Base stations, communication methods, and integrated circuits

Abstract

To improve the efficiency of cell selection in wireless communication. [Solution] The terminal comprises a receiving circuit that receives parameters relating to cell selection, which are set based on at least one of the terminal's function, type, and operating mode, and a control circuit that performs cell selection processing based on the parameters.

Description

[Technical Field]

[0001] This disclosure relates to terminals and communication methods. [Background technology]

[0002] In recent years, driven by the expansion and diversification of wireless services, the Internet of Things (IoT) is expected to develop dramatically. The use of mobile communication is expanding beyond smartphones and other information terminals to encompass a wide range of fields, including cars, homes, home appliances, and industrial equipment. To support this service diversification, significant improvements in the performance and functionality of mobile communication systems are required, including increased system capacity, an increase in the number of connected devices, and low latency. Fifth-generation mobile communication systems (5G) possess features such as large capacity and ultra-high speed (eMBB: enhanced Mobile Broadband), massive machine-type communication (mMTC: massive Machine Type Communication), and ultra-reliable and low-latency communication (URLLC: Ultra Reliable and Low Latency Communication), enabling flexible wireless communication to meet diverse needs.

[0003] The 3rd Generation Partnership Project (3GPP), an international standardization organization, is working on the specification of New Radio (NR) as one of the 5G wireless interfaces. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2020 / 196537 [Non-patent literature]

[0005] [Non-Patent Document 1] 3GPP TS38.104 V15.12.0, “NR Base Station (BS) radio transmission and reception (Release 15),” December 2020. [Non-Patent Document 2] RP-202928, “New WID on NR coverage enhancements,” China Telecom, December 2020. [Non-Patent Document 3] RP-202933, “New WID on support of reduced capability NR devices,” Ericsson, Nokia, December 2020. [Non-Patent Document 4] 3GPP TS38.304 V16.3.0, “User Equipment (UE) procedures in Idle mode and RRC Inactive state (Release 16),” December 2020. [Non-Patent Document 5] 3GPP TS36.304 V16.3.0, “User Equipment (UE) procedures in idle mode (Release 16),” December 2020. [Non-Patent Document 6] 3GPP TS38.213 V16.4.0, “Physical layer procedures for control (Release 16),” December 2020. [Overview of the project]

[0006] However, there is room for further consideration regarding the method of selecting cells in wireless communication.

[0007] Non-limiting embodiments of this disclosure contribute to providing terminals, base stations, and communication methods that can improve the efficiency of cell selection in wireless communication.

[0008] A terminal according to one embodiment of the present disclosure comprises a receiving circuit that receives parameters relating to cell selection, which are set based on at least one of the functions, types, and operating modes of the terminal, and a control circuit that performs the cell selection process based on the parameters.

[0009] These comprehensive or specific embodiments may be implemented as systems, devices, methods, integrated circuits, computer programs, or recording media, or as any combination of systems, devices, methods, integrated circuits, computer programs, and recording media.

[0010] According to one embodiment of the present disclosure, the efficiency of cell selection in wireless communication can be improved.

[0011] Further advantages and effects of one embodiment of this disclosure will be made apparent from the specification and drawings. Such advantages and / or effects are provided by several embodiments and features described in the specification and drawings, but not all of them are necessarily provided in order to obtain one or more identical features. [Brief explanation of the drawing]

[0012] [Figure 1] This diagram shows an example of how to select cells when the coverage differs between the uplink and downlink. [Figure 2] A diagram showing an example of how to select cells. [Figure 3] Block diagram showing some example configurations of the terminal. [Figure 4] Block diagram showing an example of a base station configuration. [Figure 5] Block diagram showing an example of terminal configuration [Figure 6] A flowchart illustrating an example of terminal operation. [Figure 7] A diagram showing an example of parameters used for cell selection. [Figure 8] Diagram of a representative architecture of a 3GPP NR system [Figure 9]Schematic diagram showing the functional separation between NG-RAN and 5GC. [Figure 10] Sequence diagram of the setup / reconfiguration procedure for Radio Resource Control (RRC) connection. [Figure 11] This schematic diagram illustrates usage scenarios for high-capacity, high-speed communication (eMBB: enhanced Mobile Broadband), massive machine type communications (mMTC: massive machine type communications), and highly reliable, ultra-low-latency communications (URLLC: Ultra Reliable and Low Latency Communications). [Figure 12] Block diagram illustrating an exemplary 5G system architecture for a non-roaming scenario. [Modes for carrying out the invention]

[0013] Embodiments of this disclosure will be described in detail below with reference to the drawings.

[0014] In NR, for example, in addition to frequency bands below 6GHz, mainly the 700MHz to 3.5GHz band, which have been used for cellular communications (for example, also called Frequency Range 1 (FR1)), millimeter-wave bands such as 28GHz or 39GHz (for example, also called FR2), which can secure a wide bandwidth, may be utilized (see, for example, Non-Patent Document 1). Furthermore, in FR1, for example, higher frequency bands may be used compared to the frequency bands used in Long Term Evolution (LTE) or 3G (3rd Generation mobile communication systems), such as the 3.5GHz band. The higher the frequency band, the greater the radio wave propagation loss, and the more likely the radio wave reception quality is to deteriorate. For this reason, in NR, for example, when higher frequency bands are used compared to LTE or 3G, it is expected that a communication area (or coverage) of the same level as that of Radio Access Technology (RAT) such as LTE or 3G will be secured, in other words, appropriate communication quality will be ensured. For example, in Release 17 (referred to as "Rel.17"), methods for improving coverage in NR are considered (see, for example, Non-Patent Document 2).

[0015] Furthermore, NR is exploring the possibility of developing simpler, lower-cost devices (also known as UE: User Equipment) that reduce the number of antennas, maximum bandwidth, or power consumption compared to devices such as smartphones (see, for example, Non-Patent Document 3). Such low-cost devices may also be called, for example, devices that support Reduced Capability (hereinafter also referred to as "RedCap devices").

[0016] [Example of how cell selection works] In NR, for example, when a terminal is in an IDLE or INACTIVE state, a process is defined for determining which cell the terminal will connect to (see, for example, Non-Patent Document 4). This process (or operation) is called, for example, "cell selection" or "cell reselection." Note that cell selection and cell reselection may be collectively referred to as "cell selection." For example, "cell selection" may include processing related to "cell reselection." The following describes an example of the operation of cell selection in NR.

[0017] For example, during the initial cell selection of an idle terminal, the terminal may search (in other words, scan) multiple (e.g., all) channels (e.g., RF channels or frequencies) of the frequency band corresponding to NR (e.g., called the NR frequency band or NR band), depending on the terminal's capability with respect to radio frequency (RF).

[0018] For example, a terminal may search for the strongest cell (e.g., the strongest cell) at each frequency. Here, the cell strength may be determined based on at least one of the following: for example, the received signal power (e.g., RSRP: Reference Signal Received Power) and the received quality (e.g., RSRQ: Reference Signal Received Quality).

[0019] Alternatively, if the terminal possesses, for example, measurement and control information received in the past, or information regarding frequencies or cell parameters obtained from previously detected cells, the terminal may perform cell selection based on this information (also known as cell selection by leveraging stored information). In this case, the terminal does not need to search all RF channels in the NR frequency band.

[0020] In the above cell selection, when the terminal finds a suitable cell, it selects (or in other words, camps on) that cell. Here, a "suitable cell" may be, for example, a cell that meets the criteria for cell selection and permits access by the terminal. Also, as the cell selection criteria, for example, it is stipulated to satisfy the following formula (1) (for example, refer to Non-Patent Document 4). Srxlev > 0 AND Squal > 0 (1)

[0021] Here, Srxlev is the received power level related to cell selection (for example, expressed in [dB]), and Squal is the received quality level related to cell selection (for example, expressed in [dB]), and each may be given by the following formulas (2) and (3). Srxlev = Q rxlevmeas - (Q rxlevmin + Q rxlevminoffset ) - Pcompensation - Qoffset temp (2) Squal = Q qualmeas - (Q qualmin + Q qualminoffset ) - Qoffset temp (3)

[0022] In formula (2), Q rxlevmeas is the received power measured by the terminal (for example, RSRP), Q rxlevmin is the minimum required received power (for example, expressed in [dBm]), Q rxlevminoffset is the offset value for Q rxlevmin , Pcompensation is the correction value related to the uplink transmission power capability of the terminal (for example, expressed in [dB]), and Qoffset temp is the temporarily applied offset value (for example, expressed in [dB]). Also, in formula (3), Q qualmeas is the received quality measured by the terminal (for example, RSRQ), Q qualmin is the minimum required received quality (for example, expressed in [dB]), Q qualminoffset is the offset value for Q qualminThis is the offset value relative to [the given value].

[0023] For example, the "Q" in equations (2) and (3) rxlevminoffset " and "Q qualminoffset This may be applied to the measurement results of high-priority PLMN when the terminal selects Visitor Public Land Mobile Network (VPLMN).

[0024] Furthermore, after selecting a cell (Camp on) via cell selection, the terminal may perform a cell re-selection process.

[0025] The minimum required received power (e.g., Q) is a parameter related to cell selection and cell re-selection. rxlevmin ), Minimum required reception quality (e.g., Q qualmin ), offset value (for example, Q rxlevminoffset and Q qualminoffset The minimum required received power Q, and the correction value (Pcompensation), may be transmitted (in other words, signaled or set) from the base station (also called a gNB) to the terminal by broadcast information (e.g., SIB: System Information Block). For example, the minimum required received power Q rxlevmin and minimum required reception quality Q qualmin This information may be communicated to the terminal via the parameters "q-RxLevMin" and "q-RxQualMin," respectively, transmitted by SIB.

[0026] In the cell selection criteria described above, for example, Srxlev and Squal each determine the cell coverage measured by RSRP and RSRQ. For example, as shown in Figure 1, if the coverage of the uplink is narrower than the coverage of the downlink, Q rxlevmin Or Q qualmin By setting the value appropriately, the terminal can select cells that satisfy the coverage of the uplink within the connectable range. For example, as shown in Figure 1, Q rxlevmin This may be set based on the difference between the coverage of the downlink and the coverage of the uplink.

[0027] Note that Figure 1 is Q rxlevmin An example will be shown, Q qualmin The same applies to this as well. Furthermore, below, "Q" is used as an example of a parameter for cell selection criteria. rxlevmin This will explain the parameter for the criteria for cell selection, Q. rxlevmin Not limited to Q qualmin Alternatively, other parameters such as an offset value may also be used.

[0028] Furthermore, Rel.17 considers improvements to NR coverage, for example. For instance, coverage enhancement (CE) for uplink channels such as the Physical Uplink Shared Channel (PUSCH), the Physical Uplink Control Channel (PUCCH), or Msg.3 PUSCH (or Msg. A) in random access procedures is being considered.

[0029] As an example, as shown in Figure 2, a terminal with coverage extension capabilities (e.g., CovEnh.UE) can extend the coverage of the uplink compared to an existing terminal (in other words, a terminal without coverage extension capabilities). In this case, for example, existing broadcast information (in the example in Figure 2, Q rxlevmin Using cell selection criteria based on ), a terminal with coverage extension may not be able to connect to a cell in the extended uplink coverage area, even though its uplink coverage has been extended, because it does not meet the cell selection criteria. In other words, a terminal with coverage extension shown in Figure 2 will notify Q using the same notification information as existing terminals. rxlevmin Using this cell selection criterion may result in not connecting to the appropriate cell.

[0030] Furthermore, as mentioned above, NR is considering the introduction of low-cost terminals that have fewer antennas, less maximum bandwidth, or less power consumption compared to general terminals such as smartphones. Because such low-cost terminals have reduced functionality compared to other terminals, their coverage may differ. Therefore, for example, if cell selection criteria based on the same information as those used for broadcast information for other terminals are used for low-cost terminals, they may not connect to the appropriate cell.

[0031] Furthermore, in NR, for example, if a terminal supports Supplementary Uplink (SUL) frequencies, a parameter for SUL frequencies, "q-RxLevMinSUL," is notified separately from "q-RxLevMin," which is a parameter for existing cell selection criteria, and this parameter Q is used to calculate the cell selection criteria. rxlevmin It may be set to this.

[0032] Furthermore, in LTE, for example, cell selection operations for coverage extension for MTC-compatible terminals (hereinafter referred to as "MTC terminals") are defined (see, for example, Non-Patent Document 5). For example, if a terminal does not meet the cell selection criteria in normal coverage, the terminal is notified of a parameter for coverage extension, "Q", which is separate from the parameters for the cell selection criteria. rxlevmin_CE " is used for calculating the cell selection criteria. rxlevmin It may be set to this. The terminal can, for example, set parameter Q for coverage expansion. rxlevmin_CE If the cell selection criteria are met, it can be determined that the terminal is operating in coverage enhancement mode.

[0033] Furthermore, if a terminal does not meet the cell selection criteria in normal coverage, for example, the parameter Q for coverage expansion... rxlevmin_CE If the cell selection criteria are not met, the parameter for cell selection criteria in normal coverage and the parameter Q for coverage expansion will be used. rxlevmin_CE Separately, a parameter "Q" for coverage enhancement mode (for example, called coverage enhancement mode B) is notified. rxlevmin_CE1" is used for calculating the cell selection criteria. rxlevmin It may be set to this. The terminal can, for example, set parameter Q for coverage expansion. rxlevmin_CE1 If the cell selection criteria are met, it can be determined that the terminal is operating in coverage extension mode B.

[0034] When applying the same method as described above for LTE coverage extension in NR coverage extension, for example, a parameter for coverage extension (e.g., called "q-RxLevCovEnh") which is notified separately from the existing cell selection criterion parameter q-RxLevMin, is used for calculating the cell selection criterion Q rxlevmin This can be set. However, simply adding parameters for coverage extension does not adequately address the various functions of NR, such as SUL frequency, synchronization signals using multiple beams, or two-step random access (e.g., 2-step Random Access Channel (RACH)). Furthermore, NR may introduce various types of terminals, including low-cost terminals, not just terminals that support coverage extension functions, and there is room for consideration regarding the cell selection criteria for these terminals and terminals with the aforementioned NR functions.

[0035] Therefore, in a non-limiting embodiment of this disclosure, for example, a method for improving the efficiency of cell selection in wireless communication will be described.

[0036] [Overview of the communication system] Each embodiment of the present disclosure comprises a base station 100 and a terminal 200.

[0037] Figure 3 is a block diagram showing a partial configuration example of a terminal 200 according to one embodiment of the present disclosure. In the terminal 200 shown in Figure 3, the receiving unit 201 (corresponding to, for example, a receiving circuit) receives parameters related to cell selection, which are set based on at least one of the functions, types, and operating modes of the terminal 200. The control unit 206 (corresponding to, for example, a control circuit) performs cell selection processing based on the parameters.

[0038] (Embodiment 1) [Base station configuration] Figure 4 is a block diagram showing an example configuration of a base station 100 according to Embodiment 1. In Figure 4, the base station 100 includes a control unit 101, a signal generation unit 102, a transmission unit 103, a reception unit 104, an extraction unit 105, a demodulation unit 106, and a decoding unit 107.

[0039] The control unit 101 determines, for example, information regarding the reception of a signal to the terminal 200 and outputs the determined information to the signal generation unit 102. The signal to the terminal 200 may include, for example, an SSB (synchronization signal (SS) / physical broadcast channel (PBCH) Block) used for initial access, and system information (for example, a System Information Block). Furthermore, the information regarding the reception of an SS / PBCH block, SIB, or Master Information Block (MIB) may include, for example, information regarding radio resources for transmitting the SS / PBCH block, SIB, or MIB.

[0040] Furthermore, the control unit 101 determines, for example, the parameters for the terminal 200 to calculate the cell selection criteria and outputs the determined information to the signal generation unit 102. The parameters for calculating the cell selection criteria include, for example, a parameter for calculating at least one of the cell selection criteria Srxlev and Squal (for example, Q rxlevmin Q qualmin Q rxlevminoffset Q qualminoffset This may include at least one of the following: , and Pcompensation.

[0041] Furthermore, the control unit 101 determines, for example, information regarding the operation method for the initial access to the terminal 200, and outputs the determined information to the signal generation unit 102. The information regarding the operation method for the initial access may include, for example, information such as the wireless resources of the uplink signal (e.g., PRACH or Msg.3 (Msg.A)) during the initial access, and the number of repetitions. The control unit 101 may also output the determined information to at least one of the extraction unit 105, demodulation unit 106, and decoding unit 107. The method for determining the initial access operation in the control unit 101 will be described later.

[0042] The signal generation unit 102 generates a signal for the terminal 200 (for example, at least one of a data signal, an SS / PBCH block, an SIB bit sequence, or an MIB bit sequence) based on information input from the control unit 101. For example, the SIB bit sequence may include information (or parameters) regarding cell selection criteria input from the control unit 101. The signal generation unit 102 may also perform encoding on the generated signal bit sequence.

[0043] The signal generation unit 102 modulates the generated signal (or encoded bit sequence), for example. The signal generation unit 102 also maps the modulated signal (e.g., symbol sequence) to the wireless resource based on information indicating the wireless resource input from the control unit 101, for example. The signal generation unit 102 outputs the signal mapped to the wireless resource to the transmission unit 103.

[0044] The transmitting unit 103 may, for example, perform a transmission waveform generation process such as orthogonal frequency division multiplexing (OFDM) on the signal input from the signal generation unit 102. Furthermore, the transmitting unit 103 may, for example, perform an inverse fast Fourier transform (IFFT) on the signal in the case of OFDM transmission that adds a cyclic prefix (CP), and then add the CP to the signal after the IFFT. The transmitting unit 103 also performs RF processing on the signal, such as D / A conversion and upconversion, and transmits the wireless signal to the terminal 200 via the antenna.

[0045] The receiving unit 104 performs RF processing, such as downconverting or A / D conversion, on the uplink signal from the terminal 200 received via the antenna. In the case of OFDM transmission, the receiving unit 104 also performs Fast Fourier Transform (FFT) processing on the received signal and outputs the resulting frequency domain signal to the extraction unit 105.

[0046] The extraction unit 105 extracts the portion of the wireless resource transmitted by the terminal 200, for example, based on information input from the control unit 101, and outputs the extracted wireless resource portion to the demodulation unit 106.

[0047] The demodulation unit 106 demodulates the received signal input from the extraction unit 105 based on information input from the control unit 101, for example, and outputs the demodulation result to the decoding unit 107.

[0048] The decoding unit 107 performs error correction decoding of PRACH detection or uplink signal (e.g., Msg.3 or Msg.A) based on information input from the control unit 101 and the demodulation result input from the demodulation unit 106, and obtains the detection result or the received bit sequence after decoding.

[0049] [Device Configuration] Figure 5 is a block diagram showing an example configuration of a terminal 200 according to one embodiment of the present disclosure. For example, in Figure 5, the terminal 200 includes a receiving unit 201, an extraction unit 202, a demodulation unit 203, a decoding unit 204, a measurement unit 205, a control unit 206, a signal generation unit 207, and a transmission unit 208.

[0050] The receiving unit 201 receives, for example, a downlink signal (e.g., a data signal or control information) from the base station 100 via an antenna, and performs RF processing such as downconverting or A / D conversion on the wirelessly received signal to obtain a received signal (baseband signal). In addition, when the receiving unit 201 receives an OFDM signal, it performs FFT processing on the received signal to convert the received signal into the frequency domain. The receiving unit 201 outputs the received signal to the extraction unit 202.

[0051] The extraction unit 202, for example, based on information about the radio resources of the downlink signal input from the control unit 206, extracts the radio resource portion from the received signal input from the receiving unit 201 that may contain the downlink signal (e.g., SS / PBCH block, SIB, or MIB), and outputs it to the demodulation unit 203 and the measurement unit 205.

[0052] The demodulation unit 203 demodulates the received signal input from the extraction unit 202 based on information input from the control unit 206, for example, and outputs the demodulation result to the decoding unit 204.

[0053] The decoding unit 204, for example, uses the demodulation result input from the demodulation unit 203 to perform error-correction decoding of the downlink signal (e.g., PBCH, SIB, or MIB) and obtains control information contained in the PBCH, SIB, or MIB. The decoding unit 204 outputs the obtained control information to the control unit 206. The decoding unit 204 may also output, for example, the downlink received data obtained by decoding.

[0054] The measurement unit 205 may, for example, measure at least one of the received power (e.g., RSRP) and received quality (e.g., RSRQ) based on the received signal input from the extraction unit 202. For example, the measurement unit 205 outputs the obtained measurement results (e.g., RSRP and RSRQ) to the control unit 206.

[0055] The control unit 206 may control cell selection based on signals input from the decoding unit 204 (e.g., MIB or SIB). For example, the control unit 206 may control cell selection or cell re-selection based on parameters for calculating cell selection criteria obtained from the MIB or SIB, and measurement results input from the measurement unit 205 (e.g., RSRP and RSRQ). Examples of cell selection or cell re-selection operations in the control unit 206 will be described later.

[0056] Furthermore, the control unit 206 determines an initial access operation (for example, random access operation, RACH resource setting, or transmit power control) if the criteria for cell selection or cell re-selection are met, and outputs the determined information to the signal generation unit 207.

[0057] Furthermore, the control unit 206 may determine information (e.g., radio resources or coded modulation information) related to the reception of a downlink signal or the transmission of an uplink signal based on the signal input from the decoding unit 204. The control unit 206 outputs the determined information to, for example, the extraction unit 202, the demodulation unit 203, and the signal generation unit 207.

[0058] The signal generation unit 207 generates an uplink signal (e.g., a PRACH signal, Msg.A, or Msg.3) based on information input from the control unit 206. The signal generation unit 207 may also perform encoding or modulation processing on the generated uplink signal. The signal generation unit 207 maps the generated signal to a wireless resource and outputs the uplink signal mapped to the wireless resource to the transmission unit 208.

[0059] The transmitting unit 208 generates a transmission signal waveform, such as OFDM, from the signal input from the signal generation unit 207. Furthermore, in the case of OFDM transmission using CP, for example, the transmitting unit 208 performs IFFT processing on the signal and adds CP to the signal after IFFT. Alternatively, when generating a single-carrier waveform, the transmitting unit 208 may perform DFT (Discrete Fourier Transform) processing, for example, after modulation processing or before mapping processing (not shown). The transmitting unit 208 also performs RF processing, such as D / A conversion and upconversion, on the transmission signal and transmits the radio signal to the base station 100 via the antenna.

[0060] [Example of operation of base station 100 and terminal 200] An example of operation in a base station 100 and terminal 200 having the above configuration will be described.

[0061] In this embodiment, when terminal 200 selects a cell, the parameter for the cell selection criterion may be set based on at least one of the "functions" of terminal 200, the "type" of terminal 200, and the "operating mode" of terminal 200.

[0062] Examples of functions (e.g., capabilities) that terminal 200 may have include functions corresponding to Rel.15, functions corresponding to Rel.16, functions corresponding to Rel.17, coverage extension functions, and random access methods (e.g., 4-stage or 2-stage random access). Functions may also be defined by UE Capabilities. Terminal 200 may have, for example, at least one of these functions. However, the functions of terminal 200 are not limited to these and may have other functions.

[0063] An example of a terminal 200 type is one that is classified based on at least one of the following: the number of antennas, the supported bandwidth, and the power consumption. For example, terminal 200 types include RedCap terminals, MTC terminals, and existing (or general) terminals. However, the terminal 200 types are not limited to these, and other types may be defined. Also, for example, the terminal 200 type may be defined by UE Capability.

[0064] The operation mode of terminal 200 may be based on settings determined, for example, based on the status of terminal 200 (e.g., measurement condition). For example, the operation mode may be defined by a combination of the type of terminal 200, the function set for the actual operation of terminal 200 (e.g., coverage extension or random access method), and parameters (e.g., number of repetitions). The frequency of the selected cell may also be defined by either FR1 or FR2.

[0065] For example, the parameters for cell selection criteria may differ between devices with (or that support) coverage extensions and existing devices (e.g., devices that do not have (or do not support) coverage functionality).

[0066] For example, a first parameter that can be used for cell selection criteria by existing terminals and multiple (e.g., all) terminals 200 of NR may be notified from the base station 100 to the terminals 200 by "q-RxLevMin", and a second parameter that can be used for cell selection criteria by some terminals 200 (e.g., terminals 200 with coverage extension functions) may be notified from the base station 100 to the terminals 200 by "q-RxLevMin2".

[0067] The following describes an example of the operation related to cell selection according to this embodiment.

[0068] For example, during the initial cell selection of terminal 200 in the idle state, terminal 200 may search (scan) multiple (e.g., all) RF channels (or frequencies) of the NR band, depending on the RF capabilities of terminal 200. For example, terminal 200 may search for the strongest cell (e.g., the strongest cell) in each RF channel (frequency).

[0069] Alternatively, if terminal 200 has measurement and control information received in the past or information about frequencies or cell parameters obtained from cells detected in the past, terminal 200 may perform cell selection based on that information (cell selection by leveraging stored information). In this case, terminal 200 does not need to search multiple NR frequency bands.

[0070] When terminal 200 finds a suitable cell (for example, a cell that meets the cell selection criteria and to which terminal 200 is permitted access), it selects (camps on) that cell.

[0071] For example, the criteria for selecting cells may be defined as satisfying the following formula (4). Srxlev > 0 AND Squal > 0 (4)

[0072] Here, Srxlev is the received power level with respect to cell selection (e.g., expressed in [dB]), and Squal is the received quality level with respect to cell selection (e.g., expressed in [dB]), which may be given by equations (5) and (6), respectively. Srxlev = Q rxlevmeas - (Q rxlevmin + Q rxlevminoffset ) - Pcompensation - Qoffset temp (5) Saldehyde = Q qualmeas - (Q qualmin + Q qualminoffset ) - Qoffset temp (6)

[0073] In equation (5), Q rxlevmeas Q is the received power (e.g., RSRP) measured by terminal 200, and rxlevmin Q is the minimum required received power (e.g., expressed in [dBm]), and rxlevminoffset Q rxlevmin Qoffset is an offset value for the above, where Pcompensation is a correction value (e.g., expressed in [dB]) for the uplink transmit power capability of terminal 200, and temp is a temporarily applied offset value (for example, expressed in [dB]). Also, in equation (6), Q qualmeas Q is the reception quality measured by terminal 200 (e.g., RSRQ), and Q qualmin Q is the minimum required reception quality (e.g., expressed in [dB]), and qualminoffset Q qualmin This is the offset value relative to [the given value].

[0074] For example, the "Q" in equations (5) and (6) rxlevminoffset " and "Q qualminoffset This may be applied to the measurement results of high-priority PLMN when terminal 200 selects VPLMN.

[0075] Furthermore, terminal 200 may perform a cell re-selection process after selecting a cell (Camp on) through cell selection.

[0076] The minimum required received power (e.g., Q) is a parameter related to cell selection and cell re-selection. rxlevmin ), Minimum required reception quality (e.g., Q qualmin ), offset value (for example, Q rxlevminoffset and Q qualminoffset The ), and the correction value (Pcompensation) may be transmitted (in other words, signaled or set) from the base station 100 to the terminal 200 by broadcast information (e.g., SIB).

[0077] For example, the minimum required received power Q rxlevmin , and minimum required reception quality Q qualminThis information may be notified to terminal 200 by the first parameters "q-RxLevMin" and "q-RxQualMin" transmitted by SIB, respectively.

[0078] Furthermore, for example, if terminal 200 supports SUL frequencies, terminal 200 will be notified of a parameter for SUL frequencies, "q-RxLevMinSUL", in addition to the first parameter q-RxLevMin, for the calculation of the cell selection criteria Q rxlevmin (For example, you can set it to equation (5)).

[0079] Furthermore, for example, if terminal 200 does not meet the cell selection criteria using the above-mentioned q-RxLevMin or q-RxLevMinSUL, terminal 200 will use a second parameter, "q-RxLevMin2", which is notified separately from the first parameter q-RxLevMin and the parameter for SUL frequency q-RxLevMinSUL, to calculate the cell selection criteria. rxlevmin (For example, it may be set to formula (5)). Terminal 200 may determine that it will operate in the operating mode corresponding to the second parameter (for example, coverage extension mode) if it satisfies the cell selection criteria using the second parameter.

[0080] The second parameter is the minimum required received power Q in equation (5) described above. rxlevmin The parameters are not limited to those corresponding to the above; for example, the offset value Q shown in equation (7) can be used for calculating the cell selection criterion Srxlev in equation (5). offset2 It may be set as follows. S rxlev = Q rxlevmeas - (Q rxlevmin + Q offset2 + Q rxlevminoffset ) - Pcompensation - Qoffset temp (7)

[0081] Furthermore, if terminal 200 is capable of setting a second parameter (for example, if it has a coverage extension function), terminal 200 may perform cell selection using the cell selection criteria of the second parameter without applying the cell selection criteria using the first parameter.

[0082] Furthermore, while an example has been described here in which the second parameter is introduced to the cell selection criterion by RSRP (e.g., Srxlev), the embodiment is not limited to this. For example, in this embodiment, the second parameter may be introduced to the cell selection criterion by RSRP (e.g., Srxlev) or to the cell selection criterion by RSRQ (e.g., Squal). Also, the second parameter may be introduced to either the cell selection criterion by RSRP (e.g., Srxlev) or the cell selection criterion by RSRQ (e.g., Squal), or to both.

[0083] Furthermore, the second parameter is the minimum required received power Q. rxlevmin Parameters related to received power, such as the minimum required received quality Q, are also acceptable. qualmin These could be parameters related to reception quality. Furthermore, the second and third parameters could be, for example, the offset value Q used to determine the cell selection criteria. rxlevminoffset Q qualminoffset Qoffset temp Alternatively, other parameters such as the correction value Pcompensation may be used.

[0084] Furthermore, the second parameter q-RxLevMin2 mentioned above is just an example; for example, a terminal 200 with coverage extension capabilities may be notified with "q-RxLevMinCovEnh," and a RedCap terminal may be notified with "q-RxLevMinRedCap." The second parameter may also be set depending on the functions of the terminal 200 or the type of terminal 200.

[0085] Also, there may be multiple levels of cell selection criteria (or rather, parameter candidates for cell selection criteria) that can be used by some terminals 200. For example, if the cell selection criteria calculated by the above-mentioned q-RxLevMin or q-RxLevMinSUL in the terminal 200 are not satisfied, the terminal 200 may set a second parameter q-RxLevMin2, which is notified separately from q-RxLevMin and q-RxLevMinSUL, to Q rxlevmin (e.g., Q rxlevmin2 ) for calculating the cell selection criteria. For example, if the terminal 200 satisfies the cell selection criteria based on the second parameter, the terminal 200 may determine that it operates in an operation mode corresponding to the second parameter (e.g., a coverage extension mode with a relatively small number of Repetitions).

[0086] Furthermore, if the cell selection criteria calculated by the second parameter q-RxLevMin2 in the terminal 200 are not satisfied, the terminal 200 may set a third parameter q-RxLevMin3, which is notified separately from the first and second parameters, to Q rxlevmin (e.g., Q rxlevmin3 ) for calculating the cell selection criteria. For example, if the terminal 200 satisfies the cell selection criteria based on the third parameter, the terminal 200 may determine that it operates in an operation mode corresponding to the third parameter (e.g., a coverage extension mode with a relatively large number of Repetitions).

[0087] Note that the number of levels of cell selection criteria is not limited to three and may be four or more.

[0088] For example, if the terminal 200 finds an appropriate cell, it may select (Camp on) the cell and start an initial access operation (e.g., a random access operation).

[0089] The operation example regarding cell selection in the terminal 200 has been described above.

[0090] Next, an operation example after the terminal 200 selects (Camp on) a cell will be described.

[0091] The terminal 200 may control the initial access operation based on, for example, the determination result of cell selection (e.g., whether it meets the cell selection criteria). For example, the terminal 200 may control the setting of RACH resources or the random access operation according to the parameters (e.g., the first parameter or the second parameter) applied when the above-described cell selection criteria are met.

[0092] <Example of setting RACH resources> The terminal 200 may determine the RACH resources to be applied in the initial access based on, for example, the parameters applied when the cell selection criteria are met. For example, the RACH resources or the RACH preamble may be different from the parameters applied to the cell selection criteria.

[0093] For example, the RACH resources or the RACH preamble set when the cell selection criteria calculated by the first parameter are met, and the RACH resources or the RACH preamble set when the cell selection criteria calculated by the second parameter are met may be set respectively.

[0094] For example, when the cell selection criteria calculated by the first parameter correspond to the existing coverage, the RACH resources using the existing PRACH sequence may be set. Also, for example, when the cell selection criteria calculated by the second parameter correspond to the coverage expansion, the RACH resources using a plurality of PRACH sequences may be set.

[0095] In addition, the RACH resource is not limited to being set based on the value of the parameter applied to the cell selection criterion. For example, it may be set based on the difference (gap) between the cell selection criterion Srxlev calculated by the first parameter and the cell selection criterion Srxlev calculated by the second (or second or more) parameter. For example, when the difference between the cell selection criteria Srxlev corresponding to the first parameter and the second parameter is below a threshold value (e.g., X dB), and when it is greater than the threshold value X dB, the RACH resource or the RACH preamble may be set respectively.

[0096] In addition, the parameter set according to the parameter applied when satisfying the cell selection criterion is not limited to the RACH resource (or in addition to the RACH resource), and may also be the number of repetitions at the time of Msg.3 transmission.

[0097] For example, for the terminal 200 that satisfies the cell selection criterion calculated by the first parameter, Msg.3 Repetition is not applied, and for the terminal 200 that satisfies the cell selection criterion calculated by the second parameter, Msg.3 Repetition may be applied. Also, for example, the number of repetitions at the time of Msg.3 transmission may be different between the case where the cell selection criterion calculated by the first parameter is satisfied and the case where the cell selection criterion calculated by the second parameter is satisfied. Also, for example, when there are multiple levels of cell selection criteria available for some terminals 200, the number of repetitions of Msg.3 Repetition may be different according to each level.

[0098] In addition, the number of repetitions of Msg.3 Repetition is the cell selection criterion S calculated by the first parameter rxlev and the cell selection criterion S calculated by the second (or second or more) parameter rxlev and may be set based on the difference therebetween.

[0099] <Example of RACH operation> Terminal 200 may determine the RACH operation to apply based, for example, on the parameters applied when the cell selection criteria are met. For example, the RACH operation may differ depending on the parameters applied to the cell selection criteria.

[0100] For example, the random access method may differ depending on the parameters applied to the cell selection criteria.

[0101] For example, terminals 200 that satisfy the cell selection criteria calculated by the first parameter may be configured to be applicable to both 4-step random access (e.g., 4-step RACH, also called Type-1 random access procedure) and 2-step random access (e.g., 2-step RACH or Type-2 random access procedure). On the other hand, terminals 200 that satisfy the cell selection criteria calculated by the second parameter may be configured to be applicable to 4-step RACH. In other words, terminals 200 that satisfy the cell selection criteria calculated by the second parameter may be configured not to be applicable to 2-step RACH.

[0102] In NR, for example, if both 2-step RACH and 4-step RACH are applicable, terminal 200 may select either 2-step RACH or 4-step RACH based on "msgA-RSRP-Threshold". In this embodiment, for example, the value of msgA-RSRP-Threshold may be determined according to the parameters applied when the cell selection criteria are met.

[0103] Furthermore, the number of RACH Repetitions in the RACH operation may differ depending on the parameters applied to the cell selection criteria. For example, terminal 200 may not apply RACH Repetition when the cell selection criteria calculated by the first parameter are met, but may apply RACH Repetition when the cell selection criteria calculated by the second parameter are met. Also, for example, the number of RACH Repetitions may differ depending on whether the cell selection criteria calculated by the first parameter or the cell selection criteria calculated by the second parameter are met. Furthermore, for example, if some terminals 200 have multiple levels of usable cell selection criteria, the number of RACH Repetitions may be determined separately for each level.

[0104] Furthermore, when RACH Repetition is applied, terminal 200 can suppress the decrease in the utilization efficiency of RACH resources by applying the method described in Patent Document 1.

[0105] <Example of paging resource settings> Terminal 200 may determine which resource (e.g., PO: Paging Occasion) will receive the paging signal based on the parameters applied when the cell selection criteria are met. For example, PO may differ depending on the parameters applied to the cell selection criteria.

[0106] For example, terminal 200 may set an existing PO if it satisfies the cell selection criteria calculated by the first parameter, and apply a Repetition to the PO if it satisfies the cell selection criteria calculated by the second parameter. Alternatively, for example, terminal 200 may vary the number of Repetitions of the PO depending on the parameter used to calculate the cell selection criteria.

[0107] Furthermore, the PO setting (e.g., whether or not there is a Repetition or the number of Repetitions) is not limited to being based on parameters applied to the cell selection criteria, but may also be based on, for example, the difference (gap) between the cell selection criterion Srxlev calculated by the first parameter and the cell selection criterion Srxlev calculated by the second (or more than one) parameter.

[0108] The above describes an example of what happens after terminal 200 selects a cell (Camp on).

[0109] The above-mentioned setting examples or operation examples may be combined. For example, terminal 200 may control the RACH resource, paging resource (PO), the number of repetitions of signals (e.g., Msg.3 and at least one of RACH and paging signals), or at least one of the RACH operations, depending on the parameters that satisfy the cell selection criteria.

[0110] Furthermore, regarding the cell re-selection criteria, similar to the cell selection criteria described above, parameters for the cell re-selection criteria used for cell re-selection may be set separately for the functions the terminal has, the type of terminal, or the operating mode of the terminal.

[0111] Figure 6 is a flowchart showing an example of the cell selection operation (for example, cell selection operation and operation after cell selection) in the terminal 200 according to this embodiment.

[0112] In Figure 6, terminal 200 determines, for example, whether or not a certain cell has been detected (ST101). If terminal 200 does not detect a cell (ST101: No), it may repeat the process of ST101.

[0113] On the other hand, if terminal 200 detects a cell (ST101: Yes), it measures at least one of the following: for example, the received power level (e.g., RSRP) and the received quality level (e.g., RSRQ) (ST102).

[0114] Terminal 200 calculates, for example, a cell selection criterion (e.g., at least one of Srxlev and Squal) using a first parameter (ST103).

[0115] Terminal 200 determines whether the cell selection criteria using the first parameter are met (ST104). For example, terminal 200 may determine whether equation (4) is met based on the results measured in ST102 (e.g., RSRP and RSRQ) and the cell selection criteria calculated in ST103 (e.g., Srxlev and Squal).

[0116] If the cell selection criteria using the first parameter are met (ST104: Yes), terminal 200 selects the detected cell as the connected cell (ST105).

[0117] On the other hand, if the cell selection criteria using the first parameter are not met (ST104: No), terminal 200 calculates, for example, a cell selection criterion using the second parameter (for example, at least one of Srxlev and Squal) (ST106).

[0118] Terminal 200 determines whether the cell selection criteria using the second parameter are met (ST107). For example, terminal 200 may determine whether equation (4) is met based on the results measured in ST102 (e.g., RSRP and RSRQ) and the cell selection criteria calculated in ST106 (e.g., Srxlev and Squal).

[0119] If the cell selection criteria using the second parameter are met (ST107:Yes), terminal 200 selects the detected cell as the connected cell (ST108). On the other hand, if the cell selection criteria using the second parameter are not met (ST107:No), terminal 200 may perform the process in ST101.

[0120] If terminal 200 selects a connected cell (for example, after processing ST105 or ST108), it may control the initial access behavior according to the parameters applied when the cell selection criteria were met (for example, either the first parameter or the second parameter) (ST109). The initial access behavior may include, for example, at least one of the following: setting the RACH resource, setting the Repetition, setting the RACH operation, or setting the PO, as described above.

[0121] Figure 6 illustrates, as an example, the case where there are two parameters for cell selection criteria: a first parameter and a second parameter. The number of parameters for cell selection criteria (e.g., number of candidates) is not limited to two; there may be three or more. For example, if three or more parameters are set, and the cell selection criterion using the second parameter is not met (e.g., S107:No in Figure 6), terminal 200 may calculate a cell selection criterion using a third (or third or more) parameter.

[0122] Furthermore, Figure 6 illustrates, as an example, a case where the cell selection criteria using the second parameter are applied when the cell selection criteria using the first parameter are not met, but the case is not limited to this. For example, terminal 200 may apply the cell selection criteria using the second parameter and not apply the cell selection criteria using the first parameter.

[0123] Furthermore, the operation sequence of terminal 200 is not limited to that shown in Figure 6. For example, terminal 200 may apply the cell selection criteria using the first parameter if the cell selection criteria using the second parameter are not met.

[0124] The above describes examples of the operation of the base station 100 and terminal 200.

[0125] Thus, in this embodiment, terminal 200 receives parameters related to cell selection, which are set based on at least one of the functions, types, and operating modes of terminal 200, and performs cell selection processing based on the received parameters. Through this processing, terminal 200 can perform cell selection according to, for example, a cell selection criterion set separately for at least one of the functions, types, and operating modes of terminal 200.

[0126] Therefore, according to this embodiment, for example, a terminal 200 in an IDLE state or an INACTIVE state can select an appropriate cell by cell selection or cell re-selection according to the function, type, or operating mode of the terminal 200.

[0127] Furthermore, for example, random access operation or RACH resources are determined according to the parameters applied when terminal 200 meets the cell selection criteria. This allows base station 100 to recognize the function, type, or operating mode of terminal 200 by receiving a random access signal, and to appropriately schedule subsequent initial accesses (e.g., Msg.2, Msg.B, and Msg.3) for terminal 200.

[0128] Furthermore, according to this embodiment, for example, the parameters used in the cell selection criteria are set to correspond to various functions in NR such as coverage expansion, two-stage random access, four-stage random access, or support for SUL frequencies, or to various types such as low-cost terminals (e.g., RedCap terminals). As a result, terminal 200 can appropriately select cells according to the function, type, or operating mode of terminal 200.

[0129] Therefore, according to this embodiment, the efficiency of cell selection in wireless communication can be improved.

[0130] (Embodiment 2) The configuration of the base station 100 and terminal 200 according to this embodiment may be the same as that of the configuration in Embodiment 1.

[0131] In this embodiment, when terminal 200 selects a cell, the parameters for the cell selection criteria may be set separately for at least two combinations of the functions of terminal 200, the type of terminal 200, and the operating mode of terminal 200.

[0132] For example, the parameters for cell selection criteria may differ between terminals with coverage extensions and existing terminals (e.g., terminals without coverage functionality). For instance, parameters for cell selection criteria may be individually set for terminal 200 having functionality A (e.g., coverage extension) and functionality B (e.g., 2-step RACH functionality) (in other words, terminal 200 having a combination of functionality A and functionality B), and for RedCap terminals having functionality A (in other words, terminal 200 having a combination of functionality A and RedCap).

[0133] For example, a first parameter that can be used for cell selection criteria by existing terminals and multiple (e.g., all) terminals 200 of NR may be notified from base station 100 to terminal 200 by "q-RxLevMin", a second parameter that can be used for cell selection criteria by some terminals 200 (e.g., terminals 200 with coverage extension function) may be notified from base station 100 to terminal 200 by "q-RxLevMin2", and a third parameter that can be used for cell selection criteria by some terminals 200 (e.g., terminals 200 with coverage extension function and 2-step RACH function) may be notified from base station 100 to terminal 200 by "q-RxLevMin3".

[0134] The following describes an example of the operation of cell selection according to this embodiment.

[0135] For example, in the initial cell selection of the terminal 200 in the IDLE state, the terminal 200 may search (scan) multiple (e.g., all) RF channels (or frequencies) of the NR band according to the RF capabilities of the terminal 200. For example, the terminal 200 may search for stronger cells (e.g., the strongest cell) in each RF channel (frequency).

[0136] Alternatively, when the terminal 200 holds information regarding frequencies or cell parameters obtained from the measurement control information received in the past or the cells detected in the past, the terminal 200 may perform cell selection based on that information (Cell selection by leveraging stored information). In this case, the terminal 200 may not need to search multiple NR frequency bands.

[0137] When the terminal 200 finds a suitable cell (e.g., a cell that meets the cell selection criteria and access to which is permitted for the terminal 200), the terminal 200 camps on that cell.

[0138] As the cell selection criteria, for example, it may be defined to satisfy the following formula (8). Srxlev > 0 AND Squal > 0 (8)

[0139] Here, Srxlev is the received power level related to cell selection (e.g., expressed in [dB]), and Squal is the received quality level related to cell selection (e.g., expressed in [dB]), and they may be given by the following formulas (9) and (10) respectively. Srxlev = Q rxlevmeas - (Q rxlevmin + Q rxlevminoffset ) - Pcompensation - Qoffset temp (9) Squal = Q qualmeas - (Q qualmin + Q qualminoffset ) - Qoffset temp (10)

[0140] In equation (9), Q rxlevmeas Q is the received power (e.g., RSRP) measured by terminal 200, and rxlevmin Q is the minimum required received power (e.g., expressed in [dBm]), and rxlevminoffset Q rxlevmin Qoffset is an offset value for the above, where Pcompensation is a correction value (e.g., expressed in [dB]) for the uplink transmit power capability of terminal 200, and temp Q is a temporarily applied offset value (for example, expressed in [dB]). Also, in equation (10), Q qualmeas Q is the reception quality measured by terminal 200 (e.g., RSRQ), and Q qualmin Q is the minimum required reception quality (e.g., expressed in [dB]), and qualminoffset Q qualmin This is the offset value relative to [the given value].

[0141] For example, the "Q" in equations (9) and (10) rxlevminoffset " and "Q qualminoffset This may be applied to the measurement results of high-priority PLMN when terminal 200 selects VPLMN.

[0142] Furthermore, terminal 200 may perform a cell re-selection process after selecting a cell (Camp on) through cell selection.

[0143] The minimum required received power (e.g., Q) is a parameter related to cell selection and cell re-selection. rxlevmin ), Minimum required reception quality (e.g., Q qualmin ), offset value (for example, Q rxlevminoffset and Q qualminoffset The ), and the correction value (Pcompensation) may be transmitted (in other words, signaled or set) from the base station 100 to the terminal 200 by broadcast information (e.g., SIB).

[0144] For example, the minimum required received power Q rxlevmin , and minimum required reception quality Q qualminThis information may be notified to terminal 200 by the first parameters "q-RxLevMin" and "q-RxQualMin" transmitted by SIB, respectively.

[0145] Furthermore, for example, if terminal 200 supports SUL frequencies, terminal 200 will be notified of a parameter for SUL frequencies, "q-RxLevMinSUL", in addition to the first parameter q-RxLevMin, for the calculation of the cell selection criteria Q rxlevmin (For example, you can set it to equation (9)).

[0146] Furthermore, for example, if terminal 200 does not meet the cell selection criteria using the above-mentioned q-RxLevMin or q-RxLevMinSUL, terminal 200 will use a second parameter, "q-RxLevMin2", which is notified separately from the first parameter q-RxLevMin and the parameter for SUL frequency q-RxLevMinSUL, to calculate the cell selection criteria. rxlevmin (For example, you can set it to equation (9)).

[0147] Here, the second parameter q-RxLevMin2 is used for calculating the cell selection criterion Q. rxlevmin A configurable terminal 200 may be defined as, for example, a terminal 200 having function A (e.g., coverage extension function). A terminal 200 may determine that it operates in an operating mode corresponding to the second parameter (e.g., coverage extension mode) if it satisfies a cell selection criterion using the second parameter.

[0148] Furthermore, for example, if the cell selection criteria using the first and second parameters described above are not met in terminal 200, terminal 200 will use a third parameter, "q-RxLevMin3", which is notified separately from the first and second parameters, for the calculation of the cell selection criteria. rxlevmin (For example, you can set it to equation (9)).

[0149] Here, the third parameter q-RxLevMin3 is used for calculating the cell selection criterion Q.rxlevmin A configurable terminal 200 may be defined as a terminal 200 having function A (e.g., coverage extension function) and function B (e.g., 2-step RACH function). A terminal 200 may be determined to operate in an operating mode corresponding to the third parameter (e.g., coverage extension mode and 2-step RACH mode) if it satisfies a cell selection criterion using a third parameter.

[0150] Furthermore, the third parameter q-RxLevMin3 is used for calculating the cell selection criterion. rxlevmin The terminal 200 that can be configured is not limited to the example described above, and may also be other combinations of functions, types, and operating modes of the terminal 200 (for example, a RedCap terminal having function A).

[0151] Furthermore, the second and third parameters are the minimum required received power Q in equation (9) described above. rxlevmin The parameters are not limited to those corresponding to the above; for example, the offset value Q shown in equation (11) can be used for calculating the cell selection criterion Srxlev in equation (9). offset2or3 It may be set as follows. S rxlev = Q rxlevmeas - (Q rxlevmin + Q offset2or3 + Q rxlevminoffset ) - Pcompensation - Qoffset temp (11)

[0152] Furthermore, for example, terminal 200 may perform cell selection using a cell selection criterion that uses at least one of the second and third parameters, without applying a cell selection criterion that uses the first parameter.

[0153] Furthermore, while an example has been described here in which the second and third parameters are introduced to the cell selection criteria by RSRP (e.g., Srxlev), the embodiment is not limited to this. For example, in this embodiment, the second and third parameters may be introduced to the cell selection criteria by RSRP (e.g., Srxlev) or to the cell selection criteria by RSRQ (e.g., Squal). Also, the second and third parameters may be introduced to either the cell selection criteria by RSRP (e.g., Srxlev) or the cell selection criteria by RSRQ (e.g., Squal), or to both.

[0154] Furthermore, the second and third parameters are the minimum required received power Q. rxlevmin Parameters related to received power, such as the minimum required received quality Q, are also acceptable. qualmin These could be parameters related to reception quality. Furthermore, the second and third parameters could be, for example, the offset value Q used to determine the cell selection criteria. rxlevminoffset Q qualminoffset Qoffset temp Alternatively, other parameters such as the correction value Pcompensation may be used.

[0155] Furthermore, the second and third parameters q-RxLevMin2 and q-RxLevMin3 described above are just examples. For example, a terminal 200 with coverage extension functionality may be notified with "q-RxLevMinCovEnh", a RedCap terminal may be notified with "q-RxLevMinRedCap", a terminal with coverage extension functionality and 2-step RACH functionality may be notified with "q-RxLevMinCovEnh_2SR", a RedCap terminal with coverage functionality may be notified with "q-RxLevMinRedCap_CovEnh", and the second and third parameters may be set separately for each combination of functions or types of terminal 200.

[0156] Figure 7 shows an example of the parameter "q-RxLevMin" for cell selection criteria corresponding to the coverage extension function and the 2-step RACH function. As shown in Figure 7, the parameters for cell selection criteria may be set according to the combination of whether the coverage extension function is enabled (CovEnh:〇) or disabled (CovEnh:×) and whether the 2-step RACH function is enabled (2-step RACH:〇) or disabled (2-step RACH:×).

[0157] In Figure 7, for terminal 200 which has the 2-step RACH function and does not have the coverage extension function (2-step RACH: ○, CovEnh: ×), the first parameter (for example, Q) rxlevmin ) Parameters notified separately (for example, Q rxlevmin_2SR ) may be set, and the first parameter (for example, Q) may be set. rxlevmin ) may be set. In other words, there may be combinations of functions that terminal 200 has or types of terminal 200 in which the same first parameter as an existing terminal is set.

[0158] Furthermore, there may be multiple levels of cell selection criteria (in other words, candidate parameters for cell selection criteria) that are available to some terminals 200, depending on the combination of functions possessed by the terminal 200 and the type of terminal 200.

[0159] Terminal 200 may, for example, select a suitable cell (camp on) and start an initial access operation (for example, a random access operation) if it finds one.

[0160] The above describes an example of cell selection operation on terminal 200.

[0161] Next, we will explain an example of what happens after terminal 200 selects a cell (Camp on).

[0162] The terminal 200 may control the initial access operation based on, for example, the determination result of cell selection (for example, whether the cell selection criteria are satisfied), similar to that in the first embodiment. For example, the terminal 200 may control the RACH resource or the setting of the PO or the random access operation according to the parameters (for example, the first parameter, the second parameter, or the third parameter) applied when the above-mentioned cell selection criteria are satisfied, similar to that in the first embodiment.

[0163] <Example of RACH resource setting> The terminal 200 may determine, for example, the RACH resource applied in the initial access based on the parameters applied when the cell selection criteria are satisfied, similar to that in the first embodiment. For example, the RACH resource or the RACH preamble may be different from the parameters applied to the cell selection criteria.

[0164] In addition, the RACH resource is not limited to being set based on the value of the parameter applied to the cell selection criteria. For example, it may be set based on the difference (gap) between the cell selection criteria Srxlev calculated by the first parameter and the cell selection criteria Srxlev calculated by the second (or second or more) parameter. For example, when the difference between the cell selection criteria Srxlev corresponding to the first parameter and the second parameter is less than or equal to a threshold value (for example, X dB), and when it is greater than the threshold value X dB, the RACH resource or the RACH preamble may be set respectively. Note that it is not limited to the difference between the cell selection criteria Srxlev in the first parameter and other parameters, and the difference between the cell selection criteria Srxlev among the second or more parameters may also be used.

[0165] Also, the parameter set according to the parameter applied when satisfying the cell selection criterion may be not limited to (or in addition to) the RACH resource, but may also be the number of repetitions at the time of Msg.3 transmission. For example, the number of repetitions at the time of Msg.3 transmission when satisfying the cell selection criterion calculated by each of the first parameter, the second parameter, and the third parameter may be set individually (for example, to different values). Also, for example, when there are multiple levels of cell selection criteria available for some terminals 200, the number of repetitions of Msg.3 Repetition may be different according to each level.

[0166] Also, the number of repetitions of Msg.3 Repetition may be set based on the difference between the cell selection criterion S calculated by the first parameter rxlev and the cell selection criterion S calculated by the second (or second or more) parameter. rxlev

[0167] <Example of RACH operation> The terminal 200 may determine the RACH operation to apply, for example, based on the parameter applied when satisfying the cell selection criterion, similar to Embodiment 1. For example, the RACH operation may be different from the parameter applied to the cell selection criterion.

[0168] Also, for example, similar to Embodiment 1, the number of RACH Repetitions in the RACH operation may be different based on the parameter applied to the cell selection criterion.

[0169] <Example of paging resource setting> The terminal 200 may determine the resource (for example, PO) for receiving the paging signal, for example, based on the parameter applied when satisfying the cell selection criterion, similar to Embodiment 1. For example, the PO may be different from the parameter applied to the cell selection criterion.

[0170] ​Furthermore, the PO setting (e.g., whether or not there is a Repetition or the number of Repetitions) is not limited to being based on parameters applied to the cell selection criteria, but may also be based on, for example, the difference (gap) between the cell selection criterion Srxlev calculated by the first parameter and the cell selection criterion Srxlev calculated by the second (or more than one) parameter.

[0171] The above describes an example of what happens after terminal 200 selects a cell (Camp on).

[0172] The above-mentioned setting examples or operation examples may be combined. For example, terminal 200 may control the RACH resource, paging resource (PO), the number of repetitions of signals (e.g., Msg.3 and at least one of RACH and paging signals), or at least one of the RACH operations, depending on the parameters that satisfy the cell selection criteria.

[0173] Furthermore, regarding the cell re-selection criteria, similar to the cell selection criteria described above, parameters for the cell re-selection criteria used for cell re-selection may be set separately for the functions the terminal has, the type of terminal, or the operating mode of the terminal.

[0174] In this embodiment, for example, in the flowchart shown in Figure 6, during the processing of ST106, terminal 200 may calculate cell selection criteria using parameters set separately for combinations of functions possessed by terminal 200, types of terminal 200, or operating modes of terminal 200.

[0175] The above describes examples of the operation of the base station 100 and terminal 200.

[0176] Thus, in this embodiment, terminal 200 receives parameters related to cell selection, which are set based on at least two combinations of the functions, types, and operating modes of terminal 200, and performs cell selection processing based on the received parameters. Through this processing, terminal 200 can perform cell selection according to, for example, cell selection criteria set separately for each combination of the functions, types, and operating modes of terminal 200.

[0177] Therefore, according to this embodiment, for example, a terminal 200 in an IDLE state or an INACTIVE state can select an appropriate cell by cell selection or cell re-selection according to a combination of the function, type, or operating mode of the terminal 200.

[0178] Furthermore, for example, random access operation or RACH resources are determined according to the combination of parameters applied when terminal 200 meets the cell selection criteria. This allows base station 100 to recognize the function, type, or operating mode of terminal 200 by receiving a random access signal, and to appropriately schedule subsequent initial accesses (e.g., Msg.2, Msg.B, and Msg.3) for terminal 200.

[0179] Furthermore, according to this embodiment, for example, the parameters used in the cell selection criteria are set to correspond to various combinations of functions in NR, such as coverage expansion, two-stage random access, four-stage random access, or support for SUL frequencies, and various types of terminals, such as low-cost terminals (e.g., RedCap terminals). As a result, terminal 200 can appropriately select cells according to the combination of functions, types, or operating modes of terminal 200.

[0180] Therefore, according to this embodiment, the efficiency of cell selection in wireless communication can be improved.

[0181] (Embodiment 3) The configuration of the base station 100 and terminal 200 according to this embodiment may be the same as that of the configuration in Embodiment 1.

[0182] In this embodiment, when terminal 200 is notified of multiple parameters for cell selection criteria during cell selection by terminal 200, a method for determining the priority or order of application to cell selection (e.g., cell selection criteria) for multiple parameters will be described.

[0183] The following describes examples of cell selection methods according to this embodiment (Option 1 and Option 2).

[0184] [Option 1] In Option 1, if multiple parameters for cell selection criteria are notified to terminal 200, terminal 200 may, for example, apply the parameters according to a set priority or order to calculate the cell selection criteria and determine whether or not the cell selection criteria are met.

[0185] The priority or order of multiple parameters may be predetermined for the terminal 200, for example, by notification (or setting) from the base station 100.

[0186] For example, if the parameters of cell selection criteria available to a terminal 200 having function A (e.g., coverage extension function) and function B (e.g., 2-step RACH function) are notified by "q-RxLevMinA" and "q-RxLevMinB", respectively, the terminal 200 having functions A and B may prioritize applying the cell selection criteria with q-RxLevMinB applied, and if the cell selection criteria calculated by q-RxLevMinB are not met, it may calculate the cell selection criteria with q-RxLevMinA applied and determine whether or not the cell selection criteria are met.

[0187] In other words, the parameters corresponding to function B have a higher priority than the parameters corresponding to function A, and terminal 200 may select cells in the order of parameters corresponding to function B, then parameters corresponding to function A.

[0188] The operation of Option 1 may include, for example, the calculation of cell selection criteria using the first parameter and the calculation of cell selection criteria using the second parameter when the cell selection criteria applied to the first parameter are not met, as in Embodiment 1 described above. In other words, the predetermined order may be set to cell selection by q-RxLevMin, cell selection by q-RxLevMinB, and cell selection by RxLevMinA.

[0189] [Option 2] In Option 2, if multiple parameters for cell selection criteria are notified to terminal 200, terminal 200 may, for example, determine the order based on the parameter values. Terminal 200 may, for example, apply the parameters according to the determined order to calculate the cell selection criteria and determine whether or not the cell selection criteria are met.

[0190] For example, terminal 200 is Q rxlevmin You may apply the parameters in descending order of their values ​​to calculate the cell selection criteria and then determine whether or not the cell selection criteria are met.

[0191] As an example, let's consider the case where a terminal 200 having function A (e.g., coverage extension function) and function B (e.g., 2-step RACH function) is notified of the available cell selection criteria parameters by "q-RxLevMinA = X dB" and "q-RxLevMinB = Y dB", respectively, and X < Y. In this case, the terminal 200 having functions A and B may prioritize applying the cell selection criteria that apply q-RxLevMinB, where the parameter value is greater than q-RxLevMinA. If the cell selection criteria calculated by q-RxLevMinB are not met, the terminal may calculate the cell selection criteria that apply q-RxLevMinA and determine whether the criteria are met.

[0192] Note that the order of parameters applied to the cell selection criteria does not have to be in descending order of parameter values; it can also be in ascending order.

[0193] The above explains Option 1 and Option 2.

[0194] Next, an example of the operation of cell selection according to this embodiment will be described.

[0195] The following describes, as an example, the operation of cell selection in terminal 200 having function A (e.g., coverage extension function) and function B (e.g., 2-step RACH function). Furthermore, the following describes the case where the parameter q-RxLevMin2 corresponding to function A and the parameter q-RxLevMin3 corresponding to function B are notified to terminal 200, and the priority of q-RxLevMin3 is higher than that of q-RxLevMin2. Therefore, terminal 200 will, for example, apply the cell selection criterion to which q-RxLevMin3 is applied preferentially, using Option 1 or Option 2.

[0196] For example, during the initial cell selection of terminal 200 in the idle state, terminal 200 may search (scan) multiple (e.g., all) RF channels (or frequencies) of the NR band, depending on the RF capabilities of terminal 200. For example, terminal 200 may search for the strongest cell (e.g., the strongest cell) in each RF channel (frequency).

[0197] Alternatively, if terminal 200 has measurement and control information received in the past or information about frequencies or cell parameters obtained from cells detected in the past, terminal 200 may perform cell selection based on that information (cell selection by leveraging stored information). In this case, terminal 200 does not need to search multiple NR frequency bands.

[0198] When terminal 200 finds a suitable cell (for example, a cell that meets the cell selection criteria and to which terminal 200 is permitted access), it selects (camps on) that cell.

[0199] For example, the criteria for selecting cells may be defined as satisfying the following formula (12). Srxlev > 0 AND Squal > 0 (12)

[0200] Here, Srxlev is the received power level with respect to cell selection (e.g., expressed in [dB]), and Squal is the received quality level with respect to cell selection (e.g., expressed in [dB]), which may be given by equations (13) and (14), respectively. Srxlev = Q rxlevmeas - (Q rxlevmin + Q rxlevminoffset ) - Pcompensation - Qoffset temp (13) Saldehyde = Q qualmeas - (Q qualmin + Q qualminoffset ) - Qoffset temp (14)

[0201] In equation (13), Q rxlevmeas Q is the received power (e.g., RSRP) measured by terminal 200, and rxlevmin Q is the minimum required received power (e.g., expressed in [dBm]), and rxlevminoffset Q rxlevmin Qoffset is an offset value for the above, where Pcompensation is a correction value (e.g., expressed in [dB]) for the uplink transmit power capability of terminal 200, and temp Q is a temporarily applied offset value (for example, expressed in [dB]). Also, in equation (14), Q qualmeas Q is the reception quality measured by terminal 200 (e.g., RSRQ), and Q qualmin Q is the minimum required reception quality (e.g., expressed in [dB]), and qualminoffset Q qualmin This is the offset value relative to [the given value].

[0202] For example, the "Q" in equations (13) and (14) rxlevminoffset " and "Q qualminoffsetThis may be applied to the measurement results of high-priority PLMN when terminal 200 selects VPLMN.

[0203] Furthermore, terminal 200 may perform a cell re-selection process after selecting a cell (Camp on) through cell selection.

[0204] The minimum required received power (e.g., Q) is a parameter related to cell selection and cell re-selection. rxlevmin ), Minimum required reception quality (e.g., Q qualmin ), offset value (for example, Q rxlevminoffset and Q qualminoffset The ), and the correction value (Pcompensation) may be transmitted (in other words, signaled or set) from the base station 100 to the terminal 200 by broadcast information (e.g., SIB).

[0205] For example, the minimum required received power Q rxlevmin , and minimum required reception quality Q qualmin This information may be notified to terminal 200 by the first parameters "q-RxLevMin" and "q-RxQualMin" transmitted by SIB, respectively.

[0206] Furthermore, for example, if terminal 200 supports SUL frequencies, terminal 200 will be notified of a parameter for SUL frequencies, "q-RxLevMinSUL", in addition to the first parameter q-RxLevMin, for the calculation of the cell selection criteria Q rxlevmin (For example, you can set it to equation (13)).

[0207] Furthermore, for example, if terminal 200 does not meet the cell selection criteria using the above-mentioned q-RxLevMin or q-RxLevMinSUL, terminal 200 will notify a third, higher-priority parameter "q-RxLevMin3", which is notified separately from the first parameter q-RxLevMin and the parameter q-RxLevMinSUL for the SUL frequency, for the calculation of the cell selection criteria. rxlevmin (For example, you can set it to equation (13)).

[0208] Here, the third parameter q-RxLevMin3 is set to Q for calculating the cell selection criterion rxlevmin The terminal 200 that can be set may be defined as, for example, a terminal 200 having function B (e.g., 2-step RACH function). When the terminal 200 satisfies the cell selection criterion using the third parameter, the terminal 200 may determine that it operates in the operation mode corresponding to the third parameter (e.g., 2-step RACH mode).

[0209] Also, for example, when the terminal 200 does not satisfy the cell selection criterion using the first and third parameters described above, the terminal 200 sets a second parameter "q-RxLevMin2" with a low priority, which is notified separately from the first and third parameters, to Q for calculating the cell selection criterion rxlevmin (e.g., Equation (13)).

[0210] Here, the second parameter q-RxLevMin2 is set to Q for calculating the cell selection criterion rxlevmin The terminal 200 that can be set may be defined as, for example, a terminal 200 having function A (e.g., coverage extension function). When the terminal 200 satisfies the cell selection criterion using the second parameter, the terminal 200 may determine that it operates in the operation mode corresponding to the second parameter (e.g., coverage extension mode).

[0211] Note that the second and third parameters are not limited to the parameters corresponding to the minimum required received power Q in Equation (12) described above. For example, for calculating the cell selection criterion Srxlev in Equation (13), an offset value Q shown in the following Equation (15) may be set rxlevmin as offset2or3 shown below. Srxlev = Q rxlevmeas - (Q rxlevmin + Q offset2or3 + Q rxlevminoffset ) - Pcompensation - Qoffset temp (15)

[0212] Furthermore, for example, terminal 200 may perform cell selection using cell selection criteria based on the second and third parameters, without applying cell selection criteria based on the first parameter.

[0213] Furthermore, while this description has focused on the case where the second and third parameters are introduced to the cell selection criteria by RSRP (e.g., Srxlev), it is not limited to this. For example, in this embodiment, the second and third parameters may be introduced to the cell selection criteria by RSRP (e.g., Srxlev) or to the cell selection criteria by RSRQ (e.g., Squal). Also, the second and third parameters may be introduced to either the cell selection criteria by RSRP (e.g., Srxlev) or the cell selection criteria by RSRQ (e.g., Squal), or to both.

[0214] Furthermore, the second and third parameters are the minimum required received power Q. rxlevmin Parameters related to received power, such as the minimum required received quality Q, are also acceptable. qualmin These could be parameters related to reception quality. Furthermore, the second and third parameters could be, for example, the offset value Q used to determine the cell selection criteria. rxlevminoffset Q qualminoffset Qoffset temp Alternatively, other parameters such as the correction value Pcompensation may be used.

[0215] Furthermore, the cell selection criteria (in other words, candidate parameters for cell selection criteria) that some terminals 200 can use may be at multiple levels, in addition to the functions that terminals 200 have and at least one of the types of terminals 200.

[0216] Terminal 200 may, for example, select a suitable cell (camp on) and start an initial access operation (for example, a random access operation) if it finds one.

[0217] The above describes an example of cell selection operation on terminal 200.

[0218] Terminal 200 may, for example, control the initial access operation based on the cell selection determination result (e.g., whether or not the cell selection criteria are met), similar to Embodiment 1. Furthermore, terminal 200 may, similar to Embodiment 1, control at least one of the RACH resource or PO settings or random access operations according to the parameters applied when the above-mentioned cell selection criteria are met (e.g., the first parameter, the second parameter, or the third parameter).

[0219] Furthermore, regarding the cell re-selection criteria, similar to the cell selection criteria, parameters for the cell re-selection criteria used for cell re-selection may be set separately for the functions the terminal has, the type of terminal, or the operating mode of the terminal.

[0220] As described above, in this embodiment, terminal 200 receives parameters related to cell selection, which are set based on at least one of the functions, types, and operating modes of terminal 200, and performs cell selection processing based on the received parameters. Terminal 200 also determines the priority or order for applying to cell selection among a plurality of parameters used as cell selection criteria. Through this process, terminal 200 can perform cell selection according to cell selection criteria set separately for each combination of functions, types, and operating modes of terminal 200, for example.

[0221] Therefore, according to this embodiment, for example, a terminal 200 in an IDLE state or an INACTIVE state can select an appropriate cell by cell selection or cell re-selection according to the function, type, or operating mode of the terminal 200.

[0222] Furthermore, for example, random access operation or RACH resources are determined according to the parameters applied when terminal 200 meets the cell selection criteria. This allows base station 100 to recognize the function, type, or operating mode of terminal 200 by receiving a random access signal, and to appropriately schedule subsequent initial accesses (e.g., Msg.2, Msg.B, and Msg.3) for terminal 200.

[0223] Furthermore, according to this embodiment, for example, in the cell selection criteria, parameters used in the cell selection criteria, as well as the priority or order between parameters, are set to correspond to various functions in NR such as coverage expansion, two-stage random access, four-stage random access, or support for SUL frequencies, and to various types such as low-cost terminals (e.g., RedCap terminals). As a result, terminal 200 can appropriately select cells according to the combination of functions, types, or operating modes of terminal 200.

[0224] Therefore, according to this embodiment, the efficiency of cell selection in wireless communication can be improved.

[0225] (Embodiment 4) The configuration of the base station 100 and terminal 200 according to this embodiment may be the same as that of the configuration in Embodiment 1.

[0226] In NR, for example, the measurement of RSRP uses reference signals (e.g., SSS and PBCH DMRS) included in the synchronization signal block (SS / PBCH block).

[0227] This embodiment describes a method for calculating cell selection criteria in multibeam operation where transmit beamforming is applied to an SS / PBCH block, for example. For example, in this embodiment, the parameters for cell selection criteria may be parameters related to the reception of the beamforming synchronization signal (e.g., SS / PBCH block).

[0228] For example, a first parameter that can be used by an existing terminal and a plurality (e.g., all) of NR terminals for cell selection criteria is notified to the terminal 200 by "nrofSS-BlocksToAverage" and "absThreshSS-BlocksConsolidation", and a second parameter that can be used by some terminals 200 (e.g., terminals 200 having a coverage extension function) for cell selection criteria may be notified to the terminal 200 by "nrofSS-BlocksToAverage2" and "absThreshSS-BlocksConsolidation2".

[0229] "nrofSS-BlocksToAverage" and "nrofSS-BlocksToAverage2" may indicate, for example, the number of beams (or SS blocks) for averaging measurement values. Also, "absThreshSS-BlocksConsolidation" and "absThreshSS-BlocksConsolidation2" may indicate thresholds for averaging (or integrating) measurement values.

[0230] For example, in any of Embodiments 1, 2, and 3, when the cell that measures RSRP or RSRQ by the terminal 200 is operating in multi-beam mode, the terminal 200 may determine a beam that satisfies the following criteria as the measurement target.

[0231] For example, when calculating cell selection criteria using the first parameter, if nrofSS-BlocksToAverage and absThreshSS-BlocksConsolidation are set by SIB, and there are measurement values of beams that exceed the value of absThreshSS-BlocksConsolidation, the terminal 200 may average the measurement values of the nrofSS-BlocksToAverage beams with the largest values among the beams that exceed the value of absThreshSS-BlocksConsolidation to calculate the RSRP or RSRQ of the cell.

[0232] On the other hand, if, for example, nrofSS-BlocksToAverage is not set by SIB, absThreshSS-BlocksConsolidation is not set, or there are no beam measurements that exceed the value of absThreshSS-BlocksConsolidation, terminal 200 may set the higher beam measurement (for example, the highest measurement) to the RSRP or RSRQ of the cell.

[0233] Furthermore, for example, if a cell measuring RSRP or RSRQ is operating in multi-beam mode, terminal 200 may determine a beam that satisfies the following criteria as the target for measurement in the cell selection criteria calculated using a second (or more than second) parameter.

[0234] For example, if nrofSS-BlocksToAverage2 and absThreshSS-BlocksConsolidation2 are set by SIB, and there are beam measurements that exceed the value of absThreshSS-BlocksConsolidation2, terminal 200 may calculate the RSRP or RSRQ of the cell by averaging the measurements of the two beams with the largest nrofSS-BlocksToAverage values ​​among the beams that exceed the value of absThreshSS-BlocksConsolidation2.

[0235] On the other hand, if, for example, nrofSS-BlocksToAverage2 is not set by SIB, absThreshSS-BlocksConsolidation2 is not set, or there are no beam measurements that exceed the value of absThreshSS-BlocksConsolidation2, terminal 200 may set the higher beam measurement (for example, the highest measurement) to the RSRP or RSRQ of the cell.

[0236] Note that the second parameters nrofSS-BlocksToAverage2 and absThreshSS-BlocksConsolidation2, which can be used for cell selection criteria, are examples only and are not limited to these. For example, a terminal 200 with coverage extension functions may be notified of "nrofSS-BlocksToAverageCovEnh" and "absThreshSS-BlocksConsolidationCovEnh", and a RedCap terminal may be notified of "nrofSS-BlocksToAverageRedCap" and "absThreshSS-BlocksConsolidationRedCap", and the second parameters may be set separately depending on the functions of the terminal 200, the type of terminal, the operating mode, or a combination thereof.

[0237] Furthermore, in this embodiment, for example, a second parameter may be set for at least one of nrofSS-BlocksToAverage2 and absThreshSS-BlocksConsolidation2, depending on the function, type, or operating mode of the terminal 200, or a combination thereof.

[0238] Furthermore, the cell selection criteria (in other words, candidate parameters for cell selection criteria) available to some terminals 200 may be at multiple levels, depending on the combination of functions and types of terminals 200. For example, if multiple parameters (or candidate parameters) are set for at least one of nrofSS-BlocksToAverage2 and absThreshSS-BlocksConsolidation2, a priority or order may be set among the multiple parameters, similar to Embodiment 3.

[0239] Furthermore, regarding the cell re-selection criteria, similar to the cell selection criteria, parameters for the cell re-selection criteria used for cell re-selection may be set separately for the functions, types, or operating modes of the terminal 200, or a combination thereof.

[0240] Thus, according to this embodiment, even in a cell operating in a multi-beam configuration, a terminal 200 in an IDLE state or INACTIVE state can appropriately select a cell by cell selection or cell re-selection based on the functions, type, or operating mode of the terminal 200.

[0241] (Embodiment 5) The configuration of the base station 100 and terminal 200 according to this embodiment may be the same as that of the configuration in Embodiment 1.

[0242] This embodiment describes a method for controlling the transmit power during the initial access operation, depending on the parameters applied when the cell selection criteria are met. For example, the transmit power control during the initial access operation may differ depending on the parameters applied when the cell selection criteria are met.

[0243] For example, the transmission power control method applied to a terminal 200 that satisfies the cell selection criteria using the first parameter may be different from the transmission power control method applied to a terminal 200 that satisfies the cell selection criteria using the second parameter.

[0244] For example, if the cell selection criterion using the first parameter corresponds to existing coverage, existing transmit power control (see, for example, Non-Patent Document 6) may be applied, and if the cell selection criterion using the second parameter corresponds to coverage expansion, maximum transmit power (e.g., Pcmax) may be applied.

[0245] Furthermore, the transmit power control method may be set based on the difference between the cell selection criterion Srxlev calculated by the first parameter and the cell selection criterion Srxlev calculated by the second (or second or more) parameter. For example, if the difference between the cell selection criterion Srxlev calculated by the first parameter and the cell selection criterion Srxlev calculated by the second (or second or more) parameter is X [dB] or less, an existing transmit power control (see, for example, Non-Patent Document 6) may be applied, and if the difference is greater than X [dB], the maximum transmit power (e.g., Pcmax) may be applied.

[0246] Furthermore, in this embodiment, the transmission power control method is, for example, the parameter used in the cell selection criterion described above, or the cell selection criterion S. rxlev The setting is not limited to being based on the difference between them, but may also be controlled based on at least one of the RACH resource, RACH operation, and the number of repetitions when sending Msg.3, as described in Embodiment 1.

[0247] Furthermore, the transmit power control corresponding to the cell selection criteria using the first and second parameters is not limited to the existing transmit power control and transmit power control using the maximum transmit power described above, but may be performed by other methods.

[0248] Thus, according to this embodiment, a terminal 200 in an IDLE state or an INACTIVE state can perform an initial access operation with appropriate transmission power based on the function, type, or operating mode of the terminal 200.

[0249] The embodiments of one example of this disclosure have been described above.

[0250] Furthermore, at least two of the embodiments described above (Embodiments 1 to 5) may be combined. For example, terminal 200 may apply at least two of the following: the parameter setting method for cell selection criteria from any of Embodiments 1 to 3, the cell selection method for a multi-beam cell in Embodiment 4, and the transmission power control method in Embodiment 5.

[0251] Furthermore, although this embodiment has been described assuming that the first parameter and the second (or more than one) parameter are notified to the terminal 200 by SIB, the notification method for at least one of these parameters is not limited to SIB, and for example, they may be notified by MIB. Also, the first parameter and the second (or more than one) parameter may be notified by at least one of SIB1, SIB2, and SIB4 among the SIBs.

[0252] Furthermore, the above embodiment assumes communication between a base station 100 and a terminal 200. However, one embodiment of this disclosure is not limited to this and may also be applied to communication between terminals (for example, Sidelink communication).

[0253] Furthermore, in each of the embodiments described above, the notification of the parameter values ​​for cell selection criteria from the base station 100 to the terminal 200 is not limited to this case. For example, information associated with the parameter for cell selection criteria (e.g., an index or other control information) may also be notified to the terminal 200.

[0254] Furthermore, in the embodiments described above, as an example, a case in which cell selection criteria based on both the received power level and the received quality level are applied, as shown in equations (4), (8), and (12), was explained. However, the cell selection criteria are not limited to these, and for example, criteria based on either the received power level or the received quality may also be used.

[0255] Furthermore, the downlink control channel, downlink data channel, uplink control channel, and uplink data channel are not limited to PDCCH, PDSCH, PUCCH, and PUSCH, respectively; other control channel names may also be used.

[0256] Furthermore, while the above-described embodiment assumes RRC signaling for the upper layer signaling, it may be replaced with Medium Access Control (MAC) signaling and DCI notifications, which are physical layer signaling.

[0257] Furthermore, the parameters applied in the above-described embodiment are merely examples and are not limited to this.

[0258] (Control signal) In this disclosure, the downlink control signal (information) related to this disclosure may be a signal (information) transmitted by the PDCCH of the physical layer, or a signal (information) transmitted by the MAC CE (Control Element) or RRC of the upper layer. Furthermore, the downlink control signal may be a predefined signal (information).

[0259] The uplink control signal (information) related to this disclosure may be a signal (information) transmitted by PUCCH at the physical layer, or a signal (information) transmitted by MAC CE or RRC at the upper layer. The uplink control signal may also be a predefined signal (information). Furthermore, the uplink control signal may be replaced with UCI (uplink control information), 1st stage SCI (sidelink control information), or 2nd stage SCI.

[0260] (base station) In this disclosure, a base station may be a TRP (Transmission Reception Point), cluster head, access point, RRH (Remote Radio Head), eNodeB (eNB), gNodeB (gNB), BS (Base Station), BTS (Base Transceiver Station), master unit, gateway, etc. In side-link communication, a terminal may be replaced by a base station. A base station may also be a relay device that relays communication between a higher-level node and a terminal. Furthermore, a base station may also be a roadside unit.

[0261] (Uphill rink / Downhill rink / Side rink) This disclosure may be applied to uplink, downlink, or sidelink. For example, this disclosure may be applied to uplink PUSCH, PUCCH, PRACH, downlink PDSCH, PDCCH, PBCH, and sidelink PSSCH (Physical Sidelink Shared Channel), PSCCH (Physical Sidelink Control Channel), and PSBCH (Physical Sidelink Broadcast Channel).

[0262] Note that PDCCH, PDSCH, PUSCH, and PUCCH are examples of downlink control channels, downlink data channels, uplink data channels, and uplink control channels. PSCCH and PSSCH are examples of sidelink control channels and sidelink data channels. PBCH and PSBCH are examples of broadcast channels, and PRACH is an example of a random access channel.

[0263] (Data channel / Control channel) This disclosure may be applied to either data channels or control channels. For example, the channels in this disclosure may be replaced with PDSCH, PUSCH, PSSCH for data channels and PDCCH, PUCCH, PBCH, PSCCH, PSBCH for control channels.

[0264] (reference signal) In this disclosure, the reference signal is a signal known to both the base station and the terminal, and may also be called an RS (Reference Signal) or pilot signal. The reference signal may be any of the following: DMRS, CSI-RS (Channel State Information - Reference Signal), TRS (Tracking Reference Signal), PTRS (Phase Tracking Reference Signal), CRS (Cell-specific Reference Signal), or SRS (Sounding Reference Signal).

[0265] (Time interval) In this disclosure, the unit of time resource is not limited to one or a combination of slots and symbols, but may also be other time resource units such as frames, superframes, subframes, slots, time slots, subslots, minislots, symbols, OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier - Frequency Division Multiple Access) symbols, etc. Furthermore, the number of symbols contained in one slot is not limited to the number of symbols exemplified in the embodiments described above, but may be other numbers of symbols.

[0266] (Frequency band) This disclosure may apply to either the licensed band or the unlicensed band.

[0267] (communication) This disclosure may be applied to any of the following: communication between a base station and a terminal (Uu-link communication), communication between terminals (Sidelink communication), or V2X (Vehicle to Everything) communication. For example, the channels in this disclosure may be replaced with PSCCH, PSSCH, PSFCH (Physical Sidelink Feedback Channel), PSBCH, PDCCH, PUCCH, PDSCH, PUSCH, or PBCH.

[0268] Furthermore, this disclosure may be applied to either terrestrial networks or non-terrestrial networks (NTN) using satellites or high-altitude pseudo-satellites (HAPS). It may also be applied to terrestrial networks with large cell sizes, ultra-wideband transmission networks, and other networks where transmission delay is large relative to symbol length or slot length.

[0269] (Antenna port) An antenna port refers to a logical antenna (antenna group) composed of one or more physical antennas. That is, an antenna port does not necessarily refer to a single physical antenna; it can refer to an array antenna or other structure composed of multiple antennas. For example, the number of physical antennas an antenna port consists of is not specified; it is defined as the smallest unit from which a terminal can transmit a reference signal. Furthermore, an antenna port may also be defined as the smallest unit from which the weighting of a precoding vector is multiplied.

[0270] <5G NR System Architecture and Protocol Stack> 3GPP is continuing work on the next release of fifth-generation mobile phone technology (also simply called "5G"), which includes the development of new radio access technologies (NR) operating in the frequency range up to 100 GHz. The initial version of the 5G standard was completed at the end of 2017, which will enable the prototyping and commercial deployment of devices (e.g., smartphones) that comply with the 5G NR standard.

[0271] For example, the system architecture as a whole assumes an NG-RAN (Next Generation - Radio Access Network) with gNBs. The gNBs provide the UE-side termination for the user plane (SDAP / PDCP / RLC / MAC / PHY) and control plane (RRC) protocols of the NG radio access. The gNBs are connected to each other by Xn interfaces. Furthermore, the gNBs are connected to the NGC (Next Generation Core) by Next Generation (NG) interfaces, more specifically to the AMF (Access and Mobility Management Function) (e.g., a specific core entity performing AMF) by NG-C interfaces, and to the UPF (User Plane Function) (e.g., a specific core entity performing UPF) by NG-U interfaces. The NG-RAN architecture is shown in Figure 8 (see, for example, 3GPP TS 38.300 v15.6.0, section 4).

[0272] The NR user plane protocol stack (see, for example, 3GPP TS 38.300, section 4.4.1) includes the PDCP (Packet Data Convergence Protocol (see section 6.4 of TS 38.300)) sublayer, RLC (Radio Link Control (see section 6.3 of TS 38.300)) sublayer, and MAC (Medium Access Control (see section 6.2 of TS 38.300)) sublayer, which are terminated on the network side in gNB. Additionally, a new Access Stratum (AS) sublayer (SDAP: Service Data Adaptation Protocol) is introduced on top of PDCP (see, for example, 3GPP TS 38.300, section 6.5). Furthermore, a control plane protocol stack is defined for NR (see, for example, TS 38.300, section 4.4.2). An overview of Layer 2 functionality is described in section 6 of TS 38.300. The functions of the PDCP sublayer, RLC sublayer, and MAC sublayer are listed in sections 6.4, 6.3, and 6.2 of TS 38.300, respectively. The functions of the RRC layer are listed in section 7 of TS 38.300.

[0273] For example, the Medium-Access-Control layer handles scheduling and scheduling-related functions, including the multiplexing of logical channels and the handling of various neural networks.

[0274] For example, the Physical Layer (PHY) is responsible for coding, PHY HARQ processing, modulation, multi-antenna processing, and mapping signals to appropriate physical time-frequency resources. The Physical Layer also handles the mapping of transport channels to physical channels. The Physical Layer provides services to the MAC layer in the form of transport channels. A physical channel corresponds to a set of time-frequency resources used for transmitting a particular transport channel, and each transport channel is mapped to a corresponding physical channel. For example, physical channels include uplink physical channels such as PRACH (Physical Random Access Channel), PUSCH (Physical Uplink Shared Channel), and PUCCH (Physical Uplink Control Channel), and downlink physical channels such as PDSCH (Physical Downlink Shared Channel), PDCCH (Physical Downlink Control Channel), and PBCH (Physical Broadcast Channel).

[0275] NR use cases / deployment scenarios may include enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), and massive machine type communications (mMTC), each with diverse requirements in terms of data rate, latency, and coverage. For example, eMBB is expected to support peak data rates (20 Gbps on the downlink and 10 Gbps on the uplink) and effective (user-experienced) data rates approximately three times that of IMT-Advanced. URLLC, on the other hand, imposes more stringent requirements for ultra-low latency (0.5 ms for both UL and DL for user plane latency) and high reliability (1-10⁻⁵ within 1 ms). Finally, mMTC preferably has a high connectivity density (1,000,000 devices / km² in urban environments). 2 ), wide coverage in harsh environments, and extremely long-lasting batteries (15 years) for low-cost devices may be required.

[0276] Therefore, an OFDM neurology suitable for one use case (e.g., subcarrier spacing, OFDM symbol length, cyclic prefix (CP) length, number of symbols per scheduling interval) may not be effective for other use cases. For example, low-latency services may preferably require a shorter symbol length (and thus a larger subcarrier spacing) and / or fewer symbols per scheduling interval (also known as TTI) than mMTC services. Furthermore, deployment scenarios with large channel delay spreads may preferably require a longer CP length than scenarios with short delay spreads. The subcarrier spacing may be optimized on a case-by-case basis to maintain similar CP overhead. There may be one or more subcarrier spacing values ​​supported by NR. Accordingly, subcarrier spacings of 15kHz, 30kHz, 60kHz, etc. are currently being considered. The symbol length Tu and subcarrier spacing Δf are directly related by the equation Δf = 1 / Tu. Similar to LTE systems, the term “resource element” can be used to mean the smallest resource unit consisting of one subcarrier for the length of one OFDM / SC-FDMA symbol.

[0277] In the new 5G-NR wireless system, resource grids for subcarriers and OFDM symbols are defined for each neurology and each carrier, for both the uplink and downlink. Each element of the resource grid is called a resource element and is identified based on the frequency index in the frequency domain and the symbol position in the time domain (see 3GPP TS 38.211 v15.6.0).

[0278] <Functional separation between NG-RAN and 5GC in 5G NR> Figure 9 shows the functional separation between NG-RAN and 5GC. The logical nodes of NG-RAN are gNB or ng-eNB. 5GC has logical nodes AMF, UPF, and SMF.

[0279] For example, gNB and ng-eNB host the following main functions: - Radio resource management functions such as radio bearer control, radio admission control, connection mobility control, and dynamic allocation (scheduling) of resources to UEs on both uplink and downlink; - Compression, encryption, and integrity protection of the IP header of the data; - Selection of the AMF when the UE attaches if routing to the AMF cannot be determined from the information provided by the UE; - Routing of user plane data toward UPF; - Routing of control plane information to AMF; - Setting up and disconnecting connections; - Scheduling and sending paging messages; - Scheduling and transmission of system notification information (originating from AMF or Operation, Admission, Maintenance functions (OAM)); - Setting up measurements and measurement reporting for mobility and scheduling; - Transport-level packet marking on the uplink; - Session management; - Support for network slicing; - Management of QoS flows and mapping to data radio bearers; - Support for UEs in the RRC_INACTIVE state; - NAS message delivery function; - Sharing of wireless access network; Dual connectivity; - Close cooperation between NR and E-UTRA.

[0280] The Access and Mobility Management Function (AMF) hosts the following main functions: - A function to terminate Non-Access Stratum (NAS) signaling; - Security of NAS signaling; - Security control of Access Stratum (AS); - Core Network (CN) node-to-node signaling for mobility between 3GPP access networks; - Reachability of the UE in idle mode (including control and execution of paging retransmissions); - Management of registration areas; - Support for intra-system and inter-system mobility; - Access authentication; - Access authorization including roaming permission checks; - Mobility management and control (enrollment and policies); - Support for network slicing; - Selection of Session Management Function (SMF).

[0281] Furthermore, the User Plane Function (UPF) hosts the following main functions: - Anchor points for intra-RAT mobility / inter-RAT mobility (where applicable); - External PDU (Protocol Data Unit) session points for interconnection with data networks; - Routing and forwarding of packets; - Packet inspection and enforcement of policy rules in the user plane; - Reporting traffic usage; - Uplink classifier to support routing of traffic flow to data networks; - A Branching Point for supporting a multi-homed PDU session; - QoS processing for the user plane (e.g., packet filtering, gating, UL / DL rate enforcement); - Verification of uplink traffic (mapping for the QoS flow of SDF); - Downlink packet buffering and triggering function for downlink data notification.

[0282] Finally, the Session Management Function (SMF) hosts the following main functions: - Session management; - IP address allocation and management for the UE; - Selection and control of the UPF; - A function for setting up traffic steering in the User Plane Function (UPF) to route traffic to the appropriate destination; - Enforcement of control part policies and QoS; - Notification of downlink data.

[0283] <Procedures for RRC connection setup and reconfiguration> Figure 10 shows some of the interactions between the UE, gNB, and AMF (5GC entity) when the UE moves from RRC_IDLE to RRC_CONNECTED in the NAS part (see TS 38.300 v15.6.0).

[0284] RRC is a higher-layer signaling protocol used for configuring UEs and gNBs. During this transition, the AMF prepares UE context data (including, for example, PDU session context, security key, UE Radio Capability, UE Security Capabilities, etc.) and sends it to the gNB along with an Initial Context Setup Request. The gNB then activates AS security together with the UE. This is done by the gNB sending a SecurityModeCommand message to the UE, to which the UE responds with a SecurityModeComplete message. Subsequently, the gNB sends an RRCReconfiguration message to the UE, and upon receiving an RRCReconfigurationComplete from the UE, the gNB reconfigures itself to set up the Signaling Radio Bearer 2 (SRB2) and Data Radio Bearer (DRB). For signaling-only connections, the RRCReconfiguration step is omitted because SRB2 and DRB are not set up. Finally, gNB notifies AMF that the setup procedure is complete with an Initial Context Setup Response.

[0285] Accordingly, this disclosure provides a 5th Generation Core (5GC) entity (e.g., AMF, SMF, etc.) comprising a control circuit that establishes a Next Generation (NG) connection with a gNodeB during operation, and a transmission unit that sends an initial context setup message to the gNodeB via the NG connection during operation so that a signaling radio bearer between the gNodeB and the user equipment (UE) is set up. Specifically, the gNodeB transmits Radio Resource Control (RRC) signaling, including an Information Element (IE), to the UE via the signaling radio bearer. The UE then transmits on the uplink or receives on the downlink based on the resource allocation setting.

[0286] <IMT Usage Scenarios from 2020 Onward> Figure 11 shows some use cases for 5G NR. The 3rd generation partnership project for new radio (3GPP NR) is considering three use cases envisioned by IMT-2020 to support a wide variety of services and applications. The first phase of specification development for enhanced mobile-broadband (eMBB) has been completed. Current and future work will include expanding eMBB support, as well as standardization for ultra-reliable and low-latency communications (URLLC) and massive machine-type communications (mMTC). Figure 11 shows some examples of conceptual use scenarios for IMT beyond 2020 (see, for example, ITU-R M.2083 Figure 2).

[0287] URLLC use cases have stringent performance requirements, such as throughput, latency, and availability. URLLC use cases are envisioned as one of the key technologies to enable future applications such as wireless control of industrial production or manufacturing processes, telemedicine surgery, automation of power transmission and distribution in smart grids, and traffic safety. The ultra-high reliability of URLLC is supported by identifying technologies that meet the requirements set by TR 38.913. In NR URLLC in Release 15, a key requirement is that the target user plane latency is 0.5 ms for UL (uplink) and 0.5 ms for DL ​​(downlink). The general URLLC requirement for a single packet transmission is a block error rate (BLER) of 1E-5 for a 32-byte packet size when the user plane latency is 1 ms.

[0288] From a physical layer perspective, reliability can be improved in many ways. Current room for reliability improvement includes defining a separate CQI table for URLLC, a more compact DCI format, and PDCCH iterations. However, this room for improvement may expand towards achieving ultra-high reliability as NR becomes more stable and developed (in terms of critical requirements for NR URLLC). Specific use cases for NR URLLC in Release 15 include augmented reality / virtual reality (AR / VR), e-health, e-safety, and mission-critical applications.

[0289] Furthermore, the technical enhancements targeted by NR URLLC aim to improve latency and reliability. Technical enhancements for latency improvement include configurable neurology, non-slot-based scheduling with flexible mapping, grant-free (configured grant) uplink, slot-level iteration on data channels, and preemption on downlink. Preemption means that a transmission for which a resource has already been allocated is stopped, and that allocated resource is used for other transmissions with lower latency / higher priority requirements that are requested later. Thus, transmissions that were already permitted are replaced by later transmissions. Preemption is applicable regardless of the specific service type. For example, a transmission of service type A (URLLC) may be replaced by a transmission of service type B (eMBB, etc.). Technical enhancements for reliability improvement include a dedicated CQI / MCS table for the 1E-5 target BLER.

[0290] A key characteristic of mMTC (massive machine type communication) use cases is the extremely large number of connected devices that typically transmit relatively small amounts of data that are less susceptible to latency. These devices require low cost and very long battery life. From a noise reduction (NR) perspective, utilizing a very narrow bandwidth is one solution that saves power from the user interface (UE) and extends battery life.

[0291] As mentioned above, the scope of reliability improvements in NR is expected to broaden. High reliability or very high reliability is a critical requirement in all cases, for example, for URLLC and mMTC. Several mechanisms can improve reliability from both a radio and network perspective. Generally, there are two to three key areas that can help improve reliability. These areas include compact control channel information, data channel / control channel repetition, and diversity in the frequency, time, and / or spatial domains. These areas are generally applicable to reliability improvements regardless of the specific communication scenario.

[0292] Regarding NR URLLC, further use cases with more stringent requirements are envisioned, such as factory automation, transportation, and power distribution. These stringent requirements include high reliability (up to 10⁻⁶ levels), high availability, packet size up to 256 bytes, and time synchronization down to a few microseconds (depending on the use case, the value can be 1 microsecond or a few microseconds depending on the frequency range and short latency of approximately 0.5 ms to 1 ms (e.g., 0.5 ms latency in the target user plane)).

[0293] Furthermore, for NR URLLC, several technical enhancements may be possible from the perspective of the physical layer. These technical enhancements include enhancements to the PDCCH (Physical Downlink Control Channel) related to compact DCI, repetition of the PDCCH, and increased monitoring of the PDCCH. Also, the enhancement of UCI (Uplink Control Information) is related to the enhancement of enhanced HARQ (Hybrid Automatic Repeat Request) and CSI feedback. Additionally, enhancements to the PUSCH related to mini-slot level hopping, and enhancements to retransmission / repetition may be possible. The term "mini-slot" refers to a Transmission Time Interval (TTI) that contains fewer symbols than a slot (a slot has 14 symbols).

[0294] <QoS Control> The QoS (Quality of Service) model of 5G is based on QoS flows and supports both QoS flows that require a guaranteed flow bit rate (GBR: Guaranteed Bit Rate QoS flows) and QoS flows that do not require a guaranteed flow bit rate (non-GBR QoS flows). Therefore, at the NAS level, a QoS flow is the finest granularity QoS differentiation in a PDU session. A QoS flow is identified within a PDU session by a QoS Flow ID (QFI: QoS Flow ID) that is carried in an encapsulation header via the NG-U interface.

[0295] For each UE, the 5GC establishes one or more PDU sessions. For each UE, the NG-RAN establishes at least one Data Radio Bearers (DRB) in accordance with the PDU session, as shown above, for example, referring to Figure 10. Additional DRBs for the QoS flow of that PDU session can be configured later (when this is done is up to the NG-RAN). The NG-RAN maps packets belonging to various PDU sessions to various DRBs. NAS-level packet filters in the UE and 5GC associate UL and DL packets with QoS flows, while AS-level mapping rules in the UE and NG-RAN associate UL and DL QoS flows with DRBs.

[0296] Figure 12 shows the non-roaming reference architecture for 5G NR (see TS 23.501 v16.1.0, section 4.23). An Application Function (AF) (for example, an external application server hosting 5G services, as illustrated in Figure 11) interacts with the 3GPP core network to provide services. This may involve accessing the Network Exposure Function (NEF) to support applications that affect traffic routing, or interacting with the policy framework for policy control (e.g., QoS control) (see Policy Control Function (PCF)). Based on operator deployment, Application Functions considered trusted by the operator can interact directly with the relevant Network Functions. Application Functions not authorized by the operator to directly access the Network Functions interact with the relevant Network Functions using an external exposure framework via the NEF.

[0297] Figure 12 further illustrates the functional units of the 5G architecture, namely the Network Slice Selection Function (NSSF), Network Repository Function (NRF), Unified Data Management (UDM), Authentication Server Function (AUSF), Access and Mobility Management Function (AMF), Session Management Function (SMF), and Data Network (DN, e.g., operator services, internet access, or third-party services). All or part of the core network functions and application services may be deployed and operate in a cloud computing environment.

[0298] Accordingly, the Disclosure provides an application server (e.g., AF in a 5G architecture) comprising: a transmitter that, in operation, transmits a request to at least one of the 5GC functions (e.g., NEF, AMF, SMF, PCF, UPF, etc.) that includes QoS requirements for at least one of the URLLC service, eMMB service, and mMTC service, in order to establish a PDU session including a radio bearer between the gNodeB and UE in accordance with QoS requirements; and a control circuit that, in operation, performs the service using the established PDU session.

[0299] This disclosure can be implemented in software, hardware, or software in conjunction with hardware. Each functional block used in the description of the above embodiments may be implemented in part or in whole as an integrated circuit (LSI), and each process described in the above embodiments may be controlled in part or in whole by a single LSI or a combination of LSIs. An LSI may consist of individual chips, or it may consist of a single chip that includes some or all of the functional blocks. An LSI may have data inputs and outputs. Depending on the degree of integration, LSIs may be referred to as ICs, system LSIs, super LSIs, or ultra LSIs.

[0300] The method of integration is not limited to LSIs; it may also be implemented using dedicated circuits, general-purpose processors, or dedicated processors. Furthermore, FPGAs (Field Programmable Gate Arrays) that can be programmed after LSI manufacturing, or reconfigurable processors that allow for the reconfiguration of the connections and settings of circuit cells within the LSI, may also be used. This disclosure may be implemented as digital or analog processing.

[0301] Furthermore, if advancements in semiconductor technology or related technologies lead to the emergence of integrated circuit technologies that replace LSIs, then naturally, these technologies could be used to integrate functional blocks. The application of biotechnology, for example, is a possible possibility.

[0302] This disclosure is applicable to all types of devices, systems, and equipment having communication capabilities (collectively referred to as communication equipment). Communication equipment may include a radio transceiver and a processing / control circuit. A radio transceiver may include a receiver and a transmitter, or both as functions. A radio transceiver (transmitter, receiver) may include an RF (Radio Frequency) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, or similar. Non-exclusive examples of communication devices include telephones (mobile phones, smartphones, etc.), tablets, personal computers (PCs) (laptops, desktops, notebooks, etc.), cameras (digital still / video cameras, etc.), digital players (digital audio / video players, etc.), wearable devices (wearable cameras, smartwatches, tracking devices, etc.), game consoles, digital book readers, telehealth / telemedicine devices, vehicles or mobile transport with communication capabilities (cars, airplanes, ships, etc.), and combinations of the above-mentioned devices.

[0303] Communication devices are not limited to portable or movable devices, but also include all kinds of non-portable or fixed devices, devices, and systems, such as smart home devices (appliances, lighting equipment, smart meters or measuring instruments, control panels, etc.), vending machines, and any other "things" that may exist on an IoT (Internet of Things) network.

[0304] Communication includes data communication via cellular systems, wireless LAN systems, and communication satellite systems, as well as data communication using combinations of these.

[0305] Furthermore, the communication device also includes devices such as controllers and sensors that are connected to or linked to a communication device that performs the communication functions described in this disclosure. For example, this includes controllers and sensors that generate control signals and data signals used by the communication device that performs the communication functions of the communication device.

[0306] Furthermore, communication equipment includes infrastructure facilities such as base stations, access points, and any other devices, devices, and systems that communicate with or control the aforementioned non-limited types of equipment.

[0307] A terminal according to one embodiment of the present disclosure comprises a receiving circuit that receives parameters relating to cell selection, which are set based on at least one of the functions, types, and operating modes of the terminal, and a control circuit that performs the cell selection process based on the parameters.

[0308] In one embodiment of this disclosure, the parameter is a parameter relating to the received power.

[0309] In one embodiment of this disclosure, the parameter is a parameter relating to reception quality.

[0310] In one embodiment of the present disclosure, the parameter is an offset value used to determine the cell selection.

[0311] In one embodiment of the present disclosure, the parameter is a parameter relating to the reception of a beamforming synchronization signal.

[0312] In one embodiment of this disclosure, there are multiple candidate parameters.

[0313] In one embodiment of the present disclosure, the control circuit controls the initial access operation based on the determination result of the cell selection.

[0314] In one embodiment of the present disclosure, the control circuit controls the initial access operation based on the parameters that satisfy the criteria for cell selection.

[0315] In one embodiment of the present disclosure, the control circuit controls the initial access operation based on the difference between a plurality of reference values ​​for cell selection based on each of the different parameters.

[0316] In one embodiment of the present disclosure, the control circuit determines the resources of the random access channel in controlling the initial access operation.

[0317] In one embodiment of the present disclosure, the control circuit determines the number of repetitions of the uplink signal in controlling the initial access operation.

[0318] In one embodiment of the present disclosure, the control circuit controls the transmission power of the uplink signal in controlling the initial access operation.

[0319] In one embodiment of the present disclosure, the control circuit sets the parameters based on at least two combinations of the function, type, and operating mode of the terminal.

[0320] In one embodiment of the present disclosure, the control circuit determines the priority or order of application of a plurality of parameters to the cell selection.

[0321] In a communication method according to one embodiment of the present disclosure, the terminal receives a parameter relating to cell selection, which is set based on at least one of the terminal's function, type, and operating mode, and performs the cell selection process based on the parameter.

[0322] All disclosures in the specification, drawings, and abstract contained in the Japanese application 2021-004451, filed on January 14, 2021, are incorporated herein by reference. [Industrial applicability]

[0323] One embodiment of this disclosure is useful for wireless communication systems. [Explanation of symbols]

[0324] 100 base stations 101, 206 Control Unit 102,207 Signal generation unit 103, 208 Transmitter 104, 201 Receiver 105, 202 Extraction part 106, 203 Demodulation section 107, 204 Decoding section 205 Measuring section 200 terminals

Claims

1. A control circuit that sets parameters related to cell selection by the terminal, which are set based on at least one of the terminal's function, type, and operating mode, A transmission circuit that transmits the aforementioned parameters to the terminal, It is equipped with, The parameters include a first minimum required received power value for the Supplementary uplink (SUL) frequency, a first offset value added to the first minimum required received power value for calculating the received power level used for determining cell selection, a second minimum required received power value different from the first minimum required received power value, and a second offset value added to the second minimum required received power value for calculating the received power level used for determining cell selection. The control circuit controls the process of re-selecting a cell by the terminal after the terminal has performed the cell selection process. Terminal.

2. The aforementioned parameters include parameters relating to received power. The terminal according to claim 1.

3. The aforementioned parameters include parameters related to reception quality, The terminal according to claim 2.

4. The control circuit determines to perform the cell selection process if the parameter relating to the received power and the parameter relating to the received quality are greater than 0. The terminal according to claim 3.

5. If the terminal supports the SUL frequency, the first minimum requested received power value is obtained from the parameters for the SUL frequency transmitted by the System Information Block (SIB). If the terminal does not support the SUL frequency, the second minimum requested received power value is obtained from parameters different from those for the SUL frequency transmitted by the SIB. The terminal according to claim 1.

6. The base station is, A parameter relating to cell selection by the terminal is set based on at least one of the terminal's function, type, and operating mode. The aforementioned parameters are transmitted to the terminal, The parameters include a first minimum required received power value for the Supplementary uplink (SUL) frequency, a first offset value added to the first minimum required received power value for calculating the received power level used for determining cell selection, a second minimum required received power value different from the first minimum required received power value, and a second offset value added to the second minimum required received power value for calculating the received power level used for determining cell selection. Controls the process of re-selecting cells by the terminal after the terminal has performed the cell selection process. Communication method.

7. A control circuit that sets parameters related to cell selection by the terminal, which are set based on at least one of the terminal's function, type, and operating mode, A transmission circuit that transmits the aforementioned parameters to the terminal, Control, The parameters include a first minimum required received power value for the Supplementary uplink (SUL) frequency, a first offset value added to the first minimum required received power value for calculating the received power level used for determining cell selection, a second minimum required received power value different from the first minimum required received power value, and a second offset value added to the second minimum required received power value for calculating the received power level used for determining cell selection. The control circuit controls the process of re-selecting a cell by the terminal after the terminal has performed the cell selection process. Integrated circuit.

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