, operating according to the first resource configuration information received from the first parent IAB node in the MCG. operating according to the first resource configuration information received from the first parent IAB node in the MCG comprises:

2. The method of claim 1, wherein, determining whether to transmit or receive data between the second parent IAB node and the IAB node based on a direction of resources for data transmission and reception between the first parent IAB node and the IAB node. operating according to the first resource configuration information received from the first parent IAB node in the MCG comprises:

3. The method of claim 1, wherein, determining whether to transmit or receive data between a child IAB node or a user equipment, UE, and the IAB node based on the first resource configuration information; and transmitting or receiving data with the child IAB node or the UE based on the determination. 4.The method of claim 3, wherein, determining whether to transmit or receive data between a child IAB node or a user equipment, UE, and the IAB node based on the first resource configuration information comprises: determining whether to transmit or receive data between the child IAB node or the UE and the IAB node based on a direction of resources for data transmission and reception between the first parent IAB node and the IAB node. operating according to the first resource configuration information received from the first parent IAB node in the MCG comprises:

5. The method of claim 1, wherein, determining whether to transmit or receive data between the second parent IAB node and the IAB node based on a resource type of resources for data transmission and reception between a child IAB node or a user equipment, UE, and the IAB node. operating according to the first resource configuration information received from the first parent IAB node in the MCG when a direction of resources for data transmission and reception between the first parent IAB node and the IAB node is for downlink comprises:

6. The method of claim 1, wherein, determining to receive data from the second parent IAB node when a direction of resources configured for data transmission and reception between the second parent IAB node and the IAB node is for downlink; and determining to receive data from a child IAB node or a user equipment, UE, when a direction of resources configured for data transmission and reception between the child IAB node or the UE and the IAB node is for uplink. ​ 7. The method of claim 1, wherein, when a direction of resources configured for data transmission and reception between the first parent IAB node and the IAB node is for uplink, operating according to the first resource configuration information received from the first parent IAB node in the MCG includes: when a direction of resources configured for data transmission and reception between the second parent IAB node and the IAB node is for uplink, determining to transmit data to the second parent IAB node; and when a direction of resources configured for data transmission and reception between a child IAB node or a user equipment (UE) and the IAB node is for downlink, determining to transmit data to the child IAB node or the UE.

8. The method of claim 1, wherein, operating according to the first resource configuration information received from the first parent IAB node in the MCG includes one of: transmitting, by the IAB node, data to the second parent IAB node based on the second resource configuration information, receiving, by the IAB node, data from the second parent IAB node based on the second resource configuration information, or ignoring, by the IAB node, the second resource configuration information. 9.An integrated access and backhaul (IAB) node for transmitting and receiving data in a wireless communication system, the IAB node comprising: a transceiver; and at least one processor configured to: receive first resource configuration information from a first parent IAB node in a master cell group (MCG), receive second resource configuration information from a second parent IAB node in a secondary cell group (SCG), identify whether there is simultaneous transmission and reception in the MCG and the SCG based on the first resource configuration information and the second resource configuration information, and operate according to the first resource configuration information received from the first parent IAB node in the MCG in case that there is simultaneous transmission and reception in the MCG and the SCG and the IAB node cannot simultaneously transmit and receive. The at least one processor is further configured to determine whether to transmit or receive data between the second parent IAB node and the IAB node based on a direction of resources used for data transmission and reception between the first parent IAB node and the IAB node.

10. The IAB node of claim 9, wherein, The at least one processor is further configured to:

11. The IAB node of claim 9, wherein, determine whether to transmit or receive data between a child IAB node or a user equipment (UE) and the IAB node based on the first resource configuration information, and transmit or receive data with the child IAB node or the UE based on the determination. 12.The IAB node of claim 11, wherein the at least one processor is further configured to determine whether to transmit or receive data between the child IAB node or the UE and the IAB node based on a direction of resources used for data transmission and reception between the first parent IAB node and the IAB node. ​ 13. The IAB node of claim 11, wherein, The at least one processor is further configured to determine whether to transmit or receive data between the second parent IAB node and the IAB node based on a resource type of a resource used for data transmission and reception between a child IAB node or a user equipment (UE) and the IAB node.

14. The IAB node of claim 9, wherein, When a direction of a resource used for data transmission and reception between the first parent IAB node and the IAB node is for downlink, the at least one processor is further configured to: determine to receive data from the second parent IAB node when a direction of a resource configured for data transmission and reception between the second parent IAB node and the IAB node is for downlink; and determine to receive data from a child IAB node or a user equipment (UE) when a direction of a resource configured for data transmission and reception between the child IAB node or the UE and the IAB node is for uplink.

15. The IAB node of claim 9, wherein, When a direction of a resource used for data transmission and reception between the first parent IAB node and the IAB node is for uplink, the at least one processor is further configured to: determine to transmit data to the second parent IAB node when a direction of a resource configured for data transmission and reception between the second parent IAB node and the IAB node is for uplink; and determine to transmit data to a child IAB node or a user equipment (UE) when a direction of a resource configured for data transmission and reception between the child IAB node or the UE and the IAB node is for downlink.

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