KR20220053500A - Apparatus and method for transmitting and receiving data in non-terrestrial network system - Google Patents

Abstract

A wireless transmission and reception method performed by a terminal is provided. The wireless transmission and reception method includes the steps of: receiving query information for capability information of the terminal from a base station; transmitting the capability information of the terminal to the base station; and receiving information on the maximum number of hybrid automatic repeat request (HARQ) processes from the base station.

Description

Apparatus and method for transmitting and receiving data in a non-terrestrial network system

The present invention relates to a wireless communication system, and more particularly, to an apparatus and method for transmitting and receiving data in a non-terrestrial network system.

3GPP paved the way for commercial application of 5G by completing the first global 5G New Radio (NR) standard in Release (Rel)-15. In addition, NR-based Non-Terrestrial Network (NTN) is being considered as one of the evolutionary stages of NR for the activation of 5G and expansion of the ecosystem. Due to its wide service coverage capabilities and reduced vulnerability of space/air platforms to physical attacks and natural disasters, NTN provides unserviced areas (isolated or remote areas, on board aircraft or ships) and underserved areas ( It can provide 5G services in a cost-effective manner in suburban or rural areas). It also provides continuity of service to passengers on board M2M and IoT devices or mobile platforms (aircraft, ship, high-speed train, bus, etc.) Enables 5G service support. Together, it can support the availability of 5G networks by providing efficient multicast/broadcast resources for data delivery to the network edge or user terminals. These benefits can be provided through a standalone NTN or an integrated network of ground and non-terrestrial, and are expected to have an impact in transport, public safety, media and entertainment, eHealth, energy, agriculture, finance, automotive, and more. .

The NR-based NTN standardization study of the 3GPP RAN Working Group (WG) started through approval as a Rel-15 study item (SI) for RAN plenary and RAN1 at RAN#75, a RAN plenary meeting in March 2017. The purpose of the SI is to develop a channel model of NTN and study NTN scenario and the influence of NR accordingly, and it is summarized in Technical Report (TR) TR 38.811. Based on this, it was proposed as a Rel-16 item for standard issues requiring NTN standardization, and was approved as Rel-16 SI at the RAN#80 meeting in June 2018.

An object of the present invention is to provide an apparatus and method for transmitting and receiving data in a non-terrestrial network system.

According to one aspect of the present invention, there is provided a method of wireless transmission and reception performed by a terminal. The wireless transmission/reception method includes the steps of receiving query information on the capability information of the terminal from the base station, transmitting the capability information of the terminal to the base station, and the maximum number of HARQ (Hybrid Automatic Repeat request) processes from the base station. receiving information.

According to another aspect of the present invention, the capability information of the terminal includes the number of HARQ processes that the terminal can support.

According to another aspect of the present invention, the capability information of the terminal includes at least one of whether the terminal supports a Non-Terrestrial Network (NTN) or information on the size of an HARQ buffer that the terminal can support.

According to another aspect of the present invention, when the terminal supports the NTN, the maximum number of HARQ processes is set to be larger than when the NTN is not supported.

According to another aspect of the present invention, the maximum number of HARQ processes is implemented either 32 or 64.

According to another aspect of the present invention, when the number of HARQ processes indicates 0, the terminal deactivates HARQ feedback.

According to another aspect of the present invention, a wireless transmission/reception method performed by a base station is provided. The radio transmission/reception method includes the steps of transmitting query information for capability information of a terminal to the terminal, receiving capability information of the terminal, determining the number of Hybrid Automatic Repeat request (HARQ) processes, HARQ to the terminal and transmitting information regarding the number of processes.

According to another aspect of the present invention, the capability information of the terminal includes the number of HARQ processes that the terminal can support.

According to another aspect of the present invention, the number of HARQ processes is determined based on at least one of whether the terminals in the serving cell of the base station support NTN (Non-Terrestrial Network) and the buffer size of the terminal.

According to another aspect of the present invention, the number of HARQ processes is transmitted through a Radio Resource Control (RRC) message.

According to another aspect of the present invention, the number of HARQ processes is implemented as any one of 1 to 32.

According to another aspect of the present invention, when the number of HARQ processes indicates 0, deactivation of HARQ feedback is instructed to the terminal.

According to another aspect of the present invention, a terminal for performing radio transmission and reception is provided. The terminal receives query information on the capability information of the terminal from the base station, transmits the capability information of the terminal to the base station, and receives information about the maximum number of HARQ (Hybrid Automatic Repeat request) processes from the base station It includes a transceiver.

According to another aspect of the present invention, the capability information of the terminal includes the number of HARQ processes that the terminal can support.

According to another aspect of the present invention, the capability information of the terminal includes at least one of whether the terminal supports a Non-Terrestrial Network (NTN) or information on the size of an HARQ buffer that the terminal can support.

According to another aspect of the present invention, when the terminal supports the NTN, the maximum number of HARQ processes is set to be larger than when the NTN is not supported.

According to another aspect of the present invention, the maximum number of HARQ processes is implemented either 32 or 64.

According to another aspect of the present invention, when the number of HARQ processes indicates 0, the terminal deactivates HARQ feedback.

According to another aspect of the present invention, a base station for performing wireless transmission and reception is provided. The base station transmits query information on the capability information of the terminal to the terminal, receives the capability information of the terminal, and a transceiver and a HARQ (Hybrid Automatic Repeat request) for transmitting information on the maximum number of HARQ processes to the terminal ) includes a processor that determines the number of processes.

According to another aspect of the present invention, the capability information of the terminal includes the number of HARQ processes that the terminal can support.

According to another aspect of the present invention, the capability information of the terminal includes at least one of whether the terminal supports a Non-Terrestrial Network (NTN) or information on the size of an HARQ buffer that the terminal can support.

According to another aspect of the present invention, when the terminal supports the NTN, the maximum number of HARQ processes is set to be larger than when the NTN is not supported.

According to another aspect of the present invention, the maximum number of HARQ processes is implemented either 32 or 64.

According to another aspect of the present invention, when the number of HARQ processes indicates 0, deactivation of HARQ feedback is instructed to the terminal.

More efficient data transmission/reception is possible in a network cell included in the non-terrestrial network system. In addition, it is possible to perform more efficient HARQ operation.

1 is a conceptual diagram illustrating a wireless communication system according to an embodiment of the present invention.
2 is an exemplary diagram illustrating an NR system to which a data transmission method according to an embodiment of the present invention can be applied.
3 is a diagram for explaining a resource grid supported by a radio access technology to which this embodiment can be applied.
4 is a diagram for explaining a bandwidth part supported by a radio access technology to which the present embodiment can be applied.
5 is a diagram exemplarily illustrating a synchronization signal block in a radio access technology to which the present embodiment can be applied.
6 is a diagram for explaining a random access procedure in a radio access technology to which this embodiment can be applied.
7 is a diagram for explaining various forms of a non-terrestrial network structure to which an embodiment can be applied.
8 is a diagram for explaining a HARQ processing period for setting the number of HARQ processes.
9 is a flowchart illustrating a procedure for setting the number of HARQ processes according to an embodiment.
10 is a flowchart illustrating a procedure for setting the number of HARQ processes according to another embodiment.
11 shows a terminal and a network node in which an embodiment of the present invention is implemented.

Since the present invention can have various changes and can have various embodiments, specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention. In describing each figure, like reference numerals have been used for like elements.

In this specification, terms such as “first”, “second”, “A”, and “B” may be used to describe various components, but the components should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component. The term “and/or” also includes combinations of a plurality of related listed items or any of a plurality of related listed items.

When an element is referred to as being “connected” or “connected” to another element, it is understood that it may be directly connected or connected to the other element, but other elements may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that the other element does not exist in the middle.

The terminology used herein is used only to describe specific embodiments, and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In this specification, terms such as "comprise" or "have" are intended to designate that a feature, number, step, operation, component, part, or a combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, terms used herein have the same meanings as commonly understood by those of ordinary skill in the art to which the present invention belongs, including technical or scientific terms. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present specification. does not

Hereinafter, preferred embodiments according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a conceptual diagram illustrating a wireless communication system according to an embodiment of the present invention.

Referring to FIG. 1 , a wireless communication system 100 includes a plurality of communication nodes 110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3. , 130-4, 130-5, 130-6).

Each of the plurality of communication nodes may support at least one communication protocol. For example, each of the plurality of communication nodes is a CDMA (Code Division Multiple Access) based communication protocol, WCDMA (Wideband CDMA) based communication protocol, TDMA (Time Division Multiple Access) based communication protocol, FDMA (Frequency Division Multiple) Access) based communication protocol, OFDM (Orthogonal Frequency Division Multiplexing) based communication protocol, OFDMA (Orthogonal Frequency Division Multiple Access) based communication protocol, SC (Single Carrier)-FDMA based communication protocol, NOMA (Non-Orthogonal Multiplexing) Access)-based communication protocol, space division multiple access (SDMA)-based communication protocol, etc. may be supported.

The wireless communication system 100 includes a plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 and a plurality of user equipments 130-1, 130-2, 130-3, 130-4, 130-5, 130-6).

Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may form a macro cell. Each of the fourth base station 120-1 and the fifth base station 120-2 may form a small cell. The fourth base station 120-1, the third terminal 130-3, and the fourth terminal 130-4 may belong to the coverage of the first base station 110-1. The second terminal 130-2, the fourth terminal 130-4, and the fifth terminal 130-5 may belong to the coverage of the second base station 110-2. The fifth base station 120-2, the fourth terminal 130-4, the fifth terminal 130-5, and the sixth terminal 130-6 may belong to the coverage of the third base station 110-3. . The first terminal 130-1 may belong to the coverage of the fourth base station 120-1. The sixth terminal 130-6 may belong to the coverage of the fifth base station 120-2.

Here, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 is a NodeB, an evolved NodeB, and a next generation Node B (NodeB). B, gNB), BTS (Base Transceiver Station), radio base station (radio base station), radio transceiver (radio transceiver), access point (access point), access node (node), roadside unit (road side unit, RSU), DU (Digital Unit), CDU (Cloud Digital Unit), RRH (Radio Remote Head), RU (Radio Unit), TP (Transmission Point), TRP (transmission and reception point), to be referred to as a relay node (relay node), etc. can Each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6 is a terminal, an access terminal, a mobile terminal, It may be referred to as a station, a subscriber station, a mobile station, a portable subscriber station, a node, a device, and the like.

A plurality of communication nodes (110-1, 110-2, 110-3, 120-1, 120-2, 130-1, 130-2, 130-3, 130-4, 130-5, 130-6) Each can support cellular (cellular) communication (eg, long term evolution (LTE), LTE-A (advanced), NR (New Radio), etc. defined in the 3rd generation partnership project (3GPP) standard). Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may operate in different frequency bands or may operate in the same frequency band. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to each other through an ideal backhaul or a non-ideal backhaul, and the ideal backhaul Alternatively, information may be exchanged with each other through a non-ideal backhaul. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may be connected to a core network (not shown) through an ideal backhaul or a non-ideal backhaul. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 transmits a signal received from the core network to the corresponding terminals 130-1, 130-2, 130-3, 130 -4, 130-5, 130-6), and a signal received from the corresponding terminal (130-1, 130-2, 130-3, 130-4, 130-5, 130-6) is transmitted to the core network can be sent to

Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may support OFDM-based downlink transmission. In addition, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 may support OFDM or DFT-Spread-OFDM-based uplink transmission. In addition, each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 transmits multiple input multiple output (MIMO) (eg, single user (SU)-MIMO, MU (Multi User)-MIMO, massive MIMO, etc.), Coordinated Multipoint (CoMP) transmission, carrier aggregation transmission, transmission in an unlicensed band, direct device to device, D2D) communication (or Proximity services (ProSe)) may be supported, etc. Here, each of the plurality of terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6 Base stations 110-1, 110-2, 110-3, 120-1, 120-2 and corresponding operations and/or base stations 110-1, 110-2, 110-3, 120-1, 120-2 ) can perform operations supported by

For example, the second base station 110-2 may transmit a signal to the fourth terminal 130-4 based on the SU-MIMO method, and the fourth terminal 130-4 may transmit a signal based on the SU-MIMO method. A signal may be received from the second base station 110 - 2 . Alternatively, the second base station 110 - 2 may transmit a signal to the fourth terminal 130 - 4 and the fifth terminal 130 - 5 based on the MU-MIMO scheme, and the fourth terminal 130 - 4 . and each of the fifth terminals 130 - 5 may receive a signal from the second base station 110 - 2 by the MU-MIMO method. Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 may transmit a signal to the fourth terminal 130-4 based on the CoMP scheme, and the fourth The terminal 130-4 may receive signals from the first base station 110-1, the second base station 110-2, and the third base station 110-3 by the CoMP method. Each of the plurality of base stations 110-1, 110-2, 110-3, 120-1, and 120-2 includes the terminals 130-1, 130-2, 130-3, 130-4, 130-5, 130-6) and a signal may be transmitted/received based on the CA method.

Each of the first base station 110-1, the second base station 110-2, and the third base station 110-3 coordinates D2D communication between the fourth terminal 130-4 and the fifth terminal 130-5. (coordination), each of the fourth terminal 130-4 and the fifth terminal 130-5 is D2D communication by the coordination of each of the second base station 110-2 and the third base station 110-3 can be performed.

Hereinafter, even when a method (eg, transmission or reception of a signal) performed in a first communication node among communication nodes is described, a second communication node corresponding thereto corresponds to the method performed in the first communication node A method (eg, receiving or transmitting a signal) may be performed. That is, when the operation of the terminal is described, the corresponding base station may perform the operation corresponding to the operation of the terminal. Conversely, when the operation of the base station is described, the corresponding terminal may perform the operation corresponding to the operation of the base station.

Also, hereinafter, downlink (DL) means communication from a base station to a terminal, and uplink (UL) means communication from a terminal to a base station. In the downlink, the transmitter may be a part of the base station, and the receiver may be a part of the terminal. In the uplink, the transmitter may be a part of the terminal, and the receiver may be a part of the base station.

Recently, as the spread of smartphones and Internet of Things (IoT) terminals is rapidly spreading, the amount of information exchanged through a communication network is increasing. Accordingly, in the next-generation wireless access technology, an environment (eg, enhanced mobile broadband communication) that provides a faster service to more users than the existing communication system (or the existing radio access technology) )) needs to be considered. To this end, design of a communication system in consideration of MTC (Machine Type Communication) providing a service by connecting a plurality of devices and objects is being discussed. In addition, the design of a communication system (eg, URLLC (Ultra-Reliable and Low Latency Communication) that considers a service and/or terminal sensitive to communication reliability and/or latency) is being discussed

Hereinafter, in this specification, for convenience of description, the next-generation radio access technology is referred to as a New Radio Access Technology (RAT), and a wireless communication system to which the New RAT is applied is referred to as a New Radio (NR) system. In the present specification, NR-related frequencies, frames, subframes, resources, resource blocks, regions, bands, subbands, control channels, data channels, synchronization signals, various reference signals, various signals, or various messages are past or present. It can be interpreted in various meanings used or used in the future.

2 is an exemplary diagram illustrating an NR system to which a data transmission method according to an embodiment of the present invention can be applied.

NR, a next-generation wireless communication technology that is being standardized in 3GPP, provides an improved data rate compared to LTE, and is a radio access technology that can satisfy various QoS requirements required for each segmented and detailed usage scenario. . In particular, enhancement Mobile BroadBand (eMBB), massive MTC (mmTC), and Ultra Reliable and Low Latency Communications (URLLC) have been defined as representative usage scenarios of NR. As a method for satisfying the requirements for each scenario, a frame structure that is flexible compared to LTE is provided. The frame structure of NR supports a frame structure based on multiple subcarriers. The basic subcarrier spacing (SubCarrier Spacing, SCS) becomes 15 kHz, and 15 kHz*2^n (n=0, 1, 2, 3, 4) supports a total of 5 types of SCS.

Referring to Figure 2, the NG-RAN (Next Generation-Radio Access Network) is a control plane (RRC) protocol termination for the NG-RAN user plane (SDAP / PDCP / RLC / MAC / PHY) and UE (User Equipment) It is composed of gNBs that provide Here, NG-C represents a control plane interface used for the NG2 reference point between the NG-RAN and the 5GC (5 Generation Core). NG-U represents the user plane interface used for the NG3 reference point between NG-RAN and 5GC.

The gNBs are interconnected through the Xn interface and connected to the 5GC through the NG interface. More specifically, the gNB is connected to an Access and Mobility Management Function (AMF) through the NG-C interface and to a User Plane Function (UPF) through the NG-U interface.

In the NR system of FIG. 2, multiple numerologies may be supported. Here, the numerology may be defined by a subcarrier spacing and a cyclic prefix (CP) overhead. In this case, the plurality of subcarrier intervals may be derived by scaling the basic subcarrier interval by an integer. Also, although it is assumed that very low subcarrier spacing is not used at very high carrier frequencies, the numerology used can be selected independently of the frequency band.

In addition, in the NR system, various frame structures according to a number of numerologies may be supported.

<NR Waveform, Pneumologic and Frame Structure>

In NR, a CP-OFDM waveform using a cyclic prefix is used for downlink transmission, and CP-OFDM or DFT-S-OFDM is used for uplink transmission. OFDM technology is easy to combine with MIMO (Multiple Input Multiple Output), and has advantages of using a low-complexity receiver with high frequency efficiency.

Meanwhile, in NR, since the requirements for data rate, delay rate, coverage, etc. are different for each of the three scenarios described above, it is necessary to efficiently satisfy the requirements for each scenario through the frequency band constituting an arbitrary NR system. . To this end, a technique for efficiently multiplexing a plurality of different numerology-based radio resources has been proposed.

Specifically, the NR transmission numerology is determined based on sub-carrier spacing and cyclic prefix (CP), and the μ value is used as an exponential value of 2 based on 15 kHz as shown in Table 1 below. is changed to

μ subcarrier spacing
(kHz) Cyclic prefix Supported for data Supported for synch 0 15 Normal Yes Yes One 30 Normal Yes Yes 2 60 Normal, Extended Yes No 3 120 Normal Yes Yes 4 240 Normal No Yes

As shown in Table 1 above, the NR numerology can be divided into five types according to the subcarrier spacing. This is different from the fact that the subcarrier interval of LTE, one of the 4G communication technologies, is fixed at 15 kHz. Specifically, in NR, subcarrier intervals used for data transmission are 15, 30, 60, and 120 kHz, and subcarrier intervals used for synchronization signal transmission are 15, 30, 120, 240 kHz. In addition, the extended CP is applied only to the 60 kHz subcarrier interval. On the other hand, as for the frame structure in NR, a frame having a length of 10 ms is defined, which is composed of 10 subframes having the same length of 1 ms. One frame can be divided into half frames of 5 ms, and each half frame includes 5 subframes. In the case of a 15 kHz subcarrier interval, one subframe consists of one slot, and each slot consists of 14 OFDM symbols.

<NR Physical Resources>

In relation to a physical resource in NR, an antenna port, a resource grid, a resource element, a resource block, a bandwidth part, etc. are considered do.

An antenna port is defined such that a channel on which a symbol on an antenna port is carried can be inferred from a channel on which another symbol on the same antenna port is carried. When the large-scale property of a channel on which a symbol on one antenna port is carried can be inferred from a channel on which a symbol on another antenna port is carried, the two antenna ports are QC/QCL (quasi co-located or It can be said that there is a quasi co-location) relationship. Here, the wide range characteristic includes at least one of a delay spread, a Doppler spread, a Doppler shift, an average delay, and a spatial Rx parameter.

3 is a diagram for explaining a resource grid supported by a radio access technology to which this embodiment can be applied.

Referring to FIG. 3 , in the resource grid, since NR supports a plurality of numerologies on the same carrier, a resource grid may exist according to each numerology. In addition, the resource grid may exist according to an antenna port, a subcarrier interval, and a transmission direction.

A resource block consists of 12 subcarriers, and is defined only in the frequency domain. In addition, a resource element is composed of one OFDM symbol and one subcarrier. Accordingly, as in FIG. 3 , the size of one resource block may vary according to the subcarrier interval. In addition, NR defines "Point A" serving as a common reference point for a resource block grid, a common resource block, a physical resource block, and the like.

4 is a diagram for explaining a bandwidth part supported by a radio access technology to which the present embodiment can be applied.

In NR, unlike LTE in which the carrier bandwidth is fixed at 20 MHz, the maximum carrier bandwidth is set from 50 MHz to 400 MHz for each subcarrier interval. Therefore, it is not assumed that all terminals use all of these carrier bandwidths. Accordingly, in NR, as shown in FIG. 4, a bandwidth part (BWP) may be designated within the carrier bandwidth and used by the terminal. In addition, the bandwidth part is associated with one neurology and is composed of a subset of continuous common resource blocks, and may be dynamically activated according to time. Up to four bandwidth parts are configured in the terminal, respectively, in uplink and downlink, and data is transmitted/received using the activated bandwidth part at a given time.

In the case of a paired spectrum, the uplink and downlink bandwidth parts are set independently, and in the case of an unpaired spectrum, to prevent unnecessary frequency re-tunning between downlink and uplink operations For this purpose, the downlink and uplink bandwidth parts are set in pairs to share a center frequency.

<NR Initial Connection>

In NR, the terminal accesses the base station and performs a cell search and random access procedure in order to perform communication.

Cell search is a procedure in which the terminal synchronizes with the cell of the corresponding base station using a synchronization signal block (SSB) transmitted by the base station, obtains a physical layer cell ID, and obtains system information.

5 is a diagram exemplarily illustrating a synchronization signal block in a radio access technology to which the present embodiment can be applied.

Referring to FIG. 5, the SSB consists of a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS) occupying 1 symbol and 127 subcarriers, respectively, and a PBCH spanning 3 OFDM symbols and 240 subcarriers. .

The UE receives the SSB by monitoring the SSB in the time and frequency domains.

SSB can be transmitted up to 64 times in 5ms. A plurality of SSBs are transmitted using different transmission beams within 5 ms, and the UE performs detection on the assumption that SSBs are transmitted every 20 ms when viewed based on one specific beam used for transmission. The number of beams that can be used for SSB transmission within 5 ms time may increase as the frequency band increases. For example, up to 4 SSB beams can be transmitted in 3 GHz or less, and SSB can be transmitted using up to 8 different beams in a frequency band of 3 to 6 GHz and up to 64 different beams in a frequency band of 6 GHz or more.

Two SSBs are included in one slot, and the start symbol and the number of repetitions within the slot are determined according to the subcarrier interval as follows.

On the other hand, the SSB is not transmitted at the center frequency of the carrier bandwidth, unlike the SS of the conventional LTE. That is, the SSB may be transmitted in a place other than the center of the system band, and a plurality of SSBs may be transmitted in the frequency domain when wideband operation is supported. Accordingly, the UE monitors the SSB using a synchronization raster that is a candidate frequency location for monitoring the SSB. The carrier raster and synchronization raster, which are the center frequency location information of the channel for initial access, are newly defined in NR. Compared to the carrier raster, the synchronization raster has a wider frequency interval than that of the carrier raster. can

The UE may acquire the MIB through the PBCH of the SSB. MIB (Master Information Block) includes minimum information for the terminal to receive the remaining system information (RMSI, Remaining Minimum System Information) broadcast by the network. In addition, the PBCH includes information on the position of the first DM-RS symbol in the time domain, information for the UE to monitor SIB1 (eg, SIB1 neurology information, information related to SIB1 CORESET, search space information, PDCCH related parameter information, etc.), offset information between the common resource block and the SSB (the position of the absolute SSB in the carrier is transmitted through SIB1), and the like. Here, the SIB1 neurology information is equally applied to some messages used in the random access procedure for accessing the base station after the UE completes the cell search procedure. For example, the neurology information of SIB1 may be applied to at least one of messages 1 to 4 for the random access procedure.

The aforementioned RMSI may mean System Information Block 1 (SIB1), and SIB1 is periodically broadcast (eg, 160 ms) in the cell. SIB1 includes information necessary for the UE to perform an initial random access procedure, and is periodically transmitted through the PDSCH. In order for the UE to receive SIB1, it must receive neurology information used for SIB1 transmission and CORESET (Control Resource Set) information used for scheduling SIB1 through the PBCH. The UE checks scheduling information for SIB1 by using SI-RNTI in CORESET, and acquires SIB1 on PDSCH according to the scheduling information. SIBs other than SIB1 may be transmitted periodically or may be transmitted according to the request of the terminal.

6 is a diagram for explaining a random access procedure in a radio access technology to which this embodiment can be applied.

Referring to FIG. 6 , upon completion of cell search, the terminal transmits a random access preamble for random access to the base station. The random access preamble is transmitted through the PRACH. Specifically, the random access preamble is transmitted to the base station through a PRACH consisting of continuous radio resources in a specific slot that is periodically repeated. In general, when a UE initially accesses a cell, a contention-based random access procedure is performed, and when random access is performed for beam failure recovery (BFR), a contention-free random access procedure is performed.

The terminal receives a random access response to the transmitted random access preamble. The random access response may include a random access preamble identifier (ID), a UL grant (uplink radio resource), a Temporary Cell - Radio Network Temporary Identifier (TC-RNTI), and a Time Advance Command (TAC). Since one random access response may include random access response information for one or more UEs, the random access preamble identifier may be included to inform which UE the included UL Grant, TC-RNTI, and TAC are valid. The random access preamble identifier may be an identifier for the random access preamble received by the base station. The TAC may be included as information for the UE to adjust uplink synchronization. The random access response may be indicated by a random access identifier on the PDCCH, that is, RA-RNTI (Random Access - Radio Network Temporary Identifier).

Upon receiving the valid random access response, the terminal processes information included in the random access response and performs scheduled transmission to the base station. For example, the UE applies the TAC and stores the TC-RNTI. In addition, data stored in the buffer of the terminal or newly generated data is transmitted to the base station by using the UL grant. In this case, information for identifying the terminal should be included.

Non-Terrestrial Network

A non-terrestrial network refers to a network or a segment of a network using airborne vehicles such as a High Altitude Platform (HAPS) or a spaceborne vehicle such as a satellite. According to NTN defined in 3GPP, an artificial satellite is a network node that is connected to a terminal through wireless communication and provides a wireless access service to the terminal. In one aspect, a satellite in NTN may be configured to perform the same or similar functions and operations as a base station in a terrestrial network. In this case, from the viewpoint of the terminal, the artificial satellite may be recognized as another base station. In that respect, the artificial satellite introduced herein may be a concept included in a base station in a broad sense. That is, a person skilled in the art can obviously derive an embodiment in which the base station is replaced with a satellite from the embodiments depicting the base station or describing the function of the base station. Accordingly, even if such embodiments are not explicitly disclosed herein, such embodiments fall within the scope of the present specification and the spirit of the present invention.

3GPP is developing a technology for supporting NR operation in a non-terrestrial network using the aforementioned satellite or air transport vehicle. However, in a non-terrestrial network, the distance between a base station and a terminal is longer than in a terrestrial network using a terrestrial base station. This can result in very large round trip delays (RTDs). For example, in the NTN scenario using Geostationary Earth Orbiting (GEO) located at an altitude of 35,768 km, the RTD is 544.751 ms, and in the NTN scenario using HAPS located at an altitude of 229 km, the RTD is known to be 3.053 ms. In addition, the RTD in the NTN scenario using the LEO (Low Earth Orbiting) satellite system can appear up to 25.76ms. As described above, in order to perform a communication operation to which the NR protocol is applied in a non-terrestrial network, a technology for supporting the base station and the terminal to perform the NR operation is required even under such propagation delay.

7 is a diagram for explaining various forms of a non-terrestrial network structure to which an embodiment can be applied.

Referring to FIG. 7 , the non-terrestrial network may be designed in a structure in which a terminal performs wireless communication using a device located in the sky. For example, the non-terrestrial network may be implemented in a structure in which a satellite or air transport device is positioned between a terminal and a base station (gNB) to relay communication, such as in the 710 structure. As another example, the non-terrestrial network may be implemented in a structure in which a satellite or air transport apparatus performs some or all of the functions of a base station (gNB) to perform communication with a terminal, such as a 720 structure. As another example, the non-terrestrial network may be implemented in a structure in which a satellite or air transport device is positioned between a relay node and a base station (gNB) to relay communication, such as in the 730 structure. As another example, the non-terrestrial network may be implemented in a structure in which a satellite or air transport device performs some or all of the functions of a base station (gNB) to perform communication with a relay node, such as in the 740 structure.

Therefore, in this specification, a configuration for performing communication with a terminal in connection with a core network is described as a network node or a base station, but this may refer to the aforementioned airborne vehicles or spaceborne vehicles. If necessary, a network node or a base station may refer to the same device or may be used to distinguish different devices according to a non-terrestrial network structure.

That is, a network node or a base station refers to an apparatus for transmitting and receiving data to and from a terminal in a non-terrestrial network structure, and controlling an access procedure and data transmission/reception procedure of the terminal. Accordingly, when the airborne vehicles or the spaceborne vehicle apparatus performs some or all of the functions of the base station, the network node or the base station may refer to an airborne vehicle or a spaceborne vehicle apparatus. On the other hand, when airborne vehicles or spaceborne vehicles perform a role of relaying signals of separate terrestrial base stations, a network node or base station may refer to a terrestrial base station.

Each embodiment provided below may be applied to an NR terminal through an NR base station or may be applied to an LTE terminal through an LTE base station. In addition, each embodiment provided below can be applied to an LTE terminal that connects to an eLTE base station connected through a 5G system (or 5G Core Network), and EN-DC (E-UTRA NR) that provides LTE and NR wireless connection at the same time Dual Connectivity) terminal or NE-DC (NR E-UTRA Dual Connectivity) terminal may be applied.

HARQ operation in non-terrestrial networks

In NR, the HARQ retransmission scheme is applied to improve data reliability. In the case of synchronous HARQ, the retransmission time is systematically promised. Accordingly, the uplink grant message sent by the base station to the terminal needs only to be transmitted during initial transmission, and subsequent retransmission is performed by the ACK/NACK signal. In the case of asynchronous HARQ, since retransmission times are not promised to each other, the base station must send a retransmission request message to the terminal. In addition, in the case of non-adaptive HARQ, the frequency resource or MCS for retransmission is the same as the previous transmission, and in the case of adaptive HARQ, the frequency resource or MCS for retransmission may be different from the previous transmission. For example, in the case of the asynchronous adaptive HARQ method, since the frequency resource or MCS for retransmission varies for each transmission time, the retransmission request message may include UE ID, RB allocation information, HARQ process ID/number, RV, and NDI information. .

For NR, asynchronous adaptive HARQ is supported in downlink transmission. The base station may provide the HARQ-ACK feedback timing to the terminal dynamically in DCI or semi-statically in the RRC configuration. According to the 3GPP TS 38.321 MAC standard, the MAC entity includes one HARQ entity for each serving cell, and each HARQ entity maintains 16 downlink HARQ processes. Each HARQ process is associated with a HARQ process identifier (HARQ process identifier). HARQ functions to ensure delivery between the terminal and the base station in the physical layer. According to the TS 38.321 MAC standard, the HARQ operation (HARQ Operation/HARQ Procedure) for this is as follows. First, in downlink transmission, uplink feedback (HARQ feedback) is performed in response to downlink transmission/retransmission on PUCCH or PUSCH. Next, in uplink transmission, uplink HARQ retransmission may be triggered without waiting for feedback on previous transmission.

In addition, NR supports asynchronous (Asynchronous) adaptive (Adaptive) HARQ in uplink transmission. The base station schedules uplink transmission and retransmission using the uplink grant on DCI. The MAC entity includes one HARQ entity for each serving cell, and each HARQ entity maintains 16 uplink HARQ processes.

However, HARQ RTT (Round Trip Time) in general NR is several ms units, whereas in non-terrestrial networks, propagation delay can range from several ms to hundreds of ms depending on the orbit of the satellite, so HARQ RTT in non-terrestrial networks can be much larger than NR. Therefore, in the case of a non-terrestrial network, it is necessary to improve the optimization of HARQ, such as whether the number of HARQ processes should be extended and a method for indicating the extended number of HARQ processes.

According to an embodiment of the present invention, an apparatus and method for setting an HARQ process in a non-terrestrial network are provided. As mentioned above, the 3GPP NR communication system is designed to support a maximum of 16 HARQ processes. As shown in FIG. 8 , the number of HARQ processes is based on a maximum period during which a base station transmits a data transport block and a new transmission or retransmission is performed after receiving an ACK/NACK from the terminal.

Theoretically, the number of HARQ processes can increase as much as RTT. In NR, HARQ RTT is a few milliseconds. On the other hand, since propagation delay in NTN can range from a few ms to hundreds of ms depending on the satellite orbit, the HARQ RTT of NTN can be much larger compared to NR. Therefore, NTN requires a change in the HARQ method such as the number of HARQ processes due to a large RTT. For example, assuming that the subcarrier spacing (SCS) is 120 kHz in the NTN environment in which a round trip delay (RTD) of 32 ms exists, the number of HARQ processes can be accommodated up to 256. However, this is feasible only when the terminal supports a very large buffer (memory) size and process performance. Therefore, the problem of increasing the number of HARQ processes is ultimately directly related to the problem of the terminal's capability, and accordingly, a procedure for setting the appropriate number of HARQ processes between the terminal and the base station is required.

Set the number of HARQ processes

In order for the base station or the network node to set the appropriate number of HARQ processes for the terminal in the NTN system, the terminal needs to know information about the number of HARQ processes that can be supported first. To this end, the terminal must be able to inform the base station of the maximum number of HARQ processes that it can support, either explicitly or implicitly.

<Explicit method>

The explicit method includes explicitly notifying the base station of the number of HARQ processes that the terminal can support, and the base station determining and setting the number of HARQ processes based on this. For this, information on the number of HARQ processes supported by UE may be used.

About the number of HARQ processes that can be supported

Supported number of HARQ processes information (SupportedNumOfHARQ-processes) is an RRC message, for example, indicates any one of 8, 16, 32, and 64, and may be expressed in the syntax shown in Table 2.

SupportedNumOfHARQ-processes ENUMERATED {n8, n16, n32, n64} OPTIONAL, -- Need S

How to transmit information on the number of supported HARQ processes

Information on the number of supportable HARQ processes may be transmitted from the terminal to the base station in various ways.

As an example, information on the number of supportable HARQ processes may be transmitted while being included in UE NR capability information. In this case, the capability information of the terminal may be defined as shown in Table 3.

Referring to Table 3, the terminal capability information includes physical layer parameters (phy-Parameters). The physical layer parameters again include common physical layer parameter (Phy-ParametersCommon) information. Table 4 is a part of exemplary common physical layer parameter information.

Referring to Table 4, the physical layer parameter includes information on the number of supportable HARQ processes (SupportedNumOfHARQ-processes). However, this shows an embodiment in which information on the number of supportable HARQ processes is included in the terminal capability information, and it goes without saying that the information on the number of supportable HARQ processes may be included in another field in the terminal capability information.

Procedure for setting the number of HARQ processes

9 is a flowchart illustrating a procedure for setting the number of HARQ processes according to an embodiment. This is exemplarily accompanied by a procedure for transmitting terminal capability information.

Referring to FIG. 9 , the base station transmits inquiry information for inquiring terminal capability information to the terminal (S910). The query information includes information for querying the number of HARQ processes that the UE can support.

The terminal transmits terminal capability information including information on the number of supportable HARQ processes to the base station (S920).

The base station determines the number of HARQ processes to be used for uplink transmission or downlink transmission in the serving cell based on information on the number of supportable HARQ processes (S930). Here, the serving cell may be a cell configured for NTN. The number of HARQ processes is determined in consideration of various parameters such as whether the terminals support NTN in the serving cell and the buffer size of the terminal. As an example, when the number of HARQ processes supported by all terminals in the NTN serving cell is 32, the base station may determine the number of 32 HARQ processes for the terminal.

The base station transmits an RRC message including information on the set number of HARQ processes to the terminal (S940). Here, the RRC message may be configured grant configuration information (ConfiguredGrantConfig) or serving cell configuration information for PDSCH (PDSCH-ServingCellConfig).

When the RRC message is configured grant configuration information, it may be defined as shown in Table 5.

Referring to Table 5, the determined number of HARQ processes (nrofHARQ-Processes) may be any one of 1 to 32.

When the RRC message is serving cell configuration information for the PDSCH, it may be defined as shown in Table 6.

Referring to Table 6, the number of HARQ processes determined for the PDSCH (nrofHARQ-ProcessesForPDSCH) may be any one of 2, 4, 6, 10, 12, 16, or 32.

Meanwhile, according to an embodiment of the present invention, a method of disabling the HARQ procedure may be considered in consideration of the limit on the extension of the number of HARQ processes reflecting the increased RTD of the non-terrestrial network. Deactivation of HARQ feedback may follow the HARQ deactivation instruction through DCI in one aspect. In another aspect, HARQ deactivation may be indicated by setting and forwarding the number of HARQ processes to zero. For example, the number of HARQ processes through the RRC message (nrofHARQ-ProcessesForPDSCH) may be set to 0 to indicate deactivation of the HARQ procedure. Meanwhile, according to one aspect, deactivation of the HARQ procedure may be performed by the terminal. For example, the UE may transmit information on the number of supportable HARQ processes (SupportedNumOfHARQ-processes) to 0 and transmit it to the network node. For example, the HARQ process number information may be transmitted to the network node through an RRC message, but is not limited thereto.

<Implicit Method>

The implicit method includes information for inferring the maximum number of HARQ processes supported by the terminal to the base station, and the base station sets the appropriate number of HARQ processes for the terminal based on this information.

Information from which the maximum number of HARQ processes can be inferred is a parameter used by the base station to determine the number of HARQ processes. Hereinafter, information from which the maximum number of HARQ processes can be inferred is abbreviated and referred to as a “decision parameter”. The determination parameters are described in detail below.

decision parameters

As an example, the determination parameter may include information on whether the terminal supports NTN (or flag information). In order for the UE to support NTN, it should be designed to support at least the number of HARQ processes (eg, 32 or more) suitable for NTN. Accordingly, that the UE supports NTN may mean that the UE supports the number of HARQ processes greater than 16 required for NR. Accordingly, the base station may determine and set the maximum number of HARQ processes for the terminal to 32 suitable for NTN based on NTN support information. For example, if the NTN support information indicates that NTN is supported, the number of HARQ processes by the base station is larger (for example, up to 32) than the maximum number of HARQ processes generally supported by NR (for example, 16) can be set. Alternatively, if the NTN support information indicates that NTN is not supported, the number of HARQ processes may be set by the base station to be less than or equal to the maximum number of HARQ processes generally supported by NR (eg, 16).

Here, the description of the maximum number of HARQ processes suitable for NTN as 32 is an example, and of course, it may be a number larger than this.

As another example, the determination parameter may include information on the size of the HARQ buffer supportable by the UE. In order to support a larger number of HARQ processes, the UE must have a larger HARQ buffer than in the prior art. Accordingly, the fact that the size information of the HARQ buffer is larger than that of the prior art may mean that the UE supports the number of HARQ processes greater than 16 required for NR. Accordingly, the base station may determine and set the number of HARQ processes for the terminal to 32 suitable for NTN based on the size information of the HARQ buffer. Here, the description of the number of HARQ processes suitable for NTN as 32 is an example, and of course it can be a larger number than this.

As another example, the determination parameter may include both information on whether the UE supports NTN and information on the size of a supportable HARQ buffer. Even if the UE supports NTN, the size of the actual HARQ buffer may not be able to handle the increased number of HARQ processes. In this case, the base station should appropriately determine the number of HARQ processes according to the size of the HARQ buffer. Conversely, although the size of the HARQ buffer can sufficiently cover the number of HARQ processes required for NTN, there may be cases in which the UE does not support NTN. In this case, the base station must operate the number of HARQ processes according to the existing NR.

As such, the determination parameter is information that helps the base station to determine the maximum number of HARQ processes for the NTN, and one or two or more may be used in combination, and either parameter may act as a constraint in determining the number of HARQ processes. there is.

How to transmit decision parameters

Various methods may be used for the procedure in which the terminal transmits the determination parameter to the base station. As an example, the determination parameter may be transmitted while being included in UE NR capability information. In this case, the capability information of the terminal may be defined as shown in Table 3 above.

Procedure for setting the number of HARQ processes

10 is a flowchart illustrating a procedure for setting the number of HARQ processes according to another embodiment. Of course, this is only an example, and the procedure for setting the number of HARQ processes based on the determination parameter may be performed along with the transmission procedure of the terminal capability information as well as the transmission procedure of other RRC messages.

Referring to FIG. 10 , the base station transmits inquiry information for inquiring terminal capability information to the terminal ( S1010 ).

The terminal transmits terminal capability information including the determination parameter to the base station (S1020).

The base station determines the number of HARQ processes to be used for uplink transmission or downlink transmission in the serving cell based on at least one determination parameter (S1030). Here, the serving cell may be a cell configured for NTN. The number of HARQ processes is determined in consideration of various parameters such as whether the terminals support NTN in the serving cell and the buffer size of the terminal. As an example, when the number of HARQ processes supported by all terminals in the NTN serving cell is 32, the base station may determine the maximum number of HARQ processes for the terminal. As another example, even if the UE supports NTN, the size of the actual HARQ buffer may not be able to handle the increased number of HARQ processes. In this case, the base station may determine the number of HARQ processes to be 32 or less (eg, 16) according to the size of the HARQ buffer. Conversely, although the size of the HARQ buffer can sufficiently cover the number of HARQ processes required for NTN, there may be cases in which the UE does not support NTN. Even in this case, the base station determines the number of HARQ processes according to the existing NR.

The base station transmits an RRC message including information on the set number of HARQ processes to the terminal (S1040). Here, the RRC message may be configured grant configuration information (ConfiguredGrantConfig) or serving cell configuration information for PDSCH (PDSCH-ServingCellConfig).

When the RRC message is configured grant configuration information, it may be defined as shown in Table 7.

Referring to Table 7, the determined number of HARQ processes (nrofHARQ-Processes) may be any one of 1 to 32.

When the RRC message is serving cell configuration information for the PDSCH, it may be defined as shown in Table 8.

Referring to Table 8, the number of HARQ processes determined for the PDSCH (nrofHARQ-ProcessesForPDSCH) may be any one of 2, 4, 6, 10, 12, 16, or 32.

Meanwhile, as described above, according to an embodiment of the present invention, a method of disabling the HARQ procedure may be considered in the non-terrestrial network. Implicitly, a method of deactivating the HARQ procedure based on the measured RTT information may be considered. For example, a network node such as a base station may receive a determination parameter from the terminal and deactivate the HARQ procedure based on the determination parameter, for example, the determination parameter may include RTT-related information measured in the terminal, HARQ may be deactivated in response to determining that the RTT exceeds a predetermined threshold. In another aspect, the network node may directly measure the RTT with the UE, and may deactivate the HARQ procedure based on the measured RTT. According to one aspect, deactivation of HARQ may be indicated to the terminal by indicating by setting the number of HARQ processes to 0.

Meanwhile, according to one aspect, deactivation of the HARQ procedure may be performed by the terminal. For example, the UE may measure the RTT and determine HARQ deactivation in response to determining that the measured RTT exceeds a predetermined threshold. According to one aspect, when HARQ deactivation is determined, the terminal may transmit information on the number of supportable HARQ processes (SupportedNumOfHARQ-processes) to 0 and transmit it to the network node. For example, the HARQ process number information may be transmitted to the network node through an RRC message, but is not limited thereto.

11 shows a terminal and a network node in which an embodiment of the present invention is implemented.

Referring to FIG. 11 , the terminal 1100 includes a processor 1110 , a memory 1120 , and a transceiver 1130 . The processor 1110 may be configured to implement functions, processes and/or methods of a terminal described in this specification. The layers of the air interface protocol may be implemented in the processor 1110 .

The memory 1120 is connected to the processor 1110 and stores various information for driving the processor 1110 . The transceiver 1130 is connected to the processor 1110 to transmit a radio signal to the network node 1200 or receive a radio signal from the network node 1200 .

The network node 1200 includes a processor 1210 , a memory 1220 , and a transceiver 1230 . In this embodiment, the network node 1200 is a node of a non-terrestrial network, and may include an artificial satellite that performs a radio access procedure according to the present specification. Alternatively, in the present embodiment, the network node 1200 is a node of a terrestrial network, and may include a base station that performs a radio access procedure according to the present specification.

The processor 1210 may be configured to implement the functions, processes and/or methods of a network node or base station described herein. The layers of the air interface protocol may be implemented in the processor 1210 . The memory 1220 is connected to the processor 1210 and stores various information for driving the processor 1210 . The transceiver 1230 is connected to the processor 1210 to transmit a radio signal to the terminal 1100 or receive a radio signal from the terminal 1100 .

The processors 1110 and 1210 may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits, and/or data processing devices. The memories 1120 and 1220 may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media, and/or other storage devices. The transceivers 1130 and 1230 may include a baseband circuit for processing a radio frequency signal. When the embodiment is implemented in software, the above-described technique may be implemented as a module (process, function, etc.) that performs the above-described function. The modules may be stored in the memories 1120 and 1220 and executed by the processors 1110 and 1210 . The memories 1120 and 1220 may be inside or outside the processors 1110 and 1210 , and may be connected to the processors 1110 and 1210 through various well-known means.

In the exemplary system described above, methods that can be implemented according to the features of the present invention described above have been described on the basis of a flowchart. For convenience, the methods have been described as a series of steps or blocks, but the claimed features of the invention are not limited to the order of steps or blocks, and some steps may occur in a different order or concurrently with other steps as described above. In addition, those skilled in the art will understand that the steps shown in the flowchart are not exhaustive and that other steps may be included or that one or more steps in the flowchart may be deleted without affecting the scope of the present invention.

Claims (20)

In the wireless transmission/reception method performed by a terminal,
Receiving query information on the capability information of the terminal from the base station;
transmitting capability information of the terminal to the base station; and
Receiving information on the maximum number of Hybrid Automatic Repeat request (HARQ) processes from the base station
A wireless transmission/reception method comprising a. According to claim 1,
The capability information of the terminal is a radio transmission/reception method, characterized in that it includes the number of HARQ processes that the terminal can support. According to claim 1,
The capability information of the terminal includes at least one of whether the terminal supports a non-terrestrial network (NTN) or information on the size of an HARQ buffer that the terminal supports. 4. The method of claim 3,
When the terminal supports the NTN, the maximum number of HARQ processes is set to be larger than when the NTN is not supported. 5. The method of claim 4,
The wireless transmission/reception method, characterized in that the maximum number of HARQ processes is either 32 or 64. In the wireless transmission/reception method performed by a base station,
transmitting query information on the capability information of the terminal to the terminal;
receiving capability information of the terminal;
determining a number of Hybrid Automatic Repeat request (HARQ) processes;
Transmitting information about the number of HARQ processes to the terminal
A wireless transmission/reception method comprising a. 7. The method of claim 6,
The capability information of the terminal is a radio transmission/reception method, characterized in that it includes the number of HARQ processes that the terminal can support. 7. The method of claim 6,
The capability information of the terminal includes at least one of whether the terminal supports a non-terrestrial network (NTN), or information on the size of an HARQ buffer that the terminal supports. 9. The method of claim 8,
When the terminal supports the NTN, the maximum number of HARQ processes is set to be larger than when the NTN is not supported. 10. The method of claim 9,
The wireless transmission/reception method, characterized in that the maximum number of HARQ processes is either 32 or 64. Receiving query information about the capability information of the terminal from the base station,
Transmitting the capability information of the terminal to the base station,
Transceiver for receiving information on the number of HARQ (Hybrid Automatic Repeat request) processes from the base station
A terminal comprising a. 12. The method of claim 11,
The terminal's capability information is a terminal, characterized in that it includes the number of HARQ processes that the terminal can support. 12. The method of claim 11,
The terminal capability information includes at least one of whether the terminal supports a Non-Terrestrial Network (NTN) or information on the size of an HARQ buffer that the terminal supports. 14. The method of claim 13,
When the terminal supports the NTN, the maximum number of HARQ processes is set to be larger than when the terminal does not support the NTN. 15. The method of claim 14,
The terminal, characterized in that the number of the HARQ process is either 32 or 64. Transmitting query information on the capability information of the terminal to the terminal,
Receive the capability information of the terminal,
a transceiver for transmitting information on the number of HARQ processes to the terminal; and
Processor that determines the number of Hybrid Automatic Repeat request (HARQ) processes
A base station comprising a. 17. The method of claim 16,
The capability information of the terminal is a base station, characterized in that it includes the number of HARQ processes that the terminal can support. 17. The method of claim 16,
The capability information of the terminal includes at least one of whether the terminal supports a Non-Terrestrial Network (NTN) or information on the size of an HARQ buffer that the terminal can support. 19. The method of claim 18,
The base station, characterized in that when the terminal supports the NTN, the maximum number of HARQ processes is set to be larger than when the NTN is not supported. 20. The method of claim 19,
The base station, characterized in that the maximum number of HARQ processes is either 32 or 64.

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