terminal

Abstract

The terminal comprises: a control unit which sets the cell identification information of the target cell as a variable when the resetting process of the target cell is performed in the conditional resetting; and a sending unit which sends a message including the cell identification information set as the variable to the network.

Description

Technical Field

[0001] The present disclosure relates to a terminal that sends a message related to a failure. Background Art

[0002] In the 3rd Generation Partnership Project (3GPP), the fifth generation mobile communication system (also called 5G, New Radio (NR) or Next Generation (NG)) is standardized, and the standardization of the next generation called Beyond 5G, 5G Evolution or 6G is also underway.

[0003] In 3GPP's version 16, for specifications before version 15, procedures such as Conditional Handover (sometimes also called CHO), MCG (Master Cell Group) recovery (Recovery) in dual connectivity (Dual Connectivity), and Dual Active Protocol Stack (DAPS) Handover were introduced. CHO is the process of switching from a source cell to a target cell without sending a re-establishment request message for the target cell to the network. MCG Recovery (MCG Recovery) is the process of resetting the MCG by sending MCGFailureInformation to the SCG (Secondary Cell Group) when a link failure of the MCG occurs. DAPS Handover is a switching process performed while maintaining the link of the source cell.

[0004] Prior art literature

[0005] Non-patent literature

[0006] Non-licensed document 1: 3GPP TS 36.331 V16.1.0, 3rd Generation Partnership Project; Technical Specification Group Radio Access Network; NR; Radio Resource Control (RRC) protocol specification (Release 16), 3GPP, July 2020 Summary of the invention

[0007] However, for the purpose of SON (Self Organizing Network) or MDT (Minimization of Drive Test), it is desirable to collect messages related to link failures between a network and UE (User Equipment).

[0008] As a result of intensive research conducted by the inventors, it was found that in the above-mentioned CHO and MCG Recovery, DAPSHandover, etc., there are cases where messages related to failure are not properly sent to the network.

[0009] Therefore, the following disclosure has been made in view of such a situation, and an object of the disclosure is to provide a terminal capable of appropriately sending a message related to a failure to a network.

[0010] One method of the present disclosure is a terminal comprising: a control unit, which sets the cell identification information of the target cell as a variable when a reconfiguration process of the target cell is performed in a conditional reconfiguration; and a sending unit, which sends a message including the cell identification information set as the variable to a network.

[0011] One embodiment of the present disclosure is a terminal comprising: a control unit, which sets "an information element configured to be able to identify whether a recovery process of the first cell group using the second cell group is set" as a variable when a link failure of the first cell group occurs in a dual connection using the first cell group and the second cell group; and a sending unit, which sends a message including the information element set as the variable to a network.

[0012] One embodiment of the present disclosure is a terminal comprising: a control unit, which sets an information element indicating a failure type as a variable when a synchronization failure of the second cell group occurs and transmission to the first cell group is stopped in a dual connection using a first cell group and a second cell group; and a sending unit, which sends a message including the information element set as the variable to a network.

[0013] One embodiment of the present disclosure is a terminal comprising: a control unit, which sets an information element showing quality information related to the second cell group as a variable when a link failure occurs in either the first cell group or the second cell group in a dual connection using the first cell group and the second cell group and transmission to the first cell group and the second cell group cannot be performed; and a sending unit, which sends a message including the information element set as the variable to a network.

[0014] One method of the present disclosure is a terminal comprising: a control unit, which sets an information element indicating the link failure in a specific handover from a source cell to a target cell as a variable when a link failure of the source cell occurs in the specific handover; and a sending unit, which sends a message including the information element set as the variable to a network, wherein the specific handover is a handover performed while maintaining the link of the source cell.

[0015] One embodiment of the present disclosure is a terminal comprising: a control unit, which sets identification information related to a non-public mobile communication network as a variable when a connection failure occurs in a cell included in the non-public mobile communication network; and a sending unit, which sends a message including the identification information set as the variable to the network. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a diagram schematically showing the overall structure of the wireless communication system 10 .

[0017] Figure 2 is a functional block diagram of UE 200.

[0018] Figure 3 1 is a diagram showing an operation example of the wireless communication system 10 .

[0019] Figure 4 1 is a diagram showing an operation example of the wireless communication system 10 .

[0020] Figure 5 1 is a diagram showing an operation example of the wireless communication system 10 .

[0021] Figure 6 1 is a diagram showing an operation example of the wireless communication system 10 .

[0022] Figure 7 1 is a diagram showing an operation example of the wireless communication system 10 .

[0023] Figure 8 1 is a diagram showing an operation example of the wireless communication system 10 .

[0024] Fig. 9This is a diagram showing an example of UEInformationRequest (ASN.1 format).

[0025] Fig.10 This is a diagram showing an example of UEInformationResponse (ASN.1 format).

[0026] Fig.11 This is a diagram showing an example of the hardware configuration of the UE 200 . DETAILED DESCRIPTION

[0027] Hereinafter, the embodiments will be described with reference to the drawings. In addition, the same or similar reference numerals are given to the same functions and structures, and the description thereof will be appropriately omitted.

[0028] (1) Overall schematic structure of wireless communication system

[0029] Figure 1 1 is a schematic diagram of the overall structure of the wireless communication system 10 of this embodiment. The wireless communication system 10 is a wireless communication system that complies with Long Term Evolution (LTE) and 5G New Radio (NR). In addition, LTE can be called 4G, and NR can be called 5G.

[0030] In addition, LTE and NR can also be interpreted as radio access technologies (RATs). In this embodiment, LTE can be called the first radio access technology and NR can be called the second radio access technology.

[0031] The wireless communication system 10 includes an evolved universal terrestrial radio access network 20 (hereinafter referred to as E-UTRAN 20) and a next generation radio access network 30 (hereinafter referred to as NG RAN 30). In addition, the wireless communication system 10 includes a terminal 200 (hereinafter referred to as UE 200, User Equipment).

[0032] The E-UTRAN 20 includes an eNB 100A which is a radio base station compliant with LTE. The NG RAN 30 includes a gNB 100B which is a radio base station compliant with 5G (NR).

[0033] eNB 100A, gNB 100B and UE 200 are capable of supporting carrier aggregation (CA) using multiple component carriers (CCs), dual connectivity (DC) in which the UE communicates with multiple NG-RAN nodes simultaneously, etc.

[0034] The E-UTRAN 20 is connected to the core network 40 for LTE. In addition, the E-UTRAN 20, the NG RAN 30, and the core network 40 may be simply referred to as a network 120.

[0035] A management server 50 (hereinafter referred to as an OAM server 50: Operation Administration and Management server) may be provided in the core network 40. The OAM server 50 may execute processes related to SON (Self Organizing Network) or MDT (Minimization of Drive Test).

[0036] eNB 100A and gNB 100B may form an area (also referred to as a cell) capable of performing wireless communications with UE 200, specifically, may form area A1 or area A2.

[0037] Here, area A1 may also be interpreted as an area in which UE 200 can communicate with eNB 100A. Area A2 may also be interpreted as an area in which UE 200 can communicate with gNB 100B. Area A1 and area A2 may overlap with each other, and in the area in which area A1 overlaps with area A2, EN-DC (E-UTRA-NR Dual Connectivity) or NE-DC (NR-EUTRA Dual Connectivity) in which UE 200 can communicate with both eNB 100A and gNB 100B simultaneously may be performed. In addition, in Figure 2 In the example, the case where the base station capable of communicating with the UE 200 in area A1 is the eNB 100A is illustrated, but the base station capable of communicating with the UE 200 in area A1 may also be the gNB 100B provided in the NG RAN 30. In such a case, NR-DC (NR-NR Dual Connectivity) in which the UE 200 communicates with two or more gNBs 100B (or cells) simultaneously can be performed.

[0038] Here, in the above-mentioned DC, the group of cells that can perform processing related to C-plane (control plane) and U-plane (user plane) can be called the first cell group (MCG: Master Cell Group). In the above-mentioned DC, the group of cells that can perform processing related to U-plane (user plane) can be called the second cell group (SCG: Secondary Cell Group). For example, in the above-mentioned EN-DC, eNB 100A can be called MN (Master Node), and gNB 100B can be called SN (Secondary Node). In the above-mentioned NE-DC, eNB 100A can be called SN, and gNB100B can be called MN.

[0039] (2) Functional block structure of wireless communication system

[0040] Next, a functional block configuration of the wireless communication system 10 will be described. Specifically, a functional block configuration of the UE 200 will be described.

[0041] Figure 2 is a functional block diagram of UE 200. Figure 2 As shown, UE 200 includes a radio signal transceiver 210 , an amplifier 220 , a modulation and demodulation unit 230 , a control signal and reference signal processing unit 240 , an encoding and decoding unit 250 , a data transceiver 260 , and a control unit 270 .

[0042] The wireless signal transceiver 210 transmits and receives wireless signals conforming to LTE or NR. The wireless signal transceiver 210 supports Massive MIMO, CA and DC using a plurality of CCs in a bundled manner, and the like.

[0043] The amplifier 220 is composed of a PA (Power Amplifier) / LNA (Low Noise Amplifier) ​​etc. The amplifier 220 amplifies the signal output from the modulation and demodulation unit 230 to a predetermined power level. In addition, the amplifier 220 amplifies the RF signal output from the wireless signal transmission and reception unit 210 .

[0044] The modem unit 230 performs data modulation / demodulation, transmission power setting, resource block allocation, etc. for each predetermined communication target (eNB 100A or gNB 100B). In the modem unit 230, CP-OFDM (Cyclic Prefix-Orthogonal Frequency Division Multiplexing) / Discrete Fourier Transform-Spread (DFT-S-OFDM) can be applied. In addition, DFT-S-OFDM is used not only for uplink (UL) but also for downlink (DL).

[0045] The control signal / reference signal processing unit 240 performs processing related to various control signals transmitted and received by the UE 200 and processing related to various reference signals transmitted and received by the UE 200 .

[0046] Specifically, the control signal / reference signal processing unit 240 receives various control signals sent from the gNB 100A or gNB 100B via a predetermined control channel, such as a control signal of the radio resource control layer (RRC). In addition, the control signal / reference signal processing unit 240 sends various control signals to the eNB 100A or gNB 100B via a predetermined control channel.

[0047] The control signal / reference signal processing unit 240 performs processing using reference signals (RS) such as a demodulation reference signal (DMRS: Demodulation Reference Signal) and a phase tracking reference signal (PTRS: Phase Tracking Reference Signal).

[0048] DMRS is a terminal-specific reference signal (pilot signal) known between a base station and a terminal for estimating a fading channel used for data demodulation. PTRS is a terminal-specific reference signal for estimating phase noise, which is a problem in a high frequency band.

[0049] In addition, the reference signal may include a channel state information reference signal (CSI-RS: Channel State Information-Reference Signal), a sounding reference signal (SRS: Sounding Reference Signal), and a positioning reference signal (PRS: Positioning Reference Signal) for position information in addition to DMRS and PTRS.

[0050] In addition, the channel includes control channels and data channels. The control channel includes PDCCH (Physical Downlink Control Channel), PUCCH (Physical Uplink Control Channel), RACH (including Random Access Channel, Downlink Control Information (DCI) including Random Access Radio Network Temporary Identifier (RA-RNTI)) and Physical Broadcast Channel (PBCH).

[0051] In addition, the data channel includes PDSCH (Physical Downlink Shared Channel) and PUSCH (Physical Uplink Shared Channel). Data means data transmitted via the data channel. The data channel may be replaced by a shared channel.

[0052] Here, the control signal and reference signal processing unit 240 receives downlink control information (DCI). DCI includes fields storing DCI formats (DCI Formats), carrier indicator (CI: Carrier indicator), BWP indicator (BWPindicator), FDRA (Frequency Domain Resource Allocation: frequency domain resource allocation), TDRA (Time Domain Resource Allocation: time domain resource allocation), MCS (Modulation and Coding Scheme: modulation and coding scheme), HPN (HARQ Process Number: HARQ process number), NDI (New Data Indicator: new data indicator), RV (Redundancy Version: redundancy version), etc., as existing fields.

[0053] The value stored in the DCI Format field is an information element that specifies the format of the DCI. The value stored in the CI field is an information element that specifies the CC to which the DCI is applied. The value stored in the BWP indicator field is an information element that specifies the BWP to which the DCI is applied. The BWP that can be specified by the BWP indicator is set by the information element (BandwidtPart-Config) contained in the RRC message. The value stored in the FDRA field is an information element that specifies the frequency domain resources to which the DCI is applied. The frequency domain resources are determined by the value stored in the FDRA field and the information element (RA Type) contained in the RRC message. The value stored in the TDRA field is an information element that specifies the time domain resources to which the DCI is applied. The time domain resources are determined by the value stored in the TDRA field and the information element (pdsch-TimeDomainAllocationList) contained in the RRC message. The time domain resources can also be determined by the value stored in the TDRA field and the default table. The value stored in the MCS field is an information element that specifies the MCS to which the DCI is applied. The MCS is determined by the value stored in the MCS and the MCS table. The MCS table can be specified by the RRC message or determined by RNTI scrambling. The value stored in the HPN field is an information element that specifies the HARQ process to which the DCI is applied. The value stored in the NDI field is an information element used to determine whether the data to which the DCI is applied is the initially transmitted data. The value stored in the RV field is an information element that specifies the redundancy of the data to which the DCI is applied.

[0054] In an embodiment, the control signal / reference signal processing unit 240 constitutes a sending unit that sends a message including an information element set as a variable. The variable is a variable in which an information element related to a connection failure is set. The variable can be called VarRLF-Report. The variable can also be called rlf-Report contained in VarRLF-Report. Connection failure can include radio link failure (RLF; Radio Link Failure). Connection failure can also include handover failure (HOFailure). Connection failure can also include RACH (Random Access Channel: Random Access Channel) failure. The message including rlf-Report can be an RRC message. The message including rlf-Report can also include UEInformationResponse sent according to UEInformationRequest. The message including rlf-Report can also include an RRC reconfiguration completion message (RRC Reconfiguration Completemessage) used in the RRC reconfiguration process.

[0055] The encoding / decoding unit 250 can perform data segmentation / concatenation and channel coding / decoding, etc. according to each predetermined communication target (eNB 100A or gNB 100B).

[0056] Specifically, the encoding / decoding unit 250 divides the data output from the data transceiver unit 260 into predetermined sizes and performs channel coding on the divided data. In addition, the encoding / decoding unit 250 decodes the data output from the modulation / demodulation unit 230 and concatenates the decoded data.

[0057] The data transceiver 260 performs transmission and reception of protocol data units (PDUs) and service data units (SDUs). Specifically, the data transceiver 260 performs assembly / disassembly of PDUs / SDUs in multiple layers (such as the medium access control layer (MAC), the radio link control layer (RLC), and the packet data convergence protocol layer (PDCP)). In addition, the data transceiver 260 performs error correction and retransmission control of data based on the hybrid automatic repeat request (HARQ).

[0058] The control unit 270 controls each functional block constituting the UE 200. In the embodiment, the control unit 270 is a control unit that sets the information element related to the connection failure as a variable when a connection failure occurs. As described above, the variable can be called VarRLF-Report or rlf-Report. In particular, in the embodiment, the case where the connection failure shown below occurs is described.

[0059] (2.1) Conditional Resetting

[0060] Conditional re-establishment (hereinafter referred to as CHO) is described below. CHO is a process of switching from a source cell to a target cell without sending an RRC re-establishment request message for a target cell to the network 300. In the prior art, when RLF occurs in CHO, since an RRC re-establishment request is not sent, there is no opportunity to send a message related to RLF. Based on this understanding, the control unit 270 performs the following actions.

[0061] When the target cell reconfiguration procedure (RRC reconfiguration procedure) is performed in CHO, the control unit 270 sets the identification information of the target cell as a variable. More specifically, when a HO Failure occurs in CHO, the control unit 270 may set the identification information of the target cell as a variable. The variable may be called reestablishmentCellId included in VarRLF-Report. The variable may also be a variable that can identify that RRC reconfiguration is applied in CHO. In this case, the variable may also be called reestablishmentCellId CHO.

[0062] For example, when receiving an RRC reconfiguration message or executing conditional reconfiguration, the control unit 270 sets the identification information of the selected cell in the reestablishmentCellId (or reestablishmentCellId CHO) included in the VarRLF-Report during the T311 startup period when the RRC reconfiguration for executing conditional reconfiguration is applied in the cell selection. The selected cell can be considered as the target cell selected in the cell selection (for example, CHO) of the RRC reconfiguration. The selected cell can also be considered as the target cell in which HO Failure occurs in CHO. The identification information of the selected cell can be GCI (Global Cell Identity). In addition, T311 is a timer that is started according to the start of the RRC reestablishment procedure. The RRC Reestablishment Procedure is a process performed when a HO Failure occurs in CHO.

[0063] Here, the UE 200 may include the information elements set in reestablishmentCellId (or reestablishmentCellId CHO) in the UEInformationResponse when explicitly requested by the network 300 through the UEInformationRequest. In such a case, the UEInformationRequest may include the information elements (e.g., cHOFailureReestablishmentReport) requesting the information elements set in reestablishmentCellId (or reestablishmentCellId CHO). It is also possible that the UE 200 autonomously includes the information elements set in reestablishmentCellId (or reestablishmentCellId CHO) in the UEInformationResponse even if it is not explicitly requested through the UEInformationRequest.

[0064] According to such a configuration, even when RLF occurs in CHO, it is possible to report the RLF to the network 300 .

[0065] (2.2)MCG Recovery

[0066] The following describes the actions that assume the following situation: When a link failure (Failure) of the MCG occurs in the DC, MCG Recovery is performed. MCG Recovery is a process of resetting the MCG by sending MCGFailureInformation to the SCG when an RLF of the MCG occurs. In the prior art, since the RRC re-establishment request is not sent in the MCG Recovery, there is no opportunity to send messages related to the RLF. Here, based on such insights, the control unit 270 performs the actions shown below.

[0067] When an MCG Failure occurs in the DC, the control unit 270 sets an information element configured to be able to identify whether a recovery process (MCG Recovery) of the MCG using the SCG is set as a variable. Whether MCGRecovery is set can be replaced by whether T316 is set. T316 is a timer that is started by sending MCGFailureInformation. In other words, T316 is a timer that measures the time allowed in MCG Recovery. The variable can also be referred to as t316Configured included in VarRLF-Report. The information element indicating the type of failure can be expressed by the presence or absence of the information element "indicating that T316 is set" (true).

[0068] According to such a structure, RLF can be distinguished into (A) RLF caused by MCG Failure occurring in UE 200 without MCG Recovery configuration (UE 200 without T316 configuration), and (B) RLF caused by MCG Failure occurring in UE 200 with MCG Recovery configuration (UE 200 with T316 configuration).

[0069] Here, UE 200 may include the information elements set in t316Configured in UEInformationResponse when explicitly requested by UEInformationRequest from network 300. In such a case, UEInformationRequest may include an information element (t316ConfiguredReport) requesting the information elements set in t316Configured. Even if not explicitly requested by UEInformationRequest, UE 200 may autonomously include the information elements set in t316Configured in UEInformationResponse.

[0070] (2.3) SCG Sync Failure

[0071] The following describes the operation assuming that a synchronization failure (Sync Failure) of the SCG occurs in the DC. In the prior art, it is impossible to identify the RLF that occurs when an SCG Sync Failure occurs and transmission to the MCG is stopped. Based on this understanding, the control unit 270 performs the following operation.

[0072] When SCG Sync Failure occurs in the DC and transmission to the MCG is stopped, the control unit 270 sets an information element indicating the failure type as a variable. The failure type may also be called connectionFailureType. The information element indicating the failure type may also be called reconfigureWithSyncFailureSCG.

[0073] For example, when T304 of the SCG has expired and the transmission to the MCG has been stopped, the control unit 270 sets reconfigureWithSyncFailureSCG in the VarRLF-Report. reconfigureWithSyncFailureSCG can be set in the connectionFailureType included in the VarRLF-Report. T304 can be a timer that is started based on the reception of an RRC Connection Reconfiguration message, etc. T304 can also be a timer that measures the time allowed for a change in a cell included in an MCG or SCG. T304 can also be a timer that is started when the UE 200 performs a conditional handover execution in the CHO. T304 can also be a timer that measures the time allowed for a conditional handover execution in the CHO.

[0074] Furthermore, the control unit 270 may set reconfigureWithSyncFailureSCG in VarRLF-Report in a manner that enables the RAN of the SCG to be identified. Specifically, when the above-mentioned situation occurs in EN-DC, the control unit 270 may set SCGFailureInformation in a variable (nr-SCGFailureInfoNR) representing EN-DC. When the above-mentioned situation occurs in NR-DC, the control unit 270 may set SCGFailureInformation in a variable (nr-SCGFailureInfo) representing NR-DC. When the above-mentioned situation occurs in NE-DC, the control unit 270 may set SCGFailureInformation in a variable (eutra-SCGFailureInfo) representing EN-DC. nr-SCGFailureInfoNR, nr-SCGFailureInfo, and eutra-SCGFailureInfoNR may be considered as examples of variables that may be included in VarRLF-Report. nr-SCGFailureInfoNR, nr-SCGFailureInfo, eutra-SCGFailureInfoNR can also be variables different from connectionFailureType.

[0075] In addition, SCGFailureInformation may include measResultFrequencyList. measResultFrequencyList includes the measurement result of the frequency set in UE200 in a manner measured by the measurement configuration (measConfig). SCGFailureInformation may also include measResultSCG-Failure. measResultSCG-Failure includes the measurement result of the frequency set in UE200 in a manner measured during the RRC reconfiguration process.

[0076] According to such a structure, it is possible to distinguish between (A) RLF caused by switching failure (expiration of T304 of MCG) and (B) RLF caused by expiration of T304 of SCG and stop of transmission to MCG.

[0077] (2.4) Quality information related to SCG

[0078] The following describes the reporting of quality information related to the SCG. In the prior art, when the following situations occur in the DC, the procedure for reporting the quality information related to the SCG is not specified, and the quality information related to the SCG cannot be reported. The above situations refer to (A) SCG Failure (expiration of T310 of SCG) and the situation where transmission to the MCG cannot be performed, and (B) MCG Failure (expiration of T310 of MCG) and the situation where transmission to the SCG cannot be performed. The situation where transmission to the MCG cannot be performed includes the situation where transmission to the MCG is stopped. The situation where transmission to the SCG cannot be performed may include the situation where transmission to the SCG is stopped, and may also include the situation where the PSCell (Primary Secondary Cell) is in the process of being changed. Here, based on such insights, the control unit 270 performs the actions shown below.

[0079] When a link failure occurs in at least one of the MCG and the SCG in the DC and transmission to the MCG and the SCG cannot be performed, the control unit 270 sets an information element indicating quality information related to the SCG as a variable.

[0080] For example, when T310 of the SCG expires and stops sending to the MCG, the control unit 270 may set an information element (SCGFailureInformation) indicating quality information related to the SCG in sCGFailureInfo. sCGFailureInfo is an example of a variable that can be included in VarRLF-Report. As described above, SCGFailureInformation may include measResultSCG-Failure or measResultSCG-Failure.

[0081] Furthermore, the control unit 270 may set SCGFailureInformation in VarRLF-Report in a manner that enables the RAN of the SCG to be identified. Specifically, when the above-mentioned situation occurs in EN-DC, the control unit 270 may set SCGFailureInformation in the variable (nr-SCGFailureInfoNR) representing EN-DC. When the above-mentioned situation occurs in NR-DC, the control unit 270 may set SCGFailureInformation in the variable (nr-SCGFailureInfo) representing NR-DC. When the above-mentioned situation occurs in NE-DC, the control unit 270 may set SCGFailureInformation in the variable (eutra-SCGFailureInfo) representing EN-DC. nr-SCGFailureInfoNR, nr-SCGFailureInfo, and eutra-SCGFailureInfoNR may be considered as examples of variables that may be included in VarRLF-Report.

[0082] For example, when T310 of MCG expires and stops sending to SCG, the control unit 270 can set the information element (measResultSCG) representing the quality information related to SCG in mCGFailureInfo. mCGFailureInfo is an example of a variable that can be included in VarRLF-Report. Similar to SCGFailureInformation, measResultSCG can include measResultSCG-Failure or measResultSCG-Failure. measResultSCG can also be included in MCGFailureInformation.

[0083] Furthermore, the control unit 270 may set MCGFailureInformation in VarRLF-Report in a manner that can identify the RAN of the MCG. Specifically, when the above-mentioned situation occurs in EN-DC, the control unit 270 may set MCGFailureInformation in a variable (eutra-MCGFailureInfo) representing EN-DC. When the above-mentioned situation occurs in NR-DC or NE-DC, the control unit 270 may set MCGFailureInformation in a variable (nr-MCGFailureInfo) representing NR-DC or NE-DC. MCGFailureInformation includes an information element (measResultSCG) representing quality information related to the SCG. eutra-MCGFailureInfo and nr-MCGFailureInfo can be considered as an example of variables that can be included in VarRLF-Report.

[0084] According to such a structure, even in the case of (A) or (B) described above, quality information related to the SCG can be reported.

[0085] (2.5)DAPS Handover

[0086] The following describes DAPS (Dual Active Protocol Stack) handover. DAPS Handover is an example of a specific handover from a source cell to a target cell, and is a handover performed while maintaining the link of the source cell. In the prior art, the RLF of the source cell (hereinafter referred to as source PCell; Primary Cell) is not considered, and there is no opportunity to send a message related to the RLF of the source PCell. Here, based on such insights, the control unit 270 performs the actions shown below.

[0087] When a link failure (RLF) of the source PCell occurs in DAPS, the control unit 270 sets an information element indicating a link failure in DAPS as a variable.

[0088] For example, when a link failure (RLF) of the source PCell occurs in DAPS, the control unit 270 may set the identification information of the source PCell in VarRLF-Report. The variable in which the identification information of the source PCell is set may also be referred to as failedPSCellId. The identification information of the source PCell may include cellGlobalId. The identification information of the source PCell may also include PCI (Physical Cell ID) and ARFCN (Absolute Radio Frequency Channel Number). Furthermore, when a link failure (RLF) of the source PCell occurs in DAPS, the control unit 270 may also set the quality information of the source PCell or the location information (location Information) of the UE 200 in VarRLF-Report.

[0089] According to such a structure, even when RLF of source PCell occurs in DAPS, RLF of source PCell can be reported.

[0090] Here, the identification information of the source PCell may be included in the UEInformationResponse sent according to the UEInformationRequest. When the UE 200 is explicitly requested from the network 300 through the UEInformationRequest, the UE 200 may include the identification information of the source PCell in the UEInformationResponse. Even if it is not explicitly requested through the UEInformationRequest, the UE 200 may autonomously include the identification information of the source PCell in the UEInformationResponse. Furthermore, the identification information of the source PCell may also be included in the RRC Reconfiguration Complete message used in the RRC reconfiguration process.

[0091] (2.6) NPN connection failure

[0092] The following describes a case where a connection failure occurs in a cell included in a non-public communication network (hereinafter referred to as NPN). In the prior art, there is no research on the collection of messages related to the connection failure in such a case. Based on this understanding, the control unit 270 performs the following actions.

[0093] In the event of a connection failure of a cell included in an NPN, the control unit 270 sets the identification information related to the NPN as a variable. The NPN may include an independent NPN (SNPN) operated by the operator of the NPN, or may include an NPN deployed with the support of a PLMN (also referred to as a PNI-NPN (Public Network Integrated NPN). The connection failure may include a radio link failure (RLF) or a failure in the RACH process (RACH Failure). The identification information related to the NPN may be identification information of the NPN (e.g., NPN-Identity). The identification information related to the NPN may also include identification information of the cell included in the NPN. For example, when the NPN is an SNPN, the identification information related to the NPN may be an NID (Network Identity), and when the NPN is a PNI-NPN, the identification information related to the NPN may be a CAG-ID (Closed Access Group Identity).

[0094] According to such a configuration, information on the connection failure of the NPN can be collected, and SON or MDT can be appropriately applied.

[0095] (3) Operation of wireless communication system

[0096] Next, the operation of the wireless communication system 10 will be described. Hereinafter, the operation of the wireless communication system 10 will be described by dividing into the above-mentioned application scenarios.

[0097] (3.1) Conditional Resetting

[0098] Below, refer to Figure 3 The above-mentioned CHO is described. Figure 3 In the example, network 300 may be NG RAN30.

[0099] like Figure 3As shown, in step S10, UE 200 receives an RRC Reconfiguration message from network 300. The RRC Reconfiguration message may include an information element for performing CHO. UE 200 may start T311 and start CHO according to the reception of the RRC Reconfiguration message.

[0100] In step S11, UE 200 detects HO Failure in CHO.

[0101] In step S12, UE 200 sets the identification information of the target cell as a variable. When T311 is started, UE 200 may set the identification information of the target cell as a variable. The variable may be reestablishmentCellId or reestablishmentCellId CHO.

[0102] In step S13, UE 200 performs RRC connection re-establishment with network 300 in order to set up a connection with a new cell.

[0103] In step S14, the UE 200 receives a UEInformationRequest from the network 300. The UEInformationRequest may include an information element (reestablishmentCellId or reestablishmentCellId CHO) that explicitly requests identification information of a target cell.

[0104] In step S15, UE 200 sends UEInformationResponse to network 300. UEInformationResponse includes identification information of the target cell (reestablishmentCellId or an information element set in reestablishmentCellId CHO).

[0105] (3.2)MCG Recovery

[0106] The following is an explanation of the above-mentioned MCG Recovery. Figure 4 In the example, network 300 may be NG RAN30.

[0107] like Figure 4As shown, in step S20, UE 200 detects MCG Failure.

[0108] In step S21, UE 200 sets the information element "MCG Recovery configured to identify whether or not a MCG using SCG is configured" as a variable. Here, the description will be continued assuming that MCG Recovery is configured. The variable may be t316ConfiguredReport.

[0109] In step S22, UE 200 performs MCG Recovery. Specifically, UE 200 sends MCGFailureInformation to SCG. Here, the description is continued assuming that MCG is not recovered by MCG Recovery.

[0110] In step S23, UE 200 performs RRC connection re-establishment with network 300 in order to establish a connection with a new cell.

[0111] In step S24, UE 200 receives UEInformationRequest from network 300. UEInformationRequest may include an information element (t316ConfiguredReport) explicitly requesting "an information element indicating whether MCG Recovery is configured".

[0112] In step S25, UE 200 transmits UEInformationResponse to network 300. UEInformationResponse includes an information element "configured to be able to identify whether MCG Recovery is configured" (t316ConfiguredReport).

[0113] (3.3) SCG Sync Failure

[0114] The following is an explanation of the above-mentioned SCG Sync Failure. Figure 5 In the example, the network 300 may be the NG RAN 30 or the E-UTRAN 20.

[0115] like Figure 5As shown, in step S30, UE 200 detects RLF in DC. As the main causes of RLF, (A) handover failure (expiration of T304 of MCG) and (B) expiration of T304 of SCG and stop of transmission to MCG are considered. Here, the explanation is continued assuming that the main cause of RLF is (B).

[0116] In step S31, UE 200 sets an information element indicating a failure type as a variable. The information element indicating a failure type is an information element for distinguishing from the main cause (A), and includes an information element indicating the main cause (B).

[0117] In step S32, UE 200 performs RRC connection re-establishment with network 300 in order to establish a connection with a new cell.

[0118] In step S33, UE 200 receives UEInformationRequest from network 300. UEInformationRequest may contain an information element explicitly requesting a failure type of RLF.

[0119] In step S34, UE 200 sends UEInformationResponse to network 300. UEInformationResponse includes an information element indicating the failure type (here, reconfigureWithSyncFailureSCG). As described above, reconfigureWithSyncFailureSCG can be set in a manner that allows RAN to identify SCG.

[0120] (3.4) Quality information related to SCG

[0121] The following describes the quality information related to SCG. Figure 6 In the example, the network 300 may be the NG RAN 30 or the E-UTRAN 20.

[0122] like Figure 6 As shown, in step S40, UE 200 detects RLF in DC. As the main causes of RLF, consider (A) SCG Failure (expiration of T310 of SCG) and the case where transmission to MCG cannot be performed, and (B) MCG Failure (expiration of T310 of MCG) and the case where transmission to SCG cannot be performed.

[0123] In step S41, the UE 200 stores the information element representing the quality information related to the SCG as a variable. For example, in the case where the main cause of the RLF is (A), the UE 200 may set the information element representing the quality information related to the SCG in sCGFailureInfo. In the case where the main cause of the RLF is (B), the UE 200 may set the information element representing the quality information related to the SCG in mCGFailureInfo.

[0124] In step S42, UE 200 performs RRC connection re-establishment with network 300 in order to establish a connection with a new cell.

[0125] In step S43, UE 200 receives UEInformationRequest from network 300. UEInformationRequest may contain an information element explicitly requesting quality information.

[0126] In step S44, UE 200 sends UEInformationResponse to network 300. UEInformationResponse includes an information element indicating quality information related to SCG. As described above, the information element indicating quality information related to SCG may be set in a manner that allows the RAN of SCG or MCG to be identified.

[0127] (3.5) DAPS switching

[0128] The following describes DAPS switching. Figure 7 In the example, the network 300 may be the NG RAN 30.

[0129] In step S50, UE 200 receives an RRC Reconfiguration message from network 300. The RRC Reconfiguration message may contain an information element for performing DAPS handover.

[0130] In step S51, UE 200 detects a link failure (RLF) of a source PCell.

[0131] In step S52, UE 200 sets the identification information of the source PCell as a variable.

[0132] In step S53, UE 200 sends an RRC ReconfigurationComplete message to network 300 (target cell). In this way, DAPS handover is completed. Here, the RRC Reconfiguration Complete message may include an information element (rlf-InfoAvailable) indicating whether identification information of the source PCell is set due to RLF of the source PCell.

[0133] In step S54, UE 200 receives UEInformationRequest from network 300. UEInformationRequest may include an information element explicitly requesting identification information of source PCell. In the case where the information element (rlf-InfoAvailable) is included in the RRC Reconfiguration Complete message, network 300 may send UEInformationRequest to UE 200.

[0134] In step S55, UE 200 sends UEInformationResponse to network 300. UEInformationResponse includes identification information of source PCell.

[0135] exist Figure 7 In the example, the case where the identification information of the source PCell is included in the UEInformationResponse is illustrated. However, the implementation is not limited to this. The identification information of the source PCell may also be included in the RRCReconfiguration Complete message of step S53.

[0136] (3.6) NPN connection failure

[0137] The following describes the connection failure of NPN. Figure 8 In the example, the network 300 may be the NG RAN 30.

[0138] like Figure 8 As shown, in step S60, UE 200 detects a connection failure of a cell included in the NPN. The connection failure may include a radio link failure (RLF) or a failure in a RACH process (RACH Failure).

[0139] In step S61, UE 200 sets identification information related to NPN as a variable.

[0140] In step S62, UE 200 receives UEInformationRequest from network 300. UEInformationRequest may contain an information element explicitly requesting identification information related to the NPN.

[0141] In step S63, UE 200 sends UEInformationResponse to network 300. UEInformationResponse includes identification information (NPN-Identity) related to NPN.

[0142] (4) Example of information element structure

[0143] Fig. 9 This is an example of the structure of the information element of UEInformationRequest. Fig. 9 As shown, UEInformationRequest may include the above-mentioned "cHOFailureReestablishmentReport" and "t316ConfiguredReport".

[0144] Fig.10 This is an example of the structure of the information element of UEInformationResponse. Fig.10 As shown, UEInformationResponse can contain "reestablishmentCellIdCHO", "t316Configured", "sCGFailureInfo", "mCGFailureInfo", "connectionFailureType", "failedPSCellId".

[0145] (5) Function / Effect

[0146] In the embodiment, in the case of assuming various newly introduced technologies (CHO, MCG Recovery, DAPS switching, etc.), a message related to connection failure can be appropriately sent. Therefore, SON or MDT can be appropriately operated.

[0147] (6) Other Implementation Methods

[0148] Although the embodiments have been described above, the present invention is not limited to the description of the embodiments, and it is obvious that various modifications and improvements can be made by those skilled in the art.

[0149] In the embodiment, CHO is illustrated as an example of conditional re-establishment. However, the embodiment is not limited thereto. Conditional re-establishment may also be CPC (Conditional PCell Change). In CPC, the PSCell may be changed without sending an RRC Re-establishment Request message to the network 300.

[0150] In addition, the block diagram ( Figure 2 ) shows blocks in units of functions. These functional blocks (structural parts) are implemented by any combination of at least one of hardware and software. In addition, there is no particular limitation on the implementation method of each functional block. That is, each functional block can be implemented using a device that is physically or logically combined, or two or more physically or logically separated devices can be directly or indirectly connected (for example, using wires, wirelessly, etc.) and implemented using these multiple devices. The functional block can also be implemented by combining software with the above-mentioned one device or the above-mentioned multiple devices.

[0151] Functionally, it includes judging, determining, judging, calculating, calculating, processing, deriving, investigating, searching, confirming, receiving, sending, outputting, accessing, solving, selecting, selecting, establishing, comparing, assuming, expecting, regarding, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, assigning, etc., but is not limited to these. For example, the functional block (structural part) that enables the sending function is called a transmitting unit or a transmitter. In short, as mentioned above, there is no particular limitation on the implementation method.

[0152] Furthermore, the above-mentioned UE 200 (the device) may also function as a computer that performs the processing of the wireless communication method of the present disclosure. Fig.11 FIG. 1 is a diagram showing an example of a hardware configuration of an eNB 100A. Fig.11 As shown, the eNB 100A may be configured as a computer device including a processor 1001, a memory 1002 (memory), a storage 1003 (storage), a communication device 1004, an input device 1005, an output device 1006, and a bus 1007.

[0153] In the following description, the word "device" may be replaced by "circuit", "device", "unit", etc. The hardware structure of the device may include one or more of the devices shown in the figure, or may exclude some of the devices.

[0154] Each functional block of the device (refer to Figure 2 ) is implemented by any hardware element or combination of hardware elements in the computer device.

[0155] In addition, each function in the device is implemented by the following method: predetermined software (program) is read into hardware such as processor 1001 and memory 1002, so that processor 1001 performs calculations and controls the communication of communication device 1004 or controls at least one of the reading and writing of data in memory 1002 and storage 1003.

[0156] The processor 1001 controls the entire computer by, for example, executing an operating system. The processor 1001 may be constituted by a central processing unit (CPU) including an interface with peripheral devices, a control device, a calculation device, a register, and the like.

[0157] In addition, the processor 1001 reads a program (program code), a software module, data, etc. from at least one of the memory 1003 and the communication device 1004 to the memory 1002, and performs various processes accordingly. As a program, a program that causes a computer to perform at least a part of the actions described in the above-mentioned embodiments is used. In addition, with respect to the above-mentioned various processes, although it is described that the above-mentioned various processes are performed by one processor 1001, the above-mentioned various processes can also be performed simultaneously or sequentially by more than two processors 1001. The processor 1001 can also be installed by more than one chip. In addition, the program can also be sent from the network via a telecommunication line.

[0158] The memory 1002 is a computer-readable recording medium, and may be composed of at least one of a read-only memory (ROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a random access memory (RAM), etc. The memory 1002 may also be referred to as a register, a cache, a main memory (main storage device), etc. The memory 1002 may store a program (program code), a software module, etc. that can execute a method according to an embodiment of the present disclosure.

[0159] The memory 1003 is a computer-readable recording medium, and may be composed of at least one of an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a floppy disk, a magneto-optical disk (e.g., a compact disk, a digital versatile disk, a Blu-ray (registered trademark) disk), a smart card, a flash memory (e.g., a card, a stick, a key drive), a Floppy (registered trademark) disk, a magnetic strip, etc. The memory 1003 may also be referred to as an auxiliary storage device. The above-mentioned recording medium may be, for example, a database, a server, and other appropriate media including at least one of the memory 1002 and the memory 1003.

[0160] The communication device 1004 is hardware (transceiver) used to communicate between computers via at least one of a wired network and a wireless network, and is also called a network device, a network controller, a network card, a communication module, etc.

[0161] The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc., for example, in order to realize at least one of frequency division duplex (FDD) and time division duplex (TDD).

[0162] The input device 1005 is an input device that receives input from the outside (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.). The output device 1006 is an output device that implements output to the outside (e.g., a display, a speaker, an LED light, etc.). In addition, the input device 1005 and the output device 1006 may also be integrally formed (e.g., a touch panel).

[0163] In addition, the processor 1001 and the memory 1002 and other devices are connected via a bus 1007 for communicating information. The bus 1007 may be configured using a single bus or may be configured using different buses for each device.

[0164] Furthermore, the device may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), a field programmable gate array (FPGA), and the like, and may implement a part or all of each functional block through the hardware. For example, the processor 1001 may also be implemented using at least one of these hardware.

[0165] In addition, the notification of information is not limited to the form / implementation method described in the present disclosure, and other methods may also be used. For example, the notification of information may be implemented through physical layer signaling (e.g., downlink control information (DCI: Downlink Control Information), uplink control information (UCI: Uplink Control Information), high-layer signaling (e.g., RRC signaling, medium access control (MAC: Medium Access Control) signaling, broadcast information (Master Information Block (MIB: Master Information Block), System Information Block (SIB: System Information Block)), other signals or a combination thereof. In addition, RRC signaling may also be referred to as an RRC message, such as an RRC Connection Setup message, an RRC Connection Reconfiguration message, etc.

[0166] Each form / embodiment described in the present disclosure may also be applied to at least one of 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 (registered trademark), GSM (registered trademark), CDMA 2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-Wide Band (UWB), Bluetooth (registered trademark), a system using other appropriate systems, and a next-generation system extended therefrom. In addition, a combination of a plurality of systems (for example, a combination of at least one of LTE and LTE-A with 5G, etc.) may also be applied.

[0167] The processing procedures, timings, processes, etc. of each form / implementation described in this disclosure may be changed in order without contradiction. For example, for the method described in this disclosure, the elements of various steps are presented in an illustrative order, but are not limited to the specific order presented.

[0168] In the present disclosure, specific actions performed by a base station are sometimes performed by its upper node depending on the situation. In a network consisting of one or more network nodes having a base station, various actions performed to communicate with a terminal can be performed by at least one of the base station and other network nodes other than the base station (for example, consider MME or S-GW, etc., but not limited to this). In the above, the case where there is one other network node other than the base station is illustrated, but the other network node may also be a combination of multiple other network nodes (for example, MME and S-GW).

[0169] Information, signals (information, etc.) can be output from a higher layer (or lower layer) to a lower layer (or higher layer), and can also be input or output via multiple network nodes.

[0170] The input or output information can be stored in a specific location (e.g., memory) or managed using a management table. The input or output information can be rewritten, updated, or appended. The output information can also be deleted. The input information can also be sent to other devices.

[0171] The determination may be made by a value represented by one bit (0 or 1), by a Boolean value (Boolean: true or false), or by comparison of numerical values ​​(for example, comparison with a predetermined value).

[0172] Each form / implementation described in the present disclosure may be used alone or in combination, and may be switched according to execution. In addition, notification of scheduled information is not limited to being performed explicitly (e.g., notification of "yes X"), but may also be performed implicitly (e.g., notification of the scheduled information is not performed).

[0173] Software, whether referred to as software, firmware, middleware, microcode, hardware description language, or by other names, shall be interpreted broadly to refer to commands, sets of commands, codes, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc.

[0174] In addition, software, commands, information, etc. may be sent and received via a transmission medium. For example, when software is sent from a website, server, or other remote source using at least one of wired technology (coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), etc.) and wireless technology (infrared, microwave, etc.), at least one of these wired technology and wireless technology is included in the definition of transmission medium.

[0175] The information, signals, etc. described in the present disclosure may also be represented by any of a variety of different technologies. For example, the data, commands, instructions, information, signals, bits, symbols, chips, etc. that may be involved in the above description as a whole may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any combination of these.

[0176] In addition, the terms described in the present disclosure and the terms required for understanding the present disclosure may be replaced with terms having the same or similar meanings. For example, at least one of a channel and a symbol may also be a signal (signaling). In addition, a signal may also be a message. In addition, a component carrier (CC) may also be referred to as a carrier frequency, a cell, a frequency carrier, etc.

[0177] As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0178] In addition, the information, parameters, etc. described in the present disclosure may be represented by absolute values, relative values ​​to predetermined values, or other corresponding information. For example, wireless resources may also be indicated by indexes.

[0179] The names used for the above parameters are non-limiting in any respect. Furthermore, the formulas etc. using these parameters may sometimes differ from those explicitly disclosed in this disclosure. Various channels (e.g., PUCCH, PDCCH, etc.) and information elements may be identified by appropriate names, and the various names assigned to these various channels and information elements are non-limiting in any respect.

[0180] In the present disclosure, the terms "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", "component carrier" and the like are used interchangeably. Sometimes, the base station is also referred to as macro cell, small cell, femto cell, pico cell and the like.

[0181] A base station can accommodate one or more (for example, 3) cells (also called sectors). When a base station accommodates multiple cells, the overall coverage area of ​​the base station can be divided into multiple smaller areas, each of which can also provide communication services through a base station subsystem (for example, a small base station for indoor use (Remote Radio Head: RRH).

[0182] The terms "cell" or "sector" refer to a part or the entirety of a coverage area of ​​at least one of a base station and a base station subsystem that provide communication services within the coverage area.

[0183] In the present disclosure, terms such as “mobile station (MS)”, “user terminal (user terminal)”, “user equipment (UE)”, and “terminal” may be used interchangeably.

[0184] For mobile stations, those skilled in the art sometimes also use the following terms: 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 terms.

[0185] At least one of the base station and the mobile station may also be referred to as a transmitting device, a receiving device, a communication device, etc. In addition, 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 means of transportation (e.g., a car, an airplane, etc.), a mobile body that moves in an unmanned manner (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). In addition, at least one of the base station and the mobile station also includes a device that does not necessarily move during communication operations. 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.

[0186] In addition, the base station in the present disclosure may also be replaced by a mobile station (user terminal, the same below). For example, various forms / implementations of the present disclosure may also be applied to a structure in which the communication between a base station and a mobile station is replaced by communication between multiple mobile stations (for example, may also be referred to as device-to-device (D2D: Device-to-Device), vehicle-to-everything system (V2X: Vehicle-to-Everything), etc.). In this case, it is also possible to set a structure in which the mobile station has the functions of the base station. In addition, terms such as "uplink" and "downlink" may also be replaced by terms corresponding to terminal-to-terminal communication (for example, "side"). For example, uplink channels, downlink channels, etc. may also be replaced by side channels.

[0187] Likewise, the mobile station in the present disclosure may be replaced by a base station. In this case, the base station may have the same functions as the mobile station.

[0188] A radio frame may be composed of one or more frames in the time domain. In the time domain, one or more frames may also be referred to as subframes. A subframe may further be composed of one or more time slots in the time domain. A subframe may also be a fixed time length (e.g., 1 ms) that is not dependent on a parameter set (numerology).

[0189] A parameter set may be a communication parameter applied to at least one of the transmission and reception of a certain signal or channel. The parameter set may, for example, represent at least one of a subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), the number of symbols per TTI, a radio frame structure, a specific filtering process performed by a transceiver in the frequency domain, a specific windowing process performed by a transceiver in the time domain, and the like.

[0190] A slot may be composed of one or more symbols (OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, etc.) in the time domain. A slot may be a time unit based on a parameter set.

[0191] A time slot may contain multiple mini-slots. Each mini-slot may be composed of one or more symbols in the time domain. In addition, a mini-slot may also be referred to as a sub-slot. A mini-slot may be composed of fewer symbols than a time slot. A PDSCH (or PUSCH) transmitted in units of time greater than a mini-slot may be referred to as a PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a mini-slot may be referred to as a PDSCH (or PUSCH) mapping type B.

[0192] A radio frame, a subframe, a time slot, a mini-time slot, and a symbol all represent time units for transmitting signals. A radio frame, a subframe, a time slot, a mini-time slot, and a symbol may be referred to by other corresponding names.

[0193] For example, one subframe may also be referred to as a transmission time interval (TTI), multiple consecutive subframes may also be referred to as a TTI, and one time slot or one mini time slot may also be referred to as a TTI. That is, at least one of a subframe and a TTI may be a subframe (1ms) in existing LTE, a period shorter than 1ms (e.g., 1-13 symbols), or a period longer than 1ms. In addition, the unit representing a TTI may not be referred to as a subframe, but may be referred to as a time slot, a mini time slot, or the like.

[0194] Here, TTI refers to, for example, the minimum time unit for scheduling in wireless communication. For example, in the LTE system, the base station schedules the allocation of wireless resources (frequency bandwidth, transmission power, etc. that can be used in each user terminal) to each user terminal in units of TTI. In addition, the definition of TTI is not limited to this.

[0195] TTI can be a transmission time unit for data packets (transport blocks), code blocks, code words, etc. after channel coding, and can also be a processing unit for scheduling, link adaptation, etc. In addition, when TTI is given, the time interval (e.g., the number of symbols) to which the transport block, code block, code word, etc. is actually mapped can be shorter than the TTI.

[0196] In addition, when 1 time slot or 1 mini time slot is called TTI, more than one TTI (i.e., more than one time slot or more than one mini time slot) can constitute the minimum time unit of scheduling. In addition, the number of time slots (number of mini time slots) constituting the minimum time unit of scheduling can be controlled.

[0197] A TTI having a time length of 1 ms may also be referred to as a normal TTI (TTI in LTE Rel.8-12), a normal TTI, a long TTI, a normal subframe, a normal subframe, a long subframe, a time slot, etc. A TTI shorter than a normal TTI may be referred to as a shortened TTI, a short TTI, a partial or fractional TTI, a shortened subframe, a short subframe, a mini-time slot, a sub-time slot, a time slot, etc.

[0198] In addition, for a long TTI (for example, a normal TTI, a subframe, etc.), it can be replaced with a TTI having a time length exceeding 1ms, and for a short TTI (for example, a shortened TTI, etc.), it can be replaced with a TTI length that is smaller than the long TTI (longTTI) and has a TTI length of more than 1ms.

[0199] A resource block (RB) is a resource allocation unit in the time domain and the frequency domain. In the frequency domain, it may contain one or more consecutive subcarriers. The number of subcarriers contained in an RB may be the same regardless of the parameter set, for example, it may be 12. The number of subcarriers contained in an RB may also be determined according to the parameter set.

[0200] In addition, the time domain of an RB may include one or more symbols, and may be the length of 1 slot, 1 mini slot, 1 subframe, or 1 TTI. 1 TTI, 1 subframe, etc. may be composed of one or more resource blocks, respectively.

[0201] In addition, one or more RBs may be referred to as a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, and the like.

[0202] In addition, a resource block may be composed of one or more resource elements (RE). For example, 1 RE may be a radio resource region of 1 subcarrier and 1 symbol.

[0203] A bandwidth part (BWP) (also referred to as a partial bandwidth, etc.) may represent a subset of contiguous common resource blocks (RBs) for a parameter set in a carrier. Here, the common RBs may be identified by the index of the RBs relative to the common reference point of the carrier. PRBs may be defined in a BWP and numbered within the BWP.

[0204] The BWP may include a BWP for UL (UL BWP) and a BWP for DL ​​(DL BWP). One or more BWPs may be configured for a UE within one carrier.

[0205] At least one of the set BWPs may be active, and it is not assumed that the UE transmits or receives a predetermined signal / channel outside the activated BWP. In addition, "cell", "carrier" and the like in the present disclosure may be replaced with "BWP".

[0206] The above structures of radio frames, subframes, time slots, mini-time slots, and symbols are only examples. For example, the number of subframes included in a radio frame, the number of time slots per subframe or radio frame, the number of mini-time slots included in a time slot, the number of symbols and RBs included in a time slot or mini-time slot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP: Cyclic Prefix) length, and the like can be changed in various ways.

[0207] The terms "connected", "coupled" or all variations of these terms are intended to indicate any direct or indirect connection or combination between two or more elements, and may include the situation where there is one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The combination or connection between elements may be a physical combination or connection, a logical combination or connection, or a combination of these. For example, "access" may be used to replace "connection". In the context of the present disclosure, two elements may be considered to be "connected" or "coupled" to each other using at least one of one or more wires, cables, and printed electrical connections, and as some non-limiting and non-inclusive examples, electromagnetic energy having wavelengths in the wireless frequency domain, microwave region, and light (both visible and invisible) region may be used to "connect" or "couple" to each other.

[0208] The reference signal may be referred to as Reference Signal (RS) for short, or may be referred to as a pilot signal depending on the applied standard.

[0209] The phrase "according to" used in the present disclosure does not mean "only according to" unless otherwise expressly stated. In other words, the phrase "according to" means both "only according to" and "at least according to".

[0210] The “unit” in the structure of each of the above-mentioned devices may be replaced with a “section”, “circuit”, “device” or the like.

[0211] Any reference to an element using the designations "first", "second", etc. used in this disclosure does not necessarily limit the number or order of these elements. These designations can be used as a simple method to distinguish between two or more elements in this disclosure. Therefore, a reference to a first element and a second element does not mean that only two elements can be taken or that the first element must precede the second element in any form.

[0212] When the terms "include," "including," and variations thereof are used in the present disclosure, these terms are intended to be inclusive, as is the term "comprising." Furthermore, the term "or" used in the present disclosure does not mean an exclusive or.

[0213] In the present disclosure, when an article is added by translation, such as a, an, and the in English, for example, the present disclosure may also include a case where the noun following the article is in a plural form.

[0214] The terms "determining" and "determining" used in the present disclosure sometimes also include a variety of actions. "Judgment" and "determination" may include, for example, considering matters that have been judged, calculated, calculated, processed, derived, investigated, searched (for example, searched in a table, database or other data structure), confirmed (ascertaining) as matters that have been "judged" or "determined", etc. In addition, "judgment" and "determination" may include matters that have been received (for example, receiving information), transmitted (for example, sending information), input, output, accessed (for example, accessing data in memory) as matters that have been "judged" or "determined", etc. In addition, "judgment" and "determination" may include matters that have been resolved (resolving), selected (selecting), chosen (choosing), established (establishing), compared (comparing), etc. as matters that have been "judged" or "determined". That is, "judgment" and "decision" can include matters that are considered to be "judged" and "decided". In addition, "judgment (decision)" can also be replaced by "assuming", "expecting", "considering", etc.

[0215] In the present disclosure, the term "A is different from B" may also mean "A and B are different from each other". In addition, the term may also mean "A and B are different from C, respectively". The terms "separate" and "combined" may also be interpreted in the same way as "different".

[0216] The present disclosure is described in detail above, but it should be clear to those skilled in the art that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure can be implemented as a modification and variation without departing from the subject matter and scope of the present disclosure as determined by the claims. Therefore, the purpose of the description of the present disclosure is to illustrate and not to have any limiting meaning on the present disclosure.

[0217] Description of symbols

[0218] 10: Wireless communication system;

[0219] 20: E-UTRAN;

[0220] 30: NG RAN;

[0221] 40: core network;

[0222] 50: E-SMLC;

[0223] 100A: eNB;

[0224] 100B: gNB;

[0225] 200:UE;

[0226] 210: wireless signal transceiver;

[0227] 220: Enlargement;

[0228] 230: Modem unit;

[0229] 240: control signal and reference signal processing unit;

[0230] 250: encoding / decoding unit;

[0231] 260: data transceiver unit;

[0232] 270: Control Department;

[0233] 1001: processor;

[0234] 1002: Memory;

[0235] 1003: memory;

[0236] 1004: Communication devices;

[0237] 1005: input device;

[0238] 1006: output device;

[0239] 1007: Bus.

Claims

1. A terminal, wherein: The terminal has: a control unit that sets cell identification information of the new target cell as a variable when a new target cell is selected during activation of a timer, wherein the timer is activated in accordance with the start of a failed re-establishment process accompanied by condition resetting; and A sending unit sends a message including the cell identification information set as the variable to the new target cell.

2. The terminal according to claim 1, wherein: The message is a terminal information response.

3. A base station, wherein: The base station has: a control unit, assuming that, in a case where a new target cell is selected during the start of a timer, the terminal sets the cell identification information of the new target cell as a variable, wherein the timer is started according to the start of a failed re-establishment process accompanied by condition resetting; and A receiving unit receives, when the terminal is connected to the new target cell, a message including the cell identification information set as the variable from the terminal.

4. A wireless communication system comprising a terminal and a base station, wherein: The terminal includes a control unit, wherein when a new target cell is selected in the start of a timer, the control unit sets the cell identification information of the new target cell as a variable, wherein the timer is started according to the start of a failed re-establishment process accompanied by condition resetting, The base station includes a receiving unit configured to receive, when the terminal is connected to the new target cell, a message including the cell identification information set as the variable from the terminal.

5. A wireless communication method, wherein: The wireless communication method comprises the following steps: In a case where a new target cell is selected in starting a timer that is started according to the start of a failed re-establishment procedure accompanied by condition resetting, setting cell identification information of the new target cell as a variable; and A message including the cell identification information set as the variable is sent to the new target cell.

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