KR20210017947A - Apparatus and method for transmitting uplink datat in wireless communication system - Google Patents

Abstract

The present disclosure relates to a 5^th generation (5G) or pre-5G communication system for supporting a data transfer rate higher than that of a 4^th generation (4G) communication system such as a long-term evolution (LTE) system. The present disclosure is provided to transmit uplink data in a wireless communication system. A method for operating a terminal comprises the steps of: storing first data in a pending buffer when transmission of the first data fails in a first uplink resource allocated for transmission of the first data; and transmitting at least a portion of the first data in a second uplink resource allocated for transmission of second data. Therefore, the transfer rate can be increased.

Description

Apparatus and method for transmitting uplink data in a wireless communication system {APPARATUS AND METHOD FOR TRANSMITTING UPLINK DATAT IN WIRELESS COMMUNICATION SYSTEM}

The present disclosure generally relates to a wireless communication system, and more particularly, to an apparatus and method for transmitting uplink data in a wireless communication system.

4G (4 ^th generation) to meet the traffic demand in the radio data communication system increases since the commercialization trend, efforts to develop improved 5G (5 ^th generation) communication system, or pre-5G communication system have been made. For this reason, the 5G communication system or the pre-5G communication system is called a Beyond 4G Network communication system or a Long Term Evolution (LTE) system (Post LTE) system.

In order to achieve a high data rate, the 5G communication system is being considered for implementation in the ultra-high frequency (mmWave) band (for example, the 60 gigabyte (60 GHz) band). In order to mitigate the path loss of radio waves in the ultra-high frequency band and increase the transmission distance of radio waves, in 5G communication systems, beamforming, massive MIMO, and Full Dimensional MIMO (FD-MIMO) ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed.

In addition, in order to improve the network of the system, in 5G communication system, advanced small cell, advanced small cell, cloud radio access network (cloud RAN), ultra-dense network , Device to Device communication (D2D), wireless backhaul, moving network, cooperative communication, CoMP (Coordinated Multi-Points), and interference cancellation And other technologies are being developed.

In addition, in the 5G system, the advanced coding modulation (Advanced Coding Modulation, ACM) method of FQAM (Hybrid Frequency Shift Keying and Quadrature Amplitude Modulation) and SWSC (Sliding Window Superposition Coding), and advanced access technology, FBMC (Filter Bank Multi Carrier) ), NOMA (Non Orthogonal Multiple Access), and SCMA (Sparse Code Multiple Access) are being developed.

Based on the above discussion, the present disclosure provides an apparatus and method for effectively transmitting uplink data in a wireless communication system.

In addition, the present disclosure provides an apparatus and method for preventing loss of an uplink due to transmission failure in a wireless communication system.

According to various embodiments of the present disclosure, in a method of operating a terminal in a wireless communication system, when transmission of the first data fails in a first uplink resource allocated for transmission of first data, the first data is A process of storing in a pending buffer and a process of transmitting at least a portion of the first data in a second uplink resource allocated for transmission of the second data.

According to various embodiments of the present disclosure, in a wireless communication system, a terminal includes a transceiver and at least one processor connected to the transceiver. The at least one processor stores the first data in a pending buffer and transmits the second data as the transmission of the first data fails in a first uplink resource allocated for transmission of the first data. In the second uplink resource allocated for transmission, at least a part of the first data may be transmitted.

The apparatus and method according to various embodiments of the present disclosure may rapidly perform new transmission for a set uplink and increase a transmission rate.

The effects obtainable in the present disclosure are not limited to the above-mentioned effects, and other effects not mentioned may be clearly understood by those of ordinary skill in the technical field to which the present disclosure belongs from the following description. will be.

1A illustrates an example of a wireless communication system according to various embodiments of the present disclosure.
1B shows another example of a wireless communication system according to various embodiments of the present disclosure.
2 illustrates a configuration of a base station in a wireless communication system according to various embodiments of the present disclosure.
3 illustrates a configuration of a terminal in a wireless communication system according to various embodiments of the present disclosure.
4 illustrates a configuration of a communication unit in a wireless communication system according to various embodiments of the present disclosure.
5 illustrates a protocol structure in a wireless communication system according to various embodiments of the present disclosure.
6 illustrates transmission according to LBT type 1 in a wireless communication system according to various embodiments of the present disclosure.
7 illustrates transmission according to LBT type 2 in a wireless communication system according to various embodiments of the present disclosure.
8A and 8B illustrate uplink data transmission when a listen-before-talk (LBT) is successful in a wireless communication system according to various embodiments of the present disclosure.
9A and 9B illustrate uplink data transmission when an LBT fails in a wireless communication system according to various embodiments of the present disclosure.
10 is a flowchart of a terminal for transmitting uplink data in a wireless communication system according to various embodiments of the present disclosure.
11 is another flowchart of a terminal for transmitting uplink data in a wireless communication system according to various embodiments of the present disclosure.

Terms used in the present disclosure are used only to describe a specific embodiment, and may not be intended to limit the scope of other embodiments. Singular expressions may include plural expressions unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by one of ordinary skill in the technical field described in the present disclosure. Among the terms used in the present disclosure, terms defined in a general dictionary may be interpreted as having the same or similar meaning as the meaning in the context of the related technology, and unless explicitly defined in the present disclosure, an ideal or excessively formal meaning Is not interpreted as. In some cases, even terms defined in the present disclosure cannot be interpreted to exclude embodiments of the present disclosure.

In various embodiments of the present disclosure described below, a hardware approach is described as an example. However, since various embodiments of the present disclosure include technology using both hardware and software, various embodiments of the present disclosure do not exclude a software-based approach.

Hereinafter, the present disclosure relates to an apparatus and method for transmitting uplink data in a wireless communication system. Specifically, the present disclosure is a transmission failure due to a listen-before-talk (LBT) operation when operating a configured grant, that is, a configured uplink transmission in a wireless communication system (e.g., transmission interruption due to detection of other transmissions) In the case of ), it describes a technique that can prevent the loss of data that could not be transmitted.

In the following description, a term referring to a signal, a term referring to a channel, a term referring to control information, a term referring to network entities, a term referring to a component of a device, etc. are for convenience of description. It is illustrated. Accordingly, the present disclosure is not limited to terms to be described later, and other terms having an equivalent technical meaning may be used.

In the following description, a physical channel and a signal may be used in combination with data or control signals. For example, a physical downlink shared channel (PDSCH) is a term that refers to a physical channel through which data is transmitted, but the PDSCH may also be used to refer to data. That is, in the present disclosure, the expression'transmitting a physical channel' may be interpreted equivalently to the expression'transmitting data or signals through a physical channel'.

Hereinafter, in the present disclosure, higher signaling refers to a signal transmission method transmitted from a base station to a terminal using a downlink data channel of a physical layer, or from a terminal to a base station using an uplink data channel of a physical layer. Higher level signaling may be understood as radio resource control (RRC) signaling or media access control (MAC) control element (CE).

In addition, in the present disclosure, in order to determine whether a specific condition is satisfied or satisfied, an expression exceeding or less than is used, but this is only a description for expressing an example, and more or less descriptions are excluded. Not to do. Conditions described as'greater than' may be replaced with'greater than', conditions described as'less than' may be replaced with'less than', and conditions described as'more and less' may be replaced with'greater than and less'

In addition, the present disclosure describes various embodiments using terms used in some communication standards (eg, 3rd Generation Partnership Project (3GPP)), but this is only an example for description. Various embodiments of the present disclosure may be easily modified and applied to other communication systems.

1 illustrates a wireless communication system according to various embodiments of the present disclosure.

1A shows an example of a wireless communication system according to various embodiments of the present disclosure. The wireless communication system shown in FIG. 1A may include a system to which LTE is applied (eg, an evolved packet system (EPS)). Hereinafter, in the present disclosure, a system to which LTE is applied may be simply referred to as an'LTE system'. The cell of the LTE system may be referred to as an'LTE cell'.

Referring to Figure 1a, the radio access network of the LTE system is composed of base stations (110ba, 110b, 110c, 110d), a mobility management entity (Mobility Management Entity, MME, 130) and S-GW (140, Serving-Gateway) Can be. The terminal 120 may access an external network through the base stations 110ba to 110d and the S-GW 140.

In FIG. 1A, base stations 110ba to 110d may correspond to an existing node B of a universal mobile telecommunication system (UMTS) system. The base station may be connected to the UE 120 through a radio channel and may perform a more complex role than that of the existing Node B. In the LTE system, all user traffic, including real-time services such as voice over internet protocol (VoIP) through internet protocol, can be serviced through a shared channel. Accordingly, there is a need for a device for scheduling by collecting state information such as a buffer state, an available transmission power state, and a channel state of the terminals, and the base stations 110ba to 110d can take care of this.

One base station can typically control multiple cells. For example, in order to implement a transmission rate of 100 Mbps, the LTE system may use orthogonal frequency division multiplexing (OFDM) in a 20 MHz bandwidth, for example, as a wireless access technology. In addition, an adaptive modulation and coding (AMC) scheme for determining a modulation scheme and a channel coding rate according to a channel state of the terminal may be applied. The S-GW 140 is a device that provides a data bearer, and may create or remove a data bearer under the control of the MME 130. The MME is a device responsible for various control functions as well as a mobility management function for a terminal, and can be connected to a plurality of base stations.

In addition to the base station, each of the base stations 110ba to 110d is'access point (AP)','eNodeB', '5G node', and'genodby' (next generation nodeB, gNB)','wireless point','transmission/reception point (TRP)', or other terms having an equivalent technical meaning. Each of the terminal 120 and the terminal 130 is a terminal other than'user equipment (UE)','mobile station','subscriber station', and'remote terminal. )','wireless terminal', or'user device', or another term having an equivalent technical meaning.

1B shows another example of a wireless communication system according to various embodiments of the present disclosure. The structure of the wireless communication system shown in FIG. 1B may include a system to which new radio (NR) is applied. According to an embodiment, NR may refer to a communication system capable of achieving a higher data rate, high reliability, and/or low-latency data communication compared to LTE. Hereinafter, in the present disclosure, a system to which NR is applied may be simply referred to as a'NR system', a '5G communication system', or a'next-generation mobile communication system'. A cell of an NR system may be referred to as a'NR cell'.

Referring to Figure 1b, the radio access network of the next-generation mobile communication system (hereinafter referred to as NR (new radio) or 5g) is a next-generation base station (New Radio Node B, hereinafter NR gNB or NR base station, 110e) and a next-generation radio core network (New Radio). Core Network, NR CN, 150). Next-generation wireless user equipment (New Radio User Equipment, NR terminal or terminal, 120) may access the external network through the NR gNB (110e) and NR CN (150).

In FIG. 1B, the NR gNB 110e may correspond to an eNB of an existing LTE system. The NR gNB 110e is connected to the terminal 120 through a radio channel, and may provide a service superior to that of the existing Node B. In a next-generation mobile communication system, all user traffic can be serviced through a shared channel. Accordingly, there is a need for a device that collects and schedules state information such as a buffer state, an available transmit power state, and a channel state of terminals, and the NR gNB 110e can take charge of this. One NR gNB can control multiple cells. In the next-generation mobile communication system, in order to implement ultra-high speed data transmission compared to the current LTE, a bandwidth greater than the current maximum bandwidth may be applied. In addition, a beamforming technique may be additionally applied by using OFDM as a wireless access technique. In addition, an adaptive modulation and coding (AMC) scheme for determining a modulation scheme and a channel coding rate according to a channel state of the terminal may be applied.

The NR CN 150 may perform functions such as mobility support, bearer setup, and QoS setup. The NR CN is a device responsible for various control functions as well as a mobility management function for a terminal, and can be connected to a plurality of base stations. In addition, the next-generation mobile communication system may be linked to an existing LTE system, and the NR CN 150 may be connected to the MME 130 through a network interface. The MME may be connected to the eNB 110f, which is an existing base station.

2 illustrates a configuration of a base station in a wireless communication system according to various embodiments of the present disclosure. The configuration illustrated in FIG. 2 can be understood as the configuration of the base station 110a. Terms such as'?? unit' and'?? group' used hereinafter refer to units that process at least one function or operation, which may be implemented as hardware or software, or a combination of hardware and software.

Referring to FIG. 2, the base station includes a wireless communication unit 210, a backhaul communication unit 220, a storage unit 230, and a control unit 240.

The wireless communication unit 210 performs functions for transmitting and receiving signals through a wireless channel. For example, the wireless communication unit 210 performs a function of converting between a baseband signal and a bit stream according to the physical layer standard of the system. For example, when transmitting data, the wireless communication unit 210 generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the wireless communication unit 210 restores the received bit stream through demodulation and decoding of the baseband signal.

In addition, the wireless communication unit 210 up-converts the baseband signal into a radio frequency (RF) band signal and transmits it through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. To this end, the wireless communication unit 210 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital to analog convertor (DAC), an analog to digital convertor (ADC), and the like. In addition, the wireless communication unit 210 may include a plurality of transmission/reception paths. Further, the wireless communication unit 210 may include at least one antenna array composed of a plurality of antenna elements.

In terms of hardware, the wireless communication unit 210 may be composed of a digital unit and an analog unit, and the analog unit includes a plurality of sub-units according to operating power, operating frequency, etc. It can be composed of. The digital unit may be implemented with at least one processor (eg, a digital signal processor (DSP)).

The wireless communication unit 210 transmits and receives signals as described above. Accordingly, all or part of the wireless communication unit 210 may be referred to as a'transmitter', a'receiver', or a'transceiver'. In addition, in the following description, transmission and reception performed through a wireless channel are used to mean that the above-described processing is performed by the wireless communication unit 210.

The backhaul communication unit 220 provides an interface for performing communication with other nodes in the network. That is, the backhaul communication unit 220 converts the bit stream transmitted from the base station to another node, for example, another access node, another base station, an upper node, a core network, etc., into a physical signal, and converts a physical signal received from another node. Convert to bit string.

The storage unit 230 stores data such as a basic program, an application program, and setting information for the operation of the base station. The storage unit 230 may be formed of a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. In addition, the storage unit 230 provides stored data according to the request of the control unit 240.

The controller 240 controls overall operations of the base station. For example, the controller 240 transmits and receives signals through the wireless communication unit 210 or through the backhaul communication unit 220. In addition, the control unit 240 writes and reads data in the storage unit 230. In addition, the control unit 240 may perform functions of a protocol stack required by a communication standard. According to another implementation example, the protocol stack may be included in the wireless communication unit 210. To this end, the control unit 240 may include at least one processor. According to various embodiments, the controller 240 may control the base station to perform operations according to various embodiments to be described later.

3 illustrates a configuration of a terminal in a wireless communication system according to various embodiments of the present disclosure. The configuration illustrated in FIG. 3 may be understood as the configuration of the terminal 120. Terms such as'?? unit' and'?? group' used hereinafter refer to units that process at least one function or operation, which may be implemented as hardware or software, or a combination of hardware and software.

Referring to FIG. 3, the terminal includes a communication unit 310, a storage unit 320, and a control unit 330.

The communication unit 310 performs functions for transmitting and receiving signals through a wireless channel. For example, the communication unit 310 performs a function of converting between a baseband signal and a bit stream according to the physical layer standard of the system. For example, when transmitting data, the communication unit 310 generates complex symbols by encoding and modulating a transmission bit stream. In addition, when receiving data, the communication unit 310 restores the received bit stream through demodulation and decoding of the baseband signal. In addition, the communication unit 310 up-converts the baseband signal into an RF band signal and transmits it through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the communication unit 310 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, and the like.

In addition, the communication unit 310 may include a plurality of transmission/reception paths. Furthermore, the communication unit 310 may include at least one antenna array composed of a plurality of antenna elements. In terms of hardware, the communication unit 310 may be composed of a digital circuit and an analog circuit (eg, a radio frequency integrated circuit (RFIC)). Here, the digital circuit and the analog circuit may be implemented in one package. In addition, the communication unit 310 may include a plurality of RF chains. Furthermore, the communication unit 310 may perform beamforming.

The communication unit 310 transmits and receives signals as described above. Accordingly, all or part of the communication unit 310 may be referred to as a'transmitting unit', a'receiving unit', or a'transmitting/receiving unit'. In addition, in the following description, transmission and reception performed through a wireless channel are used in a sense including the processing as described above is performed by the communication unit 310.

The storage unit 320 stores data such as a basic program, an application program, and setting information for the operation of the terminal. The storage unit 320 may be formed of a volatile memory, a nonvolatile memory, or a combination of a volatile memory and a nonvolatile memory. In addition, the storage unit 320 provides stored data according to the request of the control unit 330.

The controller 330 controls overall operations of the terminal. For example, the control unit 330 transmits and receives signals through the communication unit 310. In addition, the control unit 330 writes and reads data in the storage unit 320. In addition, the control unit 330 may perform functions of a protocol stack required by a communication standard. To this end, the control unit 330 may include at least one processor or a micro processor, or may be a part of a processor. In addition, a part of the communication unit 310 and the control unit 330 may be referred to as a communication processor (CP). According to various embodiments, the controller 330 may control the terminal to perform operations according to various embodiments to be described later. According to an embodiment, when the LBT for transmitting uplink data fails, the controller 330 instructs to store the data in a pending buffer, and then receives an uplink grant for receiving new data transmission, Data stored in the pending buffer can be controlled to be transmitted with priority.

4 illustrates a configuration of a communication unit in a wireless communication system according to various embodiments of the present disclosure. 4 shows an example of a detailed configuration of the wireless communication unit 210 of FIG. 2 or the communication unit 310 of FIG. 3. Specifically, FIG. 4 is a part of the wireless communication unit 210 of FIG. 2 or the communication unit 310 of FIG. 3, and illustrates components for performing beamforming.

4, the wireless communication unit 210 or the communication unit 310 includes an encoding and modulating unit 402, a digital beamforming unit 404, a plurality of transmission paths 406-1 to 406-N, and an analog beam. It includes a forming part 408.

The encoding and modulating unit 402 performs channel encoding. For channel encoding, at least one of a low density parity check (LDPC) code, a convolution code, and a polar code may be used. The encoding and modulating unit 402 generates modulation symbols by performing constellation mapping.

The digital beamforming unit 404 performs beamforming on a digital signal (eg, modulation symbols). To this end, the digital beamforming unit 404 multiplies the modulation symbols by beamforming weights. Here, the beamforming weights are used to change the size and phase of a signal, and may be referred to as a'precoding matrix', a'precoder', and the like. The digital beamforming unit 404 outputs digitally beamformed modulation symbols through a plurality of transmission paths 406-1 to 406-N. In this case, according to a multiple input multiple output (MIMO) transmission scheme, modulation symbols may be multiplexed or the same modulation symbols may be provided through a plurality of transmission paths 406-1 to 406-N.

The plurality of transmission paths 406-1 to 406-N convert digital beamformed digital signals into analog signals. To this end, each of the plurality of transmission paths 406-1 to 406-N may include an inverse fast fourier transform (IFFT) operation unit, a cyclic prefix (CP) insertion unit, a DAC, and an up-conversion unit. The CP insertion unit is for an orthogonal frequency division multiplexing (OFDM) scheme, and may be excluded when another physical layer scheme (eg, filter bank multi-carrier (FBMC)) is applied. That is, the plurality of transmission paths 406-1 to 406-N provide an independent signal processing process for a plurality of streams generated through digital beamforming. However, depending on the implementation method, some of the components of the plurality of transmission paths 406-1 to 406-N may be used in common.

The analog beamforming unit 408 performs beamforming on an analog signal. To this end, the analog beamforming unit 408 multiplies the analog signals by beamforming weights. Here, the beamforming weights are used to change the magnitude and phase of the signal. Specifically, the analog beamforming unit 440 may be configured in various ways according to a connection structure between the plurality of transmission paths 406-1 to 406-N and antennas. For example, each of the plurality of transmission paths 406-1 to 406-N may be connected to one antenna array. As another example, a plurality of transmission paths 406-1 to 406-N may be connected to one antenna array. As another example, the plurality of transmission paths 406-1 to 406-N may be adaptively connected to one antenna array, or may be connected to two or more antenna arrays.

5 illustrates a protocol structure in a wireless communication system according to various embodiments of the present disclosure.

Referring to FIG. 5, the radio protocol consists of packet data convergence protocol (PDCP, 505, 540), radio link control (RLC, 510, 535), and medium access control (MAC) 515 and 530, respectively, at a terminal and a base station. The packet data convergence protocol (PDCP) 505 and 540 are responsible for operations such as IP header compression/restore, and the RLCs 510 and 535 reconstruct a PDCP packet data unit (PDU) to an appropriate size. The MACs 515 and 530 are connected to several RLC layer devices configured in one terminal, and perform an operation of multiplexing RLC PDUs to MAC PDUs and demultiplexing RLC PDUs from MAC PDUs. The physical layers 520 and 525 channel-code and modulate upper layer data, make them into OFDM symbols, and transmit them through a wireless channel, or demodulate OFDM symbols received through a radio channel, and perform channel decoding to transmit them to the higher layers. . In addition, the physical layer also uses hybrid automatic repeat request (HARQ) for additional error correction, and the receiving end transmits whether or not a packet transmitted by the transmitting end is received in 1 bit. This is referred to as HARQ acknowledgment (ACK)/negative ACK (NACK) information. The downlink HARQ ACK/NACK information for uplink data transmission is transmitted through a PHICH (physical HARQ indicator channel) physical channel in the case of LTE, and the PDCCH (physical channel) through which downlink/uplink resource allocation, etc. is transmitted in the case of NR. dedicated control channel), it is possible to determine whether retransmission is necessary or whether it is necessary to perform new transmission through scheduling information of the corresponding terminal. This is because asynchronous HARQ is applied in NR.

Information included in the scheduling information of the PDCCH may include a HARQ process identifier (ID), a new data indicator (NDI), a redundancy version identifier (RVID), and the like. The HARQ process ID is transmitted to support the HARQ operation in parallel, for example, when transmitting downlink data, even if the ACK of the corresponding data has not yet been fed back after transmission is performed with HARQ process ID = 1, HARQ New data can be scheduled with process ID = 2. In the case of NR, 16 HARQ process IDs are supported in the uplink. In addition, NDI can be used to inform whether the corresponding data is new data. For example, when the base station transmits downlink, when the NDI value is 0 for a specific HARQ process ID value, a new transmission may be indicated, and when the base station is 1, a retransmission may be indicated. Alternatively, depending on whether the value itself is the same value as the previous value or a different value, it may indicate whether a new transmission or retransmission is performed. Meanwhile, the redundancy version (RV) is information indicating which packet is to be transmitted among a plurality of duplicate packets generated for retransmission when the packet is retransmitted.

Uplink HARQ ACK/NACK information for downlink data transmission may be transmitted through a physical uplink control channel (PUCCH) or a physical uplink shared channel (PUSCH) physical channel. In general, PUCCH is transmitted in the uplink of a primary cell (PCell) to be described later. However, if the terminal supports it, the base station may additionally transmit a PUCCH to the terminal in a secondary cell (SCell), which is referred to as a PUCCH SCell.

Although not shown in FIG. 5, a radio resource control (RRC) layer exists above the PDCP layer of the terminal and the base station, respectively, and the RRC layer is responsible for transmission/reception of configuration control messages related to access and measurement for radio resource control. do.

The PHY layers 520 and 525 may be composed of one or a plurality of frequencies/carriers, and a technology for simultaneously setting and using a plurality of frequencies is referred to as a carrier aggregation (carrier aggregation, hereinafter referred to as “CA”) technology. CA is a technology that uses only one carrier for communication between the terminal and the base station, and can increase the amount of transmission by the number of secondary carriers by using one or more secondary carriers in addition to the primary carrier. Meanwhile, in the case of LTE, a cell in a base station using a primary carrier is referred to as a PCell, and a cell in a base station using a secondary carrier is referred to as an SCell.

Meanwhile, the 5G system described above considers a scenario of operating in an unlicensed band. A system operating in the unlicensed band may be referred to as NR-U. In addition, the unlicensed band refers to a frequency band that anyone can freely use without a separate license in the regulatory permit at the corresponding frequency. For example, as an unlicensed band, there is a 2.4 GHz or 5 GHz band, and a wireless LAN and Bluetooth perform communication using the corresponding frequency.

In order to perform communication in the unlicensed band, the device must transmit and receive data according to the regulations set by each country. In more detail, according to regulations, before a device (e.g., a base station and a terminal) transmits in an unlicensed band, the device'listens' to see if the unlicensed band is occupied by another device, and if it is determined that it is empty, ' 'Transfer' should be performed. The method of listening and transmitting when empty is called LBT. Regulations for performing LBT are defined for each country and for each unlicensed band, and the device should perform LBT when communicating in the unlicensed band according to the defined regulations. LBT is largely classified into two types, type 1 and type 2, and transmission according to type 1 and type 2 will be described below with reference to FIGS. 6 and 7.

6 illustrates transmission according to LBT type 1 in a wireless communication system according to various embodiments of the present disclosure. LBT type 1 is a method of randomly determining a time to observe whether other devices are transmitting before transmission, and transmitting when the channel is empty for the determined random time. For example, the device first _listens for a fixed time T _d , and when empty, determines whether the channel is empty for a random time N. In this case, it is possible to differentially determine how to determine the values of T _d and N according to the priority and importance of the traffic, and a total of four different grades can be defined. The class is referred to as a channel access priority class ("CAPC").

In addition, according to CAPC, it has a time length of T _d = 16 + m _p * 9 (μs), and N = random (0, CW _p ) * 9 (μs). Here, the CW value starts from CW _min,p , increases approximately twice each time transmission fails _, and has a maximum CW _max,p value. For example, when performing LBT using a CAPC of 3 method, T _d has a length of 16 + 3 * 9 = 43 μs, and N is selected as a random value between 0 and 15 for initial transmission. . For example, if 7 is selected as the random value, N becomes 7 * 9 = 63 μs, and the device can transmit data when the channel is empty for 106 μs. An example of LBT-related variables according to CACP is shown in Table 1 below.

)CAPC (

)

allowed

sizes One One 3 7 2 ms {3,7} 2 One 7 15 3 ms {7,15} 3 3 15 63 8 or 10 ms {15,31,63} 4 7 15 1023 8 or 10 ms {15,31,63,127,255,511,1023}

If N is selected as 7, when it is determined that the channel is occupied by another device in the middle of determining whether the channel is empty (e.g., 3 out of 7 and 4), i.e., received signal strength indicator (RSSI) ) Is greater than or equal to a predetermined threshold, the device waits until the other device finishes occupying the channel, waits for T _d again, determines whether the channel is empty for the remaining 4 times, and performs transmission. As can be seen from [Table 1], the LBT scheme with low CAPC is used when transmitting high-priority traffic.

On the other hand, if the device occupies the channel once as it determines that the channel is empty, the time that the device can occupy the channel as much as possible is referred to as T _mcot,p . That is, the time in which the terminal can occupy the channel as much as possible is limited according to the CAPC value. For example, in the case of CAPC = 1, which has a high priority, the probability of occupying a channel is high, while the time to occupy a channel is relatively short. For example, when the CAPC is 3 or 4, the device can use a long value (eg, 10 ms) only when there is no heterogeneous device such as a wireless LAN.

7 illustrates transmission according to LBT type 2 in a wireless communication system according to various embodiments of the present disclosure. In the LBT type 2, a time for observing whether other peripheral devices are transmitting before transmission is fixed, and accordingly, transmission is performed immediately when the channel is empty for the fixed time. That is, when transmission is required, the device observes the channel for a fixed period of time during T _short (=T _f +T _s ), that is, senses it, and can immediately transmit data when it is determined that it is empty. This is an LBT method that can be used when transmitting signals with very high priority. For example, a signal having a relatively high importance such as a random access preamble and a PUCCH is preferably transmitted by the LBT type 2 method.

When the base station dynamically allocates resources for transmitting downlink data and the base station transmits data, the LBT type and CAPC may be determined according to the type of transmitted data. In addition, when the base station dynamically allocates a resource for transmitting uplink data and the terminal transmits data to the base station with the corresponding resource, the base station determines the LBT type and CAPC to be used when the terminal transmits data, and instructs the terminal. . That is, when the base station transmits uplink resource allocation information to the terminal through the PDCCH, the LBT type and CAPC for uplink data transmission may be indicated. In addition, when the base station determines that the LBT operation of the terminal is not required, the base station may instruct not to perform the LBT. For example, in the case of a TDD system in which the downlink and uplink frequencies are the same, when the base station occupies a channel once and the switching time between downlink and uplink is very short, the base station is treated as continuing to occupy the channel, LBT operation of the terminal may not be required. For example, if the base station occupies a channel once using CAPC = 4, the base station is treated as occupying the channel in both downlink and uplink for 8 or 10 ms, and the terminal transmitting during the corresponding period performs LBT operation. Can be omitted. In this case, when the base station schedules the uplink to the terminal, the base station may indicate that the LBT operation is not required. Or, when the base station allocates uplink resources to the terminal, when it is always determined to allocate the uplink resources of the corresponding terminal within the base station's T _mcot,p , the base station uses a message of the RRC layer (eg, RRCReconfiguration message). Thus, it is possible to instruct the terminal that there is no need to perform the LBT operation. In this case, the PDCCH transmitted to the terminal may not include the LBT type and CAPC in the uplink resource allocation.

In addition, it is possible to use a method of allocating a periodic resource without dynamically allocating resources for uplink transmission each time, and such periodic resources are called a configured grant and a configured uplink grant. Is referred to.

In the case of a configured grant used in a licensed band, each periodic resource is mapped to a specific HARQ process ID, and only new data can be transmitted in the periodic resource. Therefore, when retransmission is required, the base station dynamically allocates resources to the terminal to perform retransmission. Similar operations can be performed in the unlicensed band. In other words, as in the licensed band, periodic resources are mapped to a specific HARQ process ID, and only new data can be transmitted. In this case, when the terminal performs LBT to transmit data to the corresponding resource, but fails to transmit, a problem occurs that the corresponding packet cannot be transmitted for a while. To solve this, periodic resources are mapped with a specific HARQ process ID as in the licensed band, and the HARQ process ID to be transmitted for each periodic resource under the determination of the terminal and whether it is a new transmission or retransmission is not restricted to transmit only new data. May be indicated separately. This allows the UE to transmit information on the HARQ process ID, NDI, and RVID (hereinafter, collectively referred to as UCI) as described above to the PUSCH resource transmitting the data, when the UE transmits data, so that the received data is This is to try to figure out what kind of data it is.

8A and 8B illustrate uplink data transmission when LBT is successful in a wireless communication system according to various embodiments of the present disclosure. 8A and 8B assume a scenario in which a UE accesses a base station, operates in an RRC connection (RRC_CONNECTED) state, and uplink resources 801 configured to enable periodic uplink transmission are allocated. Although the periodic uplink resource corresponds to a configured grant in the unlicensed band (i.e., the UE determines data to be transmitted and transmits including UCI information), the present invention is that periodic uplink resources are necessarily used in the unlicensed band. Is not limited to

In the case of transmitting periodic uplink data, it is determined whether or not the data is retransmitted when retransmitting the corresponding data through the HARQ process ID used at the time of new transmission. Since the value of the HARQ process ID does not increase infinitely, the HARQ process ID used once can be reused for subsequent new data transmission. For example, in the case of FIG. 8A, the same HARQ process ID (eg, HPID=x) is used in the resource 803 and the resource 805. In the case of FIG. 8B, the same HARQ process ID (eg, HPID=x) is used in the resource 853 and the resource 855.

The HARQ process ID may be determined according to an OFDM symbol, a slot, and a subframe identifier at a time point at which the UE transmits uplink data. For example, it may be determined as [Equation 1] below the HARQ process ID.

In [Equation 1], ID _symbol denotes the identifier of the current symbol, P _uplink denotes a set uplink allocation period, and numberOfConfGrant-Processes denotes the number of uplink processes of the terminal configured by the base station.

Referring to FIG. 8A, when uplink data transmission is required, the UE performs LBT before transmitting data through periodic resources 801, and transmits uplink data when LBT is successful. At this time, the UE notifies the corresponding transmission corresponding to a certain HARQ process ID, the corresponding transmission is a new transmission (eg, NDI = 0), and the transmitted RV value so that the base station can decode the corresponding data. In addition, when data transmission is successful, the terminal starts two types of timers.

The first timer is referred to as a configured grant timer (CGT) 815, and the CGT 815 is used to ensure retransmission by blocking new transmissions using the corresponding HARQ process ID while being driven. When the CGT 815 has expired, it means that the base station has successfully received the corresponding data, and a new transmission using the corresponding HARQ process ID is allowed.

The second timer is referred to as a configured grant retransmission timer (CGRT) 811 or 813. The CGRT 811 or 813 is used to ensure a time for the base station to determine whether or not to successfully receive retransmission while being driven. If the CGRT (811 or 813) is expired, it means that the base station has not successfully received the data, and thus retransmission of the data is allowed.

Accordingly, after the UE performs initial transmission in the resource 803, the CGT 815 and the CGRT 811 are started. Thereafter, if the downlink feedback information (DFI) indicating that the data is successfully received from the base station is not received until the CGRT 811 expires, the terminal determines that the data is not successfully transmitted, and retransmits the data. I can. Accordingly, the UE retransmits the corresponding data in the periodic uplink resource 805 and starts the CGRT 813 again.

On the other hand, when the base station has successfully received the data, the base station can inform the terminal that the data has been successfully received by transmitting the DFI 821. The terminal receiving the DFI (821) confirms that the data has been successfully transmitted, and since it is no longer necessary to drive the CGRT (813), the CGRT (813) at the first time point (823) at which the DFI (821) is received. Stop (stop). Thereafter, when the CGT 815 expires at the second time point 825, the terminal may use the corresponding HARQ process ID for other new data.

Referring to FIG. 8B, when uplink data transmission is required, the UE performs LBT before transmitting data through periodic resources 851, and transmits uplink data when LBT is successful. At this time, the UE notifies the corresponding transmission corresponding to a certain HARQ process ID, the corresponding transmission is a new transmission (eg, NDI = 0), and the transmitted RV value so that the base station can decode the corresponding data. In addition, when data transmission is successful, the terminal starts two types of timers, that is, the CGT 865 and the CGRT 861.

Thereafter, if the CGRT 861 does not receive the DFI indicating that the data has been successfully received from the base station until the expiration of the CGRT 861, the UE determines that the data has not been successfully transmitted, and may retransmit the data. Accordingly, the UE retransmits the corresponding data in the periodic uplink resource 855 and starts the CGRT 863 again.

On the other hand, if the base station does not successfully receive the corresponding data, it is no longer left to the terminal, and the base station can induce retransmission by dynamically allocating resources. To this end, the base station may transmit downlink control information 871 indicating retransmission of the corresponding HARQ process ID to the terminal through the PDCCH. The terminal receiving the downlink control information 871 controls the CGRT 863, which was managed for retransmission using the configured grant, at the first time 873 (e.g., the time at which the indicating downlink control information 871 is received) Stop and restart the CGT (875). Accordingly, the UE retransmits the corresponding data from the uplink resource 881 allocated by the downlink control information 871 received through the PDCCH. In addition, when the PDCCH is received, the terminal restarts the CGT 877 when the actual data is transmitted. Accordingly, the UE restarts the CGT 875 or 877 when dynamic resources are scheduled and transmitted from the base station, and is subject to the control of the base station.

9A and 9B illustrate uplink data transmission when an LBT fails in a wireless communication system according to various embodiments of the present disclosure. The examples of FIGS. 9A and 9B assume a scenario in which a UE accesses a base station, operates in an RRC connection (RRC_CONNECTED) state, and uplink resources 801 configured to enable periodic uplink transmission are allocated. Although the periodic uplink resource corresponds to a configured grant in the unlicensed band (i.e., the UE determines data to be transmitted and transmits including UCI information), the present invention is that periodic uplink resources are necessarily used in the unlicensed band. Is not limited to

Referring to FIG. 9A, if uplink data transmission is required, the UE performs LBT before transmitting data through periodic resources 901. In the case of FIG. 9A, the LBT performed on the resource 903 fails. At this time, performing LBT means that after generating a packet to be transmitted, a channel occupancy state is observed in order to transmit the generated packet. However, since the actual transmission has not been made, the CGT does not start. Thereafter, when the time to use the configured uplink resource 905 using the same HARQ process ID as the uplink resource 903 from which transmission has failed comes, since the CGT is not driven inside the terminal, the terminal performs a new transmission. To do this, the transmission failed data stored in the buffer corresponding to the HARQ process ID is removed, and new data is overwritten. Accordingly, the packet intended to be transmitted from the resource 903 is lost.

In order to prevent packet loss as illustrated in FIG. 9A, an operation as illustrated in FIG. 9B may be performed. Referring to FIG. 9B, when uplink data transmission is required, the terminal performs LBT before transmitting data through periodic resources 951. In the case of FIG. 9B, the LBT performed on the resource 953 fails. At this time, performing LBT means that after generating a packet to be transmitted, a channel occupancy state is observed in order to transmit the generated packet. However, since the actual transmission is not performed due to the failure of the LBT, the CGT does not start. In this case, in order to prevent the loss of the corresponding packet, the terminal stores data included in the packet intended to be transmitted from the resource 953 in the pending buffer 999. Here, the data stored in the pending buffer 999 is not data that has been transmitted but failed to be received by a receiving device (eg, a base station), but data that has not been transmitted from a transmitting device (eg, a terminal), so it cannot be understood as retransmission data. No. The pending buffer 999 may be referred to as a'new data buffer', a'LBT failure buffer', a'transmission failure buffer', or other terms having an equivalent technical meaning.

Since the terminal has not attempted to transmit a packet due to a failure of the LBT in the resource 953, the data stored in the pending buffer 999 may be treated as new data that has not been transmitted. Thereafter, the UE determines whether data stored in the pending buffer 999 can be transmitted from the first available resource among the dynamic uplink resource 961 or the configured uplink resource 951 for new data transmission, and the pending buffer Attempt to transfer the data stored in (999). In this case, the HARQ process ID used in the uplink resource 961 for new data transmission may be different from the HARQ process ID used in the resource 953. In addition, in order to determine whether transmission is possible, the terminal determines the size of an uplink resource allocated to the corresponding transmission. A specific method of determining the size of a resource is as follows.

According to an embodiment, when the size of the resource for new data transmission is equal to or greater than the size of the resource required to transmit the data stored in the pending buffer 999, the terminal transmits the data stored in the pending buffer 999 do. On the other hand, when the size of the resource for new data transmission is smaller than the size of the resource required to transmit the data stored in the pending buffer 999, the terminal sends a packet including other new data instead of the data stored in the pending buffer 999. Can be created and transmitted.

According to another embodiment, when the size of the resource for new data transmission is equal to or greater than the size of the resource required to transmit the data stored in the pending buffer 999, the terminal transmits the data stored in the pending buffer 999 , It is possible to transmit more new data according to the size of the remaining resources. In other words, the terminal may generate and transmit a packet including data stored in the pending buffer 999 and new data. When the size of the resource for new data transmission is smaller than the size of the resource required to transmit the data stored in the pending buffer 999, the terminal may transmit a packet including a part of the data stored in the pending buffer 999. . Excluded parts that are not part of the transmitted data may be a control message (eg, MAC CE (control element)) generated at the MAC layer, and data provided by an upper layer of the MAC layer (eg, MAC SDU (service data unit)) ) May be included in some of the transmitted data. In addition, when resources are insufficient to transmit all data provided by the upper layer, the terminal may further exclude some of the data according to the priority of each logical channel set by the RRC layer.

Referring to FIG. 9B, after a transmission failure due to an LBT failure in the resource 953, when a dynamic uplink resource 961 for new data transmission is allocated, the terminal uses the corresponding uplink resource 961 to the pending buffer ( 999) is determined whether or not to transmit. In order to transmit all or part of the data, the UE transfers data to the buffer of the HARQ process ID corresponding to the corresponding uplink resource 961 and attempts to transmit all or part of the data. In the case of the dynamically allocated uplink resource 961, the base station explicitly informs the HARQ process ID of this resource through the PDCCH upon resource allocation. Here, the HARQ process ID may be different from the HARQ process ID used in the resource 953 at the time of an existing initial transmission attempt.

As described above, the terminal may prevent data loss by transmitting new data that has not been transmitted due to the failure of the LBT using the HARQ process ID of the uplink for new transmission.

10 is a flowchart of a terminal for transmitting uplink data in a wireless communication system according to various embodiments of the present disclosure. 10 illustrates an operation method of the terminal 120.

Referring to FIG. 10, in step 1001, the terminal receives information on a configured grant (configure grant, CG). The terminal accesses the base station and, while operating in an RRC connected state, may receive information on a grant for allocating periodic uplink resources from the base station. In other words, the terminal is allocated uplink resources configured to enable periodic uplink transmission from the base station. Here, the periodic uplink resource may be a grant configured in an unlicensed band, but the present invention is not limited thereto. For example, a plurality of configured grants may be set in one cell.

In step 1003, the terminal determines a packet to be transmitted for each configured grant. The UE determines which data is transmitted using which HARQ process ID for each periodic uplink resource arrival. In addition to the HARQ process ID, an RV may also be determined. Here, the packet is a transmission unit of data, and may include a MAC protocol data unit (PDU), a transport block (TB), a message, and the like.

In step 1005, the terminal attempts an initial transmission of the determined packet using the configured grant. That is, the terminal may perform LBT and transmit a packet if the LBT is successful. That is, the transmission of the packet may be determined according to the success of the LBT.

In step 1007, the terminal checks whether the transmission is successful. Here, the success of the transmission means transmission of the packet according to the success of the LBT, and does not mean the success of decoding at the base station. That is, the failure of transmission means that the packet cannot be transmitted due to the failure of the LBT.

If the transmission is successful, in step 1011, the terminal starts a timer related to the packet. For example, the timer is one of a first timer (e.g., CGT) for blocking new transmission using the HARQ process ID or a second timer (e.g., CGRT) for ensuring a time to determine whether or not successful reception at the base station. Contains at least one. For example, if the transmission is the initial transmission, the terminal starts the CGT. For another example, if the transmission is not the initial transmission, that is, retransmission, the terminal starts or restarts the CGRT.

On the other hand, if the transmission fails, in step 1011, the terminal stores the packet to be transmitted in the pending buffer. The data stored in the pending buffer is treated as new data, not retransmission data, and then may be transmitted using dynamically allocated uplink resources or periodically allocated uplink resources.

In the embodiment described with reference to FIG. 10, the case where the LBT fails has been described. However, according to another embodiment, when a plurality of configured uplink grants are configured and the allocation periods of uplink resources overlap, in a situation in which uplink transmission with a low priority among the overlapped uplink transmissions cannot be performed, the above-described Operations can be performed. That is, data that fail to transmit due to a low priority, not LBT failure, may also be stored in the pending buffer and then transmitted later.

11 is another flowchart of a terminal for transmitting uplink data in a wireless communication system according to various embodiments of the present disclosure. 11 illustrates a method of operating the terminal 120.

Referring to FIG. 11, in step 1101, the UE receives information on uplink resources for new data transmission from the base station. The information on the uplink resource may include information on a resource dynamically allocated from the base station through a PDCCH or information on a configured uplink resource.

In step 1103, the terminal determines whether a packet exists in the Msg3 buffer. The Msg3 buffer is a buffer for storing a message transmitted from the terminal to the base station in step 3 of the random access procedure when performing random access to the base station due to initial access or the like. If data exists in the Msg3 buffer, in step 1105, the terminal generates a packet including data stored in the Msg3 buffer. That is, the terminal generates Msg3 for random access.

When there is no data in the Msg3 buffer, in step 1107, the terminal determines whether data exists in the pending buffer. The presence of data in the pending buffer means that there is data that has failed to be transmitted according to a decision based on the failure or priority of the LBT.

If data exists in the pending buffer, in step 1109, the terminal generates a packet including at least a portion of the data stored in the pending buffer in consideration of the resource size. According to an embodiment, the terminal checks whether the size of the allocated uplink resource is greater than or equal to the size of the resource required to transmit data stored in the pending buffer. If the size of the allocated uplink resource is greater than or equal to the size of the resource required to transmit the data stored in the pending buffer, the UE transfers the data stored in the pending buffer to the buffer of the HARQ process ID corresponding to the uplink resource allocation. The data is moved and a packet including the moved data is generated. Here, the movement of the data may include an operation of flushing the pending buffer. In this case, if the allocated uplink resource remains, the terminal may further include additional new data in the packet or fill the remaining space with padding. If the size of the allocated uplink resource is smaller than the size of the resource required to transmit the data stored in the pending buffer, the terminal may generate a packet including only part of the data stored in the pending buffer. However, according to another embodiment, if the size of the allocated uplink resource is smaller than the size of the resource required to transmit the data stored in the pending buffer, the terminal generates a packet including new data other than the data stored in the pending buffer. can do.

If there is no data in the pending buffer, in step 1111, the terminal generates a packet including new data. That is, the terminal generates a packet including new data to be transmitted in the allocated uplink resource.

In step 1113, the terminal transmits a packet. That is, the terminal transmits the packet generated in step 1105, step 1109, or step 1111 to the base station. At this time, transmission failure may occur again due to LBT failure or priority determination.

As in the embodiment described with reference to FIG. 11, the terminal may transmit uplink data stored in the buffer. In FIG. 11, the terminal checks the pending buffer regardless of the type of uplink resource information. However, according to another embodiment, the terminal may check the pending buffer only when an additional condition is satisfied. For example, when periodic uplink resources allocated by a configured grant are available, a condition for performing an operation of checking a pending buffer may be limited. That is, data stored in the pending buffer may be limited to not being transmitted through dynamically allocated resources. In this case, if periodically allocated resources (e.g., resources 951 of FIG. 9B) are available, the terminal determines whether a packet exists in the pending buffer, and the data stored in the pending buffer is a resource by a configured grant. Can be transmitted from

In addition, a case in which the base station configures a plurality of configured uplink grants to the terminal may be considered. Here, resources allocated by a plurality of configured uplink grants may have the same or different periods. In this case, according to an embodiment, the UE may be limited to transmit data only to configured uplink grants in which transmission has failed, and not to transmit data through other configured uplink grant(s) and dynamically allocated resources. To this end, the terminal may generate and manage a separate pending buffer for each configured uplink grant. Alternatively, according to another embodiment, the terminal may be limited to transmit in any configured uplink grants without distinction of configured uplink grants and not to transmit through dynamically allocated resources. That is, when a transmission failure occurs in a resource allocated by the first configured uplink grant, the UE can transmit the data that has failed to be transmitted to a resource allocated by the first configured uplink grant or another second configured uplink grant. However, it may be prohibited to transmit data that has failed to be transmitted using dynamically allocated resources.

The uplink data transmission procedure based on the buffer operation according to the various embodiments described above may be expressed as [Table 2], [Table 3], or [Table 4] below.

For each uplink grant, the HARQ entity shall:
1> identify the HARQ process associated with this grant, and for each identified HARQ process:
2> if the received grant was not addressed to a Temporary C-RNTI on PDCCH, and the NDI provided in the associated HARQ information has been toggled compared to the value in the previous transmission of this TB of this HARQ process; or
2> if the uplink grant was received on PDCCH for the C-RNTI and the HARQ buffer of the identified process is empty; or
2> if the uplink grant was received in a Random Access Response; or
2> if the uplink grant was received on PDCCH for the C-RNTI in ra-ResponseWindow and this PDCCH successfully completed the Random Access procedure initiated for beam failure recovery; or
2> if the uplink grant is part of a bundle of the configured uplink grant, and may be used for initial transmission according to clause 6.1.2.3 of TS 38.214 [7], and if no MAC PDU has been obtained for this bundle:
3> if there is a MAC PDU in the Msg3 buffer and the uplink grant was received in a Random Access Response; or:
3> if there is a MAC PDU in the Msg3 buffer and the uplink grant was received on PDCCH for the C-RNTI in ra-ResponseWindow and this PDCCH successfully completed the Random Access procedure initiated for beam failure recovery:
4> obtain the MAC PDU to transmit from the Msg3 buffer.
4> if the uplink grant size does not match with size of the obtained MAC PDU; and
4> if the Random Access procedure was successfully completed upon receiving the uplink grant:
5> indicate to the Multiplexing and assembly entity to include MAC subPDU(s) carrying MAC SDU from the obtained MAC PDU in the subsequent uplink transmission;
5> obtain the MAC PDU to transmit from the Multiplexing and assembly entity.
3> else if there is a pending MAC PDU in the pending MAC PDU buffer:
4> obtain the MAC PDU from the pending MAC PDU buffer.
4> flush the pending MAC PDU buffer;
4> if the uplink grant size does not match with size of the obtained MAC PDU:
5> indicate to the Multiplexing and assembly entity to include MAC subPDU(s) carrying MAC SDU from the obtained MAC PDU in the subsequent uplink transmission;
5> obtain the MAC PDU to transmit from the Multiplexing and assembly entity.
3> else:
4> obtain the MAC PDU to transmit from the Multiplexing and assembly entity, if any;
3> if a MAC PDU to transmit has been obtained:
4> deliver the MAC PDU and the uplink grant and the HARQ information of the TB to the identified HARQ process;
4> instruct the identified HARQ process to trigger a new transmission;
4> if the uplink grant is addressed to CS-RNTI; or
4> if the uplink grant is a configured uplink grant; or
4> if the uplink grant is addressed to C-RNTI, and the identified HARQ process is configured for a configured uplink grant:
5> start or restart the configuredGrantTimer , if configured, for the corresponding HARQ process when the transmission is performed.
5> if the transmission is not performed (eg due to LBT failure):
6> store the MAC PDU to the pending MAC PDU buffer.
3> else:
4> flush the HARQ buffer of the identified HARQ process.
2> else (ie retransmission):
3> if the uplink grant received on PDCCH was addressed to CS-RNTI and if the HARQ buffer of the identified process is empty; or
3> if the uplink grant is part of a bundle and if no MAC PDU has been obtained for this bundle; or
3> if the uplink grant is part of a bundle of the configured uplink grant, and the PUSCH duration of the uplink grant overlaps with a PUSCH duration of another uplink grant received on the PDCCH or in a Random Access Response for this Serving Cell:
4> ignore the uplink grant.
3> else:
4> deliver the uplink grant and the HARQ information (redundancy version) of the TB to the identified HARQ process;
4> instruct the identified HARQ process to trigger a retransmission;
4> if the uplink grant is addressed to CS-RNTI; or
4> if the uplink grant is addressed to C-RNTI, and the identified HARQ process is configured for a configured uplink grant:
5> start or restart the configuredGrantTimer , if configured, for the corresponding HARQ process when the transmission is performed.

For each uplink grant, the HARQ entity shall:
1> identify the HARQ process associated with this grant, and for each identified HARQ process:
2> if the received grant was not addressed to a Temporary C-RNTI on PDCCH, and the NDI provided in the associated HARQ information has been toggled compared to the value in the previous transmission of this TB of this HARQ process; or
2> if the uplink grant was received on PDCCH for the C-RNTI and the HARQ buffer of the identified process is empty; or
2> if the uplink grant was received in a Random Access Response; or
2> if the uplink grant was received on PDCCH for the C-RNTI in ra-ResponseWindow and this PDCCH successfully completed the Random Access procedure initiated for beam failure recovery; or
2> if the uplink grant is part of a bundle of the configured uplink grant, and may be used for initial transmission according to clause 6.1.2.3 of TS 38.214 [7], and if no MAC PDU has been obtained for this bundle:
3> if there is a MAC PDU in the Msg3 buffer and the uplink grant was received in a Random Access Response; or:
3> if there is a MAC PDU in the Msg3 buffer and the uplink grant was received on PDCCH for the C-RNTI in ra-ResponseWindow and this PDCCH successfully completed the Random Access procedure initiated for beam failure recovery:
4> obtain the MAC PDU to transmit from the Msg3 buffer.
4> if the uplink grant size does not match with size of the obtained MAC PDU; and
4> if the Random Access procedure was successfully completed upon receiving the uplink grant:
5> indicate to the Multiplexing and assembly entity to include MAC subPDU(s) carrying MAC SDU from the obtained MAC PDU in the subsequent uplink transmission;
5> obtain the MAC PDU to transmit from the Multiplexing and assembly entity.
3> else if there is a pending MAC PDU in the pending MAC PDU buffer; and
3> if the uplink grant size is greater than or equal to the size of the obtained MAC PDU:
4> obtain the MAC PDU from the pending MAC PDU buffer.
4> flush the pending MAC PDU buffer.
3> else:
4> obtain the MAC PDU to transmit from the Multiplexing and assembly entity, if any;
3> if a MAC PDU to transmit has been obtained:
4> deliver the MAC PDU and the uplink grant and the HARQ information of the TB to the identified HARQ process;
4> instruct the identified HARQ process to trigger a new transmission;
4> if the uplink grant is addressed to CS-RNTI; or
4> if the uplink grant is a configured uplink grant; or
4> if the uplink grant is addressed to C-RNTI, and the identified HARQ process is configured for a configured uplink grant:
5> start or restart the configuredGrantTimer , if configured, for the corresponding HARQ process when the transmission is performed.
5> if the transmission is not performed (eg due to LBT failure):
6> store the MAC PDU to the pending MAC PDU buffer.
3> else:
4> flush the HARQ buffer of the identified HARQ process.
2> else (ie retransmission):
3> if the uplink grant received on PDCCH was addressed to CS-RNTI and if the HARQ buffer of the identified process is empty; or
3> if the uplink grant is part of a bundle and if no MAC PDU has been obtained for this bundle; or
3> if the uplink grant is part of a bundle of the configured uplink grant, and the PUSCH duration of the uplink grant overlaps with a PUSCH duration of another uplink grant received on the PDCCH or in a Random Access Response for this Serving Cell:
4> ignore the uplink grant.
3> else:
4> deliver the uplink grant and the HARQ information (redundancy version) of the TB to the identified HARQ process;
4> instruct the identified HARQ process to trigger a retransmission;
4> if the uplink grant is addressed to CS-RNTI; or
4> if the uplink grant is addressed to C-RNTI, and the identified HARQ process is configured for a configured uplink grant:
5> start or restart the configuredGrantTimer , if configured, for the corresponding HARQ process when the transmission is performed.

For each uplink grant, the HARQ entity shall:
1> identify the HARQ process associated with this grant, and for each identified HARQ process:
2> if the received grant was not addressed to a Temporary C-RNTI on PDCCH, and the NDI provided in the associated HARQ information has been toggled compared to the value in the previous transmission of this TB of this HARQ process; or
2> if the uplink grant was received on PDCCH for the C-RNTI and the HARQ buffer of the identified process is empty; or
2> if the uplink grant was received in a Random Access Response; or
2> if the uplink grant was received on PDCCH for the C-RNTI in ra-ResponseWindow and this PDCCH successfully completed the Random Access procedure initiated for beam failure recovery; or
2> if the uplink grant is part of a bundle of the configured uplink grant, and may be used for initial transmission according to clause 6.1.2.3 of TS 38.214 [7], and if no MAC PDU has been obtained for this bundle:
3> if there is a MAC PDU in the Msg3 buffer and the uplink grant was received in a Random Access Response; or:
3> if there is a MAC PDU in the Msg3 buffer and the uplink grant was received on PDCCH for the C-RNTI in ra-ResponseWindow and this PDCCH successfully completed the Random Access procedure initiated for beam failure recovery:
4> obtain the MAC PDU to transmit from the Msg3 buffer.
4> if the uplink grant size does not match with size of the obtained MAC PDU; and
4> if the Random Access procedure was successfully completed upon receiving the uplink grant:
5> indicate to the Multiplexing and assembly entity to include MAC subPDU(s) carrying MAC SDU from the obtained MAC PDU in the subsequent uplink transmission;
5> obtain the MAC PDU to transmit from the Multiplexing and assembly entity.
3> else if there is a pending MAC PDU in the pending MAC PDU buffer; and
3> if the uplink grant is a configured uplink grant associated with the pending buffer; and
3> if the uplink grant size is greater than or equal to the size of the obtained MAC PDU:
4> obtain the MAC PDU from the pending MAC PDU buffer;
4> flush the pending MAC PDU buffer.
3> else:
4> obtain the MAC PDU to transmit from the Multiplexing and assembly entity, if any;
3> if a MAC PDU to transmit has been obtained:
4> deliver the MAC PDU and the uplink grant and the HARQ information of the TB to the identified HARQ process;
4> instruct the identified HARQ process to trigger a new transmission;
4> if the uplink grant is addressed to CS-RNTI; or
4> if the uplink grant is a configured uplink grant; or
4> if the uplink grant is addressed to C-RNTI, and the identified HARQ process is configured for a configured uplink grant:
5> start or restart the configuredGrantTimer , if configured, for the corresponding HARQ process when the transmission is performed.
5> if the transmission is not performed (eg due to LBT failure):
6> store the MAC PDU to the associated pending MAC PDU buffer.
NOTE: The pending MAC PDU buffer is maintained per configured UL grant configuration.
3> else:
4> flush the HARQ buffer of the identified HARQ process.
2> else (ie retransmission):
3> if the uplink grant received on PDCCH was addressed to CS-RNTI and if the HARQ buffer of the identified process is empty; or
3> if the uplink grant is part of a bundle and if no MAC PDU has been obtained for this bundle; or
3> if the uplink grant is part of a bundle of the configured uplink grant, and the PUSCH duration of the uplink grant overlaps with a PUSCH duration of another uplink grant received on the PDCCH or in a Random Access Response for this Serving Cell:
4> ignore the uplink grant.
3> else:
4> deliver the uplink grant and the HARQ information (redundancy version) of the TB to the identified HARQ process;
4> instruct the identified HARQ process to trigger a retransmission;
4> if the uplink grant is addressed to CS-RNTI; or
4> if the uplink grant is addressed to C-RNTI, and the identified HARQ process is configured for a configured uplink grant:
5> start or restart the configuredGrantTimer , if configured, for the corresponding HARQ process when the transmission is performed.

According to the above-described various embodiments, when the terminal fails to transmit a packet, it may transmit the packet to an uplink resource for the next new data transmission, thereby preventing data loss and reducing delay.

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

When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. One or more programs stored in a computer-readable storage medium are configured to be executable by one or more processors in an electronic device (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.

These programs (software modules, software) include random access memory, non-volatile memory including flash memory, read only memory (ROM), and electrically erasable programmable 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 It may be stored in an optical storage device or a magnetic cassette. Alternatively, it may be stored in a memory composed of a combination of some or all of them. In addition, a plurality of configuration memories may be included.

In addition, the program is through a communication network composed of a communication network such as the Internet, an intranet, a local area network (LAN), a wide area network (WAN), or a storage area network (SAN), or a combination thereof. It may be stored in an attachable storage device that can be accessed. Such a storage device may access a device performing an embodiment of the present disclosure through an external port. In addition, a separate storage device on the communication network may access a device performing an embodiment of the present disclosure.

In the above-described specific embodiments of the present disclosure, components included in the disclosure are expressed in the singular or plural according to the presented specific embodiments. However, the singular or plural expression is selected appropriately for the situation presented for convenience of description, and the present disclosure is not limited to the singular or plural constituent elements, and even constituent elements expressed in plural are composed of the singular or in the singular. Even the expressed constituent elements may be composed of pluralities.

Meanwhile, although specific embodiments have been described in the detailed description of the present disclosure, various modifications are possible without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure is limited to the described embodiments and should not be determined, and should be determined by the scope of the claims as well as the equivalents of the claims to be described later.

Claims (16)

In the method of operating a terminal in a wireless communication system,
As the transmission of the first data fails in a first uplink resource allocated for transmission of first data, storing the first data in a pending buffer; and
A method comprising transmitting at least a part of the first data in a second uplink resource allocated for transmission of second data.
The method according to claim 1,
The transmission of the first data is failed due to at least one of failure of a listen before talk (LBT) operation or determination of priority.
The method according to claim 1,
A hybrid automatic repeat request (HARQ) process ID (identifier) used in the first uplink resource is different from the HARQ process ID used in the second uplink resource.
The method according to claim 1,
The first uplink resource is one of periodic resources allocated by a configured grant.
The method according to claim 1,
The second uplink resource is a resource dynamically allocated according to downlink control information.
The method according to claim 1,
If the first size of the second uplink resource is greater than the second size of the resource required to transmit the first data, the second uplink resource includes at least a portion of the first data and the second data How the packet is sent.
The method according to claim 1,
When the first size of the second uplink resource is smaller than the second size of the resource required to transmit the first data, a packet including part of the first data is transmitted in the second uplink resource .
The method of claim 7,
Some of the first data is selected by excluding a media access controller (MAC) control element (CE) from the first data or excluding data belonging to a low priority logical channel.
In a terminal in a wireless communication system,
Transceiver and,
And at least one processor connected to the transceiver,
The at least one processor,
As transmission of the first data fails in a first uplink resource allocated for transmission of first data, the first data is stored in a pending buffer,
A terminal controlling to transmit at least a part of the first data in a second uplink resource allocated for transmission of second data.
The method of claim 9,
The transmission of the first data is a terminal that fails due to at least one of a failure of a listen before talk (LBT) operation or a priority determination.
The method of claim 9,
A hybrid automatic repeat request (HARQ) process ID (identifier) used in the first uplink resource is different from the HARQ process ID used in the second uplink resource.
The method of claim 9,
The first uplink resource is one of periodic resources allocated by a configured grant.
The method of claim 9,
The second uplink resource is a resource dynamically allocated according to downlink control information.
The method of claim 9,
If the first size of the second uplink resource is greater than the second size of the resource required to transmit the first data, the second uplink resource includes at least a portion of the first data and the second data The terminal to which the packet is transmitted.
The method of claim 9,
When the first size of the second uplink resource is smaller than the second size of the resource required to transmit the first data, the terminal to which a packet including a part of the first data is transmitted in the second uplink resource .
The method of claim 15,
A portion of the first data is selected by excluding a media access controller (MAC) control element (CE) from the first data or excluding data belonging to a low-priority logical channel.

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