Patent Publication Number: US-11395171-B2

Title: Interference measurement

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     Pursuant to 35 U.S.C. § 119(a), this application claims the benefit of earlier filing date and right of priority to Korean Patent Application No. 10-2019-0087427, filed on Jul. 19, 2019, the contents of which are all hereby incorporated by reference herein in their entirety. 
     BACKGROUND OF THE DISCLOSURE 
     Field of the Disclosure 
     The present disclosure relates to mobile communication. 
     Related Art 
     With the success of Evolved Universal Terrestrial Radio Access Network (E-UTRAN) for the fourth-generation mobile communication which is Long Term Evolution (LTE)/LTE-Advanced (LTE-A), the next generation mobile communication, which is the fifth-generation (so called 5G) mobile communication, has been attracting attentions and more and more researches are being conducted. 
     For the fifth-generation (so called 5G) mobile communication, a new radio access technology (New RAT or NR) have been studied and researched. 
     An NR cell may operate not just in standalone deployment (SA), but also in a non-standalone deployment (NSA). According to the NSA deployment, a UE may be connected in dual connectivity (DC) with an E-UTRAN (that is, LTE/LTE-A) cell and the NR cell. This type of dual connectivity is called EN-DC. 
     Meanwhile, Time Division Duplex (TDD) and Frequency Division Duplex (FDD) can also be used in NR as in LTE/LTE-A. 
     In the case of TDD, a ratio of DL to UL can be set differently by changing a DL/UL configuration in response to the amount of traffic. However, when the same frequency band or a neighboring frequency band is used, a serving cell and a neighboring cell (or including a case in which a serving cell provider differs from a neighboring cell provider) may use the same DL/UL configuration in order to minimize the influence of interference. In this case, DL/UL configuration flexibility decreases. 
     However, there is no efficient method for using a DL/UL ratio in response to the amount of traffic of a cell more efficiently. 
     SUMMARY OF THE DISCLOSURE 
     Accordingly, a disclosure of the present specification has been made in an effort to solve the aforementioned problem. 
     Accordingly, in an effort to solve the aforementioned problem, a disclosure of the present specification provides a method for measuring Cross Link Interference (CLI). The method for measuring Cross Link Interference (CLI), the method performed by a User Equipment (UE) and comprising: detecting a Sounding Reference Signal (SRS) from a neighbor UE; performing measurement based on the SRS; transmitting a measurement report including an interference value. 
     The interference value may be determined based on the measurement and a table, wherein the table includes a plurality of interference values, each of which is defined for a range of the measured values. 
     The range of the measured values may be defined with 1 dB resolution. 
     The method may further comprise: transmitting capability information of UE to base station, wherein the capability information includes information is about whether UE is able to measure Cross Link Interference (CLI) 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a wireless communication system. 
         FIG. 2  illustrates a structure of a radio frame according to FDD in 3GPP LTE. 
         FIG. 3  illustrates a procedure for cell detection and measurement. 
         FIGS. 4A to 4C  are diagrams illustrating exemplary architecture for a service of the next-generation mobile communication. 
         FIG. 5  illustrates an example of a subframe type in NR. 
         FIG. 6  illustrates an example of an SS block in NR. 
         FIG. 7  illustrates an example of beam sweeping in NR. 
         FIG. 8  illustrates an example of performing measurement in an EN (E-UTRAN and NR)-DC case. 
         FIG. 9  shows interference attributable to a UE and a BS in a neighbor cell in wireless communication. 
         FIG. 10  shows a process of reporting from a UE to a BS for CLI measurement. 
         FIG. 11  shows a process of measuring interference with an adjacent UE and reporting it to a BS. 
         FIG. 12  is a block diagram illustrating a wireless device and a base station, by which the disclosure of this specification can be implemented. 
         FIG. 13  is a detailed block diagram illustrating a transceiver of the wireless device shown in  FIG. 12 . 
         FIG. 14  shows a wireless communication system according to an embodiment. 
         FIG. 15  is a block diagram of a network node according to an embodiment. 
         FIG. 16  is a block diagram showing a structure of a terminal according to an embodiment. 
         FIG. 17  shows an example of a 5G usage scenario. 
         FIG. 18  shows an AI system  1  according to an embodiment. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     The technical terms used herein are used to merely describe specific embodiments and should not be construed as limiting the present disclosure. Further, the technical terms used herein should be, unless defined otherwise, interpreted as having meanings generally understood by those skilled in the art but not too broadly or too narrowly. Further, the technical terms used herein, which are determined not to exactly represent the spirit of the disclosure, should be replaced by or understood by such technical terms as being able to be exactly understood by those skilled in the art. Further, the general terms used herein should be interpreted in the context as defined in the dictionary, but not in an excessively narrowed manner. 
     The expression of the singular number in the present disclosure includes the meaning of the plural number unless the meaning of the singular number is definitely different from that of the plural number in the context. In the following description, the term ‘include’ or ‘have’ may represent the existence of a feature, a number, a step, an operation, a component, a part or the combination thereof described in the present disclosure, and may not exclude the existence or addition of another feature, another number, another step, another operation, another component, another part or the combination thereof. 
     The terms ‘first’ and ‘second’ are used for the purpose of explanation about various components, and the components are not limited to the terms ‘first’ and ‘second’. The terms ‘first’ and ‘second’ are only used to distinguish one component from another component. For example, a first component may be named as a second component without deviating from the scope of the present disclosure. 
     It will be understood that when an element or layer is referred to as being “connected to” or “coupled to” another element or layer, it can be directly connected or coupled to the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly connected to” or “directly coupled to” another element or layer, there are no intervening elements or layers present. 
     Hereinafter, exemplary embodiments of the present disclosure will be described in greater detail with reference to the accompanying drawings. In describing the present disclosure, for ease of understanding, the same reference numerals are used to denote the same components throughout the drawings, and repetitive description on the same components will be omitted. Detailed description on well-known arts which are determined to make the gist of the disclosure unclear will be omitted. The accompanying drawings are provided to merely make the spirit of the disclosure readily understood, but not should be intended to be limiting of the disclosure. It should be understood that the spirit of the disclosure may be expanded to its modifications, replacements or equivalents in addition to what is shown in the drawings. 
     As used herein, ‘base station’ generally refers to a fixed station that communicates with a wireless device and may be denoted by other terms such as eNB (evolved-NodeB), BTS (base transceiver system), or access point. 
     As used herein, ‘user equipment (UE)’ may be stationary or mobile, and may be denoted by other terms such as device, wireless device, terminal, MS (mobile station), UT (user terminal), SS (subscriber station), MT (mobile terminal) and etc. 
       FIG. 1  illustrates a wireless communication system. 
     As seen with reference to  FIG. 1 , the wireless communication system includes at least one base station (BS). The BS is classified into a gNB  20   a  and an eNB  20   b . The gNB  20   a  is for 5G mobile communication such as NR. And, the eNB  20   b  is for 4G mobile communication such as LTE or LTE-A 
     Each BS (e.g., gNB  20   a  and eNB  20   b ) provides a communication service to specific geographical areas (generally, referred to as cells)  20 - 1 ,  20 - 2 , and  20 - 3 . The cell can be further divided into a plurality of areas (sectors). 
     The UE  10  generally belongs to one cell and the cell to which the UE belong is referred to as a serving cell. ABS that provides the communication service to the serving cell is referred to as a serving BS. Since the wireless communication system is a cellular system, another cell that neighbors to the serving cell is present. Another cell which neighbors to the serving cell is referred to a neighbor cell. A BS that provides the communication service to the neighbor cell is referred to as a neighbor BS. The serving cell and the neighbor cell are relatively decided based on the UE. 
     Hereinafter, a downlink means communication from the BS  20  to the UE  10  and an uplink means communication from the UE  10  to the BS  200 . In the downlink, a transmitter may be a part of the BS  20  and a receiver may be a part of the UE  10 . In the uplink, the transmitter may be a part of the UE  10  and the receiver may be a part of the BS  20 . 
     Meanwhile, the wireless communication system may be generally divided into a frequency division duplex (FDD) type and a time division duplex (TDD) type. According to the FDD type, uplink transmission and downlink transmission are achieved while occupying different frequency bands. According to the TDD type, the uplink transmission and the downlink transmission are achieved at different time while occupying the same frequency band. A channel response of the TDD type is substantially reciprocal. This means that a downlink channel response and an uplink channel response are approximately the same as each other in a given frequency area. Accordingly, in the TDD based wireless communication system, the downlink channel response may be acquired from the uplink channel response. In the TDD type, since an entire frequency band is time-divided in the uplink transmission and the downlink transmission, the downlink transmission by the base station and the uplink transmission by the terminal may not be performed simultaneously. In the TDD system in which the uplink transmission and the downlink transmission are divided by the unit of a subframe, the uplink transmission and the downlink transmission are performed in different subframes. 
     &lt;Carrier Aggregation&gt; 
     A carrier aggregation system is now described. 
     A carrier aggregation system aggregates a plurality of component carriers (CCs). A meaning of an existing cell is changed according to the above carrier aggregation. According to the carrier aggregation, a cell may signify a combination of a downlink component carrier and an uplink component carrier or an independent downlink component carrier. 
     Further, the cell in the carrier aggregation may be classified into a primary cell, a secondary cell, and a serving cell. The primary cell signifies a cell operated in a primary frequency. The primary cell signifies a cell which UE performs an initial connection establishment procedure or a connection reestablishment procedure or a cell indicated as a primary cell in a handover procedure. The secondary cell signifies a cell operating in a secondary frequency. Once the RRC connection is established, the secondary cell is used to provide an additional radio resource. 
     As described above, the carrier aggregation system may support a plurality of component carriers (CCs), that is, a plurality of serving cells unlike a single carrier system. 
     The carrier aggregation system may support a cross-carrier scheduling. The cross-carrier scheduling is a scheduling method capable of performing resource allocation of a PDSCH transmitted through other component carrier through a PDCCH transmitted through a specific component carrier and/or resource allocation of a PUSCH transmitted through other component carrier different from a component carrier basically linked with the specific component carrier. 
     &lt;Introduction of Dual Connectivity (DC)&gt; 
     Recently, a scheme for simultaneously connecting UE to different base stations, for example, a macro cell base station and a small cell base station, is being studied. This is called dual connectivity (DC). 
     In DC, the eNodeB for the primary cell (Pcell) may be referred to as a master eNodeB (hereinafter referred to as MeNB). In addition, the eNodeB only for the secondary cell (Scell) may be referred to as a secondary eNodeB (hereinafter referred to as SeNB). 
     A cell group including a primary cell (Pcell) implemented by MeNB may be referred to as a master cell group (MCG) or PUCCH cell group  1 . A cell group including a secondary cell (Scell) implemented by the SeNB may be referred to as a secondary cell group (SCG) or PUCCH cell group  2 . 
     Meanwhile, among the secondary cells in the secondary cell group (SCG), a secondary cell in which the UE can transmit Uplink Control Information (UCI), or the secondary cell in which the UE can transmit a PUCCH may be referred to as a super secondary cell (Super SCell) or a primary secondary cell (Primary Scell; PScell). 
     Hereinafter, the LTE system will be described in detail. 
       FIG. 2  shows a downlink radio frame structure according to FDD of 3 rd generation partnership project (3GPP) long term evolution (LTE). 
     The radio frame includes 10 sub-frames indexed 0 to 9. One sub-frame includes two consecutive slots. Accordingly, the radio frame includes 20 slots. The time taken for one sub-frame to be transmitted is denoted TTI (transmission time interval). For example, the length of one sub-frame may be 1 ms, and the length of one slot may be 0.5 ms. 
     The structure of the radio frame is for exemplary purposes only, and thus the number of sub-frames included in the radio frame or the number of slots included in the sub-frame may change variously. 
     One slot includes NRB resource blocks (RBs) in the frequency domain. For example, in the LTE system, the number of resource blocks (RBs), i.e., NRB, may be one from 6 to 110. 
     The resource block is a unit of resource allocation and includes a plurality of sub-carriers in the frequency domain. For example, if one slot includes seven OFDM symbols in the time domain and the resource block includes 12 sub-carriers in the frequency domain, one resource block may include 7×12 resource elements (REs). 
     The physical channels in 3GPP LTE may be classified into data channels such as PDSCH (physical downlink shared channel) and PUSCH (physical uplink shared channel) and control channels such as PDCCH (physical downlink control channel), PCFICH (physical control format indicator channel), PHICH (physical hybrid-ARQ indicator channel) and PUCCH (physical uplink control channel). 
     The uplink channels include a PUSCH, a PUCCH, an SRS (Sounding Reference Signal), and a PRACH (physical random access channel). 
     &lt;Measurement and Measurement Report&gt; 
     Supporting mobility of a UE  100  is essential in a mobile communication system. Thus, the UE  100  constantly measures a quality of a serving cell which is currently providing a service, and a quality of a neighbor cell. The UE  10  reports a result of the measurement to a network at an appropriate time, and the network provides optimal mobility to the UE through a handover or the like. Measurement for this purpose is referred to as a Radio Resource Management (RRM). 
     Meanwhile, the UE  100  monitors a downlink quality of a primary cell (Pcell) based on a CRS. This is so called Radio Link Monitoring (RLM). 
       FIG. 3  shows a procedure for cell detection and measurement. 
     Referring to  FIG. 3 , a UE detects a neighbor cell based on Synchronization Signal (SS) which is transmitted from the neighbor cell. The SS may include a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS). 
     When the serving cell  200   a  and the neighbor cell respectively transmit Cell-specific Reference Signals (CRSs), the UE  100  measures the CRSs and transmits a result of the measurement to the serving cell  200   a . In this case, the UE  100  may compare power of the received CRSs based on received information on a reference signal power. 
     At this point, the UE  100  may perform the measurement in the following three ways. 
     1) RSRP (reference signal received power): This represents an average reception power of all REs that carry the CRS which is transmitted through the whole bands. In this case, instead of the CRS, an average reception power of all REs that carry the CSI RS may also be measured. 
     2) RSS (received signal strength indicator): This represents a reception power which is measured through the whole bands. The RSSI includes all of signal, interference and thermal noise. 
     3) RSRQ (reference symbol received quality): This represents a CQI, and may be determined as the RSRP/RSSI according to a measured bandwidth or a sub-band. That is, the RSRQ signifies a signal-to-noise interference ratio (SINR). Since the RSRP is unable to provide a sufficient mobility, in handover or cell reselection procedure, the RSRQ may be used instead of the RSRP. 
     The RSRQ may be obtained by RSSI/RSSP. 
     Meanwhile, the UE  100  receives a radio resource configuration information element (IE) from the serving cell  100   a  for the measurement. The radio resource configuration information element (IE) is used to configure/modify/cancel a radio bearer or to modify an MAC configuration. The radio resource configuration IE includes subframe pattern information. The subframe pattern information is information on a measurement resource restriction pattern on the time domain, for measuring RSRP and RSRQ of a serving cell (e.g., PCell). 
     Meanwhile, the UE  100  receives a measurement configuration information element (IE) from the serving cell  100   a  for the measurement. A message including the measurement configuration information element (IE) is called a measurement configuration message. Here, the measurement configuration information element (IE) may be received through an RRC connection reconfiguration message. If the measurement result satisfies a report condition in the measurement configuration information, the UE reports the measurement result to a base station. A message including the measurement result is called a measurement report message. 
     The measurement configuration IE may include measurement object information. The measurement object information is information of an object which is to be measured by the UE. The measurement object includes at least one of an intra-frequency measurement object which is an object of intra-cell measurement, an inter-frequency measurement object which is an object of inter-cell measurement and an inter-RAT measurement object which is an object of inter-RAT measurement. For example, the intra-cell measurement object indicates a neighbor cell that has a frequency band which is identical to that of a serving cell, the inter-cell measurement object indicates a neighbor cell that has a frequency band which is different from that of a serving cell, and the inter-RAT measurement object indicates a neighbor cell of a RAT which is different from that of a serving cell. 
     
       
         
           
               
             
               
                 TABLE 1 
               
               
                   
               
               
                 Measurement object field description 
               
               
                   
               
             
            
               
                 carrierFreq 
               
               
                 This indicates an E-UTRA carrier frequency to which this  
               
               
                 configuration is applied. 
               
               
                 measCycleSCell 
               
               
                 This indicates a cycle for measurement of a secondary cell  
               
               
                 (SCell) in a non-activated state. Its value may be set  
               
               
                 to 40, 160, 256, etc. If the value is 160, it 
               
               
                 indicates that measurement is performed every 160 subframes. 
               
               
                   
               
            
           
         
       
     
     Meanwhile, the measurement configuration IE includes an information element (IE) as shown in the following table. 
     
       
         
           
               
             
               
                 TABLE 2 
               
               
                   
               
               
                 MeasConfig field description 
               
               
                   
               
             
            
               
                 allowInterruptions 
               
               
                 If its value is True, it indicates that interruption of transmission  
               
               
                 and reception with a serving cell is allowed when  
               
               
                 measurement of subcarriers of an Scell in a non- 
               
               
                 active state is performed using MeasCycleScell. 
               
               
                 meas GapC onfig 
               
               
                 It indicates configuration or cancelation of a measurement gap. 
               
               
                   
               
            
           
         
       
     
     The “measGapConfig” is used to configure or cancel a measurement gap (MG). The MG is a period for cell identification and RSRP measurement on an inter frequency different from that of a serving cell. 
     
       
         
           
               
             
               
                 TABLE 3 
               
               
                   
               
               
                 MeasGapConfig field description 
               
               
                   
               
             
            
               
                 gap Offset 
               
               
                 Any one of gp0 and gp1 may be set as a value of gapOffset.  
               
               
                 gp0 corresponds to a gapoffset of pattern ID  
               
               
                 “0” having MGRP = 40 ms. gp1 corresponds to a 
               
               
                 gapoffset of pattern ID “1” having MGRP = 80 ms. 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
               
             
               
                 TABLE 4 
               
               
                   
               
               
                   
                   
                 Measurement  
                 Minimum available time for 
               
               
                 Gap 
                 Measurement 
                 Gap 
                 inter-frequency and inter-RAT 
               
               
                 pattern 
                 Gap Length 
                 Repetition Period 
                 measurements during 480 ms 
               
               
                 Id 
                 (MGL) 
                 (MGRP) 
                 period 
               
               
                   
               
             
            
               
                 0 
                 6 ms 
                 40 ms 
                 60 ms 
               
               
                 1 
                 6 ms 
                 80 ms 
                 30 s  
               
               
                   
               
            
           
         
       
     
     When the UE requires a measurement gap to identify and measure a cell at an inter-frequency and inter-RAT, the E-UTRAN (i.e., the base station) may provide a single measurement gap (MG) pattern with a predetermined gap period to the UE. Without transmitting or receiving any data from the serving cell for the measurement gap period, the UE retunes its RF chain to be adapted to the inter-frequency and then performs measurement at the corresponding inter-frequency. 
     &lt;Carrier Aggregation&gt; 
     A carrier aggregation system is now described. 
     A carrier aggregation system aggregates a plurality of component carriers (CCs). A meaning of an existing cell is changed according to the above carrier aggregation. According to the carrier aggregation, a cell may signify a combination of a downlink component carrier and an uplink component carrier or an independent downlink component carrier. 
     Further, the cell in the carrier aggregation may be classified into a primary cell, a secondary cell, and a serving cell. The primary cell signifies a cell operated in a primary frequency. The primary cell signifies a cell which UE performs an initial connection establishment procedure or a connection reestablishment procedure or a cell indicated as a primary cell in a handover procedure. The secondary cell signifies a cell operating in a secondary frequency. Once the RRC connection is established, the secondary cell is used to provide an additional radio resource. 
     As described above, the carrier aggregation system may support a plurality of component carriers (CCs), that is, a plurality of serving cells unlike a single carrier system. 
     The carrier aggregation system may support a cross-carrier scheduling. The cross-carrier scheduling is a scheduling method capable of performing resource allocation of a PDSCH transmitted through other component carrier through a PDCCH transmitted through a specific component carrier and/or resource allocation of a PUSCH transmitted through other component carriers different from a component carrier basically linked with the specific component carrier. 
     &lt;Introduction of Dual Connectivity (DC)&gt; 
     Recently, a scheme for simultaneously connecting UE to different base stations, for example, a macro cell base station and a small cell base station, is being studied. This is called dual connectivity (DC). 
     In DC, the eNodeB for the primary cell (Pcell) may be referred to as a master eNodeB (hereinafter referred to as MeNB). In addition, the eNodeB only for the secondary cell (Scell) may be referred to as a secondary eNodeB (hereinafter referred to as SeNB). 
     A cell group including a primary cell (Pcell) implemented by MeNB may be referred to as a master cell group (MCG) or PUCCH cell group  1 . A cell group including a secondary cell (Scell) implemented by the SeNB may be referred to as a secondary cell group (SCG) or PUCCH cell group  2 . 
     Meanwhile, among the secondary cells in the secondary cell group (SCG), a secondary cell in which the UE can transmit Uplink Control Information (UCI), or the secondary cell in which the UE can transmit a PUCCH may be referred to as a super secondary cell (Super SCell) or a primary secondary cell (Primary Scell; PScell). 
     &lt;Next-Generation Mobile Communication Network&gt; 
     With the success of Evolved Universal Terrestrial Radio Access Network (E-UTRAN) for the fourth-generation mobile communication which is Long Term Evolution (LTE)/LTE-Advanced (LTE-A), the next generation mobile communication, which is the fifth-generation (so called 5G) mobile communication, has been attracting attentions and more and more researches are being conducted. 
     The fifth-generation communication defined by the International Telecommunication Union (ITU) refers to providing a maximum data transmission speed of 20 Gbps and a maximum transmission speed of 100 Mbps per user in anywhere. It is officially called “IMT-2020” and aims to be released around the world in 2020. 
     The ITU suggests three usage scenarios, for example, enhanced Mobile BroadBand (eMBB), massive Machine Type Communication (mMTC), and Ultra Reliable and Low Latency Communications (URLLC). 
     URLLC relates to a usage scenario in which high reliability and low delay time are required. For example, services like autonomous driving, automation, and virtual realities requires high reliability and low delay time (for example, 1 ms or less). A delay time of the current 4G (LTE) is statistically 21-43 ms (best 10%), 33-75 ms (median). Thus, the current 4G (LTE) is not sufficient to support a service requiring a delay time of 1 ms or less. Next, eMBB relates to a usage scenario in which an enhanced mobile broadband is required. 
     That is, the fifth-generation mobile communication system aims to achieve a capacity higher than the current 4G LTE and is capable of increasing a density of mobile broadband users and support Device-to-Device (D2D), high stability, and Machine Type Communication (MTC). Researches on 5G aims to achieve reduced waiting time and less batter consumption, compared to a 4G mobile communication system, in order to implement the IoT. For the 5G mobile communication, a new radio access technology (New RAT or NR) may be proposed. 
       FIGS. 4A to 4C  are diagrams illustrating exemplary architecture for a next-generation mobile communication service. 
     Referring to  FIG. 4A , a UE is connected in dual connectivity (DC) with an LTE/LTE-A cell and a NR cell. 
     The NR cell is connected with a core network for the legacy fourth-generation mobile communication, that is, an Evolved Packet core (EPC). 
     Referring to  FIG. 4B , the LTE/LTE-A cell is connected with a core network for 5th generation mobile communication, that is, a Next Generation (NG) core network, unlike the example in  FIG. 4A . 
     A service based on the architecture shown in  FIGS. 4A and 4B  is referred to as a non-standalone (NSA) service. 
     Referring to  FIG. 4 , a UE is connected only with an NR cell. A service based on this architecture is referred to as a standalone (SA) service. 
     Meanwhile, in the above new radio access technology (NR), using a downlink subframe for reception from a base station and using an uplink subframe for transmission to the base station may be considered. This method may be applied to paired spectrums and not-paired spectrums. A pair of spectrum indicates including two subcarrier for downlink and uplink operations. For example, one subcarrier in one pair of spectrum may include a pair of a downlink band and an uplink band. 
       FIG. 5  shows an example of subframe type in NR. 
     A transmission time interval (TTI) shown in  FIG. 5  may be called a subframe or slot for NR (or new RAT). The subframe (or slot) in  FIG. 5  may be used in a TDD system of NR (or new RAT) to minimize data transmission delay. As shown in  FIG. 4 , a subframe (or slot) includes  14  symbols as does the current subframe. A front symbol of the subframe (or slot) may be used for a downlink control channel, and a rear symbol of the subframe (or slot) may be used for a uplink control channel. Other channels may be used for downlink data transmission or uplink data transmission. According to such structure of a subframe (or slot), downlink transmission and uplink transmission may be performed sequentially in one subframe (or slot). Therefore, a downlink data may be received in the subframe (or slot), and a uplink acknowledge response (ACK/NACK) may be transmitted in the subframe (or slot). A subframe (or slot) in this structure may be called a self-constrained subframe. If this structure of a subframe (or slot) is used, it may reduce time required to retransmit data regarding which a reception error occurred, and thus, a final data transmission waiting time may be minimized. In such structure of the self-contained subframe (slot), a time gap may be required for transition from a transmission mode to a reception mode or vice versa. To this end, when downlink is transitioned to uplink in the subframe structure, some OFDM symbols may be set as a Guard Period (GP). 
     &lt;Support of Various Numerologies&gt; 
     In the next generation system, with development of wireless communication technologies, a plurality of numerologies may be provided to a UE. 
     The numerologies may be defined by a length of cycle prefix (CP) and a subcarrier spacing. One cell may provide a plurality of numerology to a UE. When an index of a numerology is represented by μ, a subcarrier spacing and a corresponding CP length may be expressed as shown in the following table. 
     
       
         
           
               
               
               
             
               
                 TABLE 5 
               
               
                   
               
               
                 M 
                 Δf = 2 μ  · 15 [kHz] 
                 CP 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                 0 
                 15 
                 Normal 
               
               
                 1 
                 30 
                 Normal 
               
               
                 2 
                 60 
                 Normal, Extended 
               
               
                 3 
                 120 
                 Normal 
               
               
                 4 
                 240 
                 Normal 
               
               
                   
               
            
           
         
       
     
     In the case of a normal CP, when an index of a numerology is expressed by μ, the number of OLDM symbols per slot N slot   symb , the number of slots per frame Nframe,μslot, and the number of slots per subframe Nsubframe,μslot are expressed as shown in the following table. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 6 
               
               
                   
                   
               
               
                   
                 μ 
                 N slot   symb   
                 N frame,μ   slot   
                 N subframe,μ   slot   
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                   
                 0 
                 14 
                 10 
                 1 
               
               
                   
                 1 
                 14 
                 20 
                 2 
               
               
                   
                 2 
                 14 
                 40 
                 4 
               
               
                   
                 3 
                 14 
                 80 
                 8 
               
               
                   
                 4 
                 14 
                 160 
                 16 
               
               
                   
                 5 
                 14 
                 320 
                 32 
               
               
                   
                   
               
            
           
         
       
     
     In the case of an extended CP, when an index of a numerology is represented by μ, the number of OLDM symbols per slot N slot   symb , the number of slots per frame Nframe,μslot, and the number of slots per subframe Nsubframe,μslot are expressed as shown in the following table. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 7 
               
               
                   
                   
               
               
                   
                 M 
                 N slot   symb   
                 N frame,μ   slot   
                 N subframe,μ   slot   
               
               
                   
                   
               
             
            
               
                   
                 2 
                 12 
                 40 
                 4 
               
               
                   
                   
               
            
           
         
       
     
     Meanwhile, in the next-generation mobile communication, each symbol may be used for downlink or uplink, as shown in the following table. In the following table, uplink is indicated by U, and downlink is indicated by D. In the following table, X indicates a symbol that can be flexibly used for uplink or downlink. 
     
       
         
           
               
               
             
               
                 TABLE 8 
               
             
            
               
                   
               
               
                 For- 
                 Symbol Number in Slot 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                 mat 
                 0 
                 1 
                 2 
                 3 
                 4 
                 5 
                 6 
                 7 
                 8 
                 9 
                 10 
                 11 
                 12 
                 13 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                 0 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
               
               
                 1 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
               
               
                 2 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
               
               
                 3 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 X 
               
               
                 4 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 X 
                 X 
               
               
                 5 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 X 
                 X 
                 X 
               
               
                 6 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 X 
                 X 
                 X 
                 X 
               
               
                 7 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 X 
                 X 
                 X 
                 X 
                 X 
               
               
                 8 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 U 
               
               
                 9 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 U 
                 U 
               
               
                 10 
                 X 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
               
               
                 11 
                 X 
                 X 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
               
               
                 12 
                 X 
                 X 
                 X 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
               
               
                 13 
                 X 
                 X 
                 X 
                 X 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
               
               
                 14 
                 X 
                 X 
                 X 
                 X 
                 X 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
               
               
                 15 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
               
               
                 16 
                 D 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
               
               
                 17 
                 D 
                 D 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
               
               
                 18 
                 D 
                 D 
                 D 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
               
               
                 19 
                 D 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 U 
               
               
                 20 
                 D 
                 D 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 U 
               
               
                 21 
                 D 
                 D 
                 D 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 U 
               
               
                 22 
                 D 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 U 
                 U 
               
               
                 23 
                 D 
                 D 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 U 
                 U 
               
               
                 24 
                 D 
                 D 
                 D 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 U 
                 U 
               
               
                 25 
                 D 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 U 
                 U 
                 U 
               
               
                 26 
                 D 
                 D 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 U 
                 U 
                 U 
               
               
                 27 
                 D 
                 D 
                 D 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 U 
                 U 
                 U 
               
               
                 28 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 X 
                 U 
               
               
                 29 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 X 
                 X 
                 U 
               
               
                 30 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 X 
                 X 
                 X 
                 U 
               
               
                 31 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 X 
                 U 
                 U 
               
               
                 32 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 X 
                 X 
                 U 
                 U 
               
               
                 33 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 X 
                 X 
                 X 
                 U 
                 U 
               
               
                 34 
                 D 
                 X 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
               
               
                 35 
                 D 
                 D 
                 X 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
               
               
                 36 
                 D 
                 D 
                 D 
                 X 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
               
               
                 37 
                 D 
                 X 
                 X 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
               
               
                 38 
                 D 
                 D 
                 X 
                 X 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
               
               
                 39 
                 D 
                 D 
                 D 
                 X 
                 X 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
               
               
                 40 
                 D 
                 X 
                 X 
                 X 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
               
               
                 41 
                 D 
                 D 
                 X 
                 X 
                 X 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
               
               
                 42 
                 D 
                 D 
                 D 
                 X 
                 X 
                 X 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
               
               
                 43 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 X 
                 X 
                 X 
                 X 
                 U 
               
               
                 44 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 U 
                 U 
               
               
                 45 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 X 
                 X 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
               
               
                 46 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 X 
                 D 
                 D 
                 D 
                 D 
                 D 
                 D 
                 X 
               
               
                 47 
                 D 
                 D 
                 D 
                 D 
                 D 
                 X 
                 X 
                 D 
                 D 
                 D 
                 D 
                 D 
                 X 
                 X 
               
               
                 48 
                 D 
                 D 
                 X 
                 X 
                 X 
                 X 
                 X 
                 D 
                 D 
                 X 
                 X 
                 X 
                 X 
                 X 
               
               
                 49 
                 D 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
                 D 
                 X 
                 X 
                 X 
                 X 
                 X 
                 X 
               
               
                 50 
                 X 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
                 X 
                 U 
                 U 
                 U 
                 U 
                 U 
                 U 
               
               
                 51 
                 X 
                 X 
                 U 
                 U 
                 U 
                 U 
                 U 
                 X 
                 X 
                 U 
                 U 
                 U 
                 U 
                 U 
               
               
                 52 
                 X 
                 X 
                 X 
                 U 
                 U 
                 U 
                 U 
                 X 
                 X 
                 X 
                 U 
                 U 
                 U 
                 U 
               
               
                 53 
                 X 
                 X 
                 X 
                 X 
                 U 
                 U 
                 U 
                 X 
                 X 
                 X 
                 X 
                 U 
                 U 
                 U 
               
               
                 54 
                 D 
                 D 
                 D 
                 D 
                 D 
                 X 
                 U 
                 D 
                 D 
                 D 
                 D 
                 D 
                 X 
                 U 
               
               
                 55 
                 D 
                 D 
                 X 
                 U 
                 U 
                 U 
                 U 
                 D 
                 D 
                 X 
                 U 
                 U 
                 U 
                 U 
               
               
                 56 
                 D 
                 X 
                 U 
                 U 
                 U 
                 U 
                 U 
                 D 
                 X 
                 U 
                 U 
                 U 
                 U 
                 U 
               
               
                 57 
                 D 
                 D 
                 D 
                 D 
                 X 
                 X 
                 U 
                 D 
                 D 
                 D 
                 D 
                 X 
                 X 
                 U 
               
               
                 58 
                 D 
                 D 
                 X 
                 X 
                 U 
                 U 
                 U 
                 D 
                 D 
                 X 
                 X 
                 U 
                 U 
                 U 
               
               
                 59 
                 D 
                 X 
                 X 
                 U 
                 U 
                 U 
                 U 
                 D 
                 X 
                 X 
                 U 
                 U 
                 U 
                 U 
               
               
                 60 
                 D 
                 X 
                 X 
                 X 
                 X 
                 X 
                 U 
                 D 
                 X 
                 X 
                 X 
                 X 
                 X 
                 U 
               
               
                 61 
                 D 
                 D 
                 X 
                 X 
                 X 
                 X 
                 U 
                 D 
                 D 
                 X 
                 X 
                 X 
                 X 
                 U 
               
               
                   
               
            
           
         
       
     
     &lt;Operating Band in NR&gt; 
     An operating band in NR is as follows. 
     An operating band shown in Table 9 is a reframing operating band that is transitioned from an operating band of LTE/LTE-A. This operating band is referred to as FR1 band. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 9 
               
               
                   
               
               
                 NR 
                 Uplink  
                 Downlink  
                 Duple 
               
               
                 operating 
                 Operating Band 
                 Operating Band 
                 x 
               
               
                 band 
                 F UL _low-F UL _high 
                 F DL _low-F DL _high 
                 Mode 
               
               
                   
               
             
            
               
                 n1 
                 1920 MHz-1980 MHz 
                 2110 MHz-2170 MHz 
                 FDD 
               
               
                 n2 
                 1850 MHz-1910 MHz 
                 1930 MHz-1990 MHz 
                 FDD 
               
               
                 n3 
                 1710 MHz-1785 MHz 
                 1805 MHz-1880 MHz 
                 FDD 
               
               
                 n5 
                 824 MHz-849 MHz 
                 869 MHz-894 MHz 
                 FDD 
               
               
                 n7 
                 2500 MHz-2570 MHz 
                 2620 MHz-2690 MHz 
                 FDD 
               
               
                 n8 
                 880 MHz-915 MHz 
                 925 MHz-960 MHz 
                 FDD 
               
               
                 n12 
                 699 MHz-716 MHz 
                 729 MHz-746 MHz 
                 FDD 
               
               
                 n20 
                 832 MHz-862 MHz 
                 791 MHz-821 MHz 
                 FDD 
               
               
                 n25 
                 1850 MHz-1915 MHz 
                 1930 MHz-1995 MHz 
                 FDD 
               
               
                 n28 
                 703 MHz-748 MHz 
                 758 MHz-803 MHz 
                 FDD 
               
               
                 n34 
                 2010 MHz-2025 MHz 
                 2010 MHz-2025 MHz 
                 TDD 
               
               
                 n38 
                 2570 MHz-2620 MHz 
                 2570 MHz-2620 MHz 
                 TDD 
               
               
                 n39 
                 1880 MHz-1920 MHz 
                 1880 MHz-1920 MHz 
                 TDD 
               
               
                 n40 
                 2300 MHz-2400 MHz 
                 2300 MHz-2400 MHz 
                 TDD 
               
               
                 n41 
                 2496 MHz-2690 MHz 
                 2496 MHz-2690 MHz 
                 TDD 
               
               
                 n50 
                 1432 MHz-1517 MHz 
                 1432 MHz-1517 MHz 
                 TDD1 
               
               
                 n51 
                 1427 MHz-1432 MHz 
                 1427 MHz-1432 MHz 
                 TDD 
               
               
                 n66 
                 1710 MHz-1780 MHz 
                 2110 MHz-2200 MHz 
                 FDD 
               
               
                 n70 
                 1695 MHz-1710 MHz 
                 1995 MHz-2020 MHz 
                 FDD 
               
               
                 n71 
                 663 MHz-698 MHz 
                 617 MHz-652 MHz 
                 FDD 
               
               
                 n74 
                 1427 MHz-1470 MHz 
                 1475 MHz-1518 MHz 
                 FDD 
               
               
                 n75 
                 N/A 
                 1432 MHz-1517 MHz 
                 SDL 
               
               
                 n76 
                 N/A 
                 1427 MHz-1432 MHz 
                 SDL 
               
               
                 n77 
                 3300 MHz-4200 MHz 
                 3300 MHz-4200 MHz 
                 TDD 
               
               
                 n78 
                 3300 MHz-3800 MHz 
                 3300 MHz-3800 MHz 
                 TDD 
               
               
                 n79 
                 4400 MHz-5000 MHz 
                 4400 MHz-5000 MHz 
                 TDD 
               
               
                 n80 
                 1710 MHz-1785 MHz 
                 N/A 
                 SUL 
               
               
                 n81 
                 880 MHz-915 MHz 
                 N/A 
                 SUL 
               
               
                 n82 
                 832 MHz-862 MHz 
                 N/A 
                 SUL 
               
               
                 n83 
                 703 MHz-748 MHz 
                 N/A 
                 SUL 
               
               
                 n84 
                 1920 MHz-1980 MHz 
                 N/A 
                 SUL 
               
               
                 n86 
                 1710 MHz-1780 MHz 
                 N/A 
                 SUL 
               
               
                   
               
            
           
         
       
     
     The following table shows an NR operating band defined at high frequencies. 
     This operating band is referred to as FR2 band. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 10 
               
               
                   
               
               
                 NR 
                   
                   
                   
               
               
                 Operating 
                 Uplink Operating Band 
                 Downlink Operating Band 
                 Duplex 
               
               
                 Band 
                 F UL _low-F UL _high 
                 F DL _low-F DL _high 
                 Mode 
               
               
                   
               
             
            
               
                 n257 
                 26500 MHz-29500 MHz 
                 26500 MHz-29500 MHz 
                 TDD 
               
               
                 n258 
                 24250 MHz-27500 MHz 
                 24250 MHz-27500 MHz 
                 TDD 
               
               
                 n260 
                 37000 MHz-40000 MHz 
                 37000 MHz-40000 MHz 
                 TDD 
               
               
                 n261 
                 27500 MHz-28350 MHz 
                 27500 MHz-28350 MHz 
                 TDD 
               
               
                   
               
            
           
         
       
     
     Meanwhile, when the operating band shown in the above table is used, a channel bandwidth is used as shown in the following table. 
     
       
         
           
               
               
               
               
               
               
               
               
               
               
               
               
             
               
                 TABLE 11 
               
               
                   
               
               
                   
                 5 
                 10 
                 15 
                 20 
                 25 
                 30 
                 40 
                 50 
                 60 
                 80 
                 100 
               
               
                 SCS 
                 MHz 
                 MHz 
                 MHz 
                 MHz 
                 MHz 
                 MHz 
                 MHz 
                 MHz 
                 MHz 
                 MHz 
                 MHz 
               
               
                 (kHz) 
                 N RB   
                 N RB   
                 N RB   
                 N RB   
                 N RB   
                 N RB   
                 N RB   
                 N RB   
                 N RB   
                 N RB   
                 N RB   
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
               
               
            
               
                 15 
                 25 
                 52 
                 79 
                 106 
                 133 
                 [160]  
                 216 
                 270 
                 N/A 
                 N/A 
                 N/A 
               
               
                 30 
                 11 
                 24 
                 38 
                 51 
                 65 
                 [78] 
                 106 
                 133 
                 162 
                 217 
                 273 
               
               
                 60 
                 N/A 
                 11 
                 18 
                 24 
                 31 
                 [38] 
                 51 
                 65 
                 79 
                 107 
                 135 
               
               
                   
               
            
           
         
       
     
     In the above table, SCS indicates a subcarrier spacing. In the above table, NRB indicates the number of RBs. 
     Meanwhile, when the operating band shown in the above table is used, a channel bandwidth is used as shown in the following table. 
     
       
         
           
               
               
               
               
               
             
               
                 TABLE 12 
               
               
                   
               
               
                   
                 50 
                 100 
                 200 
                 400 
               
               
                 SCS 
                 MHz 
                 MHz 
                 MHz 
                 MHz 
               
               
                 (kHz) 
                 N RB   
                 N RB   
                 N RB   
                 N RB   
               
               
                   
               
             
            
               
                  60 
                 66 
                 132 
                 264 
                 N.A 
               
               
                 120 
                 32 
                  66 
                 132 
                 264 
               
               
                   
               
            
           
         
       
     
     &lt;SS block in NR&gt; 
     In the 5G NR, information required for a UE to perform an initial access, that is, a Physical Broadcast Channel (PBCH) including a Master Information Block (MIB) and a synchronization signal (SS) (including PSS and SSS) are defined as an SS block. In addition, a plurality of SS blocks may be grouped and defined as an SS burst, and a plurality of SS bursts may be grouped and defined as an SS burst set. It is assumed that each SS block is beamformed in a particular direction, and various SS blocks existing in an SS burst set are designed to support UEs existing in different directions. 
       FIG. 6  is a diagram illustrating an example of an SS block in NR. 
     Referring to  FIG. 6 , an SS burst is transmitted in every predetermined periodicity. Accordingly, a UE receives SS blocks, and performs cell detection and measurement. 
     Meanwhile, in the 5G NR, beam sweeping is performed on an SS. A detailed description thereof will be provided with reference to  FIG. 7 . 
       FIG. 7  is a diagram illustrating an example of beam sweeping in the NR. 
     A base station transmits each SS block in an SS burst over time while performing beam sweeping. In this case, multiple SS blocks in an SS burst set are transmitted to support UEs existing in different directions. In  FIG. 6 , the SS burst set includes one to six SS blocks, and each SS burst includes two SS blocks. 
       FIG. 8  shows an example of performing measurement in EN (E-UTRAN and NR) DC case. 
     Referring to  FIG. 8 , the UE  100  are connected in EN-DC with an E-UTRAN (that is, LTE/LTE-A) cell. Here, a Pcell in EN-DC may be an E-UTRAN (that is, LTE/LTE-A) cell, and a PSCell in EN-DC may be an NR cell. 
     The UE  100  may receive measurement configuration (or “measconfig”) information element (IE) of the E-UTRAN (that is, LTE/LTE-A) cell. The measurement configuration (or “measconfig”) IE received from the E-UTRAN (that is, LTE/LTE-A) cell may further include fields shown in the following table, in addition to the fields shown in Table 2. 
     
       
         
           
               
             
               
                 TABLE 13 
               
               
                   
               
               
                 MeasConfig field description 
               
               
                   
               
             
            
               
                 fr1-Gap 
               
               
                 This field exists when a UE is configured with EN-DC. This field 
               
               
                 indicates whether a gap is applied to perform measurement on 
               
               
                 FR1 band (that is, a band shown in Table 9). 
               
               
                 mgta 
               
               
                 It indicates whether to apply a timing advance (TA) of 0.5 ms 
               
               
                 for a measurement gap configuration provided by the E-UTRAN. 
               
               
                   
               
            
           
         
       
     
     The measurement configuration (or “measconfig”) IE may further include a measGapConfig field for setting a measurement gap (MG), as shown in Table 2. 
     A gapoffset field within the measGapConfig field may further include gp4, gp5, . . . , gp11 for EN-DC, in addition to the example shown in Table 3. 
     Meanwhile, the UE  100  may receive a measurement configuration (“measconfig”) IE of an NR cell, which is a PSCell, directly from the NR cell or through the E-UTRAN cell which is a Pcell. 
     Meanwhile, the measurement configuration (“measconfig”) IE of the NR cell may include fields as shown in the following table. 
     
       
         
           
               
             
               
                 TABLE 14 
               
               
                   
               
               
                 MeasConfig field description 
               
               
                   
               
             
            
               
                 measGapConfig 
               
               
                 It indicates configuration or cancelation of a measurement gap 
               
               
                 s-MeasureConfig 
               
               
                 It indicates a threshold value for measurement of NR SpCell 
               
               
                 RSRP when a UE needs to perform measurement on a non- 
               
               
                 serving cell. 
               
               
                   
               
            
           
         
       
     
     The above measGapConfig may further include fields as shown in the following table. 
     
       
         
           
               
             
               
                 TABLE 15 
               
               
                   
               
               
                 MeasGapConfig field description 
               
               
                   
               
             
            
               
                 gapFR2 
               
               
                 It indicates a measurement gap configuration applicable for 
               
               
                 FR2 frequency range. 
               
               
                 gapOffset 
               
               
                 It indicates a gap offset of a gap pattern with an MGRP. 
               
               
                 mgl 
               
               
                 It indicates a measurement gap length by ms. There may be 
               
               
                 3 ms, 4 ms, 6 ms, etc. 
               
               
                 mgrp 
               
               
                 It indicates a measurement gap repetition period by ms. 
               
               
                 mgta 
               
               
                 It indicates whether to apply a timing advance (TA) of 
               
               
                 0.5 ms for a measurement gap configuration. 
               
               
                   
               
            
           
         
       
     
     Meanwhile, as shown in the drawing, the UE  100  receives a radio resource configuration information element (IE) of the E-UTRAN (that is, LTE/LTE-A) cell which is a Pcell. In addition, the UE may receive a radio resource configuration IE of an NR cell, which is a PS Cell, from the NR cell or through the E-UTRAN cell which is a Pcell. The radio resource configuration IE includes subframe pattern information, as described above with reference to  FIG. 3 . 
     The UE  100  performs measurement and reports a measurement result. Specifically, the UE  100  interrupts data transmission and reception with the E-UTRAN (that is, LTE/LTE-A) cell during the measurement gap, retunes its own RF chain, and performs measurement based on receipt of an SS block from an NR cell. 
     &lt;Disclosure of the Present Specification&gt; 
     Hereinafter, the disclosure of the present specification proposes operation methods of a base station and a UE for reducing power consumption reduction of the UE during cross link interference (CLI) in a network supporting flexible duplex in 5G NR networks. 
     In the case of 5G NR networks, Time Division Duplex (TDD) and Frequency Division Duplex (FDD) can be used in the range of operation band FR 1  (e.g., 6 GHz or lower) and TDD can be used in the range of operation band FR 2  (e.g., 6 GHz or higher). 
     In the case of TDD, a ratio of DL to UL can be set differently by changing a DL/UL configuration in response to the amount of traffic. However, when the same frequency band or a neighboring frequency band is used, a serving cell and a neighboring cell (or including a case in which a serving cell provider differs from a neighboring cell provider) may use the same DL/UL configuration in order to minimize the influence of interference. In this case, DL/UL configuration flexibility decreases. 
     In the case of FDD, a DL/UL ratio cannot be changed because a DL frequency and a UL frequency are differently set irrespective of the amount of DL/UL traffic. 
     Accordingly, the disclosure of the present specification proposes a method of applying flexible duplex in order to increase system capacity using a DL/UL ratio in response to the amount of traffic more efficiently. 
       FIG. 9  shows interference attributable to a UE and a BS in a neighbor cell in wireless communication. 
     To transmit a signal from a BS to a UE is called DL transmission. To transmit a signal from a UE to a BS is called UL transmission. An UL signal is a signal transmitted to a BS, and is not beamformed and transmitted in a specific location direction after the location of the BS is recognized, but is transmitted omni-directionally. Accordingly, an adjacent UE may be influenced by the transmission of the signal. Likewise, a DL signal is a signal transmitted from a BS to a UE, but is not beamformed and transmitted in a specific location direction after the location of the UE is recognized, but is transmitted omni-directionally. Accordingly, a BS in a neighbor cell may be influenced by the transmission of the signal. 
     From the viewpoint of a UE, a DL (downlink) signal is a receiving signal, and an UL (uplink) signal is a transmitting signal. Accordingly, in a process of transmitting, by a UE, an UL signal, interference may be applied to an adjacent UE. 
     On the contrary, from the viewpoint of a BS, a DL signal is a transmitting signal. An UL signal is a receiving signal. Accordingly, in a process of transmitting, by a BS, a DL signal, interference may be applied to an adjacent BS. 
     Such interference may have a great influence on the same frequency band or an adjacent frequency band. For example, assuming that a UE uses a specific frequency band to receive a DL signal, if an adjacent UE uses the specific frequency band or the adjacent frequency band to transmit an UL signal, the UE may not easily distinguish between the DL signal from a BS and the UL signal transmitted by the adjacent UE. Accordingly, the influence of interference may be increased. 
     In a 5G NR network, TDD (time division duplex) and FDD (frequency division duplex) are used in a frequency of less than 6 GHz, and TDD is used in a frequency of 6 GHz or more. In the case of TDD, the frequency ratios of DL and UL may be differently set depending on the amount of traffic by setting DL/UL configurations. If the frequency ratios of DL and UL are differently set based on the amount of traffic of each cell, interference between UEs or BSs may greatly occur as described above due to UL/DL between neighbor cells. In such a case, in order to avoid the influence of interference, the same DL/UL configuration may be used. In this case, the flexibility of a DL/UL configuration may be limited. 
     In order to increase a system capacity through more efficient use based on the amount of traffic of a cell, a flexible duplex scheme of flexibly changing the ratio of DL and UL frequencies may be applied. ABS of each cell may measure interference of UL/DL in order to determine whether frequency ratios of UL and DL are flexibly operated based on interference strength. 
     Such measurement may be called as cross link interference (CLI) measurement. That is, when a base station uses flexible duplex for each cell, a first UE of a serving cell can measure interference from a second UE of an interfering cell. When the level of the measured interference is high, the base station can stop use of flexible duplex and control UL/DL configurations such that a UL/DL configuration of a neighboring cell corresponds to a UL/DL configuration of the serving cell or control interference through power control. 
     To measure a CLI, the first UE of the serving cell monitors a reference signal (referred to as a CLI-RS in the present specification) transmitted from the second UE of the neighboring cell at predetermined intervals and reports a measurement value with respect to the CLI-RS to the corresponding network. The CLI-RS may be transmitted using an existing sounding reference signal (SRS) or a newly defined CSI-RS. 
       FIG. 10  shows a process of reporting from a UE to a BS for CLI measurement. 
     CLI measurement may be performed only when a UE supports CLI measurement. 
     Accordingly, prior to the CLI measurement, the UE needs to report whether CLI measurement is possible, that is, capability information, to a BS. 
     First, the BS may transmit, to the UE, a message for requesting capability information of the UE, for example, UECapabilityEnqiry. 
     Accordingly, the UE may transmit, to the BS, a message including its own capability information, for example, UECapabilitylnformation. 
       FIG. 11  shows a process of measuring interference with an adjacent UE and reporting it to a BS. 
     A UE may detect a sounding reference signal (SRS) from an adjacent UE in order to measure interference. The UE may derive or determine Reference Signal Received Power (RSRP) or Received Signal Strength Indicator (RSSI) using the detected SRS. 
     The UE may determine an interference value as in the following table based on a value of RSRP. 
     
       
         
           
               
               
               
             
               
                   
               
               
                 Interference 
                   
                   
               
               
                 value 
                 Measured quantity value 
                 Unit 
               
               
                   
               
             
            
               
                 SRS_RSRP_0 
                 SS-RSRP &lt; −140 
                 dBm 
               
               
                 SRS_RSRP_1 
                 −140 ≤ SRS-RSRP &lt; −139 
                 dBm 
               
               
                 SRS_RSRP_2 
                 −139 ≤ SRS-RSRP &lt; −138 
                 dBm 
               
               
                 SRS_RSRP_3 
                 −138 ≤ SRS-RSRP &lt; −137 
                 dBm 
               
               
                 SRS_RSRP_4 
                 −137 ≤ SRS-RSRP &lt; −136 
                 dBm 
               
               
                 . . . 
                 . . . 
                 . . . 
               
               
                 SRS_RSRP_107 
                 −34 ≤ SRS-RSRP &lt; −33 
                 dBm 
               
               
                 SRS_RSRP_108 
                 −33 ≤ SRS-RSRP &lt; −32 
                 dBm 
               
               
                 SRS_RSRP_109 
                 −32 ≤ SRS-RSRP &lt; −31 
                 dBm 
               
               
                   
               
            
           
         
       
     
     Alternatively, the UE may determine an interference value as in the following table based on a value of RSSI. 
     
       
         
           
               
               
               
             
               
                   
               
               
                 interference 
                   
                   
               
               
                 value 
                 Measured quantity value 
                 Unit 
               
               
                   
               
             
            
               
                 CLI_RSSI_00 
                 CLI-RSSI &lt; −100 
                 dBm 
               
               
                 CLI_RSSI_01 
                 −100 ≤ CLI-RSSI &lt; −99 
                 dBm 
               
               
                 CLI_RSSI_02 
                 −99 ≤ CLI-RSSI &lt; −98 
                 dBm 
               
               
                 . . . 
                 . . . 
                 . . . 
               
               
                 CLI_RSSI_139 
                 38 ≤ CLI-RSSI &lt; 39 
                 dBm 
               
               
                 CLI_RSSI_140 
                 39 ≤ CLI-RSSI &lt; 40 
                 dBm 
               
               
                   
               
            
           
         
       
     
     As described above, a degree of interference attributable to an adjacent UE may be digitized for each section to represent a degree of interference more conveniently and may be transmitted. 
     A UE may transmit the digitized interference value to a BS. In response thereto, the BS may use the interference value to determine frequency ratios of UL and DL. 
     Computer-readable media including instructions based on execution by at least one processor may perform the aforementioned operations. 
       FIG. 15  is a block diagram illustrating a wireless device and a base station, by which the disclosure of this specification can be implemented. 
     Referring to  FIG. 15 , a wireless device  100  and a base station  200  may implement the disclosure of this specification. 
     The wireless device  100  includes a processor  101 , a memory  102 , and a transceiver  103 . Likewise, the base station  200  includes a processor  201 , a memory  202 , and a transceiver  203 . The processors  101  and  201 , the memories  102  and  202 , and the transceivers  103  and  203  may be implemented as separate chips, or at least two or more blocks/functions may be implemented through one chip. 
     Each of the transceivers  103  and  203  includes a transmitter and a receiver. When a particular operation is performed, either or both of the transmitter and the receiver may operate. Each of the transceivers  103  and  203  may include one or more antennas for transmitting and/or receiving a radio signal. In addition, each of the transceivers  103  and  203  may include an amplifier configured for amplifying a Rx signal and/or a Tx signal, and a band pass filter for transmitting a signal to a particular frequency band. 
     Each of the processors  101  and  201  may implement functions, procedures, and/or methods proposed in this specification. Each of the processors  101  and  201  may include an encoder and a decoder. For example, each of the processors  101  and  202  may perform operations described above. Each of the processors  101  and  201  may include an application-specific integrated circuit (ASIC), a different chipset, a logic circuit, a data processing device, and/or a converter which converts a base band signal and a radio signal into each other. 
     Each of the memories  102  and  202  may include a Read-Only Memory (ROM), a Random Access Memory (RAM), a flash memory, a memory card, a storage medium, and/or any other storage device. 
       FIG. 16  is a detailed block diagram illustrating a transceiver of the wireless device shown in  FIG. 15 . 
     Referring to  FIG. 16 , a transceiver  110  includes a transmitter  111  and a receiver  112 . The transmitter  111  includes a Discrete Fourier Transform (DFT) unit  1111 , a subcarrier mapper  1112 , an IFFT unit  1113 , a CP insertion unit  1114 , a wireless transmitter  1115 . In addition, the transceiver  1110  may further include a scramble unit (not shown), a modulation mapper (not shown), a layer mapper (not shown), and a layer permutator, and the transceiver  110  may be disposed in front of the DFT unit  1111 . That is, in order to prevent a peak-to-average power ratio (PAPR) from increasing, the transmitter  111  may transmit information to pass through the DFT unit  1111  before mapping a signal to a subcarrier. A signal spread (or pre-coded for the same meaning) by the DFT unit  111  is subcarrier-mapped by the subcarrier mapper  1112 , and then generated as a time domain signal by passing through the IFFT unit  1113 . 
     The DFT unit  111  performs DFT on input symbols to output complex-valued symbols. For example, if Ntx symbols are input (here, Ntx is a natural number), a DFT size may be Ntx. The DFT unit  1111  may be called a transform precoder. The subcarrier mapper  1112  maps the complex-valued symbols to subcarriers of a frequency domain. The complex-valued symbols may be mapped to resource elements corresponding to a resource block allocated for data transmission. The subcarrier mapper  1112  may be called a resource element mapper. The IFFT unit  113  may perform IFFT on input symbols to output a baseband signal for data, which is a time-domain signal. The CP inserter  1114  copies a rear portion of the baseband signal for data and inserts the copied portion into a front part of the baseband signal. The CP insertion prevents Inter-Symbol Interference (ISI) and Inter-Carrier Interference (ICI), and therefore, orthogonality may be maintained even in multi-path channels. 
     Meanwhile, the receiver  112  includes a wireless receiver  1121 , a CP remover  1122 , an FFT unit  1123 , and an equalizer  1124 , and so on. The wireless receiver  1121 , the CP remover  1122 , and the FFT unit  1123  of the receiver  112  performs functions inverse to functions of the wireless transmitter  1115 , the CP inserter  1114 , and the IFFT unit  113  of the transmitter  111 . The receiver  112  may further include a demodulator. 
     An example in which a disclosure of the present specification can be utilized will be described as follows. 
     &lt;General Description on Device to Which Disclosure of the Present Specification is Applicable&gt; 
     Hereinafter, a device to which the present disclosure is applicable will be described. 
       FIG. 17  shows a wireless communication system according to an embodiment. 
     Referring to  FIG. 17 , a wireless communication system may include a first device  100   a  and a second device  100   b.    
     The first device  100   a  may be a base station, a network node, a transmitting terminal, a receiving terminal, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with self-driving capability, a connected car, a drone (or an unmanned aerial vehicle (UAV)), an artificial intelligence (AI) module, a robot, an augmented reality (AR) device, a virtual reality (VR) device, a mixed reality (MR) device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a FinTech device (or a financial device), a security device, a climate/environment device, a device related to a 5G service, or a device related to a field of the 4th industrial revolution. 
     The second device  100   b  may be a base station, a network node, a transmitting terminal, a receiving terminal, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with self-driving capability, a connected car, a drone (or an unmanned aerial vehicle (UAV)), an artificial intelligence (AI) module, a robot, an augmented reality (AR) device, a virtual reality (VR) device, a mixed reality (MR) device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a FinTech device (or a financial device), a security device, a climate/environment device, a device related to a 5G service, or a device related to a field of the 4th industrial revolution. 
     For example, a terminal may include a mobile phone, a smart phone, a laptop computer, a digital broadcasting terminal, a personal digital assistants (PDA), a portable multimedia player (PMP), a navigation, a slate PC, a table PC, an ultrabook, a wearable device (e.g., a smartwatch, a smart glass, a head mounted display (HMD)), or the like. For example, the HMD may be a display device worn on a head. For example, the HMD may be used to implement VR, AR, or MR. 
     For example, the drone may be an unmanned aerial vehicle which flies by using a radio control signal. For example, the VR device may include a device for realizing an object, background, or the like of a virtual world. For example, the AR device may include a device for realizing an object or background of a virtual world by connecting with an object or background or the like of a real world. For example, the MR device may include a device for realizing an object or background of a virtual world by merging an object, background, or the like of a real world. For example, the hologram device may include a device for recording and reproducing stereoscopic information to realize a 360-degree stereoscopic image, by utilizing light interference which occurs when two laser beams called holography are met. For example, the public safety device may include an image relay device or an image device or the like which can be worn on a user&#39;s body. For example, the MTC device and the IoT device may be devices not requiring direct human intervention or manipulation. For example, the MTC device and the IoT device may include a smart meter, a bending machine, a thermometer, a smart bulb, a door lock, or various sensors. For example, the medical device may be a device used for diagnosing, curing, alleviating, treating, or preventing a disease. For example, the medial device may be a device used for diagnosing, curing, alleviating or ameliorating an injury or disorder. For example, the medial device may be a device used for inspecting, replacing, or modifying a structure or function. For example, the medical device may be a device used for controlling pregnancy. For example, the medical device may include a diagnostic device, a surgical device, a (in vitro) diagnostic device, a hearing aid, or a treatment device. For example, the security device may be a device installed to prevent potential hazards and maintain security. For example, the security device may be a camera, a CCTV, a recorder, or a black box. For example, the Fin-Tech device may be a device capable of providing financial services such as mobile payment. For example, the Fin-tech device may include a payment device or a point of sales (POS). For example, the climate/environmental device may include a device for monitoring or predicting climates/environments. 
     The first device  100   a  may include at least one processor such as a processor  1020   a , at least one memory such as a memory  1010   a , and at least one transceiver such as a transceiver  1031   a . The processor  1020   a  may perform the aforementioned functions, procedures, and/or methods. The processor  1020   a  may perform one or more protocols. For example, the processor  1020   a  may perform one or more layers of a radio interface protocol. The memory  1010   a  may be coupled to the processor  1020   a , and may store various types of information and/or commands. The transceiver  1031   a  may be coupled to the processor  1020   a , and may be controlled to transmit/receive a radio signal. 
     The second device  100   b  may include at least one processor such as a processor  1020   b , at least one memory such as a memory  1010   b , and at least one transceiver such as a transceiver  1031   b . The processor  1020   b  may perform the aforementioned functions, procedures, and/or methods. The processor  1020   b  may perform one or more protocols. For example, the processor  1020   b  may perform one or more layers of a radio interface protocol. The memory  1010   b  may be coupled to the processor  1020   b , and may store various types of information and/or commands. The transceiver  1031   b  may be coupled to the processor  1020   b , and may be controlled to transmit/receive a radio signal. 
     The memory  1010   a  and/or the memory  1010   b  may be connected internally or externally to the processor  1020   a  and/or the processor  1020   b , respectively, or may be connected to other processors through various techniques such as wired or wireless connections. 
     The first device  100   a  and/or the second device  100   b  may have one or more antennas. For example, an antenna  1036   a  and/or an antenna  1036   b  may be configured to transmit/receive a radio signal. 
       FIG. 18  is a block diagram of a network node according to an embodiment. 
     In particular,  FIG. 18  shows an example of the network node of  FIG. 17  in greater detail, when a base station is divided into a central unit (CU) and a distributed unit (DU). 
     Referring to  FIG. 18 , base stations W 20  and W 30  may be connected to a core network W 10 , and the base station W 30  may be connected to the neighboring base station W 20 . For example, an interface between the base stations W 20  and W 30  and the core network W 10  may be referred to as NG, and an interface between the base station W 30  and the neighboring base station W 20  may be referred to as Xn. 
     The base station W 30  may be divided into a CU W 32  and DUs W 34  and W 36 . That is, the base station W 30  may be managed by being separated in a layered manner. The CU W 32  may be connected to one or more DUs W 34  and W 36 . For example, an interface between the CU W 32  and the DUs W 34  and W 36  may be referred to as F 1 . The CU W 32  may perform a function of higher layers of the base station, and the DUs W 34  and W 36  may perform a function of lower layers of the base station. For example, the CU W 32  may be a logical node for hosting radio resource control (RRC), service data adaptation protocol (SDAP), and packet data convergence protocol (PDCP) layers of the base station (e.g., gNB), and the DUs W 34  and W 36  may be a logical node for hosting radio link control (RLC), media access control (MAC), and physical (PHY) layers of the base station. Alternatively, the CU W 32  may be a logical node for hosting RRC and PDCP layers of the base station (e.g., en-gNB). 
     Operations of the DUs W 34  and W 36  may be partially controlled by the CU W 32 . One DU W 34  or W 36  may support one or more cells. One cell may be supported only by one DU W 34  or W 36 . One DU W 34  or W 36  may be connected to one CU W 32 , and one DU W 34  or W 36  may be connected to a plurality of CUs by proper implementation. 
       FIG. 19  is a block diagram showing a structure of a terminal according to an embodiment. 
     In particular,  FIG. 19  shows an example of the terminal of  FIGS. 16 and 18  in greater detail. 
     A terminal includes a memory  1010 , a processor  1020 , a transceiver  1031 , a power management module  1091 , a battery  1092 , a display  1041 , an input unit  1053 , a speaker  1042 , a microphone  1052 , a subscriber identification module (SIM) card, and one or more antennas. 
     The processor  1020  may be configured to implement the proposed functions, procedures, and/or methods described in the present specification. Layers of a radio interface protocol may be implemented in the processor  1020 . The processor  1020  may include application-specific integrated circuits (ASICs), other chipsets, logic circuits, and/or data processing units. The processor  1020  may be an application processor (AP). The processor  1020  may include at least one of a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPS), and a modulator and demodulator (modem). An example of the processor  1020  may include an SNAPDRAGON™ series processor manufactured by Qualcomm®, an EXYNOS™ series processor manufactured by Samsung®, an A series processor manufactured by Apple®, a HELIO™ series processor manufactured by MediaTek®, an ATOM™ series processor manufactured by INTEL®, or a corresponding next-generation processor. 
     The power management module  1091  manages power for the processor  1020  and/or the transceiver  1031 . The battery  1092  supplies power to the power management module  1091 . The display  1041  outputs a result processed by the processor  1020 . The input unit  1053  receives an input to be used by the processor  1020 . The input unit  1053  may be displayed on the display  1041 . The SIM card is an integrated circuit used to safely store an international mobile subscriber identity (IMSI) used to identify and authenticate a subscriber and a key related thereto in a portable phone and a portable phone device such as a computer. Contacts information may be stored in many SIM cards. 
     The memory  1010  is operatively coupled to the processor  1020 , and stores a variety of information for operating the processor  1020 . The memory  1010  may include a read-only memory (ROM), a random access memory (RAM), a flash memory, a memory card, a storage medium, and/or other equivalent storage devices. When the embodiment is implemented in software, the techniques explained in the present specification can be implemented with a module (i.e., procedure, function, etc.) for performing the functions explained in the present specification. The module may be stored in the memory  1010  and may be performed by the processor  1020 . The memory  1010  may be implemented inside the processor  1020 . Alternatively, the memory  1010  may be implemented outside the processor  1020 , and may be coupled to the processor  1020  in a communicable manner by using various well-known means. 
     The transceiver  1031  is operatively coupled to the processor  1020 , and transmits and/or receives a radio signal. The transceiver  1031  includes a transmitter and a receiver. The transceiver  1031  may include a baseband signal for processing a radio frequency signal. The transceiver controls one or more antennas to transmit and/or receive a radio signal. In order to initiate communication, the processor  1020  transfers command information to the transceiver  1031 , for example, to transmit a radio signal constituting voice communication data. The antenna serves to transmit and receive a radio signal. When the radio signal is received, the transceiver  1031  may transfer a signal to be processed by the processor  1020 , and may convert the signal into a baseband signal. The processed signal may be converted into audible or readable information which is output through the speaker  1042 . 
     The speaker  1042  outputs a result related to a sound processed by the processor  1020 . The microphone  1052  receives a sound-related input to be used by the processor  1020 . 
     A user presses (or touches) a button of the input unit  1053  or drives voice (activates voice) by using the microphone  1052  to input command information such as a phone number or the like. The processor  1020  receives the command information, and performs a proper function such as calling the phone number or the like. Operational data may be extracted from the SIM card or the memory  1010 . In addition, the processor  1020  may display command information or operational information on the display  1041  for user&#39;s recognition and convenience. 
     &lt;Scenario to Which Disclosure of the Present Specification is Applicable&gt; 
     Hereinafter, a scenario to which the aforementioned disclosures of the present disclosure are applicable will be described. 
     In the present specification, an always-on PDU session for URLLC having a low latency characteristic may be used for artificial intelligence, robots, autonomous driving, extended reality, etc., in the 5G scenario described below. 
     &lt;5G-Usage Scenario&gt; 
       FIG. 20  shows an example of a 5G usage scenario. 
     The 5G usage scenario of  FIG. 20  is for exemplary purposes only, and thus technical features of the present disclosure are also applicable to other 5G usage scenarios not shown in  FIG. 20 . 
     Referring to  FIG. 20 , three main requirement areas of 5G includes: (1) an enhanced mobile broadband (eMBB) area; (2) a massive machine type communication (mMTC) area; and (3) an ultra-reliable and low latency communications (URLLC) area. In some usage examples, a plurality of areas may be required for optimization. In other usage examples, only one key performance indicator (KPI) may be focused. The 5G supports these various usage examples in a flexible and reliable manner. 
     The eMBB focuses on overall improvement of a data rate, latency, user density, mobile broadband access capacity, and coverage. The eMBB aims at a throughput of about 10 Gbps. The eMBB allows to surpass basic mobile Internet access, and covers sufficient interactive tasks, media in a cloud or augmented reality, and entertainment application. Data is one of the core engine for 5G, and it seems that a dedicated voice service can be seen for the first time in the 5G era. In the 5G, it is expected that voice will be simply processed with an application program by using a data connection provided by a communication system. A main reason of an increased traffic amount is an increase in a content size and an increase in the number of applications requiring a high data transfer rate. A streaming service (audio and video), interactive video, and mobile Internet connectivity will be more widely used as more devices are connected to the Internet. These many applications require always-on connectivity to push real-time information and notifications to a user. There is a rapid increase in cloud storage and applications in a mobile communication platform, which is applicable to both work and entertainment. The cloud storage is a special example of driving an increase in an uplink data transfer rate. The 5G is also used for a remote task on the cloud, and requires much lower end-to-end latency to maintain excellent user experience when a tactile interface is used. Taking entertainment for example, cloud games and video streaming are another key element requiring improvement in mobile broadband capability. The entertainment is essential in a smartphone and a tablet anywhere, including a high mobility environment such as a train, a car, and an airplane. Another usage example is augmented reality and information retrieval for entertainment. Herein, the augmented reality requires very low latency and an instantaneous data amount. 
     The mMTC is designed to enable communication between a plenty of low-cost devices driven by batteries and is intended to support an application such as smart metering, logistics, and field and body sensors. The mMTC aims at about 10-year-lifespan batteries and/or about million devices per square kilometer (1 km2). The mMTC may configure a sensor network by seamlessly connecting an embedded sensor in all sectors, and is one of the most expected 5G usage examples. Potentially, it is predicted that the number of IoT devices will reach 20.4 billion by 2020. A smart network utilizing industrial IoT is one of areas where the 5G plays a key role in enabling smart cities, asset tracking, smart utilities, agriculture, and security infrastructures. 
     The URLLC allows a device and a machine to communicate with very high reliability, very low latency, and high availability, and thus is identical to communication and control between self-driving vehicles, industrial control, factory automation, mission-critical applications such as remote operations and healthcare, smart grids, and public safety applications. The URLLC aims at a latency of about lms. The URLLC includes a new service which will change the industry through a link with high-reliability/ultra-low latency such as remote control and self-driving vehicles. A level of reliability and latency is essential for smart grid control, industrial automation, robotics, and drone control and adjustment. 
     Next, a plurality of usage examples included in the triangle of  FIG. 20  will be described in greater detail. 
     In 5G, fiber-to-the-home (FTTH) and cable-based broadband (or DOCSIS) may be compensated as a means of providing a stream rated in the range from hundreds of megabits per second to gigabits per second. This fast speed may be required not only in virtual reality (VR) and augmented reality (AR) but also in transferring TV broadcasting in the resolution of at least 4 K (6K, 8K, or higher). VR and AR applications include almost immersive sports events. A specific application may require a special network configuration. For example, in case of the VR game, a game company may have to integrate a core server with an edge network server of an operator in order to minimize latency. 
     Automotive is expected to become an important new engine for 5G, together with many usages for mobile communications for vehicles. For example, entertainment for a passenger demands high capacity and high mobile broadband at the same time. This is because future users will continue to expect high-quality connectivity regardless of their locations and speeds. Another usage example of the automotive sector is an augmented reality dashboard. Through the augmented reality dashboard, a driver is able to identify an object, in the dark, shown above that the driver is seeing through a windshield. The augmented reality dashboard displays information to be reported to the deriver as to a distance and movement of an object in an overlapping manner. In the future, a radio module will enable communication between vehicles, information exchange between a vehicle and a supported infrastructure, and information exchange between an automotive and another connected device (e.g., a device carried by a pedestrian). The safety system guides an alternative course of action so that the driver can drive more safely, thereby decreasing a risk of accidents. A next step will be a remote control vehicle or a self-driving vehicle. This requires very reliable and very fast communication between different self-driving vehicles and/or between an automotive and an infrastructure. In the future, the self-driving vehicle will perform all driving activities, and the driver will focus only on erroneous traffic which cannot be identified by the vehicle itself. A technical requirement of the self-driving vehicle is ultra-low latency and ultra-high reliability so that traffic safety is increased to a level that cannot be achieved by humans. 
     A smart city and a smart home, referred to as a smart society, will be embedded in a high-density wireless sensor network as an example of a smart network. A distributed network of an intelligent sensor will identify a condition for cost and energy-efficient maintenance of a city or home. A similar configuration may be performed for each household. A temperature sensor, a window and heating controller, a burglar alarm, and home appliance are all wirelessly connected. Many of these sensors typically require a low data rate, low power, and low cost. For example, however, real-time HD video may be required in a specific-type device for surveillance. 
     Since consumption and distribution of energy, including heat or gas, are highly dispersed, automated control of a distributed sensor network is required. The smart grid interconnects these sensors by using digital information and communication techniques to collect information and act according to the information. This information may include acts of suppliers and consumers, allowing the smart grid to improve distribution of fuels such as electricity in an efficient, reliable, production sustainable, and automated manner. The smart grid may be regarded as another sensor network with low latency. 
     The health sector has many applications which can benefit from mobile communication. A communication system may support telemedicine which provides a clinical care in remote locations. This may help to reduce a barrier for a distance, and may improve access to a medical service which cannot be persistently used in a far rural area. This is also used to save lives in a critical care and an emergency situation. A wireless sensor network based on mobile communication may provide remote monitoring and sensors for parameters such as heart rates and blood pressure. 
     Wireless and mobile communications are becoming gradually important in an industrial application sector. Wiring is expensive in terms of installation and maintenance cost. Therefore, a possibility of replacing a cable with a wireless link that can be reconfigured is an attractive opportunity in many industrial sectors. However, to achieve this, wireless connectivity is required to operate with latency, reliability, and capacity similar to those of a cable, and to be managed in a simplified manner. Low latency and very low error probability are new requirements, which requires 5G connectivity. 
     Logistics and cargo tracking are an important usage example for mobile communication which enables inventory and package tracking anywhere by using a location-based information system. An example of using logistics and cargo tracking typically requires a low data rate, but requires wide range and reliable location information. 
     &lt;Artificial Intelligence (AI)&gt; 
     Artificial intelligence refers to a sector that studies artificial intelligence and a methodology for creating it. Machine learning refers to a sector that defines various problems dealt in an artificial intelligent sector and studies a methodology for solving the problems. The machine learning is also defined as an algorithm that improves performance of a task through a steady experience for a certain task. 
     An artificial neural network (ANN) is a model used in machine learning, and may refer to an overall model having problem-solving ability and consisting of artificial neurons (nodes) constructing a network by combining synapses. The ANN may be defined by a connectivity pattern between neurons of different layers, a leaning processor for updating a model parameter, and an activation unction for generating an output value. 
     &lt;Robot&gt; 
     A robot may mean a machine which automatically operates or processes a given task according to its own capability. In particular, a robot having a function of performing an operation by recognizing an environment and by autonomously making a decision may be referred to as an intelligent robot. 
     The robot may be classified for industrial, medical, household, and military purposes depending on the purpose or field of use. 
     The robot may include a driving unit having an actuator or a motor to perform various physical operations such as moving a robot joint. In addition, a movable robot may include a wheel, a brake, a propeller, and the like in the driving unit, thereby being able to driving on the ground or flying in the air through the driving unit. 
     &lt;Self-Driving (Autonomous—Driving)&gt; 
     Self-driving means an autonomous-driving technique, and a self-driving vehicle means a vehicle that travels without user&#39;s manipulation or with minimum user&#39;s manipulation. 
     For example, the self-driving may include all of a technique for maintaining a lane while driving, a technique for automatically controlling speed such as adaptive cruise control, a technique for automatically travelling along a predetermined route, and a technique for travelling by automatically setting a route when a destination is determined. 
     The vehicle may include all of a vehicle having only an internal combustion engine, a hybrid vehicle having an internal combustion engine and an electric motor together, and an electric vehicle having only an electric motor, and may include not only an automotive vehicle but also a train, a motorcycle, etc. 
     In this case, the self-driving vehicle may be regarded as a robot having an autonomous-driving function. 
     &lt;eXtended Reality (XR)&gt; 
     Extended reality collectively refers to virtual reality (VR), augmented reality (AR), and mixed reality (MR). A VR technique is a computer graphic technique providing real-world objects and backgrounds only as CG images. An AR technique a computer graphic technique providing virtual CG images together on real object images. An MR technique is a computer graphic technique providing virtual objects in the real world in a mixed and combined manner. 
     The MR technique is similar to the AR technology in a sense that a real object and a virtual object are shown together. However, the AR technology in which the virtual object is used as a complement to the real object differs from the MR technology in which the virtual object and the real object are used in an equal manner. 
     The XR technique may be applied to a head-mount display (HMD), a head-up display (HUD), a mobile phone, a tablet PC, a laptop, a desktop, TV, a digital signage, etc., and a device to which the XR technique is applied may be referred to as an XR device. 
       FIG. 21  shows an AI system  1  according to an embodiment. 
     Referring to  FIG. 21 , in the AI system  1 , at least one of an AI server  200 , a robot  100   a , a self-driving vehicle  100   b , an XR device  100   c , a smart phone  100   d , and a home appliance  100   e  is connected to a cloud network  10 . Herein, the robot  100   a , self-driving vehicle  100   b , XR device  100   c , smart phone  100   d , or home appliance  100   e  to which the AI technique is applied may be referred to as AI devices  100   a  to  100   e.    
     The cloud network  10  may mean a network which constructs part of a cloud computing infrastructure or which exists in the cloud computing infrastructure. Herein, the cloud network  10  may be configured by using a 3G network, a 4G or long term evolution (LTE) network, or a 5G network. 
     That is, each of the devices  100   a  to  100   e  and  200  constituting the AI system  1  may be connected to each other through the cloud network  10 . In particular, the devices  100   a  to  100   e  and  200  may communicate with each other via a base station, but may communicate with each other directly without having to use the base station. 
     The AI server  200  may include a server which performs AI processing and a server which performs an operation for big data. 
     The AI server  200  may be connected to at least one of the AI devices constituting the AI system  1 , that is, the robot  100   a , the self-driving vehicle  100   b , the XR device  100   c , the smart phone  100   d , and the home appliance  100   e  through the cloud network  10 , and may assist at least part of AI processing of the connected AI devices  100   a  to  100   e.    
     In this case, the AI server  200  may serve to learn an artificial neural network according to a machine learning algorithm on behalf of the AI devices  100   a  to  100   e , and may directly store a learning model or transmit it to the AI devices  100   a  to  100   e.    
     In this case, the AI server  200  may receive input data from the AI devices  100   a  to  100   e , infer a result value for the input data received using the learning module, and generate a control command or a response based on the inferred result value to transmit it to the AI devices  100   a  to  100   e.    
     Alternatively, the AI devices  100   a  to  100   e  may infer the result value for the input data by using a direct learning model and generate a control command and a response based on the inferred result value. 
     Hereinafter, various embodiments of the AI devices  100   a  to  100   e  to which the aforementioned techniques are applied will be described. 
     &lt;AI+Robot&gt; 
     The robot  100   a  may be implemented as a guide robot, a carrying robot, a cleaning robot, a wearable robot, an entertainment robot, a pet robot, an unmanned flying robot, etc., by applying the AI technique. 
     The robot  100   a  may include a robot control module for controlling an operation, and the robot control module may mean a software module or a chip implementing the software module as hardware. 
     The robot  100   a  may use sensor information acquired from various types of sensors to obtain status information of the robot  100   a , to detect (recognize) a surrounding environment and an object, to generate map data, to determine a travel route and a driving plan, to determine a response for user interaction, or to determine an operation. 
     Herein, the robot  100   a  may use the sensor information acquired from at least one sensor among a lidar, a radar, and camera to determine a travel path and a driving plan. 
     The robot  100   a  may use a leaning model consisting of at least one artificial neural network to perform the aforementioned operations. For example, the robot  100   a  may use the leaning model to recognize a surrounding environment and an object, and may use the recognized surrounding environment information or object information to determine an operation. Herein, the leaning model may be learned directly from the robot  100   a  or learned from an external device such as the AI server  200  or the like. 
     In this case, the robot  100   a  may generate a result and perform an operation by directly using the learning model. However, it is also possible to perform an operation by transmitting sensor information to the external device such as the AI server  200  or the like and by receiving a result generated based thereon. 
     The robot  100   a  may determine the travel path and the driving plan by using at least one of map date, object information detected from sensor information, and object information acquired from an external device, and may control a driving unit so that the robot  100   a  travels according to the determined travel path and driving plan. 
     The map data may include object identification information on various objects arranged in a space in which the robot  100   a  moves. For example, the map data may include object identification information on stationary objects such as walls, doors, or the like and movable objects such as flowerpots, desks, or the like. In addition, the object identification information may include a name, a type, a distance, a location, or the like. 
     In addition, the robot  100   a  may control the driving unit on the basis of a user&#39;s control/interaction to travel or perform an operation. In this case, the robot  100   a  may acquire the intention information of an interaction based on a user&#39;s action or voice utterance, and may determine a response based on the acquired intention information to perform an operation. 
     &lt;Combinations of AI, Robot, Autonomous-Driving, and XR&gt; 
     The self-driving vehicle  100   b  may be implemented as a mobile robot, a vehicle, an unmanned aerial vehicle, or the like, by applying an AI technology. 
     The XR device  100   c  may be implemented as a Head-Mount Display (HMD), a Head-Up Display (HUD) equipped in a vehicle, a television, a mobile phone, a smart phone, a computer, a wearable device, a home appliance, a digital signage, a vehicle, a stationary robot, a mobile robot, or the like, by applying the AI technology. 
     The robot  100   a  may be implemented as a guide robot, a carrying robot, a cleaning robot, a wearable robot, an entertainment robot, a pet robot, an unmanned flying robot, or the like, by applying the AI technology and an autonomous-driving technology. 
     The robot  100   a  may be implemented as a guide robot, a carrying robot, a cleaning robot, a wearable robot, an entertainment robot, a pet robot, an unmanned aerial robot, a drone, or the like, by applying the AI technology and an XR technology. 
     The self-driving vehicle  100   b  may be implemented as a mobile robot, a vehicle, an unmanned aerial vehicle, or the like by applying the AI technology and the XR technology. 
     Although exemplary embodiments of the present disclosure have been described above, the scope of the present disclosure is not limited to the specific embodiments and the present disclosure may be modified, changed, or improved in various ways within the scope of the present disclosure and the category of the claims.