Terminal device, base station device, and method

Abstract

This terminal device comprises: a reception unit for receiving a first RRC message including a parameter for synchronous reset from a base station device to an SpCell of a first cell group; and a processing unit that causes a suspended wireless bearer to resume on the basis of reception of the first RRC message. The processing unit determines whether to cause all suspended wireless bearers to resume on the basis of whether first information is included in the first RRC message.

Description

[Technical Field]

[0001] The present invention relates to a terminal device, a base station device, and a method. This application claims priority to Japanese Patent Application No. 2020-173019, filed on October 14, 2020, the contents of which are incorporated herein by reference. [Background technology]

[0002] The 3rd Generation Partnership Project (3GPP), 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, technical studies and standardization of E-UTRA (Evolved Universal LTE Terrestrial Radio Access) have begun in 3GPP as a radio access technology (Radio Access Technology: RAT) for 3.9G and 4G cellular mobile communication systems. Currently, 3GPP is 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. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] 3GPP TS 38.300v 16.2.0,"NR;NR and NG-RAN Overall description; Stage 2" pp10-134 [Non-patent document 2] 3GPP TS 36.300 v16.2.0,"Evolved Universal Terrestrial Radio Access (E-UTRA)and Evolved Universal Terrestrial Radio Access Network (E-UTRAN);Overall description; Stage 2" pp19-361 [Non-patent document 3] 3GPP TS 38.331 v16.2.0,"NR;Radio Resource Control (RRC);Protocol specifications"pp21-861 [Non-patent document 4] 3GPP TS 36.331 v16.1.0,"Evolved Universal Terrestrial Radio Access (E-UTRA);Radio Resource Control (RRC);Protocol specifications" pp25-1012 [Non-Patent Document 5] 3GPP TS 37.340 v16.2.0,"EvolvedUniversal Terrestrial Radio Access (E-UTRA)and NR; Multi-Connectivity; Stage 2" pp6-67 [Non-patent document 6] 3GPP TS 38.321 v16.1.0, "NR;Medium Access Control (MAC) protocol specification" pp8-148 Summary of the Invention [Problem to be solved by the invention]

[0006] As an extension of NR, there is a dual connectivity (also called multi-connectivity) technology that enables communication between one or more base station devices and a terminal device using multiple cell groups to enable large-volume data communication. With this dual connectivity, in order to communicate in each cell group, the terminal device must monitor each cell group for messages addressed to it. To ensure low-latency communication when large-volume data communication occurs, the terminal device must constantly monitor multiple cell groups, which poses a problem of consuming a lot of power. For this reason, research is being conducted on a technology that reduces the frequency of monitoring some cell groups or stops monitoring them altogether (cell group deactivation technology).

[0007] In addition to the behavior of terminal devices when a cell group is in an inactive state, it is also necessary to consider the behavior of terminal devices when they are activated (returned) from an inactive state.

[0008] 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, and a method that can efficiently perform communication control. [Means for solving the problem]

[0009] In order to achieve the above object, one aspect of the present invention provides the following means: 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 a first RRC message from the base station device, the first RRC message including parameters for synchronous reconfiguration of an SpCell of a first cell group; and a processor that resumes suspended radio bearers based on the reception of the first RRC message, the processor determining whether to resume all suspended radio bearers based on whether first information is included in the first RRC message.

[0010] Another aspect of the present invention is a base station device that communicates with a terminal device, comprising: a transmitting unit that transmits to the terminal device a first RRC message including parameters for synchronous reconfiguration of an SpCell of a first cell group; and a processing unit that causes the terminal device to resume suspended radio bearers based on the transmission of the first RRC message, wherein the processing unit causes the terminal device to determine whether to resume all suspended radio bearers depending on whether first information is included in the first RRC message.

[0011] 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 a first RRC message from the base station device, the first RRC message including parameters for synchronous reconfiguration of an SpCell of a first cell group; and resuming suspended radio bearers based on the reception of the first RRC message, and determining whether to resume all suspended radio bearers based on whether first information is included in the first RRC message.

[0012] Another aspect of the present invention is a method applied to a base station device communicating with a terminal device, comprising the steps of: transmitting a first RRC message to the terminal device, the first RRC message including parameters for synchronous reconfiguration of an SpCell of a first cell group; and causing the terminal device to resume suspended radio bearers based on the transmission of the first RRC message, wherein the terminal device determines whether to resume all suspended radio bearers depending on whether first information is included in the first RRC message.

[0013] Another aspect of the present invention is an integrated circuit implemented in a terminal device that communicates with a base station device, which causes the terminal device to perform the functions of receiving a first RRC message from the base station device, the first RRC message including parameters for synchronous reconfiguration of an SpCell of a first cell group, and resuming suspended radio bearers based on the reception of the first RRC message, and the processing unit determines whether to resume all suspended radio bearers based on whether the first information is included in the first RRC message.

[0014] Another aspect of the present invention is an integrated circuit implemented in a base station device that communicates with a terminal device, which causes the base station device to perform the functions of transmitting a first RRC message to the terminal device, the first RRC message including parameters for synchronous reconfiguration of an SpCell of a first cell group, and of causing the terminal device to resume suspended radio bearers based on the transmission of the first RRC message, and the processing unit causes the terminal device to determine whether to resume all suspended radio bearers based on whether first information is included in the first RRC message.

[0015] 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. [Effects of the Invention]

[0016] According to one aspect of the present invention, a terminal device, a base station device, a method, and an integrated circuit can realize efficient communication control processing. [Brief explanation of the drawings]

[0017] [Figure 1]1 is a schematic diagram of a communication system according to an embodiment of the present invention. [Figure 2] FIG. 1 is a diagram illustrating an example of an E-UTRA protocol configuration according to an embodiment of the present invention. [Figure 3] FIG. 1 is a diagram of an example of an NR protocol configuration according to an embodiment of the present invention. [Figure 4] FIG. 2 is a diagram showing an example of a flow of procedures for various settings in an RRC according to an embodiment of the present invention. [Figure 5] FIG. 2 is a block diagram showing the configuration of a terminal device according to an embodiment of the present invention. [Figure 6] FIG. 1 is a block diagram showing a configuration of a base station device according to an embodiment of the present invention. [Figure 7] An example of an ASN.1 description included in a message regarding re-establishment of an RRC connection in NR in an embodiment of the present invention. [Figure 8] 10 is an example of an ASN.1 description included in a message regarding re-establishment of an RRC connection in E-UTRA according to an embodiment of the present invention. [Figure 9] 3 shows an example of ASN.1 description of an RRC reconfiguration message according to an embodiment of the present invention. [Figure 10] 10 shows an example of ASN.1 description of a cell group configuration information element in the embodiment of the present invention. [Figure 11] 10 shows an example of an ASN.1 description of SpCell settings in an embodiment of the present invention. [Figure 12] 10 is an example of ASN.1 description of a synchronization-attached reconfiguration information element according to an embodiment of the present invention. [Figure 13] 10 shows an example of an ASN.1 description of a ServingCellConfigCommon information element in the embodiment of the present invention. [Figure 14] 10 shows an example of ASN.1 description of an SCell configuration information element according to an embodiment of the present invention. [Figure 15] 10 shows an example of processing by a terminal device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0019] LTE (and LTE-A, LTE-A Pro) and NR may be defined as different radio access technologies (RATs). NR may also be defined as a technology included in LTE. LTE may also be defined as a technology included in NR. LTE that can connect to NR via Multi Radio Dual connectivity (MR-DC) may be distinguished from conventional LTE. LTE that uses 5GC in the core network may be distinguished from conventional LTE that uses EPC in the core network. Conventional LTE may refer to LTE that does not implement technologies standardized in 3GPP Release 15 or later. Embodiments of the present invention may be applied to NR, LTE, and other RATs. In the following description, terms related to LTE and NR are used; however, embodiments of the present invention may be applied to other technologies that use other terminology. In the embodiments of the present invention, the term E-UTRA may be replaced with the term LTE, and the term LTE may be replaced with the term E-UTRA.

[0020] In the embodiments of the present invention, the names of the nodes and entities and the processes performed by the nodes and entities are described when the radio access technology is E-UTRA or NR, but the embodiments of the present invention may be used for other radio access technologies. The names of the nodes and entities in the embodiments of the present invention may be different names.

[0021] Figure 1 is a schematic diagram of a communication system according to an embodiment of the present invention. Note that the functions of each node, radio access technology, core network, interface, etc. described using Figure 1 are only some of the functions closely related to the embodiment of the present invention, and the system may have other functions.

[0022] 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 an E-UTRA protocol, which will be described later. The E-UTRA protocol may be configured from an E-UTRA User Plane (UP) protocol, which will be described later, and an E-UTRA Control Plane (CP) protocol, which will be described later. 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.

[0023] 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.

[0024] 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.

[0025] 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 an NR user plane (User Plane: UP) protocol described below and an 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.

[0026] 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.

[0027] 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.

[0028] The eNB102 may have the function of connecting to the 5GC110. The eNB102 with the function of connecting to the 5GC110 may be referred to as an ng-eNB. The interface 114 is an interface between the eNB102 and the 5GC110 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 an Access and Mobility Management Function (AMF: not shown) in the 5GC110. The user plane interface of the interface 114 may terminate in a User Plane Function (UPF: not shown) in the 5GC110. 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, eNB, ng-eNB, gNB, etc. may be simply referred to as a network.

[0029] 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 referred to as 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 referred to as an Xn interface.

[0030] 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.

[0031] 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. In addition, 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.

[0032] The UE 122 may be a terminal device capable of receiving broadcast 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.

[0033] When the UE 122 communicates with the eNB 102 and / or the gNB 108, a radio connection may be established by establishing a radio bearer (RB) between the UE 122 and the eNB 102 and / or the gNB 108. A radio bearer used for CP may be referred to as a signaling radio bearer (SRB). A radio bearer used for UP may be referred to as a data radio bearer (DRB Data Radio Bearer). Each radio bearer may be assigned a radio bearer identity (ID). A radio bearer identity for an SRB may be referred to as an SRB identity (SRB ID). A radio bearer identity for a DRB may be referred to as a DRB identity (DRB ID).

[0034] 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 DRB established between the UE 122 and the eNB 102 and / or the gNB 108 may be 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.

[0035] 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, Identifier, or ID). Furthermore, each QoS flow may be identified by a QoS flow identifier (Identity, Identifier, or ID). Furthermore, the same QoS may be guaranteed for data such as IP packets and Ethernet frames passing through the same QoS flow.

[0036] 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.

[0037] In the following description, the eNB102 and / or the gNB108 will also be simply referred to as a base station device, and the UE122 will also be simply referred to as a terminal device or a UE.

[0038] FIG. 2 is a diagram showing an example of an E-UTRA protocol architecture according to an embodiment of the present invention. FIG. 3 is a diagram showing an example of an NR protocol architecture according to an embodiment of the present invention. Note that the functions of each protocol described using FIG. 2 and / or FIG. 3 are only some of the functions closely related to the embodiment of the present invention, and other functions may also be included. Note that in the embodiment of the present invention, an uplink (UL) may be a link from a terminal device to a base station device. Also, in each embodiment of the present invention, a downlink (DL) may be a link from a base station device to a terminal device.

[0039] 2A is a diagram of an E-UTRA user plane (UP) protocol stack. As shown in FIG. 2A, the E-UTRAN UP protocol may be a protocol between the UE 122 and the eNB 102. That is, the E-UTRAN 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.

[0040] 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 E-UTRA 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.

[0041] 2(B) is a diagram of the E-UTRAN control plane (CP) protocol configuration. As shown in FIG. 2(B), in the E-UTRAN 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-UTRAN 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.

[0042] 3B is a diagram of the NR control plane (CP) protocol configuration. As shown in FIG. 3B, 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 E-UTRAN 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.

[0043] 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.

[0044] In the embodiments of the present invention, the terms PHY (PHY layer), MAC (MAC layer), RLC (RLC layer), PDCP (PDCP layer), RRC (RRC layer), and NAS (NAS layer) may be used without distinguishing between the E-UTRA protocol and the NR protocol. 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.

[0045] In the embodiments of the present invention, 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, PHY 300, MAC 302, RLC 304, PDCP 306, and RRC 308 may be referred to as NR PHY, NR MAC, NR RLC, NR RLC, and NR RRC, respectively. Furthermore, PHY 200, MAC 302, RLC 304, PDCP 306, and RRC 308 may be referred to as NR PHY, NR MAC, NR RLC, NR PDCP, and NR RRC, respectively.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] Here, the physical channels will be described.

[0050] The physical channels used for wireless communication between a terminal device and a base station device may include the following physical channels.

[0051] 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)

[0052] The PBCH may be used to broadcast system information required by a terminal device.

[0053] In addition, in NR, the PBCH may be used to broadcast a time index (SSB-Index) within the period of a synchronization signal block (SS / PBCH block, also referred to as SSB).

[0054] 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. The DCI format may be used for scheduling the PUSCH in the serving cell. The PUSCH may be used for transmitting user data, transmitting an RRC message (described later), and the like.

[0055] 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).

[0056] 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.

[0057] 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 signaling (also referred to as an RRC message) and MAC control elements. Here, in the PDSCH, the RRC signaling transmitted from the base station apparatus may be signaling common to multiple terminal apparatuses in a cell. The RRC signaling transmitted from the base station apparatus may also be signaling dedicated to a certain terminal apparatus (also referred to as dedicated signaling). That is, terminal apparatus-specific (UE-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.

[0058] The PRACH may be used to transmit a random access preamble and may be used for initial connection establishment procedures, handover procedures, connection re-establishment procedures, synchronization (timing adjustment) for uplink transmissions, and to indicate requests for PUSCH (UL-SCH) resources.

[0059] An example of the function of the MAC will be described below. The MAC may be called a MAC sublayer.

[0060] The MAC may have the function of mapping various logical channels to corresponding transport channels. A logical channel 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 channel may be divided into a control channel that transmits control information and a traffic channel that transmits user information. The logical channel may also be divided into an uplink logical channel and a downlink logical channel. 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.

[0061] The MAC may also have a function for performing error correction through HARQ (Hybrid Automatic Repeat reQuest). The MAC may also have a scheduling report (SR) function for reporting scheduling information. The MAC may also have a function for performing priority processing between terminal devices using dynamic scheduling. The MAC may also have a function for performing priority processing between logical channels within one terminal device. The MAC may also have a function for performing priority processing of overlapping resources within one terminal device.

[0062] The E-UTRA MAC may have the capability to identify Multimedia Broadcast Multicast Services (MBMS), and the NR MAC may have the capability to identify Multicast / Broadcast Services (MBS).

[0063] The MAC may have a function for selecting a transport format, a function for performing discontinuous reception (DRX) and / or discontinuous transmission (DTX), a function for executing a random access (RA) procedure, a power headroom report (PHR) function for reporting information on available transmission power, a buffer status report (BSR) function for reporting information on the amount of data in the transmission buffer, etc.

[0064] The NR MAC may have a bandwidth adaptation (BA) function. The MAC PDU format used in the E-UTRA MAC may differ from the MAC PDU format 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.

[0065] This section describes logical channels for uplink (UL) and / or downlink (DL) used in E-UTRA and / or NR.

[0066] The BCCH (Broadcast Control Channel) may be a downlink logical channel for broadcasting control information such as system information (SI).

[0067] A PCCH (Paging Control Channel) may be a downlink logical channel for carrying paging messages.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] The MTCH (Multicast Traffic Channel) may be a point-to-multipoint downlink channel for transmitting data from a base station to a terminal. The MTCH may be a multicast logical channel. The MTCH may be used by a terminal only when the terminal receives MBMS.

[0072] 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 logical channel. The MCCH may be used by a terminal device only when the terminal device receives MBMS or is interested in receiving MBMS.

[0073] The SC-MTCH (Single Cell Multicast Traffic Channel) may be a point-to-multipoint downlink channel for transmitting data from a base station device to a terminal device using SC-PTM. The SC-MTCH may be a multicast logical channel. The SC-MTCH may be used by a terminal device only when the terminal device receives MBMS using SC-PTM (Single Cell Point-To-Multipoint).

[0074] The SC-MCCH (Single Cell Multicast Control Channel) may be a point-to-multipoint downlink channel for transmitting MBMS control information for one or more SC-MTCHs from a base station device to a terminal device. The SC-MCCH may be a multicast logical channel. The SC-MCCH may be used by a terminal device only when the terminal device receives MBMS using SC-PTM or is interested in receiving MBMS using SC-PTM.

[0075] This section describes the mapping of logical channels and transport channels for the uplink in E-UTRA and / or NR.

[0076] The CCCH may be mapped to an uplink shared channel (UL-SCH), which is an uplink transport channel.

[0077] The DCCH may be mapped to an uplink shared channel (UL-SCH), which is an uplink transport channel.

[0078] The DTCH may be mapped to an uplink shared channel (UL-SCH), which is an uplink transport channel.

[0079] This section describes the mapping of logical channels and transport channels for the downlink in E-UTRA and / or NR.

[0080] The BCCH may be mapped to a downlink transport channel, a Broadcast Channel (BCH) and / or a Downlink Shared Channel (DL-SCH).

[0081] The PCCH may be mapped to a PCH (Paging Channel), which is a downlink transport channel.

[0082] The CCCH may be mapped to a DL-SCH (Downlink Shared Channel), which is a downlink transport channel.

[0083] The DCCH may be mapped to a DL-SCH (Downlink Shared Channel), which is a downlink transport channel.

[0084] The DTCH may be mapped to a DL-SCH (Downlink Shared Channel), which is a downlink transport channel.

[0085] The MTCH may be mapped to a Multicast Channel (MCH), which is a downlink transport channel.

[0086] The MCCH may be mapped to a Multicast Channel (MCH), which is a downlink transport channel.

[0087] The SC-MTCH may be mapped to a DL-SCH (Downlink Shared Channel), which is a downlink transport channel.

[0088] The SC-MTCH may be mapped to a DL-SCH (Downlink Shared Channel), which is a downlink transport channel.

[0089] An example of the function of the RLC will be described below: The RLC may be called an RLC sublayer.

[0090] The E-UTRA RLC may have a function to segment and / or concatenate data provided from the PDCP of the upper layer and provide it to the lower layer. The E-UTRA RLC may have a function to reassemble and reorder the data provided from the lower layer and provide it to the upper layer.

[0091] The NR RLC may have the function of adding a sequence number to data provided by the PDCP in the upper layer that is independent of the sequence number added by the PDCP. The NR RLC may also have the function of segmenting data provided by the 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 retransmitting data and / or requesting retransmission (Automatic Repeat reQuest: ARQ).

[0092] RLC may also have a function to perform 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 instruction to send a status report sent from the transmitting side of RLC to the receiving side may be called a poll. RLC may also have a function to detect data duplication. RLC may also have a function to discard data.

[0093] RLC may have three modes: transparent mode (TM), unacknowledged mode (UM), and acknowledged mode (AM). In TM, data received from a higher layer is not segmented and no RLC header is 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, data received from a higher layer is segmented and / or combined, and an RLC header is added, but data retransmission control is not performed. The UM RLC entity may be a unidirectional entity or a bidirectional entity. If the UM RLC entity is a unidirectional entity, it may be configured as a transmitting UM RLC entity or a receiving UM RLC entity. If the UM RLC entity is a bidirectional entity, it may be configured as a UM RLC entity consisting of a transmitting side and a receiving side. In AM, it may perform operations such as segmenting and / or combining data received from a higher layer, adding an RLC header, and controlling data retransmission. The 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. Also, data provided to a lower layer in UM and / or data provided from a lower layer may be referred to as a UMD PDU. Also, data provided to a lower layer in AM or data provided from a lower layer may be referred to as an AMD PDU.

[0094] The RLC PDU format used in E-UTRA RLC and the RLC PDU format used in NR RLC may be different. RLC PDUs may include data RLC PDUs and control RLC PDUs. Data RLC PDUs may be called RLC DATA PDUs (RLC Data PDUs). Control RLC PDUs may be called RLC CONTROL PDUs (RLC Control PDUs).

[0095] An example of the function of PDCP will be described below. PDCP may be called a PDCP sublayer.

[0096] 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(R) 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 re-ordering function. PDCP may also have a PDCP SDU retransmission function. PDCP may also have a data discard function using a discard timer. PDCP may also have a duplication function. PDCP may also have a function for discarding duplicately received data.

[0097] 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).

[0098] An example of the function of the SDAP will be described below: SDAP is a service data adaptation protocol layer.

[0099] 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.

[0100] An example of the RRC function will be described.

[0101] 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 gNB 108 or the eNB 102 connected to the 5GC 100. 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 be different from the RRC messages and parameters used in NR RRC.

[0102] The RRC message may be sent using the BCCH of the logical channel, may be sent using the PCCH of the logical channel, may be sent using the CCCH of the logical channel, may be sent using the DCCH of the logical channel, or may be sent using the MCCH of the logical channel.

[0103] 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.

[0104] 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.

[0105] RRC messages sent 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. Other RRC messages may also be included.

[0106] RRC messages transmitted 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. Other RRC messages may also be included.

[0107] RRC messages transmitted 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. Other RRC messages may also be included.

[0108] 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.

[0109] 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 another layer.

[0110] Note that layers (not shown) above the AS layer of the terminal device may include an IP layer, a TCP (Transmission Control Protocol) layer above the IP layer, a UDP (User Datagram Protocol) layer, and the like. Furthermore, an Ethernet layer may be present above the AS layer of the terminal device. The layer above the AS layer of the terminal device may be called a PDU layer (PDU layer). The PDU layer may include an IP layer, a TCP layer, a UDP layer, an Ethernet layer, and the like. An application layer may be present above the IP layer, the TCP layer, the UDP layer, the Ethernet layer, the PDU layer, and the like. The application layer may include SIP (Session Initiation Protocol) and SDP (Session Description Protocol) used in IMS (IP Multimedia Subsystem), which is one of the service networks standardized by 3GPP. Furthermore, the application layer may include RTP (Real-time Transport Protocol) used for media communication, and / or protocols such as RTCP (Real-time Transport Control Protocol) and HTTP (HyperText Transfer Protocol) for media communication control. Furthermore, the application layer may include codecs for various media. The RRC layer may also be a layer above the SDAP layer.

[0111] Next, the states and state transitions of the UE 122 in LTE and NR will be described.

[0112] When the UE 122 connected to the EPC or 5GC has an RRC connection established, 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.

[0113] Note that when UE 122 is connected to the EPC, it does not have the RRC_INACTIVE state, but the suspension of the RRC connection may be initiated by E-UTRAN. 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.

[0114] The definition of RRC connection suspension may be different for UE 122 connected to EPC 104 and UE 122 connected to 5GC 110. In addition, all or part of the procedure for UE 122 to recover from RRC connection suspension may be different when UE 122 is connected to EPC (when suspended in RRC_IDLE state) and when UE 122 is connected to 5GC (when suspended in RRC_INACTIVE state).

[0115] The RRC_CONNECTED state, RRC_INACTIVE state, and RRC_IDLE state may be referred to as the RRC connected mode, RRC inactive mode, and RRC idle mode, respectively, or may simply be referred to as the connected mode, inactive mode, and idle mode, if there is no risk of misunderstanding.

[0116] 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.

[0117] 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.

[0118] A cell group configured by a base station device for a terminal device will now be described. A cell group may consist of only one special cell (SpCell). Alternatively, a cell group may consist of one SpCell and one or more secondary cells (SCells). That is, a cell group may consist of one SpCell and, optionally, one or more SCells. Note that when a MAC entity is associated with a master cell group (MCG), the SpCell may refer to a primary cell (PCell). Also, when a MAC entity is associated with a secondary cell group (SCG), the SpCell may refer to a primary SCG cell (PSCell). Also, when a MAC entity is not associated with a cell group, the SpCell may refer to a PCell. The PCell, PSCell, and SCell are serving cells. The SpCell may support PUCCH transmission and contention-based random access. The SpCell may always be in an activated state. 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 when a terminal device re-establishes an RRC connection. The PCell may also be a cell used in the random access procedure during handover. The PSCell may be a cell used in the random access procedure when adding a secondary node (SN), which will be described later. The SpCell may also be a cell used for purposes other than those mentioned above. Note that when a cell group is composed of an SpCell and one or more SCells, it can be said that carrier aggregation (CA) is configured for this cell group.Furthermore, for a terminal device in which CA is configured, a cell that provides additional radio resources to an SpCell may refer to an SCell.

[0119] A group of serving cells configured by RRC that uses the same timing reference cell and the same timing advance value for the uplink configured cells may be called a Timing Advance Group (TAG). A TAG including an SpCell of a MAC entity may refer to a Primary Timing Advance Group (PTAG). A TAG other than the above PTAG may refer to a Secondary Timing Advance Group (STAG).

[0120] Furthermore, when Dual Connectivity (DC) or Multi-Radio Dual Connectivity (MR-DC) is performed, a cell group may be added from a base station device to a terminal device. 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). MR-DC may be a technology included in DC. To perform DC, a 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.

[0121] Furthermore, when a DC is not configured, a cell group configured in a terminal device may be called an MCG. Furthermore, when a DC is not configured, an SpCell configured in a terminal device may be a PCell.

[0122] Note that 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. 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.

[0123] In addition, in the 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 an RRC message from the base station device. In EN-DC and 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. In 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. In NR-DC, both the MAC entities for the MCG and the SCG may 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, and one MAC entity for each cell group may be rephrased as one MAC entity for each SpCell.

[0124] Radio bearers will now be described. SRB0 to SRB2 may be defined as SRBs for E-UTRA, or other SRBs may be defined. SRB0 to SRB3 may be defined as SRBs for NR, or other SRBs may be defined.

[0125] SRB0 may be an SRB for RRC messages that are transmitted and / or received using the logical channel CCCH.

[0126] SRB1 may be an SRB for RRC messages and for NAS messages before the establishment of SRB2. RRC messages transmitted and / or received using SRB1 may include piggybacked NAS messages. All RRC and NAS messages transmitted and / or received using SRB1 may use the logical channel DCCH.

[0127] SRB2 may be an SRB for NAS messages and RRC messages including logged measurement information. All RRC and NAS messages sent and / or received using SRB2 may use the logical channel DCCH. SRB2 may also have a lower priority than SRB1.

[0128] SRB3 may be an SRB for transmitting and / or receiving specific RRC messages when EN-DC, NGEN-DC, NR-DC, etc. are configured in the terminal device. The logical channel DCCH may be used for all RRC messages and NAS messages transmitted and / or received using SRB3. Other SRBs may also be provided for other uses. DRB may be a radio bearer for user data. The logical channel DTCH may be used for RRC messages transmitted and / or received using DRB.

[0129] The following describes a radio bearer in a terminal device. The radio bearer may include an RLC bearer. The RLC bearer may consist of one or two RLC entities and logical channels. When an RLC bearer has two RLC entities, the RLC entities may be a TM RLC entity and / or a transmitting RLC entity and a receiving RLC entity in a unidirectional UM mode RLC entity.

[0130] SRB0 may consist of one RLC bearer. The RLC bearer of SRB0 may consist of a TM RLC entity and a logical channel. SRB0 may be always established in a terminal device in all states (such as RRC idle state, RRC connected state, and RRC inactive state). SRB1 may be established and / or configured in a terminal device by an RRC message received from a base station device when the terminal device transitions from an RRC idle state to an RRC connected state. SRB1 may consist of one PDCP entity and one or more RLC bearers. The RLC bearer of SRB1 may consist of an AM RLC entity and a logical channel. SRB2 may be established and / or configured in a terminal device by an RRC message received from a base station device in an RRC connected state with AS security activated. SRB2 may consist of one PDCP entity and one or more RLC bearers. The RLC bearer of SRB2 may consist of an AM RLC entity and a logical channel. The PDCPs of SRB1 and SRB2 on the base station device side may be placed in the master node. When a secondary node in EN-DC, NGEN-DC, or NR-DC is added or the secondary node is changed, one SRB3 may be established and / or configured in the terminal device by an RRC message received from the base station device by a terminal device in an RRC connected state with AS security activated. SRB3 may be a direct SRB between the terminal device and the secondary node. SRB3 may consist of one PDCP entity and one or more RLC bearers. The RLC bearer of SRB3 may consist of an AM RLC entity and a logical channel. The PDCP of SRB3 on the base station device side may be placed in the secondary node.

[0131] One or more DRBs may be established and / or configured in a terminal device by an RRC message received from a base station device by a terminal device in an RRC connected state with AS security activated. A DRB may consist of one PDCP entity and one or more RLC bearers. An RLC bearer of a DRB may consist of an AM or UM RLC entity and a logical channel.

[0132] In MR-DC, a radio bearer in which a PDCP is placed in the master node may be called an MN terminated bearer. In MR-DC, a radio bearer in which a PDCP is placed in a secondary node may be called an SN terminated bearer. In MR-DC, a radio bearer in which an RLC bearer exists only in an MCG may be called an MCG bearer. In MR-DC, a radio bearer in which an RLC bearer exists only in an SCG may be called an SCG bearer. In DC, a radio bearer in which an RLC bearer exists in both an MCG and an SCG may be called a split bearer.

[0133] When MR-DC is configured in a terminal device, the bearer type of SRB1 and SRB2 established / and / or configured in the terminal device may be an MN terminated MCG bearer and / or an MN terminated split bearer. Also, when MR-DC is configured in a terminal device, the bearer type of SRB3 established / and / or configured in the terminal device may be an SN terminated SCG bearer. Also, when MR-DC is configured in a terminal device, the bearer type of the DRB established / and / or configured in the terminal device may be any of all bearer types.

[0134] For an RLC bearer established and / or configured in a cell group configured with E-UTRA, the RLC entity established and / or configured may be an E-UTRA RLC. For an RLC bearer established and / or configured in a cell group configured with NR, the RLC entity established and / or configured may be an NR RLC. When an EN-DC is configured in the terminal device, the PDCP entity established and / or configured for an MN-terminated MCG bearer may be either an E-UTRA PDCP or an NR PDCP. When an EN-DC is configured in the terminal device, the PDCP entity established and / or configured for radio bearers of other bearer types, i.e., MN-terminated split bearers, MN-terminated SCG bearers, SN-terminated MCG bearers, SN-terminated split bearers, and SN-terminated SCG bearers, may be an NR PDCP. When an NGEN-DC, NE-DC, or NR-DC is configured in the terminal device, the PDCP entity established and / or configured for radio bearers of all bearer types may be an NR PDCP.

[0135] In NR, a DRB established and / or configured in a terminal device may be associated with one PDU session. One SDAP entity may be established and / or configured for one PDU session in the terminal device. The SDAP entity, PDCP entity, RLC entity, and logical channels established and / or configured in the terminal device may be established and / or configured by an RRC message received by the terminal device from the base station device.

[0136] Regardless of whether MR-DC is configured, a network configuration in which the master node is eNB102 and EPC104 is the core network may be called E-UTRA / EPC. Also, a network configuration in which the master node is eNB102 and 5GC110 is the core network may be called E-UTRA / 5GC. Also, a network configuration in which the master node is gNB108 and 5GC110 is the core network may be called NR or NR / 5GC. When MR-DC is not configured, the above-mentioned master node may refer to a base station device that communicates with a terminal device.

[0137] Next, handover in LTE and NR will be described. A handover may be a process in which a UE 122 in an RRC connected state changes its serving cell. A handover may be performed when the UE 122 receives an RRC message instructing a handover from the eNB 102 and / or the gNB 108. The RRC message instructing a handover may be a message related to reconfiguration of the RRC connection including a parameter instructing a handover (e.g., an information element named MobilityControlInfo or an information element named ReconfigurationWithSync). The above-mentioned information element named MobilityControlInfo may be referred to as a mobility control setting information element, mobility control setting, or mobility control information. The above-mentioned information element named ReconfigurationWithSync may be referred to as a reconfiguration with synchronization information element, or reconfiguration with synchronization. The RRC message instructing a handover may be a message indicating movement to a cell of another RAT (e.g., MobilityFromEUTRACommand or MobilityFromNRCommand). Alternatively, handover may be referred to as reconfiguration with sync. The conditions under which UE 122 can perform handover may include some or all of the following: AS security is activated, SRB2 is established, and at least one DRB is established.

[0138] The terminal device may execute a process in which the serving cell is not changed based on an RRC message instructing a handover. That is, the terminal device may execute a handover process in which the same cell as the current serving cell is set as the target cell.

[0139] The flow of RRC messages 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 an embodiment of the present invention. Fig. 4 shows an example of a flow when an RRC message is sent from a base station device (eNB102 and / or gNB108) to a terminal device (UE122).

[0140] 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 paging information. The base station device may also create an RRC message in order to have a specific terminal device perform a process. The process to be performed by the specific terminal device may include, for example, security 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 setting, handover, and security key update. The base station device may also create an RRC message in order to respond to an RRC message transmitted from the terminal device. The response to the RRC message transmitted from the terminal device may include, for example, a response to an RRC setup request, a response to an RRC reconnection request, or a response to an RRC resumption request. An RRC message includes various information (parameters) for notification and configuration. These parameters may be called fields and / or information elements, and may be described using a description format called ASN.1 (Abstract Syntax Notation One).

[0141] 4, the base station device then transmits the created RRC message to the terminal device (step S402). Next, the terminal device performs processing such as setting according to the received RRC message if necessary (step S404). After performing the processing, the terminal device may transmit an RRC message as a response to the base station device (not shown).

[0142] The RRC messages may be used for other purposes, not limited to the above examples.

[0143] In MR-DC, the RRC on the master node side may be used to transfer RRC messages for SCG side configuration (cell group configuration, radio bearer configuration, measurement configuration, etc.) between the terminal device. For example, in EN-DC or NGEN-DC, an NR RRC message may be included in the form of a container in an E-UTRA RRC message transmitted and received between the eNB 102 and the UE 122. In NE-DC, an E-UTRA RRC message may be included in the form of a container in an NR RRC message transmitted and received between the gNB 108 and the UE 122. The RRC message for SCG side configuration may be transmitted and received between the master node and a secondary node.

[0144] In addition, regardless of whether MR-DC is used, the RRC message for E-UTRA transmitted from eNB102 to UE122 may include an RRC message for NR, and the RRC message for NR transmitted from gNB108 to UE122 may include an RRC message for E-UTRA.

[0145] An example of parameters included in an RRC message related to RRC connection reconfiguration will be described. FIG. 7 shows an example of ASN.1 description representing fields and / or information elements related to radio bearer configuration included in the message related to RRC connection reconfiguration in NR in FIG. 4. FIG. 8 shows an example of ASN.1 description representing fields and / or information elements related to radio bearer configuration included in the message related to RRC connection reconfiguration in E-UTRA in FIG. 4. In the ASN.1 examples according to the embodiments of the present invention, including but not limited to FIGS. 7 and 8, the symbols "omitted" and "omitted" are not part of the ASN.1 notation and indicate that other information has been omitted. Note that information elements may be omitted even in places where "omitted" or "omitted" is not written. Note that the ASN.1 examples according to the embodiments of the present invention do not strictly follow the ASN.1 notation. The ASN.1 examples according to the embodiments of the present invention show examples of parameters of an RRC message according to the embodiments of the present invention, and other names and notations may be used. Note that in order to avoid complication of explanation, only examples of main information closely related to one embodiment of the present invention are shown. Note that parameters described in ASN.1 may be referred to as information elements without being distinguished as fields, information elements, etc. Furthermore, in the embodiments of the present invention, fields, information elements, etc. described in ASN.1 included in an RRC message may be referred to as information or parameters. Note that the message related to reconfiguration of the RRC connection may be an RRC reconfiguration message in NR or an RRC connection reconfiguration message in E-UTRA.

[0146] Cell activation and deactivation will now be described. In a terminal device communicating via dual connectivity, a master cell group (MCG) and a secondary cell group (SCG) are configured by the above-mentioned message related to re-establishment of the RRC connection. Each cell group may be composed of a special cell (SpCell) and zero or more other cells (secondary cells: SCell). The SpCell of the MCG is also referred to as a PCell. The SpCell of the SCG is also referred to as a PSCell. Cell deactivation does not apply to the SpCell, but may apply to the SCell.

[0147] Furthermore, cell deactivation may not be applied to PCells but may be applied to PSCells. In this case, cell deactivation may be performed differently for SpCells and SCells.

[0148] Cell activation and deactivation may be processed by a MAC entity that exists for each cell group. An SCell configured in a terminal device may be activated and / or deactivated by the following (A), (B), and / or (C). (A) Receipt of MAC CE indicating SCell activation / deactivation (B) SCell inactivity timer configured for each SCell for which PUCCH is not configured (SCell is deactivated based on the expiration of the timer) (C) SCell state (sCellState) set for each SCell by an RRC message (the SCell is activated based on the inclusion of the SCell state field in the SCell configuration)

[0149] Specifically, the MAC entity of the terminal device may perform some or all of the following processes (AD) for each SCell configured in the cell group.

[0150] (Processing AD) (1) If the RRC parameter (SCell state) is set to activated when the SCell is configured, or if a MAC CE for activating the SCell is received, the MAC entity of the UE 122 performs the process (AD-1). Otherwise, if a MAC CE for deactivating the SCell is received, or if the SCell inactivity timer expires for an SCell in the active state, the MAC entity of the UE 122 performs the process (AD-2). (2) If an uplink grant or downlink allocation is notified by the PDCCH of an active SCell, or if an uplink grant or downlink allocation for an active SCell is notified by the PDCCH of a serving cell, or if a MAC PDU is transmitted in the configured uplink grant, or if a MAC PDU is received in the configured downlink allocation, the MAC entity of UE 122 restarts the SCell inactivity timer associated with that SCell. (3) If the SCell becomes inactive, the MAC entity of the UE 122 performs the process (AD-3).

[0151] (Process AD-1) The MAC entity of the terminal device may perform some or all of the following (1) to (3). (1) If, in NR, this SCell was in an inactive state before receiving a MAC CE activating this SCell, or if the RRC parameter (sCellState) configured for the SCell at the time of SCell configuration is set to activated, the MAC entity of UE 122 performs process (AD-1-1). (2) The MAC entity of the UE 122 starts, or restarts (if already started), the SCell inactivity timer associated with that SCell. (3) If the Active DL BWP is not a Dormant BWP, the MAC entity of the UE 122 (re)initializes a suspended Type 1 configured uplink grant associated with this SCell according to the stored configuration, if any, and the MAC entity of the UE 122 triggers a PHR.

[0152] (Process AD-1-1) The MAC entity of the terminal device may perform some or all of the following (1) to (3). (1) If the BWP indicated by the first active downlink BWP identifier (firstActiveDownlinkBWP-Id) set in the RRC message for that SCell is not set to a dormant BWP, the MAC entity of UE 122 performs process (AD-1-1-1). (2) If the BWP indicated by the first active downlink BWP identifier (firstActiveDownlinkBWP-Id) configured in the RRC message for that SCell is configured as a dormant BWP, the MAC entity of UE 122 stops the BWP inactivity timer (bwp-InactivityTimer) for this serving cell if it is running. (3) The MAC entity of UE122 activates the downlink BWP indicated by the first active downlink BWP identifier (firstActiveDownlinkBWP-Id) and the uplink BWP indicated by the first active uplink BWP identifier (firstActiveUplinkBWP-Id) configured for that SCell in the RRC message.

[0153] (Process AD-1-1-1) The MAC entity of the terminal device may activate the SCell at a predetermined timing and apply (perform) normal SCell operations including some or all of the following (A) to (E). (A) Transmission of Sounding Reference Signal (SRS) in this SCell (B) Reporting of Channel State Information (CSI) for this SCell (C) Monitoring PDCCH in this SCell (D) Monitoring of PDCCH for this SCell (when scheduling for this SCell is performed in another serving cell) (E) If PUCCH is configured, PUCCH transmission on this SCell

[0154] (Process AD-2) The MAC entity of the terminal device may perform some or all of the following (A) to (D): (A) This SCell is deactivated at a predetermined timing. (B) Stop the SCell inactivity timer associated with this SCell. (C) Deactivate all Active BWPs associated with this SCell. (D) Flushes the HARQ buffer associated with this SCell.

[0155] (Process AD-3) The MAC entity of the terminal device may perform some or all of the following (A) to (D): (A) Do not transmit SRS on this SCell. (B) Do not report CSI for this SCell. (C) Do not transmit PUCCH, UL-SCH, and / or RACH on this SCell. (D) Do not monitor the PDCCH of this SCell and / or the PDCCH for this SCell.

[0156] As described above, the MAC entity performs the process (AD) to activate and deactivate the SCell.

[0157] Furthermore, as described above, when an SCell is added, the initial state of the SCell may be set by an RRC message.

[0158] Here, the SCell deactivation timer will be described. For an SCell for which a PUCCH is not configured, the value of the SCell deactivation timer (information regarding the time at which the timer is considered to have expired) may be notified by an RRC message. For example, if information indicating 40 ms as the value of the SCell deactivation timer is notified by an RRC message, the timer is considered to have expired when the notified time (here, 40 ms) has elapsed without the timer being stopped after the timer is started or restarted in the above process (AD). Furthermore, the SCell deactivation timer may be a timer named sCellDeactivationTimer.

[0159] Here, the band portion (BWP) will be explained.

[0160] A BWP may be a part or all of the band of the serving cell. A BWP may also be referred to as a carrier BWP. One or more BWPs may be configured in a terminal device. A BWP may be configured by information included in broadcast information associated with a synchronization signal detected in an initial cell search. A BWP may also be a frequency bandwidth associated with a frequency at which an initial cell search is performed. A BWP may also be configured by RRC signaling (e.g., dedicated RRC signaling). A downlink BWP (DL BWP) and an uplink BWP (UL BWP) may also be configured separately. One or more uplink BWPs may also be associated with one or more downlink BWPs. Furthermore, the correspondence between the uplink BWP and the downlink BWP may be a predetermined correspondence, or may be correspondence based on RRC signaling (e.g., Dedicated RRC signaling), or may be correspondence based on physical layer signaling (e.g., Downlink Control Information (DCI) notified on a Downlink Control Channel), or may be a combination thereof.

[0161] A BWP may be configured by a group of consecutive physical resource blocks (PRBs). Furthermore, parameters of the BWP (one or more BWPs) of each component carrier may be configured for a terminal device in a connected state. The BWP parameters for each component carrier may include some or all of the following: (A) type of cyclic prefix, (B) subcarrier spacing, (C) frequency location of the BWP (e.g., start location or center frequency location on the lower frequency side of the BWP) (for example, ARFCN may be used for the frequency location, or an offset from a specific subcarrier of the serving cell may be used. The offset may be in units of subcarriers or resource blocks. Both the ARFCN and the offset may be configured.), (D) bandwidth of the BWP (e.g., the number of PRBs), (E) resource configuration information for the control signal, and (F) center frequency location of the SS block (for example, ARFCN may be used for the frequency location, or an offset from a specific subcarrier of the serving cell may be used. The offset may be in units of subcarriers or resource blocks. Both the ARFCN and the offset may be configured.) Furthermore, the resource configuration information for the control signal may be included in the configuration of the BWP for at least some or all of the PCell and / or PSCell.

[0162] A terminal device may transmit and receive in an active BWP among one or more configured BWPs. Among one or more BWPs configured for one serving cell associated with the terminal device, at most one uplink BWP and / or at most one downlink BWP may be configured to be active BWPs at a given time. An activated downlink BWP is also referred to as an Active DL BWP. An activated uplink BWP is also referred to as an Active UL BWP.

[0163] Next, we will explain BWP deactivation. One or more BWPs may be configured in one serving cell. BWP switching in the serving cell is used to activate a deactivated BWP (also called an inactive BWP) and deactivate an activated BWP.

[0164] BWP switching is controlled by the PDCCH indicating a downlink assignment or uplink grant, the BWP inactivity timer, RRC signaling, or the MAC entity itself due to the initiation of a random access procedure. The active BWP of the serving cell is indicated by RRC or PDCCH.

[0165] Next, we will explain dormant BWP. Entering into or leaving a dormant BWP is performed by BWP switching. This control is performed by PDCCH for each SCell or for each group called a dormant SCell group. The configuration of a dormant SCell group is indicated by RRC signaling. In the current specifications, dormant BWP applies only to SCells. Note that dormant BWP does not change a certain BWP to a dormant state, but may be interpreted as one BWP configured for dormancy among one or more BWPs configured for a UE. There may be multiple BWPs configured for dormancy for a UE.

[0166] The fact that a certain BWP is a dormant BWP may be indicated by the absence of a specific parameter in the BWP configuration. For example, the fact that a BWP is a dormant BWP may be indicated by the absence of a PDCCH-Config information element, which is an information element for configuring UE-specific PDCCH parameters, included in the downlink BWP configuration. Furthermore, the fact that a BWP is a dormant BWP may be indicated by the absence of some of the parameters included in the PDCCH-Config information element, which is an information element for configuring UE-specific PDCCH parameters, included in the downlink BWP configuration. For example, the fact that a BWP is a dormant BWP may be indicated by the absence of some or all of the search space-related configuration, which is configured by the PDCCH-Config information element and defines where and / or how PDCCH candidates are searched for (searched), being configured in the BWP configuration.

[0167] In addition, in some configurations, the configuration of dormant BWP on an SpCell such as a PCell or a PSCell and a PUCCH SCell on which PUCCH transmission can be performed may not be supported.

[0168] When a UE receives a PDCCH in an SpCell indicating that it will exit a dormant BWP outside a set period (active time), it activates the downlink BWP indicated by the first downlink BWP identifier previously notified by RRC signaling.

[0169] A UE that receives a PDCCH in an SpCell indicating that it will exit a dormant BWP within a certain set period (active time) activates the downlink BWP indicated by the second downlink BWP identifier previously notified by RRC signaling.

[0170] Upon receiving the PDCCH indicating entry into a dormant BWP, the UE activates the downlink BWP indicated by the third downlink BWP identifier (dormantDownlinkBWP-Id) notified in advance by RRC signaling.

[0171] The above-mentioned entry and exit of the dormant BWP is performed by BWP switching, and when a new BWP is activated, the previously active BWP is deactivated. In other words, when exiting a dormant BWP, the dormant BWP is deactivated, and when entering a dormant BWP, the dormant BWP is activated.

[0172] Here, the PDCCH indicating entry into a dormant BWP and the PDCCH indicating exit from a dormant BWP will be described.

[0173] For example, a UE configured with discontinuous reception (DRX) in the SpCell may monitor the PDCCH in the Active BWP of the SpCell to detect a certain DCI format (e.g., DCI format 2_6) outside the active time of DRX. The CRC of the DCI format may be scrambled with a certain RNTI (e.g., PS-RNTI). A UE configured with a dormant SCell group determines switching of the Active DL BWP based on bitmap information included in the payload of DCI format 2_6. For example, if a certain bit in the bitmap is associated with one dormant SCell group and the bit is 1, if the Active DL BWP is a dormant BWP, BWP switching may be performed to another pre-configured BWP, and if the Active DL BWP is not a dormant BWP, the UE may remain at that BWP. Alternatively, if the bit is 0, BWP switching may be performed so that the Active DL BWP becomes a dormant BWP.

[0174] The UE does not need to monitor the PDCCH for the purpose of detecting DCI format 2_6 during the DRX active time.

[0175] A UE configured with discontinuous reception (DRX) in the SpCell may monitor the PDCCH in the Active BWP of the SpCell to detect a certain DCI format (e.g., DCI formats 0_1 and 1_1) during the active time of DRX. The CRC of the DCI format may be scrambled with a certain RNTI (e.g., C-RNTI or MCS-C-RNTI). A UE configured with a dormant SCell group may determine switching of the Active DL BWP based on bitmap information included in the payload of DCI format 0_1 ​​or DCI format 1_1. For example, if a certain bit in the bitmap is associated with one dormant SCell group and the bit is 1, BWP switching may be performed to another pre-configured BWP if the Active DL BWP is a dormant BWP, and if the Active DL BWP is not a dormant BWP, the UE may remain at that BWP. Alternatively, if the bit is 0, BWP switching may be performed so that the Active DL BWP becomes a dormant BWP. Furthermore, the "different pre-set BWP" may be a BWP different from the "different pre-set BWP" used in the description of DCI format 2_6.

[0176] The UE does not need to monitor the PDCCH for the purpose of detecting DCI format 0_1 ​​and DCI format 1_1 outside the DRX active time.

[0177] Monitoring the PDCCH indicating exiting the dormant BWP may mean monitoring the PDCCH for the purpose of detecting DCI format 2_6 outside of the active time of DRX, and monitoring the PDCCH for the purpose of detecting DCI format 0_1 ​​and DCI format 1_1 during the active time of DRX.

[0178] In each activated serving cell in which a BWP is configured, the MAC entity may perform some or all of the following (A) to (H) if the BWP is activated (active BWP) and is not a dormant BWP: (A) Transmit UL-SCH with that BWP. (B) If a PRACH occasion is configured, transmit the RACH in that BWP. (C) Monitor the PDCCH with that BWP. (D) If PUCCH is configured, transmit PUCCH in that BWP. (E) Report the CSI in that BWP. (F) If SRS is configured, send SRS in that BWP. (G) Receive DL-SCH with that BWP. (H) Initialize any configured uplink grants of grant type 1 that were set up and suspended in that BWP.

[0179] In each activated serving cell in which a BWP is configured, the MAC entity may perform some or all of the following (A) to (G) if the BWP is activated (active BWP) and if the BWP is dormant BWP. (A) If the BWP inactivity timer of the serving cell for this BWP is running, stop it. (B) Do not monitor the PDCCH of that BWP. (C) Do not monitor the PDCCH for that BWP. (D) DL-SCH is not received in that BWP. (F) Do not send SRS with that BWP. (G) Do not transmit UL-SCH in that BWP. (H) Do not transmit RACH in that BWP. (I) Do not transmit PUCCH in that BWP. (J) Clear the configured downlink assignment and the configured uplink grant of grant type 2 associated with that SCell. (K) Suspend the configured uplink grant of grant type 1 associated with that SCell. (L) If beam failure settings are configured, detect beam failure and perform beam failure recovery if beam failure is detected.

[0180] A MAC entity may, if a BWP is deactivated, do some or all of the following: (A) Do not transmit UL-SCH in that BWP. (B) Do not transmit a RACH in that BWP. (C) Do not monitor the PDCCH in that BWP. (D) Do not transmit PUCCH in that BWP. (E) Not reporting a CSI in that BWP. (F) Do not send SRS with that BWP. (G) DL-SCH is not received in that BWP. (H) Clear the configured uplink grant of grant type 2 set in that BWP. (I) Suspend the configured uplink grant of grant type 1 of the deactivated BWP (inactive BWP).

[0181] Next, we will explain the random access procedure for a UE configured with BWP. When initiating the random access procedure in a serving cell, the MAC entity may perform some or all of the following steps (A) to (E) on the selected carrier of the serving cell. (A) If the resource (occasion) for transmitting the PRACH is not configured for the Active UL BWP, (A1) switch the Active UL BWP to the BWP indicated by the RRC parameter (initialUplinkBWP), and (A2) if the serving cell is an SpCell, switch the Active UL BWP to the BWP indicated by the RRC parameter initialDownlinkBWP. (B) If the resource (occasion) for transmitting the PRACH is configured for the Active UL BWP, if the serving cell is an SpCell and the Active DL BWP and the Active UL BWP do not have the same identifier (bwp-Id), the Active DL BWP is switched to a BWP with the same identifier as the Active UL BWP's identifier. (C) If the BWP inactivity timer associated with the Active Downlink BWP of this serving cell is running, stop this timer. (D) If the serving cell is an SCell, stop the BWP inactivity timer associated with the SpCell's Active DL BWP if this timer is running. (E) Perform the random access procedure on the Active DL BWP of the SpCell and the Active UL BWP of this serving cell.

[0182] Next, the BWP inactivity timer will be described. For each activated serving cell for which the BWP inactivity timer is set, the MAC entity performs the following process (A). The BWP inactivity timer may also be a timer named bwp-InactivityTimer. (A) If the default downlink BWP identifier (defaultDownlinkBWP-Id) is configured and the Active DL BWP is not the BWP indicated by the identifier (dormantDownlinkBWP-Id), or if the default downlink BWP identifier (defaultDownlinkBWP-Id) is not configured and the Active DL BWP is not the initialDownlinkBWP and the Active DL BWP is not the BWP indicated by the identifier (dormantDownlinkBWP-Id), the MAC entity performs the following processes (A-1) and (A-2). (A-1) If a PDCCH addressed to the C-RNTI or CS-RNTI indicating a downlink assignment or uplink grant is received in an Active DL BWP, or if a PDCCH addressed to the C-RNTI or CS-RNTI indicating a downlink assignment or uplink grant for an Active DL BWP is received, or if a MAC PDU is sent with a configured uplink grant or a MAC PDU is received with a configured downlink assignment, the MAC entity performs the following process (A-1-1). (A-1-1) If a random access procedure associated with this serving cell is not in progress or an ongoing random access procedure associated with this serving cell is successfully completed by receiving a PDCCH addressed to the C-RNTI, start or restart the BWP inactivity timer associated with the Active DL BWP. (A-2) If the BWP inactivity timer associated with the Active DL BWP expires, the MAC entity performs the following process (A-2-1). (A-2-1) If defaultDownlinkBWP-Id is set, BWP switching is performed to the BWP indicated by this defaultDownlinkBWP-Id, and if not, BWP switching is performed to the initialDownlinkBWP.

[0183] Furthermore, if the MAC entity receives a PDCCH for BWP switching and switches the Active DL BWP, it may perform the following process (A). (A) If the default downlink BWP identifier (defaultDownlinkBWP-Id) is set and the switched-to Active DL BWP is not the BWP indicated by the identifier (dormantDownlinkBWP-Id), and if the switched-to Active DL BWP is not the BWP indicated by dormantDownlinkBWP-Id, start or restart the BWP inactivity timer associated with the Active DL BWP.

[0184] Next, we will explain the procedures for beam failure detection and recovery.

[0185] In the MAC entity, a beam failure recovery procedure may be configured by RRC for each serving cell. Beam failure is detected by counting beam failure instance notifications notified to the MAC entity from the lower layer (PHY layer). The MAC entity may perform some or all of the following processes (A), (B), and (C) for each serving cell to detect beam failure. (A) If a beam failure instance notification is received from the lower layer, start or restart the timer (beamFailureDetectionTimer) and increment the counter (BFI-COUNTER) by 1. If the value of BFI_COUNTER is equal to or greater than the configured threshold (beamFailureInstanceMaxCount), perform the process in (A-1) below. (A-1) If the serving cell is an SCell, trigger beam failure recovery (BFR) for this serving cell; otherwise, start a random access procedure in the SpCell. (B) If the beamFailureDetectionTimer for this serving cell expires, or if the beamFailureDetectionTimer, beamFailureInstanceMaxCount, and / or reference signal settings for beam failure detection are changed by higher layers, set BFI_COUNTER to 0. (C) If the serving cell is an SpCell and the random access procedure is completed successfully, set BFI_COUNTER to 0, stop the timer (beamFailureRecoveryTimer), and consider the beam failure recovery procedure to be completed successfully. Otherwise, if the serving cell receives a PDCCH addressed to the C-RNTI on the SCell that indicates a new uplink grant for transmitting information for beam failure recovery of the SCell (e.g., information contained in the SCell BFR MAC CE), or if the SCell is in an inactive state, set BFI_COUNTER to 0, consider the beam failure recovery procedure to be completed successfully, and cancel all beam failure recoveries (BFRs) triggered for this serving cell.

[0186] The MAC entity shall perform the following process (A) if at least one Beam Failure Recovery (BFR) has been triggered by the Beam Failure Recovery procedure and has not been canceled. (A) If the UL-SCH resource can contain the BFR MAC CE of the SCell and its subheader taking into account the priority of the logical channel, include the BFR MAC CE of the SCell and its subheader. Otherwise, if the UL-SCH resource can contain the truncated BFR MAC CE of the SCell and its subheader taking into account the priority of the logical channel, include the truncated BFR MAC CE of the SCell and its subheader. Otherwise, trigger a scheduling request for SCell beam failure recovery.

[0187] The dormancy of an SCell is achieved by activating a dormant BWP in the SCell. Even when the SCell is in the dormant state, CSI measurement, automatic gain control (AGC), and beam management including beam failure recovery in the SCell may be performed.

[0188] Next, a method for adding a PSCell of an SCG and zero or more SCells to a terminal device will be described.

[0189] The addition of a PSCell of an SCG and zero or more SCells may be performed by an RRC message related to reconfiguration of an RRC connection. Figures 9 to 13 show examples of ASN.1 descriptions representing fields and / or information elements related to the addition of a PSCell of an SCG and zero or more SCells, which are included in a message related to reconfiguration of an RRC connection in NR.

[0190] To avoid complicating the explanation, the messages and / or information elements in each figure may differ from the actual message structure and / or information element structure, and some structured fields and information elements may be expanded and / or fields and information elements that are not directly related to the explanation may be omitted.

[0191] As shown in Fig. 9, an RRC reconfiguration message (RRCReconfiguration message) may be used to add a PSCell and zero or more SCells of an SCG. The RRC reconfiguration message may include some or all of the following information (A) to (E). The RRC reconfiguration message may also include other information. (A) RRC transaction identifier (rrc-TransactionIdentifier) (B) Configuration for adding, modifying, and releasing radio bearers (radioBearerConfig) (C) Secondary cell group settings (secondaryCellGroup) (D) Master cell group settings (masterCellGroup) (E) RRC configuration of secondary cell group in MR-DC (mrdc-SecondaryCellGroupConfig)

[0192] When an RRC reconfiguration message is notified to a terminal device using SRB3, the SCG configuration may be notified by the above setting (C) of the RRC Reconfiguration message. Also, when an RRC reconfiguration message is notified to a terminal device using SRB1, the SCG configuration may be notified by an RRC reconfiguration message generated by a secondary node, which is included in the above setting (E) of the RRC Reconfiguration message generated by the master node. In this case, the SCG configuration may be notified by the above setting (C) included in the RRC reconfiguration message generated by the secondary node. Also, a separate message may be used for the SCG configuration.

[0193] The configuration of the secondary cell group may be provided by a cell group configuration information element (CellGroupConfigIE). As shown in Figure 10, the cell group configuration information element may include some or all of the following information (A) to (H). The cell group configuration information element may also include other information. (A) Cell group identifier (cellGroupId) (B) Configuration for adding and / or modifying RLC bearers (rlc-BearerToAddModList) (C) Configuration for RLC bearer release (rlc-BearerToReleaseList) (D) MAC configuration for this cell group (mac-CellGroupConfig) (E) PHY configuration for this cell group (physicalCellGroupConfig) (F) SpCell configuration (spCellConfig) (G) Settings for adding and modifying SCells (sCellToAddModList) (H) Settings for releasing SCells (sCellToReleaseList)

[0194] The SpCell may be added and / or configured by the SpCell configuration in (F) above, and the SCell may be added, modified, and / or released by the configurations in (G) and (H) above. These may also be done by other messages.

[0195] The above SpCell settings may include some or all of the following information (A) to (D), as shown in Fig. 11. The SpCell settings may also include other information. (A) Index for identifying serving cells (servCellIndex) (B) Reconfiguration with Sync (C) Information on timer values ​​and constants used to determine radio link failures (rlf-TimersAndConstants) (D) SpCell device-specific parameter configuration (spCellConfigDedicated)

[0196] The above-mentioned information elements for synchronized reconfiguration may include some or all of the following information (A) to (D), as shown in Fig. 12. The synchronized reconfiguration information may also include other information. (A) SpCell cell-specific parameter settings (spCellConfigCommon) (B) New UE identifier (UE-Identity) value (newUE-Identity) (C) Value of timer T304 (t304) (D) RACH terminal device specific parameter setting (rach-ConfigDedicated)

[0197] The above-mentioned RACH UE-specific parameter configuration may include a parameter (CFRA) used for continuation-free random access. If this CFRA is not included in the configuration, the UE may perform contiguous random access in the random access procedure. The CFRA may include information on RA occasions used for contiguous random access.

[0198] The above-mentioned configuration of the cell-specific parameters of the SpCell may be provided by an information element (ServingCellConfigCommon IE) used to configure the cell-specific parameters of the serving cell. The information element used to configure the cell-specific parameters of the serving cell may include some or all of the following information (A) to (D), as shown in Fig. 13. Furthermore, the information element used to configure the cell-specific parameters of the serving cell may also include other information. (A) Physical cell identifier (physCellId) (B) Downlink common parameters in the cell (downlinkConfigCommon) (C) Uplink common parameters in the cell (uplinkConfigCommon) (D) Configuration of terminal device-specific parameters (including some cell-specific parameters) of SCell (sCellConfigDedicated) (E) SSB subcarrier spacing information (ssbSubcarrierSpacing)

[0199] The downlink common parameters in a cell may include downlink frequency information (frequencyInfoDL) and / or initial downlink BWP information (initialDownlinkBWP). The downlink frequency information may include information on the frequency of SSBs used in this serving cell.

[0200] The above-mentioned configuration for adding or modifying an SCell may be provided by one or more SCell configuration information elements (SCellConfigIE). The SCell configuration information element may include some or all of the following information (A) to (D), as shown in Fig. 14. The SCell configuration information element may also include other information. (A) Identifier for identifying SCell (sCellIndex) (B) Configuring cell-specific parameters for SCell (sCellConfigCommon) (C) Configuration of terminal device-specific parameters (including some cell-specific parameters) of SCell (sCellConfigDedicated) (D) Information that indicates SCell activation / inactivation (sCellState-r16)

[0201] As an example, a procedure for adding a PSCell and zero or more SCells to an SCG using the above RRC message and information elements will be described. Note that the RRC message and information elements used in the description are examples, and the names and structures when implemented are not limited to these.

[0202] The RRC entity of the terminal device that has received the RRCReconfiguration message may perform some or all of the following (A) to (F). The terminal device that has received the RRCReconfiguration message may also perform other processing. (A) If the RRCReconfiguration contains a masterCellGroup, then process (BD-1) for the master cell group based on this masterCellGroup. (B) If the RRCReconfiguration includes a secondaryCellGroup, process (BD-1) is performed on the secondary cell group based on this secondaryCellGroup. (C) If the RRCReconfiguration contains a radioBearerConfig, configure the radio bearer based on this radioBearerConfig. (D) Set the content to be included in the RRC reconfiguration complete message. (E) If the SpCell configuration (spCellConfig) of the received secondary cell group configuration includes reconfigurationWithSync, start the random access procedure in that SpCell. (F) If the SpCell configuration (spCellConfig) of the MCG or SCG includes reconfigurationWithSync and the above random access procedure is successfully completed in the NR cell group, stop timer T304 for that cell group.

[0203] (Process BD-1) The RRC entity of the terminal device may perform some or all of the following (A) to (G). (A) If CellGroupConfig includes spCellConfig including reconfigurationWithSync, the RRC entity of the terminal device performs some or all of the following (1) to (3). (1) Execute process (BD-2). (2) Resume all suspended radio bearers. (3) Resume SCG transmission for all radio bearers if suspended. (B) If the CellGroupConfig contains an rlc-BearerToReleaseList, release of the RLC bearer is performed based on this rlc-BearerToReleaseList. (C) If CellGroupConfig contains rlc-BearerToAddModList, add and / or modify RLC bearers based on this rlc-BearerToAddModList. (D) If the CellGroupConfig contains a mac-CellGroupConfig, configure the MAC entity of this cell group based on this mac-CellGroupConfig. (E) If sCellToReleaseList is included in CellGroupConfig, release of SCell is performed based on this sCellToReleaseList. (F) If the CellGroupConfig contains an spCellConfig, configure the SpCell based on this spCellConfig. (G) If the CellGroupConfig contains sCellToAddModList, add and / or modify SCells based on this sCellToAddModList.

[0204] (Process BD-2) The RRC entity of the terminal device may perform some or all of the following (A) to (). (A) If AS security is not activated, execute the process to transition to RRC_IDLE and end the procedure. (B) Start timer T304 for the SpCell (to be configured) using the value of t304 included in reconfigurationWithSync. (C) If downlink frequency information (frequencyInfoDL) is included in reconfigurationWithSync, the cell indicated by the physical cell identifier (physCellId) included in reconfigurationWithSync at the SSB frequency indicated in frequencyInfoDL is determined to be the target SpCell. (D) If the downlink frequency information (frequencyInfoDL) is not included in reconfigurationWithSync, the cell indicated by the physical cell identifier (physCellId) included in reconfigurationWithSync at the SSB frequency of the original SpCell (Source SpCell) is determined to be the target SpCell. (E) Initiate downlink synchronization of the target SpCell. (F) Acquire the MIB of the target SpCell. (G) If a specific bearer (DAPS bearer) is not established, perform some or all of the following steps (1) to (4). (1) Reset the MAC entity of this cell group. (2) If an SCell not included in SCellToAddModList is configured in this cell group, this SCell is put into an inactive state. (3) The value of newUE-Identity is applied as the C-RNTI of this cell group. (4) Configure the lower layer based on the received spCellConfigCommon.

[0205] Next, timer T304 will be described. Timer T304 may exist for each cell group. Furthermore, the value (time information at which the timer expires) of a certain timer (here, timer T304) may be notified by an RRC message. For example, if information indicating a timer value of 1000 ms is notified by an RRC message, the timer may be considered to have expired if the notified time (1000 ms in this example) has elapsed since the timer was started or restarted without the timer being stopped.

[0206] Based on receiving an RRC reconfiguration message including reconfigurationWithSync, the terminal device may start timer T304 for the cell group to which the reconfigurationWithSync setting applies.

[0207] The terminal device may stop timer T304 for the cell group to which the reconfigurationWithSync setting applies based on the successful completion of random access to the target SpCell indicated by reconfigurationWithSync.

[0208] The terminal device may stop timer T304 for the SCG based on the SCG being released.

[0209] The terminal device may perform an RRC connection re-establishment procedure if the MCG timer T304 expires and if a specific bearer (DAPS bearer) is not configured.

[0210] The terminal device may notify the network of the failure of the synchronized reconfiguration by initiating an SCG failure information procedure when the SCG timer T304 expires.

[0211] The operation of the terminal device when the timer T304 of the SCG expires will now be further described.

[0212] If timer T304 of the secondary cell group expires, the RRC entity of the terminal device performs the following process (A) if MCG transmission is not suspended, and performs the following process (B) if MCG transmission is suspended. (A) If the terminal device specific preamble provided in rach-ConfigDedicated is set, release it and start the SCG failure information procedure to report the failure of the SCG synchronized reconfiguration. (B) Initiate the RRC connection re-establishment procedure.

[0213] Next, the SCG failure information procedure will be described, which may be referred to as the SCG failure information procedure.

[0214] This procedure may be used to notify the E-UTRAN or NR master node about an SCG failure experienced by the terminal device.

[0215] The RRC entity of the terminal device may initiate this procedure to report an SCG failure when MCG or SCG transmission is not suspended and any of the following conditions (A) to (D) is met: (A) SCG wireless link failure detected (B) SCG synchronization setting failure detected (C)SCG setting failure detected (D) The lower layer of the SCG notifies the failure of the integrity check for SRB3.

[0216] The RRC entity of the terminal device initiating this procedure performs some or all of the following (A) to (E). (A) Suspend SCG transmission for all SRBs and DRBs. (B) Reset the SCG MAC. (C) If timer T304 in this SCG is running, stop it. (D) If conditional reconfiguration for PSCell change is set, stop this evaluation. (E) Set the content to be included in the SCG Failure Information (SCGFailureInformation) message and submit this message to the lower layer for transmission.

[0217] The lower layer of the RRC of the terminal device may transmit the SCG failure information (SCGFailureInformation) message to the base station device.

[0218] Next, activation and deactivation of SCG will be explained.

[0219] In LTE and / or NR, a state in which the SCG is deactivated (SCG deactivated state) may be included as part of the RRC_CONNECTED state.

[0220] In LTE and / or NR, a state in which an SCG is deactivated (SCG deactivated state) may be a state in which a terminal device performs some or all of the following (A) to (J) in the SpCell (PSCell) of that SCG and / or in all cells of that SCG. (A) Do not transmit SRS in that cell. (B) Do not report CSI for that cell. (C) Do not transmit PUCCH, UL-SCH, and / or RACH in that cell. (D) Do not monitor the PDCCH of that cell and / or the PDCCH for that cell. (E) Not monitoring the PDCCH of that cell and / or the PDCCH for that cell addressed to the C-RNTI, MCS-C-RNTI, and / or CS-RNTI indicating an uplink grant for UL-SCH transmission in that cell. (F) Do not perform automatic gain control (AGC) on that cell. (G) No beam management, including beam failure recovery, is performed in that cell. (H) Radio Link Monitoring (RLM) is not performed in that cell. (I) In that cell, the BWP that has been set as a dormant BWP is called the active BWP. (J) The C-RNTI is not monitored on the PDCCH in the activated dormant BWP of the cell.

[0221] In addition, becoming an SCG inactive state may be referred to as entering an inactive SCG. In addition, the SCG inactive state may be a state in which the Active BWPs of all cells of the SCG are dormant BWPs. In addition, the above-mentioned SCG inactive state may be a state in which the SCG transitions from an activated state (SCG active state) described later when an RRC entity instructs entry into an inactive SCG.

[0222] In LTE and / or NR, the state in which the SCG is activated (SCG active state) may be included as part of the RRC_CONNECTED state.

[0223] In LTE and / or NR, an activated state of an SCG (SCG activated state) may be a state in which a terminal device performs some or all of the following (A) to (J) in the SpCell (PSCell) of that SCG and / or in any cell of that SCG. (A) Transmit SRS in that cell. (B) Report the CSI for that cell. (C) Transmit PUCCH, UL-SCH, and / or RACH in that cell. (D) Monitor the PDCCH of that cell and / or the PDCCH for that cell. (E) Monitor the PDCCH of that cell and / or the PDCCH for that cell addressed to the C-RNTI, MCS-C-RNTI, and / or CS-RNTI indicating an uplink grant for UL-SCH transmission in that cell. (F) Automatic gain control (AGC) is performed on that cell. (G) The cell performs beam control (beam management) including beam failure recovery. (H) Radio Link Monitoring (RLM) is performed in that cell. (I) In that cell, a BWP that has been set as a dormant BWP is not set as an active BWP. (J) Monitor the C-RNTI on the PDCCH in the activated BWP of that cell.

[0224] Furthermore, becoming an SCG active state may be referred to as entering an activated SCG. Furthermore, the SCG active state may be a state in which the Active BWPs of the SpCell and / or one or more SCells of the SCG are not dormant BWPs. Furthermore, the above-mentioned SCG inactive state may be a state to which the SCG transitions from an inactive state (SCG inactive state) when an RRC entity instructs the SCG to leave the inactive SCG.

[0225] In LTE and / or NR, a terminal device may transition an SCG to an inactive state (in other words, may deactivate an SCG) based on receiving some or all of the following (A) to (B). Note that the messages and control elements in (A) to (B) below may be notified to the terminal device from a cell group other than the SCG. Furthermore, each piece of information may be notified to the terminal device by an RRC message, a MAC information element, or a physical control channel. (A) Information instructing inactivation of SCG (B) Information instructing SpCell inactivation

[0226] Furthermore, the terminal device may transition the SCG from the active state to the inactive state based on a timer related to the deactivation of the SCG. Furthermore, the terminal device may transition the SCG from the active state to the inactive state based on a timer related to the deactivation of the PSCell.

[0227] In addition, the terminal device may transition the SCG from an inactive state to an active state when initiating a random access procedure due to a scheduling request (in other words, initiated by the MAC entity itself). The MAC entity of the terminal device may also obtain an instruction to activate the SCG, an instruction to resume from an inactive SCG, an instruction to resume from a dormant state of the SpCell, and / or other information from the RRC entity of the terminal device.

[0228] In LTE and / or NR, a terminal device may transition an SCG from an inactive state to an active state (in other words, may activate an SCG) based on receiving some or all of the following (A) to (D). Note that the messages and control elements (A) to (D) below may be notified to the terminal device from a cell group other than the SCG. Furthermore, each piece of information may be notified to the terminal device via an RRC message, a MAC information element, or a physical control channel. (A) Information that directs SCG activation (B) Information that directs the return of SCG from its inactive state (Resume) (C) Information that directs SpCell activation (D) Information that directs the return of SpCell from its inactivated state

[0229] Furthermore, the terminal device may transition the SCG from the inactive state to the active state based on a timer related to the deactivation of the SCG. Furthermore, the terminal device may transition the SCG from the inactive state to the active state based on a timer related to the deactivation of the PSCell.

[0230] In addition, the terminal device may transition the SCG from the inactive state to the active state when initiating a random access procedure due to a scheduling request triggered to transmit a MAC PDU including a MAC SDU. In addition, the terminal device may transition the SCG from the inactive state to the active state when initiating a random access procedure.

[0231] In addition, the terminal device may transition the SCG from an inactive state to an active state when initiating a random access procedure due to a scheduling request (in other words, initiated by the MAC entity itself). The MAC entity of the terminal device may also obtain an instruction to activate the SCG, an instruction to resume from an inactive SCG, an instruction to resume from a dormant state of the SpCell, and / or other information from the RRC entity of the terminal device.

[0232] Inactivation of an SCG may also be referred to as entering a dormant SCG. Alternatively, inactivation of an SCG may be activation of the dormant BWP of the SpCells in the cell group. Inactivation of an SCG may also be referred to as SCG dormancy or SCG suspension.

[0233] When an SCG is in a deactivated state, all uplink transmissions in the SCG may be stopped. In this case, information about the SCG may be transmitted in another cell group (e.g., MCG). Alternatively, information about the SCG may be transmitted in the SCG that has left the deactivated state (activated SCG).

[0234] There may be cases where a random access procedure in an SpCell (PSCell) is initiated in a deactivated SCG by the MAC entity triggering a scheduling request to transmit a MAC PDU containing a MAC CE, or directly by the MAC entity, where the MAC PDU may not contain a MAC SDU.

[0235] On the other hand, a random access procedure in the SpCell (PSCell) may be initiated in a deactivated SCG by triggering a scheduling request to transmit a MAC PDU containing data (MAC SDU) from a higher layer, such as user data or an RRC message.

[0236] The return of an SCG from an inactive state (activation of an SCG) may be referred to as leaving a dormant SCG. The return of an SCG from an inactive state may also be a BWP switch from a dormant BWP to another (non-dormant) BWP in the SpCell of the cell group.

[0237] The restoration of SCG from an inactivated state may also be referred to as SCG activation.

[0238] A terminal device that deactivates an SCG may perform some or all of the following processes (A) to (F) in the SCG. (A) All SCells are in an inactive state. (B) All SCell inactivity timers associated with the active SCell are considered to have expired. (C) All SCell inactivity timers associated with the dormant SCell are considered to have expired. (D) Do not start or restart the SCell inactivity timers associated with all SCells. (E) Ignore the MAC CE that activates the SCell. For example, in the process (AD), if a MAC CE that activates the SCell is received and an instruction to deactivate the SCG has not been issued (or the SCG is not in a deactivated state), perform process (AD-1). (F) Executing the process (AD-2). For example, when inactivation of SCG is instructed in the process (AD) (or when SCG is inactivated), the process (AD-2) is executed.

[0239] A terminal device that restores an SCG from an inactivated state may perform some or all of the following processes (A) to (D) in the SCG. (A) To activate all SCells, process (AD-1) is executed. (B) All SCells remain in the deactivated state. However, since they are not in the deactivated state, for example, if a MAC CE to activate an SCell is received in the process (AD), since no instruction to deactivate the SCG has been given (or the SCG is not in the deactivated state), the process (AD-1) may be performed. (C) When the SCG returns from the deactivated state based on an RRC message, if this RRC message includes parameters related to random access to some or all SCells, a random access procedure is initiated on the target SCell based on the notified parameters. (D) When the recovery of the SCG from an inactivated state is performed based on an RRC message, if this RRC message includes information specifying the state of the SCell, a decision is made based on that information as to whether the state of each SCell should be set to an active state or an inactive state.

[0240] Based on the above description, various embodiments of the present invention will be described. Note that the processes described above may be applied to the processes omitted in the following description.

[0241] Fig. 5 is a block diagram showing the configuration of a terminal device (UE 122) according to an embodiment of the present invention. To avoid complicating the explanation, Fig. 5 shows only the main components closely related to one embodiment of the present invention.

[0242] 5 includes a receiver 500 that receives an RRC message or the like from a base station device, a processor 502 that performs processing according to parameters included in the received message, and a transmitter 504 that transmits the RRC message or the like to the base station device. The 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, MAC layer processor, RLC layer processor, PDCP layer processor, SDAP processor, RRC layer processor, and NAS layer processor.

[0243] Fig. 6 is a block diagram showing the configuration of a base station device according to an embodiment of the present invention. To avoid complication of explanation, Fig. 6 shows only main components closely related to one embodiment of the present invention. The base station device may be an eNB 102 or a gNB 108.

[0244] 6 includes a transmitter 600 that transmits an RRC message or the like to the UE 122, a processor 602 that creates an RRC message including parameters and transmits it to the UE 122, causing the processor 502 of the UE 122 to process it, and a receiver 604 that receives the RRC message or the like from the UE 122. The processor 602 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 602 may include some or all of the functions of the physical layer processor, MAC layer processor, RLC layer processor, PDCP layer processor, SDAP processor, RRC layer processor, and NAS layer processor.

[0245] Various examples of processing by the terminal device according to the embodiment of the present invention will be described below.

[0246] FIG. 15 is a diagram showing an example of processing performed by the terminal device in the embodiment of the present invention.

[0247] The terminal device (UE 122) receives an RRC message from the base station device (eNB 102 or gNB 108) (step S1500). This RRC message may include information for determining whether to activate or deactivate the secondary cell group.

[0248] The terminal device may initiate a random access procedure in an SpCell of the secondary cell group based on whether the received RRC message includes information indicating that the secondary cell group is to be in an active state or does not include information indicating that the secondary cell group is to be in an inactive state.The terminal device may not initiate a random access procedure in an SpCell of the secondary cell group based on whether the received RRC message includes information indicating that the secondary cell group is to be in an inactive state or does not include information indicating that the secondary cell group is to be in an active state (step S1502).

[0249] Furthermore, the terminal device may start a first timer based on whether a received RRC message includes information indicating that a secondary cell group is to be in an active state or does not include information indicating that a secondary cell group is to be in an inactive state. The terminal device may not start the first timer based on whether a received RRC message includes information indicating that a secondary cell group is to be in an inactive state or does not include information indicating that a secondary cell group is to be in an active state. The terminal device may stop the first timer based on successful completion of a random access procedure in an SpCell of the secondary cell group. The terminal device may also stop the first timer when the secondary cell group is released and / or deactivated. When the first timer expires, the terminal device may initiate an SCG failure information procedure for reporting SCG failure information. The SCG failure information may include information indicating that SCG activation has failed.

[0250] The terminal device may place a cell group in an inactive state based on whether a received RRC message includes information indicating that the cell group is to be placed in an inactive state or does not include information indicating that the cell group is to be placed in an active state.The terminal device may place a cell group in an active state based on whether a received RRC message includes information indicating that the cell group is to be placed in an active state or does not include information indicating that the cell group is to be placed in an inactive state and based on the successful completion of a random access procedure in an SpCell of the cell group.

[0251] This allows the terminal device to efficiently activate and deactivate cell groups.

[0252] An example in which the RRC message is an RRC reconfiguration message will be described below. The terminal device receives the RRC reconfiguration message from the base station device (eNB 102 or gNB 108). This RRC reconfiguration message may include information for determining whether to activate or deactivate the secondary cell group.

[0253] When the secondary cell group configuration included in the RRC reconfiguration message includes a synchronized reconfiguration information element, the terminal device (1) initiates a random access procedure based on whether the received RRC reconfiguration message includes information indicating that the secondary cell group is to be in an active state or does not include information indicating that the secondary cell group is to be in an inactive state, and (2) does not initiate a random access procedure based on whether the received RRC reconfiguration message includes information indicating that the secondary cell group is to be in an inactive state or does not include information indicating that the secondary cell group is to be in an active state.

[0254] Furthermore, the terminal device does not start timer T304 based on the fact that the received RRC reconfiguration message includes information indicating that the secondary cell group is to be deactivated, even if the secondary cell group configuration in this RRC reconfiguration message includes a synchronized reconfiguration information element. Alternatively, the terminal device starts timer T304 based on the fact that the secondary cell group configuration in this RRC reconfiguration message includes a synchronized reconfiguration information element, and stops timer T304 based on the fact that the received RRC reconfiguration message includes information indicating that the secondary cell group is to be deactivated or does not include information indicating that the secondary cell group is to be activated.

[0255] This allows the terminal device to efficiently activate and deactivate cell groups using an RRC reconfiguration message.

[0256] A method of indicating whether the SCG is in an active state or an inactive state when a PSCell of the SCG and zero or more SCells are added to a terminal device will be described.

[0257] The terminal device receives an RRC message for adding a PSCell of the SCG and zero or more SCells. This RRC message may be an RRC reconfiguration message shown in Figure 9. When a PSCell is added, the RRC message may include a synchronized reconfiguration information element including configuration of cell-specific parameters of the SpCell, such as a physical cell identifier.

[0258] The RRC message may also include information indicating whether the SCG is in an active state or an inactive state. For example, the information may be included in the configuration of the target cell group (for example, a cell group configuration information element). For example, the information may be included in a synchronized reconfiguration information element included in the cell group configuration information element of the target cell group. For example, the information may be included in any information element included in the RRC message.

[0259] The information may be information indicating whether a cell group is to be in an active state or an inactive state. The information may also be information indicating that a cell group is to be in an active state. In this case, the cell group may be in an inactive state based on the absence of this information. The information may also be information indicating that a cell group is to be in an inactive state. In this case, the cell group may be in an active state based on the absence of this information. The information may also be information indicated by other information elements. Note that, if the information is not included in the configuration of the target cell group, the information may include information indicating which cell group is the target. Note that, if there is only one cell group (secondary cell group) that can be the target, the information does not need to include information indicating which cell group is the target.

[0260] For example, the information may be a field (scgState-r17) having a value of "deactivated" of ENUMERATED type. In this case, the terminal device may determine that the field (scgState-r17) having a value of "deactivated" is a cell group that deactivates the target cell group when it is included in the RRC message, and may determine that the target cell group is a cell group that activates the target cell group when this field is not included in the RRC message. Also, for example, the information may be a field (scgState-r17) having values ​​of "deactivated" and "activated" of ENUMERATED type. In this case, the terminal device may determine that the field (scgState-r17) having a value of "deactivated" is a cell group that deactivates the target cell group when it is included in the RRC message, and may determine that the RRC message is not a message for activating and / or deactivating a cell group when this field is not included in the RRC message.

[0261] In a terminal device that receives an RRC reconfiguration message, the RRC entity of the terminal device may perform some or all of the following (A) to (D). (A) If the RRCReconfiguration includes a secondaryCellGroup, the following (A-1) to (A-7) are executed for the secondary cell group based on this secondaryCellGroup. (A-1) If CellGroupConfig includes spCellConfig including reconfigurationWithSync, the RRC entity of the terminal device performs some or all of the following (A-1-1) to (A-1-9). (A-1-1) If AS security is not activated, execute the process to transition to RRC_IDLE and end the procedure. (A-1-2) Timer T304 for the SpCell (to be configured) is started using the value of t304 included in reconfigurationWithSync. Here, if the RRC reconfiguration message includes information indicating that the cell group to be configured is to be deactivated, timer T304 may not be started. If the RRC reconfiguration message includes information indicating that the cell group to be configured is to be deactivated, timer T304 may be stopped if it is running. (A-1-3) If downlink frequency information (frequencyInfoDL) is included in reconfigurationWithSync, the cell indicated by the physical cell identifier (physCellId) included in reconfigurationWithSync at the SSB frequency indicated in frequencyInfoDL is determined to be the target SpCell. (A-1-4) If the downlink frequency information (frequencyInfoDL) is not included in reconfigurationWithSync, the cell indicated by the physical cell identifier (physCellId) included in reconfigurationWithSync at the SSB frequency of the original SpCell (Source SpCell) is determined to be the target SpCell. (A-1-5) Start downlink synchronization of the target SpCell. (A-1-6) Acquire the MIB of the target SpCell. (A-1-7) If a specific bearer (DAPS bearer) is not configured, perform some or all of the following steps (A-1-7-1) to (A-1-7-4). (A-1-7-1) Reset the MAC entity of this cell group. (A-1-7-2) If an SCell not included in SCellToAddModList is set in this cell group, this SCell is put into an inactive state. (A-1-7-3) The value of newUE-Identity is applied as the C-RNTI of this cell group. (A-1-7-4) Configure the lower layer based on the received spCellConfigCommon. (A-1-8) Resume all suspended radio bearers. Here, if the RRC reconfiguration message includes information indicating that the cell group to be configured is to be deactivated, some suspended radio bearers (e.g., SRB3) may not be restored (or all suspended radio bearers except for some radio bearers (e.g., SRB3) may be restored). If the RRC reconfiguration message includes information indicating that the cell group to be configured is to be deactivated, some radio bearers (e.g., SRB3) may be suspended. (A-1-9) If the SCG transmission for all radio bearers is suspended, it is resumed. Here, if the RRC reconfiguration message includes information indicating that the cell group to be configured is to be deactivated, the SCG transmission for all radio bearers may be suspended. (A-2) If the CellGroupConfig contains an rlc-BearerToReleaseList, release of the RLC bearer is performed based on this rlc-BearerToReleaseList. (A-3) If CellGroupConfig includes rlc-BearerToAddModList, add and / or modify RLC bearers based on this rlc-BearerToAddModList. (A-4) If the CellGroupConfig contains a mac-CellGroupConfig, the MAC entity of this cell group is configured based on this mac-CellGroupConfig. (A-5) If sCellToReleaseList is included in CellGroupConfig, release of SCell is performed based on this sCellToReleaseList. (A-6) If the CellGroupConfig contains an spCellConfig, configure the SpCell based on this spCellConfig. (A-7) If sCellToAddModList is included in CellGroupConfig, add and / or modify SCells based on this sCellToAddModList. (B) Set the content to be included in the RRC reconfiguration complete message. (C) If the SpCell configuration (spCellConfig) of the received secondary cell group configuration includes "reconfigurationWithSync", the random access procedure is initiated in that SpCell. Here, if the RRC reconfiguration message includes information indicating that the cell group to be configured is to be deactivated, the random access procedure may not be initiated in the SpCell of the target cell group. Also, if the RRC reconfiguration message includes information indicating that the cell group to be configured is to be deactivated, the MAC entity of the cell group to be configured may be notified that the cell group is to be deactivated. (D) If the SpCell configuration (spCellConfig) of the MCG or SCG includes "reconfigurationWithSync" and the random access procedure is successfully completed in the NR cell group, timer T304 of the cell group is stopped. Here, if the RRC reconfiguration message includes information indicating that the cell group to be configured is to be deactivated, timer T304 of the cell group may be stopped if the SpCell configuration (spCellConfig) of the MCG or SCG includes "reconfigurationWithSync." Also, if the RRC reconfiguration message includes information indicating that the cell group to be configured is to be deactivated, the MAC entity of the cell group to be configured may be notified that the cell group is to be activated.

[0262] The terminal device may also stop T304 for an SCG based on the SCG being released and / or becoming inactive.

[0263] The terminal device may set a secondary cell group to an inactive state based on whether the received RRC configuration message includes information indicating that the secondary cell group is to be in an inactive state or does not include information indicating that the secondary cell group is to be in an active state.The terminal device may set a secondary cell group to an active state based on whether the received RRC configuration message includes information indicating that the secondary cell group is to be in an active state or does not include information indicating that the secondary cell group is to be in an inactive state and based on the successful completion of a random access procedure in the SpCell of the secondary cell group.

[0264] This allows the terminal device to efficiently activate and deactivate cell groups using an RRC reconfiguration message.

[0265] The above procedure can also be applied to indicating whether an SCG configured in a terminal device is in an active state or an inactive state, without adding a PSCell and / or SCell to the SCG.

[0266] Another method of indicating to the terminal device whether the SCG is in an active or inactive state will now be described.

[0267] The terminal device receives an RRC message, which may be the RRC reconfiguration message shown in Figure 9 or another RRC message.

[0268] The RRC message may include information indicating whether the SCG is in an active state or an inactive state.

[0269] The information may be information indicating whether to activate or deactivate a cell group. Alternatively, the information may be information indicating that the cell group is to be activated. In this case, the cell group may be deactivated based on the absence of this information. Alternatively, the information may be information indicating that the cell group is to be deactivated. In this case, the cell group may be activated based on the absence of this information. Alternatively, the information may be information indicated by another information element. Note that, if the information is not included in the configuration of a target cell group, the information may include information indicating which cell group is the target. Note that, if there is only one cell group (secondary cell group) that can be the target, the information does not need to include information indicating which cell group is the target. Note that the information indicating that the cell group is to be activated may include an information element (rach-ConfigDedicated) including a terminal device-specific parameter used in a random access procedure.

[0270] In a terminal device that receives an RRC message that includes information indicating that a cell group is to be activated or that does not include information indicating that a cell group is to be deactivated, the RRC entity of the terminal device may perform some or all of the following (A) to (F). (A) A second timer (also referred to as timer T304X) for the SpCell of the target cell group is started. The value used for the second timer may be included in the RRC message, the value of t304 may be used, or a default value may be used. (B) Resume all suspended radio bearers. (C) Resume SCG transmission for all radio bearers if suspended. (D) Initiate a random access procedure in the SpCell of the target cell group. (E) When the random access procedure is successfully completed in the target cell group, the second timer for the cell group is stopped. (F) Notify the MAC entity of the target cell group that the cell group has become active.

[0271] In addition, in a terminal device that receives an RRC message that includes information indicating that a cell group is to be in an inactive state or that does not include information indicating that a cell group is to be in an active state, the RRC entity of the terminal device may perform some or all of the following (A) to (D). (A) If the second timer (also referred to herein as timer T304X) for the SpCell of the target cell group is running, stop it. (B) Suspend some radio bearers (e.g., SRB3). (C) Suspend SCG transmission for all radio bearers. (D) Notify the MAC entity of the target cell group that the cell group has become inactive.

[0272] The terminal device may stop the second timer for the SCG based on the SCG being released and / or the SCG becoming inactive.

[0273] The operation of the terminal device when the second timer expires will now be described.

[0274] If the second timer of the secondary cell group expires, the RRC entity of the terminal device performs the following process (A) if the MCG transmission is not suspended, and performs the following process (B) if the MCG transmission is suspended. (A) If the terminal device specific preamble provided in rach-ConfigDedicated is set, release it and start the SCG failure information procedure to report the failure of the SCG synchronized reconfiguration. (B) Initiate the RRC connection re-establishment procedure.

[0275] This allows the terminal device to efficiently activate and deactivate cell groups using RRC messages.

[0276] The mechanism of conditional reconfiguration in NR will be described. The network may configure one or more target SpCell candidates in a terminal device through conditional reconfiguration. The terminal device may evaluate the conditions of each configured target SpCell candidate. The terminal device may select one of the target SpCell candidates that satisfies the execution conditions associated with each candidate and apply the conditional reconfiguration associated with that cell. The network may provide the configuration for the target SpCell to the terminal device using a conditional reconfiguration information element (ConditionalReconfiguration IE). The terminal device may store the conditional reconfiguration information provided in the conditional reconfiguration information element as one or more entries in a variable (VarConditionalReconfig).

[0277] When a terminal device receives an RRC reconfiguration message, if the SCG's SpCell configuration (spCellConfig) includes reconfigurationWithSync, if this RRC reconfiguration message is a message for activating an SCG that is set in the terminal device and in an inactive state, or for deactivating an SCG that is set in the terminal device and in an active state, the variable (VarConditionalReconfig) may be retained, and if this RRC reconfiguration message is not a message for activating an SCG that is set in the terminal device and in an inactive state, or a message for deactivating an SCG that is set in the terminal device and in an active state, all entries in the variable (VarConditionalReconfig) may be deleted.

[0278] An example of an embodiment will be described. A terminal device communicating with a base station device receives from the base station device a first RRC message instructing addition of an SpCell to a first cell group and a second RRC message instructing transition of the first cell group from a first state in which the SpCell does not monitor a PDCCH to a second state in which the SpCell monitors a PDCCH. The terminal device may include a processing unit that starts a first timer upon reception of the first RRC message and starts a second timer upon reception of the second RRC message. The processing unit of the terminal device may further generate failure information for the first cell group based on expiration of the first timer or the second timer.

[0279] For example, the first cell group may be a secondary cell group. The first RRC message may be an RRC reconfiguration message including a synchronization-attached reconfiguration information element. The second RRC message may be an RRC reconfiguration message or another RRC message. The first timer may be timer T304. The first state may be a state in which an SCG is deactivated. The second state may be a state in which an SCG is activated. The generation of the failure information for the first cell group may be the initiation of an SCG failure information procedure.

[0280] The processing unit may also stop the first timer based on the satisfaction of any one of the following conditions: random access to the SpCell has been successfully completed, a first cell group has been released, and the first cell group has entered a first state. The processing unit may also stop the second timer based on the satisfaction of any one of the following conditions: random access to the SpCell has been successfully completed, a first cell group has been released, and the first cell group has entered a first state.

[0281] An example of an embodiment will be described. A terminal device may include a receiver that receives a first RRC message including parameters for synchronous reconfiguration of an SpCell of a first cell group from a base station device, and a processor that starts a first timer based on the reception of the first RRC message. The processor may determine whether to start the first timer based on whether first information is included in the first RRC message, and may generate failure information for the first cell group based on expiration of the first timer.

[0282] The first cell group may be a secondary cell. The synchronized reconfiguration may be a synchronized reconfiguration information element included in an RRC reconfiguration message, or part of information included in the synchronized reconfiguration information element. That is, the first RRC message may be an RRC reconfiguration message. The first information may be information indicating that the first cell group is to be deactivated. Alternatively, the first information may indicate that the first cell group is to be activated when the first information is not included. The first timer may be timer T304. The generation of failure information for the first cell group may be the initiation of an SCG failure information procedure.

[0283] An example of an embodiment will be described. A terminal device may include a receiver that receives a first RRC message including parameters for synchronous reconfiguration of an SpCell of a first cell group from a base station device, a processor that processes the first RRC message, and a transmitter that transmits a random access preamble in the SpCell based on the reception of the first RRC message. The processor may determine whether to transmit the random access preamble in the SpCell based on whether first information is included in the first RRC message.

[0284] The first cell group may be secondary cells. The synchronization reconfiguration may be a synchronization-with-reconfiguration information element included in an RRC reconfiguration message, or part of information included in the synchronization-with-reconfiguration information element. That is, the first RRC message may be an RRC reconfiguration message. The first information may be information indicating that the first cell group is to be deactivated. Alternatively, the first information may indicate that the first cell group is to be activated when the first information is not included.

[0285] An example of an embodiment will be described. A terminal device may include: a receiving unit that receives a first RRC message including parameters for synchronous reconfiguration of an SpCell of a first cell group from the base station device; and a processing unit that resumes suspended radio bearers based on the reception of the first RRC message. The processing unit may determine whether to resume all suspended radio bearers based on whether first information is included in the first RRC message. Furthermore, the processing unit may determine whether to resume transmission of SCGs for all suspended radio bearers based on whether first information is included in the first RRC message.

[0286] The first cell group may be secondary cells. The synchronization reconfiguration may be a synchronization-with-reconfiguration information element included in an RRC reconfiguration message, or part of information included in the synchronization-with-reconfiguration information element. That is, the first RRC message may be an RRC reconfiguration message. The first information may be information indicating that the first cell group is to be deactivated. Alternatively, the first information may indicate that the first cell group is to be activated when the first information is not included.

[0287] In the above explanation, an example was shown in which a base station device uses an RRC reconfiguration message (first message) including a synchronized reconfiguration information element, or another RRC message (second message), to instruct a terminal device to activate and deactivate a cell group that has been configured in the terminal device. However, this is not limited to this, and the first message may be used to activate the cell group and the second message to deactivate the cell group, or the second message may be used to activate the cell group and the first message to deactivate the cell group.

[0288] In addition, the RRC entity of the terminal device that deactivates the SCG may perform some or all of the following (A) to (E). (A) Suspend SCG transmission for all SRBs and DRBs. (B) Reset the SCG MAC. (C) If the first timer in this SCG is running, stop it. (D) If conditional reconfiguration for PSCell change is set, stop this evaluation. (E) Submit to the lower layer for transmission a message indicating completion of deactivation.

[0289] In addition, the RRC entity of the terminal device that activates the SCG may perform some or all of the following (A) to (D). (A) Resume SCG transmission for all SRBs and DRBs. (B) Reset the SCG MAC. (C) If conditional reconfiguration for PSCell changes is configured, start (or resume) this evaluation. (D) Submit to the lower layer for transmission a message indicating the completion of activation.

[0290] Furthermore, "including information indicating that the cell group is to be in an inactive state" does not necessarily mean that the terminal device does not include information indicating that the cell group is to be in an inactive state. For example, "including information indicating that the cell group is to be in an inactive state" may simply mean that the first information is included, or that the second information is not included. The terminal device may perform the above-described processing based on the inclusion of the first information or the absence of the second information. Similarly, "including information indicating that the cell group is to be in an active state" does not necessarily mean that the terminal device does not include information indicating that the cell group is to be in an active state. For example, "including information indicating that the cell group is to be in an active state" may simply mean that the second information is included, or that the first information is not included. The terminal device may perform the above-described processing based on the inclusion of the second information or the absence of the first information.

[0291] In addition, the above-mentioned reconfiguration information element with synchronization (ReconfigurationWithSync) is always included when configuring a secondary cell group (A) adding a PSCell, (B) resuming SCG transmission in NR-DC or (NG)EN-DC from a suspended state, (C) updating system information required in the PSCell, and (D) changing the security key of the AS, but it may also be included when activating an SCG and / or deactivating an SCG.

[0292] "Including information indicating that the cell group is to be in an inactive state" may include not including information indicating that the cell group is to be in an active state. Similarly, "Including information indicating that the cell group is to be in an active state" may include not including information indicating that the cell group is to be in an inactive state.

[0293] Furthermore, activating (deactivating) a cell group and activating (deactivating) the SpCells of that cell group may be interchangeable. Similarly, placing a cell group in an active state (inactive state) and placing the SpCells of that cell group in an active state (inactive state) may be interchangeable.

[0294] The radio bearer in the above description may be a DRB, an SRB, or a combination of a DRB and an SRB.

[0295] In the above description, expressions such as "link," "associate," and "link" may be interchangeable.

[0296] In the above description, "the above" may be replaced with "the above-mentioned."

[0297] In the above description, the "SpCell of an SCG" may be replaced with the "PSCell."

[0298] In the above description, the "dormant state" may be rephrased as the "inactive state," and the "state after recovery from the dormant state" may be rephrased as the "active state." Furthermore, in the above description, the terms "activated" and "inactivated" may be rephrased as the "active state" and "inactive state," respectively.

[0299] In the above explanation, "transition from X to Y" may be rephrased as "X becomes Y." Also, "activated BWP" may be rephrased as "Active BWP."

[0300] Furthermore, in each example of processing or each example of processing flow in the above description, some or all of the steps may not be executed. Furthermore, in each example of processing or each example of processing flow in the above description, the order of the steps may be different. Furthermore, in each example of processing or each example of processing flow in the above description, some or all of the processing within each step may not be executed. Furthermore, in each example of processing or each example of processing flow in the above description, the order of the processing within each step may be different. Furthermore, in the above description, "performing B based on A being true" may be rephrased as "performing B." In other words, "performing B" may be executed independently of "being true."

[0301] In the above explanation, "A may be replaced with B" may mean replacing A with B, as well as replacing B with A. Also, in the above explanation, when it is written that "C may be D" and "C may be E", it may also mean that "D may be E". Also, in the above explanation, when it is written that "F may be G" and "G may be H", it may also mean that "F may be H".

[0302] In the above explanation, if the conditions "A" and "B" are contradictory conditions, the condition "B" may be expressed as the "other" condition of the condition "A."

[0303] Various aspects of the terminal device and method according to embodiments of the present invention will now be described.

[0304] (1) A first embodiment of the present invention is a terminal device that communicates with a base station device, comprising: a receiving unit that receives a first RRC message from the base station device, the first RRC message including parameters for synchronous reconfiguration of an SpCell of a first cell group; and a processing unit that resumes suspended radio bearers based on the reception of the first RRC message, wherein the processing unit determines whether to resume all suspended radio bearers based on whether the first RRC message includes first information.

[0305] (2) A second embodiment of the present invention is a base station device that communicates with a terminal device, comprising: a transmitting unit that transmits a first RRC message to the terminal device, the first RRC message including parameters for synchronous reconfiguration of an SpCell of a first cell group; and a processing unit that causes the terminal device to resume suspended radio bearers based on the transmission of the first RRC message, wherein the processing unit causes the terminal device to determine whether to resume all suspended radio bearers depending on whether first information is included in the first RRC message.

[0306] (3) A third embodiment of the present invention is a method applied to a terminal device communicating with a base station device, comprising the steps of: receiving a first RRC message from the base station device, the first RRC message including parameters for synchronous reconfiguration of an SpCell of a first cell group; and resuming suspended radio bearers based on the reception of the first RRC message, and determining whether to resume all suspended radio bearers based on whether the first RRC message includes first information.

[0307] (4) A fourth embodiment of the present invention is a method applied to a base station device communicating with a terminal device, comprising the steps of: transmitting a first RRC message to the terminal device, the first RRC message including parameters for synchronous reconfiguration of an SpCell of a first cell group; and causing the terminal device to resume suspended radio bearers based on the transmission of the first RRC message, and causing the terminal device to determine whether to resume all suspended radio bearers depending on whether first information is included in the first RRC message.

[0308] (5) A fifth embodiment of the present invention is an integrated circuit implemented in a terminal device that communicates with a base station device, and causes the terminal device to perform the functions of receiving a first RRC message from the base station device, the first RRC message including parameters for synchronous reconfiguration of an SpCell of a first cell group, and resuming suspended radio bearers based on the reception of the first RRC message, and the processing unit determines whether to resume all suspended radio bearers based on whether the first information is included in the first RRC message.

[0309] (6) A sixth embodiment of the present invention is an integrated circuit implemented in a base station device that communicates with a terminal device, and causes the base station device to perform the functions of transmitting a first RRC message to the terminal device, the first RRC message including parameters for synchronous reconfiguration of an SpCell of a first cell group, and of causing the terminal device to resume suspended radio bearers based on the transmission of the first RRC message, and the processing unit causes the terminal device to determine whether to resume all suspended radio bearers depending on whether first information is included in the first RRC message.

[0310] A program running on an apparatus according to one aspect of the present invention may be a program that controls a central processing unit (CPU) or the like to cause a computer to function so as to realize the functions of the above-described embodiment according to one aspect of the present invention. The program or information handled by the program is temporarily loaded into volatile memory such as random access memory (RAM) during processing, or stored in nonvolatile memory such as flash memory or a hard disk drive (HDD), and is read, modified, and written by the CPU as needed.

[0311] Note that a part of the device in the above-described embodiment may be implemented by a computer. In this case, a program for implementing 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.

[0312] Furthermore, the term "computer-readable recording medium" may 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 a case. 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 recorded in the computer system.

[0313] 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 technologies that can replace current integrated circuits, integrated circuits based on that technology may also be used.

[0314] The present invention is not limited to the above-described embodiment. Although an example of a device has been described in the embodiment, the present invention 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.

[0315] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and design modifications and the like are also included within the scope of the gist of the present invention. Furthermore, various modifications of one aspect of the present invention are possible 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 the present invention. Furthermore, configurations in which elements described in the above embodiments are substituted with elements that achieve the same effect are also included. [Industrial Applicability]

[0316] One aspect of the present invention can be used in, for example, a communication system, a communication device (for example, a mobile phone device, a base station device, a wireless LAN device, or a sensor device), an integrated circuit (for example, a communication chip), or a program. [Explanation of symbols]

[0317] 100 E-UTRA 102 eNB 104 EPC 106NR 108 gNB 110 5GC 112, 114, 116, 118, 120, 124 Interface 122UE 200, 300 PHY 202, 302 MAC 204, 304 RLC 206, 306 PDCP 208, 308 RRC 310 SDAP 210, 312 NAS 500, 604 Receiver 502, 602 Processing section 504, 600 Transmitter

Claims

1. A terminal device that communicates with a base station device, a receiving unit that receives a first RRC message including parameters for synchronous reconfiguration of an SpCell of a first cell group from the base station device; a processing unit that initiates downlink synchronization to a target Spcell indicated by the parameter based on reception of the first RRC message; Equipped with the processing unit determines whether to start a first timer based on whether first information is included in the first RRC message; determining that the synchronization reestablishment has failed based on the expiration of the first timer; Terminal device.

2. A method applied to a terminal device that communicates with a base station device, comprising: receiving a first RRC message including parameters for synchronous reconfiguration of an SpCell of a first cell group in the terminal device; initiating downlink synchronization to a target SpCell indicated by the parameter based on receiving the first RRC message; determining that resynchronization has failed based on the expiration of a first timer; and determining whether to start the first timer based on whether first information is included in the first RRC message; method.

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