KR20210061845A - Apparatus and method for handling exceptional transmission resource pool in wireless communication system - Google Patents

Abstract

The present invention relates to a communication technique for converging a 5G communication system with IoT technology to support higher data rates after a 4G system and a system thereof, wherein the present invention transmits sidelink data by selecting a resource from an exceptional transmission resource pool in the wireless communication system. The terminal according to the present invention comprises the processes of: determining the need to use the exceptional transmission resource pool; judging the establishment of the exceptional transmission resource pool; determining whether the conditions for use of the exceptional transmission resource pool are satisfied; transmitting data of a sidelink logical channel and/or sidelink flow that satisfies the conditions of use of the exceptional transmission resource pool through a resource selected from the exceptional transmission resource pool; waiting for a normal resource pool to be established if it is judged that the conditions for using the exceptional transmission resource pool are not satisfied. Accordingly, transmission collision and packet reception rate degradation due to congestion may be effectively prevented.

Description

Apparatus and method for handling exceptional transmission resource pool for sidelink in wireless communication system {APPARATUS AND METHOD FOR HANDLING EXCEPTIONAL TRANSMISSION RESOURCE POOL IN WIRELESS COMMUNICATION SYSTEM}

The present disclosure generally relates to a wireless communication system, and more particularly, to an apparatus and method for using an exceptional resource pool among sidelink radio transmission resources 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, 5G communication systems are being considered for implementation in an ultra-high frequency (mmWave) band (eg, such as a 60 gigabyte (60 GHz) band). In order to mitigate the path loss of radio waves in the ultra-high frequency band and increase the propagation 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.

Meanwhile, the Internet is evolving from a human-centered connection network in which humans create and consume information, to an Internet of Things (IoT) network that exchanges and processes information between distributed components such as objects. IoE (Internet of Everything) technology, which combines IoT technology with big data processing technology through connection with cloud servers, etc., is also emerging. In order to implement IoT, technological elements such as sensing technology, wired/wireless communication and network infrastructure, service interface technology, and security technology are required. , M2M), and MTC (Machine Type Communication) technologies are being studied. In the IoT environment, intelligent IT (Internet Technology) services that create new value in human life by collecting and analyzing data generated from connected objects can be provided. IoT is the field of smart home, smart building, smart city, smart car or connected car, smart grid, healthcare, smart home appliance, advanced medical service, etc. through the convergence and combination of existing IT (information technology) technology and various industries. Can be applied to.

Accordingly, various attempts have been made to apply a 5G communication system to an IoT network. For example, technologies such as sensor network, machine to machine (M2M), and machine type communication (MTC) are implemented by techniques such as beamforming, MIMO, and array antenna, which are 5G communication technologies. will be. The application of a cloud radio access network (cloud RAN) as the big data processing technology described above can be said as an example of the convergence of 5G technology and IoT technology.

In addition, a terminal direct communication (sidelink communication) using a 5G communication system is being studied. For example, the direct terminal communication is applied to, for example, vehicle-to-everything (hereinafter referred to as'V2X'), and it is expected that various services can be provided to the user.

Based on the above discussion, the present disclosure provides an apparatus and method for processing an exceptional resource pool for transmitting sidelink data in a wireless communication system.

The present invention for solving the above problem is a control signal processing method in a wireless communication system, the method comprising: receiving a first control signal transmitted from a base station; Processing the received first control signal; And transmitting a second control signal generated based on the processing to the base station.

In the apparatus and method according to various embodiments of the present disclosure, when normal resources to transmit data through direct communication cannot be obtained, by using exceptional transmission resources, deterioration of service quality due to service interruption can be eliminated. Transmission collision due to congestion caused by excessive use and a decrease in packet reception rate can be effectively eliminated.

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.

1 illustrates 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 is a diagram illustrating a configuration of a communication unit in a wireless communication system according to various embodiments of the present disclosure.
5 illustrates a structure of a radio time-frequency resource of a wireless communication system according to various embodiments of the present disclosure.
6A to 6D illustrate examples of scenarios for sidelink communication in a wireless communication system according to various embodiments of the present disclosure.
7A and 7B illustrate examples of a sidelink communication transmission method in a wireless communication system according to various embodiments of the present disclosure.
8 illustrates an operation flow of a terminal using an exceptional resource pool according to various embodiments of the present disclosure.
9 illustrates an operation flow of a terminal using an exceptional resource pool according to various embodiments of the present disclosure.
10 illustrates an operation flow of a terminal using an exceptional resource pool according to various embodiments of the present disclosure.
11 illustrates an operation flow of a terminal using an exceptional resource pool according to various embodiments of the present disclosure.

Terms used in the present disclosure are only used 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 a person 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 meanings as those in the context of the related technology, and unless explicitly defined in the present disclosure, an ideal or excessively formal meaning It should not be 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 processing transmission resources for transmitting sidelink data in a wireless communication system. Specifically, the present disclosure relates to a method for transmitting data using an exceptional transmission resource pool in sidelink communication between a terminal and a terminal.

In the present disclosure, the operation of the terminal is a process of determining whether the condition for using the exceptional transmission resource pool is satisfied, the process of determining whether to set the exceptional transmission resource pool, and determining whether to set threshold information for determining the use of the exceptional transmission resource pool. The process of determining whether at least one of the congestion level of the pool or/and the priority of the sidelink logical channel or/and the delay time of the sidelink logical channel satisfies the corresponding threshold condition, and the resource is removed from the exceptional transmission resource pool. The process of selecting and transferring data

It may include at least one of.

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 referring to a physical channel through which data is transmitted, but 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. It is not to do. Conditions described as'above' may be replaced with'greater than', conditions described as'less than' and'less than', and conditions described as'above and below' may be replaced with'greater than and below'

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

According to various embodiments of the present disclosure, a method of operating a terminal in a wireless communication system includes a process of determining the use of a sidelink exceptional transmission resource pool, a process of determining whether a sidelink exceptional transmission resource pool is set, and a sidelink exceptional transmission resource pool. The process of measuring the congestion situation of the transmission resource pool, the process of obtaining the congestion level threshold information of the sidelink exceptional transmission resource pool, and the use of the exceptional transmission resource pool based on the congestion status of the sidelink exceptional transmission resource pool and the set threshold information It may include a process of determining, and a process of transmitting sidelink data using an exceptional transmission resource pool. In addition, a method of operating a terminal according to various embodiments of the present disclosure includes a process of determining a latency requirement of a sidelink flow to be transmitted, a process of determining the use of an exceptional transmission resource pool based on the latency requirement of a sidelink flow, and It may include a process of transmitting sidelink data using an exceptional transmission resource pool.

In addition, the method of operating a terminal according to various embodiments of the present disclosure includes a process of determining a latency requirement of a sidelink logical channel to be transmitted, and determining the use of an exceptional transmission resource pool based on the latency requirement of a sidelink logical channel. It may include a process and a process of transmitting sidelink data using an exceptional transmission resource pool.

In addition, a method of operating a terminal according to various embodiments of the present disclosure may include a process of receiving HARQ feedback through HARQ feedback resources of an exceptional transmission resource pool.

In addition, 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 determines the necessity of using the exceptional transmission resource pool, determines whether the exceptional transmission resource pool is set, measures the congestion level of the exceptional transmission resource pool, determines the use of the exceptional transmission resource pool, and performs exceptional transmission. Sidelink data can be transmitted using a resource pool. The at least one processor may determine a latency requirement of a sidelink flow to use the exceptional transmission resource pool, and transmit sidelink data using the exceptional transmission resource pool. The at least one processor may determine a latency requirement of a sidelink logical channel to use the exceptional transmission resource pool, and transmit sidelink data using the exceptional transmission resource pool. The at least one processor may receive HARQ feedback transmitted from HARQ feedback resources of an exceptional transmission resource pool.

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

1 illustrates a base station 110, a first terminal 120, and a second terminal 130 as some of nodes using a radio channel in a wireless communication system. FIG. 1 shows only one base station, but this is only an example, and another base station that is the same as or similar to the base station 110 may be further included.

The base station 110 is a network infrastructure that provides wireless access to the terminals 120 and 130. The base station 110 has coverage defined as a certain geographic area based on a distance at which signals can be transmitted. In addition to the base station, the base station 110 includes'access point (AP)','eNodeB, eNB', '5G node', and'next generation nodeB. , gNB)','wireless point','transmission/reception point (TRP)', or another term having an equivalent technical meaning.

Each of the first terminal 120 and the second terminal 130 is a device used by a user and performs communication with the base station 110 through a wireless channel. The link from the base station 110 to the first terminal 120 or the second terminal 130 is a downlink (DL), the first terminal 120 or the second terminal 130 to the base station 110 The link is referred to as uplink (UL). In addition, the first terminal 120 and the second terminal 130 may communicate with each other through a wireless channel. In this case, the link between the first terminal 120 and the second terminal 130 is referred to as a sidelink, and the sidelink may be mixed with the PC5 interface. In some cases, at least one of the first terminal 120 and the second terminal 130 may be operated without a user's involvement. For example, at least one of the first terminal 120 and the second terminal 130 is a device that performs machine type communication (MTC) and may not be carried by a user. Each of the first terminal 120 and the second terminal 130 is a terminal other than'user equipment (UE)','mobile station','subscriber station','remote It may be referred to as a remote terminal, a wireless terminal, or a user device, or another term having an equivalent technical meaning.

The base station 110, the first terminal 120, and the second terminal 130 may transmit and receive radio signals in a millimeter wave (mmWave) band (eg, 28 GHz, 30 GHz, 38 GHz, 60 GHz). In this case, in order to improve the channel gain, the base station 110, the first terminal 120, and the second terminal 130 may perform beamforming. Here, beamforming may include transmission beamforming and reception beamforming. For example, the base station 110, the first terminal 120, and the second terminal 130 may impart directivity to a transmitted signal or a received signal. To this end, the base station 110 and the terminals 120 and 130 may select the serving beams 112, 113, 121, 131 through a beam search or beam management procedure. . After the serving beams 112, 113, 121, 131 are selected, subsequent communication may be performed through a resource in a QCL (quasi co-located) relationship with the resource transmitting the serving beams 112, 113, 121, 131. have.

If the large-scale characteristics of the channel carrying the symbol on the first antenna port can be inferred from the channel carrying the symbol on the second antenna port, the first antenna port and the second antenna port are in a QCL relationship. Can be evaluated. For example, a wide range of features include delay spread, Doppler spread, Doppler shift, average gain, average delay, and spatial receiver parameter. It may include at least one of.

The first terminal 120 and the second terminal 120 shown in FIG. 1 may support vehicle communication. In the case of vehicle communication, in the LTE system, standardization work for V2X technology based on device-to-device (D2D) communication structure was completed in 3GPP Release 14 and Release 15, and V2X technology is currently based on 5G NR. Efforts to develop are underway. NR V2X plans to support unicast communication, groupcast (or multicast) communication, and broadcast communication between the terminal and the terminal. In addition, NR V2X, unlike LTE V2X, which aims to transmit and receive basic safety information necessary for vehicle driving on the road, is a group driving (platooning), advanced driving (advanced driving), extended sensor (extended sensor), remote driving (remote driving) and Together, we aim to provide more advanced services.

V2X service can be divided into basic safety service and advanced service. Basic safety services include vehicle notification (CAM (cooperative awareness messages) or BSM (basic safety message)) service, left turn notification service, front vehicle collision warning service, emergency vehicle approach notification service, front obstacle warning service, intersection signal information. It may include detailed services such as services. In addition, V2X information may be transmitted and received using a broadcast, unicast, or groupcast transmission method. The advanced service not only strengthens the quality of service (QoS) requirements than the basic safety service, but also unicasts in addition to broadcast so that V2X information can be transmitted and received within a specific vehicle group or V2X information between two vehicles. And a scheme for transmitting and receiving V2X information using a groupcast transmission method. Advanced services may include detailed services such as platoon driving service, autonomous driving service, remote driving service, and extended sensor-based V2X service.

Hereinafter, a sidelink (SL) refers to a signal transmission/reception path between the terminal and the terminal, which can be mixed with the PC5 interface. Hereinafter, a base station is a subject that performs resource allocation of a terminal, and may be a base station supporting both V2X communication and general cellular communication, or a base station supporting only V2X communication. For example, the base station may mean an NR base station (eg, gNB), an LTE base station (eg, eNB), or a road site unit (RSU). The terminal is a vehicle that supports vehicle-to-vehicular communication (V2V), as well as general user equipment and mobile stations, and vehicle-to-pedestrian communication (vehicular-to-pedestrian, V2P). ), a vehicle or a pedestrian's handset (for example, a smartphone), a vehicle that supports vehicle-to-network communication (vehicular-to-network, V2N), or a vehicle-to-transportation infrastructure (vehicular-to-infrastructure) , V2I) support vehicle and an RSU equipped with a terminal function, an RSU equipped with a base station function, or a part of a base station function and an RSU equipped with a part of the terminal function may be included. In addition, the V2X terminal used in the following description may be referred to as a terminal. That is, in connection with V2X communication, the terminal can be used as a V2X terminal.

The base station and the terminal are connected through the Uu interface. Uplink (UL) refers to a radio link through which the UE transmits data or control signals to the base station, and downlink (DL) refers to a radio link through which the base station transmits data or control signals to the UE.

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 110. Used below'… Boo','… A term such as'group' refers to a unit that processes at least one function or operation, which may be implemented by hardware or software, or a combination of hardware and software.

Referring to FIG. 2, the base station 110 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 then 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. Furthermore, 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 operation power, operation 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 is used in a sense including the processing as described above 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. For example, the backhaul communication unit 220 converts a bit stream transmitted from the base station 110 to another node, for example, another access node, another base station, an upper node, a core network, etc., into a physical signal, and Converts the received physical signal into a 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 110. 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 control unit 240 controls overall operations of the base station 110. For example, the control unit 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 110 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. Used below'… Boo','… A term such as'group' refers to a unit that processes at least one function or operation, which may be implemented by hardware or software, or a combination of hardware and software.

Referring to FIG. 3, the terminal 120 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 then 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 include a digital circuit and an analog circuit (eg, 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 is 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 120. 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 120. 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 controller 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 120 to perform operations according to various embodiments to be described later.

4 is a diagram illustrating 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.

Referring to FIG. 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 a different 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 digital beamforming unit 404 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 structure of a radio time-frequency resource of a wireless communication system according to various embodiments of the present disclosure.

Referring to FIG. 5, in the radio resource domain, the horizontal axis represents the time domain and the vertical axis represents the frequency domain. The minimum transmission unit in the time domain is an OFDM symbol or a DFT-S-OFDM symbol, and one of N _symb OFDM symbols or DFT-S-OFDM symbols 530 Included in the slot 505 of. Unlike the slot, in the NR system, the length of the subframe may be defined as 1.0 ms, and the length of the radio frame 500 may be defined as 10 ms. The minimum transmission unit in the frequency domain is a subcarrier, and the bandwidth of the entire system transmission bandwidth may include a total of N _BW subcarriers 525. Specific values such as N _symb and N _BW can be variably applied depending on the system.

The basic unit of the time-frequency resource region is a resource element (RE) 510, which may be represented by an OFDM symbol index or a DFT-S-OFDM symbol index and a subcarrier index. A resource block (RB 515) _{may be defined as N RB} consecutive subcarriers 520 in the frequency domain. In general, the minimum transmission unit of data is an RB unit, and in an NR system generally N _symb = 14, N _RB = 12.

The structure of the radio time-frequency resource as shown in FIG. 5 is applied to the Uu interface. In addition, the radio time-frequency resource as shown in FIG. 5 can be similarly applied to the sidelink.

6A to 6D illustrate examples of scenarios for sidelink communication in a wireless communication system according to various embodiments of the present disclosure.

6A illustrates an in-coverage scenario in which sidelink terminals 620a and 620b are located within the coverage of the base station 610. The sidelink terminals 620a and 620b may receive data and control information from the base station 610 through downlink (DL). In addition, the sidelink terminals 620a and 620b may transmit data and control information to the base station through uplink (UL). In this case, the data and control information may be data and control information for sidelink communication, or data and control information for general cellular communication other than sidelink communication. In addition, sidelink terminals 620a and 520b in FIG. 6A may transmit and receive data and control information for sidelink communication through a sidelink.

6B illustrates a case of partial coverage in which the first terminal 620a is located within the coverage of the base station 610 and the second terminal 620b is located outside the coverage of the base station 610 among sidelink terminals. . The first terminal 620a located within the coverage of the base station 610 may receive data and control information from the base station through downlink or transmit data and control information to the base station through uplink. The second terminal 620b located outside the coverage of the base station 610 cannot receive data and control information from the base station through downlink, and cannot transmit data and control information to the base station through uplink. The second terminal 620b may transmit and receive data and control information for sidelink communication with the first terminal 620a through a sidelink.

6C is an example of a case in which sidelink terminals (eg, a first terminal 620a and a second terminal 620b) are located outside the coverage of a base station. Accordingly, the first terminal 620a and the second terminal 620b cannot receive data and control information from the base station through downlink, and cannot transmit data and control information to the base station through uplink. The first terminal 620a and the second terminal 620b may transmit and receive data and control information for sidelink communication through a sidelink.

6D shows that the first terminal 620a and the second terminal 620b performing sidelink communication are connected to different base stations (eg, the first base station 610a, the second base station 610b) or (example : RRC connection state) or camping (eg, RRC connection release state, RRC idle state), an example of performing inter-cell sidelink communication. In this case, the first terminal 620a may be a sidelink transmitting terminal and the second terminal 620b may be a sidelink receiving terminal. Alternatively, the first terminal 620a may be a sidelink receiving terminal and the second terminal 620b may be a sidelink transmitting terminal. The first terminal 620a may receive a sidelink-only system information block (SIB) from the base station 610a to which it is connected (or camping), and the second terminal 620b is It is possible to receive a sidelink-only SIB from another base station (620b) (or it is camping). In this case, the information of the sidelink-only SIB received by the first terminal 620a and the information of the sidelink-only SIB received by the second terminal 620b may be different from each other. Accordingly, it is necessary to unify information in order to perform sidelink communication between terminals located in different cells.

In the example shown in FIGS. 6A to 6D, for convenience of explanation, a sidelink system consisting of two terminals (eg, a first terminal 610a and a second terminal 620b) has been described as an example, but the present invention Is not limited thereto, and may be applied to a sidelink system in which three or more terminals participate. In addition, the uplink and downlink between the base station 610 and the sidelink terminals may be referred to as a Uu interface, and the sidelink between the sidelink terminals may be referred to as a PC-5 interface. In the following description, uplink or downlink and Uu interfaces, sidelinks, and PC-5 may be used interchangeably.

Meanwhile, in the present disclosure, the terminal is a vehicle supporting vehicle-to-vehicular communication (vehicular-to-vehicular, V2V), a vehicle supporting vehicle-to-pedestrian communication (vehicular-to-pedestrian, V2P), or a handset of a pedestrian (eg: Smartphone), vehicle-to-network communication (vehicular-to-network, V2N), or vehicle-to-infrastructure communication (vehicular-to-infrastructure, V2I) . In addition, in the present disclosure, the terminal may mean a road side unit (RSU) equipped with a terminal function, an RSU equipped with a base station function, or an RSU equipped with a part of the base station function and a part of the terminal function.

7A and 7B illustrate examples of a sidelink communication transmission method in a wireless communication system according to various embodiments of the present disclosure. 7A illustrates a unicast method, and FIG. 7B illustrates a groupcast method.

As shown in FIG. 7A, the transmitting terminal 720a and the receiving terminal 720b may perform one-to-one communication. The transmission scheme shown in FIG. 7A may be referred to as unicast communication. As shown in FIG. 7B, the transmitting terminal 720a or 720d and the receiving terminals 720b, 720c, 720e, 720f, and 720g may perform one-to-many communication. The transmission scheme shown in FIG. 7B may be referred to as groupcast or multicast. In FIG. 7B, a first terminal 720a, a second terminal 720b, and a third terminal 720c form a group, perform groupcast communication, and the fourth terminal 720d, Terminal 5 (720e), terminal 6 (720f), terminal 7 (720g) may form different groups and perform groupcast communication. Terminals may perform groupcast communication within a group to which they belong, and may perform unicast, groupcast, or broadcast communication with at least one other terminal belonging to different groups. In FIG. 7B, two groups are illustrated, but the present invention is not limited thereto, and may be applied even when a larger number of groups are formed.

Meanwhile, although not shown in FIGS. 7A or 7B, sidelink terminals may perform broadcast communication. Broadcast communication refers to a method in which all sidelink terminals receive data and control information transmitted by a sidelink transmitting terminal through a sidelink. For example, in FIG. 7B, if the first terminal 720a is a transmitting terminal, the remaining terminals 720b, 720c, 720d, 720e, 720f, and 720g receive data and control information transmitted by the first terminal 720a. can do.

The aforementioned sidelink unicast communication, groupcast communication, and broadcast communication are supported in an in-coverage scenario, a partial-coverage scenario, or an out-of-coverage scenario. Can be.

In the case of the NR sidelink, unlike in the LTE sidelink, a transmission type in which a vehicle terminal transmits data to only one specific terminal through unicast and a transmission type in which data is transmitted to a plurality of specific terminals through groupcast are supported. Can be considered. For example, when considering a service scenario such as platooning, which is a technology that connects two or more vehicles to one network and moves in a cluster form, such unicast and groupcast technologies can be usefully used. Specifically, unicast communication can be used for the purpose of a group leader terminal connected by platooning to control one specific terminal, and groupcast communication for the purpose of simultaneously controlling a group consisting of a plurality of specific terminals. Can be used.

Resource allocation in the V2X system can be used in the following ways.

(1) Mode 1 resource allocation

Scheduled resource allocation is a method in which a base station allocates resources used for sidelink transmission to RRC-connected terminals in a dedicated scheduling scheme. The scheduled resource allocation method can be effective for interference management and resource pool management (dynamic allocation and/or semi-persistent transmission) because the base station can manage the resources of the sidelink. When there is data to be transmitted to other terminal(s), the RRC connected mode terminal informs the base station that there is data to be transmitted to the other terminal(s) by using an RRC message or a MAC control element (hereinafter'CE') Can be transmitted. For example, the RRC message transmitted from the terminal to the base station may be a sidelink terminal information (SidelinkUEInformation), terminal assistance information (UEAssistanceInformation) message, and the MAC CE is a buffer status report (BSR) for V2X communication. A BSR MAC CE, SR (scheduling request), etc. including at least one of information on the size of data buffered for sidelink communication and an indicator indicating that it is the same may be applicable.

(2) Mode 2 resource allocation

Second, UE autonomous resource selection provides the sidelink transmission/reception resource pool for V2X to the terminal as system information or RRC message (for example, RRC Reconfiguration message, PC5-RRC message), and the terminal It is a method of selecting a resource pool and a resource according to this set rule. The terminal autonomous resource selection may correspond to one of the following resource allocation methods or a plurality of methods.

> UE autonomously selects sidelink resource for transmission.

> The UE assists in sidelink resource selection for other UEs (UE assists sidelink resource selection for other UEs).

> The terminal receives the configured grant of the NR for sidelink transmission (UE is configured with NR configured grant for sidelink transmission).

> The UE may schedule sidelink transmission of other UEs (UE schedules sidelink transmission of other UEs).

-The resource selection method of the terminal may include zone mapping, sensing-based resource selection, random selection, and the like.

-In addition, even if it exists in the coverage of the base station, it may not be possible to perform resource allocation or resource selection in a scheduled resource allocation or terminal autonomous resource selection mode.In this case, the terminal is a preconfigured sidelink transmission/reception resource pool. Through the V2X sidelink communication can also be performed.

-In addition, when the terminals for V2X communication exist outside the coverage of the base station, the terminal may perform V2X sidelink communication through a preset sidelink transmission/reception resource pool.

SLRB configuration and SLRB for transmitting sidelink flows or packets are mapped to an SL logical channel group (LCG), and the SL LCG may be mapped to an SL logical channel. SLRB configuration and SLRB include source index, destination index, cast type, QFI (QoS flow identifier)/PFI (ProSe flow identifier or PC5 flow identifier) or priority, etc. It can be classified as a combination of.

(1) Exceptional transmission resource pool usage plan

The exceptional resource pool is a transmission resource set to be temporarily used when it is determined that the terminal cannot use the normal resource pool.

In a wireless communication system according to various embodiments of the present disclosure, when an exceptional resource pool for transmission is used to transmit and receive data based on a sidelink between terminals, at least one or a combination of the following [Table 1] may be included.

If a terminal performing direct communication between terminals determines the necessity of using an exceptional resource pool for transmission and has exceptional resource pool setting information, the terminal randomly selects a transmission resource from the exceptional resource pool and selects the selected resource. Data can be transmitted through. Data transmitted by the UE in a resource randomly selected from the exceptional resource pool may include at least one of sidelink control information (SCI), sidelink user packet, and sidelink HARQ feedback.

The exceptional resource pool can be used in sidelink unicast, sidelink groupcast, and sidelink broadcast based transmission schemes. As an embodiment, when the exceptional resource pool is used in a sidelink unicast or sidelink groupcast-based transmission scheme, a resource for transmitting and receiving HARQ feedback may be selected from the exceptional resource pool. As an embodiment, the transmitting terminal may provide the HARQ feedback resource information to the receiving terminal by randomly selecting a HARQ feedback transmission/reception resource from an exceptional resource pool. The transmitting terminal and the receiving terminal may respectively receive and transmit HARQ feedback from the HARQ feedback resource information.

As another embodiment, when the exceptional resource pool is used in sidelink unicast, sidelink groupcast, and sidelink broadcast transmission schemes, the transmitting terminal may perform HARQ repetition transmission, and the resource for HARQ repetition transmission is It can be arbitrarily selected from the exceptional resource pool.

When multiple terminals use the exceptional resource pool, congestion use for the exceptional resource pool may occur. Accordingly, transmission collisions between terminals may occur in the exceptional resource pool, and the packet reception rate may decrease, resulting in a decrease in service quality and reliability. Therefore, it is necessary to apply a congestion control scheme for the exceptional resource pool. The terminal may determine whether to use the exceptional resource pool or/and the priority of use based on at least one or a combination of the congestion degree of the exceptional pool and the QoS of a service using the exceptional pool.

As an embodiment, a congestion threshold may be set for an exceptional resource pool. The congestion level threshold may correspond to a reference value of a channel busy ratio (CBR). The CBR may represent the share of the resource pool, the usage rate, and the like. When the UE measures the CBR for the resource pool, if the CBR of the pool exceeds the threshold, it may be determined that it is congested, and if the CBR of the pool does not exceed the threshold, it may be determined that it is not congested. If the CBR of the pool does not exceed the threshold, the UE may transmit sidelink data by selecting a resource from the exceptional resource pool (randomly selected). When the number of exceptional resource pools is more than one, the congestion threshold may be set for all pools or may be set for each pool. When configured for each pool, the terminal may determine whether the CBR threshold condition for each pool is satisfied, and select an exceptional pool that satisfies the condition, and may select a resource from the pool to transmit sidelink data. The terminal may obtain the congestion level threshold through at least one of an RRC dedicated message, an SIB message, and pre-configuration set by the system.

The operation of the terminal will be described in detail with reference to FIG. 8. First, in step 801, the terminal may determine whether at least one of the conditions of [Table 1] is satisfied. As a result of the determination in step 801, when at least one of the conditions in [Table 1] is satisfied, the terminal may determine to use an exceptional transmission resource pool. The terminal may determine whether an exceptional transmission resource pool is set in step 803. The exceptional transmission resource pool may be configured in at least one of an RRC-dedicated message, an SIB message, and pre-configuration. If it is determined that the exceptional transmission resource pool is set as a result of the determination in step 803, the terminal may check the setting of the congestion level threshold for the use of the exceptional transmission resource pool in step 805. In step 807, the terminal may measure the degree of congestion for the exceptional transmission resource pool. In step 809, the terminal may determine whether the congestion degree of the exceptional transmission resource pool satisfies a threshold. For example, if the congestion degree of the pool is lower than the threshold, it may be determined that the threshold condition is satisfied. If the congestion of the pool is higher than the threshold, it can be determined that the threshold condition is not satisfied. As a result of the determination in step 809, when it is determined that the congestion degree of the exceptional transmission resource pool satisfies the threshold condition, the terminal may arbitrarily select a transmission resource from the exceptional transmission resource pool and may transmit sidelink data through the transmission resource. As a result of the determination in step 801, if it is determined that at least one condition in [Table 1] is not satisfied, the terminal may proceed to operation 1 in step 813. For example, in operation 1, the UE may select a transmission resource from a normal transmission resource pool rather than an exceptional transmission resource pool, or may transmit sidelink data through the acquired transmission resource after being allocated a transmission resource from the base station. As a result of the determination in step 803, if it is determined that the exceptional transmission resource pool is not set, the terminal may proceed to operation 2 in step 815. For example, in operation 2, the UE may wait for a normal transmission resource pool other than an exceptional transmission resource pool to be established, or wait for a transmission resource to be allocated from the base station. When a normal transmission resource pool is established or transmission resources are allocated from the base station, the terminal may transmit sidelink data through the acquired transmission resources. As a result of the determination in step 809, if it is determined that the congestion degree of the pool does not satisfy the threshold condition, the terminal may proceed to operation 2 in step 815. As another embodiment of the case in which the terminal determines that the pool congestion level does not satisfy the threshold condition proceeds to operation 2 in step 815, the terminal may wait until the congestion level of the exceptional transmission resource pool satisfies the threshold. As another embodiment, the UE stops using the exceptional transmission resource pool when a normal transmission resource pool is established while waiting until the congestion level of the exceptional transmission resource pool satisfies a threshold to acquire transmission resources or allocate transmission resources from the base station. can do.

As an embodiment, a priority threshold may be set for an exceptional resource pool. The priority threshold may be set based on the priority of the sidelink logical channel. The priority threshold may be set based on a priority of a sidelink flow transmitted through a sidelink logical channel. The priority threshold may be set based on the priority of the sidelink packet to be transmitted. Here, an embodiment of the sidelink packet may include a sidelink MAC CE (control element). The UE compares the priority of the sidelink flow and/or the sidelink logical channel and/or the sidelink packet corresponding to the data to be transmitted with the priority threshold, and the priority of the sidelink flow and/or the sidelink logical channel and/or the sidelink packet. If it is determined that is high, a resource may be selected from the exceptional resource pool, and sidelink data corresponding to a sidelink logical channel and/or a sidelink flow and/or a sidelink packet satisfying the above condition may be transmitted through the selected resource. The priority threshold may be set for all pools or may be set for each pool when there is more than one exceptional resource pool. When configured for each pool, the UE may select an exceptional pool by determining whether the priority threshold condition for each pool is satisfied, and select a resource from the selected pool to transmit sidelink data. The UE may obtain the priority threshold through at least one of an RRC dedicated message, a SIB message, and pre-configuration set by the system. The method of using an exceptional resource pool based on priority has the advantage of being able to preferentially process a sidelink flow or/and a sidelink logical channel or/and a sidelink packet with a high priority.

Meanwhile, referring to FIG. 9 according to an embodiment of the present invention, the terminal may determine whether at least one of the conditions of [Table 1] is satisfied in step 901. As a result of the determination in step 901, when at least one of the conditions of [Table 1] is satisfied, the terminal may determine to use the exceptional transmission resource pool. Specifically, the terminal may determine whether an exceptional transmission resource pool is set in step 903. The exceptional transmission resource pool may be configured in at least one of an RRC-dedicated message, an SIB message, and pre-configuration. If it is determined that the exceptional transmission resource pool is set as a result of the determination in step 903, the terminal may check the priority threshold setting for the use of the exceptional transmission resource pool in step 905. In step 907, the UE may check the priority of the sidelink flow and/or the sidelink logical channel and/or the sidelink packet corresponding to the data to be transmitted. In step 909, the UE may determine whether the priority of the sidelink flow and/or the sidelink logical channel and/or the sidelink packet satisfies a priority threshold. For example, if the priority of the sidelink flow and/or the sidelink logical channel and/or the sidelink packet is higher than the priority threshold, it may be determined that the threshold condition is satisfied. If the priority of the sidelink flow and/or the sidelink logical channel and/or the sidelink packet is lower than the priority threshold, it may be determined that the threshold condition is not satisfied. As a result of the determination in step 909, if it is determined that the priority of the sidelink flow and/or the sidelink logical channel and/or the sidelink packet satisfies the priority threshold condition, the terminal may randomly select a transmission resource from the exceptional transmission resource pool, and the Sidelink data can be transmitted through transmission resources. As a result of the determination in step 901, if it is determined that at least one condition in [Table 1] is not satisfied, the terminal may proceed to operation 1 in step 913. For example, in operation 1, the UE may select a transmission resource from a normal transmission resource pool rather than an exceptional transmission resource pool, or may transmit sidelink data through the acquired transmission resource after being allocated a transmission resource from the base station. As a result of the determination in step 903, if it is determined that the exceptional transmission resource pool is not set, the terminal may proceed to operation 2 in step 915. For example, in operation 2, the UE may wait for a normal transmission resource pool other than an exceptional transmission resource pool to be established, or wait for a transmission resource to be allocated from the base station. When a normal transmission resource pool is established or transmission resources are allocated from the base station, the terminal may transmit sidelink data through the acquired transmission resources. As a result of the determination in step 909, if it is determined that the priority of the sidelink flow and/or the sidelink logical channel and/or the sidelink packet does not satisfy the threshold condition, the terminal may proceed to operation 2 in step 915. As another embodiment of the case in which the terminal determined that the priority threshold condition is not satisfied proceeds to operation 2 in step 915, the terminal may wait until the priority threshold for the exceptional transmission resource pool is satisfied. As another embodiment, the UE stops using the exceptional transmission resource pool when a normal transmission resource pool is established while waiting until the priority threshold for the exceptional transmission resource pool is satisfied to acquire transmission resources or allocate transmission resources from the base station. can do.

As an embodiment, a latency threshold may be set for an exceptional resource pool. The latency threshold may be set based on a packet delay budget of a PQI (ProSe QoS indicator) or 5QI (5G QoS indicator) of a sidelink flow. The latency threshold may be set based on a latency request value of a sidelink logical channel. The latency threshold may be set based on a latency request value of a sidelink packet. Here, an embodiment of the sidelink packet may include a MAC CE (control element). The UE compares the latency of the sidelink flow and/or the sidelink logical channel and/or the sidelink packet corresponding to the data to be transmitted with the latency threshold, so that the latency of the sidelink flow and/or the sidelink logical channel and/or the sidelink packet is reduced. If it is determined that it is less than the threshold, a resource can be selected from an exceptional resource pool, and sidelink data corresponding to a sidelink logical channel and/or a sidelink flow and/or a sidelink packet satisfying the above condition can be transmitted through the selected resource. . The latency threshold may be set for all pools or for each pool when there is more than one exceptional resource pool. When configured for each pool, the UE determines whether the latency of the sidelink logical channel and/or the sidelink flow and/or the sidelink packet for each pool satisfies the latency threshold condition and selects an exceptional pool that satisfies the threshold condition. It can be selected, and sidelink data can be transmitted by selecting a resource from the pool. The terminal may obtain the latency threshold through at least one of an RRC dedicated message, an SIB message, and pre-configuration set by the system. The method of using an exceptional resource pool based on latency has the advantage of being able to preferentially process a sidelink flow or/and a sidelink logical channel or/and a sidelink packet having a short data transmission request time. A method of determining the use of the exceptional transmission resource pool based on the latency is similar to that of FIG. 9, and a latency threshold may be set for the use of the exceptional transmission resource pool, and the terminal It is possible to perform an operation of determining whether the latency of the link logical channel and/or the sidelink packet satisfies the latency threshold.

As an embodiment, at least one or a combination of a CBR threshold, a priority threshold, and a latency threshold may be set for the exceptional resource pool. When multiple pools are set, the threshold may be set to a value applied to all pools or may be set for each pool. The terminal may measure the degree of congestion for the exceptional resource pool, and may compare the measured congestion degree and the CBR threshold. When the priority threshold is set equal to the CBR threshold, the terminal is configured with a sidelink flow and/or sidelink logical channel and/or side with a priority higher than the priority threshold corresponding to the sidelink flow and/or sidelink logical channel and/or sidelink packet. For a link packet, when the CBR threshold is satisfied, a transmission resource may be randomly selected from an exceptional resource pool to transmit sidelink data corresponding to the sidelink flow and/or the sidelink logical channel and/or the sidelink packet. When the latency threshold is set equal to the CBR threshold, the terminal is configured to provide a sidelink flow and/or a sidelink logical channel and/or a sidelink that satisfies a latency threshold corresponding to a sidelink flow and/or a sidelink logical channel and/or a sidelink packet. For a packet, when the CBR threshold is satisfied, a transmission resource may be randomly selected from an exceptional resource pool to transmit sidelink data corresponding to the sidelink flow and/or the sidelink logical channel and/or the sidelink packet. When the CBR threshold, the priority threshold, and the latency threshold are set together, and when it is determined that all of the conditions for each of the thresholds are satisfied, the UE may select a resource from the exceptional transmission resource pool and transmit data.

Meanwhile, referring to FIG. 10 according to an embodiment of the present invention, the terminal may determine whether at least one of the conditions of [Table 1] is satisfied in step 1001. As a result of the determination in step 1001, when at least one of the conditions of [Table 1] is satisfied, the terminal may determine to use an exceptional transmission resource pool. The terminal may determine whether an exceptional transmission resource pool is set in step 1003. The exceptional transmission resource pool may be configured in at least one of an RRC-dedicated message, an SIB message, and pre-configuration. As a result of the determination in step 1003, if it is determined that the exceptional transmission resource pool is set, the terminal may check the setting of the congestion level threshold and the priority threshold for the use of the exceptional transmission resource pool in step 1005. The terminal may measure the congestion degree for the exceptional transmission resource pool in step 1007. In step 1007, the terminal may check the priority of the sidelink flow and/or the sidelink logical channel and/or the sidelink packet corresponding to the data to be transmitted. Here, an embodiment of the sidelink packet may include a sidelink MAC control element (CE). The terminal may determine whether the congestion degree of the exceptional transmission resource pool satisfies a threshold in step 1009. For example, if the congestion degree of the pool is lower than the threshold, it may be determined that the threshold condition is satisfied. If the congestion of the pool is higher than the threshold, it can be determined that the threshold condition is not satisfied. In step 1009, the UE may determine whether the priority of the sidelink flow and/or the sidelink logical channel and/or the sidelink packet satisfies a priority threshold. For example, if the priority of the sidelink flow and/or the sidelink logical channel and/or the sidelink packet is higher than the priority threshold, it may be determined that the threshold condition is satisfied. If the priority of the sidelink flow and/or the sidelink logical channel and/or the sidelink packet is lower than the priority threshold, it may be determined that the threshold condition is not satisfied. As a result of the determination in step 1009, if it is determined that the congestion of the exceptional transmission resource pool satisfies the threshold condition and the priority of the sidelink flow and/or the sidelink logical channel and/or the sidelink packet satisfies the priority threshold condition, the UE A transmission resource can be arbitrarily selected from the transmission resource pool, and sidelink data can be transmitted through the transmission resource. As a result of the determination in step 1001, if it is determined that at least one condition in [Table 1] is not satisfied, the terminal may proceed to operation 1 in step 1013. For example, in operation 1, the UE may select a transmission resource from a normal transmission resource pool rather than an exceptional transmission resource pool, or may transmit sidelink data through the acquired transmission resource after being allocated a transmission resource from the base station. As a result of the determination in step 1003, if it is determined that the exceptional transmission resource pool is not set, the terminal may proceed to operation 2 in step 1015. For example, in operation 2, the UE may wait for a normal transmission resource pool other than an exceptional transmission resource pool to be established, or wait for a transmission resource to be allocated from the base station. When a normal transmission resource pool is established or transmission resources are allocated from the base station, the terminal may transmit sidelink data through the acquired transmission resources. As a result of the determination in step 1009, if it is determined that at least one of the threshold condition of the exceptional transmission resource pool congestion or the priority of a sidelink flow and/or a sidelink logical channel and/or a sidelink packet is not satisfied, the terminal 1015 You can proceed to step 2 of operation. As another embodiment of the case in which the terminal determines that the priority threshold condition is not satisfied in step 1015 proceeds to operation 2, the terminal may wait until the priority threshold for the exceptional transmission resource pool is satisfied. As another embodiment, the UE stops using the exceptional transmission resource pool when a normal transmission resource pool is established while waiting until the priority threshold for the exceptional transmission resource pool is satisfied to acquire transmission resources or allocate transmission resources from the base station. can do.

In the embodiment of FIG. 10, the case where the congestion level threshold and the priority threshold are set has been described, and even when the latency threshold is set together, the operation of the terminal based on the priority threshold can be similarly applied.

As an embodiment, at least one or a combination of a CBR threshold, a priority threshold, and a latency threshold may be set for the exceptional resource pool. The terminal may measure the degree of congestion for the exceptional resource pool, and may compare the measured congestion degree and the CBR threshold. When the measured congestion degree for the exceptional resource pool satisfies the CBR threshold, the terminal may transmit sidelink data through a resource arbitrarily selected from the exceptional resource pool. When the measured congestion degree for the exceptional resource pool does not satisfy the CBR threshold, the terminal may check the set priority threshold (and/or latency threshold). When the priority threshold (and/or latency threshold) is set, the UE has a priority (and/or latency) for a sidelink flow and/or a sidelink logical channel and/or a sidelink packet is a priority threshold (and/or a latency threshold). You can determine whether you are satisfied with When it is determined that there is a sidelink flow and/or a sidelink logical channel and/or a sidelink packet that satisfies the priority threshold (and/or latency threshold), the terminal randomly selects a transmission resource from the exceptional resource pool and the sidelink flow And/or sidelink data corresponding to a sidelink logical channel and/or a sidelink packet may be transmitted.

Meanwhile, referring to FIG. 11 according to an embodiment of the present invention, the terminal may determine whether at least one of the conditions of [Table 1] is satisfied in step 1101. As a result of the determination in step 1101, when at least one of the conditions of [Table 1] is satisfied, the terminal may determine to use an exceptional transmission resource pool. The terminal may determine whether an exceptional transmission resource pool is set in step 1103. The exceptional transmission resource pool may be configured in at least one of an RRC-dedicated message, an SIB message, and pre-configuration. As a result of the determination in step 1103, if it is determined that the exceptional transmission resource pool is set, the terminal may check configuration information for at least one or a combination of a congestion level threshold, a priority threshold, and a latency threshold for the use of the exceptional transmission resource pool in step 1105. . When multiple exceptional transmission resource pools are set, at least one or a combination of the congestion threshold, priority threshold, and latency threshold may be set for each pool or may be set in common for all pools. The terminal may measure a congestion degree for the exceptional transmission resource pool in step 1107. The terminal may determine whether the congestion degree of the exceptional transmission resource pool satisfies a threshold in step 1109. For example, if the congestion degree of the pool is lower than the threshold, it may be determined that the threshold condition is satisfied. If the congestion of the pool is higher than the threshold, it can be determined that the threshold condition is not satisfied. If the terminal determines that the pool congestion level satisfies the threshold condition according to the determination in step 1109, the terminal may arbitrarily select a transmission resource from the exceptional transmission resource pool in step 1111 and transmit sidelink data through the transmission resource. If the UE determines that the pool congestion does not satisfy the threshold condition according to the determination in step 1109, the UE determines the priority of the sidelink flow and/or sidelink logical channel and/or sidelink packet corresponding to the data to be transmitted in step 1113 (and /Or latency). In step 1115, the UE may determine whether the priority (and/or latency) of the sidelink flow and/or sidelink logical channel and/or sidelink packet satisfies a priority threshold (and/or latency threshold). For example, if the priority of the sidelink flow and/or the sidelink logical channel and/or the sidelink packet is higher than the priority threshold, the terminal may determine that the threshold condition is satisfied. If the priority of the sidelink flow and/or the sidelink logical channel and/or the sidelink packet is lower than the priority threshold, the terminal may determine that the threshold condition is not satisfied. For example, if the latency of the sidelink flow and/or the sidelink logical channel and/or the sidelink packet has a higher priority than the latency threshold, the terminal may determine that the threshold condition is satisfied. If the latency of the sidelink flow and/or the sidelink logical channel and/or the sidelink packet is lower than the latency threshold, the terminal may determine that the threshold condition is not satisfied. As a result of the determination in step 1115, if it is determined that the priority (and/or latency) of the sidelink flow and/or the sidelink logical channel and/or the sidelink packet satisfies the priority threshold (and/or latency threshold) condition, the terminal In step 1117, a resource for transmitting data of a sidelink flow and/or a sidelink logical channel and/or a sidelink packet that satisfies the condition may be arbitrarily selected from the set exceptional transmission resource pool, and the sidelink through the selected transmission resource Link data can be transmitted. As a result of the determination in step 1101, if it is determined that at least one condition in [Table 1] is not satisfied, the terminal may proceed to operation 1 in step 1119. For example, in operation 1, the UE may select a transmission resource from a normal transmission resource pool rather than an exceptional transmission resource pool, or may transmit sidelink data through the acquired transmission resource after being allocated a transmission resource from the base station. As a result of the determination in step 1103, if it is determined that the exceptional transmission resource pool is not set, the terminal may proceed to operation 2 in step 1121. For example, in operation 2, the UE may wait for a normal transmission resource pool other than an exceptional transmission resource pool to be established, or wait for a transmission resource to be allocated from the base station. When a normal transmission resource pool is established or transmission resources are allocated from the base station, the terminal may transmit sidelink data through the acquired transmission resources. As a result of the determination in step 1115, if it is determined that the priority (and/or latency) of the sidelink flow and/or the sidelink logical channel and/or the sidelink packet does not satisfy the priority threshold (and/or latency threshold) condition, the terminal May proceed to operation 2 of step 1121. In step 1121, the terminal waits for the establishment of a normal transmission resource pool capable of transmitting data of a sidelink flow and/or a sidelink logical channel and/or a sidelink packet that does not satisfy the threshold condition of step 1115, or You can wait for the transmission resource to be allocated. As another embodiment of the operation performed by the terminal in step 1121, which determines that the threshold condition is not satisfied in step 1115, the terminal may wait until the threshold value for the exceptional transmission resource pool is satisfied. As another embodiment, the UE stops using the exceptional transmission resource pool when a normal transmission resource pool is established while waiting until the threshold for the exceptional transmission resource pool is satisfied to acquire transmission resources or allocate transmission resources from the base station. I can.

When one or more exceptional transmission resource pools are set, the terminal may determine whether there is a sidelink flow and/or a sidelink logical channel that satisfies at least one or a combination of the CBR, priority, and latency for each exceptional transmission resource pool. According to the above criteria, data of a sidelink flow and/or a sidelink logical channel satisfying the use condition of the exceptional transmission resource pool may be transmitted using a resource randomly selected from a corresponding exceptional transmission resource pool.

(2) Sidelink bearer configuration parameter processing method

As an embodiment, when the RRC state of the terminal is changed, when the configuration parameter of the sidelink bearer is changed, the terminal may release the existing sidelink bearer and create a new sidelink bearer. The new sidelink bearer may apply the configuration parameter of the changed sidelink bearer. When a terminal performs sidelink unicast-based packet transmission/reception with another terminal, information on release of an existing sidelink bearer and creation of a new sidelink bearer is obtained through sidelink unicast RRC (PC5-RRC) signaling between the two terminals. Can be exchanged. The terminal that transmitted the information on the release of the existing sidelink bearer and the creation of a new sidelink bearer stops data transmission using the existing sidelink bearer, emptying the data buffer corresponding to the existing sidelink bearer, and setting information corresponding to the existing sidelink bearer. At least one operation during deletion may be performed. Upon receiving the information on the release of the existing sidelink bearer and the creation of a new sidelink bearer, the terminal stops receiving data using the existing sidelink bearer, emptying the data buffer corresponding to the existing sidelink bearer, and setting information corresponding to the existing sidelink bearer. At least one operation during deletion may be performed.

As another embodiment, when the RRC state of the terminal is changed, only parameters changed in the existing sidelink bearer may be updated without performing an operation of releasing the existing sidelink bearer. When a terminal performs sidelink unicast-based packet transmission/reception with another terminal, information on parameters that need to be updated in the existing sidelink bearer may be exchanged between the two terminals through sidelink unicast RRC (PC5-RRC) signaling. have. The transmitting terminal may transmit the SDAP of the packet including an end-marker to inform the other receiving terminal of information that data transmission to which the existing parameters are applied in the existing sidelink bearer is completed and data transmission by applying the updated parameters is started. The receiving terminal may process the update parameter information received in the PC5-RRC signaling and the end-marker of the SDAP to receive a packet through a sidelink bearer to which the update parameter is applied. The updated parameter may include at least one of a PDCP configuration parameter, an RLC configuration parameter, and a security key configuration parameter.

In the case of sidelink groupcast or sidelink broadcast, a transmitting terminal that determines that a parameter change is necessary in an existing sidelink bearer may update a corresponding parameter and transmit a packet through a sidelink bearer to which the updated parameter is applied. In sidelink groupcast or sidelink broadcast, the receiving terminal does not need to separately receive information about the parameter update of the sidelink bearer from the transmitting terminal. The receiving terminal can process the received packet by itself.

The RRC state change of the terminal includes at least one of a change from RRC_CONNECTED to RRC_IDLE or RRC_INACTIVE, a change from RRC_IDLE or RRC_INACTIVE to RRC_CONNECTED, a change from IN-COVERAGE to OUT-OF-COVERAGE, and a change from OUT-OF-COVERAGE to IN-COVERAGE can do.

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 for causing 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. (EEPROM: Electrically Erasable Programmable Read Only Memory), magnetic disc storage device, Compact Disc-ROM (CD-ROM), Digital Versatile Discs (DVDs), or other types 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 accessed through a communication network such as Internet, Intranet, Local Area Network (LAN), Wide LAN (WLAN), or Storage Area Network (SAN), or a combination of these. It may be stored in an (access) attachable storage device. 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 may be made 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 and equivalents as well as the scope of the claims to be described later.

110: base station
120: first terminal
130: second terminal

Claims (1)

In the control signal processing method in a wireless communication system,
Receiving a first control signal transmitted from a base station;
Processing the received first control signal; And
And transmitting a second control signal generated based on the processing to the base station.

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