JP7695936B2 - 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. 2020-99022, filed in Japan on June 8, 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 currently studying and formulating standards for 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 the fifth generation cellular system (Non-Patent Document 1). 5GC (5 Generation Core Network), a core network for the fifth generation cellular system, 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 of the NR technologies is dual connectivity (also called multi-connectivity), which uses multiple cell groups to enable large-volume data communication between one or multiple base station devices and terminal devices. In this dual connectivity, in order to communicate in each cell group, the terminal device needs to monitor the presence or absence of messages addressed to it in each cell group. The terminal device needs to constantly monitor multiple cell groups so that it can communicate with low latency when large-volume data communication occurs, which causes the problem of consuming a lot of power. For this reason, research has begun on a technology to monitor some cell groups infrequently or to stop monitoring them (cell group dormant technology) (Non-Patent Document 3).

Currently, when it comes to cell group hibernation, we are considering how to handle cells (SpCells) that are always in an active state, but it is also necessary to consider cells other than SpCells.

One aspect of the present invention has been made in consideration of the above-mentioned circumstances, and has as one of its objectives to provide a terminal device, a base station device, a method, and an integrated circuit that can efficiently perform communication control.

In order to achieve the above object, one aspect of the present invention takes the following measures. That is, a first embodiment of the present invention is a terminal device, comprising a control unit that transitions from a first state to a second state when instructed to enter a second state of a cell group, the first state being a state in which a first BWP is activated in an SpCell of the cell group, the first BWP monitors a downlink control channel (PDCCH), and performs measurement of channel state information (CSI) for the first BWP, and the second state being a state in which a second BWP is activated in an SpCell of the cell group, the second BWP does not monitor a PDCCH, and performs measurement of channel state information (CSI) for the second BWP.

(2) A second embodiment of the present invention is a base station device that communicates with a terminal device, and includes a control unit that transitions the terminal device from a first state to a second state by instructing the terminal device to enter a second state of a cell group, wherein the first state is a state in which a first BWP is activated in an SpCell of the cell group, a downlink control channel (PDCCH) is monitored in the first BWP, and channel state information (CSI) measurements are performed for the first BWP, and the second state is a state in which a second BWP is activated in an SpCell of the cell group, a PDCCH is not monitored in the second BWP, and channel state information (CSI) measurements are performed for the second BWP.

(3) A third embodiment of the present invention is a method applied to a terminal device, comprising a step of transitioning from a first state to a second state when instructed to enter a second state of a cell group, the first state being a state in which a first BWP is activated in an SpCell of the cell group, a downlink control channel (PDCCH) is monitored in the first BWP, and channel state information (CSI) measurements are performed for the first BWP, and the second state being a state in which a second BWP is activated in an SpCell of the cell group, a PDCCH is not monitored in the second BWP, and channel state information (CSI) measurements are performed for the second BWP.

(4) A fourth embodiment of the present invention is a method applied to a base station device communicating with a terminal device, comprising a step of transitioning the terminal device from a first state to a second state by instructing the terminal device to enter a second state of a cell group, the first state being a state in which a first BWP is activated in an SpCell of the cell group, a downlink control channel (PDCCH) is monitored in the first BWP, and channel state information (CSI) measurements are performed for the first BWP, and the second state being a state in which a second BWP is activated in an SpCell of the cell group, a PDCCH is not monitored in the second BWP, and channel state information (CSI) measurements are performed for the second BWP.

(5) A fifth embodiment of the present invention is an integrated circuit implemented in a terminal device, which causes the terminal device to perform a function of transitioning from a first state to a second state when instructed to enter a second state of a cell group, wherein the first state is a state in which a first BWP is activated in an SpCell of the cell group, a downlink control channel (PDCCH) is monitored in the first BWP, and channel state information (CSI) measurements are performed for the first BWP, and the second state is a state in which a second BWP is activated in an SpCell of the cell group, a PDCCH is not monitored in the second BWP, and channel state information (CSI) measurements are performed for the second BWP.

(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 a function of transitioning the terminal device from a first state to a second state by instructing the terminal device to enter a second state of a cell group, the first state being a state in which a first BWP is activated in an SpCell of the cell group, a downlink control channel (PDCCH) is monitored in the first BWP, and channel state information (CSI) measurements are performed for the first BWP, and the second state being a state in which a second BWP is activated in an SpCell of the cell group, a PDCCH is not monitored in the second BWP, and channel state information (CSI) measurements are performed for the second BWP.

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

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 a base station device in NR in each embodiment of the present invention. FIG. 13 is a diagram showing an example of a flow of a procedure for various settings in the RRC 208 and/or the RRC 308 in each embodiment of the present invention. FIG. 2 is a block diagram showing a configuration of a terminal device in each embodiment of the present invention. FIG. 2 is a block diagram showing a configuration of a base station device in each embodiment of the present invention. An example of an 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. 4 shows an example of processing relating to SCG sleep in an embodiment of the present invention. 4 shows an example of processing relating to SCG sleep in an embodiment of the present invention. 4 shows an example of processing relating to SCG sleep in an embodiment of the present invention.

Below, the embodiment of the present invention is described in detail 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 that can be connected by 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. In the following description, the description will be given using terms related to LTE and NR, but this embodiment may be applied to other technologies using other terms. In addition, 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 and the like, and is composed of cell groups (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 and the like, and was designed as a core network for E-UTRA100. Interface 112 is an interface between eNB 102 and EPC 104, and includes a control plane (Control Plane: CP) through which control signals pass, and a user plane (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 a cell group (Cell Group: CG) consisting of one or more frequency bands. gNB (g Node B) 108 is a base station device 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 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. In addition, 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 that supports 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: Radio Bearer) 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: Signaling Radio Bearer), and the radio bearer used for UP is called a data radio bearer (DRB Data Radio Bearer).

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 in each embodiment of the present invention.

Figure 2 (A) is a protocol stack diagram of the UP used when UE 122 communicates with eNB 102 in E-UTRA 100.

PHY (Physical layer) 200 is a wireless physical layer that provides transmission services to a higher layer using a physical channel. PHY 200 is connected to a 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.

MAC202 is a medium access control layer that maps various logical channels to various transport channels. MAC202 is connected to the higher-level RLC (Radio Link Control layer) 204 (described later) via a logical channel. Logical channels are broadly divided according to the type of information transmitted, into control channels that transmit control information and traffic channels that transmit user information. MAC202 may have a function to control PHY200 to perform discontinuous transmission (DRX/DTX), a function to execute a random access procedure, a function to notify transmission power information, a function to perform HARQ control, and the like. MAC302 may also have a function to control the activation state of a cell 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 the lower layer can transmit the 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 unnecessary 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 divided 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.

In addition to PHY 200, MAC 202, RLC 204, and PDCP 206, the CP protocol stack includes 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 establishment, re-establishment, suspension, and resumption of RRC connections, re-setting of RRC connections, such as establishment, change, and release of radio bearers (RBs) and cell groups, and controls logical channels, transport channels, and physical channels, as well as setting 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 eNB 102 and the RRC 208 of the UE 122. In addition, a portion of the RB that is configured by the RLC 204 and a logical channel may be referred to as an RLC bearer. In addition, in contrast to the NAS layer which carries signals between the MME and the UE 122, some or all of the layers of the PHY 200, the MAC 202, the RLC 204, the PDCP 206, and the RRC 208 which carry signals and data between the UE 122 and the eNB 102 may be referred to as an AS (Access Strarum) layer.

The above-mentioned functional classification of MAC 202, RLC 204, PDCP 206, and RRC 208 is an example, and some or all of the functions may not be implemented. In addition, 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), application layer, etc. 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 of the PDCP layer (not shown). 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 UE 122 communicates with gNB 108 in NR 106.

PHY (Physical layer) 300 is a radio physical layer of NR and may provide transmission services to a higher layer 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 UE 122 and the PHY of gNB 108 via a radio physical channel.

Now let us 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 referred to as 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 be referred to as DCI formats) are defined for the transmission of downlink control information. That is, a field for downlink control information is defined as a DCI and mapped to information bits. The PDCCH is transmitted in a PDCCH candidate. The terminal device monitors a set of PDCCH candidates in a 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, transmitting 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: System Information) and random access response (RAR: Random Access Response).

The PUSCH may be used to transmit uplink data from the MAC layer (UL-SCH: Uplink Shared CHannel) or HARQ-ACK and/or CSI together with uplink data. The PUSCH may also be used to transmit only CSI, or only HARQ-ACK and CSI. That is, the PUSCH may be used to transmit only UCI. The PDSCH or PUSCH may also be used to transmit RRC signaling (also referred to as an RRC message) and MAC control elements (MAC CE). Here, in the PDSCH, the RRC signaling transmitted from the base station device may be common signaling for multiple terminal devices in the cell. The RRC signaling transmitted from the base station device may also be dedicated signaling (also referred to as dedicated signaling) for a certain terminal device. That is, the terminal device 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 a random access preamble. The PRACH may be used for initial connection establishment procedures, handover procedures, connection re-establishment procedures, synchronization (timing adjustment) for uplink transmissions, and to indicate requests for PUSCH (UL-SCH) resources.

MAC302 is a medium access control layer that maps various logical channels to various transport channels. MAC302 may be connected to a higher-level RLC (Radio Link Control layer) 304 (described later) via a logical channel. The logical channels are broadly divided according to the type of information transmitted, and may be divided into a control channel that transmits control information and a traffic channel that transmits user information. MAC302 may have a function to control PHY300 to perform intermittent transmission (DRX/DTX), a function to execute a random access procedure, a function to notify information on transmission power, a function to perform HARQ control, and the like. MAC302 may also have a function to control the activation state of a cell 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 sections. PDCP 306 may have a header compression function that compresses unnecessary control information. PDCP 306 may also have the functions of encrypting data and protecting the integrity of data.

SDAP (Service Data Adaptation Protocol) 310 is a service data adaptation protocol layer that has the function of mapping (mapping) the downlink QoS flow sent from 5GC 110 to a terminal device via a base station device to a DRB, and mapping the uplink QoS flow sent from the terminal device to 5GC 110 via a base station device to a DRB, and storing mapping rule information.

The data processed in MAC 302, RLC 304, PDCP 306, and SDAP 310 are called 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 are called MAC SDU (Service Data Unit), RLC SDU, PDCP SDU, and SDAP SDU, respectively. A divided RLC SDU is called an RLC SDU segment.

Figure 3 (B) is a protocol stack diagram of the CP used by UE 122 in NR 106 when communicating with gNB 108 and AMF (Access and Mobility Management function), a logical node that provides functions such as authentication and mobility management.

In addition to PHY 300, MAC 302, RLC 304, and PDCP 306, the CP protocol stack includes 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 establishment, re-establishment, suspension, and resumption of RRC connections, reconfiguration of RRC connections, such as establishment, change, and release of radio bearers (RBs) and cell groups, and controls logical channels, transport channels, and physical channels, as well as handover and measurement settings. 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. In addition, the portion of the RB that is composed of 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 which carries signals between the AMF and the UE 122, some or all of the layers of the PHY 300, MAC 302, RLC 304, PDCP 306, RRC 308, and SDAP 310 which 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. In addition, some or all of the functions of each layer may be included in another layer.

Note that the layer above the AS layer (not shown) may be called 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. Note that the PDU layer may be a layer above the user plane of the AS layer. The RRC layer and the NAS (non access strarum) layer may also be any or all of the upper layers of the SDAP layer and the 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 above the IP layer, the TCP (Transmission Control Protocol) layer, the UDP (User Datagram Protocol) layer, and the application layer.

In addition, 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 according to an RRC message transmitted from the RRC layer of the base station device. In addition, the MAC layer (MAC layer), RLC layer (RLC layer), PDCP layer (PDCP layer), and SDAP layer (SDAP layer) may be called the MAC sublayer (MAC sublayer), RLC sublayer (RLC sublayer), PDCP sublayer (PDCP sublayer), and SDAP sublayer (SDAP sublayer), respectively.

In addition, each layer belonging to the AS layer set in any or all of the terminal device and the base station device, or the function of each layer may be called an entity. That is, the physical layer (PHY layer), MAC layer, RLC layer, PDCP layer, SDAP layer, and RRC layer, in which any or all of the establishment, configuration, and control are performed in any or all of the terminal device and the base station device, or the function of each layer may be called a physical entity (PHY entity), MAC entity, RLC entity, PDCP entity, SDAP entity, and RRC entity, respectively. In addition, each layer may include one or more entities. In addition, the PDCP entity and the RLC entity may be established, configured, and controlled for each radio bearer. In addition, the MAC entity may be established, configured, and controlled for each cell group. In addition, the SDAP entity may be established, configured, and 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, MAC202, RLC204, PDCP206, and RRC208 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. MAC302, RLC304, PDCP306, and RRC308 may be referred to as MAC for NR, RLC for NR, RLC for NR, and RRC for NR, respectively. Or, they may be written with spaces, such as E-UTRA PDCP or LTE PDCP, NR PDCP, etc.

Also, 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. In E-UTRA 100, NR PDCP may be used as PDCP even when UE 122 communicates with eNB 102.

Next, the state transition of UE122 in LTE and NR will be described. UE122 connected to EPC or 5GC may be in RRC_CONNECTED state when RRC connection has been established. The state in which RRC connection is established may include a state in which UE122 holds some or all of the UE context described below. The state in which RRC connection is established may also include a state in which UE122 can transmit and/or receive unicast data. UE122 may be in RRC_INACTIVE state when RRC connection is paused (if UE122 is connected to 5GC). If not, UE122 may be in 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 an identifier (resumeIdentity) used for restoration. When UE 122 retains the UE's AS context, the restoration of the RRC connection is permitted by the E-UTRAN, and UE 122 needs to transition from the RRC_IDLE state to the RRC_CONNECTED state, the restoration of the suspended RRC connection may be initiated by a higher layer (e.g., the NAS layer).

That is, the definition of dormancy may be different for UE 122 connected to EPC and UE 122 connected to 5GC. In addition, all or part of the procedure for UE 122 to return from dormancy may be different when UE 122 is connected to EPC (dormant in RRC_IDLE state) and when UE 122 is connected to 5GC (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), the inactive state (inactive mode), and the idle state (idle mode), respectively, or as the RRC connected state (RRC connected mode), the RRC inactive state (RRC inactive mode), and the RRC idle state (RRC idle mode).

The UE AS context held by UE122 may include all or part of the following: the current RRC setting, the current security context, the PDCP state including the ROHC (RObust Header Compression) state, the C-RNTI (Cell Radio Network Temporary Identifier) used in the source PCell, the cell identifier, and the physical cell identifier of the source PCell. The UE AS context held by any 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 included in the UE AS context held by UE122.

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

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 particular terminal device needs to perform processing, such as security settings, reconfiguration of an RRC connection (radio line bearer processing (establishment, change, release, etc.), cell group processing (establishment, addition, change, release, etc.), measurement settings, handover settings, etc.), or release of an RRC connection state. The RRC message includes information (parameters) for various information notifications and settings. In the 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 method called ASN. 1 (Abstract Syntax Notation One).

The RRC message may be generated for other purposes. For example, the RRC message may be used to configure Dual Connectivity (DC) or Multi-Radio Dual Connectivity (MR-DC).

In FIG. 4, the base station device then transmits the created RRC message to the terminal device (step S402). Next, the terminal device performs processing such as setting according to the received RRC message if necessary (step S404).

Dual Connectivity (DC) may be a technology for performing data communication using radio resources of both cell groups formed by two base station devices (nodes), that is, a master cell group (MCG) formed by a master node (MN) and a secondary cell group (SCG) formed by a secondary node (SN). The master node and the secondary node may be the same node (same base station device). MR-DC may be a technology for performing data communication using radio resources of both E-UTRA and NR RATs (Radio Access Technology) by grouping the cells of each RAT and assigning them to a UE, and using radio resources of both MCG and SCG. In MR-DC, the master node may be a base station having 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 RRC functions, such as modifying and releasing an SCG, etc.

In the MR-DC, the RRC of the RAT on the master node side may be used to configure both the MCG and the 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), and 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, an E-UTRA RRC message may be transmitted 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. In addition, the RRC message transmitted from the eNB 102 to the UE 122 may be transmitted from the eNB 102 to the UE 122 via the gNB 108. In addition, the configuration of this RRC message is non-MR-DC, and may be used for E-UTRA/5GC in which the 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, an NR RRC message may be transmitted and received between gNB108 and UE122 in NE-DC (NR-E-UTRA Dual Connectivity). In this case, the RRC message may include not only NR configuration information but also LTE (E-UTRA) configuration information. In addition, the RRC message transmitted from gNB108 to UE122 may be transmitted from gNB108 to UE122 via eNB102.

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

Figure 7 is an example of an ASN. 1 description showing some or all of the fields and information elements related to cell group setting included in the message related to RRC connection reconfiguration in NR in Figure 4. Also, Figure 8 is an example of an ASN. 1 description showing some or all of the fields and information elements related to cell group setting 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 the embodiment of the present invention, <Omitted> and <Omitted> indicate that other information is omitted, not that they are part of the ASN. 1 notation. Note that information elements may be omitted even in places where <Omitted> or <Omitted> is not written. Note that the ASN. 1 examples in the embodiment of the present invention do not correctly follow the ASN. 1 notation method, but show an example of parameters of a message related to RRC connection reconfiguration in the embodiment of the present invention, and other names and other notations may be used. Also, in the ASN. In order to avoid the description from becoming complicated, the example of FIG. 1 shows only examples of main information closely related to one embodiment of the present invention. Note that the parameters described in ASN.1 may not be distinguished as fields, information elements, etc., and may all be referred to as information elements. In addition, in the embodiment of the present invention, parameters such as fields and information elements described in ASN.1 included in the RRC message may 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 FIG. 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 the terminal device from a cell of the SCG. mrdc-SecondaryCellGroupConfig may include settings related to the SCG when notified to the 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 an SCell belonging to the cell group. The sCellToReleaseList may include information related to the deletion of an SCell belonging to the cell group.

In FIG. 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 regarding 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 the SCell belonging to the cell group (such as sCellToAddModListSCG-r12), and/or information related to the deletion of the SCell belonging to the cell group (such as sCellToReleaseListSCG-r12). In addition, information indicating the initial state of the SCell may be included in settings related to the addition or modification of the SCell at the time of handover, and/or settings related to the addition or modification of the SCell when adding the SCell. For example, information indicating either an active state (Activated) or a dormant state (Dormant) 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 including 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 a serving cell (e.g., PCell and/or PSCell) using a certain type of reference signal (e.g., cell-specific reference signal (CRS)). The terminal device may also receive a setting (radio link monitoring setting: RadioLinkMonitoringConfig) indicating which reference signal is to be used for radio link monitoring in the serving cell (e.g., PCell and/or PSCell) from the base station device, and perform radio link monitoring using one or more set reference signals (herein referred to as RLM-RS). The terminal device may also perform radio link monitoring using other signals. The physical layer processing unit of the terminal device may notify the upper layer of synchronization when the conditions for being synchronized in the serving cell (e.g., PCell and/or PSCell) are met.

The radio link monitoring setting may include information indicating the purpose of monitoring and identifier information indicating a reference signal. For example, the purpose of monitoring may include a purpose of monitoring radio link failure, a purpose of monitoring beam failure, or both purposes. For example, the identifier information indicating the reference signal may include information indicating an identifier (SSB-Index) of the synchronization signal block (SSB) of the cell. That is, the reference signal may include a synchronization signal. 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) set in the terminal device.

In the SpCell (PCell in the MCG and PSCell in the SCG), the RRC layer processing unit of the terminal device may start (Start) or restart (Restart) the timer (T310) of the SpCell when it receives a predetermined number (N310) of consecutive out-of-sync notifications from the physical layer processing unit in each SpCell. In addition, the RRC layer processing unit of the terminal device may stop (Stop) the timer (T310) of the SpCell when it receives a predetermined number (N311) of consecutive in-sync notifications in each SpCell. When the timer (T310) of each SpCell expires, if the SpCell is a PCell, the RRC layer processing unit of the terminal device may transition to an idle state or perform a procedure to re-establish an RRC connection. Furthermore, 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 set in the terminal device. When DRX is set in the terminal device, the RRC layer processing unit of the terminal device may set the period for measuring the radio link quality and the interval for notifying the upper layer to different values than when DRX is not set in the physical layer processing unit. Note that even when DRX is set, when the timer is running, the period for measuring the radio link quality to estimate synchronization and the interval for notifying the upper layer may be set to the values when DRX is not set.

In addition, 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).

In addition, 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 is not limited to this.

The following describes cell activation and deactivation. In a terminal device communicating with dual connectivity, a master cell group (MCG) and a secondary cell group (SCG) are configured by a message regarding the reconfiguration of the RRC connection described above. Each cell group may be composed of a special cell (SpCell) and zero or more other cells (secondary cells: SCell). The SpCell of the MCG is also referred to as a PCell. The SpCell of the SCG is also referred to as a PSCell. Cell deactivation does not apply to the SpCell, but may apply to the SCell.

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) set 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.

(Processing AD)
If a MAC CE that activates the SCell is received, process (AD-1) is performed. Otherwise, if a MAC CE that deactivates the SCell is received, or if the timer (sCellDeactivationTimer) expires in the active SCell, process (AD-2) is performed. If an uplink grant or downlink allocation is notified by the PDCCH of the active SCell, or if an uplink grant or downlink allocation 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 allocation, 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 put into an active state and normal SCell operations, including some or all of (A) to (E) below, are applied (implemented).
(A) Transmitting Sounding Reference Signals (SRS) in this SCell; (B) Reporting Channel State Information (CSI) for this SCell; (C) Monitoring PDCCH in this SCell; (D) Monitoring PDCCH 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 the activating MAC CE in the NR, some or all of the following (A) to (B) shall be implemented.
(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.

Also, the timer associated with this SCell (sCellDeactivationTimer) is started or restarted (if already started).

(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 in 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 the SCell are performed by the MAC entity performing processing (AD).

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

Here, the timer (sCellDeactivationTimer) will be described. For an SCell in which PUCCH is not set, 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 information indicating 40 ms as the value of the timer (sCellDeactivationTimer) is notified by an RRC message, the timer is considered to have expired when the notified time (here, 40 ms) has elapsed without the timer being stopped after the timer is started or restarted in the above process (AD).

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

The BWP may be a part or the whole of the band of the serving cell. The BWP may be referred to as a carrier BWP. One or more BWPs may be set in the terminal device. A certain BWP may be set by information included in the broadcast information associated with a synchronization signal detected in the initial cell search. A certain BWP may be a frequency bandwidth associated with a frequency at which the initial cell search is performed. A certain BWP may be set by RRC signaling (e.g., Dedicated RRC signaling). A downlink BWP (DL BWP) and an uplink BWP (UL BWP) may be set separately. One or more uplink BWPs may 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 of these.

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

A terminal device may transmit and receive in an active BWP among one or more configured BWPs. For a terminal device, among one or more BWPs configured for one serving cell, at a certain time, up to one uplink BWP and/or up to one downlink BWP may be configured to be active BWPs. An activated downlink BWP is also called an Active DL BWP. An activated uplink BWP is also called an Active UL BWP.

Next, we will explain the deactivation of BWP. One serving cell may be configured with one or more BWPs. 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 the 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 setting of the dormant SCell group is indicated by RRC signaling. In addition, in the current specification, the dormant BWP is applied only to the SCell. Note that a dormant BWP does not change a certain BWP to a dormant state, but may be interpreted as one BWP set for dormancy among one or more BWPs set for the UE. In addition, there may be multiple BWPs set for dormancy in the UE.

A certain BWP may be indicated as a dormant BWP by the absence of a specific parameter in the BWP configuration. For example, the absence of a PDCCH-Config information element, which is an information element for setting UE-specific (specific) PDCCH parameters, included in the downlink BWP configuration, may indicate that the BWP is a dormant BWP. Also, for example, the absence of some of the parameters included in the PDCCH-Config information element, which is an information element for setting UE-specific (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 settings related to the search space that defines where and/or how to search for PDCCH candidates, which are set by the PDCCH-Config information element, may indicate that the BWP is a dormant BWP.

In addition, the current specifications do not support setting dormant BWP for SpCells such as PCell and PSCell, and PUCCH SCells that can transmit PUCCH.

When a UE receives a PDCCCH in an SpCell indicating that it will exit a dormant BWP outside a certain configured 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 PDCCCH in an 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 PDCCCH indicating entry into a dormant BWP, it activates the downlink BWP indicated by the third downlink BWP identifier (dormantDownlinkBWP-Id) that was notified in advance by RRC signaling.

The above-mentioned entry and exit into a dormant BWP is performed by BWP switching, and when a new BWP is activated, the BWP that was active until then 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 explain the PDCCH indicating entering a dormant BWP and the PDCCH indicating leaving a dormant BWP.

For example, a UE with discontinuous reception (DRX) configured in the SpCell may monitor the PDCCH in the Active BWP of the SpCell to detect a certain DCI format (e.g., DCI format 2_6) outside the active time of DRX. The CRC of the DCI format may be scrambled with a certain RNTI (e.g., PS-RNTI). A UE with a dormant SCell group configured may determine switching of the Active DL BWP based on the bitmap information included in the payload of DCI format 2_6. For example, if a bit in the bitmap is linked to one dormant SCell group and the bit is 1, if the Active DL BWP is a dormant BWP, BWP switching may be performed to another BWP configured in advance, and 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 a dormant BWP.

During DRX active time, the UE does not need to monitor the PDCCCH for the purpose of detecting DCI format 2_6.

A UE configured with discontinuous reception (DRX) in the SpCell may monitor the PDCCH in the SpCell's Active BWP to detect a DCI format (e.g., DCI formats 0_1 and 1_1) during the active time of DRX. The CRC of the DCI format may be scrambled with a certain RNTI (e.g., C-RNTI or MCS-C-RNTI). A UE configured with a dormant SCell group determines whether to switch the Active DL BWP based on the bitmap information included in the payload of DCI format 0_1 or DCI format 1_1. For example, a bit in the bitmap may be associated with one dormant SCell group, and when the bit is 1, if the Active DL BWP is a dormant BWP, BWP switching may be performed to another BWP that has been preset, and if the Active DL BWP is not a dormant BWP, the BWP may remain in that BWP. Also, when the bit is 0, BWP switching may be performed so that the Active DL BWP becomes a dormant BWP. Also, the "pre-set another BWP" may be a BWP different from the "pre-set 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 the DRX active time.

Monitoring the PDCCH indicating leaving a 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 (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 (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 that 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.

The MAC entity shall, if the BWP is deactivated, do some or all of the following: (A) through (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 inactive BWP.

Next, a random access procedure in a UE with a BWP configured will be described. When a random access procedure is started in a serving cell, the MAC entity performs some or all of the following processes (A) to (E) in 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 that 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 (bwp-InactivityTimer) associated with the Active DL BWP of the SpCell 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 uplink grant for an Active DL BWP is received, or if a PDCCH addressed to the C-RNTI or CS-RNTI indicating a downlink assignment or uplink grant for an Active DL BWP is received, or if a MAC PDU is 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, perform BWP switching to the BWP indicated by this defaultDownlinkBWP-Id; if not, perform BWP switching to initialDownlinkBWP.

Furthermore, if the MAC entity receives a PDCCH for BWP switching and switches the Active DL BWP, it performs the following process (A).
(A) If a default downlink BWP identifier (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, the procedures for beam failure detection and recovery will be explained.

The MAC entity may be configured by the RRC with a beam failure recovery procedure for each serving cell. Beam failure is detected by counting beam failure instance notifications notified to the MAC entity from the lower layer (PHY layer). The MAC entity may perform some or all of the following processes (A), (B), and (C) for each serving cell to detect beam failure.
(A) If a beam failure instance notification is received from 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 has expired or if the beamFailureDetectionTimer, beamFailureInstanceMaxCount, and/or reference signal settings for beam failure detection have been 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 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 completed successfully, and cancel all beam failure recovery (BFR) 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 BFR MAC CE and its subheader of the SCell considering the priority of the logical channel, include the BFR MAC CE and its subheader of the SCell, otherwise, if the UL-SCH resource can contain the truncated BFR MAC CE and its subheader of the SCell considering the priority of the logical channel, include the truncated BFR MAC CE and its subheader of the SCell, otherwise, trigger a scheduling request for SCell beam failure recovery.

The SCell is put into hibernation by activating the hibernation BWP in the SCell. In addition, even when the SCell is in hibernation, CSI measurement, automatic gain control (AGC), and beam management including beam failure recovery may be performed in the SCell.

Next, we will explain about 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 implements 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 that has been 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 the PDCCH indicating leaving the dormant BWP is monitored.
(H) The C-RNTI is not monitored on the PDCCH in the activated dormant BWP of this SpCell.

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. In addition, the dormancy of an SCG may be activating a dormant BWP of an SpCell of the cell group.
(A) Reception of an RRC message instructing SCG to be in hibernation (B) Reception of a MAC control element instructing SCG to be in hibernation (C) Reception of an RRC message instructing SpCell to be in hibernation (D) Reception of a MAC control element instructing SpCell to be in hibernation (E) Reception of another RRC message (F) Reception of another MAC control element (G) Expiration of a timer related to SCG hibernation (H) Expiration of a timer related to PSCell hibernation

In LTE and/or NR, a terminal device may determine and/or execute the return (Resume) from the dormant state of an SCG based on some or all of (A) to (H) below. 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 return of the SCG from the dormant state may be referred to as leaving the dormant SCG. The return of the SCG from the dormant state may be a BWP switch from a dormant BWP to another (non-dormant) BWP in the SpCell of the cell group.
(A) Reception of an RRC message instructing the SCG to resume from dormancy (B) Reception of a MAC control element instructing the SCG to resume from dormancy (C) Reception of an RRC message instructing the SpCell to resume from dormancy (D) Reception of a MAC control element instructing the SpCell to resume from dormancy (E) Reception of other RRC messages (F) Reception of other MAC control elements (G) Timer related to SCG dormancy (H) Timer related to PSCell dormancy

A terminal device that performs sleep for an SCG may perform some or all of the following processes (A) to (F) in that SCG.
(A) All SCells are in an inactive state.
(B) All timers (sCellDeactivationTimers) associated with the active SCell are deemed 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 any SCell.
(E) Ignore the MAC CE that activates the SCell. For example, in the process (AD), when 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), the process (AD-1) is performed.
(F) Execute the process (AD-2) For example, when an SCG sleep command is issued (or the SCG goes into a sleep state) in the process (AD), the process (AD-2) is executed.

A terminal device that performs recovery from a hibernation 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 are kept in an inactive state. However, since they are not in a dormant state, for example, when a MAC CE to activate the 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 a dormant state based on an RRC message, if the RRC message includes parameters related to random access to some or all of the SCells, a random access procedure is initiated in the target SCell based on the notified parameters.

Figure 9 is a diagram showing 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 SpCell (second cell) of the SCG (i.e., SCell) to be in an inactive state.

The above operation enables efficient state change in the process of putting an SCG to sleep without separately transmitting a MAC CE for changing the state of the SCell of the SCG to an inactive state. Also, when the SCG sleep is executed based on an RRC message, the initial state was conventionally set in the RRC layer and the state change was performed in the MAC layer, but the above operation makes it possible to efficiently change the state of the SCG while avoiding mismatches between instructions from the RRC layer and the MAC layer.

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

For example, when the SpCell is in a dormant state (dormant BWP is activated), the UE may monitor the PDCCH in the Active BWP of the SpCell 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 may determine switching of the Active DL BWP based on bitmap information included in the payload of DCI format 2_6. For example, if a bit in the bitmap is linked to one dormant SCell group and the bit is 1, if the Active DL BWP is a dormant BWP, BWP switching may be performed to another BWP configured in advance, and 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 a 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.

If the system is configured with discontinuous reception in the SpCell during the dormant state of the SpCell, a UE configured with discontinuous reception (DRX) in the SpCell may monitor the PDCCH in the Active BWP of the SpCell to detect a certain DCI format (e.g., DCI formats 0_1 and 1_1) during the active time of DRX. The CRC of the DCI format may be scrambled with a certain RNTI (e.g., C-RNTI or MCS-C-RNTI). A UE configured with a dormant SCell group determines switching of the Active DL BWP based on bitmap information included in the payload of DCI format 0_1 or DCI format 1_1. For example, if a bit in the bitmap is associated with one dormant SCell group and the bit is 1, if the Active DL BWP is a dormant BWP, BWP switching is performed to another BWP that has been pre-configured, and the Active DL
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 preset BWP" may be a BWP different from the "another preset BWP" used in the explanation 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 the DRX active time.

Monitoring the PDCCH indicating the exit from the dormant BWP may be 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 configured for discontinuous reception in the SpCell when the SpCell is in a dormant state, monitoring the PDCCH indicating leaving the dormant BWP may mean monitoring the PDCCH for the purpose of detecting DCI format 2_6 outside of the active time of DRX, and monitoring the PDCCH for the purpose of detecting DCI format 0_1 and DCI format 1_1 during the active time of DRX. 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 may be stopped in the SCG. In this case, information about the SCG may be transmitted in another cell group (e.g., MCG). Alternatively, information about the SCG may be transmitted in the SCG that has left the 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 of performing uplink transmission in the SCG when the SCG is in a dormant state is described.

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

The MAC entity may be configured with a beam failure recovery procedure for each serving cell by the RRC. 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 the lower layer (PHY layer). The MAC entity may perform some or all of the following processes (A), (B), and (C) in each serving cell for beam failure detection.
(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 the 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. That is, 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 has expired or if the beamFailureDetectionTimer, beamFailureInstanceMaxCount, and/or reference signal settings for beam failure detection have been 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 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 completed successfully, and cancel all beam failure recovery (BFR) 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 a 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 a pending scheduling request.

As mentioned above, a random access procedure in the SpCell (PSCell) may be initiated in a dormant SCG by triggering a scheduling request by the MAC entity 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 transmission and RACH transmission 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) measurement is performed for the first BWP. The first state may also be a state in which discontinuous reception (DRX) is set.

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 returned 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 the second state is transitioned 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 the second state is transitioned when a return from a dormant state is instructed from an RRC entity. Also, for example, the first state may be a state in which the PDCCH indicating the exit from a dormant BWP is not monitored.

In a 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 a PDCCH addressed to a C-RNTI, MCS-C-RNTI, and/or CS-RNTI indicating an uplink grant 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 a PDCCH addressed to a C-RNTI, MCS-C-RNTI, and/or CS-RNTI indicating an uplink grant for UL-SCH transmission and a PDCCH 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 only a PDCCH indicating leaving a dormant BWP is monitored in the second BWP. Furthermore, the second state may be a state in which a 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 third state is a state in which limited UL-SCH transmission and RACH transmission are possible in an SpCell of a certain cell group. The third state may be a state in which RACH transmission is possible in an 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 for limited UL-SCH transmission. The third state may be part of a first state in which the cell group (SCG) has returned from a dormant state, or may be a state different from the first state in which the cell group (SCG) has returned from a dormant state.

For example, the third state may be a state to which the second state transitions when a random access procedure triggered by a MAC entity is initiated. Also, for example, the third state may be a state to which the second state transitions when the value of BFI_COUNTER is equal to or greater than a set threshold. Also, for example, the third state may be a state to which the second state transitions when the value of BFI_COUNTER is equal to or greater than a set threshold and a random access procedure is initiated in the PSCell. Also, for example, the third state may be a state to which the second state transitions when the value of BFI_COUNTER is equal to or greater than a set 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 the SpCell of the cell group, and a PDCCH indicating leaving a dormant BWP is monitored in the third BWP. Furthermore, the third state may be a state in which a PDCCH addressed to a C-RNTI, MCS-C-RNTI, and/or CS-RNTI indicating an uplink grant is not monitored in the third BWP. Furthermore, the third state may be a state in which a measurement of channel state information (CSI) is performed for the third BWP. When the 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 second state is transitioned 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 second state is transitioned 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 second state is transitioned when a MAC SDU is not included in a MAC PDU that includes a specific MAC CE.

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

Also, for example, the third state may be a state to which a transition occurs 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 to 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. In addition, one or more BWPs may be configured in each of the first to third BWPs. In addition, 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 and a BWP other than the first BWP becoming an inactivated BWP may have the same meaning. Transitioning to the second state and a BWP other than the second BWP becoming an activated BWP may have the same meaning. Transitioning to the third state and a BWP other than the third BWP becoming an activated BWP may have the same meaning.

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 the uplink BWP. The configuration of the third BWP may include at least the parameters necessary for monitoring the PDCCH to receive a response to the random access preamble (random access response). The configuration of the third BWP may include the configuration of the uplink BWP. The configuration of the uplink BWP may include information necessary for transmitting the random access preamble.

As another example, the dormant state of the SCG may be the third state. In other words, the SCG entering the dormant state may have the same meaning as transitioning to the third state. In this case, the second state may be defined as a 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 a dormant state. In addition, when the SCG is in a dormant state, power saving is possible by monitoring only necessary signals.

MCG Failure: The purpose of this procedure may be to inform the network about an MCG failure (i.e., 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-establishment.

As shown in FIG. 11, a UE with split SRB1 or SRB3 configured 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 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 MCG failure is initiated, MCG transmissions for all SRBs and DRBs other than SRB0 are suspended. Also, when the procedure for reporting SCG failure is initiated, SCG transmissions for all SRBs and DRBs are suspended.

Timer T316 is a timer that starts when an MCG failure information message is sent and is stopped when transmission in the MCG recovers, when an RRC Release 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 the SpCell of the cell group, the fourth BWP monitors only the PDCCH indicating the exit from the dormant BWP, and performs channel state information (CSI) measurement for the fourth BWP. The fourth state may also be a state in which a fourth BWP is activated in the SpCell of the cell group, the fourth BWP does not monitor the C-RNTI on the PDCCH, and performs channel state information (CSI) measurement for the fourth BWP. The fourth state may also be the third state described above.

When the procedure to report MCG failure is initiated, the UE suspends MCG transmission for all SRBs and DRBs other than 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 with split SRB1 or SRB3 configured 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 conditions (A) to (B) below 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 control of the procedure for reporting MCG failures without adding new conditions.

Figure 5 is a block diagram showing the configuration of a terminal device (UE122) in each embodiment of the present invention. Note that in order 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 is composed of a receiver 500 that receives an RRC message or the like from a base station device, a processor 502 that performs processing according to some or all of the setting information of various information elements (IEs), various fields, and various conditions, etc., contained in the received message, and a transmitter 504 that transmits an RRC message or the like to the base station device. The above-mentioned base station device may be an eNB 102 or a gNB 108. The processor 502 may include some or all of the functions of various layers (e.g., a physical layer, a MAC layer, an RLC layer, a PDCP layer, an RRC layer, and an NAS layer). That is, the processor 502 may include some or all of the physical layer processor, the MAC layer processor, the RLC layer processor, the PDCP layer processor, the RRC layer processor, and the NAS layer processor.

Figure 6 is a block diagram showing the configuration of a base station device in each embodiment of the present invention. In order 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 eNB102 or gNB108.

The base station device shown in FIG. 6 includes a transmitter 600 that transmits an RRC message to UE 122, a processor 602 that creates an RRC message including some or all of the setting information of various information elements (IEs), various fields, and various conditions, and transmits the RRC message to UE 122 to cause the processor 502 of UE 122 to perform processing, and a receiver 604 that receives an RRC message from UE 122. The processor 602 may include some or all of the functions of various layers (e.g., 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 of the process examples or process flow examples in the above description, some or all of the steps may not be executed. Furthermore, in each of the process examples or process flow examples in the above description, the order of the steps may be different. Furthermore, in each of the process examples or process flow examples in the above description, some or all of the processing within each step may not be executed. Furthermore, in each of the process examples or process flow examples in the above description, the order of the processing within each step may be different.

Various aspects of the terminal device in an embodiment of the present invention are described below.

(1) A first embodiment of the present invention is a terminal device comprising a control unit that transitions from a first state to a second state when instructed to enter a second state of a cell group, the first state being a state in which a first BWP is activated in an SpCell of the cell group, the downlink control channel is monitored in the first BWP, and channel state information (CSI) measurements are performed for the first BWP, and the second state being a state in which a second BWP is activated in an SpCell of the cell group, the second BWP is monitored only for a PDCCH indicating leaving a dormant BWP, and channel state information (CSI) measurements are performed for the second BWP.

(2) A second embodiment of the present invention is a base station device that communicates with a terminal device, comprising a control unit that transitions the terminal device from a first state to a second state by instructing the terminal device to enter a second state of a cell group, the first state being a state in which a first BWP is activated in an SpCell of the cell group, a downlink control channel is monitored in the first BWP, and channel state information (CSI) measurements are performed for the first BWP, and the second state being a state in which a second BWP is activated in an SpCell of the cell group, and only a PDCCH indicating leaving a dormant BWP is monitored in the second BWP, and channel state information (CSI) measurements are performed for the second BWP.

(3) A third embodiment of the present invention is a method applied to a terminal device, comprising a step of transitioning from a first state to a second state when instructed to enter a second state of a cell group, the first state being a state in which a first BWP is activated in an SpCell of the cell group, a downlink control channel is monitored in the first BWP, and channel state information (CSI) measurements are performed for the first BWP, and the second state being a state in which a second BWP is activated in an SpCell of the cell group, and only a PDCCH indicating leaving a dormant BWP is monitored in the second BWP, and channel state information (CSI) measurements are performed for the second BWP.

(4) A fourth embodiment of the present invention is a method applied to a base station device communicating with a terminal device, comprising a step of transitioning the terminal device from a first state to a second state by instructing the terminal device to enter a second state of a cell group, the first state being a state in which a first BWP is activated in an SpCell of the cell group, a downlink control channel is monitored in the first BWP, and channel state information (CSI) measurements are performed for the first BWP, and the second state being a state in which a second BWP is activated in an SpCell of the cell group, and only a PDCCH indicating leaving a dormant BWP is monitored in the second BWP, and channel state information (CSI) measurements are performed for the second BWP.

(5) A fifth embodiment of the present invention is an integrated circuit implemented in a terminal device, which causes the terminal device to perform a function of transitioning from a first state to a second state when instructed to enter a second state of a cell group, the first state being a state in which a first BWP is activated in an SpCell of the cell group, the downlink control channel is monitored in the first BWP, and channel state information (CSI) measurements are performed for the first BWP, and the second state being a state in which a second BWP is activated in an SpCell of the cell group, the second BWP is monitored only for a PDCCH indicating leaving a dormant BWP, and channel state information (CSI) measurements are performed for the second BWP.

(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 a function of transitioning the terminal device from a first state to a second state by instructing the terminal device to enter a second state of a cell group, the first state being a state in which a first BWP is activated in an SpCell of the cell group, a downlink control channel is monitored in the first BWP, and channel state information (CSI) measurements are performed for the first BWP, and the second state being a state in which a second BWP is activated in an SpCell of the cell group, and only a PDCCH indicating leaving a dormant BWP is monitored in the second BWP, and channel state information (CSI) measurements are performed for the second BWP.

A program that operates on an apparatus according to one aspect of the present invention may be a program that controls a Central Processing Unit (CPU) or the like to cause a computer to function so as to realize the functions of the above-described embodiment according to one aspect of the present invention. The program or information handled by the program is temporarily loaded into a volatile memory such as a Random Access Memory (RAM) during processing, or is stored in a non-volatile memory such as a flash memory or a Hard Disk Drive (HDD), and is read, modified, and written by the CPU as necessary.

It should be noted that a part of the device in the above-mentioned embodiment may be realized by a computer. In that case, a program for realizing 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 realize the control function. The "computer system" referred to here is a computer system built into the device, and includes hardware such as an operating system and peripheral devices. Furthermore, the "computer-readable recording medium" may be any of a semiconductor recording medium, optical recording medium, magnetic recording medium, etc.

Furthermore, "computer-readable recording medium" may also include something 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 something 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. The above program may also be one that realizes part of the functions described above, or one that can realize the functions described above in combination with a program already recorded in the computer system.

In addition, each functional block or feature of the device used in the above-mentioned embodiment may be implemented or performed by an electric circuit, typically an integrated circuit or a plurality of integrated circuits. The electric 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. In addition, if an integrated circuit technology that replaces the current integrated circuits emerges due to the advancement of semiconductor technology, it is also possible to use an integrated circuit based on that technology.

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

Although an embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and design modifications and the like that do not depart from the gist of the present invention are also included. 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. Also included are configurations in which elements described in the above embodiments are substituted for elements that have the same effect.

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

100 E-UTRA
102 eNB
104 EPC
106 N.R.
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 S.D.A.P.
210, 312 NAS
500, 604 Receiving unit 502, 602 Processing unit 504, 600 Transmitting unit

Claims (6)

A terminal device ,
a control unit that transitions from a first state to a second state when instructed to enter the second state of the cell group;
The first state is
A first BWP is activated in an SpCell of the cell group;
Monitoring a downlink control channel (PDCCH) in the first BWP;
and performing channel state information (CSI) measurements for the first BWP ;
The second state is
A second BWP is activated in an SpCell of the cell group;
All SCells of the cell group are deactivated,
In the second BWP, a PDCCH is not monitored;
and performing channel state information (CSI) measurements for the second BWP .
Terminal device. A base station device that communicates with a terminal device ,
A control unit that transitions the terminal device from a first state to a second state by instructing the terminal device to enter a second state of a cell group;
The first state is
A first BWP is activated in an SpCell of the cell group;
Monitoring a downlink control channel (PDCCH) in the first BWP;
and performing channel state information (CSI) measurements for the first BWP ;
The second state is
A second BWP is activated in an SpCell of the cell group;
All SCells of the cell group are deactivated,
In the second BWP, a PDCCH is not monitored;
and performing channel state information (CSI) measurements for the second BWP .
Base station equipment. A method applied to a terminal device , comprising:
transitioning from the first state to the second state when instructed to enter the second state of the cell group;
The first state is
A first BWP is activated in an SpCell of the cell group;
Monitoring a downlink control channel (PDCCH) in the first BWP;
and performing channel state information (CSI) measurements for the first BWP ;
The second state is
A second BWP is activated in an SpCell of the cell group;
All SCells of the cell group are deactivated,
In the second BWP, a PDCCH is not monitored;
and performing channel state information (CSI) measurements for the second BWP .
method. A method applied to a base station device that communicates with a terminal device , comprising:
transitioning the terminal device from a first state to a second state by instructing the terminal device to enter a second state of a cell group;
The first state is
A first BWP is activated in an SpCell of the cell group;
Monitoring a downlink control channel (PDCCH) in the first BWP;
and performing channel state information (CSI) measurements for the first BWP ;
The second state is
A second BWP is activated in an SpCell of the cell group;
All SCells of the cell group are deactivated,
In the second BWP, a PDCCH is not monitored;
and performing channel state information (CSI) measurements for the second BWP .
method. An integrated circuit implemented in a terminal device ,
causing the terminal device to perform a function of transitioning from a first state to a second state when instructed to enter a second state of a cell group;
The first state is
A first BWP is activated in an SpCell of the cell group;
Monitoring a downlink control channel (PDCCH) in the first BWP;
and performing channel state information (CSI) measurements for the first BWP ;
The second state is
A second BWP is activated in an SpCell of the cell group;
All SCells of the cell group are deactivated,
In the second BWP, a PDCCH is not monitored;
and performing channel state information (CSI) measurements for the second BWP .
Integrated circuits. An integrated circuit implemented in a base station device that communicates with a terminal device ,
causing the base station device to perform a function of transitioning the terminal device from a first state to a second state by instructing the terminal device to enter a second state of a cell group;
The first state is
A first BWP is activated in an SpCell of the cell group;
Monitoring a downlink control channel (PDCCH) in the first BWP;
and performing channel state information (CSI) measurements for the first BWP ;
The second state is
A second BWP is activated in an SpCell of the cell group;
In the second BWP, a PDCCH is not monitored;
All SCells of the cell group are deactivated,
and performing channel state information (CSI) measurements for the second BWP .
Integrated circuits.

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