Terminals, communication methods, and base stations

Abstract

This invention provides terminals, communication methods, base stations, and wireless communication systems that support procedures for adding and modifying secondary cells (secondary nodes). [Solution] The terminal UE controls the execution of the addition / modification procedure for secondary cells (secondary nodes, SNs), and if the addition / modification procedure (RRC (Radio Resource Control Layer) Reconfiguration) is successful, it sends a message SCGFailureInfo to the network containing execution information indicating the type of addition / modification procedure and whether the master node MN or secondary node led the addition / modification procedure.

Description

Technical Field

[0001] The present disclosure relates to a terminal, a communication method, and a base station that support procedures for adding and changing secondary cells (secondary nodes).

Background Art

[0002] The 3rd Generation Partnership Project (3GPP: registered trademark) has specified the 5th generation mobile communication system (also called 5G, New Radio (NR), or Next Generation (NG)), and is also promoting the specification of the next generation, such as Beyond 5G, 5G Evolution, or 6G.

[0003] For example, in Release 17 of 3GPP, in order to realize more efficient addition or change of a Primary SCell (PSCell), procedures for adding and changing conditional secondary cells (secondary nodes) (CPAC: conditional PSCell addition / change) with simplified procedures are defined. In conditional PSCell addition / change, an execution condition for a terminal (User Equipment, UE) to determine whether addition or change of a PSCell is possible can be defined.

[0004] Also, in 3GPP Release 18, the expansion of SON (Self-Organising Networks) / MDT (Minimization of Drive Tests) is under consideration, and CPAC is also targeted (Non-Patent Document 1).

Prior Art Documents

Non-Patent Documents

[0005]

Non-Patent Document 1

[0006] CPAC can succeed or fail depending on factors such as the quality of the PSCell. However, the network (wireless base station, gNB) has a problem in that it cannot recognize whether CPAC has succeeded or failed. For this reason, optimizing CPAC in the network is difficult.

[0007] Therefore, the following disclosure is made in light of these circumstances and aims to provide terminals and wireless communication methods that can contribute to the optimization of CPAC.

[0008] One aspect of the present disclosure is a terminal (UE200) comprising a control unit (control unit 240) that controls the execution of a secondary cell addition / modification procedure, and a transmission unit (RRC processing unit 220) that, when the addition / modification procedure is successful or unsuccessful, sends a message to the network containing execution information indicating the type of the addition / modification procedure and that a master node or secondary node led the addition / modification procedure.

[0009] One aspect of the present disclosure is a wireless communication method comprising the steps of a terminal performing an add-or-modify procedure for a secondary cell, and the terminal sending a message to the network, if the add-or-modify procedure is successful or unsuccessful, the message containing the type of add-or-modify procedure and execution information indicating that a master node or secondary node led the add-or-modify procedure. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic diagram of the overall configuration of the wireless communication system 10. [Figure 2] This is a functional block diagram of the eNB100A and gNB100B. [Figure 3] This is a functional block diagram of the UE200. [Figure 4] This figure shows an example of a CPAC failure reporting sequence related to Operation Example 1 (using SCGFailureInfo). [Figure 5] This figure shows an example of a CPAC failure reporting sequence related to Operation Example 1 (using UE information response). [Figure 6] This figure shows an example of the reporting sequence for CPAC success related to Operation Example 2 (using SCGSuccessInfo). [Figure 7] This figure shows an example of the reporting sequence for successful CPAC operation (using UE information response) related to Operation Example 2. [Figure 8] This figure shows an example of the hardware configuration of eNB100A, gNB100B, and UE200. [Figure 9] This is a diagram showing an example configuration of vehicle 2001. [Modes for carrying out the invention]

[0011] The embodiments will be described below with reference to the drawings. Note that identical or similar reference numerals are used to denote the same functions and components, and their descriptions will be omitted as appropriate.

[0012] (1) Overall outline of the wireless communication system Figure 1 is a schematic diagram of the overall configuration of the wireless communication system 10 according to this embodiment. The wireless communication system 10 is a wireless communication system that conforms to Long Term Evolution (LTE) and 5G New Radio (NR). Note that LTE may also be called 4G, and NR may also be called 5G. Furthermore, the wireless communication system 10 may also be a wireless communication system that conforms to a method called Beyond 5G, 5G Evolution, or 6G.

[0013] LTE and NR may also be interpreted as radio access technologies (RATs), and in this embodiment, LTE may be referred to as the first radio access technology and NR as the second radio access technology.

[0014] The wireless communication system 10 includes an Evolved Universal Terrestrial Radio Access Network 20 (hereinafter referred to as E-UTRAN20) and a Next Generation-Radio Access Network 30 (hereinafter referred to as NG RAN30). The wireless communication system 10 also includes a terminal 200 (hereinafter referred to as UE200, User Equipment).

[0015] E-UTRAN20 includes eNB100A, a radio base station compliant with LTE. NG RAN30 includes gNB100B, a radio base station compliant with 5G(NR). Furthermore, NG RAN30 may be connected to a User Plane Function (UPF40), which is included in the 5G system architecture and provides user plane functionality.

[0016] Furthermore, E-UTRAN20 and NG RAN30 (or eNB100A or gNB100B) may simply be referred to as the network. Also, the specific configuration of the wireless communication system 10, including the number of eNBs, gNBs, and UEs, is not limited to the example shown in Figure 1.

[0017] eNB100A, gNB100B, and UE200 can support carrier aggregation (CA) using multiple component carriers (CCs), dual connectivity where multiple component carriers are transmitted simultaneously between multiple NG-RAN Nodes and the UE, etc.

[0018] eNB100A, gNB100B, and UE200 perform wireless communication via radio bearers, specifically, Signalling Radio Bearer (SRB) or Data Radio Bearer (DRB).

[0019] In this embodiment, Multi-Radio Dual Connectivity (MR-DC), specifically, E-UTRA-NR Dual Connectivity (EN-DC) may be executed, where eNB100A constitutes the master node (MN) and gNB100B constitutes the secondary node (SN), or NR-E-UTRA Dual Connectivity (NE-DC) may be executed, where gNB100B constitutes the MN and eNB100A constitutes the SN. Alternatively, NR-NR Dual Connectivity (NR-DC) where gNB constitutes both the MN and SN may be executed.

[0020] Thus, UE200 supports dual connectivity to connect to both eNB100A and gNB100B.

[0021] eNB100A may be included in the master cell group (MCG), and gNB100B may be included in the secondary cell group (SCG). That is, gNB100B is the SN included in the SCG. As described above, it may also be NE-DC, etc. For example, gNB100B may be the MN and eNB100A may be the SN.

[0022] eNB100A and gNB100B may be referred to as radio base stations or network devices.

[0023] Furthermore, the wireless communication system 10 may support conditional addition or change (CPAC) of Primary SCells (PSCells). A PSCell is a type of secondary cell. PSCell means Primary SCell (secondary cell), and it may be interpreted as corresponding to any of several SCells.

[0024] Note that "secondary cell" may be interpreted as "secondary node (SN)" or "secondary cell group (SCG)." Conditional PSCell addition / change enables efficient and rapid addition or modification of secondary cells.

[0025] A conditional PSCell addition / change may be interpreted as a simplified procedure for adding or changing a conditional secondary cell. Alternatively, a conditional PSCell addition / change may mean at least one of either an addition (CPA) or a change (CPC) of an SCell.

[0026] Furthermore, the wireless communication system 10 may support conditional inter-SN PSCell change procedures. Specifically, MN-initiated conditional PSCell change and / or SN-initiated conditional PSCell change may be supported.

[0027] Furthermore, the wireless communication system 10 may support SN-initiated inter-SN CPC procedures, which are SN-driven inter-SN CPCs, and / or SN-initiated intra-SN CPC procedures, which are CPCs within the same SN, as conditional PSCell changes (CPCs). The SN-initiated inter-SN CPC procedure may also be called an SN-initiated conditional inter-SN Change.

[0028] (2) Functional block configuration of the wireless communication system Next, the functional block configuration of the wireless communication system 10 will be described. Specifically, the functional block configurations of eNB100A, gNB100B, and UE200 will be described.

[0029] (2.1) eNB100A and gNB100B Figure 2 is a functional block diagram of the eNB100A and gNB100B. As shown in Figure 2, the eNB100A and gNB100B include a wireless communication unit 110, an RRC / Xn processing unit 120, a DC processing unit 130, and a control unit 140. Note that Figure 2 only shows the main functional blocks relevant to the description of the embodiment, and the eNB100A and gNB100B have other functional blocks (e.g., a power supply unit). Also, Figure 2 shows the functional block configuration of the eNB100A and gNB100B; please refer to Figure 8 for the hardware configuration.

[0030] The wireless communication unit 110 transmits a downlink signal (DL signal) according to a predetermined wireless system (LTE or NR). The wireless communication unit 110 also receives an uplink signal (UL signal) according to a predetermined wireless system (LTE or NR).

[0031] The RRC / Xn processing unit 120 performs various processes related to the Radio Resource Control Layer (RRC) and the Xn interface. Specifically, the RRC / Xn processing unit 120 can send an RRC Reconfiguration to the UE200. The RRC / Xn processing unit 120 can also receive an RRC Reconfiguration Complete, which is a response to the RRC Reconfiguration, from the UE200.

[0032] Furthermore, the RRC / Xn processing unit 120 can receive information related to the SCG from the UE200. Specifically, the RRC / Xn processing unit 120 can receive SCGFailureInfo from the UE200, which is a message containing information about SCG failures. Alternatively, the RRC / Xn processing unit 120 can receive SCGSuccessInfo from the UE200, which is a message containing information about the normal operation of the SCG. SCGSuccessInfo is a provisional name and should simply mean that the conditional PSCell addition / change (CPAC) was completed successfully.

[0033] Furthermore, the RRC / Xn processing unit 120 can send a UE information request to the UE200 requesting the transmission of information, and can receive a UE information response from the UE200 in response to the UE information request.

[0034] In this embodiment, the eNB100A supports LTE, in which case the name of the RRC message may be RRC Connection Reconfiguration or RRC Connection Reconfiguration Complete.

[0035] Furthermore, in the case of a radio base station supporting LTE (Evolved Universal Terrestrial Radio Access Network (E-UTRAN)), the X2 interface may be used instead of the Xn interface. Alternatively, both the Xn and X2 interfaces may be used in combination. The following explanation will use the Xn interface as an example.

[0036] The RRC / Xn processing unit 120 can send and receive inter-node messages via the Xn interface. For example, when configuring a secondary node (SN), the RRC / Xn processing unit 120 may receive messages concerning SCell (which may include PSCell, hereafter the same) from other radio base stations, specifically the master node (MN).

[0037] More specifically, the RRC / Xn processing unit 120 of the SN constituting the source-secondary node (S-SN) may receive an SN Addition Request from the MN. Furthermore, the RRC / Xn processing unit 120 may send an SN Addition Request Ack back to the MN based on the receipt of the SN Addition Request.

[0038] Furthermore, the RRC / Xn processing unit 120 of the S-SN may send an SN Status Transfer to the target secondary node (T-SN).

[0039] The SN Status Transfer may include the count value of the first downlink (DL) Service Data Unit (SDU) that S-SN transfers to T-SN, or a count value for discarding DL SDUs that have already been transferred at each data radio bearer (DRB). Note that a Protocol Data Unit (PDU) may be used instead of an SDU.

[0040] The RRC / Xn processing unit 120 of the SN constituting the S-SN may transmit (transfer) the SN Status Transfer to the T-SN via the MN. Alternatively, the RRC / Xn processing unit 120 of the SN constituting the S-SN may transmit the SN Status Transfer directly to the T-SN without going through the MN, or it may transmit the SN Status Transfer to the MN and T-SN in parallel.

[0041] On the other hand, when configuring an MN, the RRC / Xn processing unit 120 may receive messages from the SN regarding the addition or modification of SCells. The RRC / Xn processing unit 120 may receive messages regarding the addition of SCells and messages regarding the modification of SCells, respectively.

[0042] More specifically, the RRC / Xn processing unit 120 may receive an SN change required and / or an SN Addition Request Ack from the SN.

[0043] Furthermore, the RRC / Xn processing unit 120 may send and receive inter-node messages containing information regarding CPAC failure (abnormal termination) or success (normal termination). Specifically, the RRC / Xn processing unit 120 constituting the MN may send an SCG failure information report or an SCG success information report to the SN.

[0044] The DC processing unit 130 performs processing related to dual connectivity, specifically Multi-RAT Dual Connectivity (MR-DC). In this embodiment, since eNB100A supports LTE and gNB100B supports NR, the DC processing unit 130 may perform processing related to E-UTRA-NR Dual Connectivity (EN-DC). As mentioned above, the type of DC is not limited, and for example, it may support NR-E-UTRA Dual Connectivity (NE-DC) or NR-NR Dual Connectivity (NR-DC).

[0045] The DC processing unit 130 can send and receive messages as defined in 3GPP TS37.340 and other standards, and can perform processing related to setting up and releasing the DC between eNB100A, gNB100B, and UE200.

[0046] The control unit 140 controls each functional block that constitutes the eNB100A. In particular, in this embodiment, it performs control related to the addition or modification of secondary nodes.

[0047] The control unit 140 controls the execution of SCell addition and modification procedures, particularly conditional PSCell addition / change. Specifically, the control unit 140 can work in conjunction with SN (or MN) to perform SCell addition (addition, CPA) or modification (change, CPC) based on the execution condition.

[0048] Furthermore, the control unit 140 may change the settings related to CPAC based on SCGFailureInfo or SCGSuccessInfo received by the RRC / Xn processing unit 120. SCGFailureInfo or SCGSuccessInfo may include information about the CPAC (which may also be called execution information) if the CPAC fails (abnormal termination) or succeeds (normal termination). Details of the information about the CPAC will be described later.

[0049] In this embodiment, the channel includes a control channel and a data channel. The control channel includes PDCCH (Physical Downlink Control Channel), PUCCH (Physical Uplink Control Channel), PRACH (Physical Random Access Channel), and PBCH (Physical Broadcast Channel), among others.

[0050] Furthermore, data channels include PDSCH (Physical Downlink Shared Channel) and PUSCH (Physical Uplink Shared Channel), among others.

[0051] Reference signals include Demodulation Reference Signal (DMRS), Sounding Reference Signal (SRS), Phase Tracking Reference Signal (PTRS), and Channel State Information-Reference Signal (CSI-RS), while signals include channels and reference signals. Data may refer to data transmitted via a data channel.

[0052] (2.2)UE200 Figure 3 is a functional block diagram of the UE200. As shown in Figure 3, the UE200 comprises a wireless communication unit 210, an RRC processing unit 220, a DC processing unit 230, and a control unit 240. Note that Figure 3 only shows the main functional blocks relevant to the description of the embodiment, and the UE200 has other functional blocks (e.g., a power supply unit). Also, Figure 3 shows the functional block configuration of the UE200; please refer to Figure 8 for the hardware configuration.

[0053] The wireless communication unit 210 transmits an uplink signal (UL signal) according to LTE or NR. The wireless communication unit 210 also receives a downlink signal (DL signal) according to LTE or NR. In other words, the UE200 can access eNB100A (E-UTRAN20) and gNB100B (NG RAN30) and supports dual connectivity (specifically, EN-DC).

[0054] The RRC processing unit 220 performs various processes in the Radio Resource Control Layer (RRC). Specifically, the RRC processing unit 220 can send and receive messages in the Radio Resource Control Layer.

[0055] In this embodiment, the RRC processing unit 220 can send a message containing information about SCG failures, namely SCGFailureInfo, or a message containing information about the normal operation of the SCG, namely SCGSuccessInfo, to the network (specifically, eNB100A or gNB100B). Both SCGFailureInfo and SCGSuccessInfo may be sent, or only one of them may be sent.

[0056] Furthermore, the RRC processing unit 220 can send a UE information response, which is a response message to a UE information request that requests the UE200 to send information, to the network.

[0057] The RRC processing unit 220 can send a message (SCGFailureInfo / SCGSuccessInfo, UE information response) to the network containing information (execution information) indicating the type of CPAC and whether the master node (MN) or secondary node (SN) initiated the CPAC, if the CPAC is successful or unsuccessful. In this embodiment, the RRC processing unit 220 constitutes the transmission unit.

[0058] Information regarding CPAC failures may be referred to as CPAC failure info. Information regarding CPAC successes may be referred to as PSCell change success info (or successful PSCell change report). Note that CPAC failure info and PSCell change success info are provisional names and may be referred to by other similar names.

[0059] The type of CPAC can be either CPA or CPC, and the information indicating that MN or SN initiated the CPAC should be a designation that distinguishes between MN-initiated CPA / CPC or SN-initiated CPC. CPAC may also be called conditional reconfiguration.

[0060] If CPAC fails, the RRC processing unit 220 may send a message containing the execution condition of the CPAC associated with the secondary cell (PSCell) where CPAC failed. Specifically, the execution condition may include condeventA3, condeventA4, condeventA5, condEventD1, condEventT1, etc., as defined in 3GPP TS38.331. Alternatively, the RRC processing unit 220 may send a message containing the identification information (CondReconfigId) of the conditional reconfiguration associated with the PSCell.

[0061] The RRC processing unit 220 may send the message including the elapsed time since the start of CPAC. Specifically, the message may include a name called timeSinceCPACReconfig. timeSinceCPACReconfig may indicate the elapsed time from the reception of the latest conditional reconfiguration settings to the start of the execution of the previous conditional reconfiguration for the target PSCell. In the case of an SCG radio link failure (RLF), timeSinceCPACReconfig may indicate the elapsed time from the SCG radio link failure to the reception of the latest conditional reconfiguration.

[0062] The RRC processing unit 220 may transmit the message containing the identification information of UE200. Specifically, the C-RNTI (Cell Radio Network Temporary Identifier) ​​may be included in the message. The C-RNTI may be set by MN for UE200 or by SN for UE200. Alternatively, other RNTIs (e.g., TC-RNTI) or other information that uniquely identifies UE200 may be used instead of C-RNTI.

[0063] If CPAC fails, the RRC processing unit 220 may send a message containing information about candidate secondary cells (candidate PSCells) other than the secondary cell (PSCell) that failed CPAC. Specifically, the CondReconfigId associated with the candidate PSCell may be included in the message. Note that any information that can identify the candidate PSCell (such as the Physical Cell ID (PCI)) may be used instead of the CondReconfigId.

[0064] The RRC processing unit 220 may send the PSCell change success info (execution information) message if CPAC is successful, depending on the setting for whether or not to send the PSCell change success info. Specifically, the RRC processing unit 220 may send SCGSuccessInfo, which includes PSCell change success info, if it is instructed to do so by signaling from the network at the RRC or other layers, or by pre-configuration. Note that the setting for whether or not to send PSCell change success info may be interpreted as the setting for whether or not to send SCGSuccessInfo.

[0065] The DC processing unit 230 performs processing related to dual connectivity, specifically MR-DC. As described above, in this embodiment, the DC processing unit 230 may perform processing related to EN-DC, but it may also support NE-DC and / or NR-DC.

[0066] The DC processing unit 230 can access both the eNB100A and the gNB100B and perform configurations at multiple layers, including the RRC (such as the Media Access Control Layer (MAC), the Radio Link Control Layer (RLC), and the Packet Data Convergence Protocol Layer (PDCP)).

[0067] The control unit 240 controls each functional block that constitutes the UE200. In particular, in this embodiment, the control unit 240 controls the execution of conditional PSCell addition / change.

[0068] Specifically, the control unit 240 can control the execution of conditional PSCell addition / change (addition / modification procedure) of secondary cells (specifically, PSCells).

[0069] Specifically, the control unit 240 may monitor the execution condition of conditional PSCell addition / change and determine whether or not there is a target PSCell that satisfies the execution condition. If there is a target PSCell that satisfies the execution condition, the control unit 240 may apply the RRC reconfiguration of the target PSCell and send RRC Reconfiguration Complete back to the MN.

[0070] (3) Operation of the wireless communication system Next, the operation of the wireless communication system 10 will be described. Specifically, the operation of the wireless communication system 10 regarding the procedure for adding / changing conditional secondary cells (secondary nodes) will be described.

[0071] (3.1) Prerequisites and Issues As described above, the wireless communication system 10 is compatible with MR-DC and can support conditional PSCell addition / change (CPAC). CPAC may succeed or fail depending on the communication status with the candidate PSCell, i.e., the quality of the candidate PSCell.

[0072] The following example aims to optimize CPAC by enabling the network to recognize information regarding CPAC failures (abnormal termination) or successes (normal termination) by the UE200.

[0073] Specifically, in the following example, if MR-DC CPA or CPC fails, information regarding the failure will be reported. Conversely, if MR-DC CPA or CPC is successful, information regarding the success will be reported.

[0074] (3.2) Example of operation 1 Figure 4 shows an example of the CPAC failure reporting sequence for Operation Example 1 (using SCGFailureInfo). Figure 5 shows an example of the CPAC failure reporting sequence for Operation Example 1 (using UE information response).

[0075] As shown in Figures 4 and 5, UE200 may send SCGFailureInfo or UE information response containing CPAC failure info to the network, specifically to the MN. As shown in Figure 4, SCGFailureInfo may be sent after receiving RRC Reconfiguration Complete, but it may also be sent after sending RACH. Figure 4 also shows an example where access to the PSCell formed by T-SN1 failed. The timing of sending the UE information request shown in Figure 5 can be arbitrarily determined by the MN.

[0076] CPAC failure info may include the following information (execution information):

[0077] • An indication that can distinguish between MN-initiated CPA / CPC and SN-initiated CPC. For example, it may include the type of execution condition associated with the PSCell in which the CPA or CPC failed. Specifically, it may include an indication that it is set by condExecutioncond (see 3GPP TS38.331) or set in condExecutionCondSCG.

[0078] condExecutioncond may be interpreted as the execution condition that must be met to trigger the execution of a conditional reconfiguration. condExecutionCondSCG may be interpreted as the execution condition that must be met to trigger the execution of a conditional reconfiguration of an inter-SN CPC initiated by an SN.

[0079] • Execution condition associated with cells where CPAC failed Specifically, condeventA3, condeventA4, condeventA5, condEventD1, and condEventT1 (see 3GPP TS38.331) may be included. condeventA3, condeventA4, condeventA5, condEventD1, and condEventT1 may be defined as follows:

[0080] ·CondEvent A3: Conditional reconfiguration candidate becomes amount of offset better than PCell / PSCell; ·CondEvent A4: Conditional reconfiguration candidate becomes better than absolute threshold; ·CondEvent A5: PCell / PSCell becomes worse than absolute threshold1 AND Conditional reconfiguration candidate becomes better than another absolute threshold2; ·CondEvent D1: Distance between UE and a reference location referenceLocation1 becomes larger than configured threshold distanceThreshFromReference1 and distance between UE and a reference location referenceLocation2 of conditional reconfiguration candidate becomes shorter than configured threshold distanceThreshFromReference2; ·CondEvent T1: Time measured at UE becomes more than configured threshold t1-Threshold but is less than t1-Threshold + duration; Alternatively, it may include a CondReconfigId associated with the cell where CPAC failed. Based on the reported CondReconfigId, the MN may determine that it has set condExecutioncond or condExecutionCondSCG.

[0081] • Unexecuted candidate PSCell(s) and associated CondReconfigId In the case of MN-initiated CPA / CPC, the measurement by UE200 is set by MN, so MN may optimize CPAC based on SCGFailureInfo (or UE information response). In the case of SN-initiated CPC, the measurement by UE200 is set by SN, so MN may send CPAC failure info to SN via Xn-AP, and SN may optimize CPC based on CPAC failure info.

[0082] Furthermore, CPAC optimization may include measurement configurations for the UE200, such as the content of the execution condition and the selection of candidate PSCell(s).

[0083] • Indication of CPA or CPC •timeSinceCPACReconfig timeSinceCPACReconfig may also be defined as follows:

[0084] ·In case of CPA / CPC failure, this field is used to indicate the time elapsed between the initiation of the last conditional reconfiguration execution towards the target PSCell cell and the reception of the latest conditional reconfiguration. · C-RNTI in MN and / or C-RNTI in SN C-RNTI in MN is the C-RNTI that MN sets for UE200, and C-RNTI in SN is the C-RNTI that SN sets for UE200. This makes it possible to identify the UE200 that sent the CPAC failure info.

[0085] (3.3) Example of operation 2 Figure 6 shows an example of the CPAC success reporting sequence for Operation Example 2 (using SCGSuccessInfo). Figure 7 shows an example of the CPAC success reporting sequence for Operation Example 2 (using UE information response).

[0086] As shown in Figures 6 and 7, UE200 may send SCGSuccessInfo or UE information response containing a successful PSCell change report to the network, specifically to the MN. As shown in Figure 6, UE200 may send SCGSuccessInfo after receiving RRC Reconfiguration Complete (Containing SN RRCReconfigurationComplete) or after sending RACH. If RACH (Random Access Procedure) is successful, UE200 may send SCGSuccessInfo at any time after success. Alternatively, UE200 may send SCGSuccessInfo in response to a request for SCGSuccessInfo from the network.

[0087] A successful PSCell change report (and PSCell change success info) may include the following information (execution information):

[0088] • An indication that can distinguish between MN-initiated CPA / CPC and SN-initiated CPC. For example, it may include the type of execution condition associated with a PSCell in which a CPA or CPC was successful. Specifically, it may include an indication that it is set by condExecutioncond (see 3GPP TS38.331) or set in condExecutionCondSCG.

[0089] • Execution condition associated with cells where CPAC failed Specifically, condeventA3, condeventA4, condeventA5, condEventD1, and condEventT1 (see 3GPP TS38.331) may be included.

[0090] Alternatively, it may include a CondReconfigId associated with a cell where CPAC was successful. Based on the reported CondReconfigId, the MN may determine that it has set condExecutioncond or condExecutionCondSCG.

[0091] • Unexecuted candidate PSCell(s) and associated CondReconfigId In the case of MN-initiated CPA / CPC, the measurement by UE200 is set by MN, so MN may optimize CPAC based on SCGFailureInfo (or UE information response). In the case of SN-initiated CPC, the measurement by UE200 is set by SN, so MN may send CPAC failure info to SN via Xn-AP, and SN may optimize CPC based on CPAC failure info.

[0092] •timeSinceCPACReconfig timeSinceCPACReconfig may also be defined as follows:

[0093] ·This field is used to indicate the time elapsed between the initiation of the last conditional reconfiguration execution towards the target PScell ​​and the reception of the latest conditional reconfiguration for this target PScell. • Indication of CPA or CPC • Information on the RACH resources used (e.g., RA-InformationCommon) ·successful PSCell change report cause(t304-cause, t310-cause, t312-cause) t304, t310, and t312 indicate the timer type and are defined in 3GPP TS38.331.

[0094] ·Source PSCell ID / Measurement quality (RSRP (Reference Signal Received Power), RSRQ (Reference Signal Received Quality), SINR (Signal-to-Interference plus Noise power Ratio)) ·Target PSCell ID / measurement quality (RSRP, RSRQ, SINR) ·Neighbor PSCell / Candidate PSCell ID / Measurement quality (RSRP, RSRQ, SINR) • UE200 Location Information · C-RNTI in MN and / or C-RNTI in SN Furthermore, UE200 may internally maintain a successful PSCell change report. In this case, the retention of the successful PSCell change report (retention time, number of reports to retain, etc.) may be controlled using a variable (VarSuccessfulPScellChangeReport (tentative name)). Since UE200 does not need to immediately report the successful PSCell change report to the network, it may store it in the variable VarSuccessfulPScellChangeReport. It is preferable for UE200 to inform the network that it is holding a successful PSCell change report. The network may request the UE200 to report this information if it needs it.

[0095] Having a successful PSCell change report can be communicated to the network by including in the UE-MeasurementAvailable IE in the following message that a successful PSCell change report or SCGSuccessInfo is available. RRC Reconfiguration Complete RRCSetupComplete • RRC Reopening Complete • RCResumeComplete

[0096] Furthermore, as shown in Figures 6 and 7, the MN may send an SCG success information report, including PSCell change success info, via XnAP.

[0097] If the SCGSuccessInfo reporting format (report config) is configured in advance by the network, the UE200 may send SCGSuccessInfo after CPAC success. If the reporting format (report config) is not configured, the UE200 may send SCGSuccessInfo in response to instructions or requests from the network. This can reduce the sending of unnecessary SCGSuccessInfo and contribute to the efficient use of resources.

[0098] (4) Action and Effects According to the embodiment described above, the following effects can be obtained. Specifically, if CPAC fails, UE200 can send SCGFailureInfo or UE information response containing CPAC failure info to the network. Also, if CPAC is successful, UE200 can send SCGSuccessInfo or UE information response containing a successful PSCell change report to the network. The CPAC failure info and successful PSCell change report include indications that can distinguish between MN-initiated CPA / CPC and SN-initiated CPC.

[0099] Therefore, the network can distinguish between the types of CPACs when they succeed or fail. In the case of MN-initiated CPA / CPC, the MN can optimize the CPAC, specifically the Measurement configuration, based on the CPAC failure info and / or successful PSCell change report. On the other hand, in the case of SN-initiated CPC, the MN forwards the CPAC failure info and / or successful PSCell change report to the SN, and the SN can optimize the CPAC based on the CPAC failure info and / or successful PSCell change report.

[0100] Furthermore, by using timeSinceCPACReconfig, the UE200 can report the time from when it receives CPAC settings from the network until CPAC succeeds or fails, which is expected to be helpful in optimizing CPAC.

[0101] Furthermore, the CPAC failure info and successful PSCell change report may include the C-RNTI (in MN, SN) assigned to the UE200. This is expected to facilitate and ensure the linking of the UE200 with the CPAC failure info and successful PSCell change report, further contributing to CPAC optimization.

[0102] (5) Other embodiments Although embodiments have been described above, it will be obvious to those skilled in the art that the invention is not limited to those embodiments described and that various modifications and improvements are possible.

[0103] For example, in the embodiment described above, an EN-DC with MN being eNB and SN being gNB was described as an example, but as mentioned above, other DCs may also be used. Specifically, an NR-DC with MN being gNB and SN being gNB, or an NE-DC with MN being gNB and SN being eNB, may also be used.

[0104] Furthermore, although the above-described embodiments mainly used conditional PSCell addition / change as an example, operations similar to those described above may also be applied to CHO (Conditional Handover) or Conditional SCG change.

[0105] Furthermore, in the above description, configure, activate, update, indicate, enable, specify, and select may be interpreted interchangeably. Similarly, link, associate, correspond, and map may be interpreted interchangeably, as may allocate, assign, monitor, and map.

[0106] Furthermore, "specific," "dedicated," "UE specific," and "UE individual" may be interpreted interchangeably. Similarly, "common," "shared," "group-common," "UE common," and "UE shared" may be interpreted interchangeably.

[0107] Furthermore, the block diagrams (Figures 2 and 3) used in the description of the embodiments above show functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Moreover, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one device that is physically or logically coupled, or it may be realized using two or more physically or logically separated devices that are directly or indirectly connected (for example, using wired or wireless connections). A functional block may also be realized by combining the above one device or the above multiple devices with software.

[0108] Functions include, but are not limited to, judgment, decision, judgment, calculation, calculation, processing, derivation, investigation, exploration, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, assumption, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating (mapping), and assigning. For example, a functional block (configuration part) that enables transmission is called a transmitting unit or transmitter. In any case, as mentioned above, the method of implementation is not particularly limited.

[0109] Furthermore, the eNB100A, gNB100B, and UE200 (the devices) described above may function as computers that process the wireless communication method of this disclosure. Figure 8 shows an example of the hardware configuration of the device. As shown in Figure 8, the device may be configured as a computer device including a processor 1001, memory 1002, storage 1003, communication device 1004, input device 1005, output device 1006, and bus 1007.

[0110] In the following explanation, the term "device" can be replaced with "circuit," "device," "unit," etc. The hardware configuration of the device may include one or more of the devices shown in the diagram, or it may be configured to omit some of the devices.

[0111] Each functional block of the device (see Figure 2.3) is implemented by any hardware element of the computer device, or a combination of such hardware elements.

[0112] Furthermore, each function in the device is realized by loading predetermined software (programs) onto hardware such as the processor 1001 and memory 1002, which allows the processor 1001 to perform calculations, control communication by the communication device 1004, and control at least one of data reading and writing in the memory 1002 and storage 1003.

[0113] The processor 1001 controls the entire computer, for example, by running an operating system. The processor 1001 may consist of a central processing unit (CPU) that includes interfaces with peripheral devices, control units, arithmetic units, registers, and so on.

[0114] Furthermore, the processor 1001 reads programs (program code), software modules, data, etc., from at least one of the storage 1003 and the communication device 1004 into the memory 1002 and executes various processes accordingly. The program used is one that causes the computer to execute at least a part of the operations described in the above embodiment. Moreover, the above-mentioned various processes may be executed by one processor 1001, or by two or more processors 1001 simultaneously or sequentially. The processor 1001 may be implemented by one or more chips. The program may be transmitted from a network via a telecommunications line.

[0115] Memory 1002 is a computer-readable recording medium and may consist of at least one of the following: Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), Random Access Memory (RAM), etc. Memory 1002 may also be called a register, cache, main memory, etc. Memory 1002 can store a program (program code), software modules, etc., that can execute a method according to one embodiment of this disclosure.

[0116] Storage 1003 is a computer-readable recording medium and may consist of at least one of the following: an optical disc such as a Compact Disc ROM (CD-ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disc, a digital multipurpose disc, a Blu-ray® disc), a smart card, flash memory (e.g., a card, a stick, a key drive), a floppy® disk, a magnetic strip, etc. Storage 1003 may also be called an auxiliary storage device. The recording medium described above may also be, for example, a database, server, or other suitable medium including at least one of memory 1002 and storage 1003.

[0117] The communication device 1004 is hardware (transceiver / receiver device) for communicating between computers via at least one of a wired network and a wireless network, and is also called a network device, network controller, network card, communication module, etc.

[0118] The communication device 1004 may be configured to include, for example, a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc., in order to implement at least one of frequency division duplex (FDD) and time division duplex (TDD).

[0119] The input device 1005 is an input device that accepts input from an external source (e.g., a keyboard, mouse, microphone, switch, button, sensor, etc.). The output device 1006 is an output device that outputs to an external source (e.g., a display, speaker, LED lamp, etc.). The input device 1005 and the output device 1006 may be configured as an integrated unit (e.g., a touch panel).

[0120] Furthermore, each device, such as the processor 1001 and the memory 1002, is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or different buses may be configured for each device.

[0121] Furthermore, the device may include hardware such as a microprocessor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a programmable logic device (PLD), and a field-programmable gate array (FPGA), and some or all of each functional block may be implemented by such hardware. For example, processor 1001 may be implemented using at least one of these hardware components.

[0122] Furthermore, notification of information is not limited to the embodiments / models described herein and may be carried out by other means. For example, notification of information may be carried out by physical layer signaling (e.g., Downlink Control Information (DCI), Uplink Control Information (UCI)), upper layer signaling (e.g., RRC signaling, Medium Access Control (MAC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB))), other signals, or combinations thereof. RRC signaling may also be called RRC messages, and may be, for example, RRC Connection Setup messages, RRC Connection Reconfiguration messages, etc.

[0123] Each aspect / embodiment described herein may be applied to at least one of the following: Long Term Evolution (LTE), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), Future Radio Access (FRA), New Radio (NR), W-CDMA®, GSM®, CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi®), IEEE 802.16 (WiMAX®), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth®, and other appropriate systems, as well as next-generation systems extended based thereon. Furthermore, multiple systems may be applied in combination (for example, a combination of at least one of LTE and LTE-A with 5G).

[0124] The processing procedures, sequences, flowcharts, etc., of each aspect / embodiment described herein may be reordered, provided they are consistent with each other. For example, the methods described herein present various step elements in an exemplary order and are not limited to that specific order.

[0125] The specific operations described in this disclosure as being performed by a base station may, in some cases, be performed by its upper node. In a network consisting of one or more network nodes having a base station, it is clear that various operations performed for communication with a terminal can be performed by the base station and at least one other network node (for example, an MME or S-GW, but not limited to these). Although the above example illustrates the case where there is one other network node besides the base station, it may also be a combination of multiple other network nodes (for example, an MME and an S-GW).

[0126] Information and signals (such as data) can be output from a higher layer (or lower layer) to a lower layer (or higher layer). Input and output may occur via multiple network nodes.

[0127] Input and output information may be stored in a specific location (e.g., memory) or managed using a management table. Input and output information may be overwritten, updated, or appended to. Output information may be deleted. Input information may be sent to other devices.

[0128] The determination may be made by a value represented by 1 bit (0 or 1), by a boolean value (true or false), or by a numerical comparison (for example, a comparison with a predetermined value).

[0129] Each aspect / embodiment described herein may be used individually, in combination, or switched between as needed during implementation. Furthermore, notification of specific information (e.g., notification that "X is") is not limited to explicit notification, but may also be implicit (e.g., by not providing such notification).

[0130] Software should be broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, and so on, whether they are called software, firmware, middleware, microcode, hardware description languages, or by any other name.

[0131] Furthermore, software, instructions, information, etc., may be transmitted and received via a transmission medium. For example, if software is transmitted from a website, server, or other remote source using at least one of wired technology (such as coaxial cable, fiber optic cable, twisted pair, or Digital Subscriber Line (DSL)) and wireless technology (such as infrared or microwave), then at least one of these wired and wireless technologies is included in the definition of a transmission medium.

[0132] The information, signals, etc. described in this disclosure may be represented using any of the various different technologies. For example, the data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0133] In addition, terms used in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of the channel and symbol may be a signal (signaling). Also, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, cell, frequency carrier, etc.

[0134] The terms “system” and “network” as used in this disclosure are interchangeable.

[0135] Furthermore, the information, parameters, etc., described in this disclosure may be expressed using absolute values, relative values ​​from a given value, or other corresponding information. For example, wireless resources may be indicated by an index.

[0136] The names used for the parameters described above are not restrictive in any way. Furthermore, the formulas and other expressions using these parameters may differ from those expressly disclosed in this disclosure. Since various channels (e.g., PUCCH, PDCCH, etc.) and information elements can be identified by any suitable name, the various names assigned to these various channels and information elements are not restrictive in any way.

[0137] In this disclosure, terms such as "Base Station (BS)," "wireless base station," "fixed station," "NodeB," "eNodeB (eNB)," "gNodeB (gNB)," "access point," "transmission point," "reception point," "transmission / reception point," "cell," "sector," "cell group," "carrier," and "component carrier" may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

[0138] A base station can house one or more (e.g., three) cells (also called sectors). If a base station houses multiple cells, the entire coverage area of ​​the base station can be divided into multiple smaller areas, each of which can also be provided with communication services by a base station subsystem (e.g., a small indoor base station (Remote Radio Head: RRH)).

[0139] The terms "cell" or "sector" refer to a portion or all of the coverage area of ​​at least one of the base stations and base station subsystems that provide communication services in this coverage.

[0140] In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably.

[0141] A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other appropriate term.

[0142] At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may be a device mounted on a mobile body, the mobile body itself, etc. The mobile body may be a vehicle (e.g., a car, an airplane, etc.), an unmanned mobile body (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). At least one of the base station and the mobile station may be a device that does not necessarily move during communication operation. For example, at least one of the base station and the mobile station may be an Internet of Things (IoT) device such as a sensor.

[0143] Furthermore, the term "base station" in this disclosure may be interpreted as "mobile station" (user terminal, hereinafter the same). For example, each aspect / embodiment of this disclosure may be applied to a configuration in which communication between a base station and a mobile station is replaced with communication between multiple mobile stations (which may be called, for example, Device-to-Device (D2D), Vehicle-to-Everything (V2X), etc.). In this case, the mobile station may have the functions that a base station has. Also, terms such as "uplink" and "downlink" may be interpreted as terms corresponding to terminal-to-terminal communication (for example, "side"). For example, uplink channel, downlink channel, etc. may be interpreted as side channel.

[0144] Similarly, the term "mobile station" in this disclosure may be interpreted as "base station." In this case, the base station may be configured to have the functions that a mobile station has.

[0145] A wireless frame may consist of one or more frames in the time domain. Each of these one or more frames in the time domain may be called a subframe. A subframe may further consist of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

[0146] Numerology may be communication parameters applied to at least one of the transmission and reception of a signal or channel. Numerology may include, for example, at least one of the following: subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame configuration, specific filtering processes performed by the transceiver in the frequency domain, and specific windowing processes performed by the transceiver in the time domain.

[0147] A slot may consist of one or more symbols in the time domain (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol). A slot may also be a time unit based on neurology.

[0148] A slot may include multiple minislots. Each minislot may consist of one or more symbols in the time domain. Minislots may also be called subslots. Minislots may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called a PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called a PDSCH (or PUSCH) mapping type B.

[0149] Wireless frames, subframes, slots, minislots, and symbols all represent units of time when transmitting a signal. Different names may be used for each of these terms.

[0150] For example, one subframe may be called a Transmit Time Interval (TTI), multiple consecutive subframes may be called a TTI, or one slot or one minislot may be called a TTI. In other words, at least one of a subframe and a TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (e.g., 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, etc., instead of a subframe.

[0151] Here, TTI refers to, for example, the smallest unit of time for scheduling in wireless communication. For example, in an LTE system, the base station schedules each user terminal to allocate wireless resources (such as the frequency bandwidth and transmission power available to each user terminal) in TTI units. However, the definition of TTI is not limited to this.

[0152] TTI may be a transmission time unit for channel-encoded data packets (transport blocks), code blocks, code words, etc., or it may be a processing unit for scheduling, link adaptation, etc. Given a TTI, the actual time interval (e.g., number of symbols) to which the transport block, code block, code word, etc. are mapped may be shorter than the given TTI.

[0153] Furthermore, if one slot or one mini-slot is referred to as TTI, then one or more TTIs (i.e., one or more slots or one or more mini-slots) may constitute the minimum time unit of scheduling. In addition, the number of slots (number of mini-slots) that constitute this minimum time unit of scheduling may be controlled.

[0154] A TTI with a time length of 1ms may also be called a normal TTI, long TTI, normal subframe, long subframe, slot, etc. A TTI shorter than a normal TTI may also be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, mini slot, sub slot, slot, etc.

[0155] Furthermore, long TTIs (e.g., normal TTIs, subframes, etc.) may be interpreted as TTIs with a time length exceeding 1 ms, and short TTIs (e.g., shortened TTIs, etc.) may be interpreted as TTIs with a TTI length less than that of a long TTI but 1 ms or more.

[0156] A resource block (RB) is a resource allocation unit in the time domain and frequency domain, and in the frequency domain, it may contain one or more consecutive subcarriers. The number of subcarriers in an RB may be the same regardless of the neurology, for example, 12. The number of subcarriers in an RB may be determined based on the neurology.

[0157] Furthermore, the time domain of the RB may contain one or more symbols and may be the length of one slot, one minislot, one subframe, or one TTI. One TTI, one subframe, etc., may each consist of one or more resource blocks.

[0158] One or more RBs may also be called a Physical RB (PRB), Sub-Carrier Group (SCG), Resource Element Group (REG), PRB pair, RB pair, etc.

[0159] Furthermore, a resource block may consist of one or more resource elements (REs). For example, one RE may be a radio resource area comprising one subcarrier and one symbol.

[0160] A Bandwidth Part (BWP), also known as a partial bandwidth, may represent a subset of consecutive common resource blocks (RBs) for a given neurology on a given carrier. Here, the common RBs may be identified by an index of the RBs relative to the carrier's common reference point. PRBs may be defined and numbered within a BWP.

[0161] A BWP may include BWPs for UL (UL BWP) and BWPs for DL ​​(DL BWP). One or more BWPs may be set within a single carrier for a UE.

[0162] At least one of the configured BWPs may be active, and the UE does not need to assume that it will send or receive a given signal / channel outside of the active BWP. In this disclosure, terms such as "cell" and "carrier" may be read as "BWP".

[0163] The structures described above, such as wireless frames, subframes, slots, minislots, and symbols, are merely illustrative. For example, the number of subframes included in a wireless frame, the number of slots per subframe or wireless frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, and the number of symbols, symbol length, and cyclic prefix (CP) length within the TTI can be varied in various ways.

[0164] The terms “connected,” “coupled,” or any variation thereof, mean any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are “connected” or “coupled” with each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, “connection” may be reinterpreted as “access.” As used in this disclosure, two elements may be considered to be “connected” or “coupled” with each other using at least one of one or more wires, cables, and printed electrical connections, and, in some non-limiting and non-exclusive examples, electromagnetic energy having wavelengths in the radio frequency domain, microwave domain, and optical (both visible and invisible) domain.

[0165] The reference signal can also be abbreviated as Reference Signal (RS), and may be called a pilot depending on the applicable standard.

[0166] In this disclosure, the phrase "based on" does not mean "based solely on" unless otherwise specified. In other words, the phrase "based on" means both "based solely on" and "based at least on."

[0167] In the configuration of each of the above devices, "means" may be replaced with "part," "circuit," "device," etc.

[0168] Any reference to elements using designations such as “First,” “Second,” etc., as used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Accordingly, references to the First and Second elements do not imply that only two elements may be employed therein, or that the First element must precede the Second element in any way.

[0169] Where the terms “include,” “including,” and variations thereof are used in this disclosure, these terms are intended to be inclusive, as is the term “comprising.” Furthermore, the term “or” as used in this disclosure is not intended to mean exclusive OR.

[0170] In this disclosure, if articles are added through translation, such as a, an, and the in English, this disclosure may include the fact that the noun following these articles is plural.

[0171] As used in this disclosure, the terms “determining” and “determining” may encompass a wide variety of actions. “Determining” may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiry (e.g., searching in a table, database, or other data structure), and ascertaining. “Determining” may also include, for example, receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, and accessing (e.g., accessing data in memory). Furthermore, "judgment" and "decision" can include considering something as having been "judged" or "decided" after resolving, selecting, choosing, establishing, comparing, etc. In other words, "judgment" and "decision" can include considering something as having been "judged" or "decided" after some action. Also, "judgment (decision)" can be reinterpreted as "assuming," "expecting," or "considering."

[0172] In this disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also mean "A and B are each different from C." Terms such as "separate" and "combine" may be interpreted similarly to "different."

[0173] Figure 9 shows an example of the configuration of vehicle 2001. As shown in Figure 9, vehicle 2001 includes a drive unit 2002, a steering unit 2003, an accelerator pedal 2004, a brake pedal 2005, a shift lever 2006, left and right front wheels 2007, left and right rear wheels 2008, an axle 2009, an electronic control unit 2010, various sensors 2021 to 2029, an information service unit 2012, and a communication module 2013.

[0174] The drive unit 2002 is composed of, for example, an engine, a motor, or a hybrid of an engine and a motor.

[0175] The steering unit 2003 includes at least a steering wheel (also called a handle) and is configured to steer at least one of the front wheels and the rear wheels based on the operation of the steering wheel performed by the user.

[0176] The electronic control unit 2010 consists of a microprocessor 2031, memory (ROM, RAM) 2032, and communication ports (IO ports) 2033. Signals from various sensors 2021 to 2027 installed in the vehicle are input to the electronic control unit 2010. The electronic control unit 2010 may also be called an ECU (Electronic Control Unit).

[0177] Signals from various sensors 2021-2028 include current signals from the current sensor 2021 that senses motor current, front and rear wheel rotation speed signals obtained by the rotation speed sensor 2022, front and rear wheel air pressure signals obtained by the air pressure sensor 2023, vehicle speed signals obtained by the vehicle speed sensor 2024, acceleration signals obtained by the acceleration sensor 2025, accelerator pedal depression signals obtained by the accelerator pedal sensor 2029, brake pedal depression signals obtained by the brake pedal sensor 2026, shift lever operation signals obtained by the shift lever sensor 2027, and detection signals obtained by the object detection sensor 2028 for detecting obstacles, vehicles, pedestrians, etc.

[0178] The Information Services Unit 2012 consists of various devices for providing various types of information, such as driving information, traffic information, and entertainment information, including a car navigation system, audio system, speakers, television, and radio, and one or more ECUs that control these devices. The Information Services Unit 2012 uses information acquired from external devices via a communication module 2013, etc., to provide various multimedia information and multimedia services to the occupants of Vehicle 1.

[0179] The driver assistance system unit 2030 consists of various devices that provide functions to prevent accidents or reduce the driver's workload, such as millimeter-wave radar, LiDAR (Light Detection and Ranging), cameras, positioning locators (e.g., GNSS), map information (e.g., high-definition (HD) maps, autonomous vehicle (AV) maps), gyro systems (e.g., IMU (Inertial Measurement Unit), INS (Inertial Navigation System)), AI (Artificial Intelligence) chips, and AI processors, as well as one or more ECUs that control these devices. The driver assistance system unit 2030 also sends and receives various information via the communication module 2013 to realize driver assistance functions or autonomous driving functions.

[0180] The communication module 2013 can communicate with the microprocessor 2031 and components of the vehicle 1 via its communication port. For example, the communication module 2013 sends and receives data via its communication port 2033 between the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, left and right front wheels 2007, left and right rear wheels 2008, axle 2009, the microprocessor 2031 and memory (ROM, RAM) 2032 in the electronic control unit 2010, and sensors 2021 to 2028 provided in the vehicle 2001.

[0181] The communication module 2013 is a communication device that can be controlled by the microprocessor 2031 of the electronic control unit 2010 and can communicate with external devices. For example, it can send and receive various types of information to and from external devices via wireless communication. The communication module 2013 may be located either inside or outside the electronic control unit 2010. The external device may be, for example, a base station or a mobile station.

[0182] The communication module 2013 transmits current signals from current sensors input to the electronic control unit 2010 to an external device via wireless communication. The communication module 2013 also transmits, via wireless communication, other signals input to the electronic control unit 2010, including front and rear wheel rotation speed signals obtained by the rotation speed sensor 2022, front and rear wheel air pressure signals obtained by the air pressure sensor 2023, vehicle speed signals obtained by the vehicle speed sensor 2024, acceleration signals obtained by the acceleration sensor 2025, accelerator pedal depression signals obtained by the accelerator pedal sensor 2029, brake pedal depression signals obtained by the brake pedal sensor 2026, shift lever operation signals obtained by the shift lever sensor 2027, and detection signals obtained by the object detection sensor 2028 for detecting obstacles, vehicles, pedestrians, etc.

[0183] The communication module 2013 receives various information (traffic information, signal information, distance information, etc.) transmitted from external devices and displays it on the information service unit 2012 installed in the vehicle. The communication module 2013 also stores the various information received from external devices in memory 2032, which is available to the microprocessor 2031. Based on the information stored in memory 2032, the microprocessor 2031 may control the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, left and right front wheels 2007, left and right rear wheels 2008, axles 2009, sensors 2021-2028, etc., installed in the vehicle 2001.

[0184] (Note) The disclosure described above may also be expressed as follows:

[0185] The first feature is a control unit that controls the execution of the procedure for adding and modifying secondary cells, If the aforementioned addition / modification procedure is successful or unsuccessful, the transmitting unit sends a message to the network containing the type of the addition / modification procedure and execution information indicating that the master node or secondary node led the addition / modification procedure. It is a terminal equipped with [a certain feature].

[0186] The second feature is that, in the first feature, if the addition / modification procedure fails, the transmitting unit transmits a message that includes the execution conditions for the addition / modification procedure associated with the secondary cell in which the addition / modification procedure failed.

[0187] The third feature is that, in the first or second feature, the transmitting unit transmits the message including the elapsed time from the start of the addition / modification procedure.

[0188] The fourth feature is that, in the first to third features, the transmitting unit transmits the message including the identification information of the terminal.

[0189] The fifth feature is that, in the first to fourth features, if the addition / modification procedure fails, the transmission unit transmits the message containing information about candidate secondary cells other than the secondary cell for which the addition / modification procedure failed.

[0190] The sixth feature is that, in the first to fifth features, if the addition / modification procedure is successful, the transmission unit transmits the message according to the setting of whether or not the execution information needs to be transmitted.

[0191] Although the present disclosure has been described in detail above, it will be clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in modified and altered forms without departing from the intent and scope of the present disclosure as defined by the claims. Therefore, the descriptions in the present disclosure are illustrative and not intended to be restrictive in any way. [Explanation of Symbols]

[0192] 10 Wireless communication systems 20 E-UTRAN 30 NG RAN 40 UPF 100A eNB 100B gNB 110 Wireless Communication Section 120 RRC / Xn Processing Unit 130 DC Processing Unit 140 Control Unit 200 UE 210 Wireless Communication Section 220 RRC Processing Unit 230 DC Processing Unit 240 Control Unit 1001 Processor 1002 memory 1003 Storage 1004 Communication device 1005 Input device 1006 Output device 1007 Bus 2001 Vehicle 2002 Drive Unit 2003 Steering Department 2004 Accelerator pedal 2005 Brake pedal 2006 Shift Lever 2007 Left and right front wheels 2008 Left and right rear wheels 2009 Axle 2010 Electronic Control Unit 2012 Information Services Department 2013 Communication Module 2021 Current Sensor 2022 Rotation speed sensor 2023 Pneumatic Sensor 2024 Vehicle Speed ​​Sensor 2025 Accelerometer 2026 Brake Pedal Sensor 2027 Shift lever sensor 2028 Object Detection Sensor 2029 Accelerator pedal sensor 2030 Driver Support Systems Department 2031 Microprocessor 2032 memory (ROM, RAM) 2033 Communication Port

Claims

1. In a dual connectivity configuration where a first cell group formed by a first node and a second cell group formed by a second node are configured on a terminal, an addition / modification procedure is performed to add or modify a specific cell within the second cell group. A control unit that holds a success report regarding the success of the aforementioned addition / modification procedure, The system includes a transmission unit that, in response to a request from the network, sends a message including the success report to the network. Terminal.

2. The aforementioned specific cell is the cell in the second cell group that establishes the RRC connection. The terminal according to claim 1.

3. The success report includes information indicating whether the addition / modification procedure is initiated by the second node. The terminal according to claim 1.

4. The aforementioned success report includes information indicating the elapsed time from the receipt of the conditional reset corresponding to the candidate cell in the addition / modification procedure to the start of the execution of the conditional reset. The terminal according to claim 1.

5. The aforementioned success report includes information indicating the type of timer related to the success of the aforementioned addition / modification procedure. The terminal according to claim 1.

6. The transmitting unit transmits information indicating that it holds the success report to the network. The terminal according to claim 1.

7. A communication method performed by a terminal, In a dual connectivity configuration where a first cell group formed by a first node and a second cell group formed by a second node are configured on the terminal, an add / modify procedure is performed to add or modify a specific cell within the second cell group. To maintain a success report regarding the success of the aforementioned addition / modification procedure, The system includes sending a message containing the success report to the network in response to a request from the network. Communication method.

8. In a dual connectivity configuration where a terminal is configured with a first cell group formed by a first node and a second cell group formed by a second node, a transmission unit sends a request message to the terminal requesting a success report regarding the success of an add / modify procedure for adding or modifying a specific cell within the second cell group. The system includes a receiving unit that receives a message from the terminal, including the aforementioned success report. Base station.

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