Terminal device, method, and integrated circuit

Abstract

The present invention is a terminal device for communicating with a base station device, the terminal device comprising: a receiving unit for receiving a first message from the base station device; and a processing unit for establishing a second PDCP entity based on a first setting and using the same setting as that for a first Packet Data Convergence Protocol (PDCP) entity for a first signaling radio bearer, the first setting being set based on the first message.

Description

Technical Field

[0001] This invention relates to terminal devices, methods, and integrated circuits.

[0002] This application claims priority to Japanese Patent Application No. 2020-007314, filed on January 21, 2020, the contents of which are incorporated herein by reference. Background Technology

[0003] The 3rd Generation Partnership Project (3GPP) studied radio access methods and radio networks (hereinafter referred to as "Long Term Evolution (LTE: registered trademark)" or "Evolved Universal Terrestrial Radio Access (EUTRA)") and core networks (hereinafter referred to as "Evolved Packet Core (EPC)"). EUTRA is also known as E-UTRA.

[0004] Furthermore, within 3GPP, technical research and standardization were conducted on LTE-Advanced Pro, an extension of LTE, and NR (New Radiotechnology), a new radio access technology, as radio access methods and wireless network technologies for fifth-generation cellular systems (Non-Patent Document 1). Additionally, research was also conducted on 5GC (5Generation Core Network), the core network for fifth-generation cellular systems (Non-Patent Document 2).

[0005] Existing technical documents

[0006] Non-patent literature

[0007] Non-patent document 1: 3GPP RP-170855, "Work Item on New Radio (NR) Access Technology"

[0008] Non-patent document 2: 3GPP TS 23.501v15.3.0, “System Architecture for the 5G System; Stage 2”

[0009] Non-patent document 3: 3GPP TS 36.300, v15.3.0, "Evolved Universal Terestrial Radio Access (E-UTRA) and Evolved Universal Terestrial Radio Access Network (E-UTRAN); Overall description; Stage 2"

[0010] Non-patent literature 4: 3GPP TS 36.331 v15.4.0, "Evolved Universal Terestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specifications"

[0011] Non-patent literature 5: 3GPP TS 36.323 v15.3.0, "Evolved Universal Terestrial Radio Access (E-UTRA); Packet Data Convergence Protocol (PDCP) specification"

[0012] Non-patent document 6: 3GPP TS 36.322v15.3.0, "Evolved Universal Terestrial RadioAccess (E-UTRA): Radio Link Control (RLC) protocol specification"

[0013] Non-patent document 7: 3GPP TS 36.321v15.3.0, "Evolved Universal Terestrial RadioAccess (E-UTRA); Medium Access Control (MAC) protocol specification"

[0014] Non-patent literature 8: 3GPP TS 37.340v 15.3.0, "Evolved Universal Terestrial Radio Access (E-UTRA) and NR; Multi-Connectivity; Stage 2"

[0015] Non-patent literature 9: 3GPP TS 38.300v 15.3.0, "NR; NR and NG-RAN Overall description; Stage 2"

[0016] Non-patent literature 10: 3GPP TS 38.331 v15.4.0, "NR; Radio Resource Control (RRC); Protocol specifications"

[0017] Non-patent literature 11: 3GPP TS 38.323 v15.3.0, "NR; Packet Data Convergence Protocol (PDCP) specification"

[0018] Non-patent document 12: 3GPP TS 38.322 v15.3.0, “NR; Radio Link Control (RLC) protocol specification”

[0019] Non-patent literature 13: 3GPP TS38.321 v15.3.0, "NR; Medium Access Control (MAC) protocol specification"

[0020] Non-patent document 14: 3GPP TS 23.401 v15.0.0, "General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access"

[0021] Non-patent document 15: 3GPP TS 23.502 v15.3.0, “Procedure for 5G System; Stage 2”

[0022] Non-patent document 16: 3GPP TS 37.324 v15.1.0, "NR; Service Data Adaptation Protocol (SDAP) specification"

[0023] Non-patent document 17: 3GPP Draft_Report_v1.doc, “Report of 3GPP TSG RAN2#105 meeting, Athens, Greece” http: / / www.3gpp.org / ftp / TSG_RAN / WG2_RL2 / TSGR2_105 / Report / Draft_Report_v1.zip

[0024] Non-patent literature 18: 3GPP RP-181544, "Revised WID: Even further mobility enhancement in E-UTRAN"

[0025] Non-patent document 19: 3GPP RP-181433, "New WID: NR mobility enhancements"

[0026] Non-patent document 20: 3GPP R2-1901364, "Detail for non-splitbearer option forsimultaneous connectivity"

[0027] Non-patent document 21: 3GPP TS 33.401 v15.9.0, “3GPP System Architecture Evolution (SAE); Security architecture”

[0028] Non-patent document 22: 3GPP TS 33.501 v15.6.0, “Security architecture and procedures for 5G System” Summary of the Invention

[0029] The problem the invention aims to solve

[0030] As part of LTE technology research, mechanisms for further extending existing LTE mobility extension technologies were investigated. Furthermore, mechanisms for extending existing NR mobility technologies were also studied in NR technology research (Non-Patent Documents 18, 19). These studies mainly include: research on technologies that minimize user data transmission and reception interruptions (RUDI: Reduce User Data Interruption) during inter-cell movement (handover) in the connection between base station equipment and terminal equipment; and research on improvements in handover robustness.

[0031] In RUDI, the mechanism for enabling two protocol stacks to exist simultaneously in a cell group (DAPS: Dual Active Protocol Stack) has been studied, but the detailed terminal actions for efficient control of mobility have not yet been studied.

[0032] One aspect of the present invention is made in view of the above-mentioned problems, and one of its objectives is to provide a terminal device, method, or integrated circuit that can efficiently control mobility.

[0033] Technical solution

[0034] To achieve the above objectives, one embodiment of the present invention adopts the following approach. Specifically, the first embodiment of the present invention is a terminal device that communicates with a base station device. The terminal device includes: a receiving unit that receives a first message from the base station device; and a processing unit that, based on a first setting, establishes a second PDCP entity using the same settings as those for a first Packet Data Convergence Protocol (PDCP) entity for a first signaling radio bearer, wherein the first setting is based on the first message.

[0035] (2) The second embodiment is the terminal device described in (1), wherein when the processing unit establishes the second PDCP entity, it causes some or all of the values ​​of the state variables used in the first PDCP entity to be inherited by the second PDCP entity.

[0036] (3) The third embodiment is a communication method for a terminal device for communicating with a base station device, wherein the computer of the terminal device has: a receiving process for receiving a first message from the base station device; and a processing process for establishing a second PDCP entity based on a first setting and using the same setting as that for a first packet data convergence protocol (PDCP) entity for a first signaling radio bearer, the first setting being set based on the first message.

[0037] (4) The fourth embodiment is the communication method described in (3), wherein, during the processing, when the second PDCP entity is established, some or all of the values ​​of the state variables used in the first PDCP entity are inherited by the second PDCP entity.

[0038] (5) The fifth embodiment is a base station apparatus for communicating with a terminal device. The base station apparatus includes: a transmitting unit for transmitting a first message to the terminal device; and a processing unit for establishing a second PDCP entity based on a first setting that is the same as the setting for a first packet data convergence protocol (PDCP) entity for a first signaling radio bearer. The first setting is set based on the first message.

[0039] (6) The sixth embodiment is the base station apparatus described in (5), wherein when the processing unit establishes the second PDCP entity, it causes some or all of the values ​​of the state variables used in the first PDCP entity to be inherited by the second PDCP entity.

[0040] (7) The seventh embodiment is a communication method of a base station device for communicating with a terminal device, wherein the computer of the base station device has: a sending process for sending a first message to the terminal device; and a processing process for establishing a second PDCP entity based on a first setting using the same setting as that for a first packet data convergence protocol (PDCP) entity for a first signaling radio bearer, the first setting being set based on the first message.

[0041] (8) The eighth embodiment is the communication method described in (7), wherein, during the processing, when the second PDCP entity is established, some or all of the values ​​of the state variables used in the first PDCP entity are inherited by the second PDCP entity.

[0042] It should be noted that these specific solutions can be implemented by systems, devices, methods, integrated circuits, computer programs, or recording media, or by any combination of systems, devices, methods, integrated circuits, computer programs, and recording media.

[0043] Beneficial effects

[0044] According to one aspect of the present invention, the terminal device can achieve efficient mobility processing. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the communication system according to various embodiments of the present invention.

[0046] Figure 2This is a protocol stack diagram of the UP and CP of the terminal device and the base station device in the E-UTRA of various embodiments of the present invention.

[0047] Figure 3 This is a protocol stack diagram of the UP and CP of the terminal device and the base station device in the NR of various embodiments of the present invention.

[0048] Figure 4 This is a diagram illustrating an example of the flow of processes for various settings in RRC208 and / or RRC308 of various embodiments of the present invention.

[0049] Figure 5 This is a block diagram illustrating the configuration of the terminal device according to various embodiments of the present invention.

[0050] Figure 6 This is a block diagram illustrating the configuration of a base station device according to various embodiments of the present invention.

[0051] Figure 7 This is a diagram illustrating an example of the switching processes in EUTRA according to various embodiments of the present invention.

[0052] Figure 8 This is a diagram illustrating an example of the processing related to switching in NR in various embodiments of the present invention.

[0053] Figure 9 This is a diagram illustrating an example of the start and stop conditions for each timer in an embodiment of the present invention.

[0054] Figure 10 This is a diagram illustrating an example of a mobilityControlInfo information element in an embodiment of the present invention.

[0055] Figure 11 This is a diagram illustrating another example of the mobilityControlInfo information element in an embodiment of the present invention.

[0056] Figure 12 This is a diagram illustrating an example of the synchronous reset information element in an embodiment of the present invention.

[0057] Figure 13 This is a diagram illustrating another example of the synchronous reset of information elements in an embodiment of the present invention.

[0058] Figure 14 This is a diagram illustrating an example of an ASN.1 description included in a message relating to the resetting of an RRC connection in an NR, representing an embodiment of the present invention.

[0059] Figure 15This is a diagram illustrating an example of an ASN.1 description included in a message relating to the resetting of an RRC connection in an E-UTRA, representing an embodiment of the present invention.

[0060] Figure 16 This is a diagram illustrating an example of the process flow of process A in an embodiment of the present invention.

[0061] Figure 17 This is a diagram illustrating an example of the process flow of process B in an embodiment of the present invention.

[0062] Figure 18 This is a diagram illustrating an example of the process flow of process C in an embodiment of the present invention.

[0063] Figure 19 This is a diagram illustrating an example of the process flow of processing H in an embodiment of the present invention.

[0064] Figure 20 This is a diagram illustrating an example of the ASN.1 description of various embodiments of the present invention for setting parameters for whether to apply a connection-before-disconnection switch to the wireless bearer.

[0065] Figure 21 This is another example of the description in ASN.1, which illustrates various embodiments of the present invention, of parameters used to set whether to apply a connection-before-disconnection switch to the wireless bearer.

[0066] Figure 22 This is a diagram illustrating another example of the process flow of a solution E according to an embodiment of the present invention.

[0067] Figure 23 This is a diagram illustrating another example of the process flow of process B in an embodiment of the present invention.

[0068] Figure 24 This is a diagram illustrating another example of the process flow for processing LA according to an embodiment of the present invention.

[0069] Figure 25 This is a diagram illustrating an example of a processing method of UE122 according to various embodiments of the present invention.

[0070] Figure 26 This is a diagram illustrating another example of the processing method of UE122 according to various embodiments of the present invention.

[0071] Figure 27 This is a diagram illustrating another example of the processing method of UE122 according to various embodiments of the present invention.

[0072] Figure 28 This is a diagram illustrating another example of the processing method of UE122 according to various embodiments of the present invention. Detailed Implementation

[0073] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0074] LTE (and LTE-A Pro) and NR can be defined as different Radio Access Technologies (RATs). Furthermore, NR can be defined as a technology included in LTE. LTE can be defined as a technology included in NR. Furthermore, LTE capable of connecting to NR via Multi Radio Dual connectivity can be distinguished from existing LTE. Furthermore, LTE with a 5GC core network can be distinguished from existing LTE with an EPC core network. This implementation can be applied to NR, LTE, and other RATs. In the following description, terms associated with LTE and NR are used, but they can also be applied to other technologies using other terms. Furthermore, the term E-UTRA in this implementation can be replaced by the term LTE, and vice versa.

[0075] Figure 1 This is a schematic diagram of the communication system according to various embodiments of the present invention.

[0076] E-UTRA100 is a radio access technology described in Non-Patent Document 3, etc., comprising a Cell Group (CG) consisting of one or more frequency bands. eNB (E-UTRAN Node B) 102 is the base station device of E-UTRA100. EPC (Evolved Packet Core) 104 is the core network described in Non-Patent Document 14, etc., designed as a core network for E-UTRA100. Interface 112 is the interface between eNB102 and EPC104, containing a control plane (CP) through which control signals pass and a user plane (UP) through which user data passes.

[0077] NR106 is a radio access technology described in Non-Patent Document 9, etc., which includes a Cell Group (CG) consisting of one or more frequency bands. gNB (g Node B) 108 is a base station device for NR106. 5GC110 is a core network described in Non-Patent Document 2, etc., designed as a core network for NR106, but can also be used as a core network for E-UTRA100 with the function of connecting to 5GC110. The following E-UTRA100 may include E-UTRA100 with the function of connecting to 5GC110.

[0078] Interface 114 is the interface between eNB102 and 5GC110; interface 116 is the interface between gNB108 and 5GC110; interface 118 is the interface between gNB108 and EPC104; interface 120 is the interface between eNB102 and gNB108; and interface 124 is the interface between EPC104 and 5GC110. Interfaces 114, 116, 118, 120, and 124 can be interfaces that connect only to the CP, only to the UP, or both the CP and UP. Furthermore, interfaces 114, 116, 118, 120, and 124 may not exist depending on the communication system provided by the telecommunications operator.

[0079] UE122 is a terminal device corresponding to either or both of E-UTRA100 and NR106. As described in either or both of Non-Patent Document 3 and Non-Patent Document 9, when UE122 connects to the core network via either or both of E-UTRA100 and NR106, a logical path called a Radio Bearer (RB) is established between UE122 and either or both of E-UTRA100 and NR106. The radio bearer used for CP is called a Signaling Radio Bearer (SRB), and the radio bearer used for UP is called a Data Radio Bearer (DRB). Each RB is uniquely identified by being assigned an RB Identity (or RB ID). The RB identifier used for SRB is called an SRB Identity (or SRB ID), and the RB identifier used for DRB is called a DRB Identity (or DRB ID).

[0080] As described in Non-Patent Document 3, when the destination core network of UE122 is EPC104, each DRB already established between UE122 and either or all of E-UTRA100 and NR106 is further uniquely associated with each EPS (Evolved Packet System) bearer within EPC104. Each EPS bearer is uniquely identified by being assigned an EPS bearer identifier (Identity or ID). Furthermore, the same QoS is guaranteed for data transmitted through the same EPS bearer.

[0081] As described in Non-Patent Document 9, when the destination core network of UE122 is 5GC110, one or more DRBs already established between UE122 and either or all of E-UTRA100 and NR106 are further associated with one of the PDU (Packet Data Unit) sessions to be established within 5GC110. One or more QoS flows exist in each PDU session. Each DRB may or may not be associated with any QoS flow. Each PDU session is identified by a PDU session identifier (Identity or ID). Furthermore, each QoS flow is identified by a QoS flow identifier. Moreover, the same QoS is guaranteed for data passing through the same QoS flow.

[0082] In EPC104, neither or both of the PDU session and QoS flow exist, and in 5GC110, there is no EPS bearer. In other words, when UE122 is connected to EPC104, UE122 has EPS bearer information, and when UE122 is connected to 5GC110, UE122 has either or both of the PDU session and QoS flow information.

[0083] Figure 2 This is a protocol stack diagram of the UP and CP of the terminal device and base station device of the E-UTRA Radio Access Layer in various embodiments of the present invention.

[0084] Figure 2 (A) is the protocol stack diagram of the UP used when UE122 communicates with eNB102 in E-UTRA100.

[0085] PHY (Physical layer) 200 is the radio physical layer, which provides transmission services to the upper layer using a physical channel. PHY 200 connects to the upper-level MAC (Medium Access Control layer) 202 (described later) via a transport channel. Data moves between MAC 202 and PHY 200 via the transport channel. Data transmission and reception between the PHYs of UE122 and eNB102 are conducted via the radio physical channel.

[0086] MAC202 is a medium access control layer that maps multiple logical channels to multiple transmission channels. MAC202 connects to the higher-level RLC (Radio Link Control layer) 204 (described later) via logical channels. Logical channels are broadly classified according to the type of information transmitted, into control channels for transmitting control information and service channels for transmitting user information. MAC202 has functions such as controlling PHY200 for intermittent transmit / receive (DRX / DTX), performing random access procedures, notifying transmit power, and performing HARQ control (Non-Patent Document 7).

[0087] RLC204 is a radio link control layer that segments data received from the upper-level PDCP (Packet Data Convergence Protocol Layer) 206 (described later) and adjusts the data size to enable the lower layer to transmit data appropriately. RLC204 has three modes: Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). In TM mode, no segmentation of data received from the upper layer and no appending of RLC headers are performed. In UM mode, segmentation of data received from the upper layer and appending of RLC headers are performed, but no retransmission control is performed. In AM mode, segmentation of data received from the upper layer, appending of RLC headers, and retransmission control are performed. The retransmission control function can be used to ensure the requested QoS (Quality of Service) for each data transmission. During data retransmission control, information about undelivered data sent from the RLC receiver to the transmitter is called a status report. Furthermore, the instruction to send a reminder status report from the transmitting side of the RLC to the receiving side is called polling. It should be noted that sometimes data sent to the lower layer under TM is called TMD PDU, data sent to the lower layer under UM is called UMD PDU, and data sent to the lower layer under AM is called AMD PDU. (Non-Patent Document 6).

[0088] PDCP206 is a packet data convergence protocol layer used for efficient transmission of user data such as IP packets over wireless networks. PDCP206 can have header compression functionality to compress unnecessary control information. Furthermore, PDCP206 can also have data encryption functionality (Non-Patent Document 5).

[0089] It should be noted that the data processed in MAC202, RLC204, and PDCP206 are respectively referred to as MAC PDU (Protocol Data Unit), RLC PDU, and PDCP PDU. Furthermore, the data transferred from the upper layer to MAC202, RLC204, or PDCP206, or transferred to the upper layer, are respectively referred to as MAC SDU (Service Data Unit), RLC SDU, and PDCP SDU. Additionally, the segmented RLC SDU is referred to as an RLC SDU segment.

[0090] Furthermore, to distinguish between data and control uses, PDCP PDUs can also be called PDCP DATA PDUs and PDCP CONTROL PDUs, respectively. Similarly, to distinguish between data and control uses, RLC PDUs can also be called RLC DATA PDUs and RLC CONTROL PDUs, respectively.

[0091] Figure 2 (B) is the protocol stack diagram of the CP used when UE122 communicates with eNB102 and MME (Mobility Management Entity), which is a logical node that provides authentication, mobility management and other functions, in E-UTRA100.

[0092] In the CP protocol stack, besides PHY200, MAC202, RLC204, and PDCP206, there are also RRC (Radio Resource Control layer) 208 and NAS (Non-Access Strarum) 210. RRC208 is a radio link control layer that handles RRC connection establishment, re-establishment, suspending, and resuming; RRC connection reconfiguration, such as the establishment, modification, and release of radio bearers (RBs) and cell groups; control of logical channels, transport channels, and physical channels; and handover and measurement settings. RBs can be divided into Signaling Radio Bearers (SRBs) and Data Radio Bearers (DRBs). SRBs can be used as paths for sending RRC messages as control information. DRBs can be used as paths for sending user data. Each RB can be configured between eNB102 and UE122's RRC208. Furthermore, the portion of the RB consisting of RLC204 and the logical channel can be referred to as the RLC bearer (Non-Patent Document 4). Additionally, for the NAS layer that transmits signals between the MME and UE122, a portion or all of the layers from PHY200, MAC202, RLC204, PDCP206, and RRC208 that transmit signals and data between UE122 and eNB102 can be referred to as the AS (Access Strarum) layer.

[0093] The functional classification of MAC202, RLC204, PDCP206, and RRC208 described above is an example; it is not necessary to implement only some or all of these functions. Furthermore, some or all of the functions of each layer can be included in other layers.

[0094] It should be noted that the IP layer and the layers above it, such as TCP (Transmission Control Protocol), UDP (User Datagram Protocol), and the application layer, are above the PDCP layer (not shown). Furthermore, the RRC layer and NAS (non-access cascade) layer are also above the PDCP layer (not shown). In other words, the PDCP layer is below the RRC layer, NAS layer, IP layer, and the layers above it, such as TCP (Transmission Control Protocol), UDP (User Datagram Protocol), and the application layer.

[0095] Figure 3 This is a protocol stack diagram of the UP and CP of the terminal device and the base station device in the NR wireless access layer of various embodiments of the present invention.

[0096] Figure 3 (A) is the protocol stack diagram of the UP used when UE122 communicates with gNB108 in NR106.

[0097] PHY (Physical layer) 300 is the radio physical layer of NR, which can provide transmission services to the upper layer using a physical channel. PHY 300 can connect to the upper-level MAC (Medium Access Control layer) 302 (described later) via a transport channel. Data can move between MAC 302 and PHY 300 via the transport channel. Data can be sent and received between the PHY of UE122 and gNB108 via the radio physical channel.

[0098] Here, the physical channel will be explained.

[0099] The following physical channels can be used in wireless communication between terminal devices and base station devices.

[0100] PBCH (Physical Broadcast Channel)

[0101] PDCCH (Physical Downlink Control Channel)

[0102] PDSCH (Physical Downlink Shared Channel)

[0103] PUCCH (Physical Uplink Control Channel)

[0104] PUSCH (Physical Uplink Shared Channel)

[0105] PRACH (Physical Random Access Channel)

[0106] PBCH is used to broadcast system information required by the terminal device.

[0107] In addition, in NR, PBCH can be used as a time index (SSB-Index) within the period of a block of broadcast synchronization signals (also known as SS / PBCH block).

[0108] The PDCCH is used to transmit (or transport) Downlink Control Information (DCI) in downlink wireless communication (wireless communication from base station device 3 to terminal device). Here, one or more DCIs (also called DCI formats) are defined for the transmission of downlink control information. That is, fields for downlink control information are defined as DCIs and mapped to information bits. The PDCCH is transmitted in PDCCH candidates. The terminal device monitors the set of PDCCH candidates in the serving cell. Monitoring means attempting to decode the PDCCH according to a certain DCI format. A certain DCI format can be used for PUSCH scheduling in the serving cell. PUSCH can be used for transmitting user data, transmitting RRC messages, etc.

[0109] PUCCH can be used to transmit uplink control information (UCI) in uplink wireless communication (wireless communication from a terminal device to a base station device). Here, the uplink control information may include channel state information (CSI) indicating the state of the downlink channel. Furthermore, the uplink control information may include a scheduling request (SR) for requesting UL-SCH resources. Additionally, the uplink control information may include HARQ-ACK (Hybrid Automatic Repeat request ACK knowledgement).

[0110] PDSCH can be used to send downlink data from the MAC layer (DL-SCH: Downlink SharedCHannel). In addition, in the case of downlink, it is also used to send system information (SI), random access response (RAR), etc.

[0111] PUSCH can be used to transmit HARQ-ACK and / or CSI along with uplink data (UL-SCH: Uplink Shared Channel) or uplink data from the MAC layer. Alternatively, it can be used to transmit only CSI or only HARQ-ACK and CSI. That is, it can also be used to transmit only UCI. Furthermore, PDSCH or PUSCH can be used to transmit RRC signaling (also known as RRC messages) and MAC control elements. Here, in PDSCH, the RRC signaling transmitted from the base station device can be signaling shared by multiple terminal devices within the cell. Alternatively, the RRC signaling transmitted from the base station device can be signaling dedicated to a specific terminal device (also known as dedicated signaling). That is, dedicated signaling can be used to transmit terminal device-specific (UE-specific) information to a specific terminal device. Additionally, PUSCH can be used to transmit UE capabilities in the uplink.

[0112] PRACH can be used to send random access preambles. PRACH can be used to indicate the initial connection establishment process, the handover procedure, the connection re-establishment process, synchronization (timing adjustment) sent for the uplink, and requests for PUSCH (UL-SCH) resources.

[0113] MAC302 is a medium access control layer that maps multiple logical channels to multiple transport channels. MAC302 can connect to the higher-level RLC (Radio Link Control layer) 304 (described later) via logical channels. Logical channels can be broadly classified according to the type of information transmitted, into control channels transmitting control information and service channels transmitting user information. MAC302 may have functions such as controlling PHY300 for intermittent transmit / receive (DRX / DTX), executing random access procedures, notifying transmit power information, and performing HARQ control (Non-Patent Document 13).

[0114] RLC304 is a radio link control layer that segments data received from the upper-level PDCP (Packet Data Convergence Protocol Layer) 306 (described later) and adjusts the data size to enable appropriate data transmission by lower layers. RLC304 has three modes: Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). In TM mode, no segmentation of data received from the upper layer and no appending of RLC headers are performed. In UM mode, segmentation of data received from the upper layer and appending of RLC headers are performed, but retransmission control is not performed. In AM mode, segmentation of data received from the upper layer, appending of RLC headers, and retransmission control are performed. The retransmission control function can be used to ensure the requested QoS (Quality of Service) of each data transmission. During data retransmission control, information about undelivered data sent from the RLC receiver to the transmitter is called a status report. Furthermore, the instruction to send a urging status report from the transmitting side of the RLC to the receiving side is called polling. It should be noted that sometimes data sent to the lower layer under TM is called TMD PDU, data sent to the lower layer under UM is called UMD PDU, and data sent to the lower layer under AM is called AMD PDU. (Non-Patent Document 12).

[0115] PDCP306 is a packet data convergence protocol layer used for efficient transmission of user data such as IP packets over wireless networks. PDCP306 can have header compression functionality to compress unnecessary control information. Furthermore, PDCP306 can also have data encryption and data integrity protection functions (Non-Patent Document 11).

[0116] SDAP (Service Data Adaptation Protocol) 310 is a Service Data Adaptation Protocol layer with the following functions: establishing (mapping) the correspondence between the downlink QoS flow sent from 5GC110 to the terminal device via the base station device and the DRB, and mapping the uplink QoS flow sent from the terminal device to 5GC110 via the base station device and the DRB, and storing mapping rule information (Non-Patent Document 16).

[0117] It should be noted that the data processed in MAC302, RLC304, PDCP306, and SDAP310 are respectively referred to as MAC PDU (Protocol Data Unit), RLC PDU, PDCP PDU, and SDAP PDU. Furthermore, the data transferred from the upper layer to MAC302, RLC304, PDCP306, and SDAP310, or the data transferred to the upper layer, are respectively referred to as MAC SDU (Service Data Unit), RLC SDU, PDCP SDU, and SDAP SDU. Additionally, the segmented RLC SDU is referred to as an RLC SDU segment.

[0118] Furthermore, to distinguish between data and control uses, SDAP PDUs can also be referred to as SDAP DATA PDUs and SDAP CONTROL PDUs, respectively. Similarly, to distinguish between data and control uses, PDCP PDUs can also be referred to as PDCP DATA PDUs and PDCP CONTROL PDUs, respectively. Finally, to distinguish between data and control uses, RLC PDUs can also be referred to as RLC DATA PDUs and RLC CONTROL PDUs, respectively.

[0119] Figure 3 (B) is the protocol stack diagram of the CP used when UE122 communicates with gNB108 and AMF (Access and Mobility Management function), which is a logical node providing authentication, mobility management and other functions, in NR106.

[0120] In the CP protocol stack, besides PHY300, MAC302, RLC304, and PDCP306, there are also RRC (Radio Resource Control layer) 308 and NAS (non-access strawrum) 312. RRC308 is a radio link control layer that handles RRC connection establishment, re-establishment, suspending, and resuming; RRC connection reconfiguration, such as establishing, changing, and releasing radio bearers (RBs) and cell groups; control of logical channels, transport channels, and physical channels; and handover and measurement settings. RBs can be divided into signaling radio bearers (SRBs) and data radio bearers (DRBs). SRBs can be used as paths for sending RRC messages as control information. DRBs can be used as paths for sending user data. The configuration of each RB can be performed between the gNB108 and UE122's RRC308. Furthermore, the portion of the RB consisting of RLC304 and the logical channel can also be referred to as the RLC bearer (Non-Patent Document 10). Additionally, relative to the NAS layer that transmits signals between the AMF and UE122, some or all of the layers among PHY300, MAC302, RLC304, PDCP306, RRC308, and SDAP310 that transmit signals and data between UE122 and gNB108 can be referred to as the AS (Access Strarum) layer.

[0121] In addition, SRBs can be defined as SRB0 to SRB3 as follows. SRB0 can be an SRB used for RRC messages via the Common Control Channel (CCCH) using a logical channel. SRB1 can be an SRB used for RRC messages (possibly including piggybacked NAS messages) and for NAS messages before the establishment of SRB2, or it can use the Dedicated Control Channel (DCCH) entirely. SRB2 can be an SRB used for NAS messages, or it can use the DCCH entirely. Furthermore, SRB2 can have a lower priority than SRB1. SRB3 can be an SRB used for specific RRC messages when UE122 is configured with EN-DC, NGEN-DC, NR-DC, etc., or it can use the DCCH entirely. Other SRBs can also be prepared for other purposes.

[0122] The functional classification of MAC302, RLC304, PDCP306, SDAP310, and RRC308 described above is an example; it is not necessary to implement only some or all of these functions. Furthermore, some or all of the functions of each layer can also be included in other layers.

[0123] It should be noted that, as described in Non-Patent Document 2, the layer above the AS layer (not shown) can also be referred to as the PDU layer. The PDU layer can include the IP layer and any or all of the layers above the IP layer, such as the TCP (Transmission Control Protocol) layer, the UDP (User Datagram Protocol) layer, and other layers. The application layer can be above the PDU layer or included within the PDU layer. It should be noted that the PDU layer can be the AS layer above the user plane. Furthermore, the RRC layer and the NAS (non-access straw) layer can also be any or all of the layers above the SDAP layer and the PDCP layer (not shown). In other words, any or all of the SDAP layer and the PDCP layer can be the lower layer of the RRC layer, the NAS layer, the IP layer, and any or all of the layers above the IP layer, such as the TCP (Transmission Control Protocol) layer, the UDP (User Datagram Protocol) layer, and the application layer.

[0124] It should be noted that, in the various embodiments of the present invention, any or all of the following used in IMS, such as SIP (Session Initiation Protocol), SDP (Session Description Protocol), RTP (Real-time Transport Protocol), RTCP (Real-time Transport Control Protocol), HTTP (Hypertext Transfer Protocol), and various media codecs, can belong to the application layer.

[0125] It should be noted that the physical layer, MAC layer, RLC layer, PDCP layer, and SDAP layer of the terminal device can be established, configured, and controlled through the RRC layer of the terminal device, or all of them. Furthermore, the RRC layer of the terminal device can establish and / or configure the physical layer, MAC layer, RLC layer, PDCP layer, and SDAP layer based on the RRC messages sent from the RRC layer of the base station device. Additionally, the MAC layer, RLC layer, PDCP layer, and SDAP layer can also be referred to as MAC sublayer, RLC sublayer, PDCP sublayer, and SDAP sublayer, respectively.

[0126] It should be noted that the AS layer or its functions, which are configured in either or all of the terminal device and base station device, can also be referred to as entities. That is, the physical layer (PHY layer), MAC layer, RLC layer, PDCP layer, SDAP layer, and RRC layer, or their functions, that are established, configured, and controlled in either or all of the terminal device and base station device can be referred to as physical entities (PHY entities), MAC entities, RLC entities, PDCP entities, SDAP entities, and RRC entities, respectively. Furthermore, each layer may include one or more entities of that layer. Additionally, PDCP entities and RLC entities can be established, configured, and controlled on a per-radio-bearer basis, or all of them. Furthermore, MAC entities can be established, configured, and controlled on a per-cell-group basis, or all of them. Furthermore, SDAP entities can be established, configured, and controlled on a per-PDU-session basis, or all of them.

[0127] It should be noted that the COUNT value can be used in the PDCP layer or PDCP entity for encryption or integrity protection. The COUNT value can consist of the HFN (Hyper Frame Number) and the sequence number (SN) appended to the header of the PDCP PDU. The sequence number is incremented by 1 each time a PDCP DATA PDU is generated in the PDCP layer or PDCP entity on the sending side. The HFN is incremented by 1 each time the sequence number reaches its maximum value.

[0128] It should be noted that, in the various embodiments of the present invention, to distinguish between the E-UTRA protocol and the NR protocol, MAC202, RLC204, PDCP206, and RRC208 will be referred to as E-UTRA MAC or LTE MAC, E-UTRA RLC or LTE RLC, E-UTRA PDCP or LTE PDCP, and E-UTRA RRC or LTE RRC, respectively. Furthermore, MAC302, RLC304, PDCP306, and RRC308 will be referred to as NR MAC, NR RLC, NR RLC, and NR RRC, respectively. Alternatively, spaces may be used to denote terms such as E-UTRA PDCP or LTE PDCP, NR PDCP, etc.

[0129] In addition, such as Figure 1 As shown, eNB102, gNB108, EPC104, and 5GC110 can be connected via interfaces 112, 116, 118, 120, and 114. Therefore, to accommodate various communication systems, Figure 2 RRC208 can be replaced with Figure 3 RRC308. In addition, Figure 2 PDCP206 can also be replaced with Figure 3 PDCP306. In addition... Figure 3 The RRC308 may include Figure 2 The functions of RRC208. In addition. Figure 3 PDCP306 can be Figure 2 PDCP206. Furthermore, in E-UTRA100, even when UE122 is communicating with eNB102, NR PDCP can be used as the PDCP.

[0130] Next, the state transitions of UE122 in LTE and NR will be explained. When an RRC connection has been established, UE122 connected to the EPC or 5GC can be in the RRC_CONNECTED state. The state of having an RRC connection can include UE122 maintaining some or all of the UE context described later. Furthermore, the state of having an RRC connection can also include UE122 being able to send and / or receive unicast data. Additionally, UE122 can be in the RRC_INACTIVE state when the RRC connection is terminated (if UE122 is connected to the 5GC). If these conditions are not met, UE122 can be in the RRC_IDLE state.

[0131] It should be noted that UE122 connected to the EPC does not have the RRC_INACTIVE state, but it can initiate the termination of the RRC connection via E-UTRAN. In this case, when the RRC connection is terminated, UE122 retains the UE's AS context and the resumeIdentity for recovery and transitions to the RRC_IDLE state. When UE122 retains the UE's AS context, allows the recovery of the RRC connection via E-UTRAN, and UE122 needs to transition from the RRC_IDLE state to the RRC_CONNECTED state, the recovery of the terminated RRC connection can be initiated via a higher layer (e.g., the NAS layer).

[0132] That is, the definition of abort can be different for UE122 connected to EPC and UE122 connected to 5GC. In addition, the recovery process from abort can be wholly or partially different for UE122 connected to EPC (aborted in RRC_IDLE state) and connected to 5GC (aborted in RRC_INACTIVE state).

[0133] It should be noted that the RRC_CONNECTED, RRC_INACTIVE, and RRC_IDLE states can be referred to as connected mode, inactive mode, and idle mode, respectively. They can also be referred to as RRC connected mode, RRC inactive mode, and RRC idle mode.

[0134] The AS context of the UE maintained by UE122 may include all or a portion of the following information: the current RRC settings, the current security context, the PDCP state including the ROHC (Robust Header Compression) state, the C-RNTI (Cell Radio Network Temporary Identifier) ​​used in the PCell of the connection source, the cell identifier, and the physical cell identifier of the PCell of the connection source. It should be noted that the AS context of the UE maintained by either or both of eNB102 and gNB108 may include the same information as the AS context of the UE maintained by UE122, or it may include information different from the information included in the AS context of the UE maintained by UE122.

[0135] Security context can refer to all or part of the information in the following: encryption key at the AS level, NH (Next Hop parameter), NCC (Next Hop Chaining Counter parameter) derived from the access key used for the next hop, identifier of the selected AS-level encryption algorithm, and counters used for playback protection.

[0136] Next, handover in LTE and NR will be explained. Handover can refer to the process of UE122 changing its serving cell in the RRC connection state. Handover can occur when UE122 receives an RRC message indicating handover from eNB102 and / or gNB108. The RRC message indicating handover can be a message related to the reconfiguration of the RRC connection, including parameters indicating handover (e.g., an information element named MobilityControlInfo as described in Non-Patent Document 4 or an information element named ReconfigurationWithSync as described in Non-Patent Document 10), or it can be a message indicating movement to a cell of another RAT (e.g., MobilityFromEUTRACommand as described in Non-Patent Document 4 or MobilityFromNRCommand as described in Non-Patent Document 10). Furthermore, the conditions under which UE122 can perform handover may include some or all of the following: AS security is activated, SRB2 has been established, or at least one DRB has been established.

[0137] Figure 4This is a diagram illustrating an example of the flow of procedures for various settings in RRC208 and / or (and / or) RRC308 of various embodiments of the present invention. Figure 4 This is an example of a procedure in which an RRC message is sent from a base station device (eNB102 and / or gNB108) to a terminal device (UE122).

[0138] exist Figure 4 In step S400, the base station device generates an RRC message. The generation of the RRC message in the base station device can occur when the base station device distributes broadcast information (SI: System Information) or paging information, or when it is determined that the base station device needs to process a specific terminal device, such as security-related settings, resetting of the RRC connection (processing of wireless bearers (establishment, modification, release, etc.), processing of cell groups (establishment, addition, modification, release, etc.), determination settings, handover settings, etc.), and release of the RRC connection status. Furthermore, the RRC message can be used as a handover command to different RATs. The RRC message includes information (parameters) for various information notifications and settings. In specifications related to RRC, such as Non-Patent Document 4 or Non-Patent Document 10, these parameters may also be referred to as fields and / or information elements, and are described using the ASN.1 (Abstract Syntax Notation One) notation.

[0139] exist Figure 4 Next, the base station device sends the generated RRC message to the terminal device (step S402). Then, the terminal device processes the received RRC message if necessary (step S404).

[0140] It should be noted that the generation of RRC messages is not limited to the examples above. As described in Non-Patent Document 4, Non-Patent Document 10, etc., they can also be generated for other purposes.

[0141] For example, RRC messages can be used for settings related to dual connectivity (DC) and multi-radio dual connectivity (MR-DC) as described in Non-Patent Document 8.

[0142] Dual Connectivity (DC) can refer to the following technology: data communication is performed using the radio resources of two cell groups (nodes) composed of two base station devices: a Master Cell Group (MCG) composed of a Master Node (MN) and a Secondary Cell Group (SCG) composed of Secondary Nodes (SN). Furthermore, the Master Node and the Secondary Node can be the same node (the same base station device). Additionally, MR-DC as described in Non-Patent Document 8 can refer to the following technology: cell grouping of cells in both E-UTRA and NR RATs (Radio Access Technology) according to each RAT and allocating them to the UE, using the radio resources of both the MCG and SCG for data communication. In MR-DC, the Master Node can refer to a base station with the main RRC functions of MR-DC, such as the addition, establishment, modification, and release of Secondary Nodes (RBs), and the addition, modification, release, and handover of MCGs. The Secondary Node can refer to a base station with some RRC functions, such as the modification and release of SCGs.

[0143] In the MR-DC described in Non-Patent Document 8, the RRC of the RAT on the master node side can be used to configure both the MCG and SCG. For example, in the EN-DC (E-UTRA-NR Dual Connectivity) of the MR-DC where the core network is EPC104 and the master node is eNB102 (also known as extended eNB102), and in the NGEN-DC (NG-RAN E-UTRA-NR Dual Connectivity) of the MR-DC where the core network is 5GC110 and the master node is eNB102, the E-UTRA RRC message described in Non-Patent Document 4 can be sent and received between eNB102 and UE122. In this case, the RRC message can include not only LTE (E-UTRA) configuration information, but also NR configuration information described in Non-Patent Document 10. Furthermore, the RRC message sent from eNB102 to UE122 can also be sent from eNB102 to UE122 via gNB108. In addition, the configuration of this RRC message can also be used for non-MR-DC, that is, eNB102 (extended eNB) using 5GC as the core network for E-UTRA / 5GC (option 5 described in non-patent document 17).

[0144] Furthermore, conversely, in the MR-DC described in Non-Patent Document 8, in the NE-DC (NR-E-UTRA Dual Connectivity) of the MR-DC where the core network is 5GC110 and the master node is gNB108, RRC messages for NR as described in Non-Patent Document 10 can be sent and received between gNB108 and UE122. In this case, the RRC message can include not only NR configuration information but also LTE (E-UTRA) configuration information as described in Non-Patent Document 4. Furthermore, the RRC message sent from gNB108 to UE122 can also be sent from gNB108 to UE122 via eNB102.

[0145] It should be noted that, not limited to the use of MR-DC, the E-UTRA RRC message sent from eNB102 to UE122 may include the NR RRC message, and the NR RRC message sent from gNB108 to UE122 may include the E-UTRA RRC message.

[0146] Furthermore, a network configuration with eNB102 as the master node and EPC104 as the core network can also be called E-UTRA / EPC. Similarly, a network configuration with eNB102 as the master node and 5GC110 as the core network can be called E-UTRA / 5GC. Additionally, a network configuration with gNB108 as the master node and 5GC110 as the core network can be called NR or NR / 5GC. Moreover, this designation is not limited to the case where a DC is configured. In the absence of a DC, the aforementioned master node can refer to a base station device that communicates with the terminal device.

[0147] Figure 14 It means in Figure 4 An example of any or all of the fields and information elements related to radio bearer settings included in a message relating to the reconfiguration of an RRC connection in NR. Furthermore, Figure 15 It means in Figure 4 An example of any or all of the fields and information elements related to radio bearer settings included in a message relating to the reconfiguration of an RRC connection in E-UTRA, as described in ASN.1. Not limited to... Figure 14 , Figure 15In the examples of ASN.1 in the embodiments of the present invention, "<omitted>" and "<omitted in the middle>" indicate the omission of other information, rather than the omission of a part of the ASN.1 description. It should be noted that information elements may also be omitted where there is no "<omitted>" or "<omitted in the middle>". It should be noted that in the embodiments of the present invention, the examples of ASN.1 do not correctly follow the ASN.1 description method, but rather describe an example of parameters of a message related to the resetting of an RRC connection in the embodiments of the present invention; other names and descriptions may also be used. Furthermore, to avoid complicating the explanation, the examples of ASN.1 only represent examples of key information closely related to the present invention. It should be noted that sometimes parameters described by ASN.1 are not distinguished as fields, information elements, etc., but are all referred to as information elements. Furthermore, in the embodiments of the present invention, parameters such as fields and information elements included in the RRC message and described by ASN.1 are sometimes referred to as information. It should be noted that messages related to the resetting of an RRC connection can refer to RRC reset messages in NR or RRC connection reset messages in E-UTRA.

[0148] exist Figure 14 In this context, the information element represented by RadioBearerConfig is related to the settings of radio bearers such as SRB and DRB, including the PDCP setting information element and SDAP setting information element described later. The information element represented by SRB-ToAddMod within the information element represented by RadioBearerConfig can represent SRB (Signaling Radio Bearer) settings, and is sometimes also referred to as SRB setting information element or signaling radio bearer setting information element. Furthermore, the information element represented by SRB-ToAddModList can be a list of information representing SRB settings. Similarly, the information element represented by DRB-ToAddMod within the information element represented by RadioBearerConfig can represent DRB (Data Radio Bearer) settings, and is sometimes also referred to as DRB setting information element or data radio bearer setting information element. The information element represented by DRB-ToAddModList can be a list of information representing DRB settings. It should be noted that sometimes either or both of SRB settings and DRB settings are referred to as radio bearer settings.

[0149] The SRB-Identity information element in the SRB configuration information element contains the SRB identifier (SRB Identity) of the SRB to be added or changed, or it can be an identifier that uniquely identifies the SRB in each terminal device. It is sometimes also referred to as the SRB identifier information element, radio bearer identifier information element, or signaling radio bearer identifier information element.

[0150] The information element represented by DRB-Identity in the DRB configuration information element is the DRB identifier (DRB Identity) of the DRB to be added or changed, or it can be an identifier that uniquely identifies the DRB in each terminal device. Sometimes it is also referred to as the DRB identifier information element, radio bearer identifier information element, or data radio bearer identifier information element. The value of the DRB identifier is... Figure 14 In the example, it is set to an integer value from 1 to 32, but other values ​​are also possible. In the case of DC, the DRB identifier is unique within the range of UE122.

[0151] The information element represented by cnAssociation in the DRB configuration information element can be an information element indicating whether EPCI04 or 5GC110 is used in the core network, and is sometimes referred to as the core network association establishment information element. That is, when UE122 is connected to EPC, the DRB is associated with the EPS bearer identifier information element (eps-BearerIdentity) in cnAssociation or the EPS bearer identifier (EPS beareridentity) as the value of the EPS bearer identifier information element. When UE122 is connected to 5GC110, the DRB is associated with the SDAP entity set according to the SDAP configuration information element (sdap-Config) described later, or the PDU session information element included in the SDAP configuration information element described later, or the PDU session identifier as the value of the PDU session information element, or the PDU session shown by the PDU session information element. That is, the information represented by cnAssociation may include the EPS bearer identifier information element (eps-BearerIdentity) in the case of using EPC104 in the core network when using EN-DC, and the information element representing SDAP configuration (sdap-Config) in the case of using core network 5GC110, i.e., when not using EN-DC.

[0152] In the case of a core network of 5GC110, the information element represented by sdap-Config can be information related to the setting or resetting of SDAP entities that determines the mapping method between QoS flows and DRBs (map). Sometimes it is also referred to as SDAP setting information element.

[0153] The field or information element represented by pdu-session or PDU-SessionID included in the SDAP configuration information element can be the PDU session identifier of the QoS flow to which the radio bearer establishes a mapping (map) corresponding to the value of the radio bearer identifier information element belongs, as described in Non-Patent Document 2. It is sometimes also referred to as the PDU session identifier information element. The value of the PDU session identifier information element can be a non-negative integer. Furthermore, in each terminal device, one PDU session identifier can correspond to multiple DRB identifiers.

[0154] The information element represented by `mappedQoS-FlowsToAdd` included in the SDAP configuration information element can be information from a list of QoS flow representations (QFI: QoS Flow Identity) information elements (sometimes referred to as appended QoS flow information elements) included in the DRB configuration information element of this SDAP configuration information element, which correspond to the radio bearer identifier information element's value and are either mapped or appended to it. The aforementioned QoS flow can be the QoS flow of the PDU session shown in the PDU session information element included in this SDAP configuration information element.

[0155] Furthermore, the information element represented by `mappedQoS-FlowsToRelease` included in the SDAP configuration information element can be information from a list of QoS flow representations (QFI: QoS Flow Identity) information elements (sometimes referred to as released QoS flow information elements) included in the DRB configuration information element of this SDAP configuration information element, which corresponds to the value of the radio bearer identifier information element and is associated with the radio bearer. The aforementioned QoS flow can be the QoS flow of the PDU session shown in the PDU session information element included in this SDAP configuration information element.

[0156] The information element represented by QFI can be a QoS flow identifier, which uniquely identifies a QoS flow as described in Non-Patent Document 2, and is sometimes referred to as a QoS flow identifier information element. The value of the QoS flow identifier information element can be a non-negative integer. Furthermore, the value of the QoS flow identifier information element can be unique for a PDU session.

[0157] In addition, the SDAP configuration information elements may include, besides, an uplink header information element indicating whether uplink data transmitted via the configured DRB contains an uplink SDAP header, a downlink header information element indicating whether downlink data received via the configured DRB contains a downlink SDAP header, and a default bearer information element indicating whether the configured DRB is the default radio bearer (default DRB).

[0158] Furthermore, the information elements represented by pdcp-Config or PDCP-Config in the SRB configuration information elements and DRB configuration information elements can be information elements related to the configuration of the NRPDCP entity used for establishing and changing PDCP306 for SRB and / or DRB, and are sometimes also referred to as PDCP configuration information elements. Information elements related to the configuration of the NR PDCP entity may include information elements indicating the size of the uplink sequence number, information elements indicating the size of the downlink sequence number, information elements indicating the header compression (RoHC) profile, re-ordering timer information elements, etc.

[0159] The information element represented by RadioBearerConfig, which includes the information element represented by DRB-ToReleaseList, can include information indicating one or more DRB identifiers to be released.

[0160] exist Figure 15In this context, the information element represented by RadioResourceConfigDedicated can be used for setting, modifying, and releasing radio bearers. The information element represented by SRB-ToAddMod within the information element represented by RadioResourceConfigDedicated can represent SRB (Signaling Radio Bearer) settings; sometimes it is also referred to as an SRB setting information element or a signaling radio bearer setting information element. The information element represented by SRB-ToAddModList can be a list of SRB setting information. The information element represented by DRB-ToAddMod within the information element represented by RadioResourceConfigDedicated can represent DRB (Data Radio Bearer) settings; sometimes it is also referred to as a DRB setting information element or a data radio bearer setting information element. The information element represented by DRB-ToAddModList can be a list of DRB setting information. It should be noted that sometimes either or both of SRB settings and DRB settings are referred to as radio bearer settings.

[0161] The SRB-Identity information element in the SRB configuration information element contains the SRB identifier (SRB Identity) of the SRB to be added or changed, or it can be an identifier that uniquely identifies the SRB in each terminal device. It is sometimes also referred to as the SRB identifier information element, radio bearer identifier information element, or signaling radio bearer identifier information element. Figure 15 The information element represented by SRB-Identity can be one that has the same characteristics as... Figure 14 Information elements that have the same function as information elements represented by SRB-Identity.

[0162] The information element represented by DRB-Identity in DRB configuration is the DRB identifier (DRB Identity) of the DRB to be added or changed, or it can be an identifier that uniquely identifies the DRB in each terminal device. Sometimes it is also referred to as the DRB identifier information element, radio bearer identifier information element, or data radio bearer identifier information element. The value of the DRB identifier is... Figure 15 The example uses an integer value between 1 and 32, but other values ​​are also possible. Figure 15 The information element represented by DRB-Identity can be one that has the same characteristics as... Figure 14 The information element represented by DRB-Identity has the same function as the information element.

[0163] The information element represented by eps-BearerIdentity in the DRB configuration information element can be an EPS bearer identifier that uniquely identifies the EPS bearer in each terminal device. The information element represented by eps-BearerIdentity is sometimes also called the EPS bearer identifier information element. The value of the EPS bearer identifier is... Figure 15 In the example, it is set to an integer value between 1 and 15, but other values ​​can also be used. Figure 15 The information element represented by eps-BearerIdentity can be one that has the same characteristics as... Figure 14 The information element represented by eps-BearerIdentity has the same function as the information element. Furthermore, the EPS bearer identifier and the DRB identifier can be mapped one-to-one in each terminal device.

[0164] Furthermore, the information elements represented by pdcp-Config or PDCP-Config in the SRB configuration information elements and DRB configuration information elements can be information elements related to the establishment and modification of PDCP206 for SRB and / or DRB, and are sometimes referred to as PDCP configuration information elements. Information elements related to the configuration of the E-UTRA PDCP entity may include information elements indicating the serial number size, information elements indicating the header compression (RoHC) profile, re-ordering timer information elements, etc.

[0165] also, Figure 14 or Figure 15 Some or all of the information elements shown may be optional. That is, Figure 14 or Figure 15 The information elements shown can be included in messages related to resetting the RRC connection as needed and under certain conditions. Furthermore, in addition to information elements related to radio bearer settings, messages related to resetting the RRC connection may also include information elements indicating the application of a full configuration. Information elements indicating the application of a full configuration can be represented by information element names such as `fullConfig`, or by using terms such as `true` or `enable` to indicate the application of a full configuration.

[0166] The information element represented by RadioResourceConfigDedicated, which includes the information element represented by DRB-ToReleaseList, can include information indicating one or more DRB identifiers to be released.

[0167] In the following description, eNB102 and / or gNB108 will be referred to as base station devices only, and UE122 will be referred to as terminal devices only.

[0168] During the establishment, re-establishment, or handover of an RRC connection, a serving cell provides NAS mobility information. During the re-establishment or handover of an RRC connection, a serving cell provides security input. This serving cell is referenced as the primary cell (PCell). Furthermore, depending on the capabilities of the terminal device, one or more serving cells (secondary cells, SCells) can be added and configured along with the primary cell.

[0169] Furthermore, a set of serving cells consisting of two subsets can be configured for the terminal device. These two subsets can consist of: a cell group (primary cell group) comprising one or more serving cells including a primary cell (PCell) and one or more cell groups (secondary cell group) comprising one or more serving cells including a primary secondary cell (PSCell) but not a primary cell. The primary and secondary cells can be cells configured with PUCCH resources.

[0170] An example of actions related to Radio Link Failure (RLF) of a terminal device with an RRC-based connection is illustrated.

[0171] The terminal device obtains the following information from the base station devices within the service area via broadcast information and RRC messages to each user: the values ​​of timers (e.g., T310, T313) used to detect physical layer problems of the serving cell (t310, t313); threshold values ​​N310, N313 for the number of out-of-sync (OoS) detections; and threshold values ​​N311, N314 for the number of in-sync (IS) detections. Furthermore, the values ​​of the timers and the threshold values ​​can be set to default values. Additionally, the names of the timers can differ between EUTRA and NR.

[0172] To perform radio link monitoring, the physical layer processing unit of the terminal device, for example, when estimating the radio link quality of the serving cell based on information such as the received power of the received reference signal and / or the received power of the synchronization signal and / or the packet error rate, and finds that the quality is worse than a specific threshold (Qout) for a certain period of time (e.g., TEvaluate_Qout = 200ms), notifies the upper-layer RRC layer processing unit of "out-of-sync". Furthermore, the physical layer processing unit, for example, when estimating the radio link quality of the serving cell based on information such as the received power of the received reference signal and / or the received power of the synchronization signal and / or the packet error rate, and finds that the quality exceeds a specific threshold (Qin) for a certain period of time (e.g., TEvaluate_Qin = 100ms), notifies the upper-layer RRC layer processing unit of "in-sync". It should be noted that the physical layer processing unit can notify the upper layer of "out-of-sync" or "in-sync" at intervals of more than a specific interval (e.g., TReport_sync = 10ms).

[0173] Here, for example, the threshold Qout can be defined as follows: the downlink radio link cannot be reliably received, and the block error rate of the hypothetical downlink control channel (PDCCH) transmission based on predetermined parameters is a first specific proportion. Furthermore, for example, the threshold Qin can also be defined as follows: the downlink radio link quality can be received significantly and more reliably than in the Qout state, and the block error rate of the hypothetical downlink control channel transmission based on predetermined parameters is a second specific proportion. Furthermore, multiple block error rates (levels of threshold Qout and threshold Qin) can be defined based on the frequency used, subcarrier spacing, service category, etc. Furthermore, the first specific proportion and / or the second specific proportion can be predetermined values ​​specified in the specifications. Furthermore, the first specific proportion and / or the second specific proportion can also be values ​​notified or broadcast to the terminal device by the base station device.

[0174] The terminal device can use a certain type of reference signal (e.g., cell-specific reference signal (CRS)) in the serving cell (e.g., PCell and / or PSCell) for radio link monitoring. Furthermore, the terminal device can receive a setting (RadioLinkMonitoringConfig) from the base station indicating which reference signal to use for radio link monitoring in the serving cell (e.g., PCell and / or PSCell), and use one or more of the set reference signals (here referred to as RLM-RS) for radio link monitoring. Alternatively, the terminal device can also use other signals for radio link monitoring. The physical layer processing unit of the terminal device can notify the upper layer of synchronization if the conditions for synchronization are met in the serving cell (e.g., PCell and / or PSCell).

[0175] The wireless link monitoring settings may include information indicating the purpose of monitoring and identifier information indicating a reference signal. For example, the purpose of monitoring may include monitoring for wireless link failures, monitoring for beam failures, or both. Furthermore, for example, the identifier information indicating the reference signal may include information indicating the identifier (SSB-Index) of the cell's Synchronization Signal Block (SSB). That is, the reference signal may include a synchronization signal. Additionally, for example, the identifier information indicating the reference signal may include information indicating an identifier associated with the Channel State Information Reference Signal (CSI-RS) set on the terminal device.

[0176] In the main cell, the RRC layer processing unit of the terminal device can start or restart the timer (T310) if it receives synchronization notifications from the physical layer processing unit a predetermined number of times (N310 times). Furthermore, the RRC layer processing unit of the terminal device can stop the timer (T310) if it receives synchronization notifications a predetermined number of times (N311 times). The RRC layer processing unit of the terminal device can perform a transition to an idle state or a re-establishment process of the RRC connection when the timer (T310) expires. For example, the terminal device's action can vary depending on the establishment status of AS security. If AS security is not established, the terminal device can transition to the RRC IDLE state; if AS security is established, the terminal device can perform a re-establishment process of the RRC connection. Furthermore, in determining whether to start or restart the timer T310, the condition can be that timers T300, T301, T304, and T311 are not running.

[0177] exist Figure 9 The diagram illustrates an example of the start, stop, and expiration conditions for the various timers described in EUTRA. It should be noted that timer names and / or message names may differ in NR, but the same conditions can still be applied.

[0178] Furthermore, in both primary and secondary cells, the RRC layer processing unit of the terminal device can start or restart the timer (T313) if it receives synchronization notifications from the physical layer processing unit a predetermined number of times (N313 times). Additionally, the RRC layer processing unit of the terminal device can stop the timer (T313) if it receives synchronization notifications a predetermined number of times (N314 times). The RRC layer processing unit of the terminal device can execute the SCG failure information procedure to notify the network of SCG failures when the timer (T313) expires.

[0179] Furthermore, in each SpCell (PCell in MCG and PSCell in SCG), the RRC layer processing unit of the terminal device can start or restart the timer (T310) of that SpCell if it receives synchronization notifications from the physical layer processing unit a predetermined number of times (N310 times) consecutively. Additionally, the RRC layer processing unit of the terminal device can stop the timer (T310) of that SpCell if it receives synchronization notifications a predetermined number of times (N311 times) consecutively. When the timer (T310) of each SpCell expires, if the SpCell is a PCell, the RRC layer processing unit of the terminal device can perform a transition to an idle state or a re-establishment of the RRC connection. Furthermore, if the SpCell is a PSCell, an SCG failure information procedure can be executed to notify the network of SCG failures.

[0180] The above description is an example of the case where Intermittent Receiver Optimization (DRX) is not configured for the terminal device. When DRX is configured for the terminal device, the RRC layer processing unit of the terminal device can set the period for measuring radio link quality and the notification interval to the upper layer for the physical layer processing unit to values ​​different from those when DRX is not configured. It should be noted that even when DRX is configured, while the aforementioned timers (T310, T313) are running, the period for measuring radio link quality used to estimate synchronization and the notification interval to the upper layer can be set to the values ​​when DRX is not configured.

[0181] Furthermore, for example, in order to detect early physical layer problems, the RRC layer processing unit of the terminal device can start a timer (T314) if it receives notifications of early synchronization from the physical layer processing unit a predetermined number of times (N310 times). Furthermore, the RRC layer processing unit of the terminal device can stop the timer (T314) if it receives synchronization notifications a predetermined number of times (N311 times) while T314 is running.

[0182] Furthermore, for example, in order to detect early physical layer improvements, the RRC layer processing unit of the terminal device can start a timer (T315) if it receives early synchronization notifications from the physical layer processing unit a predetermined number of times (N311 times) consecutively. Furthermore, the RRC layer processing unit of the terminal device can stop the timer (T315) if it receives synchronization notifications a predetermined number of times (N311 times) consecutively while T315 is running.

[0183] Furthermore, for example, when reporting a measurement to the base station device, if the measurement settings include performing a first measurement (e.g., a measurement using timer T312), and if timer T310 is running while timer T312 is not running, then timer T312 is started. The RRC layer processing unit of the terminal device can stop the timer (T312) if synchronization is received continuously for a predetermined number of times (N311 times).

[0184] Furthermore, the RLM-RS can be undefined if it is not explicitly or implicitly configured by the network. That is, if the RLM-RS is not configured by the network (e.g., a base station device), the terminal device may not need to perform radio link monitoring.

[0185] Furthermore, RLM-RS is a reference signal used in wireless link monitoring, and multiple RLM-RS can be configured for a terminal device. An RLM-RS resource can be an SS block or a CSI-RS resource (or port).

[0186] In addition, wireless link monitoring using CRS can be performed in EUTRA cells, and wireless link monitoring using RLM-RS can be performed in NR cells, but it is not limited to these.

[0187] This paper describes the detection of wireless link faults based on wireless link monitoring.

[0188] When the terminal device receives a notification of a random access problem from the MAC layer of the MCG when timer T310 expires, timer T312 expires, or when multiple specific timers have not run, or when it receives a notification from the RLC layer of the MCG that the retransmission count of the SRB or DRB has reached the maximum number of retransmissions, the terminal device determines that it has detected a wireless link failure in the MCG. The specific timers do not include timers T310 and T312.

[0189] Alternatively, within the MAC entity, if the random access preamble has been retransmitted a predetermined number of times, and if the random access preamble is transmitted in the SpCell, the MAC entity of the cell group including the SpCell will notify the upper layer (in this case, the RRC entity) of the random access issue.

[0190] When the terminal device determines that a wireless link failure is detected in the MCG, it stores various information as wireless link failure information. Then, if the AS security is not activated, it sets the release reason to "other" and begins the process of leaving RRC_CONNECTED. If the AS security is activated, the RRC connection re-establishment process begins.

[0191] When the terminal device detects a radio link failure in the SCG when timer T313 expires, when it is notified of a random access problem from the MAC layer of the SCG, or when it is notified from the RLC layer of the SCG that the retransmission has reached the maximum number of retransmissions, it will determine that the terminal device has detected a radio link failure in the SCG and start processing to report the information associated with the SCG radio link failure to the base station device.

[0192] When timer T314 expires, the terminal device determines that it has detected an "early synchronization out" event and begins processing to report the associated information to the base station device.

[0193] When the terminal device expires timer T315, it determines that the terminal device has detected an "early synchronization" event and begins processing to report the associated information to the base station device.

[0194] The process of re-establishing an RRC connection is explained.

[0195] The purpose of the RRC connection re-establishment process is to re-establish the RRC connection, which may be accompanied by an SRB1 recovery process, secure reactivation, and PCell-only settings.

[0196] The re-establishment process of the RRC connection can be started when any of the following conditions (A) to (E) are met.

[0197] (A) When a wireless link failure of the MCG is detected

[0198] (B) When the handover fails (when the synchronization reset in the MCG in NR fails)

[0199] (C) When moving to another RAT fails

[0200] (D) When notified from the lower level of a failure of the integrity check related to SRB1 or SRB2.

[0201] (E)RRC connection reset failure

[0202] When the re-establishment process of the RRC connection begins, the terminal device performs some or all of the following processes (A) to (J).

[0203] (A) If timer T310 is running, stop timer T310.

[0204] (B) If timer T312 is running, stop timer T312.

[0205] (C) If timer T313 is running, stop timer T313.

[0206] (C) If timer T314 is running, stop timer T314.

[0207] (D) Start timer T311

[0208] (E) Suspend all RBs except SRB0

[0209] (F) Reset MAC

[0210] (G) If configured, release the MCG's SCell.

[0211] (H) Apply the default physical channel settings

[0212] (I) Apply the default MAC master settings to MCG

[0213] (J) Performing the cell selection process

[0214] When the optimal cell of the same RAT is selected through the cell selection process, the terminal device performs the following processing.

[0215] If the terminal device is connected to 5GC and the selected cell can only be connected in EPC, or if the terminal device is connected to EPC and the selected cell can only be connected in 5GC, then the release reason is set to "RRC connection failed", and the action of leaving RRC_CONNECTED is executed. Otherwise, timer T311 is stopped, timer T301 is started, and the sending of the RRC connection re-establishment request message begins.

[0216] When timer T311 expires, the terminal device sets the release reason to "RRC connection failed" and executes the action to leave RRC_CONNECTED.

[0217] If timer T301 expires or the selected cell is no longer the optimal cell from the cell selection reference point, the terminal device will set the release reason to "RRC connection failure" and execute the action of leaving RRC_CONNECTED.

[0218] The switching process is explained.

[0219] use Figure 7 This section illustrates an example of the processing involved in switching between the same RATs (i.e., between EUTRAs) within EUTRA. Using... Figure 7 The description is for illustrative purposes only; some processing steps may be omitted, while others may be included. Alternatively, other processing steps may be performed as part of the switching process.

[0220] exist Figure 7 In the process, the base station device (Source eNB) of the handover source determines the neighboring cells configured by the terminal device (step S701).

[0221] The terminal device performs the measurement set by the source eNB and reports the measurement results to the source eNB based on the reporting conditions (step S702).

[0222] The source eNB determines the switching of terminal devices based on information such as reported measurement results (step S703).

[0223] The source eNB issues a handover request message (step S704) containing information required to prepare for handover to the base station device (Target eNB) that serves as the handover destination.

[0224] Admission control can be implemented in the target eNB. The target eNB sets the required resources. (Step S705).

[0225] The target eNB sends a Handover Request Acknowledgment message (HANDOVER REQUEST ACKNOWLEDGE message) to the source eNB (step S706). The Handover Request Acknowledgment message includes a container that is transparently sent to the terminal device as an RRC message for handover execution. The container may include a new C-RNTI, the target eNB's security algorithm identifier for the selected security algorithm, a preamble for a dedicated random access channel (Random Access Preamble), and some or all of the target cell's system information.

[0226] The source eNB sends the first RRC connection reconfiguration message (RRCConnectionReconfiguration message) received from the target eNB (including the information element (IE) of mobility control information) to the terminal device (step S707).

[0227] It should be noted that when the terminal device has configured Make-Before-Break HO (MBB-HO) via the first RRC connection reset message, after receiving the first RRC connection reset message, it will maintain the connection with the source eNB at least in the target eNB until the initial uplink transmission is performed. It should also be noted that the aforementioned Make-Before-Break HO can be selected from multiple settings. For example, it can be determined that Make-Before-Break HO is configured by setting the makeBeforeBreak-r14 field included in the already standardized mobilityControlInfo information element to True. Furthermore, for example, it can be determined that Make-Before-Break HO is configured by setting the newly defined makeBeforeBreak-r16 field included in the mobilityControlInfo information element to True. Moreover, the makeBeforeBreak-r16 field can use information elements including various settings as values.

[0228] The source eNB sends an SN STATUS TRANSFER message to the target eNB to convey the reception status of the uplink PDCP sequence number and the transmission status of the downlink PDCP sequence number (step S708).

[0229] If a RACH-less handover is not configured via the first RRC connection reset message, the terminal device performs synchronization with the target eNB and accesses the target cell using a random access channel. In this case, if a dedicated random access preamble is indicated via the first RRC connection reset message, a contention-free random access procedure is performed; otherwise, a contention-based random access procedure is performed. If a RACH-less handover is configured via the first RRC connection reset message, the terminal device performs synchronization with the target eNB (step S709).

[0230] If the RACH-less handover is not configured via the first RRC connection reset message, the target eNB will return the uplink allocation and timing advance information to the terminal device (step S710).

[0231] If a RACH-less handover is configured via the first RRC connection reset message, and a periodic pre-allocated uplink grant cannot be obtained via the first RRC connection reset message, the terminal device receives the uplink grant via the target cell's PDCCH. The terminal device uses the initial available uplink grant after synchronization with the target cell (step S710a).

[0232] When a terminal device successfully accesses the target cell without RACH-less handover, it sends an RRC Connection Reconfiguration Complete message to the target eNB to confirm the handover. This message indicates the completion of the handover process. The RRC Connection Reconfiguration Complete message includes a C-RNTI, which the target eNB verifies as the accepted C-RNTI.

[0233] When RACH-less handover is configured and the terminal device receives an uplink grant, the terminal device sends an RRC Connection Reconfiguration Complete message to the target eNB to confirm the handover. The RRC Connection Reconfiguration Complete message includes a C-RNTI, which the target eNB verifies against the accepted C-RNTI. The handover process is completed when the terminal device receives the UE contention resolution identity MAC control element from the target eNB (step S711).

[0234] The target eNB sends a path switch request to the MME to notify the terminal device that the cell has been changed (step S712).

[0235] The MME sends a Modify Bearer Request message to the Serving Gateway (S-GW) (step S713).

[0236] The S-GW switches the downlink data path to the target side. The S-GW sends one or more end-of-line marker packets to the source eNB, releasing the user plane resources to the source eNB (step S714).

[0237] The S-GW sends a Modify Bearer Response message to the MME (step S715).

[0238] The MME acknowledges the path switch request via a PATH SWITCH REQUEST ACKNOWLEDGE message (step S716).

[0239] The target eNB indicates the success of the handover by sending a UE CONTEXT RELEASE message to the source eNB, triggering the release of resources by the source eNB. The target eNB may send this message after accepting the path handover request acknowledgment message (step S717).

[0240] The source eNB can release radio and C-plane resources associated with the UE context upon receiving a UE context release message. In-process data transmission can then continue (step S718).

[0241] When timer T304 expires, the terminal device performs some or all of the following processes (A) to (D).

[0242] (A) The configuration of the dedicated random access channel reset via the first RRC connection is considered unusable.

[0243] (B) Return the terminal device settings to the dedicated physical channel settings and the MAC layer master settings, as well as the settings used in the PCell of the switching source, except for the semi-persistent (semi-static) scheduling settings.

[0244] (C) Store associated information as handover failure information

[0245] (D) Begin the RRC connection re-establishment process and end the RRC connection reset process.

[0246] The details of the processing of a terminal device that receives a first RRC connection reset message are described below. The first RRC connection reset message may include a mobility control information element (mobilityControlInfo). The mobilityControlInfo information element includes parameters (e.g., the identifier of the target cell, carrier frequency information) related to mobility controlled by the network from other RATs to or within the EUTRA.

[0247] If an RRC connection reset message (first RRC connection reset message) including the mobilityControlInfo information element is received, and the terminal device can satisfy the settings of the message, then the terminal device performs some or all of the following processes (A) to (G).

[0248] (A) If timer T310 is running, stop timer T310.

[0249] (B) If timer T312 is running, stop timer T312.

[0250] (C) If timer T314 is running, stop timer T314.

[0251] (D) Start timer T304 with the value (t304) included in the mobilityControlInfo information element.

[0252] (E) If carrier frequency information is included, then that frequency is determined to be the target cell's frequency; otherwise, the source PCell's frequency is determined to be the target cell's frequency.

[0253] (F) If an access restriction timer is running, stop the timer.

[0254] (G) Start downlink synchronization in the target cell

[0255] use Figure 8 This section illustrates an example of the processing involved in handover within an NR between the same RAT (i.e., between NRs). Using... Figure 8 The description is for illustrative purposes only; some processing steps may be omitted, while others may be included. Alternatively, other processing steps may be performed as part of the switching process.

[0256] exist Figure 8 In the process, the base station device of the switching source (Source gNB) sets the neighboring cell measurement for the terminal device, the terminal device performs the measurement set by the source gNB, and reports the measurement result to the source gNB (step S801).

[0257] The source gNB determines the switching of the terminal device based on information such as the reported measurement results (step S802).

[0258] The source gNB issues a handover request message (step S803) containing information required to prepare for handover to the base station device (Target gNB) that is the handover destination.

[0259] Admission control can be implemented in the target gNB (step S804).

[0260] The target gNB prepares for handover by sending a handover request acknowledgement message (HANDOVER REQUESTACKNOWLEDGE message) to the source gNB (step S805). The handover request acknowledgement message includes a container that is transparently sent to the terminal device as an RRC message for handover execution.

[0261] The source gNB sends the container (first RRC Reconfiguration message) received from the target gNB to the terminal device (step S806). The RRC Reconfiguration message may include the identifier of the target cell, the new C-RNTI, the security algorithm identifier of the target gNB for the selected security algorithm, the set of resources for the dedicated random access channel, the UE-specific CSI-RS settings, common random access channel resources, and part or all of the system information of the target cell.

[0262] It should be noted that, if the terminal device is configured with Make-Before-Break HO (MBB-HO) via the first RRC reset message, after receiving the first RRC reset message, it can maintain the connection with the source gNB at least in the target gNB until the initial uplink transmission is performed.

[0263] The source eNB sends an SN state transition message to the target gNB to convey the reception status of the uplink PDCP sequence number and the transmission status of the downlink PDCP sequence number (step S807).

[0264] If a RACH-less handover is not configured via the first RRC reset message, the terminal device performs synchronization with the target eNB and accesses the target cell using a random access channel. In this case, if a dedicated random access preamble is indicated via the first RRC reset message, a contention-free random access procedure is performed; otherwise, a contention-based random access procedure is performed. If a RACH-less handover is configured via the first RRC reset message, the terminal device performs synchronization with the target gNB.

[0265] If the RACH-less handover is not configured via the first RRC reset message, the target gNB can return the uplink allocation and timing advance information to the terminal device.

[0266] If a RACH-less handover is configured via the first RRC reset message, and a periodic pre-allocated uplink grant cannot be obtained via the first RRC reset message, the terminal device receives the uplink grant via the target cell's PDCCH. The terminal device uses the initial available uplink grant after synchronization with the target cell.

[0267] When a terminal device successfully accesses the target cell without RACH-less handover, it can send an RRC Reconfiguration Complete message to the target gNB to confirm the handover. This RRC Reconfiguration Complete message indicates the completion of the handover process. The RRC Reconfiguration Complete message includes a C-RNTI, which the target gNB can verify against the accepted C-RNTI.

[0268] When RACH-less handover is configured and the terminal device receives an uplink grant, the terminal device can send an RRC Reconfiguration Complete message to the target gNB to confirm the handover. The RRC Reconfiguration Complete message includes a C-RNTI, which the target gNB can verify against the C-RNTI of the accepted RRC Reconfiguration Complete message. Alternatively, the handover process of the terminal device can be completed (step S808) when the terminal device receives the UE contentionresolutionidentity MAC control element from the target gNB.

[0269] The target eNB sends a PATH SWITCH REQUEST message to the AMF to switch the downlink data path of the 5GC to the target gNB, so that the target gNB can establish an NG-C interface instance (step S809).

[0270] 5GC switches the downlink data path to the target gNB. UPF (User Plane Function) sends one or more end-of-line marker packets to the source eNB, releasing the user plane resources to the source gNB (step S810).

[0271] AMF acknowledges the path switch request via a PATH SWITCH REQUEST ACKNOWLEDGE message (step S811).

[0272] The target gNB indicates a successful handover by sending a UE CONTEXT RELEASE message to the source eNB, triggering the release of resources by the source gNB. The target gNB may send this message after receiving a path handover request acknowledgment message from the AMF. The source gNB may release radio and C-plane-associated resources related to the UE context upon receiving the UE context release message. In-process data transmission can continue (step S812).

[0273] When timer T304 expires, the terminal device performs some or all of the following processes (A) to (D).

[0274] (A) If the MCG's timer T304 expires, the setting of the MCG's dedicated random access channel, which was reset via the first RRC connection reset message, is released.

[0275] (B) If the timer T304 of the MCG expires, the settings of the terminal device will be returned to the settings used in the PCell of the switching source.

[0276] (D) If the MCG timer T304 expires, the RRC connection re-establishment process begins.

[0277] (E) If the SCG's timer T304 expires, the setting of the SCG's dedicated random access channel, which was reset via the first RRC connection reset message, is released.

[0278] (E) If the SCG timer T304 expires, begin the process of reporting SCG synchronization reset failure.

[0279] The details of the processing of the terminal device receiving the first RRC reset message are explained below. The first RRC reset message may include a "reconfigurationWithSync" information element. The "reconfigurationWithSync" information element may include the SpCell settings for each cell group (MCG, SCG) in the RRC reset message. The "reconfigurationWithSync" information element includes parameters related to the reset accompanying synchronization with the target SpCell (e.g., the target SpCell settings, the terminal device's new identifier, etc.).

[0280] The terminal device that receives an RRC reset message (first RRC reset message) including the reconfigurationWithSync information element performs some or all of the following processes (A) to (E).

[0281] (A) If security is not activated, the release reason is set to "Other" to begin the process of leaving RRC_CONNECTED. The process of leaving RRC_CONNECTED can be the process of entering RRC_IDLE.

[0282] (B) If timer T310 of the SpCell being the object is running, then stop timer T310 of the SpCell being the object.

[0283] (C) Start the timer T304 of the SpCell object with the value (t304) included in the reconfigurationWithSync information element.

[0284] (D) If downlink frequency information is included, then that frequency is determined to be the SSB frequency of the target cell; otherwise, the SSB frequency of the source SpCell is determined to be the SSB frequency of the target cell.

[0285] (E) Start downlink synchronization in the target cell

[0286] As described above, in EUTRA and / or NR, when the terminal device is configured with Make-Before-Break HO (MBB-HO), the terminal device can maintain a connection with the source eNB or source gNB in ​​the target eNB or target gNB until the first uplink transmission is performed or any time period. Currently, timer T310 stops upon receiving the first RRC connection reset message or the first RRC reset message. Therefore, in the serving cell (source cell) of the source eNB or source gNB thereafter, the terminal device cannot determine whether the radio link failure is considered to be caused by a physical layer problem. Furthermore, while timer T304 is running, in the serving cell (source cell) of the source eNB or source gNB, the terminal device cannot determine whether the radio link failure is considered to be caused by a problem with random access notified from the MAC layer. Additionally, in the source cell, when the maximum number of retransmissions in the RLC is reached, it is considered a radio link failure, and the RRC connection re-establishment process is performed.

[0287] It should be noted that in Make-Before-Break HO (MBB-HO), protocol layers activated on both the source and destination sides can be used to maintain communication with the source eNB or source gNB until the first uplink transmission is performed by the destination eNB or destination gNB, or for any time period. Therefore, Make-Before-Break HO can also be referred to as DAPS (Dual Active Protocol Stack) handover. In DAPS handover, two covert keys and / or two integrity keys and / or two RoHC protocols can be set in the PDCP entity for both the source and destination. Two RLC bearers can also be set for both the source and destination, and two MAC entities can also be set for both the source and destination. Furthermore, some or all of the covert keys, integrity keys, RoHC protocols, RLC bearers, and MAC bearers set for the source and destination can be used simultaneously or alternately during DAPS handover. Hereinafter, Make-Before-Break HO can be replaced with DAPS handover.

[0288] Furthermore, the following application of connect-before-disconnect handover can also be an application of DAPS handover. Additionally, configuring connect-before-disconnect handover (MBB-HO) on the terminal device can refer to configuring DAPS handover on the terminal device. Furthermore, configuring connect-before-disconnect handover (MBB-HO) (configuring DAPS handover) on the terminal device can refer to applying MBB-HO (DAPS handover) to any radio bearer configured in the terminal device, or it can refer to applying MBB-HO (DAPS handover) to at least one of the radio bearers configured in the terminal device.

[0289] Next, Conditional Handover will be explained. In NR, Conditional Handover can refer to an RRC reset using an RRC reset message, which includes: an information element (Conditional Handover Setting) containing information included in the Synchronization Reset Information Element, and information indicating the conditions for applying that information element (Conditional Handover Condition). In LTE, Conditional Handover can refer to an RRC Connection Reset using an RRC Connection Reset message, which includes: an information element (Conditional Handover Setting) containing information included in the Mobility Control Information Element, and information indicating the conditions for applying that information element (Conditional Handover Condition).

[0290] In NR, condition switching settings may include some or all of the settings in (A) to (F) below.

[0291] (A) Cell Group Configuration Information (CellGroupConfig)

[0292] (B) indicates whether it is a full setting.

[0293] (C) NAS layer messages

[0294] (D) System Information

[0295] (E) Measurement Setup

[0296] (F) Wireless Bearer Configuration

[0297] The settings information of the cell group may include some or all of the settings in (1) to (6) below.

[0298] (1) Cell group identifier

[0299] (2) Information carried by RLC

[0300] (3) MAC layer configuration information of cell group

[0301] (4) Physical (PHY) layer configuration information for cell groups

[0302] (5) SpCell configuration information (which may include synchronization reset information elements)

[0303] (6) Scell ​​Information

[0304] Furthermore, the wireless bearer settings may include some or all of the settings in (1) to (3) below.

[0305] (1) SRB settings

[0306] (2) DRB settings

[0307] (3) Security settings (e.g., information related to the algorithms for integrity protection and encryption of SRB and / or DRB (securityAlgorithmConfig), information indicating which key (MCG) or secondary (SCG) is used (keyToUse), etc.)

[0308] In LTE, the conditional switching settings may include some or all of the settings in (A) to (E) below.

[0309] (A) Measurement setup

[0310] (B) Mobility control information elements

[0311] (C) NAS layer messages

[0312] (D) Wireless Resource Settings

[0313] (E) Security settings (e.g., information related to algorithms for integrity protection against SRB and / or DRB and encryption algorithms (SecurityAlgorithmConfig))

[0314] The wireless resource settings may include some or all of the settings in (1) to (4) below.

[0315] (1) SRB information

[0316] (2) DRB Information

[0317] (3) MAC layer configuration information of cell group

[0318] (4) Physical (PHY) layer configuration information for cell groups

[0319] In LTE and / or NR, condition switching conditions may include some or all of the conditions in (A) to (D) below.

[0320] (A) The cell that switches to the destination (target) is better than the current (source) PCell that has been offset.

[0321] (B) The cell for handover destination (target) is better than a certain threshold, while PCell is worse than other thresholds.

[0322] (C) The cell for switching destinations (targets) is better than a certain threshold.

[0323] (D) Unconditional (Immediate Execution)

[0324] In the comparisons under the aforementioned condition switching conditions, RSRP, RSRQ, and / or RS-SINR can be used as quantities. Furthermore, the network can be configured to use a specific quantity. Additionally, information indicating which quantity to use can be included in the condition switching conditions.

[0325] Information elements representing condition switching settings and / or condition switching conditions can be included as part of an RRC message in the switching source, or stored in a container (information element storing bit strings) included in the RRC message.

[0326] Based on the above description, various embodiments of the present invention will be described. It should be noted that the processes described above can be applied to the processes omitted in the following description.

[0327] This demonstrates an example of efficiently performing MBB-HO by changing the procedures related to wireless link monitoring in MBB-HO.

[0328] First, in the primary cell (PCell) of the SpCell (MCG), regardless of whether timer T304 is running under a specific condition (first condition), the RRC layer processing unit of UE122 can start or restart timer T310 if it has received synchronization notifications from the physical layer processing unit for a predetermined number of consecutive times (N310 times). Furthermore, the RRC layer processing unit of UE122 can stop timer T310 if it has received synchronization for a predetermined number of consecutive times (N311 times). Additionally, in determining whether to start or restart timer T310, the condition can be that timers T300, T301, and T311 are not running.

[0329] When the RRC layer processing unit of UE122 satisfies any of the following conditions (A) to (E), it determines that a radio link failure has been detected in the MCG.

[0330] (A) When timer T310 expires (Expires)

[0331] (B) Timer T312 expires

[0332] (C) When receiving notification (instruction) about a random access problem from the MAC entity of the MCG while timers T300, T301, T304, and T311 are not running.

[0333] (D) Under the first condition, when timer T304 is running and a notification of a random access problem is received from the MCG's MAC entity...

[0334] (E) When receiving a notification from the RLC layer of the MCG indicating that the maximum number of retransmissions for the SRB or DRB has been reached.

[0335] The first condition can be that makeBeforeBreak-r16 is configured for UE122. For example, configuring makeBeforeBreak-r16 could mean that, in the case of EUTRA, UE122 receives an RRC connection reset message containing fields of makeBeforeBreak-r16 within the mobilityControlInfo information element. Furthermore, configuring makeBeforeBreak-r16 could mean, in the case of NR, receiving an RRC reset message containing fields of makeBeforeBreak-r16 within the synchronization reset information element. Conversely, not configuring makeBeforeBreak-r16 could mean, in the case of EUTRA, UE122 receives an RRC connection reset message containing fields of makeBeforeBreak-r16 not included in the mobilityControlInfo information element. Additionally, not configuring makeBeforeBreak-r16 could mean, in the case of EUTRA, UE122 receives an RRC connection reset message containing a makeBeforeBreak-r16 message with a false value. Furthermore, not setting makeBeforeBreak-r16 could, for example, mean receiving an RRC reset message in the case of NR where makeBeforeBreak-r16 is not included in the fields of the synchronization reset information element.

[0336] Furthermore, setting makeBeforeBreak-r16 could, for example, mean that in the case of EUTRA, UE122 receives an RRC connection reconfiguration message included in the terminal device-specific radio resource configuration (radioBearerConfigDedicated) information element. Additionally, setting makeBeforeBreak-r16 could, for example, mean that in the case of NR, UE122 receives an RRC reconfiguration message included in a field of the data radio bearer configuration information element.

[0337] makeBeforeBreak-r16 can, for example, have enumerated type values ​​including true, or information elements as values ​​that include the information needed for the before-after-break switching.

[0338] Furthermore, the condition (E) can be the following (E2).

[0339] (E2) When timers T300, T301, T304, and T311 are not running, and a notification indicating that the maximum number of retransmissions for an SRB or DRB has been reached is received from the RLC layer of the MCG; or, under the first condition, when timer T304 is running, and a notification indicating that the maximum number of retransmissions for an SRB or DRB has been reached is received from the RLC layer of the MCG.

[0340] When UE122 determines that a radio link failure is detected in the MCG, it stores various information as radio link failure information. Then, if the AS security is not activated, it can set the release reason to "other" to begin the RRC_CONNECTED process.

[0341] Furthermore, under AS security activation, if the first condition is met, the transmission of some or all of the MCG's SRB and / or DRB can be suspended, and the MCG's MAC entity can be reset.

[0342] Furthermore, if the AS security is activated but not under the first condition, the RRC connection re-establishment process will begin.

[0343] The re-establishment process of the RRC connection can be started when any of the following conditions (A) to (E) are met.

[0344] (A) When a wireless link failure of the MCG is detected under conditions other than the first condition

[0345] (B) When the handover fails (when the synchronization reset in the MCG in NR fails)

[0346] (C) When moving to another RAT fails

[0347] (D) When notified from the lower level of a failure of the integrity check related to SRB1 or SRB2.

[0348] (E)RRC connection reset failure

[0349] Furthermore, if any of the above conditions are met, under the first condition, and if no radio link failure is detected in the MCG of the switching source, the process of notifying the switching failure in the MCG of the switching source can be started without initiating the re-establishment process of the RRC connection.

[0350] If the first condition is that makeBeforeBreak-r16 is set for UE122, then the set makeBeforeBreak-r16 can be released when timer T304 expires or when the process of notifying the handover failure in the MCG of the handover source begins.

[0351] When the re-establishment process of the RRC connection begins, UE122 performs some or all of the following processes (A) to (J).

[0352] (A) If timer T310 is running, stop timer T310.

[0353] (B) If timer T312 is running, stop timer T312.

[0354] (C) If timer T313 is running, stop timer T313.

[0355] (C) If timer T314 is running, stop timer T314.

[0356] (D) Start timer T311

[0357] (E) Suspend all RBs except SRB0

[0358] (F) Reset MAC

[0359] (G) If configured, release the MCG's SCell.

[0360] (H) Apply the default physical channel settings

[0361] (I) Apply the default MAC master settings to MCG

[0362] (J) Performing the cell selection process

[0363] Next, we will examine the following scenario: After UE122 sends an RRC connection reset completion message or an RRC reset completion message to the target cell during handover processing, data transmission and reception occur via the cell groups of the handover MCG (also known as the Target MCG or Current MCG) and the Source MCG (the case where the operation takes place in a Dual protocol stack). An example of the processing in this scenario is shown. It should be noted that the following processing is not limited to the dual protocol stack scenario and can also be applied to other scenarios.

[0364] First, in the primary cell of the SpCell acting as the source MCG, regardless of whether the source MCG's timer T304 is running under a specific condition (first condition), the RRC layer processing unit of UE122 can start or restart the source MCG's timer (T310) if it receives synchronization notifications from the source MCG's physical layer processing unit for a predetermined number of consecutive times (N310 times). Furthermore, the UE122's RRC layer processing unit can stop the timer (T310) if it receives synchronization notifications from the source MCG's physical layer processing unit for a predetermined number of consecutive times (N311 times). Additionally, in determining whether to start or restart the timer T310, the condition can be that the source MCG's timers T300, T301, and T311 are not running.

[0365] When any of the following conditions (A) to (E) are met, the RRC layer processing unit of UE122 determines that a radio link failure has been detected in the source MCG.

[0366] (A) When the timer T310 of the source MCG expires.

[0367] (B) When the timer T312 of the source MCG expires.

[0368] (C) When receiving notification (instruction) about a random access problem from the MAC entity of the source MCG while timers T300, T301, T304, and T311 of the source MCG are not running.

[0369] (D) Under the first condition, when the source MCG's timer T304 is running and a notification of a random access problem is received from the source MCG's MAC entity...

[0370] (E) When receiving a notification from the RLC layer of the source MCG indicating that the retransmission of SRB or DRB has reached the maximum number of retransmissions.

[0371] The first condition can be that UE122 is configured with makeBeforeBreak-r16.

[0372] In addition, the first condition can be either makeBeforeBreak-r14 or makeBeforeBreak-r16 set for UE122.

[0373] Furthermore, the condition (E) can be the following (E2).

[0374] (E2) When timers T300, T301, T304, and T311 of the source MCG are not running, and a notification indicating that the maximum number of retransmissions of the SRB or DRB has been reached is received from the RLC layer of the source MCG; or, under the first condition, when timer T304 is running, and a notification indicating that the maximum number of retransmissions of the SRB or DRB has been reached is received from the RLC layer of the source MCG.

[0375] When a radio link failure is detected in the source MCG, UE122 may suspend the transmission of part or all of the SRB and / or DRB of the source MCG and reset the MAC entity of the source MCG.

[0376] UE122 can treat an MCG as a source MCG when makeBeforeBreak-r16 is set in the current MCG.

[0377] In addition, UE122 can treat the MCG of the handover source as the source MCG when the initial uplink grant is allocated via PDCCH in the cell where the handover destination is located.

[0378] In addition, UE122 can treat the MCG of the switching source as the source MCG when an RRC reset completion message is sent.

[0379] In addition, UE122 can regard the MCG of the handover source as the source MCG when it receives the UE contention resolution identity MAC control element from the target gNB.

[0380] In addition, UE122 can release the existing source MCG if makeBeforeBreak-r16 is set in the current MCG, and treat the current MCG as the new source MCG.

[0381] In this way, unnecessary re-establishment processing in MBB-HO can be prevented by identifying and processing the radio link failures of the source MCG and the radio link failures of the current MCG, thus achieving efficient mobility.

[0382] An example of the operation of MBB-HO is explained. Here, an example is shown using an RRC reset message in NR that includes a CellGroupConfig containing synchronization reset information elements. It should be noted that the description of receiving information elements in the following descriptions of each process may also mean that information elements are included in the RRC reset message that triggers each process, unless otherwise stated. Furthermore, unless otherwise stated, the information elements used in each process may correspond to the information elements used in Non-Patent Document 10.

[0383] The terminal device performs process A based on the received CellGroupConfig information element. Additionally, the terminal device performs process L based on the received masterKeyUpdate information element. Furthermore, the terminal device performs process I based on the received RadioBearerConfig information element.

[0384] It should be noted that indentation and symbols are used for each item in each treatment described below. For example, treatment A, treatment B, treatment C, and treatment H are respectively represented by indentation and symbols. Figure 16 , Figure 17 , Figure 18 , Figure 19 The process shown in the diagram will be explained in the same way, but other processes will also be explained in the same way.

[0385] (Process A) Perform the following processing based on the received CellGroupConfig information element.

[0386] (A-0) If CellGroupConfig includes configuration information for SpCells containing synchronization reset information (spCellConfig information element), and the synchronization reset information includes information indicating that the RRC reset is an MBB-HO (e.g., MakeBeforeBreak-r16), then

[0387] (A-0-1) Copy the current terminal device settings (source settings) as the target settings. Unless otherwise explicitly stated, the following subsequent processing can be performed on the copied target settings. For example, in the case of MBB-HO, the "current terminal device settings" of each processing can be regarded as "the target settings of the current terminal device". In addition, for example, the settings to be copied may include some or all of the following: (1) bearer-related settings (e.g., settings related to SRB, settings related to DRB, etc.), (2) cell group settings (e.g., settings of SpCell, settings of SCell, settings of each entity, etc.), (3) variables held inside the terminal device (measurement settings (VarMeasConfig), measurement results (VarMeasReportList), timers, counters, etc.), and (4) security-related settings (e.g., each key). In addition, the bearer settings to be copied may not include SRB-related settings. That is, regarding DRB, both source settings and target settings can be managed, and regarding SRB, settings may not be copied, but rather the settings may be switched from source settings to target settings. Furthermore, information that determines whether to copy SRB settings can be included in the RRC reset message that includes a synchronization reset. For example, the MakeBeforeBreak-r16 message may include this information.

[0388] (A-1) If CellGroupConfig includes configuration information for SpCells (spCellConfig information element) that contains synchronization reset information, then

[0389] (A-1-1) Perform the following processing B.

[0390] (A-1-2) If it is in a suspended state, then restore all suspended radio bearers and restore transmission in SCG for all radio bearers.

[0391] (A-2) If CellGroupConfig includes a list of released RLC bearers (rlc-BearerToReleaseList information element), then

[0392] (A-2-1) Perform the following processing C.

[0393] (A-3) If CellGroupConfig includes a list of RLC bearers to be appended and / or modified (rlc-BearerToAddModList information element), then

[0394] (A-3-1) Perform the following processing D.

[0395] (A-4) If CellGroupConfig includes the MAC settings for the cell group (mac-CellGroupConfig information element), then

[0396] (A-4-1) Configure the MAC entity of the cell group in process E described later. It should be noted that, in various embodiments of the present invention, "configuring" using the information elements included in the RRC message by the terminal device can mean applying the information included in the information elements to the terminal device's settings.

[0397] (A-5) If CellGroupConfig includes a list of SCells to be released (sCellToReleaseList information element), then

[0398] (A-5-1) The release of SCell is performed in the process F described later.

[0399] (A-6) If CellGroupConfig includes the configuration information for SpCell (spCellConfig information element), then

[0400] (A-6-1) Set SpCell in the processing G described later.

[0401] (A-7) If CellGroupConfig includes a list of SCells to be appended and / or modified (sCellToAddModList information element), then

[0402] (A-7-1) Perform the addition and / or modification of SCell in process H described later.

[0403] (Process B)

[0404] (B-1) If the security of AS is not activated, perform the transition to RRC_IDLE and end process B.

[0405] (B-2) If it is running, stop the timer T310 of the corresponding SpCell.

[0406] (B-3) Start the corresponding SpCell timer T304 by synchronously resetting the timer value of t304 included in the timer.

[0407] (B-4) If frequency information (frequencyInfoDL) is included, then

[0408] (B-4-1) The target SpCell is considered as a cell whose physical cell identifier is represented by the physical cell identifier information (physCellId) included in the synchronization reset at the SSB frequency represented by frequencyInfoDL.

[0409] (B-5) Otherwise,

[0410] (B-5-1) The target SpCell is considered as a cell whose physical cell identifier is represented by the physical cell identifier information (physCellId) included in the synchronization reset at the SSB frequency of the source SpCell.

[0411] (B-6) Initiate the synchronization of the target's SpCell downlink.

[0412] (B-7) Apply the established BCCH settings.

[0413] (B-8) If necessary, obtain the Master Information Block (MIB) as part of the broadcast information.

[0414] (B-9) If the synchronization reset includes information represented as MBB-HO

[0415] (B-9-1) If no MAC entity exists in the target cell group, then

[0416] (B-9-1-1) Generates the MAC entity of the target cell group (only the target MAC entity is referred to as the target MAC entity).

[0417] (B-9-2) Apply the default (default) MAC cell group settings to the target's MAC entity.

[0418] (B-9-3) If configured, the SCell of the target cell group will be considered inactive (deactivated).

[0419] (B-9-4) Use the value of newUE-Identity as the C-RNTI of the target cell group.

[0420] (B-10) Otherwise,

[0421] (B-10-1) Reset the MAC entity of this cell group.

[0422] (B-10-2) If configured, the SCell of that cell group is considered inactive (deactivated).

[0423] (B-10-3) Apply the value of newUE-Identity as the C-RNTI for this cell group.

[0424] (B-11) Configure the lower layer based on the settings of SpCell (spCellConfigCommon) included in the synchronous reset.

[0425] (B-12) If necessary, configure the lower layer based on other information included in the synchronization reset.

[0426] (Process C)

[0427] (C-1a) As part of the current terminal device settings, the values ​​of the logical channel identifiers included in rlc-BearerToReleaseList are respectively...

[0428] (C-1b) As a result of the release of the SCG, the values ​​of the released logical channel identifiers are respectively...

[0429] (C-1-1) Release the corresponding logical channel and the RLC entity associated with the logical channel.

[0430] (Process D)

[0431] The following processing is performed on the RLC bearer settings (RLC-BearerConfig) included in the received rlc-BearerToAddModList information element.

[0432] (D-1) If the current terminal device settings include the received logical channel identifier RLC bearer,

[0433] (D-1-1) If a message indicating the re-establishment of the RLC is received, then

[0434] (D-1-1-1) Re-establish the RLC entity

[0435] (D-1-2) Reconfigure the RLC entity based on the received RLC settings (rlc-Config).

[0436] (D-1-3) Reset the logical channel according to the received MAC logical channel configuration (mac-LogicalChannelConfig).

[0437] (D-2) Otherwise,

[0438] (D-2-1) If the settings for the logical channel identifier for the SRB and the RLC are included, then

[0439] (D-2-1-1) Create an RLC entity based on the default settings.

[0440] (D-2-2) Otherwise,

[0441] (D-2-2-1) Based on the received RLC settings (rlc-Config), create an RLC entity.

[0442] (D-2-3) If logical channel identifiers and MAC logical channel settings for SRBs are included, then

[0443] (D-2-3-1) Based on the established (default) settings, set the MAC entity corresponding to the logical channel.

[0444] (D-2-4) Otherwise,

[0445] (D-2-4-1) Based on the received MAC logical channel settings, set the MAC entity corresponding to the logical channel.

[0446] (D-2-5) Based on the radio bearer identifier information (servedRadioBearer) included in the RLC bearer settings, establish a correspondence between the logical channel and the PDCP entity.

[0447] (Process E)

[0448] (E-1) If the CellGroupConfig is being reset to an SCG, and the SCG MAC is not part of the current terminal device's settings, then

[0449] (E-1-1) Generate the SCG MAC entity.

[0450] (E-2) Reset the MAC main configuration of the cell group based on the MAC cell group settings (mac-cell) other than those related to the addition, modification and / or release of the timing advance group (TAG).

[0451] (E-3) If the received MAC cell group settings include information related to TAG release (tag-ToReleaseList),

[0452] (E-3-1) If the identifier of a TAG included in tag-ToReleaseList is part of the current terminal device settings, then for each TAG identifier, release the TAG represented by the TAG identifier.

[0453] (E-4) If the received MAC cell group settings include information related to the addition and / or modification of tags (tag-ToAddModList),

[0454] (E-4-1) If the identifier of a TAG included in tag-ToAddModList is not part of the current terminal device settings, then for each TAG identifier,

[0455] (E-4-1-1) Append the TAG corresponding to the identifier of the TAG according to the received advance timer.

[0456] (E-4-2) If the identifiers of the tags included in tag-ToAddModList are part of the current terminal device settings, then for each tag's identifier,

[0457] (E-4-2-1) Reset the TAG corresponding to the TAG identifier based on the received advance timer.

[0458] (Process F)

[0459] (F-1) If the release is triggered by receiving the release list (sCellToReleaseList) of the SCell, then

[0460] (F-1-1) For the values ​​of each SCell index (sCellIndex) included in sCellToReleaseList,

[0461] (F-1-1-1) If the existing terminal device settings include an SCell with a value of sCellIndex, then

[0462] (F-1-1-1-1) Release the SCell.

[0463] (Process G)

[0464] (G-1) If SpCell is configured to include information about timers and constants related to Radio Link Failure (RLF), then

[0465] (G-1-1) Based on rlf-TimersAndConstants, set the timer and constant for the RLF of this cell group.

[0466] (G-2) Otherwise, if rlf-TimersAndConstants are not set for the cell group, then

[0467] (G-2-1) Use the timer and constant values ​​received through system information to set the timer and constant for the RLF of this cell group.

[0468] (G-3) If the SpCell configuration includes a dedicated SpCell configuration (spCellConfigDedicated), then

[0469] (G-3-1) Configure SpCell according to spCellConfigDedicated.

[0470] (G-3-2) If configured, the BWP represented by the identifier (firstActiveUplinkBWP-Id) of the first active uplink BWP (Bandwidth part) is considered the active uplink BWP.

[0471] (G-3-3) If configured, the BWP represented by the identifier (firstActiveDownlinkBWP-Id) of the first active downlink BWP (Bandwidth part) is considered the active downlink BWP.

[0472] (G-3-4) If the reference signal used for wireless link monitoring is reset according to the received dedicated SpCell settings,

[0473] (G-3-4-1) If it is running, stop the timer T310 corresponding to SpCell.

[0474] (G-3-4-2) Stop counters N310 and N311.

[0475] (H processing)

[0476] (H-1) For each value in sCellIndex included in sCellToAddModList that is not part of the current terminal device settings.

[0477] (H-1-1) Appends the SCell corresponding to sCellIndex.

[0478] (H-1-2) Configures the lower layer in such a way that SCell is considered inactive.

[0479] (H-1-3) A list of measurement identifiers (measIdList) for each variable (VarMeasConfig) that maintains the measurement settings.

[0480] (H-1-3-1a) If SCell cannot be applied to the measurement corresponding to the measurement identifier, and

[0481] (H-1-3-1b) If the SCell is included in the list of triggered cells (cellsTriggeredList) defined by the variable (VarMeasReportList) that maintains measurement reports for that measurement identifier, then

[0482] (H-1-3-1-1) Remove the SCell from the list of triggered cells (cellsTriggeredList) defined by the variable (VarMeasReportList) that maintains the measurement report for this measurement identifier.

[0483] (H-2) refers to the values ​​in sCellIndex included in sCellToAddModList that are part of the current terminal device settings.

[0484] (H-2-1) Change the setting of the SCell corresponding to sCellIndex.

[0485] (Process I)

[0486] (I-1) If RadioBearerConfig includes srb3-ToRelease, then

[0487] (I-1-1) Release the PDCP entity and SRB identifier of SRB3.

[0488] (I-2) If RadioBearerConfig includes SRB-ToAddModList, then

[0489] (I-2-1) Perform SRB addition and / or reset.

[0490] (I-3) If RadioBearerConfig includes drb-ToReleaseList, then

[0491] (I-3-1) The DRB is released in the process J described later.

[0492] (I-4) If RadioBearerConfig includes DRB-ToAddModList, then

[0493] (I-4-1) Perform the addition and / or reset of the DRB in the process K described later.

[0494] (I-5) Release all SDAP entities that have not been established with DRB, and notify the upper layer of the release of user plane resources that have established PDU sessions with the released SDAP entities.

[0495] In Process I, in the case of MBB-HO, during the processes of adding, resetting, and / or releasing the SRB, both the source setting and the target setting can be managed. The target setting is not processed in Processes I-1 and I-2; instead, the current SRB setting is reset in Processes I-1 and I-2. That is, the SRB can manage only one setting. In this case, the source's SRB setting before the reset can be saved separately in case of switching failure, etc.

[0496] As described in process I-5, in the case of MBB-HO, all SDAP entities not associated with either the source's or target's DRB can be released, and the release of user plane resources for PDU sessions associated with the released SDAP entities can be notified to the upper layer. For example, MBB-HO can be performed based on an RRC reset message including synchronization reset. In the target cell, until a message to release the source's configuration (e.g., RRC message, MAC CE, etc.) is received, SDAP entities that have established corresponding relationships with either or both of the source's and target's DRBs are not released. Instead, when the source's DRB is released upon receiving a message to release the source's configuration, all SDAP entities not associated with the (target) DRB are released, and the release of user plane resources for PDU sessions associated with the released SDAP entities is notified to the upper layer.

[0497] The aforementioned "receiving the message indicating the release of the source's settings" can be renamed as detecting a request. This request can be renamed as information. Detecting a request can refer to the received RRC message including specific information elements (e.g., information elements indicating the release of the source's settings), the received MAC control element including specific information (e.g., information indicating the release of the source's settings), or the acceptance of the first uplink grant in the SpCell. Detecting a request can also refer to the random access procedure being successful. Detecting a request can also refer to the random access procedure being successful in either or both of the following situations: (A) synchronous reconfiguration included in the SpCellConfig; (B) the random access procedure being triggered by the RRC entity providing (submitting) a message to the lower layer to notify the RRC reconfiguration completion (e.g., an RRC connection reconfiguration completion message in LTE, or an RRC reconfiguration completion message in NR). Furthermore, detecting a request can also refer to any of the actions detected by installing a terminal device.

[0498] (Process J)

[0499] (J-1a) For each drb-ToReleaseList included as part of the settings of the current terminal device, or

[0500] (J-1b) For each DRB identifier that is released as a result of the full setting

[0501] (J-1-1) Release the PDCP entity and DRB identifier.

[0502] (J-1-2) If an SDAP entity is configured to be associated with this DRB, then

[0503] (J-1-2-1) Instructs the release of the DRB to the SDAP associated with the DRB.

[0504] (J-1-3) If the DRB is associated with an identifier carried by the EPS,

[0505] (J-1-3-1) If a new bearer is not added to either NR or E-UTRA in the same EPS bearer identifier, then

[0506] (J-1-3-1-1) Notifies the upper layer of the release of the DRB and the EPS bearer identifier of the released DRB.

[0507] As described in process J-1-3-1, in the case of MBB-HO, if no new bearer is added in either the source or target configuration for the same EPS bearer, the release of the DRB and the EPS bearer identifier of the released DRB can be notified to the upper layer. For example, MBB-HO can be performed based on an RRC reset message including synchronization reset. In the target cell, until a message for releasing the source configuration (e.g., RRC message, MAC CE, etc.) is received, if no bearer is associated in either the source or target configuration for the same EPS bearer, the release of the DRB and the EPS bearer identifier of the released DRB are not notified to the upper layer. Instead, when the message for releasing the source configuration is received and the source DRB is released, if no new bearer is added in either the NR or E-UTR for the same EPS bearer identifier, the release of the DRB and the EPS bearer identifier of the released DRB are notified to the upper layer.

[0508] (Process K)

[0509] (K-1) For each DRB identifier included in the DRB-ToAddModList that is not part of the current terminal device's settings,

[0510] (K-1-1) Establish a PDCP entity and configure the PDCP entity according to the received PDCP settings (pdcp-Config).

[0511] (K-1-2) If the PDCP entity of this DRB is not set by cipheringDisabled,

[0512] (K-1-2-1a) If the target RAT for the switch is E-UTRA / 5GC, or

[0513] (K-1-2-1b) If the terminal device is only connected to E-UTRA / 5GC, then

[0514] (K-1-2-1-1) The PDCP entity is set up using the encryption algorithm and key settings of Non-Patent Document 4.

[0515] (K-1-2-2) Otherwise,

[0516] (K-1-2-2-1) The PDCP entity is configured according to the encryption algorithm of the security configuration (securityConfig), and the key is represented by the parameter (keyToUse) associated with the master key (KeNB or KgNB) or the secondary key (S-KgNB).

[0517] (K-1-3) If the PDCP entity of this DRB is configured for integrity protection, then

[0518] (K-1-3-1) The PDCP entity is configured according to the integrity protection algorithm of the security configuration (securityConfig), and the key is represented by the parameter (keyToUse) associated with the master key (KeNB or KgNB) or the secondary key (S-KgNB).

[0519] (K-1-4) If SDAP settings (sdap-Config) are included,

[0520] (K-1-4-1) If there is no SDAP for the received PDU session, then

[0521] (K-1-4-1-1) Create an SDAP entity.

[0522] (K-1-4-1-2) If there was no SDAP for a received PDU session prior to this reset, then

[0523] (K-1-4-1-2-1) notifies the upper layer of the establishment of user plane resources for this PDU session.

[0524] (K-1-4-2) Configure the SDAP entity based on the received SDAP settings and associate the DRB with the SDAP entity.

[0525] (K-1-5) If the DRB is associated with the EPS bearer identifier

[0526] (K-1-5-1) If the DRB is set via NR or E-UTRA before receiving the reset in the same EPS bearer identifier, then

[0527] (K-1-5-1-1) associates the established DRB with the corresponding EPS bearer identifier.

[0528] (K-1-5-2) Otherwise,

[0529] (K-1-5-2-1) Notifies the upper layer of the establishment of the DRB and the EPS bearer identifier of the established DRB.

[0530] (K-2) For each DRB identifier included in the DRB-ToAddModList that is part of the current terminal device settings,

[0531] (K-2-1) If the parameter reestablishPDCP is set,

[0532] (K-2-1-1a) If the target of the switch has a RAT of E-UTRA / 5GC, or

[0533] (K-2-1-1b) If the terminal device is only connected to E-UTRA / 5GC

[0534] (K-2-1-1-1) If the PDCP entity of the DRB is not set by cipheringDisabled, then

[0535] (K-2-1-1-1-1) The PDCP entity is set up using the encryption algorithm and key settings of Non-Patent Document 4.

[0536] (K-2-1-2) Otherwise,

[0537] (K-2-1-2-1) If the PDCP entity of this DRB is not set to cipheringDisabled, then

[0538] (K-2-1-2-1-1) The PDCP entity is configured according to the encryption algorithm of the security configuration (securityConfig), and the key is represented by the parameter (keyToUse) associated with the master key (KeNB or KgNB) or the secondary key (S-KgNB).

[0539] (K-2-1-2-2) If the PDCP entity of this DRB is configured for integrity protection, then

[0540] (K-2-1-2-2-1) The PDCP entity is configured according to the integrity protection algorithm of the security configuration (securityConfig), and the key is indicated by the parameter (keyToUse) associated with the master key (KeNB or KgNB) or the secondary key (S-KgNB).

[0541] (K-2-1-3) If drb-ContinueROHC is included in pdcp-Config, then

[0542] (K-2-1-3-1) Notifies the lower layer that drb-ContinueROHC is set.

[0543] (K-2-1-4) Recreate the PDCP entity of the DRB.

[0544] (K-2-2) Otherwise, if recoverPDCP is configured, then

[0545] (K-2-2-1) triggers the execution of data recovery for the PDCP entity of this DRB.

[0546] (K-2-3) If PDCP settings are included, then

[0547] (K-2-3-1) Reset the PDCP entity according to the received PDCP settings.

[0548] (K-2-4) If SDAP settings are included, then

[0549] (K-2-4-1) Reset the SDAP entity based on the received SDAP settings.

[0550] (K-2-4-2) For each QFI added via mappedQoS-FlowsToAdd, if a QFI value is set, release the QFI value from the old DRB.

[0551] As part of process K-1-4-1-2, in the case of MBB-HO, if the SDAP of the received PDU session does not exist in either the source or target settings before receiving the reset, a notification for the establishment of user plane resources for that PDU session can be sent to the upper layer. Alternatively, as part of process K-1-4-1-2, in the case of MBB-HO, if the SDAP of the received PDU session does not exist in the source settings before receiving the reset, a notification for the establishment of user plane resources for that PDU session can be sent to the upper layer.

[0552] In process K-1-5-2, in the case of MBB-HO, if the same bearer identifier DRB was not set in the source and target settings via NR or E-UTRA before receiving the reset, the establishment of the DRB and the EPS bearer identifier of the established DRB can be notified to the upper layer. Alternatively, in process K-1-5-2, in the case of MBB-HO, if the same bearer identifier DRB was not set in the source settings via NR or E-UTRA before receiving the reset, the establishment of the DRB and the EPS bearer identifier of the established DRB can be notified to the upper layer.

[0553] (Processing L)

[0554] (L-1) If the terminal device is connected to E-UTRA / EPC

[0555] (L-1-1) If sk-Counter is included, then

[0556] (L-1-1-1) Update the S-KgNB key based on the KgNB key and the received sk-Counter.

[0557] (L-1-1-2) Generate (Derive): the KRRCenc key and the KUPenc key. The KRRCenc key is used to protect the RRC signal generated from the KgNB via an encryption algorithm. Additionally, the KUPenc key is used to protect the user plane services (user data) generated from the KgNB via an encryption algorithm.

[0558] (L-1-1-3) Generate the KRRCint and KUPint keys based on the KgNB key. The KRRCint key is used to protect the RRC signal generated from the KgNB through the integrity algorithm. Furthermore, the KUPint key is used to protect the user plane services (user data) generated from the KgNB through the integrity algorithm.

[0559] (L-2) Otherwise,

[0560] (L-1-2) If the received masterKeyUpdate includes nas-Container, then (L-1-2-1) forward nas-Container to the upper layer.

[0561] (L-1-3) If keySetChangeIndicator is "true", then

[0562] (L-1-3-1) Generate or update KgNB based on KAMF.

[0563] (L-1-4) Otherwise,

[0564] (L-1-4-1) Generate or update the KgNB key based on the current KgNB key or NextHop(NH).

[0565] (L-1-5) Stores the value of nextHopChainingCount.

[0566] (L-1-6) Generate the key associated with the KgNB key as follows.

[0567] (L-1-6-1) If SecurityConfig includes securityAlgorithmConfig, then

[0568] (L-1-6-1-1) Generate KRRCenc and KUPenc keys associated with the cipheringAlgorithm included in securityAlgorithmConfig based on the KgNB key.

[0569] (L-1-6-1-2) Generate KRRCint and KUPint keys associated with integrityProtAlgorithm included in securityAlgorithmConfig based on the KgNB key.

[0570] (L-1-6-2) Otherwise,

[0571] (L-1-6-2-1) Generate the KRRCenc key and KUPenc key associated with the current cipheringAlgorithm based on the KgNB key.

[0572] (L-1-6-2-2) Generate KRRCint and KUPint keys associated with the current integrityProtAlgorithm based on the KgNB key.

[0573] An example of the operation of MBB-HO will be explained. Here, an example of using an RRC connection reset message including a mobility control information (mobilityControlInfo) element in LTE is shown. It should be noted that the description of receiving information elements is mentioned in the following descriptions of each process, but unless otherwise stated, it may also mean that the information element is included in the RRC connection reset message that triggers each process. Furthermore, unless otherwise stated, the information elements used in each process can be established to correspond to the information elements used in Non-Patent Document 4.

[0574] The terminal device receives an RRC connection reset message including mobilityControlInfo. If the terminal device can meet the settings included in the message, it performs the following process LA.

[0575] (Processing LA)

[0576] (LA-1) Use the timer value of t304 included in mobilityControlInfo to start timer T304.

[0577] (LA-2) If carrierFreq is included, then

[0578] (LA-2-1) The physical cell identifier on the frequency represented by carrierFreq will be regarded as the target PCell by the cell represented by targetPhysCellId.

[0579] (LA-3) Otherwise,

[0580] (LA-3-1) The physical cell identifier on the frequency of the source PCell will be the cell represented by targetPhysCellId as the target PCell.

[0581] (LA-4) Initiate downlink synchronization to the target PCell.

[0582] (LA-5-1) After ceasing uplink transmission and / or downlink reception with the source cell, the terminal device performs the remaining processing of the procedure, including MAC reset.

[0583] (LA-6) If makeBeforeBreak-r16 is set, then

[0584] (LA-6-1) The current terminal device settings (source settings) are copied to the target settings. Unless otherwise explicitly stated, the copied target settings may be processed by performing the following reconfiguration process. For example, in the case of MBB-HO, the "current terminal device settings" of each process can be regarded as the "target settings of the current terminal device". In addition, the settings to be copied may include, for example, (1) bearer settings (e.g., SRB settings, DRB settings, etc.), (2) cell group settings (e.g., SpCell settings, SCell settings, RLC entity settings, MAC entity settings, PHY settings, etc.), (3) internal variables (measurement settings (VarMeasConfig), measurement results (VarMeasReportList), timers, counters, etc.), and (4) security-related settings (e.g., each key). In addition, the bearer settings to be copied may not include SRB settings. In other words, regarding DRB, both source and target settings can be managed. Regarding SRB, settings can be switched from source to target settings instead of copied. Furthermore, information determining whether to copy SRB settings can be included in the RRC connection reset message, which includes `mobilityControlInfo`. For example, `MakeBeforeBreak-r16` may include this information.

[0585] (LA-7) If configured, the MAC addresses of the MCG and SCG are reset. With MakeBeforeBreak-r16 configured, the MAC addresses of the source MCG and SCG may not be reset. Alternatively, with MakeBeforeBreak-r16 configured, the MAC address of the target may be reset instead of the source MAC address.

[0586] (LA-8) Re-establish PDCP for all radio bearers set up and established via PDCP configuration. With MakeBeforeBreak-r16 configured, PDCP re-establishment applies only to the target PDCP. Alternatively, in the case of Single PDCP (described later), if MakeBeforeBreak-r16 is configured, PDCP establishment and / or re-establishment may not be performed if a PDCP already exists associated with the target radio bearer. That is, if MakeBeforeBreak-r16 is configured, PDCP establishment and / or re-establishment may be performed even if a PDCP does not exist associated with the target radio bearer.

[0587] (LA-9) For all established radio bearers, if configured, re-establish the RLC of MCG and the RLC of SCG.

[0588] (LA-10) uses the value of newUE-Identity as C-RNTI.

[0589] (LA-11) Configures the lower layer based on the received cell-wide common radio resource settings (radioResourceConfigCommon).

[0590] (LA-12) Configure the lower layer based on other information included in the received mobilityControlInfo.

[0591] (LA-13) If the received RRC connection reset message includes sCellToReleaseList, then

[0592] (LA-13-1) Perform the release of SCell.

[0593] (LA-14) If the received RRC connection reset message includes sCellGroupToReleaseList, then

[0594] (LA-14-1) Perform the release of the SCell group.

[0595] (LA-15a) If the received RRC connection reset message includes scg-Configuration, or

[0596] (LA-15b) If the current terminal device settings include more than one Split DRB, and the received RRC connection reset message includes DRB-ToAddModList, then

[0597] (LA-15-1) Perform SCG reset.

[0598] (LA-16) If the received RRC connection reset message includes terminal-specific radio resource settings (radioResourceConfigDedicated), then

[0599] (LA-16-1) Radio resource settings are performed in the processing LB described later.

[0600] (LA-17) If the RRC connection reset message includes security settings (securityConfigHO-v1530),

[0601] (LA-17-1) If a nas-Container is received, then

[0602] (LA-17-1-1) Transfer the nas-Container to the upper layer.

[0603] (LA-17-2) If keyChangeIndicator-r15 is received and keyChangeIndicator-r15 is "true", then

[0604] (LA-17-2-1) Update the KeNB key based on the KAMF key.

[0605] (LA-17-3) Otherwise,

[0606] (LA-17-3-1) Update the KeNB key based on the current KeNB or NextHop(NH).

[0607] (LA-17-4) Stores the value of nextHopChainingCount-r15.

[0608] (LA-17-5) If securityAlgorithmConfig-r15 is received, then

[0609] (LA-17-5-1) Generates a KRRCint key associated with the received integrityProtAlgorithm.

[0610] (LA-17-5-2) Generates the KRRCenc key and KUPenc key associated with the received cipheringAlgorithm. The KRRCenc key is used to protect the RRC signal generated from the KeNB via the encryption algorithm. Additionally, the KUPenc key is used to protect user plane services (user data) generated from the KeNB via the encryption algorithm.

[0611] (LA-17-6) Otherwise,

[0612] (LA-17-6-1) Generate a KRRCint key associated with the current integrityProtAlgorithm based on the KeNB key.

[0613] (LA-17-6-2) Generate KRRCenc and KUPenc keys associated with the current cipheringAlgorithm based on the KeNB key.

[0614] (LA-18) If the received RRC connection reset message includes sCellToAddModList, then

[0615] (LA-18-1) Perform additions and / or modifications to SCell.

[0616] (LA-19) If the received RRC connection reset message includes sCellGroupToAddModList, then

[0617] (LA-19-1) Perform additions and / or modifications to the SCell group.

[0618] (LA-20) If the received RRC connection reset message includes measConfig, then

[0619] (LA-20-1) Perform the measurement settings.

[0620] (LA-21) Performs automatic deletion of measurement identifiers.

[0621] (LA-22) Provides the RRC connection reset complete message to the lower layer for sending.

[0622] (LA-23) If the MAC address is successful during the random access process, then

[0623] (LA-23-1) Stop timer T304 and end the process.

[0624] (Handling LB)

[0625] (LB-1) If the received radioResourceConfigDedicated includes SRB-ToAddModList, then

[0626] (LB-1-1) will then be performed in the processing LC described later, where SRB will be added and / or reset.

[0627] (LB-2) If the received radioResourceConfigDedicated includes drb-ToReleaseList, then

[0628] (LB-2-1) Perform DRB release in the LD process described later.

[0629] (LB-3) If the received radioResourceConfigDedicated includes DRB-ToAddModList, then

[0630] (LB-3-1) Perform the addition and / or reset of the DRB in the processing LE described later.

[0631] (LB-4) If the received radioResourceConfigDedicated includes mac-MainConfig, then

[0632] (LB-4-1) The master settings of MAC are executed in the LF process described later.

[0633] (LC processing)

[0634] (LC-1) For each SRB identifier included in the SRB-ToAddModList that is not part of the current terminal device's settings,

[0635] (LC-1-1) Establish a PDCP entity using the current security settings.

[0636] (LC-1-2) If an rlc-BearerConfigSecondary with the value "Configuration" is received, then

[0637] (LC-1-2-1) Based on the received rlc-BearerConfigSecondary, a secondary MCG RLC entity is established and associated with the DCCH logical channel.

[0638] (LC-1-2-2) Configures the PDCP entity for E-UTRA to be replicated in an active manner.

[0639] (LC-2) For each SRB identifier included in the SRB-ToAddModList that is part of the current terminal device settings,

[0640] (LC-2-1) If pdcp-verChange is included (i.e., change from NR PDCP to E-UTRA PDCP), then...

[0641] (LC-2-1-1) Establish the PDCP entity of E-UTRA using the current security settings.

[0642] (LC-2-1-2) associates the main RLC of the SRB with the established PDCP entity.

[0643] (LC-2-1-3) Release the NR PDCP of the SRB.

[0644] (LC-2-2) Based on the received rlc-Config, reset the main RLC entity.

[0645] (LC-2-3) Reset the main DCCH logical channel according to the received logical channel configuration (logicalChannelConfig).

[0646] (LC-2-4) If rlc-BearerConfigSecondary with a value of "Release" is included, then

[0647] (LC-2-4-1) Release the auxiliary MCGRLC entity and its associated DCCH logical channel.

[0648] (LC-2-5) If an rlc-BearerConfigSecondary with the value "Configuration" is received,

[0649] (LC-2-5-1) If the existing SRB configuration does not include a secondary RLC bearer, then

[0650] (LC-2-5-1-1) Based on the received rlc-BearerConfigSecondary, a secondary MCG RLC entity is established and associated with the DCCH logical channel.

[0651] (LC-2-5-1-2) Configures the PDCP entity for E-UTRA to be copied in an active manner.

[0652] (LC-2-5-2) Otherwise,

[0653] (LC-2-5-2-1) The secondary MCG RLC entity is reconfigured based on the received rlc-BearerConfigSecondary to associate with the DCCH logical channel.

[0654] (Processing LD)

[0655] (LD-1a) For each DRB identifier included in the drb-ToReleaseList that is part of the settings of the current terminal device, or,

[0656] (LD-2b) For each DRB identifier value released as a result of a full setting.

[0657] (LD-2-1) If the release of the DRB is the result of a full setting, then

[0658] (LD-2-1-1) Release the PDCP entity of E-UTRA or NR.

[0659] (LD-2-2) Otherwise, if the DRB is set along with PDCP settings, then

[0660] (LD-2-2-1) Release the PDCP entity of E-UTRA.

[0661] (LD-2-3) Otherwise,

[0662] (LD-2-3-1) Recreate the RLC entity for this DRB.

[0663] (LD-2-4) Release the RLC entity.

[0664] (LD-2-5) Release the DTCH logical channel.

[0665] (LD-2-6) If the terminal device is connected to the EPC

[0666] (LD-2-6-1) If the DRB is set with PDCP settings and a new DRB is appended to the same EPS bearer identifier via DRB-ToAddModList, nr-radioBearerConfig1, or nr-radioBearerConfig2,

[0667] (LD-2-6-1-1) If the process is triggered by a switch, then

[0668] (LD-2-6-1-1-1) After a successful switchover, the release of the DRB and the EPS bearer identifier of the released DRB will be notified to the upper layer.

[0669] (LD-2-6-1-2) Otherwise,

[0670] (LD-2-6-1-2-1) Immediately notify the upper layer of the release of the DRB and the EPS bearer identifier of the released DRB.

[0671] (Processing LE)

[0672] (LE-1) For each DRB identifier included in the DRB-ToAddModList that is not part of the current terminal device's settings,

[0673] (LE-1-1) If DRB-ToAddModListSCG is not received or the DRB identifier is not included in DRB-ToAddModListSCG.

[0674] (LE-1-1-1) If pdcp-Config is included, a PDCP entity is created based on pdcp-Config and configured using the current MCG security settings.

[0675] (LE-1-1-2) If rlc-Config is included, then MCG RLC is built based on rlc-Config.

[0676] (LE-1-1-3) If logical channel identifier (logicalChannelIdentity) and logical channel configuration (logicalChannelConfig) are included, then the MCG DTCH logical channel is established based on logicalChannelIdentity and logicalChannelConfig.

[0677] (LE-1-1-4) If rlc-BearerConfigSecondary with "Configuration" as its value is included, then

[0678] (LE-1-1-4-1) Based on rlc-BearerConfigSecondary, a secondary MCG RLC entity is established and associated with the DTCH logical channel. Then, the established RLC entity is associated with an E-UTRA PDCP that has the same DRB identifier value in the current terminal device settings.

[0679] (LE-1-2) If a DRB is set in the same EPS carrier identifier, then

[0680] (LE-1-2-1) Associates the established DRB with the EPS bearer identifier.

[0681] (LE-1-3) Otherwise, if the DRB-ToAddModList entry includes pdcp-config (i.e., a bearer is established in the PDCP of E-UTRA), then

[0682] (LE-1-3-1) Notifies the upper layer of the establishment of the DRB and the EPS bearer identifier of the established DRB.

[0683] (LE-2) For each DRB identifier included in the DRB-ToAddModList that is part of the current terminal device settings, then

[0684] (LE-2-1) Reset each layer and / or load according to the included settings.

[0685] (Processing LF)

[0686] (LF-1) Reset the MAC main configuration based on the MA main configuration information element (mac-MainConfig) other than the settings related to the addition, modification and / or release of the secondary timing advance group (STAG).

[0687] (LF-2) If the received mac-MainConfig includes information related to the release of STAG (stag-ToReleaseList),

[0688] (LF-2-1) If the identifier of a STAG included in stag-ToReleaseList is part of the current terminal device settings, then release the STAG represented by the identifier of the STAG for each STAG identifier.

[0689] (LF-3) If the received mac-MainConfig includes information related to STAG additions and / or modifications (stag-ToAddModList),

[0690] If the identifier of the STAG included in (LF-3-1)stag-ToAddModList is not part of the current terminal device settings, then for each TAG identifier,

[0691] (LF-3-1-1) Append the STAG corresponding to the identifier of the STAG according to the received timeAlignmentTimerSTAG.

[0692] (LF-3-2) If the identifiers of the STAGs included in stag-ToAddModList are part of the current terminal device settings, then for each STAG identifier,

[0693] (LF-3-2-1) Reset the STAG corresponding to the STAG identifier based on the received timeAlignmentTimerSTAG.

[0694] Another example of MBB-HO action is illustrated here. An example of using an RRC reset message that includes conditional switching settings in NR is shown.

[0695] For example, the RRC message sent by the base station device may include a conditional handover information element. The conditional handover information element may include a list of information elements (conditional handover settings) containing information included in one or more synchronization reset information elements. Furthermore, the conditional handover information element may include information elements (conditional handover conditions) indicating the conditions for applying each conditional handover setting, or a portion or all of the conditional handover settings.

[0696] The conditional switching setting may include some or all of the information included in RadioBearerConfig and CellGroupConfig. Furthermore, the conditional switching setting may include information indicating that it is an MBB-HO. Additionally, the conditional switching condition may include threshold information for determining whether a condition is met using a reference signal. Furthermore, the conditional switching condition may also include information indicating that the conditional switching setting should be applied immediately. For example, if the conditional switching condition indicates that the conditional switching setting should be applied immediately, and information indicating that it is an MBB-HO is added to the conditional switching setting, then processing A and processing I are performed based on the information included in the conditional switching setting, thereby achieving MBB-HO. Of course, if the condition is met even if the conditional switching condition is another condition, then processing A and processing I are performed based on the information included in the conditional switching setting, thereby achieving conditional MBB-HO.

[0697] In the MBB-HO of the NR, the terminal device can adopt a PDCP (Single PDCP) configuration that is common to both the source and the target.

[0698] For example, in the case of a 5GC core network, in the source configuration, logical channels, DRBs (or SRBs), and RLC bearers are associated through RLC bearer configuration, and then DRBs, PDCP entities, and PDU sessions are associated through drb-ToAddMod. Similarly, in the target configuration, logical channels, DRBs (or SRBs), and RLC bearers are also associated through RLC bearer configuration, and then DRBs (or SRBs), PDCP entities, and PDU sessions are associated through drb-ToAddMod. In this case, for example, logical channels, DRBs (or SRBs), and / or RLC bearers associated with the same DRB identifier (or SRB identifier) ​​in both the source and target configurations can be associated with a PDCP. Furthermore, for example, logical channels, DRBs (or SRBs), and / or RLC bearers associated with the same PDU sessions in both the source and target configurations can be associated with a PDCP.

[0699] For example, in the case of a 5GC core network, in the source configuration, logical channels, DRBs (or SRBs), and RLC bearers are associated through RLC bearer configuration, and then DRBs, PDCP entities, and PDU sessions are associated through drb-ToAddMod. Similarly, in the target configuration, logical channels, DRBs (or SRBs), and RLC bearers are also associated through RLC bearer configuration, and then DRBs (or SRBs), PDCP entities, and PDU sessions are associated through drb-ToAddMod. In this case, for example, logical channels, DRBs (or SRBs), and / or RLC bearers associated with the same DRB identifier (or SRB identifier) ​​in both the source and target configurations can be associated with a single SDAP.

[0700] Furthermore, for example, in the case where the core network is EPC, the DRB (or SRB), PDCP entity, logical channel, RLC entity (and / or RLC bearer), and EPS bearer are associated in the source configuration. Similarly, the DRB (or SRB), PDCP entity, logical channel, RLC entity (and / or RLC bearer), and EPS bearer are also associated in the target configuration. In this case, for example, logical channels and RLC entities (and / or RLC bearers) associated with the same DRB identifier (or SRB identifier) ​​in both the source and target configurations can be associated with a PDCP entity. Furthermore, for example, logical channels, RLC entities (and / or RLC bearers), and DRB (or SRB) associated with the same EPS bearer identifier in both the source and target configurations can be associated with a PDCP.

[0701] In the above-described scenario, the terminal device can be considered to have the same PDCP settings for both the source and the target associated with a PDCP. Alternatively, the terminal device can apply the PDCP settings of the target to the PDCP settings of the source.

[0702] Furthermore, when the source's DRB (or SRB) and the target's DRB, which have the same DRB identifier, are associated with a PDCP entity, the source and target's security keys (e.g., KUPenc, KUPint, KRRCenc, and / or KRRCint, etc.) are different, thus managing multiple security keys within a single PDCP entity.

[0703] Another example of MBB-HO operation is illustrated here. An example of using an RRC connection reset message that includes conditional switching settings in LTE is shown.

[0704] For example, the RRC message sent by the base station device may include a conditional handover information element. This conditional handover information element may include a list of information elements (conditional handover settings) containing information included in one or more of the mobilityControlInfo information elements. Furthermore, the conditional handover information element may include information elements (conditional handover conditions) indicating the conditions for applying each conditional handover setting, or a portion or all of the conditional handover settings.

[0705] The conditional handover settings may include some or all of the information included in the cell-wide common radio resource settings (radioBearerConfigCommon) and the terminal device-specific radio resource settings (radioBearerConfigDedicated). Furthermore, the conditional handover settings may also include information indicating MBB-HO (e.g., MakeBeforeBreak-r16). Additionally, the conditional handover conditions may include threshold information for determining whether a condition is met using a reference signal. Furthermore, the conditional handover conditions may include information indicating immediate application of the conditional handover settings. For example, if the conditional handover conditions indicate immediate application of the conditional handover settings, and information indicating MBB-HO is included in the conditional handover settings, the processing LA is performed based on the information included in the conditional handover settings, thereby enabling MBB-HO. Of course, if the condition is met even when the conditional handover conditions are other conditions, the processing LA is performed based on the information included in the conditional handover settings, thereby enabling conditional MBB-HO.

[0706] In the LTE MBB-HO (MakeBeforeBreak-r16), the terminal device can adopt a PDCP (Single PDCP) configuration that is common to both the source and the target.

[0707] For example, in the case of a 5GC core network, in the source configuration, logical channels, DRBs (or SRBs), and RLC bearers are associated through RLC bearer configuration, and then DRBs, PDCP entities, and PDU sessions are associated through drb-ToAddMod. Similarly, in the target configuration, logical channels, DRBs (or SRBs), and RLC bearers are also associated through RLC bearer configuration, and then DRBs (or SRBs), PDCP entities, and PDU sessions are associated through drb-ToAddMod. In this case, for example, logical channels, DRBs (or SRBs), and / or RLC bearers associated with the same DRB identifier (or SRB identifier) ​​in both the source and target configurations can be associated with a PDCP. Furthermore, for example, logical channels, DRBs (or SRBs), and / or RLC bearers associated with the same PDU sessions in both the source and target configurations can be associated with a PDCP.

[0708] For example, in the case of a 5GC core network, in the source configuration, logical channels, DRBs (or SRBs), and RLC bearers are associated through RLC bearer configuration, and then DRBs, PDCP entities, and PDU sessions are associated through drb-ToAddMod. Similarly, in the target configuration, logical channels, DRBs (or SRBs), and RLC bearers are also associated through RLC bearer configuration, and then DRBs (or SRBs), PDCP entities, and PDU sessions are associated through drb-ToAddMod. In this case, for example, logical channels, DRBs (or SRBs), and / or RLC bearers associated with the same DRB identifier (or SRB identifier) ​​in both the source and target configurations can be associated with a single SDAP.

[0709] Furthermore, for example, in the case where the core network is EPC, the DRB (or SRB), PDCP entity, logical channel, RLC entity (and / or RLC bearer), and EPS bearer are associated in the source configuration. Similarly, the DRB (or SRB), PDCP entity, logical channel, RLC entity (and / or RLC bearer), and EPS bearer are also associated in the target configuration. In this case, for example, logical channels and RLC entities (and / or RLC bearers) associated with the same DRB identifier (or SRB identifier) ​​in both the source and target configurations can be associated with a PDCP entity. Furthermore, for example, logical channels, RLC entities (and / or RLC bearers), and DRB (or SRB) associated with the same EPS bearer identifier in both the source and target configurations can be associated with a PDCP.

[0710] In the above-described scenario, the terminal device can be considered to have the same PDCP settings for both the source and the target associated with a PDCP. Alternatively, the terminal device can apply the PDCP settings of the target to the PDCP settings of the source.

[0711] Furthermore, when the source's DRB and the target's DRB (or SRB) with the same DRB identifier are associated with a PDCP entity, the source and target's security keys (e.g., KUPenc) are different, thus managing multiple security keys within a single PDCP entity.

[0712] It should be noted that MakeBeforeBreak-r16 can include information indicating which layer of the target should be generated or not generated until the connection to the target is completed.

[0713] It should be noted that, in the case of NR, the process (E) may include the following processes (E2-1). For example, such as Figure 22 As shown, process (E2-1) can be performed between process (E-1) and process (E-2), but is not limited to this. Furthermore, in the case of LTE, process (LF) may include the following processes (E2-1). For example, process (E2-1) may be performed before process (LF-1), but is not limited to this.

[0714] (E2-1) If it is an MBB-HO, and the MAC entity for the target (also known as the secondary MAC entity) exists as part of the current terminal device's settings, then

[0715] (E2-1-1) Generates a secondary MAC entity.

[0716] Therefore, in the processing based on the MAC layer settings, MAC entities can be generated appropriately.

[0717] Furthermore, in the case of NR, the processing within the range of processing (B-9) of (process B) can be, for example, as follows: Figure 23 The process shown is (B2-9). Furthermore, in the case of MBB-HO, the settings for "the cell group" in the subsequent processes (B-9) of process (B) can be applied to the target.

[0718] (B2-9) If the synchronization reset includes information indicating that it is an MBB-HO.

[0719] (B2-9-1) If the MAC entity used for the target (also known as the secondary MAC entity) exists as part of the current terminal device's settings, then

[0720] (B2-9-1-1) Do not reset the existing MAC entity (also known as the primary MAC entity) for this cell group.

[0721] (B2-9-1-2) Generates a secondary MAC entity.

[0722] (B2-9-2) Apply the default MAC cell group settings to the secondary MAC entity. Alternatively, apply the same settings as the primary MAC entity to the secondary MAC entity.

[0723] (B2-9-3) Reset the secondary MAC entity.

[0724] (B2-9-4) If this setting is made, the SCell of that cell group is considered to be in an inactive state (Deactivated state).

[0725] (B2-9-5) Use the value of newUE-Identity as the C-RNTI for this cell group.

[0726] Furthermore, in the case of LTE, the processing within the range of processing (LA-6) to processing (LA-7) of the (processing LA) can be, for example, as follows: Figure 24 The treatments shown are (LA2-6) and (LA2-7).

[0727] (LA2-6) If makeBeforeBreak-r16 is set, then

[0728] (LA2-6-1) The current terminal device settings (source settings) are copied as the target settings. Unless otherwise explicitly stated, the copied target settings can be processed by performing the following reconfiguration process. For example, in the case of MBB-HO, the "current terminal device settings" of each process can be regarded as the "target settings of the current terminal device". In addition, the settings to be copied may include, for example, some or all of the following: (1) bearer settings (e.g., SRB settings, DRB settings, etc.), (2) cell group settings (e.g., SpCell settings, SCell settings, RLC entity settings, MAC entity settings, PHY settings, etc.), (3) internal variables (measurement settings (VarMeasConfig), measurement results (VarMeasReportList), timers, counters, etc.), and (4) security-related settings (e.g., each key). In addition, the bearer settings to be copied may not include SRB settings. That is, regarding DRB, both source settings and target settings can be managed, and regarding SRB, the settings may not be copied, but rather the settings may be switched from source settings to target settings. Furthermore, information determining whether to copy SRB settings can be included in the RRC connection reset message, which includes mobilityControlInfo. For example, this information can be included in MakeBeforeBreak-r16. Additionally, the copying process can be accompanied by the generation of entities at each layer (e.g., RLC entities, MAC entities).

[0729] (LA2-6-2) If the MAC entity used for the target (also known as the secondary MAC entity) exists as part of the current terminal device's settings, then

[0730] (LA2-6-2-1) Do not reset the existing MAC entity (also known as the primary MAC entity) for this cell group.

[0731] (LA2-6-2-2) Generates a secondary MAC entity.

[0732] (LA2-6-3) If necessary, reset the secondary MAC entity.

[0733] (LA2-7) Otherwise

[0734] (LA2-7-1) If configured, reset the MAC of MCG and SCG.

[0735] Therefore, even if the MAC cell group setting is not included in the NR RRC reset message, the MAC entity can still be generated appropriately. Furthermore, even if the MAC master setting is not included in the EUTRA RRC connection reset message, the MAC entity can still be generated appropriately.

[0736] Furthermore, in (Process I), (Process J), or other processes, when the terminal device receives a message setting the release source, it may release the current primary MAC entity and treat the current secondary MAC entity as the primary MAC entity. Alternatively, when the terminal device receives a message setting the release source, it may reset the current primary MAC entity, not treating the current primary MAC entity as the primary MAC entity, but instead treating the current secondary MAC entity as the primary MAC entity.

[0737] Therefore, MAC entities can be managed appropriately.

[0738] It should be noted that in the above processes, the handover is performed when makeBeforeBreak-r16 includes the primary cell group settings (also known as MBB-HO), and the secondary cell group change is performed when makeBeforeBreak-r16 includes the secondary cell group settings (also known as MBB-SCG Change).

[0739] In addition, the terminal device may notify the base station device of some or all of the following information: (1) information indicating whether it supports performing either MBB-HO or MBB-SCG Change that maintains communication using more than two cell groups (e.g., Dual Connectivity, MultiConnectivity); (2) information indicating whether it supports performing MBB-HO that maintains communication using more than two cell groups (e.g., Dual Connectivity); (3) information indicating whether it supports performing MBB-SCG Change that maintains communication using more than two cell groups (e.g., Dual Connectivity); and (4) information indicating whether it supports performing both MBB-HO and MBB-SCG Change that maintain Dual Connectivity. For example, the information may be included in a message (e.g., UECapabilityInformation) in which the terminal device notifies the base station device of its radio access capability. Furthermore, the information may be notified as information independent of the frequency band combinations supported by the terminal device. Furthermore, the information may also be notified as information for each frequency band combination supported by the terminal device. Furthermore, the information may not be notified to the base station device.

[0740] Furthermore, the terminal device can release one or more cell groups other than the MCG to perform an MBB-HO. The terminal device can perform the MBB-HO even when performing an MBB-HO that maintains communication using two or more cell groups is not supported. Furthermore, the terminal device can release one or more cell groups other than the MCG to perform an MBB-SCG Change. The terminal device can also perform the MBB-SCG Change even when performing an MBB-SCG Change that maintains communication using two or more cell groups is not supported. Furthermore, the terminal device can perform a normal secondary cell group change (SCG Change) that is not an MBB-SCG Change. The terminal device can perform the secondary cell group change even when performing an MBB-SCG Change that maintains communication using two or more cell groups is not supported. SCG Change can be renamed as sync SCG reconfiguration. Furthermore, handover (HO) can be renamed as sync MCG reconfiguration.

[0741] It should be noted that when copying the current terminal device settings (source settings) as the target settings (the (A-0-1) and / or (LA-6-1) and / or (LA2-6-1)), some or all of the timer values ​​held internally in the terminal device can be inherited after copying (in the target). That is, the values ​​before copying (source) can be retained after copying (target) and continued in the target, meaning it can be started or restarted from the values ​​at the time of copying. Furthermore, some or all of the timer values ​​may not be inherited after copying (in the target). That is, the values ​​before copying (source) are not retained after copying (target) and are initialized. In the case of initialization, it can be started or restarted from the values ​​initialized in the target. The process of inheriting some or all of the timer values ​​from the source in the target can also be performed in some or all of the radio bearers. For example, in an SRB, some or all of the timer values ​​from the source can be inherited in the target; in a DRB, initialization can be performed in the target without inheriting some or all of the timer values ​​from the source. The copied timers may be some or all of the timers in each of the PDCP entity and / or RLC entity and / or MAC entity. In addition, the copied timers may include some or all of the timers listed in (A) to (E) below.

[0742] (A) A discard timer that is started on the sending side of the PDCP entity each time an SDU is received from the upper layer. The corresponding PDCP SDU can be discarded when the discard timer expires.

[0743] (B) A reordering timer used on the receiving side of the PDCP entity to detect the loss of PDCP data PDUs. It may also be a timer under the name t-Reordering as described in Non-Patent Document 5 and / or Non-Patent Document 11.

[0744] (C) A reassembly timer used as a timer for detecting the loss of RLC SDUs on the receiving side of the RLC entity. It may also be a timer named t-Reassembly as described in Non-Patent Document 6 and / or a timer named t-Reordering as described in Non-Patent Document 12.

[0745] (D) A polling retransmission timer used as a timer for polling retransmissions on the transmitting side of the RLC entity. It may also be a timer named t-PollRetransmit as described in Non-Patent Document 6 and / or Non-Patent Document 12.

[0746] (E) A status prohibition timer used as a timer for prohibiting the transmission of status PDUs on the receiving side of the RLC entity. It may also be a timer named t-StatusProhibit as described in Non-Patent Document 6 and / or Non-Patent Document 12.

[0747] It should be noted that when copying the current terminal device settings (source settings) as the target settings (the (A-0-1) and / or (LA-6-1) and / or (LA2-6-1)), some or all of the values ​​of state variables, counters, and other variables held internally in the terminal device can be inherited after copying (in the target). That is, the values ​​before copying (source) can be retained after copying (in the target) and continued in the target, meaning it can start or restart from the values ​​at the time of copying. Furthermore, the values ​​of some or all of the state variables, counters, and other variables can also be inherited after copying (in the target). That is, the values ​​before copying (source) are not retained after copying (in the target) but are initialized. In the case of initialization, it can start or restart from the values ​​initialized in the target. The processing of inheriting some or all of the values ​​of state variables, counters, and other variables from the source in the target can also be performed in some or all of the radio bearers. For example, in an SRB, the target can inherit some or all of the values ​​of state variables, counters, and other variables from their source. In a DRB, the target can be initialized without inheriting some or all of the values ​​of state variables, counters, and other variables from their source. The copied state variables, counters, and other variables can be some or all of the state variables, counters, and other variables from each entity of the PDCP entity and / or RLC entity and / or MAC entity. Furthermore, the copied state variables, counters, and other variables can include some or all of the state variables, counters, and other variables listed in (A) to (E) below.

[0748] (A) represents the state variable indicating the COUNT value of the PDCP PDU to be transmitted next on the transmitting side of the PDCP entity. It may also be a state variable with the name TX_NEXT as described in Patent Document 11.

[0749] (B) represents a state variable indicating the COUNT value of the PDCP SDU to be received next at the receiving side of the PDCP entity. It can also be a state variable with the name RX_NEXT, which is not described in Patent Document 11.

[0750] (C) represents the state variable indicating the COUNT value of the first PDCP SDU among the waiting PDCP SDUs that have not been transmitted at the upper layer on the receiving side of the PDCP entity. It can also be a state variable with the name RX_DELIV as described in Patent Document 11.

[0751] (C) represents the state variable indicating the next COUNT value of the COUNT value of the PDCP PDU that triggers the reordering timer on the receiving side of the PDCP entity. It can also be a state variable with the name RX_REORD, which is not described in Patent Document 11.

[0752] Figure 10It means Figure 4 An example of the ASN.1 description of the EUTRA RRC connection reset message. Furthermore, Figure 11 It means Figure 4 Another example of the ASN.1 description of the EUTRA RRC connection reset message. Furthermore, Figure 12 It means Figure 4 An example of the ASN.1 description of the RRC reset message for NR in the NR. Furthermore, Figure 13 It means Figure 4 Another example of the ASN.1 description of the RRC reset message for NR in NR.

[0753] exist Figure 10 and Figure 11 In this context, the information element represented by mobilityControlInfo includes parameters related to network control of mobility to EUTRA. The information element represented by mobilityControlInfo may include some or all of the following information (A) to (H).

[0754] (A) Target's physical cell identifier

[0755] (B) t304 represents the information from the start to the expiration time of timer T304.

[0756] (C) represents the newUE-Identity of the new identifier (C-RNTI) for UE122.

[0757] (D) Wireless Resource Settings

[0758] (E) Setting up a dedicated random access channel

[0759] (F) makeBeforeBreak-r14 as a parameter to set the existing (Release14) connect-before-break switching.

[0760] (G) rach-Skip-r14 as a parameter for setting RACH-less switching

[0761] (H) makeBeforeBreak-r16, which sets the parameters for the before-after switching in this implementation.

[0762] Figure 10 This indicates that makeBeforeBreak-r16 is an enumerated example. Figure 11This indicates that makeBeforeBreak-r16 has the information element MakeBeforeBreak-r16 as its value, and the information element MakeBeforeBreak-r16 has multiple fields.

[0763] exist Figure 12 and Figure 13 The information elements shown in the synchronization reset are, for example, information elements that include parameters related to PCell switching, PSCell addition, and changes. The information elements shown in the synchronization reset may include some or all of the information below (A) to (F).

[0764] (A) SpCell settings

[0765] (B) t304 represents the information from the start to the expiration time of timer T304.

[0766] (C) represents the newUE-Identity of the new identifier (RNTI) for UE122.

[0767] (D) Setting up a dedicated random access channel

[0768] (E) makeBeforeBreak-r16, which sets the parameters for the before-break switching in this implementation.

[0769] (F) rach-Skip-r16 as a parameter for setting RACH-less switching

[0770] Figure 12 This indicates that makeBeforeBreak-r16 is an enumerated example. Figure 13 This indicates that makeBeforeBreak-r16 has the information element MakeBeforeBreak-r16 as its value, and the information element MakeBeforeBreak-r16 has multiple fields.

[0771] also, Figures 10-13 Some or all of the fields shown may be optional. That is, Figures 10-13 The fields shown can be included in the message based on conditions.

[0772] It should be noted that the eNB102 or gNB108 can be configured to apply connect-before-disconnect (MBB-HO) to each radio bearer. When configuring MBB-HO for each radio bearer, the parameters related to MBB-HO can be set below the radio bearer settings (information elements represented by SRB-ToAddMod and / or DRB-ToAddMod) (lower layer), or they can exist below the information elements shown by PDCP-Config. Furthermore, when configuring MBB-HO for each radio bearer per-bearer, the information for the radio bearer applying MBB-HO can be placed above the radio bearer settings (upper layer), instead of placing the parameters related to MBB-HO below the radio bearer settings or below the information elements shown by PDCP-Config.

[0773] Figure 20 An example of ASN.1 is shown, illustrating various embodiments of the present invention, for setting whether to apply connect-before-disconnect (MBB-HO) parameters (information elements or fields) to a radio bearer to be established or set up. Figure 20 The example shows a parameter under PDCP-Config for setting whether to apply connect-before-disconnect handover to the radio bearer to be established or configured. However, under radio bearer settings, this parameter can exist anywhere. It should be noted that the above "whether to apply connect-before-disconnect handover to the radio bearer to be established or configured" can be rewritten as "whether to perform connect-before-disconnect handover on the radio bearer to be established or configured," "whether to apply connect-before-disconnect handover to the radio bearer," or similar expressions. Furthermore, the above "whether to apply connect-before-disconnect handover to the radio bearer to be established or configured" can also be rewritten as "whether to apply connect-before-disconnect handover to the PDCP entity," "whether to perform connect-before-disconnect handover on the PDCP entity," or "the PDCP entity has a second setting and a third setting," etc. The second setting can refer to the handover source (handover source) setting. The third setting can refer to the handover target (handover destination) setting. The second setting can refer to a primary setting. The third setting can refer to a secondary setting. Furthermore, if the meaning of switching between connection and disconnection is expressed by setting the source and target of a PDCP entity and / or the main and auxiliary settings, it can be referred to as other expressions.

[0774] exist Figure 20 In the example, the field expressed by mbb-drb is used as a parameter to indicate whether to apply a connect-then-disconnect switch for the wireless bearer to be established or set up, but it can also be a field and / or information element with other names. Figure 20 (A) shows an example where mbb-drb is an enumeration type. Figure 20(B) shows an example of an MBB-DRB with an information element as its value, where the information element of the MBB-DRB has one or more fields. Figure 20 In (A), it can be shown that when the field represented by mbb-drb is true, the application of connection-before-disconnection handover is performed on the PDCP entity and / or the radio bearer associated with the PDCP entity as configured by PDCP-Config. Furthermore, in Figure 20 In (B), the MBB-DRB information element may include, as a setting for the handover destination, some or all of the following parameters (not shown): the identifier of the cell group of the handover destination (a field named targetCellGroupId), the logical channel identifier associated with the PDCP entity at the handover destination (a field named targetLogicalChannelIdentity), and other parameters.

[0775] It should be noted that, Figure 20 The fields shown in the image, represented by mbb-drb, are only... Figures 10 to 13 The settings shown in the example are optional and can be present if they have the same parameters as makeBeforeBreak-r16. Figures 10 to 13 The example shown indicates that, without setting parameters equivalent to makeBeforeBreak-r16, the field represented by mbb-drb may not exist.

[0776] Figure 21 The example shown is an example of ASN.1 containing information about the wireless bearer that enables the application to switch between connected and disconnected states. Figure 21 As shown, as Figure 11 and / or Figure 13 One of the parameters of the MakeBeforeBreak-r16 information element (e.g., Figure 11 and / or Figure 13 The parameter A or parameter B shown may contain information about the wireless bearer used for connection-before-disconnect switching. Figure 21 In the example, the parameter "information on the wireless bearer for application connect-before-disconnect switching" is described using fields represented by mbb-drb and mbb-drbList (a list of mbb-drbs), but can also be fields and / or information elements with other names. For example... Figure 21As shown, the information of the radio bearer used in the above-mentioned application-based connection-before-disconnection handover can refer to some or all of the following parameters: radio bearer identifier (the field represented by drb-Identity), cell group identifier of the handover destination (the field named targetCellGroupId), logical channel identifier associated with the PDCP entity at the handover destination (the field named targetLogicalChannelIdentity), and other parameters (not shown). Furthermore, in Figure 21 In the example, without the parameter "information on the radio bearer for which connection-before-disconnection is applied", connection-before-disconnection can be applied to all radio bearers or all data radio bearers. Furthermore, as... Figure 21 The "Information on the radio bearer for application connection-before-disconnection switching" only shows information on the data radio bearer (DRB), but may also include information on the signaling radio bearer (SRB).

[0777] Figure 5 This is a block diagram illustrating the configuration of the terminal device (UE122) according to various embodiments of the present invention. It should be noted that, to avoid unnecessary detail, in... Figure 5 Only the main components closely related to the present invention are shown.

[0778] Figure 5 The UE122 shown comprises a receiving unit 500 that receives RRC messages from a base station device, a processing unit 502 that processes configuration information based on any or all of the various information elements (IEs), fields, and conditions included in the received messages, and a transmitting unit 504 that sends RRC messages to the base station device. The base station device mentioned above sometimes refers to eNB102 and sometimes to gNB108. Furthermore, the processing unit 502 may include some or all of the functions of various layers (e.g., physical layer, MAC layer, RLC layer, PDCP layer, RRC layer, and NAS layer). That is, the processing unit 502 may include some or all of the physical layer processing unit, MAC layer processing unit, RLC layer processing unit, PDCP layer processing unit, RRC layer processing unit, and NAS layer processing unit.

[0779] Figure 6 This is a block diagram illustrating the configuration of a base station apparatus according to various embodiments of the present invention. It should be noted that, to avoid unnecessary detail, in... Figure 6 Only the main components closely related to the present invention are shown. The base station device described above sometimes refers to eNB102 and sometimes to gNB108.

[0780] Figure 6The base station apparatus shown includes: a transmitting unit 600 that transmits RRC messages to UE 122; a processing unit 602 that generates RRC messages including configuration information such as various information elements, various fields, and various conditions, and transmits them to UE 122 for processing by the processing unit 502 of UE 122; and a receiving unit 604 that receives RRC messages from UE 122. Furthermore, the processing unit 602 may include some or all of the functions of various layers (e.g., physical layer, MAC layer, RLC layer, PDCP layer, RRC layer, and NAS layer). That is, the processing unit 602 may include some or all of the physical layer processing unit, MAC layer processing unit, RLC layer processing unit, PDCP layer processing unit, RRC layer processing unit, and NAS layer processing unit.

[0781] Figure 25 This is an example of a processing method for UE122 according to various embodiments of the present invention. The processing unit 602 of the base station device (eNB102 and / or gNB108) generates a message related to the resetting of the RRC connection for causing UE122 to process, and sends it to UE122 (not shown) by the sending unit 600. The receiving unit 500 of UE122 receives the message related to the resetting of the RRC connection sent by the base station device (step S2500).

[0782] The processing unit 502 of UE122 checks whether the message related to the reconfiguration of the aforementioned RRC connection includes the first information. If the first information is not included, it can be determined that it is not a call-before-disconnect handover. If the first information is included, it can be determined that it is a call-before-disconnect handover. Furthermore, if the first information is included, it can be determined that a call-before-disconnect handover is applied to a portion or all of the radio bearers currently configured in UE122, or that a call-before-disconnect handover can be applied. Furthermore, if the first information is included in the message related to the reconfiguration of the aforementioned RRC connection, the processing unit 502 of UE122 can generate a target cell group and / or MAC entity for the call-before-disconnect handover (step S2502).

[0783] The processing unit 502 of UE122 can also determine, based on the first information mentioned above, whether the message related to the resetting of the RRC connection includes the second information. If the second information is not included, it can be determined that no connect-before-disconnect handover will be applied to any radio bearers currently configured in UE122. If the second information is included, it can be determined, based on the second information, whether or not connect-before-disconnect handover will be applied to any radio bearers currently configured in UE122 (step S2504).

[0784] It should be noted that the first information mentioned above in steps S2502 and / or S2504 may refer to the information of the MBB-HO mentioned above. Furthermore, the first information mentioned above is as follows: Figure 10 or Figure 11 As shown, it can be included in the mobilityControlInfo information element, such as Figure 12 As shown Figure 13 It can also be included in the reconfigurationWithSync information element.

[0785] The processing unit 502 of UE122 can change or reset the cell group associated with the RLC bearer of the radio bearer that has not applied the above-mentioned first-connect-then-disconnect handover from the first cell group to the second cell group (step S2506).

[0786] Furthermore, the processing unit 502 of UE122 can establish a second RLC bearer for the radio bearer that applies the above-described call-before-disconnect handover, and associate it with the PDCP entity of the radio bearer that applies the above-described call-before-disconnect handover. In addition, at this time, the above-described second RLC bearer can be associated with the second cell group mentioned above (step S2506) (step S2508).

[0787] It should be noted that the second information mentioned above in steps S2504 and / or S2506 and / or S2508 may refer to whether or not the above ( Figure 21 and / or Figure 22 (As shown in the image) Information on the wireless bearer application connection-to-disconnect switching to be established or configured.

[0788] Furthermore, in step S2506 and / or step S2508, the second cell group may refer to a cell group generated based on the situation where the first information mentioned above is included in the message related to the resetting of the RRC connection mentioned above in step S2502.

[0789] Furthermore, in step S2506, changing or resetting the cell group associated with the RLC bearer of the radio bearer that has not applied the above-mentioned first cell group to the above-mentioned second cell group may refer to performing some or all of the following actions (A) and (B) on the RLC entity of the radio bearer that has not applied the above-mentioned first-to-last-disconnection handover and / or the logical channel of the radio bearer that has not applied the above-mentioned first-to-last-disconnection handover.

[0790] (A) Reset the RLC entity of the first cell group to the RLC entity of the second cell group.

[0791] (B) The logical channel of the first cell group is reset to the logical channel of the second cell group.

[0792] It should be noted that the aforementioned logical channel may refer to the DTCH logical channel. Furthermore, the aforementioned first cell group may refer to the cell group associated with the radio bearer that has not applied the aforementioned connect-before-disconnect handover before the handover is performed.

[0793] In step S2508, establishing an association between the second RLC bearer and the second cell group may refer to performing some or all of the following actions (C) and (D).

[0794] (C) Set or reset the RLC entity carried by the second RLC to the RLC entity of the second cell group.

[0795] (D) Set or reset the logical channel carried by the second RLC to the logical channel of the second cell group.

[0796] It should be noted that the logical channel mentioned above may refer to the DTCH logical channel.

[0797] Furthermore, in steps S2506 and / or S2508, both the first cell group and the second cell group can be primary cell groups (MCGs). Furthermore, in steps S2506 and / or S2508, the first cell group and the second cell group can be referred to as the first MAC entity and the second MAC entity, respectively. The aforementioned second MAC entity can refer to the target MAC entity for the handover generated in step S2502. Furthermore, the aforementioned first cell group can refer to the source MCG during the handover and / or the MCG when no handover is performed. Furthermore, the aforementioned second cell group can refer to the target MCG during the handover. Furthermore, the aforementioned first MAC entity can refer to the source MAC entity during the handover and / or the MAC entity when no handover is performed. Furthermore, the aforementioned second MAC entity can refer to the target MAC entity during the handover.

[0798] Furthermore, in step S2506, before changing the cell group associated with the RLC bearer that has not applied the call-before-disconnect handover from the first cell group to the second cell group, the radio bearer that has not applied the call-before-disconnect handover can be copied. The copying of the radio bearer can refer to preparing a radio bearer with the same settings as the aforementioned radio bearer. Furthermore, the copying of the radio bearer can refer to preparing a radio bearer with the same settings as the aforementioned radio bearer and with the same data being processed as the aforementioned radio bearer. Furthermore, the data being processed by the aforementioned radio bearer may include PDUs and / or SDUs stored at each layer, buffers at each layer, variables stored at each layer, timer values, etc. Furthermore, either the radio bearer that has not applied the call-before-disconnect handover or the copied radio bearer can be stopped. Furthermore, the process of "changing the cell group associated with the RLC bearer that has not applied the call-before-disconnect handover from the first cell group to the second cell group" in step S2506 can be performed on the bearer for which the aforementioned stopping is not performed. Furthermore, the aforementioned cessation of wireless bearer transmission may include the cessation of uplink transmission or the cessation of downlink reception.

[0799] Furthermore, in step S2502 above, it can be determined that all radio bearer applications should be switched from connection to disconnection based on the inclusion of the first information in the message related to the resetting of the RRC connection, thus replacing the processing in step S2504 above. In this case, the processing in step S2506 above may also be omitted.

[0800] Figure 26This is another example of the processing method of UE122 according to various embodiments of the present invention. The processing unit 502 of UE122, which attempts to handover from a handover source to a handover destination, detects that the first timer has expired (step S2600). It should be noted that the aforementioned first timer may also refer to a timer used to detect handover failure, etc. Furthermore, the aforementioned first timer may also refer to a timer that starts when a message related to the reconfiguration of an RRC connection, including parameters indicating handover (an information element named MobilityControlInfo as described in Non-Patent Document 4 or an information element named ReconfigurationWithSync as described in Non-Patent Document 10), is received, or when moving from a cell of a different RAT (CellChangeOrder as described in Non-Patent Document 4), and stops when the handover is successful, the CellChangeOrder is successful, or random access to the corresponding (handover destination) SpCell is successful. Furthermore, if the aforementioned first timer expires, it can be considered a handover failure. Furthermore, if the aforementioned first timer expires, UE122 may also initiate an RRC connection re-establishment process. Furthermore, when UE122 initiates the re-establishment of the RRC connection upon the expiration of the aforementioned first timer, the settings of UE122 can be returned to the settings of the handover source. Additionally, when the aforementioned first timer expires during a handover to a different RAT, the cell of the handover source can be selected to re-establish the aforementioned RRC connection. Furthermore, the aforementioned first timer can also refer to timer T304 as described in Non-Patent Document 4 or Non-Patent Document 10. It should be noted that the aforementioned handover can also refer to the processing of UE122 changing its serving cell in the RRC connection state as described in Non-Patent Document 3. Furthermore, the aforementioned handover can also be a process performed upon receiving a message related to the re-establishment of the RRC connection, including parameters indicating handover (information elements named MobilityControlInfo as described in Non-Patent Document 4 or ReconfigurationWithSync as described in Non-Patent Document 10), or it can be a message indicating movement to a cell of another RAT (e.g., MobilityFromEUTRACommand as described in Non-Patent Document 4 or MobilityFromNRCommand as described in Non-Patent Document 10). Furthermore, the aforementioned handover can also refer to DAPS handover.

[0801] In step S2600, the processing unit 502 of UE122, which detected that the first timer had expired, can then determine whether a first setting has been performed on UE122. If a first setting has been performed on UE122, some or all of the settings for the handover destination (target) can be released based on the first setting (step S2602). It should be noted that the aforementioned first setting may refer to settings related to DAPS handover, or settings related to radio bearers applying DAPS handover. Furthermore, the aforementioned case of performing a first setting can be referred to as the case of setting for DAPS handover of any radio bearer, or the case of setting for DAPS handover of at least one radio bearer, or similar other expressions. Furthermore, the aforementioned release of some or all of the settings for the handover destination (target) may refer to the release of some or all of the settings for the handover destination (target), including RLC entities and logical channels, for radio bearers applying DAPS handover. Furthermore, the aforementioned release of the handover destination (target) setting can refer to releasing some or all of the settings for the handover destination (target) for radio bearers that are not using DAPS handover, including the PDCP entity and bearer identifier, RLC entity and logical channel, and the corresponding rules of QoS flows and radio bearers in SDAP. Additionally, the MAC entity of the handover destination (target) can also be reset when the aforementioned release of the handover destination (target) setting is performed.

[0802] Furthermore, in step S2602, the processing unit 502 of UE122 can determine whether a first setting has been performed on UE122. If a first setting has been performed on UE122, it can also determine whether a radio link failure has been detected in the primary cell of the handover source. If no radio link failure has been detected in the primary cell of the handover source, some or all of the settings for the handover destination (target) can be released based on the aforementioned first setting of UE122 and the absence of a radio link failure detected in the primary cell of the handover source. It should be noted that the aforementioned primary cell can be a PCell (Primary Cell) or a SpCell (Special Cell).

[0803] Furthermore, in step S2600, the processing unit 502 that detects the expiration of the first timer of UE122 can determine whether a first setting has been performed on UE122. If a first setting has been performed on UE122, the security key for the handover source setting is updated based on the first setting (step S2604). It should be noted that the aforementioned first setting may refer to a setting related to DAPS handover, or a setting related to a radio bearer to which DAPS handover is applied. Furthermore, the aforementioned case of performing a first setting can be referred to as a case of setting for DAPS handover of any radio bearer, or a case of setting for DAPS handover of at least one radio bearer, or similar other expressions. Furthermore, the aforementioned setting of the security key for the handover source can be referred to as a security key set for the handover source. Furthermore, the aforementioned update of the security key may refer to a process including some or all of the following (A) to (B).

[0804] (A) Generate a base station key based on the current base station key or NH (Next Hop) information.

[0805] (B) Generate one or all of the following: the secret key for SRB, the integrity key for SRB, the secret key for DRB, and the integrity key for DRB.

[0806] Furthermore, in step S2604, whether the security key has been updated or not, some or all of the following processes (C) to (F) may be performed.

[0807] (C) For some or all of the SRBs, set up a lower layer so that the above-mentioned SRB integrity key or the set SRB integrity key and the set integrity algorithm can be used for integrity protection processing.

[0808] (D) For some or all of the DRBs, set up a lower layer so that integrity protection processing can be performed using the DRB integrity key or the set DRB integrity key and set integrity algorithm.

[0809] (E) For some or all of the SRBs, set up a lower layer so that the SRBs can be encrypted using the aforementioned secret key or the set SRB secret key and the set secret algorithm.

[0810] (F) For a portion or all of the DRBs, set up a lower layer so that encryption can be performed using the aforementioned DRB secret key or the set DRB secret key and the set secret algorithm.

[0811] It should be noted that in step S2604, the base station key can be either the KeNB or the KgNB described in Non-Patent Document 21. Furthermore, in step S2604, the integrity key for the SRB and the integrity key for the DRB can be KRRCint and KUPint, respectively, as described in Non-Patent Document 21 and / or Non-Patent Document 22. Additionally, in step S2604, the secrecy key for the SRB and the secrecy key for the DRB can be KRRCenc and KUPenc, respectively, as described in Non-Patent Document 21 and / or Non-Patent Document 22. Furthermore, in step S2604, the aforementioned NH (NextHop) can be the NH (Next Hop) described in Non-Patent Document 21 and / or Non-Patent Document 22. Furthermore, in step S2604, the lower layer can be a PDCP layer or a PDCP entity.

[0812] Furthermore, the process in step S2604 (C) can also be modified to set a lower layer for all SRBs except SRB1, so as to perform integrity protection using the aforementioned SRB integrity key or the set SRB integrity key and the set integrity algorithm. Furthermore, the process in step S2604 (E) can also be modified to set a lower layer for all SRBs except SRB1, so as to perform encryption using the aforementioned SRB secrecy key or the set SRB secrecy key and the set secrecy algorithm. Furthermore, in step S2600, some or all of the processes in step S2604 can be performed after UE122 detects that the first timer has expired and before sending the first RRC message to the base station device of the handover source. Furthermore, in step S2600, some or all of the processes in step S2604 can be performed after UE122 detects that the first timer has expired and after sending the first RRC message to the base station device of the handover source. The first RRC message mentioned above may refer to an RRC message used to notify of a failed DAPS handover to the target. Furthermore, after sending the first RRC message to the base station device of the handover source, a lower layer can be configured for SRB1 or some or all radio bearers to perform integrity protection processing using the aforementioned SRB integrity key or a configured SRB integrity key and configured integrity algorithm. Additionally, after sending the first RRC message to the base station device of the handover source, a lower layer can be configured for SRB1 or some or all radio bearers to perform encryption processing using the aforementioned SRB secrecy key or a configured SRB secrecy key and configured secrecy algorithm. Furthermore, in step S2604, some or all radio bearers can be suspended before or after updating the security key. Additionally, after UE122 detects the expiration of the first timer, some or all of the suspended radio bearers can be resumed when or before sending the first RRC message to the base station device of the handover source. The aforementioned resumed radio bearer may include SRB1 or all SRBs.

[0813] Furthermore, in step S2600, some or all of the processing in step S2604 can be performed when the UE122 detects that the first timer has expired, or after receiving the first RRC message from the base station device of the switching source.

[0814] Furthermore, in step S2600, some or all of the processing in step S2604 can be performed after UE122 detects the expiration of the first timer, based on the inclusion of parameters indicating security key updates in the first RRC message received from the handover source base station device. The first RRC message received from the handover source base station device can be a message related to the resetting of the RRC connection, a message related to the resumption of the RRC connection, or other RRC messages. The parameters indicating security key updates can be included in the aforementioned RRC message based on the failure of the DAPS handover. Furthermore, the parameters indicating security key updates can refer to the parameter (field) represented by the name securityConfigHO as described in Non-Patent Document 4, or the parameter (field) represented by the name masterKeyUpdate as described in Non-Patent Document 10.

[0815] Furthermore, in step S2604, the MAC entity of the handover source can be reset. This resetting of the MAC entity can be performed before or after the security key update process of the handover source, or it can be performed after UE122 detects the expiration of the first timer and before sending the first RRC message to the base station device of the handover source, or it can be performed after sending the first RRC message. Additionally, the resetting of the MAC entity can also be performed after UE122 detects the expiration of the first timer and when receiving the first RRC message from the base station device of the handover source, or after receiving the first RRC message. Furthermore, in step S2604, a portion or all of the PDCP entities of the radio bearer can be re-established before or after the security key update process of the handover source.

[0816] Furthermore, in step S2604, the processing unit 502 of UE122 can determine whether a first setting has been performed on UE122. If a first setting has been performed on UE122, it can also determine whether a radio link failure has been detected in the primary cell of the handover source. If no radio link failure has been detected in the primary cell of the handover source, the security key for the handover source setting and the aforementioned processing can be updated based on the first setting performed on UE122 and the absence of a radio link failure detected in the primary cell of the handover source. It should be noted that the primary cell can be a PCell (Primary Cell) or a SpCell (Special Cell).

[0817] Furthermore, in step S2604, based on the first setting performed on UE122 and / or the absence of a radio link failure detected in the primary cell of the handover source, a process can be performed to revert the settings used in the handover source for some or all radio bearers. This reverting of settings used in the handover source can be performed on radio bearers for which DAPS handover has not been applied. Furthermore, the reverting of settings used in the handover source for some or all radio bearers in step S2604 can be performed before or after the security key update process, or after UE122 detects the expiration of the first timer and before sending the first RRC message to the base station device of the handover source, or after sending the first RRC message.

[0818] It should be noted that in step S2604, the security key update may also be performed without being based on the first setting of UE122 and / or the absence of a radio link failure detected in the primary cell of the handover source.

[0819] It should be noted that in step S2604, the security key may not need to be updated.

[0820] The receiving unit 500 of UE122 can receive messages related to the resetting of the RRC connection from the base station device. The processing unit 502 of UE122 can establish or reset the radio bearer based on the aforementioned messages related to the resetting of the RRC connection (step S2606). It should be noted that some or all of the processing in step S2604 can be performed when establishing or resetting the radio bearer in step S2606.

[0821] Furthermore, in steps S2604 and / or S2606, based on the first setting performed on UE122 and / or the absence of a radio link failure detected in the primary cell of the handover source, some or all of the data existing in the buffer may be discarded for some or all of the radio bearers. The data existing in the buffer may refer to some or all of PDCP SDU, PDCP PDU, RLC SDU, RLC SDU segment, RLC PDU, MAC SDU, and MAC PDU. Additionally, the data existing in the buffer may also include data existing in the retransmission buffer. The process of discarding some or all of the data existing in the buffer based on the first setting performed on UE122 and / or the absence of a radio link failure detected in the primary cell of the handover source may also be performed after the process of reverting the settings used in the handover source for radio bearers where DAPS handover was not applied. Furthermore, the aforementioned process of discarding part or all of the data existing in the buffer based on the first setting of UE122 and / or the absence of a radio link failure detected in the primary cell of the handover source can also be performed after the process of reverting the settings used in the handover source to the bearer (UM DRB) that has been set or established in the radio bearer where DAPS handover has not been applied. Furthermore, the aforementioned process of discarding part or all of the data existing in the buffer based on the first setting of UE122 and / or the absence of a radio link failure detected in the primary cell of the handover source can also be performed by a discard timer set in the PDCP entity. The aforementioned discard timer can also refer to a timer with the name discardTimer as described in Non-Patent Document 5 and / or Non-Patent Document 11. The aforementioned discard timer can be a timer started on the transmitting side of the PDCP entity each time an SDU is received from the upper layer, and the SDU can also be discarded upon the expiration of the discard timer. The value of the discard timer in the target discard timer at the expiration time point of the first timer can also be applied to the value of the aforementioned discard timer. That is, when performing the process of reverting the wireless bearer to the settings used in the switching source, the discard timer in the target can be kept at its value, and the discard timer in the target can be continued in the wireless bearer that reverts to the settings used in the switching source.Furthermore, the radio bearer that performs the above-mentioned processing of discarding part or all of the data existing in the buffer based on the first setting of UE122 and / or the absence of radio link failure detected in the primary cell of the handover source can be pre-configured via RRC messages.

[0822] Furthermore, in steps S2604 and / or S2606, based on the first setting performed on UE122 and / or the absence of a radio link failure detected in the primary cell of the handover source, some or all of the timers set in each entity may be stopped and / or started and / or restarted for some or all radio bearers. The aforementioned timers set in each entity may refer to some or all of the timers in each entity of the PDCP entity and / or RLC entity and / or MAC entity. The aforementioned process of stopping and / or starting and / or restarting some or all of the timers set in each entity based on the first setting performed on UE122 and / or the absence of a radio link failure detected in the primary cell of the handover source may also be performed after the process of reverting the settings used in the handover source for radio bearers where DAPS handover was not applied. The aforementioned process of stopping and / or starting and / or restarting some or all of the timers set in each entity based on the first setting of UE122 and / or the absence of a radio link failure detected in the primary cell of the handover source can also be performed after the process of reverting the settings used in the handover source to the settings of the radio bearer that has been set or established with RLCUM in the radio bearer that has not applied DAPS handover. Furthermore, the radio bearer for which the aforementioned process of stopping and / or starting and / or restarting some or all of the timers set in each entity based on the first setting of UE122 and / or the absence of a radio link failure detected in the primary cell of the handover source can be preset via RRC messages. Furthermore, the aforementioned timers set in each entity may also include some or all of the timers listed in (A) to (D) below.

[0823] (A) A reordering timer used on the receiving side of the PDCP entity to detect the loss of PDCP data PDUs. It may also be a timer under the name t-Reordering as described in Non-Patent Document 5 and / or Non-Patent Document 11.

[0824] (B) A reassembly timer used as a timer for detecting the loss of RLC SDU at the receiving side of the RLC entity. It may also be a timer named t-Reassembly as described in Non-Patent Document 6 and / or a timer named t-Reordering as described in Non-Patent Document 12.

[0825] (C) A polling retransmission timer used as a timer for polling retransmissions on the transmitting side of the RLC entity. It may also be a timer named t-PollRetransmit as described in Non-Patent Document 6 and / or Non-Patent Document 12.

[0826] (D) The status prohibition timer, which serves as a timer for prohibiting the transmission of the status PDU on the receiving side of the RLC entity, may also be a timer with the name t-StatusProhibit as described in Non-Patent Document 6 and / or Non-Patent Document 12.

[0827] Furthermore, in steps S2604 and / or S2606, based on the first setting performed on UE122 and / or the absence of a radio link failure detected in the primary cell of the handover source, some or all of the state variables set in each e-entity may be set and / or reset to their initial values ​​for some or all radio bearers. The aforementioned state variables set in each entity may refer to some or all of the state variables in each entity of the PDCP entity and / or RLC entity and / or MAC entity. The process of setting and / or resetting some or all of the state variables set in each entity to their initial values ​​based on the first setting performed on UE122 and / or the absence of a radio link failure detected in the primary cell of the handover source can also be performed after the process of reverting the settings used in the handover source for radio bearers that have not undergone DAPS handover. The aforementioned process of setting and / or resetting some or all of the state variables set in each entity to their initial values ​​based on the first setting of UE122 and / or the absence of a radio link failure detected in the primary cell of the handover source can also be performed after the process of reverting the settings used in the handover source to those of the bearers (UM DRBs) that have been set or established with RLC UM in radio bearers that have not applied DAPS handover. Furthermore, the radio bearers that perform the aforementioned process of setting and / or resetting some or all of the state variables set in each entity to their initial values ​​based on the first setting of UE122 and / or the absence of a radio link failure detected in the primary cell of the handover source can also be pre-configured via RRC messages.

[0828] Furthermore, in steps S2604 and / or S2606, based on the first setting performed on UE122 and / or the absence of a radio link fault detected in the primary cell of the handover source, a portion or all of the radio bearers may be reverted to the settings used in the handover source, but at this time, a portion or all of the data may not be reverted to the settings or states used in the handover source. The aforementioned portion or all of the data may refer to a portion or all of PDCP SDU, PDCP PDU, RLC SDU, RLC SDU segment, RLC PDU, MAC SDU, and MAC PDU. This process of reverting the settings used in the handover source to a portion or all of the radio bearers based on the first setting performed on UE122 and / or the absence of a radio link fault detected in the primary cell of the handover source, but at this time, a portion or all of the data may not be reverted to the settings or states used in the handover source, can be performed on radio bearers for which DAPS handover has not been applied, or on UM bearers for which DAPS handover has not been applied. Furthermore, the radio bearers that perform the above-mentioned processing based on the first setting of UE122 and / or the absence of radio link failure detected in the primary cell of the handover source, and revert some or all of the settings used in the handover source but at this time some or all of the data are not reverted to the settings or states used in the handover source, can also be pre-configured via RRC messages.

[0829] Furthermore, in steps S2604 and / or S2606, based on the first setting performed on UE122 and / or the absence of a radio link fault detected in the primary cell of the handover source, some or all radio bearers may be reverted to the settings used in the handover source. However, at this time, the values ​​of some or all timers may not be reverted to the settings or states used in the handover source, but instead are set to initial values, and the process may be started or restarted. This process, based on the first setting performed on UE122 and / or the absence of a radio link fault detected in the primary cell of the handover source, may be performed on some or all radio bearers to revert to the settings used in the handover source. However, the values ​​of some or all timers may not be reverted to the settings or states used in the handover source, but instead are set to initial values, and the process may be started or restarted. This process may be performed on radio bearers for which DAPS handover has not been applied, or on UM bearers for which DAPS handover has not been applied. Furthermore, the radio bearers that perform the above-mentioned process of reverting the settings used in the handover source to some or all radio bearers based on the first setting of UE122 and / or the absence of radio link failure detected in the primary cell of the handover source, but at this time, the values ​​of some or all timers are not reverted to the settings or states used in the handover source but are set to initial values, and then started or restarted, can also be preset via RRC messages. The aforementioned some or all timers may include some or all of the timers listed in (A) to (E) below.

[0830] (A) A discard timer that is started on the sending side of the PDCP entity each time an SDU is received from the upper layer. The corresponding PDCP SDU can be discarded when the discard timer expires.

[0831] (B) A reordering timer used on the receiving side of the PDCP entity to detect the loss of PDCP data PDUs.

[0832] (C) A reassembly timer used as a timer for detecting the loss of RLC SDU on the receiving side of the RLC entity.

[0833] (D) A polling retransmission timer used as a timer for polling retransmissions on the sending side of an RLC entity.

[0834] (E) A state disable timer used on the receiving side of the RLC entity to disable the transmission of state PDUs.

[0835] Furthermore, in steps S2604 and / or S2606, a process can also be performed based on the first setting performed on UE122 and / or the absence of a radio link fault detected in the primary cell of the handover source. This process involves reverting some or all radio bearers to the settings used in the handover source, but at this time, some or all state variables are not reverted to their original values; instead, they are set to initial values, and the process is initiated or restarted. This process, based on the first setting performed on UE122 and / or the absence of a radio link fault detected in the primary cell of the handover source, involves reverting some or all radio bearers to the settings used in the handover source. However, at this time, the values ​​of some or all state variables are not reverted to their original values; instead, they are set to initial values, and the process is initiated or restarted. This process can be performed on radio bearers for which DAPS handover has not been applied, and it can also be performed on UM bearers for which DAPS handover has not been applied. Furthermore, the radio bearers that perform the aforementioned process—based on the initial setting of UE122 and / or the absence of a radio link failure detected in the primary cell of the handover source—can also be pre-configured via RRC messages. This involves reverting some or all radio bearers to the settings used in the handover source, but instead setting some or all state variables to initial values ​​instead of reverting them to the settings or states used in the handover source, and then initiating or restarting the process. The aforementioned "some or all" state variables can refer to some or all of the state variables of the PDCP entity, the RLC entity, or the MAC entity.

[0836] Furthermore, in steps S2604 and / or S2606, based on the first setting of UE122 and / or the absence of a radio link failure detected in the primary cell of the handover source, some or all of the PDCP entities of the radio bearer may perform status report transmission and / or data recovery. The aforementioned status report may also refer to the status report described in Non-Patent Document 5 and / or Non-Patent Document 11. That is, the aforementioned status report may refer to a report used to convey the COUNT value of a PDCP SDU awaiting reception (a PDCP SDU that failed to be received) to the transmitting side. Furthermore, the aforementioned data recovery may also refer to the data recovery described in Non-Patent Document 5 and / or Non-Patent Document 11. That is, the aforementioned data recovery may refer to the processing of retransmitting PDCP data PDUs (PDCP Data PDUs) that did not receive a notification of successful transmission from the lower layer in a radio bearer (AM DRB) with configured or established RLC AM. The aforementioned process of performing status report transmission and / or data recovery in the PDCP entities of some or all radio bearers, based on the first configuration of UE122 and / or the absence of radio link failure detected in the primary cell of the handover source, can be performed on radio bearers undergoing DAPS handover. Furthermore, the aforementioned process of performing status report transmission and / or data recovery in the PDCP entities of some or all radio bearers, based on the first configuration of UE122 and / or the absence of radio link failure detected in the primary cell of the handover source, can also be performed on AM DRBs undergoing DAPS handover.

[0837] It should be noted that some or all of the term "handover source" in steps S2600 to S2606 can be changed to "PCell of the handover source" or "cell group of the handover source". Similarly, some or all of the term "handover destination" in steps S2600 to S2606 can be changed to "PCell of the handover destination" or "cell group of the handover destination".

[0838] Figure 27 This is another example of the processing method of UE122 according to various embodiments of the present invention. The processing unit 502 of UE122 receives a first message from gNB108. For example, the first message may be a message related to the reconfiguration of the RRC connection, which includes parameters indicating the handover (an information element named MobilityControlInfo as described in Non-Patent Document 4 or an information element named ReconfigurationWithSync as described in Non-Patent Document 10).

[0839] Upon receiving the first message, the processing unit 502 of UE122 may determine whether a first setting has been performed (step S2700) if the first message includes parameters indicating the handover. If the first setting has been performed, UE122 may establish a second PDCP entity using the same settings as those for the first PDCP entity of the first signaling radio bearer (SRB) (step S2702). Furthermore, UE122 may also terminate the first PDCP entity (step S2704).

[0840] The termination of a PDCP entity can refer to some or all of the following processes: (A) the cessation of data transmission and reception with the upper and / or lower layers, (B) the retention of the values ​​of state variables, and (C) the retention of the values ​​of timers.

[0841] It should be noted that the aforementioned first setting may refer to settings related to DAPS handover, or settings related to the radio bearer to which DAPS handover is applied. Furthermore, the aforementioned situation of performing the first setting can be rewritten as the situation of performing DAPS handover on any radio bearer, or as the situation of performing DAPS handover on at least one radio bearer, or similar other expressions. Additionally, "whether the first setting has been performed" and "whether the first setting has been set" can be used interchangeably.

[0842] Furthermore, the settings in step S2702 may also include state variables related to the PDCP entity. Furthermore, the settings in step S2702 may also include constants related to the PDCP entity. Furthermore, the settings in step S2702 may also include timers related to the PDCP entity.

[0843] Furthermore, the execution order of steps S2702 and S2704 can also be reversed.

[0844] Therefore, the source settings can be stopped and maintained during DAPS switching, and appropriate parameters can be provided to the SRB that needs to be set to the target.

[0845] Figure 28 This is another example of the processing method of UE122 according to various embodiments of the present invention. The processing unit 502 of UE122 receives a first message from gNB108. For example, the first message may be a message related to the reconfiguration of the RRC connection, which includes parameters indicating the handover (an information element named MobilityControlInfo as described in Non-Patent Document 4 or an information element named ReconfigurationWithSync as described in Non-Patent Document 10).

[0846] Upon receiving the first message, the processing unit 502 of UE122 can also determine whether a first setting has been performed on the first message. If a first setting has been performed, the first PDCP entity for the DRB can be reset to a third PDCP entity (step S2800). When a first setting is performed for each DRB, the first PDCP entity for the DRB with the first setting can also be reset to a third PDCP entity. Here, the first PDCP entity may refer to a PDCP entity that sets one confidentiality key, one integrity key, and / or one RoHC protocol. Furthermore, the third PDCP entity may refer to a PDCP entity that sets two confidentiality keys, two integrity keys, and / or two RoHC protocols, for both source and destination applications.

[0847] UE122 determines whether the first message includes the second information (step S2802).

[0848] If the first message includes the second information, UE122 may set the target's covert key (second covert key) based on the third information included in the first message (step S2804).

[0849] UE122 may apply the covert key (first covert key) used for the source as the covert key (second covert key) used for the target (step S2806) even if the second information is not included in the first message.

[0850] It should be noted that the aforementioned first setting may refer to settings related to DAPS handover, or settings related to the radio bearer to which DAPS handover is applied. Furthermore, the aforementioned situation of performing the first setting can be rewritten as the situation of performing DAPS handover on any radio bearer, or as the situation of performing DAPS handover on at least one radio bearer, or similar other expressions. Additionally, "whether the first setting has been performed" and "whether the first setting has been set" can be used interchangeably.

[0851] It should be noted that steps S2802 to S2806 can also be omitted if the settings of each DRB included in the first message include information to disable confidentiality. In other words, steps S2802 to S2806 can also be performed without including information to disable confidentiality.

[0852] It should be noted that the second information mentioned above can be the MasterKeyUpdate information element in Non-Patent Document 10. The second information may also include information indicating that UE122 must derive a new KeNB (e.g., keySetChangeIndicator in Non-Patent Document 10) and / or NCC. The second information may also be other information elements.

[0853] It should be noted that the aforementioned third information can be the securityConfig described in Non-Patent Document 10. The third information may also include information indicating the settings for the security algorithm used and / or which key among the master and secondary keys is being used. The third information element can also be other information elements.

[0854] Alternatively, if the settings of each DRB included in the first message include information indicating that integrity protection is enabled, UE122 may perform the following processing.

[0855] UE122 determines whether the first message includes the second information. If the first message includes the second information, UE122 can set an integrity key (also called an integrity protection key) (second integrity key) for the target based on the third information included in the first message. If the first message does not include the second information, UE122 can apply the integrity key (first integrity key) used for the source as the integrity key (second integrity key) used for the target.

[0856] Therefore, for example, it enables efficient setting of confidentiality and / or integrity keys, such as in situations where key changes are not required during DAPS switching.

[0857] Thus, in the embodiments of the present invention, efficient communication can be performed during the handover of UE122.

[0858] The radio bearers mentioned above can be DRB, SRB, or both DRB and SRB.

[0859] The source and target mentioned above can also be referred to as the source cell and (in RRC messages, etc.) the target cell.

[0860] The source and target mentioned above can also be referred to as the source cell group and (in RRC messages, etc.) the target cell group.

[0861] Furthermore, in the above description, a radio bearer that uses DAPS handover can refer to a DRB that uses DAPS handover. Conversely, a radio bearer that does not use DAPS handover can refer to a DRB that does not use DAPS handover.

[0862] Furthermore, in the above explanation, expressions such as "related", "establish correspondence", and "establish association" can be used interchangeably.

[0863] Furthermore, in the examples of processes or processes described above, some or all of the steps may not be performed. Furthermore, the order of the steps may differ in the examples of processes or processes described above. Furthermore, in the examples of processes or processes described above, some or all of the processes in each step may not be performed. Furthermore, the order of the processes in each step may differ in the examples of processes or processes described above.

[0864] In the above description, "in the case of MBB-HO" and / or "is MBB-HO" can refer to the situation where, during an RRC connection reset including MobilityControlInfo in LTE or an RRC reset including synchronization reset in NR, transmission and / or reception in the target cell are performed while the transmission and / or reception of user data in the source cell continue. Other names indicating equivalent actions can also be used. Furthermore, "in the case of MBB-HO" and / or "is MBB-HO" can refer to the situation where, in LTE or NR, specific information elements (e.g., Figures 10-13 , Figure 21 The MakeBeforeBreak-r16 information elements and / or shown in the document Figures 20-22 The MBB-DRB shown includes cases in RRC reset messages. Furthermore, "in the case of MBB-HO" and / or "is MBB-HO" can also refer to a situation where the time during which data communication between the terminal device and the base station device is not possible (interruption time) is set to zero milliseconds (0 msec) or close to zero milliseconds, and can also be expressed by other names.

[0865] Furthermore, in the above description, "settings related to MBB-HO" can refer to the settings for transmitting and / or receiving user data in the target cell while continuing to transmit and / or receive user data in the source cell during an RRC connection reset including MobilityControlInfo in LTE or an RRC reset including synchronization reset in NR. It can also be expressed by another name indicating an equivalent setting. Additionally, "settings related to MBB-HO" can also refer to specific information elements (e.g., in LTE or NR)... Figures 10-13 , Figure 21 The MakeBeforeBreak-r16 information elements and / or shown in the document Figures 20-21The MBB-DRB shown includes cases in RRC reset messages. Furthermore, "in the case of MBB-HO" and / or "is MBB-HO" can also refer to a situation where the time during which data communication between the terminal device and the base station device is not possible (interruption time) is set to zero milliseconds (0 msec) or close to zero milliseconds, and can also be expressed by other names.

[0866] Furthermore, in the above description, "MBB-HO" can include the situation where the target primary cell group and the source primary cell group coexist. Additionally, "MBB-HO" can refer to a situation where, during RRC connection reconfiguration including MobilityControlInio in LTE or during RRC reconfiguration including synchronization reconfiguration in NR, in a portion or all of the radio bearers configured in the terminal device, transmission and / or reception of user data in the target cell continues while transmission and / or reception in the source cell. It can also be expressed by other names indicating equivalent processing. Furthermore, "MBB-HO" can refer to a specific first information element (e.g., ...) in LTE or NR. Figures 10-13 , Figure 21 The MakeBeforeBreak-r16 information element shown is included in messages related to the reconfiguration of the RRC connection. Furthermore, the radio bearer described above, which transmits and / or receives user data in the target cell while continuing to transmit and / or receive user data in the source cell, can be a radio bearer applying a connection-before-disconnection handover. A radio bearer applying the aforementioned connection-before-disconnection handover can refer to a specific second information element (e.g., Figures 20-21 The wireless bearer shown in the figure is represented by mbb-drb.

[0867] Furthermore, in the above description, "MBB-HO" can refer to a situation where the time during which data communication between the terminal device and the base station device cannot be performed (interruption time) is set to zero milliseconds (0mssec) or close to zero milliseconds (RUDI: Reduce User Data Interruption), or it can be expressed by other names.

[0868] It should be noted that in various embodiments of the present invention, the switching can be renamed as Reconfiguration With Sync. For example, the switch from connection to disconnection can be renamed as Connection to disconnection with synchronous reconfiguration.

[0869] It should be noted that, in the above explanation, "A can be renamed B" includes not only renaming A to B, but also renaming B to A. Furthermore, in the above explanation, when "C can be D" and "C can be E" are stated, it can include the case where "D can be E". Additionally, in the above explanation, when "F can be G" and "G can be H" are stated, it can include the case where "F can be H".

[0870] Furthermore, in the above explanation, when condition "A" is the opposite of condition "B", condition "B" can be expressed as an "other" condition of condition "A".

[0871] Hereinafter, various embodiments of the terminal device according to the present invention will be described.

[0872] (1) A first embodiment of the present invention is a terminal device that communicates with a base station device. The terminal device includes: a receiving unit that receives a first message from the base station device; and a processing unit that sets and / or resets the terminal device based on the first message, sets a first setting based on a first data radio bearer (DRB) established in the terminal device, establishes a second PDCP entity using the same setting as the setting for a first PDCP entity for a first signaling radio bearer (SRB), and terminates the first PDCP entity.

[0873] (2) In the first embodiment, when the second PDCP entity is established, some or all of the values ​​of the state variables, constants and / or timers used in the first PDCP entity are inherited by the second PDCP entity.

[0874] (3) In the first embodiment, the establishment of the second PDCP entity is performed before the access layer security key in the terminal device is updated based on the second information included in the first message.

[0875] (4) The second embodiment is a method for a terminal device that communicates with a base station device, the method comprising: a receiving step of receiving a first message from the base station device; and a processing step of setting and / or resetting the terminal device based on the first message, setting a first setting based on a first data radio bearer (DRB) established in the terminal device, establishing a second PDCP entity using the same setting as the setting for a first PDCP entity for a first signaling radio bearer (SRB), and terminating the first PDCP entity.

[0876] (4) The third embodiment is an integrated circuit installed in a terminal device that communicates with a base station device, enabling the terminal device to perform the following functions: receiving a first message from the base station device; setting and / or resetting the terminal device based on the first message, setting a first setting based on a first data radio bearer (DRB) established in the terminal device, establishing a second PDCP entity using the same setting as the setting for a first PDCP entity for a first signaling radio bearer (SRB), and terminating the first PDCP entity.

[0877] The program operating in the apparatus of this invention can be a program that controls the Central Processing Unit (CPU) or similar components to enable the computer to perform its functions, thereby achieving the functions described in the embodiments of this invention. During processing, the program or the information processed by the program is temporarily read into volatile memory such as Random Access Memory (RAM) or stored in non-volatile memory such as Flash Memory or Hard Disk Drive (HDD), and is read, modified, and written by the CPU as needed.

[0878] It should be noted that a portion of the apparatus described in the above embodiments can be implemented using a computer. In this case, a program for implementing the control function can be recorded on a computer-readable recording medium, and the program recorded on the recording medium can be read into a computer system and executed. The term "computer system" here refers to a computer system built into the device, and is configured to include hardware such as an operating system and peripherals. Furthermore, the "computer-readable recording medium" can be any of a semiconductor recording medium, an optical recording medium, a magnetic recording medium, etc.

[0879] Furthermore, a "computer-readable recording medium" can include: a medium that dynamically stores a program for a short period of time, such as a communication line in the case of transmitting a program via a network such as the Internet or a communication line such as a telephone line; or a medium that stores a program for a fixed period of time, such as volatile memory within a computer system that serves as a server or client in this case. In addition, the program can be a program used to implement the functions described above, or it can be a program that can implement the functions described above by combining with programs already recorded in the computer system.

[0880] Furthermore, the functional blocks or features of the apparatus used in the above embodiments can be implemented or executed by circuits, typically by integrated circuits or multiple integrated circuits. Circuits designed to perform the functions described in this specification may include: general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic elements, discrete gate or transistor logic, discrete hardware components, or combinations thereof. A general-purpose processor may be a microprocessor, or alternatively, a conventional processor, controller, microcontroller, or state machine. The general-purpose processor or the circuits described above may be constructed from digital circuits or analog circuits. Furthermore, in cases where advancements in semiconductor technology have led to the development of integrated circuit technologies that replace existing integrated circuits, integrated circuits based on such technologies may also be used.

[0881] It should be noted that the invention described in this application is not limited to the embodiments described above. While one example of the device is described in the embodiments, the invention is not limited thereto and can be applied to fixed or non-movable electronic devices installed indoors or outdoors, such as AV equipment, kitchen equipment, cleaning / washing equipment, air conditioning equipment, office equipment, vending machines, and other terminal devices or communication devices in daily life.

[0882] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the specific configuration is not limited to these embodiments, and design changes that do not depart from the spirit of the present invention are also included. Furthermore, the present invention can be modified in various ways within the scope of the technical solutions shown, and embodiments obtained by appropriately combining technical solutions disclosed in different embodiments are also included within the technical scope of the present invention. In addition, it also includes configurations obtained by replacing elements that have the same effect as those described in the above embodiments with each other.

[0883] Industrial availability

[0884] One aspect of the present invention can be used, for example, in communication systems, communication devices (e.g., mobile phone devices, base station devices, wireless LAN devices, or sensor devices), integrated circuits (e.g., communication chips), or programs.

Claims

1. A terminal device for communicating with a base station device, the terminal device comprising: The receiving unit receives a first message from the base station device; and The processing unit, based on the dual-active protocol stack (DAPS) switching setting configured for any radio bearer via the first message, establishes a second PDCP entity for the first signaling radio bearer using the same settings as the first packet data aggregation protocol (PDCP) entity for the first signaling radio bearer. In the wireless bearer with the DAPS switching settings configured, two covert keys and / or two integrity keys and / or two RoHC protocols are configured for the source and the target.

2. The terminal device according to claim 1, wherein, When the processing unit establishes the second PDCP entity, The values ​​of some or all of the state variables used in the first PDCP entity are inherited by the second PDCP entity.

3. A communication method for a terminal device for communicating with a base station device, wherein, The computer of the terminal device has: During the receiving process, a first message is received from the base station device; as well as The processing procedure, based on the dual-active protocol stack (DAPS) switching setting configured for any radio bearer through the first message, establishes a second PDCP entity for the first signaling radio bearer using the same settings as the first packet data aggregation protocol (PDCP) entity for the first signaling radio bearer. In the wireless bearer with the DAPS switching settings configured, two covert keys and / or two integrity keys and / or two RoHC protocols are configured for the source and the target.

4. The communication method according to claim 3, wherein, During the processing, when the second PDCP entity is established, The values ​​of some or all of the state variables used in the first PDCP entity are inherited by the second PDCP entity.

5. A base station apparatus for communicating with a terminal device, the base station apparatus comprising: The sending unit sends a first message to the terminal device; and The processing unit, based on the dual-active protocol stack (DAPS) switching setting configured for any radio bearer through the first message, considers the terminal device to be establishing a second PDCP entity for the first signaling radio bearer using the same settings as the first packet data aggregation protocol (PDCP) entity for the first signaling radio bearer. In the wireless bearer with the DAPS switching settings configured, two covert keys and / or two integrity keys and / or two RoHC protocols are configured for the source and the target.

6. The base station apparatus according to claim 5, wherein, When the processing unit establishes the second PDCP entity, The values ​​of some or all of the state variables used in the first PDCP entity are inherited by the second PDCP entity.

7. A communication method for a base station device for communicating with a terminal device, wherein, The computer of the base station device has: During the sending process, a first message is sent to the terminal device; as well as The processing procedure, based on the dual-active protocol stack (DAPS) switching setting configured for any radio bearer through the first message, is considered as the terminal device establishing a second PDCP entity for the first signaling radio bearer using the same settings as the first packet data aggregation protocol (PDCP) entity for the first signaling radio bearer. In the wireless bearer with the DAPS switching settings configured, two covert keys and / or two integrity keys and / or two RoHC protocols are configured for the source and the target.

8. The communication method according to claim 7, wherein, During the processing, when the second PDCP entity is established, The values ​​of some or all of the state variables used in the first PDCP entity are inherited by the second PDCP entity.

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