Second wireless communication device and first wireless communication device

Abstract

The present invention has a transmission unit that transmits messages to a first wireless communication device, a reception unit that receives messages from the first wireless communication device, and a processing unit that, when a secondary cell group that has been set to the first wireless communication device is to be deactivated, incorporates a parameter related to the deactivation of the secondary cell group into a first message that is transmitted by the transmission unit to the first wireless communication device. Upon receiving the first message that includes the parameter related to the deactivation of the secondary cell group, the first wireless communication device deactivates the secondary cell group and performs first processing on a wireless bearer that is among established wireless bearers and satisfies a first condition.

Description

Technical Field

[0001] The present invention relates to a wireless communication device.

Background Art

[0002] In the current network, wireless communication networks using mobile terminals (such as smartphones and feature phones) are expanding. In the expansion of wireless communication, further speed increase and large capacity are required.

[0003] As a technology for realizing high speed and large capacity, there is DC (Dual Connectivity). DC is a technology in which a terminal device wirelessly connects to base station devices of a master base station device and a secondary base station device, and performs wireless communication using carriers (hereinafter sometimes referred to as cell groups) of the respective base station devices.

[0004] Furthermore, as the generations of wireless communication standards progress, for example, an eNodeB (hereinafter sometimes referred to as an eNB), which is a base station device corresponding to 4G (Four-Generation) or 5G (Five-Generation), and a gNodeB (hereinafter sometimes referred to as a gNB), which is a base station device corresponding to 5G-Advanced or NR (New Radio), MR-DC (Multi Radio Dual Connectivity), which is a DC technology using these, has attracted attention.

[0005] When the amount of data transmitted and received by a terminal device in MR-DC is large, for example, the terminal device transmits and receives data with both the master base station device and the secondary base station device. On the other hand, when the amount of data transmitted and received by the terminal device in MR-DC is small, for example, by deactivating a cell group (secondary cell group) belonging to the secondary base station device, it is considered to temporarily stop data transmission and reception with the secondary base station device to save power.

[0006] Technologies related to MR-DC are described in the following prior art documents.

Prior Art Documents

Non-Patent Documents

[0007]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Non-Patent Document 4

Non-Patent Document 5

Non-Patent Document 6

Non-Patent Document 7

Non-Patent Document 8

Non-Patent Document 9

Non-Patent Document 10

Non-Patent Document 11

Non-Patent Document 12

Non-Patent Document 13

Non-Patent Document 14

Non-Patent Document 15

Non-Patent Document 16

Non-Patent Document 17

Non-Patent Document 18

Non-Patent Document 19

Non-Patent Document 20

Non-Patent Document 21

Non-Patent Document 22

Non-Patent Document 23

Non-Patent Document 24

Non-Patent Document 25

Non-Patent Document 26

Non-Patent Document 27

Non-Patent Document 28

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-63321 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-107720 [Summary of the Invention] [Problems to be Solved by the Invention]

[0009] However, the opportunity and timing for the terminal device to shift the secondary cell group from the suspended state (inactive state) to the active state have not been determined as a standard specification.

[0010] For example, if the terminal device activates the secondary cell group at an unnecessary timing, unnecessary power will be consumed.

[0011] Therefore, one disclosure aims to provide a wireless communication device that suppresses power consumption of a terminal device in activating communication between the terminal device in the secondary cell group inactive state and the secondary base station device in MR-DC. [Means for Solving the Problems]

[0012] A first wireless communication device includes a transmission unit that transmits a message, a reception unit that receives a message from the first wireless communication device, and a processing unit that, when deactivating a secondary cell group set in the first wireless communication device, includes a parameter related to the deactivation of the secondary cell group in a first message transmitted from the transmission unit to the first wireless communication device. When the first wireless communication device receives the first message including the parameter related to the deactivation of the secondary cell group, it deactivates the secondary cell group and executes a first process on a radio bearer that satisfies a first condition among the established radio bearers. [Effects of the Invention]

[0013] One disclosure can suppress power consumption of a terminal device in activating communication between the terminal device in the secondary cell group inactive state and the secondary base station device in MR-DC.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Figure 22

DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, this embodiment will be described in detail with reference to the drawings. The problems and examples in this specification are merely examples and do not limit the scope of the rights of this application. In particular, even if the expressions are different, as long as they are technically equivalent, the technology of this application can be applied to different expressions and does not limit the scope of rights.

[0016] FIG. 1 is a diagram showing a configuration example of a communication system 10. The communication system 10 includes a terminal device 100, base station devices 200-1 and 2, and a core network 300. The communication system 10 is a wireless communication system in which the terminal device 100 communicates with the base station devices 200-1 and 2 via MR-DC. For example, the base station device 200-1 is a master base station device, and the base station device 200-2 is a secondary base station device. Hereinafter, the master base station device may be referred to as MN (Master Node), and the secondary base station device may be referred to as SN (Secondly Node).

[0017] The terminal device 100 wirelessly connects to the base station devices 200-1 and 2 and performs wireless communication using MR-DC. The terminal device 100 is a tablet terminal or a smartphone that supports multiple generations (for example, 4G and 5G, E-UTRA (Evolved Universal Terrestrial Radio Access), which is a 4G radio access technology, and NR, which is a 5G radio access technology, etc.).

[0018] The base station devices 200-1 and 2 (hereinafter may be referred to as the base station device 200) are communication devices that wirelessly connect to the terminal device 100 and perform wireless communication using MR-DC. Also, the base station devices 200-1 and 2 are, for example, connected to each other by wire and communicate. The base station device 200 is, for example, connected to the core network 300 by wire and communicates. The base station device 200 is, for example, either an eNodeB or a gNodeB base station device.

[0019] The core network 300 is a network corresponding to a certain generation. The core network 300 is, for example, a core network corresponding to 5G (hereinafter may be referred to as 5GC) or an EPC (Evolved Packet Core) corresponding to 4G.

[0020] Details of MR-DC realized in the communication system 10 will be described later.

[0021] <Configuration example of base station device 200> Figure 2 is a diagram showing a configuration example of the base station device 200. The base station device 200 is a communication device or a relay device having a CPU (Central Processing Unit) 210, a storage 220, a memory 230, a wireless communication circuit 240, and a network interface 250.

[0022] Storage 220 is an auxiliary storage device such as a flash memory, HDD (Hard Disk Drive), or SSD (Solid State Drive) that stores programs and data. Storage 220 stores a wireless communication program 221, an MR-DC master node program 222, and an MR-DC secondary node program 223.

[0023] Memory 230 is an area for loading the programs stored in Storage 220. Memory 230 may also be used as an area where the programs store data.

[0024] The wireless communication circuit 240 is a circuit that wirelessly connects to the terminal device 100 and conducts communication. The base station device 200 receives, for example, signals transmitted from the terminal device 100 via the wireless communication circuit 240 and transmits signals to the terminal device 100.

[0025] NI (network Interface) 250 is, for example, a communication device that connects to other base station devices 200 to realize inter-base station communication. Also, NI 250 is, for example, a communication device that connects to the core network 300 (communication devices constituting the core network 300) and conducts communication. NI 250 is, for example, a NIC (network Interface Card). The base station device 200 receives signals from other communication devices via NI 250 and transmits signals to other communication devices.

[0026] CPU 210 is a processor that loads the programs stored in Storage 220 into Memory 230, executes the loaded programs, constructs each part, and realizes each process.

[0027] By executing the wireless communication program 221, CPU 210 conducts wireless communication processing. The wireless communication processing is processing for wirelessly connecting to the terminal device 100, wirelessly communicating with the terminal device 100, or relaying the communication that the terminal device 100 conducts with other communication devices.

[0028] By executing the MR-DC master node program 222, the CPU 210 constructs a second transmission unit, a second reception unit, and a second processing unit, and performs MR-DC master node processing. The MR-DC master node processing is processing for performing control on the master node side in MR-DC. The base station apparatus 200 performs communication corresponding to various types of MR-DC described later in the MR-DC master node processing.

[0029] By executing the MR-DC secondary node program 223, the CPU 210 constructs a second transmission unit, a second reception unit, and a second processing unit, and performs MR-DC secondary node processing. The MR-DC secondary node processing is processing for performing control on the secondary node side in MR-DC. The base station apparatus 200 performs communication corresponding to various types of MR-DC described later in the MR-DC secondary node processing.

[0030] <Configuration example of the terminal device 100> FIG. 3 is a diagram showing a configuration example of the terminal device 100. The terminal device 100 is a communication device having a CPU 110, a storage 120, a memory 130, and a communication circuit 140.

[0031] The storage 120 is an auxiliary storage device such as a flash memory, an HDD, or an SSD that stores programs and data. The storage 120 stores a terminal-side wireless communication program 121 and a terminal-side MR-DC program 122.

[0032] The memory 130 is an area for loading the program stored in the storage 120. Also, the memory 130 may be used as an area where the program stores data.

[0033] The communication circuit 140 is a circuit that connects to the base station apparatus 200 and performs communication. The communication circuit 140 is, for example, a network card corresponding to a wireless connection.

[0034] CPU110 is a processor that loads the programs stored in storage 120 into memory 130, executes the loaded programs, constructs each component, and realizes each process.

[0035] By executing the terminal-side wireless communication program 121, CPU110 performs terminal-side wireless communication processing. The terminal-side wireless communication processing is a process of performing wireless connection with the base station device 200, wireless communication with the base station device 200, or communication with other communication devices via the base station device 200.

[0036] By executing the terminal-side MR-DC program 122, CPU110 constructs a transmission unit, a reception unit, and a processing unit, and performs terminal-side MR-DC processing. The terminal-side MR-DC processing is a process of controlling communication in MR-DC. The terminal device 100 performs communication corresponding to various types of MR-DC described below in the terminal-side MR-DC processing.

[0037] <Protocol Stack> An example of the protocol stack of the communication system 10 will be described. In the communication system 10, a series of protocols for transmitting and receiving data, shown in a hierarchical structure, is called a protocol stack. In the following example, the case where the base station device 200 is a gNB and the core network 300 is a 5GC will be described. Also, the terminal device 100 (UE: User Equipment) is assumed to be compatible with the gNB and the 5G core.

[0038] Hereinafter, the protocol stacks of the C-Plane (Control Plane) and the U-Plane (User Plane) will be described. The C-Plane indicates, for example, control signals (messages) transmitted and received in communication. The U-Plane indicates, for example, data signals (messages) of user data transmitted and received.

[0039] FIG. 4 is a diagram showing an example of a protocol stack of the U-Plane. Further, FIG. 5 is a diagram showing an example of a protocol stack of the C-Plane. In FIGS. 4 and 5, SDAP, PDCP, RLC, MAC, PHY, NAS, and RRC respectively indicate the names of the layers. Hereinafter, each of SDAP, PDCP, RLC, MAC, PHY, NAS, and RRC may be referred to as an SDAP sublayer, a PDCP sublayer, an RLC sublayer, a MAC sublayer, a PHY sublayer, a NAS sublayer, an RRC sublayer, or an SDAP layer, a PDCP layer, an RLC layer, a MAC layer, a PHY layer, a NAS layer, an RRC layer. Also, each of SDAP, PDCP, RLC, MAC, PHY, NAS, and RRC may be referred to as an SDAP entity, a PDCP entity, an RLC entity, a MAC entity, a PHY entity, a NAS entity, an RRC entity.

[0040] In FIG. 4, the U-Plane is composed of SDAP (Service Data Adaptation Protocol), PDCP (Packet Data Convergence Protocol), RLC (Radio Link Control), MAC (Medium Access Control), and PHY (Physical), and is terminated at the terminal device 100 (UE) and the base station device 200 (gNB).

[0041] The PHY uses a physical channel to transmit control information and data between the terminal device 100 and the base station device 200. The direction from the base station device 200 to the terminal device may be called the downlink (down, DL), and the direction from the terminal device 100 to the base station device may be called the uplink (up, UL).

[0042] The MAC performs mapping between a logical channel (LCH) and a transport channel, multiplexing / demultiplexing of MAC SDUs, a scheduling report, error correction through HARQ (Hybrid Automatic Repeat reQuest), priority control, etc.

[0043] The SDU (Service Data Unit) indicates the data passed from the upper sublayer or passed to the upper layer in each sublayer. Also, the PDU (Protocol Data Unit) indicates the data passed from the lower sublayer or passed to the lower sublayer in each sublayer.

[0044] Also, RLC, PDCP, and SDAP have control PDUs, which may be referred to as control PDUs. Also, in order to distinguish them from control PDUs, other PDUs may be referred to as data PDUs.

[0045] RLC has three modes: Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). RLC performs transfer of upper layer PDUs, assignment of sequence numbers (in the case of UM and AM), segmentation of data (in the case of UM and AM), and reassembly (in the case of AM), reassembly of SDUs (in the case of UM and AM), duplicate detection (in the case of AM), discarding of RLC SDUs (in the case of UM and AM), RLC re - establishment, etc.

[0046] PDCP performs data transfer in the U - Plane and C - Plane, PDCP sequence number management, header compression, encryption / decryption, integrity protection / integrity verification, timer - based SDU discarding, routing for split bearers, re - ordering and in - order delivery, etc.

[0047] SDAP performs mapping between QoS (Quality of service) flows and data radio bearers (DRBs: Data Radio Bearer), marking of QoS flow identifiers (QFI) for downlink (DL) packets and uplink (UL) packets, etc.

[0048] As upper layers of the U-Plane, there are layers such as IP (Internet Protocol), TCP (Transmission Control Protocol), UDP (User Datagram Protocol), and applications.

[0049] In FIG. 5, the C-Plane is composed of PDCP, RLC, MAC, and RRC (Radio Resource Control), and terminates at the terminal device 100 and the base station device 200. Also, the C-Plane is composed of NAS (Non Access Stratum) and terminates between the terminal device 100 and the AMF (Access and Mobility management Function), which is a device of the core network 300. PDCP, RLC, and MAC are the same as those of the U-Plane.

[0050] RRC performs functions including broadcast of system information (SI) related to AS (Access Stratum) and NAS, paging, establishment / maintenance / release of the RRC connection between the terminal device 100 and the base station device 200, addition / change / release of carrier aggregation (CA), addition / change / release of dual connectivity (DC), security functions including management of security keys, establishment / configuration / maintenance / release of signaling radio bearers (SRB) and data radio bearers (DRB), mobility functions, QoS management functions, control of terminal device measurement reports and reporting, detection and recovery of radio link failure (RLF), transfer of NAS messages, etc.

[0051] NAS performs authentication, mobility management, security control, etc.

[0052] In addition, when the device of the core network 300 is an EPC (Evolved Packet Core), there is no SDAP in the U-Plane. Also, the NAS in the C-Plane is between the terminal device 100 and the device of the core network 300, and terminates with the MME (Mobility Management Entity) that constitutes the EPC.

[0053] <Channel> The channels used in the communication system 10 will be described. Hereinafter, examples of channels corresponding to NR will be shown, but the channels to be used are not limited to the following. Also, channels with the same name can be used in generations other than NR.

[0054] <1. Physical Channel> The PBCH (Physical Broadcast CHannel) is a channel used to transmit broadcast information from the base station device 200 to the terminal device 100.

[0055] The PDCCH (Physical Downlink Control CHannel) is a channel used to transmit downlink control information (Downlink Control Information: DCI) and the like from the base station device 200 to the terminal device 100.

[0056] The PDSCH (Physical Downlink Shared CHannel) is a channel used to transmit data from the upper layer and the like from the base station device 200 to the terminal device 100.

[0057] The PUCCH (Physical Uplink Control CHannel) is a channel used to transmit uplink control information (Uplink Control Information: UCI) and the like from the terminal device 100 to the base station device 200.

[0058] The PUSCH (Physical Uplink Shared Channel) is a channel used to transmit data from the upper layer, etc., from the terminal device 100 to the base station device 200.

[0059] The PRACH (Physical Random Access Channel) is a channel used to transmit a random access preamble, etc., from the terminal device 100 to the base station device 200.

[0060] <2. Transport Channel> The BCH (Broadcast Channel) is mapped to the PBCH which is a physical channel.

[0061] The DL-SCH (Downlink Shared Channel) is mapped to the PDSCH which is a physical channel.

[0062] The PCH (Paging Channel) is mapped to the PDSCH which is a physical channel.

[0063] The UL-SCH (Downlink Shared Channel) is mapped to the PUSCH which is a physical channel.

[0064] The RACH (Random Access Channel(s)) is mapped to the PRACH which is a physical channel.

[0065] <3. Logical Channel> The BCCH (Broadcast Control Channel) is a downlink channel for notifying system information and is mapped to the BCH of the transport channel.

[0066] The PCCH (Paging Control Channel) is a downlink channel for carrying paging messages and is mapped to the PCH of the transport channel.

[0067] The CCCH (Common Control Channel) is a channel for transmitting control information (such as RRC messages) between the terminal device 100 and the base station device 200. It is a channel used for terminal devices 100 that do not maintain (do not have) an RRC connection with the base station device 200. The downlink is mapped to the DL-SCH of the transport channel, and the uplink is mapped to the UL-SCH of the transport channel.

[0068] The DCCH (Dedicated Control Channel) is a point-to-point bidirectional channel for transmitting dedicated control information (such as RRC messages) between the terminal device 100 and the base station device 200. It is used for terminal devices 100 that have an RRC connection with the base station device 200. The downlink is mapped to the DL-SCH of the transport channel, and the uplink is mapped to the UL-SCH of the transport channel.

[0069] The DTCH (Dedicated Transport Channel) is a point-to-point terminal-specific bidirectional channel for transmitting user information (user data). The downlink is mapped to the DL-SCH of the transport channel, and the uplink is mapped to the UL-SCH of the transport channel.

[0070] <RRC message> The RRC message will be described. The RRC message is a message containing information necessary for communication in a cell, and includes the MIB (Master Information Block), System Information Block, etc. The parameters included in the RRC message may be referred to as fields or information elements (IEs: Information Element).

[0071] In addition, the RRC message includes a message related to the establishment of an RRC connection. Examples of messages related to the establishment of an RRC connection include, for example, an RRC setup request message (RRCSetupRequest), an RRC setup message (RRCSetup), an RRC setup complete message (RRCSetupComplete), etc.

[0072] In addition, the RRC message includes a message related to the initial activation of AS (Access Stratum) security. Examples of messages related to the initial activation of AS security include, for example, a security mode command message (SecurityModeCommand), etc.

[0073] In addition, the RRC message includes a message related to the reconfiguration of an RRC connection. Examples of messages related to the reconfiguration of an RRC connection include, for example, an RRC reconfiguration message (RRCReconfiguration), an RRC reconfiguration complete message (RRCReconfigurationComplete), etc.

[0074] Figure 6 is a diagram showing an example of the message format of RRCReconfiguration. Format E1 is a parameter of RRC Reconfiguration.

[0075] RRC Reconfiguration has radioBearerConfig, radioBearerConfig2, masterCellGroup, seconderyCellGroup, masterKeyUpdate, and sk-counter as parameters.

[0076] radioBearerConfig and radioBearerConfig2 are settings related to MN terminated bearers or SN terminated bearers, including SRB settings, DRB settings, security settings, etc. SRB settings (DRB settings) include SRB identifiers (DRB identifiers), PDCP settings, parameters indicating PDCP re-establishment, etc. Security settings include a parameter (keyToUse) indicating whether to use the master key or the secondary key.

[0077] masterCellGroup and seconderyCellGroup are MCG settings and SCG settings respectively, including cell group identifiers, RLC bearer settings, SpCell settings, etc. RLC bearer settings include logical channel identifiers, RLC settings, radio bearer identifiers (SRB identifiers or DRB identifiers) associated with the RLC bearer, etc. SpCell settings include information necessary for synchronous reconfiguration, etc.

[0078] masterKeyUpdate includes information necessary for master key update.

[0079] sk-counter includes information necessary for secondary key generation.

[0080] Format E11 is a diagram showing an example of the parameters of RadioBearerConfig included in RRCReconfiguration.

[0081] Format E12 is a diagram showing an example of the parameters of CellGroupConfig included in RRCReconfiguration.

[0082] Format E111 is a diagram showing an example of the parameters of SRB-ToAddMod included in RadioBearerConfig.

[0083] Format E112 is a diagram showing an example of the parameters of DRB-ToAddMod included in RadioBearerConfig.

[0084] Format E113 is a diagram showing an example of parameters of SecurityConig included in RadioBearerConfig.

[0085] Format E121 is a diagram showing an example of parameters of RLC-BearerConfig included in CellGroupConfig.

[0086] Format E122 is a diagram showing an example of parameters of SpCellConfig included in CellGroupConfig.

[0087] In addition, the RRC message further includes messages related to re-establishment of the RRC connection, messages related to release and suspension of the RRC connection, messages related to resumption of the RRC connection, messages related to the capabilities of the terminal device, messages related to terminal information, messages related to radio link failures of MCG and SCG, etc.

[0088] Note that the message related to reconfiguration of the RRC connection performs establishment, setting, change, release, and synchronized reconfiguration of radio bearers, cell groups, measurement information, etc.

[0089] <Radio bearer> An example of the radio bearer of communication system 10 will be described.

[0090] <1. Signaling radio bearer> A signaling radio bearer (SRB) is a radio bearer for transmitting RRC messages and NAS messages.

[0091] SRB0 is a radio bearer for RRC messages using the CCCH (Common Control CHannel) logical channel.

[0092] SRB1 is a radio bearer for RRC messages and NAS messages that use the DCCH (Dedicated Control Channel) logical channel before SRB2, which will be described later, is established.

[0093] SRB2 is a radio bearer for NAS messages and RRC messages that include measured information with history logged, and uses the DCCH (Dedicated Control Channel) logical channel. The priority of SRB2 is lower than that of SRB1 and may be set by the base station device 200 after AS security is activated.

[0094] SRB3 is a radio bearer for RRC messages when EN-DC or NGEN-DC or NR-DC is set in the terminal device 100, and uses the DCCH (Dedicated Control Channel) logical channel. Note that EN-DC, NGEN-DC, and NR-DC are types of MR-DC, and the details of the types of MR-DC will be described later.

[0095] <2. Data Radio Bearer> A Data Radio Bearer (DRB) is a radio bearer for transmitting user data.

[0096] <Protocol Configuration of SRB and DRB> SRB1 and SRB2 are composed of one PDCP and one or more RLC bearers. The RLC bearer is composed of RLC and the MAC logical channel. MAC is assumed to exist for each cell group described later. The mode of RCL is AM.

[0097] SRB3 is composed of one PDCP and one RLC bearer. The mode of RLC is AM.

[0098] The DRB consists of one PDCP and one or more RLC bearers. The mode of RLC is UM or AM. When RLC is UM, the DBR is called UM DBR, and when RLC is AM, it may be called AM D BR In some cases. Also, D BR is associated with one SDAP when the core network 300 is 5GC (5G-compliant core), and is associated with one EPS bearer (or EPS bearer identity) when the core network 300 is EPC.

[0099] Note that 5GC is a core network standardized for 5G and is described, for example, in 3GPP specifications such as TS 23.501 and TS 23.502.

[0100] Also, EPC is a core network standardized for 4G and is described, for example, in 3GPP specifications such as TS 23.401 and TS 23.402.

[0101] <Cell Group> A cell group (CG: Cell Group) indicates the cell configuration in MR-DC. In MR-DC, cell groups are classified into a master cell group (MCG: Master Cell Group) and a secondary cell group (SCG: Secondly Cell Group).

[0102] Figure 7 is a diagram showing an example of the cell group configuration of the communication system 10. In Figure 6, the master node (MN) is the base station device 200-1, and the secondary node (SN) is the base station device 200-2. The master node is the base station device 200 that provides a C-Plane connection to the core network 300 in MR-DC. The secondary node is the base station device 200 that does not provide a C-Plane to the core network 300 but provides additional radio resources to the terminal device 100 in MR-DC.

[0103] CG is composed of one Special Cell (SpCell), or one SpCell and one or more Secondary Cells (SCell).

[0104] The SpCell in MCG may be called the Primary Cell (PCell). Also, the SpCell in SCG may be called the Primary Scg Cell (PSCell).

[0105] In FIG. 7, MCG is composed of one PCell and two SCell. Also, in FIG. 7, SCG is composed of one PSCell and two SCell.

[0106] MCG is, for example, the CG when MR-DC is not configured, or the CG belonging to the master node when MR-DC is configured.

[0107] SCG is the CG belonging to the secondary node in MR-DC.

[0108] The PCell in MCG operates on the primary frequency and is the cell used by the terminal device 100 for initial connection establishment procedures or connection re-establishment procedures. The connection establishment and re-establishment procedures include random access procedures.

[0109] The PSCell in SCG is the cell used for random access procedures when the terminal device 100 executes Reconfiguration With Sync.

[0110] The SCell provides additional radio resources to the terminal device 100 for which carrier aggregation is configured, in addition to the SpCell.

[0111] <Types of MR-DC> The types of MR-DC will be described. MR-DC is classified into four types according to the type (corresponding generation) of the base station apparatuses 200 of the master node and the secondary node, and the type (corresponding generation) of the core network 300.

[0112] FIG. 8 is a diagram showing an example of the types of MR-DC. Hereinafter, each type of MR-DC will be described. Also, in FIG. 8, the master node is the base station apparatus 200-1, and the secondary node is the base station apparatus 200-2.

[0113] FIG. 8A is a diagram showing an example of EN-DC. EN-DC (E-UTRA-NR DC) is an MR-DC in which an eNB, which is a base station apparatus 200 of E-UTRA, is the master node, a gNB, which is a base station apparatus 200 of NR, is the secondary node, and the core network 300 is configured by EPC.

[0114] FIG. 8B is a diagram showing an example of NGEN-DC. NGEN-DC (NG-RAN E-UTRA-NR DC) is an MR-DC in which an eNB is the master node, a gNB is the secondary node, and the core network 300 is configured by 5GC.

[0115] FIG. 8C is a diagram showing an example of NE-DC. NE-DC (NR-E-UTRA DC) is an MR-DC in which a gNB is the master node, an eNB is the secondary node, and the core network 300 is configured by 5GC.

[0116] FIG. 8D is a diagram showing an example of NR-DC. NR-DC (NR-NR DC) is an MR-DC in which a gNB is the master node, a different gNB is the secondary node, and the core network 300 is configured by 5GC.

[0117] EN-DC and NGEN-DC may be referred to as (NG)EN-DC. The secondary node of EN-DC may be referred to as an en-gNB. Also, the master node of NGEN-DC may be referred to as an ng-eNB.

[0118] Note that FIG. 8 assumes a state in which SRB1 and SRB2 are established as the C-Plane interfaces between the terminal device 100 and the base station device 200-1. When split SRB1, split SRB2, or SRB3 is established, a part of the C-Plane message may be transmitted and received between the secondary node and the terminal device 100. A part of the C-Plane message received at the secondary node is transmitted to the master node via the inter-base station interface. Also, a part of the C-Plane message transmitted from the secondary node is transmitted from the master node to the secondary node via the inter-base station interface.

[0119] <MR-DC bearer type> The bearer type in MR-DC will be described. Hereinafter, a configuration in which PDCP is terminated at the master node and the master node has PDCP on its side may be referred to as MN-terminated. Also, a configuration in which PDCP is terminated at the secondary node and the secondary node has PDCP on its side may be referred to as SN-terminated. The bearer type is classified into the following six types.

[0120] 1) MCG bearer, which is MN-terminated and the RLC bearer exists on the MCG side.

[0121] 2) Split bearer, which is MN-terminated and the RLC bearer exists on both the MCG and SCG sides. pl it (split) bearer.

[0122] 3) SCG bearer, which is MN-terminated and the RLC bearer exists on the SCG side.

[0123] 4) MCG bearer, which is SN-terminated and the RLC bearer exists on the MCG side.

[0124] 5) Split bearer, which is SN-terminated and the RLC bearer exists on both the MCG and SCG sides. pliT bearer

[0125] 6) An SCG bearer that is SN-terminated and for which the RLC bearer exists on the SCG side

[0126] The DRB is composed of any one of the above six bearer types

[0127] SRB1 and SRB2 are MCG bearers that are MN-terminated, or S pl iT bearers. SRB1 and SRB2 are S pl When composed of iT bearers, they are respectively s pl iT S RB 1 and s pl iT S RB Sometimes called 2

[0128] S RB S3 is composed of SN-Terminated SCG bearers

[0129] Also, in the case of an S pl iT bearer, a Primary Path is set. The Primary Path indicates the base station device 200 to which the terminal device 100 (preferably) transmits data in the initial state. The Primary Path is specified by a cell group (MCG, SCG) and an LCH. The terminal device 100 transmits data to the base station device 200 of the Parimary Path as long as the amount of uplink data to be transmitted does not exceed the threshold. When the threshold is exceeded, the terminal device 100 may transmit data to either base station device 200

[0130] Also, the security keys used in PDCP are different between the case of being MN-Terminated (master key) and the case of being SN-Teminated (secondary key)

[0131] <Synchronized Reconfiguration (Handover)> The reconfiguration with sync (handover) will be described. Reconfiguration With Sync indicates the procedure executed in the terminal device 100 by including, in the RRC reconfiguration message (RRCReconfiguration) transmitted from the base station device 200 to the terminal device 100, a parameter indicating that reconfiguration with sync is to be performed (reconfigurationWithSync: hereinafter may be referred to as the reconfiguration with sync parameter).

[0132] FIG. 9 is a diagram showing an example of reconfiguration with sync. The terminal device (UE) 100 changes the current source PCell to the target PCell (S1). The reconfiguration with sync parameter is separately included under the parameter for MCG configuration (hereinafter may be referred to as the MCG configuration parameter) and under the parameter for SCG configuration (hereinafter may be referred to as the SCG configuration parameter). That is, when it is included under the MCG configuration parameter, it means reconfiguration with sync of MCG, and when it is included under the SCG configuration parameter, it means reconfiguration with sync of SCG.

[0133] Reconfiguration with sync is a procedure in which the terminal device 100 changes the PCell or PSCell, and includes operations such as random access to the new (target) PCell or PSCell, MAC reset, RLC re-establishment, and PDCP data recovery (in the case of AM DRB).

[0134] Also, reconfiguration with sync may involve a change in the security key. In this case, in addition to the above, PDCP re-establishment is performed.

[0135] When the security key is changed, a new key is generated in the RRC of the terminal device 100, and PDCP is re-established, so that the new key is applied to PDCP.

[0136] <Qos flow remapping in SDAP> In the terminal device 100, when the DRB to which a certain QoS flow corresponds (maps) is changed, an end marker control PDU is transmitted for the DRB before the change.

[0137] A QoS flow is a service data flow (SDF: Service Data Flow) having the same QoS requirements and is identified by a QoS flow identifier (QFI). The SDF is, for example, an IP flow, an Ethernet flow, etc., and varies depending on the upper layer.

[0138] FIG. 10 is a diagram showing an example in which an end marker control PDU is transmitted. For example, in the terminal device 100, the DRB to which QoS flow 1 is associated is changed from DRB1 to DRB2 (S2). At this time, the terminal device 100 transmits the data of QoS flow 1 that remains before being instructed to change, using the DRB1 before the change. Then, the terminal device 100 transmits an end marker control PDU (end marker M1) indicating that it is the last time to transmit the data of QoS flow 1 using DRB1, using DRB1. Thereby, the base station device 200 can recognize that the data of QoS flow 1 will not be transmitted using the DRB1 before the change hereafter. Note that the association between the QoS flow and the DRB may be performed by parameters included in the RRC reconfiguration message or by header information included in the downlink SDAP data PDU. The latter is called reflective mapping.

[0139] <RRC state (mode)> The RRC state of the terminal device 100 indicates the state regarding the RRC connection of the terminal device 100. The state in which the RRC connection with the base station device 200 is not established may be called the RRC idle mode (RRC_IDLE). The state in which the RRC connection with the base station device 200 is established may be called the RRC connected mode (RRC_CONNECTED). The state in which the RRC connection with the base station device 200 is temporarily suspended (suspended) may be called the RRC inactive mode (RRC_INACTIVE).

[0140] <SCG Inactive> (NG) In EN-DC or NR-DC, communication between the secondary node and the terminal device 100 may be restricted by deactivating the SCG configured in the terminal device 100. Hereinafter, the state where the SCG is in the inactive state may be referred to as during SCG deactivation (during SCG deactivation). Also, the state where the SCG is in the active state may be referred to as during SCG (re)activation (during SCG (re)activation). Also, deactivating the SCG may be referred to as SCG deactivation (SCG deactivation). Also, activating the inactive SCG may be referred to as SCG (re)activation (SCG (re)activation).

[0141] Furthermore, hereinafter, "reactivation" and "reattivate" shall each include "activation" and "activate".

[0142] The terminal device 100 during SCG deactivation shall satisfy a condition including some or all of the following conditions.

[0143] · When receiving a message regarding reconfiguration of the RRC of the SCG (for example, RRC reconfiguration message, RRCReconfiguration) from the base station device 200, execute processing according to this message · Do not perform uplink transmission to the SCG side · May process uplink data for the SCG side · In the PSCell, do not monitor (receive) the PDCCH · Do not transmit the PUSCH to the SCG side Note that the terminal device 100 during SCG deactivation may perform RRC connection mode communication with the base station device 200 using the MCG.

[0144] [First Embodiment] The first embodiment will be described. In the communication between the terminal device 100 and the secondary node (base station device 200), the communication system 10 appropriately controls the switching from during SCG deactivation to during SCG (re)activation, or the switching from during SCG (re)activation to during SCG deactivation. Appropriate control means, for example, controlling so as not to perform unnecessary switching in order to achieve power saving, or controlling to delay the switching timing until the necessary timing.

[0145] <Transition Processing to SCG Deactivation> FIG. 11 is a diagram showing an example of a sequence in which the state of the SCG transitions to inactive. The base station device 200 is, for example, the master node in MR-DC. MR-DC in FIG. 11 includes, for example, (NG)EN-DC and NR-DC. Also, on the sequence of FIG. 11, although there is one base station device 200, it may be configured with a plurality of master nodes and secondary nodes. Also, on the sequence of FIG. 11, the message transmitted and received with the base station device 200 may be transmitted and received with either the master node or the secondary node. When the process executed by the base station device 200 in FIG. 11 is executed by the master node, the message transmitted from the terminal device 100 to the secondary node shall be transmitted to the master node via inter-base station communication. Also, the process executed by the base station device 200 may be executed by either the master node or the secondary node. Note that, in order to satisfy the above-described conditions, the terminal device 100 shall not transmit a message to the secondary node during SCG deactivation, and further, shall not receive the PDCCH from the secondary node.

[0146] In the sequence of FIG. 11, the terminal device 100 sets the SCG (S101) and is in the process of SCG (re)activation. The setting of the SCG is performed when the terminal device 100 receives an RRC reconfiguration message including SCG setting parameters from the base station device 200. S CGThe set parameters include, for example, NR S CG the set parameters.

[0147] The terminal device 100 transmits a terminal information notification to the base station device 200 (S102). The terminal information notification is, for example, an RRC message or a parameter included in an RRC message. Also, the terminal information notification may be, for example, the UE assistance information in the RRC message, or a message with another name.

[0148] The terminal information notification includes, for example, information indicating whether power saving is required in the terminal device 100. The terminal device 100 determines whether power saving is required according to, for example, the remaining battery level.

[0149] Also, the terminal information notification includes, for example, information indicating whether SCG deactivation (or release of SCG) is required. The terminal device 100 determines the necessity according to, for example, the communication volume (data communication volume) with the secondary node.

[0150] Also, when the terminal information notification has received the synchronized reconfiguration parameters of the SCG during SCG deactivation (has been instructed to perform the synchronized reconfiguration of the SCG), it may include information indicating whether to execute (want to execute) immediately.

[0151] Furthermore, the terminal information notification may include information indicating that when UL data is generated, without permission from the base station device 200 (without transmitting the SCG reactivation request in process S110 described later), the terminal device 100 wants to execute the reactivation of the SCG. Thereby, a part of the messages between the base station device 200 and the terminal device 100 in the SCG reactivation can be omitted.

[0152] When the base station device 200 receives the terminal information notification (S102), it performs the SCG deactivation determination process (S103). Note that the base station device 200 also executes the SCG deactivation determination process S103 when an event occurs that requires (or may require) SCG deactivation, other than when it receives the terminal information notification.

[0153] The SCG deactivation determination process S103 is a process for determining whether to perform SCG deactivation on the terminal device 100. The base station device 200 determines, for example, according to the communication volume between the terminal device 100 and the secondary node in the SCG deactivation determination process S103. For example, when the communication volume with the secondary node is below a predetermined value during a predetermined period, or when communication with the secondary node has not occurred for a predetermined time, etc., when the communication volume with the secondary node is small, the base station device 200 determines to perform SCG deactivation.

[0154] Also, the base station device 200 determines, for example, according to the amount of allocatable radio resources of the secondary node in the SCG deactivation determination process S103. For example, when the amount of available radio resources of the secondary node is below a predetermined value, the base station device 200 determines to perform SCG deactivation.

[0155] When the base station device 200 determines to perform SCG deactivation in the SCG deactivation determination process S103, it transmits an SCG deactivation instruction to the terminal device 100 (S104). The SCG deactivation instruction is a message for instructing the terminal device 100 to execute SCG deactivation. The SCG deactivation instruction is, for example, an RRC message or a parameter included in an RRC message. Also, the SCG deactivation instruction may be, for example, SCG deactivation of an RRC message, or RRCReconfiguration, or may be a message with another name.

[0156] The SCG activation instruction includes information on whether to immediately execute all or part of the SCG synchronized reconfiguration process when, for example, the terminal device 100 is instructed to perform a synchronized reconfiguration of the SCG during SCG deactivation. In the case of information indicating immediate execution of all, the terminal device 100 immediately executes the synchronized reconfiguration of the SCG. Also, in the case of not immediately executing part or all, the terminal device 100 executes the unprocessed part of the SCG synchronized reconfiguration process when performing SCG reactivation later (hold the synchronized reconfiguration), or does not execute part or all of the SCG synchronized reconfiguration process (discard part or all of the synchronized reconfiguration instruction (parameters)).

[0157] Also, the SCG activation instruction may include information indicating to immediately execute part or all of the SCG synchronized reconfiguration process when, for example, the terminal device 100 is instructed to perform a synchronized reconfiguration of the SCG during SCG deactivation and does not meet at least the first condition. In this case, the terminal device 100 immediately executes the synchronized reconfiguration of the SCG when it does not meet at least the first condition. Also, in this case, the terminal device 100 executes part or all of the SCG synchronized reconfiguration process when performing SCG reactivation later (hold part or all of the SCG synchronized reconfiguration process) when it meets at least the first condition, or does not execute part or all of the SCG synchronized reconfiguration process (discard part or all of the synchronized reconfiguration instruction (parameters)).

[0158] The first condition is, for example, to satisfy a condition including all or part of the following conditions 1 to 4.

[0159] Condition 1: The SCG synchronized reconfiguration is associated with a change in the security key (KgNB or KeNB) of the master node, or a change in the AS security key generated from the security key of the master node Condition 2: The synchronized reconfiguration of the SCG is accompanied by a change in the security key (S-KgNB or S-KeNB) of the secondary node, or a change in the AS security key generated from the security key of the secondary node. Condition 3: There is no radio bearer using the master key among the radio bearers associated with the SCG RLC bearer. Condition 4: All radio bearers associated with the SCG RLC bearer use the secondary key. Note that the radio bearer using the master key may be a radio bearer in which the parameter (keyToUse) indicating whether to use the master key or the secondary key is set to master (or primary). Also, the radio bearer using the secondary key may be a radio bearer in which the parameter (keyToUse) indicating whether to use the master key or the secondary key is set to secondary.

[0160] When at least this first condition is satisfied, the terminal device 100 will not interfere with communication in MR-DC (especially communication using the master node) even if it does not immediately execute some or all of the synchronized reconfiguration process of the SCG. As a result, the terminal device 100 can suppress power consumption because it does not perform unnecessary SCG reactivation.

[0161] Note that the SCG deactivation instruction may include information instructing to immediately execute the synchronized reconfiguration of the SCG, for example, when the terminal device 100 is instructed to perform the synchronized reconfiguration of the SCG during SCG deactivation. In this case, the terminal device 100 immediately executes the synchronized reconfiguration of the SCG regardless of the first condition.

[0162] Also, the SCG deactivation instruction may include information indicating an instruction to execute SCG reactivation without permission from the base station device 200, for example, when UL data is generated. In this case, the terminal device 100 immediately executes SCG reactivation.

[0163] When the terminal device 100 receives an SCG deactivation instruction (S104), it performs SCG deactivation processing (S105). The SCG deactivation processing S105 is a process of transitioning to SCG deactivation. Note that when the terminal device 100 receives an SCG deactivation instruction, it determines that it is necessary to perform the SCG deactivation processing S105, and it may perform the SCG deactivation processing (S105). Also, when the terminal device 100 does not receive an SCG deactivation instruction, it determines that it is not necessary to perform the SCG deactivation processing S105, and it may not perform the SCG deactivation processing (S105).

[0164] In the SCG deactivation processing S105, the terminal device 100 stops some or all of the timers that are running for the SCG. Also, the terminal device 100 resets some or all of the counters set for the SCG. Also, the terminal device 100 resets the MAC of the SCG. Further, the terminal device 100 performs a second process on all or some of the radio bearers that satisfy at least a second condition. The second condition is, for example, being an SCG bearer or being a split bearer with a Primary Path set for the SCG.

[0165] Note that the timers that are running for the SCG to be stopped may include a timer for detecting an SCG radio link failure. Also, the timers that are running for the SCG to be stopped may include a timer related to an SCG measurement report.

[0166] Also, the counters set for the SCG to be reset may include a counter for detecting an SCG radio link failure.

[0167] Also, "perform the second process for all or some of the radio bearers that satisfy at least the second condition" may mean that the terminal device 100 determines whether each radio bearer satisfies at least the second condition, and if it is determined that at least the second condition is satisfied, the second process may be performed for this radio bearer.

[0168] Also, "perform the second process for all or some of the radio bearers that satisfy at least the second condition" may mean that the terminal device 100 determines whether each radio bearer satisfies at least the second condition, and if it is determined that at least the second condition is satisfied and it is further determined that the second process needs to be performed for this radio bearer, the second process may be performed for this radio bearer.

[0169] Regarding the second condition of "being an SCG bearer", for the radio bearer (PDCP), it may be that neither a parameter (moreThanOneRLC) indicating one or more RLCs nor a parameter (primaryPath) indicating the Primary Path is set, and the RLC bearer of the radio bearer is in the SCG. Also, the second condition of "being an SCG bearer" may be that only the RLC bearer of the radio bearer exists in the SCG. This "RLC bearer of the radio bearer" may be an RLC bearer related to the radio bearer.

[0170] Also, regarding the second condition of "being a split bearer with the Primary Path set in the SCG", it may be that the Primary Path (or the parameter indicating the Primary Path) of the radio bearer (PDCP) is set in the SCG (or refers to the SCG).

[0171] The second process is a process that is executed for all or some of the radio bearers that satisfy at least the second condition. The second process is all or part of the process and pre-processing when transitioning to SCG deactivation. The second process includes, for example, all or part of the following processes. Hereinafter, all or some of the radio bearers that satisfy at least the second condition may be referred to as the second radio bearers.

[0172] · Transmit immediately (until SCG is deactivated) or discard all data that has not been transmitted in the PDCP of the second radio bearer. · If the reordering timer is operating in the PDCP of the second radio bearer, stop it and transmit all stored PDCP SDUs to the upper layer in order after header decompression. · Re-establish the RLC of the second radio bearer. Also, the second process may be performed or may include the following procedure.

[0173] In the process of immediately transmitting data that has not been transmitted in PDCP, for example, in the case of a UM DRB, PDCP SDUs that have been assigned a sequence number but have not been delivered to the lower layer are regarded as PDCP SDUs that have just been received from the upper layer and are transmitted in order. In this case, it is not necessary to restart the discard timer.

[0174] Also, in the process of immediately transmitting data that has not been transmitted in PDCP, for example, in the case of an AM DRB or in the case of an AM DRB where the PDCP entity is not suspended, PDCP SDUs for which transmission success has not been confirmed from the lower layer and PDCP SDUs that have been assigned a sequence number but have not been delivered to the lower layer are transmitted in order.

[0175] Also, in the process of immediately transmitting data that has not been completely transmitted in PDCP, for example, in the case of an AM DRB for the Uu interface (the interface between the terminal device 100 and the base station device 200) where the PDCP entity is suspended, PDCP SDUs for which transmission success has not been confirmed from the lower layer and PDCP SDUs that have been assigned sequence numbers but have not been delivered to the lower layer are regarded as PDCP SDUs that have just been received from the upper layer and are transmitted in order. At this time, it is not necessary to restart the discard timer.

[0176] Note that the discard timer may be a timer used to discard the corresponding PDCP SDU when it expires.

[0177] An example of the operation inside the terminal that performs the second process for all or some of the radio bearers that satisfy at least the second condition will be described.

[0178] For example, the RRC of the terminal device 100 gives a second notification to the PDCP of all or some of the radio bearers that are SCG bearers or split bearers. The PDCP may be replaced by the lower layer(s). The PDCP that has received the second notification performs the second process when it is an SCG bearer (when there is one related RLC) or a split bearer (when there are two or more related RLCs) and a Primary path is set on the SCG side.

[0179] Also, for example, the RRC of the terminal device 100 gives a second notification to the second radio bearer. The PDCP may be replaced by the lower layer(s). The PDCP that has received the second notification performs the second process.

[0180] Some of the radio bearers that satisfy at least the second condition may be, for example, SRBs that satisfy at least the second condition or DRBs that satisfy at least the second condition. However, this is not the limit.

[0181] The second notification is a notification that includes information instructing, for example, the discard of PDCP data. The second notification may also be a notification that includes information instructing the immediate transmission of data for which transmission has not been completed.

[0182] In addition, the second notification may include information indicating that the SCG is deactivated, such as SCG deactivated or CG UL transmission prohibited (suspended).

[0183] Furthermore, the second notification may include all or part of this information. Also, the second notification may be a plurality of messages that include part of this information.

[0184] Thereby, for example, even when the PDCP of the SCG is re-established in a case where the terminal device 100 has received an instruction for synchronized reconfiguration of the SCG but executes it with a delay without executing it immediately, it is possible to suppress the occurrence of uplink transmission by transmitting UL data for which transmission has not been successful. The terminal device 100 can suppress unnecessary SCG reactivation and can suppress power consumption.

[0185] Also, the RRC of the terminal device 100 transmits the second information to the SDAP associated with the DRB among the second radio bearers in the SCG deactivation process S105.

[0186] The second information is information indicating that UL transmission of the DRB is prohibited (or stopped), or that the cell group associated with the DRB is being deactivated, etc., indicating that UL transmission cannot be performed with the DRB.

[0187] In addition, the second information may be transmitted to the SDAP together with all or part of the following information. Also, the second information may be all or part of the following information.

[0188] · The DRB identifier of the DRB · The QoS flow identifier associated with the DRB Note that "transmit the second information to the SDAP associated with the DRB among the second radio bearers" may mean that the terminal device 100 determines whether each DRB satisfies at least the second condition, and when it is determined that at least the second condition is satisfied, the second information may be transmitted to the SDAP associated with this DRB.

[0189] Also, "transmit the second information to the SDAP associated with the DRB among the second radio bearers" may mean that the terminal device 100 determines whether each DRB satisfies at least the second condition, and when it is determined that at least the second condition is satisfied and it is determined that it is necessary to transmit the second information to the SDAP associated with this DRB, the second information may be transmitted to the SDAP associated with this DRB.

[0190] Note that the transmission process of the second information may be executed when at least the DRB satisfying the second condition is associated with the SDAP (if SDAP entity associated with this DRB configured). The terminal device 100 may determine whether each DRB is associated with the SDAP, and when it is determined that it is associated with the SDAP, it may determine whether this DRB satisfies at least the second condition. Also, the terminal device 100 may determine whether each DRB satisfies at least the second condition, and when it is determined that at least the second condition is satisfied, it may determine whether this DRB is associated with the SDAP.

[0191] <RRC reconfiguration message reception process during SCG deactivation> FIG. 12 is a diagram showing an example of a sequence in which the terminal device 100 receives an RRC reconfiguration message during SCG deactivation.

[0192] During the SCG deactivation, the base station device 200 transmits an RRC reconfiguration message (the first message) to the terminal device 100 (S106). The RRC reconfiguration message is an RRC message regarding the reconfiguration of the RRC connection sent from the base station device 200 to the terminal device 100, and is used to establish, configure, change, release, and perform synchronized reconfiguration of radio bearers, cell groups, measurement information, etc. The RRC reconfiguration message may be, for example, an RRCReconfiguration of the RRC message, or may be a message with another name.

[0193] When the base station device 200 determines that a change in the settings of the terminal device 100 (a change in the settings in the RRC connection mode) is necessary, it generates an RRC reconfiguration message and transmits it to the terminal device 100.

[0194] The base station device 200, for example, CG when an X2 handover is required, determines that a change in the settings of the terminal device 100 is necessary.

[0195] Also, the base station device 200, for example, when a change in the security key is required, determines that a change in the settings of the terminal device 100 is necessary. When the base station device 200 determines that a re - establishment of PDCP related to the security key whose change is required (using a key generated from the security key) is necessary, it determines that a change in the settings of the terminal device 100 is necessary.

[0196] Also, the base station device 200, for example, when a change in the QoSflow to DRB mapping rule (a rule indicating the correspondence (map) between the QoS flow and the DRB) is required, determines that a change in the settings of the terminal device 100 is necessary.

[0197] The RRC reconfiguration message includes, for example, the following information.

[0198] · Information indicating an instruction to perform synchronized reconfiguration of the SCG · Information indicating that when including information indicating an instruction to perform synchronized reconfiguration of the SCG, if it does not meet at least the first condition, immediately instruct to perform synchronized reconfiguration of the SCG · Information indicating that when including information indicating an instruction to perform synchronized reconfiguration of the SCG, if it meets at least the first condition, at the time of SCG reactivation, instruct to perform synchronized reconfiguration of the SCG · Information indicating that when including information indicating an instruction to perform synchronized reconfiguration of the SCG, if it is during SCG deactivation, immediately instruct to perform synchronized reconfiguration of the SCG · Information indicating that when including information indicating an instruction to perform synchronized reconfiguration of the SCG, at the time of SCG reactivation, instruct to perform synchronized reconfiguration of the SCG Note that the first condition is the matter of the first condition described in process S103. That is, the first condition is to meet a condition including all or part of the following conditions 1 to 4, for example.

[0199] Condition 1: The synchronized reconfiguration of the SCG is associated with a change in the security key (KgNB or KeNB) of the master node, or a change in the AS security key generated from the security key of the master node Condition 2: The synchronized reconfiguration of the SCG is associated with a change in the security key (S-KgNB or S-KeNB) of the secondary node, or a change in the AS security key generated from the security key of the secondary node Condition 3: There is no radio bearer using the master key in the radio bearers associated with the SCG RLC bearer Condition 4: All radio bearers associated with the SCG RLC bearer use the secondary key Note that a radio bearer using the master key may be a radio bearer in which a parameter (keyToUse) indicating whether to use the master key or the secondary key is set to the master (or primary). Also, a radio bearer using the secondary key may be a radio bearer in which a parameter (keyToUse) indicating whether to use the master key or the secondary key is set to the secondary.

[0200] Note that when the base station device 200 determines that it does not want the terminal device 100 to immediately execute the synchronized reconfiguration of the SCG, the RRC reconfiguration message may not include the synchronized reconfiguration parameter in the parameter (for example, named seconderyCellGroup) meaning the SCG configuration (it may not request the synchronized reconfiguration of the SCG).

[0201] Also, when the terminal device 100 is in the process of deactivating the SCG, the base station device 200 may determine that it is optional (not mandatory) to include the synchronized reconfiguration parameter of the SCG in the RRC reconfiguration message to the terminal device 100.

[0202] For example, the base station device 200 does not include the synchronized reconfiguration parameter of the SCG when, for example, the security key of the secondary node needs to be updated, but the terminal device 100 is in the process of deactivating the SCG and there is no RLC bearer related to the master key on the SCG side.

[0203] Also, when the base station device 200 satisfies at least the third condition and the terminal device 100 is not in the process of SCG deactivation, it is determined that it is essential to include the reconfiguration parameters synchronized with SCG in the RRC reconfiguration message to the terminal device 100, and the reconfiguration parameters synchronized with SCG may be always included. Further, even when the base station device 200 satisfies at least the third condition, when the terminal device 100 is in the process of SCG deactivation, it is determined that it is optional (not essential) to include the reconfiguration parameters synchronized with SCG in the RRC reconfiguration message to the terminal device 100, and the reconfiguration parameters synchronized with SCG may not be included.

[0204] The third condition is, for example, a change in the AS security key generated from the security key of the secondary node (S-KgNB or S-KeNB) in NR-DC, one or more radio bearers using the secondary key are set in the terminal device 100, and the processing associated with receiving the RRC reconfiguration request by the radio bearer is not released even if it is performed.

[0205] Also, the third condition may be, for example, that the base station device 200 is an MN handover in (NG)EN-DC.

[0206] Also, the third condition may be, for example, that the base station device 200 performs SCG reactivation.

[0207] Further, when the base station device 200 includes a change in the AS security key generated from the security key of the master node (KgNB or KeNB) in the RRC reconfiguration message to the terminal device 100 and does not include the reconfiguration parameters synchronized with SCG, when the terminal device 100 is not in the process of SCG deactivation, it is determined to release all existing SCG RLC bearers associated with the radio bearer using the master key, and it may be determined to release all existing SCG RLC bearers associated with the radio bearer using the master key.

[0208] Also, when the base station device 200 includes, in the RRC reconfiguration message to the terminal device 100, a change in the AS security key generated from the security key of the master node (KgNB or KeNB), and does not include the synchronized reconfiguration parameters of the SCG, if the terminal device 100 is in the process of SCG deactivation, it may determine that it is not necessary to release all existing SCG RLC bearers associated with the radio bearers using the master key, and it may also determine that it is not necessary to release all existing SCG RLC bearers associated with the radio bearers using the master key.

[0209] Further, the base station device 200 may include, in the RRC reconfiguration message, a parameter indicating an instruction to perform synchronized reconfiguration of the SCG and a parameter indicating an instruction to perform SCG deactivation.

[0210] Note that including the synchronized reconfiguration parameters of the SCG may mean including the synchronized reconfiguration parameters in the SCG configuration parameters. Also, a radio bearer using the master key may be a radio bearer in which a parameter (keyToUse) indicating whether to use the master key or the secondary key is set to master (or primary). Also, a radio bearer using the secondary key may be a radio bearer in which a parameter (keyToUse) indicating whether to use the master key or the secondary key is set to secondary.

[0211] When the terminal device 100 receives the RRC reconfiguration message (S106), it performs RRC reconfiguration message reception processing during SCG deactivation (S107). The terminal device 100 executes processing according to the information (parameters) included in the RRC reconfiguration message in the RRC reconfiguration message reception processing S107 during SCG deactivation.

[0212] The RRC reconfiguration message includes, for example, the following parameters.

[0213] · Synchronization-associated reconfiguration parameter (indicating an instruction to execute synchronization-associated reconfiguration) · Parameter indicating PDCP re-establishment (indicating an instruction to execute PDCP re-establishment) · Parameter meaning the setting of QoS flow to DRB mapping rule (indicating an instruction to execute reconfiguration of QoS flow to DRB mapping rule) The processing when each parameter is included will be described below.

[0214] <1. When including synchronization-associated reconfiguration parameter> When the received RRC reconfiguration message includes a synchronization-associated reconfiguration parameter, if the terminal device 100 satisfies a predetermined condition and the SCG-side radio bearer is suspended, it resumes the UL communication of the suspended SCG-side radio bearer. The predetermined condition is, for example, that the SCG deactivation is not in progress. Note that "when satisfying the predetermined condition" may also be paraphrased as "judging whether the predetermined condition is satisfied, and if so". Also, the predetermined condition may be, for example, any one of the following Conditions 1 to 3.

[0215] (Condition 1) Satisfying a condition including all or part of the following conditions · The procedure of CellGroupConfig is initiated by MCG configuration parameters and the SCG deactivation is not in progress · The process has been initiated by SCG configuration parameters (Condition 2) Satisfying a condition including all or part of the following conditions · The procedure of CellGroupConfig is initiated by MCG configuration parameters and the SCG deactivation is not in progress · The procedure is started by the SCG configuration parameter, is in the process of SCG deactivation, and includes a parameter that means immediately performing synchronized reconfiguration of the SCG (or does not include a parameter that means not immediately performing synchronized reconfiguration of the SCG). · The procedure is started by the SCG configuration parameter and is not in the process of SCG deactivation. (Condition 3) Meeting a condition that includes all or part of the following conditions · Not being in the process of SCG deactivation · Being in the process of SCG deactivation and including a parameter that means immediately performing synchronized reconfiguration of the SCG (or does not include a parameter that means not immediately performing synchronized reconfiguration of the SCG). Note that when the terminal device 100 is in the process of SCG deactivation, it may be determined that the SCG-side radio bearer is not in a suspended state but in another state (for example, a state where the SCG is deactivated, a state where uplink transmission is prohibited, etc.). When the terminal device 100 includes a synchronized reconfiguration parameter, it may resume UL communication of the suspended SCG-side radio bearer regardless of whether it is in the process of SCG deactivation or not.

[0216] Also, when the received RRC reconfiguration message includes the synchronized reconfiguration parameter of the SCG, the terminal device 100 may perform the following processing.

[0217] · The terminal device 100 may immediately execute the synchronized reconfiguration process of the SCG Further, the terminal device 100 does not immediately execute some or all of the processes of the synchronized reconfiguration of the SCG, and for the processes that are not immediately executed, they are executed during the SCG reactivation. The processes to be immediately executed include, for example, on the SCG side, MAC reset, applying the identifier of the new terminal device 100 as the C-RNTI of the Cell Groupe, etc. Also, the processes to be executed during the SCG reactivation include, for example, on the SCG side, random access processing (which may include the process of setting the lower layer according to the parameter (SpCellConfigCommon) meaning the received common SpCell configuration), starting a timer for detecting a synchronized reconfiguration failure, etc.

[0218] Note that the terminal device 100 may determine whether to immediately perform the process of synchronized reconfiguration of the SCG based on the SCG deactivation instruction in process S104 or the parameter included in the RRC reconfiguration message in process S106 (the parameter indicating whether to immediately execute the synchronized reconfiguration of the SCG). For example, the terminal device 100 may immediately execute when at least the first condition is not met, and may execute during the SCG reactivation when the condition is met. Further, after executing the above-described process, the terminal device 100 may return to the state of being in the SCG deactivation again.

[0219] Note that the first condition is the same as the first condition described in process S103. That is, the first condition is to satisfy a condition including all or some of the following conditions 1 to 4, for example.

[0220] Condition 1: The synchronized reconfiguration of the SCG is accompanied by a change in the security key (KgNB or KeNB) of the master node, or a change in the AS security key generated from the security key of the master node. Condition 2: The synchronized reconfiguration of the SCG is accompanied by a change in the security key (S-KgNB or S-KeNB) of the secondary node, or a change in the AS security key generated from the security key of the secondary node. Condition 3: There is no radio bearer that uses the master key among the radio bearers associated with the SCG RLC bearer Condition 4: All radio bearers associated with the SCG RLC bearer shall use the secondary key Note that the radio bearer that uses the master key may be the radio bearer in which the parameter (keyToUse) indicating whether to use the master key or the secondary key is set to master (or primary). Also, the radio bearer that uses the secondary key may be the radio bearer in which the parameter (keyToUse) indicating whether to use the master key or the secondary key is set to secondary

[0221] <When including parameters indicating PDCP re - establishment> When the received RRC re - configuration message includes a parameter indicating PDCP re - establishment, for example, the terminal device 100 immediately performs PDCP re - establishment. In this case, if there is data for which transmission has not been completed in the PDCP of all or some of the radio bearers that satisfy at least the second condition, after the SCG is re - activated, the terminal device 100 may transmit the data

[0222] Also, the terminal device 100 may perform PDCP re - establishment of all or some of the radio bearers that satisfy at least the second condition after the SCG is re - activated. In this case, the PDCP that performs PDCP re - establishment after SCG re - activation does not perform the processing corresponding to the PDCP SDU even if it receives the PDCP SDU from the upper layer

[0223] Note that the second condition may be the second condition in process 105, that is, being an SCG bearer or a split bearer with the Primary Path set to the SCG

[0224] Note that, in the process of transmitting data that has not been completely transmitted in PDCP, for example, in the case of UM DRB, the PDCP SDU that has a sequence number assigned but has not been delivered to the lower layer is regarded as a PDCP SDU just received from the upper layer, and is transmitted in order. In this case, it is not necessary to restart the discard timer.

[0225] Also, in the process of transmitting data that has not been completely transmitted in PDCP, for example, in the case of AM DRB, or in the case of an AM DRB where the PDCP entity is not suspended, the PDCP SDU for which transmission success has not been confirmed from the lower layer, and the PDCP SDU that has a sequence number assigned but has not been delivered to the lower layer are transmitted in order.

[0226] Also, in the process of transmitting data that has not been completely transmitted in PDCP, for example, in the case of an AM DRB for the Uu interface (the interface between the terminal device 100 and the base station device 200) where the PDCP entity is suspended, the PDCP SDU for which transmission success has not been confirmed from the lower layer, and the PDCP SDU that has a sequence number assigned but has not been delivered to the lower layer are regarded as PDCP SDUs just received from the upper layer, and are transmitted in order. In this case, it is not necessary to restart the discard timer.

[0227] Note that the discard timer may be a timer used to discard the corresponding PDCP SDU when it expires.

[0228] The base station device 200 may include a parameter in the RRC reconfiguration message of process S106 indicating that the re-establishment process for the PDCP of all or some of the radio bearers that satisfy at least the second condition is to be immediately performed (or is to be performed after the SCG is reactivated). The terminal device 100 may determine from the parameter whether to immediately perform the re-establishment process for the PDCP of all or some of the radio bearers that satisfy at least the second condition or to perform it after the SCG is reactivated.

[0229] <When including a parameter meaning the setting of the <3.QoS flow to DRB mapping rule> When the received RRC reconfiguration message includes a parameter (mappedQoS-FlowToAdd) meaning the setting of the QoS flow to DRB mapping rule, the terminal device 100 performs the following processing. The QoS flow to DRB mapping rule indicates, for example, the correspondence between the QoS flow and the DRB.

[0230] For example, when a predetermined condition is satisfied, the terminal device 100 performs end marker processing. The end marker processing is the processing of constructing an end marker control PDU, mapping it to the DRB before the change, and transmitting it to the lower layer. Note that "when a predetermined condition is satisfied" may also be stated as "judging whether a predetermined condition is satisfied, and if it is satisfied".

[0231] For example, assume that the mappedQoS-FlowToAdd included in the received RRC reconfiguration message is a parameter for the first QoS flow.

[0232] When the terminal device 100 satisfies a condition including all or part of the following Conditions 1 to 3, if the DRB of the QoS flow to DRB mapping rule stored for the first QoS flow (that is, the DRB corresponding to the first QoS flow that has already been stored) does not correspond to the second information received from the RRC of the terminal device 100 in process S105, the terminal device 100 performs end marker processing. Also, even when the terminal device 100 satisfies a condition including all or part of the following Conditions 1 to 3, if the DRB of the QoS flow to DRB mapping rule stored for the first QoS flow corresponds to the second information received from the RRC of the terminal device 100 in process S105, the terminal device 100 does not perform end marker processing.

[0233] (Condition 1) In process S105, the second information is notified to the SDAP associated with at least the data radio bearer that satisfies the second condition. (Condition 2) For the first QoS flow, the stored QoS flow to DRB mapping rule is different from the QoS flow to DRB mapping rule set by (mappedQoS-FlowToAdd included in the received RRC reconfiguration message). In other words, for the first QoS flow, the DRB associated with the newly received QoS flow to DRB mapping rule is changed from the DRB associated with the stored (already received) QoS flow to DRB mapping rule. (Condition 3) The uplink SDAP header is set in the DRB of the stored QoS flow to DRB mapping rule. Also, when the SDAP entity has already been established, there is no QoS flow to DRB mapping rule for the first QoS flow (not stored), and the default DRB is set, the terminal device 100 may perform all or part of the following processing.

[0234] (Process 1) If the default DRB is a DRB that does not correspond to the second information received from the RRC of the terminal device 100 in process S105, construct an end marker control PDU, map it to the default DRB, and transmit it to the lower layer. (Process 2) If the default DRB is a DRB that corresponds to the second information received from the RRC of the terminal device 100 in process S105, do not perform all or part of the construction of the end marker control PDU, mapping the constructed end marker control PDU to the default DRB, and transmission to the lower layer. Note that the QoS flow to DRB mapping rule may be the QoS flow to DRB mapping rule for the uplink (UL QoS flow to DRB mapping rule).

[0235] Also, when a second notification is made from the RRC of the terminal device 100 to the PDCP in process S105 (when the PDCP recognizes that it is the PDCP of a radio bearer that satisfies at least the second condition), the terminal device 100 creates an end marker control PDU (SDAP Control PDU) and transmits it to the PDCP. When the PDCP of the terminal device 100 receives the SDAP Control PDU, it discards the received SDAP Control PDU. Alternatively, if the PDCP of the terminal device 100 is a split bearer and the primary path is in the SCG, the SDAP Control PDU may be discarded.

[0236] Note that, when the base station apparatus 200 is implemented, the terminal apparatus 100 may be prevented from transmitting an end marker control PDU to the SCG during SCG deactivation. For example, the base station apparatus 200 does not include mappedQoS-FlowToAdd in the RRC reconfiguration message transmitted to the terminal apparatus 100 during SCG deactivation. Also, for example, when the base station apparatus 200 includes mappedQoS-FlowToAdd in the RRC reconfiguration message transmitted to the terminal apparatus 100 during SCG deactivation, the base station apparatus 200 performs settings so that the terminal apparatus 100 does not transmit an end marker control PDU to the SCG side.

[0237] In addition, when the terminal apparatus 100 determines that it cannot process according to the RRC reconfiguration message received from the base station apparatus 200, the terminal apparatus 100 may initiate a procedure for re-establishing the RRC connection or a procedure related to a radio link failure of the SCG with respect to the base station apparatus 200. For example, when the RRC reconfiguration message received from the base station apparatus 200 does not include a synchronized reconfiguration parameter even though it meets the condition of requiring a synchronized reconfiguration parameter, the terminal apparatus 100 determines that it cannot process according to the received RRC reconfiguration message. Also, for example, when end marker transmission to the SCG occurs due to the RRC reconfiguration message received from the base station apparatus 200 even though the terminal apparatus 100 is in the process of SCG deactivation, the terminal apparatus 100 determines that it cannot process according to the received RRC reconfiguration message.

[0238] FIG. 13 is a diagram showing an example of a sequence of UL data arrival during SCG deactivation. The terminal apparatus 100 receives UL data (S108) during SCG deactivation. The arrival of UL data indicates that data to be transmitted to the base station apparatus 200 has been generated. For example, it may be that a PDCP SDU arrives (is transmitted) at the PDCP, or that a MAC SDU arrives (is transmitted) at the MAC on the SCG side.

[0239] When the UL data arrives (S108), the terminal device 100 performs UL data transmission processing during SCG deactivation (S109). The UL data transmission processing S109 during SCG deactivation is a process of determining whether to transmit the UL data to the master node or the secondary node and whether to transmit it immediately, and transmitting the UL data at an appropriate timing. Hereinafter, the UL data transmission processing S109 during SCG deactivation will be described separately for the case where the PDCP SDU arrives at the PDCP and the case where the MAC SDU arrives at the MAC on the SCG side.

[0240] <1. When the PDCP SDU arrives at the PDCP> For example, in process S105, when the terminal device 100 receives a second notification from the RRC of the terminal device 100 to the PDCP (when the PDCP recognizes that it is a radio bearer that satisfies at least the second condition), the PDCP of the terminal device 100 that has detected the arrival of the PDCP SDU notifies the RRC of the terminal device 100 that UL data has been generated. Here, when there is a primary path to the SCG in the split bearer, the terminal device 100 may notify the RRC of the terminal device 100 when receiving the PDCP SDU from the upper layer. On the other hand, when there is a primary path to the MCG in the split bearer, the terminal device 100 may notify the RRC of the terminal device 100 when the transmission data volume exceeds or is likely to exceed the threshold.

[0241] The RRC of the terminal device 100 that has received the notification that UL data has been generated from the PDCP of the terminal device 100 transmits a SCG reactivation request to the base station device 200 (S110). The SCG reactivation request may be a message requesting to perform SCG reactivation or a message including parameters requesting to perform SCG reactivation.

[0242] Also, the SCG reactivation request is, for example, an RRC message. Also, the SCG reactivation request may be, for example, the SCG reactivation request in the RRC message, or may be a message with another name.

[0243] <When the MAC SDU arrives at the MAC on the SCG side> The RRC processing of the terminal device 100 is the same as when the above-mentioned PDCP SDU arrives at the PDCP. When the MAC of the terminal device 100 detects the arrival of the MAC SDU, it notifies the RRC of the terminal device 100 that UL data has been generated. Also, the MAC of the terminal device 100 may perform SCG reactivation and perform preparations for transmitting UL data (for example, executing a random access procedure for the secondary node, etc.). The terminal device 100 may, for example, in processing S107 or the like, perform the synchronized reconfiguration of the SCG in advance if there is a synchronized reconfiguration of the SCG that was not immediately executed. Also, the MAC of the terminal device 100 may perform all processing related to SCG reactivation after receiving the SCG reactivation instruction from the base station device 200.

[0244] Also, the MAC of the terminal device 100 may perform SCG reactivation and start transmitting UL data without notifying the RRC of the terminal device 100 that UL data has been generated. Before starting to transmit UL data, the terminal device 100 may perform the synchronized reconfiguration of the SCG in processing S107 or the like if there is a synchronized reconfiguration of the SCG that was not immediately executed.

[0245] If the terminal device 100, for example, received in processing S104, the SCG deactivation instruction includes an instruction for the processing when UL data is generated during SCG deactivation (for example, whether SCG reactivation can be executed without transmitting the SCG reactivation request), the terminal device 100 may follow this instruction.

[0246] The base station device 200 determines whether SCG reactivation of the terminal device 100 is necessary. When the base station device 200 meets the conditions including some or all of the following Condition 1 to Condition 3, it determines that SCG reactivation of the terminal device 100 is necessary.

[0247] (Condition 1) A SCG reactivation request is received from the terminal device 100 (Condition 2) DL data to be transmitted to the terminal device 100 via SCG is generated (Condition 3) The remaining amount of radio resources of the secondary node is sufficient (equal to or greater than the threshold) Note that if the terminal device 100 is in the process of deactivating SCG, the base station device 200 may determine at any time whether SCG reactivation of the terminal device 100 is necessary.

[0248] When the base station device 200 determines that SCG reactivation is necessary, it transmits (permits) an SCG reactivation instruction instructing the implementation of SCG reactivation to the terminal device 100 (S111). The SCG reactivation instruction is, for example, an RRC message. Also, the SCG reactivation instruction may be, for example, RRCReconiguration of the RRC message or a message with another name.

[0249] When the terminal device 100 receives the SCG reactivation instruction (S111), it performs SCG reactivation processing (S112). The SCG reactivation processing S112 is a process in which the terminal device 100 reactivates SCG.

[0250] Note that the RRC of the terminal device 100 may send a third notification to the PDCP that sent the second notification in process S105. The third notification may be a notification indicating SCG reactivation or a notification indicating the release of SCG deactivation. For example, it may be "SCG has been reactivated" or "UL transmission of SCG has been permitted (resumed)". When the PDCP of the terminal device 100 receives the third notification, it resumes the UL transmission of SCG.

[0251] [Second Embodiment] During SCG deactivation, in the terminal device 100 SDAP entity, RDI (Reflective QoS flow to DRB mapping Indication) is set to '1', and a downlink SDAP data PDU is received. Assume that the received downlink SDAP data PDU contains a QoS flow identifier (QFI) for the second QoS flow. Note that the reception of this downlink SDAP data PDU may be performed via a DRB associated with an RLC bearer in MCG.

[0252] When the terminal device 100 satisfies a condition including all or part of the following conditions 1 to 3, when the DRB of the QoS flow to DRB mapping rule stored for the second QoS flow (that is, the DRB corresponding to the first QoS flow that has already been stored) does not correspond to the second information received from the RRC of the terminal device 100 in the first embodiment, the terminal device 100 performs end marker processing. Also, even when the terminal device 100 satisfies a condition including all or part of the following conditions 1 to 3, when the DRB of the QoS flow to DRB mapping rule stored for the second QoS flow corresponds to the second information received from the RRC of the terminal device 100, the terminal device 100 does not perform end marker processing. Note that end marker processing is a process of constructing an end marker control PDU, mapping it to the DRB before the change, and transmitting it to the lower layer.

[0253] (Condition 1) In process S105 in the first embodiment, the second information is notified to the SDAP associated with the DRB that satisfies at least the second condition. (Condition 2) For the first QoS flow, the stored QoS flow to DRB mapping rule is different from the QoS flow to DRB mapping rule of the received downlink SDAP data PDU. In other words, for the second QoS flow, the DRB associated with the QoS flow to DRB mapping rule newly received in the downlink SDAP data PDU is changed from the DRB associated with the stored QoS flow to DRB mapping rule. (Condition 3) The uplink SDAP header is set in the DRB of the stored QoS flow to DRB mapping rule. Also, when there is no QoS flow to DRB mapping rule for the second QoS flow (not stored) and the default DRB is set, the terminal device 100 may perform all or part of the following processes.

[0254] (Process 1) When the default DRB is a DRB that does not correspond to the second information received from the RRC of the terminal device 100 in the first embodiment, construct an end marker control PDU, map it to the default DRB, and transmit it to the lower layer. (Process 2) When the default DRB is a DRB that corresponds to the second information received from the RRC of the terminal device 100 in the first embodiment, do not perform all or part of the construction of the end marker control PDU, mapping of the constructed end marker control PDU to the default DRB, and transmission to the lower layer. Note that the QoS flow to DRB mapping rule may be a QoS flow to DRB mapping rule for the uplink (UL QoS flow to DRB mapping rule).

[0255] When the terminal device 100 receives an RRC reconfiguration message, if the synchronized reconfiguration parameters of the SCG are included in the RRC reconfiguration message, it determines whether to immediately execute some or all of the synchronized reconfiguration process of the SCG. When the terminal device 100 determines not to immediately execute some or all of the synchronized reconfiguration process of the SCG, it executes the unexecuted synchronized reconfiguration process of the SCG at the time of SCG reactivation. The terminal device 100 determines not to immediately execute, for example, when some or all of the following conditions are met.

[0256] · The SCG is in the deactivation state. · The synchronized reconfiguration of the SCG is associated with a change in the security key (KgNB or KeNB) of the master node, or a change in the AS security key generated from the security key of the master node. · The synchronized reconfiguration of the SCG is associated with a change in the security key (S-KgNB or S-KeNB) of the secondary node, or a change in the AS security key generated from the security key of the secondary node. · There is no radio bearer using the master key among the radio bearers associated with the SCG RLC bearer. · All the radio bearers associated with the SCG RLC bearer use the secondary key. · It is instructed by the base station device to execute at the time of SCG reactivation. Thereby, the execution of SCG reactivation due to the execution of the synchronized reconfiguration of the SCG can be suppressed, and the power consumption of the terminal device 100 can be suppressed.

[0257] In addition, when the base station device 200 determines that it does not want the terminal device 100 to immediately execute the synchronized reconfiguration of the SCG, it does not include the synchronized reconfiguration parameters in the SCG configuration parameters of the RRC reconfiguration message. The base station device 200 determines that it does not want to immediately execute, for example, when it meets the conditions including some or all of the following conditions.

[0258] ·During SCG activation ·The synchronized reconfiguration of SCG is associated with a change in the security key (KgNB or KeNB) of the master node, or a change in the AS security key generated from the security key of the master node ·The synchronized reconfiguration of SCG is associated with a change in the security key (S-KgNB or S-KeNB) of the secondary node, or a change in the AS security key generated from the security key of the secondary node ·There is no radio bearer using the master key among the radio bearers associated with the SCG RLC bearer ·All radio bearers associated with the SCG RLC bearer use the secondary key Note that the radio bearer using the master key may be the radio bearer in which the parameter (keyToUse) indicating whether to use the master key or the secondary key is set to master (or primary). Also, the radio bearer using the secondary key may be the radio bearer in which the parameter (keyToUse) indicating whether to use the master key or the secondary key is set to secondary

[0259] Thereby, the execution of SCG reactivation by performing synchronized reconfiguration can be suppressed, and the power consumption of the terminal device 100 can be suppressed

[0260] Also, when the RRC reconfiguration message received from the base station device 200 during SCG deactivation contains the synchronized reconfiguration parameters of MCG but does not contain the synchronized reconfiguration of SCG, the terminal device 100 does not resume UL transmission of SCG

[0261] Thereby, the execution of SCG reactivation by performing synchronized reconfiguration can be suppressed, and the power consumption of the terminal device 100 can be suppressed

[0262] Also, when the terminal device 100 receives an SCG deactivation instruction from the base station device 200, it performs Process A on the radio bearer that meets Condition A.

[0263] Condition A is that it is an SCG bearer or a split bearer with a Primary Path set to the SCG.

[0264] Process A is a process of immediately transmitting or discarding the data for which transmission has not been completed in the PDCP entity of the radio bearer that meets Condition A. Also, when a re - establishment request for the PDCP entity of the radio bearer that meets Condition A is made, in the process of re - establishing the PDCP entity, the transmission of the data for which transmission has not been completed may not be performed immediately but may be performed at the time (after) of SCG re - activation. Also, when the PDCP entity of the radio bearer that meets Condition A receives an SDAP Control PDU from the upper layer, Process A is to discard it.

[0265] Thereby, the execution of SCG re - activation due to the occurrence of UL transmission can be suppressed, and the power consumption of the terminal device 100 can be suppressed.

[0266] Also, when the RRC of the terminal device 100 receives an SCG deactivation instruction from the base station device 200, it notifies Information A to the SDAP associated with the radio bearer (DRB) that meets Condition A.

[0267] Information A is information including that the UL transmission of the DRB is prohibited (stopped) or that the cell group associated with the DRB is in the process of de - activation, etc., which means that UL transmission cannot be performed with the DRB.

[0268] Thereby, the execution of SCG re - activation due to the occurrence of UL transmission can be suppressed, and the power consumption of the terminal device 100 can be suppressed.

[0269] Also, when the DRB corresponding to the first QoS flow changes in SDAP in the terminal device 100 and the DRB before the change is the DRB notified from RRC, the terminal device 100 does not transmit the SDAP Control SDU to the DRB before the change.

[0270] Further, the base station device 200 may be implemented not to generate an end marker when the terminal device 100 is in the process of SCG deactivation. For example, during SCG deactivation, the base station device 200 controls not to re-associate the QoS flow associated with the DRB that is an SCG bearer or a split bearer and has a primary path set to SCG to another DRB, so as to control not to generate an end marker. Also, for example, before the SCG deactivation instruction in process 104 in the first embodiment, or in the SCG deactivation instruction, the base station device 200 controls to (re)-associate all or part of the QoS flows associated with the DRBs that satisfy at least the second condition to the DRBs that do not satisfy at least the second condition, so as to control not to generate an end marker.

[0271] Thereby, the execution of SCG reactivation due to the occurrence of UL transmission can be suppressed, and the power consumption of the terminal device 100 can be suppressed.

[0272] Also, when UL data is generated (arrives), the terminal device 100 may be instructed (specified) by the base station device 200 whether to request SCG reactivation from the base station device or the terminal device 100 performs SCG reactivation spontaneously. For example, the terminal device 100 performs the following process.

[0273] When the RRC of the terminal device 100 receives an SCG deactivation instruction from the base station device 200, it transmits Notification A to the PDCP entity of the radio bearer that meets Condition A. Notification A is a notification indicating that SCG deactivation is in progress or that UL transmission on the SCG side is prohibited (interrupted). When the PDCP entity of the radio bearer that meets Condition A receives data from the upper layer, the PDCP entity of the terminal device 100 notifies the RRC of the terminal device 100 that UL data has been generated. The RRC of the terminal device 100 generates an SCG deactivation request and transmits it to the base station device 200. When the RRC of the terminal device 100 receives an SCG reactivation message from the base station device 200, it transmits a notification indicating that SCG has been reactivated or that UL transmission on the SCG side has started (resumed) to the PDCP entity of the radio bearer that transmitted the second notification.

[0274] Alternatively, when UL data is generated in the MAC of the terminal device 100, the terminal device 100 executes a random access procedure to enable UL transmission. If there is a synchronized reconfiguration of the SCG that has not been immediately executed, the terminal device 100 executes it first.

[0275] Thereby, when UL transmission occurs in the RLC bearer on the SCG side during SCG deactivation, the terminal device 100 can perform appropriate processing. Also, thereby, the terminal device 100 can notify the base station device 200 that UL transmission has occurred in the RLC bearer on the SCG side during SCG deactivation, and can perform SCG reactivation autonomously or according to the instruction of the base station device 200.

[0276] [Other Embodiments] The embodiments may be combined with each other. Also, the messages in the sequence do not have to be performed in the given order, and the order may be changed. Further, some of the messages in the sequence may not be performed. For example, the processing during SCG deactivation in the terminal device 100 only needs to be during SCG deactivation, and the messages in the sequence may be omitted.

[0277] Also, in each embodiment, what is described as the function or processing of the terminal device 100 may be the function or processing of the base station device 200. Also, in each embodiment, what is described as the function or processing of the base station device 200 may be the function or processing of the terminal device 100.

[0278] Also, in each embodiment, the "radio bearer" may be a signaling radio bearer, a data radio bearer, or both a signaling radio bearer and a data radio bearer.

[0279] FIGs. 14 to 22 are diagrams showing examples of the modified image of the 3GPP specification. The shaded part indicates the modified portion. Note that the specification number, chapter number, etc. are examples and are not limited to the examples in the figures.

[0280] In summary, it is as follows.

[0281] A first radio communication device (terminal device 100) having a receiving unit that receives from a second radio communication device (base station device 200), a transmitting unit that transmits to the second radio communication device, and a processing unit, wherein when the first RRC message transmitted from the opposing radio communication device includes parameters related to SCG deactivation, the processing unit deactivates the SCG and performs a first process on the radio bearers established in the first radio communication device that satisfy a first condition.

[0282] The first condition is that it is an SCG bearer or a split bearer with a primary path set on the SCG side, for the first radio communication device.

[0283] The first process is a first radio communication device that immediately transmits data that has not been transmitted in the PDCP entity of a radio bearer that satisfies the first condition.

[0284] The first process is a first radio communication device that discards all data that has not been transmitted in the PDCP entity of a radio bearer that satisfies the first condition.

[0285] When a re - establishment request for the PDCP entity of a radio bearer that satisfies the first condition among the radio bearers established in the first radio communication device is made while the SCG is inactive, the processing unit does not transmit data that has not been transmitted in the re - establishment process of the PDCP entity. When a re - establishment request for the PDCP entity of a radio bearer that does not satisfy the first condition among the radio bearers established in the first radio communication device is made, data that has not been transmitted is transmitted in the re - establishment process of the PDCP entity. This is the first radio communication device.

[0286] A second radio communication device having a second transmission unit that transmits to the first radio communication device, a second reception unit that receives from the first radio communication device, and a second processing unit. When the second processing unit deactivates the secondary cell group set in the first radio communication device, it includes parameters related to the deactivation of the SCG in the first RRC message transmitted by the second transmission unit, thereby deactivating the SCG and causing the first process to be executed for a radio bearer that satisfies the first condition among the radio bearers established in the first radio communication device.

[0287] A second radio communication device having a second transmission unit that transmits to the first radio communication device, a second reception unit that receives from the first radio communication device, and a second processing unit. The second processing unit includes a parameter indicating that the synchronized re - setting parameter of the SCG included in the RRC re - setting message is not immediately executed but is executed after the SCG is re - activated in the RRC re - setting message transmitted to the first radio communication device.

[0288] A first radio communication device, comprising a transmission unit that transmits to a second radio communication device, a reception unit that receives from the second radio communication device, and a processing unit. When the processing unit receives an RRC reconfiguration message from the second radio communication device and the RRC reconfiguration message contains a parameter indicating that the synchronized reconfiguration parameters of the SCG are not to be executed immediately but after SCG reactivation, the processing unit executes a synchronized reconfiguration procedure according to the synchronized reconfiguration parameters of the SCG after SCG reactivation. When the RRC reconfiguration message does not contain a parameter indicating that the synchronized reconfiguration parameters of the SCG are not to be executed immediately but after SCG reactivation, the processing unit immediately executes a synchronized reconfiguration procedure according to the synchronized reconfiguration parameters of the SCG.

[0289] A second radio communication device, comprising a second transmission unit that transmits to the first radio communication device, a second reception unit that receives from the first radio communication device, and a second processing unit. When the second processing unit transmits an RRC reconfiguration message to the first radio communication device and satisfies a second condition, the second processing unit includes the synchronized reconfiguration parameters of the SCG in the RRC reconfiguration message as essential. When the second condition is not satisfied, the second processing unit includes the synchronized reconfiguration parameters of the SCG in the RRC reconfiguration message as required.

[0290] The second condition is a change in the AS security key generated from the security key of the secondary node in NR-DC, and at least one of the radio bearers configured in the first communication device has a secondary key, at least one radio bearer is not released by the RRC reconfiguration message, and the SCG is not deactivated.

[0291] The second condition is a handover of the master node in EN-DC and the SCG is not deactivated.

[0292] The second condition is the reactivation of the SCG.

[0293] A first radio communication device, comprising a transmission unit that transmits to a second radio communication device, a reception unit that receives from the second radio communication device, and a processing unit, wherein when the processing unit receives from the second radio communication device an RRC reconfiguration message including synchronization reconfiguration parameters and satisfies a third condition, the processing unit resumes uplink transmission of an SCG radio bearer that has been suspended.

[0294] The first radio communication device, wherein the third condition is a procedure started by MCG configuration parameters and SCG is not deactivated.

[0295] The first radio communication device, wherein the third condition is a procedure started by SCG configuration parameters.

[0296] A second radio communication device, comprising a second transmission unit that transmits to the first radio communication device, a second reception unit that receives from the first radio communication device, and a second processing unit, wherein when the second processing unit deactivates a secondary cell group set in the first radio communication device, the second processing unit includes parameters related to SCG deactivation in a first RRC message transmitted by the second transmission unit, causing the RRC of the first radio communication device to give a first notification to an SDAP entity associated with a radio bearer that satisfies a fourth condition among the radio bearers established in the first radio communication device.

[0297] The second radio communication device, wherein the fourth condition is that the radio bearer is an SCG bearer or a split bearer with a primary path set to SCG.

[0298] The second radio communication device, wherein the first notification is a notification indicating that uplink transmission of a radio bearer that satisfies the fourth condition has been suspended.

[0299] The second radio communication device, wherein the first notification is given when an SDAP entity is associated with a radio bearer that satisfies the fourth condition.

[0300] A first radio communication device includes a transmitting unit that transmits to a second radio communication device, a receiving unit that receives from the second radio communication device, and a processing unit. When a parameter related to the inactivation of the SCG is included in a first RRC message transmitted from a second transmitting unit of the second radio communication device, the processing unit inactivates the SCG, and the RRC of the first radio communication device gives a first notification to an SDAP entity associated with a radio bearer that satisfies a fourth condition among the radio bearers established in the first radio communication device.

[0301] The fourth condition is that the radio bearer is an SCG bearer or a split bearer with a primary path set to the SCG, for the first radio communication device.

[0302] The first notification is a notification indicating that the uplink transmission of a radio bearer that satisfies the fourth condition has been temporarily stopped, for the first radio communication device.

[0303] The first notification is given to a radio bearer that satisfies the fourth condition when an SDAP entity is associated with it, for the first radio communication device.

[0304] A second radio communication device includes a second transmitting unit that transmits to the first radio communication device, a second receiving unit that receives from the first radio communication device, and a second processing unit. When inactivating a secondary cell group set in the first radio communication device, the second processing unit includes a parameter related to the inactivation of the SCG in a first RRC message transmitted from the second transmitting unit to inactivate the SCG, and executes a first process on a radio bearer that satisfies a first condition among the radio bearers established in the first radio communication device.

[0305] The first condition is that the radio bearer is an SCG bearer or a split bearer with a primary path set to the SCG, for the second radio communication device.

[0306] The first process is that when uplink data is generated for a radio bearer that satisfies the first condition, the second radio communication device transmits a message for requesting SCG reactivation to the first radio communication device.

[0307] A first radio communication device includes a receiving unit that receives from the second radio communication device, a transmitting unit that transmits to the second radio communication device, and a processing unit. When the first RRC message transmitted from the second transmitting unit of the second radio communication device includes parameters related to deactivation of the SCG, the processing unit deactivates the SCG and performs the first process on the radio bearer that satisfies the first condition among the radio bearers established in the first radio communication device.

[0308] The first condition for the first radio communication device is that it is an SCG bearer or a split bearer with a primary path set to the SCG.

[0309] The first process for the first radio communication device is that when uplink data is generated for a radio bearer that satisfies the first condition, it transmits a message for requesting SCG reactivation to the second radio communication device.

Explanation of Signs

[0310] 10: Communication system 100: Terminal device 110: CPU 120: Storage 121: Terminal-side radio communication program 122: Terminal-side MR-DC program 130: Memory 140: Communication circuit 200: Base station device 210: CPU 220: Storage 221: Radio communication program 222: MR-DC master node program 223: MR-DC secondary node program 230: Memory 240: Wireless communication circuit 250: Network interface 300: Core network

Claims

1. A transmitting unit that transmits a message to the first wireless communication device, a receiving unit that receives a message from the first wireless communication device, and a processing unit that, when deactivating a secondary cell group set in the first wireless communication device, includes a parameter related to the deactivation of the secondary cell group in a first message transmitted from the transmitting unit to the first wireless communication device. The processing unit controls the first wireless communication device to transmit the first message including the parameter related to the deactivation of the secondary cell group, and controls the first wireless communication device that has deactivated the secondary cell group upon receiving the first message not to perform a process of re-associating a QoS flow associated with a DRB set for the deactivated secondary cell group with another DRB, and executes a first process. A second wireless communication device.

2. The first process includes a process of immediately transmitting data for which transmission has not been completed in a PDCP entity of a radio bearer of the secondary cell group to the first wireless communication device. The second wireless communication device according to Claim 1.

3. The first process includes a process of discarding all data for which transmission has not been completed in a PDCP entity of a radio bearer of the secondary cell group. The second wireless communication device according to Claim 1.

4. A first receiving unit that receives a message from a second wireless communication device, a first transmitting unit that transmits a message to the second wireless communication device, and a processing unit that, when the first message transmitted from the second wireless communication device includes a parameter related to the deactivation of a secondary cell group, deactivates the secondary cell group. The processing unit performs a first process of controlling not to perform a process of re-associating a QoS flow associated with a DRB set for the deactivated secondary cell group with another DRB. A first wireless communication device.

5. The first process includes a process of immediately transmitting data for which transmission has not been completed in a PDCP entity of a radio bearer of the secondary cell group. The first wireless communication device according to Claim 4.

6. The first process includes a process of discarding all data for which transmission has not been completed in the PDCP entity of the radio bearer of the secondary cell group. The first wireless communication device according to claim 4.

7. When the processing unit receives a re-establishment request for the first PDCP entity of the radio bearer of the secondary cell group among the established radio bearers while the secondary cell group is inactive, in the process of re-establishing the first PDCP entity, transmission of data for which transmission has not been completed is not performed. When the processing unit receives a re-establishment request for the second PDCP entity of the radio bearer that does not belong to the secondary cell group among the established radio bearers, transmission of data for which transmission has not been completed is performed in the process of re-establishing the second PDCP entity. The first wireless communication device according to claim 4.

8. The processing unit controls so as not to perform the process of re-associating the QoS flow associated with the DRB set for the secondary cell group with another DRB, thereby controlling not to transmit the control PDU via the secondary cell group. The first wireless communication device according to claim 4.

Images