Terminal device, method, and integrated circuit

The terminal device and integrated circuit efficiently determine the MBS frequency of interest using FSAI-based system information, overcoming the challenge of larger satellite cells in non-terrestrial networks to provide effective multicast broadcast services.

WO2026034020A1PCT designated stage Publication Date: 2026-02-12SHARP KK
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Patent Information

Application Number
PCT/JP2025/022057
Authority / Receiving Office
WO · WO
Patent Type
Applications
Current Assignee / Owner
Priority Date
2024-08-07
Filing Date
2025-06-19
Publication Date
2026-02-12

AI Technical Summary

Technical Problem

The challenge of providing efficient multicast broadcast services in non-terrestrial networks, where satellite cells are larger than terrestrial cells, making it difficult to target specific areas such as countries or states.

Method used

A terminal device and integrated circuit that determine the MBS frequency of interest based on system information indicating a range area linked to a Frequency Selection Area Identifier (FSAI), allowing efficient communication control processing for multicast broadcast services.

Benefits of technology

Enables efficient communication control for multicast broadcast services by determining the MBS frequency of interest within the specified range area, addressing the challenge of larger satellite cells in non-terrestrial networks.

✦ Generated by Eureka AI based on patent content.

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Abstract

This terminal device comprises: a reception unit for receiving, from a base station device, information that associates a specific carrier frequency with one or more frequency selection area identifiers, target area information that indicates one or more target areas, and information that associates the one or more target areas with one of the frequency selection area identifiers; and a processing unit. For each of the one or more frequency selection area identifiers associated with a specific MBS session, the processing unit: determines whether the terminal device is located in any of the one or more target areas associated with the frequency selection area identifier; and, on the basis of the determination, determines whether or not the carrier frequency associated with the frequency selection area identifier is an MBS frequency of interest.
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Description

Terminal device, method, and integrated circuit

[0001] This application claims priority from Japanese Patent Application No. 2024-131139, filed on August 7, 2024, the contents of which are incorporated herein by reference.

[0002] The 3rd Generation Partnership Project (3GPP, registered trademark), a standardization project for cellular mobile communication systems, is conducting technical studies and formulating standards for cellular mobile communication systems, including radio access, core networks, services, etc.

[0003] For example, 3GPP has begun technical studies and standardization of E-UTRA (Evolved Universal Terrestrial Radio Access) as a radio access technology (RAT) for 3.9G and 4G cellular mobile communication systems. 3GPP is currently conducting technical studies and standardization of E-UTRA extension technologies. E-UTRA is also called Long Term Evolution (LTE: registered trademark), and the extension technologies are sometimes called LTE-Advanced (LTE-A) and LTE-Advanced Pro (LTE-A Pro).

[0004] Additionally, 3GPP has begun technical studies and standardization of NR (New Radio, or NR Radio access) as a radio access technology (RAT) for 5th Generation (5G) cellular mobile communication systems. 3GPP is currently conducting technical studies and standardization of NR extension technologies.

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

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

[0008] In order to achieve the above object, one aspect of the present invention takes the following measures.

[0009] (1) That is, one aspect of the present invention is a terminal device comprising: a receiving unit that receives first system information transmitted from a base station device; a processing unit; and a transmitting unit; wherein the first system information includes information indicating a first range area, the first range area being linked to a Frequency Selection Area Identifier (FSAI) indicating a second range area, the FSAI being associated with an MBS session distributed to the second range area, and the FSAI being associated with a first frequency; the processing unit, based on determining that the terminal device is located within the first range area linked to a certain FSAI (first FSAI), determines that the first frequency associated with the first FSAI is an MBS frequency of interest; the transmitting unit transmits information indicating the MBS frequency of interest to the base station device; and the first FSAI is an FSAI linked to an MBS session that the terminal device is receiving through a broadcast MRB or an MBS session that the terminal device is interested in receiving through a broadcast MRB.

[0010] (2) Another aspect of the present invention is a method applied to a terminal device, the method comprising the steps of receiving first system information transmitted from a base station device, the first system information including information indicating a first range area, the first range area being linked to a Frequency Selection Area Identifier (FSAI) indicating a second range area, the FSAI being associated with an MBS session distributed to the second range area, and the FSAI being associated with a first frequency, the method comprising the steps of: receiving first system information transmitted from a base station device; determining that the terminal device is located within the first range area linked to a certain FSAI (first FSAI), and determining that the first frequency associated with the first FSAI is an MBS frequency of interest; and transmitting information indicating the MBS frequency of interest to the base station device.

[0011] (3) Another aspect of the present invention is an integrated circuit implemented in a terminal device, wherein first system information includes information indicating a first range of areas, the first range of areas being linked to Frequency Selection Area Identities (FSAIs) indicating a second range of areas, the FSAIs being associated with an MBS session distributed to the second range of areas, and the FSAIs being associated with a first frequency, and the integrated circuit causes the terminal device to perform the following functions: receiving first system information transmitted from a base station device; determining that the terminal device is located within the first range of areas linked to a certain FSAI (first FSAI), and determining that the first frequency associated with the first FSAI is an MBS frequency of interest; and transmitting information indicating the MBS frequency of interest to the base station device.

[0012] These comprehensive or specific aspects may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium.

[0013] According to one aspect of the present invention, a terminal device, a method, and an integrated circuit can realize efficient communication control processing.

[0014] 1 is a schematic diagram of a communication system according to the present embodiment. 2 is a diagram of an example of an E-UTRA protocol configuration according to the present embodiment. 3 is a diagram of an example of an NR protocol configuration according to the present embodiment. 4 is a diagram showing an example of a procedure flow for various settings in RRC according to the present embodiment. 5 is a block diagram showing the configuration of a terminal device according to the present embodiment. 6 is a block diagram showing the configuration of a base station device according to the present embodiment. 7 is an example of processing according to the present embodiment. 8 is an example of an ASN.1 description of target area information according to the present embodiment. 9 is an example of an ASN.1 description of a system information block according to the present embodiment.

[0015] Hereinafter, this embodiment will 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 (Radio Access Technologies: RATs). LTE connectable to NR via Multi-Radio Dual Connectivity (MR-DC) may be distinguished from conventional LTE. LTE using 5GC for the core network (Core Network: CN) may be distinguished from conventional LTE using EPC for the 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. While the following description uses terms related to LTE and NR, this embodiment may also be applied to technologies using other terms and / or other radio access technologies. In this embodiment, the terms E-UTRA and LTE may be interchangeable.

[0017] In this embodiment, the names of each node and entity, and the processes in each node and entity when the radio access technology is E-UTRA or NR will be described, but this embodiment may be applied to other radio access technologies. The names of each node and entity, and the names of parameters and messages in this embodiment may be different from those described in this embodiment.

[0018] Fig. 1 is a schematic diagram of a communication system according to this embodiment. Note that the functions of each node, radio access technology, core network, interface, etc. described using Fig. 1 are only some of the functions closely related to this embodiment, and the system may have other functions.

[0019] E-UTRA 100 may be a radio access technology. E-UTRA 100 may also be an air interface between UE 122 and eNB 102. The air interface between UE 122 and eNB 102 may be referred to as a Uu interface. eNB (E-UTRAN Node B) 102 may be a base station device of E-UTRA 100. eNB 102 may have the E-UTRA protocol described below. The E-UTRA protocol may be configured from an E-UTRA User Plane (UP) protocol described below and an E-UTRA Control Plane (CP) protocol described below. eNB 102 may terminate the E-UTRA User Plane (UP) protocol and the E-UTRA Control Plane (CP) protocol for UE 122. A radio access network configured by eNBs may be referred to as E-UTRAN.

[0020] The EPC (Evolved Packet Core) 104 may be a core network. The interface 112 is an interface between the eNB 102 and the EPC 104 and may be referred to as an S1 interface. The interface 112 may include 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 the interface 112 may terminate at a Mobility Management Entity (MME: not shown) in the EPC 104. The user plane interface of the interface 112 may terminate at a Serving Gateway (S-GW: not shown) in the EPC 104. The control plane interface of the interface 112 may be referred to as an S1-MME interface. The user plane interface of the interface 112 may be referred to as an S1-U interface.

[0021] Note that one or more eNBs 102 may be connected to the EPC 104 via an interface 112. An interface (not shown) may exist between the multiple eNBs 102 connected to the EPC 104. The interface between the multiple eNBs 102 connected to the EPC 104 may be referred to as an X2 interface.

[0022] The NR 106 may be a radio access technology. The NR 106 may also be an air interface between the UE 122 and the gNB 108. The air interface between the UE 122 and the gNB 108 may be referred to as a Uu interface. The gNB (g Node B) 108 may be a base station device of the NR 106. The gNB 108 may have the NR protocol described below. The NR protocol may be composed of the NR user plane (User Plane: UP) protocol described below and the NR control plane (Control Plane: CP) protocol described below. The gNB 108 may terminate the NR user plane (User Plane: UP) protocol and the NR control plane (Control Plane: CP) protocol for the UE 122.

[0023] 5GC110 may be a core network. Interface 116 is an interface between gNB108 and 5GC110 and may be referred to as an 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 terminate in an Access and Mobility Management Function (AMF: not shown) in 5GC110. The user plane interface of interface 116 may terminate in a User Plane Function (UPF: not shown) in 5GC110. The control plane interface of interface 116 may be referred to as an NG-C interface. The user plane interface of interface 116 may be referred to as an NG-U interface.

[0024] Note that one or more gNBs 108 may be connected to 5GC 110 via interface 116. An interface (not shown) may exist between multiple gNBs 108 connected to 5GC 110. The interface between multiple gNBs 108 connected to 5GC 110 may be referred to as an Xn interface.

[0025] The eNB 102 may have the capability to connect to the 5GC 110. The eNB 102 with the capability to connect to the 5GC 110 may be referred to as an ng-eNB. The interface 114 is an interface between the eNB 102 and the 5GC 110 and may be referred to as an NG interface. The 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 the interface 114 may terminate in the AMF within the 5GC 110. The user plane interface of the interface 114 may terminate in the UPF within the 5GC 110. The control plane interface of the interface 114 may be referred to as an NG-C interface. The user plane interface of the interface 114 may be referred to as an NG-U interface. A radio access network consisting of an ng-eNB or a gNB may be referred to as an NG-RAN. The NG-RAN, E-UTRAN, etc. may simply be referred to as a network. Furthermore, the network may include an eNB, ng-eNB, gNB, etc.

[0026] Note that one or more eNBs 102 may be connected to 5GC 110 via interface 114. An interface may exist between multiple eNBs 102 connected to 5GC 110 (not shown). The interface between multiple eNBs 102 connected to 5GC 110 may be called an Xn interface. Furthermore, an eNB 102 connected to 5GC 110 and a gNB 108 connected to 5GC 110 may be connected by interface 120. The interface 120 between an eNB 102 connected to 5GC 110 and a gNB 108 connected to 5GC 110 may be called an Xn interface.

[0027] The gNB 108 may have the function of connecting to the EPC 104. A gNB 108 with the function of connecting to the EPC 104 may be referred to as an en-gNB. Interface 118 is an interface between the gNB 108 and the EPC 104 and may be referred to as an S1 interface. A user plane interface through which user data passes may exist in interface 118. The user plane interface of interface 118 may terminate in an S-GW (not shown) in the EPC 104. The user plane interface of interface 118 may be referred to as an S1-U interface. Furthermore, the eNB 102 connecting to the EPC 104 and the gNB 108 connecting to the EPC 104 may be connected by interface 120. The interface 120 between the eNB 102 connecting to the EPC 104 and the gNB 108 connecting to the EPC 104 may be referred to as an X2 interface.

[0028] The interface 124 is an interface between the EPC 104 and the 5GC 110, and may be an interface that passes only the CP, only the UP, or both the CP and the UP. Also, some or all of the interfaces such as the interface 114, the interface 116, the interface 118, the interface 120, and the interface 124 may not exist depending on the communication system provided by the communication carrier or the like.

[0029] The UE 122 may be a terminal device capable of receiving system information and paging messages transmitted from the eNB 102 and / or the gNB 108. The UE 122 may also be a terminal device capable of wireless connection with the eNB 102 and / or the gNB 108. The UE 122 may also be a terminal device capable of simultaneously establishing a wireless connection with the eNB 102 and a wireless connection with the gNB 108. The UE 122 may have an E-UTRA protocol and / or an NR protocol. The wireless connection may be a Radio Resource Control (RRC) connection.

[0030] Furthermore, the UE 122 may be a terminal device capable of connecting to the EPC 104 and / or the 5GC 110 via the eNB 102 and / or the gNB 108. When the core network to which the eNB 102 and / or the gNB 108, with which the UE 122 communicates, is connected is the EPC 104, each Data Radio Bearer (DRB) (described later) established between the UE 122 and the eNB 102 and / or the gNB 108 may be further uniquely associated with each EPS (Evolved Packet System) bearer passing through the EPC 104. 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 the eNB102 and / or gNB108 with which the UE122 communicates is connected is the 5GC110, each DRB established between the UE122 and the eNB102 and / or gNB108 may be further linked to one of the PDU (Packet Data Unit) sessions established within the 5GC110. One or more QoS flows may exist in each PDU session. Each DRB may be mapped to one or more QoS flows, or may not be mapped to any QoS flow. Each PDU session may be identified by a PDU session identifier (Identity, or ID). Furthermore, each QoS flow may be identified by a QoS flow identifier (Identity, or ID). Furthermore, the same QoS may be guaranteed for data such as IP packets and Ethernet frames passing through the same QoS flow.

[0032] There may be no PDU sessions and / or QoS flows in the EPC 104, and no EPS bearers in the 5GC 110. When the UE 122 is connected to the EPC 104, the UE 122 has information about the EPS bearers, but may not have information about the PDU sessions and / or QoS flows. When the UE 122 is connected to the 5GC 110, the UE 122 has information about the PDU sessions and / or QoS flows, but may not have information about the EPS bearers.

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

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

[0035] 2A is a diagram of an E-UTRA user plane (UP) protocol stack. As shown in FIG. 2A, the E-UTRA UP protocol may be a protocol between the UE 122 and the eNB 102. That is, the E-UTRA UP protocol may be a protocol that terminates at the eNB 102 on the network side. As shown in FIG. 2A, the E-UTRA user plane protocol stack may be composed of a PHY (Physical layer) 200, which is a radio physical layer, a MAC (Medium Access Control) 202, which is a medium access control layer, a RLC (Radio Link Control) 204, which is a radio link control layer, and a PDCP (Packet Data Convergence Protocol) 206, which is a packet data convergence protocol layer.

[0036] FIG. 3A is a diagram of an NR user plane (UP) protocol stack. As shown in FIG. 3A, the NRUP protocol may be a protocol between the UE 122 and the gNB 108. That is, the NR UP protocol may be a protocol that terminates at the gNB 108 on the network side. As shown in FIG. 3A, the NR user plane protocol stack may be composed of a radio physical layer, PHY 300, a medium access control layer, MAC 302, a radio link control layer, RLC 304, a packet data convergence protocol layer, PDCP 306, and a service data adaptation protocol layer, SDAP (Service Data Adaptation Protocol) 310.

[0037] 2(B) is a diagram of the E-UTRA control plane (CP) protocol configuration. As shown in FIG. 2(B), in the E-UTRA CP protocol, RRC (Radio Resource Control) 208, which is a radio resource control layer, may be a protocol between the UE 122 and the eNB 102. That is, RRC 208 may be a protocol that terminates at the eNB 102 on the network side. Also, in the E-UTRA CP protocol, NAS (Non Access Stratum) 210, which is a non-AS (Access Stratum) layer, may be a protocol between the UE 122 and the MME. That is, NAS 210 may be a protocol that terminates at the MME on the network side.

[0038] 3(B) is a diagram of the NR control plane (CP) protocol configuration. As shown in FIG. 3(B), in the NR CP protocol, the radio resource control layer RRC 308 may be a protocol between the UE 122 and the gNB 108. That is, the RRC 308 may be a protocol that terminates at the gNB 108 on the network side. Also, in the NR CP protocol, the non-AS layer NAS 312 may be a protocol between the UE 122 and the AMF. That is, the NAS 312 may be a protocol that terminates at the AMF on the network side.

[0039] The AS (Access Stratum) layer may be a layer that terminates between the UE 122 and the eNB 102 and / or the gNB 108. That is, the AS layer may be a layer that includes some or all of the PHY 200, the MAC 202, the RLC 204, the PDCP 206, and the RRC 208, and / or a layer that includes some or all of the PHY 300, the MAC 302, the RLC 304, the PDCP 306, the SDAP 310, and the RRC 308.

[0040] In the present embodiment, the E-UTRA protocol and the NR protocol may not be distinguished from each other, 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 respectively refer to 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, 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. The SDAP (SDAP layer) may also be the SDAP (SDAP layer) of the NR protocol.

[0041] In this embodiment, when distinguishing between E-UTRA protocols and NR protocols, the PHY 200, MAC 202, RLC 204, PDCP 206, and RRC 208 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. The PHY 200, MAC 202, RLC 204, PDCP 206, and RRC 208 may also 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. Furthermore, when distinguishing between E-UTRA protocols and NR protocols, PHY300, MAC302, RLC304, PDCP306, and RRC308 may be referred to as NR PHY, NR MAC, NR RLC, NR RLC, and NR RRC, respectively. Furthermore, PHY300, MAC302, RLC304, PDCP306, and RRC308 may be referred to 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. An entity having some or all of the functions of the MAC layer may be referred to as a MAC entity. An entity having some or all of the functions of the RLC layer may be referred to as an RLC entity. An entity having some or all of the functions of the PDCP layer may be referred to as a PDCP entity. An entity having some or all of the functions of the SDAP layer may be referred to as an SDAP entity. An entity having some or all of the functions of the RRC layer may be referred to as an RRC entity. The MAC entity, RLC entity, PDCP entity, SDAP entity, and RRC entity may be referred to as MAC, RLC, PDCP, SDAP, and RRC, respectively.

[0043] Note that data provided from MAC, RLC, PDCP, and SDAP to lower layers, and / or 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. Data provided from higher layers to MAC, RLC, PDCP, and SDAP, and / or 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. A segmented RLC SDU may be referred to as an RLC SDU segment.

[0044] Here, the base station apparatus and the terminal apparatus exchange (transmit and receive) signals in a higher layer. The higher layer may be referred to as an upper layer, and the terms may be interchangeable. For example, the base station apparatus and the terminal apparatus may transmit and receive RRC messages (also referred to as RRC signaling) in a Radio Resource Control (RRC) layer. The base station apparatus and the terminal apparatus may also transmit and receive MAC control elements in a Medium Access Control (MAC) layer. The RRC layer of the terminal apparatus acquires system information broadcast from the base station apparatus. Here, the RRC messages, system information, and / or MAC control elements are also referred to as higher layer signals (higher layer signaling) or higher layer parameters (higher layer parameters). Each of the parameters included in the higher layer signals received by the terminal apparatus may be referred to as a higher layer parameter. For example, in PHY layer processing, an upper layer means a layer higher than the PHY layer, and therefore may mean one or more of a MAC layer, an RRC layer, an RLC layer, a PDCP layer, an NAS (Non Access Stratum) layer, etc. For example, in MAC layer processing, an upper layer may mean one or more of an RRC layer, an RLC layer, a PDCP layer, an NAS layer, etc.

[0045] Hereinafter, the meaning of "A is given (provided) by an upper layer" or "A is given (provided) by an upper layer" may mean that an upper layer (mainly an RRC layer, a MAC layer, etc.) of a terminal device receives A from a base station device, and the received A is given (provided) from the upper layer of the terminal device to a lower layer (mainly a MAC layer or a physical layer) of the terminal device. For example, in a terminal device, "an upper layer parameter is provided" may mean that an upper layer signal is received from a base station device, and the upper layer parameter included in the received upper layer signal is provided from the upper layer of the terminal device to the lower layer of the terminal device. Setting an upper layer parameter in a terminal device may mean that the upper layer parameter is given (provided) to the terminal device. For example, setting an upper layer parameter in a terminal device may mean that the terminal device receives an upper layer signal from a base station device and sets the received upper layer parameter in the upper layer. However, setting an upper layer parameter in a terminal device may also include setting a default parameter that is given in advance to the upper layer of the terminal device. When describing 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" may be used. In the terminal device, "submitting a message to a lower layer" from the RRC entity may mean submitting a message to the PDCP layer. In the terminal device, "submitting a message to a lower layer" from the RRC layer may mean submitting a message to a 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, the lower layer may mean one or more of 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 to receive 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 to transmit data to the PHY of the base station device via an uplink (UL) physical channel. The PHY may be connected to a higher MAC via a transport channel. The PHY may pass data to the MAC via the transport channel. The PHY may also 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 channels will be described. The physical channels used for wireless communication between a terminal device and a 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 broadcast system information required by a terminal device.

[0050] In addition, in NR, the PBCH may be used to broadcast a time index (SSB-Index) within a synchronization signal block (SSB) period.

[0051] The PDCCH may be used to transmit (or carry) downlink control information (DCI) in downlink wireless communication (wireless communication from a base station device to a terminal device). Here, one or more DCIs (which may also be referred to as DCI formats) may be defined for transmitting the downlink control information. That is, a field for the downlink control information may be defined as DCI and mapped to information bits. The PDCCH may be transmitted in PDCCH candidates. The terminal device may monitor a set of PDCCH candidates in a serving cell. Monitoring the set of PDCCH candidates may mean attempting to decode the PDCCH according to a certain DCI format. Furthermore, the terminal device may monitor the PDCCH candidates at configured monitoring occasions in one or more configured control resource sets (CORESETs) configured by search space configuration. The DCI format may be used for scheduling the PUSCH in the serving cell. The PUSCH may be used for transmitting user data, transmitting RRC messages (described later), and the like.

[0052] The PUCCH may be used to transmit uplink control information (UCI) in uplink wireless communication (wireless communication from a terminal device to a base station device). Here, the uplink control information may include channel state information (CSI) used to indicate the state of a downlink channel. The uplink control information may also include a scheduling request (SR) used to request an uplink shared channel (UL-SCH) resource. The uplink control information may also include a hybrid automatic repeat reQuest ACKnowledgement (HARQ-ACK).

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

[0054] The PUSCH may be used to transmit uplink data from the MAC layer (UL-SCH: Uplink Shared CHannel) or HARQ-ACK and / or CSI together with uplink data. The PUSCH may also be used to transmit only CSI, or only HARQ-ACK and CSI. That is, the PUSCH may be used to transmit only UCI. The PDSCH or PUSCH may also be used to transmit RRC messages and MAC CE (described later). Here, in the PDSCH, an RRC message transmitted from a base station apparatus may be signaling common to multiple terminal apparatuses within a cell. The RRC message transmitted from a base station apparatus may also be signaling dedicated to a certain terminal apparatus. That is, terminal apparatus-specific information may be transmitted using signaling dedicated to a certain terminal apparatus. The PUSCH may also be used to transmit UE capabilities in the uplink.

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

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

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

[0058] The 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 CCCH (Common Control Channel) may be a logical channel for transmitting control information between a terminal device and a base station device. The CCCH may be used when the terminal device does not have an RRC connection. The 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 bidirectionally, point-to-point, between a terminal device and a base station device. The dedicated control information may be control information dedicated to each terminal device. The DCCH may be used when the terminal device has an RRC connection.

[0062] A DTCH (Dedicated Traffic Channel) 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 dedicated to each terminal device. A DTCH may exist in both uplink and downlink.

[0063] The MCCH (Multicast Control Channel) may be a point-to-multipoint downlink channel for transmitting MBMS control information for one or more MTCHs from a base station device to a terminal device. The MCCH may be a multicast and / or broadcast logical channel. The MCCH may carry the MBS Broadcast Configuration provided in the cell where the MCCH is transmitted.

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

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

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

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

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

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

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

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

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

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

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

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

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

[0077] An example of the RLC function will be described. The RLC may also be called an RLC sublayer. The E-UTRA RLC may have the function of segmenting and / or concatenating data provided by the PDCP in the upper layer and providing it to the lower layer. The E-UTRA RLC may have the function of reassembling and reordering data provided by the lower layer and providing it to the upper layer. The NR RLC may have the function of adding a sequence number independent of the sequence number added by PDCP to data provided by the PDCP in the upper layer. The NR RLC may also have the function of segmenting data provided by PDCP and providing it to the lower layer. The NR RLC may also have the function of reassembling data provided by the lower layer and providing it to the upper layer. The RLC may also have the function of data retransmission and / or retransmission request (Automatic Repeat reQuest: ARQ). RLC may also have the function of performing error correction using ARQ. The control information sent from the receiving side of RLC to the transmitting side to indicate data that needs to be retransmitted in order to perform ARQ may be called a status report. The status report transmission instruction sent from the transmitting side of RLC to the receiving side may be called a poll. RLC may also have the function of detecting data duplication. RLC may also have the function of discarding 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 segmented, and an RLC header does not need to be added. The TM RLC entity is a unidirectional entity and may be configured as a transmitting TM RLC entity or a receiving TM RLC entity.In UM, the RLC entity performs functions such as segmenting and / or concatenating data received from a higher layer and adding an RLC header, but does not require data retransmission control. A UM RLC entity may be a unidirectional or bidirectional entity. If the UM RLC entity is unidirectional, it may be configured as a transmitting UM RLC entity or a receiving UM RLC entity. If the UM RLC entity is bidirectional, it may be configured as a UM RLC entity consisting of a transmitting side and a receiving side. In AM, the RLC entity may perform functions such as segmenting and / or concatenating data received from a higher layer, adding an RLC header, and controlling data retransmission. An AM RLC entity is a bidirectional entity and may be configured as an AM RLC consisting of a transmitting side and a receiving side. Note that data provided to a lower layer in TM and / or data provided from a lower layer may be referred to as a TMD PDU. Data provided to a lower layer in UM and / or data provided from a lower layer may be referred to as a UMD PDU. Furthermore, data provided to or from a lower layer in AM may be referred to as an AMD PDU. The RLC PDU format used in E-UTRA RLC may differ from the RLC PDU format used in NR RLC. RLC PDUs may include data RLC PDUs and control RLC PDUs. Data RLC PDUs may be referred to as RLC DATA PDUs (RLC Data PDUs). Control RLC PDUs may be referred to as RLC CONTROL PDUs (RLC Control PDUs).

[0078] An example of PDCP functions will be described. PDCP may be called a 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 wireless interfaces. The protocol used for IP packet header compression / decompression may be called the ROHC (Robust Header Compression) protocol. The protocol used for Ethernet frame header compression / decompression may be called the EHC (Ethernet (registered trademark) Header Compression) protocol. PDCP may also have a data encryption / decryption function. PDCP may also have a data integrity protection / verification function. PDCP may also have a reordering 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 duplicately received data. The 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 may differ from that used in NR PDCP. PDCP PDUs may include 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] An example of the SDAP function will be described. The SDAP is a service data adaptation protocol layer. The SDAP may have the function of mapping the downlink QoS flow sent from the 5GC 110 to the terminal device via the base station device to a data radio bearer (DRB), and / or the function of mapping the uplink QoS flow sent from the terminal device to the 5GC 110 via the base station device to a DRB. The SDAP may also have the function of storing mapping rule information. The SDAP may also have the function of marking a QoS flow identifier (QoS Flow ID: QFI). Note that SDAP PDUs may include data SDAP PDUs and control SDAP PDUs. The data SDAP PDU may be called an SDAP DATA PDU (SDAP Data PDU). The control SDAP PDU may be called an SDAP CONTROL PDU (SDAP Control PDU). Note that one SDAP entity in the terminal device may exist for each PDU session.

[0080] An example of the functions of the RRC will be described. The RRC may have a broadcast function. The RRC may have a paging function from the EPC 104 and / or the 5GC 110. The RRC may have a paging function from the eNB 102 connected to the gNB 108 or the 5GC 110. The RRC may also have an RRC connection management function. The RRC may also have a radio bearer control function. The RRC may also have a cell group control function. The RRC may also have a mobility control function. The RRC may also have terminal device measurement reporting and terminal device measurement reporting control functions. The RRC may also have a QoS management function. The RRC may also have a radio link failure detection and recovery function. The RRC may use RRC messages to perform broadcasting, paging, RRC connection management, radio bearer control, cell group control, mobility control, terminal device measurement reporting and terminal device measurement reporting control, QoS management, radio link failure detection and recovery, etc. Note that the RRC messages and parameters used in E-UTRA RRC may differ from the RRC messages and parameters used in NR RRC.

[0081] RRC messages may be sent using the BCCH logical channel. Additionally or alternatively, RRC messages may be sent using the PCCH logical channel. Additionally or alternatively, RRC messages may be sent using the CCCH logical channel. Additionally or alternatively, RRC messages may be sent using the DCCH logical channel. Additionally or alternatively, RRC messages may be sent using the MCCH logical channel. RRC messages sent using the DCCH are also referred to as dedicated RRC signaling, or RRC signaling.

[0082] The RRC messages sent using the BCCH may include, for example, a Master Information Block (MIB), various types of System Information Blocks (SIBs), or other RRC messages.The RRC messages sent using the PCCH may include, for example, paging messages or other RRC messages.

[0083] RRC messages transmitted in the uplink (UL) direction using the CCCH may include, for example, an RRC setup request message (RRC Setup Request), an RRC resume request message (RRC Resume Request), an RRC reestablishment request message (RRC Reestablishment Request), an RRC system information request message (RRC System Info Request), etc. Also, for example, an RRC connection request message (RRC Connection Request), an RRC connection resume request message (RRC Connection Resume Request), an RRC connection reestablishment request message (RRC Connection Reestablishment Request), etc. Other RRC messages may also be included.

[0084] The RRC message transmitted in the downlink (DL) direction using the CCCH may include, for example, an RRC connection reject message (RRC Connection Reject), an RRC connection setup message (RRC Connection Setup), an RRC connection reestablishment message (RRC Connection Reestablishment Reject), an RRC connection reestablishment reject message (RRC Connection Reestablishment Reject), etc. Also, for example, an RRC reject message (RRC Reject), an RRC setup message (RRC Setup), etc. Also, other RRC messages may be included.

[0085] The RRC signaling sent in the uplink (UL) direction using the 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, a UE Capability Information message, etc. Also, 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, a UE Capability Information message, etc. Also, other RRC signaling may be included.

[0086] The RRC signaling sent in the downlink (DL) direction using the DCCH may include, for example, an RRC connection reconfiguration message, an RRC connection release message, a security mode command message, a UE capability inquiry message, etc. Also, for example, an RRC reconfiguration message, an RRC resume message, an RRC release message, an RRC reestablishment message, a security mode command message, a UE capability inquiry message, etc. Also, other RRC signaling may be included.

[0087] The RRC messages sent in the downlink (DL) direction using the MCCH may include, for example, an MBS broadcast configuration message (MBSBroadcastConfiguration message) and may also include other RRC signaling.

[0088] An example of the functions of the NAS will be described. The NAS may have an authentication function. The NAS may also have a function for performing mobility management. The NAS may also have a security control function.

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

[0090] Next, state transitions of the UE 122 in LTE and NR will be described. When the UE 122 connected to EPC or 5GC has an established RRC connection, the UE 122 may be in an RRC_CONNECTED state. The state in which the RRC connection is established may include a state in which the UE 122 holds some or all of the UE context described below. The state in which the RRC connection is established may also include a state in which the UE 122 can transmit and / or receive unicast data. The UE 122 may be in an RRC_INACTIVE state when the RRC connection is suspended. The UE 122 may be in the RRC_INACTIVE state when the UE 122 is connected to 5GC and the RRC connection is suspended. When the UE 122 is neither in the RRC_CONNECTED state nor in the RRC_INACTIVE state, the UE 122 may be in an RRC_IDLE state.

[0091] Note that when UE 122 is connected to the EPC, it does not have the RRC_INACTIVE state, but the E-UTRAN may initiate suspension of the RRC connection. When UE 122 is connected to the EPC, when the RRC connection is suspended, UE 122 may transition to the RRC_IDLE state while retaining the UE AS context and an identifier (resumeIdentity) used for resuming. A layer above the RRC layer of UE 122 (e.g., the NAS layer) may initiate resumption of the suspended RRC connection when UE 122 retains the UE AS context, is permitted to resume the RRC connection by E-UTRAN, and UE 122 needs to transition from the RRC_IDLE state to the RRC_CONNECTED state.

[0092] The definition of dormancy may be different for UE 122 connected to EPC 104 and UE 122 connected to 5GC 110. In addition, some or all of the procedures for UE 122 to return from dormancy may be different when UE 122 is connected to EPC (when UE 122 is dormant in RRC_IDLE state) and when UE 122 is connected to 5GC (when UE 122 is dormant in RRC_INACTIVE state).

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

[0094] The UE AS context held by the UE 122 may be information including all or some of the following: a current RRC configuration, a current security context, a PDCP state including a ROHC (Robust Header Compression) state, a C-RNTI (Cell Radio Network Temporary Identifier) ​​used in the source PCell, a cell identifier (cellIdentity), and a physical cell identifier of the source PCell. Note that the UE AS context held by one or all of the eNB 102 and the gNB 108 may include the same information as the UE AS context held by the UE 122, or may include information different from the information included in the UE AS context held by the UE 122.

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

[0096] Next, the serving cell will be described. In a terminal device in an RRC connected state in which CA and / or DC, which will be described later, are not configured, the serving cell may be configured with one primary cell (PCell). In addition, in a terminal device in an RRC connected state in which CA and / or DC, which will be described later, are configured, multiple serving cells may refer to a set of multiple cells (set of cell(s)) configured with one or more special cells (SpCells) and all of one or more secondary cells (SCells). The SpCell may support PUCCH transmission and contention-based random access (CBRA), and the SpCell may be always activated. The 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 connected state. The PCell may also be a cell used in the RRC connection re-establishment procedure in which the terminal device re-establishes the RRC connection. The PCell may also be a cell used in the random access procedure during handover. The PSCell may be a cell used for a random access procedure when adding a secondary node, which will be described later. The SpCell may be a cell used for purposes other than those described above.

[0097] When a group of serving cells configured for a terminal device is composed of an SpCell and one or more SCells, it may be considered that carrier aggregation (CA) is configured for the terminal device. Also, for a terminal device in which CA is configured, a cell providing additional radio resources to the SpCell may refer to an SCell.

[0098] A cell group configured by a base station device for a terminal device will now be described. A cell group may be configured with one SpCell. A cell group may also be configured with one SpCell and one or more SCells. That is, a cell group may be configured with one SpCell and, optionally, one or more SCells. A cell group may also be expressed as a set of cells (set of cell(s)).

[0099] Dual Connectivity (DC) may be a technology for performing data communication using 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, a cell group may be added from the base station device to a terminal device. To perform DC, the first base station device may add a second base station device. The first base station device may be called a master node (MN). A cell group configured by the master node may be called a master cell group (MCG). The second base station device may be called a secondary node (SN). A cell group configured by the secondary node may be called a secondary cell group (SCG). The master node and the secondary node may be configured within the same base station device.

[0100] Furthermore, when DC is not configured, the cell group configured in the terminal device may be called an MCG. Furthermore, when DC is not configured, the SpCell configured in the terminal device may be a PCell. Furthermore, an NR in which DC is not configured may be called an NR standalone (NR SA).

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

[0102] In addition, in a terminal device, one MAC entity may exist for each cell group. For example, when DC or MR-DC is configured in the terminal device, there may be one MAC entity for the MCG and one MAC entity for the SCG. The MAC entity for the MCG in the terminal device may always be established in the terminal device in all states (such as RRC idle state, RRC connected state, and RRC inactive state). The MAC entity for the SCG in the terminal device may be created by the terminal device when an SCG is configured in the terminal device. The MAC entity for each cell group in the terminal device may be configured by the terminal device receiving RRC signaling from a base station device. When the MAC entity is associated with an MCG, the SpCell may refer to the PCell. When the MAC entity is associated with an SCG, the SpCell may refer to the primary SCG cell (PSCell). When the MAC entity is not associated with a cell group, the SpCell may refer to the PCell. The PCell, PSCell, and SCell are serving cells. In the EN-DC and the NGEN-DC, the MAC entity for the MCG may be an E-UTRA MAC entity, and the MAC entity for the SCG may be an NR MAC entity. Also, in the NE-DC, the MAC entity for the MCG may be an NR MAC entity, and the MAC entity for the SCG may be an E-UTRA MAC entity. Also, in the NR-DC, the MAC entities for the MCG and the SCG may both be NR MAC entities. The existence of one MAC entity for each cell group may be rephrased as the existence of one MAC entity for each SpCell. Also, the existence of one MAC entity for each cell group may be rephrased as the existence of one MAC entity for each SpCell.

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

[0104] In FIG. 4, the base station device creates an RRC message (step S400). The base station device may create an RRC message in order to deliver system information (SI) or a paging message. The base station device may also create an RRC message in order to transmit RRC signaling that causes a specific terminal device to perform a process. The process that the specific terminal device is to perform may include, for example, security-related settings, RRC connection reconfiguration, handover to a different RAT, RRC connection suspension, and RRC connection release. The RRC connection reconfiguration process may include, for example, radio bearer control (establishment, modification, release, etc.), cell group control (establishment, addition, modification, release, etc.), measurement configuration, handover, security key update, etc. The base station device may also create an RRC message in order to respond to RRC signaling transmitted from the terminal device. A response to an RRC signaling transmitted from a terminal device may include, for example, a response to an RRC setup request, a response to an RRC reconnection request, a response to an RRC resume request, etc. An RRC message includes information (parameters) for various information notifications and settings. These parameters may be fields of an RRC message and / or information elements, or field values ​​(including information elements). The structure of an RRC message may be described using a description method called ASN.1 (Abstract Syntax Notation One).

[0105] 4, the base station device then transmits the created RRC signaling to the terminal device (step S402). Next, the terminal device performs processing such as setting according to the received RRC signaling if necessary (step S404). After performing the processing, the terminal device may transmit RRC signaling as a response to the base station device (not shown).

[0106] RRC signaling may be used for other purposes, not limited to the above examples.

[0107] In the MR-DC, the RRC on the master node side may be used to transfer RRC signaling for SCG-side configuration (cell group configuration, radio bearer configuration, measurement configuration, etc.) between the terminal device and the UE. For example, in the EN-DC or the NGEN-DC, the E-UTRA RRC signaling transmitted and received between the eNB 102 and the UE 122 may include the NR RRC signaling in the form of a container. In the NE-DC, the E-UTRA RRC signaling transmitted and received between the gNB 108 and the UE 122 may include the E-UTRA RRC signaling in the form of a container. The RRC signaling for the SCG-side configuration may be transmitted and received between the master node and the secondary node.

[0108] Regardless of whether MR-DC is used or not, 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] The system information will be explained.

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

[0111] The MIB may be periodically transmitted from the base station device on the BCH. The MIB may include parameters necessary for acquiring SIB1. SIB1 may be periodically transmitted from the base station device on the DL-SCH. SIB1 may include information regarding the availability and scheduling of other SIBs. For example, SIB1 may include multiple fields, and one of the multiple fields may include system information scheduling information. The system information scheduling information may include information regarding whether one or more SIBs are being broadcast, information regarding the broadcast periodicity, and / or other information.

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

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

[0114] The terminal device may apply the system information acquisition procedure when selecting a cell, reselecting a cell, returning from out-of-coverage to in-coverage, etc. The terminal device may also apply the system information acquisition procedure when it does not have a valid version of the SIB.

[0115] The system information change notification will be explained.

[0116] A change period may be used for the system information change, i.e., updated system information messages (other than some SI messages such as ETWS and CMAS, which will be described later) may be broadcast in the next change period after the system information change instruction is sent.

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

[0118] The terminal device may receive an indication regarding system information changes and / or Public Warning System (PWS) notifications using short messages transmitted on the DCI. To receive short messages for paging occasions, the terminal device may monitor the PDCCH at PDCCH monitoring occasions for paging.

[0119] A terminal device that receives the 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 a specific bit (etwsAndCmasIndication bit) is set among multiple bits that constitute the short message. Note that 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 in SIB1 includes information on SIB6, immediately acquire SIB6. SIB6 may be a system information block that includes an ETWS primary notification. Process (c): If the terminal device is ETWS capable and the system information scheduling information in SIB1 includes information on SIB7, immediately acquire SIB7. SIB7 may be a system information block containing an ETWS secondary notification. Step (d): If the terminal device is CMAS capable and the system information scheduling information of SIB1 contains information on SIB8, it immediately obtains SIB8. SIB8 may be a system information block containing a CMAS notification.

[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 the fact that 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 is a change in an SIB other than SIB6, 7, and 8.

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

[0122] We will explain the MBS service.

[0123] Among MBS services, broadcast services may provide the same service and the same specific content data to all terminal devices (UEs 122) in a geographical area simultaneously. Broadcast services may be delivered to terminal devices using broadcast sessions. Terminal devices may be able to receive broadcast services in the RRC_IDLE, RRC_INACTIVE, and RRC_CONNECTED states.

[0124] Among MBS services, a multicast service may simultaneously provide the same service and the same specific content data to one or more specific terminal devices (also referred to as a UE set). The multicast service may be distributed to terminal devices using a multicast session. Terminal devices can receive the multicast service using mechanisms such as Point to Point (PTP) distribution and / or Point to Multipoint (PTM) distribution. HARQ feedback / retransmission can be applied to both PTP and PTM transmission.

[0125] For MBS delivery, some or all of the following logical channels may be used: MTCH: PTM downlink channel for transmitting MBS data of a multicast or broadcast session from the network to the terminal device DTCH: PTP channel defined for transmitting MBS data of a multicast session from the network to the terminal device MCCH: PTM downlink channel used for transmitting MBS broadcast control information and / or MBS multicast control information of one or more MTCHs associated with the terminal device from the network

[0126] An example of how RNTIs are used in PTM transmission is shown below. A terminal device can receive different services using the same or different G-RNTIs. A terminal device can receive different services using the same or different G-CS-RNTIs.

[0127] In a multicast service, the gNB may deliver MBS data packets using the following methods: PTP transmission: The gNB may independently deliver a separate copy of the MBS data packet to each terminal device. That is, the gNB may schedule a terminal-specific PDSCH using a terminal-specific PDCCH scrambled with a terminal-specific RNTI (e.g., C-RNTI), and deliver a separate copy of the MBS data packet scrambled with the same terminal-specific RNTI to each terminal device. PTM transmission: The gNB may deliver a single copy of the MBS data packet to a set of UEs. That is, the gNB may schedule a group-common PDSCH using a group-common PDCCH scrambled with a group-common RNTI, and deliver a single copy of the MBS data packet scrambled with the same group-common RNTI to the set of UEs.

[0128] When both PTM and PTP transmissions are configured for a terminal device, the gNB may dynamically determine whether to deliver multicast data to a specific terminal device via the PTM leg and / or the PTP leg based on information such as the MBS session QoS requirements, the number of participating terminal devices, and terminal device-specific reception quality feedback. Furthermore, regardless of the determination, the same QoS requirements may be applied to both PTM and PTP transmissions.

[0129] The MBS broadcast may be receivable by a terminal device in the RRC_IDLE, RRC_INACTIVE, and RRC_CONNECTED states. The terminal device may receive the MBS configuration for the broadcast session (e.g., parameters required for MTCH reception) via the 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 the MCCH: The MCCH may provide a list of some or all broadcast services transmitted on the MTCH and / or information related to the broadcast session. The information related to the broadcast session may include the MBS session ID, associated G-RNTI scheduling information, and information about neighboring cells providing a particular service on the MTCH. The MCCH content may be transmitted within a periodically occurring time domain window defined by the MCCH repetition period, the MCCH window period, and the radio frame / slot offset. The MCCH uses a modification period, and MCCH content may only be allowed to change at modification period boundaries. A notification mechanism may be used to notify of changes to the MCCH content due to the start, modification, or stop of a broadcast session and changes to neighboring cell information. Upon receiving an MCCH change notification, the terminal device may obtain an updated MCCH in the same MCCH modification period in which the change notification was sent.

[0131] The continuity of broadcast services in the RRC_IDLE state and the RRC_INACTIVE state will be described.

[0132] The mobility procedure for MBS reception allows a terminal device to start or continue receiving MBS services when changing cells. The gNB can indicate on the MCCH a list of neighboring cells that offer the same MBS broadcast service as the one offered in the serving cell. This allows the terminal device to request unicast reception of the service before moving to a cell that does not offer the MBS broadcast service using PTM transmission. To avoid the need to read MBS broadcast-related system information on neighboring frequencies, the terminal device can learn on which frequencies the MBS broadcast service via PTM is offered via the MBS User Service Description (USD) or a combination of the following: USD System Information (System Information Block: SIB, e.g., SIB21)

[0133] A User Service Description (USD) will now be described. One 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 the MBS user service, an identifier for the MBS user service that is unique within the scope of the MBS system, information indicating when the MBS user service is active, and / or one or more MBS distribution session description objects for the MBS user service. Each of the MBS distribution session description objects may include some or all of the following: a URL to a session description document carrying parameters for the MBS distribution session; information about the service area of ​​the MBS distribution session; one or more MBS Frequency Selection Area Identifiers (FSAIs, also referred to as MBS FASIs) associated with the 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 MBS service type, such as whether it is broadcast or multicast, and Temporary Mobile Group Identity (TMGI) information. The TMGI may be configured to include the service ID of the MBS, a Mobile Country Code (MCC), and a Mobile Network Code (MNC). Note that the configuration of the USD is an example, and the USD may not include some of the parameters, or may include other parameters in addition to or instead of them. The USD may also have a different configuration from the configuration described above. One USD may be considered as one object (also referred to as a USD object), and a version-controlled document including one or more of the USD objects may be referred to as a User Service Descriptions document.

[0134] The MBS FSAI may be used by a terminal device to select a frequency for an MBS broadcast session (also referred to as a broadcast MBS session).

[0135] In the RRC_IDLE and RRC_INACTIVE states, the terminal device 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 can receive these MBS broadcast services while camped on a frequency that provides these MBS broadcast services and can make this frequency the highest priority frequency if certain conditions are met. If an MBS broadcast service that the terminal device is interested in becomes unavailable (e.g. after the session has ended) or if the terminal device is no longer interested in receiving the service, the terminal device does not need to prioritize the frequency that provides these MBS broadcast services.

[0136] The continuity of the MBS broadcast service in the RRC_CONNECTED state will be described.

[0137] To ensure the continuity of MBS broadcast services, a terminal device in the RRC_CONNECTED state can send an MBS Interest Indication (MII) consisting of the following information to the gNB: A list of MBS frequencies that the terminal device is receiving or is interested in receiving, sorted in descending order of importance Reception priorities of MBS frequencies, unicast bearers, and multicast MRBs that the terminal device is receiving or is interested in receiving If an SIB (e.g., SIB20) containing information necessary to obtain the configuration of an MCCH and / or MTCH for MBS broadcast is provided on the PCell or SCell, a list of MBS broadcast services that the terminal device is receiving or is interested in receiving

[0138] The reporting of MBS Interest Indication may be implicitly enabled / disabled based on the presence or absence of a SIB (e.g., SIB21) containing mapping information between the current carrier frequency and / or neighboring carrier frequencies and MBS Frequency Selection Area Identities (FSAIs). 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 the broadcasted MBS data packets using the following methods: PTM transmission: The gNB may deliver a single copy of the MBS data packet to a set of UEs. For example, the gNB may use a group-common PDCCH CRC-scrambled with a group-common RNTI to schedule a group-common PDSCH scrambled with the same group-common RNTI.

[0140] We will explain MBS Broadcast in detail.

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

[0142] The MCCH may be used to deliver an MBS Broadcast Configuration message (MBSBroadcastConfiguration message), which indicates the MBS broadcast sessions offered in the cell and the scheduling information related to these sessions. Optionally, the MBSBroadcastConfiguration message may include a list of neighboring cells that provide the same MBS broadcast service as the one offered in the current cell. The configuration information required for the terminal device to receive the MCCH may be provided in SIB1 and SIB20. Furthermore, information regarding the service continuity of the MBS broadcast may be provided in SIB21.

[0143] The MCCH information (i.e., information transmitted in messages transmitted on the MCCH) may be transmitted periodically within a configured transmission window with a configurable recurrence period. The MCCH transmission (and associated radio resources and MCS) may be indicated by a PDCCH addressed to the 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 MCCH message reception in the MCCH transmission window may be the same as the PDCCH monitoring occasion of SIB1. If searchspaceMCCH is set to non-zero, the PDCCH monitoring occasion for MCCH messages may be determined based on the search space indicated by searchspaceMCCH.

[0145] A change in MCCH information occurs only in a specific radio frame, and the concept of a modification period may be used. Within the modification period, the same MCCH information may be transmitted a number of times defined by its scheduling. If the network modifies some or all of the MCCH information, the network may notify the terminal device of the change from the start of the MCCH modification period using the PDCCH that schedules the MCCH. If the terminal device receives or is interested in receiving an MBS service transmitted using an MBS broadcast and receives the new MCCH information from the same slot in which it received the modification notification, the terminal device may apply the previously acquired MCCH information until it acquires the new MCCH information.

[0146] The terminal device may apply an MCCH information acquisition procedure to acquire information on MBS broadcast configurations broadcast by the network. The MCCH information acquisition procedure may be applied to MBS broadcast services that an MBS-capable terminal device in RRC_IDLE state, RRC_INACTIVE state, or RRC_CONNECTED state in which a BWP with a common search space configured by searchSpaceMCCH is the active BWP is receiving or is interested in receiving.

[0147] If interested in receiving the MBS broadcast service, the terminal device 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 entering a cell providing SIB20 (e.g., upon power-on, after the terminal device moves), when receiving SIB20 on the SCell via dedicated signaling, and when notified that the MCCH information has changed due to the start of a new MBS service. A terminal device receiving data via a broadcast MRB may apply the MCCH information acquisition procedure when notified that the MCCH information has changed due to a change in the MCCH information other than a change due to the start of a new MBS service. Unless explicitly specified in the MCCH information acquisition procedure, the MCCH information acquisition procedure may overwrite stored MCCH information.

[0148] A terminal device receiving or interested in receiving an MBS broadcast service may start acquiring an MBSBroadcastConfiguration message transmitted using the MCCH from the slot in which it was notified that there was a change in the MCCH information if the MCCH information acquisition procedure was triggered based on being notified that there was a change in the MCCH information. Also, if the terminal device has entered a cell that provides SIB20 or has received information included in SIB20 broadcast on an SCell by RRC signaling, the terminal device may start acquiring an MBSBroadcastConfiguration message transmitted using the MCCH from the next recurrence 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 a broadcast MRB transmitted on the MTCH, or when the configuration of a broadcast MRB received by the terminal device is changed. The broadcast MRB configuration procedure may apply to an MBS broadcast service that an MBS-capable terminal device in RRC_IDLE state, RRC_INACTIVE state, or RRC_CONNECTED state where a BWP with a common search space configured by searchSpaceMTCH or searchSpaceMCCH is the active BWP is receiving or is interested in receiving.

[0150] A terminal device may apply (initiate) a broadcast MRB configuration procedure to start receiving an MBS session for an MBS broadcast service that it is interested in. The broadcast MRB configuration procedure may be initiated by an MBS-capable terminal device that is interested in receiving an MBS broadcast service at the start of an MBS session, when it enters a cell that provides the MBS broadcast service, when it becomes interested in an ongoing MBS broadcast service, when the terminal device's capability restrictions are lifted and it no longer prevents it from receiving the ongoing MBS broadcast service, etc.

[0151] The terminal device may apply (initiate) a broadcast MRB release procedure to stop receiving a session of an MBS broadcast service. The broadcast MRB release procedure may be initiated when the MBS session is stopped, when the terminal device moves away from a cell broadcasting an MBS service of interest, when it loses interest in the MBS service, when a capacity restriction that prevents reception of the associated service is initiated, etc.

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

[0153] The terminal device may establish a PDCP entity, an RLC entity, and / or an SDAP entity according to the information about this broadcast MRB included in the MBSBroadcastConfiguration message. The terminal device may also configure the MAC layer based on the scheduling information (mtch-SchedulingInfo) of the MTCH. The terminal device may also configure the PHY layer based on the configuration applied to this broadcast MRB. The terminal device may also receive the DL-SCH in the same cell as the cell where it received the MBSBroadcastConfiguration message for establishing the broadcast MRB, using the G-RNTI and / or mtch-SchedulingInfo for this MBS broadcast service.

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

[0155] The terminal device may release the PDCP entity, the RLC entity, and the associated MAC and PHY configurations. The terminal device may also release the SDAP entity that no longer has an associated MRB.

[0156] The above-mentioned MBS broadcast configuration message (MBSBroadcastConfiguration message) may include information (MBS session information list) indicating one or more MBS broadcast sessions. Additionally 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 public land mobile network (PLMN) identifier information or an index value associated with the PLMN identifier information. Additionally or alternatively, the TMGI may include an identifier (service ID) for identifying the MBS service within the PLMN. Additionally or alternatively, the MBS session information list may include one or more entries, and each entry in the MBS session information list may include a G-RNTI used for scheduling and scrambling transmission of the MTCH. Additionally or alternatively, each entry in the MBS session information list may include broadcast MRB configuration (e.g., PDCP configuration and RLC configuration).

[0157] We will explain MBS Interest Indication.

[0158] The terminal device may perform an 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 is interested in receiving an MBS broadcast service. In addition, this procedure may be used to indicate to the network whether a terminal device in the RRC_CONNECTED state prioritizes MBS broadcast reception or unicast / multicast MRB reception. Additionally or alternatively, 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, including when an RRC connection is successfully established / resumed, when entering or leaving a broadcast service area, when an MBS broadcast session is started or stopped, when interest in the MBS broadcast service changes, when the priority of MBS broadcast reception and unicast / multicast reception changes, when the serving cell changes to a PCell that provides SIB21 (i.e., when SIB21 is included in the scheduling information of SIB1), when SIB20 on an SCell is received via dedicated signaling, during handover, and when an RRC connection is re-established. This may also include when the serving cell is changed to a PCell that provides a parameter (nonServingCellMII) in SIB1 indicating that the non-serving cell may transmit an MBS Interest Indication to the serving cell for receiving the MBS broadcast service, when the non-serving cell starts or stops receiving the MBS broadcast service, or when the Common Frequency Range (CFR) information or subcarrier spacing for MBS broadcast reception is changed in the non-serving cell. If the UE does not have the CFR information and subcarrier spacing for MBS broadcast reception in the non-serving cell, the UE may obtain this information from the non-serving cell before transmitting the MBS Interest Indication.

[0161] The terminal device that initiated this procedure may perform some or all of the following steps (a) to (b) if SIB21 is provided by the PCell or if nonServingCellMII is provided by the PCell in SIB1: (a) confirm that it has obtained a valid version of SIB21 for the PCell; (b) if the UE has not transmitted an MBS Interest Indication since last entering the RRC_CONNECTED state, or if the UE has connected to a PCell that does not provide SIB21 or does not include nonServingCellMII in SIB1 since last transmitting 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 MBS frequencies of interest is not empty, and start transmitting the MBSInterestIndication message.

[0162] Additionally or alternatively, if SIB21 is not provided by the PCell and nonServingCellMII is not provided in SIB1 by the PCell, the terminal device that initiated this procedure may perform the following process (pa) based on some or all of the following conditions (ca) to (ce) being satisfied, or may perform the following process (pb) based on none of the conditions (ca) to (ce) being satisfied: (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 mbs-FreqList included in the last MBS Interest Indication; (cc) Either the subcarrier spacing or CFR information for MBS broadcast reception in non-serving cells has changed since the last transmission of an MBS Interest Indication. (cd) Subcarrier spacing and CFR information for MBS broadcast reception in a non-serving cell has been obtained from a non-serving cell that was 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 changed since the last transmission of an MBS Interest Indication.(pa) Set the content of the MBS Interest Indication according to the MBS Interest Indication content preparation procedure and start transmitting the MBSInterestIndication message. (pb) If SIB20 is provided on the PCell or SCell and (1) since the UE last transmitted an MBS Interest Indication, the UE has been connected to a PCell that does not provide SIB20 and the UE has not been provided with 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 transmitting the MBSInterestIndication message.

[0163] (MBS frequencies of interest determination procedure)

[0164] The terminal device may determine (judge) a frequency as part of the MBS frequencies of interest based on the fact that all of the following conditions (ca) to (cc) are satisfied for that frequency: (ca) At least one MBS session that the terminal device is receiving or is interested in receiving via a broadcast MRB has started or is about to start; (cb) For at least one MBS session that the terminal device is receiving or is interested in receiving via a broadcast MRB, SIB21 obtained from the PCell or a non-serving cell includes information on mapping between the frequency and one or more MBS FSAIs indicated in the USD of this MBS session, or the frequency is not included in SIB21 but is indicated in the USD of this session; and (cc) At least one band combination including the frequency is included in information on band combinations supported by the terminal device (e.g., supportedBandCombinationList) included in the terminal device capability information (e.g., UE-NR-Capability) notified to the network by the terminal device.

[0165] (MBS services of interest determination procedure)

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

[0167] (Procedure for Setting the Contents of MBS Interest Indication)

[0168] The terminal device may provide content for the MBS Interest Indication.

[0169] The terminal device may perform some or all of the following processes (pa) to (pd) based on (1) having a valid version of SIB21 and (2) the set of interested MBS frequencies determined by the procedure for determining MBS frequencies of interest being non-empty: (pa) Set the list (mbs-FreqList) of interested MBS frequencies to be included in the MBS Interest Indication, sorted in descending order. (pb) Include the parameter mbs-Priority in the MBS Interest Indication based on the terminal device prioritizing MBS broadcast reception over any unicast / multicast MRB reception. By transmitting mbs-Priority in the MBS Interest Indication, 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 provision of SIB20 for the PCell or SCell, Set the list (mbs-ServiceList) of interested MBS services to be included in the MBS Interest Indication, sorted in descending order. (pd) Based on the fact that SIB1 for the PCell includes nonServningCellMII and the set of MBS frequencies for receiving MBS broadcasts in non-serving cells 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 acquired cfr-InfoMBS and subcarrierSpacing for receiving MBS broadcasts in non-serving cells, the cfr-InfoMBS and subcarrierSpacing may be included in the content of the MBS Interest Indication.

[0170] Based on the above description, various embodiments of the present invention will be described. Note that the above-described processes may be applied to processes that are omitted in the following description.

[0171] Fig. 5 is a block diagram showing the configuration of a terminal device (UE 122) in this embodiment. To avoid complicating the explanation, Fig. 5 shows only the main components closely related to this embodiment.

[0172] 5 includes a receiver 500 that receives control information (such as DCI, MAC control elements, RRC signaling, and broadcast information) from a base station device, a processor 502 that performs processing according to parameters included in the received control information, and a transmitter 504 that transmits the control information (such as UCI, MAC control elements, and RRC signaling) to the base station device. This base station device may be the eNB 102 or the gNB 108. The processor 502 may include some or all of the functions of various layers (e.g., the physical layer, MAC layer, RLC layer, PDCP layer, SDAP layer, RRC layer, and NAS layer). That is, the processor 502 may include some or all of the functions of the physical layer processor (PHY processor), MAC layer processor (MAC processor), RLC layer processor (RLC processor), PDCP layer processor (PDCP processor), SDAP processor (SDAP processor), RRC layer processor (RRC processor), and NAS layer processor (NAS processor).

[0173] Fig. 6 is a block diagram showing the configuration of a base station device in this embodiment. To avoid complicating the explanation, Fig. 6 shows only main components closely related to this embodiment. This base station device may be an eNB 102 or a gNB 108.

[0174] The base station apparatus shown in FIG. 6 includes a transmitter 600 that transmits control information (DCI, RRC signaling, broadcast information, etc.) to UE 122, a processor 602 that creates control information (DCI, RRC signaling including parameters, broadcast information, etc.) and transmits it to UE 122, causing processing unit 502 of UE 122 to process it, and a receiver 604 that receives control information (UCI, RRC signaling, etc.) from UE 122. Furthermore, processing unit 602 may include some or all of the functions of various layers (e.g., physical layer, MAC layer, RLC layer, PDCP layer, SDAP layer, RRC layer, and NAS layer). That is, 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 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 described with reference to FIGS.

[0176] 7 is a diagram showing an example of processing by the terminal device (UE 122) in this embodiment. The processing unit 502 of the terminal device receives first information and second information from the base station device (step S700). The processing unit 502 of the terminal device determines, based on the second information, which of one or more MBS sessions identified by the received first information is available for reception (step S702). The processing unit 502 of the terminal device performs an operation based on the determination (step S704).

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

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

[0179] The second information received from the base station device in step S700 may include information indicating one or more ranges of areas (target areas). Each of the target areas may be expressed, for example, by any one of the following (a) to (d), or any combination thereof: (a) a list including one or more entries, each of which represents an area indicated by a Reference Location (geographical coordinates indicated by longitude and latitude) and additional information (e.g., radius, diameter, and / or angle); (b) a list including one or more entries, each of which represents an area formed by connecting multiple Reference points; (c) an SSB index; and (d) other information indicating a geographical area.

[0180] Each of the target areas may be identified by an identifier. The identifier that identifies the target area is also referred to as a target area identifier. The target area identifier may be included in the second information together with information indicating the target area. FIG. 8 is a diagram showing an example of the above case (a). FIG. 8 shows an example in which a list (MBSAreaInfoList) including a 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, a target area indicated by an SSB index may mean that a certain SSB index is associated with a certain target area. For example, if a terminal device can receive an SSB with a certain SSB index, the terminal device can be considered to be located in the target area associated with that SSB index. Furthermore, being able to receive the SSB may mean that the received power of the SSB is equal to or greater than a certain threshold. This threshold may be notified in the first information, may be notified in the second information, or may be a predetermined value.

[0182] The one or more target areas notified by the second information may be associated with an MBS session.

[0183] For example, zero or more target areas may be associated with each entry of the MBS session information list included in the MBS broadcast configuration message. In this case, for example, each entry of the MBS session information list may include a list having zero or more target area identifiers in the entry. Additionally or alternatively, a TMGI included in each entry of the MBS session information list may be associated with zero or more target areas. Additionally or alternatively, a G-RNTI included in each entry of the MBS session information list may be associated with zero or more target areas. Additionally or alternatively, a PLMN included in each entry of the MBS session information list may be associated with zero or more target areas. Additionally or alternatively, a service ID included in each entry of the MBS session information list may be associated with zero or more target areas. FIG. 9 is a diagram showing an example in which a target area identifier is included in an MBS broadcast configuration message. The MBS broadcast configuration message (MBSBroadcastConfiguration) includes an MBS session information list (MBS-SessionInfoList), each entry of which includes a TMGI and a G-RNTI, and optionally includes a list (TargetAreaList) whose entries each include one or more target area identifiers. In other words, if a TargetAreaList is not included in an entry of the MBS session information list, it may be indicated that the entry is associated with zero target areas.

[0184] Alternatively, for example, SIB20 may include configuration information necessary for receiving one or more MCCHs, and each piece of configuration information necessary for receiving the MCCHs may be associated with zero or more target areas. In this case, all MBS sessions notified in an MBS broadcast configuration message received based on configuration information necessary for receiving a certain MCCH may be associated with zero or more target areas that are associated with the configuration information necessary for receiving this MCCH.

[0185] Furthermore, one or more MBS sessions may be associated with each of the target areas notified in the second information. Additionally or alternatively, one or more FSAIs may be associated with each of the target areas notified in the second information. Additionally or alternatively, one or more FSAIs may be associated with each of the one or more target areas notified in the second information. Additionally or alternatively, one or more MBS services may be associated with each of the target areas notified in the second information. Additionally or alternatively, one or more MBS sessions may be associated with each of the MBS services.

[0186] For example, Fig. 10 shows an example in which one or more FSAIs are associated with one or more target areas notified by the second information in SIB21. As shown in Fig. 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 associating FSAIs with frequencies different from the frequency of the serving cell (MBS-FSAI-InterFreqList), and / or a list associating FSAIs 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 of the MBS FSAIs.

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

[0188] The determination in step S702 may be, for example, a determination by the terminal device in a procedure for determining an MBS service of interest as to whether a certain MBS service is not associated with any target area. Additionally or alternatively, the determination in step S702 may be, for example, a determination by the terminal device in a procedure for determining an MBS service of interest as to whether the terminal device is located in a specific target area. In this case, in step S704, the terminal device may determine (judge) that MBS service is part of the MBS services of interest based on the determination.

[0189] For example, the terminal device may determine (judge) that the MBS service is part of the MBS services of interest based on the fact that all of the following conditions (ca) to (cc) and condition (cd) are satisfied: (ca) the terminal device is receiving or is interested in receiving the MBS service via a broadcast MRB; (cb) a session for the MBS service has started or is about to start; (cc) one or more MBS FSAIs (Frequency Selection Area Identities) in the USD (User Service Description) for the MBS service are included for frequencies belonging to the set of MBS frequencies of interest determined by the procedure for determining MBS frequencies of interest in SIB21 acquired from the PCell, or SIB21 acquired from the PCell does not provide frequency mapping information for the MBS service, but the USD of the MBS service includes frequencies belonging to the set of MBS frequencies of interest determined by the procedure for determining MBS frequencies of interest. (cd) the MBS service is not associated with any of the target areas notified in the second information, or the MBS service is associated with one or more target areas notified in the second information, and the terminal device is located in the associated target area. (ce) one or more Frequency Selective Area Identifiers (FSAIs) are associated with the MBS service, and the terminal device is located in any of the one or more target areas associated with those Frequency Selective Area Identifiers (FSAIs). (cf) (1) the MBS service is not associated with any of the target areas notified in the second information, or (2) one or more Frequency Selective Area Identifiers (FSAIs) are associated with the MBS service, and the terminal device is located in any of the one or more target areas associated with those Frequency Selective Area Identifiers (FSAIs).

[0190] Additionally or alternatively, the determination in step S702 may be, for example, the terminal device determining whether a certain MBS frequency is not associated with any target area in the procedure for determining an MBS frequency of interest. Additionally or alternatively, the determination in step S702 may be, for example, the terminal device determining whether the terminal device is located in a target area associated with a certain frequency in the procedure for determining an MBS frequency of interest. In this case, in step S704, the terminal device may determine (judge) that frequency to be part of the MBS frequencies of interest based on the determination.

[0191] For example, the terminal device may determine (judge) a certain frequency (first frequency) as part of the MBS frequencies of interest based on whether some or all of the following conditions (ca) to (cd) are satisfied for the first frequency: (ca) At least one MBS session that the terminal device is receiving or is interested in receiving through a broadcast MRB has started or is about to start; (cb) For at least one MBS session that the terminal device is receiving or is interested in receiving through a broadcast MRB, SIB21 obtained from a PCell or a non-serving cell includes information on mapping between the first frequency and one or more MBS FSAIs indicated in the USD for this MBS session, or the first frequency is not included in SIB21 but is indicated in the USD for this MBS session; and (cc) At least one band combination including the first frequency is included in information on band combinations supported by the terminal device (e.g., supportedBandCombinationList) included in terminal device capability information (e.g., UE-NR-Capability) notified to the network by the terminal device. (cd) The terminal device is located within one or more of the target areas associated with a frequency selective area identifier (FSAI), the one or more frequencies associated with the frequency selective area identifier include the first frequency, and the frequency selective area identifier is associated with one or more MBS sessions that the terminal device is receiving or is interested in receiving via a broadcast MRB.

[0192] The terminal device may apply the above-mentioned procedure for determining MBS services of interest in the aforementioned MBS Interest Indication procedure. Additionally or alternatively, the terminal device may apply the above-mentioned procedure for determining MBS services of interest in other procedures.

[0193] As the above-mentioned MBS session information list, a list consisting only of entries not associated with a target area and a list consisting of entries associated with zero or more target areas may be independently included in the MBS broadcast configuration message. In this way, a conventional terminal device that does not support the operation of this embodiment can receive an MBS broadcast service that is not limited to a target area by acquiring only the list consisting only of entries not associated with a target area, and a terminal device that supports the operation of this embodiment can receive both an MBS broadcast service that is not limited to a target area and an MBS broadcast service that is limited to a target area by acquiring both lists.

[0194] The above-described mechanism enables a base station device to provide a terminal device with an MBS broadcast service by PTM distribution in a specific area within a cell without using PTP distribution, and enables the terminal device to receive the MBS broadcast service in an appropriate area within the cell.

[0195] In the above description, the processing unit 502 of the UE 122 may be a processing unit that performs processing of the RRC layer.

[0196] Each piece of target area information may be information indicating a target area of ​​part or all of the cell, or information indicating an area independent of the cell. Additionally or alternatively, each piece of target area information may be information common to one or more cells. Additionally or alternatively, each piece of area information may be information indicating an area based on a relative position with respect to a reference location of the cell. Additionally or alternatively, each piece of area information may be information indicating an area based on an absolute position independent of the cell.

[0197] Furthermore, other information may be notified to the terminal device as the second information, rather than information indicating the target area. For example, the terminal device may be notified of information on MBS broadcast services and / or MBS sessions that the terminal device is permitted to receive from the network (base station device). For example, the information may include information such as the G-RNTI and service ID of the MBS sessions that the terminal device is permitted to receive. Additionally or alternatively, the information may include information necessary for decoding the MBS sessions that the terminal device is permitted to receive. Additionally, the information may include information indicating a period during which the information is valid (e.g., a timer value). The network (base station device) may notify the information based on location information notified by the terminal device. Additionally or alternatively, the network (base station device) may notify the information based on a report of measurement results of reference signals transmitted from one or more cells notified by the terminal device. Additionally or alternatively, the network (base station device) may notify the information based on other information.

[0198] In addition, in each embodiment, the first information and / or the second information may be notified to the terminal device by any one or any combination of an RRC message, RRC signaling, a message of a layer above the RRC layer, and a MAC control element.

[0199] Furthermore, the aforementioned target area (or intended area) may be called a target service area (or intended service area), or may be called by another name.

[0200] Furthermore, in each embodiment, the determination of whether the terminal device is located within the target area may be made based on a known method. For example, the known method may be positioning using radio waves from a communication system (e.g., OTDOA (Observed Time Difference Of Arrival)), positioning using GNSS (Global Navigation Satellite System), positioning using Bluetooth (registered trademark), a positioning method using another mechanism, or a combination of the above positioning methods.

[0201] The processes described in each embodiment may be applied to a non-terrestrial network, and may also be applied to a terrestrial network.

[0202] In addition, in the above description, expressions such as "link to," "corresponding to," and "associate with" may be interchangeable.

[0203] In the above description, expressions such as "determined to be A," "A is set," and "A is included" may be interchangeable.

[0204] In the above description, "transition from X to Y" may be rephrased as "X becomes Y." Also, in the above description, "cause a transition" may be rephrased as "determine a transition."

[0205] In addition, in the above-described examples of processes or process flows, some or all of the steps may not be executed. In addition, in the above-described examples of processes or process flows, the order of the steps may be different. In addition, in the above-described examples of processes or process flows, some or all of the processing within each step may not be executed.

[0206] In the above description, when it is stated that "C may be D" and "C may be E", it may also include that "D may be E". Also, in the above description, when it is stated that "F may be G" and "G may be H", it may also include that "F may be H".

[0207] The program that runs on the device according to this embodiment may be a program that controls a central processing unit (CPU) or the like to make a computer function so as to realize the functions of this embodiment. The program or the information handled by the program is temporarily loaded into a volatile memory such as a random access memory (RAM) during processing, or stored in a nonvolatile memory such as a flash memory or a hard disk drive (HDD), and is read, modified, and written by the CPU as needed.

[0208] Note that a part of the device in the above-described embodiment may be realized by a computer. In this case, a program for realizing this control function may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read and executed by a computer system. The "computer system" here refers to a computer system built into the device, including hardware such as an operating system and peripheral devices. Furthermore, the "computer-readable recording medium" may be any of a semiconductor recording medium, an optical recording medium, a magnetic recording medium, etc.

[0209] Furthermore, the term "computer-readable recording medium" may also include a medium that dynamically stores a program for a short period of time, such as a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line, or a medium that stores a program for a certain period of time, such as a volatile memory within a computer system that serves as a server or client in such cases. The program may also be one that realizes part of the above-mentioned functions, or one that can realize the above-mentioned functions in combination with a program already stored in the computer system.

[0210] Furthermore, each functional block or feature of the device used in the above-described embodiments may be implemented or performed by an electrical circuit, typically an integrated circuit or multiple integrated circuits. The electrical circuit designed to perform the functions described herein may include a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or a combination 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 be composed of digital circuits or analog circuits. Furthermore, if advances in semiconductor technology result in the emergence of integrated circuit technology that replaces current integrated circuits, integrated circuits based on that technology may also be used.

[0211] It should be noted that the present embodiment is not limited to the above-described embodiment. In the embodiment, an example of a device is described, but the present embodiment is not limited to this, and can be applied to terminal devices or communication devices such as stationary or non-movable electronic devices installed indoors or outdoors, for example, AV equipment, kitchen equipment, cleaning / washing equipment, air conditioning equipment, office equipment, vending machines, and other household appliances.

[0212] Although this embodiment has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment and includes design modifications within the scope of the gist of this embodiment. 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. Furthermore, configurations in which elements described in the above embodiment are substituted with elements that achieve the same effect are also included.

[0213] One aspect of the present invention can be used, for example, in a communication system, a communication device (e.g., a mobile phone device, a base station device, a wireless LAN device, or a sensor device), an integrated circuit (e.g., a communication chip), or a program.

[0214] 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 Processor 504, 600 Transmitter

Claims

1. A terminal device comprising: a receiving unit that receives first system information transmitted from a base station device; a processing unit; and a transmitting unit; wherein the first system information includes information indicating a first range area; the first range area is linked to a Frequency Selection Area Identifier (FSAI) that indicates a second range area; the FSAI is associated with an MBS session distributed to the second range area, and the FSAI is further associated with a first frequency; the processing unit determines that the terminal device is located within the first range area linked to a certain FSAI (first FSAI), and determines that the first frequency associated with the first FSAI is an MBS frequency of interest; the transmitting unit transmits information indicating the MBS frequency of interest to the base station device; and the first FSAI is an FSAI linked to an MBS session that the terminal device is receiving through a broadcast MRB or an MBS session that the terminal device is interested in receiving through a broadcast MRB.

2. A method applicable to a terminal device, wherein first system information includes information indicating a first range area, the first range area being linked to a Frequency Selection Area Identifier (FSAI) indicating a second range area, the FSAI being associated with an MBS session distributed to the second range area, and the FSAI being further associated with a first frequency, the method comprising the steps of: receiving first system information transmitted from a base station device; determining that the terminal device is located within the first range area linked to a certain FSAI (first FSAI), and determining that the first frequency associated with the first FSAI is an MBS frequency of interest; and transmitting information indicating the MBS frequency of interest to the base station device.

3. An integrated circuit implemented in a terminal device, wherein first system information includes information indicating a first range of areas, the first range of areas being linked to Frequency Selection Area Identities (FSAIs) indicating a second range of areas, the FSAIs being associated with MBS sessions distributed to the second range of areas, and the FSAIs being further associated with a first frequency, the integrated circuit causing the terminal device to perform the following functions: receiving first system information transmitted from a base station device; determining that the first frequency associated with a certain FSAI (first FSAI) is an MBS frequency of interest based on determining that the terminal device is located within the first range of areas linked to the first FSAI; and transmitting information indicating the MBS frequency of interest to the base station device.