JP7719051B2 - 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. 2020-41468, filed on March 11, 2020, the contents of which are incorporated herein by reference.

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

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

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

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

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

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

(1) In order to achieve the above object, one aspect of the present invention takes the following measures. That is, a first embodiment of the present invention is a terminal device that communicates using a first cell group including a first cell and a second cell group including a second cell, and includes: a receiving unit that receives a message notifying that the second cell group is to be set to a first state; and a processing unit that transitions cells other than the second cell included in the second cell group to an inactive state based on the message; the first state is a state in which the second cell is not in an inactive state and the terminal device does not monitor a physical downlink control channel in the second cell; and the first cell and the second cell are cells that support at least a physical uplink control channel and contention-based random access.

(2) A second embodiment of the present invention is a base station device that communicates with a terminal device using a first cell group including a first cell and a second cell group including a second cell, and includes a transmitting unit that transmits a message notifying that the second cell group is in a first state, and a processing unit that generates the message, wherein the first state is a state in which the second cell is not in an inactive state and the terminal device does not monitor a physical downlink control channel in the second cell, and the first cell and the second cell are cells that support at least a physical uplink control channel and contention-based random access.

(3) A third embodiment of the present invention is a method applied to a terminal device that communicates using a first cell group including a first cell and a second cell group including a second cell, comprising the steps of receiving a message notifying that the second cell group is to be set to a first state, and transitioning cells other than the second cell included in the second cell group to an inactive state based on the message, wherein the first state is a state in which the second cell is not in an inactive state and the terminal device does not monitor a physical downlink control channel in the second cell, and the first cell and the second cell are cells that support at least a physical uplink control channel and contention-based random access.

(4) A fourth embodiment of the present invention is a method applied to a base station device that communicates with a terminal device using a first cell group including a first cell and a second cell group including a second cell, comprising the steps of: transmitting a message notifying that the second cell group is in a first state; and generating the message; wherein the first state is a state in which the second cell is not in an inactive state and the terminal device does not monitor a physical downlink control channel in the second cell; and the first cell and the second cell are cells that support at least a physical uplink control channel and contention-based random access.

(5) A fifth embodiment of the present invention is an integrated circuit implemented in a terminal device that communicates using a first cell group including a first cell and a second cell group including a second cell, and that causes the terminal device to perform the functions of receiving a message notifying that the second cell group is to be set to a first state and transitioning cells other than the second cell included in the second cell group to an inactive state based on the message, wherein the first state is a state in which the second cell is not in an inactive state and the terminal device does not monitor a physical downlink control channel in the second cell, and the first cell and the second cell are cells that support at least a physical uplink control channel and contention-based random access.

(6) A sixth embodiment of the present invention is an integrated circuit implemented in a base station device that communicates with a terminal device using a first cell group including a first cell and a second cell group including a second cell, and causes the base station device to perform a function of sending a message notifying that the second cell group is in a first state and a function of generating the message, wherein the first state is a state in which the second cell is not in an inactive state and the terminal device does not monitor a physical downlink control channel in the second cell, and the first cell and the second cell are cells that support at least a physical uplink control channel and contention-based random access.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

PDCP 206 is a packet data convergence protocol layer for efficiently transmitting user data such as IP packets over wireless sections. PDCP 206 may have a header compression function that compresses 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 segmented RLC SDU is called an RLC SDU segment.

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

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

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

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

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

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

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

Now let's explain the physical channels.

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

PBCH (Physical Broadcast Channel)
PDCCH (Physical Downlink Control Channel)
PDSCH (Physical Downlink Shared Channel)
PUCCH (Physical Uplink Control Channel)
PUSCH (Physical Uplink Shared Channel)
PRACH (Physical Random Access Channel)

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

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

The PDCCH is used to transmit (or carry) downlink control information (DCI) in downlink wireless communication (wireless communication from a base station device to a terminal device). Here, one or more DCIs (which may also be referred to as DCI formats) are defined for transmitting downlink control information. That is, a field for downlink control information is defined as DCI and mapped to information bits. The PDCCH is transmitted in PDCCH candidates. The terminal device monitors a set of PDCCH candidates in the serving cell. Monitoring means attempting to decode the PDCCH according to a certain DCI format. A certain DCI format may be used for scheduling the PUSCH in the serving cell. The PUSCH may be used for transmitting user data, RRC messages, etc.

The PUCCH may be used to transmit uplink control information (UCI) in uplink wireless communication (wireless communication from a terminal device to a base station device). Here, the uplink control information may include channel state information (CSI: Channel State Information) used to indicate the state of the downlink channel. The uplink control information may also include a scheduling request (SR: Scheduling Request) used to request UL-SCH resources. The uplink control information may also include a hybrid automatic repeat request ACKnowledgement (HARQ-ACK).

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Figure 7 is an example of an ASN.1 description representing some or all of the fields and information elements related to cell group configuration included in the message related to RRC connection reconfiguration in NR in Figure 4. Figure 8 is an example of an ASN.1 description representing some or all of the fields and information elements related to cell group configuration included in the message related to RRC connection reconfiguration in E-UTRA in Figure 4. Not limited to Figures 7 and 8, in the ASN.1 examples in embodiments of the present invention, <Omitted> and <Omitted> are not part of the ASN.1 notation and indicate the omission of other information. Note that information elements may be omitted even where there is no notation such as <Omitted> or <Omitted>. Note that the ASN.1 examples in embodiments of the present invention do not strictly follow the ASN.1 notation method, but represent an example of parameters of a message related to RRC connection reconfiguration in embodiments of the present invention, and other names and notations may be used. Also, in the ASN.1 examples in embodiments of the present invention, <Omitted> and <Omitted> are not part of the ASN.1 notation and indicate the omission of other information. Note that the ASN.1 examples in embodiments of the present invention do not strictly follow the ASN.1 notation method and represent an example of parameters of a message related to RRC connection reconfiguration in embodiments of the present invention, and other names and notations may be used. In order to avoid complication of explanation, Example 1 shows only an example of main information closely related to one embodiment of the present invention. Note that parameters described in ASN.1 may not be distinguished as fields, information elements, etc., and may all be referred to as information elements. Also, in the embodiment of the present invention, parameters such as fields and information elements described in ASN.1 included in an RRC message may also be referred to as information. Note that the message related to the reconfiguration of the RRC connection may be an RRC reconfiguration message in NR or an RRC connection reconfiguration message in E-UTRA.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

As shown in Non-Patent Document 6 and Non-Patent Document 7, cell activation and deactivation may be processed by a MAC entity that exists for each cell group. An SCell configured in a terminal device may be activated and/or deactivated by the following (A) and/or (B).
(A) Reception of MAC CE indicating SCell activation/deactivation (B) Timer (sCellDeactivationTimer) configured for each SCell where PUCCH is not configured

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

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

(Process AD-1)

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

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

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

(Process AD-2)

Deactivate this SCell.

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

Deactivate all activated BWPs associated with this SCell.

Flush the HARQ buffer associated with this SCell.

(Process AD-3)
Some or all of the following (A) to (D) will be implemented.
(A) Do not transmit SRS on this SCell.
(B) Do not report CSI for this SCell.
(C) Do not transmit PUCCH, UL-SCH, and/or RACH on this SCell.
(D) Do not monitor the PDCCH of this SCell and/or the PDCCH for this SCell.

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

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

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

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

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

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

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

Next, we will explain SCG dormancy.

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

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

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 of (A) to (F) below may be notified to the terminal device from a cell group other than the SCG.
(A) Receipt of an RRC message instructing SCG to be dormant (B) Receipt of a MAC control element instructing SCG to be dormant (C) Receipt of an RRC message instructing SpCell to be dormant (D) Receipt of a MAC control element instructing SpCell to be dormant (E) Receipt of another RRC message (F) Receipt of another MAC control element (G) Expiration of a timer related to SCG dormancy (H) Expiration of a timer related to PSCell dormancy

In LTE and / or NR, the terminal device may determine and / or execute the return from the SCG dormant state (Resume) based on some or all of the following (A) to (H). Note that the messages and control elements of (A) to (F) below may be notified to the terminal device from a cell group other than the SCG.
(A) Receipt of an RRC message instructing the SCG to return from dormancy. (B) Receipt of a MAC control element instructing the SCG to return from dormancy. (C) Receipt of an RRC message instructing the SpCell to return from dormancy. (D) Receipt of a MAC control element instructing the SpCell to return from dormancy. (E) Receipt of other RRC messages. (F) Receipt of other MAC control elements. (G) Timer related to SCG dormancy. (H) Timer related to PSCell dormancy.

A terminal device that puts an SCG into sleep mode may perform some or all of the following processes (A) to (F) in the SCG.
(A) All SCells are in an inactive state.
(B) All timers associated with the active SCell (sCellDeactivationTimer) are considered to have expired.
(C) All timers associated with the dormant SCell (sCellDeactivationTimer) are considered to have expired.
(D) Do not start or restart the timer (sCellDeactivationTimer) associated with all SCells.
(E) Ignore the MAC CE that activates the SCell. For example, in the process (AD), if a MAC CE that activates the SCell is received and the SCG is not instructed to be dormant (or the SCG is not in a dormant state), perform process (AD-1).
(F) Execute the process (AD-2). For example, in the process (AD), when an instruction to put the SCG to sleep is issued (or the SCG enters a sleep state), the process (AD-2) is executed.

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

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

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

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

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

Figure 6 is a block diagram showing the configuration of a base station device in each embodiment of the present invention. To avoid complicating the explanation, Figure 6 shows only the main components closely related to the present invention. The above-mentioned base station device may be an eNB 102 or a gNB 108.

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

Furthermore, in each example of processing or each example of processing flow in the above description, some or all of the steps may not be executed. Furthermore, in each example of processing or each example of processing flow in the above description, the order of the steps may be different. Furthermore, in each example of processing or each example of processing flow in the above description, some or all of the processing within each step may not be executed. Furthermore, in each example of processing or each example of processing flow in the above description, the order of the processing within each step may be different.

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

(1) A first embodiment of the present invention is a terminal device that communicates using a first cell group including a first cell and a second cell group including a second cell, and includes a receiving unit that receives a message notifying that the second cell group is to be set to a first state, and a processing unit that transitions cells other than the second cell included in the second cell group to an inactive state based on the message, wherein the first state is a state in which the second cell is not in an inactive state and the terminal device does not monitor a physical downlink control channel in the second cell, and the first cell and the second cell are cells that support at least a physical uplink control channel and contention-based random access.

(2) A second embodiment of the present invention is a base station device that communicates with a terminal device using a first cell group including a first cell and a second cell group including a second cell, and includes a transmitting unit that transmits a message notifying that the second cell group is in a first state, and a processing unit that generates the message, wherein the first state is a state in which the second cell is not in an inactive state and the terminal device does not monitor a physical downlink control channel in the second cell, and the first cell and the second cell are cells that support at least a physical uplink control channel and contention-based random access.

(3) A third embodiment of the present invention is a method applied to a terminal device that communicates using a first cell group including a first cell and a second cell group including a second cell, comprising the steps of receiving a message notifying that the second cell group is to be set to a first state, and transitioning cells other than the second cell included in the second cell group to an inactive state based on the message, wherein the first state is a state in which the second cell is not in an inactive state and the terminal device does not monitor a physical downlink control channel in the second cell, and the first cell and the second cell are cells that support at least a physical uplink control channel and contention-based random access.

(4) A fourth embodiment of the present invention is a method applied to a base station device that communicates with a terminal device using a first cell group including a first cell and a second cell group including a second cell, comprising the steps of: transmitting a message notifying that the second cell group is in a first state; and generating the message; wherein the first state is a state in which the second cell is not in an inactive state and the terminal device does not monitor a physical downlink control channel in the second cell; and the first cell and the second cell are cells that support at least a physical uplink control channel and contention-based random access.

(5) A fifth embodiment of the present invention is an integrated circuit implemented in a terminal device that communicates using a first cell group including a first cell and a second cell group including a second cell, and that causes the terminal device to perform the functions of receiving a message notifying that the second cell group is to be set to a first state and transitioning cells other than the second cell included in the second cell group to an inactive state based on the message, wherein the first state is a state in which the second cell is not in an inactive state and the terminal device does not monitor a physical downlink control channel in the second cell, and the first cell and the second cell are cells that support at least a physical uplink control channel and contention-based random access.

(6) A sixth embodiment of the present invention is an integrated circuit implemented in a base station device that communicates with a terminal device using a first cell group including a first cell and a second cell group including a second cell, and causes the base station device to perform a function of sending a message notifying that the second cell group is in a first state and a function of generating the message, wherein the first state is a state in which the second cell is not in an inactive state and the terminal device does not monitor a physical downlink control channel in the second cell, and the first cell and the second cell are cells that support at least a physical uplink control channel and contention-based random access.

A program running on a device according to 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 embodiments of the present invention. During processing, the program or the information handled by the program is temporarily loaded into volatile memory such as random access memory (RAM), or stored in non-volatile memory such as flash memory or a hard disk drive (HDD), and is read, modified, and written by the CPU as needed.

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

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

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

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

Although the embodiments of the present invention have been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment and includes design modifications within the scope of the invention. Furthermore, the present invention is susceptible to various modifications within the scope of the claims, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included within the technical scope of the present invention. Furthermore, configurations in which elements described in the above embodiments are substituted with elements that achieve the same effect are also included.

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

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

Claims (6)

A terminal device that communicates using a first cell group including a first cell and a second cell group including a second cell,
a receiving unit that receives a message notifying that the second cell group is to be set to a first state;
a processing unit that transitions cells other than the second cell included in the second cell group to an inactive state based on the message ;
Equipped with
the first state is a state in which the second cell is not in an inactive state and the terminal device does not monitor a physical downlink control channel in the second cell;
When transitioning from the first state to another state, cells other than the second cell included in the second cell group are kept in an inactive state;
the first cell and the second cell are cells that support at least a physical uplink control channel and a contention-based random access ;
Terminal device. A base station device that communicates with a terminal device using a first cell group including a first cell and a second cell group including a second cell,
a transmitter that transmits a message notifying that the second cell group is to be in a first state;
a processing unit for generating the message ;
Equipped with
the first state is a state in which the second cell is not in an inactive state and the terminal device does not monitor a physical downlink control channel in the second cell;
When transitioning from the first state to another state, cells other than the second cell included in the second cell group are kept in an inactive state;
the first cell and the second cell are cells that support at least a physical uplink control channel and a contention-based random access ;
Base station equipment. A method applied to a terminal device that communicates using a first cell group including a first cell and a second cell group including a second cell, the method comprising:
receiving a message indicating that the second cell group is to be placed in a first state;
transitioning cells other than the second cell included in the second cell group to an inactive state based on the message ;
Equipped with
the first state is a state in which the second cell is not in an inactive state and the terminal device does not monitor a physical downlink control channel in the second cell;
When transitioning from the first state to another state, cells other than the second cell included in the second cell group are kept in an inactive state;
the first cell and the second cell are cells that support at least a physical uplink control channel and a contention-based random access ;
method. A method applied to a base station device that communicates with a terminal device using a first cell group including a first cell and a second cell group including a second cell, the method comprising:
transmitting a message informing the second cell group of a first state;
generating the message ;
Equipped with
the first state is a state in which the second cell is not in an inactive state and the terminal device does not monitor a physical downlink control channel in the second cell;
When transitioning from the first state to another state, cells other than the second cell included in the second cell group are kept in an inactive state;
the first cell and the second cell are cells that support at least a physical uplink control channel and a contention-based random access ;
method. An integrated circuit implemented in a terminal device that communicates using a first cell group including a first cell and a second cell group including a second cell,
receiving a message informing the second cell group of a first state;
a function of transitioning cells other than the second cell included in the second cell group to an inactive state based on the message ;
to the terminal device,
the first state is a state in which the second cell is not in an inactive state and the terminal device does not monitor a physical downlink control channel in the second cell;
When transitioning from the first state to another state, cells other than the second cell included in the second cell group are kept in an inactive state;
the first cell and the second cell are cells that support at least a physical uplink control channel and a contention-based random access ;
Integrated circuit. An integrated circuit implemented in a base station device that communicates with a terminal device using a first cell group including a first cell and a second cell group including a second cell,
a function of transmitting a message notifying that the second cell group is in a first state;
a function for generating said message ;
to the base station device,
the first state is a state in which the second cell is not in an inactive state and the terminal device does not monitor a physical downlink control channel in the second cell;
When transitioning from the first state to another state, cells other than the second cell included in the second cell group are kept in an inactive state;
the first cell and the second cell are cells that support at least a physical uplink control channel and a contention-based random access ;
Integrated circuit.