Terminal, base station, and wireless communication method

Abstract

To provide a terminal and a wireless communication method for appropriately controlling PEI (Paging Early Indication) monitoring.SOLUTION: In a wireless communication system, a terminal 10 includes: a receiving unit 101 that receives downlink control information including a field indicating a paging target subgroup in a plurality of paging periods; and a control unit 103 that controls monitoring in the plurality of paging periods based on a value of the field. The receiving unit 101 receives information about the total number of subgroups and information about the number of the plurality of paging periods, and the control unit 103 determines the number of bits of the field in the downlink control information based on the information about the total number of subgroups and the information about the number of the plurality of paging periods.SELECTED DRAWING: Figure 14

Description

Technical Field

[0001] The present disclosure relates to a terminal and a wireless communication method.

Background Art

[0002] In the Third Generation Partnership Project (3GPP), which is an international standards organization, Release 15 of New Radio (NR), which is the fifth generation (5G) Radio Access Technology (RAT), has been standardized as a successor to Long Term Evolution (LTE), which is the 3.9th generation RAT, and LTE-Advanced, which is the 4th generation RAT (for example, Non-Patent Document 1). LTE and / or LTE-Advanced are also called Evolved Universal Terrestrial Radio Access (E-UTRA).

[0003] In E-UTRA and / or NR, network-initiated connection setup is performed by paging. For example, in NR, a terminal in the idle state or inactive state monitors downlink control information (DCI) transmitted using a downlink control channel (e.g., Physical Downlink Control Channel (PDCCH)) during a paging period (hereinafter referred to as "paging period"). The terminal receives a paging message via a downlink shared channel (e.g., Physical Downlink Shared Channel (PDSCH)) scheduled by the DCI. The terminal reduces the power consumption of the terminal by performing discontinuous reception (DRX) while sleeping outside the paging period.

Prior Art Documents

Non-Patent Documents

[0004] [Non-Patent Document 1] 3GPP TS 38.300 V15.2.0 (2018-06) [Summary of the Invention] [Problems to be Solved by the Invention]

[0005] In 3GPP (for example, Release 17 of NR), a plurality of terminals assigned to the same paging period are divided into predetermined units (hereinafter referred to as "subgroups"), and paging is performed in units of subgroups (hereinafter referred to as "subgrouping"). Also, by previously instructing the terminal 10 about the subgroup to be paged during the paging period (hereinafter referred to as "Paging early indication (PEI)"), it is expected to improve the power saving effect by subgrouping.

[0006] PEI is considered to be configured, for example, based on DCI, based on a Secondary Synchronization Signal (SSS), or based on a Tracking Reference Signal (TRS). When introducing DCI-based PEI, it is necessary to appropriately control the monitoring of the PEI.

[0007] The present disclosure has been made in view of such circumstances, and one of the objectives is to provide a terminal and a wireless communication method capable of appropriately controlling the monitoring of PEI. [Means for Solving the Problems]

[0008] A terminal according to one aspect of the present disclosure includes a receiving unit that receives downlink control information including a field indicating a subgroup of paging targets in a plurality of paging periods, and a control unit that controls monitoring in the plurality of periods based on a value of the field. The receiving unit receives information regarding the total number of subgroups and information regarding the number of the plurality of periods, and the control unit determines the number of bits of the field in the downlink control information based on the information regarding the total number of subgroups and the information regarding the number of the plurality of periods.

Advantages of the Invention

[0009] According to one aspect of the present disclosure, monitoring of PEI can be appropriately controlled.

Brief Description of the Drawings

[0010]

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Mode for Carrying Out the Invention

[0011] Embodiments of the present disclosure will be described with reference to the accompanying drawings. In each figure, those with the same reference numerals may have the same or similar configurations.

[0012] FIG. 1 is a diagram showing an example of the outline of a wireless communication system according to the present embodiment. As shown in FIG. 1, the wireless communication system 1 may include a terminal 10, a base station 20, and a core network 30. Note that the numbers of the terminal 10 and the base station 20 shown in FIG. 1 are merely examples and are not limited to the numbers shown.

[0013] As the radio access technology (RAT) of the wireless communication system 1, for example, NR is assumed, but it is not limited thereto, and various RATs such as RATs after the sixth generation can be used.

[0014] The terminal 10 is a predetermined terminal or device such as, for example, a smartphone, a personal computer, an in-vehicle terminal, an in-vehicle device, a stationary device, a telematics control unit (TCU), etc. The terminal 10 may be referred to as a user equipment (UE), a mobile station (MS), a user terminal, a radio apparatus, a subscriber terminal, an access terminal, etc. The terminal 10 may be mobile or fixed. The terminal 10 is configured to be communicable using, for example, NR as a RAT.

[0015] The base station 20 forms one or more cells C and communicates with the terminal 10 using the cells. The cell C may be mutually paraphrased as a serving cell, a carrier, a component carrier (CC), etc. For example, the base station 20 may set and communicate with the terminal 10 one primary cell and one or more secondary cells (also referred to as carrier aggregation). That is, one or more cells C include at least a primary cell and may include a secondary cell.

[0016] Also, for one cell C, one or more Bandwidth Parts (BWPs) may be configured. Here, the BWP mainly used when the terminal 10 makes an initial access to the cell is also referred to as the Initial Downlink BWP and the Initial Uplink BWP. For example, the base station 20 may include information used to configure the frequency position, bandwidth, subcarrier spacing, and / or cyclic prefix for each of the Initial Downlink BWP and the Initial Uplink BWP in system information (e.g., System Information Block (SIB) 1) and notify it. Also, the base station 20 may include information used to configure the frequency position, bandwidth, subcarrier spacing, and / or cyclic prefix for each of the Initial Downlink BWP and the Initial Uplink BWP in the Master Information Block (MIB) and notify it.

[0017] The base station 20 may be referred to as a gNodeB (gNB), en-gNB, Next Generation-Radio Access Network (NG-RAN) node, low-power node, Central Unit (CU), Distributed Unit (DU), gNB-DU, Remote Radio Head (RRH), Integrated Access and Backhaul / Backhauling (IAB) node, etc. The base station 20 is not limited to one node and may be composed of a plurality of nodes (e.g., a combination of a lower node such as a DU and an upper node such as a CU).

[0018] The core network 30 is, for example, but not limited to, a core network (5G Core Network: 5GC) corresponding to NR. Devices on the core network 30 (hereinafter also referred to as "core network devices") perform mobility management such as paging and location registration of the terminal 10. The core network device may be connected to the base station 20 via a predetermined interface (for example, S1 or NG interface).

[0019] The core network device may include, for example, at least one of an Access and Mobility Management Function (AMF) that manages C-plane information (for example, information related to access and mobility management, etc.) and a User Plane Function (UPF) that performs transmission control of U-plane information (for example, user data).

[0020] In the wireless communication system 1, the terminal 10 receives a downlink (DL) signal from the base station 20 and / or transmits an uplink (UL) signal. One or more cells C are configured in the terminal 10, and at least one of the configured cells is activated. The maximum bandwidth of each cell is, for example, 20 MHz or 400 MHz, etc.

[0021] Also, the terminal 10 performs cell search based on synchronization signals from the base station 20 (for example, a Primary Synchronization Signal (PSS) and / or a Secondary Synchronization Signal (SSS)). Cell search is a procedure in which the terminal 10 acquires time and frequency synchronization in the cell and detects the identifier of the cell (for example, a physical layer cell ID).

[0022] A block including at least one of the above synchronization signal, notification channel (e.g., Physical Broadcast Channel (PBCH)), and Demodulation Reference Signal (DMRS) for demodulating the notification channel is also called a Synchronization Signal Block (SSB), an SS / PBCH block, etc. One or more SSBs may constitute one SS burst, and one or more SS bursts may constitute one SS burst set. The SS burst set may be transmitted at a predetermined period (e.g., 20 ms (2 radio frames)). In the case of multi-beam operation, SSBs with different indexes may correspond to different beams, and the beam direction may be sequentially switched and transmitted by beam sweeping.

[0023] The system information broadcast in cell C may include the Master Information Block (MIB) broadcast via the PBCH and / or the System Information Block (e.g., SIBx, x = 1, 2,...) broadcast via the downlink shared channel (e.g., Physical Downlink Shared Channel (PDSCH)). Here, SIB1 is also referred to as Remaining system information (RMSI).

[0024] Based on parameters (hereinafter referred to as "RRC parameters") included in the system information or Radio Resource Control (RRC) message, the terminal 10 determines a search space and / or a Control Resource Set (CORESET), and monitors Downlink Control Information (DCI) transmitted via the downlink control channel (e.g., Physical Downlink Control Channel (PDCCH)) within the search space associated with the CORESET. Note that the RRC message may include, for example, an RRC setup message, an RRC reconfiguration message, an RRC resume message, an SIB, an MIB, etc.

[0025] Monitoring of DCI means that the terminal 10 blindly decodes PDCCH candidates in the search space in the assumed DCI format. The number of bits of the DCI format (also referred to as size, bit width, etc.) is predetermined or derived according to the number of bits of the fields included in the DCI format. The terminal 10 detects DCI for the terminal 10 based on the number of bits of the DCI format and a specific radio network temporary identifier (RNTI) used for scrambling of the cyclic redundancy check (CRC) bits (also referred to as CRC parity bits) of the DCI format (hereinafter referred to as "CRC scrambling"). Monitoring of DCI is also called PDCCH monitoring, monitoring, etc. Also, the period for performing DCI monitoring is also called a PDCCH monitoring occasion.

[0026] The search space may include a search space (hereinafter referred to as "common search space (CSS)") commonly used by one or more terminals 10 and a UE-specific search space (USS). For example, the terminal 10 may monitor a CSS (for example, Type0-PDCCH CSS set or Type2-PDCCH CSS set) set by RRC parameters (for example, RRC IE "pagingSearchSpace") to detect DCI (for example, also called DCI format 1_0, "paging DCI", etc.) scrambled by a specific RNTI (for example, Paging (P)-RNTI). The terminal 10 receives a paging message via the PDSCH scheduled using the DCI. Here, the base station 20 may set a specific RNTI (for example, P-RNTI) for the terminal 10 according to the RRC parameters.

[0027] Here, the Type0-PDCCH CSS set may be configured using the information included in the MIB. For example, the base station 20 may configure the Type0-PDCCH CSS set for the terminal 10 by transmitting, in the MIB, the information for configuring the CORESET and / or the information for configuring the search space. Here, the CORESET configured using the information included in the MIB is also referred to as CORESET#0. Further, the search space configured using the information included in the MIB is also referred to as search space#0. CORESET#0 and search space#0 respectively mean a CORESET with index#0 (i.e., CORESET with ID#0) and a search space with index#0 (i.e., Search Space with ID#0). That is, the PDCCH monitoring opportunity corresponding to the Type0-PDCCH CSS set may be configured using the information included in the MIB. Here, the PDCCH monitoring opportunity corresponding to the Type0-PDCCH CSS set is also referred to as the PDCCH monitoring opportunity for SIB1.

[0028] Also, the Type2-PDCCH CSS set may be configured using the information included in the system information (e.g., SIB1). For example, the base station 20 may configure the Type2-PDCCH CSS set for the terminal 10 by transmitting, in the system information, information for configuring the index of the CORESET and / or information for configuring the index of the search space. Here, the CORESET configured using the information included in the system information may be CORESET#0 or CORESET#x (e.g., x = 1, 2, …). Also, the search space configured using the information included in the system information may be search space#0 or search space#x (e.g., x = 1, 2, …). That is, a value other than “0” may be set for each of the index of the CORESET and the index of the search space configured using the information included in the system information. That is, the PDCCH monitoring opportunity corresponding to the Type2-PDCCH CSS set may be configured using the information included in the system information.

[0029] Also, the terminal 10 may monitor the USS to detect DCI (e.g., DL assignment or UL grant) scrambled by a specific RNTI (e.g., Cell(C)-RNTI), and control data reception using the PDSCH scheduled by the DCI or data transmission using an uplink shared channel (e.g., Physical Uplink Shared Channel: PUSCH). Note that a set of one or more search spaces may be referred to as a search space set, a set including one or more CSSs may be referred to as a CSS set, a set including one or more USSs may be referred to as a USS set, and so on.

[0030] (Paging) Paging is used for network-initiated connection setup when the terminal 10 is in an idle state or an inactive state. Also, paging is used for the transmission of short messages regardless of the state of the terminal 10 (e.g., idle state, inactive state, or connected state) for the instruction of system information update and / or public warning. Public warnings include, for example, the Earthquake and Tsunami Warning System (ETWS), the Commercial Mobile Alert System (CMAS), etc.

[0031] Here, the idle state is a state in which the RRC layer connection (hereinafter referred to as the "RRC connection") between the terminal 10 and the base station 20 is not established, and is also called RRC_IDLE, idle mode, RRC idle mode, etc. The terminal 10 in the idle state receives the system information notified by the cell on which it camps. When the RRC connection of the terminal 10 in the idle state is established, it transitions to the connected state.

[0032] Also, the inactive state is a state in which the above RRC connection is established but suspended, and is also called the RRC_INACTIVE state, inactive mode, RRC inactive mode, etc. The terminal 10 in the inactive state receives the system information notified by the camp-on cell. When the RRC connection of the terminal 10 in the inactive state is resumed, it transitions to the connected state, and when the RRC connection is released, it transitions to the idle state.

[0033] The connected state is a state in which the above RRC connection is established, and is also called the RRC_CONNECTED state, the connected mode, the RRC connected mode, etc. When the RRC connection of the terminal 10 in the connected state is released, it transitions to the idle state, and when the RRC connection is suspended, it transitions to the inactive state.

[0034] The terminal 10 performs PDCCH monitoring during the paging period and performs DRX in which it sleeps outside the paging period. The paging period may be, for example, a paging frame (PF) and / or a paging occasion (PO). A PO is composed of one or more time units. The time unit may be, for example, one or more slots, one or more subframes, or one or more symbols. A PO may include one or more PDCCH monitoring opportunities.

[0035] FIG. 2 is a diagram showing an example of DRX for paging according to the present embodiment. As shown in FIG. 2, a PF is provided in a predetermined cycle called a DRX cycle. The PF may be composed of, for example, one radio frame and may be identified by a system frame number (SFN). One radio frame is composed of 10 subframes #0 to #9, and when the subcarrier spacing is 15 kHz, for example, it is composed of 10 slots #0 to #9. Needless to say, the number of slots per PF varies according to the subcarrier spacing.

[0036] For example, in FIG. 2, the number of POs N per PF s is 1. The terminal 10 synchronizes time and frequency before the PF (or PO or PDCCH monitoring opportunity within the PO). For example, but not limited to, an SSB is used for the time and frequency synchronization. In FIG. 2, the terminal 10 detects a paging DCI in the PDCCH monitoring opportunity within the PO and receives a paging message via a PDSCH scheduled by the paging DCI.

[0037] The paging message is transmitted in multiple cells C within the tracking area in the case of CN-led paging, and is transmitted across one or more cells C within the RAN area in the case of RAN-led paging. The RAN area is identified by a RAN Area Identifier (RAI), and the tracking area is identified by a Tracking Area Identifier (TAI). The RAN area includes one or more cells C, and the tracking area includes one or more RAN areas.

[0038] The terminal 10 controls the establishment of a connection with the network side (e.g., CN30 and / or base station 20) based on a list of one or more terminal identifiers in the paging message (e.g., the RRC IE "pagingRecordList") and the terminal identifier assigned to the terminal 10. For example, the terminal 10 may start the connection establishment procedure with the network side when the terminal identifier assigned to the terminal 10 is included in the list. Here, the terminal identifier is the identifier of the terminal 10, and may be, for example, the 5G S-Temporary Mobile Subscription Identifier (5G-S-TMSI), which is a temporary terminal identifier that uniquely identifies the terminal 10 within the tracking area.

[0039] Note that in FIG. 2, the number of POs N per PF s is assumed to be one, but is not limited thereto and may be multiple. Also, in FIG. 2, it is assumed that the PO is one subframe (slot), but as described above, the time unit constituting the PO is not limited thereto. Also, in FIG. 2, the PO associated with a certain PF is provided within the PF, but is not limited thereto and may start from a predetermined position before or after the PF. Also, the PDCCH monitoring opportunity for a certain PO may span multiple radio frames.

[0040] The SFN of the PF of the terminal 10 may be determined based on the 5G-S-TMSI which is the above terminal identifier and the DRX cycle T. For example, the SFN for PF may be determined according to the following formula 1 based on a predetermined offset PF_Offset, the DRX cycle T, the number of PFs N within the DRX cycle T, and the number of POs N per PF s and may be determined based on (Formula 1) (SFN + PF_Offset) mod T = (T div N) * (UE_ID mod N) Here, UE_ID = 5G-S-TMSI mod 1024

[0041] According to the above formula 1, a plurality of terminals 10 are allocated for the same paging period (for example, PF and / or PO). On the other hand, for the terminal 10 to receive the paging DCI, it cannot be determined which paging is for the terminal 10 without decoding the list of terminal identifiers in the paging message. Therefore, among the plurality of terminals 10 sharing the same paging period, the terminals 10 that are not the paging targets in the paging period may perform unnecessary time and frequency synchronization and PDCCH monitoring in the PO. As a result, the power consumption of the terminals 10 that are not the paging targets in the paging period may be wasted.

[0042] (Subgrouping) In order to reduce the waste of power consumption of the terminals 10 that are not the paging targets, it is also considered to divide the plurality of terminals 10 allocated for the same paging period into predetermined units (hereinafter referred to as "subgroups") and perform paging for each subgroup. Specifically, subgrouping based on the terminal identifier and subgrouping based on the network are considered.

[0043] In the subgrouping based on the terminal identifier, the terminal 10 determines the subgroup allocated to itself based on the above terminal identifier. Specifically, in addition to the terminal identifier 5G-S-TMSI, the terminal 10 also includes the number of PFs N within the DRX cycle T, the number of POs N per PF s and the total number of subgroups N sgBased on at least one of them, the identifier of the subgroup (hereinafter referred to as "subgroup ID") may be determined. For example, the terminal 10 may determine the subgroup ID according to the following formula 2. (Formula 2) Subgroup ID = floor (UE ID / (N*N s ) mod N sg Here, UE_ID = 5G-S-TMSI mod 1024

[0044] On the other hand, in network-based subgrouping, subgrouping is performed on the network side (for example, the base station 20 or the CN 30). The network-side device may determine the subgroup to be assigned to the terminal 10 based on the information managed on the network side (for example, the mobility state of the terminal 10, the paging probability, and / or the power consumption profile of the terminal 10, etc.). The network-side device notifies the terminal 10 of the information indicating the determined subgroup (for example, the subgroup ID).

[0045] (PEI) When performing the above subgrouping, instructing the terminal 10 in advance of the subgroup to be paged during the paging period (hereinafter referred to as "Paging early indication (PEI)") can contribute to reducing unnecessary power consumption. Specifically, based on the PEI, the terminal 10 can reduce the power consumption by skipping PDCCH monitoring and / or receiving and / or decoding paging messages during the paging period when the subgroup to which it belongs is not the paging target.

[0046] For the PEI, a DCI-based, SSS-based, or Tracking Reference Signal (TRS)-based approach, etc., is under consideration. Hereinafter, in this embodiment, an explanation will be given assuming a DCI-based PEI, but it can also be appropriately applied to an SSS-based or TRS-based PEI. Note that the TRS may also be referred to as a Non-zero power channel state information reference signal (NZP-CSI-RS).

[0047] FIGS. 3(A) and (B) are diagrams showing an example of the PEI according to this embodiment. For example, as shown in FIGS. 3(A) and (B), a PDCCH monitoring opportunity for the PEI (hereinafter referred to as a "PEI monitoring opportunity") may be determined based on the time position of an SS burst, an SS burst set, and / or a PO. The terminal 10 may detect SSBs within one or more SS bursts and perform time and frequency synchronization for the PO. For example, the period of the SS burst set may be 0.5 ms (e.g., 0.5 radio frames (also referred to as a half frame)). That is, the SSB and the SS burst may be included within a period of 0.5 ms. For example, the base station 20 may transmit information (e.g., the RRC IE "ssb-periodicityServingCell") for setting the period of a half frame for the reception of the SSB (i.e., the period of the SS burst set) to the terminal 10.

[0048] Also, for a half frame including an SSB, the index of the first symbol for an SSB candidate may be determined based on the subcarrier spacing (SCS) of the SSB. For example, for each of the cases where the subcarrier spacing of the SSB is 15 kHz, 30 kHz, 120 kHz, and 240 kHz, the position in the time domain (e.g., the position of an OFDM symbol) for an SSB candidate may be defined. Here, the base station 20 may transmit information (e.g., RRC IE "ssbSubcarrierSpacing") used to set the subcarrier spacing of the SSB to the terminal 10. Also, the base station 20 may transmit information (e.g., RRC IE "ssb-PositionsInBurst") used to set the position in the time domain where the SSB is actually transmitted among SSB candidates to the terminal 10.

[0049] For example, in FIG. 3(A), each PEI monitoring opportunity may be configured based on a time offset for each SS burst or each set of SS bursts. Note that in FIG. 3(A), the time offset is given from the end of each SS burst, but the time offset from the beginning of each SS burst or each set of SS bursts may be given. The terminal 10 does not necessarily need to set a PEI monitoring opportunity for each SS burst or each set of SS bursts, and it is sufficient if a PEI monitoring opportunity is set in at least one SS burst or one set of SS bursts detected by the terminal 10. For example, in FIG. 3(A), one or more PEIs (here, 3 PEIs) correspond to one PO, but it is not limited thereto. That is, for example, the base station 20 sets a time offset by RRC parameters, and the terminal 10 may monitor a PDCCH for a DCI format including a PEI at a monitoring opportunity determined based on the set time offset.

[0050] For example, the period of the time offset from the SS burst or the SS burst set may be determined based on the subcarrier spacing of the SSB. For example, when the subcarrier spacing of the SSB is set to 15 kHz and the time offset is set to 1 ms, the terminal 10 may start monitoring the PDCCH for the DCI format including the PEI at the symbol 10 slots after the SS burst or the SS burst set. Also, when the subcarrier spacing of the SSB is set to 30 kHz and the time offset is set to 1 ms, the terminal 10 may start monitoring the PDCCH for the DCI format including the PEI at the symbol 20 slots after the SS burst or the SS burst set.

[0051] Further, for example, the period of the time offset from the SS burst or the SS burst set may be determined based on the subcarrier spacing of the initial downlink BWP. For example, when the subcarrier spacing of the initial downlink BWP is set to 15 kHz and the time offset is set to 1 ms, the terminal 10 may start monitoring the PDCCH for the DCI format including the PEI at the symbol 10 slots after the SS burst or the SS burst set. Also, when the subcarrier spacing of the initial downlink BWP is set to 30 kHz and the time offset is set to 1 ms, the terminal 10 may start monitoring the PDCCH for the DCI format including the PEI at the symbol 20 slots after the SS burst or the SS burst set.

[0052] On the other hand, in FIG. 3(B), each PEI monitoring opportunity is provided at a time position with a predetermined gap with respect to a specific PO at a predetermined period T2. As shown in FIG. 3(B), one PEI may correspond to one or more POs (here, 2POs). Note that FIGS. 3(A) and (B) are merely examples, and the PEI monitoring opportunity is not limited to what is shown in the figures. For example, a monitoring window including a plurality of PEI monitoring opportunities may be provided. That is, the base station 20 may set a monitoring window (monitoring period) in which the terminal 10 executes monitoring of the PDCCH for the DCI format including the PEI.

[0053] The PEI monitored at the PEI monitoring opportunity as described above only needs to be included in a predetermined DCI format. For example, the PEI may be included in an existing DCI format (e.g., DCI format 1_0), or may be included in a newly defined DCI format. Further, the DCI format including the PEI is CRC scrambled by a specific RNTI (e.g., P-RNTI). Note that the PEI is not limited to being included in the DCI format, and the DCI format itself may be called the PEI.

[0054] Also, the search space set for monitoring the PDCCH (i.e., PDCCH candidate) for the DCI format including the PEI may be the search space used for monitoring the paging DCI (e.g., Type0-PDCCH CSS set, or Type2-PDCCH CSS set), or may be a newly set search space for PDCCH monitoring for the DCI format including the PEI. As described above, the Type0-PDCCH CSS set may be set using the information included in the MIB. Also, the Type2-PDCCH CSS set and the newly set search space may be set using the information included in the system information (e.g., SIB1). That is, the newly set search space may be a CSS set.

[0055] For example, when the base station 20 sets a search space used for monitoring a PDCCH for a DCI format including a PEI by using information included in system information (e.g., SIB1), information for setting an index of a CORESET and / or information for setting an index of a search space may be included in the system information (e.g., SIB1) and transmitted.

[0056] Here, when the CORESET #0 and / or the search space #0 is set by the base station 20, the terminal 10 may monitor a PDCCH for a DCI format including a PEI in a Type0-PDCCH CSS set. That is, when the index #0 is set for the CORESET by using the information for setting the index of the CORESET included in the system information, the terminal 10 may monitor a PDCCH for a DCI format including a PEI in a PDCCH monitoring opportunity corresponding to the Type0-PDCCH CSS set. Also, when the index #0 is set for the search space by using the information for setting the index of the search space included in the system information, the terminal 10 may monitor a PDCCH for a DCI format including a PEI in a PDCCH monitoring opportunity corresponding to the Type0-PDCCH CSS set. That is, when the CORESET #0 and / or the search space #0 is set by using the system information, the terminal 10 may monitor a PDCCH for a DCI format including a PEI in a PDCCH monitoring opportunity (i.e., a PDCCH monitoring opportunity corresponding to the CORESET #0 and / or the search space #0) set by using the information included in the MIB.

[0057] Here, when an index other than #0 is set for the CORESET by using the information for setting the index of the CORESET included in the system information, the terminal 10 may monitor the PDCCH for the DCI format including the PEI in the CORESET with the set index. Further, when an index other than #0 is set for the search space by using the information for setting the index of the search space included in the system information, the terminal 10 may monitor the PDCCH for the DCI format including the PEI in the search space with the set index. That is, when the CORESET #x (for example, x = 1, 2, …) and / or the search space #x (for example, x = 1, 2, …) is set by using the system information, the terminal 10 may monitor the PDCCH for the DCI format including the PEI in the PDCCH monitoring opportunity corresponding to the CORESET #x (for example, x = 1, 2, …) and / or the search space #x (for example, x = 1, 2, …).

[0058] Here, in relation to the PEI, the first operation and / or the second operation may be defined. For example, in the first operation, the PEI may indicate that the terminal 10 executes monitoring during a paging period (i.e., PF and / or PO) when the subgroup corresponding to the terminal 10 is the target of paging. That is, in the first operation, the PEI may indicate that the subgroup corresponding to the terminal 10 is being paged. For example, when the subgroup corresponding to the terminal 10 (to which the terminal 10 belongs) is paged, the PEI is transmitted, and when the subgroup is not paged, the PEI may not be transmitted. Also, in the first operation, the PEI may indicate that the terminal 10 executes monitoring during the paging period when the subgroup corresponding to the terminal 10 is being paged. That is, in the first operation, if the terminal 10 does not detect the PEI in a PEI monitoring opportunity corresponding to a certain paging period (for example, all PEI monitoring opportunities corresponding to a certain paging period), the terminal 10 may not execute the monitoring during the certain paging period (the terminal 10 may not be required to execute the monitoring during the certain paging period).

[0059] Also, in the second operation, the PEI may indicate whether the terminal 10 executes monitoring during a paging period (i.e., PF and / or PO). That is, in the second operation, the PEI may indicate whether the subgroup corresponding to the terminal 10 is being paged. In this case, regardless of whether the subgroup corresponding to the terminal 10 (to which the terminal 10 belongs) is paged, the PEI is transmitted. The PEI may be, for example, a bitmap (e.g., FIG. 4 or 6) described later, or a code point (e.g., FIG. 5 or 7) described later. That is, in the second operation, if the terminal 10 does not detect the PEI in a PEI monitoring opportunity corresponding to a certain paging period (for example, all PEI monitoring opportunities corresponding to a certain paging period), the terminal 10 may execute the monitoring during the certain paging period (the terminal 10 may be required to execute the monitoring during the certain paging period).

[0060] Here, in the first operation and the second operation, to perform monitoring during a certain paging period may include monitoring a PDCCH for a DCI format (for example, DCI format 1_0 with CRC parity bits scrambled by P-RNTI) scrambled by a specific RNTI (for example, P-RNTI) during the certain paging period. Also, to perform monitoring during a certain paging period may include decoding a PDSCH scheduled using a DCI format scrambled by the specific RNTI (for example, receiving a paging message) during the certain paging period.

[0061] Also, in the first operation and the second operation, not performing (or skipping) monitoring during a certain paging period may include not monitoring the PDCCH for the DCI format scrambled by the specific RNTI during the certain paging period. Also, in the first operation and the second operation, not performing monitoring during a certain paging period may include not decoding (e.g., receiving a paging message) the PDSCH scheduled using the DCI format scrambled by the specific RNTI during the certain paging period. That is, in the first operation and the second operation, not performing (or skipping) monitoring during a certain paging period may include monitoring the PDCCH for the DCI format scrambled by the specific RNTI and not decoding the PDSCH scheduled using the DCI format during the certain paging period (e.g., only performing decoding of the short message included in the DCI format and not performing decoding of the PDSCH may be included). Note that, in the first operation and the second operation, not performing (or skipping) monitoring during a certain paging period may include not performing both the monitoring of the PDCCH and the decoding of the PDSCH during the certain paging period.

[0062] In this embodiment, the name "PEI" is merely an example, and any name may be used as long as the information has a function similar to the function described in this embodiment.

[0063] By the way, as described above, in PDCCH monitoring, the terminal 10 detects DCI for the terminal 10 based on the number of bits of the DCI format to be monitored and the RNTI used for CRC scrambling of the DCI format. Therefore, in order for the terminal 10 to detect the PEI in the PEI monitoring opportunity, it is necessary to grasp the number of bits of the PEI in advance. If the terminal 10 cannot grasp the number of bits of the PEI in advance, there is a risk that the monitoring of the PEI cannot be appropriately controlled.

[0064] When performing the above subgrouping, the total number N of subgroups sg is also considered to be determined for each predetermined unit (cell C, RNA area, or tracking area). In this case, the number of bits of the PEI can vary according to the total number N of subgroups sg Therefore, in this embodiment, the terminal 10 appropriately controls the monitoring in the PEI monitoring opportunity by determining the number of bits of the PEI based on the total number N of subgroups sg

[0065] Hereinafter, in this embodiment, the monitoring control (first aspect) of the PEI indicating the paging target subgroup in one paging period and the monitoring control (second aspect) of the PEI indicating the paging target subgroups in each of a plurality of paging periods will be described. Note that the monitoring of the PEI may be rephrased as the monitoring of DCI (or DCI format) including the PEI.

[0066] Note that hereinafter, each paging period used in the first and second aspects is, for example, a PO, but is not limited thereto.

[0067] Also, in the first aspect, although one PEI monitoring opportunity is provided for each PO, it is not limited thereto, and a plurality of PEI monitoring opportunities may be provided for each PO.

[0068] ​Also, although a plurality of POs used in the second aspect are to be associated with one PF, it is not limited thereto. In the second aspect, although one PEI monitoring opportunity is provided for each PF, it is not limited thereto, and a plurality of PEI monitoring opportunities may be provided for each PF. Further, a PEI corresponding to a plurality of POs respectively associated with a plurality of PFs may be used.

[0069] (First aspect) In the first aspect, the terminal 10 receives a DCI including a field indicating a paging target subgroup in the PO (hereinafter referred to as “subgroup indication field”). Note that the PEI may correspond to the subgroup indication field or may correspond to the DCI including the subgroup indication field. Here, the terminal 10 receives, for each PO, a DCI including the subgroup indication field as the PEI, and controls the execution of monitoring in the PO based on the value of the subgroup indication field. Hereinafter, mainly, controlling the monitoring of the paging DCI in the PO based on the value of the subgroup indication field (that is, the value of the PEI) will be described, but the operations related to the PEI may be the first operation and / or the second operation described above.

[0070] Further, the terminal 10 receives information regarding the total number N sg of subgroups (hereinafter referred to as “total number of subgroups information”). The total number N sg of subgroups may be, for example, the total number of subgroups to which a plurality of terminals 10 to which PFs of the same SFN are determined based on the above terminal identifier (for example, 5G-S-TMSI) respectively belong. The total number of subgroups information may indicate, for example, any one of 2 to 16 as the total number N sg of subgroups.

[0071] Specifically, the terminal 10 may receive the total number of subgroup information by signaling of a higher layer (for example, a Non-Access Stratum (NAS) layer, a Radio Resource Control (RRC) layer, etc.) (hereinafter referred to as "higher layer signaling"). The total number of subgroup information is included in the system information (for example, System Information Block (SIB) 1) broadcast from the base station 20, and may be called "nrofPagingSubGroup" or the like.

[0072] Based on the total number of subgroup information, the terminal 10 determines the number of bits of the subgroup indication field as the PEI (that is, the field of the PEI). That is, the terminal 10 may determine the number of bits of the DCI format including the PEI based on the number of bits. The terminal 10 blindly decodes the PDCCH candidates in the search space at the PEI monitoring opportunity based on the number of bits of the DCI format to detect the PEI. That is, the terminal 10 may determine the number of bits of the subgroup indication field (that is, the field of the PEI) in the DCI format based on the total number of subgroup information notified by the base station 20.

[0073] For example, the subgroup indication field as the PEI may be composed of a bitmap with the same number of bits as the total number of subgroups indicated by the total number of subgroup information, or may be composed of code points with the number of bits determined based on the total number of subgroups N sg and may be composed of code points with the number of bits determined based on the total number of subgroups N sg . That is, the code point may correspond to the PEI (the field of the PEI).

[0074] <Bitmap> FIG. 4 is a diagram showing an example of the PEI according to the first aspect of the present embodiment. In FIG. 4, for example, the above-mentioned total number of subgroups N sgis 16, and it is assumed that the terminal 10 belongs to subgroup #1 among subgroups #0 to #15. Note that the subgroup #1 to which the terminal 10 belongs may be derived by the terminal 10 itself based on the terminal identifier (for example, 5G-S-TMSI) assigned to the terminal 10, or may be notified to the terminal 10 from the network side.

[0075] In FIG. 4, each subgroup indication field as a PEI is composed of a bitmap with the number of bits equal to the total number of subgroups N sg = 16. The 16 bits in the bitmap respectively correspond to subgroups #0 to #15. For example, in FIG. 4, the most significant bit (MSB) (also referred to as the leftmost bit) corresponds to subgroup #0, the second bit from the left corresponds to subgroup #1, and the 3rd to 16th bits correspond to subgroups #2 to #15.

[0076] For example, in FIG. 4, it is shown by the subgroup indication field in the PEI corresponding to each of PO#0 to #2 that the paging targets of PO#0 are subgroups #0 and #1, the paging targets of PO#1 are subgroups #2 and #3, and the paging targets of PO#2 are subgroups #4 and #5. As described above, since the terminal 10 belongs to subgroup #1, the terminal 10 monitors the paging DCI in PO#0 in which subgroup #1 is included in the paging target, but may skip monitoring the paging DCI in PO#1 and #2 in which subgroup #1 is not included in the paging target. Also, for example, the terminal 10 belonging to subgroup #1 may execute decoding of PDSCH in PO#0 and may not execute decoding of PDSCH in PO#1 and #2.

[0077] As shown in FIG. 4, the subgroup indication field as a PEI is the total number of subgroups N sgWhen it is configured with a bitmap having the same number of bits, even when one or more subgroups within one PO are to be paged, the subgroup to be paged can be easily specified.

[0078] <Code point> FIG. 5 is a diagram showing another example of the PEI according to the first aspect of the present embodiment. In FIG. 5, the description will be centered on the differences from FIG. 4. In FIG. 5, the subgroup indication field as each PEI is composed of code points having the number of bits determined based on the total number of subgroups N sg = 16. One or more subgroups associated with each code point (i.e., each of the values set in the field of the PEI) may be determined in advance in the specification or may be notified to the terminal 10 by upper layer signaling. For example, in FIG. 5, the code point "0000" indicates subgroup #0, "0001" indicates subgroup #1, and "0010" to "1111" indicate subgroups #2 to #15. For example, the base station 20 may include the correspondence between each code point (i.e., each of the values set in the field of the PEI) and one or more subgroups in the system information (e.g., SIB1) and notify it. That is, the terminal 10 may identify one or more subgroups based on the correspondence and the value set in the field of the PEI.

[0079] Note that in FIG. 5, each code point indicates one subgroup, but each code point may indicate one or more subgroups determined in advance or notified by upper layer signaling. Thus, when the subgroup indication field is configured as a code point indicating one or more subgroups, the number of bits of the subgroup indication field may be indicated, for example, by ceil(log2(N sg ))). In FIG. 5, since N sg = 16, the subgroup indication field is 4 bits.

[0080] For example, in FIG. 5, it is indicated by the subgroup indication fields within the 3PEIs of each of PO#0 to #2 that the paging target of PO#0 is subgroup #0, the paging target of PO#1 is subgroup #1, and the paging target of PO#2 is subgroup #2. As described above, since the terminal 10 belongs to subgroup #1, the terminal 10 monitors the paging DCI in PO#1 in which subgroup #1 is included in the paging target, but may skip monitoring the paging DCI in PO#0 and #2 in which subgroup #1 is not included in the paging target. Also, for example, the terminal 10 belonging to subgroup #1 may execute decoding of the PDSCH in PO#1 and may not execute decoding of the PDSCH in PO#0 and #2.

[0081] As shown in FIG. 5, when the subgroup indication field as the PEI is composed of code points indicating one or more subgroups, compared with the case of the bitmap shown in FIG. 4, the number of bits of the subgroup indication field can be reduced, and the overhead due to the PEI can be reduced.

[0082] Note that in FIGS. 4 and 5, a PEI monitoring opportunity is provided before each PO, but a PEI monitoring opportunity may be provided within the PO. For example, a PEI monitoring opportunity is provided in a slot or symbol before the PDCCH monitoring opportunity within the PO, and monitoring of the paging DCI in the PDCCH monitoring opportunity within the PO may be controlled as described above based on the PEI detected within the PO. Thus, FIGS. 4 and 5 are merely illustrative and not limited to what is shown.

[0083] In the first aspect, since the number of bits of the subgroup indication field is appropriately determined based on the total number N of subgroups sg monitoring in the PEI monitoring opportunity can be appropriately performed. Also, since the subgroup serving as the paging target in each PO can be specified using the DCI-based PEI for each PO, the subgroup to be paged can be dynamically controlled for each PO.

[0084] Here, the base station 20 may set whether to operate in the first operation or the second operation with respect to the terminal 10. For example, the base station 20 may include information (hereinafter also referred to as "monitoring operation instruction") for setting whether the terminal 10 operates in the first operation or the second operation in system information (for example, SIB1) and notify it. For example, the monitoring operation instruction may be commonly set for one or more terminals 10. Also, for example, the monitoring operation instruction may be set for a group of terminals 10 that monitor a DCI format (the same DCI format) including the PEI.

[0085] That is, when the terminal 10 instructed to execute the first operation does not detect the PEI in a PEI monitoring opportunity corresponding to a certain paging period (for example, all PEI monitoring opportunities corresponding to a certain paging period), it may not execute the monitoring in the certain paging period. Also, when the terminal 10 set to execute the second operation does not detect the PEI in a PEI monitoring opportunity corresponding to a certain paging period (for example, all PEI monitoring opportunities corresponding to a certain paging period), it may execute the monitoring in the certain paging period.

[0086] Also, the base station 20 may include the monitoring operation instruction in a DCI format (for example, DCI format 1_0 scrambled by P-RNTI with CRC) and transmit it. Here, the base station 20 may include the monitoring operation instruction in a short message and transmit it. For example, a 1-bit information field may be defined as a field for instructing the monitoring operation and transmitted together with the PEI field (for example, subgroup indication field).

[0087] Also, an instruction for the monitoring operation may be defined and included in a field of the PEI (for example, a subgroup instruction field). For example, the base station 20 may use a value set in a field of the PEI (for example, a value set in the subgroup instruction field) to instruct one or more subgroups and / or monitoring operations. Further, the base station 20 may include the correspondence between each code point (i.e., each of the values set in the field of the PEI) and one or more subgroups and / or monitoring operations in system information (for example, SIB1) and notify it. That is, the terminal 10 may identify one or more subgroups and / or monitoring operations based on the correspondence and the value set in the field of the PEI.

[0088] For example, based on an instruction for a monitoring operation associated with a certain paging period (i.e., PF and / or PO) in a certain DRX cycle (for example, the nth DRX cycle), the terminal 10 may determine an operation (the first operation or the second operation) in a corresponding paging period (i.e., the PF and / or PO in the (n + 1)th DRX cycle that is the same as the PF and / or PO in the nth DRX cycle) in the next DRX cycle (for example, the (n + 1)th DRX cycle).

[0089] Here, as a default operation in the terminal 10, the first operation or the second operation may be defined. For example, when only the total number N sg of subgroups is notified by the base station 20 (i.e., the total number N sgIf only [the relevant condition] is set and no monitoring operation is instructed, the terminal 10 may execute the first operation or the second operation. For example, as a default operation, by the terminal 10 executing the first operation, when the terminal 10 does not detect the PEI, it is possible to stipulate not to execute the monitor during a certain paging period, and the power consumption in the terminal 10 can be reduced. Also, as a default operation, by the terminal 10 executing the second operation, when the terminal 10 does not detect the PEI, it is possible to stipulate to execute the monitor during a certain paging period, and the paging DCI and / or PDSCH can be surely detected and / or received.

[0090] (Second aspect) The terminal 10 receives a DCI including a PEI corresponding to a plurality of POs, that is, a DCI including a field (hereinafter referred to as "PO / subgroup indication field") indicating a paging target subgroup for each of the plurality of POs. The terminal 10 receives the DCI and controls the execution of monitoring in the plurality of POs based on the value of the PO / subgroup indication field as the PEI. Hereinafter, it is assumed that the plurality of POs are a plurality of POs associated with the same PF, but it is not limited thereto. Also, hereinafter, mainly, it will be described that the monitoring of the paging DCI in the PO is controlled based on the value of the PO / subgroup indication field (that is, the value of the PEI), but the operation related to the PEI may be the first operation and / or the second operation described above. The second aspect will be mainly described centering on the differences from the first aspect.

[0091] In addition to the above subgroup total number information, the terminal 10 may receive information (hereinafter referred to as "PO number information") regarding the number N s of the above plurality of POs (for example, the number of POs associated with the same PF). The terminal 10 may receive the subgroup total number information and the PO number information by upper layer signaling. The subgroup total number information and / or the PO number information may be included in system information (for example, SIB1) notified from the base station 20.

[0092] Based on the total number of subgroup information and the number of POs information, the terminal 10 determines the number of bits of the PO / subgroup indication field as the PEI. The terminal 10 controls the monitoring of the PEI based on the number of bits.

[0093] The PO / subgroup indication field may be composed of a bitmap with the number of bits equal to the multiplication value of the total number of subgroups N indicated by the total number of subgroup information sg and the number of POs N indicated by the number of POs information. s

[0094] Alternatively, the PO / subgroup indication field may include a subgroup indication field (also referred to as the first field) with the number of bits determined based on the total number of subgroups N sg and a field with the number of bits determined based on the number of POs (hereinafter referred to as the "PO indication field", also referred to as the second field).

[0095] Alternatively, the PO / subgroup indication field may be a single field indicating which subgroup is the paging target in which PO among a plurality of POs. The number of bits of the PO / subgroup indication field is determined based on the total number of subgroups N sg and the number of POs N s and may be equal to, for example, the total number of bits of the above subgroup indication field and PO indication field.

[0096] <bitmap> FIG. 6 is a diagram showing an example of the PEI according to the second aspect of the present embodiment. In FIG. 6, for example, four POs #0 to #3 are associated with one PF, and the number of POs N s is 4. Also, the total number of subgroups N sg is 16, and it is assumed that the terminal 10 belongs to subgroup #1 among subgroups #0 to #15. Note that in FIG. 6, the description will be centered on the differences from FIG. 4.

[0097] ​In FIG. 6, the PO / subgroup indication field as the PEI is a bitmap with a number of bits equal to the product of the total number of subgroups N sg = 16 and the number of POs N s = 4, i.e., 64 bits. The 64 bits in the bitmap correspond to subgroups #0 to #15 of PO #0, subgroups #0 to #15 of PO #1, subgroups #0 to #15 of PO #2, and subgroups #0 to #15 of PO #3. Thus, the corresponding bit in the bitmap may be determined with the index of the PO first and the index of the subgroup second.

[0098] For example, in FIG. 6, it is indicated by a single PO / subgroup indication field that the paging target of PO #0 is subgroups #0 to #3, the paging target of PO #1 is subgroups #4 to #7, the paging target of PO #2 is subgroups #8 to #11, and the paging target of PO #3 is subgroups #12 to #15. As described above, since the terminal 10 belongs to subgroup #1, the terminal 10 monitors the paging DCI in PO #0 in which subgroup #1 is included in the paging target, but may skip monitoring the paging DCI in POs #1 to #3 in which subgroup #1 is not included in the paging target. Also, for example, the terminal 10 belonging to subgroup #1 may execute decoding of the PDSCH in PO #0 and not execute decoding of the PDSCH in POs #1 to #3.

[0099] As shown in FIG. 6, when the PO / subgroup indication field as the PEI is configured as a bitmap with a number of bits equal to the product of the total number of subgroups N sg and the number of POs N s , when one or more subgroups are paging targets for each of a plurality of POs, the paging target subgroups can be easily specified.

[0100] <Code Point> FIG. 7 is a diagram showing another example of the PEI according to the second aspect of the present embodiment. In FIG. 7, the description will focus on the differences from FIGS. 5 or 6. In FIG. 7, as the PEI, instead of the PO / subgroup indication field, a subgroup indication field and a PO indication field may be included. The subgroup indication field is as described in FIG. 5. The PO indication field is composed of code points of 2 bits in number determined based on the number of POs N s =4. The POs associated with each code point may be determined in advance in the specification or may be notified to the terminal 10 by upper layer signaling. For example, in FIG. 7, the code point "00" indicates PO#0, and "01", "10", and "11" indicate PO#1, #2, and #3.

[0101] Note that in FIG. 7, each code point of the PO indication field indicates one PO, but each code point may indicate one or more POs determined in advance or notified by upper layer signaling. Thus, when the PO indication field is configured as a code point indicating one or more POs, the number of bits of the PO indication field may be, for example, ceil(log2(number of POs N s ))).

[0102] The PO indication field and the subgroup indication field may be defined as separate fields in the PEI, or may be defined as a single PO / subgroup indication field in which the PO indication field and the subgroup indication field are concatenated. For example, for the 6-bit bit value shown in FIG. 7, it is assumed that the leftmost 2 bits indicate the value of the PO indication field and the remaining 4 bits indicate the value of the subgroup indication field. Also, in FIG. 7, tables for the PO indication field and the subgroup indication field are provided respectively, but a single table for the PO / subgroup indication field may be provided. In the single table, for example, a 6-bit code point may be associated with information indicating which subgroup of which PO is the paging target.

[0103] For example, in FIG. 7, in each of the sub-groups #0 to #15 of PO#0 to #3, only the sub-group #1 of PO#1 is the paging target, which is indicated by a 6-bit PO / sub-group indication field (i.e., the value of PEI) in a single DCI format. As described above, since the terminal 10 belongs to the sub-group #1, the terminal 10 monitors the paging DCI in PO#1 where the sub-group #1 is included in the paging target, but may skip monitoring the paging DCI in PO#0, #2, and #3 where the sub-group #1 is not included in the paging target.

[0104] As shown in FIG. 7, when the PO / sub-group indication field as the PEI is composed of code points, compared with the case of the bitmap shown in FIG. 6, the number of bits of the PO / sub-group indication field can be reduced, and the overhead due to the PEI can be reduced.

[0105] Note that in FIGS. 6 and 7, a PEI monitoring opportunity is provided before the first PO#0 among the plurality of PO#0 to #3 associated with the same PF, but a PEI monitoring opportunity may be provided in at least one of the plurality of POs. For example, a PEI monitoring opportunity is provided in a slot or symbol before the PDCCH monitoring opportunity in the first PO#0, and the monitoring of the paging DCI in the PDCCH monitoring opportunity in the PO#0 to #3 is controlled as described above based on each PEI detected in the PO#0. Also, in FIGS. 6 and 7, the PO#0 to #3 associated with the same PF are arranged at equal intervals, but this is not limiting, and at least two POs may be temporally continuous. Thus, FIGS. 6 and 7 are merely illustrative and not limited to what is shown. Also, although not shown, a DCI format including a plurality of sub-group indication fields corresponding to the plurality of POs as the PEI may be used. For example, in FIG. 7, 16 bits are prepared as the PEI corresponding to PO#0 to #3, and the paging target sub-groups of PO#0 to #3 may be specified by the four sub-group indication fields as the PEI.

[0106] In the second aspect, the total number of subgroups N sg and the number of POs N s Based on this, the number of bits of the PO / subgroup indication field (or the PO indication field and the subgroup indication field) is appropriately determined, so that monitoring in the PEI monitoring opportunity can be appropriately performed. Also, since a DCI-based PEI corresponding to a plurality of POs can be used to specify the paging target subgroups in the plurality of POs, the PEI monitoring opportunity of the terminal 10 can be reduced compared to the first aspect.

[0107] (Third aspect) Next, as the third aspect of the present embodiment, the terminal operation in the PO will be described. In the above first and second aspects, a DCI-based PEI is assumed, but here, the PEI may be information or a signal indicating the paging target subgroup in the PO, and is not limited to the DCI-based, and is also applicable to the SSS-based, TRS-based, etc.

[0108] As described with reference to FIGS. 4 to 7, when the subgroup indicated by the PEI includes the subgroup assigned to the terminal 10, the terminal 10 monitors the paging DCI in the PO, and receives the paging message via the PDSCH scheduled using the paging DCI. On the other hand, when the subgroup indicated by the PEI does not include the subgroup assigned to the terminal 10, the terminal 10 may skip monitoring the paging DCI in the PO. By this skip, wasteful power consumption in the PO that is not a paging target can be prevented.

[0109] Incidentally, the paging DCI can be used not only for scheduling the PDSCH that transmits the paging message, but also for transmitting short messages. The short message is used, for example, for at least one of notification of update of system information (for example, BCCH other than SIB6, SIB7, and SIB8), ETWS primary notification, ETWS secondary notification, and CMAS notification.

[0110] FIGS. 8(A) to 8(C) are diagrams showing an example of the paging DCI according to the present embodiment. In FIG. 8, DCI format 1_0 scrambled by P-RNTI is assumed as the paging DCI, but it is not limited thereto. As shown in FIGS. 8(A) to 8(C), the paging DCI includes a Short Message indicator.

[0111] As shown in FIG. 8(A), the short message identifier "10" may indicate that only the short message exists in the paging DCI. As shown in FIG. 8(B), the short message identifier "01" may indicate that scheduling information (for example, allocation information of frequency domain resources and time domain resources, etc.) for the paging message exists in the paging DCI but the short message does not exist. As shown in FIG. 8(C), the short message identifier "11" may indicate that both the above scheduling information and the short message exist in the paging DCI.

[0112] For example, the value "1" of the MSB of the short message in the paging DCI in FIGS. 8(A) and (C) may indicate the update notification of the above system information. Also, the value "1" of the second bit from the left of the short message may indicate that it is at least one of an ETWS initial notification, an ETWS secondary notification, and a CMAS notification. Hereinafter, when distinguishing between the paging DCI shown in FIG. 8(A) and the paging DCI including the paging scheduling information shown in FIGS. 8(B) and (C), they are also referred to as "DCI for short message" and "DCI for paging scheduling".

[0113] As described above, by skipping the monitoring of the paging DCI in a PO where the subgroup to which the terminal itself belongs is not a paging target, the power consumption of the terminal 10 can be saved. On the other hand, also in the said PO, the DCI for short message (for example, FIG. 8(A)) for the terminal 10 is transmitted. For this reason, if the terminal 10 skips the monitoring of the paging DCI in the said PO in order to save power consumption, it may not be able to receive the DCI for short message and may not be able to detect at least one of the update notification of system information, ETWS, and CMAS.

[0114] Therefore, the terminal 10 may continue to monitor the paging DCI shown in FIGS. 8(A) to (C) in each PO regardless of the subgroup indicated by the PEI (that is, whether or not the subgroup to which the terminal itself belongs is a paging target).

[0115] Specifically, when the subgroup indicated by the PEI does not include the subgroup assigned to the terminal 10, or when the PEI is not received, the terminal 10 does not perform (skips) the reception and / or decoding of the PDSCH in the PO (hereinafter referred to as "reception / decoding"). In this case, the terminal 10 receives / decodes the short message included in the DCI for short message (for example, FIG. 8(A)) detected by PDCCH monitoring in the PO without performing the reception / decoding of the PDSCH.

[0116] Also, when the subgroup indicated by the PEI does not include the subgroup assigned to the terminal 10, or when the PEI is not received, even if the terminal 10 detects the DCI for paging scheduling (e.g., FIGS. 8(B) or (C)) based on PDCCH monitoring in the PO, it may not perform the reception / decoding of the PDSCH. That is, when the terminal 10 detects the DCI for paging scheduling based on PDCCH monitoring in the PO, it may only perform the reception / decoding of the short message and not perform the reception / decoding of the PDSCH. That is, when the terminal 10 detects the DCI for paging scheduling based on PDCCH monitoring in the PO, it may ignore (skip) the scheduling information (i.e., the scheduling information for paging) included in the DCI for paging scheduling. That is, when the terminal 10 detects the DCI for paging scheduling, it may only perform the reception / decoding of the short message in the DCI for paging scheduling.

[0117] As described above, in subgrouping, a plurality of terminals are divided into subgroups, and paging is performed on a subgroup basis. Here, the plurality of terminals may include terminals that do not support the PEI (e.g., terminals corresponding to releases prior to Release 17 of NR, terminals without the capabilities corresponding to the PEI, etc.). Then, the base station 20 transmits, in a certain PO, the DCI for paging scheduling including the scheduling information for terminals that do not support the PEI, and performs the scheduling of the PDSCH. On the other hand, in the certain PO, the terminal 10 that supports the PEI detects the DCI for paging scheduling including the scheduling information transmitted for terminals that do not support the PEI. That is, the scheduling information included in the DCI for paging scheduling transmitted in the certain PO is for terminals that do not support the PEI, and the terminal 10 that supports the PEI (i.e., the terminal 10) may ignore the scheduling information.

[0118] In this way, when the terminal 10 detects the paging scheduling DCI, by only performing the reception / decoding of the short message and not performing the reception / decoding of the PDSCH, it becomes possible to coexist (schedule) a terminal that does not support PEI and a terminal that supports PEI in the same PO. Also, it becomes possible to cause a terminal that does not support PEI to perform the reception / decoding of the PDSCH and to cause a terminal that supports PEI to ignore the reception / decoding of the PDSCH, thereby realizing efficient scheduling. Further, it becomes possible to cause a terminal that supports PEI to perform the reception / decoding of the short message, and to notify system information updates, ETWS, and CMAS.

[0119] On the other hand, when the subgroup indicated by the PEI includes the subgroup assigned to the terminal 10, the terminal 10 performs the reception / decoding of the PDSCH in the PO (that is, receives / decodes the paging message transmitted via the PDSCH). This is because in the PO where the subgroup to which the terminal itself belongs is the paging target, paging scheduling DCI (for example, FIG. 8(B) or (C)) is detected.

[0120] As described above, regardless of whether a paging message for the subgroup to which the terminal 10 belongs is transmitted in the PO, the terminal 10 performs PDCCH monitoring (for example, monitoring of the paging DCI shown in FIGS. 8(A) to (C)) in the PO.

[0121] Note that when the terminal 10 receives the setting information regarding the reception of PEI (for example, the above total number of subgroup information), it may monitor the PEI. When the terminal 10 does not receive the setting information, it determines that the subgrouping is not performed, does not monitor the PEI, performs PDCCH monitoring in each set PO, and may receive / decrypt the paging message based on the detected paging DCI. Also, the terminal 10 may receive the setting information by upper layer signaling.

[0122] FIG. 9 is a diagram showing an example of the operation of the terminal in the PO according to the third aspect of the present embodiment. In FIG. 9, the PEI described in the first aspect is assumed. As described above, the PEI is not limited to this. For example, in FIG. 9, it is assumed that the paging target of PO#0 is subgroup#0 and the paging target of PO#1 is subgroup#1 as indicated by the PEI. Also, it is assumed that the terminal 10 belongs to subgroup#1. In FIG. 9, the description will be centered on the differences from FIGS. 4 to 7.

[0123] As shown in FIG. 9, the terminal 10 continues PDCCH monitoring in each PO regardless of which subgroup each PO uses as the paging target. For example, even in PO#0 for which the subgroup#1 to which the terminal 10 belongs is not the paging target, the terminal 10 performs PDCCH monitoring, detects the DCI for short message (for example, FIG. 8(A)), and receives the short message. In the PO#0, since the subgroup#1 is not the paging target, the DCI for paging scheduling (for example, FIG. 8(B) or (C)) is not transmitted and not detected. Therefore, in the PO#0, the terminal 10 does not receive / decrypt the paging message.

[0124] On one hand, in PO#1 that pages the subgroup #1 to which the terminal 10 belongs, paging scheduling DCI (for example, FIGS. 8(B) or (C)) is transmitted. The terminal 10 detects the paging scheduling DCI by monitoring the PDCCH in PO#1, and receives / decodes a paging message via the PDSCH scheduled by the paging scheduling DCI.

[0125] Note that in PO#1, short message DCI for the terminal 10 (for example, FIG. 8(A)) may also be transmitted. When the terminal 10 detects the short message DCI by monitoring the PDCCH in PO#1, the terminal 10 may receive the short message included in the short message DCI.

[0126] In FIG. 9, since PDCCH monitoring continues even in a PO where the subgroup to which the terminal itself belongs is not a paging target, when paging DCI (for example, DCI format 1_0 scrambled by P-RNTI for CRC) is shared for both short message and scheduling, a short message can be received in the PO.

[0127] (Fourth aspect) Next, as the fourth aspect of the present embodiment, the operation of deriving a subgroup will be described. Note that the first to third aspects can be applied to both cases where subgrouping is performed based on a terminal identifier and a network base. Here, the operation of deriving the subgroup to which the terminal 10 belongs will be described in the case where subgrouping is performed based on a network base. Also, the PEI may be information or a signal indicating the paging target subgroup in a PO, and is not limited to the DCI base, and is also applicable to the SSS base, the TRS base, etc. Note that the fourth aspect can be combined with the first or second aspect and / or the third aspect.

[0128] Configuration of the subgroup (for example, total number of subgroups N sgetc.) are determined for each predetermined unit (e.g., cell, tracking area, or RAN area, etc.) based on various factors such as paging strategies and load conditions, and it is also assumed that the composition of the subgroup may be different between different units. For example, in cell A, the total number of subgroups N sg is 2, while in cell B, it is assumed that the total number of subgroups N sg is 4.

[0129] In this way, when the composition of the subgroup is different between different units, the subgroup assigned from the network to terminal 10 may be different between these different units. For example, in cell A where the total number of subgroups N sg is 2, terminal 10 belongs to subgroup #1, while in cell B where the total number of subgroups N sg is 4, it is assumed that terminal 10 belongs to subgroup #0. In this case, due to the movement between different units (e.g., cells A and B), there may be an inconsistency in the subgroup assigned to terminal 10.

[0130] Therefore, in the fourth PO-related operation, the CN device (e.g., the AMF) may assign a subgroup to terminal 10 for each of the plurality of total numbers of subgroups N sg and notify terminal 10 of information regarding the set of the assigned subgroups (hereinafter referred to as "subgroup set information"). Terminal 10 may receive the subgroup set information by NAS signaling, for example, in the registration procedure to the CN device. Note that the assignment of each subgroup for each total number of subgroups N sg may be performed by the RAN (e.g., base station 20), and terminal 10 may receive the subgroup set information by RRC signaling.

[0131] FIG. 10 is a diagram showing an example of subgroup set information according to the fourth aspect of the present embodiment. As shown in FIG. 10, in the subgroup set information, the total number of subgroups N sg and the total number of subgroups N sgInformation about the subgroup assigned to the terminal 10 (e.g., subgroup ID) may be associated. For example, in FIG. 10, the total number of subgroups N sg = 2, 3, 4,..., 16, the subgroup IDs assigned to the terminal 10 are shown respectively.

[0132] The CN device may determine the subgroup to which the terminal 10 belongs based on at least one of the performance of the terminal 10, the network load, the paging strategy, and the number of terminals 10 assigned to the same PF for each total number of subgroups N sg Each time, from a maximum of N sg subgroups #0 to #N sg - 1.

[0133] The terminal 10 derives the subgroup to which the terminal 10 belongs in the cell where it camps based on the above subgroup set information and the above total number of subgroup information.

[0134] FIG. 11 is a diagram showing an example of the subgroup derivation operation according to the fourth aspect of the present embodiment. In FIG. 11, it is assumed that the terminal 10 has received the subgroup set information shown in FIG. 10. Also, in FIG. 11, a PEI (e.g., FIG. 5) including a subgroup indication field composed of code points is assumed, but as described above, the PEI is not limited to this. In FIG. 11, the description will be centered on the differences from FIGS. 4 to 7.

[0135] For example, in FIG. 11, it is assumed that the terminal 10 moves from cell A to cell B. In cell A, the total number of subgroups N sg = 2, and the subgroup indication field in the PEI is 1 bit. Here, it is assumed that the subgroup indication field values "0" and "1" indicate subgroups #0 and #1 respectively. On the other hand, in cell B, the total number of subgroups N sg = 4, and the subgroup indication field in the PEI is 2 bits. Here, it is assumed that the subgroup indication field values "00", "01", "10", and "11" indicate subgroups #0, #1, #2, and #3 respectively.

[0136] In FIG. 11, for terminal 10, the total number N of subgroups of cell A sg is 2, and in FIG. 10, since subgroup #1 is associated with the total number N of subgroups sg = 2, it is determined that terminal 10 belongs to group #1 in cell A. On the other hand, for terminal 10, the total number N of subgroups of cell B Sub is 4, and in FIG. 10, since subgroup #0 is associated with the total number N of subgroups sg = 4, it is determined that terminal 10 belongs to group #0 in cell B. sg As shown in FIG. 11, when terminal 10 is camped on cell A, it is indicated by the PEI that the paging target of PO#0 is subgroup #1 and the paging target of PO#1 is subgroup #0. As described above, since terminal 10 belongs to subgroup #1 in cell A, terminal 10 may monitor the paging DCI in PO#0 while skipping the monitoring of the paging DCI in PO#1. Although not shown, it goes without saying that the short message may be continuously received by continuing to monitor the paging DCI in PO#1. Sub

[0137] Also, when terminal 10 is camped on cell B, it is indicated by the PEI that the paging target of PO#0 is subgroup #3 and the paging target of PO#1 is subgroup #0. As described above, since terminal 10 belongs to subgroup #0 in cell B, terminal 10 may skip the monitoring of the paging DCI in PO#0 while monitoring the paging DCI in PO#1. Although not shown, it goes without saying that the short message may be continuously received by continuing to monitor the paging DCI in PO#0.

[0138]

[0139] ​​FIG. 12 is a diagram showing an example of a specification change regarding the total number of subgroup information in the present embodiment. As described above, the total number of subgroup information is notified to the terminal 10 by upper layer signaling. In FIG. 12, an example in which the total number of subgroup information is included in SIB1 is shown, but it is needless to say that the present invention is not limited to this.

[0140] As shown in FIG. 12, the total number of subgroup information (for example, RRC IE "nrofPagingSubGroup") may be included in the RRC IE "DownlinkConfigCommonSIB" within the RRC IE "ServingCellConfigCommonSIB" of SIB1. The total number of subgroup information specifies the total number N of subgroups supported in cell C sg with values from 2 to 16.

[0141] For example, when the terminal 10 has the total number of subgroup information (for example, RRC IE "nrofPagingSubGroup") in SIB1 and the terminal 10 supports the paging subgroup, the total number N of subgroups indicated by the total number of subgroup information (for example, RRC IE "nrofPagingSubGroup") sg may be set as the subgroup assigned to the terminal 10 and given by the upper layer (for example, NAS defined in TS24.501).

[0142] Thereby, as shown in FIG. 11, even when the terminal 10 moves between cells with different total numbers N of subgroups sg the terminal 10 can derive the subgroup assigned to itself.

[0143] (Configuration of Radio Communication System) Next, the configuration of each device of the radio communication system 1 as described above will be described. Note that the following configuration is for showing the necessary configuration in the description of the present embodiment, and does not exclude the possibility that each device includes functional blocks other than those shown in the figure.

[0144] <Hardware Configuration> FIG. 13 is a diagram showing an example of the hardware configuration of each device in the wireless communication system according to the present embodiment. Each device (for example, terminal 10, base station 20, CN 30, etc.) in the wireless communication system 1 includes a processor 11, a storage device 12, a communication device 13 that performs wired or wireless communication, an input device that accepts various input operations, and an input / output device 14 that outputs various information.

[0145] The processor 11 is, for example, a CPU (Central Processing Unit), and controls each device in the wireless communication system 1. The processor 11 may execute various processes described in the present embodiment by reading a program from the storage device 12 and executing it. Each device in the wireless communication system 1 may be configured by one or more processors 11. Also, each of these devices may be called a computer.

[0146] The storage device 12 is composed of, for example, a memory, an HDD (Hard Disk Drive), and / or an SSD (Solid State Drive) and other storage. The storage device 12 may store various information necessary for the execution of processing by the processor 11 (for example, a program executed by the processor 11, etc.).

[0147] The communication device 13 is a device that communicates via a wired and / or wireless network, and may include, for example, a network card, a communication module, a chip, an antenna, etc. Also, the communication device 13 may include an amplifier, an RF (Radio Frequency) device that processes radio signals, and a BB (BaseBand) device that performs baseband signal processing.

[0148] The RF device generates a radio signal to be transmitted from antenna A by performing, for example, D / A conversion, modulation, frequency conversion, power amplification, etc. on the digital baseband signal received from the BB device. Also, the RF device generates a digital baseband signal by performing frequency conversion, demodulation, A / D conversion, etc. on the radio signal received from the antenna and transmits it to the BB device. The BB device performs processing to convert the digital baseband signal into a packet and processing to convert the packet into a digital baseband signal.

[0149] The input / output device 14 includes, for example, an input device such as a keyboard, a touch panel, a mouse and / or a microphone, and an output device such as a display and / or a speaker.

[0150] The hardware configuration described above is merely an example. Each device in the wireless communication system 1 may omit some of the hardware described in FIG. 13 or may include hardware not described in FIG. 13. Also, the hardware shown in FIG. 13 may be constituted by one or a plurality of chips.

[0151] <Functional block configuration> ≪Terminal≫ FIG. 14 is a diagram showing an example of the functional block configuration of the terminal according to the present embodiment. As shown in FIG. 14, the terminal 10 includes a receiving unit 101, a transmitting unit 102, and a control unit 103.

[0152] Note that all or part of the functions realized by the receiving unit 101 and the transmitting unit 102 can be realized using the communication device 13. Also, all or part of the functions realized by the receiving unit 101 and the transmitting unit 102, and the control unit 103 can be realized by the processor 11 executing a program stored in the storage device 12. Further, the program can be stored in a storage medium. The storage medium storing the program may be a non-transitory computer readable medium. The non-transitory storage medium is not particularly limited, and may be, for example, a storage medium such as a USB memory or a CD-ROM.

[0153] The receiving unit 101 receives a downlink signal. Also, the receiving unit 101 may receive information and / or data transmitted via the downlink signal. Here, "receive" may include performing reception-related processes such as at least one of reception of a radio signal, demapping, demodulation, decoding, monitoring, and measurement. The downlink signal may include, for example, at least one of PDSCH, PDCCH, downlink reference signal, synchronization signal, PBCH, etc.

[0154] The receiving unit 101 monitors PDCCH candidates in the search space and detects DCI. The receiving unit 101 may receive downlink user data and / or upper layer control information (for example, Medium Access Control Element (MAC CE), RRC message, or NAS message, etc.) via the PDSCH scheduled using the DCI.

[0155] Specifically, the receiving unit 101 may receive system information (e.g., SIB1, etc.). Further, the receiving unit 101 may receive information regarding the total number of subgroups (e.g., the above-mentioned total subgroup number information). For example, the receiving unit 101 receives the information regarding the total number of subgroups by upper layer signaling. Also, the receiving unit 101 may receive information regarding the number of multiple paging periods (e.g., the above-mentioned PO number information). For example, the receiving unit 101 receives the information regarding the number of the multiple paging periods by upper layer signaling. The upper layer signaling is, for example, NAS signaling, system information, or RRC signaling.

[0156] Further, the receiving unit 101 may receive downlink control information including a field indicating a paging target subgroup in a paging period (e.g., a subgroup indication field as a PEI) (first aspect, for example, FIGS. 4 and 5).

[0157] Also, the receiving unit 101 may receive downlink control information including a field indicating a paging target subgroup in a plurality of paging periods (e.g., a PO / subgroup indication field as a PEI, or a PO indication field and a subgroup indication field) (second aspect, for example, FIGS. 6 and 7).

[0158] The receiving unit 101 may receive downlink control information (e.g., paging DCI) monitored in a paging period, and receive a paging message via a downlink shared channel scheduled using the downlink control information.

[0159] The receiving unit 101 may receive information indicating a subgroup assigned to the terminal 10 by the network (network-based subgrouping).

[0160] The receiving unit 101 receives setting information regarding the reception of information or a signal (e.g., PEI) indicating a subgroup to be paged during a paging period. The setting information may be, for example, the total number of subgroup information described above.

[0161] The receiving unit 101 may receive information or a signal (e.g., PEI) indicating a subgroup to be paged during a paging period.

[0162] If the subgroup indicated by the information or signal (e.g., PEI) indicating the subgroup to be paged during the paging period does not include the subgroup assigned to the terminal 10, the receiving unit 101 may not perform reception and / or decoding of the downlink shared channel (e.g., FIG. 9). If the information or the signal is not received, the receiving unit may not perform reception and / or decoding of the downlink shared channel. The receiving unit 101 may receive a short message included in the downlink control information detected during the paging period without performing reception and / or decoding of the downlink shared channel.

[0163] If the subgroup indicated by the information or signal (e.g., PEI) indicating the subgroup to be paged during the paging period includes the subgroup assigned to the terminal 10, the receiving unit 101 may perform reception and / or decoding of the downlink shared channel based on the downlink control information detected during the paging period (e.g., FIG. 9).

[0164] The receiving unit 101 receives information regarding a set of sub - groups assigned to the terminal 10 in each of the total numbers of a plurality of sub - groups (e.g., the sub - group set information in FIG. 10), and information regarding the total number of sub - groups in a predetermined unit (e.g., the above - mentioned total number of sub - groups information). The predetermined unit may be, for example, the cell in which the terminal 10 camps on, the tracking area to which the terminal 10 belongs, or the RAN area to which the terminal 10 belongs. The receiving unit 101 receives the information regarding the set of sub - groups by NAS signaling, and may receive the information regarding the total number of sub - groups by the NAS signaling, system information, or RRC signaling.

[0165] The transmitting unit 102 transmits an uplink signal. Also, the transmitting unit 102 may transmit information and / or data transmitted via the uplink signal. Here, "transmit" may include performing processing related to transmission such as at least one of encoding, modulation, mapping, and transmission of a radio signal. The uplink signal may include, for example, at least one of an uplink shared channel (e.g., Physical Uplink Shared Channel: PUSCH), a random access preamble (e.g., Physical Random Access Channel: PRACH), and an uplink reference signal.

[0166] The transmitting unit 102 may transmit uplink user data and / or control information of a higher layer (e.g., MAC CE, RRC message, etc.) via a PUSCH scheduled using the DCI received by the receiving unit 101.

[0167] The control unit 103 performs various controls in the terminal 10.

[0168] For example, the control unit 103 controls the execution of the monitor during the paging period (for example, the execution of the monitor during the paging period in the first and / or second operations related to PEI) based on the value of the field in the downlink control information (first aspect). Further, the control unit 103 may determine the number of bits of the field in the downlink control information based on the information regarding the total number of subgroups. The field may be composed of a bitmap having the same number of bits as the total number of subgroups (for example, FIG. 4). The field may be composed of code points having the number of bits determined based on the total number of subgroups (for example, FIG. 5).

[0169] If the subgroup indicated by the value of the field in the downlink control information does not include the subgroup assigned to the terminal 10, the control unit 103 may skip the execution of the monitor during the paging period (for example, monitoring of paging DCI, and / or reception and / or decoding of PDSCH) (for example, FIGS. 4 and 5).

[0170] If the subgroup indicated by the value of the field in the downlink control information includes the subgroup assigned to the terminal 10, the control unit 103 may execute the monitor during the paging period (for example, monitoring of paging DCI, and / or reception and / or decoding of PDSCH) (for example, FIGS. 4 and 5).

[0171] The control unit 103 controls the execution of monitoring in a plurality of paging periods (for example, the execution of monitoring in the paging periods in the first and / or second operations related to PEI) based on the value of the field in the downlink control information (second aspect). Further, the control unit 103 may determine the number of bits of the field in the downlink control information based on the information regarding the total number of the subgroups and the information regarding the number of the plurality of periods. The field may be configured by a bitmap having the number of bits equal to the multiplication value of the total number of the subgroups and the number of the plurality of paging periods (for example, FIG. 6). The field may include a first field having the number of bits determined based on the total number of the subgroups and a second field having the number of bits determined based on the number of the plurality of periods (for example, FIG. 7). The field may be configured by concatenating a code point having the number of bits determined based on the total number of the subgroups and a code point having the number of bits determined based on the number of the plurality of periods (for example, FIG. 7).

[0172] When the subgroup included in at least one of the plurality of paging periods indicated by the value of the field in the downlink control information does not include the subgroup assigned to the terminal 10, the control unit 103 may skip the execution of the monitoring in the paging period (for example, paging DCI monitoring and / or reception and / or decoding of PDSCH) (for example, FIGS. 6 and 7).

[0173] When the subgroup included in at least one of the plurality of periods indicated by the value of the field in the downlink control information includes the subgroup assigned to the terminal, the control unit 103 may execute the monitoring (for example, monitoring of paging DCI and / or reception and / or decoding of PDSCH) in the paging period (for example, FIGS. 6 and 7).

[0174] The control unit 103 may derive a subgroup assigned to the terminal 10 based on the terminal identifier (e.g., 5G-S-TMSI) assigned to the terminal 10 and the total number of the subgroups (subgrouping based on the terminal identifier).

[0175] The control unit 103 may control reception of information or a signal (e.g., PEI) indicating a paging target subgroup during a paging period. Further, the control unit 103 may monitor downlink control information (e.g., paging DCI) in which CRC bits are scrambled by a specific RNTI during the paging period regardless of the subgroup indicated by the information or the signal (third aspect).

[0176] The control unit 103 derives a subgroup to which the terminal 10 belongs in the predetermined unit based on information regarding the set of the subgroups and information regarding the total number of the subgroups (fourth aspect).

[0177] When the receiving unit 101 receives information or a signal (e.g., PEI) indicating a paging target subgroup during a paging period, the control unit 103 may control monitoring of downlink control information (e.g., paging DCI) during the paging period based on the subgroup indicated by the information or the signal and the derived subgroup (fourth aspect). When the subgroup indicated by the information or the signal does not include the derived subgroup, the control unit 103 may skip monitoring of the downlink control information during the paging period (e.g., FIG. 11). When the subgroup indicated by the information or the signal includes the derived subgroup, the control unit 103 may perform monitoring of the downlink control information during the period (e.g., FIG. 11). The control unit 103 may perform monitoring of the downlink control information during the paging period regardless of the subgroup indicated by the information or the signal.

[0178] ≪Base Station≫ FIG. 15 is a diagram showing an example of the functional block configuration of the base station according to the present embodiment. As shown in FIG. 15, the base station 20 includes a receiving unit 201, a transmitting unit 202, and a control unit 203.

[0179] Note that all or part of the functions realized by the receiving unit 201 and the transmitting unit 202 can be realized using the communication device 13. Also, all or part of the functions realized by the receiving unit 201 and the transmitting unit 202, and the control unit 203 can be realized by the processor 11 executing a program stored in the storage device 12. Further, the program can be stored in a storage medium. The storage medium storing the program may be a computer-readable non-transitory storage medium. The non-transitory storage medium is not particularly limited, and may be, for example, a storage medium such as a USB memory or a CD-ROM.

[0180] The receiving unit 201 receives the uplink signal. Also, the receiving unit 201 may receive information and / or data transmitted via the uplink signal.

[0181] The transmitting unit 202 transmits the downlink signal. Also, the transmitting unit 202 may transmit information and / or data transmitted via the downlink signal. Specifically, the transmitting unit 202 may transmit system information (e.g., SIB1). Also, the transmitting unit 202 may transmit information regarding the total number of subgroups (e.g., the above-mentioned total subgroup number information). Also, the transmitting unit 202 may transmit information regarding the number of multiple paging periods (e.g., the above-mentioned PO number information).

[0182] Also, the transmitting unit 202 may transmit downlink control information including a field indicating the paging target subgroup in a paging period (e.g., PO) (e.g., a subgroup indication field as PEI) (the first aspect, for example, FIGS. 4 and 5).

[0183] Further, the transmitting unit 202 may transmit downlink control information including a field (e.g., a PO / subgroup indication field as PEI, or a PO indication field and a subgroup indication field) indicating a subgroup of paging targets in a plurality of paging periods (e.g., a plurality of POs) (a second aspect, e.g., FIGS. 6 and 7).

[0184] The transmitting unit 202 may transmit downlink control information (e.g., paging DCI) monitored in a paging period, and transmit a paging message via a downlink shared channel scheduled using the downlink control information.

[0185] The transmitting unit 202 may transmit information indicating a subgroup assigned to the terminal 10 by the network (network-based subgrouping).

[0186] The transmitting unit 202 transmits setting information regarding reception of information or a signal (e.g., PEI) indicating a subgroup of paging targets in a paging period. The setting information may be, for example, the above subgroup total number information.

[0187] The transmitting unit 202 may transmit information or a signal (e.g., PEI) indicating a subgroup of paging targets in a paging period.

[0188] The transmitting unit 202 may transmit information regarding a set of subgroups assigned to the terminal 10 in each of a plurality of subgroup totals (e.g., subgroup set information in FIG. 10) and information regarding the subgroup total in a predetermined unit (e.g., the above subgroup total number information).

[0189] The control unit 203 performs various controls in the base station 20. Note that some information transmitted from the transmitting unit 202 of the base station may be transmitted by a transmitting unit in a device on the core network 30.

[0190] (Other embodiments) The various signals, information, and parameters in the above embodiments may be signaled at any layer. That is, the above various signals, information, and parameters may be replaced with signals, information, and parameters of any layer such as a higher layer (e.g., Non Access Stratum (NAS) layer, RRC layer, MAC layer, etc.) or a lower layer (e.g., physical layer). Also, the notification of predetermined information is not limited to being explicitly performed and may be implicitly performed (e.g., by not notifying information or by using other information).

[0191] Moreover, the names of the various signals, information, parameters, IEs, channels, time units, and frequency units in the above embodiments are merely illustrative and may be replaced with other names. For example, a slot may have any name as long as it is a time unit having a predetermined number of symbols. Also, an RB may have any name as long as it is a frequency unit having a predetermined number of subcarriers. Also, "first ~" and "second ~" are merely for identifying a plurality of information or signals and the order may be appropriately interchanged.

[0192] Furthermore, the uses of the terminal 10 in the above embodiments (e.g., for RedCap, IoT, etc.) are not limited to the examples and may be used in any use (e.g., eMBB, URLLC, Device-to-Device (D2D), Vehicle-to-Everything (V2X), etc.) as long as it has the same function. Also, the formats of various information are not limited to the above embodiments and may be appropriately changed such as bit representation (0 or 1), boolean value (Boolean: true or false), integer value, character, etc. Also, the singular and plural in the above embodiments may be changed to each other.

[0193] The embodiments described above are for facilitating the understanding of the present disclosure and are not for limiting the interpretation of the present disclosure. The flowcharts, sequences, each element included in the embodiments, and their arrangements, indexes, conditions, etc. described in the embodiments are not limited to those exemplified and can be changed as appropriate. Also, at least a part of the configurations described in the above embodiments can be partially replaced or combined.

Description of Reference Numerals

[0194] 1... Wireless communication system, 20... Base station, 30... Core network, 101... Receiver, 102... Transmitter, 103... Control unit, 201... Receiver, 202... Transmitter, 203... Control unit, 11... Processor, 12... Storage device, 13... Communication device, 14... Input / output device

Claims

1. a receiving unit that receives system information including information indicating the total number of subgroups in a paging opportunity and information indicating the number of the paging opportunities, and first downlink control information including a field indicating a subgroup in the paging opportunity; a control unit that determines the number of bits of the field based on the information indicating the total number of subgroups and the information indicating the number of the paging opportunities, and controls execution of monitoring of a physical downlink control channel (PDCCH) for second downlink control information in the paging opportunity based on the value of the field; A terminal comprising the above.

2. The field is composed of a bitmap having the number of bits equal to the multiplication value of the total number of subgroups and the number of the paging opportunities, The terminal according to claim 1.

3. Each bit from the most significant bit to the least significant bit of the bitmap corresponds to a subgroup equal to the multiplication value of the total number of subgroups and the number of the paging opportunities, first in ascending order of the index value of the paging opportunity, and second in ascending order of the index value of the subgroup. The terminal according to claim 2.

4. When the control unit does not detect the first downlink control information or the value of the field does not indicate a subgroup in the paging opportunity to which the terminal belongs, the control unit skips execution of the monitoring of the PDCCH for the second downlink control information in the paging opportunity. The terminal according to claim 1.

5. When the value of the field indicates a subgroup in the paging opportunity to which the terminal belongs, the control unit executes the monitoring of the PDCCH for the second downlink control information in the paging opportunity. The terminal according to claim 1.

6. The control unit derives an index value of the subgroup of the paging opportunity to which the terminal belongs based on an identifier of the terminal and the total number of subgroups. The terminal according to claim 4 or claim 5.

7. The receiving unit receives information indicating the subgroup of the paging opportunity to which the terminal belongs from a network. The terminal according to claim 4 or claim 5.

8. a control unit that determines the total number of subgroups of a paging opportunity and the number of the paging opportunities, and determines a subgroup of the paging opportunity of a terminal; A transmitting unit that transmits system information including information indicating the total number of the subgroups and information indicating the number of paging opportunities, and downlink control information including a field indicating a subgroup of the paging opportunities. The number of bits of the field is determined based on the information indicating the total number of the subgroups and the information indicating the number of paging opportunities. Base station.

9. The field is composed of a bitmap having a number of bits equal to the multiplication value of the total number of the subgroups and the number of paging opportunities. The base station according to claim 8.

10. Each bit from the most significant bit to the least significant bit of the bitmap corresponds first to the ascending order of the index value of the paging opportunity, second to the ascending order of the index value of the subgroup, and to a subgroup equal to the multiplication value of the total number of the subgroups and the number of paging opportunities. The base station according to claim 9.

11. A step of receiving, from a base station, system information including information indicating the total number of subgroups in a paging opportunity and information indicating the number of paging opportunities. A step of receiving, from the base station, first downlink control information including a field indicating a subgroup in the paging opportunity. A step of determining the number of bits of the field based on the information indicating the total number of the subgroups and the information indicating the number of paging opportunities. A step of controlling the execution of monitoring of a physical downlink control channel (PDCCH) for second downlink control information in the paging opportunity based on the value of the field. having A wireless communication method for a terminal.

12. The field is composed of a bitmap having a number of bits equal to the multiplication value of the total number of the subgroups and the number of paging opportunities. The wireless communication method according to claim 11.

13. Each bit from the most significant bit to the least significant bit of the bitmap corresponds first to the ascending order of the index value of the paging opportunity, second to the ascending order of the index value of the subgroup, and to a subgroup equal to the multiplication value of the total number of the subgroups and the number of paging opportunities. The wireless communication method according to claim 12.

14. If the first downlink control information is not detected, or if the value of the field does not indicate the subgroup in the paging occasion to which the terminal belongs, skip the execution of the monitoring of the PDCCH for the second downlink control information in the paging occasion. The wireless communication method according to claim 11.

15. If the value of the field indicates the subgroup in the paging occasion to which the terminal belongs, execute the monitoring of the PDCCH for the second downlink control information in the paging occasion. The wireless communication method according to claim 11.

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