Method and device for transmitting and receiving data information in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates. The present disclosure relates to a method for transmitting and receiving data information in a wireless communication system and a device capable of performing same.

Description

Method and device for transmitting and receiving data information in a wireless communication system

[0001] The present disclosure relates to the operation of a terminal and a base station in a wireless communication system. Specifically, the present disclosure relates to a method for transmitting and receiving data information in a wireless communication system and a device capable of performing the same.

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in the sub-6GHz frequency band such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band called millimeter wave (mmWave) such as 28GHz and 39GHz ('Above 6GHz'). In addition, for 6G mobile communication technology, which is called the system after 5G communication (Beyond 5G), implementation in the terahertz band (for example, the 3 terahertz (3THz) band at 95GHz) is being considered to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and an ultra-low latency time that is reduced to one-tenth.

[0003] In the early stages of 5G mobile communication technology, the goal is to support services and satisfy performance requirements for enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC). These include beamforming and massive MIMO to mitigate path loss of radio waves in ultra-high frequency bands and increase the transmission distance of radio waves, support for various numerologies (such as operation of multiple subcarrier intervals) and dynamic operation of slot formats for efficient use of ultra-high frequency resources, initial access technology to support multi-beam transmission and wideband, definition and operation of BWP (Bidth Part), new channel coding methods such as LDPC (Low Density Parity Check) codes for large-capacity data transmission and Polar Code for reliable transmission of control information, and L2 pre-processing (L2). Standardization has been made for network slicing, which provides dedicated networks specialized for specific services, and pre-processing.

[0004] Currently, discussions are underway to improve and enhance the initial 5G mobile communication technology in consideration of the services that 5G mobile communication technology was intended to support, and physical layer standardization is in progress for technologies such as V2X (Vehicle-to-Everything) to help autonomous vehicles make driving decisions and increase user convenience based on their own location and status information transmitted by vehicles, NR-U (New Radio Unlicensed) for the purpose of system operation that complies with various regulatory requirements in unlicensed bands, NR terminal low power consumption technology (UE Power Saving), Non-Terrestrial Network (NTN), which is direct terminal-satellite communication to secure coverage in areas where communication with terrestrial networks is impossible, and Positioning.

[0005] In addition, standardization of wireless interface architecture / protocols is in progress for technologies such as intelligent factories (Industrial Internet of Things, IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) that provides nodes for expanding network service areas by integrating wireless backhaul links and access links, Mobility Enhancement technology including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step random access (2-step RACH for NR) that simplifies random access procedures. Standardization is also in progress for system architecture / services such as 5G baseline architecture (e.g., Service-based Architecture, Service-based Interface) for grafting Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) that provides services based on the location of the terminal.

[0006] Once these 5G mobile communication systems are commercialized, an explosive increase in connected devices will be connected to the communication network, necessitating enhanced functionality and performance of 5G mobile communication systems and integrated operation of these connected devices. To this end, new research will be conducted on improving 5G performance and reducing complexity, supporting AI services, supporting metaverse services, and drone communications by utilizing eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0007] In addition, the development of these 5G mobile communication systems includes new waveforms to ensure coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), Array Antenna, and Large Scale Antenna, metamaterial-based lenses and antennas to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), Reconfigurable Intelligent Surface (RIS) technology, as well as full duplex technology to improve the frequency efficiency and system network of 6G mobile communication technology, satellite, AI (Artificial Intelligence) from the design stage and AI-based communication technology that realizes system optimization by internalizing end-to-end AI support functions, and ultra-high-performance communication and computing resources to provide services with complexity that exceeds the limits of terminal computing capabilities. It can serve as a basis for the development of next-generation distributed computing technologies that can be realized by utilizing them.

[0008] As described above and with the development of wireless communication systems, various services have become available, and methods for providing these services smoothly are required.

[0009] The disclosed embodiments provide a device and method for effectively providing services in a mobile communication system. Specifically, the present invention provides a method and device for transmitting and receiving data information in a measurement gap.

[0010] In a method performed by a terminal of a communication system according to one embodiment of the present disclosure for achieving the above-described technical task, the method comprises the steps of: receiving configuration information for a measurement gap from a base station; receiving DCI (downlink control information) including information indicating whether to perform measurement in a specific measurement gap from the base station; confirming whether to perform measurement in the specific measurement gap based on the configuration information and the information indicating whether to perform measurement; and performing the measurement or transmitting and receiving data in the specific measurement gap based on the confirmation.

[0011] The DCI may be a DCI for scheduling data. In addition, the specific measurement gap may correspond to one measurement gap. In addition, the specific measurement gap may exist after a specific offset from the last symbol of the CORESET (control resource set) in which the DCI is received.

[0012] In addition, in a method performed by a base station of a communication system, the method comprises: a step of transmitting setting information for a measurement gap to a terminal; a step of transmitting DCI (downlink control information) including information indicating whether to perform measurement in a specific measurement gap to the terminal; and whether the measurement is performed or data transmission and reception is performed in the specific measurement gap is characterized in that it is based on the setting information and the information indicating whether to perform the measurement.

[0013] In addition, in a terminal of a communication system, the terminal is characterized by including a transmitter / receiver; and a control unit configured to receive setting information on a measurement gap from a base station, receive DCI (downlink control information) including information indicating whether to perform measurement in a specific measurement gap from the base station, determine whether to perform measurement in the specific measurement gap based on the setting information and the information indicating whether to perform measurement, and perform the measurement or transmit / receive data in the specific measurement gap based on the determination.

[0014] In addition, in a method performed by a base station of a communication system, the method comprises a transceiver; and a control unit configured to transmit setting information for a measurement gap to a terminal, and to transmit DCI (downlink control information) including information indicating whether to perform measurement in a specific measurement gap to the terminal, wherein whether measurement is performed or data transmission and reception is performed in the specific measurement gap is characterized in that it is based on the setting information and the information indicating whether to perform measurement.

[0015] The disclosed embodiments provide devices and methods capable of effectively providing services in a mobile communication system. In particular, according to at least one embodiment of the present disclosure, a terminal and a base station can transmit and receive data in a measurement gap, thereby reducing traffic delay and enabling efficient data transmission and reception.

[0016] Figure 1 is a diagram illustrating the basic structure of the time-frequency domain, which is a radio resource domain in which data or control channels are transmitted in a 5G communication system.

[0017] Figure 2 is a diagram illustrating the frame, subframe, and slot structure in a 5G communication system.

[0018] Figure 3 is a diagram illustrating an example of bandwidth portion settings in a 5G wireless communication system.

[0019] FIG. 4 is a diagram illustrating an example of a control region (CORESET) in which a downlink control channel is transmitted in a 5G communication system.

[0020] FIG. 5 is a diagram illustrating an example of a basic unit of time and frequency resources that constitute a downlink control channel that can be used in a 5G communication system.

[0021] FIG. 6 is a diagram illustrating an example of a wireless protocol structure of a base station and a terminal in a single cell, carrier aggregation (CA), and DC (dual connectivity) situation.

[0022] FIG. 7 is a diagram illustrating an example of a situation in which a measurement gap and SS / PBCH block are transmitted and received according to one embodiment of the present disclosure.

[0023] FIG. 8 is a diagram illustrating an example of a measurement gap setting method according to one embodiment of the present disclosure.

[0024] FIG. 9 is a diagram illustrating an example of a procedure in which a terminal performs a measurement gap according to one embodiment of the present disclosure.

[0025] FIG. 10 is a diagram illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0026] FIG. 11 is a diagram illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0027] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0028] In describing the embodiments, descriptions of technical details that are well known in the technical field to which the present disclosure pertains and are not directly related to the present disclosure will be omitted. This is to avoid obscuring the gist of the present disclosure by omitting unnecessary explanations and to convey the gist more clearly.

[0029] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0030] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present disclosure is complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Like reference numerals designate like elements throughout the specification. In addition, when describing the present disclosure, if a specific description of a related function or configuration is determined to unnecessarily obscure the gist of the present disclosure, the detailed description thereof will be omitted. In addition, the terms described below are terms defined in consideration of the functions of the present disclosure, and may vary depending on the intention or custom of the user or operator. Therefore, the definitions should be made based on the contents throughout the specification.

[0031] Hereinafter, the base station is an entity that performs resource allocation of the terminal, and may be at least one of a gNode B, an eNode B, a Node B, a BS (base station), a wireless access unit, a base station controller, or a node on a network. The terminal may include a UE (user equipment), an MS (mobile station), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. In the present disclosure, downlink (DL) refers to a wireless transmission path of a signal transmitted from a base station to a terminal, and uplink (UL) refers to a wireless transmission path of a signal transmitted from a terminal to a base station. In addition, although the LTE or LTE-A system may be described below as an example, the embodiments of the present disclosure may also be applied to other communication systems having a similar technical background or channel type. For example, the 5th generation mobile communication technology (5G, new radio, NR) developed after LTE-A may be included here, and the 5G below may also be a concept that includes existing LTE, LTE-A, and other similar services. In addition, the present disclosure may be applied to other communication systems with some modifications within a scope that does not significantly deviate from the scope of the present disclosure, as judged by a person having skilled technical knowledge.

[0032] At this time, it will be understood that each block of the processing flowchart drawings and combinations of the flowchart drawings can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flowchart block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flowchart block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0033] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0034] Here, the term '~ unit' used in this embodiment means software or hardware components such as FPGA (field programmable gate array) or ASIC (application specific integrated circuit), and the '~ unit' performs certain roles. However, the '~ unit' is not limited to software or hardware. The '~ unit' may be configured to be on an addressable storage medium or may be configured to play one or more processors. Accordingly, as an example, the '~ unit' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. Additionally, the components and '~parts' may be implemented to activate one or more CPUs within a device or secure multimedia card. In addition, in an embodiment, the '~parts' may include one or more processors.

[0035] Wireless communication systems are evolving from providing voice-oriented services in the early days to broadband wireless communication systems that provide high-speed, high-quality packet data services, such as communication standards such as 3GPP's HSPA (High Speed ​​Packet Access), LTE (Long Term Evolution or E-UTRA (Evolved Universal Terrestrial Radio Access)), LTE-Advanced (LTE-A), LTE-Pro, 3GPP2's HRPD (High Rate Packet Data), UMB (Ultra Mobile Broadband), and IEEE's 802.16e.

[0036] As a representative example of the above-mentioned broadband wireless communication system, the LTE system employs the OFDM (orthogonal frequency division multiplexing) method in the downlink and the SC-FDMA (single carrier frequency division multiple access) method in the uplink. The above-mentioned multiple access method typically allocates and operates the time-frequency resources for transmitting data or control information to each user so that they do not overlap, that is, so as to achieve orthogonality, thereby enabling each user's data or control information to be distinguished.

[0037] As a future communication system beyond LTE, 5G communication systems must be able to freely reflect the diverse needs of users and service providers. Therefore, they must support services that simultaneously satisfy these diverse requirements. Services being considered for 5G communication systems include enhanced mobile broadband (eMBB), massive machine type communication (mMTC), and ultra-reliable low-latency communication (URLLC).

[0038] eMBB aims to provide data transmission rates that are significantly higher than those supported by existing LTE, LTE-A, or LTE-Pro. For example, in a 5G communication system, eMBB must be able to support a peak data rate of 20 Gbps in the downlink and a peak data rate of 10 Gbps in the uplink from the perspective of a single base station. Furthermore, 5G communication systems must provide not only the peak data rate but also the increased user-perceived data rate for terminals. To meet these requirements, improvements in various transmission and reception technologies, including improved multi-input, multi-output (MIMO) transmission technology, are required. Furthermore, while LTE transmits signals using a maximum transmission bandwidth of 20 MHz in the 2 GHz band, 5G communication systems can meet the data transmission rates required by 5G communication systems by using a wider frequency bandwidth than 20 MHz in the 3-6 GHz or higher 6 GHz band.

[0039] At the same time, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. To efficiently provide the Internet of Things, mMTC requires supporting the connection of a large number of terminals within a cell, improving terminal coverage, extending battery life, and reducing terminal costs. The Internet of Things provides communication functions by attaching various sensors and various devices, so a large number of terminals (for example, 1,000,000 terminals / km) are required within a cell. 2 ) must be able to support. Furthermore, terminals supporting mMTC are likely to be located in shadow areas not covered by cells, such as basements of buildings, due to the nature of the service, and thus may require wider coverage than other services provided by 5G communication systems. Terminals supporting mMTC must be comprised of low-cost terminals, and because it is difficult to frequently replace the terminal's battery, a very long battery life time, such as 10 to 15 years, may be required.

[0040] Finally, URLLC refers to a cellular-based wireless communication service used for a specific purpose (mission-critical). For example, services such as remote control of robots or machinery, industrial automation, unmanaged aerial vehicles, remote health care, and emergency alerts can be considered. Therefore, the communication provided by URLLC must provide very low latency and very high reliability. For example, a service supporting URLLC must satisfy an air interface latency of less than 0.5 milliseconds and at the same time, a 10 -5The following packet error rate requirements apply. Therefore, for services supporting URLLC, 5G systems must provide a smaller transmit time interval (TTI) than other services, while simultaneously requiring design considerations such as allocating a wide range of resources in the frequency band to ensure communication link reliability.

[0041] The three services of a 5G communication system—eMBB, URLLC, and mMTC—can be multiplexed and transmitted in a single system. To meet the different requirements of each service, different transmission and reception techniques and parameters can be used. Of course, the 5G communication system is not limited to the three services described above.

[0042] Below, the frame structure of the 5G communication system is described in more detail with reference to drawings.

[0043] Figure 1 is a diagram illustrating the basic structure of the time-frequency domain, which is a radio resource domain in which data or control channels are transmitted in a 5G communication system.

[0044] The horizontal axis of Figure 1 represents the time domain, and the vertical axis represents the frequency domain. The basic unit of resources in the time and frequency domains is a resource element (RE, 101), which can be defined as 1 OFDM symbol (102) on the time axis and 1 subcarrier (103) on the frequency axis. In the frequency domain (For example, 12) consecutive REs can form one resource block (RB, 104).

[0045] Figure 2 is a diagram illustrating the frame, subframe, and slot structure in a 5G communication system.

[0046] Figure 2 illustrates an example of a structure of a frame (frame, 200), a subframe (subframe, 201), and a slot (slot, 202, 203). One frame (200) can be defined as 10 ms. One subframe (201) can be defined as 1 ms, and therefore one frame (200) can be composed of a total of 10 subframes (201). One slot (202, 203) can be defined as 14 OFDM symbols (i.e., the number of symbols per slot =14). 1 subframe (201) may be composed of one or more slots (202, 203), and the number of slots (202, 203) per 1 subframe (201) may vary depending on the setting value μ (204, 205) for the subcarrier spacing. In the example of Fig. 2, the cases where μ = 0 (204) and μ = 1 (205) as the subcarrier spacing setting value are illustrated. When μ = 0 (204), 1 subframe (201) may be composed of one slot (202), and when μ = 1 (205), 1 subframe (201) may be composed of two slots (203). That is, the number of slots per 1 subframe ( ) may vary, and accordingly the number of slots per frame ( ) may vary. Depending on the subcarrier spacing setting μ and can be defined as shown in Table 1 below.

[0047] μ 0141011142022144043148084141601651432032

[0048] Next, the bandwidth part (BWP) setting in the 5G communication system will be explained in detail with reference to the drawing.

[0049] Figure 3 is a diagram illustrating an example of bandwidth portion settings in a 5G wireless communication system.

[0050] Figure 3 shows an example in which the UE bandwidth (300) is set to two bandwidth portions, namely, bandwidth portion #1 (BWP#1, 301) and bandwidth portion #2 (BWP#2, 302). The base station can set one or more bandwidth portions to the UE, and can set the following information for each bandwidth portion.

[0051] BWP ::= SEQUENCE {bwp-Id BWP-Id,(bandwidth part identifier)locationAndBandwidth INTEGER (1..65536),(bandwidth part location)subcarrierSpacing ENUMERATED {n0, n1, n2, n3, n4, n5},(subcarrier spacing)cyclicPrefix ENUMERATED { extended}(cyclic prefix)}

[0052] Of course, the above example is not limited, and in addition to the above configuration information, various parameters related to the bandwidth portion may be configured for the terminal. The above information may be transmitted from the base station to the terminal via upper layer signaling, for example, radio resource control (RRC) signaling. At least one of the configured bandwidth portions may be activated. Whether or not the configured bandwidth portion is activated may be semi-statically transmitted from the base station to the terminal via RRC signaling or dynamically transmitted via downlink control information (DCI).

[0053] According to some embodiments, a terminal before RRC connection can receive an initial bandwidth portion (initial BWP) for initial access from a base station through a master information block (MIB). More specifically, the terminal can receive configuration information about a control region (control resource set, CORESET) and a search space for transmitting a PDCCH for receiving system information (which may correspond to remaining system information, RMSI or system information block 1, SIB1) required for initial access through the MIB received on a physical broadcast channel (PBCH) during the initial access phase. The control region and search space configured by the MIB can each be regarded as having an identity (ID) of 0.

[0054] The base station can notify the terminal of configuration information such as frequency allocation information, time allocation information, and numerology for control area #0 through MIB. In addition, the base station can notify the terminal of configuration information for monitoring cycle and occasion for control area #0, i.e. configuration information for search space #0, through MIB. The terminal can regard the frequency area set as control area #0 obtained from the MIB as an initial bandwidth part for initial access, and the terminal can receive the PDSCH (physical downlink shared channel) on which the SIB is transmitted through the configured initial bandwidth part. In addition to receiving the SIB, the initial bandwidth part can also be utilized for other system information (OSI), paging, and random access. In this case, the identifier (ID) of the initial bandwidth part can be regarded as 0.

[0055] The settings for the bandwidth portion supported by the above 5G communication system can be used for various purposes.

[0056] In some embodiments, when the bandwidth supported by a terminal is smaller than the system bandwidth, this can be supported through bandwidth portion configuration. For example, the base station can configure the frequency position of the bandwidth portion for the terminal, allowing the terminal to transmit and receive data at a specific frequency position within the system bandwidth.

[0057] Additionally, in some embodiments, a base station may configure multiple bandwidth segments for a terminal to support different numerologies. For example, to support data transmission and reception using both 15 kHz and 30 kHz subcarrier spacing for a given terminal, two bandwidth segments may be configured with subcarrier spacings of 15 kHz and 30 kHz, respectively. The different bandwidth segments may be frequency division multiplexed, and when data is to be transmitted and received using a specific subcarrier spacing, the bandwidth segment configured for that subcarrier spacing may be activated.

[0058] Furthermore, in some embodiments, the base station may configure bandwidth portions with different bandwidth sizes for the terminal to reduce power consumption. For example, if the terminal supports a very large bandwidth, such as 100 MHz, and constantly transmits and receives data within that bandwidth, significant power consumption may occur. In particular, monitoring unnecessary downlink control channels with a large bandwidth of 100 MHz in a traffic-free environment may be very inefficient in terms of power consumption. To reduce power consumption, the base station may configure a bandwidth portion with a relatively small bandwidth, such as 20 MHz, for the terminal. In a traffic-free environment, the terminal may perform monitoring operations in the 20 MHz bandwidth portion, and when data is generated, it may transmit and receive data in the 100 MHz bandwidth portion according to instructions from the base station.

[0059] When one or more bandwidth parts are set for a terminal, the base station can instruct the terminal to change (or switch, transition) the bandwidth part using the bandwidth part indicator field in the DCI. For example, in FIG. 3, when the currently activated bandwidth part of the terminal is bandwidth part #1 (301), the base station can instruct the terminal to bandwidth part #2 (302) using the bandwidth part indicator in the DCI, and the terminal can perform a bandwidth part change to bandwidth part #2 (302) indicated by the bandwidth part indicator in the received DCI.

[0060] As described above, since DCI-based bandwidth part change can be indicated by DCI scheduling PDSCH or PUSCH, when a terminal receives a bandwidth part change request, it must be able to receive or transmit PDSCH or PUSCH scheduled by the corresponding DCI without difficulty in the changed bandwidth part. To this end, the standard stipulates the delay time (T) required when changing the bandwidth part. BWP ) and can be defined as follows, for example:

[0061] μNR Slot length (ms)BWP switch delay T BWP (slots)Type 1 Note 1 01110.5220.25330.1256Note 1: Depends on UE capability.Note 2: If the BWP switch involves changing of SCS, the BWP switch delay is determined by the larger one between the SCS before BWP switch and the SCS after BWP switch.

[0062] The bandwidth-partial change delay time requirement supports Type 1 or Type 2 depending on the terminal's capability. The terminal can report the supported bandwidth-partial delay time type to the base station.

[0063] According to the requirement for bandwidth part change delay time mentioned above, when the terminal receives DCI including bandwidth part change indicator in slot n, the terminal changes to the new bandwidth part indicated by the bandwidth part change indicator in slot n+T. BWPIt can be completed at a later time, and transmission and reception for the data channel scheduled by the DCI can be performed in the new bandwidth portion that has been changed. If the base station wants to schedule a data channel in the new bandwidth portion, the terminal's bandwidth portion change delay time (T BWP ), time domain resource allocation for the data channel can be determined by considering the bandwidth portion change delay time. That is, when the base station schedules the data channel with a new bandwidth portion, the data channel can be scheduled after the bandwidth portion change delay time in the method of determining the time domain resource allocation for the data channel. Accordingly, the terminal determines that the DCI instructing the bandwidth portion change is a bandwidth portion change delay time (T BWP ) may not be expected to indicate a slot offset (K0 or K2) value smaller than that.

[0064] If the terminal receives DCI (e.g., DCI format 1_1 or 0_1) indicating a bandwidth change, the terminal may not perform any transmission or reception during the time period corresponding to the third symbol of the slot in which the PDCCH including the DCI is received, to the start point of the slot indicated by the slot offset (K0 or K2) value indicated by the time domain resource allocation indicator field in the DCI. For example, if the terminal receives DCI indicating a bandwidth change in slot n and the slot offset value indicated by the DCI is K, the terminal may not perform any transmission or reception from the third symbol of slot n to the symbol before slot n+K (i.e., the last symbol of slot n+K-1).

[0065] Next, we will explain the SS / PBCH (synchronization signal / physical broadcast channel) block in 5G.

[0066] An SS / PBCH block may refer to a physical layer channel block consisting of a PSS (primary SS), SSS (secondary SS), and PBCH. Specifically, it is as follows.

[0067] - PSS: A signal that serves as a reference for downlink time / frequency synchronization and provides some information about the cell ID (identifier).

[0068] - SSS: It serves as a reference for downlink time / frequency synchronization and provides the remaining cell ID information not provided by PSS. Additionally, it can serve as a reference signal for PBCH demodulation.

[0069] - PBCH: Provides essential system information required for the terminal's data channel and control channel transmission and reception. Essential system information may include search space-related control information indicating radio resource mapping information for the control channel, and scheduling control information for a separate data channel that transmits system information.

[0070] - SS / PBCH Block: An SS / PBCH block is composed of a combination of PSS, SSS, and PBCH. One or more SS / PBCH blocks can be transmitted within a 5ms period, and each transmitted SS / PBCH block can be distinguished by an index.

[0071] The terminal can detect PSS and SSS in the initial access stage, and decode PBCH. It can obtain MIB from PBCH and set control region #0 (which may correspond to a control region with a control region index of 0) therefrom. The terminal can monitor control region #0 assuming that the selected SS / PBCH block and the DMRS (demodulation reference signal) transmitted in control region #0 are quasi-co-located (QCL). The terminal can receive system information through downlink control information transmitted in control region #0. The terminal can obtain RACH (random access channel) related configuration information required for initial access from the received system information. The terminal can transmit PRACH (physical RACH) to the base station considering the selected SS / PBCH index, and the base station receiving the PRACH can obtain information on the SS / PBCH block index selected by the terminal. The base station can know that the terminal has selected a block among each SS / PBCH block and monitors the control region #0 associated with it.

[0072] Next, we will specifically explain downlink control information (DCI) in 5G communication systems.

[0073] In a 5G communication system, scheduling information for uplink data (or physical uplink shared channel (PUSCH)) or downlink data (or physical downlink shared channel (PDSCH)) is transmitted from a base station to a terminal via DCI. The terminal can monitor a fallback DCI format and a non-fallback DCI format for the PUSCH or PDSCH. The fallback DCI format may consist of fixed fields defined between the base station and the terminal, and the non-fallback DCI format may include configurable fields.

[0074] DCI can be transmitted over the physical downlink control channel (PDCCH) after going through the channel coding and modulation process. A cyclic redundancy check (CRC) is attached to the DCI message payload, and the CRC can be scrambled with a radio network temporary identifier (RNTI) corresponding to the identity of the UE. Different RNTIs can be used depending on the purpose of the DCI message, such as UE-specific data transmission, power control command, or random access response (RAR). That is, the RNTI is not transmitted explicitly, but is included in the CRC calculation process. When the UE receives a DCI message transmitted over the PDCCH, it verifies the CRC using the assigned RNTI. If the CRC verification result is correct, the UE can determine that the message was transmitted to the UE.

[0075] For example, a DCI scheduling a PDSCH for system information (SI) may be scrambled with SI-RNTI. A DCI scheduling a PDSCH for a RAR message may be scrambled with RA-RNTI. A DCI scheduling a PDSCH for a paging message may be scrambled with P-RNTI. A DCI notifying a slot format indicator (SFI) may be scrambled with SFI-RNTI. A DCI notifying a transmit power control (TPC) may be scrambled with TPC-RNTI. A DCI scheduling a UE-specific PDSCH or PUSCH may be scrambled with C-RNTI (cell RNTI).

[0076] DCI format 0_0 can be used as a fallback DCI for scheduling PUSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 0_0 with the CRC scrambled with C-RNTI can include, for example, the following information.

[0077] - Identifier for DCI formats - [1] bit- Frequency domain resource assignment - [ ] bits- Time domain resource assignment - X bits- Frequency hopping flag - 1 bit.- Modulation and coding scheme - 5 bits- New data indicator - 1 bit- Redundancy version - 2 bits- HARQ process number - 4 bits- TPC command for scheduled PUSCH - [2] bits- UL / SUL indicator (uplink / supplementary UL indicator) - 0 or 1 bit

[0078] DCI format 0_1 ​​can be used as a fallback DCI for scheduling PUSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 0_1 ​​with the CRC scrambled with C-RNTI can include, for example, the following information.

[0079] - Carrier indicator - 0 or 3 bits- UL / SUL indicator - 0 or 1 bit- Identifier for DCI formats - [1] bits- Bandwidth part indicator - 0, 1, or 2 bits- Frequency domain resource assignment- For resource allocation type 0 bits- For resource allocation type 1, bits- Time domain resource assignment -1, 2, 3, or 4 bits- VRB-to-PRB mapping (virtual resource block-to-physical resource block mapping) - 0 or 1 bit, only for resource allocation type 1.○ 0 bit if only resource allocation type 0 is configured;○ 1 bit otherwise.- Frequency hopping flag - 0 or 1 bit, only for resource allocation type 1.○ 0 bit if only resource allocation type 0 is configured;○ 1 bit otherwise.- Modulation and coding scheme - 5 bits- New data indicator - 1 bit- Redundancy version - 2 bits- HARQ process number - 4 bits- 1st downlink assignment index (first downlink allocation index)- 1 or 2 bits○ 1 bit for semi-static HARQ-ACK codebook (semi-static HARQ-ACK In case of codebook);○ 2 bits for dynamic HARQ-ACK codebook with single HARQ-ACK codebook(When dynamic HARQ-ACK codebook is used with single HARQ-ACK codebook).- 2nd downlink assignment index (2nd downlink assignment index) - 0 or 2 bits○ 2 bits for dynamic HARQ-ACK codebook with two HARQ-ACK sub-codebooks(When dynamic HARQ-ACK codebook is used with two HARQ-ACK sub-codebooks);○ 0 bit otherwise.TPC command for scheduled PUSCH - 2 bits- SRS resource indicator (SRS resource indicator) -. or bits○ bits for non-codebook based PUSCH transmission; ○ bits for codebook based PUSCH transmission. - Precoding information and number of layers - up to 6 bits - Antenna ports - up to 5 bits - SRS request - 2 bits - CSI request - 0, 1, 2, 3, 4, 5, or 6 bits - CBG transmission information - 0, 2, 4, 6, or 8 bits - PTRS-DMRS association (Phase tracking reference signal-demodulation reference signal relationship) - 0 or 2 bits - beta_offset indicator - 0 or 2 bits - DMRS sequence initialization - 0 or 1 bit

[0080] DCI format 1_0 can be used as a fallback DCI for scheduling PDSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 1_0 with the CRC scrambled with C-RNTI can include, for example, the following information.

[0081] - Identifier for DCI formats - [1] bit- Frequency domain resource assignment -[ ] bits- Time domain resource assignment - X bits- VRB-to-PRB mapping - 1 bit.- Modulation and coding scheme - 5 bits- New data indicator - 1 bit- Redundancy version - 2 bits- HARQ process number - 4 bits- Downlink assignment index - 2 bits- TPC command for scheduled PUCCH - [2] bits- PUCCH resource indicator (physical uplink control channel, PUCCH) - 3 bits- PDSCH-to-HARQ feedback timing indicator (PDSCH-to-HARQ feedback timing indicator) - [3] bits

[0082] DCI format 1_1 can be used as a fallback DCI for scheduling PDSCH, in which case the CRC can be scrambled with C-RNTI. DCI format 1_1 with the CRC scrambled with C-RNTI can include, for example, the following information.

[0083] - Carrier indicator - 0 or 3 bits- Identifier for DCI formats - [1] bits- Bandwidth part indicator - 0, 1 or 2 bits- Frequency domain resource assignment○ For resource allocation type 0, bits○ For resource allocation type 1, bits- Time domain resource assignment -1, 2, 3, or 4 bits- VRB-to-PRB mapping - 0 or 1 bit, only for resource allocation type 1.○ 0 bit if only resource allocation type 0 is configured;○ 1 bit otherwise.- PRB bundling size indicator - 0 or 1 bit - Rate matching indicator - 0, 1, or 2 bits - ZP CSI-RS trigger - 0, 1, or 2 bits For transport block 1 (for the first transport block): - Modulation and coding scheme - 5 bits - New data indicator - 1 bit - Redundancy version - 2 bits For transport block 2 (for the second transport block): - Modulation and coding scheme - 5 bits - New data indicator - 1 bit - Redundancy version - 2 bits - HARQ process number - 4 bits - Downlink assignment index - 0 or 2 or 4 bits - TPC command for scheduled PUCCH - 2 bits - PUCCH resource indicator - 3 bits - PDSCH-to-HARQ_feedback timing indicator - 3 bits - Antenna ports - 4, 5, or 6 bits- Transmission configuration indication - 0 or 3 bits- SRS request - 2 bits- CBG transmission information - 0, 2, 4, 6, or 8 bits- CBG flushing out information - 0 or 1 bit- DMRS sequence initialization - 1 bit.

[0084] Below, the downlink control channel in a 5G communication system will be described in more detail with reference to drawings.

[0085] FIG. 4 is a diagram illustrating an example of a control region (CORESET) in which a downlink control channel is transmitted in a 5G communication system. FIG. 4 is a diagram illustrating an example in which two control regions (control region #1 (401), control region #2 (402)) are set within a UE bandwidth part (410) on the frequency axis and within one slot (420) on the time axis. The control regions (401, 402) can be set to specific frequency resources (403) within the entire UE bandwidth part (410) on the frequency axis. The time axis can be set to one or more OFDM symbols, which can be defined as the control region length (control resource set duration, 404). Referring to the example illustrated in FIG. 4, control region #1 (401) is set to a control region length of two symbols, and control region #2 (402) is set to a control region length of one symbol.

[0086] In the aforementioned 5G communication system, the control region can be established by the base station to the terminal via higher-layer signaling (e.g., system information, MIB, RRC signaling). Establishing a control region for the terminal means providing information such as the control region identifier, the frequency location of the control region, and the symbol length of the control region. For example, the information may include the following:

[0087] ControlResourceSet ::= SEQUENCE {-- Corresponds to L1 parameter 'CORESET-ID' controlResourceSetId ControlResourceSetId,(Control domain identifier (Identity)) frequencyDomainResources BIT STRING (SIZE (45)),(Frequency axis resource allocation information) duration INTEGER (1..maxCoReSetDuration),(Time axis resource allocation information) cce-REG-MappingType CHOICE {(CCE-to-REG mapping method) interleaved SEQUENCE {reg-BundleSize ENUMERATED {n2, n3, n6},(REG bundle size) precoderGranularity ENUMERATED {sameAsREG-bundle, allContiguousRBs}, interleaverSize ENUMERATED {n2, n3, n6}(interleaver size) shiftIndex INTEGER(0..maxNrofPhysicalResourceBlocks-1) OPTIONAL(Interleaved Shift)},nonInterleaved NULL},tci-StatesPDCCH SEQUENCE(SIZE (1..maxNrofTCI-StatesPDCCH)) OF TCI-StateId OPTIONAL,(QCL setting information)tci-PresentInDCI ENUMERATED {enabled} OPTIONAL, -- Need S}

[0088] In Table 8, the tci-StatesPDCCH (simply named TCI (transmission configuration indication) state) configuration information may include information on one or more SS / PBCH block indices or CSI-RS (channel state information reference signal) indices that are in a QCL relationship with the DMRS transmitted in the corresponding control region.

[0089] FIG. 5 is a diagram illustrating an example of a basic unit of time and frequency resources that constitute a downlink control channel that can be used in a 5G communication system. According to FIG. 5, the basic unit of time and frequency resources that constitute a control channel can be referred to as a REG (resource element group, 503), and a REG (503) can be defined as 1 OFDM symbol (501) on the time axis and 1 PRB (physical resource block, 502) on the frequency axis, i.e., 12 subcarriers. A base station can concatenate REGs (503) to constitute a downlink control channel allocation unit.

[0090] As illustrated in FIG. 5, if the basic unit to which a downlink control channel is allocated in a 5G communication system is referred to as a CCE (control channel element, 504), 1 CCE (504) may be composed of multiple REGs (503). Taking the REG (503) illustrated in FIG. 5 as an example, the REG (503) may be composed of 12 REs, and if 1 CCE (504) is composed of 6 REGs (503), 1 CCE (504) may be composed of 72 REs. When a downlink control region is established, the region may be composed of multiple CCEs (504), and a specific downlink control channel may be mapped to and transmitted by one or multiple CCEs (504) according to an aggregation level (AL) within the control region. CCEs (504) within the control area are distinguished by numbers, and the numbers of the CCEs (504) can be assigned according to a logical mapping method.

[0091] The basic unit of the downlink control channel illustrated in FIG. 5, that is, the REG (503), may include both the REs to which the DCI is mapped and the areas to which the DMRS (505), which is a reference signal for decoding the REs, is mapped. As shown in FIG. 5, three DMRSs (505) may be transmitted within one REG (503). The number of CCEs required to transmit the PDCCH may be 1, 2, 4, 8, or 16 depending on the aggregation level, and different numbers of CCEs may be used to implement link adaptation of the downlink control channel. For example, when AL = L, one downlink control channel may be transmitted through L CCEs. The terminal must detect a signal without knowing information about the downlink control channel, and a search space representing a set of CCEs is defined for blind decoding. A search space is a set of downlink control channel candidates, consisting of CCEs that a terminal must attempt to decode at a given aggregation level. Since there are multiple aggregation levels, each of which creates a single bundle of 1, 2, 4, 8, or 16 CCEs, a terminal can have multiple search spaces. A search space set can be defined as the set of search spaces at all configured aggregation levels.

[0092] Search spaces can be categorized into common search spaces and UE-specific search spaces. A certain group of UEs, or all UEs, can search the common search space of the PDCCH to receive cell-common control information, such as dynamic scheduling of system information or paging messages. For example, PDSCH scheduling allocation information for transmitting SIBs, including cell operator information, can be received by searching the common search space of the PDCCH. In the case of the common search space, since a certain group of UEs, or all UEs, must receive the PDCCH, it can be defined as a set of pre-arranged CCEs. Scheduling allocation information for UE-specific PDSCH or PUSCH can be received by searching the UE-specific search space of the PDCCH. The UE-specific search space can be defined UE-specifically as a function of the UE's identity and various system parameters.

[0093] In a 5G communication system, parameters for a search space for a PDCCH can be set from a base station to a terminal via higher-layer signaling (e.g., SIB, MIB, RRC signaling). For example, the base station can set the number of PDCCH candidates at each aggregation level L, the monitoring period for the search space, the monitoring occasion for each symbol within a slot for the search space, the search space type (common search space or terminal-specific search space), the combination of DCI format and RNTI to be monitored in the corresponding search space, the control region index to be monitored for the search space, etc. to the terminal. For example, the following information can be included.

[0094] SearchSpace ::= SEQUENCE {-- Identity of the search space. SearchSpaceId = 0 identifies the SearchSpace configured via PBCH (MIB) or ServingCellConfigCommon.searchSpaceId SearchSpaceId,(search space identifier)controlResourceSetId ControlResourceSetId,(control space identifier)monitoringSlotPeriodicityAndOffset CHOICE {(monitoring slot level period)sl1 NULL,sl2 INTEGER (0..1),sl4 INTEGER (0..3),sl5 INTEGER (0..4),sl8 INTEGER (0..7),sl10 INTEGER (0..9),sl16 INTEGER (0..15),sl20 INTEGER (0..19)} OPTIONAL,duration(monitoring length) INTEGER (2..2559)monitoringSymbolsWithinSlot BIT STRING (SIZE (14)) OPTIONAL,(슬롘 내 나이스 심보)nrofCandidates SEQUENCE {(집성 별보 PDCCH 이리군 수)aggregationLevel1 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8},aggregationLevel2 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8},aggregationLevel4 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8},aggregationLevel8 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8},aggregationLevel16 ENUMERATED {n0, n1, n2, n3, n4, n5, n6, n8}},searchSpaceType CHOICE {(தமாற்க்குக்க்கு திய்தை)-- Configures this search space as common search space (CSS) and DCI formats to monitor.common SEQUENCE {(공통이이국이)}ue-Specific SEQUENCE {(단말-특정이스국)-- Indicates whether the UE monitors in this USS for DCI formats 0-0 and 1-0 or for formats 0-1 and 1-1.formats ENUMERATED {formats0-0-And-1-0, formats0-1-And-1-1},...}.

[0095] Depending on the configuration information, the base station may configure one or more search space sets for the terminal. In some embodiments, the base station may configure search space set 1 and search space set 2 for the terminal, and may configure the terminal to monitor DCI format A scrambled with X-RNTI in search space set 1 in a common search space, and may configure the terminal to monitor DCI format B scrambled with Y-RNTI in search space set 2 in a terminal-specific search space.

[0096] According to the configuration information, one or more search space sets may exist in a common search space or a terminal-specific search space. For example, search space set #1 and search space set #2 may be configured as a common search space, and search space set #3 and search space set #4 may be configured as terminal-specific search spaces.

[0097] In the common search space, the following combinations of DCI formats and RNTIs can be monitored. Of course, the examples below are not limited to these.

[0098] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, SP-CSI-RNTI, RA-RNTI, TC-RNTI, P-RNTI, SI-RNTI

[0099] - DCI format 2_0 with CRC scrambled by SFI-RNTI

[0100] - DCI format 2_1 with CRC scrambled by INT-RNTI

[0101] - DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

[0102] - DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

[0103] In a terminal-specific search space, the following combinations of DCI formats and RNTIs can be monitored, although the examples below are not limited.

[0104] - DCI format 0_0 / 1_0 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0105] - DCI format 1_0 / 1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

[0106] The RNTIs specified may follow the definitions and uses below.

[0107] C-RNTI (cell RNTI): For terminal-specific PDSCH scheduling purposes

[0108] TC-RNTI (temporary cell RNTI): For terminal-specific PDSCH scheduling purposes

[0109] CS-RNTI (configured scheduling RNTI): Used for terminal-specific PDSCH scheduling that is set semi-statically.

[0110] RA-RNTI (random access RNTI): Used for PDSCH scheduling in the random access phase.

[0111] P-RNTI (paging RNTI): Used for scheduling PDSCH where paging is transmitted.

[0112] SI-RNTI (system information RNTI): Used for scheduling PDSCH where system information is transmitted.

[0113] INT-RNTI (interruption RNTI): Used to indicate whether pucturing is in progress for PDSCH.

[0114] TPC-PUSCH-RNTI (transmit power control for PUSCH RNTI): Used to indicate power control commands for PUSCH.

[0115] TPC-PUCCH-RNTI (transmit power control for PUCCH RNTI): Used to indicate power control commands for PUCCH (physical uplink control channel).

[0116] TPC-SRS-RNTI (transmit power control for SRS RNTI): Used to indicate power adjustment commands for SRS (sounding reference signal).

[0117] The aforementioned specified DCI formats may follow the definitions below.

[0118] DCI formatUsage0_0Scheduling of PUSCH in one cell0_1Scheduling of PUSCH in one cell1_0Scheduling of PDSCH in one cell1_1Scheduling of PDSCH in one cell2_0Notifying a group of UEs of the slot format2_1Notifying a group of UEs of the PRB(s) and OFDM symbol(s) where UE may assume no transmission is intended for the UE2_2Transmission of TPC commands for PUCCH and PUSCH2_3Transmission of a group of TPC commands for SRS transmissions by one or more UEs

[0119] In a 5G communication system, the search space of aggregation level L in CORESET p and search space set s can be expressed as in the following mathematical expression 1.

[0120] [Mathematical Formula 1]

[0121]

[0122] - L: Integration level

[0123] - n CI : Carrier Index

[0124] - n CCE,p : Total number of CCEs present in CORESET p

[0125] - : slot index

[0126] - : Number of PDCCH candidates for aggregation level L

[0127] - = 0, ..., -1: PDCCH candidate index of aggregation level L

[0128] - l = 0, ..., L -1

[0129] - , Y p,-1 = nRNTI≠0, A p = 39827 for p mod 3 = 0, A p = 39829 for p mod 3 = 1, A p = 39839 for p mod 3 = 2, D= 65537

[0130] - n RNTI : Terminal identifier

[0131] The value can be 0 for a common search space.

[0132] In the case of a terminal-specific search space, the value may correspond to a value that changes depending on the terminal's identity (C-RNTI or ID set to the terminal by the base station) and the time index.

[0133] In a 5G communication system, since multiple search space sets can be set with different parameters (e.g., parameters in Table 10), the set of search space sets monitored by a terminal at each point in time can be different. For example, if search space set #1 is set with an X-slot period and search space set #2 is set with a Y-slot period and X and Y are different, the terminal can monitor both search space set #1 and search space set #2 in a specific slot, or can monitor either search space set #1 or search space set #2 in a specific slot.

[0134] In LTE and NR, a terminal, while connected to a serving base station, can perform a procedure to report its supported capabilities to the base station. In the description below, this is referred to as a UE capability report.

[0135] A base station can transmit a UE capability inquiry message requesting a capability report to a connected terminal. The message can include a UE capability request for each RAT (radio access technology) type of the base station. The RAT type-specific request can include information on a combination of supported frequency bands, etc. In addition, in the case of the UE capability inquiry message, UE capabilities for multiple RAT types can be requested through a single RRC message container transmitted by the base station, or the base station can include multiple UE capability inquiry messages including UE capability requests for each RAT type and transmit them to the terminal. That is, the UE capability inquiry can be repeated multiple times in one message, and the terminal can configure a corresponding UE capability information message and report it multiple times. In the next-generation mobile communication system, a UE capability request can be performed for MR-DC (Multi-RAT dual connectivity), including NR, LTE, and EN-DC (E-UTRA - NR dual connectivity). Additionally, the terminal capability inquiry message is typically transmitted initially after the terminal is connected to the base station, but the base station may request it under any conditions when necessary.

[0136] In the above step, the terminal that received the terminal capability report request from the base station configures the terminal capability based on the RAT type and band information requested from the base station. The terminal can configure the terminal capability as follows.

[0137] 1. If the UE receives a list of LTE and / or NR bands from the base station as a UE capability request, the UE configures a band combination (BC) for EN-DC and NR stand-alone (SA). That is, based on the bands requested to the base station via FreqBandList, it configures a candidate list of BCs for EN-DC and NR SA. Furthermore, the bands are prioritized in the order listed in FreqBandList.

[0138] 2. If the base station requests a terminal capability report by setting the 'eutra-nr-only' flag or the 'eutra' flag, the terminal completely removes NR SA BCs from the list of configured BC candidates. This operation can only occur when the LTE base station (eNB) requests the 'eutra' capability.

[0139] 3. Afterwards, the terminal removes fallback BCs from the BC candidate list constructed in the above step. Here, a fallback BC refers to a BC that can be obtained by removing at least one band corresponding to a secondary cell (SCell) from a random BC. This step can be omitted because the BC before removing the band corresponding to at least one SCell can already cover the fallback BC. This step is also applied to MR-DC, i.e., to LTE bands. The BCs remaining after this step are the final candidate BC list.

[0140] 4. The terminal selects BCs to report by selecting BCs that match the requested RAT type from the final candidate BC list above. In this step, the terminal constructs the supportedBandCombinationList in a set order. That is, the terminal constructs BCs and UE capabilities to report in the order of the preset rat-Type (nr -> eutra-nr -> eutra). In addition, it constructs a featureSetCombination for the constructed supportedBandCombinationList, and constructs a list of 'candidate feature set combinations' from the candidate BC list from which the list for the fallback BC (containing capabilities of the same or lower level) is removed. The 'candidate feature set combinations' above include feature set combinations for both NR and EUTRA-NR BCs, and can be obtained from the feature set combinations of the UE-NR-Capabilities and UE-MRDC-Capabilities containers.

[0141] 5. Also, if the requested rat Type is eutra-nr and has an effect, featureSetCombinations are included in both containers: UE-MRDC-Capabilities and UE-NR-Capabilities. However, the NR feature set is included only in UE-NR-Capabilities.

[0142] After terminal capabilities are configured, the terminal transmits a terminal capability information message containing the terminal capabilities to the base station. Based on the terminal capabilities received from the terminal, the base station then performs appropriate scheduling and transmission / reception management for the terminal.

[0143] FIG. 6 is a diagram illustrating an example of a wireless protocol structure of a base station and a terminal in a single cell, carrier aggregation (CA), and DC (dual connectivity) situation.

[0144] Referring to FIG. 6, the wireless protocol of the 5G communication system is composed of NR SDAP (service data adaptation protocol, 625, 670), NR PDCP (Packet data convergence protocol, 630, 665), NR RLC (radio link control, 635, 660), and NR MAC (medium access control, 640, 655) in the terminal and NR base station, respectively.

[0145] The main functions of NR SDAP (625, 670) may include some of the following functions:

[0146] - Transfer of user plane data

[0147] - Mapping function between a QoS (quality of service) flow and a data bearer for both DL and UL.

[0148] - Marking QoS flow ID in both DL and UL packets

[0149] - Ability to map reflective QoS flow to data bearer for the uplink SDAP PDUs (reflective QoS flow to DRB mapping for the UL SDAP PDUs).

[0150] For the above SDAP layer device, the terminal can be configured by an RRC message for each PDCP layer device, each bearer, or each logical channel, whether to use the header of the SDAP layer device or whether to use the function of the SDAP layer device, and when the SDAP header is configured, the terminal can instruct the NAS QoS reflection configuration 1-bit indicator (NAS reflective QoS) and the AS QoS reflection configuration 1-bit indicator (AS reflective QoS) of the SDAP header to update or reset the mapping information for the QoS flow and data bearer of the uplink and downlink. The SDAP header can include QoS flow ID information indicating QoS. The QoS information can be used as data processing priority, scheduling information, etc. to support a smooth service.

[0151] The main functions of NR PDCP (630, 665) may include some of the following functions:

[0152] - Header compression and decompression (ROHC (Robust Header Compression) only)

[0153] - User data transfer function

[0154] - In-sequence delivery of upper layer PDUs

[0155] - Out-of-sequence delivery of upper layer PDUs

[0156] - PDCP PDU reordering for reception

[0157] - Duplicate detection of lower layer SDUs

[0158] - Retransmission function (Retransmission of PDCP SDUs)

[0159] - Encryption and decryption functions (Ciphering and deciphering)

[0160] - Timer-based SDU discard in uplink.

[0161] The reordering function of the NR PDCP device above refers to a function of reordering PDCP PDUs received from a lower layer in order based on the PDCP SN (sequence number), and may include a function of transmitting data to an upper layer in the reordered order. Alternatively, the reordering function of the NR PDCP device may include a function of transmitting data directly without considering the order, a function of recording lost PDCP PDUs by reordering the order, a function of reporting a status of lost PDCP PDUs to the transmitting side, and a function of requesting retransmission of lost PDCP PDUs.

[0162] The main functions of NR RLC (635, 660) may include some of the following functions:

[0163] - Data transfer function (Transfer of upper layer PDUs)

[0164] - In-sequence delivery of upper layer PDUs

[0165] - Out-of-sequence delivery of upper layer PDUs

[0166] - ARQ function (Error Correction through ARQ)

[0167] - Concatenation, segmentation and reassembly of RLC SDUs

[0168] - Re-segmentation of RLC data PDUs

[0169] - Reordering of RLC data PDUs

[0170] - Duplicate detection function

[0171] - Protocol error detection

[0172] - RLC SDU discard function

[0173] - RLC re-establishment function

[0174] In the above, the in-sequence delivery function of the NR RLC device refers to the function of sequentially delivering RLC SDUs received from a lower layer to an upper layer. The in-sequence delivery function of the NR RLC device may include a function of reassembling and delivering a single RLC SDU when it is received divided into multiple RLC SDUs, a function of rearranging received RLC PDUs based on the RLC SN (sequence number) or PDCP SN (sequence number), a function of recording lost RLC PDUs by rearranging the order, a function of reporting the status of lost RLC PDUs to the transmitting side, and a function of requesting retransmission of lost RLC PDUs. The in-sequence delivery function of an NR RLC device may include a function to sequentially deliver to the upper layer only the RLC SDUs up to the lost RLC SDU when there is a lost RLC SDU, or may include a function to sequentially deliver to the upper layer all RLC SDUs received before the timer starts if a predetermined timer has expired even if there is a lost RLC SDU. Alternatively, the in-sequence delivery function of an NR RLC device may include a function to sequentially deliver to the upper layer all RLC SDUs received up to the present if a predetermined timer has expired even if there is a lost RLC SDU.In addition, the RLC PDUs may be processed in the order in which they are received (in the order of arrival, regardless of the order of the serial numbers (SN)) and delivered to the PDCP device out of order (out-of-sequence delivery). In the case of segments, the segments stored in the buffer or to be received later may be received, reconstructed into a complete RLC PDU, processed, and delivered to the PDCP device. The NR RLC layer may not include a concatenation function, and the function may be performed in the NR MAC layer or replaced with a multiplexing function of the NR MAC layer.

[0175] The out-of-sequence delivery function of the NR RLC device mentioned above refers to the function of directly delivering RLC SDUs received from a lower layer to an upper layer regardless of the order, and may include a function of reassembling and delivering RLC SDUs when an original RLC SDU is received divided into multiple RLC SDUs, and may include a function of storing and arranging the RLC SN or PDCP SN of received RLC PDUs to record lost RLC PDUs.

[0176] NR MAC (640, 655) can be connected to multiple NR RLC layer devices configured in one terminal, and the main functions of NR MAC can include some of the following functions.

[0177] - Mapping function (Mapping between logical channels and transport channels)

[0178] - Multiplexing / demultiplexing of MAC SDUs

[0179] - Scheduling information reporting function

[0180] - HARQ function (Error correction through HARQ)

[0181] - Priority handling between logical channels of one UE

[0182] - Priority handling between UEs by means of dynamic scheduling

[0183] - MBMS service identification function

[0184] - Transport format selection function

[0185] - Padding function

[0186] The NR PHY layer (645, 650) can perform operations of channel coding and modulating upper layer data, converting it into OFDM symbols and transmitting it through a wireless channel, or demodulating and channel decoding OFDM symbols received through a wireless channel and transmitting them to a higher layer.

[0187] The above wireless protocol structure can have various detailed structures depending on the carrier (or cell) operation method. For example, when a base station transmits data to a terminal based on a single carrier (or cell), the base station and the terminal use a protocol structure that has a single structure for each layer, as in 600. On the other hand, when a base station transmits data to a terminal based on CA using multiple carriers in a single TRP, the base station and the terminal use a protocol structure that has a single structure up to RLC but multiplexes the PHY layer through the MAC layer, as in 610. As another example, when a base station transmits data to a terminal based on DC using multiple carriers in multiple TRPs, the base station and the terminal use a protocol structure that has a single structure up to RLC but multiplexes the PHY layer through the MAC layer, as in 620.

[0188] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings. The contents of the present disclosure can be applied to FDD and TDD systems. In the present disclosure below, upper signaling (or upper layer signaling) refers to a signal transmission method in which a base station transmits a signal to a terminal using a downlink data channel of a physical layer, or a terminal transmits a signal to a base station using an uplink data channel of a physical layer, and may also be referred to as RRC signaling, PDCP signaling, or a MAC (medium access control) control element (MAC control element; MAC CE).

[0189] In the present disclosure, determining the priority between A and B may be referred to in various ways, such as selecting a higher priority according to a predetermined priority rule and performing an action corresponding to it, or omitting or dropping an action for a lower priority.

[0190] In the following disclosure, the above examples are described through a number of embodiments, but they are not independent and one or more embodiments may be applied simultaneously or in combination.

[0191] Here, we will explain the measurement gap. Before a handover, the UE typically measures the cell power (signal quality) of the target cell and reports it to the base station. Based on the reported measurement results, the base station can decide whether to handover the UE to the target cell. Measuring the signal quality of the target cell when it is on the same frequency as the serving cell (intra-frequency measurement) may require more complexity from the UE's perspective, compared to measuring the signal quality of the target cell when it is on a different frequency (inter-frequency measurement) from the current cell. This is because this may require the implementation of two RF transceivers for measuring at different frequencies. This type of two-transceiver solution presents several practical challenges. First, implementing an additional transceiver requires additional cost. Second, if the frequency of the serving cell and the frequency of the target cell are close to each other, interference between the frequencies may occur.

[0192] To address this issue, a measurement gap was introduced. During this gap, the terminal essentially does not transmit or receive. Therefore, since there is no signal transmission or reception during the measurement gap, the terminal can switch to the target cell, perform signal quality measurements, and then return to the serving cell. To achieve this, the base station can pre-configure the terminal with upper-level signals related to the measurement gap, enabling the terminal to measure the signal quality of the target cell during the gap.

[0193] If a UE requires a measurement gap to identify and measure intra-frequency cells and / or inter-frequency cells and / or inter-RAT E-UTRAN cells, and if the UE does not support independent measurement gap patterns for different frequency ranges, the network shall provide a single per-UE measurement gap pattern for simultaneous monitoring of all frequency layers so that the requirements of the following clauses apply.

[0194] If a UE requires a measurement gap to identify and measure intra-frequency cells and / or inter-frequency cells and / or inter-RAT E-UTRAN cells, and if the UE supports independent measurement gap patterns for different frequency ranges, the network shall provide either a per-frequency range measurement gap pattern to independently and simultaneously monitor all frequency layers of each frequency range or a single per-UE measurement gap pattern to simultaneously monitor all frequency layers of all frequency ranges, for the requirements of the following clauses to apply.

[0195] When a terminal is configured via LPP (LTE Positioning Protocol) to measure RSTD (reference signal time difference), PRS (positioning reference signal)-RSRP (reference signal received power) and terminal Rx-Tx time difference, the network must provide:

[0196] - Measurement gap pattern per single terminal for simultaneous monitoring of all positioning frequency layers and intra-frequency, inter-frequency and / or inter-RAT frequency layers of all frequency ranges or

[0197] - For measurement gap patterns other than measurement gap patterns #24 and #25, if the terminal supports independent measurement gap patterns for different frequency ranges for PRS measurements, frequency range-specific measurement gap patterns for simultaneous monitoring of all positioning frequency layers and intra-frequency, inter-frequency cell and / or inter-RAT frequency layers in that frequency range.

[0198] During the Per-UE measurement gap, the terminal

[0199] - It is not required to perform reception / transmission from or to the E-UTRAN PCell, E-UTRAN SCell(s) and NR serving cell, except for reception of signals used for radio resource management (RRM) measurement(s) and random access procedures according to TS38.321.

[0200] - Except for receiving signals used for RRM measurement(s), PRS measurement(s) and random access procedures according to TS38.321, it is not required to perform reception / transmission to or transmit to the corresponding NR serving cell for the SA (single carrier or CA configuration).

[0201] - Except for receiving signals used for RRM measurement(s), PRS measurement(s) and random access procedures according to TS38.321, it is not required to perform reception / transmission to or from the corresponding PCell, SCell(s) and E-UTRAN serving cell for NR-E-UTRA dual connectivity.

[0202] - Except for receiving signals used for RRM measurement(s), PRS measurement(s) and random access procedures according to TS38.321, it is not required to perform reception / transmission to or transmit to the corresponding NR serving cell for NR-DC.

[0203] During the Per-FR measurement gap, the terminal

[0204] - Except for receiving signals used for RRM measurement(s) and random access procedures according to TS38.321, it is not required to perform reception / transmission from or to the corresponding E-UTRAN PCell, E-UTRAN SCell(s) and NR serving cell.

[0205] - It is not necessary to perform reception / transmission to or transmit to the corresponding NR serving cell, except for reception of signals used for RRM measurement(s), PRS measurement(s) and random access procedures according to TS38.321.

[0206] - Except for receiving signals used for RRM measurement(s), PRS measurement(s) and random access procedures according to TS38.321, it is not required to perform reception / transmission to or from the corresponding PCell, SCell(s) and E-UTRAN serving cell for NR-E-UTRA dual connectivity.

[0207] - It is not necessary to perform reception / transmission to or transmit to the corresponding NR serving cell, except for reception of signals used for RRM measurement(s), PRS measurement(s) and random access procedures according to TS38.321.

[0208] The terminal shall support the measurement gap patterns listed in Table 11 based on the applicability specified in Table 12. The terminal determines the measurement gap timing based on the gap offset configuration and measurement gap timing advance configuration provided by higher layer signaling as specified in TS 38.331 and TS 36.331.

[0209] Gap Pattern IdMeasurement Gap Length (MGL, ms)Measurement Gap Repetition Period(MGRP, ms)06401680234033804620561606420744084809416010320113160125.520135.540145.580155.5160163.520173.540183.580193.5160201.520211.540221.580231.51602410802520160

[0210] Measurement gap pattern configurationServing cellMeasurement Purpose Note 5 Applicable Gap Pattern IdPer-UEMeasurementgapE-UTRA + FR1, orE-UTRA + FR2,or E-UTRA +FR1 + FR2non-NR RAT Note1,2 0,1,2,3FR1 and / or FR2 Note 7 0-11, 24, 25non-NR RAT Note1,2 and FR1 and / or FR2 Note 7 0, 1, 2, 3, 4, 6, 7, 8,10, 24Per-FRmeasurementgapE-UTRA and, FR1 if configurednon-NR RAT Note1,2 0,1,2,3FR2 if configuredNo gapE-UTRA and, FR1 if configuredFR1 only0-11FR2 if configuredNo gapE-UTRA and, FR1 if configuredFR2 onlyNo gapFR2 if configured12-23E-UTRA and, FR1 if configurednon-NR RAT Note1,2and FR10, 1, 2, 3, 4, 6, 7, 8,10FR2 if configuredNo gapE-UTRA and, FR1 if configuredFR1 and FR20-11FR2 if configured12-23E-UTRA and, FR1 if configurednon-NR RAT Note1,2 and FR20, 1, 2, 3, 4, 6, 7, 8,10FR2 if configured12-23E-UTRA and, FR1 if configurednon-NR RAT Note1,2 and FR1 and FR20, 1, 2, 3, 4, 6, 7, 8,10FR2 if configured12-23

[0211] Note: In E-UTRA-NR dual connectivity mode, if GSM or UTRA TDD or UTRA FDD inter-RAT frequency layer is configured to be monitored, only measurement gap pattern #0 and #1 can be used for per-FR gap in E-UTRA and FR1 if configured, or for per-UE gap. In NR-E-UTRA dual connectivity mode, if UTRA FDD inter-RAT frequency layer is configured to be monitored for SRVCC, only measurement gap pattern #0 and #1 can be used for per-FR gap in E-UTRA and FR1 if configured, or for per-UE gap.

[0212] NOTE 1: In E-UTRA-NR dual connectivity mode, non-NR RAT includes E-UTRA, UTRA and / or GSM. In NR-E-UTRA dual connectivity mode, non-NR RAT means E-UTRA, and UTRA for SRVCC.

[0213] NOTE 2: Void

[0214] NOTE 3: When E-UTRA inter-frequency RSTD measurements are configured and the UE requires measurement gaps for performing such measurements, only Gap Pattern #0 can be used.

[0215] NOTE 4: For UE supportingsupportedGapPattern-NRonly-NEDCormeasGapPatterns-NRonly-ENDC-r16but not supportingsupportedGapPatternfor the corresponding gap patterns among GP2-11, the corresponding gap patterns are not applicable to measurement of non-NR RATs as defined in NOTE 1.

[0216] NOTE 5: Inclusion of positioning measurements: Measurement purpose which includes E-UTRA measurements includes also E-UTRA RSRP and E-UTRA RSRQ measurements for E-CID.

[0217] NOTE 6: Measurement gap patterns #24 and #25 can be requested [2] only when the UE is configured at least with any of RSTD, UE Rx-Tx, or PRS-RSRP measurements requiring such gaps and can only be used during the corresponding positioning measurement period

[0218] NOTE 7: Inclusion of positioning measurements for measurement gaps: Measurement purpose which includes any of FR1 and FR2 measurements includes also RSTD, UE Rx-Tx, and PRS-RSRP measurements.

[0219] FIG. 7 is a diagram illustrating an example of a situation in which a measurement gap and an SS / PBCH block are transmitted and received according to an embodiment of the present disclosure. In FIG. 7, 700 is a measurement gap setting resource (704) of a terminal in a situation in which a measurement gap repetition period is 40 ms, a measurement gap length is 6 ms, and a measurement offset is 0 set as a higher-order signal in Table 11. In FIG. 7, 702 is a diagram illustrating a situation in which an SS / PBCH block is set to a 20 ms repetition period and an SS / PBCH block (706) is transmitted during a 5 ms period. In FIG. 7, 700 and 702 are the same frame, and for convenience of explanation, a situation in which a measurement gap is set periodically and a situation in which an SS / PBCH block is periodically transmitted and received are illustrated separately. The terminal may be able to measure the received signal quality by performing channel estimation with SS / PBCH blocks in the intra-frequency or inter-frequency region in the measurement gap. Generally, the base station sets the length of the measurement gap period to be slightly longer than the SS / PBCH block period, because when measuring a different frequency band or a different RAT's frequency band, the terminal may need additional time for RF retuning. The measurement gap may include all or part of the SS / PBCH block transmission resources. The period of the SS / PBCH block transmission and reception and the period of the measurement gap may be the same, or the period of the measurement gap may be longer than the period of the SS / PBCH block transmission and reception, as in FIG. 7. In FIG. 7, SFN stands for system frame number, and one SFN consists of 10 subframes.

[0220] Hereinafter, the scheduling constraints caused by the measurement gap will be described. As described in Fig. 7, the terminal may not transmit or receive uplink or downlink channels during the measurement gap period, according to the following procedure. During the activated measurement gap, the terminal operates in the serving cell in the corresponding frequency range of the measurement gap set as the upper signal related to the measurement gap, referring to Table 13.

[0221] 1> Do not transmit HARQ feedback, SR and CSI. 1> Do not report SRS. 1> Do not transmit UL-SCH except Msg3 or MSG A payload. 1> If ra-ResponseWindow or ra-ContentionResolutionTimer or msgB-ResponseWindow is running: 2> Scan PDCCH. 1> else 2> Do not monitor PDCCH. 2> Do not receive on DL-SCH.

[0222] The terminal does not perform general data transmission and reception for the measurement gap set by the base station, as described in Table 13 above. Therefore, in the case of delay-sensitive services such as XR services, additional delay may occur due to the inability to perform data transmission and reception during the relevant section, which may lead to failure to meet XR service requirements. For example, if XR traffic occurs at the start of a measurement gap, the terminal cannot perform data transmission and reception during the measurement gap section, and can transmit and receive data immediately after the measurement gap ends. Therefore, in this case, a delay is likely to occur at least during the measurement gap section. Furthermore, the more frequently the measurement gap is repeated, the more frequently this situation may occur. Therefore, a method may be needed to set the measurement gap section more adaptively to process traffic such as XR services more quickly.

[0223] [Example 1]

[0224] The base station may be able to adaptively instruct the terminal via DCI or MAC CE whether to perform channel measurements in the upcoming measurement gap. Alternatively, based on Table 13, the terminal may be able to receive or transmit data scheduled by a specific DCI format or a DCI format including a CRC scrambled with an RNTI even during the measurement gap period. This may enable the base station to more smoothly support delay-sensitive services such as XR services. For example, if the terminal receives a DCI format and is scheduled to receive a PDSCH or transmit a PUSCH in a resource region where the DCI format overlaps or partially overlaps with the measurement gap, the terminal may be able to receive the PDSCH or transmit the PUSCH according to the scheduling information without performing channel estimation of the target cell.

[0225] As an example, referring to FIG. 7, a terminal may be able to adaptively receive a PDSCH or transmit a PUSCH according to information separately provided by a base station in a measurement gap (704) period set in SFN 4 in a situation where a measurement gap (704) is periodically set. The DCI format may be a terminal-specific DCI format or a terminal-common DCI format. The terminal-specific DCI format is DCI information provided to a specific terminal, and the terminal-common DCI format is DCI information commonly transmitted to one or more group terminals. The terminal-specific DCI format may include an additional bit field that notifies whether a measurement gap is performed in addition to the DCI that schedules the PDSCH or PUSCH to the terminal. By detecting the bit field, the terminal may be able to determine whether to use one or more measurement gap periods set in the future as a resource for performing data transmission and reception, or to utilize the measurement gap period for existing channel estimation.

[0226] Alternatively, it may be possible to indicate whether one or more measurement gap intervals set in the future are used as resources for performing data transmission and reception through MAC CE, or whether they are utilized as measurement gap intervals for existing channel estimation. For example, a base station transmits a PDSCH including a MAC CE, and a terminal, after receiving the PDSCH, transmits a UCI including HARQ-ACK information via a PUCCH or PUSCH. If the slot in which the PUCCH or PUSCH is transmitted is n, it may be possible to determine that the MAC CE information indicated by the base station has been applied from slot n+k. The MAC CE information may be able to indicate the time or frequency domain in which a measurement gap (repetition) interval periodically set as a higher signal is activated or deactivated.

[0227] Alternatively, it may be possible to indicate which measurement gap interval is disabled or enabled for future measurement gap repetition intervals using bitmap information, with each bit value (0 or 1) in the bitmap. A disabled measurement gap interval means that the terminal does not perform channel estimation in the measurement gap interval and determines that data transmission and reception are possible. On the other hand, an enabled measurement gap interval means that the terminal operates according to Table 13 in the measurement gap interval.

[0228] Alternatively, the UE may be able to inform the base station whether to use the configured measurement gap period in the future through a scheduling request (SR) or a configured grant PUSCH (CG PUSCH) transmission before the measurement gap. For example, the base station may provide s-MeasureConfig information to the UE. The s-MeasureConfig information indicates threshold information for controlling NR SpCell (special cell) RSRP measurement when the UE is requested to perform measurements for cells other than the serving cell. In the s-MeasureConfig information, the selection of ssb-RSRP corresponds to cell RSRP based on the SS / PBCH block, and the selection of csi-RSRP corresponds to cell RSRP of the CSI-RS. Depending on whether the measurement value is higher or lower than the threshold, the UE may not perform channel information measurement of the adjacent cell during the measurement gap period. This allows the UE to reduce power consumption required for channel measurement.

[0229] However, since the base station does not know whether the terminal performs channel information measurement of the neighboring cell according to the s-MeasureConfig information during the measurement gap period, it needs to know this accurately. Therefore, it may be possible for the terminal to provide the base station with information about whether or not it performs channel information measurement of the neighboring cell according to the s-MeasureConfig information during the measurement gap period through an uplink channel such as SR or CG PUSCH. And based on this information, the base station may be able to schedule data transmission and reception during the measurement gap period when the terminal does not perform channel estimation.

[0230] Alternatively, if the above-described method was in the form of notifying whether Table 13 is applied or not for the measurement gap section set by the upper signal, it may be possible to notify a separate time section using DCI format or MAC CE. For example, as explained based on FIG. 7, if the base station indicates that SFN 4 to SFN 8 are to be used for data transmission and reception at a specific point in time using DCI format or MAC CE, the terminal may be able to give priority to data transmission and reception regardless of whether or not a measurement gap exists in between.

[0231] Before transmitting and receiving data in the above measurement gap, the terminal transmits the relevant terminal capability to the base station, and the base station determines which terminals support the above-mentioned function. Thereafter, the base station provides the terminal with information on whether the measurement gap can be adaptively changed for data transmission and reception through upper signal configuration. It may be possible to support the above-mentioned operation after such terminal capability report and the base station configuration according to it. Alternatively, although the above-described method was described assuming that the entire measurement gap section in FIG. 7 is used as a section for data transmission and reception, it may be possible that only a portion of the measurement gap section is changed to a section for data transmission and reception. For example, among the measurement gaps configured in the first six subframes of SFN=4 in FIG. 7, it may be possible that only some subframes are not used as measurement gaps. In this case, it may be possible to assume that the terminal performs measurements only in the remaining subframes used as measurement gaps. If the number of remaining subframes used as measurement gaps is less than a certain number, the terminal may not perform measurements. For example, if only two subframes remain as a measurement gap, the terminal may not perform measurements.

[0232] [Example 2]

[0233] The first embodiment described above describes methods and procedures for changing the measurement gaps that were previously set periodically to allow data transmission and reception for delay-sensitive services such as XR services. However, measurement gaps were introduced in mobile communication systems for the purpose of enabling the base station or the terminal to determine whether to perform a handover through channel estimation between the serving cell and the target cell. Therefore, the less frequent the measurement gaps, the more likely it is that the terminal will not be able to perform a handover in a timely manner or, in severe cases, may not be able to maintain cell connection. Therefore, it is necessary to consider an additional measurement gap to compensate for the inability to perform a measurement gap at a specific time.

[0234] FIG. 8 is a diagram illustrating an example of a measurement gap setting method according to an embodiment of the present disclosure. In FIG. 8, 800 is a measurement gap setting resource (804) of a terminal in a situation where a measurement gap repetition period is 40 ms, a measurement gap length is 6 ms, and a measurement offset is 0 set as a higher-order signal in Table 11. In FIG. 8, 802 illustrates a situation where an SS / PBCH block is set to a 20 ms repetition period, and an SS / PBCH block (806) is transmitted for a 5 ms period. For example, if a measurement gap (804) preset for SFN=4 of 800 is changed to a period for data transmission and reception according to the method described in the first embodiment, and the terminal receives a PDSCH or PUSCH in the period, it may be possible to set a separate additional measurement gap (808) other than the measurement gap (804) preset periodically as a higher-order signal.

[0235] Providing an additional measurement gap (808) may be supported by at least one of the following methods, or a combination thereof. Furthermore, the provision of an additional measurement gap (808) may be limited to cases where a previous or subsequent measurement gap (804) is deactivated. Accordingly, when a previous or subsequent measurement gap (804) is not deactivated, the terminal may not apply the following methods, and the base station may not provide the terminal with information for performing the following methods.

[0236] - Method 2-1: This is a method of notifying through DCI information. For example, the base station can notify multiple terminals of whether an additional measurement gap is set through a group common DCI such as DCI format 2_x. Each terminal can identify the bit area that it should search in the group common DCI and determine whether an additional measurement gap to be applied exists. Alternatively, the base station can notify a specific terminal of whether an additional measurement gap is set through DCI format 1_x or DCI format 2_x. For example, the base station can notify the terminal of whether an additional measurement gap exists or not through a specific DCI field within the DCI format. The section to which the additional measurement gap is applied may be set in advance as a higher-order signal, and at this time, the offset from the last symbol of the previous measurement gap and the length of the additional measurement gap may be set together. The unit of the offset and the length of the additional measurement gap may be a subframe unit or a slot unit set by the terminal in the corresponding carrier or BWP. Alternatively, the offset may be determined based on the last symbol of the CORESET in which the DCI information is transmitted. Furthermore, in addition to the above information, additional measurement gap information may be provided using the SFN number and bitmap information within the corresponding SFN interval.

[0237] As an example, referring to Fig. 8, the additional measurement gap information (808) of SFN=6 can be set by the base station to the terminal in advance as an upper signal, and the terminal can determine whether the 808 exists through DCI format reception. If the additional measurement gap exists, the terminal may follow the method defined in Table 13. Alternatively, it may be possible to follow only some of the methods defined in Table 13. If only some of the methods are followed, this may be determined by the base station settings or may be fixed regardless of the base station settings. For example, in Table 13, it may be possible to apply or not apply '1> Does not perform HARQ feedback, SR, and CSI transmission' and '1> Does not report SRS'.

[0238] - Method 2-2: This is a method of notifying through MAC CE information. For example, the base station transmits a PDSCH including MAC CE information to the terminal, and the terminal may be able to determine whether additional measurement gap information (808) is applied through a HARQ-ACK feedback report in response to this. Most methods are similar to Method 2-1, and for example, the base station may notify the terminal whether an additional measurement gap exists or not through MAC CE. At this time, it may be possible to set the offset from the last symbol of the previous measurement gap and the length of the additional measurement gap together. The unit of the offset and the length of the additional measurement gap may be a subframe unit or a slot unit set by the terminal in the corresponding carrier or BWP. It may be possible to determine the offset based on the PUCCH or PUSCH on which the HARQ-ACK feedback is transmitted and received or the last symbol of the corresponding slot. Additionally, the above MAC CE information may have a separate LCID (logical channel ID), which may enable the terminal to determine, through PDSCH reception and LCID detection, that the PDSCH includes MAC CE information indicating an additional measurement gap. In addition to the above information, it may be possible to provide additional measurement gap information using the SFN number and bitmap information within the SFN section.

[0239] As an example, referring to Fig. 8, the additional measurement gap information (808) of SFN=6 can be set by the base station to the terminal in advance as an upper signal, and the terminal can determine whether the 808 exists through MAC CE reception. If the additional measurement gap exists, the terminal may follow the method defined in Table 13. Alternatively, it may be possible to follow only some of the methods defined in Table 13. If only some of the methods are followed, this may be determined by the base station settings or may be fixed regardless of the base station settings. For example, in Table 13, it may be possible to apply or not apply '1> Does not perform HARQ feedback, SR, and CSI transmission' and '1> Does not report SRS'.

[0240] - Method 2-3: While Methods 2-1 and 2-2 were methods for indicating an additional measurement gap through an explicit signal, Method 2-3 is a method for implicitly indicating an additional measurement gap. For example, if the terminal determines that all or at least a portion of the measurement gap (804) of SFN=4 is inactive by at least one of the methods described in the first embodiment, the terminal may be able to implicitly indicate that an additional measurement gap (808) exists at SFN=6. To make this possible, information about the starting point (or offset) and the interval length for the additional measurement gap (808) at SFN=6 may need to be transmitted in advance through an upper signal. On the other hand, if the measurement gap (804) of SFN=4 is activated and the terminal performs measurement, it may be possible for the terminal to determine that there is no additional measurement gap (808). Alternatively, it may be possible to indicate together whether an additional measurement gap (808) is provided in the method described in the first embodiment.

[0241] Through the above methods, terminals can provide delay-sensitive XR services in a timely manner while also adaptively setting measurement gaps for mobility support, thereby reducing handover failure rates.

[0242] FIG. 9 is a diagram illustrating an example of a procedure for a terminal to perform a measurement gap according to one embodiment of the present disclosure. First, the terminal transmits terminal capabilities, including information on whether the terminal supports the methods described in the first or second embodiment, to the base station (900). Thereafter, the base station may transmit an upper signal including measurement gap information, such as 704 of FIG. 7 , to the terminal (910). Thereafter, the terminal performs channel estimation at a periodically set interval (704) (920). At this time, when an emergency service, such as an XR service, occurs, the terminal or base station adaptively transmits and receives measurement gap change information by applying at least one of the methods described in the first or second embodiment (930). This allows the terminal to transmit and receive data during inactive measurement gaps and perform channel estimation during active measurement gaps. Furthermore, the terminal may be able to perform channel estimation without transmitting or receiving data during additional measurement gaps. Accordingly, through this, the terminal can adaptively perform channel estimation or transmit / receive data in the measurement gap interval by applying at least one of the methods described in the first or second embodiment in addition to performing channel estimation in the measurement gap interval based on a pre-set upper signal (940).

[0243] The above flowchart illustrates exemplary methods that can be implemented according to the principles of the present disclosure, and various modifications may be made to the methods depicted in the flowcharts herein. For example, although depicted as a series of steps, various steps in each drawing may overlap, occur in parallel, occur in different orders, or occur multiple times. In other instances, steps may be omitted or replaced with other steps.

[0244] FIG. 10 is a diagram illustrating the structure of a terminal in a wireless communication system according to one embodiment of the present disclosure.

[0245] Referring to FIG. 10, the terminal may include a transceiver, which refers to a terminal receiving unit (1000) and a terminal transmitting unit (1010), a memory (not shown), and a terminal processing unit (1005, or a terminal control unit or processor). Depending on the communication method of the terminal described above, the transceiver units (1000, 1010), the memory, and the terminal processing unit (1005) of the terminal may operate. However, the components of the terminal are not limited to the examples described above. For example, the terminal may include more or fewer components than the components described above. In addition, the transceiver, the memory, and the processor may be implemented in the form of a single chip.

[0246] A transceiver unit can transmit and receive signals to and from a base station. The signals may include control information and data. To this end, the transceiver unit may include an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts the frequency of a received signal. However, this is merely one embodiment of the transceiver unit, and the components of the transceiver unit are not limited to the RF transmitter and RF receiver.

[0247] Additionally, the transceiver can receive a signal through a wireless channel and output it to the processor, and transmit a signal output from the processor through the wireless channel.

[0248] Memory can store programs and data necessary for the terminal's operation. Furthermore, memory can store control information or data included in signals transmitted and received by the terminal. Memory can be comprised of a storage medium, such as ROM, RAM, a hard disk, CD-ROM, or DVD, or a combination of such storage media. Furthermore, there can be multiple memories.

[0249] Additionally, the processor can control a series of processes to enable the terminal to operate according to the aforementioned embodiments. There may be multiple processors, and the processors can perform component control operations of the terminal by executing programs stored in memory.

[0250] FIG. 11 is a diagram illustrating the structure of a base station in a wireless communication system according to one embodiment of the present disclosure.

[0251] Referring to FIG. 11, the base station may include a transceiver, which refers to a base station receiver (1100) and a base station transmitter (1110), a memory (not shown), and a base station processor (1105, or a base station control unit or processor). Depending on the communication method of the base station described above, the transceiver (1100, 1110), the memory, and the base station processor (1105) of the base station may operate. However, the components of the base station are not limited to the examples described above. For example, the base station may include more or fewer components than the components described above. In addition, the transceiver, the memory, and the processor may be implemented in the form of a single chip.

[0252] The transceiver can transmit and receive signals with the terminal. Here, the signals may include control information and data. To this end, the transceiver may be configured with an RF transmitter that up-converts and amplifies the frequency of a transmitted signal, and an RF receiver that low-noise amplifies and down-converts the frequency of a received signal. However, this is only one embodiment of the transceiver, and the components of the transceiver are not limited to the RF transmitter and RF receiver.

[0253] Additionally, the transceiver can receive a signal through a wireless channel and output it to the processor, and transmit the signal output from the processor through the wireless channel.

[0254] The memory can store programs and data necessary for the operation of the base station. Furthermore, the memory can store control information or data included in signals transmitted and received by the base station. The memory can be comprised of a storage medium, such as ROM, RAM, a hard disk, CD-ROM, or DVD, or a combination of such storage media. Furthermore, there can be multiple memories.

[0255] The processor can control a series of processes so that the base station can operate according to the embodiments of the present disclosure described above. There may be multiple processors, and the processors can perform component control operations of the base station by executing programs stored in memory.

[0256] The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0257] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present disclosure.

[0258] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, compact disc ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage device, magnetic cassette. Or, they may be stored in a memory configured as a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

[0259] Additionally, the program may be stored on an attachable storage device that is accessible via a communication network, such as the Internet, an intranet, a local area network (LAN), a wide local area network (WLAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device implementing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communication network may be connected to a device implementing an embodiment of the present disclosure.

[0260] In the specific embodiments of the present disclosure described above, components included in the invention are expressed singularly or plurally, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in plural may be composed of singular elements, or components expressed in singular may be composed of plural elements.

[0261] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are merely specific examples to easily explain the technical contents of the present disclosure and to help the understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. In other words, it will be apparent to those skilled in the art that other modifications based on the technical idea of ​​the present disclosure are possible. In addition, each of the above embodiments can be combined and operated with each other as needed. For example, parts of one embodiment of the present disclosure and parts of another embodiment can be combined with each other to operate a base station and a terminal. For example, parts of the first embodiment and the second embodiment of the present disclosure can be combined with each other to operate a base station and a terminal. In addition, although the above embodiments have been presented based on an FDD LTE system, other modifications based on the technical idea of ​​the above embodiments can be implemented with other systems such as a TDD LTE system, 5G, or NR system.

[0262] Meanwhile, the order of description in the drawings explaining the method of the present invention does not necessarily correspond to the order of execution, and the order of precedence may be changed or executed in parallel.

[0263] Alternatively, the drawings illustrating the method of the present invention may omit some components and include only some components within a scope that does not harm the essence of the present invention.

[0264] In addition, the method of the present invention may be implemented by combining some or all of the contents included in each embodiment within a scope that does not harm the essence of the invention.

[0265] Various embodiments of the present disclosure have been described above. The foregoing description of the present disclosure is for illustrative purposes only, and the embodiments of the present disclosure are not limited to the disclosed embodiments. Those skilled in the art will appreciate that the present disclosure can be readily modified into other specific forms without altering the technical spirit or essential characteristics of the present disclosure. The scope of the present disclosure is indicated by the claims described below rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present disclosure.

Claims

1. In a method performed by a terminal of a communication system, A step of receiving setting information on a measurement gap from a base station; A step of receiving DCI (downlink control information) including information indicating whether to perform measurement in a specific measurement gap from the base station; A step of determining whether to perform measurement in the specific measurement gap based on the above setting information and information indicating whether to perform the measurement; and A method characterized by comprising a step of performing the measurement or performing data transmission and reception in the specific measurement gap based on the above confirmation.

2. In paragraph 1, A method characterized in that the above DCI is a DCI that schedules data.

3. A method according to claim 1, characterized in that the specific measurement gap corresponds to one measurement gap.

4. A method according to claim 1, characterized in that the specific measurement gap exists after a specific offset from the last symbol of the CORESET (control resource set) in which the DCI is received.

5. In the method performed by the base station of the communication system, A step of transmitting setting information for a measurement gap to a terminal; A step of transmitting DCI (downlink control information) including information indicating whether to perform measurement in a specific measurement gap to the terminal; A method characterized in that whether the measurement is performed or data transmission and reception is performed in the specific measurement gap is based on the setting information and information indicating whether the measurement is performed.

6. In paragraph 5, A method characterized in that the above DCI is a DCI that schedules data.

7. A method according to claim 5, wherein the specific measurement gap corresponds to one measurement gap.

8. A method according to claim 5, wherein the specific measurement gap exists after a specific offset from the last symbol of the CORESET (control resource set) in which the DCI is received.

9. At the terminal of the communication system, Transmitter and receiver; and Receive setting information about the measurement gap from the base station, Receive DCI (downlink control information) including information indicating whether to perform measurement in a specific measurement gap from the base station, Determine whether to perform a measurement in the specific measurement gap based on the above setting information and the information indicating whether to perform the measurement, and A terminal characterized by including a control unit configured to perform the measurement or perform data transmission and reception in the specific measurement gap based on the above confirmation.

10. In paragraph 9, A terminal characterized in that the above DCI is a DCI for scheduling data.

11. A terminal according to claim 9, characterized in that the specific measurement gap corresponds to one measurement gap.

12. A terminal according to claim 9, wherein the specific measurement gap exists after a specific offset from the last symbol of the CORESET (control resource set) in which the DCI is received.

13. In a method performed by a base station of a communication system, Transmitter and receiver; and Transmits setting information about the measurement gap to the terminal, and A control unit configured to transmit DCI (downlink control information) including information indicating whether to perform measurement in a specific measurement gap to the terminal, A base station characterized in that whether measurement is performed or data transmission and reception is performed in the specific measurement gap is based on the setting information and information indicating whether the measurement is performed.

14. In paragraph 13, A base station, characterized in that the above DCI is a DCI for scheduling data.

15. A base station according to claim 13, characterized in that the specific measurement gap corresponds to one measurement gap.

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