Terminal device, method, and integrated circuit

Abstract

This terminal device determines, on the basis of first information, whether or not a target area associated with a multicast broadcast service (MBS) session provided in a certain neighboring cell is the same as a target area associated in a first cell. The first information includes information regarding neighboring cells in which each of one or more MBS sessions provided in the first cell is similarly provided. Each of the one or more MBS sessions provided in the first cell is associated with one or more target areas. The information regarding neighboring cells includes information indicating, for each neighboring cell, whether or not a target area associated with a certain MBS session provided in the neighboring cell is the same as a target area associated in the first cell.

Description

Terminal device, method, and integrated circuit

[0001] The present invention relates to a terminal device, a method, and an integrated circuit. This application claims priority from Japanese Patent Application No. 2024-195043 filed in Japan on November 7, 2024, the content of which is incorporated herein by reference.

[0002] In the 3rd Generation Partnership Project (3GPP, registered trademark), which is a standardization project for cellular mobile communication systems, technical studies and standardization of cellular mobile communication systems, including radio access, core network, services, etc., are being carried out.

[0003] For example, in 3GPP, E-UTRA (Evolved Universal Terrestrial Radio Access) was started for technical studies and standardization as a radio access technology (RAT) for cellular mobile communication systems for the 3.9th and 4th generations. Even now, in 3GPP, technical studies and standardization of extended technologies of E-UTRA are being carried out. Note that E-UTRA is also referred to as Long Term Evolution (LTE, registered trademark), and extended technologies may be referred to as LTE-Advanced (LTE-A) and LTE-Advanced Pro (LTE-A Pro).

[0004] Also, in 3GPP, NR (New Radio, or NR Radio access) was started for technical studies and standardization as a radio access technology (RAT) for cellular mobile communication systems for the 5th generation (5G). Even now, in 3GPP, technical studies and standardization of extended technologies of NR are being carried out.

[0005] 3GPP TS 38.331 v18.2.0,"Evolved Universal Terrestrial Radio Access (E-UTRA);Radio Resource Control (RRC);Protocol specifications" pp450-455,pp608-14823GPP TS 26.517 v18.1.0,"Technical Specification Group Services and System Aspects;5G Multicast-Broadcast User Services;Protocols and Formats" pp11-21

[0006] Within 3GPP, as an extension of NR technology, for example in the study of non-terrestrial networks (NTN), the provision of multicast broadcast services is being considered. However, because the size of a single cell provided by a satellite is larger than that of a cell in a terrestrial network, it can be difficult to provide broadcast services to a specific area (e.g., within a country or state).

[0007] One aspect of the present invention has been made in view of the above circumstances, and one of its objectives is to provide a terminal device, a communication method, and an integrated circuit that can efficiently provide multicast broadcast services.

[0008] To achieve the above objective, one aspect of the present invention employs the following means.

[0009] (1) That is, one aspect of the present invention is a terminal device comprising: a receiving unit that receives first information transmitted from a base station device in a first cell; and a processing unit that determines, based on the received first information, whether or not a target area associated with a multicast broadcast service (MBS) session provided in a certain adjacent cell is the same as a target area associated in the first cell, wherein the first information includes information of adjacent cells that are similarly provided for each of the one or more MBS sessions provided in the first cell, each of the one or more MBS sessions provided in the first cell is associated with one or more target areas, and the information of the adjacent cell includes information indicating for each adjacent cell whether or not a target area associated with a certain MBS session provided in the adjacent cell is the same as a target area associated in the first cell.

[0010] (2) Another aspect of the present invention is a method applied to a terminal device, comprising the steps of: receiving first information transmitted from a base station device in a first cell; and determining, based on the received first information, whether a target area associated with a multicast broadcast service (MBS) session provided in a certain adjacent cell is the same as a target area associated in the first cell, wherein the first information includes information of adjacent cells that are similarly provided for each of the one or more MBS sessions provided in the first cell, each of the one or more MBS sessions provided in the first cell is associated with one or more target areas, and the information of the adjacent cell includes information indicating for each adjacent cell whether a target area associated with a certain MBS session provided in the adjacent cell is the same as a target area associated in the first cell.

[0011] (3) Another aspect of the present invention is an integrated circuit implemented in a terminal device, which provides the terminal device with the function of receiving first information transmitted from a base station device in a first cell, and the function of determining, based on the received first information, whether or not a target area associated with a multicast broadcast service (MBS) session provided in a certain adjacent cell is the same as a target area associated in the first cell, wherein the first information includes information of adjacent cells that are similarly provided for one or more MBS sessions provided in the first cell, each of the one or more MBS sessions provided in the first cell is associated with one or more target areas, and the information of the adjacent cell includes information indicating for each adjacent cell whether or not a target area associated with a certain MBS session provided in the adjacent cell is the same as a target area associated in the first cell.

[0012] These comprehensive or specific embodiments may be implemented as systems, devices, methods, integrated circuits, computer programs, or recording media, or as any combination of systems, devices, methods, integrated circuits, computer programs, and recording media.

[0013] According to one aspect of the present invention, terminal devices, methods, and integrated circuits can achieve efficient communication control processing.

[0014] A schematic diagram of the communication system according to this embodiment. A diagram showing an example of the E-UTRA protocol configuration according to this embodiment. A diagram showing an example of the NR protocol configuration according to this embodiment. A diagram showing an example of the procedure flow for various settings in RRC according to this embodiment. A block diagram showing the configuration of the terminal device in this embodiment. A block diagram showing the configuration of the base station device in this embodiment. An example of processing in this embodiment. An example of the ASN.1 description of the target area information in this embodiment. An example of the ASN.1 description of the system information block in this embodiment.

[0015] This embodiment will now be described in detail with reference to the drawings.

[0016] LTE (and LTE-A, LTE-A Pro) and NR may be defined as different Radio Access Technologies (RATs). Furthermore, LTE that can connect with NR via Multi-Radio Dual Connectivity (MR-DC) may be distinguished from conventional LTE. Also, LTE using 5GC in its Core Network (CN) may be distinguished from conventional LTE using EPC in its Core Network. Conventional LTE may refer to LTE that does not implement technologies standardized in 3GPP Release 15 or later. This embodiment may be applied to NR, LTE, and other RATs. The following description uses terms related to LTE and NR, but this embodiment may be applied to technologies using other terms and / or other radio access technologies. Also, the terms E-UTRA and LTE in this embodiment may be interchangeable.

[0017] In this embodiment, the names of each node and entity, and the processing at each node and entity, are described when the wireless access technology is E-UTRA or NR, but this embodiment may also be applied to other wireless access technologies. The names of each node and entity, and the names of parameters and messages in this embodiment may differ from those described in this embodiment.

[0018] Figure 1 is a schematic diagram of the communication system according to this embodiment. The functions of each node, wireless access technology, core network, interface, etc., described using Figure 1 are only some of the functions closely related to this embodiment, and other functions may also be present.

[0019] E-UTRA100 may be a wireless access technology. E-UTRA100 may also be an air interface between UE122 and eNB102. The air interface between UE122 and eNB102 may be called the Uu interface. eNB (E-UTRAN Node B)102 may be the base station equipment for E-UTRA100. eNB102 may have the E-UTRA protocol described below. The E-UTRA protocol may consist of the E-UTRA User Plane (UP) protocol and the E-UTRA Control Plane (CP) protocol described below. eNB102 may terminate the E-UTRA User Plane (UP) protocol and the E-UTRA Control Plane (CP) protocol to UE122. The wireless access network configured with eNB may be called E-UTRAN.

[0020] EPC (Evolved Packet Core) 104 may be a core network. Interface 112 is an interface between eNB 102 and EPC 104 and may be called an S1 interface. Interface 112 may have a control plane interface through which control signals pass, and / or a user plane interface through which user data passes. The control plane interface of interface 112 may terminate at a Mobility Management Entity (MME: not shown) in EPC 104. The user plane interface of interface 112 may terminate at a Serving Gateway (S-GW: not shown) in EPC 104. The control plane interface of interface 112 may be called an S1-MME interface. The user plane interface of interface 112 may be called an S1-U interface.

[0021] One or more eNB102s may be connected to the EPC104 via interface 112. Interfaces may exist between multiple eNB102s connected to the EPC104 (not shown). Interfaces between multiple eNB102s connected to the EPC104 may be called X2 interfaces.

[0022] NR106 may be a wireless access technology. NR106 may also be an air interface between UE122 and gNB108. The air interface between UE122 and gNB108 may be called a Uu interface. gNB108 may be the base station equipment for NR106. gNB108 may have the NR protocol described below. The NR protocol may consist of the NR User Plane (UP) protocol and the NR Control Plane (CP) protocol described below. gNB108 may terminate the NR User Plane (UP) protocol and the NR Control Plane (CP) protocol to UE122.

[0023] 5GC110 may be the core network. Interface 116 is the interface between gNB108 and 5GC110 and may be called the NG interface. Interface 116 may have a control plane interface through which control signals pass, and / or a user plane interface through which user data passes. The control plane interface of interface 116 may be terminated by the Access and Mobility Management Function (AMF: not shown) in 5GC110. The user plane interface of interface 116 may be terminated by the User Plane Function (UPF: not shown) in 5GC110. The control plane interface of interface 116 may be called the NG-C interface. The user plane interface of interface 116 may be called the NG-U interface.

[0024] One or more gNB108s may be connected to the 5GC110 via interface 116. Interfaces may exist between multiple gNB108s connected to the 5GC110 (not shown). The interfaces between multiple gNB108s connected to the 5GC110 may be called Xn interfaces.

[0025] eNB102 may have the function of connecting to 5GC110. eNB102 having the function of connecting to 5GC110 may be called ng-eNB. Interface 114 is the interface between eNB102 and 5GC110 and may be called NG interface. Interface 114 may have a control plane interface through which control signals pass, and / or a user plane interface through which user data passes. The control plane interface of interface 114 may be terminated at the AMF in 5GC110. The user plane interface of interface 114 may be terminated at the UPF in 5GC110. The control plane interface of interface 114 may be called NG-C interface. The user plane interface of interface 114 may be called NG-U interface. A radio access network consisting of ng-eNB or gNB may be called NG-RAN. NG-RAN, E-UTRAN, etc. may simply be called a network. Also, the network may include eNB, ng-eNB, and gNB, etc.

[0026] One or more eNB102s may be connected to the 5GC110 via interface 114. Interfaces may exist between multiple eNB102s connected to the 5GC110 (not shown). Interfaces between multiple eNB102s connected to the 5GC110 may be called Xn interfaces. Also, an eNB102 connected to the 5GC110 and a gNB108 connected to the 5GC110 may be connected via interface 120. Interface 120 between an eNB102 connected to the 5GC110 and a gNB108 connected to the 5GC110 may be called Xn interfaces.

[0027] gNB108 may have the function of connecting to EPC104. gNB108 with the function of connecting to EPC104 may be called en-gNB. Interface 118 is the interface between gNB108 and EPC104 and may be called the S1 interface. Interface 118 may have a user plane interface through which user data passes. The user plane interface of interface 118 may be terminated at the S-GW (not shown) in EPC104. The user plane interface of interface 118 may be called the S1-U interface. Also, eNB102 connected to EPC104 and gNB108 connected to EPC104 may be connected by interface 120. Interface 120 between eNB102 connected to EPC104 and gNB108 connected to EPC104 may be called the X2 interface.

[0028] Interface 124 is the interface between EPC104 and 5GC110, and may be an interface that passes only CP, only UP, or both CP and UP. In addition, some or all of interfaces such as Interface 114, Interface 116, Interface 118, Interface 120, and Interface 124 may not exist depending on the communication system provided by the telecommunications carrier.

[0029] UE122 may be a terminal device capable of receiving system information and paging messages transmitted from eNB102 and / or gNB108. UE122 may also be a terminal device capable of wireless connection with eNB102 and / or gNB108. Furthermore, UE122 may be a terminal device capable of simultaneously establishing wireless connections with eNB102 and gNB108. UE122 may have the E-UTRA protocol and / or the NR protocol. Note that the wireless connection may be a Radio Resource Control (RRC) connection.

[0030] Furthermore, UE122 may be a terminal device capable of connecting to EPC104 and / or 5GC110 via eNB102 and / or gNB108. If the core network to which eNB102 and / or gNB108, with which UE122 communicates, is connected is EPC104, then each Data Radio Bearer (DRB) established between UE122 and eNB102 and / or gNB108, as described below, may be uniquely associated with each EPS (Evolved Packet System) bearer passing through EPC104. Each EPS bearer may be identified by an EPS bearer identifier (Identity, or ID). Furthermore, the same QoS may be guaranteed for data such as IP packets and Ethernet® frames passing through the same EPS bearer.

[0031] Furthermore, if the core network to which UE122 communicates with eNB102 and / or gNB108 is connected is 5GC110, then each DRB established between UE122 and eNB102 and / or gNB108 may be further associated with one of the PDU (Packet Data Unit) sessions established within 5GC110. Each PDU session may have one or more QoS flows. Each DRB may be mapped to one or more QoS flows, or it may not be mapped to any QoS flow. Each PDU session may be identified by a PDU session identifier (Identity, or ID). Each QoS flow may also be identified by a QoS flow identifier (Identity, or ID). In addition, the same QoS may be guaranteed for data such as IP packets and Ethernet frames passing through the same QoS flow.

[0032] EPC104 does not need to have PDU sessions and / or QoS flows. Similarly, 5GC110 does not need to have an EPS bearer. When UE122 is connected to EPC104, UE122 will have information about the EPS bearer, but it does not need to have information about the PDU sessions and / or QoS flows. Similarly, when UE122 is connected to 5GC110, UE122 will have information about the PDU sessions and / or QoS flows, but it does not need to have information about the EPS bearer.

[0033] In the following description, eNB102 and / or gNB108 will also be simply referred to as base station equipment, and UE122 will also be simply referred to as terminal equipment or UE.

[0034] Figure 2 is a diagram of an example of the E-UTRA protocol architecture according to this embodiment. Figure 3 is a diagram of an example of the NR protocol architecture according to this embodiment. The functions of each protocol described using Figure 2 and / or Figure 3 are some of the functions closely related to this embodiment, and other functions may be present. In this embodiment, the uplink (UL) may be a link from a terminal device to a base station device. In this embodiment, the downlink (DL) may be a link from a base station device to a terminal device. In this embodiment, the sidelink (SL) may be a link from one terminal device to another that does not go through a base station device.

[0035] Figure 2(A) is a diagram of the E-UTRA user plane (UP) protocol stack. As shown in Figure 2(A), the E-UTRA UP protocol may be a protocol between UE122 and eNB102. That is, the E-UTRA UP protocol may be a protocol that terminates at eNB102 on the network side. As shown in Figure 2(A), the E-UTRA user plane protocol stack may consist of a radio physical layer (PHY) 200, a medium access control layer (MAC) 202, a radio link control layer (RLC) 204, and a packet data convergence protocol layer (PDCP) 206.

[0036] Figure 3(A) is a diagram of the NR User Plane (UP) protocol stack. As shown in Figure 3(A), the NRUP protocol may be a protocol between UE122 and gNB108. That is, the NR UP protocol may be a protocol that terminates at gNB108 on the network side. As shown in Figure 3(A), the NR User Plane protocol stack may consist of the wireless physical layer PHY300, the media access control layer MAC302, the wireless link control layer RLC304, the packet data convergence protocol layer PDCP306, and the service data adaptation protocol layer (service data adaptation protocol layer) SDAP (Service Data Adaptation Protocol)310.

[0037] Figure 2(B) shows the configuration of the E-UTRA control plane (CP) protocol. As shown in Figure 2(B), in the E-UTRA CP protocol, the Radio Resource Control (RRC) 208, which is the radio resource control layer, may be a protocol between the UE122 and the eNB102. That is, the RRC 208 may be a protocol that terminates at the eNB102 on the network side. Also, in the E-UTRA CP protocol, the Non Access Stratum (NAS) 210, which is the non-Access Stratum (AS) layer, may be a protocol between the UE122 and the MME. That is, the NAS 210 may be a protocol that terminates at the MME on the network side.

[0038] Figure 3(B) is a diagram of the NR control plane (CP) protocol configuration. As shown in Figure 3(B), in the NR CP protocol, the RRC308, which is the radio resource control layer, may be a protocol between the UE122 and the gNB108. That is, the RRC308 may be a protocol that terminates at the gNB108 on the network side. Also, in the NR CP protocol, the NAS312, which is a non-AS layer, may be a protocol between the UE122 and the AMF. That is, the NAS312 may be a protocol that terminates at the AMF on the network side.

[0039] The Access Stratum (AS) layer may be a layer that terminates between UE122 and eNB102 and / or gNB108. That is, the AS layer may be a layer containing some or all of PHY200, MAC202, RLC204, PDCP206, and RRC208, and / or a layer containing some or all of PHY300, MAC302, RLC304, PDCP306, SDAP310, and RRC308.

[0040] In this embodiment, the E-UTRA protocol and the NR protocol are not distinguished below, and the terms PHY (PHY layer), MAC (MAC layer), RLC (RLC layer), PDCP (PDCP layer), RRC (RRC layer), and NAS (NAS layer) may be used. In this case, PHY (PHY layer), MAC (MAC layer), RLC (RLC layer), PDCP (PDCP layer), RRC (RRC layer), and NAS (NAS layer) may be the PHY (PHY layer), MAC (MAC layer), RLC (RLC layer), PDCP (PDCP layer), RRC (RRC layer), and NAS (NAS layer) of the E-UTRA protocol, respectively, or the PHY (PHY layer), MAC (MAC layer), RLC (RLC layer), PDCP (PDCP layer), RRC (RRC layer), and NAS (NAS layer) of the NR protocol. Furthermore, SDAP (SDAP layer) may be the SDAP (SDAP layer) of the NR protocol.

[0041] Furthermore, in this embodiment, when distinguishing between the E-UTRA protocol and the NR protocol, PHY200, MAC202, RLC204, PDCP206, and RRC208 may be referred to as E-UTRA PHY or LTE PHY, E-UTRA MAC or LTE MAC, E-UTRA RLC or LTE RLC, E-UTRA PDCP or LTE PDCP, and E-UTRA RRC or LTE RRC, respectively. Also, PHY200, MAC202, RLC204, PDCP206, and RRC208 may be described as E-UTRA PHY or LTE PHY, E-UTRA MAC or LTEMAC, E-UTRA RLC or LTE RLC, E-UTRA PDCP or LTE PDCP, and E-UTRA RRC or LTE RRC, respectively. Furthermore, when distinguishing between the E-UTRA protocol and the NR protocol, PHY300, MAC302, RLC304, PDCP306, and RRC308 are sometimes referred to as NR PHY, NR MAC, NR RLC, NR RLC, and NR RRC, respectively. Alternatively, PHY300, MAC302, RLC304, PDCP306, and RRC308 may be written as NR PHY, NR MAC, NR RLC, NR PDCP, and NR RRC, respectively.

[0042] This section describes entities in the AS layer of E-UTRA and / or NR. Entities that possess some or all of the functions of the MAC layer may be called MAC entities. Entities that possess some or all of the functions of the RLC layer may be called RLC entities. Entities that possess some or all of the functions of the PDCP layer may be called PDCP entities. Entities that possess some or all of the functions of the SDAP layer may be called SDAP entities. Entities that possess some or all of the functions of the RRC layer may be called RRC entities. MAC entities, RLC entities, PDCP entities, SDAP entities, and RRC entities may be replaced with MAC, RLC, PDCP, SDAP, and RRC, respectively.

[0043] Furthermore, the data provided from MAC, RLC, PDCP, and SDAP to lower layers, and / or the data provided from lower layers to MAC, RLC, PDCP, and SDAP, may be referred to as MAC PDU (Protocol Data Unit), RLC PDU, PDCP PDU, and SDAP PDU, respectively. Also, the data provided from higher layers to MAC, RLC, PDCP, and SDAP, and / or the data provided from MAC, RLC, PDCP, and SDAP to higher layers, may be referred to as MAC SDU (Service Data Unit), RLC SDU, PDCP SDU, and SDAP SDU, respectively. In addition, a segmented RLC SDU may be referred to as an RLC SDU segment.

[0044] Here, the base station device and the terminal device exchange signals (transmit and receive) in the upper layer (higher layer). The higher layer may also be referred to as the upper layer and they may be used interchangeably. For example, the base station device and the terminal device may transmit and receive RRC messages (also referred to as RRC messages or RRC signalling) in the Radio Resource Control (RRC) layer. Also, the base station device and the terminal device may transmit and receive MAC control elements in the Medium Access Control (MAC) layer. Further, the RRC layer of the terminal device acquires system information notified from the base station device. Here, the RRC message, system information, and / or MAC control element are also referred to as upper layer signals (higher layer signaling) or upper layer parameters (higher layer parameter). Each parameter included in the upper layer signal received by the terminal device may be referred to as an upper layer parameter. For example, in the processing of the PHY layer, the upper layer means the upper layer seen from the PHY layer, and thus may mean one or more of the MAC layer, RRC layer, RLC layer, PDCP layer, Non-Access Stratum (NAS) layer, etc. For example, in the processing of the MAC layer, the upper layer may mean one or more of the RRC layer, RLC layer, PDCP layer, NAS layer, etc.

[0045] In the following, the phrases "A is provided in the upper layer" or "A is provided by the upper layer" may mean that the upper layer of the terminal device (mainly the RRC layer or MAC layer, etc.) receives A from the base station device, and that received A is provided from the upper layer of the terminal device to the lower layer of the terminal device (mainly the MAC layer or physical layer). For example, "upper layer parameters are provided" in the terminal device may mean that the terminal device receives an upper layer signal from the base station device, and the upper layer parameters contained in the received upper layer signal are provided from the upper layer of the terminal device to the lower layer of the terminal device. "Upper layer parameters are set in the terminal device" may mean that upper layer parameters are provided to the terminal device. For example, "upper layer parameters are set in the terminal device" may mean that the terminal device receives an upper layer signal from the base station device and sets the received upper layer parameters in the upper layer. However, "upper layer parameters are set in the terminal device" may also include the setting of default parameters that are pre-assigned to the upper layer of the terminal device. When describing the transmission of an RRC message from a terminal device to a base station device, the expression "submitting a message from the RRC entity of the terminal device to a lower layer" is sometimes used. In a terminal device, "submitting a message to a lower layer" from the RRC entity may also mean submitting a message to the PDCP layer. In a terminal device, "submitting a message to a lower layer" from the RRC layer may also mean submitting a message to the PDCP entity corresponding to each SRB, since RRC messages are transmitted using SRBs (SRB0, SRB1, SRB2, SRB3, etc.). When the RRC entity of the terminal device receives an indication from a lower layer, that lower layer may mean one or more layers such as the PHY layer, MAC layer, RLC layer, PDCP layer, etc.

[0046] An example of the functions of the PHY will be described. The PHY of the terminal device may have a function of receiving data transmitted from the PHY of the base station device via a downlink (DL) physical channel. The PHY of the terminal device may have a function of transmitting data to the PHY of the base station device via an uplink (UL) physical channel. The PHY may be connected to the upper MAC via a transport channel. The PHY may pass data to the MAC via the transport channel. Also, the PHY may be provided with data from the MAC via the transport channel. In the PHY, an RNTI (Radio Network Temporary Identifier) may be used to identify various control information.

[0047] Here, the physical channel will be described. The physical channels used for wireless communication between the terminal device and the base station device may include the following physical channels.

[0048] PBCH (Physical Broadcast Channel) PDCCH (Physical Downlink Control Channel) PDSCH (Physical Downlink Shared Channel) PUCCH (Physical Uplink Control Channel) PUSCH (Physical Uplink Shared Channel) PRACH (Physical Random Access Channel)

[0049] The PBCH may be used to notify the system information required by the terminal device.

[0050] Furthermore, in NR, the PBCH may be used to announce the time index (SSB-Index) within the period of the Synchronization Signal Block (SSB).

[0051] PDCCH may be used to transmit (or carry) Downlink Control Information (DCI) in downlink wireless communication (wireless communication from base station equipment to terminal equipment). Here, one or more DCIs (which may also be called DCI formats) may be defined for the transmission of downlink control information. That is, fields for downlink control information may be defined as DCIs and mapped to information bits. PDCCH may be transmitted in PDCCH candidates. Terminal equipment may monitor a set of PDCCH candidates in a serving cell. Monitoring a set of PDCCH candidates may mean attempting to decode a PDCCH according to a certain DCI format. Terminal equipment may also monitor PDCCH candidates in configured monitoring occasions within one or more configured control resource sets (CORESET) set by the search space configuration. The DCI format may be used for scheduling PUSCHs in a serving cell. PUSCHs may be used for transmitting user data or RRC messages, as described later.

[0052] PUCCH may be used to transmit Uplink Control Information (UCI) in uplink wireless communication (wireless communication from terminal equipment to base station equipment). Here, Uplink Control Information may include Channel State Information (CSI), which is used to indicate the state of the downlink channel. Furthermore, Uplink Control Information may include Scheduling Requests (SR), which are used to request UL-SCH (Uplink Shared Channel) resources. Furthermore, Uplink Control Information may include HARQ-ACK (Hybrid Automatic Repeat reQuest ACKnowledgement).

[0053] PDSCH may be used to transmit downlink data (DL-SCH: Downlink Shared Channel) from the MAC layer. In the case of downlinks, PDSCH may also be used to transmit system information (SI) and random access responses (RAR).

[0054] PUSCH may be used to transmit uplink data (UL-SCH: Uplink Shared Channel) from the MAC layer or HARQ-ACK and / or CSI along with uplink data. Alternatively, PUSCH may be used to transmit only CSI, or only HARQ-ACK and CSI. In other words, PUSCH may be used to transmit only UCI. Furthermore, PDSCH or PUSCH may be used to transmit RRC messages and MAC CE, which will be described later. Here, in PDSCH, the RRC message transmitted from the base station equipment may be a common signaling to multiple terminal devices within a cell. Alternatively, the RRC message transmitted from the base station equipment may be dedicated signaling to a particular terminal device. In other words, UE-specific information may be transmitted using dedicated signaling to a particular terminal device. Furthermore, PUSCH may be used to transmit UE Capability on the uplink.

[0055] PRACH may be used to send a random access preamble. PRACH may also be used to indicate the initial connection establishment procedure, handover procedure, connection re-establishment procedure, synchronization (timing adjustment) for uplink transmissions, and requests for UL-SCH resources.

[0056] An example of MAC functionality is described below. MAC may also be called a MAC sublayer. MAC may have the function of mapping various logical channels to corresponding transport channels. Logical channels may be identified by a Logical Channel Identity (Logical Channel ID). MAC may be connected to the higher-level RLC via logical channels. Logical channels may be divided into control channels that transmit control information and traffic channels that transmit user information, depending on the type of information being transmitted. Logical channels may also be divided into uplink logical channels and downlink logical channels. MAC may have the function of multiplexing MAC SDUs belonging to one or more different logical channels and providing them to the PHY. MAC may also have the function of demultiplexing MAC PDUs provided from the PHY and providing them to the higher layer via the logical channel to which each MAC SDU belongs. MAC may also have the function of performing error correction through HARQ (Hybrid Automatic Repeat reQuest). MAC may also have a scheduling reporting function that reports scheduling information. MAC may have a function to prioritize between terminal devices using dynamic scheduling. MAC may also have a function to prioritize between logical channels within a single terminal device. MAC may have a function to prioritize overlapping resources within a single terminal device. MAC may have a function to identify Multimedia Broadcast Multicast Services (MBMS). NR MAC may also have a function to identify Multicast Broadcast Service (MBS). MBS is also called MBS service. MBS services provided via broadcast are also called broadcast services or MBS broadcast services.MBS services provided via multicast are also referred to as multicast services or MBS multicast services. MAC may have the ability to select the transport format. MAC may have the ability to perform discontinuous reception (DRX) and / or discontinuous transmission (DTX), perform random access (RA) procedures, provide a power headroom report (PHR) function to notify information on available power, and provide a buffer status report (BSR) function to notify information on the amount of data in the transmit buffer. NR MAC may have a bandwidth adaptation (BA) function. The MAC PDU format used in E-UTRA MAC and the MAC PDU format used in NR MAC may be different. MAC PDU may also include MAC control elements (MAC CE), which are elements for controlling MAC.

[0057] This document describes the logical channels used for uplink (UL) and / or downlink (DL) in E-UTRA and / or NR.

[0058] BCCH (Broadcast Control Channel) may be a downlink logical channel for broadcasting control information, such as system information (SI).

[0059] A PCCH (Paging Control Channel) may be a downlink logical channel for carrying paging messages.

[0060] A Common Control Channel (CCCH) may be a logical channel for transmitting control information between a terminal device and a base station device. A CCCH may be used when a terminal device does not have an RRC connection. A CCCH may also be used between a base station device and multiple terminal devices.

[0061] A DCCH (Dedicated Control Channel) may be a logical channel for transmitting dedicated control information in a point-to-point, bidirectional manner between a terminal device and a base station device. Dedicated control information may be control information specific to each terminal device. A DCCH may be used when the terminal device has an RRC connection.

[0062] A Dedicated Traffic Channel (DTCH) may be a logical channel for transmitting user data point-to-point between a terminal device and a base station device. A DTCH may be a logical channel for transmitting dedicated user data. Dedicated user data may be user data specific to each terminal device. A DTCH may exist on both the uplink and downlink.

[0063] A Multicast Control Channel (MCCH) may be a point-to-multipoint downlink channel for sending MBMS control information for one or more MCCHs from a base station device to a terminal device. An MCCH may be a multicast and / or broadcast logical channel. An MCCH may carry the MBS broadcast configuration provided in the cell from which it is transmitted.

[0064] MTCH (Multicast Traffic Channel) may be a point-to-multipoint downlink channel for transmitting data from base station equipment to terminal equipment. MTCH may also be a logical channel for multicast and / or broadcast.

[0065] This section describes the mapping between logical channels and transport channels for uplinks in E-UTRA and / or NR.

[0066] CCCH may be mapped to UL-SCH (Uplink Shared Channel), which is an uplink transport channel.

[0067] DCCH may be mapped to UL-SCH (Uplink Shared Channel), which is an uplink transport channel.

[0068] DTCH may be mapped to UL-SCH (Uplink Shared Channel), which is an uplink transport channel.

[0069] This section describes the mapping between logical channels and transport channels for downlinks in E-UTRA and / or NR.

[0070] BCCH may be mapped to a downlink transport channel, BCH (Broadcast Channel), and / or DL-SCH (Downlink Shared Channel).

[0071] The PCCH may be mapped to the PCH (Paging Channel), which is a downlink transport channel.

[0072] CCCH may be mapped to DL-SCH (Downlink Shared Channel), which is a downlink transport channel.

[0073] DCCH may be mapped to DL-SCH (Downlink Shared Channel), which is a downlink transport channel.

[0074] DTCH may be mapped to DL-SCH (Downlink Shared Channel), which is a downlink transport channel.

[0075] MCCH may be mapped to DL-SCH (Downlink Shared Channel), which is a downlink transport channel.

[0076] MTCH may be mapped to DL-SCH (Downlink Shared Channel), which is a downlink transport channel.

[0077] An example of RLC functionality is described below. RLC may also be called an RLC sublayer. E-UTRA RLC may have the functionality to segment and / or concatenate data provided from the upper layer PDCP and provide it to the lower layer. E-UTRA RLC may have the functionality to reassemble and reorder data provided from the lower layer and provide it to the upper layer. NR RLC may have the functionality to add a sequence number to data provided from the upper layer PDCP that is independent of the sequence number added by the PDCP. NR RLC may also have the functionality to segment the data provided from the PDCP and provide it to the lower layer. NR RLC may also have the functionality to reassemble data provided from the lower layer and provide it to the upper layer. RLC may also have a data retransmission function and / or an automatic repeat request function (ARQ). RLC may also have a function to perform error correction using ARQ. The control information sent from the receiver to the transmitter of RLC to perform ARQ, indicating data that needs to be retransmitted, may be called a status report. The instruction to send a status report sent from the transmitter to the receiver of RLC may be called a poll. RLC may also have a function to detect data duplication. RLC may also have a function to discard data. RLC may have three modes: Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). In TM, data received from the upper layer is not split, and an RLC header does not need to be added. A TM RLC entity is a unidirectional entity and may be configured as a transmitting TM RLC entity or a receiving TM RLC entity.UM performs tasks such as splitting and / or merging data received from higher layers and adding RLC headers, but does not need to control data retransmission. UM RLC entities may be unidirectional or bidirectional. If a UM RLC entity is unidirectional, it may be configured as a transmitting UM RLC entity or a receiving UM RLC entity. If a UM RLC entity is bidirectional, it may be configured as a UM RLC entity consisting of a transmitting side and a receiving side. AM may perform tasks such as splitting and / or merging data received from higher layers, adding RLC headers, and controlling data retransmission. AM RLC entities are bidirectional entities and may be configured as AM RLCs consisting of a transmitting side and a receiving side. Data provided to lower layers by TM, and / or data provided by lower layers, may be called TMD PDUs. Similarly, data provided to lower layers by UM, and / or data provided by lower layers, may be called UMD PDUs. Furthermore, data provided to lower layers by AM, or data provided by lower layers, may be called AMD PDUs. The RLC PDU format used in E-UTRA RLC and the RLC PDU format used in NR RLC may be different. Also, there may be data RLC PDUs and control RLC PDUs. Data RLC PDUs may be called RLC DATA PDUs (RLC Data PDUs). Control RLC PDUs may be called RLC CONTROL PDUs (RLC Control PDUs).

[0078] This section describes some examples of PDCP functionality. PDCP may be referred to as the PDCP sublayer. PDCP may have a function for maintaining sequence numbers. PDCP may also have a header compression / decompression function for efficiently transmitting user data such as IP packets and Ethernet frames over the wireless section. The protocol used for compressing and decompressing IP packet headers may be called the ROHC (Robust Header Compression) protocol. The protocol used for compressing and decompressing Ethernet frame headers may be called the EHC (Ethernet® Header Compression) protocol. PDCP may also have data encryption / decryption functions. PDCP may also have data integrity protection and integrity verification functions. PDCP may also have a re-ordering function. PDCP may also have a PDCP SDU retransmission function. PDCP may also have a data discard function using a discard timer. PDCP may also have a duplication function. PDCP may also have a function for discarding duplicate received data. A PDCP entity is a bidirectional entity and may consist of a transmitting PDCP entity and a receiving PDCP entity. The PDCP PDU format used in E-UTRA PDCP and the PDCP PDU format used in NR PDCP may be different. Furthermore, there may be data PDCP PDUs and control PDCP PDUs. The data PDCP PDU may be called a PDCP DATA PDU (PDCP Data PDU). The control PDCP PDU may be called a PDCP CONTROL PDU (PDCP Control PDU).

[0079] This section describes an example of SDAP functionality. SDAP is a Service Data Adaptive Protocol Layer (SPD). SDAP may have the function of mapping downlink QoS flows sent from the 5GC110 to the terminal device via the base station equipment to the Data Radio Bearer (DRB), and / or mapping uplink QoS flows sent from the terminal device to the 5GC110 via the base station equipment to the DRB. SDAP may also have the function of storing mapping rule information. SDAP may also have the function of marking QoS flow identifiers (QoS Flow ID: QFI). Note that there may be data SDAP PDUs and control SDAP PDUs. Data SDAP PDUs may be called SDAP DATA PDUs (SDAP Data PDUs). Control SDAP PDUs may be called SDAP CONTROL PDUs (SDAP Control PDUs). Note that there may be one SDAP entity for each PDU session in the terminal device.

[0080] An example of RRC functionality is described below. RRC may have broadcast functionality. RRC may have paging functionality from EPC104 and / or 5GC110. RRC may have paging functionality from eNB102 connected to gNB108 or 5GC110. RRC may also have RRC connection management functionality. RRC may also have wireless bearer control functionality. RRC may also have cell group control functionality. RRC may also have mobility control functionality. RRC may also have terminal device measurement reporting and terminal device measurement reporting control functionality. RRC may also have QoS management functionality. RRC may also have wireless link failure detection and recovery functionality. RRC may use RRC messages to perform functions such as broadcasting, paging, RRC connection management, wireless bearer control, cell group control, mobility control, terminal device measurement reporting and terminal device measurement reporting control, QoS management, and wireless link failure detection and recovery. Note that the RRC messages and parameters used in E-UTRA RRC may differ from those used in NR RRC.

[0081] RRC messages may be sent using the logical channels BCCH. In addition to or instead, RRC messages may be sent using the logical channel PCCH. In addition to or instead, RRC messages may be sent using the logical channel CCCH. In addition to or instead, RRC messages may be sent using the logical channel DCCH. In addition to or instead, RRC messages may be sent using the logical channel MCCH. Furthermore, RRC messages sent using DCCH are referred to as dedicated RRC signaling or simply RRC signaling.

[0082] RRC messages sent using BCCH may include, for example, a Master Information Block (MIB), a System Information Block (SIB) of each type, or other RRC messages. RRC messages sent using PCCH may include, for example, a paging message or other RRC messages.

[0083] RRC messages sent in the uplink (UL) direction using CCCH may include, for example, RRC Setup Request, RRC Resume Request, RRC Reestablishment Request, and RRC System Info Request. They may also include, for example, RRC Connection Request, RRC Connection Resume Request, and RRC Connection Reestablishment Request. Other RRC messages may also be included.

[0084] RRC messages sent in the downlink (DL) direction using CCCH may include, for example, RRC Connection Reject messages, RRC Connection Setup messages, RRC Connection Reestablishment messages, and RRC Connection Reestablishment Reject messages. They may also include, for example, RRC Reject messages and RRC Setup messages. Other RRC messages may also be included.

[0085] RRC signaling sent in the uplink (UL) direction using DCCH may include, for example, a Measurement Report message, an RRC Connection Reconfiguration Complete message, an RRC Connection Setup Complete message, an RRC Connection Reestablishment Complete message, a Security Mode Complete message, and an UE Capability Information message. It may also include, for example, a Measurement Report message, an RRC Reconfiguration Complete message, an RRC Setup Complete message, an RRC Reestablishment Complete message, an RRC Resume Complete message, a Security Mode Complete message, and an UE Capability Information message. Other RRC signaling may also be included.

[0086] RRC signaling sent in the downlink (DL) direction using DCCH may include, for example, RRC Connection Reconfiguration messages, RRC Connection Release messages, Security Mode Command messages, and UE Capability Enquiry messages. It may also include, for example, RRC Reconfiguration messages, RRC Resume messages, RRC Release messages, RRC Reestablishment messages, Security Mode Command messages, and UE Capability Enquiry messages. Other RRC signaling may also be included.

[0087] RRC messages sent in the downlink (DL) direction using MCCH may include, for example, MBS broadcast configuration messages (MBSBroadcastConfiguration messages). Other RRC signaling may also be included.

[0088] This section describes some examples of NAS functionality. A NAS may have authentication capabilities. It may also have mobility management capabilities. Furthermore, a NAS may have security control capabilities.

[0089] The aforementioned PHY, MAC, RLC, PDCP, SDAP, RRC, and NAS functions are merely examples, and some or all of each function may not be implemented. Furthermore, some or all of the functions of each layer may be included in other layers.

[0090] Next, we will explain the state transitions of UE122 in LTE and NR. When a UE122 connected to an EPC or 5GC has an RRC connection, it may be in the RRC_CONNECTED state. The state of having an RRC connection may include the state in which the UE122 holds some or all of the UE context described below. The state of having an RRC connection may also include the state in which the UE122 can send and / or receive unicast data. When the RRC connection is suspended, the UE122 may be in the RRC_INACTIVE state. The UE122 may be in the RRC_INACTIVE state when it is connected to a 5GC and the RRC connection is suspended. When the UE122 is neither in the RRC_CONNECTED state nor the RRC_INACTIVE state, it may be in the RRC_IDLE state.

[0091] Note that if UE122 is connected to EPC, it does not have the RRC_INACTIVE state, but E-UTRAN may initiate the suspension of the RRC connection. When UE122 is connected to EPC and the RRC connection is suspended, UE122 may transition to the RRC_IDLE state, retaining the UE's AS context and the identifier (resumeIdentity) used for resuming. The upper layer of the UE122's RRC layer (e.g., the NAS layer) may initiate the resumption of the suspended RRC connection if UE122 retains the UE's AS context, E-UTRAN has permitted the resumption of the RRC connection, and UE122 needs to transition from the RRC_IDLE state to the RRC_CONNECTED state.

[0092] The definition of hibernation may differ between UE122 connected to EPC104 and UE122 connected to 5GC110. Furthermore, some or all of the procedure for UE122 to resume from hibernation may differ depending on whether UE122 is connected to EPC (when UE122 is hibernating in the RRC_IDLE state) or UE122 is connected to 5GC (when UE122 is hibernating in the RRC_INACTIVE state).

[0093] The RRC_CONNECTED state, RRC_INACTIVE state, and RRC_IDLE state may be referred to as connected mode, inactive mode, and idle mode, respectively, or as RRC connected mode, RRC inactive mode, and RRC idle mode.

[0094] The AS context of the UE held by UE122 may include all or part of the following information: the current RRC settings, the current security context, the PDCP status including the ROHC (RObust Header Compression) status, the C-RNTI (Cell Radio Network Temporary Identifier) ​​used by the source PCell, the cell identifier, and the physical cell identifier of the source PCell. The AS context of the UE held by any or all of eNB102 and gNB108 may include the same information as the AS context of the UE held by UE122, or it may include information different from the information included in the AS context of the UE held by UE122.

[0095] The security context may include all or part of the following at the AS level: the encryption key, the NH (Next Hop parameter), the NCC (Next Hop Chaining Counter parameter) used to derive the next hop access key, the identifier of the selected AS-level encryption algorithm, and the counter used for replay protection.

[0096] Next, we will describe the Serving Cell. In terminal devices in an RRC connection state where the CA and / or DC described later are not set, the Serving Cell may consist of one Primary Cell (PCell). Also, in terminal devices in an RRC connection state where the CA and / or DC described later are set, multiple Serving Cells may mean a set of multiple cells consisting of one or more Special Cells (SpCells) and one or more all Secondary Cells (SCells). SpCells may support PUCCH transmission and contention-based Random Access (CBRA), and SpCells may always be activated. A PCell may be a cell used in the RRC connection establishment procedure when a terminal device in an RRC idle state transitions to an RRC connection state. A PCell may also be a cell used in the RRC connection re-establishment procedure when a terminal device re-establishes the RRC connection. A PCell may also be a cell used in the random access procedure during handover. PSCell may be a cell used in the random access procedure when adding a secondary node, as described later. SpCell may be a cell used for purposes other than those mentioned above.

[0097] If a group of serving cells configured for a terminal device consists of a SpCell and one or more SCells, it may be considered that carrier aggregation (CA) is configured for the terminal device. Furthermore, for a terminal device with CA configured, a cell providing additional radio resources to a SpCell may mean an SCell.

[0098] This section describes a cell group, which is configured on a terminal device by a base station device. A cell group may consist of one SpCell. Alternatively, a cell group may consist of one SpCell and one or more SCells. In other words, a cell group may consist of one SpCell and, optionally, one or more SCells. A cell group may also be described as a set of cell(s).

[0099] Dual Connectivity (DC) is a technology that enables data communication using the radio resources of cell groups configured by a first base station device (first node) and a second base station device (second node). When DC or MR-DC (described later) is performed, cell groups may be added to terminal devices from the base station device. To perform DC, the first base station device may add a second base station device. The first base station device may be called the Master Node (MN). The cell group configured by the Master Node may be called the Master Cell Group (MCG). The second base station device may be called the Secondary Node (SN). The cell group configured by the Secondary Node may be called the Secondary Cell Group (SCG). Note that the Master Node and Secondary Node may be configured within the same base station device.

[0100] Furthermore, when a DC is not configured, the cell group configured on the terminal device may be called an MCG. Also, when a DC is not configured, the SpCell configured on the terminal device may be a PCell. Furthermore, an NR without a configured DC may be called an NR standalone (NR SA).

[0101] Furthermore, Multi-Radio Dual Connectivity (MR-DC) may be a technology that performs DC using E-UTRA for MCG and NR for SCG. Also, MR-DC may be a technology that performs DC using NR for MCG and E-UTRA for SCG. Also, MR-DC may be a technology that performs DC using NR for both MCG and SCG. MR-DC may be a technology included in DC. Examples of MR-DC using E-UTRA for MCG and NR for SCG include EN-DC (E-UTRA-NR Dual Connectivity) using EPC for the core network, and NGEN-DC (NG-RAN E-UTRA-NR Dual Connectivity) using 5GC for the core network. Also, an example of MR-DC using NR for MCG and E-UTRA for SCG is NE-DC (NR-E-UTRA Dual Connectivity) using 5GC for the core network. Also, an example of MR-DC using NR for both MCG and SCG is NR-DC (NR-NR Dual Connectivity) using 5GC for the core network.

[0102] In a terminal device, there may be one MAC entity for each cell group. For example, when a DC or MR-DC is configured on a terminal device, there may be one MAC entity for the MCG and one MAC entity for the SCG. The MAC entity for the MCG on a terminal device may always be established in all states of the terminal device (RRC idle state, RRC connected state, and RRC inactive state, etc.). The MAC entity for the SCG on a terminal device may be created by the terminal device when an SCG is configured on the terminal device. The MAC entities for each cell group on a terminal device may be established when the terminal device receives RRC signaling from the base station device. When a MAC entity is associated with an MCG, SpCell may mean a PCell. When a MAC entity is associated with an SCG, SpCell may mean a Primary SCG Cell (PSCell). When a MAC entity is not associated with a cell group, SpCell may mean a PCell. PCell, PSCell, and SCell are serving cells. In EN-DC and NGEN-DC, the MAC entity for MCG may be an E-UTRAMAC entity, and the MAC entity for SCG may be an NR MAC entity. Similarly, in NE-DC, the MAC entity for MCG may be an NR MAC entity, and the MAC entity for SCG may be an E-UTRA MAC entity. Furthermore, in NR-DC, both the MAC entities for MCG and SCG may be NR MAC entities. Note that the existence of one MAC entity for each cell group can be rephrased as one MAC entity for each SpCell. Similarly, one MAC entity for each cell group can be rephrased as one MAC entity for each SpCell.

[0103] The flow of RRC signaling transmitted and received between the terminal device and the base station device will be described. Figure 4 is a diagram showing an example of the flow of procedures for various settings in the RRC according to this embodiment. Figure 4 is an example of the flow when RRC signaling is sent from the base station device (eNB102, and / or gNB108) to the terminal device (UE122).

[0104] In Figure 4, the base station device creates an RRC message (step S400). The creation of an RRC message by the base station device may be performed to distribute system information (SI) or paging messages. Alternatively, the creation of an RRC message by the base station device may be performed to send an RRC signaling to a specific terminal device to perform an action. The actions to be performed by a specific terminal device may include, for example, security settings, RRC connection reconfiguration, handover to a different RAT, suspension of an RRC connection, and release of an RRC connection. RRC connection reconfiguration processes may include, for example, control of radio bearers (establish, change, release, etc.), control of cell groups (establish, add, change, release, etc.), measurement settings, handover, security key update, etc. The creation of an RRC message by the base station device may also be performed in response to an RRC signaling sent from a terminal device. Responses to RRC signaling transmitted from a terminal device may include, for example, responses to RRC setup requests, RRC reconnection requests, and RRC restart requests. RRC messages contain various information notifications and configuration information (parameters). These parameters may be fields of the RRC message and / or information elements, or the values ​​of fields (including information elements). The structure of an RRC message may be described using the ASN.1 (Abstract Syntax Notation One) notation scheme.

[0105] In Figure 4, the base station device then transmits the created RRC signaling to the terminal device (step S402). The terminal device then performs any necessary processing, such as configuration, according to the received RRC signaling (step S404). The terminal device that has performed the processing may transmit a response RRC signaling to the base station device (not shown).

[0106] RRC signaling may be used for purposes other than those mentioned above.

[0107] In MR-DC, the RRC signaling for SCG-side settings (cell group settings, wireless bearer settings, measurement settings, etc.) may be transmitted between the master node and the terminal device using the master node's RRC. For example, in EN-DC or NGEN-DC, the RRC signaling for NR may be included in the form of a container within the RRC signaling for E-UTRA transmitted and received between eNB102 and UE122. Similarly, in NE-DC, the RRC signaling for E-UTRA may be included in the form of a container within the RRC signaling for NR transmitted and received between gNB108 and UE122. RRC signaling for SCG-side settings may be transmitted and received between the master node and the secondary node.

[0108] Furthermore, not only when using MR-DC, the RRC signaling for E-UTRA transmitted from eNB102 to UE122 may include RRC signaling for NR, and the RRC signaling for NR transmitted from gNB108 to UE122 may include RRC signaling for E-UTRA.

[0109] This section explains the system information.

[0110] System information may be divided into a Master Information Block (MIB) and multiple System Information Blocks (SIBs). Furthermore, system information may include information blocks other than MIBs and SIBs.

[0111] MIB may be transmitted periodically from the base station equipment via BCH. MIB may contain parameters necessary to obtain SIB1. SIB1 may be transmitted periodically from the base station equipment via DL-SCH. SIB1 may contain information regarding the availability and scheduling of other SIBs. For example, SIB1 may contain multiple fields, one of which may contain system information scheduling information. System information scheduling information may contain information regarding whether one or more SIBs are broadcast, information regarding the broadcast period, and / or other information.

[0112] SIBs other than SIB1 may be included in the system information message (SI message) and transmitted from the base station equipment via DL-SCH. The system information message may contain one or more SIBs.

[0113] A terminal device may apply a system information acquisition procedure to obtain system information. This procedure may be applied to terminal devices in the RRC_IDLE state, RRC_INACTIVE state, and RRC_CONNECTED state.

[0114] The terminal device may apply the system information retrieval procedure when selecting a cell, re-selecting a cell, or returning to coverage from outside the coverage area. Furthermore, the terminal device may apply the system information retrieval procedure when it does not possess a valid version of the SIB.

[0115] This document explains the notification of changes to system information.

[0116] A change period may be used when changing system information. That is, updated system information messages (excluding some SI messages such as ETWS and CMAS, which will be described later) may be broadcast during the next change period following the transmission of the system information change instruction.

[0117] The boundary of the change period may be defined by the value of the SFN (System Frame Number) such that SFN mod m = 0 (where m is the number of wireless frames that make up the change period). The change period may be set by system information.

[0118] Terminal devices may receive instructions regarding system information changes and / or PWS (Public Warning System) notifications using short messages transmitted over DCI. To receive short messages for paging occasions, terminal devices may monitor PDCCH during PDCCH monitoring opportunities for paging.

[0119] A terminal device that receives a short message may perform some or all of the following processes (a) to (d) based on whether the terminal device is ETWS (Earthquake and Tsunami Warning System) capable or CMAS (Commercial Mobile Alert Service) capable, and whether a specific bit (etwsAndCmasIndication bit) among the multiple bits that make up the short message is set. The etwsAndCmasIndication bit may be a bit indicating the presence of an ETWS primary notification, an ETWS secondary notification, and / or a CMAS notification. Process (a): Immediately reacquire SIB1. Process (b): If the terminal device is ETWS capable and the system information scheduling information of SIB1 contains information of SIB6, immediately acquire SIB6. SIB6 may be a system information block containing an ETWS primary notification. Process (c): If the terminal device is ETWS capable and the system information scheduling information of SIB1 contains information of SIB7, immediately acquire SIB7. SIB7 may be a system information block containing ETWS secondary notifications. Process (d): If the terminal device is CMAS capable and the system information scheduling information of SIB1 contains the information of SIB8, immediately obtain SIB8. SIB8 may be a system information block containing CMAS notifications.

[0120] Furthermore, a terminal device that receives a short message may apply the system information acquisition procedure from the start of the next update period based on whether a specific bit (systemInfoModification bit) among the multiple bits that make up the short message is set. Note that the systemInfoModification bit may be a bit that indicates that there has been a change in an SIB other than SIB6, 7, or 8.

[0121] ETWS is a public warning system developed to meet regulatory requirements for earthquake and tsunami warning notifications. ETWS warning notifications may include primary notifications (short notices) and secondary notifications (providing detailed information). CMAS is another public warning system developed to deliver various types of warning notifications.

[0122] This explains the MBS service.

[0123] In the case of MBS services, broadcast services may provide the same service and the same specific content data simultaneously to all terminal devices (UE122) within a geographical area. Broadcast services may be delivered to terminal devices using broadcast sessions. Terminal devices may receive broadcast services in the RRC_IDLE, RRC_INACTIVE, and RRC_CONNECTED states.

[0124] In the case of multicast services within MBS services, the same service and the same specific content data may be provided simultaneously to one or more specific terminal devices (also referred to as UE sets). Multicast services may be delivered to terminal devices using multicast sessions. Terminal devices can receive multicast services using mechanisms such as PTP (Point to Point) delivery and / or PTM (Point to Multipoint) delivery. HARQ feedback / retransmission can be applied to both PTP and PTM transmissions.

[0125] MBS distribution may utilize some or all of the following logical channels: MTCH: A PTM downlink channel for transmitting MBS data for multicast or broadcast sessions from the network to terminal devices; DTCH: A PTP channel defined for transmitting MBS data for multicast sessions from the network to terminal devices; MCCH: A PTM downlink channel used to transmit MBS broadcast control information and / or MBS multicast control information for one or more MTCHs associated with the network to terminal devices.

[0126] This shows an example of how RNTI can be used in PTM transmission. Terminal devices can receive different services using the same or different G-RNTI. Terminal devices can receive different services using the same or different G-CS-RNTI.

[0127] In multicast services, gNBs may distribute MBS data packets using the following methods: PTP transmission: gNBs may independently distribute separate copies of MBS data packets to each terminal device. That is, gNBs may schedule terminal-specific PDSCHs using terminal-specific PDCCHs scrambled with terminal-specific RNTIs (e.g., C-RNTIs), and distribute separate copies of MBS data packets scrambled with the same terminal-specific RNTIs to each terminal device. PTM transmission: gNBs may distribute a single copy of MBS data packets to a set of UEs. That is, gNBs may schedule group-common PDSCHs using group-common PDCCHs scrambled with group-common RNTIs, and distribute a single copy of MBS data packets scrambled with the same group-common RNTIs to the set of UEs.

[0128] If a terminal device is configured for both PTM and PTP transmission, the gNB may dynamically determine whether to deliver multicast data to a particular terminal device via the PTM leg and / or the PTP leg, based on information such as MBS session QoS requirements, the number of participating terminal devices, and individual terminal device receive quality feedback. Furthermore, regardless of the aforementioned determination, the same QoS requirements may apply to both PTM and PTP transmissions.

[0129] MBS broadcasts may be received by terminal devices in the RRC_IDLE, RRC_INACTIVE, and RRC_CONNECTED states. Terminal devices may receive MBS settings for a broadcast session (e.g., parameters required for MCCH reception) via MCCH in the RRC_IDLE, RRC_INACTIVE, and RRC_CONNECTED states. The parameters required for MCCH reception may be provided via system information.

[0130] The following principles may apply to the structure of an MCCH: • An MCCH may provide a list of some or all broadcast services transmitted in an MTCH, and / or information related to a broadcast session. Information related to a broadcast session may include the MBS session ID, associated G-RNTI scheduling information, and information about neighboring cells providing specific services in the MTCH. MCCH content may be transmitted within a regularly occurring time-domain window defined by the MCCH repetition period, MCCH window period, and radio frame / slot offset. • An MCCH may use a change period, and MCCH content may only be allowed to be modified at change period boundaries. A notification mechanism may be used to notify of changes to MCCH content due to the start, modification, or termination of a broadcast session and changes in neighboring cell information. • When a terminal device receives an MCCH change notification, it may obtain the updated MCCH from the same MCCH change period in which the change notification was sent.

[0131] This section describes the continuity of broadcast services in the RRC_IDLE and RRC_INACTIVE states.

[0132] The mobility procedure for MBS reception allows terminal devices to start or continue receiving MBS services when changing cells. The gNB (Gignet Network) can, in the MCCH (Mass Cell Channel), indicate a list of neighboring cells that provide the same MBS broadcast services as the serving cell. This allows terminal devices to request unicast reception of the service before moving to a cell that does not provide MBS broadcast services using PTM (Portable Tone) transmission. To eliminate the need to read MBS broadcast-related system information for neighboring frequencies, terminal devices can know which frequencies provide MBS broadcast services via PTM through the MBS User Service Description (USD) or a combination of the following: • USD • System Information (System Information Block: SIB, e.g., SIB21)

[0133] This section describes User Service Descriptions (USDs). A single USD may contain information about a single MBS service (also referred to as an MBS user service). The USD may include one or more external service identifiers for a given MBS user service, a unique identifier for that MBS user service within the scope of the MBS system, information indicating when that MBS user service becomes active, and / or one or more MBS Distribution Session Description objects for that MBS user service. Each of the MBS Distribution Session Description objects may include, in whole or in part, a URL to a session description document carrying parameters for that MBS distribution session, information about the service area of ​​that MBS distribution session, one or more MBS Frequency Selection Area Identities (FSAIs, also referred to as MBS FASIs) associated with that MBS distribution session, and information about one or more transmission frequencies associated with each of the FSAIs. The session description document may include information indicating the type of MBS service, such as whether it is Broadcast or Multicast, and information about the Temporary Mobile Group Identity (TMGI). TMGI may consist of the MBS service ID, MCC (Mobile Country Code), and MNC (Mobile Network Code). Note that the USD configuration is an example, and the USD may not include some of the above parameters, or may include other parameters in addition to or instead of them. Also, the USD may have a configuration different from the above. A single USD may be treated as a single object (also referred to as a USD object), and a version-controlled document containing one or more such USD objects may be referred to as a User Service Descriptions document.

[0134] MBS FSAI may be used by terminal equipment to select the frequency of the MBS broadcast session (also referred to as the broadcast MBS session).

[0135] In the RRC_IDLE and RRC_INACTIVE states, terminal devices may apply the following modifications to the normal cell reselection rules: A terminal device that is receiving or interested in receiving MBS broadcast services via PTM may receive these MBS broadcast services while camping on the frequencies that provide these MBS broadcast services, and may make this frequency the highest priority frequency if certain conditions are met. If the MBS broadcast services that a terminal device is interested in become unavailable (e.g., after the session ends), or if the terminal device is no longer interested in receiving the services, the terminal device does not need to prioritize the frequencies that provide these MBS broadcast services.

[0136] This document describes the continuity of MBS broadcast services in the RRC_CONNECTED state.

[0137] A terminal device in the RRC_CONNECTED state may send an MBS Interest Indication (MII) to the gNB to ensure the continuity of MBS broadcast services. This MII consists of the following information: • A list of MBS frequencies that the terminal device is receiving or is interested in receiving, sorted in descending order of importance. • The priority of MBS frequencies, unicast bearers, and multicast MRBs that the terminal device is receiving or is interested in receiving. • If a PCell or SCell provides an SIB (e.g., SIB20) containing the information necessary to obtain the MCCH and / or MTCH settings for MBS broadcasts, a list of MBS broadcast services that the terminal device is receiving or is interested in receiving.

[0138] The reporting of an MBS interest indication may be implicitly enabled or disabled based on whether or not an SIB (e.g., SIB21) exists that contains mapping information between the current carrier frequency and / or adjacent carrier frequencies and MBS Frequency Selection Area Identities (FSAI). Furthermore, the information contained in the MBS interest indication may be exchanged between the source gNB and the target gNB during handover.

[0139] In an MBS broadcast service, the gNB may deliver broadcast MBS data packets using the following methods: PTM transmission: The gNB may deliver a single copy of the MBS data packet to the UE set. For example, the gNB may schedule a group-common PDSCH scrambled with the same group-common RNTI using a group-common PDCCH scrambled with the same group-common RNTI.

[0140] This section provides details about MBS Broadcasting.

[0141] MBS broadcast configuration information may be provided on the MCCH logical channel. Some configuration information, including Common Frequency Resources (CFR) settings for MCCH and MTCH, may be provided on logical channels other than the MCCH logical channel (e.g., BCCH, CCCH, DCCH, or DTCH).

[0142] MCCH may be used to deliver MBS broadcast configuration messages (MBSBroadcastConfiguration messages) that indicate the MBS broadcast sessions provided by a cell and the scheduling information associated with these sessions. Optionally, the MBSBroadcastConfiguration message may include a list of neighboring cells that provide the same MBS broadcast services as the current cell. Configuration information necessary for terminal devices to receive MCCH may be provided in SIB1 and SIB20. Furthermore, SIB21 may provide information regarding the continuity of MBS broadcast services.

[0143] MCCH information (i.e., information transmitted in a message transmitted via MCCH) may be transmitted periodically within a configured transmission window using a configurable repetition period. MCCH transmissions (and associated radio resources and MCS) may be indicated by a PDCCH addressed to MCCH-RNTI.

[0144] The PDCCH monitoring occasion for MCCH transmission may be determined according to the common search space indicated by searchspaceMCCH. If searchspaceMCCH is set to zero, the PDCCH monitoring occasion for receiving an MCCH message in the MCCH transmission window may be the same as the PDCCH monitoring occasion for SIB1. If searchspaceMCCH is set to a value other than zero, the PDCCH monitoring occasion for an MCCH message may be determined based on the search space indicated by searchspaceMCCH.

[0145] Changes to MCCH information may occur only in specific radio frames, and the concept of a modification period may be used. During the modification period, the same MCCH information may be transmitted a number of times defined by its scheduling. If a network changes some or all of the MCCH information, the network may notify terminal devices of the change from the start of the MCCH modification period using a PDCCH that schedules the MCCH. If a terminal device that has received notification of the change is receiving or interested in receiving MBS services transmitted using MBS broadcasts, it may obtain the new MCCH information from the same slot in which it received the notification. A terminal device may apply previously obtained MCCH information until it obtains the new MCCH information.

[0146] A terminal device may apply an MCCH information acquisition procedure to obtain information about MBS broadcast settings broadcast by the network. The MCCH information acquisition procedure may be applied to MBS broadcast services that an MBS-enabled terminal device is receiving or is interested in receiving, while in the RRC_IDLE state, RRC_INACTIVE state, or RRC_CONNECTED state where the BWP with a common search space configured by searchSpaceMCCH is the active BWP.

[0147] If a terminal device is interested in receiving the MBS broadcast service, it may apply the MCCH information acquisition procedure. A terminal device interested in receiving the MBS broadcast service may apply the MCCH information acquisition procedure when it enters a cell providing the SIB20 (e.g., when powered on, after the terminal device is moved), when it receives the SCell's SIB20 via dedicated signaling, and when it is notified that there has been a change in MCCH information due to the start of a new MBS service. A terminal device receiving data via broadcast MRB may apply the MCCH information acquisition procedure if it is notified that the MCCH information has been changed due to a change in MCCH information other than the start of a new MBS service. Unless explicitly specified in the MCCH information acquisition procedure, the MCCH information acquisition procedure may overwrite the stored MCCH information.

[0148] A terminal device receiving or interested in receiving the MBS broadcast service may, if the MCCH information acquisition procedure is triggered based on notification of a change in MCCH information, begin acquiring MBSBroadcastConfiguration messages transmitted using MCCH from the slot that was notified of a change in MCCH information. Alternatively, a terminal device may, if it enters a cell providing SIB20, or if it receives information contained in SIB20 announced by SCell via RRC signaling, begin acquiring MBSBroadcastConfiguration messages transmitted using MCCH from the next repetition period.

[0149] The broadcast MRB configuration procedure may be used by a terminal device to configure PDCP, RLC, MAC, and PHY when the terminal device starts and / or stops receiving broadcast MRBs transmitted via MTCH, or when the configuration of a broadcast MRB received by the terminal device is changed. The broadcast MRB configuration procedure may be applied to MBS broadcast services that an MBS-enabled terminal device is receiving or is interested in receiving in the RRC_IDLE state, RRC_INACTIVE state, or RRC_CONNECTED state where the BWP with a common search space configured by searchSpaceMTCH or searchSpaceMCCH is the active BWP.

[0150] A terminal device may apply (start) the broadcast MRB setup procedure to begin receiving an MBS session of an MBS broadcast service of interest. The broadcast MRB setup procedure may be started when an MBS-enabled terminal device interested in receiving an MBS broadcast service starts an MBS session, enters a cell providing an MBS broadcast service, becomes interested in an ongoing MBS broadcast service, or when the terminal device's capability restrictions are lifted and it is no longer hindered from receiving an ongoing MBS broadcast service.

[0151] A terminal device may apply (initiate) a broadcast MRB release procedure to stop receiving a session of the MBS broadcast service. The broadcast MRB release procedure may be initiated when an MBS session is terminated, when the terminal device moves away from the cell broadcasting the MBS service it is interested in, when it loses interest in the MBS service, or when a capability restriction that prevents it from receiving the relevant service is initiated.

[0152] As part of the broadcast MRB configuration procedure, the terminal device may perform the following operations:

[0153] The terminal device may establish PDCP entities, RLC entities, and / or SDAP entities according to the information about this broadcast MRB contained in the MBSBroadcastConfiguration message. The terminal device may also configure the MAC layer based on the MTCH scheduling information (mtch-SchedulingInfo). The terminal device may also configure the PHY layer based on the settings applied to this broadcast MRB. The terminal device may also receive DL-SCH in the same cell that received the MBSBroadcastConfiguration message for broadcast MRB establishment, using G-RNTI and / or mtch-SchedulingInfo for this MBS broadcast service.

[0154] As part of the broadcast MRB release procedure, the terminal device may perform the following operations:

[0155] The terminal device may release PDCP entities, RLC entities, and associated MAC and PHY settings. The terminal device may also release SDAP entities for which there is no longer an associated MRB.

[0156] The aforementioned MBS broadcast configuration message (MBSBroadcastConfiguration message) may include information indicating one or more MBS broadcast sessions (MBS session information list). In addition or alternatively, the MBS broadcast configuration message may include a list of neighboring cells providing the same MBS broadcast service. Each entry in the MBS session information list may include MBS broadcast session identifier information (TMGI). The TMGI may include PLMN (Public Land Mobile Network) identifier information, or an index value associated with PLMN identifier information. In addition or alternatively, the TMGI may include an identifier (service ID) for identifying the MBS service within the PLMN. In addition or alternatively, the MBS session information list may include one or more entries, and the entries in the MBS session information list may include G-RNTI used for MTCH scheduling and transmission scrambling. In addition or alternatively, the entries in the MBS session information list may include broadcast MRB settings (e.g., PDCP settings or RLC settings).

[0157] This explains the interest indication on MBS.

[0158] A terminal device may execute the MBS interest indication procedure. This procedure may be used to indicate to the network that a terminal device in the RRC_CONNECTED state is receiving or interested in receiving MBS broadcast services. In addition, this procedure may be used to indicate to the network that a terminal device in the RRC_CONNECTED state prefers MBS broadcast reception over unicast / multicast MRB reception. In addition to or instead of this, this procedure may be used for other purposes.

[0159] (MBS interest indication procedure)

[0160] An MBS-capable UE in the RRC_CONNECTED state may initiate the MBS interest indication procedure in several cases. These cases may include: when the RRC connection is successfully established / re-established; when entering or leaving a broadcast service area; when an MBS broadcast session is started or stopped; when there is a change in interest in the MBS broadcast service; when there is a change in the priority of MBS broadcast reception versus unicast / multicast reception; when the serving cell changes to a PCell providing SIB21 (i.e., when SIB21 is included in the schedule information of SIB1); when an SCell's SIB20 is received via dedicated signaling; during a handover; and when the RRC connection is re-established. Furthermore, when a serving cell is changed to a PCell that provides a parameter (nonServingCellMII) in SIB1 indicating that it is permissible to send an MBS interest indication to the serving cell for receiving MBS broadcast services in a non-serving cell, when reception of MBS broadcast services is started or stopped in a non-serving cell, or when the CFR (common frequency resources) information or subcarrier interval for MBS broadcast reception is changed in a non-serving cell, this may also include such cases. If the UE does not have the CFR information and subcarrier interval for MBS broadcast reception in a non-serving cell, the UE may obtain that information from the non-serving cell before sending the MBS Interest Indication.

[0161] The terminal device initiating this procedure may perform some or all of the following (a) to (b) if SIB21 is provided by the PCell, or if nonServingCellMII is provided by the PCell in SIB1: (a) Verify that it has obtained a valid version of SIB21 for the PCell. (b) If the UE has not sent an MBS Interest Indication since last entering the RRC_CONNECTED state, or if the UE has connected to a PCell that has not provided SIB21 or does not include nonServingCellMII in SIB1 since last sending an MBS Interest Indication, it may set the content of the MBSInterestIndication message according to the MBS interest indication content preparation procedure based on the fact that the set of MBS broadcast frequencies determined according to the procedure for determining the MBS frequencies of interest is not empty, and then begin sending the MBSInterestIndication message.

[0162] In addition to or instead of the above, the terminal device initiating this procedure may perform the following action (pa) if some or all of the following conditions (ca) to (ce) are met, and if SIB21 is not provided by PCell and nonServingCellMII is not provided by PCell in SIB1, then perform the following action (pb) if all of the following conditions (ca) to (ce) are not met: (ca) The set of MBS broadcast frequencies of interest determined according to the procedure for determining MBS frequencies of interest is different from the mbs-FreqList included in the last transmission of the previous MBS interest indication. (cb) The set of MBS broadcast frequencies of interest for MBS broadcast reception in non-serving cells determined according to the procedure for determining MBS frequencies of interest is different from the one included in the previous MBS interest indication. (cc) Either the subcarrier interval or CFR information for MBS broadcast reception in non-serving cells has changed since the last transmission of the MBS interest indication. (cd) Subcarrier spacing and CFR information for MBS broadcast reception in non-serving cells was obtained from non-serving cells that were not reported in the previous MBS interest indication. (ce) The priority of receiving MBS broadcast frequencies compared to receiving established unicast bearers and multicast MRBs has been changed since the last transmission of the MBS interest indication.(pa) Set the content of the MBS Interest Indication according to the MBS interest indication content preparation procedure and start sending the MBSInterestIndication message. (pb) If an SIB20 is provided on a PCell or SCell, and based on (1) since the UE last sent an MBS Interest Indication the UE has connected to a PCell that does not provide an SIB20 and the UE does not provide an SIB20 for the SCell, or (2) the set of MBS broadcast services determined according to the procedure for determining MBS services of interest is different from the list included in the last MBS Interest Indication transmission, set the content of the MBS Interest Indication according to the MBS interest indication content preparation procedure and start sending the MBSInterestIndication message.

[0163] (Procedure for determining MBS frequencies of interest)

[0164] A terminal device may determine that a frequency is part of an MBS frequency of interest on the basis that all of the following conditions (ca) through (cc) are met: (ca) At least one MBS session that the terminal device is receiving or is interested in receiving via broadcast MRB is in progress or about to begin. (cb) For at least one MBS session that the terminal device is receiving or is interested in receiving via broadcast MRB, the SIB21 obtained from the PCell or non-serving cell contains information mapping the frequency to one or more MBS FSAIs indicated by the USD of this MBS session, or the frequency is not included in the SIB21 but is indicated by the USD of this session. (cc) The terminal device's capability information that it advertises to the network (e.g., UE-NR-Capability), including information on supported band combinations (e.g., supportedBandCombinationList), includes at least one band combination that contains the frequency.

[0165] (Procedure for determining MBS services of interest)

[0166] A terminal device may determine that its MBS service is part of an MBS service of interest on the basis that all of the following conditions (ca) through (cc) are met: (ca) The terminal device is receiving or is interested in receiving the MBS service via broadcast MRB. (cb) A session of the MBS service is in progress or about to be started. (cc) One or more MBS FSAIs (Frequency Selection Area Identities) in the USD (User Service Description) for the MBS service include frequencies belonging to a set of MBS frequencies of interest determined by the procedure for determining MBS frequencies of interest in the SIB21 obtained from PCell, or the SIB21 obtained from PCell does not provide frequency mapping information for the MBS service, but the USD for the MBS service includes frequencies belonging to a set of MBS frequencies of interest determined by the procedure for determining MBS frequencies of interest.

[0167] (Procedure for preparing the contents of MBS interest indication)

[0168] The terminal device may prepare content for MBS interest indication.

[0169] A terminal device may perform some or all of the following steps (pa) through (pd) based on the fact that (1) it has a valid version of SIB21 and (2) the set of MBS frequencies of interest determined by the procedure for determining MBS frequencies of interest is not empty: (pa) It may set the MBS frequencies of interest sorted in descending order in a list to be included in the MBS interest indication (mbs-FreqList). (pb) Based on the fact that the terminal device prioritizes MBS broadcast reception over any unicast / multicast MRB reception, it may include the parameter mbs-Priority in the MBS interest indication. By including mbs-Priority in the MBS interest indication and sending it, the terminal device may inform the network that the terminal device prioritizes MBS broadcast reception over any unicast / multicast MRB reception. (pc) Based on the fact that SIB20 for PCell or SCell is provided, it may set the MBS services of interest sorted in descending order in a list to be included in the MBS interest indication (mbs-ServiceList). (pd) Based on the fact that the SIB1 for PCell includes nonServingCellMII and the set of MBS frequencies for receiving MBS broadcasts in non-serving cells, as determined by the procedure for determining MBS frequencies of interest, is not empty, (1) the content of the MBS interest indication may include freqInfoMBS, and (2) if the terminal device has obtained cfr-InfoMBS and subcarrierSpacing for receiving MBS broadcasts in non-serving, that cfr-InfoMBS and subcarrierSpacing may be included in the content of the MBS interest indication.

[0170] Based on the above description, various embodiments will be explained. Note that any processes omitted in the following description may be replaced by the processes described above.

[0171] Figure 5 is a block diagram showing the configuration of the terminal device (UE122) in this embodiment. Note that, to avoid complicating the explanation, Figure 5 only shows the main components closely related to this embodiment.

[0172] The UE122 shown in Figure 5 comprises a receiving unit 500 that receives control information (DCI, MAC control elements, RRC signaling, broadcast information, etc.) from a base station device, a processing unit 502 that processes according to the parameters included in the received control information, and a transmitting unit 504 that transmits control information (UCI, MAC control elements, RRC signaling, etc.) to the base station device. This base station device may be an eNB102 or a gNB108. Furthermore, the processing unit 502 may include some or all of the functions of various layers (for example, the physical layer, MAC layer, RLC layer, PDCP layer, SDAP layer, RRC layer, and NAS layer). That is, the processing unit 502 may include some or all of the physical layer processing unit (PHY processing unit), MAC layer processing unit (MAC processing unit), RLC layer processing unit (RLC processing unit), PDCP layer processing unit (PDCP processing unit), SDAP processing unit (SDAP processing unit), RRC layer processing unit (RRC processing unit), and NAS layer processing unit (NAS processing unit).

[0173] Figure 6 is a block diagram showing the configuration of the base station device in this embodiment. To avoid making the explanation complicated, only the main components closely related to this embodiment are shown in Figure 6. This base station device may be eNB102 or gNB108.

[0174] The base station device shown in Figure 6 consists of a transmitting unit 600 that transmits control information (DCI, RRC signaling, broadcast information, etc.) to the UE 122, a processing unit 602 that creates control information (DCI, RRC signaling including parameters, broadcast information, etc.) and transmits it to the UE 122, causing the processing unit 502 of the UE 122 to perform processing, and a receiving unit 604 that receives control information (UCI, RRC signaling, etc.) from the UE 122. Furthermore, the processing unit 602 may include some or all of the functions of various layers (for example, the physical layer, MAC layer, RLC layer, PDCP layer, SDAP layer, RRC layer, and NAS layer). That is, the processing unit 602 may include some or all of the physical layer processing unit, MAC layer processing unit, RLC layer processing unit, PDCP layer processing unit, SDAP layer processing unit, RRC layer processing unit, and NAS layer processing unit.

[0175] An example of the processing of the terminal device in this embodiment will be explained using Figures 7 to 10.

[0176] Figure 7 shows an example of processing by the terminal device (UE122) in this embodiment. The receiving unit 500 of the terminal device receives first information from the base station device (step S700). Based on the received first information, the processing unit 502 of the terminal device determines whether the target area associated with a multicast broadcast service (MBS) session provided in a certain adjacent cell is the same as the target area associated in the current cell (step S702).

[0177] The first information received from the base station device in step S700 may be, for example, any one of (a) to (c) below, or any combination thereof: (a) a message transmitted using MCCH (b) a system information block (e.g., SIB21) (c) RRC signaling transmitted using DCCH

[0178] For example, message (a) may be an MBS broadcast configuration message or another message. For example, system information block (b) may be SIB20, SIB21, or another SIB. For example, RRC signaling (c) may be an RRC reconfiguration message or another RRC message.

[0179] The terminal device may also receive second information from the base station device. The second information may include information indicating one or more areas (target areas). Each of the target areas may be represented, for example, by any one or a combination of (a) to (d) below: (a) A list containing one or more entries, with each entry being an area indicated by a Reference Location (geographic coordinates indicated by longitude and latitude) and additional information (e.g., radius, diameter, and / or angle, etc.); (b) A list containing one or more entries, with each entry being an area formed by connecting multiple Reference points; (c) An SSB index; (d) Other information indicating a geographic area.

[0180] Each of the aforementioned target areas may be identified by an identifier. The identifier used to identify the target area is also called the target area identifier. The target area identifier may be included in the second information along with the information indicating the target area. Figure 8 shows an example of the case described in (a) above. Figure 8 shows an example in which a list (MBSAreaInfoList) containing the target area identifier (TargetAreaId), a Reference Location (ReferenceLocation) indicating the target area, and radius information (mbs-DistanceRadius) is provided from the base station device to the terminal device as the second information.

[0181] Furthermore, the statement that a target area is indicated by an SSB index means that a certain SSB index is associated with a certain target area. For example, if a terminal device can receive an SSB of a certain SSB index, it can be considered that the terminal device is located in the target area associated with that SSB index. The statement that an SSB can be received means that the received power of that SSB is above (or exceeds) a certain threshold. This threshold may be notified in the first piece of information, in the second piece of information, or may be a default value.

[0182] One or more target areas notified in the second piece of information described above may be associated with an MBS session.

[0183] For example, each entry in the MBS session information list included in the MBS broadcast configuration message may be associated with zero or more target areas. In this case, for example, each entry in the MBS session information list may contain a list with zero or more target area identifiers as entries. In addition or alternatively, each entry in the MBS session information list may be associated with TMGI and zero or more target areas. In addition or alternatively, each entry in the MBS session information list may be associated with G-RNTI and zero or more target areas. In addition or alternatively, each entry in the MBS session information list may be associated with PLMN and zero or more target areas. In addition or alternatively, each entry in the MBS session information list may be associated with Service ID and zero or more target areas. Figure 9 shows an example of an MBS broadcast configuration message containing target area identifiers. The MBS broadcast configuration message (MBSBroadcastConfiguration) includes an MBS session information list (MBS-SessionInfoList), each entry in the MBS session information list includes TMGI and G-RNTI, and optionally includes a list (TargetAreaList) with one or more target area identifiers in its entries. That is, the absence of TargetAreaList in an entry of the MBS session information list indicates that the entry is associated with zero target areas.

[0184] For example, SIB20 may contain configuration information necessary to receive one or more MCCHs, and each of the configuration information necessary to receive an MCCH may be associated with zero or more target areas. In this case, all MBS sessions notified by an MBS broadcast configuration message received based on the configuration information necessary to receive a certain MCCH may be associated with zero or more target areas associated with the configuration information necessary to receive that MCCH.

[0185] Furthermore, one or more MBS sessions may be associated with each of the target areas notified by the second information. In addition to or instead of this, one or more FSAIs may be associated with each of the target areas notified by the second information. In addition to or instead of this, one or more target areas notified by the second information may be associated with each of the one or more FSAIs. In addition to or instead of this, one or more MBS services may be associated with each of the target areas notified by the second information. In addition to or instead of this, one or more MBS sessions may be associated with each of the MBS services.

[0186] For example, Figure 10 shows an example in which target areas notified by one or more of the second pieces of information described above are associated in SIB21 with each of one or more FSAIs. As shown in Figure 10, SIB21 may include a list of MBS FSAIs associated with the same frequency as the serving cell (MBS-FSAI-List), and / or a list of FSAIs associated with frequencies different from the serving cell frequency (MBS-FSAI-InterFreqList), and / or a list of FSAIs associated with target areas (MBS-FSAI-ISA-List). The MBS-FSAI-ISA-List may include information on one or more MBS FSAIs and one or more target area identifiers associated with each MBS FSAI.

[0187] Furthermore, there may be MBS services, MBS sessions, and / or FSAIs that are not associated with any target area (i.e., associated with zero target areas).

[0188] The determination in step S702 may, for example, be to determine, based on the first information received, whether the target area associated with a multicast broadcast service (MBS) session provided in a certain adjacent cell is the same as the target area associated in the first cell.

[0189] For example, the first cell may be the cell from which the terminal device acquired the first information.

[0190] For example, the association between an MBS session and a target area in the first cell may be performed by associating zero or more target areas with each entry in the MBS session information list included in the MBS broadcast configuration message transmitted in the first cell, or by any of the various methods described above.

[0191] This document describes an example of a method for determining whether the target area associated with a multicast broadcast service (MBS) session provided in an adjacent cell is the same as the target area associated in the first cell.

[0192] For example, the MBS broadcast setup message transmitted in the first cell may include an MBS neighbor cell list. The MBS neighbor cell list may include information on zero or more MBS neighbor cells. The information on the MBS neighbor cells may include, for example, the carrier frequency and the physical cell identifier, or other information. Furthermore, the MBS broadcast setup message may include a list of MBS sessions provided by the first cell. The list of MBS sessions may include information on one or more MBS sessions. Each MBS session information may include at least an MBS session identifier. In addition, each MBS session information may include information indicating the neighbor cell providing the service for that MBS session (for example, via MTCH) (mtch neighbor cell information: mtch-NeighbourCell).

[0193] For example, the mtch adjacent cell information may be a bit string, and each bit of the bit string may correspond to each cell shown in the MBS adjacent cell list. For example, if the MBS adjacent cell list consists of MBS adjacent cell information for cells A, D, and C, then based on the first bit of the mtch adjacent cell information being 1, it may be indicated that the MBS session service is provided in cell A (e.g., via MTCH). In addition or alternatively, based on the first bit of the mtch adjacent cell information being 0, it may be indicated that the MBS session service is not provided in cell A (e.g., via MTCH). In addition or alternatively, based on the second bit of the mtch adjacent cell information being 1, it may be indicated that the MBS session service is provided in cell D (e.g., via MTCH). In addition or alternatively, based on the second bit of the mtch adjacent cell information being 0, it may be indicated that the MBS session service is not provided in cell D (e.g., via MTCH). Similarly, each bit in the bit sequence of the mtch adjacent cell information may be interpreted in the following manner.

[0194] In addition, each MBS session information may include information indicating whether or not the service for that MBS session is provided in the same area (for example, in MTCH) as the target area linked in the first cell (MTCH adjacent cell target area information).

[0195] For example, the mtch adjacent cell target area information may be a bit string, and each bit of the bit string may correspond to each cell shown in the MBS adjacent cell list. For example, if the MBS adjacent cell list consists of information for MBS adjacent cells A, D, and C, then based on the first bit of the mtch adjacent cell target area information being 1, it may be indicated that the same area linked to the service of the MBS session in the first cell is the same area linked to the service of the MBS session in cell A. In addition or alternatively, based on the first bit of the mtch adjacent cell target area information being 0, it may be indicated that a different area from the target area linked to the service of the MBS session in the first cell is the area linked to the service of the MBS session in cell A. In addition or alternatively, based on the second bit of the mtch adjacent cell target area information being 1, it may be indicated that the same area linked to the service of the MBS session in the first cell is the same area linked to the service of the MBS session in cell D. In addition to or instead of the above, it may be indicated that the service of the MBS session is associated with a different area in cell D than the area associated in the first cell, based on the second bit of the mtch adjacent cell target area information being 0. Each bit of the bit sequence of the mtch adjacent cell target area information may be interpreted similarly thereafter.

[0196] Alternatively, for example, the mtch adjacent cell target area information may be a bit string, and each bit of the bit string may correspond to each cell in the mtch adjacent cell information bit string where the bit is set to 1. For example, if the MBS adjacent cell list consists of MBS adjacent cell information for cell A, cell D, and cell C, and the bit string of the MBS adjacent cell list is 101 (or 10100000 if the MBS adjacent cell list is a fixed length of, for example, 8 bits), then the mtch adjacent cell target area information may be a 2-bit variable bit string. In this case, based on the first bit being 1, it may be indicated that the same area as the target area to which the MBS session service is linked in the first cell is linked in cell A. In addition to or instead, based on the first bit of the mtch adjacent cell target area information being 0, it may be indicated that a different area from the target area to which the MBS session service is linked in the first cell is linked in cell A. In addition to or instead of the above, it may be indicated that the service of the MBS session is associated with the same area in cell C as the service associated with the first cell, based on the second bit of the mtch adjacent cell target area information being 1. In addition to or instead of the above, it may be indicated that the service of the MBS session is associated with a different area in cell C than the service associated with the first cell, based on the second bit of the mtch adjacent cell target area information being 0. This makes it possible to reduce the amount of signaling for the mtch adjacent cell target area information.

[0197] Furthermore, in a system in which, for example, a list of MBS FSAIs associated with the same frequency as the serving cell (MBS-FSAI-List) and / or a list of FSAIs associated with frequencies different from the serving cell's frequency (MBS-FSAI-InterFreqList) are broadcast in SIB21, and each FSAI is associated with a target area, the terminal device, upon receiving the SIB21 in the first cell, may notify each FSAI of information indicating whether the same area as the target area associated in the first cell is associated with the FSAI shown in each list. This information may be notified to the terminal device, for example, by including it in the SIB21, or by including it in the MCCH information.

[0198] If a terminal device determines that the same target area associated with a service of a certain MBS session in a first cell is also associated with an adjacent cell, and the terminal device is located within the target area associated with the MBS session (MBS service) that it is receiving or is interested in receiving in the first cell, it can determine that the terminal device is also located within the target area in the adjacent cell. For example, based on this determination, the terminal device can decide whether or not to perform cell reselection with increased priority of the carrier frequency of the adjacent cell without receiving the target area information transmitted in the adjacent cell. In addition to or instead of this, the terminal device may decide whether or not to receive the target area information transmitted in the adjacent cell, based on the determination of whether the same target area associated with a service of a certain MBS session in a first cell is also associated with an adjacent cell.

[0199] Furthermore, the MBS broadcast configuration message may independently include two lists as part of the MBS session information list: one consisting only of entries that do not have a target area associated with them, and another consisting of entries that have zero or more target areas associated with them. This allows conventional terminal devices that do not support the operation of this embodiment to receive MBS broadcast services that are not limited to a target area by obtaining only the list consisting only of entries that do not have a target area associated with them, while terminal devices that support the operation of this embodiment can obtain both lists to receive both MBS broadcast services that are not limited to a target area and MBS broadcast services that are limited to a target area.

[0200] The mechanism described above allows base station equipment to provide MBS broadcast services via PTM distribution to terminal equipment in specific areas within a cell without using PTP distribution. Furthermore, terminal equipment can receive MBS broadcast services in appropriate areas within the cell.

[0201] In the above description, the processing unit 502 of UE122 may be a processing unit that processes the RRC layer.

[0202] Each of the aforementioned target area information may indicate a target area of ​​a part or all of the cell, or it may indicate an area independent of the cell. In addition or alternatively, each of the aforementioned target area information may be information common to one or more cells. In addition or alternatively, each of the aforementioned area information may indicate an area based on its relative position to the cell's reference location. In addition or alternatively, each of the aforementioned area information may indicate an area based on an absolute position independent of the cell.

[0203] Furthermore, in each embodiment, the information indicating that an adjacent cell contains the same area as the target area linked in the first cell may also be information indicating that an adjacent cell contains an area that includes the target area linked in the first cell.

[0204] Furthermore, in each embodiment, "the target area to which the MBS session service is associated," "the target area to which the MBS session is associated," and "the target area to which the MBS service is associated" may be interchangeable.

[0205] Furthermore, in each embodiment, the first information and / or the second information may be notified to the terminal device by any or any combination of RRC messages, RRC signaling, messages from higher layers of the RRC layer, and MAC control elements.

[0206] Furthermore, the aforementioned target area (or intended area) may also be called a target service area (or intended service area), or may have another name.

[0207] Furthermore, in each embodiment, the determination of whether a terminal device is located within the target area may be made based on a known method. For example, a known method may be positioning using radio waves from a communication system (for example, OTDOA (Observed Time Difference Of Arrival)), positioning using GNSS (Global Navigation Satellite System), positioning using Bluetooth®, a positioning method using another mechanism, or a combination of the aforementioned positioning methods.

[0208] Furthermore, the processes described in each embodiment may be applied to non-terrestrial networks, or they may be applied to terrestrial networks in addition to non-terrestrial networks.

[0209] Furthermore, in the above explanation, expressions such as "link to," "corresponding to," and "associate with" can be used interchangeably.

[0210] Furthermore, in the above explanation, expressions such as "confirmed as A," "A is set," and "A is included" can be used interchangeably.

[0211] In the above explanation, "transition from X to Y" can be rephrased as "become X to Y". Also, in the above explanation, "cause a transition" can be rephrased as "determine a transition".

[0212] Furthermore, in the examples of processes or process flows described above, some or all of the steps may not be executed. Also, in the examples of processes or process flows described above, the order of the steps may differ. Also, in the examples of processes or process flows described above, some or all of the processes within each step may not be executed.

[0213] Furthermore, in the above explanation, if it states "C may be D" and "C may be E," it may also include the statement "D may be E." Also, in the above explanation, if it states "F may be G" and "G may be H," it may also include the statement "F may be H."

[0214] The program running in the device according to this embodiment may be a program that controls the Central Processing Unit (CPU), etc., to make the computer function in order to realize the functions of this embodiment. The program or the information handled by the program is temporarily loaded into volatile memory such as Random Access Memory (RAM) during processing, or stored in non-volatile memory such as flash memory or a Hard Disk Drive (HDD), and read, modified, and written by the CPU as needed.

[0215] Furthermore, some parts of the apparatus in the above-described embodiment may be implemented using a computer. In that case, the program for implementing this control function may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be loaded into a computer system and executed. The term "computer system" here refers to a computer system built into the apparatus, and includes hardware such as an operating system and peripheral devices. The "computer-readable recording medium" may be any of the following: a semiconductor recording medium, an optical recording medium, a magnetic recording medium, etc.

[0216] Furthermore, "computer-readable recording media" may include those that dynamically hold programs for a short period of time, such as communication lines used when transmitting programs via networks such as the Internet or communication lines such as telephone lines, as well as those that hold programs for a certain period of time, such as volatile memory inside computer systems that act as servers or clients in such cases. In addition, the above-mentioned programs may be for the purpose of realizing some of the functions described above, and may also be programs that can realize the above-mentioned functions in combination with programs already recorded in the computer system.

[0217] Furthermore, each functional block or feature of the apparatus used in the embodiments described above may be implemented or executed by an electrical circuit, typically an integrated circuit or a combination of integrated circuits. Electrical circuits designed to perform the functions described herein may include general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gates or transistor logic, discrete hardware components, or combinations thereof. The general-purpose processor may be a microprocessor, or alternatively, the processor may be a conventional processor, controller, microcontroller, or state machine. The general-purpose processor, or each of the aforementioned circuits, may consist of digital or analog circuits. Also, if advances in semiconductor technology lead to the emergence of integrated circuit technologies that replace current integrated circuits, it may be possible to use integrated circuits based on such technologies.

[0218] It should be noted that this embodiment is not limited to the embodiments described above. Although the embodiments describe an example of a device, this embodiment is not limited to this and can be applied to stationary or non-movable electronic devices installed indoors or outdoors, such as terminal devices or communication devices for AV equipment, kitchen equipment, cleaning and washing machines, air conditioning equipment, office equipment, vending machines, and other household appliances.

[0219] Although this embodiment has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design changes and the like that do not depart from the gist of this embodiment are also included. Furthermore, this embodiment can be modified in various ways within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of this embodiment. In addition, configurations in which elements described in the above embodiment that produce similar effects are substituted for each other are also included.

[0220] One aspect of the present invention can be used, for example, in communication systems, communication equipment (e.g., mobile phone devices, base station devices, wireless LAN devices, or sensor devices), integrated circuits (e.g., communication chips), or programs.

[0221] 100 E-UTRA 102 eNB 104 EPC 106 NR 108 gNB 110 5GC 112, 114, 116, 118, 120, 124 Interface 122 UE 200, 300 PHY 202, 302 MAC 204, 304 RLC 206, 306 PDCP 208, 308 RRC 310 SDAP 210, 312 NAS 500, 604 Receiver 502, 602 Processing Unit 504, 600 Transmitter

Claims

1. A terminal device comprising: a receiving unit that receives first information transmitted from a base station device in a first cell; and a processing unit that determines, based on the received first information, whether a target area associated with a multicast broadcast service (MBS) session provided in a certain adjacent cell is the same as a target area associated in the first cell, wherein the first information includes information of adjacent cells that are similarly provided for each of the one or more MBS sessions provided in the first cell, each of the one or more MBS sessions provided in the first cell is associated with one or more target areas, and the adjacent cell information includes information indicating, for each adjacent cell, whether a target area associated with a certain MBS session provided in the adjacent cell is the same as a target area associated in the first cell.

2. A method applicable to a terminal device, comprising the steps of: receiving first information transmitted from a base station device in a first cell; and determining, based on the received first information, whether a target area associated with a multicast broadcast service (MBS) session provided in a certain adjacent cell is the same as a target area associated in the first cell, wherein the first information includes information of adjacent cells provided in the same manner for each of the one or more MBS sessions provided in the first cell; each of the one or more MBS sessions provided in the first cell is associated with one or more target areas; and the adjacent cell information includes information indicating, for each adjacent cell, whether a target area associated with a certain MBS session provided in the adjacent cell is the same as a target area associated in the first cell.

3. An integrated circuit implemented in a terminal device, which causes the terminal device to perform the following functions: receiving first information transmitted from a base station device in a first cell; and determining, based on the received first information, whether a target area associated with a multicast broadcast service (MBS) session provided in a certain adjacent cell is the same as a target area associated in the first cell, wherein the first information includes information of adjacent cells provided in the same way for each of the one or more MBS sessions provided in the first cell; each of the one or more MBS sessions provided in the first cell is associated with one or more target areas; and the adjacent cell information includes information indicating, for each adjacent cell, whether a target area associated with a certain MBS session provided in the adjacent cell is the same as a target area associated in the first cell.

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