JP7739296B2 - Terminal device, base station device, method, and integrated circuit - Google Patents

Description

The present invention relates to a terminal device, a base station device, a method, and an integrated circuit.
This application claims priority to Japanese Patent Application No. 2020-133693, filed on August 6, 2020, the contents of which are incorporated herein by reference.

The radio access method and radio network for cellular mobile communications (hereinafter referred to as "Long Term Evolution (LTE: registered trademark)" or "Evolved Universal Terrestrial Radio Access: EUTRA") and the core network (hereinafter referred to as "Evolved Packet Core: EPC") are being studied in the 3rd Generation Partnership Project (3GPP). EUTRA is also referred to as E-UTRA.

In addition, 3GPP is conducting technical studies and standardization of LTE-Advanced Pro, an extension of LTE, and NR (New Radio technology), a new radio access technology, as radio access methods and wireless network technologies for fifth-generation cellular systems (Non-Patent Document 1). 5GC (5 Generation Core Network), a core network for fifth-generation cellular systems, is also being studied (Non-Patent Document 2).

3GPP RP-170855, “Work Item on New Radio (NR) Access Technology” 3GPP TS 23.501 v15.3.0, “System Architecture for the 5G System; Stage 2” 3GPP RP-182076, “WID on Multi-RAT Dual-Connectivity and Carrier Aggregation enhancements” 3GPP TS 36.300, v15.3.0, “Evolved Universal Terestrial Radio Access (E-UTRA) and Evolved Universal Terestrial Radio Access Network (E-UTRAN); Overall description; Stage 2” 3GPP TS 38.300v 15.3.0, “NR; NR and NG-RAN Overall description; Stage 2” 3GPP TS 36.321 v15.3.0, “Evolved Universal Tertrial Radio Access (E-UTRA); Medium Access Control (MAC) protocol "specification" 3GPP TS 38.321 v15.3.0, “NR; Medium Access Control (MAC) protocol specification” 3GPP TS 36.331 v15.4.0, “Evolved Universal Tertrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol "specifications" 3GPP TS 38.331 v15.4.0, “NR; Radio Resource Control (RRC); Protocol specifications”

One NR technology is dual connectivity (also known as multi-connectivity), which uses multiple cell groups to enable communication between one or more base station devices and a terminal device, enabling large-volume data communications. 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 communications occur, the terminal device must constantly monitor multiple cell groups, consuming a large amount of power. For this reason, research has begun on a technology that reduces the frequency of or stops monitoring some cell groups (cell group dormant technology) (Non-Patent Document 3).

When it comes to cell group dormancy, we are currently considering how to handle cells (SpCells) that are always in an activated state.

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, base station device, method, and integrated circuit that can efficiently perform communication control.

(1) In order to achieve the above object, one aspect of the present invention employs the following measures. That is, a first embodiment of the present invention is a terminal device in which a first cell group and a second cell group are configured, the terminal device comprising: a receiver that receives a first configuration to be applied to the second cell group and receives a second configuration to be applied to the second cell group; a storage unit that, when the second configuration to be applied to the second cell group is received, stores the first configuration and the second configuration to be applied to the second cell group; and a control unit that performs radio resource control, wherein the receiver receives first information, and the control unit performs reconfiguration using the first configuration when a first value is received as the first information, performs reconfiguration using the second configuration when a second value is received as the first information, and, when performing reconfiguration based on the first information, does not reset a MAC in the second cell group, and stops a first timer used for periodic reporting if the first timer is running.

(2) A second embodiment of the present invention is a base station device that communicates with a terminal device, comprising: a transmitter that transmits a first setting to be applied to a second cell group and a second setting to be applied to the second cell group; and a control unit that performs radio resource control, wherein the transmitter transmits first information, and the control unit transmits a first value as the first information to cause the terminal device to perform reconfiguration using the first setting, and transmits a second value as the first information to cause the terminal device to perform reconfiguration using the second setting, and when the terminal device is caused to perform reconfiguration based on the first information, the terminal device does not reset its MAC in the second cell group, and if a first timer used for periodic reporting is running, the first timer is considered to have been stopped and radio resource control is performed.

(3) A third embodiment of the present invention is a method applied to a terminal device in which a first cell group and a second cell group are configured, comprising: a step of receiving a first setting applied to the second cell group; a step of receiving a second setting applied to the second cell group; and a step of receiving first information.
The method includes a step of retaining the first setting and the second setting applied to the second cell group when a second setting applied to the second cell group is received, and a step of performing radio resource control, wherein when a first value is received as the first information, a reconfiguration is performed using the first setting, and when a second value is received as the first information, a reconfiguration is performed using the second setting, and when a reconfiguration based on the first information is performed, a MAC is not reset in the second cell group, and if a first timer used for periodic reporting is running, the first timer is stopped.

(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 configuration to be applied to a second cell group, transmitting a second configuration to be applied to the second cell group, transmitting first information, and performing radio resource control, wherein transmitting a first value as the first information causes the terminal device to perform reconfiguration using the first configuration, transmitting a second value as the first information causes the terminal device to perform reconfiguration using the second configuration, and when causing the terminal device to perform reconfiguration based on the first information, if the terminal device does not reset its MAC in the second cell group and a first timer used for periodic reporting is running, radio resource control is performed assuming that the first timer has been stopped.

(5) A fifth embodiment of the present invention is an integrated circuit implemented in a terminal device in which a first cell group and a second cell group are configured, which causes the terminal device to perform the following functions: receiving a first setting to be applied to the second cell group; receiving a second setting to be applied to the second cell group; receiving first information; when receiving the second setting to be applied to the second cell group, retaining the first setting and the second setting to be applied to the second cell group; and performing radio resource control; when receiving a first value as the first information, performing reconfiguration using the first setting; when receiving a second value as the first information, performing reconfiguration using the second setting; and when performing reconfiguration based on the first information, not resetting the MAC in the second cell group, and stopping the first timer used for periodic reporting if the first timer is running.

(6) A sixth embodiment 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 setting to be applied to a second cell group, transmitting a second setting to be applied to the second cell group, transmitting first information, and performing radio resource control, and by transmitting a first value as the first information, causes the terminal device to perform reconfiguration using the first setting, and by transmitting a second value as the first information, causes the terminal device to perform reconfiguration using the second setting, and when the terminal device is caused to perform reconfiguration based on the first information, the terminal device does not reset its MAC in the second cell group, and if a first timer used for periodic reporting is running, the first timer is considered to have been stopped and radio resource control is performed.

In addition, these comprehensive or specific aspects may be realized as a system, device, method, integrated circuit, computer program, or recording medium, or as any combination of a system, device, method, integrated circuit, computer program, and recording medium.

According to one aspect of the present invention, a terminal device can realize efficient communication control processing.

1 is a schematic diagram of a communication system according to each embodiment of the present invention. A protocol stack diagram of the UP and CP of a terminal device and a base station device in E-UTRA in each embodiment of the present invention. Protocol stack diagram of UP and CP of a terminal device and base station device in NR in each embodiment of the present invention. FIG. 10 is a diagram showing an example of a procedure flow for various settings in the RRC 208 and/or the RRC 308 according to each embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of a terminal device according to each embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of a base station device according to each embodiment of the present invention. An example of information element for cell group configuration in NR in an embodiment of the present invention. An example of an information element for cell group configuration in E-UTRA in an embodiment of the present invention. 10 shows an example of processing relating to SCG sleep in an embodiment of the present invention. 10 shows an example of processing relating to SCG sleep in an embodiment of the present invention. 10 shows an example of processing relating to SCG sleep in an embodiment of the present invention. 10 shows an example of processing relating to SCG sleep in an embodiment of the present invention.

The following describes in detail the embodiments of the present invention with reference to the drawings.

LTE (and LTE-A Pro) and NR may be defined as different radio access technologies (Radio Access Technology: RAT). NR and LTE, which can be connected via Multi Radio Dual connectivity, may be distinguished from conventional LTE. LTE whose core network is 5GC may be distinguished from conventional LTE whose core network is EPC. This embodiment may be applied to NR, LTE, and other RATs. The following description uses terms related to LTE and NR, but this embodiment may also be applied to other technologies using other terminology. The term E-UTRA in this embodiment may be replaced with the term LTE, and the term LTE may be replaced with the term E-UTRA.

Figure 1 is a schematic diagram of a communication system for each embodiment of the present invention.

E-UTRA100 is a radio access technology described in Non-Patent Document 4, etc., and is composed of cell groups (CGs) consisting of one or more frequency bands. eNB (E-UTRAN Node B) 102 is a base station device for E-UTRA100. EPC (Evolved Packet Core) 104 is a core network described in Non-Patent Document 14, etc., and was designed as a core network for E-UTRA100. Interface 112 is the interface between eNB 102 and EPC 104, and includes a control plane (CP) through which control signals pass and a user plane (UP) through which user data passes.

NR106 is a radio access technology described in Non-Patent Document 5, etc., and is composed of cell groups (Cell Groups: CGs) consisting of one or more frequency bands. gNB (g Node B) 108 is the base station equipment of NR106. 5GC110 is a core network described in Non-Patent Document 2, etc., and is designed as a core network for NR106, but may also be used as a core network for E-UTRA100 that has the function of connecting to 5GC110. Hereinafter, E-UTRA100 may include E-UTRA100 that has the function of connecting to 5GC110.

Interface 114 is an interface between eNB 102 and 5GC 110, interface 116 is an interface between gNB 108 and 5GC 110, interface 118 is an interface between gNB 108 and EPC 104, interface 120 is an interface between eNB 102 and gNB 108, and interface 124 is an interface between EPC 104 and 5GC 110. Interfaces 114, 116, 118, 120, and 124 may be interfaces that pass only CP, only UP, or both CP and UP. Furthermore, interfaces 114, 116, 118, 120, and 124 may not exist depending on the communication system provided by the telecommunications carrier.

UE122 is a terminal device compatible with some or all of E-UTRA100 and NR106. As described in Non-Patent Document 4 and some or all of Non-Patent Document 5, when UE122 connects to the core network via some or all of E-UTRA100 and NR106, a logical path called a radio bearer (RB) is established between UE122 and some or all of E-UTRA100 and NR106. The radio bearer used for CP is called a signaling radio bearer (SRB), and the radio bearer used for UP is called a data radio bearer (DRB).

Figure 2 is a protocol stack diagram of the UP and CP of a terminal device and a base station device in the E-UTRA radio access layer (radio access layer) in each embodiment of the present invention.

Figure 2(A) is a protocol stack diagram of the UP used when UE122 communicates with eNB102 in E-UTRA100.

PHY (Physical layer) 200 is a wireless physical layer that provides transmission services to higher layers using a physical channel. PHY 200 is connected to the higher MAC (Medium Access Control layer) 202 (described later) via a transport channel. Data moves between MAC 202 and PHY 200 via the transport channel. Data is transmitted and received between the PHYs of UE 122 and eNB 102 via a wireless physical channel.

MAC 202 is a medium access control layer that maps various logical channels to various transport channels. MAC 202 is connected to the higher-level RLC (Radio Link Control layer) 204 (described later) via logical channels. Logical channels are broadly categorized by the type of information transmitted, into control channels that transmit control information and traffic channels that transmit user information. MAC 202 may have functions such as controlling PHY 200 to perform discontinuous transmission/reception (DRX/DTX), executing random access procedures, notifying transmission power information, and performing HARQ control. MAC 302 may also have a function to control the activation state of cells set in the RRC layer (Non-Patent Document 6).

RLC 204 is a radio link control layer that segments data received from the higher-level PDCP (Packet Data Convergence Protocol Layer) 206 (described later) and adjusts the data size so that lower layers can transmit data appropriately.

PDCP 206 is a packet data convergence protocol layer for efficiently transmitting user data such as IP packets over wireless sections. PDCP 206 may have a header compression function for compressing control information. PDCP 206 may also have a data encryption function.

The data processed in MAC 202, RLC 204, and PDCP 206 are called MAC PDU (Protocol Data Unit), RLC PDU, and PDCP PDU, respectively. Data passed to MAC 202, RLC 204, and PDCP 206 from higher layers, or data passed to higher layers, are called MAC SDU (Service Data Unit), RLC SDU, and PDCP SDU, respectively. A segmented RLC SDU is called an RLC SDU segment.

Figure 2 (B) is a protocol stack diagram of the CP used when UE 122 communicates with eNB 102 and MME (Mobility Management Entity), a logical node that provides functions such as authentication and mobility management, in E-UTRA 100.

The CP protocol stack includes PHY 200, MAC 202, RLC 204, and PDCP 206, as well as RRC (Radio Resource Control layer) 208 and NAS (non-access strarum) 210. RRC 208 is a radio link control layer that performs processes such as establishing, re-establishing, suspending, and resuming RRC connections, as well as reconfiguring RRC connections, such as establishing, modifying, and releasing radio bearers (RBs) and cell groups, controlling logical channels, transport channels, and physical channels, and configuring handovers and measurements. The RB may be divided into a signaling radio bearer (SRB) and a data radio bearer (DRB), and the SRB may be used as a path for transmitting an RRC message, which is control information. The DRB may be used as a path for transmitting user data. Configuration of each RB may be performed between the eNB 102 and the RRC 208 of the UE 122. Furthermore, a portion of the RB that is configured with the RLC 204 and a logical channel may be referred to as an RLC bearer. In addition, in contrast to the NAS layer that carries signals between the MME and the UE 122, some or all of the layers of the PHY 200, MAC 202, RLC 204, PDCP 206, and RRC 208 that carry signals and data between the UE 122 and the eNB 102 may be referred to as the AS (Access Stratum) layer.

The functional classification of MAC 202, RLC 204, PDCP 206, and RRC 208 described above is an example, and some or all of the functions may not be implemented. Furthermore, some or all of the functions of each layer may be included in other layers.

Note that the IP layer, and the TCP (Transmission Control Protocol) layer (TCP layer), UDP (User Datagram Protocol) layer (UDP layer), and application layer (application layer) above the IP layer are upper layers (upper layers) of the PDCP layer (not shown). The RRC layer and NAS (non-access strarum) layer are also upper layers (not shown) of the PDCP layer. In other words, the PDCP layer is a lower layer (lower layer) of the RRC layer, NAS layer, IP layer, and the TCP (Transmission Control Protocol) layer, UDP (User Datagram Protocol) layer, and application layer above the IP layer.

Figure 3 is a protocol stack diagram of the UP and CP of a terminal device and a base station device in the NR radio access layer in each embodiment of the present invention.

Figure 3(A) is a protocol stack diagram of the UP used when UE122 communicates with gNB108 in NR106.

PHY (Physical layer) 300 is the radio physical layer of NR and may provide transmission services to higher layers using a physical channel. PHY 300 may be connected to a higher MAC (Medium Access Control layer) 302 (described later) via a transport channel. Data may move between MAC 302 and PHY 300 via the transport channel. Data may be transmitted and received between the PHYs of UE 122 and gNB 108 via a radio physical channel.

Now let's explain the physical channels.

The following physical channels may be used in wireless communication between a terminal device and a base station device:

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)

PBCH is used to broadcast system information required by terminal devices.

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

The PDCCH is 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) are defined for transmitting downlink control information. That is, a field for downlink control information is defined as DCI and mapped to information bits. The PDCCH is transmitted in PDCCH candidates. The terminal device monitors a set of PDCCH candidates in the serving cell. Monitoring means attempting to decode the PDCCH according to a certain DCI format. A certain DCI format may be used for scheduling the PUSCH in the serving cell. The PUSCH may be used for transmitting user data, RRC messages, etc.

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: Channel State Information) used to indicate the state of the downlink channel. The uplink control information may also include a scheduling request (SR: Scheduling Request) used to request UL-SCH resources. The uplink control information may also include a hybrid automatic repeat request ACKnowledgement (HARQ-ACK).

The PDSCH may be used to transmit downlink data (DL-SCH: Downlink Shared CHannel) from the MAC layer. In the case of downlink, it is also used to transmit system information (SI) and random access responses (RAR).

The PUSCH may be used to transmit uplink data from the MAC layer (UL-SCH: Uplink Shared CHannel) or uplink data together with HARQ-ACK and/or CSI. 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 RRC messages) and MAC control elements (MAC CEs). Here, the RRC signaling transmitted from the base station device via the PDSCH may be common signaling for multiple terminal devices within a cell. The RRC signaling transmitted from the base station device may also be dedicated signaling for a certain terminal device (also referred to as dedicated signaling). That is, UE-specific information may be transmitted using dedicated signaling for a certain terminal device. Also, the PUSCH may be used to transmit UE capabilities in the uplink.

The PRACH may be used to transmit random access preambles. The PRACH may also 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.

MAC 302 is a medium access control layer that maps various logical channels to various transport channels. MAC 302 may be connected to the higher-level RLC (Radio Link Control layer) 304 (described later) via a logical channel. Logical channels are broadly classified based on the type of information transmitted, and may be divided into control channels that transmit control information and traffic channels that transmit user information. MAC 302 may have functions such as controlling PHY 300 to perform discontinuous transmission/reception (DRX/DTX), executing random access procedures, notifying transmission power information, and performing HARQ control. MAC 302 may also have a function to control the activation state of cells set in the RRC layer (Non-Patent Document 7).

RLC 304 is a radio link control layer that segments data received from the higher-level PDCP (Packet Data Convergence Protocol Layer) 306 (described later) and adjusts the data size so that the lower layers can transmit the data appropriately.

PDCP 306 is a packet data convergence protocol layer that efficiently transmits user data such as IP packets over wireless interfaces. PDCP 306 may also have a header compression function that compresses control information. PDCP 306 may also have the functions of data encryption and data integrity protection.

SDAP (Service Data Adaptation Protocol) 310 is a service data adaptation protocol layer that has the function of mapping (mapping) downlink QoS flows sent from 5GC110 to terminal devices via base station devices to DRBs, and mapping uplink QoS flows sent from terminal devices to 5GC110 via base station devices to DRBs, and storing mapping rule information.

The data processed in MAC 302, RLC 304, PDCP 306, and SDAP 310 are referred to as MAC PDU (Protocol Data Unit), RLC PDU, PDCP PDU, and SDAP PDU, respectively. Data passed to MAC 302, RLC 304, PDCP 306, and SDAP 310 from higher layers or data passed to higher layers is referred to as MAC SDU (Service Data Unit), RLC SDU, PDCP SDU, and SDAP SDU, respectively. A segmented RLC SDU is referred to as an RLC SDU segment.

Figure 3 (B) is a protocol stack diagram of the CP used by UE122 in NR106 when communicating with gNB108 and AMF (Access and Mobility Management function), a logical node that provides functions such as authentication and mobility management.

The CP protocol stack includes PHY 300, MAC 302, RLC 304, and PDCP 306, as well as RRC (Radio Resource Control layer) 308 and NAS (non-access strarum) 312. RRC 308 is a radio link control layer that performs processes such as establishing, re-establishing, suspending, and resuming RRC connections, as well as reconfiguring RRC connections, such as establishing, modifying, and releasing radio bearers (RBs) and cell groups, controlling logical channels, transport channels, and physical channels, and configuring handovers and measurements. The RB may be divided into a signaling radio bearer (SRB) and a data radio bearer (DRB), and the SRB may be used as a path for transmitting an RRC message, which is control information. The DRB may be used as a path for transmitting user data. Each RB may be configured between the gNB 108 and the RRC 308 of the UE 122. Furthermore, the portion of the RB that is configured by the RLC 304 and a logical channel (logical channel) may be referred to as an RLC bearer. In addition, in contrast to the NAS layer that carries signals between the AMF and the UE 122, some or all of the layers of PHY 300, MAC 302, RLC 304, PDCP 306, RRC 308, and SDAP 310 that carry signals and data between the UE 122 and the gNB 108 may be referred to as the AS (Access Stratum) layer.

The functional classification of MAC 302, RLC 304, PDCP 306, SDAP 310, and RRC 308 described above is an example, and some or all of the functions may not be implemented. Furthermore, some or all of the functions of each layer may be included in another layer.

The layer above the AS layer (not shown) may be referred to as the PDU layer, as described in Non-Patent Document 2. The PDU layer may include any or all of the IP layer, the TCP (Transmission Control Protocol) layer above the IP layer, the UDP (User Datagram Protocol) layer, and other layers. The application layer may be a layer above the PDU layer or may be included in the PDU layer. The PDU layer may be a layer above the user plane of the AS layer. The RRC layer and the NAS (Non Access Stratum) layer may also be layers above any or all of the SDAP layer and PDCP layer (not shown). In other words, any or all of the SDAP layer and the PDCP layer are lower layers of any or all of the RRC layer, the NAS layer, the IP layer, and the TCP (Transmission Control Protocol) layer, the UDP (User Datagram Protocol) layer, and the application layer above the IP layer.

The physical layer, MAC layer, RLC layer, PDCP layer, and SDAP layer of the terminal device may be established, configured, and/or controlled by the RRC layer of the terminal device. The RRC layer of the terminal device may also establish and/or configure the physical layer, MAC layer, RLC layer, PDCP layer, and SDAP layer in accordance with RRC messages transmitted from the RRC layer of the base station device. The MAC layer, RLC layer, PDCP layer, and SDAP layer may also be referred to as the MAC sublayer, RLC sublayer, PDCP sublayer, and SDAP sublayer, respectively.

Note that each layer or function of each layer belonging to the AS layer configured in any or all of the terminal device and base station device may be referred to as an entity. That is, the physical layer (PHY layer), MAC layer, RLC layer, PDCP layer, SDAP layer, and RRC layer, or the functions of each layer, which are established, configured, and/or controlled in any or all of the terminal device and base station device, may be referred to as a physical entity (PHY entity), MAC entity, RLC entity, PDCP entity, SDAP entity, and RRC entity, respectively. One or more entities of each layer may be included in each layer. Furthermore, the PDCP entity and the RLC entity may be established, configured, and/or controlled for each radio bearer. Furthermore, the MAC entity may be established, configured, and/or controlled for each cell group. Furthermore, the SDAP entity may be established, configured, and/or controlled for each PDU session.

In each embodiment of the present invention, in order to distinguish between the E-UTRA protocol and the NR protocol, MAC 202, RLC 204, PDCP 206, and RRC 208 may be referred to as MAC for E-UTRA or MAC for LTE, RLC for E-UTRA or RLC for LTE, PDCP for E-UTRA or PDCP for LTE, and RRC for E-UTRA or RRC for LTE, respectively. MAC 302, RLC 304, PDCP 306, and RRC 308 may be referred to as MAC for NR, RLC for NR, RLC for NR, and RRC for NR, respectively. Alternatively, they may be written with spaces, such as E-UTRA PDCP or LTE PDCP, NR PDCP, etc.

Furthermore, as shown in FIG. 1, eNB 102, gNB 108, EPC 104, and 5GC 110 may be connected via interface 112, interface 116, interface 118, interface 120, and interface 114. Therefore, in order to support various communication systems, RRC 208 in FIG. 2 may be replaced with RRC 308 in FIG. 3. PDCP 206 in FIG. 2 may be replaced with PDCP 306 in FIG. 3. RRC 308 in FIG. 3 may include the functions of RRC 208 in FIG. 2. PDCP 306 in FIG. 3 may be PDCP 206 in FIG. 2. Furthermore, in E-UTRA 100, NR PDCP may be used as PDCP even when UE 122 communicates with eNB 102.

Next, we will explain the state transitions of UE 122 in LTE and NR. UE 122 connected to EPC or 5GC may be in the RRC_CONNECTED state when an RRC connection has been established. The state in which an RRC connection is established may include a state in which UE 122 holds some or all of the UE context described below. The state in which an RRC connection is established may also include a state in which UE 122 can transmit and/or receive unicast data. Furthermore, UE 122 may be in the RRC_INACTIVE state when the RRC connection is inactive (if UE 122 is connected to 5GC). If neither of these cases is true, UE 122 may be in the RRC_IDLE state.

Note that UE 122 connected to the EPC does not have an RRC_INACTIVE state, but the suspension of the RRC connection may be initiated by the E-UTRAN. In this case, when the RRC connection is suspended, UE 122 transitions to the RRC_IDLE state while retaining the UE's AS context and the identifier used for resumption (resumeIdentity). When UE 122 retains the UE's AS context, and the E-UTRAN has permitted the resumption of the RRC connection, and UE 122 needs to transition from the RRC_IDLE state to the RRC_CONNECTED state, the resumption of the suspended RRC connection may be initiated by a higher layer (e.g., the NAS layer).

In other words, the definition of dormancy may be different for UE122 connected to EPC and UE122 connected to 5GC. Furthermore, all or part of the procedure for UE122 to return from dormancy may be different when UE122 is connected to EPC (when it is dormant in RRC_IDLE state) and when UE122 is connected to 5GC (when it is dormant in RRC_INACTIVE state).

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

The UE AS context held by UE122 may be information including all or part of the current RRC settings, current security context, PDCP state including ROHC (RObust Header Compression) state, C-RNTI (Cell Radio Network Temporary Identifier) used in the source PCell, cell identifier (cellIdentity), and physical cell identifier of the source PCell. Note that the UE AS context held by either or all of eNB102 and gNB108 may include the same information as the UE AS context held by UE122, or may include information different from the information contained in the UE AS context held by UE122.

Figure 4 is a diagram showing an example of the flow of procedures for various settings in RRC208 and/or RRC308 in each embodiment of the present invention. Figure 4 shows an example of the flow when an RRC message is sent from a base station device (eNB102 and/or gNB108) to a terminal device (UE122).

In FIG. 4, the base station device creates an RRC message (step S400). The base station device may create an RRC message when it distributes system information (SI) or paging information, or when it determines that a specific terminal device needs to perform a certain process, such as security settings, reconfiguring an RRC connection (radio bearer processing (establishment, modification, release, etc.), cell group processing (establishment, addition, modification, release, etc.), measurement settings, handover settings, etc.), or releasing the RRC connection state. The RRC message contains information (parameters) for various information notifications and settings. In RRC specifications (Non-Patent Document 8, Non-Patent Document 9), these parameters are called fields and/or information elements and are described using a description format known as ASN.1 (Abstract Syntax Notation One).

RRC messages may also be created for other purposes. For example, RRC messages may be used to configure Dual Connectivity (DC) or Multi-Radio Dual Connectivity (MR-DC).

In Figure 4, the base station device then transmits the created RRC message to the terminal device (step S402).The terminal device then performs processing such as setting if necessary in accordance with the received RRC message (step S404).

Dual Connectivity (DC) may be a technology that performs data communication using the radio resources of both cell groups formed by two base station devices (nodes), i.e., the master cell group (MCG) formed by the master node (MN) and the secondary cell group (SCG) formed by the secondary node (SN). The master node and secondary node may also be the same node (same base station device). MR-DC may also be a technology that groups cells of both E-UTRA and NR RATs (Radio Access Technology) by RAT, assigns them to UEs, and performs data communication using the radio resources of both the MCG and SCG. In MR-DC, the master node may be a base station having the main RRC functions related to MR-DC, such as adding a secondary node, establishing, modifying, and releasing an RB, adding, modifying, releasing an MCG, handover, etc., and the secondary node may be a base station having some of the RRC functions, such as modifying and releasing an SCG.

In the MR-DC, the RRC of the RAT on the master node side may be used to configure both the MCG and SCG. For example, in EN-DC (E-UTRA-NR Dual Connectivity), which is an MR-DC when the core network is EPC104 and the master node is eNB102 (also referred to as enhanced eNB102), or in NGEN-DC (NG-RAN E-UTRA-NR Dual Connectivity), which is an MR-DC when the core network is 5GC110 and the master node is eNB102, E-UTRA RRC messages may be sent and received between eNB102 and UE122. In this case, the RRC message may include not only LTE (E-UTRA) configuration information but also NR configuration information. Furthermore, the RRC message transmitted from eNB 102 to UE 122 may be transmitted from eNB 102 to UE 122 via gNB 108. This RRC message configuration is non-MR-DC and may be used for E-UTRA/5GC in which eNB 102 (enhanced eNB) uses 5GC as a core network.

Conversely, in an MR-DC, in which the core network is 5GC110 and the master node is gNB108, NE-DC (NR-E-UTRA Dual Connectivity), which is an MR-DC, NR RRC messages may be transmitted and received between gNB108 and UE122. In this case, the RRC message may include not only NR configuration information but also LTE (E-UTRA) configuration information. Furthermore, the RRC message transmitted from gNB108 to UE122 may be transmitted from gNB108 to UE122 via eNB102.

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, or the RRC message for NR transmitted from gNB108 to UE122 may include an RRC message for E-UTRA.

Figure 7 is an example of an ASN.1 description representing some or all of the fields and information elements related to cell group configuration included in the message related to RRC connection reconfiguration in NR in Figure 4. Figure 8 is an example of an ASN.1 description representing some or all of the fields and information elements related to cell group configuration included in the message related to RRC connection reconfiguration in E-UTRA in Figure 4. Not limited to Figures 7 and 8, in the ASN.1 examples in embodiments of the present invention, <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 in embodiments of the present invention do not strictly follow the ASN.1 notation method, but represent an example of parameters of a message related to RRC connection reconfiguration in embodiments of the present invention, and other names and notations may be used. Also, in the ASN.1 examples in embodiments of the present invention, <Omitted> and <Omitted> are not part of the ASN.1 notation and indicate that other information has been omitted. In order to avoid complication of explanation, Example 1 shows only an example of main information closely related to one embodiment of the present invention. Note that parameters described in ASN.1 may not be distinguished as fields, information elements, etc., and may all be referred to as information elements. Also, in the embodiment of the present invention, parameters such as fields and information elements described in ASN.1 included in an RRC message may also be referred to as information. Note that the message related to the reconfiguration of the RRC connection may be an RRC reconfiguration message in NR or an RRC connection reconfiguration message in E-UTRA.

In Figure 7, radioBearerConfig included in the RRCReconfiguration message may include radio bearer settings. masterCellGroup may include settings related to the MCG when the MCG is NR. secondaryCellGroup may include settings related to the SCG when notified to a terminal device from a cell of the SCG. mrdc-SecondaryCellGroupConfig may include settings related to the SCG when notified to a terminal device from a cell of the MCG.

The above masterCellGroup, secondaryCellGroup, and/or mrdc-SecondaryCellGroupConfig may include a CellGroupConfig information element as a value.

The CellGroupConfig information element may include settings related to the cell group. The cellGroupId included in the CellGroupConfig information element may include identifier information for identifying the cell group. The mac-CellGroupConfig may include settings related to the MAC layer of the cell group. The spCellConfig may include settings related to the SpCell. The sCellToAddModList may include settings related to the addition or modification of SCells belonging to the cell group. The sCellToReleaseList may include information related to the deletion of SCells belonging to the cell group.

In Figure 8, sCellToReleaseList-r10 included in the RRCConnectionReconfiguration message may include information regarding the deletion of an SCell belonging to the MCG. sCellToAddModList-r10 may include settings regarding the addition or modification of an SCell belonging to the MCG. scg-Configuration-r12 may include settings related to the SCG. The scg-ConfigPartSCG-r12 included in the scg-Configuration-r12 may include settings related to the SpCell of the SCG (such as pSCellToAddMod-r12), settings related to the addition or modification of an SCell belonging to a cell group (such as sCellToAddModListSCG-r12), and / or information related to the deletion of an SCell belonging to a cell group (such as sCellToReleaseListSCG-r12). Also, settings related to the addition or modification of an SCell at the time of handover, and / or settings related to the addition or modification of an SCell when adding an SCell, may include information indicating the initial state of the SCell. For example, information indicating either an activated state or a dormant state may be included in the RRC message. If this information is included, the initial state of the SCell may be set to an activated state or a dormant state based on this information. If this information is not included, the initial state of the SCell may be set to a deactivated state.

Note that the above fields and information elements do not have to be limited to the above uses.

A terminal device that receives an RRC message containing the above information from a base station device configures the SpCell (PCell) of the MCG, the SCell of the MCG, the SpCell (PSCell) of the SCG, and/or the SCell of the SCG based on the information.

The terminal device may perform radio link monitoring in the serving cell (e.g., PCell and/or PSCell) using a certain type of reference signal (e.g., a cell-specific reference signal (CRS)). The terminal device may also receive a configuration (radio link monitoring configuration: RadioLinkMonitoringConfig) from the base station device indicating which reference signal to use for radio link monitoring in the serving cell (e.g., PCell and/or PSCell), and perform radio link monitoring using one or more configured reference signals (here referred to as RLM-RS). The terminal device may also perform radio link monitoring using other signals. If the conditions for being synchronized in the serving cell (e.g., PCell and/or PSCell) are met, the physical layer processing unit of the terminal device may notify the upper layer that it is synchronized.

The radio link monitoring configuration may include information indicating the purpose of monitoring and identifier information indicating a reference signal. For example, the purpose of monitoring may include monitoring for radio link failure, monitoring for beam failure, or both. Furthermore, for example, the identifier information indicating the reference signal may include information indicating an identifier (SSB-Index) of the cell's synchronization signal block (SSB). In other words, the reference signal may include a synchronization signal. Furthermore, for example, the identifier information indicating the reference signal may include information indicating an identifier linked to a channel state information reference signal (CSI-RS) configured in the terminal device.

In an SpCell (PCell in an MCG and PSCell in an SCG), the RRC layer processing unit of the terminal device may start or restart the timer (T310) of each SpCell when it receives a predetermined number (N310) of consecutive out-of-sync notifications from the physical layer processing unit in each SpCell. The RRC layer processing unit of the terminal device may also stop the timer (T310) of each SpCell when it receives a predetermined number (N311) of consecutive in-sync notifications in each SpCell. When the timer (T310) of each SpCell expires, the RRC layer processing unit of the terminal device may transition to an idle state or perform an RRC connection re-establishment procedure if the SpCell is a PCCell. Also, if the SpCell is a PSCell, it may execute an SCG failure information procedure to notify the network of an SCG failure.

The above explanation is an example of a case where discontinuous reception (DRX) is not configured in the terminal device. If DRX is configured in the terminal device, the RRC layer processing unit of the terminal device may set the period for measuring radio link quality and the interval for reporting to upper layers to different values than when DRX is not configured in the physical layer processing unit. Note that even when DRX is configured, when the above timer is running, the period for measuring radio link quality to estimate synchronization and the interval for reporting to upper layers may be set to the values when DRX is not configured.

Furthermore, the RLM-RS may be undefined if it is not explicitly or implicitly configured by the network. In other words, the terminal device does not need to monitor the radio link if the RLM-RS is not configured by the network (e.g., a base station device).

Furthermore, radio link monitoring using CRS may be performed in EUTRA cells, and radio link monitoring using RLM-RS may be performed in NR cells, but this is not limited to this.

This section explains cell activation and deactivation. A terminal device communicating via dual connectivity has a master cell group (MCG) and a secondary cell group (SCG) configured by the message related to the reconfiguration of the RRC connection described above. Each cell group may consist of a special cell (SpCell) and zero or more other cells (secondary cells: SCell). An SpCell in an MCG is also referred to as a PCell. An SpCell in an SCG is also referred to as a PSCell. Cell deactivation does not apply to SpCells, but may apply to SCells.

Also, cell deactivation may not be applied to the PCell but may be applied to the PSCell. In this case, cell deactivation may be a different process for the SpCell and the SCell.

As shown in Non-Patent Document 6 and Non-Patent Document 7, 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) and/or (B).
(A) Reception of MAC CE indicating SCell activation/deactivation (B) Timer (sCellDeactivationTimer) configured for each SCell where PUCCH is not configured

Specifically, the terminal device MAC entity may perform the following processing (AD) for each SCell configured in the cell group.

(Process AD)
If a MAC CE for activating the SCell is received, process (AD-1) is performed. Otherwise, if a MAC CE for deactivating the SCell is received, or if the timer (sCellDeactivationTimer) for the active SCell expires, process (AD-2) is performed. If an uplink grant or downlink assignment is notified by the PDCCH of the active SCell, or if an uplink grant or downlink assignment for the 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 assignment, the timer (sCellDeactivationTimer) associated with the SCell is restarted. If the SCell becomes inactive, process (AD-3) is performed.

(Process AD-1)

The SCell is activated and normal SCell operation is applied (implemented), including some or all of the following (A) to (E).
(A) Sounding Reference Signal (SRS) transmission in this SCell; (B) Channel State Information (CSI) reporting for this SCell; (C) PDCCH monitoring in this SCell; and (D) PDCCH monitoring for this SCell (if scheduled for this SCell in another serving cell).
(E) If PUCCH is configured, PUCCH transmission in this SCell

Also, if the SCell was in an inactive state before receiving this activating MAC CE in the NR, some or all of the following steps (A) to (B) will be performed.
(A) Activate the BWP indicated by the downlink BWP identifier (firstActiveDownlinkBWP-Id) set in the RRC message. (B) Activate the BWP indicated by the uplink BWP identifier (firstActiveUplinkBWP-Id) set in the RRC message.

It also starts or restarts (if already started) the timer associated with this SCell (sCellDeactivationTimer).

(Process AD-2)

Deactivate this SCell.

Also, the timer associated with this SCell (sCellDeactivationTimer) is stopped.

Deactivate all activated BWPs associated with this SCell.

Flush the HARQ buffer associated with this SCell.

(Process AD-3)
Some or all of the following (A) to (D) will be implemented.
(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.

As described above, activation and deactivation of SCells are performed by the MAC entity performing the process (AD).

Also, as mentioned above, when an SCell is added, the initial state of the SCell may be set by an RRC message.

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

Here, we will explain the band portion (BWP).

A BWP may be part or all of the bandwidth 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 based on 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 the 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 default 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.

A BWP may consist of a group of consecutive physical resource blocks (PRBs). Furthermore, parameters for the BWP (one or more BWPs) of each component carrier may be configured for a connected terminal device. The BWP parameters for each component carrier may include some or all of: (A) cyclic prefix type, (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, the 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) BWP bandwidth (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, the 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 BWPs of at least some or all of the PCell and/or PSCell.

A terminal device may transmit and receive using an active BWP among one or more configured BWPs. A terminal device may be configured such that, at any given time, up to one uplink BWP and/or up to one downlink BWP among one or more BWPs configured for a serving cell are active BWPs. 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.

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.

BWP switching is controlled by the PDCCH indicating a downlink assignment or uplink grant, a timer (bwp-InactivityTimer), RRC signaling, or the MAC entity itself for the initiation of a random access procedure. Active BWP of the serving cell is indicated by RRC or PDCCH.

Next, we will explain dormant BWP. Entering or leaving a dormant BWP is performed by BWP switching. This control is performed by the 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 specification, dormant BWPs only apply to SCells. Note that a dormant BWP does not change a BWP to a dormant state, but can be interpreted as one BWP configured for dormancy among one or more BWPs configured for a UE. There may also be multiple BWPs configured for dormancy for a UE.

A dormant BWP may be indicated by the absence of certain parameters in the BWP configuration. For example, 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, may indicate that the BWP is a dormant BWP. Furthermore, 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, may indicate that the BWP is a dormant BWP. For example, the absence of some or all of the search space settings, which are configured by the PDCCH-Config information element and define where and/or how PDCCH candidates are searched for, may indicate that the BWP is a dormant BWP.

In addition, the current specification does not support setting dormant BWP for SpCells such as PCells and PSCells, and for PUCCH SCells that can transmit PUCCH.

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

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

When a UE receives a PDCCH indicating entry into a dormant BWP, it activates the downlink BWP indicated by the third downlink BWP identifier (dormantDownlinkBWP-Id) previously notified by RRC signaling.

Entry into and exit from the above-mentioned 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.

Here, we will explain the PDCCH indicating entering a dormant BWP and the PDCCH indicating leaving a dormant BWP.

For example, a UE configured for discontinuous reception (DRX) in an SpCell may monitor the PDCCH in the SpCell's Active BWP to detect a certain DCI format (e.g., DCI format 2_6) outside of the DRX active time. The CRC of the DCI format may be scrambled with a certain RNTI (e.g., PS-RNTI). A UE configured for a dormant SCell group may determine whether to switch the Active DL BWP based on the bitmap information included in the payload of DCI format 2_6. For example, if a certain bit in the bitmap is associated with a dormant SCell group and the bit is 1, the UE may perform a BWP switch to another pre-configured BWP if the Active DL BWP is a dormant BWP, or may remain in that BWP if the Active DL BWP is not a dormant BWP. Also, if the bit is 0, BWP switching may be performed such that the Active DL BWP becomes the dormant BWP.

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

A UE configured for discontinuous reception (DRX) in the SpCell may monitor the PDCCH in the SpCell's Active BWP to detect a certain DCI format (e.g., DCI formats 0_1 and 1_1) during DRX active time. The CRC of the DCI format may be scrambled with a certain RNTI (e.g., C-RNTI or MCS-C-RNTI). A UE configured for a dormant SCell group determines whether to switch Active DL BWP based on the 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 if the bit is 1, and 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 BWP may remain in that BWP. Alternatively, if the bit is 0, BWP switching may be performed so that the Active DL BWP becomes a dormant BWP. The "pre-configured another BWP" may be a BWP different from the "pre-configured another BWP" used in the description of DCI format 2_6.

The UE does not need to monitor the PDCCCH for the purpose of detecting DCI format 0_1 and DCI format 1_1 outside of the DRX active time.

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

In each activated serving cell in which a BWP is configured, the MAC entity performs some or all of the following steps (A) to (H) if the BWP is activated (Active BWP) and is not a dormant BWP.
(A) Transmit UL-SCH in 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, transmit SRS in that BWP.
(G) Receive DL-SCH with that BWP.
(H) Initialize the configured uplink grant of grant type 1 that was set and suspended in that BWP.

In each activated serving cell in which a BWP is configured, the MAC entity performs some or all of the following steps (A) to (G) if the BWP is activated (Active BWP) and the BWP is a dormant BWP.
(A) If the timer (bwp-InactivityTimer) of the serving cell of 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 on that BWP.
(E) If CSI measurement is configured, perform CSI measurement in the BWP.
(F) Stop all uplink behavior, i.e., stop uplink transmissions, suspend configured uplink grants of grant type 1 associated with the cell, and clear configured uplink grants of grant type 2 associated with the cell.
(G) If the beam failure setting is set, detect beam failure and perform beam failure recovery if beam failure is detected.

If the BWP is deactivated, the MAC entity will do some or all of the following (A) to (I):
(A) Do not transmit UL-SCH in that BWP.
(B) Do not transmit RACH in that BWP.
(C) Do not monitor the PDCCH in that BWP.
(D) Do not transmit PUCCH in that BWP.
(E) Not reporting CSI in that BWP.
(F) Do not transmit SRS in that BWP.
(G) DL-SCH is not received on 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).

Next, we will explain the random access procedure for a UE configured with BWP. When starting the random access procedure in a serving cell, the MAC entity performs some or all of the following processes (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 identifier of the Active UL BWP.
(C) If the timer (bwp-InactivityTimer) associated with the Active DL BWP of this serving cell is running, stop this timer.
(D) If the serving cell is an SCell, if the timer associated with the Active DL BWP of the SpCell (bwp-InactivityTimer) is running, stop this timer.
(E) Perform a random access procedure on the Active DL BWP of the SpCell and the Active UL BWP of this serving cell.

Next, the timer (bwp-InactivityTimer) will be described. For each activated serving cell for which the timer (bwp-InactivityTimer) is set, the MAC entity performs the following process (A).
(A) If the identifier of the default downlink BWP (defaultDownlinkBWP-Id) is set and the Active DL BWP is not the BWP indicated by the identifier (dormantDownlinkBWP-Id), or if the identifier of the default downlink BWP (defaultDownlinkBWP-Id) is not set, the Active DL BWP is not the initialDownlinkBWP, and the Active DL BWP is not the BWP indicated by the identifier (dormantDownlinkBWP-Id), perform the following processes (B) and (D).
(B) If a PDCCH addressed to the C-RNTI or CS-RNTI indicating a downlink assignment or an uplink grant is received for an Active DL BWP, or if a PDCCH addressed to the C-RNTI or CS-RNTI indicating a downlink assignment or an uplink grant for an Active DL BWP is received, or if a MAC PDU is transmitted with a configured uplink grant or a MAC PDU is received with a configured downlink assignment, perform the following process (C).
(C) If a random access procedure associated with this serving cell is not ongoing 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-InactivityTimer associated with the Active DL BWP.
(D) If the bwp-InactivityTimer associated with the Active DL BWP expires, the following process (E) is performed.
(E) 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 initialDownlinkBWP.

Furthermore, if the MAC entity receives a PDCCH for BWP switching and switches Active DL BWP, it performs the following process (A).
(A) If the identifier of the default downlink BWP (defaultDownlinkBWP-Id) is set, and the switched Active DL BWP is not the BWP indicated by the identifier (dormantDownlinkBWP-Id), and if the switched Active DL BWP is not the BWP indicated by the dormantDownlinkBWP-Id, start or restart the bwp-InactivityTimer associated with the Active DL BWP.

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

The MAC entity may be configured by RRC with a beam failure recovery procedure for each serving cell. Beam failure is detected by counting beam failure instance notifications sent from the lower layer (PHY layer) to the MAC entity. 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 a lower layer, the timer (beamFailureDetectionTimer) is started or restarted, and the counter (BFI-COUNTER) is incremented by 1. If the value of BFI_COUNTER is equal to or greater than the set threshold (beamFailureInstanceMaxCount), the following process (A-1) is performed.
(A-1) If the serving cell is an SCell, trigger beam failure recovery (BFR) for this serving cell; otherwise, initiate 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 is an SCell and receives a PDCCH addressed to the C-RNTI indicating 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.

The MAC entity performs 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 SCell's BFR MAC CE and its subheader taking into account the priority of the logical channel, include the SCell's BFR MAC CE and its subheader. Otherwise, if the UL-SCH resource can contain the SCell's truncated BFR MAC CE and its subheader taking into account the priority of the logical channel, include the SCell's truncated BFR MAC CE and its subheader. Otherwise, trigger a scheduling request for SCell beam failure recovery.

The SCell is put into sleep mode by activating the sleep BWP in this SCell. Even when the SCell is in sleep mode, CSI measurement, automatic gain control (AGC), and beam management including beam failure recovery may still be performed in this SCell.

Next, we will explain SCG dormancy.

In LTE and/or NR, the state in which the SCG is dormant may be included in the RRC_CONNECTED state.

In LTE and/or NR, a state in which an SCG is dormant may be a state in which a terminal device performs some or all of the following (A) to (E) in the SpCell (PSCell) of that SCG.
(A) Do not transmit SRS in this SpCell.
(B) Do not report CSI for this SpCell.
(C) Do not transmit PUCCH, UL-SCH, and/or RACH in this SpCell.
(D) Do not monitor the PDCCH of this SpCell and/or the PDCCH for this SpCell.
(E) Discontinuous reception (DRX) is performed in this SpCell.

Furthermore, the state in which the SCG is dormant may be a state in which some or all of the processes (A) to (E) above and (F) to (H) below are performed.
(F) The BWP set as a dormant BWP in this SpCell is called an activated BWP (Active BWP).
(G) In the activated dormant BWP of this SpCell, only monitor the PDCCH indicating exiting the dormant BWP.
(H) The C-RNTI is not monitored on the PDCCH in the activated dormant BWP of this SpCell.

SCG dormancy may also be referred to as SCG suspension or SCG suspended.

Furthermore, the state in which the SCG is dormant (the state in which the SCG has entered the dormant state) may be a state in which a first value and a second value are notified from the base station device as values of a parameter (also called a field) to be applied to the terminal device, and the second value is applied to the settings of the terminal device. Furthermore, the second value may be applied to the settings of the terminal device based on receiving information indicating SCG suspend from the base station device.

Furthermore, the state in which the SCG has exited the dormant state may be a state in which a first value and a second value are notified from the base station device as the values of a parameter (also referred to as a field) to be applied to the terminal device, and the first value is applied to the settings of the terminal device. Furthermore, the first value may be applied to the settings of the terminal device based on receiving information indicating SCG non-suspend from the base station device.

In LTE and/or NR, a terminal device may determine and/or execute SCG dormancy based on some or all of the following (A) to (H). Note that the messages and control elements (A) to (F) below may be notified to the terminal device from a cell group other than the SCG.

The dormancy of an SCG may be referred to as entering a dormant SCG. The dormancy of an SCG may also be activating a dormant BWP of an SpCell of the cell group.
(A) Receipt of an RRC message instructing SCG to be dormant (B) Receipt of a MAC control element instructing SCG to be dormant (C) Receipt of an RRC message instructing SpCell to be dormant (D) Receipt of a MAC control element instructing SpCell to be dormant (E) Receipt of another RRC message (F) Receipt of another MAC control element (G) Expiration of a timer related to SCG dormancy (H) Expiration of a timer related to PSCell dormancy

In LTE and/or NR, a terminal device may determine and/or execute the resume of an SCG from a dormant state based on some or all of the following (A) to (H). Note that the messages and control elements (A) to (F) below may be notified to the terminal device from a cell group other than the SCG.

The recovery of an SCG from a dormant state may be referred to as leaving a dormant SCG. The recovery of an SCG from a dormant state may also be a BWP switch from a dormant BWP to another (non-dormant) BWP in an SpCell of the cell group.
(A) Receipt of an RRC message instructing the SCG to return from dormancy. (B) Receipt of a MAC control element instructing the SCG to return from dormancy. (C) Receipt of an RRC message instructing the SpCell to return from dormancy. (D) Receipt of a MAC control element instructing the SpCell to return from dormancy. (E) Receipt of other RRC messages. (F) Receipt of other MAC control elements. (G) Timer related to SCG dormancy. (H) Timer related to PSCell dormancy.

A terminal device that puts an SCG into sleep mode 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 timers associated with the active SCell (sCellDeactivationTimer) are considered to have expired.
(C) All timers associated with the dormant SCell (sCellDeactivationTimer) are considered to have expired.
(D) Do not start or restart the timer (sCellDeactivationTimer) 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 the SCG is not instructed to be dormant (or the SCG is not in a dormant state), perform process (AD-1).
(F) Execute the process (AD-2). For example, in the process (AD), when an instruction to put the SCG to sleep is issued (or the SCG enters a sleep state), the process (AD-2) is executed.

In addition, a terminal device that puts an SCG to sleep may perform some or all of the processes (A) to (F) above and (G) to (O) below in the SCG.
(G) Apply (reconfigure) the second setting notified by the RRC message and held.
(H) Suspend transmission of some or all of the SRBs and/or DRBs in the SCG.
(I) Suspend some or all of the SRBs and/or DRBs in the SCG, and do not transmit data on the logical channels associated with the suspended radio bearers.
(J) Change the primary path of Split SRB and/or Split DRB to MCG.
(K) If PDCP Duplication is set, deactivate PDCP Duplication.
(L) Do not reset the MAC of the SCG, or reset the MAC of the SCG and reconfigure the MAC using the settings related to the MAC included in the second settings.
(M) Re-establish each RLC of the SCG.
(N) Perform data recovery using the PDCP of the SCG.
(O) Pause or stop the timer used for periodic reporting of BSR and PHR, or release the setting of this timer.

Here, if the transmitting PDCP entity is associated with multiple RLC entities, if PDCP duplication is activated and the PDCP PDU is a PDCP Data PDU, it may duplicate this PDU and submit it to multiple RLC entities; otherwise, it may submit this PDU to the primary RLC entity or the secondary RLC entity.

A transmitting PDCP entity for which PDCP data recovery is requested by the PDCP upper layer may perform retransmission of all PDCP Data PDUs submitted to the re-established or released RLC entity for the AM DRB that have not been confirmed as successfully delivered.

If re-establishment of RLC is requested by the upper RLC layer, the terminal device may (1) discard all RLC SDUs, RLC SDU segments, and RLC PDUs, (2) stop and reset all timers, and (3) reset all state variables to their initial values.

A terminal device that performs recovery from a sleep state of an SCG may perform some or all of the following processes (A) to (C) in the SCG.
(A) Execute process (AD-1) to activate all SCells.
(B) All SCells remain in an inactive state. However, since they are not in a dormant state, for example, when a MAC CE to activate an SCell is received in the process (AD), the SCG is not instructed to be dormant (or the SCG is not in a dormant state), so the process (AD-1) may be performed.
(C) When the SCG resumes from sleep mode 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 in the target SCell based on the notified parameters.

In addition, a terminal device that performs recovery from a sleep state of an SCG may perform some or all of the processes (A) to (C) above and (D) to (L) below in the SCG.
(D) Apply (reconfigure) the first setting notified by the RRC message and retained.
(E) Resume transmission of some or all of the SRBs and/or DRBs in the SCG.
(F) Resume some or all of the SRBs and/or DRBs in the SCG.
(G) Changing the primary path of the Split SRB and/or Split DRB to the state it was in before the hiatus, or reconfiguring this primary path using the settings included in the first configuration.
(H) If PDCP Duplication is set, activate PDCP Duplication.
(I) Do not reset the MAC of the SCG, or reset the MAC of the SCG and reconfigure the MAC using the settings related to the MAC included in the first configuration.
(J) Re-establish each RLC of the SCG.
(K) Perform data recovery using the PDCP of the SCG.
(L) Resume or restart the timer used for periodic reporting of BSR and PHR, or reset this timer using the settings contained in the first configuration.

An example of the first setting and the second setting is described below.

For example, the first configuration may be part of the configuration that is immediately applied (reconfigured) to the terminal device when an RRC message is received from the base station device. Alternatively, the first configuration may be retained in the terminal device and reapplied to the terminal device based on another trigger (e.g., when exiting SCG dormancy).

Furthermore, the second setting may be a setting that is retained in the terminal device when an RRC message is received from the base station device, and may also be a setting that is applied to the terminal device based on another trigger (e.g., when entering SCG sleep).

The first configuration and the second configuration may include some or all of the configurations (information elements) related to the cell group, for example, some or all of the following configurations (A) to (B) included in the cell group configuration (CellGroupConfig information element):
(A) MAC configuration of a cell group including DRX configuration (MAC-CellGroupConfig)
(B) SpCell and/or SCell configuration including band and PUCCH configuration (SpCellConfig, SCellConfig)

The above DRX settings may include settings related to the DRX cycle. For example, the first setting may be set to any value up to 640 ms as the DRX short cycle setting, and the second setting may be set to a value greater than the short cycle set in the first setting as the DRX short cycle setting. As the DRX settings, the first setting may use settings included in the MAC-CellGroupConfig included in the CellGroupConfig information element. As the DRX settings, the second setting may use settings included in the information element related to SCG dormancy setting included in the CellGroupConfig information element.

The values of parameters applied when entering SCG sleep, such as DRX settings and partial band information, may be included in an information element regarding SCG sleep setting, and this information element regarding SCG sleep setting may be included in the CellGroupConfig information element as a second setting.

In addition, the DRX settings applied when the SCG enters sleep may be included in the existing MAC-CellGroupConfig, and the partial band settings applied when the SCG enters sleep may be included in the existing SpCellConfig.

Furthermore, the settings of the above band portions may include, for example, different DRX settings between the first setting and the second setting. This makes it possible to configure DRX for the BWP used when the SCG is asleep. The settings of the partial band of the second setting may include DRX settings, and the DRX settings included in the MAC settings may be used as the first setting.

Figure 9 shows an example of an embodiment. In Figure 9, UE 122 receives a message (RRC message) from eNB 102 or gNB 108 notifying that the SCG will be put into a dormant state (first state) (step S902). Based on the notification, UE 122 controls cells other than the SCG's SpCell (second cell) (i.e., SCells) to be in an inactive state.

The above operation enables efficient state changes during the process of putting an SCG to sleep without the need to separately send a MAC CE to change the state of the SCell of that SCG to an inactive state. Furthermore, when SCG sleep is performed based on an RRC message, the initial state was previously set in the RRC layer and the state change was performed in the MAC layer. However, the above operation makes it possible to efficiently change the state of the SCG while avoiding mismatches between RRC layer and MAC layer instructions.

Here, we will explain the PDCCH that indicates leaving dormant BWP.

For example, when the SpCell is in a dormant state (dormant BWP is activated), the UE may monitor the PDCCH in the SpCell's Active BWP to detect a certain DCI format (e.g., DCI format 2_6). The CRC of the DCI format may be scrambled with a certain RNTI (e.g., PS-RNTI). A UE with a dormant SCell group configured determines whether to switch the Active DL BWP based on the bitmap information included in the payload of DCI format 2_6. For example, if a certain bit in the bitmap is associated with a dormant SCell group and the bit is 1, if the Active DL BWP is a dormant BWP, the UE may perform a BWP switch to another pre-configured BWP; if the Active DL BWP is not a dormant BWP, the UE may remain in that BWP. Also, if the bit is 0, BWP switching may be performed such that the Active DL BWP becomes the dormant BWP.

If the system is such that discontinuous reception is configured in the SpCell when the SpCell is in dormant state, the UE does not need to monitor the PDCCH for the purpose of detecting DCI format 2_6 during DRX active time.

In a system in which discontinuous reception is configured in the SpCell when the SpCell is in dormant state, a UE configured with discontinuous reception (DRX) in the SpCell may monitor the PDCCH in the SpCell's Active BWP to detect a certain DCI format (e.g., DCI formats 0_1 and 1_1) during the DRX active time. 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 determines whether to switch 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 bit in the bitmap is associated with one dormant SCell group and the bit is 1, and the Active DL BWP is a dormant BWP, a BWP switch is performed to another BWP that has been configured in advance, and the Active DL BWP
If the BWP is not a dormant BWP, it may remain in that BWP. Also, if the bit is 0, BWP switching may be performed so that the Active DL BWP becomes a dormant BWP. Also, the "another pre-configured BWP" may be a BWP different from the "another pre-configured BWP" used in the description of DCI format 2_6.

The UE does not need to monitor the PDCCCH for the purpose of detecting DCI format 0_1 and DCI format 1_1 outside of the DRX active time.

Monitoring the PDCCH indicating exiting dormant BWP may mean monitoring the PDCCH for the purpose of detecting DCI format 2_6. In this case, it is not necessary to monitor the PDCCH for the purpose of detecting other DCI formats.

If the system is one in which discontinuous reception is configured in the SpCell when the SpCell is in dormant state, monitoring the PDCCH indicating exiting dormant BWP may mean monitoring the PDCCH for the purpose of detecting DCI format 2_6 outside of DRX active time, and monitoring the PDCCH for the purpose of detecting DCI format 0_1 and DCI format 1_1 during DRX active time. In this case, it is not necessary to monitor the PDCCH for the purpose of detecting other DCI formats.

When an SCG is in a dormant 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., an MCG). Alternatively, information about the SCG may be transmitted in the SCG that has exited the dormant state. Also, when an SCG is in a dormant state, some or all uplink transmissions may be permitted in the SCG. Here, an example is described in which uplink transmissions are performed in the SCG when the SCG is in a dormant state.

For example, we will explain beam failure recovery when beam control (beam management) including beam failure recovery is performed in an SpCell of a dormant SCG.

The MAC entity may be configured with a beam failure recovery procedure for each serving cell by RRC. Note that in a dormant SCG, the beam failure recovery procedure may be configured and/or performed only in the SpCell, or in a dormant SCG, the beam failure recovery procedure may be configured and/or performed in the SpCell and some or all of the SCells. Beam failure is detected by counting beam failure instance notifications notified to the MAC entity from a 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 a lower layer, the timer (beamFailureDetectionTimer) is started or restarted, and the counter (BFI-COUNTER) is incremented by 1. If the value of BFI_COUNTER is equal to or greater than the set threshold (beamFailureInstanceMaxCount), the following process (A-1) is performed.
(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. Note that if beam recovery is not triggered in the SCell, it is not necessary to trigger beam failure recovery for the SCell here. In other words, only when the serving cell is an SpCell, the process of starting the random access procedure in the SpCell may be performed.
(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 is an SCell and receives a PDCCH addressed to the C-RNTI indicating 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.

The MAC entity triggers a scheduling request for SCell beam failure recovery, if necessary, if at least one beam failure recovery (BFR) has been triggered by the beam failure recovery procedure and has not been canceled.

When a scheduling request is triggered, the MAC entity of the SCG initiates a random access procedure in the SpCell if no valid PUCCH resources are configured for the pending scheduling request.

As mentioned above, a random access procedure in the SpCell (PSCell) may be initiated in a dormant SCG by the MAC entity triggering a scheduling request to transmit a MAC PDU containing a MAC CE, or directly by the MAC entity. In this case, the MAC PDU may not contain any MAC SDUs.

On the other hand, a random access procedure in the SpCell (PSCell) may be initiated in a dormant 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.

Here, a state in which UL-SCH and RACH transmissions are possible in an SpCell of a certain cell group is defined as a first state. The first state may be a state in which RACH transmission is possible in the SpCell of the cell group and/or a state in which a PDCCH addressed to a C-RNTI, MCS-C-RNTI, and/or CS-RNTI indicating an uplink grant for UL-SCH transmission is monitored. The first state may also be a state in which a first BWP is activated in the SpCell of the cell group and a PDCCH addressed to a C-RNTI, MCS-C-RNTI, and/or CS-RNTI indicating an uplink grant is monitored in the first BWP. Furthermore, the first state may be a state in which channel state information (CSI) measurements are performed for the first BWP. The first state may also be a state in which discontinuous reception (DRX) is configured.

The state of monitoring a PDCCH addressed to a C-RNTI, MCS-C-RNTI, and/or CS-RNTI indicating an uplink grant for UL-SCH transmission may include a state in which the Active BWP of the SpCell of the cell group is not a dormant BWP. The first state may also be a state in which the cell group (SCG) has resumed from a dormant state. The first state may also be a state in which the cell group (SCG) is not in a dormant state.

Also, for example, the first state may be a state to which a transition from the second state occurs when a random access procedure is initiated due to a scheduling request triggered to transmit a MAC PDU including a MAC SDU. Also, for example, the first state may be a state to which a transition from the second state occurs when an RRC entity instructs the mobile station to resume from a dormant state. Also, for example, the first state may be a state in which a PDCCH indicating exiting a dormant BWP (exiting from a dormant BWP) is not monitored.

In an SpCell of a certain cell group, a state in which UL-SCH transmission and RACH transmission are stopped is defined as the second state. The second state may be a state in which the SpCell of the cell group does not transmit RACH and/or does not monitor PDCCHs addressed to C-RNTIs, MCS-C-RNTIs, and/or CS-RNTIs indicating uplink grants for UL-SCH transmission. The second state may also be a state in which a second BWP is activated in the SpCell of the cell group, and the second BWP does not monitor PDCCHs addressed to C-RNTIs, MCS-C-RNTIs, and/or CS-RNTIs indicating uplink grants for UL-SCH transmission and PDCCHs indicating leaving a dormant BWP. The second state may be a state in which a second BWP is activated in an SpCell of the cell group, and the second BWP monitors only a PDCCH indicating exiting a dormant BWP. Furthermore, the second state may be a state in which channel state information (CSI) measurement is performed for the second BWP.

The second state may be a state in which the SpCell's Active BWP is a dormant BWP.

A state in which limited UL-SCH transmission and RACH transmission are possible in an SpCell of a certain cell group is defined as a third state. The third state may be a state in which RACH transmission is possible in the SpCell of the cell group and PDCCHs addressed to C-RNTIs, MCS-C-RNTIs, and/or CS-RNTIs indicating uplink grants are monitored for limited UL-SCH transmission. The third state may be part of the first state in which the cell group (SCG) wakes up from a dormant state, or may be a state different from the first state in which the cell group (SCG) wakes up from a dormant state.

For example, the third state may be a state to which a transition from the second state occurs when a random access procedure triggered by the MAC entity is initiated. Also, for example, the third state may be a state to which a transition from the second state occurs when the value of BFI_COUNTER is equal to or greater than a configured threshold. Also, for example, the third state may be a state to which a transition from the second state occurs when the value of BFI_COUNTER is equal to or greater than a configured threshold and a random access procedure is initiated in the PSCell. Also, for example, the third state may be a state to which a transition from the second state occurs when the value of BFI_COUNTER is equal to or greater than a configured threshold and a BFR is triggered in the SCell.

The third state may also be a state in which a third BWP is activated in an SpCell of the cell group, and a PDCCH indicating leaving a dormant BWP is monitored in the third BWP. Furthermore, the third state may also be a state in which the third BWP does not monitor a PDCCH addressed to a C-RNTI, MCS-C-RNTI, and/or CS-RNTI indicating an uplink grant. Furthermore, the third state may be a state in which channel state information (CSI) measurements are performed for the third BWP. When a UE receives a PDCCH indicating leaving a dormant BWP for the UE in the third BWP, the UE may switch the BWP to a pre-configured BWP (e.g., the first BWP).

Also, for example, the third state may be a state to which the UE transitions from the second state when a random access procedure is initiated due to a scheduling request triggered to transmit a MAC PDU that does not include a MAC SDU. Also, for example, the third state may be a state to which the UE transitions from the second state when a random access procedure is initiated due to a scheduling request triggered to transmit a MAC PDU that includes a specific MAC CE. The specific MAC CE may include a BFR MAC CE. Also, for example, the third state may be a state to which the UE transitions from the second state when a MAC PDU that includes the specific MAC CE does not include a MAC SDU.

For example, as shown in FIG. 10, the UE determines whether to initiate a random access procedure in a dormant SCG (step S1000), and if random access is to be initiated, may switch the Active BWP to another BWP (e.g., a third BWP) (step S1002).

Also, for example, the third state may be a state to which a transition is made from the second state when a random access procedure is performed to request an uplink grant.

The UE may be independently configured with a BWP (first BWP) that becomes Active when the UE returns from the SCG dormant state and enters the first state, a BWP (second BWP) that becomes Active in the second state, and a BWP (third BWP) that becomes Active in the third state. Furthermore, one or more BWPs may be configured in each of the first to third BWPs. Furthermore, each of the first to third BWPs may be configured with a downlink BWP and/or an uplink BWP.

Transitioning to the first state and the first BWP becoming Active may have the same meaning. Transitioning to the second state and the second BWP becoming Active may have the same meaning. Transitioning to the third state and the third BWP becoming Active may have the same meaning.

Transitioning to the first state may mean the same thing as a BWP other than the first BWP becoming an inactivated BWP. Transitioning to the second state may mean the same thing as a BWP other than the second BWP becoming an activated BWP. Transitioning to the third state may mean the same thing as a BWP other than the third BWP becoming an activated BWP.

Some or all of the first to third BWPs may be configured in the UE by an RRC message. The configuration of the second BWP may not include some or all of the parameters necessary for monitoring the PDCCH, as described above. The configuration of the second BWP may not include the configuration of an uplink BWP. The configuration of the third BWP may include at least the parameters necessary for monitoring the PDCCH to receive a reply to the random access preamble (random access response). The configuration of the third BWP may include the configuration of an uplink BWP. The configuration of the uplink BWP may include information necessary for transmitting a random access preamble.

As another example, the dormant state of the SCG may be the third state described above. In other words, the SCG entering the dormant state and transitioning to the third state may have the same meaning. In this case, the second state may be defined as a separate state different from the dormant state of the SCG, or the second state may not exist.

This makes it possible to trigger necessary uplink transmissions even when the SCG is in sleep mode. Furthermore, by monitoring only necessary signals when the SCG is in sleep mode, power savings are possible.

MCG Failure: The purpose of this procedure may be to inform the network about an MCG failure (i.e., an MCG radio link failure) encountered by the UE. An RRC_CONNECTED UE with AS layer security active for SRB2 and at least one DRB set up may initiate a fast MCG link recovery procedure to maintain the RRC connection without re-establishing it.

As shown in FIG. 11, a UE configured with split SRB1 or SRB3 may initiate a procedure to report MCG failure (step S1102) when some or all of the following conditions (A) to (D) are met and condition (E) is also met (step S1100).
(A) Transmission of both MCG and SCG is not suspended. (B) Timer T316 is set. (C) SCG is not in the fourth state. (D) The active BWP of the SpCell of the SCG is not a dormant BWP. (E) When a radio link failure of the MCG is detected while timer T316 is not running.

Note that when the procedure for reporting an MCG failure is initiated, MCG transmission is suspended for all SRBs and DRBs other than SRB0. Also, when the procedure for reporting an SCG failure is initiated, SCG transmission is suspended for all SRBs and DRBs.

Timer T316 is a timer that starts when an MCG failure information message is sent and stops when transmission in the MCG recovers, when an RRCRelease message is received, or when a re-establishment procedure is initiated.

The fourth state may be a state in which a fourth BWP is activated in an SpCell of the cell group, the fourth BWP monitors only the PDCCH indicating exiting a dormant BWP, and performs channel state information (CSI) measurements for the fourth BWP. The fourth state may also be a state in which a fourth BWP is activated in an SpCell of the cell group, the fourth BWP does not monitor the C-RNTI on the PDCCH, and performs channel state information (CSI) measurements for the fourth BWP. The fourth state may also be the third state described above.

When the procedure to report an MCG failure is initiated, the UE suspends MCG transmission for all SRBs and DRBs except SRB0, resets the MAC of the MCG, and starts transmitting an MCG failure information message.

This allows the procedure for reporting MCG failures to be controlled taking into account the dormant state of the SCG.

We will also describe another example of MCG failure. In this example, the UE considers SCG transmission to be suspended when the active BWP of the SCG's SpCell is a dormant BWP.

A UE configured with split SRB1 or SRB3 may transition to the third state or the first state and initiate a procedure to report an MCG failure when some or all of the following conditions (A) to (B) are met and condition (C) is met:
(A) Transmission of both MCG and SCG is not suspended. (B) Timer T316 is set. (C) When a radio link failure of MCG is detected while timer T316 is not running.

This allows you to control the procedure for reporting MCG failures without adding new conditions.

Figure 12 is a diagram showing an example of an embodiment. In Figure 12, UE 122 receives a first configuration and a second configuration from eNB 102 or gNB 108 (step S1200). The first configuration and the second configuration may be notified by separate RRC messages, or may be notified in a form in which the first configuration and the second configuration are included in a single RRC message.

UE122 receives first information from eNB102 or gNB108, and if it receives a first value as the first information, it performs reconfiguration using the first setting, and if it receives a second value as the first information, it performs reconfiguration using the second setting (step S1202).

In this way, the first information can, for example, indicate which of multiple settings notified in advance to use when UE122 reconfigures itself when entering and leaving SCG suspend, allowing for efficient control when UE122 frequently enters and exits SCG suspend.

When reconfiguration is performed based on the first information, MAC may not be reset in the second cell group. Furthermore, RLC may be re-established at this time. Furthermore, PDCP data recovery may be performed at this time. Furthermore, these processes may be performed when the first information includes a specific value.

By processing in this manner, for example, when entering SCG suspend, beam control to maintain synchronization can be continued.

Furthermore, when performing reconfiguration based on the first information, some of the timers used in the MAC in the second cell group may be paused, stopped, or released. For example, by not operating timers for periodic reporting, such as a timer for periodically reporting buffer status or a timer for periodically reporting power headroom, unnecessary uplink transmissions during SCG suspend can be suppressed.

By processing in this manner, for example, when entering SCG suspend, it is possible to continue beam control to maintain a synchronized state. Also, for example, when exiting SCG suspend, it is possible to continue beam control to maintain a synchronized state.

Figure 5 is a block diagram showing the configuration of a terminal device (UE122) in each embodiment of the present invention. Note that to avoid complicating the explanation, Figure 5 shows only the main components that are closely related to one embodiment of the present invention.

The UE 122 shown in FIG. 5 comprises a receiver 500 that receives RRC messages and the like from a base station device, a processor 502 that performs processing according to some or all of the setting information of the various information elements (IEs), various fields, and various conditions contained in the received messages, and a transmitter 504 that transmits RRC messages and the like to the base station device. The base station device mentioned above may be an eNB 102 or a gNB 108. The processor 502 may also include some or all of the functions of various layers (e.g., the physical layer, MAC layer, RLC layer, PDCP layer, RRC layer, and NAS layer). That is, the processor 502 may include some or all of the physical layer processing unit, MAC layer processing unit, RLC layer processing unit, PDCP layer processing unit, RRC layer processing unit, and NAS layer processing unit.

The processing unit 502 may also include a storage unit that stores a first setting and a second setting to be applied (reconfigured) to one or more parameters of the UE 122. The processing unit 502 may also include a control unit that controls the processing of some or all of the functions of various layers.

Figure 6 is a block diagram showing the configuration of a base station device in each embodiment of the present invention. Note that, to avoid complicating the explanation, Figure 6 shows only the main components closely related to one aspect of the present invention. The above-mentioned base station device may be an eNB102 or a gNB108.

The base station device shown in FIG. 6 is configured to include a transmitter 600 that transmits RRC messages, etc. to UE 122; a processor 602 that creates an RRC message including some or all of the configuration information, such as various information elements (IEs), various fields, and various conditions, and transmits it to UE 122, thereby causing the processor 502 of UE 122 to perform processing; and a receiver 604 that receives RRC messages, etc. from UE 122. Furthermore, 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, RRC layer, and NAS layer). That is, the processor 602 may include some or all of the physical layer processor, MAC layer processor, RLC layer processor, PDCP layer processor, RRC layer processor, and NAS layer processor.

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.

The following describes various aspects of the terminal device in an embodiment of the present invention.

(1) A first embodiment of the present invention is a terminal device in which a first cell group and a second cell group are configured, comprising: a receiving unit that receives a first configuration to be applied to the second cell group and a second configuration to be applied to the second cell group; a holding unit that, when the second configuration to be applied to the second cell group is received, holds the first configuration and the second configuration to be applied to the second cell group; and a control unit that performs radio resource control, wherein the receiving unit receives first information, and the control unit, when receiving a first value as the first information, performs reconfiguration using the first configuration, and when receiving a second value as the first information, performs reconfiguration using the second configuration, and, when performing reconfiguration based on the first information, does not reset the MAC in the second cell group, and stops the first timer used for periodic reporting if the first timer is running.

(2) In the first embodiment, the first setting and the second setting are composed of the same information elements.

(3) A second embodiment of the present invention is a base station device that communicates with a terminal device, comprising: a transmitter that transmits a first setting to be applied to a second cell group and a second setting to be applied to the second cell group; and a control unit that performs radio resource control, wherein the transmitter transmits first information, and the control unit transmits a first value as the first information to cause the terminal device to perform reconfiguration using the first setting, and transmits a second value as the first information to cause the terminal device to perform reconfiguration using the second setting, and when the terminal device is caused to perform reconfiguration based on the first information, if the terminal device does not reset its MAC in the second cell group and a first timer used for periodic reporting is running, the first timer is considered to have been stopped and radio resource control is performed.

(4) A third embodiment of the present invention is a method applied to a terminal device in which a first cell group and a second cell group are configured, comprising: a step of receiving a first setting applied to the second cell group; a step of receiving a second setting applied to the second cell group; and a step of receiving first information.
The method includes a step of retaining the first setting and the second setting applied to the second cell group when a second setting applied to the second cell group is received, and a step of performing radio resource control, wherein when a first value is received as the first information, a reconfiguration is performed using the first setting, and when a second value is received as the first information, a reconfiguration is performed using the second setting, and when a reconfiguration based on the first information is performed, a MAC is not reset in the second cell group, and if a first timer used for periodic reporting is running, the first timer is stopped.

(5) 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 configuration to be applied to a second cell group, transmitting a second configuration to be applied to the second cell group, transmitting first information, and performing radio resource control, wherein transmitting a first value as the first information causes the terminal device to perform reconfiguration using the first configuration, transmitting a second value as the first information causes the terminal device to perform reconfiguration using the second configuration, and when causing the terminal device to perform reconfiguration based on the first information, if the terminal device does not reset its MAC in the second cell group and a first timer used for periodic reporting is running, radio resource control is performed assuming that the first timer has been stopped.

(6) A fifth embodiment of the present invention is an integrated circuit implemented in a terminal device in which a first cell group and a second cell group are configured, which causes the terminal device to perform the following functions: receiving a first setting to be applied to the second cell group; receiving a second setting to be applied to the second cell group; receiving first information; when receiving the second setting to be applied to the second cell group, retaining the first setting and the second setting to be applied to the second cell group; and performing radio resource control; when receiving a first value as the first information, performing reconfiguration using the first setting; when receiving a second value as the first information, performing reconfiguration using the second setting; and when performing reconfiguration based on the first information, not resetting the MAC in the second cell group, and stopping the first timer used for periodic reporting if the first timer is running.

(7) A sixth embodiment 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 setting to be applied to a second cell group, transmitting a second setting to be applied to the second cell group, transmitting first information, and performing radio resource control, and by transmitting a first value as the first information, causes the terminal device to perform reconfiguration using the first setting, and by transmitting a second value as the first information, causes the terminal device to perform reconfiguration using the second setting, and when the terminal device is caused to perform reconfiguration based on the first information, the terminal device does not reset its MAC in the second cell group, and if a first timer used for periodic reporting is running, the first timer is considered to have been stopped and radio resource control is performed.

A program running on an apparatus relating 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 relating 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 non-volatile memory such as flash memory or a hard disk drive (HDD), and is read, modified, and written by the CPU as needed.

It should be noted that a portion of the device in the above-described embodiments may be implemented by a computer. In this case, the program for implementing this control function may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be read by a computer system and executed to implement the function. The term "computer system" here refers to a computer system built into the device, and includes hardware such as an operating system and peripheral devices. Furthermore, the term "computer-readable recording medium" may be any of semiconductor recording media, optical recording media, magnetic recording media, etc.

Furthermore, "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 fixed period of time, such as volatile memory within a computer system that serves as a server or client in such cases. Furthermore, the above-mentioned program may be one that realizes part of the functions described above, or may be one that can realize the functions described above in combination with a program already recorded on the computer system.

Additionally, 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 those technologies may also be used.

Note that the present invention is not limited to the above-described embodiments. While the embodiments describe an example of a device, the present invention is not limited to this and can be applied to terminal devices or communication devices such as stationary or non-mobile electronic devices installed indoors or outdoors, such as AV equipment, kitchen equipment, cleaning/washing equipment, air conditioning equipment, office equipment, vending machines, and other household appliances.

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 includes design modifications within the scope of the gist of the 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 for elements that achieve the same effect are also included.

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

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

Claims (7)

A terminal device in which a first cell group and a second cell group are set,
a receiving unit that receives a first configuration to be applied to the second cell group and a second configuration to be applied to the second cell group;
a holding unit that holds the first configuration and the second configuration to be applied to the second cell group when a second configuration to be applied to the second cell group is received;
a control unit that performs radio resource control,
The receiving unit receives first information,
When the control unit receives a first value as the first information, the control unit performs resetting using the first setting;
When a second value is received as the first information, resetting is performed using the second setting;
A terminal device that, when performing reconfiguration based on the first information, does not reset the MAC in the second cell group, and stops a first timer used for periodic reporting if the first timer is running. The terminal device according to claim 1 , wherein the first setting and the second setting are configured with the same information element. A base station device that communicates with a terminal device,
a transmitter for transmitting a first configuration to be applied to a second cell group and a transmitter for transmitting a second configuration to be applied to the second cell group;
a control unit that performs radio resource control,
the transmitting unit transmits first information;
the control unit causes the terminal device to perform reconfiguration using the first setting by transmitting a first value as the first information;
transmitting a second value as the first information, thereby causing the terminal device to perform reconfiguration using the second setting;
A base station device that, when causing the terminal device to perform reconfiguration based on the first information, performs radio resource control by regarding the terminal device as having stopped a first timer used for periodic reporting if the terminal device does not reset a MAC in the second cell group and a first timer used for periodic reporting is running. A method applied to a terminal device in which a first cell group and a second cell group are configured,
receiving a first configuration to be applied to the second cell group; receiving a second configuration to be applied to the second cell group; and receiving first information;
When a second configuration to be applied to the second cell group is received, retaining the first configuration and the second configuration to be applied to the second cell group;
performing radio resource control;
When a first value is received as the first information, resetting is performed using the first setting;
When a second value is received as the first information, resetting is performed using the second setting;
When performing reconfiguration based on the first information, the method does not reset the MAC in the second cell group, and stops a first timer used for periodic reporting if the first timer is running. A method applied to a base station device that communicates with a terminal device, comprising:
transmitting a first configuration to be applied to a second cell group; transmitting a second configuration to be applied to the second cell group; and transmitting first information.
performing radio resource control;
transmitting a first value as the first information, thereby causing the terminal device to perform reconfiguration using the first setting;
transmitting a second value as the first information, thereby causing the terminal device to perform reconfiguration using the second setting;
A method for performing radio resource control by causing the terminal device to perform reconfiguration based on the first information, without resetting the MAC in the second cell group, and by treating a first timer used for periodic reporting as having been stopped if the first timer is running. An integrated circuit implemented in a terminal device in which a first cell group and a second cell group are set,
a function of receiving a first configuration to be applied to the second cell group; a function of receiving a second configuration to be applied to the second cell group; and a function of receiving first information;
When a second configuration to be applied to the second cell group is received, the first configuration and the second configuration to be applied to the second cell group are retained.
and causing the terminal device to perform a function of controlling radio resources;
When a first value is received as the first information, resetting is performed using the first setting;
When a second value is received as the first information, resetting is performed using the second setting;
When performing reconfiguration based on the first information, the integrated circuit does not reset a MAC in the second cell group, and stops a first timer used for periodic reporting if the first timer is running. An integrated circuit implemented in a base station device that communicates with a terminal device,
a function of transmitting a first configuration to be applied to a second cell group; a function of transmitting a second configuration to be applied to the second cell group; and a function of transmitting first information;
and causing the base station device to perform a function of controlling radio resources;
transmitting a first value as the first information, thereby causing the terminal device to perform reconfiguration using the first setting;
transmitting a second value as the first information, thereby causing the terminal device to perform reconfiguration using the second setting;
When the terminal device is caused to perform reconfiguration based on the first information, the terminal device does not reset the MAC in the second cell group, and if a first timer used for periodic reporting is running, the integrated circuit performs radio resource control by regarding the first timer as having been stopped.