WO2023238686A1

WO2023238686A1 - Communication device, base station, and communication method

Info

Publication number: WO2023238686A1
Application number: PCT/JP2023/019559
Authority: WO
Inventors: 卓宏古山; 秀明 ▲高▼橋
Original assignee: 株式会社デンソー
Priority date: 2022-06-06
Filing date: 2023-05-25
Publication date: 2023-12-14

Abstract

A communication device (100), which is eRedCap UE that has the frequency bandwidth compatible with at least the PDSCH and reduced to a prescribed bandwidth, comprises: a reception unit (112) that receives, from a base station (200), an MIB on the PBCH; and a control unit (120) that acquires, from the base station (200), a shared message, which is used shared among a plurality of the communication devices (100), on the PDSCH on the basis of the MIB. MIBs include a parameter indicating whether the base station (200) provides a second shared message stipulated for eRedCap UE, independently from a first shared message stipulated for terminal types different from the eRedCap UE.

Description

Communication device, base station, and communication method

Cross-reference to related applications

This application is based on Japan Application No. 2022-091748 filed on June 6, 2022, and claims the benefit of priority thereto, and all contents of the patent application are referred to , incorporated herein by reference.

The present disclosure relates to a communication device, a base station, and a communication method used in a mobile communication system.

In Release 17 of the technical specifications for NR (New Radio) in the 3GPP (3rd Generation Partnership Project. Registered trademark, the same applies hereinafter), which is a standardization project for mobile communication systems, it is suitable for use cases such as industrial sensors, surveillance cameras, and wearables. A new type of low-performance communication equipment (UE: User Equipment) has been introduced. Such a terminal type (also referred to as "UE type") is also referred to as "RedCap (Reduced Capability) UE."

In Release 18 of the 3GPP technical specifications, it is being considered to introduce a new terminal type that is even less complex than RedCap UE. It is assumed that the performance of such a new terminal type is between that of RedCap UE introduced in Release 17 and LPWA (Low Power Wide Area) of LTE (Long Term Evolution). Such a new terminal type is referred to as "eRedCap UE." In the following, eRedCap UE is also referred to as a "predetermined terminal type."

For eRedCap UE, (a) reducing the compatible frequency bandwidth in FR1 (Frequency Range 1) to a predetermined bandwidth (for example, 5 MHz), and (b) reducing the frequency bandwidth in FR1 to reduce the peak data rate. It has been proposed to reduce the frequency bandwidth for a data channel to a predetermined bandwidth (for example, see Non-Patent Documents 1 to 5). Here, the data channel refers to a physical channel for transmitting data, that is, a physical downlink shared channel (PDSCH) and/or a physical uplink shared channel (PUSCH). Note that the frequency bandwidth is also simply referred to as "bandwidth."

In method (a) above, the bandwidth that can be supported by both the RF (Radio Frequency) section and the BB (Base Band) section of the UE (i.e., the maximum bandwidth) is reduced, and the complexity of the RF section and the BB section is reduced. It is possible to reduce the On the other hand, with the method (b) above, it is possible to reduce the bandwidth that can be handled mainly by the BB section of the UE, and reduce the complexity of the BB section. Furthermore, with the method (b) above, it is possible to reduce changes in technical specifications for physical channel configurations other than PDSCH and/or PUSCH.

As a result of the inventor's detailed study, when a communication device of a predetermined terminal type such as the eRedCap UE described above is introduced, there is a problem with the transmission of a common message that is commonly transmitted to multiple terminals on the PDSCH. An issue was found that there is a concern that restrictions may occur.

Therefore, the present disclosure aims to provide a communication device, a base station, and a communication method that make it possible to relax restrictions on transmission of common messages even when a communication device of a predetermined terminal type such as eRedCap UE is introduced. purpose.

The communication device according to the first aspect is a communication device of a predetermined terminal type in which the frequency bandwidth that can be supported for at least a physical downlink shared channel is reduced to a predetermined bandwidth, and the communication device transmits a master information block on a physical broadcast channel. The communication device includes a receiving unit that receives data from a base station, and a control unit that obtains a common message commonly used by a plurality of communication devices from the base station on the physical downlink shared channel based on the master information block. The master information block is configured such that a second common message defined for the predetermined terminal type is provided from the base station independently of a first common message defined for a terminal type different from the predetermined terminal type. Contains a parameter indicating whether the

The base station according to the second aspect includes a transmitting unit that transmits a master information block on a physical broadcast channel, and a transmitting unit that transmits a common message commonly used for a plurality of communication devices on the physical downlink shared channel based on the master information block. and a control unit provided to the plurality of communication devices. In the master information block, a second common message defined for the predetermined terminal type is provided from the base station independently of a first common message defined for a terminal type different from the predetermined terminal type. Contains a parameter indicating whether or not. The predetermined terminal type is a terminal type in which a frequency bandwidth that can be supported at least for a physical downlink shared channel is reduced to a predetermined bandwidth.

The communication method according to the third aspect is a communication method executed by a communication device of a predetermined terminal type in which the frequency bandwidth that can be supported by at least a physical downlink shared channel is reduced to a predetermined bandwidth, receiving from a base station on a physical broadcast channel; and obtaining a common message commonly used for a plurality of communication devices from the base station on the physical downlink shared channel based on the master information block. Be prepared. The master information block is configured such that a second common message defined for the predetermined terminal type is provided from the base station independently of a first common message defined for a terminal type different from the predetermined terminal type. Contains a parameter indicating whether the

The above objects and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings. The drawing is
FIG. 1 is a diagram for explaining the configuration of a mobile communication system according to an embodiment, FIG. 2 is a diagram for explaining a configuration example of a protocol stack in a mobile communication system according to an embodiment, FIG. 3 is a diagram for explaining an overview of initial access in the mobile communication system according to the embodiment, FIG. 4 shows the value of controlResourceSetZero, which is a parameter included in pdcch-ConfigSIB1 included in MIB in the mobile communication system according to the embodiment, and the parameter for CORESET#0 (CORESET for Type0-PDCCH search space set). Correspondence with FIG. 2 is a diagram showing an example of a table shown in FIG. FIG. 5 shows the value of searchSpaceZero, which is a parameter included in pdcch-ConfigSIB1 included in MIB in the mobile communication system according to the embodiment, and the parameter for search space set #0 (PDCCH monitoring occasions for Type0-PDCCH CSS set). with It is a diagram showing an example of a table showing correspondence relationships, FIG. 6 is a diagram illustrating a paging message transmission method in the mobile communication system according to the embodiment, FIG. 7 is a diagram illustrating a system information message (SIB) transmission method in the mobile communication system according to the embodiment, FIG. 8 is a diagram illustrating a random access (RA) response transmission method in the mobile communication system according to the embodiment, FIG. 9 is a diagram showing "DCI format 1_0 with P-RNTI", "DCI format 1_0 with SI-RNTI", and "DCI format 1_0 with RA-RNTI" in the mobile communication system according to the embodiment, FIG. 10 is a diagram for explaining an overview of eRedCap UE in the mobile communication system according to the embodiment, FIG. 11 is a diagram for explaining an overview of eRedCap UE in the mobile communication system according to the embodiment, FIG. 12 is a diagram for explaining the configuration of the UE according to the embodiment, FIG. 13 is a diagram for explaining the configuration of the base station according to the embodiment, FIG. 14 is a diagram showing MIB transmission operation in the base station according to the embodiment, FIG. 15 is a diagram showing MIB reception operation in the UE (eRedCap UE) according to the embodiment, FIG. 16 is a diagram showing an example of table configuration according to the embodiment, FIG. 17 is a diagram illustrating a sequence example of an initial access method of an eRedCap UE according to an embodiment, FIG. 18 is a diagram illustrating a first PDSCH resource allocation bit number identification method according to the embodiment, FIG. 19 is a diagram illustrating an example of the correspondence between the subcarrier spacing (SCS) and the second number of resource blocks according to the embodiment, FIG. 20 is a diagram illustrating a second PDSCH resource allocation bit number identification method according to the embodiment, FIG. 21 is a diagram illustrating an example of associating the first index (controlResourceSetZero) and the second number of resource blocks according to the embodiment, FIG. 22 is a diagram for explaining an overview of the handover method for eRedCap UE according to the embodiment, FIG. 23 is a diagram illustrating an example of a handover method for eRedCap UE according to the embodiment.

A mobile communication system according to an embodiment will be described with reference to the drawings. In the description of the drawings, the same or similar parts are designated by the same or similar symbols.

(1) Overview of mobile communication system First, the configuration of the mobile communication system according to the embodiment will be described.

(1.1) System Configuration The configuration of the mobile communication system 1 according to the embodiment will be described with reference to FIG. 1.

The mobile communication system 1 is a system that complies with the technical specifications of 3GPP. Below, as the mobile communication system 1, a mobile communication system based on NR (NR Radio Access), which is a radio access technology (RAT) of the 3GPP's fifth generation (5G) system, will be mainly explained. However, the mobile communication system 1 is at least partially based on E-UTRA (Evolved Universal Terrestrial Radio Access)/LTE (Long Term Evolution), which is a 3GPP fourth generation (4G) system RAT. It has a configuration based on It's okay.

The mobile communication system 1 includes a network 10 and a UE 100 that is a communication device that communicates with the network 10. Network 10 includes a radio access network (RAN) 20 and a core network (CN) 30. RAN20 is NG-RAN (Next Generation Radio Access Network) in 5G/NR. The RAN 20 may be E-UTRAN (Evolved Universal Terrestrial Radio Access Network) in 4G/LTE. CN30 is 5GC (5th Generation Core network) in 5G/NR. The CN 30 may be an EPC (Evolved Packet Core) in 4G/LTE.

The UE 100 is a device used by a user. The UE 100 is, for example, a device such as a mobile phone terminal such as a smartphone, a tablet terminal, a notebook PC, a communication module, a communication card, or a chipset. UE 100 may be a vehicle (for example, a car, a train, etc.) or a device installed therein. The UE 100 may be a transport aircraft other than a vehicle (for example, a ship, an airplane, etc.) or a device installed therein. UE 100 may be a sensor or a device provided therein. Note that the UE 100 is a mobile station, a mobile terminal, a mobile device, a mobile unit, a subscriber station, a subscriber terminal, a subscriber device, a subscriber unit, a wireless station, a wireless terminal, a wireless device, a wireless unit, a remote station, a remote terminal. , remote device, or remote unit.

The RAN 20 includes multiple base stations 200. Each base station 200 manages at least one cell. A cell constitutes the smallest unit of communication area. For example, one cell belongs to one frequency (carrier frequency) and is composed of one component carrier. The term "cell" may represent a wireless communication resource, and may also represent a communication target of the UE 100. Therefore, base station 200 in the following description may be read as "cell". Each base station 200 can perform wireless communication with the UE 100 located in its own cell. The base station 200 communicates with the UE 100 using a RAN protocol stack. Base station 200 provides user plane and control plane protocol termination for UE 100, and is connected to CN 30 via a base station-CN network interface. The base station 200 in 5G/NR is called a gNodeB (gNB), and the base station 200 in 4G/LTE is called an eNodeB (eNB). Further, the base station-CN interface in 5G/NR is called an NG interface, and the base station-CN interface in 4G/LTE is called an S1 interface. Base station 200 is connected to adjacent base stations via a network interface between base stations. The inter-base station interface in 5G/NR is called an Xn interface, and the inter-base station interface in 4G/LTE is called an X2 interface.

CN 30 includes a core network device 300. The core network device 300 is an AMF (Access and Mobility Management Function) and/or a UPF (User Plane Function) in 5G/NR. The core network device 300 may be an MME (Mobility Management Entity) and/or an S-GW (Serving Gateway) in 4G/LTE. AMF/MME performs mobility management of UE 100. UPF/S-GW provides functions specialized for user plane processing.

(1.2) Protocol stack configuration An example of the protocol stack configuration in the mobile communication system 1 according to the embodiment will be described with reference to FIG. 2.

The protocols in the wireless section between the UE 100 and the base station 200 include a physical (PHY) layer, a medium access control (MAC) layer, a radio link control (RLC) layer, and a packet data convergence protocol (PDCP) layer. and a radio resource control (RRC) layer.

The PHY layer performs encoding/decoding, modulation/demodulation, antenna mapping/demapping, and resource mapping/demapping. Data and control information are transmitted between the PHY layer of UE 100 and the PHY layer of base station 200 via a physical channel.

A physical channel is composed of multiple OFDM symbols in the time domain and multiple subcarriers in the frequency domain. One subframe is composed of multiple OFDM symbols in the time domain. A resource block is a resource allocation unit, and is composed of multiple OFDM symbols and multiple subcarriers. A frame can be made up of 10ms and can include 10 subframes made up of 1ms. A subframe may include a number of slots depending on the subcarrier spacing.

Among the physical channels, the physical downlink control channel (PDCCH) plays a central role, for example, for the purposes of downlink scheduling allocation, uplink scheduling grant, and transmission power control. The UE 100 uses a radio network temporary identifier (RNTI) assigned to the UE 100 from the base station 200, for example, C-RNTI (Cell-RNTI), MCS-C-RNTI (Modulation and Coding Scheme-C-RNTI), and/or Blind decoding of PDCCH is performed using CS-RNTI (Configured Scheduling-RNTI), and downlink control information (DCI) that has been successfully decoded is acquired as DCI addressed to the own UE. Here, a CRC (Cyclic Redundancy Check) parity bit scrambled by the C-RNTI, MCS-C-RNTI, or CS-RNTI is added to the DCI transmitted from the base station 200.

In NR, the UE 100 can use a bandwidth narrower than the system bandwidth (i.e., the cell bandwidth). The base station 200 sets a bandwidth portion (BWP) consisting of consecutive resource blocks (PRB: Physical Resource Block) to the UE 100. UE 100 transmits and receives data and control signals in active BWP. For example, a maximum of four BWPs can be set in the UE 100. Each BWP may have a different subcarrier spacing. The respective BWPs may have overlapping frequencies. When multiple BWPs are configured for the UE 100, the base station 200 can specify which BWP to activate through downlink control.

For example, the base station 200 can configure up to three control resource sets (CORESET) for each of up to four BWPs on the serving cell. CORESET is a radio resource for control information that the UE 100 should receive. Up to 12 CORESETs can be configured in the UE 100 on the serving cell. Each CORESET has an index (ID) from 0 to 11. For example, a CORESET is composed of six resource blocks (PRBs) and one, two, or three consecutive OFDM symbols in the time domain.

The MAC layer performs data priority control, retransmission processing using Hybrid ARQ (HARQ), random access procedure, etc. Data and control information are transmitted between the MAC layer of UE 100 and the MAC layer of base station 200 via a transport channel. The MAC layer of base station 200 includes a scheduler. The scheduler determines uplink and downlink transport formats (transport block size, modulation and coding scheme (MCS)) and resources to be allocated to the UE 100.

The RLC layer uses the functions of the MAC layer and PHY layer to transmit data to the RLC layer on the receiving side. Data and control information are transmitted between the RLC layer of UE 100 and the RLC layer of base station 200 via logical channels.

The PDCP layer performs header compression/expansion, and encryption/decryption.

A service data adaptation protocol (SDAP) layer may be provided as an upper layer of the PDCP layer. The SDAP layer performs mapping between an IP flow, which is a unit in which the core network performs QoS (Quality of Service) control, and a radio bearer, which is a unit in which an access stratum (AS) performs QoS control.

The RRC layer controls logical channels, transport channels and physical channels according to the establishment, re-establishment and release of radio bearers. RRC signaling for various settings is transmitted between the RRC layer of UE 100 and the RRC layer of base station 200. When there is an RRC connection between the RRC of the UE 100 and the RRC of the base station 200, the UE 100 is in an RRC connected state. If there is no RRC connection between the RRC of the UE 100 and the RRC of the base station 200, the UE 100 is in an RRC idle state. When the RRC connection between the RRC of the UE 100 and the RRC of the base station 200 is suspended, the UE 100 is in an RRC inactive state.

A non-access stratum (NAS) layer located above the RRC layer performs session management and mobility management of the UE 100. NAS signaling is transmitted between the NAS layer of the UE 100 and the NAS layer of the core network device 300 (AMF/MME). Note that the UE 100 has an application layer and the like in addition to the wireless interface protocol.

(2) Overview of BWP and SSB Next, an overview of BWP and SSB will be explained.

(2.1) BWP BWP is defined to reduce power consumption of the UE 100 and effectively utilize broadband carriers. BWP includes initial BWP (initial DL BWP and initial UL BWP) and dedicated BWP (dedicated DL BWP and dedicated UL BWP). Up to four DL BWPs and up to four UL BWPs are configured in the UE 100 within one serving cell according to its capabilities. Note that in the following, when DL BWP and UL BWP are not distinguished, they are simply referred to as BWP.

The initial BWP is a BWP used at least for initial access, and is commonly used by multiple UEs 100. For each of the initial DL BWP and the initial UL BWP, bwp-id, which is a BWP identifier, is defined as "0". The initial BWP includes an initial BWP derived and set by a master information block (MIB) transmitted on a physical broadcast channel (PBCH), and a system information block (SIB), specifically a system information block type 1 ( There are two types: initial BWP set by SIB1). The initial BWP set by the MIB has a bandwidth according to CORESET #0, which is set using parameters included in the MIB. The initial BWP set by SIB1 is set by various parameters (locationAndBandwidth, subcarrierSpacing, cyclicPrefix) included in ServingCellConfigCommonSIB, which is an information element in SIB1.

At the time of initial access to a cell, the UE 100 that has received the synchronization signal block (SSB: Synchronization Signal/PBCH block) of the cell, controls the controlResourceS in pdcch-ConfigSIB1, which is an information element included in the PBCH (MIB). etZero (0 to 15 Obtain the bandwidth (24, 48, or 96 resource blocks) of the Type-0 PDCCH CSS set from the setting value (integer value up to). Then, the UE 100 monitors the Type-0 PDCCH CSS set to obtain SIB1, and obtains locationAndBandwidth, which is a parameter indicating the frequency position and/or bandwidth of the initial BWP, from SIB1. Until the UE 100 receives message 4 (Msg. 4) during the random access procedure in the initial access, the UE 100 uses the initial BWP set by the MIB, that is, the bandwidth based on CORESET #0 for the initial BWP. On the other hand, Msg. 4, the UE 100 uses the bandwidth set in locationAndBandwidth in SIB1 for the initial BWP. In addition, Msg. 4 may be an RRCSetup message, an RRCResume message, or an RRCReestablishment message. The UE 100 transits from, for example, an RRC idle state to an RRC connected state by such an initial access (random access procedure).

A dedicated BWP is a BWP that is set exclusively for a certain UE 100 (UE-specific). A bwp-id other than "0" may be set in the dedicated BWP. For example, a dedicated DL BWP and a dedicated UL BWP are respectively configured based on BWP-Downlink and BWP-Uplink, which are information elements included in SevingcellConfig in an RRC message that is dedicated signaling transmitted from the base station 200 to the UE 100. . For example, each of BWP-Downlink and BWP-Uplink may include various parameters (locationAndBandwidth, subcarrierSpacing, cyclicPrefix) that configure the BWP.

The base station 200 can notify the UE 100 of the BWP used for communication with the base station 200 (i.e., active BWP) among the one or more configured BWPs. For example, the base station 200 can transmit to the UE 100 a BWP identifier that indicates the BWP to be activated when performing configuration, that is, the BWP that is first used in communication with the base station 200. In addition, for controlling switching from active BWP to BWP that is not active BWP (inactive BWP) and switching from inactive BWP to active BWP, for example, PDCCH (DCI), RRC signaling, MAC control element (MAC CE) , or switching by a timer is used.

Note that communication in an active BWP includes transmission on the uplink shared channel (UL-SCH) in the BWP, transmission on the random access channel (RACH) in the BWP (physical random access channel (PRACH) opportunity is set) monitoring of the physical downlink control channel (PDCCH) in the relevant BWP, transmission on the physical uplink control channel (PUCCH) in the relevant BWP (if PUCCH resources are configured), channel state information for the relevant BWP ( The information may include at least one of a report of CSI) and reception of a downlink shared channel (DL-SCH: Down Link-Shared CHannel) in the BWP.

Here, the UL-SCH is a transport channel and is mapped to the physical uplink shared channel (PUSCH), which is a physical channel. Furthermore, data transmitted on the UL-SCH is also referred to as UL-SCH data. For example, it may correspond to UL-SCH data and uplink user data. Further, the DL-SCH is a transport channel, and is mapped to a physical downlink shared channel (PDSCH), which is a physical channel. Furthermore, data transmitted on DL-SCH is also referred to as DL-SCH data. For example, it may correspond to DL-SCH data and downlink user data.

PUCCH is used to transmit uplink control information (UCI). For example, the uplink control information includes HARQ (Hybrid Automatic Repeat Request)-ACK, CSI, and/or scheduling request (SR). HARQ-ACK includes a positive acknowledgment or a negative acknowledgment. For example, PUCCH is used to transmit HARQ-ACK for PDSCH (ie, DL-SCH (DL-SCH data, downlink user data)). Here, DL-SCH data and/or downlink user data is also referred to as a downlink transport block.

For example, the UE 100 monitors a set of PDCCH candidates in one or more CORESETs in the active DL BWP. Monitoring the PDCCH may include decoding each of the PDCCH candidates according to a monitored downlink control information (DCI) format. Here, the UE 100 may monitor the DCI format to which a CRC (cyclic redundancy check, also referred to as CRC parity bit) scrambled by the RNTI set by the base station 200 is added. Here, RNTI is SI-RNTI (System Information-RNTI), RA-RNTI (Random Access RNTI), TC-RNTI (Temporary C-RNTI), P-RNTI (Paging RNTI) TI), and/or C-RNTI (Cell-RNTI). The set of PDCCH candidates that the UE 100 monitors may be defined as a PDCCH search space set. The search space sets may include common search space sets (CSS set(s)) and/or UE-specific search space sets (USS set(s)). Therefore, the base station 200 may set a CORESET and/or a search space set to the UE 100, and the UE 100 may monitor the PDCCH in the set CORESET and/or search space set.

(2.2) SSB
The base station 200 transmits SSB in the initial DL BWP. For example, the SSB is composed of four consecutive OFDM symbols, and a primary synchronization signal (PSS), a secondary synchronization signal (SSS), a PBCH (MIB), and a demodulation reference signal (DMRS) of the PBCH are arranged. The locations of resource elements (time resources and frequency resources) to which SSBs are mapped are defined in 3GPP technical specifications, such as "TS38.211" and "TS38.213." The bandwidth of SSB is, for example, a bandwidth of 240 consecutive subcarriers, or 20RB.

The SSB associated with SIB1 is called a cell-specific SSB (CD-SSB). From the perspective of one UE 100, one serving cell is associated with one CD-SSB. Note that SIB1 is also referred to as RMSI (Remaining Minimum System information). One CD-SSB corresponds to one cell with a unique NCGI (NR Cell Global Identifier). SSBs that are not associated with SIB1 (RMSI) are referred to as non-cell-specific SSBs (Non-CD-SSBs).

(3) Overview of initial access Next, an overview of initial access in the mobile communication system 1 according to the embodiment will be described with reference to FIGS. 3 to 5.

There are the following types of bandwidth common to UEs during initial access:
・SSB (CD-SSB) bandwidth: 240 consecutive subcarriers (i.e., 20 resource blocks),
- Bandwidth of CORESET #0: 24 resource blocks, 48 resource blocks, or 96 resource blocks,
- Initial BWP bandwidth: maximum 275 resource blocks determined by locationAndBandwidth, which is a parameter set in RRC.

As shown in FIG. 3, in step S1, the base station 200 transmits SSB. UE 100 receives the SSB.

In step S2, the UE 100 determines the bandwidth of CORESET #0 (value from 0 to 15) based on the value (value from 0 to 15) of the parameter (controlResourceSetZero) included in pdcch-ConfigSIB1 included in the MIB in the SSB received in step S1. 24, 48, or 96 resource blocks). CORESET #0 is a CORESET whose ID is set to #0, and is also referred to as a CORESET for Type-0 PDCCH CSS set. Here, Type-0 PDCCH CSS set is a parameter included in pdcch-ConfigSIB1 in MIB (pdcch-ConfigSIB1) or a parameter included in PDCCH-ConfigCommon (searchSpaceSIB1 or searchS paceZero) value in the common search space. It is set as a certain search space set #0. Search space set #0 consists of search spaces whose IDs are set to #0.

In step S3, the UE 100 monitors PDCCH candidates using the Type-0 PDCCH CSS set.

In step S4, the base station 200 transmits DCI in DCI format 1_0 to which a CRC scrambled by SI-RNTI is added on the PDCCH.

In step S5, the UE 100 receives (detects) the DCI and identifies PDSCH resource allocation (time and/or frequency resources) from the DCI.

In step S6, the base station 200 transmits SIB1 on the PDSCH scheduled with "DCI format 1_0 with SI-RNTI". The UE 100 receives (acquires) the SIB1 and acquires locationAndBandwidth, which is a parameter indicating the frequency position and bandwidth of the initial BWP (initial DL BWP and initial UL BWP), from the SIB1.

Figure 4 shows the value of controlResourceSetZero, which is a parameter included in pdcch-ConfigSIB1 included in MIB, and the value for CORESET #0 (CORESET for Type0-PDCCH search space set). This is a diagram showing an example of a table showing correspondence with parameters. be.

The correspondence relationship is defined in advance in the technical specifications, and the UE 100 maintains the table. Note that the example in FIG. 4 shows a table in which the maximum channel bandwidth is 5 MHz or 10 MHz, and the subcarrier spacing (SCS) of each of SSB and PDCCH is 15 kHz.

As shown in FIG. 4, the value of controlResourceSetZero, which is a parameter included in pdcch-ConfigSIB1 included in the MIB, is an index value from 0 to 15. The UE 100 uses the table to identify the corresponding CORESET #0 parameter (for example, the number of resource blocks, the number of symbols, etc.) from the value of the index.

FIG. 5 shows the value of searchSpaceZero, a parameter included in pdcch-ConfigSIB1 included in the MIB, and search space set #0 (PDCCH monitoring occasions for Type0-PDCCH CSS set). ) is an example of a table showing the correspondence with parameters. FIG. The correspondence relationship is defined in advance in the technical specifications, and the UE 100 maintains the table.

As shown in FIG. 5, the value of searchSpaceZero, which is a parameter included in pdcch-ConfigSIB1 included in the MIB, is an index value from 0 to 15. Using the table, the UE 100 identifies the corresponding search space set #0 (for example, the number per slot, the index of the first symbol, etc.) from the value of the index.

(4) Overview of common messages Next, an overview of common messages in the mobile communication system 1 according to the embodiment will be described with reference to FIGS. 6 to 9. A common message is a message that is commonly used by a plurality of UEs 100 and is transmitted on the PDSCH. Common messages include paging messages, system information messages, and random access (RA) responses.

FIG. 6 is a diagram showing a paging message transmission method in the mobile communication system 1 according to the embodiment.

In step S11, the base station 200 transmits DCI of DCI format 1_0 to which a CRC scrambled by P-RNTI is added (hereinafter also referred to as "DCI format 1_0 with P-RNTI") on the PDCCH.

In step S12, the UE 100 receives (detects) "DCI format 1_0 with P-RNTI" by monitoring "DCI format 1_0 with P-RNTI", and receives PDSCH resources from "DCI format 1_0 with P-RNTI". Identify allocations (time and/or frequency resources).

In step S13, the base station 200 transmits a paging message on the PDSCH scheduled with "DCI format 1_0 with P-RNTI". The UE 100 receives (obtains) a paging message on the PDSCH scheduled with "DCI format 1_0 with P-RNTI".

FIG. 7 is a diagram showing a method of transmitting a system information message (SIB: System Information Block) in the mobile communication system 1 according to the embodiment.

In step S21, the base station 200 transmits a DCI of DCI format 1_0 to which a CRC scrambled by SI-RNTI is added (hereinafter also referred to as "DCI format 1_0 with SI-RNTI") on the PDCCH.

In step S22, the UE 100 receives (detects) "DCI format 1_0 with SI-RNTI" by monitoring "DCI format 1_0 with SI-RNTI", and receives PDSCH resources from "DCI format 1_0 with SI-RNTI". Identify allocations (time and/or frequency resources).

In step S23, the base station 200 transmits a system information message on the PDSCH scheduled with "DCI format 1_0 with SI-RNTI". The UE 100 receives (obtains) the system information message on the PDSCH scheduled with "DCI format 1_0 with SI-RNTI".

FIG. 8 is a diagram showing a random access (RA) response transmission method in the mobile communication system 1 according to the embodiment.

In step S31, the base station 200 transmits a DCI of DCI format 1_0 to which a CRC scrambled by RA-RNTI is added (hereinafter also referred to as "DCI format 1_0 with RA-RNTI") on the PDCCH.

In step S32, the UE 100 receives (detects) "DCI format 1_0 with RA-RNTI" by monitoring "DCI format 1_0 with RA-RNTI", and receives PDSCH resources from "DCI format 1_0 with RA-RNTI". Identify allocations (time and/or frequency resources).

In step S33, the base station 200 transmits an RA response on the PDSCH scheduled with "DCI format 1_0 with RA-RNTI". The UE 100 receives (obtains) the RA response on the PDSCH scheduled with "DCI format 1_0 with RA-RNTI".

FIG. 9 is a diagram showing "DCI format 1_0 with P-RNTI", "DCI format 1_0 with SI-RNTI", and "DCI format 1_0 with RA-RNTI" in the mobile communication system 1 according to the embodiment.

As shown in FIG. 9, such DCI format 1_0 includes a "Frequency domain resource assignment" field that indicates PDSCH resource assignment in the frequency domain, and a "Time domain resource" field that indicates PDSCH resource assignment in the time domain. assignment” field and including.

The number of bits (bit length) of the "Time domain resource assignment" field is fixed at 4 bits. On the other hand, the number of bits (bit length) in the "Frequency domain resource assignment" field is the size of CORESET #0.

It is variable depending on. Here, the CORESET #0 size is expressed by the number of resource blocks (RB number).

(5) Overview of eRedCap UE Next, an overview of the eRedCap UE in the mobile communication system 1 according to the embodiment will be described with reference to FIGS. 10 and 11.

In Release 17 of the 3GPP technical specifications, RedCap UE is introduced as a low-performance UE type suitable for use cases such as industrial sensors, surveillance cameras, and wearables. RedCap UE is also referred to as a "Reduced capability NR device." RedCap UE is a UE type (terminal type) with reduced equipment cost and complexity compared to common UE types. RedCap UE has mid-range performance and price for IoT, and for example, compared to general UE types, the maximum bandwidth used for wireless communication is set narrower, and the number of receivers is smaller. . As shown in FIG. 10, for FR1, the bandwidth that the RedCap UE can support (ie, the maximum bandwidth supported by the RedCap UE) may be 20 MHz.

In Release 18 of the 3GPP technical specifications, it is being considered to introduce a new UE type that is even less complex than the RedCap UE. It is assumed that the performance of such new UE type is between that of RedCap UE introduced in Release 17 and LPWA of LTE. Such new UE type is called "eRedCap UE". eRedCap UE has a narrower maximum bandwidth used for wireless communication than RedCap UE. The eRedCap UE corresponds to a predetermined UE type (predetermined terminal type) in which the frequency bandwidth that can be used for at least PDSCH is reduced to a predetermined bandwidth.

For eRedCap UEs, (a) reducing the compatible frequency bandwidth in FR1 to a predetermined bandwidth (e.g., 5 MHz); and (b) reducing the frequency band for the data channel in FR1 to reduce the peak data rate. It has been proposed to reduce the width. Here, the data channel refers to a physical channel that transmits data, ie, PDSCH and/or PUSCH. Note that the frequency bandwidth is also simply referred to as "bandwidth." In the following, the maximum bandwidth of the RedCap UE, particularly the maximum bandwidth of the data channel of the RedCap UE, will be referred to as "predetermined bandwidth."

As shown in FIG. 10, in the method (a) above, the bandwidth (that is, the maximum bandwidth) that can be supported by both the RF section and the BB section of the UE 100 is reduced, and the complexity of the RF section and the BB section is reduced. It is possible to reduce this. On the other hand, as shown in FIG. 11, in the method (b) above, it is possible to mainly reduce the bandwidth that can be handled by the BB section of the UE 100, and reduce the complexity of the BB section. In the example of FIG. 11, the maximum RF bandwidth that can be supported by the RF section of the UE 100 is 20 MHz, and the maximum BB band that is the frequency bandwidth (predetermined bandwidth) that can be supported by the BB section of the UE 100 is 20 MHz. An example in which the width is 5 MHz is shown. Note that the maximum BB bandwidth is not limited to 5 MHz, and may be set to 3 MHz or 4 MHz, for example. Such a bandwidth of 5 MHz (or 3 MHz or 4 MHz) may be set as a predetermined bandwidth as BWP for the eRedCap UE. In that case, the bandwidth may be referred to as "BWP of eRedCap".

In the following embodiments, either the method (a) or the method (b) above may be adopted for the eRedCap UE, but it is mainly assumed that the method (b) above is adopted.

If eRedCap UE is introduced, there is a concern that there will be restrictions on the transmission of common messages that are commonly transmitted to multiple terminals on the PDSCH. 5G systems need to accommodate multiple UE types with different capabilities. The multiple UE types include the

Release

15, 16, 17, and 18 general UE types, the Release 17 RedCap UE, and the Release 18 eRedCap UE. Here, the fact that a common message for multiple UEs 100 is transmitted in conjunction with the eRedCap UE may be a restriction on scheduling. For example, the fact that system information messages (eg, SIB1) are sent with a bandwidth of 5 MHz, for example, in line with eRedCap UEs becomes a limitation for PDSCH scheduling.

Additionally, with the current PDSCH allocation (scheduling) mechanism, there is a concern that the eRedCap UE may not be able to properly receive downlink data. As described above, in the PDSCH resource allocation method based on the size of CORESET #0, the UE 100, which has a bandwidth of, for example, 5 MHz for the data channel, uses the number of bits in the "Frequency domain resource assignment" field that indicates PDSCH resource allocation. , and downlink data cannot be properly received. More specifically, the number of bits for resource allocation of a PDSCH scheduled using P-RNTI, SI-RNTI, or RA-RNTI cannot be specified, and DCI cannot be appropriately decoded.

Additionally, there is a concern that eRedCap UE may not be able to properly support mobility. For example, there is a concern that the eRedCap UE may not be able to properly receive downlink data (especially common messages) from the target cell after handover. More specifically, after performing handover, the eRedCap UE does not know in which bandwidth it should receive the PDSCH, and cannot specify the frequency band to which the PDSCH is mapped.

(6) Configuration of UE Next, the configuration of the UE 100 according to the embodiment will be described with reference to FIG. 12. UE 100 may be an eRedCap UE. UE 100 includes a communication section 110 and a control section 120.

The communication unit 110 performs wireless communication with the base station 200 by transmitting and receiving wireless signals to and from the base station 200. The communication unit 110 includes at least one transmitting unit 111 and at least one receiving unit 112. The transmitting section 111 and the receiving section 112 may be configured to include a plurality of antennas and RF circuits. The antenna and the RF circuit convert the baseband signal into a radio signal (RF signal) and radiate the radio signal into space. The antenna and the RF circuit also receive radio signals in space and convert the radio signals into baseband signals. The RF circuit performs analog processing of signals transmitted and received via the antenna, and may include, for example, a high frequency filter, an amplifier, a modulator, a low-pass filter, and the like.

The control unit 120 performs various controls in the UE 100. Control unit 120 controls communication with base station 200 via communication unit 110. The operations of the UE 100 described above and below may be operations under the control of the control unit 120. The control unit 120 may include at least one processor that can execute a program and a memory that stores the program. The processor may execute the program to perform the operations of the control unit 120. The control unit 120 may include a digital signal processor that digitally processes signals transmitted and received via the antenna and the RF circuit. The digital processing includes processing of the RAN protocol stack. Note that the memory stores a program executed by the processor, parameters related to the program, and data related to the program. Memories include ROM (Read Only Memory), EPROM (Erasable Programmable Read Only Memory), and EEPROM (Electrically Erasable Programmable Memory). The memory may include at least one of RAM (Random Access Memory), RAM (Random Access Memory), and flash memory. All or part of the memory may be contained within the processor.

The UE 100 may be an eRedCap UE in which the frequency bandwidth that can be used for at least PDSCH is reduced to a predetermined bandwidth (for example, 5 MHz). In the UE 100 (eRedCap UE), the receiving unit 112 receives the MIB from the base station 200 on the PBCH. Based on the MIB, the control unit 120 acquires a common message commonly used by the plurality of UEs 100 from the base station 200 on the PDSCH. The MIB includes a parameter indicating whether the second common message specified for the eRedCap UE is provided from the base station 200. Here, the second common message is a common message defined independently of the first common message defined for UE types other than eRedCap UE. This enables independent transmission of common messages between the eRedCap UE and the others. Therefore, while it is possible for the base station 200 to transmit the first common message to UE types other than eRedCap UE in the same way as before, the base station 200 can transmit the second common message for eRedCap UE in a 5 MHz band, for example. It is also possible to transmit within the width. Therefore, restrictions on PDSCH scheduling can be relaxed. Note that UE types other than eRedCap UE include general UE types of

Releases

15, 16, 17, and 18, and RedCap UE of Release 17. In the following, UE types other than eRedCap UE are also referred to as "Non-eRedCap UE."

Note that "the second common message is provided from the base station 200" may also mean "the second common message is broadcast from the base station 200". The "second common message is provided by the base station 200" may also mean "the second common message is scheduled by the base station 200."

In the UE100, which is EREDCAP UE, the receiving unit 112 has a DCI, including a frequency resource allocation field (that is, "FREQUENCY DOMAIN RESORCE ASSIGNMENT" field), which indicates the perfection of PDSCH frequency resources. Receive from the base station 200 on the CH. The control unit 120 controls the predetermined bandwidth (for example, 5 MHz) or less, regardless of the number of first resource blocks (i.e., the size of CORESET #0) constituting the control resource set (CORESET #0) corresponding to the PDCCH. The number of bits of the frequency resource allocation field is specified based on the second number of resource blocks corresponding to the frequency bandwidth of . This allows the eRedCap UE to appropriately determine the number of bits in the frequency resource allocation field, and allows it to appropriately receive downlink data (especially common messages). More specifically, the number of bits for resource allocation of PDSCH scheduled using P-RNTI, SI-RNTI, or RA-RNTI can be appropriately determined, and the DCI for scheduling common messages can be appropriately determined. Can be decoded properly.

In the UE 100, which is an eRedCap UE, the receiving unit 112 receives a message from the base station 200 instructing handover to the target cell. Based on the message, the control unit 120 acquires a common message commonly used by the plurality of UEs 100 from the target cell on the PDSCH. The message is obtained by the UE 100 acquiring a second common message specified for eRedCap UE from the target cell independently of the first common message specified for UE types other than eRedCap UE (Non-eRedCap UE). Contains parameters for This allows the eRedCap UE to appropriately receive downlink data (particularly common messages) from the target cell after handover, and allows the eRedCap UE to appropriately support mobility.

The second common message may be a common message specific (dedicated) to the eRedCap UE. The second common message may be referred to as an eRedCap specific common message. Alternatively, the second common message may be a common message that can be received by Non-eRedCap UEs in addition to eRedCap UEs. The second common message may be a common message that is transmitted from the base station 200 using a frequency bandwidth that is less than or equal to a predetermined bandwidth (eg, 5 MHz). In the following, an example will be mainly assumed in which the second common message is a common message specific (dedicated) to the eRedCap UE.

(7) Configuration of base station Next, the configuration of the base station 200 according to the embodiment will be described with reference to FIG. 13. Base station 200 includes a communication section 210, a network interface 220, and a control section 230.

The communication unit 210 performs wireless communication with the UE 100 by transmitting and receiving wireless signals to and from the UE 100. The communication unit 210 includes at least one transmitting unit 211 and at least one receiving unit 212. The transmitter 211 and the receiver 212 may be configured to include multiple antennas and RF circuits. The antenna and the RF circuit convert the baseband signal into a radio signal (RF signal) and radiate the radio signal into space. The antenna and the RF circuit also receive radio signals in space and convert the radio signals into baseband signals. The RF circuit performs analog processing of signals transmitted and received via the antenna, and may include, for example, a high frequency filter, an amplifier, a modulator, a low-pass filter, and the like.

The network interface 220 sends and receives signals to and from the network. The network interface 220 receives signals from adjacent base stations connected via, for example, an Xn interface that is an interface between base stations, and transmits signals to the adjacent base stations. Further, the network interface 220 receives a signal from the core network device 300 connected via the NG interface, and transmits the signal to the core network device 300, for example.

The control unit 230 performs various controls in the base station 200. The control unit 230 controls communication with the UE 100 via the communication unit 210, for example. Further, the control unit 230 controls, for example, communication with a node (eg, an adjacent base station, the core network device 300) via the network interface 220. The operations of the base station 200 described above and below may be operations under the control of the control unit 230. The control unit 230 may include at least one processor that can execute a program and a memory that stores the program. The processor may execute the program to perform the operations of the control unit 230. The control unit 230 may include a digital signal processor that digitally processes signals transmitted and received via the antenna and the RF circuit. The digital processing includes processing of the RAN protocol stack. Note that the memory stores a program executed by the processor, parameters related to the program, and data related to the program. All or part of the memory may be contained within the processor.

In the base station 200 configured in this way, the transmitter 211 transmits the MIB on the PBCH. The control unit 230 provides the plurality of UEs 100 with a common message commonly used by the plurality of UEs 100 on the PDSCH based on the MIB. In the MIB, a second common message defined for eRedCap UE is provided from the base station 200 independently of a first common message defined for UE types other than eRedCap UE (Non-eRedCap UE). Contains a parameter indicating whether or not. This allows the base station 200 to independently transmit common messages to eRedCap UEs and others. Therefore, while it is possible for the base station 200 to transmit the first common message to UE types other than eRedCap UE in the same way as before, the base station 200 can transmit the second common message for eRedCap UE in a 5 MHz band, for example. It is also possible to transmit within the width. Therefore, restrictions on PDSCH scheduling can be relaxed.

The transmitting unit 211 transmits a message instructing handover to the target cell to the UE 100 (eRedCap UE) whose frequency bandwidth that can support at least PDSCH has been reduced to a predetermined bandwidth (for example, 5 MHz). The message is a second common message defined for eRedCap UE, independent of the first common message defined for UE types other than eRedCap UE (Non-eRedCap UE), which the UE 100 transmits from the target cell. Contains parameters to retrieve. This allows the eRedCap UE to appropriately receive downlink data (particularly common messages) from the target cell after handover, and allows the eRedCap UE to appropriately support mobility.

The base station 200 (transmission unit 211) may apply repetition transmission on the PDSCH to transmission of the second common message. Repeated transmission is a technique that allows the base station 200 to repeatedly transmit the same signal, thereby expanding the communication range of the base station 200 (that is, the coverage of the cell).

(8) Initial access method for eRedCap UE Next, an initial access method for eRedCap UE according to the embodiment will be described with reference to FIGS. 14 to 17.

The common message used during initial access may be primarily a system information message. Therefore, the first common message may be a first system information message defined for Non-eRedCap UEs. The second common message may be a second system information message defined for eRedCap UEs. The second system information message may be a system information message transmitted from the base station 200 using a frequency bandwidth that is less than or equal to a predetermined bandwidth (eg, 5 MHz). This allows independent transmission of system information messages between the eRedCap UE and the rest. Therefore, while it is possible for the base station 200 to transmit the first system information message to UE types other than eRedCap UE in the same manner as before, the base station 200 transmits the second system information message for eRedCap UE at a frequency of, for example, 5 MHz. It is also possible to transmit within the bandwidth of

The system information message includes SIB1. The first system information message includes a first SIB1 indicating the scheduling of a first other system information message (hereinafter referred to as "first SIBx") defined for the Non-eRedCap UE. On the other hand, the second system information message includes a second SIB1 indicating the scheduling of a second other system information message (hereinafter referred to as "second SIBx") defined for the eRedCap UE. Thereby, it is possible to indicate the scheduling of the first SIBx by the first SIB1 for the Non-eRedCap UE, and to indicate the scheduling of the second SIBx by the second SIB1 for the eRedCap UE.

The transmitter 211 of the base station 200 transmits the MIB on the PBCH. The MIB contains a parameter (hereinafter referred to as a "predetermined (referred to as "parameters"). Thereby, the UE 100, which is an eRedCap UE, can determine whether or not the second SIB1 is provided from the base station 200 based on a predetermined parameter in the MIB.

Specifically, the control unit 120 of the UE 100, which is an eRedCap UE, acquires the second SIB1 based on a predetermined parameter included in the MIB, and acquires the second SIBx based on the acquired second SIB1. . The second SIBx is an SIB other than SIB1 for eRedCap UE, that is, at least one of SIB2, SIB3, SIB4, . . . for eRedCap UE. Thereby, the UE 100, which is an eRedCap UE, can appropriately acquire the second SIBx.

FIG. 14 is a diagram showing MIB transmission operation in the base station 200 according to the embodiment.

In step S101, the control unit 230 of the base station 200 determines whether to provide the second SIB1.

If it is determined that the second SIB1 is to be provided (step S101: YES), in step S102, the control unit 230 of the base station 200 sets a first value (for example, "1") to a predetermined parameter in the MIB. do. On the other hand, if it is determined that the second SIB1 is not provided (step S101: NO), the control unit 230 of the base station 200 sets a second value (for example, "0") to a predetermined parameter in the MIB in step S103. ). Note that the predetermined parameter can also be regarded as a parameter indicating whether the eRedCap UE can access the base station 200 (accommodation).

In step S104, the transmitter 211 of the base station 200 transmits the MIB on the PBCH. Note that the PBCH (MIB) constitutes a part of the SSB.

Additionally, the MIB further includes the above-mentioned controlResourceSetZero and searchSpaceZero as parameters other than the predetermined parameters. controlResourceSetZero (first index) and searchSpaceZero (second index) each have a value from 0 to 15 (index value). Specifically, controlResourceSetZero (first index) indicates the setting of CORESET #0, which is a control resource set corresponding to the PDCCH used for SIB1 scheduling. searchSpaceZero (second index) indicates the setting of search space set #0, which is a common search space corresponding to the PDCCH used for SIB1 scheduling.

FIG. 15 is a diagram showing the MIB reception operation in the UE 100 (eRedCap UE) according to the embodiment.

In step S111, the receiving unit 112 of the UE 100 receives the MIB from the base station 200 on the PBCH.

In step S112, the control unit 120 of the UE 100 obtains predetermined parameters in the MIB.

In step S113, the control unit 120 of the UE 100 determines whether a first value (for example, "1") is set to a predetermined parameter in the MIB.

If it is determined that the first value (for example, "1") is set to the predetermined parameter in the MIB (step S113: YES), in step S114, the control unit 120 of the UE 100 sets the second SIB1 to It is determined that the second SIB1 is provided from the base station 200, and the second SIB1 is acquired from the base station 200. That is, the control unit 120 of the UE 100 provides the second SIB1 (second common message) in response to the predetermined parameter indicating that the second SIB1 (second common message) is provided from the base station 200. is obtained from the base station 200.

On the other hand, if it is determined that the second value (for example, "0") is set to the predetermined parameter in the MIB (step S113: NO), in step S115, the control unit 120 of the UE 100 It is determined that SIB1 is not provided from the base station 200. That is, in response to the predetermined parameter indicating that the second SIB1 (second common message) is not provided from the base station 200, the control unit 120 of the UE 100 controls whether the second SIB1 (second common message) is not provided by the base station 200 or not. It is determined that the base station 200 does not provide the information.

Note that, if it is determined that the first value (for example, "1") is set to the predetermined parameter in the MIB (step S113: YES), the control unit 120 of the UE 100, which is the eRedCap UE, Based on controlResourceSetZero (first index) and searchSpaceZero (second index), CORESET #0 for eRedCap UE and/or search space set #0 for eRedCap UE may be identified. That is, in response to the predetermined parameter in the MIB indicating that the second SIB1 (second common message) is provided from the base station 200, the control unit 120 of the UE 100, which is the eRedCap UE, The specified setting of CORESET #0 is specified based on controlResourceSetZero (first index) in the MIB. In addition, in response to the predetermined parameter in the MIB indicating that the second SIB1 (second common message) is provided from the base station 200, the control unit 120 of the UE 100, which is the eRedCap UE, The settings of the specified search space set #0 are specified based on searchSpaceZero (second index) in the MIB.

Here, the UE 100, which is an eRedCap UE, uses a table different from the table shown in FIG. 4 and the table shown in FIG. Alternatively, search space set #0 for eRedCap UE may be specified. FIG. 16 is a diagram illustrating an example of table configuration according to the embodiment.

As shown in FIG. 16, the Non-eRedCap UE 100a holds the first controlResourceSetZero table shown in FIG. 4 and the first searchSpaceZero table shown in FIG. 5. The first controlResourceSetZero table is a table for identifying the corresponding CORESET#0 parameter (CORESET#0 setting) from controlResourceSetZero (first index) in the MIB. The first searchSpaceZero table is a table for specifying the corresponding search space set #0 parameter (search space set #0 setting) from searchSpaceZero (second index) in the MIB.

On the other hand, the eRedCap UE 100b has a second controlResourceSetZero table that is different from the first controlResourceSetZero table, and a second searchSpace that is different from the first searchSpaceZero table. Zero table is maintained. The second controlResourceSetZero table specifies the corresponding CORESET#0 parameter (CORESET#0 setting), specifically, the CORESET#0 parameter for eRedCap UE, from controlResourceSetZero (first index) in the MIB. to do It's a table. The second searchSpaceZero table stores the corresponding search space set #0 parameter (search space set #0 setting) from searchSpaceZero (second index) in the MIB, specifically, search space set #0 for eRedCap UE. This is a table for specifying parameters.

In this way, the predefined CORESET #0 settings include the first CORESET setting (first controlResourceSetZero table) specified for Non-eRedCap UE, and the second CORESET setting specified for eRedCap UE. (second controlResourceSetZero table) are respectively associated with controlResourceSetZero (first index) in the MIB. The control unit 120 of the eRedCap UE 100b uses the second controlResourceSetZero table to identify the CORESET#0 setting corresponding to controlResourceSetZero (first index) in the MIB.

Furthermore, as the predefined search space set #0 settings, the first search space set #0 setting (first searchSpaceZero table) defined for Non-eRedCap UE, and the first search space set #0 setting defined for eRedCap UE. 2 search space set #0 settings (second searchSpaceZero table) are respectively associated with searchSpaceZero (second index) in the MIB. The control unit 120 of the eRedCap UE 100b uses the second searchSpaceZero table to identify the search space set #0 setting corresponding to searchSpaceZero (second index) in the MIB.

FIG. 17 is a diagram illustrating a sequence example of the initial access method of the eRedCap UE according to the embodiment.

In step S121, the base station 200 transmits an MIB including a predetermined parameter set to a first value (for example, "1"), a first index (controlResourceSetZero), and a second index (searchSpaceZero). do. The UE 100 (eRedCap UE) that has received the MIB determines that the second SIB1 will be provided from the base station 200 based on predetermined parameters.

In step S122, the UE 100 (eRedCap UE) uses the second controlResourceSetZero table to identify the CORESET #0 setting corresponding to the first index (controlResourceSetZero) in the MIB. Further, the UE 100 (eRedCap UE) uses the second searchSpaceZero table to identify the search space set #0 setting corresponding to the second index (searchSpaceZero) in the MIB.

In step S123, the UE 100 (eRedCap UE) monitors PDCCH candidates in search space set #0 (Type-0 PDCCH CSS set) based on the CORESET #0 settings and search space set #0 settings identified in step S122. .

In step S124, the base station 200 transmits DCI in DCI format 1_0 to which a CRC scrambled by SI-RNTI is added on the PDCCH.

In step S125, the UE 100 (eRedCap UE) receives (detects) the DCI and identifies PDSCH resource allocation (time and/or frequency resources) from the DCI.

In step S126, the base station 200 transmits the second SIB1 on the PDSCH scheduled with "DCI format 1_0 with SI-RNTI". The UE 100 (eRedCap UE) receives (obtains) the second SIB1.

In step S127, the UE 100 (eRedCap UE) specifies the scheduling of the second SIBx based on the second SIB1.

In step S128, the base station 200 transmits DCI in DCI format 1_0 to which a CRC scrambled by SI-RNTI is added on the PDCCH.

In step S129, the UE 100 (eRedCap UE) receives (detects) the DCI and identifies PDSCH resource allocation (time and/or frequency resources) from the DCI.

In step S130, the base station 200 transmits the second SIBx on the PDSCH scheduled with "DCI format 1_0 with SI-RNTI". The UE 100 (eRedCap UE) receives (obtains) the second SIBx. Note that the second SIBx scheduled by the second SIB1 may be identified as "eRedCap specific common message".

The base station 200 transmits a first system information message (first SIB1 and first SIBx) for Non-eRedCap UE and a second system information message (second SIB1 and second SIBx) for eRedCap UE. SIBx) transmission may be switched. That is, base station 200 may time-divisionally transmit the first system information message and the second system information message.

Alternatively, the base station 200 transmits the first system information message (first SIB1 and first SIBx) for Non-eRedCap UE and the second system information message (second SIB1 and first SIBx) for eRedCap UE. The transmission of the second SIBx) may be performed in parallel. That is, base station 200 may transmit both the first system information message and the second system information message in the same time period. In that case, the base station 200 may apply different SI-RNTIs to the DCI (PDCCH) used for transmitting the first system information message and the DCI (PDCCH) used for transmitting the second system information message. good. For example, the transmitting unit 211 of the base station 200 uses a second SI-RNTI specified for eRedCap UE independently of the first SI-RNTI specified for Non-eRedCap UE, and transmits the second SI-RNTI. System information messages may also be sent. The second SI-RNTI defined for the eRedCap UE may be identified as "eRedCap specific SI-RNTI". The control unit 120 of the UE 100 (eRedCap UE) may obtain the second system information message using the second SI-RNTI.

(9) Method for identifying the number of PDSCH resource allocated bits for eRedCap UE Next, a method for identifying the number of PDSCH resource allocated bits for eRedCap UE according to the embodiment will be described with reference to FIGS. 18 to 21. Note that the method for identifying the number of PDSCH resource allocation bits for eRedCap UE according to the embodiment may be implemented in combination with the above-described initial access method for eRedCap UE.

As described above, the DCI (PDCCH) used for transmitting a common message commonly used by a plurality of UEs 100 is a DCI of DCI format 1_0 (predetermined format) to which a predefined RNTI is applied. Here, the predefined RNTI is at least one of SI-RNTI, P-RNTI, and RA-RNTI. The DCI has a "Frequency domain resource assignment" field, which is a frequency resource assignment field indicating frequency resource assignment for the PDSCH (see FIG. 9). The common message sent on the PDSCH is at least one of a system information message, a paging message, and a random access response.

In the UE 100, which is an eRedCap UE, the receiving unit 112 receives DCI including a "Frequency domain resource assignment" field indicating frequency resource assignment of the PDSCH from the base station 200 on the PDCCH. Regardless of the first number of resource blocks configuring CORESET #0 corresponding to the PDCCH, the control unit 120 determines the number of resource blocks based on the second number of resource blocks corresponding to a frequency bandwidth equal to or less than a predetermined bandwidth (for example, 5 MHz). to specify the number of bits in the “Frequency domain resource assignment” field.

Here, the control unit 120 specifies the number of bits in the "Frequency domain resource assignment" field using the method shown in FIG. However, when specifying the number of bits in the "Frequency domain resource assignment" field, the size of CORESET #0 (i.e., the number of first resource blocks)

Instead, the second number of resource blocks for eRedCap UE is used. By defining the second number of resource blocks for eRedCap UEs independently of the first number of resource blocks, even for eRedCap UEs with reduced PDSCH bandwidth, the number of bits in the "Frequency domain resource assignment" field can be adjusted. Become properly identifiable.

In the embodiment, the "Frequency domain resource assignment" field included in "DCI format 1_0 with P-RNTI" and the "Frequency domain resource assignment" field included in "DCI format 1_0 with SI-RNTI" are "domain resource assignment" field, and "DCI format 1_0 with A second number of resource blocks is defined in common for at least two of the "Frequency domain resource assignment" fields included in "RA-RNTI".

Then, the control unit 120 identifies the PDSCH frequency resource indicated by the "Frequency domain resource assignment" field based on the identified number of bits. Furthermore, the control unit 120 identifies the PDSCH time resource indicated by the "Time domain resource assignment" field. The receiving unit 112 receives the common message on the PDSCH based on the identified frequency resources and time resources.

(9.1) First PDSCH resource allocation bit number identification method FIG. 18 is a diagram illustrating a first PDSCH resource allocation bit number identification method according to the embodiment. In the first PDSCH resource allocation bit number identification method, the second resource block number is the resource block number predefined for eRedCap UE in the technical specifications of the mobile communication system 1.

In step S201, the receiving unit 112 of the UE 100 (eRedCap UE) receives "DCI format 1_0 with P-RNTI/SI-RNTI/RA-RNTI" from the base station 200 on the PDCCH.

In step S202, the control unit 120 of the UE 100 (eRedCap UE) sets the frequency of "DCI format 1_0 with P-RNTI/SI-RNTI/RA-RNTI" based on the predefined second number of resource blocks Specify the number of bits in the "domain resource assignment" field. For example, the second number of resource blocks is predefined as 25 resource blocks (or 24 resource blocks) or 12 resource blocks (or 11 resource blocks).

The control unit 120 of the UE 100 (eRedCap UE) may determine the second number of resource blocks based on the subcarrier spacing (SCS) for the common message. For example, for each subcarrier interval (SCS), the correspondence relationship between the subcarrier interval (SCS) and the second number of resource blocks is defined in advance in the technical specifications. The receiving unit 112 of the UE 100 (eRedCap UE) receives an MIB including a parameter indicating the subcarrier spacing (SCS) for the common message from the base station 200 on the PBCH. The parameter may be subCarrierSpacingCommon included in the MIB. subCarrierSpacingCommon is the system information message, Msg. in the initial access. 2 (random access response)/Msg. 4, and a parameter for setting the subcarrier spacing (SCS) for paging messages. Control unit 120 of UE 100 (eRedCap UE) determines the second number of resource blocks based on the subcarrier spacing (SCS) indicated by the parameter and the correspondence relationship predefined in the technical specifications. FIG. 19 is a diagram illustrating an example of the correspondence between the subcarrier spacing (SCS) and the second number of resource blocks. As shown in FIG. 19, the second number of resource blocks is 25 resource blocks (or 24 resource blocks) when SCS=15kHz, and 12 resource blocks (or 11 resource blocks) when SCS=30kHz. It may be specified that

In step S203, the control unit 120 of the UE 100 (eRedCap UE) identifies the PDSCH frequency resource indicated by the "Frequency domain resource assignment" field based on the number of bits identified in step S202. Further, the control unit 120 identifies the PDSCH time resource indicated by the "Time domain resource assignment" field in "DCI format 1_0 with P-RNTI/SI-RNTI/RA-RNTI".

In step S204, the receiving unit 112 of the UE 100 (eRedCap UE) receives the common message on the PDSCH based on the frequency resource and time resource specified in step S203. Specifically, the receiving unit 112 of the UE 100 (eRedCap UE) receives a paging message, a system information message (for example, SIB1), and/or a random access response (i.e., an eRedCap specific common message) on a scheduled PDSCH. ).

(9.2) Second PDSCH resource allocation bit number identification method FIG. 20 is a diagram illustrating a second PDSCH resource allocation bit number identification method according to the embodiment. In the second PDSCH resource allocation bit number identification method, the second resource block number is the number of resource blocks determined according to a parameter (index) in the MIB. As the parameter, for example, a parameter in pdcch-ConfigSIB1 in the MIB or a spare bit in the MIB may be used. An example in which parameters in pdcch-ConfigSIB1 in the MIB are used as the parameters will be mainly described below.

In step S211, the transmitter 211 of the base station 200 transmits an MIB including a first index (controlResourceSetZero) and a second index (searchSpaceZero). The MIB may further include a parameter (subCarrierSpacingCommon) indicating subcarrier spacing (SCS) for common messages. The first index (controlResourceSetZero) and/or the second index (searchSpaceZero) are used to determine the second number of resource blocks. That is, the receiving unit 112 of the UE 100 (eRedCap UE) receives the MIB including the index for determining the second number of resource blocks from the base station 200 on the PBCH.

In step S212, the control unit 120 of the UE 100 (eRedCap UE) identifies the CORESET #0 setting corresponding to the first index (controlResourceSetZero) in the MIB, and specifies the CORESET #0 setting corresponding to the second index (searchSpaceZero) in the MIB. Specify space set #0 settings. The control unit 120 of the UE 100 (eRedCap UE) determines the second number of resource blocks based on the first index (controlResourceSetZero) and/or the second index (searchSpaceZero). Specifically, the control unit 120 of the UE 100 (eRedCap UE) determines each of the first number of resource blocks and the second number of resource blocks based on the index. The first resource block number is part of the CORESET #0 setting. On the other hand, the second resource block number is used to specify the number of bits in the "Frequency domain resource assignment" field.

Here, the control unit 120 of the UE 100 (eRedCap UE) may determine the second number of resource blocks further based on the subcarrier spacing (SCS) for the common message. The subcarrier spacing (SCS) is determined, for example, according to subCarrierSpacingCommon. Specifically, for each subcarrier interval (SCS), the correspondence relationship between the subcarrier interval (SCS) and the second number of resource blocks is defined in advance in the technical specifications. The control unit 120 of the UE 100 (eRedCap UE) uses the first index (controlResourceSetZero) and/or the second index (searchSpaceZero), the subcarrier spacing (SCS) indicated by subCarrierSpacingCommon, and the scheduled based on the specified correspondence relationship. Then, the second number of resource blocks is determined.

FIG. 21 is a diagram illustrating an example of associating the first index (controlResourceSetZero) with the second number of resource blocks. The control unit 120 of the UE 100 (eRedCap UE) maintains a table as shown in FIG. The number of resource blocks is associated. The second number of resource blocks is 15 or 8 resource blocks when the predetermined bandwidth is 3 MHz, 20 or 10 resource blocks when the predetermined bandwidth is 4 MHz, and when the predetermined bandwidth is 5 MHz, the second number of resource blocks is 15 or 8 resource blocks. In this case, there are 25 or 12 resource blocks. The second number of resource blocks is specified to be 25 resource blocks (or 24 resource blocks) when SCS=15kHz, and 12 resource blocks (or 11 resource blocks) when SCS=30kHz. Good too.

The controlResourceSetZero table shown in FIG. 21 is a table when the maximum channel bandwidth is 5 MHz or 10 MHz, and the subcarrier spacing (SCS) of each of SSB and PDCCH is 15 kHz. If the subcarrier spacing (SCS) of each of SSB and PDCCH is not 15 kHz, a controlResourceSetZero table different from that in FIG. 21 will be used. Even in the controlResourceSetZero table different from that in FIG. 21, it is assumed that the second number of resource blocks is associated with the value of controlResourceSetZero. Therefore, the control unit 120 of the UE 100 (eRedCap UE) determines the second number of resource blocks further based on the subcarrier spacing (SCS) for SSB and/or the subcarrier spacing (SCS) for PDCCH. Here, the base station 200 may set the SSB subcarrier spacing (SCS) based on a parameter (ssbSubcarrierSpacing) included in the RRC message (ServingCellConfigCommon). Furthermore, the base station 200 may set the subcarrier spacing (SCS) of the PDCCH (that is, DL BWP) based on a parameter (subcarrierSpacing) included in the RRC message (BWP-DownlinkCommon).

Although FIG. 21 is an example of associating the second number of resource blocks with controlResourceSetZero, the second number of resource blocks may be associated with searchSpaceZero using a similar method.

Returning to FIG. 20, in step S213, the transmitter 211 of the base station 200 transmits "DCI format 1_0 with P-RNTI/SI-RNTI/RA-RNTI" on the PDCCH. The receiving unit 112 of the UE 100 (eRedCap UE) receives “DCI format 1_0 with P-RNTI/SI-RNTI/RA-RNTI” from the base station 200 on the PDCCH. Here, "DCI format 1_0 with P-RNTI/SI-RNTI/RA-RNTI" may further include a field indicating the number of times the common message is repeatedly transmitted. This allows the UE 100 (eRedCap UE) to specify the number of times the common message is repeatedly transmitted.

In step S214, the control unit 120 of the UE 100 (eRedCap UE) selects "DCI format 1_0 with P-RNTI/SI-RNTI/RA-RNTI" based on the second number of resource blocks determined in step S212. Specify the number of bits in the "Frequency domain resource assignment" field.

In step S215, the control unit 120 of the UE 100 (eRedCap UE) identifies the PDSCH frequency resource indicated by the "Frequency domain resource assignment" field based on the number of bits identified in step S214. Further, the control unit 120 identifies the PDSCH time resource indicated by the "Time domain resource assignment" field in "DCI format 1_0 with P-RNTI/SI-RNTI/RA-RNTI". Further, if "DCI format 1_0 with P-RNTI/SI-RNTI/RA-RNTI" includes a field indicating the number of repeated transmissions, the control unit 120 specifies the number of repeated transmissions based on the field.

In step S216, the receiving unit 112 of the UE 100 (eRedCap UE) receives the common message on the PDSCH based on the frequency resource and time resource specified in step S215. Specifically, the receiving unit 112 of the UE 100 (eRedCap UE) receives a paging message, a system information message (for example, SIB1), and/or a random access response (i.e., an eRedCap specific common message) on a scheduled PDSCH. ).

(10) Handover method for eRedCap UE Next, a handover method for eRedCap UE according to the embodiment will be described with reference to FIGS. 22 and 23. Note that the handover method for eRedCap UE according to the embodiment may be implemented in combination with the above-described initial access method for eRedCap UE and/or the above-described method for specifying the number of PDSCH resource allocation bits for eRedCap UE.

FIG. 22 is a diagram for explaining an overview of the handover method for eRedCap UE according to the embodiment. Although FIG. 22 shows an example in which the base station 200a that manages the source cell and the base station 200b that manages the target cell are different, the source cell and the target cell may be managed by the same base station 200.

The transmitter 211 of the base station 200a that manages the source cell transmits a message instructing the UE 100 (eRedCap UE) to handover to the target cell. The message is an RRC message, for example, an RRCReconfiguration message that includes reocnconfigurationWithSync as an information element. reocnconfigurationWithSync is a parameter for synchronization reconfiguration for the target cell. The receiving unit 112 of the UE 100 (eRedCap UE) receives a message instructing handover to a target cell from the base station 200a (source cell). Based on the message, the control unit 120 of the UE 100 (eRedCap UE) acquires a common message commonly used by the plurality of UEs 100 from the base station 200b (target cell) on the PDSCH. The message includes parameters for the UE 100 to obtain a second common message defined for the eRedCap UE (i.e., an eRedCap specific common message) from the target cell. This allows the UE 100 (eRedCap UE) to appropriately communicate with the target cell. For example, the eRedCap UE can properly receive downlink data (especially common messages) from the target cell after handover, and mobility can be appropriately supported for the eRedCap UE.

As described above, the second common message is a common message transmitted from the target cell in a frequency bandwidth that is less than or equal to a predetermined bandwidth (for example, 5 MHz), and is a common message that is transmitted from the target cell using a frequency bandwidth that is less than or equal to a predetermined bandwidth (for example, 5 MHz), and is a common message that is transmitted from the target cell using a frequency bandwidth that is less than or equal to a predetermined bandwidth (for example, 5 MHz). different from the message. The common message is a system information message, the first common message is a first system information message specified for Non-eRedCap UE, and the second common message is a second system information message specified for eRedCap UE. It may also be a system information message.

FIG. 23 is a diagram illustrating an example of a handover method for eRedCap UE according to the embodiment.

In step S301, the transmitter 211 of the base station 200a that manages the source cell transmits an RRCReconfiguration message including reocnconfigurationWithSync as an information element to the UE 100 (eRedCap UE). The receiving unit 112 of the UE 100 (eRedCap UE) receives the RRCReconfiguration message from the base station 200a (source cell).

The RRCReconfiguration message may include a first parameter indicating whether a second common message (eRedCap specific common message) is provided from the target cell. For example, the control unit 120 of the UE 100 (eRedCap UE) may specify that an eRedCap specific common message is broadcast/scheduled in the target cell based on the value of the first parameter. For example, the base station 200a may include in the RRCReconfiguration message a first parameter indicating whether the second SIB1 is broadcast/scheduled in the target cell. The base station 200a may set the first parameter to a first value (for example, "1") when the second SIB1 is broadcast/scheduled in the target cell. On the other hand, the base station 200a may set the first parameter to a second value (for example, "0") when the second SIB1 is not broadcast/scheduled in the target cell.

The control unit 120 of the UE 100 (eRedCap UE) may obtain the second common message from the target cell in response to the first parameter indicating that the second common message is provided from the target cell. . The control unit 120 of the UE 100 (eRedCap UE) determines that the second common message is not provided from the target cell in response to the first parameter indicating that the second common message is not provided from the target cell. Good too.

The RRCReconfiguration message indicates whether or not the second CORESET #0 specified for eRedCap UE is provided (configured) from the target cell independently of the first CORESET #0 specified for Non-eRedCap UE. It may also include a second parameter indicating. The second CORESET #0 may be a CORESET #0 set with a bandwidth equal to or less than a predetermined bandwidth. Thereby, the control unit 120 of the UE 100 (eRedCap UE) can specify whether or not the second CORESET #0 is provided (set) from the target cell based on the second parameter. The base station 200a may set the second parameter to the first value (for example, "1") when the second CORESET #0 is provided in the target cell. On the other hand, the base station 200a may set the second parameter to a second value (for example, "0") if the second CORESET #0 is not provided in the target cell.

The RRCReconfiguration message indicates that the second search space set #0 specified for eRedCap UE is provided (set) from the target cell independently of the first search space set #0 specified for Non-eRedCap UE. It may also include a third parameter indicating whether or not. The second search space set #0 may be a search space set #0 set with a bandwidth equal to or less than a predetermined bandwidth. Thereby, the control unit 120 of the UE 100 (eRedCap UE) can specify whether or not the second search space set #0 is provided (set) from the target cell based on the third parameter. The base station 200a may set the third parameter to the first value (for example, "1") when the second search space set #0 is provided in the target cell. On the other hand, when the second search space set #0 is not provided in the target cell, the base station 200a may set the third parameter to the second value (for example, "0").

The RRCReconfiguration message may include a fourth parameter for identifying the PDSCH resource on which the second common message (eRedCap specific common message) is transmitted in the target cell. The fourth parameter may be a parameter for specifying the number of bits of the "Frequency domain resource assignment" field in "DCI format 1_0 with P-RNTI/SI-RNTI/RA-RNTI". The fourth parameter may be a parameter indicating the second number of resource blocks for specifying the number of bits. The details of such operation are similar to the second PDSCH resource allocation bit number identification method described above.

In step S302, the control unit 120 of the UE 100 (eRedCap UE) sends a second common message (eRedCap specific common message) to the base station on the PDSCH based on the parameters included in the RRCReconfiguration message received in step S301. Station 200b (target cell).

(11) Other Embodiments The operation sequences (and operation flows) in the embodiments described above do not necessarily have to be executed chronologically in the order described in the flow diagram or sequence diagram. For example, steps in an operation may be performed in a different order than depicted in a flow diagram or sequence diagram, or in parallel. Also, some of the steps in the operation may be deleted, and additional steps may be added to the process. Further, the operation sequences (and operation flows) in the above-described embodiments may be implemented separately or in combination of two or more operation sequences (and operation flows). For example, some steps of one operation flow may be added to another operation flow, or some steps of one operation flow may be replaced with some steps of another operation flow.

In the above-described embodiment, the mobile communication system 1 was explained using an NR-based mobile communication system as an example. However, the mobile communication system 1 is not limited to this example. The mobile communication system 1 may be a system compliant with any TS of LTE or other generation systems (for example, 6th generation) of the 3GPP standard. Base station 200 may be an eNB that provides E-UTRA user plane and control plane protocol termination towards UE 100 in LTE. The base station 200 may be an IAB (Integrated Access and Backhaul) donor or an IAB node.

A program that causes a computer to execute each process performed by the UE 100 or the base station 200 may be provided. The program may be recorded on a computer readable medium. Computer-readable media allow programs to be installed on a computer. Here, the computer-readable medium on which the program is recorded may be a non-transitory recording medium. The non-transitory recording medium is not particularly limited, but may be a recording medium such as a CD-ROM or a DVD-ROM. Alternatively, circuits that execute each process performed by the UE 100 or the base station 200 may be integrated, and at least a portion of the UE 100 or the base station 200 may be configured as a semiconductor integrated circuit (chip set, SoC: System on a chip).

In the embodiments described above, "transmit" may mean processing at least one layer within a protocol stack used for transmission, or physically transmitting a signal wirelessly or by wire. It may also mean sending to. Alternatively, "transmitting" may mean a combination of processing the at least one layer and physically transmitting the signal wirelessly or by wire. Similarly, "receive" may mean processing at least one layer within the protocol stack used for receiving, or physically receiving a signal, wirelessly or by wire. It can also mean that. Alternatively, "receiving" may mean a combination of processing the at least one layer and physically receiving the signal wirelessly or by wire. Similarly, "obtain/acquire" may mean obtaining information from among stored information, and may refer to obtaining information from among information received from other nodes. Alternatively, it may mean obtaining information by generating the information. Similarly, "include" and "comprise" do not mean to include only the listed items; they may include only the listed items, or in addition to the listed items. This means that it may contain further items. Similarly, in this disclosure, "or" does not mean exclusive disjunction, but rather disjunction. Furthermore, any reference to elements using the designations "first," "second," etc. used in this disclosure does not generally limit the amount or order of those elements. These designations may be used herein as a convenient way of distinguishing between two or more elements. Thus, reference to a first and second element does not imply that only two elements may be employed therein or that the first element must precede the second element in any way. In this disclosure, when articles are added by translation, for example, a, an, and the in English, these articles are used in the plural unless the context clearly indicates otherwise. shall include things.

Although the present disclosure has been described based on examples, it is understood that the present disclosure is not limited to the examples or structures. The present disclosure also includes various modifications and equivalent modifications. In addition, various combinations and configurations, as well as other combinations and configurations including only one, more, or fewer elements, are within the scope and scope of the present disclosure.

(12) Additional Notes Additional notes will be made regarding the features of the above-described embodiments.

(Additional note 1)
A communication device (100) of a predetermined terminal type in which the frequency bandwidth that can be supported for at least a physical downlink shared channel is reduced to a predetermined bandwidth,
a receiving unit (112) for receiving a master information block from a base station (200) on a physical broadcast channel;
a control unit (120) that acquires a common message commonly used by a plurality of communication devices (100) from the base station (200) on the physical downlink shared channel based on the master information block;
The master information block includes a second common message defined for the predetermined terminal type independently of a first common message defined for a terminal type different from the predetermined terminal type. A communication device (100) including a parameter indicating whether or not it is provided by a communication device (100).

(Additional note 2)
The communication device (100) according to supplementary note 1, wherein the second common message is the common message transmitted from the base station (200) using a frequency bandwidth equal to or less than the predetermined bandwidth.

(Additional note 3)
The control unit (120) sends the second common message from the base station (200) in response to the parameter indicating that the second common message is provided from the base station (200). Acquire the communication device (100) according to

supplementary note

1 or 2.

(Additional note 4)
The control unit (120) causes the second common message to be provided from the base station (200) in response to the parameter indicating that the second common message is not provided from the base station (200). The communication device (100) according to any one of Supplementary Notes 1 to 3.

(Appendix 5)
The common message is a system information message,
The first common message is a first system information message defined for a terminal type different from the predetermined terminal type,
The communication device (100) according to any one of appendices 1 to 4, wherein the second common message is a second system information message defined for the predetermined terminal type.

(Appendix 6)
The communication device (100) according to appendix 5, wherein the second system information message is the system information message transmitted from the base station (200) using a frequency bandwidth equal to or less than the predetermined bandwidth.

(Appendix 7)
The control unit (120) is configured to provide a first system information cell radio network temporary identifier (SI-RNTI) defined for the predetermined terminal type independently of a first system information cell radio network temporary identifier (SI-RNTI) defined for a terminal type different from the predetermined terminal type. The communication device (100) according to

appendix

5 or 6, wherein the second system information message is acquired using a second SI-RNTI.

(Appendix 8)
The system information message includes a system information block type 1 (SIB1);
The first system information message includes a first SIB1 indicating the scheduling of a first other system information message defined for a terminal type different from the predetermined terminal type;
The second system information message includes a second SIB1 indicating scheduling of a second other system information message defined for the predetermined terminal type. ).

(Appendix 9)
The control unit (120) includes:
obtaining the second SIB1 based on the parameters included in the master information block;
The communication device (100) according to appendix 8, wherein the second other system information message is acquired based on the acquired second SIB1.

(Appendix 10)
The master information block further includes a first index indicating a configuration of a control resource set (CORESET) corresponding to a physical downlink control channel used for scheduling the SIB1,
The control unit (120) configures the CORESET defined for the predetermined terminal type in response to the parameter indicating that the second common message is provided from the base station (200). The communication device (100) according to

appendix

8 or 9, wherein the communication device is identified based on the first index.

(Appendix 11)
The predefined CORESET settings include a first CORESET setting defined for a terminal type different from the predetermined terminal type, and a second CORESET setting defined for the predetermined terminal type. is associated with the first index,
The control unit (120) sets the second CORESET setting corresponding to the first index in response to the parameter indicating that the second common message is provided from the base station (200). The communication device (100) according to supplementary note 10.

(Appendix 12)
The master information block further includes a second index indicating a setting of a common search space corresponding to a physical downlink control channel used for scheduling the SIB1,
The control unit (120) controls the common search space defined for the predetermined terminal type in response to the parameter indicating that the second common message is provided from the base station (200). The communication device (100) according to any one of Supplementary Notes 8 to 11, wherein settings are specified based on the second index.

(Appendix 13)
The predefined common search space settings include a first common search space setting defined for a terminal type different from the predetermined terminal type, and a second common search space defined for the predetermined terminal type. each of the settings is associated with the second index,
The control unit (120) executes the second common search corresponding to the second index in response to the parameter indicating that the second common message is provided from the base station (200). The communication device (100) according to appendix 12, which specifies a space setting.

(Appendix 14)
a transmitter (211) for transmitting a master information block on a physical broadcast channel;
a control unit (230) that provides a common message commonly used by a plurality of communication devices (100) to the plurality of communication devices (100) on the physical downlink shared channel based on the master information block; ,
The master information block is configured to transmit a second common message defined for the predetermined terminal type from the base station (200) independently of a first common message defined for a terminal type different from the predetermined terminal type. including a parameter indicating whether or not to be provided;
The predetermined terminal type is a terminal type in which the frequency bandwidth that can be supported at least for a physical downlink shared channel is reduced to a predetermined bandwidth. A base station (200).

(Appendix 15)
A communication method executed by a communication device (100) of a predetermined terminal type in which the frequency bandwidth that can be supported by at least a physical downlink shared channel is reduced to a predetermined bandwidth, the method comprising:
receiving a master information block from a base station (200) on a physical broadcast channel;
a step of obtaining a common message commonly used by a plurality of communication devices (100) from the base station (200) on the physical downlink shared channel based on the master information block;
The master information block includes a second common message defined for the predetermined terminal type independently of a first common message defined for a terminal type different from the predetermined terminal type. The communication method includes a parameter indicating whether or not it is provided by the communication method.

Claims

A communication device (100) of a predetermined terminal type in which the frequency bandwidth that can be supported for at least a physical downlink shared channel is reduced to a predetermined bandwidth,
a receiving unit (112) for receiving a master information block from a base station (200) on a physical broadcast channel;
a control unit (120) that acquires a common message commonly used by a plurality of communication devices (100) from the base station (200) on the physical downlink shared channel based on the master information block;
The master information block includes a second common message defined for the predetermined terminal type independently of a first common message defined for a terminal type different from the predetermined terminal type. A communication device (100) including a parameter indicating whether or not it is provided by a communication device (100).
The communication device (100) according to claim 1, wherein the second common message is the common message transmitted from the base station (200) using a frequency bandwidth equal to or less than the predetermined bandwidth.
The control unit (120) sends the second common message from the base station (200) in response to the parameter indicating that the second common message is provided from the base station (200). The communication device (100) according to claim 1 or 2.
The control unit (120) causes the second common message to be provided from the base station (200) in response to the parameter indicating that the second common message is not provided from the base station (200). The communication device (100) according to claim 1 or 2, wherein the communication device (100) determines that the communication device does not.
The common message is a system information message,
The first common message is a first system information message defined for a terminal type different from the predetermined terminal type,
The communication device (100) according to claim 1 or 2, wherein the second common message is a second system information message defined for the predetermined terminal type.
The communication device (100) according to claim 5, wherein the second system information message is the system information message transmitted from the base station (200) using a frequency bandwidth equal to or less than the predetermined bandwidth.
The control unit (120) is configured to provide a first system information cell radio network temporary identifier (SI-RNTI) defined for the predetermined terminal type independently of a first system information cell radio network temporary identifier (SI-RNTI) defined for a terminal type different from the predetermined terminal type. The communication device (100) according to claim 5, wherein the second system information message is obtained using a second SI-RNTI.
The system information message includes a system information block type 1 (SIB1);
The first system information message includes a first SIB1 indicating the scheduling of a first other system information message defined for a terminal type different from the predetermined terminal type;
6. The communication device (100) of claim 5, wherein the second system information message includes a second SIB1 indicating scheduling of a second other system information message defined for the predetermined terminal type.
The control unit (120) includes:
obtaining the second SIB1 based on the parameters included in the master information block;
The communication device (100) according to claim 8, wherein the second other system information message is acquired based on the acquired second SIB1.
The master information block further includes a first index indicating a configuration of a control resource set (CORESET) corresponding to a physical downlink control channel used for scheduling the SIB1,
The control unit (120) configures the CORESET defined for the predetermined terminal type in response to the parameter indicating that the second common message is provided from the base station (200). The communication device (100) according to claim 8, wherein the communication device (100) is identified based on the first index.
The predefined CORESET settings include a first CORESET setting defined for a terminal type different from the predetermined terminal type, and a second CORESET setting defined for the predetermined terminal type. is associated with the first index,
The control unit (120) sets the second CORESET setting corresponding to the first index in response to the parameter indicating that the second common message is provided from the base station (200). The communication device (100) according to claim 10.
The master information block further includes a second index indicating a setting of a common search space corresponding to a physical downlink control channel used for scheduling the SIB1,
The control unit (120) controls the common search space defined for the predetermined terminal type in response to the parameter indicating that the second common message is provided from the base station (200). The communication device (100) according to claim 8, wherein settings are identified based on the second index.
The predefined common search space settings include a first common search space setting defined for a terminal type different from the predetermined terminal type, and a second common search space defined for the predetermined terminal type. each of the settings is associated with the second index,
The control unit (120) executes the second common search corresponding to the second index in response to the parameter indicating that the second common message is provided from the base station (200). 13. The communication device (100) of claim 12, wherein the communication device (100) specifies a space setting.
a transmitter (211) for transmitting a master information block on a physical broadcast channel;
a control unit (230) that provides a common message commonly used by a plurality of communication devices (100) to the plurality of communication devices (100) on the physical downlink shared channel based on the master information block; ,
The master information block is configured to transmit a second common message defined for the predetermined terminal type from the base station (200) independently of a first common message defined for a terminal type different from the predetermined terminal type. including a parameter indicating whether or not to be provided;
The predetermined terminal type is a terminal type in which the frequency bandwidth that can be supported at least for a physical downlink shared channel is reduced to a predetermined bandwidth. A base station (200).
A communication method executed by a communication device (100) of a predetermined terminal type in which the frequency bandwidth that can be supported by at least a physical downlink shared channel is reduced to a predetermined bandwidth, the method comprising:
receiving a master information block from a base station (200) on a physical broadcast channel;
a step of obtaining a common message commonly used by a plurality of communication devices (100) from the base station (200) on the physical downlink shared channel based on the master information block;
The master information block includes a second common message defined for the predetermined terminal type independently of a first common message defined for a terminal type different from the predetermined terminal type. The communication method includes a parameter indicating whether or not it is provided by the communication method.