Terminal, base station and wireless communication method

Abstract

To provide a terminal and a wireless communication method for performing operation suitable for network-based paging subgrouping.SOLUTION: In a wireless communication system, a terminal 10 includes: a receiving unit that receives information about a set of subgroups assigned to the terminal in each of a plurality of total numbers of subgroups, and information about the total number of subgroups in a predetermined unit; and a control unit that derives a subgroup to which its own terminal belongs in the predetermined unit based on the information about the set of subgroups and the information about the total number of subgroups.SELECTED DRAWING: Figure 14

Description

[Technical Field]

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

[0002] The Third Generation Partnership Project (3GPP), an international standardization organization, has specified Release 15 of New Radio (NR), a fifth generation (5G) RAT, as the successor to Long Term Evolution (LTE), a 3.9th generation radio access technology (RAT), and LTE-Advanced, a fourth generation RAT (see, 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, a network-initiated connection setup is performed by paging. For example, in NR, a terminal in an idle state or an inactive state monitors downlink control information (DCI) transmitted using a downlink control channel (e.g., a physical downlink control channel (PDCCH)) during a period for paging (hereinafter referred to as a "paging period"). The terminal receives a paging message via a downlink shared channel (e.g., a physical downlink shared channel (PDSCH)) scheduled by the DCI. The terminal reduces its power consumption by performing discontinuous reception (DRX) in which it sleeps outside the paging period. [Prior art documents] [Non-patent literature]

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

[0005] In 3GPP (for example, Release 17 of NR), a study is being conducted to divide multiple terminals assigned to the same paging period into predetermined units (hereinafter referred to as "subgroups") and perform paging on a subgroup basis (hereinafter referred to as "subgrouping"). In addition, it is expected that the power saving effect of subgrouping can be improved by instructing terminal 10 in advance which subgroup will be paging target during the paging period (hereinafter referred to as "Paging early indication (PEI)").

[0006] The subgrouping being considered involves terminal identifier-based subgrouping, in which a subgroup to which a terminal itself belongs is derived based on an identifier assigned to the terminal (hereinafter referred to as "terminal identifier") (e.g., 5G S-Temporary Mobile Subscription Identifier: 5G-S-TMSI), and network-based subgrouping, in which a subgroup to which a terminal belongs is assigned on the network side. With network-based subgrouping, there is a risk that the terminal will not be able to recognize the subgroup assigned by the network side and will not be able to operate properly.

[0007] The present disclosure has been made in consideration of the above circumstances, and one of its objects is to provide a terminal and a wireless communication method that are capable of performing operations suitable for subgrouping of network-based paging. [Means for solving the problem]

[0008] A terminal according to one aspect of the present disclosure includes a receiving unit that receives information regarding a set of subgroups assigned to the terminal for each of a plurality of total numbers of subgroups and information regarding the total number of subgroups in a predetermined unit, and a control unit that derives a subgroup to which the terminal belongs in the predetermined unit based on the information regarding the set of subgroups and the information regarding the total number of subgroups. [Effects of the Invention]

[0009] According to one aspect of the present disclosure, suitable operations for network-based paging subgrouping may be performed. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram illustrating an example of an overview of a wireless communication system according to an embodiment of the present invention. [Figure 2] FIG. 10 is a diagram illustrating an example of DRX for paging according to the present embodiment. [Figure 3] 3A and 3B are diagrams showing an example of the PEI according to this embodiment. [Figure 4] FIG. 2 is a diagram showing an example of a PEI according to the first aspect of the present embodiment. [Figure 5] FIG. 10 is a diagram showing another example of a PEI according to the first aspect of the present embodiment. [Figure 6] FIG. 10 is a diagram showing an example of a PEI according to a second aspect of the present embodiment. [Figure 7] FIG. 10 is a diagram showing another example of a PEI according to the second aspect of the present embodiment. [Figure 8] 8A to 8C are diagrams showing an example of paging DCI according to this embodiment. [Figure 9] FIG. 10 is a diagram illustrating an example of a terminal operation in a PO according to a third aspect of the present embodiment. [Figure 10] FIG. 10 is a diagram showing an example of subgroup set information according to a fourth aspect of the present embodiment. [Figure 11] FIG. 10 is a diagram illustrating an example of a subgroup derivation operation according to a fourth aspect of the present embodiment. [Figure 12] FIG. 10 is a diagram illustrating an example of a specification change related to subgroup total number information in the present embodiment. [Figure 13] FIG. 2 is a diagram illustrating an example of the hardware configuration of each device in the wireless communication system according to the present embodiment. [Figure 14] FIG. 2 is a diagram illustrating an example of a functional block configuration of a terminal according to the present embodiment. [Figure 15] FIG. 2 is a diagram illustrating an example of a functional block configuration of a base station according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

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

[0012] Fig. 1 is a diagram showing an example of an overview of a wireless communication system according to this embodiment. As shown in Fig. 1, the wireless communication system 1 may include terminals 10, base stations 20, and a core network 30. Note that the numbers of terminals 10 and base stations 20 shown in Fig. 1 are merely examples and are not limited to the numbers shown in the figure.

[0013] The radio access technology (RAT) of the radio communication system 1 is assumed to be, for example, NR, but is not limited to this, and various RATs such as RATs of the sixth generation and later can be used.

[0014] The terminal 10 is a predetermined terminal or device such as 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 also be called 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 either mobile or fixed. The terminal 10 is configured to be able to communicate using, for example, NR as a RAT.

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

[0016] Furthermore, one or more bandwidth parts (BWPs) may be configured for one cell C. Here, the BWPs mainly used when the terminal 10 makes initial access to the cell are also referred to as an initial downlink BWP (Initial DL BWP) and an initial uplink BWP (Initial UL BWP). For example, the base station 20 may broadcast 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 by including it in system information (for example, System Information Block (SIB) 1). Furthermore, the base station 20 may broadcast 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 by including it in a master information block (MIB).

[0017] The base station 20 may also be called 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 configured with multiple nodes (for example, 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, a core network compatible with NR (5G Core Network: 5GC), but is not limited to this. An apparatus on the core network 30 (hereinafter also referred to as a "core network apparatus") performs mobility management such as paging and location registration of the terminal 10. The core network apparatus may be connected to the base station 20 via a predetermined interface (for example, an 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 (e.g., information related to access and mobility management, etc.) and a User Plane Function (UPF) that controls the transmission of U-plane information (e.g., user data).

[0020] In the wireless communication system 1, a terminal 10 receives a downlink (DL) signal and / or transmits an uplink (UL) signal from a base station 20. 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.

[0021] Furthermore, the terminal 10 performs a cell search based on a synchronization signal (for example, a primary synchronization signal (PSS) and / or a secondary synchronization signal (SSS)) from the base station 20. The cell search is a procedure in which the terminal 10 acquires time and frequency synchronization in a cell and detects an identifier of the cell (for example, a physical layer cell ID).

[0022] A block including at least one of the above synchronization signal, broadcast channel (e.g., Physical Broadcast Channel (PBCH)), and broadcast channel demodulation reference signal (DMRS) is also called a synchronization signal block (SSB), SS / PBCH block, etc. One or more SSBs 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 (two radio frames)). In the case of multi-beam operation, SSBs with different indices correspond to different beams, and may be transmitted by sequentially switching the beam direction by beam sweeping.

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

[0024] The terminal 10 determines a search space and / or a control resource set (CORESET) based on system information or parameters included in a Radio Resource Control (RRC) message (hereinafter referred to as "RRC parameters"), and monitors DCI transmitted via a downlink control channel (e.g., a Physical Downlink Control Channel (PDCCH)) within the search space associated with the CORESET. 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] DCI monitoring refers to the blind decoding by the terminal 10 of PDCCH candidates within a search space in an assumed DCI format. The number of bits (also referred to as size, bit width, etc.) of the DCI format is predetermined or derived according to the number of bits of a field 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 (hereinafter referred to as "CRC scrambling") Cyclic Redundancy Check (CRC) bits (also referred to as CRC parity bits) of the DCI format. DCI monitoring is also referred to as PDCCH monitoring, monitor, etc. The period during which DCI monitoring is performed is also referred to as a PDCCH monitoring occasion.

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

[0027] Here, the Type0-PDCCH CSS set may be configured using information included in the MIB. For example, base station 20 may configure the Type0-PDCCH CSS set for terminal 10 by transmitting an MIB containing information for configuring a CORESET and / or information for configuring a search space. Here, a CORESET configured using information included in the MIB is also referred to as CORESET#0. A search space configured using information included in the MIB is also referred to as search space#0. CORESET#0 and search space#0 refer to 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), respectively. In other words, a PDCCH monitoring opportunity corresponding to the Type0-PDCCH CSS set may be configured using information included in the MIB. Here, a PDCCH monitoring opportunity corresponding to the Type0-PDCCH CSS set is also referred to as a PDCCH monitoring opportunity for SIB1.

[0028] Furthermore, the Type2-PDCCH CSS set may be configured using information included in system information (for example, SIB1). For example, base station 20 may configure a Type2-PDCCH CSS set for terminal 10 by transmitting system information including information for setting a CORESET index and / or information for setting a search space index. Here, the CORESET configured using the information included in the system information may be CORESET#0 or CORESET#x (for example, x = 1, 2, ...). Furthermore, the search space configured using the information included in the system information may be search space#0 or search space#x (for example, x = 1, 2, ...). In other words, a value other than "0" may be set to each of the CORESET index and the search space index configured using the information included in the system information. In other words, the PDCCH monitoring occasion corresponding to the Type2-PDCCH CSS set may be configured using the information included in the system information.

[0029] Furthermore, the terminal 10 may monitor the USS, detect DCI (for example, a DL assignment or an UL grant) that is CRC-scrambled by a specific RNTI (for example, Cell(C)-RNTI), and control data reception using a PDSCH scheduled using the DCI or data transmission using an uplink shared channel (for example, a Physical Uplink Shared Channel (PUSCH)). Note that a set of one or more search spaces may be called a search space set, a set including one or more CSSs is called a CSS set, and a set including one or more USSs is called a USS set, etc.

[0030] (paging) Paging is used for network-initiated connection setup when the terminal 10 is idle or inactive. Paging is also used for transmitting short messages to the terminal 10 regardless of its state (e.g., idle, inactive, or connected) to instruct system information updates and / or to issue public warnings. Public warnings include, for example, Earthquake and Tsunami Warning Systems (ETWS), Commercial Mobile Alert Systems (CMAS), etc.

[0031] Here, the idle state is a state in which an RRC layer connection (hereinafter referred to as "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 system information broadcasted by the cell on which it is camped. When an RRC connection is established, the terminal 10 in the idle state transitions to the connected state.

[0032] The inactive state is a state in which the RRC connection is established but suspended, and is also called an RRC_INACTIVE state, an inactive mode, an RRC inactive mode, etc. A terminal 10 in the inactive state receives system information broadcast by a camped-on cell. A terminal 10 in the inactive state transitions to a connected state when the RRC connection is resumed, and transitions to an idle state when the RRC connection is released.

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

[0034] The terminal 10 performs PDCCH monitoring during a 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 includes 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 occasions.

[0035] Fig. 2 is a diagram showing an example of DRX for paging according to this embodiment. As shown in Fig. 2, a PF is provided at a given cycle called a DRX cycle. A PF is made up of, for example, one radio frame and may be identified by a system frame number (SFN). One radio frame is made up of 10 subframes #0 to #9, and for example, when the subcarrier spacing is 15 kHz, it is made up of 10 slots #0 to #9. It goes without saying that the number of slots per PF differs depending on the subcarrier spacing.

[0036] For example, in Figure 2, the number of POs per PF, N s is 1. The terminal 10 performs time and frequency synchronization before the PF (or the PO or the PDCCH monitoring opportunity within the PO). For the time and frequency synchronization, for example, but not limited to, SSB is used. 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] In the case of CN initiated paging, the paging message is transmitted across multiple cells C within a tracking area, and in the case of RAN initiated paging, the paging message is transmitted across one or more cells C within a RAN area. A RAN area is identified by a RAN Area Identifier (RAI), and a tracking area is identified by a Tracking Area Identifier (TAI). A RAN area includes one or more cells C, and a tracking area includes one or more RAN areas.

[0038] The terminal 10 controls the establishment of a connection with the network side (for example, the CN 30 and / or the base station 20) based on a list of one or more terminal identifiers in the paging message (for example, an RRC IE "pagingRecordList") and a terminal identifier assigned to the terminal 10. For example, the terminal 10 may start a procedure for establishing a connection with the network side when the list includes a terminal identifier assigned to the terminal 10. Here, the terminal identifier is an identifier of the terminal 10, and may be, for example, a 5G S-Temporary Mobile Subscription Identifier (5G-S-TMSI), which is a temporary terminal identifier that uniquely identifies the terminal 10 within a tracking area.

[0039] In Figure 2, the number of POs per PF, N s However, the number of PDCCH monitoring opportunities for a PO is one, but is not limited to this and may be multiple. Also, in FIG. 2, a PO is assumed to be one subframe (slot), but as described above, the time unit constituting a PO is not limited to this. Also, in FIG. 2, a PO associated with a certain PF is provided within the PF, but is not limited to this and may start from a predetermined position before or after the PF. Also, a 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 terminal identifier, and the DRX cycle T. For example, the SFN for the PF is determined by the following formula 1, which is a predetermined offset, PF_Offset, the DRX cycle T, the number of PFs in the DRX cycle T, N, and the number of POs per PF, N s It may be determined based on the following. (Formula 1) (SFN+PF_Offset)mod T = (T div N)*(UE_ID mod N) where UE_ID = 5G-S-TMSI mod 1024

[0041] According to the above formula 1, multiple terminals 10 are assigned to the same paging period (for example, PF and / or PO). However, even if a terminal 10 receives a paging DCI, it cannot determine which terminal 10 the paging is addressed to without decoding the list of terminal identifiers in the paging message. Therefore, among multiple terminals 10 sharing the same paging period, terminals 10 that are not targeted for paging in that paging period may unnecessarily perform time and frequency synchronization and PDCCH monitoring in the PO. As a result, there is a risk that power consumption of terminals 10 that are not targeted for paging in that paging period may be wasted.

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

[0043] In the terminal identifier-based subgrouping, the terminal 10 determines the subgroup assigned to itself based on the terminal identifier. Specifically, the terminal 10 determines the number of PFs N within the DRX period T, the number of POs N per PF, in addition to the terminal identifier 5G-S-TMSI. s and the total number of subgroups, N sgFor example, the terminal 10 may determine the subgroup ID using the following formula 2. (Formula 2) Subgroup ID = floor (UE ID / (N*N s ) mod N sg where UE_ID = 5G-S-TMSI mod 1024

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

[0045] (P.E.I.) When performing the subgrouping, instructing the terminal 10 in advance which subgroups are to be paged in a paging period (hereinafter referred to as "Paging Early Indication (PEI)") can contribute to reducing unnecessary power consumption. Specifically, the terminal 10 can reduce power consumption by skipping PDCCH monitoring and / or receiving and / or decoding paging messages in a paging period in which the subgroup to which the terminal 10 belongs is not to be paged, based on the PEI.

[0046] DCI-based, SSS-based, or Tracking Reference Signal (TRS)-based PEI is under consideration. In the following, the present embodiment will be described assuming a DCI-based PEI, but it can also be applied to an SSS-based or TRS-based PEI as appropriate. Note that the TRS may also be called a non-zero power channel state information reference signal (NZP-CSI-RS).

[0047] 3A and 3B are diagrams illustrating an example of a PEI according to this embodiment. For example, as shown in FIGS. 3A and 3B, a PDCCH monitoring opportunity for a 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 an SSB in one or more SS bursts to perform time and frequency synchronization for a PO. For example, the period of an 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 0.5 ms period. For example, the base station 20 may transmit information (e.g., an RRC IE "ssb-periodicityServingCell") to the terminal 10 for setting a half-frame period for receiving SSBs (i.e., a period of an SS burst set).

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

[0049] For example, in FIG. 3(A), each PEI monitoring occasion may be configured based on a time offset for each SS burst or each SS burst set. Note that, although a time offset is assigned from the end of each SS burst in FIG. 3(A), a time offset may also be assigned from the beginning of each SS burst or each SS burst set. Terminal 10 does not need to configure a PEI monitoring occasion for each SS burst or each SS burst set; it is sufficient that a PEI monitoring occasion is configured for at least one SS burst or one SS burst set detected by terminal 10. For example, in FIG. 3(A), one or more PEIs (here, three PEIs) correspond to one PO, but this is not limited to this. That is, for example, base station 20 may configure a time offset using RRC parameters, and terminal 10 may monitor the PDCCH for a DCI format including a PEI in a monitoring occasion determined based on the configured time offset.

[0050] For example, the duration of the time offset from the SS burst or SS burst set may be determined based on the subcarrier spacing of the SSB. For example, if 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 a DCI format including PEI in the symbol 10 slots after the SS burst or SS burst set. Also, if 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 a DCI format including PEI in the symbol 20 slots after the SS burst or SS burst set.

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

[0052] On the other hand, in Figure 3(B), each PEI monitoring opportunity is provided at a predetermined period T2 at a time position with a predetermined gap for a specific PO. As shown in Figure 3(B), one PEI may correspond to one or more POs (here, two POs). Note that Figures 3(A) and 3(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 multiple PEI monitoring opportunities may be provided. That is, the base station 20 may set a monitoring window (monitoring period) in which the terminal 10 monitors the PDCCH for the DCI format including the PEI.

[0053] The PEI monitored at the above-described PEI monitoring opportunity may 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. Furthermore, the DCI format including the PEI is CRC-scrambled using a specific RNTI (e.g., P-RNTI). Note that the PEI is not limited to being included in a DCI format, and the DCI format itself may be called a PEI.

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

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

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

[0057] Here, when an index other than #0 is set for a CORESET using information for setting an index of the CORESET included in the system information, the terminal 10 may monitor a PDCCH for a DCI format including a PEI in the CORESET with the set index. Furthermore, when an index other than #0 is set for a search space using information for setting an index of a search space included in the system information, the terminal 10 may monitor a PDCCH for a DCI format including a PEI in the search space with the set index. That is, when a CORESET#x (e.g., x=1, 2, ...) and / or a search space#x (e.g., x=1, 2, ...) is set using 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 CORESET#x (e.g., x=1, 2, ...) and / or the search space#x (e.g., x=1, 2, ...).

[0058] Here, a first operation and / or a second operation may be defined in relation to the PEI. For example, in the first operation, the PEI may indicate that the terminal 10 performs monitoring in a paging period (i.e., PF and / or PO) when a subgroup corresponding to the terminal 10 is a target for 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 a subgroup corresponding to the terminal 10 (to which the terminal 10 belongs) is paged, a PEI may be 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 performs monitoring in a paging period when a subgroup corresponding to the terminal 10 is paged. That is, in the first operation, when the terminal 10 does not detect a PEI in PEI monitoring opportunities corresponding to a certain paging period (e.g., all PEI monitoring opportunities corresponding to a certain paging period), the terminal 10 may not perform monitoring in the certain paging period (monitoring in the certain paging period may not be requested).

[0059] Furthermore, in the second operation, the PEI may indicate whether the terminal 10 performs monitoring in a paging period (i.e., PF and / or PO). That is, in the second operation, the PEI may indicate whether a subgroup corresponding to the terminal 10 is paged. In this case, the PEI is transmitted regardless of whether a subgroup corresponding to the terminal 10 (to which the terminal 10 belongs) is paged. The PEI may be, for example, a bitmap (e.g., FIG. 4 or 6) described later, or a codepoint (e.g., FIG. 5 or 7) described later. That is, in the second operation, when the terminal 10 has not detected a PEI in PEI monitoring occasions corresponding to a certain paging period (e.g., all PEI monitoring occasions corresponding to a certain paging period), the terminal 10 may perform monitoring in the certain paging period (monitoring in the certain paging period may be requested).

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

[0061] Furthermore, in the first operation and the second operation, not performing monitoring in a certain paging period (or skipping monitoring) may include not monitoring a PDCCH for a DCI format CRC-scrambled by the specific RNTI in the certain paging period. Furthermore, in the first operation and the second operation, not performing monitoring in a certain paging period may include not decoding a PDSCH scheduled using a DCI format CRC-scrambled by the specific RNTI in the certain paging period (for example, not receiving a paging message). That is, in the first operation and the second operation, not performing monitoring in a certain paging period (or skipping monitoring) may include monitoring a PDCCH for a DCI format CRC-scrambled by the specific RNTI in the certain paging period, but not decoding a PDSCH scheduled using the DCI format (for example, it may include only decoding a short message included in the DCI format, but not decoding a PDSCH). In addition, in the first and second operations, not performing monitoring (or skipping monitoring) in a certain paging period may include not performing both monitoring of the PDCCH and decoding of the PDSCH in that certain paging period.

[0062] In this embodiment, the name PEI is merely an example, and any name can be used as long as the information has the same function as that described in this embodiment.

[0063] As described above, in PDCCH monitoring, terminal 10 detects DCI for 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 terminal 10 to detect PEI at a PEI monitoring opportunity, it is necessary to know the number of bits of the PEI in advance. If terminal 10 cannot know the number of bits of the PEI in advance, there is a risk that it will not be able to appropriately control PEI monitoring.

[0064] When performing the above subgrouping, the total number of subgroups is N sg It is also being considered that is determined for each predetermined unit (cell C, RNA area, or tracking area). In this case, the number of bits of PEI is determined by the total number of subgroups N sg Therefore, in this embodiment, the terminal 10 may change depending on the total number of subgroups N sg By determining the number of bits of the PEI based on the above, monitoring in the PEI monitoring opportunity is appropriately controlled.

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

[0066] In the following description, each paging period used in the first and second aspects is assumed to be, for example, a PO, but is not limited to this.

[0067] Furthermore, in the first aspect, one PEI monitoring opportunity is provided for each PO, but this is not limiting, and multiple PEI monitoring opportunities may be provided for each PO.

[0068] In addition, the multiple POs used in the second aspect are associated with one PF, but are not limited to this. In the second aspect, one PEI monitoring opportunity is provided for each PF, but are not limited to this, and multiple PEI monitoring opportunities may be provided for each PF. Furthermore, PEIs corresponding to multiple POs associated with multiple PFs may be used.

[0069] (First aspect) In a first aspect, the terminal 10 receives a DCI including a field indicating a subgroup to be paged in a PO (hereinafter referred to as a "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 a DCI including a subgroup indication field as a PEI for each PO, and controls execution of monitoring in the PO based on the value of the subgroup indication field. Hereinafter, it will be mainly described that monitoring of paging DCI in a PO is controlled based on the value of the subgroup indication field (i.e., the value of the PEI), but the operation related to the PEI may be the first operation and / or the second operation described above.

[0070] In addition, the terminal 10 has a total number of subgroups N sg The total number of subgroups N is received. sg For example, the subgroup total number information may be the total number of subgroups to which a plurality of terminals 10, for which the PF of the same SFN is determined based on the terminal identifier (for example, 5G-S-TMSI), belong. sg It may also be shown as

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

[0072] The terminal 10 determines the number of bits of the subgroup indication field as the PEI (i.e., the PEI field) based on the information on the total number of subgroups. 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 detects the PEI by blind decoding PDCCH candidates in the search space in the PEI monitoring occasion based on the number of bits of the DCI format. That is, the terminal 10 may determine the number of bits of the subgroup indication field in the DCI format (i.e., the PEI field) based on the information on the total number of subgroups broadcast by the base station 20.

[0073] For example, the subgroup indication field as PEI is the total number of subgroups N indicated by the total number of subgroups information. sg or the total number of subgroups N sg In other words, the code point may correspond to the PEI (PEI field).

[0074] <bitmap> 4 is a diagram showing an example of the PEI according to the first aspect of this embodiment. In FIG. 4, for example, the total number of subgroups N sgis 16, and the terminal 10 belongs to subgroup #1 of 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 a 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 Figure 4, the subgroup indication field for each PEI is the total number of subgroups, N sg = 16. The 16 bits in the bitmap correspond to subgroups #0 to #15, respectively. For example, in FIG. 4, the most significant bit (MSB) (also called 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, the subgroup indication fields in the PEIs corresponding to PO #0 to #2 indicate that the paging targets for PO #0 are subgroups #0 and #1, the paging targets for PO #1 are subgroups #2 and #3, and the paging targets for PO #2 are subgroups #4 and #5. As described above, since terminal 10 belongs to subgroup #1, terminal 10 monitors paging DCI in PO #0, for which subgroup #1 is included as a paging target, but may skip monitoring paging DCI in PO #1 and #2, for which subgroup #1 is not included as a paging target. Also, for example, terminal 10 belonging to subgroup #1 may decode PDSCH in PO #0, but not decode PDSCH in PO #1 and #2.

[0077] As shown in Figure 4, the subgroup indication field as PEI is set to the total number of subgroups, N sgWhen the bitmap is configured with the same number of bits as the subgroups to be paged within one PO, the subgroups to be paged can be easily specified.

[0078] <codepoint> Fig. 5 is a diagram showing another example of a PEI according to the first aspect of this embodiment. In Fig. 5, differences from Fig. 4 will be mainly explained. In Fig. 5, the subgroup indication field of each PEI indicates the total number of subgroups N sg = 16. One or more subgroups associated with each codepoint (i.e., each value set in the PEI field) may be determined in advance by a specification, or may be notified to the terminal 10 by higher layer signaling. For example, in FIG. 5, codepoint "0000" indicates subgroup #0, "0001" indicates subgroup #1, and "0010" to "1111" indicate subgroups #2 to #15. For example, the base station 20 may broadcast the correspondence between each codepoint (i.e., each value set in the PEI field) and one or more subgroups by including it in system information (e.g., SIB1). That is, the terminal 10 may identify one or more subgroups based on the correspondence and the value set in the PEI field.

[0079] In FIG. 5, each code point indicates one subgroup, but each code point may indicate one or more subgroups that are predetermined or notified by higher layer signaling. In this way, 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 is, for example, ceil(log2(N sg )) In FIG. sg = 16, so the subgroup indication field is 4 bits.

[0080] For example, in Fig. 5, the subgroup indication fields in the 3PEIs of PO #0 to PO #2 indicate 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 terminal 10 belongs to subgroup #1, terminal 10 monitors paging DCI in PO #1, which includes subgroup #1 as a paging target, but may skip monitoring paging DCI in PO #0 and PO #2, which do not include subgroup #1 as a paging target. Also, for example, terminal 10 belonging to subgroup #1 may decode PDSCH in PO #1, but not decode PDSCH in PO #0 and PO #2.

[0081] As shown in Figure 5, when the subgroup indication field as a PEI is configured with code points indicating one or more subgroups, the number of bits in the subgroup indication field can be reduced compared to the bitmap case shown in Figure 4, thereby reducing the overhead caused by the PEI.

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

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

[0084] Here, the base station 20 may configure the terminal 10 to operate in either the first operation or the second operation. For example, the base station 20 may broadcast information for configuring whether the terminal 10 operates in either the first operation or the second operation (hereinafter also referred to as a "monitoring operation instruction") in system information (for example, SIB1). For example, the monitoring operation instruction may be set commonly for one or more terminals 10. Furthermore, 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 a PEI.

[0085] That is, when the terminal 10 instructed to perform the first operation does not detect a 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 perform monitoring in the certain paging period. Also, when the terminal 10 configured to perform the second operation does not detect a 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 perform monitoring in the certain paging period.

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

[0087] Furthermore, an instruction for a monitoring operation may be included in a field of the PEI (e.g., a subgroup instruction field) and specified. For example, the base station 20 may use a value set in a field of the PEI (e.g., a value set in a subgroup instruction field) to indicate one or more subgroups and / or monitoring operations. Furthermore, the base station 20 may broadcast correspondence between each code point (i.e., each value set in a field of the PEI) and one or more subgroups and / or monitoring operations by including the correspondence in system information (e.g., SIB1). 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 (e.g., the nth DRX cycle), the terminal 10 may determine an operation (first operation or second operation) in the corresponding paging period (i.e., the PF and / or PO in the n+1th DRX cycle that is the same as the PF and / or PO in the nth DRX cycle) in the next DRX cycle (e.g., the n+1th DRX cycle).

[0089] Here, the first operation or the second operation may be defined as a default operation in the terminal 10. For example, when the total number of subgroups N sg If only N is reported (i.e., the total number of subgroups N sgWhen only the PEI is set and a monitoring operation is not instructed, the terminal 10 may execute the first operation or the second operation. For example, by having the terminal 10 execute the first operation as a default operation, it is possible to specify that monitoring is not performed in a certain paging period when the terminal 10 does not detect a PEI, thereby reducing power consumption in the terminal 10. Furthermore, by having the terminal 10 execute the second operation as a default operation, it is possible to specify that monitoring is performed in a certain paging period when the terminal 10 does not detect a PEI, thereby enabling reliable detection and / or reception of paging DCI and / or PDSCH.

[0090] (Second aspect) The terminal 10 receives DCI including PEIs corresponding to multiple POs, i.e., DCI including a field indicating a subgroup to be paged for each of the multiple POs (hereinafter referred to as a "PO / subgroup indication field"). The terminal 10 receives the DCI and controls execution of monitoring in the multiple POs based on the value of the PO / subgroup indication field as the PEI. In the following, the multiple POs are assumed to be multiple POs associated with the same PF, but are not limited to this. Furthermore, the following mainly describes controlling monitoring of paging DCI in a PO based on the value of the PO / subgroup indication field (i.e., 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 described focusing on differences from the first aspect.

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

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

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

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

[0095] Alternatively, the PO / subgroup indication field may be a single field that indicates which subgroup in which PO is the paging target among multiple POs. The number of bits in the PO / subgroup indication field is N sg and number of POs N s and may be equal to the total number of bits of the subgroup indication field and the PO indication field, for example.

[0096] <bitmap> 6 is a diagram showing an example of a 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 above, N sg It is assumed that the number of subgroups is 16, and that the terminal 10 belongs to subgroup #1 among subgroups #0 to #15. Note that the explanation of Fig. 6 will focus on the differences from Fig. 4.

[0097] In Figure 6, the PO / subgroup indication field as PEI is the total number of subgroups, N sg =16 and PO number N s It is composed of a bitmap with the number of bits equal to 64, the multiplication value of PO#0 and PO#1=4. 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. In this way, the corresponding bits in the bitmap may be determined with the PO index first and the subgroup index second.

[0098] 6, for example, a single PO / subgroup indication field indicates that the paging targets for PO #0 are subgroups #0 to #3, the paging targets for PO #1 are subgroups #4 to #7, the paging targets for PO #2 are subgroups #8 to #11, and the paging targets for PO #3 are subgroups #12 to #15. As described above, since terminal 10 belongs to subgroup #1, terminal 10 monitors paging DCI in PO #0, which includes subgroup #1 as a paging target, but may skip monitoring paging DCI in PO #1 to #3, which do not include subgroup #1 as a paging target. Also, for example, terminal 10 belonging to subgroup #1 may decode PDSCH in PO #0, but not decode PDSCH in PO #1 to #3.

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

[0100] <codepoint> FIG. 7 is a diagram showing another example of a PEI according to the second aspect of this embodiment. In FIG. 7, differences from FIG. 5 or 6 will be mainly explained. In FIG. 7, the PEI may include a subgroup indication field and a PO indication field instead of the PO / subgroup indication field. The subgroup indication field is as explained in FIG. 5. The PO indication field indicates the number of POs N s = 4. The PO associated with each code point may be determined in advance by a specification, or may be notified to the terminal 10 by higher layer signaling. For example, in Fig. 7, code point "00" indicates PO#0, and "01", "10", and "11" indicate PO#1, #2, and #3.

[0101] In FIG. 7, each code point in the PO indication field indicates one PO, but each code point may indicate one or more POs that are predetermined or notified by higher layer signaling. In this way, when the PO indication field is configured as code points indicating one or more POs, the number of bits in the PO indication field is, for example, ceil(log2(number of POs N s )) may also be indicated.

[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 that combines the PO indication field and the subgroup indication field. For example, in the 6-bit bit value shown in FIG. 7, the leftmost two bits indicate the value of the PO indication field, and the remaining four bits indicate the value of the subgroup indication field. Also, while FIG. 7 shows separate tables for the PO indication field and the subgroup indication field, a single table for the PO / subgroup indication field may be provided. In this 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] 7, for example, the 6-bit PO / subgroup indication field (i.e., the value of the PEI) in a single DCI format indicates that, among subgroups #0 to #15 of POs #0 to #3, only subgroup #1 of PO #1 is the target of paging. As described above, since terminal 10 belongs to subgroup #1, terminal 10 monitors paging DCI in PO #1, in which subgroup #1 is included in the paging targets, but may skip monitoring paging DCI in POs #0, #2, and #3, in which subgroup #1 is not included in the paging targets.

[0104] As shown in Figure 7, when the PO / subgroup indication field as a PEI is configured using code points, the number of bits in the PO / subgroup indication field can be reduced compared to the bitmap case shown in Figure 6, and the overhead caused by the PEI can be reduced.

[0105] 6 and 7, a PEI monitoring opportunity is provided before the first PO #0 among multiple POs #0 to #3 associated with the same PF. However, a PEI monitoring opportunity may be provided in at least one of the multiple POs. For example, a PEI monitoring opportunity may be provided in a slot or symbol before a PDCCH monitoring opportunity in the first PO #0, and monitoring of paging DCIs in the PDCCH monitoring opportunities in the POs #0 to #3 may be controlled as described above based on each PEI detected in the PO #0. Also, in FIGS. 6 and 7, the POs #0 to #3 associated with the same PF are arranged at equal intervals, but this is not a limitation and at least two POs may be consecutive in time. As described above, FIGS. 6 and 7 are merely examples and are not limited to those shown. Furthermore, although not shown, a DCI format including multiple subgroup indication fields as a PEI corresponding to multiple POs may be used. For example, in FIG. 7, 16 bits may be provided as a PEI corresponding to POs #0 to #3, and the subgroups to be paged in the POs #0 to #3 may be specified by four subgroup indication fields as the PEI.

[0106] In the second embodiment, the total number of subgroups N sg and number of POs N s Since the number of bits of the PO / subgroup indication field (or the PO indication field and the subgroup indication field) is appropriately determined based on the above, monitoring in the PEI monitoring opportunity can be appropriately performed. Furthermore, since it is possible to specify subgroups to be paged in the multiple POs using the DCI-based PEI corresponding to the multiple POs, it is possible to reduce the PEI monitoring opportunity of the terminal 10 compared to the first aspect.

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

[0108] 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 a paging message via a 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. This skipping can prevent unnecessary power consumption in the PO that is not the target of paging.

[0109] Incidentally, the paging DCI can be used not only for scheduling the PDSCH that transmits the paging message but also for transmitting a short message. The short message is used, for example, for notification of a modification of system information (e.g., BCCH other than SIB6, SIB7, and SIB8), an ETWS primary notification, an ETWS secondary notification, and / or a CMAS notification.

[0110] 8A to 8C are diagrams showing an example of paging DCI according to this embodiment. In Fig. 8, DCI format 1_0 that is CRC scrambled by P-RNTI is assumed as the paging DCI, but this is not limiting. As shown in Fig. 8A to 8C, the paging DCI includes a short message indicator.

[0111] As shown in Figure 8(A), a short message identifier "10" may indicate that only a short message is present in the paging DCI. As shown in Figure 8(B), a short message identifier "01" may indicate that scheduling information for a paging message (e.g., allocation information for frequency domain resources and time domain resources) is present in the paging DCI, but no short message is present. As shown in Figure 8(C), a short message identifier "11" may indicate that both the scheduling information and a short message are present in the paging DCI.

[0112] For example, the value "1" of the MSB of the short message in the paging DCI in Figures 8(A) and (C) may indicate an update notification of the system information. Also, the value "1" of the second bit from the left of the short message may indicate 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 Figure 8(A) and the paging DCI including scheduling information for paging shown in Figures 8(B) and (C), they are also referred to as a "DCI for short message" and a "DCI for paging scheduling."

[0113] As described above, by skipping monitoring of paging DCI in a PO whose subgroup to which the terminal 10 belongs is not subject to paging, it is possible to save power consumption of the terminal 10. On the other hand, a DCI for a short message (e.g., FIG. 8(A)) for the terminal 10 is transmitted in the PO as well. For this reason, if the terminal 10 skips monitoring of paging DCI in the PO to save power consumption, it may not be able to receive the DCI for a short message, and may not be able to detect at least one of the system information update notification, ETWS, and CMAS.

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

[0115] Specifically, if the subgroup indicated by the PEI does not include a subgroup assigned to the terminal 10, or if the PEI is not received, the terminal 10 does not receive and / or decode (hereinafter referred to as "reception / decoding") the PDSCH in the PO (skips it). In this case, the terminal 10 does not receive / decode the PDSCH, but receives / decodes the short message included in the DCI for short message (for example, FIG. 8(A)) detected by PDCCH monitoring in the PO.

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

[0117] As described above, in subgrouping, multiple terminals are divided into subgroups, and paging is performed on a subgroup basis. Here, the multiple terminals may include terminals that do not support PEI (e.g., terminals that support a release earlier than NR Release 17, terminals that do not have the ability to support PEI, etc.). Then, in a certain PO, base station 20 transmits paging scheduling DCI including scheduling information intended for terminals that do not support PEI, and performs PDSCH scheduling. Meanwhile, in the certain PO, terminals that support PEI (i.e., terminals 10) detect paging scheduling DCI including scheduling information transmitted intended for terminals that do not support PEI. In other words, the scheduling information included in the paging scheduling DCI transmitted in the certain PO is for terminals that do not support PEI, and terminals that support PEI (i.e., terminals 10) may ignore the scheduling information.

[0118] In this way, when terminal 10 detects DCI for paging scheduling, it only receives / decodes short messages and does not receive / decode PDSCH, thereby enabling terminals that do not support PEI and terminals that support PEI to coexist (schedule) in the same PO. Also, it is possible to have terminals that do not support PEI receive / decode PDSCH and terminals that support PEI ignore PDSCH reception / decoding, thereby realizing efficient scheduling. It is also possible to have terminals that support PEI receive / decode short messages, allowing updates to system information and notifications of ETWS and CMAS.

[0119] On the other hand, if the subgroup indicated by the PEI includes the subgroup assigned to the terminal 10, the terminal 10 receives / decodes the PDSCH in the PO (i.e., receives / decodes the paging message transmitted via the PDSCH). This is because the DCI for paging scheduling (e.g., FIG. 8(B) or (C)) is detected in the PO for which the subgroup to which the terminal 10 belongs is the paging target.

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

[0121] Note that the terminal 10 may monitor the PEI when receiving configuration information related to reception of the PEI (for example, the above-mentioned information on the total number of subgroups). If the configuration information is not received, the terminal 10 may determine that subgrouping is not performed, and may perform PDCCH monitoring in each configured PO without monitoring the PEI, and may receive / decode a paging message based on the detected paging DCI. The terminal 10 may also receive the configuration information through higher layer signaling.

[0122] Fig. 9 is a diagram showing an example of terminal operation in a PO according to the third aspect of this embodiment. Fig. 9 assumes the PEI described in the first aspect, but as mentioned above, the PEI is not limited to this. For example, in Fig. 9, it is assumed that the PEI indicates that the paging target of PO #0 is subgroup #0 and the paging target of PO #1 is subgroup #1. It is also assumed that terminal 10 belongs to subgroup #1. In Fig. 9, differences from Figs. 4 to 7 will be mainly described.

[0123] As shown in Fig. 9, terminal 10 continues PDCCH monitoring in each PO regardless of which subgroup each PO targets for paging. For example, even in PO #0, which does not target subgroup #1 to which terminal 10 belongs for paging, terminal 10 monitors PDCCH, detects DCI for short messages (e.g., Fig. 8(A)), and receives short messages. In PO #0, subgroup #1 is not targeted for paging, so DCI for paging scheduling (e.g., Fig. 8(B) or (C)) is not transmitted or detected. Therefore, in PO #0, terminal 10 does not receive / decode paging messages.

[0124] On the other hand, a paging scheduling DCI (e.g., FIG. 8(B) or (C)) is transmitted in PO#1, which targets subgroup #1 to which terminal 10 belongs. 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] In addition, in PO#1, DCI for a short message (for example, FIG. 8(A)) may also be transmitted to terminal 10. When terminal 10 detects the DCI for a short message by PDCCH monitoring in PO#1, terminal 10 may receive the short message included in the DCI for a short message.

[0126] In Figure 9, PDCCH monitoring continues even in a PO where the subgroup to which the mobile station belongs is not subject to paging, so that if a paging DCI (e.g., DCI format 1_0 CRC-scrambled by P-RNTI) is used for both short messages and scheduling, the mobile station can receive short messages in the PO.

[0127] (Fourth aspect) Next, a subgroup derivation operation will be described as a fourth aspect of this embodiment. Note that the above first to third aspects can be applied to cases where subgrouping is performed either on a terminal identifier basis or on a network basis. Here, an operation for deriving a subgroup to which a terminal 10 belongs when subgrouping is performed on a network basis will be described. Also, the PEI may be any information or signal indicating a subgroup to be paged in a PO, and is not limited to being DCI-based, and can also be applied to an SSS-based or TRS-based system, etc. Note that the fourth aspect can be combined with the above first or second aspect and / or the above third aspect.

[0128] Subgroup composition (e.g., total number of subgroups N sgThe number of subgroups (N, etc.) is determined for each predetermined unit (e.g., cell, tracking area, or RAN area) depending on various factors such as paging strategy and load status, and it is assumed that the subgroup configuration may differ between different units. For example, in cell A, the total number of subgroups is N sg is 2, but in cell B the total number of subgroups is N sg It is also assumed that is 4.

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

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

[0131] 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, the subgroup set information includes the total number of subgroups N sg and the total number of subgroups, N sg, and information about the subgroups (e.g., subgroup IDs) assigned to the terminal 10. For example, in FIG. 10, the total number of subgroups N sg =2, 3, 4, . . . , 16 indicate the subgroup IDs assigned to the terminals 10, respectively.

[0132] The CN device is sg Every, up to N sg Subgroups #0 to #N sg -1, the subgroup to which the terminal 10 belongs may be determined based on at least one of the performance of the terminal 10, the load of the network, the paging strategy, and the number of terminals 10 assigned to the same PF.

[0133] The terminal 10 derives the subgroup to which the terminal 10 belongs in the cell in which it is camped, based on the subgroup set information and the total number of subgroups information.

[0134] Fig. 11 is a diagram showing an example of a subgroup derivation operation according to the fourth aspect of this 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, it is assumed that the PEI (for example, Fig. 5) includes a subgroup indication field configured with code points, but as mentioned above, the PEI is not limited to this. In Fig. 11, differences from Figs. 4 to 7 will be mainly explained.

[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 is N sg = 2, and the subgroup indication field in the PEI is 1 bit. Here, 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, the subgroup indication field values ​​"00", "01", "10", and "11" indicate subgroups #0, #1, #2, and #3, respectively.

[0136] In FIG. 11, the terminal 10 is configured to receive the total number of subgroups N in the cell A. sg is 2, and the total number of subgroups in Figure 10 is N sg =2 is associated with subgroup #1, so in cell A Sub On the other hand, the terminal 10 determines that it belongs to group #1. sg is 4, and the total number of subgroups in Figure 10 is N sg =4 is associated with subgroup #0, so in cell B Sub It is determined that the user belongs to group #0.

[0137] 11, when terminal 10 is camped on cell A, the PEI indicates that the paging target of PO#0 is subgroup #1 and that the paging target of PO#1 is subgroup #0. As described above, terminal 10 belongs to subgroup #1 in cell A, so terminal 10 may monitor paging DCI in PO#0 while skipping monitoring paging DCI in PO#1. Although not shown, terminal 10 may of course continue monitoring paging DCI in PO#1 to receive short messages.

[0138] Furthermore, when terminal 10 is camped on cell B, the PEI indicates that the paging target of PO #0 is subgroup #3 and the paging target of PO #1 is subgroup #0. As described above, terminal 10 belongs to subgroup #0 in cell B, so terminal 10 may skip monitoring paging DCI in PO #0, while monitoring paging DCI in PO #1. Although not shown, terminal 10 may of course continue monitoring paging DCI in PO #0 to receive short messages.

[0139] 12 is a diagram showing an example of a change in specifications related to the subgroup total number information of this embodiment. As described above, the subgroup total number information is notified to the terminal 10 by higher layer signaling. While FIG. 12 shows an example in which the subgroup total number information is included in SIB1, it is needless to say that this is not limiting.

[0140] As shown in FIG. 12, the total number of subgroups information (e.g., RRC IE “nrofPagingSubGroup”) may be included in the RRC IE “DownlinkConfigCommonSIB” in the RRC IE “ServingCellConfigCommonSIB” of SIB1. The total number of subgroups information is the total number N of subgroups supported in cell C. sg Specify a value between 2 and 16.

[0141] For example, if the total number of subgroups information (for example, RRC IE “nrofPagingSubGroup”) exists in the SIB1 and the terminal 10 supports paging subgroups, the terminal 10 determines the total number of subgroups N indicated by the total number of subgroups information (for example, RRC IE “nrofPagingSubGroup”). sg (i.e., the subgroup in FIG. 10) may be set as the subgroup assigned to the terminal 10, as given by the upper layer (e.g., NAS specified in TS24.501).

[0142] As a result, as shown in FIG. 11, the terminal 10 sg Even if the terminal 10 moves between different cells, the terminal 10 can derive the subgroup assigned to it.

[0143] (Configuration of wireless communication system) Next, we will explain the configuration of each device in the above-described wireless communication system 1. Note that the following configuration is intended to show the configuration necessary for explaining this embodiment, and does not exclude each device from having a functional block other than that shown.

[0144] <Hardware configuration> 13 is a diagram showing an example of the hardware configuration of each device in the wireless communication system according to this embodiment. Each device in the wireless communication system 1 (for example, a terminal 10, a base station 20, a CN 30, etc.) includes a processor 11, a storage device 12, a communication device 13 for performing wired or wireless communication, and an input device 14 for accepting various input operations and outputting 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 this embodiment by reading and executing a program from the storage device 12. Each device in the wireless communication system 1 may be configured with one or more processors 11. Furthermore, each device may be called a computer.

[0146] The storage device 12 is configured by, for example, storage such as a memory, a hard disk drive (HDD), and / or a solid state drive (SSD), etc. The storage device 12 may store various information necessary for the processor 11 to execute processing (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. The communication device 13 may also include an amplifier, an RF (Radio Frequency) device that performs processing related to wireless signals, and a BB (BaseBand) device that performs baseband signal processing.

[0148] The RF device performs, for example, D / A conversion, modulation, frequency conversion, power amplification, etc. on the digital baseband signal received from the BB device to generate a radio signal to be transmitted from antenna A. The RF device also performs frequency conversion, demodulation, A / D conversion, etc. on the radio signal received from the antenna to generate a digital baseband signal and transmit it to the BB device. The BB device performs processing to convert the digital baseband signal into packets, and processing to convert the packets into digital baseband signals.

[0149] The input / output device 14 includes, for example, input devices such as a keyboard, a touch panel, a mouse, and / or a microphone, and output devices 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 shown in Fig. 13, or may include hardware not shown in Fig. 13. Furthermore, the hardware shown in Fig. 13 may be configured using one or more chips.

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

[0152] 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. 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. 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. The receiving unit 101 may also receive information and / or data transmitted via the downlink signal. Here, "receiving" may include, for example, performing reception-related processing such as at least one of reception, demapping, demodulation, decoding, monitoring, and measurement of a radio signal. The downlink signal may include, for example, at least one of a PDSCH, a PDCCH, a downlink reference signal, a synchronization signal, a PBCH, and the like.

[0154] The receiver 101 monitors PDCCH candidates in a search space to detect DCI. The receiver 101 may receive downlink user data and / or control information of higher layers (e.g., Medium Access Control Element (MAC CE), an RRC message, or a NAS message) via a PDSCH scheduled using DCI.

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

[0156] In addition, the receiving unit 101 may receive downlink control information including a field indicating a subgroup to be paged in a paging period (e.g., a PO) (e.g., a subgroup indication field as a PEI) (first aspect, e.g., Figures 4 and 5).

[0157] In addition, the receiving unit 101 may receive downlink control information including a field indicating a subgroup to be paged in multiple paging periods (e.g., multiple POs) (e.g., a PO / subgroup indication field as a PEI, or a PO indication field and a subgroup indication field) (second aspect, e.g., Figures 6 and 7).

[0158] The receiving unit 101 may receive downlink control information (for example, 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 related to reception of information or a signal (for example, PEI) indicating a subgroup to be paged during a paging period. The setting information may be, for example, the above-mentioned information on the total number of subgroups.

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

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

[0163] When 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 receive and / or decode 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 on a set of subgroups assigned to the terminal 10 for each of a plurality of total subgroups (for example, the subgroup set information in FIG. 10 ), and information on the total number of subgroups in a predetermined unit (for example, the above-mentioned total subgroup number information). The predetermined unit may be, for example, a cell on which the terminal 10 is camped, a tracking area to which the terminal 10 belongs, or a RAN area to which the terminal 10 belongs. The receiving unit 101 may receive the information on the set of subgroups by NAS signaling, and may receive the information on the total number of subgroups by the NAS signaling, system information, or RRC signaling.

[0165] The transmitting unit 102 transmits an uplink signal. The transmitting unit 102 may also transmit information and / or data transmitted via the uplink signal. Here, "transmitting" 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 at least one of an uplink shared channel (e.g., a physical uplink shared channel (PUSCH)), a random access preamble (e.g., a physical random access channel (PRACH)), an uplink reference signal, etc.

[0166] The transmitter 102 may transmit uplink user data and / or control information of higher layers (for example, MAC CE, RRC message, etc.) via a PUSCH that is scheduled using the DCI received by the receiver 101.

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

[0168] For example, the control unit 103 controls the execution of monitoring during a paging period (e.g., the execution of monitoring during a paging period in a first and / or second operation related to a PEI) based on the value of the field in the downlink control information (first aspect). Also, the control unit 103 may determine the number of bits of the above field in the downlink control information based on information regarding the total number of subgroups. The field may be configured as a bitmap with the same number of bits as the total number of subgroups (e.g., FIG. 4). The field may be configured as a code point with the number of bits determined based on the total number of subgroups (e.g., FIG. 5).

[0169] If the subgroup indicated by the value of the field in the downlink control information does not include a subgroup assigned to the terminal 10, the control unit 103 may skip performing the monitoring during the paging period (e.g., monitoring the paging DCI and / or receiving and / or decoding the PDSCH) (e.g., Figures 4 and 5).

[0170] If the subgroup indicated by the value of the field in the downlink control information includes a subgroup assigned to the terminal 10, the control unit 103 may perform the monitoring (e.g., monitoring of paging DCI and / or receiving and / or decoding of PDSCH) during the paging period (e.g., Figures 4 and 5).

[0171] The control unit 103 controls the execution of monitoring in a plurality of paging periods (e.g., execution of monitoring in a paging period in a first and / or second operation related to a PEI) based on the value of the field in the downlink control information (second aspect). Furthermore, the control unit 103 may determine the number of bits of the field in the downlink control information based on information on the total number of subgroups and information on the number of the plurality of periods. The field may be configured as a bitmap with a number of bits equal to the product of the total number of subgroups and the number of the plurality of paging periods (e.g., FIG. 6). The field may include a first field with a number of bits determined based on the total number of subgroups and a second field with a number of bits determined based on the number of the plurality of periods (e.g., FIG. 7). The field may be configured by concatenating a code point with a number of bits determined based on the total number of subgroups and a code point with a number of bits determined based on the number of the plurality of periods (e.g., FIG. 7).

[0172] If the subgroups in at least one of the multiple paging periods indicated by the value of the field in the downlink control information do not include a subgroup assigned to terminal 10, the control unit 103 may skip performing the monitoring (e.g., paging DCI monitoring, and / or receiving and / or decoding PDSCH) in that paging period (e.g., Figures 6 and 7).

[0173] The control unit 103 may perform the monitoring (e.g., monitoring of paging DCI and / or receiving and / or decoding of PDSCH) during a paging period when the subgroup in at least one of the multiple periods indicated by the value of the field in the downlink control information includes a subgroup assigned to the terminal (e.g., Figures 6 and 7).

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

[0175] The control unit 103 may control reception of information or a signal (e.g., PEI) indicating a subgroup to be paged during a paging period. Furthermore, the control unit 103 may monitor downlink control information (e.g., paging DCI) whose 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 the subgroup to which the terminal 10 belongs in the predetermined unit based on the information on the set of subgroups and the information on the total number of subgroups (fourth aspect).

[0177] When the receiving unit 101 receives information or a signal (e.g., PEI) indicating a subgroup to be paged in a paging period, the control unit 103 may control monitoring of downlink control information (e.g., paging DCI) in 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 in 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 monitor the downlink control information in the period (e.g., FIG. 11). The control unit 103 may monitor the downlink control information in the paging period regardless of the subgroup indicated by the information or the signal.

[0178] ≪Base station≫ 15 is a diagram showing an example of a functional block configuration of a base station according to this 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] 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. 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. 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. The receiving unit 201 may also receive information and / or data transmitted via the uplink signal.

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

[0182] In addition, the transmitting unit 202 may transmit downlink control information including a field indicating a subgroup to be paged in a paging period (e.g., PO) (e.g., a subgroup indication field as a PEI) (first aspect, e.g., Figures 4 and 5).

[0183] In addition, the transmitting unit 202 may transmit downlink control information including a field indicating a subgroup to be paged in multiple paging periods (e.g., multiple POs) (e.g., a PO / subgroup indication field as a PEI, or a PO indication field and a subgroup indication field) (second aspect, e.g., Figures 6 and 7).

[0184] The transmitter 202 may transmit downlink control information (for example, paging DCI) monitored in the 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 transmitter 202 transmits setting information related to reception of information or a signal (for example, a PEI) indicating a subgroup to be paged during a paging period. The setting information may be, for example, the above-mentioned information on the total number of subgroups.

[0187] The transmitter 202 may transmit information or a signal (eg, a PEI) indicating a subgroup to be paged in a paging period.

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

[0189] The control unit 203 performs various controls in the base station 20. Note that some of the information transmitted from the transmission unit 202 of the base station may be transmitted by a transmission unit within 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 various signals, information, and parameters may be replaced with signals, information, and parameters of any layer, such as an upper layer (e.g., a Non Access Stratum (NAS) layer, an RRC layer, a MAC layer, etc.) or a lower layer (e.g., a physical layer). Furthermore, notification of predetermined information is not limited to being explicitly performed, and may be performed implicitly (e.g., by not notifying information or by using other information).

[0191] Furthermore, the names of various signals, information, parameters, IEs, channels, time units, and frequency units in the above embodiments are merely examples and may be replaced with other names. For example, a slot may be named in any way as long as it is a time unit having a predetermined number of symbols. Furthermore, an RB may be named in any way as long as it is a frequency unit having a predetermined number of subcarriers. Furthermore, "first..." and "second..." merely identify multiple pieces of information or signals, and the order may be changed as appropriate.

[0192] Furthermore, the applications of the terminal 10 in the above embodiments (for example, RedCap, IoT, etc.) are not limited to those exemplified, and the terminal 10 may be used for any application (for example, eMBB, URLLC, Device-to-Device (D2D), Vehicle-to-Everything (V2X), etc.) as long as it has similar functions. Furthermore, the format of the various information is not limited to that in the above embodiments, and may be changed as appropriate to bit representation (0 or 1), boolean value (Boolean: true or false), integer value, character, etc. Furthermore, the singular and plural in the above embodiments may be interchangeable.

[0193] The above-described embodiments are intended to facilitate understanding of the present disclosure and are not intended to limit the present disclosure. The flowcharts, sequences, elements included in the embodiments, and their arrangements, indexes, conditions, etc. described in the embodiments are not limited to those exemplified and can be modified as appropriate. Furthermore, at least some of the configurations described in the above embodiments can be partially replaced or combined. [Explanation of symbols]

[0194] 1...wireless communication system, 20...base station, 30...core network, 101...receiving unit, 102...transmitting unit, 103...control unit, 201...receiving unit, 202...transmitting unit, 203...control unit, 11...processor, 12...storage device, 13...communication device, 14...input / output device

Claims

1. A terminal, a receiving unit configured to receive, from a base station, system information including first information for setting a search space index for physical downlink control channel (PDCCH) monitoring for a downlink control information (DCI) format including a paging early indication (PEI) and second information for setting a search space index for PDCCH monitoring for a DCI format for paging; When an index of a search space for PDCCH monitoring for a DCI format including the PEI is set to 0 based on the first information, monitoring a PDCCH for a DCI format including the PEI in a PDCCH monitoring opportunity for Remaining system information (RMSI); When an index of a search space for PDCCH monitoring for a DCI format including the PEI is set to a value other than 0 based on the first information, monitor a PDCCH for the DCI format including the PEI at a PDCCH monitoring opportunity for the PEI; a control unit that monitors a PDCCH for the paging DCI format at a PDCCH monitoring opportunity based on the second information when the PEI indicates a subgroup to which the terminal belongs; A terminal comprising:

2. When the control unit does not detect the PEI or when the PEI does not indicate a subgroup to which the terminal belongs, the control unit skips monitoring of a PDCCH for the DCI format for paging in a PDCCH monitoring opportunity based on the second information. The terminal according to claim 1 .

3. A base station, a transmitter configured to transmit, to a terminal, system information including first information for setting a search space index for physical downlink control channel (PDCCH) monitoring for a downlink control information (DCI) format including a paging early indication (PEI) and second information for setting a search space index for PDCCH monitoring for a DCI format for paging; When an index of a search space for PDCCH monitoring for a DCI format including the PEI is set to 0 based on the first information, the DCI format including the PEI is transmitted to the terminal via a PDCCH during a PDCCH monitoring opportunity for Remaining system information (RMSI); When an index of a search space for PDCCH monitoring for a DCI format including the PEI is set to a value other than 0 based on the first information, the DCI format including the PEI is transmitted to the terminal via a PDCCH during a PDCCH monitoring opportunity for the PEI; a control unit that transmits the DCI format for paging to the terminal on a PDCCH during a PDCCH monitoring opportunity based on the second information when the PEI indicates a subgroup to which the terminal belongs; A base station comprising:

4. A wireless communication method for a terminal, comprising: receiving, from a base station, system information including first information for configuring a search space index for physical downlink control channel (PDCCH) monitoring for a downlink control information (DCI) format including a paging early indication (PEI) and second information for configuring a search space index for PDCCH monitoring for a DCI format for paging; monitoring the PDCCH for the DCI format including the PEI in a PDCCH monitoring opportunity for Remaining system information (RMSI) when an index of a search space for PDCCH monitoring for the DCI format including the PEI is set to 0 based on the first information; When an index of a search space for PDCCH monitoring for a DCI format including the PEI is set to a value other than 0 based on the first information, monitoring the PDCCH for the DCI format including the PEI at a PDCCH monitoring opportunity for the PEI; If the PEI indicates a subgroup to which the terminal belongs, monitoring a PDCCH for the DCI format for paging at a PDCCH monitoring opportunity based on the second information; A wireless communication method for a terminal having the above configuration.

5. 5. The wireless communication method according to claim 4, further comprising: skipping monitoring of a PDCCH for the paging DCI format in a PDCCH monitoring opportunity based on the second information when the PEI is not detected or when the PEI does not indicate a subgroup to which the terminal belongs.

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