Terminal device, method, and integrated circuit

Abstract

This terminal device receives, from a base station device, control information relating to one or a plurality of multicast / broadcast services (MBS), and an RRC release message including one or a plurality of items of area information. During an RRC_INACTIVE state, a processing unit transmits an RRC resume request message to the base station device in order to resume RRC connection, on the basis of it not being possible to use, in a cell after cell reselection, a PTM configuration for a multicast session in which the terminal device is participating and for which stopping of G-RNTI monitoring is not indicated, and on the basis of the terminal device being located in a region about which there was notification in the area information, said region being associated with the multicast session in which the terminal device is participating and for which stopping of G-RNTI monitoring is not indicated.　

Description

Terminal device, method, and integrated circuit

[0001] This application claims priority from Japanese Patent Application No. 2024-046585, filed on March 22, 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 v18.0.0,"Evolved Universal Terrestrial Radio Access (E-UTRA);Radio Resource Control (RRC);Protocol specifications" pp70-354,pp427-435,439-14723GPP RP-234078," New WID: Non-Terrestrial Networks (NTN) forNR Phase 3",<https: / / www.3gpp.org / ftp / tsg_ran / TSG_RAN / TSGR_102 / Docs / RP-234078.zip>

[0006] In 3GPP, as an extension technology of NR, for example, in the study of non-terrestrial networks (NTN), provision of multicast / broadcast services is being considered. However, since 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) (Non-Patent Document 2).

[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 provides the following measures. That is, one aspect of the present invention provides a terminal device communicating with a base station device, the terminal device comprising: a receiver that receives, from the base station device, an RRC release message including control information related to one or more multicast broadcast services (MBSs) and one or more pieces of area information; and a processor, wherein the control information includes information associating some or all of the multicast sessions with one or more pieces of area information, each piece of area information indicating some or all of the regions in which the multicast sessions are provided; and the processor transmits an RRC resumption request message to the base station device in an RRC_INACTIVE state, based on the fact that, in a cell after cell reselection, PTM configuration for a multicast session in which it is not specified that monitoring of a G-RNTI in which the terminal device participates is stopped is unavailable and the terminal device is located in an area notified by the area information associated with the multicast session in which it is participated and in which it is not specified that monitoring of a G-RNTI is stopped.

[0009] Another aspect of the present invention is a method applied to a terminal device communicating with a base station device, comprising the steps of receiving an RRC release message from the base station device, the RRC release message including control information regarding one or more multicast broadcast services (MBS) and one or more area information; and, in an RRC_INACTIVE state, sending an RRC resumption request message to the base station device to resume the RRC connection based on the fact that, in a cell after cell reselection, PTM settings for multicast sessions in which the terminal device is participating that do not indicate that monitoring of the G-RNTI will be stopped are not available, and the terminal device is located in an area notified by the area information corresponding to a multicast session in which the terminal device is participating that does not indicate that monitoring of the G-RNTI will be stopped, wherein the control information includes information correlating some or all of the multicast sessions with one or more of the area information, and each of the area information is information indicating some or all of the areas in which the multicast sessions are provided.

[0010] Another aspect of the present invention is an integrated circuit implemented in a terminal device that communicates with a base station device, which enables the terminal device to perform the following functions: receiving an RRC release message including control information regarding one or more multicast broadcast services (MBS) provided in the cell of the base station device and one or more area information; and, in an RRC_INACTIVE state, sending an RRC resumption request message to the base station device to resume the RRC connection based on the fact that, in a cell after cell reselection, PTM settings for a multicast session in which the terminal device is participating and that does not indicate that monitoring of the G-RNTI will be stopped are not available, and the terminal device is located in an area notified by the area information that corresponds to the multicast session in which the terminal device is participating and that does not indicate that monitoring of the G-RNTI will be stopped, wherein the control information includes information that associates some or all of the multicast sessions with one or more of the area information, and each of the area information is information that indicates the area of ​​some or all of the multicast sessions.

[0011] 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.

[0012] According to one aspect of the present invention, a terminal device, a method, and an integrated circuit can realize efficient communication control processing.

[0013] 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 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. 10 is an example of an ASN.1 description of MBS broadcast settings according to the present embodiment.

[0014] Hereinafter, this embodiment will be described in detail with reference to the drawings.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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)

[0048] The PBCH may be used to broadcast system information required by a terminal device.

[0049] In addition, in NR, the PBCH may be used to broadcast a time index (SSB-Index) within a synchronization signal block (SSB) period.

[0050] 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.

[0051] 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).

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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 a single terminal device. The MAC may also have a function to prioritize processing of overlapping resources within a single 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). The MAC may also have a function to select 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 that notifies information about available transmission power, and a buffer status report (BSR) function that notifies information about the amount of data 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.

[0056] This section describes logical channels for uplink (UL) and / or downlink (DL) used in E-UTRA and / or NR.

[0057] The BCCH (Broadcast Control Channel) may be a downlink logical channel for broadcasting control information such as system information (SI).

[0058] A PCCH (Paging Control Channel) may be a downlink logical channel for carrying paging messages.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] This section describes the mapping of logical channels and transport channels for the uplink in E-UTRA and / or NR.

[0065] The CCCH may be mapped to an uplink shared channel (UL-SCH), which is an uplink transport channel.

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

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

[0068] This section describes the mapping of logical channels and transport channels for the downlink in E-UTRA and / or NR.

[0069] The BCCH may be mapped to a downlink transport channel, a Broadcast Channel (BCH) and / or a Downlink Shared Channel (DL-SCH).

[0070] The PCCH may be mapped to a PCH (Paging Channel), which is a downlink transport channel.

[0071] The CCCH may be mapped to a DL-SCH (Downlink Shared Channel), which is a downlink transport channel.

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

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

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

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

[0076] 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).

[0077] 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).

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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 the resumption of the suspended RRC connection when UE 122 retains the UE AS context, the E-UTRAN has permitted resumption of the RRC connection, and UE 122 needs to transition from the RRC_IDLE state to the RRC_CONNECTED state.

[0091] 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).

[0092] 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).

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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)).

[0098] 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.

[0099] 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).

[0100] 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 for the core network, and NGEN-DC (NG-RAN E-UTRA-NR Dual Connectivity) that uses 5GC for 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 for 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 for the core network.

[0101] 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.

[0102] 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).

[0103] 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).

[0104] 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).

[0105] RRC signaling may be used for other purposes, not limited to the above examples.

[0106] 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.

[0107] 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.

[0108] This section explains MBS (Multicast / Broadcast Services).

[0109] In an MBS broadcast service (also simply referred to as a broadcast service), the same service and the same specific content data may be provided simultaneously to all terminal devices (UEs 122) within a geographical area. 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.

[0110] In an MBS multicast service (also simply referred to as a multicast service), the same service and the same specific content data may be simultaneously provided to one or more specific terminal devices (also referred to as a UE set). The multicast service may be distributed to the terminal devices using a multicast session. The 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 is applicable to both PTP and PTM transmissions.

[0111] 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 for one or more MTCHs associated with the terminal device from the network

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] The continuity of broadcast services in the RRC_IDLE state and the RRC_INACTIVE state will be described.

[0118] 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 User Service Description (USD) or a combination of the following: - USD - System information (System Information Block: SIB, e.g. SIB21)

[0119] The USD may include information indicating a correspondence relationship between an MBS service and a frequency. For example, the USD may include at least one set of an MBS service identifier that identifies an MBS service and information about a frequency. Additionally or alternatively, the USD may include at least one of an MBS session identifier that identifies an MBS session, information about the start and end times of the MBS session, an identifier that indicates an MBS service area in which the MBS session is provided, and information about a frequency in which the MBS session is provided.

[0120] 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.

[0121] The continuity of the MBS broadcast service in the RRC_CONNECTED state will be described.

[0122] 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.

[0123] The reporting of the 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.

[0124] In a broadcast service, the gNB may deliver the broadcasted MBS data packet 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.

[0125] We will explain MBS Broadcast in detail.

[0126] 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).

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] As a broadcast MRB configuration procedure, the terminal device may perform the following operations:

[0138] 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.

[0139] As a broadcast MRB release procedure, the terminal device may perform the following operations:

[0140] 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.

[0141] 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 broadcast MBS 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 MTCH scheduling and transmission scrambling. Additionally or alternatively, each entry in the MBS session information list may include broadcast MRB configuration (e.g., PDCP configuration and RLC configuration).

[0142] We will explain MBS interest indication.

[0143] The terminal device may perform an MBS interest indication procedure. This procedure may be used to indicate to the network that the 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 the 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.

[0144] (MBS interest indication procedure)

[0145] An MBS capable UE in RRC_CONNECTED state may initiate the MBS interest indication procedure in several cases, including successful establishment / resumption of an RRC connection, entering or leaving a broadcast service area, starting or stopping an MBS broadcast session, changing interest in the MBS broadcast service, changing the priority of MBS broadcast reception versus unicast / multicast reception, changing the serving cell to a PCell that provides SIB21 (i.e., when SIB21 is included in the scheduling information of SIB1), receiving SIB20 on an SCell via dedicated signaling, handover, and RRC connection re-establishment. This may also include when the serving cell changes to a PCell that provides a parameter (nonServingCellMII) in SIB1 indicating that a non-serving cell may transmit an MBS interest indication to the serving cell for receiving the MBS broadcast service, when starting or stopping reception of the MBS broadcast service in the non-serving cell, or when the common frequency resources (CFR) information or subcarrier spacing for MBS broadcast reception in the non-serving cell is changed. 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 such information from the non-serving cell before transmitting the MBS Interest Indication.

[0146] 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 the PCell provides nonServingCellMII 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.

[0147] 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 transmission of the previous MBS interest indication; or (cc) either the subcarrier spacing or CFR information for MBS broadcast reception in non-serving cells has changed since the last transmission of the MBS interest indication. (cd) Subcarrier spacing and CFR information for MBS broadcast reception in a non-serving cell was 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.

[0148] (MBS frequencies of interest determination procedure)

[0149] 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.

[0150] (MBS services of interest determination procedure)

[0151] 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 FSAIs (Frequency Specific Application Identifiers) 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.

[0152] (Procedure for setting the contents of MBS Interest Indication)

[0153] The terminal device may provide content for the MBS interest indication.

[0154] 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 interested MBS frequencies is not empty: (pa) set the list (mbs-FreqList) to be included in the MBS interest indication sorted in descending order of the MBS frequencies of interest; (pb) include the parameter mbs-Priority in the MBS interest indication based on the terminal device's preference for 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) set the list (mbs-ServiceList) to be included in the MBS interest indication sorted in descending order of the MBS services of interest based on the provision of SIB20 for the PCell or SCell. (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.

[0155] The RRC connection release procedure will now be described.

[0156] The RRC connection release procedure may be used for the following purposes (oa) to (ob). Additionally or alternatively, the RRC connection release procedure may be used for other purposes: (oa) To release the RRC connection, including the release of established radio bearers (except broadcast MRBs), backhaul RLC channels, Uu relay RLC channels, PC5 relay RLC channels, and / or radio resources. (ob) To suspend the RRC connection, including the suspension of established radio bearers (except broadcast MRBs).

[0157] The network may initiate an RRC connection release procedure to transition the terminal device from the RRC_CONNECTED state to the RRC_IDLE state, or to transition the terminal device from the RRC_CONNECTED state to the RRC_INACTIVE state only if SRB2 and at least one DRB or multicast MRB are configured in the RRC_CONNECTED state, or in the case of IAB and NCR, only if SRB2 is configured in the RRC_CONNECTED state. This procedure may also be initiated by the network to transition the terminal device from the RRC_INACTIVE state to the RRC_INACTIVE state or the RRC_IDLE state when the terminal device attempts to resume the RRC connection (due to resumption of a suspended RRC connection or the start of an SDT). Additionally or alternatively, this procedure may be used by the network to release the terminal device and redirect it to another frequency. Additionally or alternatively, this procedure may be used for other purposes.

[0158] A terminal device that receives an RRC connection release message may perform some or all of the following processes (pa) to (pf) based on the fact that this message contains suspendConfig: (pa) Release the MAC (pb) Release the default MAC cell group configuration (pc) Apply some or all of the received suspendConfig (pd) Suspend all SRBs and DRBs (except SRB0 and broadcast MRBs) (pe) Suspend all multicast MRBs associated with multicast sessions that are not configured to be received in the RRC_INACTIVE state (pf) Enter the RRC_INACTIVE state

[0159] The reception of the MBS multicast service by a terminal device in the RRC_INACTIVE state will be described.

[0160] A terminal device configured to receive the MBS multicast service in the RRC_INACTIVE state may apply the MBS multicast procedure. The MBS multicast configuration information may be provided in the RRCRelease message and / or the multicast MCCH logical channel. If there is temporarily no data in an active multicast session or if the multicast session is deactivated, the network may notify the terminal device through the MBS multicast configuration information to stop monitoring the corresponding G-RNTI. If the terminal device is notified to stop monitoring the G-RNTIs of all multicast sessions in which it participates, the terminal device may stop monitoring the multicast MCCH-RNTI of the notified cell.

[0161] The multicast MCCH may carry an MBSMulticastConfiguration message indicating the MBS multicast sessions (multicast sessions) offered in the cell and scheduling information related to these sessions. In addition, the MBSMulticastConfiguration message may also include a list of neighboring cells that provide the same MBS multicast service as offered in the current cell for a terminal device in RRC_INACTIVE state. The configuration information required for the terminal device to receive the multicast MCCH may be provided in broadcast information (e.g., SIB24).

[0162] The multicast MCCH information acquisition procedure will now be described.

[0163] The terminal device may apply a multicast MCCH information acquisition procedure to acquire MBS multicast configuration information from the network. This procedure may be applied to a terminal device configured to receive the MBS multicast service in the RRC_INACTIVE state.

[0164] If configured to receive MBS multicast services in RRC_INACTIVE state, the terminal device may apply the multicast MCCH information acquisition procedure for updating the PTM configuration and / or when reselecting to a new cell that provides SIB 24. Additionally, a terminal device receiving MBS multicast data in RRC_INACTIVE state may apply the multicast MCCH information acquisition procedure if it is notified by the network that the multicast MCCH information has changed.

[0165] In the multicast MCCH information acquisition procedure, a terminal device configured to receive the MBS multicast service in the RRC_INACTIVE state may perform some or all of the following processes (pa) to (pb): (pa) If this procedure is triggered by being notified from the network that the multicast MCCH information has changed, it starts acquiring the MBSMulticastConfiguration message carried on the multicast MCCH in the associated cell from the slot in which this change notification was received. (pb) If the terminal device moves to another cell that provides SIB24, or if the terminal device receives an RRCRelease message and is configured to receive MBS multicast in the RRC_INACTIVE state, and the RRC release message does not include PTM configuration for at least one multicast session that does not indicate that the terminal device will stop monitoring the G-RNTI, it acquires the MBSMulticastConfiguration message carried on the multicast MCCH of the associated cell in the next recurrence period.

[0166] The terminal device may apply the settings contained in the MBSMulticastConfiguration message obtained by the above process.

[0167] The RRC connection resumption procedure will now be described.

[0168] The purpose of the RRC connection restart procedure may be to restart a suspended RRC connection, including restarting SRBs, DRBs, and multicast MRBs. Additionally or alternatively, the purpose of the RRC connection restart procedure may be to perform an RNA update. Additionally or alternatively, the purpose of the RRC connection restart procedure may be other purposes.

[0169] If the terminal device is configured to receive MBS multicast in the RRC_INACTIVE state, in the RRC_INACTIVE state, the terminal device may send an RRCResumeRequest message and / or an RRCResumeRequest1 message to resume the RRC connection based on the fulfillment of some or all of the following conditions (ca) to (cd): (ca) SIB24 is not scheduled by SIB1; (cb) PTM configuration is not available in the cell after cell selection or reselection for a multicast session in which the terminal device is participating and which does not indicate that it will stop monitoring the G-RNTI; (cc) The mbs-NeighborCellList obtained in the previous cell indicates that a multicast session in which the terminal device will stop monitoring the G-RNTI is not provided in the current serving cell for the terminal device in the RRC_INACTIVE state; (cd) The measured RSRP and / or RSRQ of the serving cell is below the threshold indicated by thresholdIndex.

[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 / or second information from the base station device (step S700). The processing unit 502 of the terminal device determines which of one or more MBS sessions identified by the received first information is available for reception, based on the second information (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, information included in any one or any combination of the following (a) to (d): (a) a message transmitted using a Multicast MCCH logical channel, (b) a system information block (e.g., SIB24), (c) RRC signaling transmitted using a DCCH (e.g., an RRC release message), and (d) a USD.

[0178] For example, the message in (a) may be an MBSMulticastConfiguration message or another message. For example, the system information block in (b) may be SIB24 or another SIB. For example, the RRC signaling in (c) may be an RRC release message or another RRC signaling or RRC message.

[0179] The second information received from the base station device in step S700 may be, for example, 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 index of an SSB, and (d) other information indicating a geographical area.

[0180] Each of the areas indicated by the entries may be identified by an identifier. Alternatively, the areas indicated by the one or more entries may be defined as one area, in which case an identifier may be associated with each of the areas indicated by the one or more entries. The identifier for identifying an area is also referred to as an area identifier. The area identifier may be included in the second information together with the entry. Figure 8 is a diagram showing an example of the above case (a). In Figure 8, a list (MBSAreaInfoList) in which one entry includes an area identifier (MBS-AreaId), a Reference Location (ReferenceLocation), and radius information (mbs-DistanceRadius) is provided from the base station device to the terminal device.

[0181] Furthermore, the region indicated by the SSB index may mean that if the terminal device can receive the indicated SSB, the terminal device is considered to be located in the region indicated by the SSB index. Furthermore, being able to receive the indicated 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] One or more areas notified by the second information may be associated with an MBS session.

[0183] For example, zero or more areas may be associated with each entry of the MBS session information list included in the MBS multicast configuration message. In this case, for example, each entry of the MBS session information list may include a list having zero or more 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 areas. Additionally or alternatively, a G-RNTI included in each entry of the MBS session information list may be associated with zero or more areas. Additionally or alternatively, a PLMN included in each entry of the MBS session information list may be associated with zero or more areas. Additionally or alternatively, a service ID included in each entry of the MBS session information list may be associated with zero or more areas. Figure 9 is a diagram showing an example in which area identifiers are included in an MBS multicast configuration message. The MBS multicast configuration message (MBSMulticastConfiguration) includes an MBS session information list (MBS-SessionInfoListMulticast), and each entry in the MBS session information list includes a TMGI and a G-RNTI, and optionally includes a list (MbsAreaList) with one or more area identifiers in the entry. In other words, if an MBS session information list entry does not include an MbsAreaList, it may indicate that the entry is associated with zero areas.

[0184] Alternatively, for example, SIB24 and / or an RRC release message may include configuration information required to receive one or more multicast MCCHs, and zero or more areas may be associated with each piece of configuration information required to receive a multicast MCCH. In this case, all MBS sessions notified in an MBS multicast configuration message received based on the configuration information required to receive a certain multicast MCCH may be associated with zero or more areas associated with the configuration information required to receive this multicast MCCH. FIG. 10 is a diagram showing an example in which area identifiers are included in SIB24. SIB24 includes a list (MulticastMcchConfigList) of configuration information required to receive one or more multicast MCCHs, and each entry (McchConfig) in the MulticastMcchConfigList includes configuration information (MCCH-Config) required to receive the multicast MCCH, and optionally includes a list (MbsAreaList) whose entries each contain one or more area identifiers. In other words, if MbsAreaList is not included in McchConfig, it may be indicated that the McchConfig is associated with zero areas.

[0185] Furthermore, one or more MBS sessions may be associated with each of the areas notified by the second information.

[0186] Furthermore, each of the areas notified by the second information may be associated with one or more FSAIs.

[0187] Furthermore, each of the areas notified by the second information may be associated with one or more MBS services (for example, MBS service identifiers notified by USD).

[0188] Also, there may be MBS sessions and / or MBS services that are not associated with any region (i.e., associated with zero regions).

[0189] The determination in step S702 may be, for example, when the terminal device is configured to receive MBS multicast in the RRC_INACTIVE state, determining whether the terminal device satisfies some or all of the following conditions (ca) to (ce) in the RRC_INACTIVE state. (ca) SIB24 is not scheduled by SIB1. (cb) In the cell after cell selection or reselection, PTM settings are not available for a multicast session that does not indicate that the terminal device will stop monitoring the G-RNTI to which it is participating. (cc) A multicast session that does not indicate that the terminal device will stop monitoring the G-RNTI by the mbs-NeighborCellList obtained in the previous cell is not provided for a terminal device in RRC_INACTIVE state in the current serving cell. (cd) The measured RSRP and / or RSRQ of the serving cell are below the threshold indicated by thresholdIndex. (ce) The terminal device is not located in the area (notified by the second information) associated with a multicast session that does not indicate that the terminal device will stop monitoring the G-RNTI to which it is participating, or the terminal device has left the area (notified by the second information) associated with a multicast session that does not indicate that the terminal device will stop monitoring the G-RNTI to which it is participating.

[0190] In step S704, the terminal device may send an RRCResumeRequest message and / or an RRCResumeRequest1 message for resuming the RRC connection based on whether some or all of the above conditions (ca) to (ce) are satisfied, thereby enabling the terminal device to resume the RRC connection when it cannot receive the multicast session based on its location in the cell.

[0191] The determination in step S702 may be, for example, when the terminal device is configured to receive MBS multicast in the RRC_INACTIVE state, determining whether the terminal device satisfies some or all of the following conditions (ca) to (cd) in the RRC_INACTIVE state. (ca) SIB24 is not scheduled by SIB1. (cb) In the cell after cell selection or reselection, PTM configuration for a multicast session that does not indicate that the terminal device will stop monitoring the G-RNTI to which it participates is not available, and the terminal device is located in an area (notified by the second information) associated with a multicast session that does not indicate that the terminal device will stop monitoring the G-RNTI to which it participates. (cc) A multicast session that does not indicate that the terminal device will stop monitoring the G-RNTI to which it participates is not provided in the current serving cell for a terminal device in RRC_INACTIVE state by the mbs-NeighborCellList acquired in the previous cell, and the terminal device is located in an area (notified by the second information) associated with a multicast session that does not indicate that the terminal device will stop monitoring the G-RNTI to which it participates. (cd) The measured RSRP and / or RSRQ of the serving cell are below the threshold indicated by thresholdIndex, and the terminal device is located in an area (notified by the second information) associated with a multicast session that does not indicate that the terminal device will stop monitoring the G-RNTI to which it participates.

[0192] In step S704, the terminal device may transmit an RRCResumeRequest message and / or an RRCResumeRequest1 message for resuming the RRC connection based on whether some or all of the above conditions (ca) to (cd) are satisfied, thereby preventing unnecessary resumption of the RRC connection when the terminal device is not authorized to receive the multicast session based on its location in the cell.

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

[0194] The above-described mechanism enables a base station device to provide a terminal device with an MBS multicast service by PTM delivery in a specific area within a cell without using PTP delivery, and enables the terminal device to receive the MBS multicast 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 area information may be information indicating a part or all of the area of ​​the cell, or information indicating an area independent of the cell. Additionally or alternatively, each piece of 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 the 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] Additionally or alternatively, information other than the information indicating the area may be notified to the terminal device as the second information or included in the second information. For example, the terminal device may be notified from the network (base station device) of information on MBS multicast services and / or MBS sessions that the terminal device is permitted to receive. 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 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, an RRC signaling, a message of an upper layer of the RRC layer, and a MAC control element. Also, the MBS session described above may be a multicast session.

[0199] In addition, in the above description, expressions such as "link to," "corresponding to," and "associate with" may be interchangeable.

[0200] In the above description, expressions such as "determined to be A," "A is set," and "A is included" may be interchangeable.

[0201] 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."

[0202] 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.

[0203] 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".

[0204] 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.

[0205] 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.

[0206] 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.

[0207] 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.

[0208] 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.

[0209] 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.

[0210] 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.

[0211] 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 that communicates with a base station device, comprising: a receiving unit that receives an RRC release message from the base station device, the RRC release message including control information related to one or more multicast broadcast services (MBS) and one or more area information; and a processing unit, wherein the control information includes information that associates some or all of the multicast sessions with one or more of the area information, each of which is information that indicates some or all of the areas in which the multicast sessions are provided; and the processing unit, in an RRC_INACTIVE state, transmits an RRC resumption request message to the base station device to resume the RRC connection based on the fact that, in a cell after cell reselection, PTM configuration for a multicast session in which the terminal device is participating and which does not indicate that monitoring of the G-RNTI in the cell is not available, and the terminal device is located in an area notified by the area information that corresponds to a multicast session in which the terminal device is participating and which does not indicate that monitoring of the G-RNTI in the cell is stopped.

2. A method applicable to a terminal device communicating with a base station device, comprising the steps of: receiving an RRC release message from the base station device, the RRC release message including control information relating to one or more multicast broadcast services (MBS) and one or more area information; and, in an RRC_INACTIVE state, transmitting an RRC resumption request message to the base station device to resume the RRC connection, based on the fact that, in a cell after cell reselection, PTM configuration for a multicast session in which the terminal device is participating and that does not indicate that monitoring of the G-RNTI in the multicast session is stopped is not available, and the terminal device is located in an area notified by the area information associated with the multicast session in which the terminal device is participating and that does not indicate that monitoring of the G-RNTI in the multicast session is stopped; wherein the control information includes information associating some or all of the multicast sessions with one or more of the area information, and each of the area information is information indicating some or all of the areas in which the multicast sessions are provided.

3. An integrated circuit implemented in a terminal device that communicates with a base station device, the integrated circuit enabling the terminal device to perform the following functions: receive an RRC release message including control information related to one or more multicast broadcast services (MBS) provided in the cell of the base station device and one or more pieces of area information; and, in an RRC_INACTIVE state, send an RRC resumption request message to the base station device to resume an RRC connection based on the fact that, in a cell after cell reselection, PTM configuration for a multicast session in which the terminal device is participating and that does not indicate that monitoring of the G-RNTI in the multicast session is stopped is not available and the terminal device is located in an area notified by the area information associated with the multicast session in which the terminal device is participating and that does not indicate that monitoring of the G-RNTI in the multicast session is stopped; the control information includes information associating some or all of the multicast sessions with one or more pieces of area information, and each piece of area information is information indicating the area of ​​some or all of the multicast sessions.

Images