COMMUNICATION CONTROL METHOD, USER EQUIPMENT, PROCESSOR, NETWORK DEVICE, MOBILE COMMUNICATION SYSTEM, AND PROGRAM

Abstract

To provide a communication control method, a user device, a network device, and a program for achieving an improved multicast broadcast service.SOLUTION: In a mobile communication system for providing a multicast broadcast service (MBS) from a base station to a user device, a base station gNB broadcasts an MBS system information block, and transmits scheduling information of an MBS traffic channel on an MBS control channel. The MBS system information block includes a search space identifier for the user device to receive the MBS control channel, and the search space identifier indicates a search space that is a resource range to be decoded by the user device in a physical downlink control channel associated with the MBS control channel.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present disclosure relates to a communication control method and a base station for use in a mobile communication system. [Background technology]

[0002] In recent years, the fifth generation (5G) mobile communication system has been attracting attention. NR (New Radio), the radio access technology (RAT) of the 5G system, has features such as high speed, large capacity, high reliability, and low latency compared to LTE (Long Term Evolution), the fourth generation radio access technology. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] 3GPP technical specification "3GPP TS 38.300 V16.2.0 (2020-07)" Summary of the Invention

[0004] The communication control method of the first aspect is a communication control method used in a mobile communication system that provides a multicast broadcast service (MBS) from a base station to a user device, comprising the steps of: the base station broadcasting an MBS system information block; and the base station transmitting scheduling information for an MBS traffic channel on an MBS control channel, the MBS system information block including a search space identifier for the user device to receive the MBS control channel, and the search space identifier indicating a search space, which is a resource range to be decoded by the user device, in a physical downlink control channel associated with the MBS control channel.

[0005] A communication control method according to a second aspect is a communication control method used in a mobile communication system that provides a multicast broadcast service (MBS) from a base station to a user device, comprising the steps of: the base station broadcasting a specified system information block used for scheduling an MBS system information block; the base station broadcasting the MBS system information block; and the base station transmitting scheduling information of an MBS traffic channel on an MBS control channel, wherein the specified system information block includes a search space identifier for the user device to receive the MBS control channel, and the search space identifier indicates a search space, which is a resource range to be decoded by the user device, in a physical downlink control channel associated with the MBS control channel.

[0006] A communication control method according to a third aspect is a communication control method used in a mobile communication system in which a base station provides a multicast broadcast service (MBS) to a user device, the method comprising the steps of: the base station broadcasting an MBS system information block; and the base station transmitting, on an MBS control channel, scheduling information for an MBS traffic channel and a search space identifier for the user device to receive the MBS traffic channel, the search space identifier indicating a search space, which is a resource range to be decoded by the user device, in a physical downlink control channel associated with the MBS traffic channel.

[0007] A communication control method according to a fourth aspect is a communication control method used in a mobile communication system that provides a multicast broadcast service (MBS) from a base station to a user device, comprising: the base station managing a cell transmitting a notification message regarding MBS transmission in an adjacent cell different from the cell to the user device in the first cell, the notification message including a search space identifier for the user device to receive a specified channel provided in the adjacent cell different from the cell, the search space identifier including a search space identifier indicating a search space, which is a resource range to be decoded by the user device, in a physical downlink control channel associated with the specified channel provided in the adjacent cell, and the specified channel being an MBS control channel or an MBS traffic channel provided in the adjacent cell.

[0008] A communication control method according to a fifth aspect is a communication control method used in a mobile communication system in which a base station provides a multicast broadcast service (MBS) to a user device, the method comprising: a base station managing a cell broadcasting an MBS system information block for the MBS; and a base station transmitting a plurality of MBS control channels in the cell, the MBS system information block including a change notification Radio Network Temporary Identifier (RNTI) for each of the plurality of MBS control channels, the change notification RNTI being an RNTI used by the user device to receive a change notification indicating that the content of the corresponding MBS control channel has been changed.

[0009] A base station according to a sixth aspect includes a processor that executes the communication control method according to any one of the first to fifth aspects. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing a configuration of a mobile communication system according to an embodiment. [Diagram 2]FIG. 2 is a diagram showing a configuration of a UE (user equipment) according to an embodiment. [Diagram 3] A diagram showing the configuration of a gNB (base station) according to an embodiment. [Figure 4] A diagram showing the configuration of a protocol stack of a wireless interface of a user plane that handles data. [Diagram 5] FIG. 2 is a diagram showing the configuration of a protocol stack of a radio interface of a control plane that handles signaling (control signals). [Figure 6] FIG. 2 is a diagram illustrating a correspondence relationship between downlink logical channels and transport channels according to an embodiment. [Figure 7] 1 is a diagram showing a method for distributing MBS data according to an embodiment. [Figure 8] FIG. 4 is a diagram showing a correspondence relationship of channels according to the embodiment. [Figure 9] FIG. 2 is a diagram showing a first operation example of the mobile communication system according to the embodiment. [Figure 10] FIG. 11 is a diagram showing a second operation example of the mobile communication system according to the embodiment. [Figure 11] FIG. 11 is a diagram showing a third operation example of the mobile communication system according to the embodiment. [Figure 12] FIG. 13 is a diagram showing an example of an operating environment in a fourth operation example of the mobile communication system according to the embodiment. [Figure 13] FIG. 11 is a diagram showing a fourth operation example of the mobile communication system according to the embodiment. [Figure 14] FIG. 11 is a diagram showing a fifth operation example of the mobile communication system according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The introduction of multicast and broadcast services to the 5G system (NR) is being considered. It is hoped that the NR multicast and broadcast services will provide improved services compared to the LTE multicast and broadcast services.

[0012] Therefore, an object of the present disclosure is to provide a communication control method that realizes an improved multicast / broadcast service.

[0013] 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 denoted by the same or similar reference numerals.

[0014] (Configuration of a mobile communication system) First, a configuration of a mobile communication system according to an embodiment will be described. Fig. 1 is a diagram showing a configuration of a mobile communication system according to an embodiment. This mobile communication system complies with the 3GPP standard 5th Generation System (5GS). In the following, 5GS will be described as an example, but the LTE (Long Term Evolution) system may be applied at least in part to the mobile communication system.

[0015] As shown in FIG. 1, the mobile communication system includes a user equipment (UE) 100, a 5G radio access network (NG-RAN) 10, and a 5G core network (5GC) 20.

[0016] The UE 100 is a mobile wireless communication device. The UE 100 may be any device that is used by a user, and may be, for example, a mobile phone terminal (including a smartphone), a tablet terminal, a notebook PC, a communication module (including a communication card or a chipset), a sensor or a device provided in a sensor, a vehicle or a device provided in a vehicle (Vehicle UE), and / or an aircraft or a device provided in an aircraft (Aerial UE).

[0017] The NG-RAN 10 includes a base station (called "gNB" in the 5G system) 200. The gNBs 200 are connected to each other via an Xn interface, which is an interface between base stations. The gNB 200 manages one or more cells. The gNB 200 performs wireless communication with the UE 100 that has established a connection with its own cell. The gNB 200 has a radio resource management (RRM) function, a routing function for user data (hereinafter simply referred to as "data"), a measurement control function for mobility control and scheduling, and the like. The term "cell" is used to indicate the smallest unit of a wireless communication area. The term "cell" is also used to indicate a function or resource for performing wireless communication with the UE 100. One cell belongs to one carrier frequency.

[0018] In addition, gNBs can also be connected to the Evolved Packet Core (EPC), which is the core network of LTE. LTE base stations can also be connected to 5GC. LTE base stations and gNBs can also be connected via an inter-base station interface.

[0019] The 5GC20 includes an Access and Mobility Management Function (AMF) and a User Plane Function (UPF) 300. The AMF performs various mobility controls for the UE 100. The AMF manages the mobility of the UE 100 by communicating with the UE 100 using Non-Access Stratum (NAS) signaling. The UPF controls data forwarding. The AMF and the UPF are connected to the gNB 200 via an NG interface, which is an interface between a base station and a core network.

[0020] FIG. 2 is a diagram showing a configuration of a UE 100 (user equipment) according to the embodiment.

[0021] As shown in FIG. 2, the UE 100 includes a receiving unit 110, a transmitting unit 120, and a control unit .

[0022] The receiving unit 110 performs various receptions under the control of the control unit 130. The receiving unit 110 includes an antenna and a receiver. The receiver converts a radio signal received by the antenna into a baseband signal (received signal) and outputs the baseband signal to the control unit 130.

[0023] The transmission unit 120 performs various transmissions under the control of the control unit 130. The transmission unit 120 includes an antenna and a transmitter. The transmitter converts a baseband signal (transmission signal) output by the control unit 130 into a radio signal and transmits it from the antenna.

[0024] The control unit 130 performs various controls in the UE 100. The control unit 130 includes at least one processor and at least one memory. The memory stores programs executed by the processor and information used in the processing by the processor. The processor may include a baseband processor and a CPU (Central Processing Unit). The baseband processor performs modulation / demodulation and encoding / decoding of baseband signals. The CPU executes programs stored in the memory to perform various processing.

[0025] FIG. 3 is a diagram showing the configuration of a gNB200 (base station) according to an embodiment.

[0026] As shown in FIG. 3, the gNB 200 includes a transmitter 210, a receiver 220, a control unit 230, and a backhaul communication unit 240.

[0027] The transmission unit 210 performs various transmissions under the control of the control unit 230. The transmission unit 210 includes an antenna and a transmitter. The transmitter converts a baseband signal (transmission signal) output by the control unit 230 into a radio signal and transmits it from the antenna.

[0028] The receiving unit 220 performs various receptions under the control of the control unit 230. The receiving unit 220 includes an antenna and a receiver. The receiver converts a radio signal received by the antenna into a baseband signal (received signal) and outputs the baseband signal to the control unit 230.

[0029] The control unit 230 performs various controls in the gNB 200. The control unit 230 includes at least one processor and at least one memory. The memory stores programs executed by the processor and information used in the processing by the processor. The processor may include a baseband processor and a CPU. The baseband processor performs modulation / demodulation and encoding / decoding of baseband signals. The CPU executes programs stored in the memory to perform various processing.

[0030] The backhaul communication unit 240 is connected to adjacent base stations via an inter-base station interface. The backhaul communication unit 240 is connected to the AMF / UPF 300 via a base station-core network interface. Note that the gNB is composed of a CU (Central Unit) and a DU (Distributed Unit) (i.e., the functions are divided), and both units may be connected to each other via an F1 interface.

[0031] FIG. 4 is a diagram showing the configuration of a protocol stack of a radio interface of a user plane that handles data.

[0032] As shown in FIG. 4, the user plane radio interface protocol includes a physical (PHY) layer, a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, and a service data adaptation protocol (SDAP) layer.

[0033] 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 the UE 100 and the PHY layer of the gNB 200 via a physical channel.

[0034] The MAC layer performs data priority control, retransmission processing using hybrid ARQ (HARQ), random access procedures, etc. Data and control information are transmitted between the MAC layer of the UE 100 and the MAC layer of the gNB 200 via a transport channel. The MAC layer of the gNB 200 includes a scheduler. The scheduler determines the uplink and downlink transport format (transport block size, modulation and coding scheme (MCS)) and the resource blocks to be assigned to the UE 100.

[0035] The RLC layer transmits data to the RLC layer on the receiving side by using the functions of the MAC layer and the PHY layer. Data and control information are transmitted between the RLC layer of the UE 100 and the RLC layer of the gNB 200 via a logical channel.

[0036] The PDCP layer performs header compression / decompression and encryption / decryption.

[0037] The SDAP layer maps IP flows, which are units for QoS (Quality of Service) control by the core network, to radio bearers, which are units for QoS control by the AS (Access Stratum). Note that if the RAN is connected to the EPC, the SDAP is not necessary.

[0038] FIG. 5 is a diagram showing the configuration of a protocol stack of a radio interface of a control plane that handles signaling (control signals).

[0039] As shown in FIG. 5, the protocol stack of the radio interface of the control plane has a Radio Resource Control (RRC) layer and a Non-Access Stratum (NAS) layer instead of the SDAP layer shown in FIG.

[0040] Between the RRC layer of the UE 100 and the RRC layer of the gNB 200, RRC signaling for various settings is transmitted. The RRC layer controls logical channels, transport channels, and physical channels according to the establishment, re-establishment, and release of radio bearers. When there is a connection (RRC connection) between the RRC of the UE 100 and the RRC of the gNB 200, the UE 100 is in an RRC connected state. When there is no connection (RRC connection) between the RRC of the UE 100 and the RRC of the gNB 200, the UE 100 is in an RRC idle state. When the connection between the RRC of the UE 100 and the RRC of the gNB 200 is suspended, the UE 100 is in an RRC inactive state.

[0041] The NAS layer, which is located above the RRC layer, performs session management, mobility management, etc. NAS signaling is transmitted between the NAS layer of the UE 100 and the NAS layer of the AMF 300.

[0042] In addition, the UE 100 has an application layer and the like in addition to the protocol of the radio interface.

[0043] (MBS) Next, an MBS according to an embodiment will be described. The MBS is a service that enables broadcast or multicast data transmission, i.e., point-to-multipoint (PTM) data transmission, from the NG-RAN 10 to the UE 100. The MBS may be called a multimedia broadcast and multicast service (MBMS). Note that use cases (service types) of the MBS include public safety communication, mission critical communication, vehicle to everything (V2X) communication, IPv4 or IPv6 multicast distribution, Internet protocol television (IPTV), group communication, and software distribution.

[0044] There are two types of MBS transmission methods in LTE: MBSFN (Multicast Broadcast Single Frequency Network) transmission and SC-PTM (Single Cell Point To Multipoint) transmission. Fig. 6 is a diagram showing a correspondence relationship between downlink logical channels and transport channels according to one embodiment.

[0045] As shown in Figure 6, the logical channels used for MBSFN transmission are MTCH (Multicast Traffic Channel) and MCCH (Multicast Control Channel), and the transport channel used for MBSFN transmission is MCH (Multicast Channel). MBSFN transmission is designed mainly for multi-cell transmission, and in an MBSFN area consisting of multiple cells, each cell synchronously transmits the same signal (same data) in the same MBSFN subframe.

[0046] The logical channels used for SC-PTM transmission are the Single Cell Multicast Traffic Channel (SC-MTCH) and the Single Cell Multicast Control Channel (SC-MCCH), and the transport channel used for SC-PTM transmission is the Downlink Shared Channel (DL-SCH). SC-PTM transmission is designed primarily for single-cell transmission, and transmits data by broadcast or multicast on a cell-by-cell basis. The physical channels used for SC-PTM transmission are the Physical Downlink Control Channel (PDCCH) and the Physical Downlink Shared Channel (PDSCH), which enable dynamic resource allocation.

[0047] In the following, an example in which an MBS is provided using a method similar to the SC-PTM transmission method will be mainly described, but an MBS may also be provided using the MBSFN transmission method. Also, an example in which an MBS is provided by multicast will be mainly described. Therefore, MBS may be read as multicast. However, an MBS may also be provided by broadcast.

[0048] In addition, MBS data refers to data provided by MBS, MBS control channel refers to MCCH or SC-MCCH, and MBS traffic channel refers to MTCH or SC-MTCH. However, MBS data may be transmitted by unicast. MBS data may also be called MBS packet or MBS traffic.

[0049] The MBS control channel is a point-to-multipoint (PTM) downlink channel used to transmit MBS control information from the gNB 200 to the UE 100. The MBS control channel is mapped to a DL-SCH (Downlink Shared Channel), which is a type of transport channel.

[0050] The MBS traffic channel is a point-to-multipoint (PTM) downlink channel used to transmit MBS data from the gNB 200 to the UE 100. The MBS traffic channel is a type of logical channel and is mapped to the DL-SCH. The MBS traffic channel and the MBS session are in one-to-one correspondence.

[0051] The DL-SCH is mapped to a Physical Downlink Shared Channel (PDSCH), which is a type of physical channel. The PDSCH is scheduled by Downlink Control Information (DCI) carried by a Physical Downlink Control Channel (PDCCH), which is a type of physical channel.

[0052] A network can provide different MBS services for each MBS session. An MBS session is identified by at least one of a Temporary Mobile Group Identity (TMGI) and a session identifier, and at least one of these identifiers is called an MBS session identifier. Such an MBS session identifier may be called an MBS service identifier or a multicast group identifier.

[0053] FIG. 7 is a diagram showing a method for delivering MBS data according to an embodiment.

[0054] As shown in Fig. 7, MBS data (MBS Traffic) is distributed from a single data source (application service provider) to multiple UEs. A 5G CN (5GC) 20, which is a 5G core network, receives the MBS data from the application service provider, creates a copy (replication) of the MBS data, and distributes it.

[0055] From the 5GC20 point of view, two delivery methods are possible: Shared MBS Traffic delivery and Individual MBS Traffic delivery.

[0056] In the shared MBS data delivery, a connection is established between NG-RAN 10, which is a 5G radio access network (5G RAN), and 5GC 20, and MBS data is delivered from 5GC 20 to NG-RAN 10. Hereinafter, such a connection (tunnel) is referred to as an "MBS connection."

[0057] The MBS connection may be referred to as a Shared MBS Traffic delivery connection or a shared transport. The MBS connection terminates in the NG-RAN 10 (i.e., the gNB 200). The MBS connection may have a one-to-one correspondence with the MBS session.

[0058] gNB200 selects either PTP (Point-to-Point: unicast) or PTM (Point-to-Multipoint: multicast or broadcast) transmission method at its own discretion, and transmits MBS data to UE100 using the selected transmission method.

[0059] On the other hand, in the individual MBS data delivery, a unicast session is established between the NG-RAN 10 and the UE 100, and the MBS data is delivered individually from the 5GC 20 to the UE 100. Such a unicast may be called a PDU session. The unicast (PDU session) is terminated at the UE 100.

[0060] (Channel correspondence) Next, the correspondence between channels according to an embodiment will be described.

[0061] Fig. 8 is a diagram showing a correspondence relationship of channels according to an embodiment. Each channel shown in Fig. 8 is provided in one cell. Fig. 8 shows an example in which multiple MBS control channels are provided in one cell, but only one MBS control channel may be provided in one cell.

[0062] 8 represents one channel, the description of "PDCCH" in each block means that the radio resource (PDSCH) of the channel in the physical layer is allocated by the PDCCH. That is, it is assumed that the broadcast control channel, the MBS control channel, and the MBS traffic channel are all mapped to the DL-SCH.

[0063] First, the gNB 200 broadcasts SIB type 1 on the broadcast control channel. SIB type 1 includes scheduling information for the MBS system information block (MBS SIB) (hereinafter referred to as "MBS SIB scheduling information"). The MBS SIB scheduling information is information for scheduling a message carrying the MBS SIB (an SI message, described later). The MBS SIB is a system information block for MBS, and is a type of OSI (Other System Information), described later.

[0064] Secondly, the gNB 200 broadcasts the MBS SIB on the broadcast control channel in accordance with the scheduling according to SIB type 1. The MBS SIB includes information indicating the scheduling of the MBS control channel (hereinafter referred to as "MBS control channel scheduling information"). The MBS SIB is transmitted at a period scheduled by a predetermined SIB (e.g., SIB type 1). The MBS control channel scheduling information is information for identifying candidate time positions at which the MBS control channel may be transmitted. Such candidate time positions may be called an MBS control channel transmission window. Such candidate time positions may be configured with a predetermined number of time units that are periodically arranged. The time unit may be a slot. Also, the time unit may be a subframe. The MBS control channel scheduling information includes a Repetition period (repetition transmission period), an Offset (offset value of the SFN for which scheduling is performed), a Start point (scheduling start subframe / slot), a Duration (scheduling period from the Start point), and / or a Modification period (modification period).

[0065] In addition, the gNB200 may provide multiple MBS control channels in a cell managed by the gNB200. For example, each MBS control channel is associated with a different service quality requirement (or service category). This makes it possible to configure an MBS control channel optimized according to the service quality requirement. In this case, the MBS SIB may schedule each of the multiple MBS control channels (MCCH#1 and MCCH#2). Different scheduling can be applied to each MBS control channel. In addition, the MBS control channel is transmitted at a period indicated by the MBS SIB.

[0066] Third, the gNB 200 broadcasts the MBS traffic channel scheduling information on the MBS control channel according to the MBS control channel scheduling information. The MBS traffic channel scheduling information is information for identifying candidate time positions at which the MBS traffic channel may be transmitted. Such candidate time positions may be configured with a predetermined number of time units that are periodically arranged. The time unit may be a slot. Also, the time unit may be a subframe. The MBS traffic channel scheduling information includes an On duration timer, a DRX inactivity timer, a Scheduling period (transmission period), and / or a Start offset (transmission SFN offset value), etc.

[0067] In FIG. 8, an example is shown in which MCCH#1 indicates one MBS traffic channel (MTCH#1) and MCCH#2 indicates two MBS traffic channels (MTCH#2 and MTCH#3). MTCH#1 is an MBS traffic channel that transmits MBS data for a delay sensitive MBS service. MTCH#2 and MTCH#3 are MBS traffic channels that transmit MBS data for a typical MBS service.

[0068] Fourth, the gNB200 transmits (e.g., PTM transmits) the MBS data on the MBS traffic channel in accordance with the MBS traffic channel scheduling information.

[0069] (Search Space) Next, a search space according to an embodiment will be described.

[0070] In the 5G / NR specification, in order to reduce the number of blind decodings in the UE 100, the resource range in the PDCCH that is the target of blind decoding by the UE 100 is limited. Such a resource range is a time-frequency resource range, and is composed of multiple resource blocks in the frequency direction and multiple symbols in the time direction. Such a resource range is called a search space. In one embodiment, the gNB 200 provides multiple search spaces in its own cell. The gNB 200 provides search space configuration information for configuring multiple search spaces in its own cell using SIB type 1 or an RRC Reconfiguration message. This allows the configuration of each search space to be dynamically changed, enabling resource optimization.

[0071] The search space setting information includes, for each of a plurality of search spaces, a set of a search space identifier for identifying the search space and a search space parameter for setting the search space. The search space parameter specifies a plurality of resource blocks and a plurality of symbols constituting the search space. The search space parameter includes, for example, ControlResourceSetID, monitoringSlotPeriodicityAndOffset, and / or monitoringSymbolsWithinSlot. ControlResourceSetID is a parameter used to specify a resource block, and monitoringSlotPeriodicityAndOffset and monitoringSymbolsWithinSlot are parameters used to specify a symbol.

[0072] In one embodiment, the gNB 200 configures, in its own cell, one special search space (hereinafter, referred to as a "specific search space") that is different from the above-mentioned multiple search spaces. The specific search space is a search space in which the UE 100 can specify multiple resource blocks and multiple symbols that configure the specific search space, i.e., scheduling and resource range, according to a preset rule. The UE 100 can specify the scheduling and resource range of the specific search space even if there is no search space configuration information from the gNB 200 for the specific search space.

[0073] The gNB200 assigns a search space identifier of "0" to a specific search space. The specific search space may be referred to as search space zero. The gNB200 does not assign a search space identifier of "0" to the above-mentioned multiple search spaces in order to distinguish between the specific search space and the above-mentioned multiple search spaces. For example, the search space includes a specific search space, search space "0", and the other search spaces, search spaces "1" to "4".

[0074] In one embodiment, the gNB 200 associates different search spaces with each type of downlink message transmitted in the cell of the gNB 200. The type of downlink message is, for example, a system information message (SI message), a paging message, etc. The SI message is a message used to carry a system information block other than SIB type 1. The system information block other than SIB type 1 is called OSI (Other System Information). For example, the gNB 200 associates an SI message with a search space (search space #1) identified by a search space identifier of "1" in the search space setting information, associates a paging message with a search space (search space #2) identified by a search space identifier of "2" in the search space setting information, and transmits information indicating this association in the SIB type 1. Hereinafter, a search space associated with an SI message carrying an OSI is called an "OSI search space."

[0075] (First operation example of mobile communication system) Next, a first operation example of the mobile communication system 1 according to an embodiment will be described.

[0076] In this first operation example, it is assumed that a search space is assigned to the MBS control channel. In this case, it is considered that a specific search space (e.g., search space "0") or any other search space (e.g., search spaces "1" to "4") is assigned to the MBS control channel. Here, the scheduling of the MBS control channel differs between when search space "0" is used and when it is otherwise (e.g., search space "1"). Note that a search space different from the search space of the OSI may be assigned to the MBS control channel. In this case, even if UE 100 knows the search space of the OSI, it cannot receive the MBS control channel.

[0077] Under such a premise, in order to receive the MBS control channel, the UE 100 needs to identify a search space associated with the MBS control channel. However, it is not possible for the UE 100 to know which search space to perform blind decoding on in order to receive the MBS control channel.

[0078] In this first operation example, the gNB 200 broadcasts the MBS SIB and transmits scheduling information of the MBS traffic channel on the MBS control channel. The MBS SIB includes a search space identifier for the UE 100 to receive the MBS control channel. The search space identifier indicates a search space, which is a resource range to be decoded by the UE 100 in the physical downlink control channel associated with the MBS control channel. This allows the UE 100 to know which search space may be used for blind decoding in order to receive the MBS control channel.

[0079] In this first operation example, when a plurality of MBS control channels are provided in one cell of the gNB 200, the MBS SIB may include a search space identifier for each of the plurality of MBS control channels. This allows the UE 100 to know which search space may be used for blind decoding in order to receive each MBS control channel, even when a plurality of MBS control channels are provided in one cell of the gNB 200.

[0080] In this first operation example, when the MBS control channel is not associated with a specific search space, the gNB 200 may broadcast an MBS SIB further including MBS control channel scheduling information indicating the scheduling of the MBS control channel. As described above, the specific search space is a search space in which the UE 100 can specify the scheduling and resource range of the MBS control channel according to a preset rule. This allows the UE 100 to grasp the scheduling of the MBS control channel even when the MBS control channel is not associated with a specific search space.

[0081] FIG. 9 is a diagram showing a first operation example of the mobile communication system 1. As shown in FIG.

[0082] 9, in step S101, the gNB 200 broadcasts the SIB type 1. The SIB type 1 includes search space configuration information and MBS SIB scheduling information. The UE 100 receives the SIB type 1 from the gNB 200.

[0083] In step S102, the gNB 200 broadcasts the MBS SIB based on the scheduling indicated by the MBS SIB scheduling information included in the SIB type 1. The UE 100 receives the MBS SIB based on the scheduling indicated by the MBS SIB scheduling information included in the SIB type 1. The MBS SIB includes MBS control channel scheduling information.

[0084] In the first operation example, the MBS SIB further includes a search space identifier (hereinafter, referred to as an "MBS control channel search space identifier") for the UE 100 to receive the MBS control channel. The MBS control channel search space identifier is one of the search space identifiers included in the search space setting information in the SIB type 1. Here, the gNB 200 associates one of a plurality of search spaces (e.g., search spaces "1" to "4") set by the search space setting information in the SIB type 1 with the MBS control channel. The gNB 200 includes in the MBS SIB a search space identifier of the search space associated with the MBS control channel.

[0085] When multiple MBS control channels are provided in a cell managed by the gNB200, the gNB200 may associate different search spaces with each MBS control channel. In this case, in step S102, the gNB200 broadcasts an MBS SIB including an MBS control channel search space identifier corresponding to each of the multiple MBS control channels. In this case, the MBS SIB includes, for each of the multiple MBS control channels, a set of an identifier of the MBS control channel and an MBS control channel search space identifier corresponding to the MBS control channel. The identifier of the MBS control channel may be the above-mentioned MBS session identifier. The identifier of the MBS control channel may be a channel identifier assigned to the MBS control channel. The identifier of the MBS control channel may be an RNTI (Radio Network Temporary Identifier) ​​assigned to the MBS control channel.

[0086] In the first operation example, the gNB 200 may include the MBS control channel scheduling information in the MBS SIB only when a specific search space is not associated with the MBS control channel. Here, when the MBS control channel is associated with a specific search space, the UE 100 can specify the resource range based on a pre-set rule without relying on the MBS control channel scheduling information. Therefore, in this case, the MBS control channel scheduling information is not required. Therefore, when the MBS control channel is not associated with a specific search space, the gNB 200 includes the MBS control channel scheduling information in the MBS SIB.

[0087] In step S103, UE100 identifies a PDCCH resource range to be decoded to receive the MBS control channel based on the MBS control channel scheduling information and MBS control channel search space identifier included in the MBS SIB received in step S102. Specifically, UE100 first determines a range of reception timing of the MBS control channel from the MBS control channel scheduling information included in the MBS SIB received in step S102. Secondly, UE100 acquires a search space parameter corresponding to the MBS control channel search space identifier included in the MBS SIB received in step S102 from the SIB type 1 received in step S101, and identifies a PDCCH resource range from the acquired search space parameter.

[0088] When UE100 receives an MBS SIB including an MBS control channel search space identifier corresponding to each of a plurality of MBS control channels, UE100 identifies a resource range to be decoded in order to receive the MBS control channel that UE100 is interested in, based on such an MBS SIB. Specifically, UE100 acquires an MBS control channel search space identifier associated with the MBS control channel that UE100 is interested in, and identifies a resource range of the PDCCH to be decoded according to the acquired MBS control channel search space identifier.

[0089] In step S104, the gNB 200 transmits MBS traffic channel scheduling information on the MBS control channel. The UE 100 receives the MBS control channel. First, the UE 100 performs decoding (blind decoding) on ​​the resource range identified in step S103 to obtain DCI carried by the PDCCH. Second, the UE 100 receives the PDSCH scheduled by the DCI, and receives the MBS control channel (MBS traffic channel scheduling information) mapped to the PDSCH.

[0090] In step S105, the gNB 200 transmits the MBS data on the MBS traffic channel. The UE 100 receives the MBS traffic channel (MBS data) based on the MBS traffic channel scheduling information received in step S104.

[0091] (Second operation example of mobile communication system) Next, a second operation example of the mobile communication system 1 according to an embodiment will be described, focusing mainly on the differences from the above-described first operation example.

[0092] In the above-mentioned first operation example, it is mainly assumed that a dedicated search space is assigned for the MBS control channel. In contrast, in the second operation example, an example in which the search space of the MBS control channel and the search space of the OSI are made common will be described. This eliminates the need to broadcast information on the search space of the MBS control channel in the MBS SIB, and allows for efficient operation.

[0093] In this second operation example, the gNB 200 broadcasts SIB type 1 used for scheduling the MBS SIB, broadcasts the MBS SIB, and transmits scheduling information of the MBS traffic channel on the MBS control channel. Here, the SIB type 1 includes a search space identifier for the UE 100 to receive the MBS control channel. Specifically, the search space identifier is commonly applied to the MBS SIB, system information blocks other than the SIB type 1, and the MBS control channel.

[0094] 10 is a diagram showing a second operation example of the mobile communication system 1. Here, explanations that overlap with the above-mentioned first operation example will be omitted.

[0095] As shown in FIG. 10, in step S201, the gNB 200 broadcasts the SIB type 1. The SIB type 1 includes search space configuration information and MBS SIB scheduling information. In a second operation example, the SIB type 1 further includes an MBS control channel search space identifier. The UE 100 receives the SIB type 1 from the gNB 200.

[0096] In step S202, the UE 100 receives an MBS SIB based on the SIB type 1. The MBS SIB includes MBS control channel scheduling information.

[0097] In a second operation example, the MBS SIB does not include an MBS control channel search space identifier.

[0098] In step S203, the UE 100 identifies a resource range to be decoded in order to receive the MBS control channel, based on the MBS control channel scheduling information received in step S202 and the MBS control channel search space identifier received in step S201.

[0099] The operations in steps S204 and S205 are similar to the operations in steps S104 and S105.

[0100] In the second operation example, the MBS control channel search space identifier may be information commonly applied to the MBS SIB and the OSI. That is, the search space associated with the SI message carrying the OSI may be the same as the search space associated with the MBS control channel. In this case, in step S201, the SIB type 1 may include information indicating that the search space associated with the SI message is the same as the search space associated with the MBS control channel. Such information may be notified from the gNB 200 to the UE 100 by another method.

[0101] In the second operation example, if the search space associated with the SI message carrying the OSI is the same as the search space associated with the MBS control channel, and the search space associated with the SI message carrying the OSI is a specific search space, the UE 100 may skip receiving the MBS SIB (the operation of step S202). In this case, the UE 100 can specify the resource range based on a preset rule without relying on the MBS control channel scheduling information. Therefore, in this case, the MBS control channel scheduling information is not necessary, and the UE 100 skips receiving the MBS SIB including the MBS control channel scheduling information.

[0102] (Third operation example of mobile communication system) Next, a third operation example of the mobile communication system 1 according to an embodiment will be described, focusing mainly on differences from the above-described first and second operation examples.

[0103] In the above first and second operation examples, the search space of the MBS control channel is mainly described. However, it is also assumed that the search space is assigned to the MBS traffic channel. In this third operation example, the search space of the MBS traffic channel is described.

[0104] In this third operation example, the gNB 200 transmits, via the MBS control channel, scheduling information for the MBS traffic channel and a search space identifier for the UE 100 to receive the MBS traffic channel. The search space identifier indicates a search space, which is a resource range to be decoded by the UE 100, in the physical downlink control channel associated with the MBS traffic channel. This allows the UE 100 to identify the search space assigned to the MBS traffic channel even when a search space is assigned to the MBS traffic channel.

[0105] In this operation example 3, the gNB 200 may transmit a search space identifier for each of the multiple MBS traffic channels. That is, the gNB 200 may specify a search space for each MBS traffic channel. This allows a different search space to be assigned to each MBS traffic channel, which makes it easier to alleviate congestion in the search space.

[0106] In this operation example 3, when the MBS traffic channel is not associated with a specific search space (e.g., search space "0"), the gNB 200 transmits the scheduling information of the MBS traffic channel and a search space identifier on the MBS control channel. When the MBS traffic channel is associated with a specific search space, the gNB 200 transmits the search space identifier without transmitting the scheduling information of the MBS traffic channel. For a specific search space, the UE 100 can derive its scheduling and resource range by itself, making it unnecessary to transmit the scheduling information of the MBS traffic channel.

[0107] 11 is a diagram showing a third operation example of the mobile communication system 1. Here, explanations that overlap with the first and second operation examples described above will be omitted.

[0108] As shown in Fig. 11, in step S301, the UE 100 receives an MBS control channel. The MBS control channel carries MBS traffic channel scheduling information.

[0109] In the third operation example, the MBS control channel further carries a search space identifier (hereinafter referred to as an "MBS traffic channel search space identifier") for the UE 100 to receive the MBS traffic channel. The MBS traffic channel search space identifier includes one of the search space identifiers included in the search space configuration information in the SIB type 1. Here, the gNB 200 associates one of the multiple search spaces configured by the search space configuration information in the SIB type 1 with the MBS traffic channel. The gNB 200 includes a search space identifier of the search space associated with the MBS traffic channel in the MBS traffic channel search space identifier.

[0110] In step S302, the UE 100 identifies a resource range to be decoded in order to receive the MBS traffic channel, based on the MBS traffic channel scheduling information and the MBS traffic channel search space identifier received in step S301.

[0111] In step S303, the UE 100 receives the MBS traffic channel. First, the UE 100 performs decoding (blind decoding) for the resource range specified in step S302 to obtain the DCI carried by the PDCCH. Second, the UE 100 receives the PDSCH scheduled by the DCI, and receives the MBS traffic channel mapped to the PDSCH. The UE 100 receives the MBS data carried by the MBS traffic channel.

[0112] In a third operation example, the MBS control channel carries MBS traffic channel scheduling information corresponding to each of a plurality of MBS traffic channels. The gNB 200 may associate a different search space with each MBS traffic channel. In this case, in step S301, the MBS control channel includes, for each of a plurality of MBS traffic channels, a set of an identifier of the MBS traffic channel and an MBS traffic channel search space identifier corresponding to the MBS traffic channel. The identifier of the MBS traffic channel is a TMGI, a session identifier, or an MBS service identifier. In step S305, the UE 100 identifies a resource range to be decoded in order to receive an MBS traffic channel (MBS session) of interest to the UE 100.

[0113] In the third operation example, when the gNB200 associates a specific search space with an MBS traffic channel, the gNB200 may not transmit MBS traffic channel scheduling information corresponding to the MBS traffic channel in the MBS control channel. Here, when the MBS traffic channel is associated with a specific search space, the UE100 can specify a resource range based on a preset rule without relying on the MBS traffic channel scheduling information. Therefore, the gNB200 does not transmit such MBS traffic channel scheduling information. In the third operation example, an example in which the MBS control channel notifies the MBS traffic channel search space identifier has been shown, but the MBS traffic channel search space identifier may be notified by the SIB type 1 or the MBS SIB. In this case, the MBS traffic channel search space identifier does not need to be notified by the MBS control channel.

[0114] (Fourth operation example of mobile communication system) Next, a fourth operation example of the mobile communication system 1 according to an embodiment will be described, focusing mainly on differences from the above-described first to third operation examples.

[0115] In the above-mentioned first to third operation examples, the operation of the gNB 200 in its own cell has been mainly described. In this fourth operation example, the gNB 200 also notifies the UE 100 in its own cell of information regarding neighboring cells. FIG. 12 is a diagram showing an example of an operation environment in this fourth operation example. As shown in FIG. 12, the gNB 200A manages the cell C1, the gNB 200B manages the cell C2, and the UE 100 is located in an overlapping area of ​​the cells C1 and C2. However, the cells C1 and C2 may be managed by one gNB 200.

[0116] In this fourth operation example, the gNB200 (gNB200A) that manages the cell C1 transmits a notification message regarding MBS transmission in a neighboring cell C2 different from the cell C1 to the UE100 in the cell C1. The notification message includes a search space identifier for the UE100 to receive a predetermined channel provided in the neighboring cell C2. The predetermined channel is an MBS control channel or an MBS traffic channel provided in the neighboring cell C2. The search space identifier indicates a search space that is a resource range that the UE100 is to decode in a physical downlink control channel associated with the predetermined channel provided in the neighboring cell C2. As a result, the UE100 that receives the notification message from the cell C1 can identify the search space of the MBS control channel or the MBS traffic channel provided in the neighboring cell C2 based on the notification message.

[0117] In the fourth operation example, when the UE 100 determines that the search space of the predetermined channel provided in the neighboring cell C2 is a specific search space (for example, search space "0") based on the search space identifier included in the notification message from the cell C1, the UE 100 may omit reception of the scheduling information of the predetermined channel transmitted from the neighboring cell C2 and may receive the predetermined channel provided in the neighboring cell C2. This allows efficient reception of the MBS control channel or MBS traffic channel of the neighboring cell C2.

[0118] 13 is a diagram showing a fourth operation example of the mobile communication system 1. Here, explanations overlapping with the first to third operation examples described above will be omitted. Here, it is assumed that the gNB 200A manages the cell C1 and the gNB 200B manages the cell C2, but one gNB 200 may manage the cells C1 and C2. The UE 100 may be in an RRC idle state or an RRC inactive state.

[0119] As shown in FIG. 13, in step S401, the gNB 200A transmits, in the cell C1, a notification message regarding MBS transmission in the cell C2. The UE 100 receives the notification message in the cell C1. The notification message may be an MBS SIB. The notification message may also be a message transmitted on an MBS control channel.

[0120] The notification message includes a search space identifier for the UE 100 to receive a predetermined channel (MBS control channel or MBS traffic channel) provided in the cell C2. The search space identifier includes one of the search space identifiers included in the search space setting information in the SIB type 1 broadcast in the cell C2. As a result, when the UE 100 residing in the cell C1 changes its own serving cell from the cell C1 to the cell C2, it can grasp the search space associated with the predetermined channel (MBS control channel or MBS traffic channel) of the cell C2 by acquiring only the SIB type 1 of the cell C2.

[0121] In step S401, the gNB 200A may notify the search space identifier of the cell C2 in step S401 only when a specific search space (search space "0") is assigned to a specific channel in the neighboring cell C2. Since the UE 100 can derive the scheduling and resource range for a specific search space by itself, if it is found that the search space is "0", it is possible to omit reception of the SIB type 1 of the neighboring cell C2. When the search space "1" is assigned to a specific channel in the neighboring cell C2, the gNB 200A may not notify the search space identifier of the cell C2 in step S401, and may implicitly indicate that the search space is not "0".

[0122] Alternatively, in step S401, gNB200A may notify the search space identifier of cell C2 only if a specific search space (search space "0") is not assigned to a specific channel in neighboring cell C2.

[0123] In step S402, UE 100 determines to receive MBS from cell C2. For example, UE 100 may determine to receive MBS from cell C2 when it reaches a cell edge of cell C1 (changing the receiving cell at the same frequency) or when the MBS service in the current cell C1 is stopped due to a change in the network settings (changing the receiving cell at a different frequency).

[0124] In step S403, UE 100 may receive SIB type 1 from cell C2.

[0125] In step S404, the UE 100 identifies the scheduling and resource range to be decoded in order to receive the predetermined channel of the neighboring cell C2 based on the search space identifier of the neighboring cell C2 included in the notification message received in step S401. Here, when the UE 100 receives the SIB type 1 of the neighboring cell C2 in step S403, the UE 100 may identify the scheduling and resource range to be decoded in order to receive the predetermined channel of the neighboring cell C2 based on the search space parameter included in the SIB type 1.

[0126] In step S405, UE 100 receives a predetermined channel of cell C2. Here, if the search space identifier notified in step S401 is search space "0", UE 100 skips receiving the MBS SIB of neighboring cell C2 and receives the MBS control channel. Furthermore, UE 100 may skip receiving the MBS control channel and directly receive the MBS traffic channel, if possible. On the other hand, if the search space identifier notified in step S401 is not search space "0", UE 100 receives the MBS SIB of neighboring cell C2.

[0127] In the above-described fourth operation example, it is assumed that the neighboring cell C2 has one predetermined channel, but the neighboring cell C2 may have a plurality of predetermined channels. When the neighboring cell C2 has a plurality of predetermined channels, the notification message transmitted in step S401 may include a search space identifier for each of the plurality of predetermined channels. This allows the UE 100 to identify a search space for receiving a desired predetermined channel even when the neighboring cell C2 has a plurality of predetermined channels.

[0128] Also, in the above-mentioned fourth operation example, the notification message may include, for each of a plurality of predetermined channels in the neighboring cell C2, bandwidth part information indicating a bandwidth part in which the predetermined channel is transmitted. The bandwidth part is a part of the entire bandwidth of the neighboring cell C2. The bandwidth part may be a BWP defined in the 5G / NR specifications. Also, the bandwidth part may be a CFR (Common Frequency Resource). This allows the UE 100 to appropriately receive the predetermined channel even when the predetermined channel is transmitted in a limited bandwidth part. An example in which the bandwidth part is a BWP (BandWidth Part) will be described below.

[0129] For example, the gNB 200A includes the transmission BWP information and / or search space identifier for each MBS control channel of the neighboring cell C2 in the notification message (MBS SIB and / or MBS control channel) transmitted in step S401. In this case, the notification message includes, for each of a plurality of MBS control channels, a set of the identifier of the MBS control channel and the search space identifier corresponding to the MBS control channel. The identifier of the MBS control channel is, for example, an MBS control channel identifier, a channel identifier assigned to the MBS control channel, or an RNTI assigned to the MBS control channel.

[0130] The gNB200A may include transmission BWP information and / or a search space identifier for each MBS traffic channel of the neighboring cell C2 in the notification message transmitted in step S401. In this case, the notification message includes, for each of a plurality of MBS traffic channels, a set of an identifier of the MBS traffic channel and a search space identifier corresponding to the MBS traffic channel. The identifier of the MBS traffic channel is, for example, an MBS traffic channel identifier, a channel identifier assigned to the MBS traffic channel, or an RNTI assigned to the MBS traffic channel.

[0131] The UE 100 receives a notification message from the gNB 200A, obtains the transmission BWP information and / or search space identifier of the MBS control channel and MBS traffic channel corresponding to the MBS service of interest in the neighbor cell C2 from the notification message, and identifies the transmission resource in the frequency direction and / or the transmission opportunity in the time direction to be received. Then, the UE 100 receives the MBS control channel and / or the MBS traffic channel of interest in the identified resource opportunity.

[0132] (Fifth operation example of mobile communication system) Next, a fifth operation example of the mobile communication system 1 according to an embodiment will be described, focusing mainly on differences from the above-described first to fourth operation examples.

[0133] In the above first to fourth operation examples, the operation related to specifying the search space has been mainly described. In this fifth operation example, the operation related to the change notification of the MBS control channel (hereinafter, referred to as "MBS control channel change notification") will be described. The MBS control channel change notification is a notification indicating that the contents of the MBS control channel, i.e., the scheduling information of the MBS traffic channel, have been changed.

[0134] The change notification RNTI is applied to the MBS control channel change notification. The change notification RNTI is an RNTI used by UE 100 to receive an MBS control channel change notification indicating that the contents of the corresponding MBS control channel have been changed. Note that the MBS control channel change notification is assumed to be used at the start of an MBS session. In this case, the MBS control channel change notification notifies UE 100 of the start of an MBS session. However, the MBS control channel change notification may be used in the middle of a session.

[0135] When multiple MBS control channels are provided in one cell, multiple MBS control channel change notifications are also provided. However, the UE 100 cannot grasp which MBS control channel change notification corresponds to which MBS control channel, and may receive unnecessary MBS control channel change notifications.

[0136] In this fifth operation example, the gNB 200 that manages a cell broadcasts an MBS SIB. The gNB 200 transmits a plurality of MBS control channels in the cell. The MBS SIB includes change notification RNTIs for each of the plurality of MBS control channels. This allows the UE 100 to grasp the change notification RNTIs corresponding to each of the plurality of MBS control channels even when the UE 100 transmits a plurality of MBS control channels in the cell.

[0137] In the fifth operation example, the UE 100 selects one change notification RNTI from among a plurality of change notification RNTIs included in the MBS SIB based on the MBS service received by the UE 100 from among a plurality of MBS control channels. This allows the UE 100 to identify the change notification RNTI corresponding to the MBS control channel corresponding to the MBS service received by the UE 100 even when a plurality of MBS control channels are transmitted in a cell.

[0138] 14 is a diagram showing a fifth operation example of the mobile communication system 1. Here, explanations that overlap with the first to fourth operation examples described above will be omitted.

[0139] 14, in step S501, the gNB 200 broadcasts the SIB type 1. The SIB type 1 includes search space configuration information and MBS SIB scheduling information. The UE 100 receives the SIB type 1 from the gNB 200.

[0140] In step S502, the gNB 200 broadcasts the MBS SIB based on the scheduling indicated by the MBS SIB scheduling information included in the SIB type 1. The UE 100 receives the MBS SIB based on the scheduling indicated by the MBS SIB scheduling information included in the SIB type 1. The MBS SIB includes MBS control channel scheduling information. In this operation example 5, the gNB 200 broadcasts, in the MBS SIB, correspondence information between the MBS control channel and the change notification RNTI. For example, the gNB 200 broadcasts, in the MBS SIB, a set of the change notification RNTI and the MBS session identifier (TMGI, session ID, or RNTI of the MBS control channel). When an ID is assigned to the MBS control channel, the gNB 200 may broadcast, in the MBS SIB, a set of the change notification RNTI and the MBS control channel ID. The UE 100 receives the MBS SIB and identifies the change notification RNTI corresponding to the MBS control channel (MBS service). Note that the MBS session may not yet be started at this point.

[0141] In step S503, UE 100 performs monitoring using the change notification RNTI (PDCCH monitoring). Here, UE 100 may monitor only the change notification RNTI associated with the MBS service of interest. Note that at this point, monitoring using the MBS control channel RNTI (PDCCH monitoring) may not be performed.

[0142] When UE100 receives the change notification RNTI from gNB200 (step S504), in step S505, it starts receiving the MBS control channel (monitoring the MBS control channel RNTI).

[0143] In step S506, UE100 receives an MBS control channel from gNB200.

[0144] In step S507, UE100 receives an MBS traffic channel from gNB200 based on the received MBS control channel.

[0145] (Other embodiments) The above-mentioned operation flows (operation examples) are not limited to being implemented separately and independently, but can be implemented by combining two or more operation flows (operation examples). For example, some steps of one operation flow may be added to another operation flow. Also, some steps of one operation flow may be replaced with some steps of another operation flow.

[0146] In the above embodiment, an example in which the base station is an NR base station (gNB) has been described, but the base station may be an LTE base station (eNB). The base station may also be a relay node such as an IAB (Integrated Access and Backhaul) node. The base station may also be a DU (Distributed Unit) of the IAB node.

[0147] A program may be provided that causes a computer to execute each process performed by the UE 100 or the gNB 200. The program may be recorded in a computer-readable medium. Using the computer-readable medium, it is possible to install the program in the computer. Here, the computer-readable medium on which the program is recorded may be a non-transient recording medium. The non-transient recording medium is not particularly limited, and may be, for example, a recording medium such as a CD-ROM or a DVD-ROM.

[0148] In addition, circuits that execute each process performed by UE100 or gNB200 may be integrated, and at least a part of UE100 or gNB200 may be configured as a semiconductor integrated circuit (chip set, SoC (System on a chip)).

[0149] The above describes the embodiments in detail with reference to the drawings, but the specific configuration is not limited to that described above, and various design changes, etc. are possible without departing from the spirit of the invention.

[0150] This application claims priority to U.S. Provisional Application No. 63 / 169,334 (filed April 1, 2021), the entire contents of which are incorporated herein by reference.

Claims

1. A communication control method used in a mobile communication system that provides a multicast and broadcast service (MBS) from a network device to a user device, comprising: The network device broadcasts a second system information block used for scheduling a first system information block including configuration information for the MBS; The second system information block includes an identifier of a search space for the user equipment to receive an MBS control channel. Communications control method.

2. the network device broadcasting the first system information block; and the network device transmitting scheduling information for an MBS traffic channel on the MBS control channel. The communication control method according to claim 1 .

3. A user device in communication with a network device providing a multicast and broadcast service (MBS), comprising: A receiving unit for receiving from the network device a second system information block used for scheduling a first system information block including configuration information for the MBS; The second system information block includes an identifier of a search space for the user equipment to receive an MBS control channel. User equipment.

4. The receiving unit is receiving the first system information block from the network device; Receive scheduling information for an MBS traffic channel on the MBS control channel. A user device according to claim 3.

5. A processor for controlling a user device in communication with a network device providing a multicast and broadcast service (MBS), comprising: receiving from the network device a second system information block used for scheduling a first system information block including configuration information for the MBS; The second system information block includes an identifier of a search space for the user equipment to receive an MBS control channel. Processor.

6. A network device for providing a multicast and broadcast service (MBS) to a user device, comprising: A transmitting unit that broadcasts a second system information block used for scheduling a first system information block including configuration information for the MBS; The second system information block includes an identifier of a search space for the user equipment to receive an MBS control channel. Network device.

7. A mobile communication system for providing a multicast and broadcast service (MBS) from a network device to a user device, comprising: The network device broadcasts a second system information block used for scheduling a first system information block including configuration information for the MBS; The second system information block includes an identifier of a search space for the user equipment to receive an MBS control channel. Mobile communication system.

8. A program for controlling a user device that communicates with a network device that provides a multicast and broadcast service (MBS), comprising: causing the user equipment to execute a process of receiving from the network equipment a second system information block used for scheduling a first system information block including configuration information for the MBS; The second system information block includes an identifier of a search space for the user equipment to receive an MBS control channel. program.

Images