WO2022085158A1

WO2022085158A1 - Terminal and wireless base station

Info

Publication number: WO2022085158A1
Application number: PCT/JP2020/039747
Authority: WO
Inventors: 天楊閔
Original assignee: 株式会社Ｎｔｔドコモ
Priority date: 2020-10-22
Filing date: 2020-10-22
Publication date: 2022-04-28
Also published as: JPWO2022085158A1

Abstract

In the present invention, UE controls the execution of an addition/change procedure for a secondary cell. If the addition/change procedure for the secondary cell fails, the UE transmits: identification information of the secondary cell for which the addition/change procedure failed; and the quality information of a serving cell and an adjacent cell.

Description

Terminals and wireless base stations

This disclosure relates to terminals and radio base stations that support the procedure for adding / changing secondary cells (secondary nodes).

The 3rd Generation Partnership Project (3GPP) specifies the 5th generation mobile communication system (also called 5G, New Radio (NR) or Next Generation (NG)), and next-generation specifications called Beyond 5G, 5G Evolution or 6G. We are also proceeding with the conversion.

For example, in 3GPP Release-17, expansion of Multi-RAT Dual Connectivity (MR-DC) is being considered (Non-Patent Document 1). Specifically, in order to realize more efficient addition or change of Primary SCell (PSCell), the procedure for adding / changing a conditional secondary cell (secondary node) (conditional PSCell addition / change) has been simplified. Support is being considered.

Also, from the viewpoint of supporting data collection for SON (Self Organizing Network), it is being considered to target the change failure of the secondary node (SN) (Non-Patent Document 2).

In the conditional PSCell addition / change described above, if the terminal (User Equipment, UE) fails the random access procedure (RA procedure) with the target secondary node (T-SN), another candidate secondary cell (specifically). May select candidate PSCell).

However, at present, when the UE selects another candidate secondary cell, it cannot be linked with the master node (MN) or the like, and another candidate secondary cell cannot be efficiently selected.

Therefore, the following disclosure was made in view of such a situation, and provides terminals and radio base stations that can reduce secondary node change failures and realize more efficient conditional PSCell addition / change. The purpose.

One aspect of the present disclosure is to identify a control unit (control unit 240) that controls execution of a secondary cell addition / modification procedure, and a secondary cell in which the addition / modification procedure fails when the addition / modification procedure fails. It is a terminal (UE200) including a transmission unit (RRC processing unit 220) for transmitting information and quality information between a serving cell and a neighboring cell.

One aspect of the present disclosure is a receiving unit (RRC processing unit 120) that receives failure information of a secondary cell group related to a procedure for adding / changing a secondary cell by a terminal (UE200), and a secondary that fails when the failure information is received. It is a radio base station (for example, eNB100A) including a control unit (control unit 140) that starts data transfer related to the terminal to another candidate secondary cell other than the cell.

One aspect of the present disclosure is a control unit (control unit 240) that controls execution of a secondary cell addition / modification procedure, a transmission unit that transmits failure information of the secondary cell group related to the addition / modification procedure, and a (RRC processing unit). 220), the control unit is a terminal (UE200) that executes a random access procedure for another selected secondary cell before transmitting the failure information when the addition / modification procedure fails.

One aspect of the present disclosure is a receiving unit (RRC processing unit 120) that receives failure information of a secondary cell group related to a procedure for adding / changing a secondary cell by a terminal (UE200), and a random operation by the terminal based on the failure information. A radio base station (eg, eNB100A) including a control unit (control unit 140) that initiates data transfer relating to the terminal to another candidate secondary cell for which the access procedure has been successful.

FIG. 1 is an overall schematic configuration diagram of the wireless communication system 10.

FIG. 2 is a functional block configuration diagram of the eNB 100A.

FIG. 3 is a functional block configuration diagram of the UE 200.

FIG. 4 is a diagram showing an example of a communication sequence according to a conventional conditional PSCell addition procedure (conditional PSCell addition).

FIG. 5 is a diagram showing an example of a communication sequence according to a conventional conditional PSCell change procedure (conditional PSCell change).

FIG. 6 is a diagram showing an example of a communication sequence according to the conditional PSCell addition procedure (conditional PSCell addition) according to the operation example 1.

FIG. 7 is a diagram showing a communication sequence example (No. 1) according to the conditional PSCell addition procedure (conditional PSCell addition) according to the operation example 2.

FIG. 8 is a diagram showing a communication sequence example (No. 2) according to the conditional PSCell addition procedure (conditional PSCell addition) according to the operation example 2.

FIG. 9 is a diagram showing an example of the hardware configuration of the eNB 100A, gNB 100B, and UE 200.

Hereinafter, embodiments will be described based on the drawings. The same functions and configurations are designated by the same or similar reference numerals, and the description thereof will be omitted as appropriate.

(1) Overall Schematic Configuration of Wireless Communication System FIG. 1 is an overall schematic configuration diagram of the wireless communication system 10 according to the present embodiment. The wireless communication system 10 is a wireless communication system according to Long Term Evolution (LTE) and 5G New Radio (NR). In addition, LTE may be called 4G, and NR may be called 5G. Further, the wireless communication system 10 may be a wireless communication system according to a method called Beyond 5G, 5G Evolution or 6G.

LTE and NR may be interpreted as radio access technology (RAT), and in this embodiment, LTE may be referred to as a first radio access technology and NR may be referred to as a second radio access technology.

The wireless communication system 10 includes Evolved Universal Terrestrial Radio Access Network 20 (hereinafter, E-UTRAN20) and Next Generation-Radio Access Network 30 (hereinafter, NG RAN30). Further, the wireless communication system 10 includes a terminal 200 (hereinafter, UE200, User Equipment).

E-UTRAN20 includes eNB100A, which is a wireless base station that complies with LTE. NG RAN30 includes gNB100B, which is a radio base station according to 5G (NR). In addition, UserPlaneFunction40 (hereinafter, UPF40), which is included in the 5G system architecture and provides user plane functions, is connected to NGRAN30. The E-UTRAN20 and NGRAN30 (may be eNB100A or gNB100B) may be simply referred to as a network.

The eNB100A, gNB100B and UE200 can support carrier aggregation (CA) using multiple component carriers (CC), and dual connectivity in which component carriers are simultaneously transmitted between multiple NG-RAN Nodes and UEs. ..

The eNB100A, gNB100B and UE200 execute wireless communication via a wireless bearer, specifically, a Signaling Radio Bearer (SRB) or a DRB Data Radio Bearer (DRB).

In this embodiment, the eNB 100A constitutes a master node (MN) and the gNB100B constitutes a secondary node (SN). Multi-Radio Dual Connectivity (MR-DC), specifically, E-UTRA-NR Dual Connectivity ( EN-DC) may be executed, or NR-E-UTRA Dual Connectivity (NE-DC) in which gNB100B constitutes MN and eNB100A constitutes SN may be executed. Alternatively, NR-NR Dual Connectivity (NR-DC) in which gNB constitutes MN and SN may be executed.

In this way, UE200 supports dual connectivity to connect to eNB100A and gNB100B.

ENB100A is included in the master cell group (MCG), and gNB100B is included in the secondary cell group (SCG). That is, gNB100B is an SN contained in SCG.

The eNB 100A and gNB 100B may be referred to as a radio base station or a network device.

Further, in the wireless communication system 10, conditional addition or change (conditional PSCell addition / change) of Primary SCell (PSCell) may be supported. PSCell is a kind of secondary cell. PSCell means Primary SCell, and may be interpreted as corresponding to any SCell among a plurality of SCells.

The secondary cell may be read as a secondary node (SN) or a secondary cell group (SCG). Conditional PSCell addition / change can enable efficient and rapid addition or modification of secondary cells.

Conditional PSCell addition / change may be interpreted as a procedure for adding / changing a conditional secondary cell with a simplified procedure. Further, conditionalPSCell addition / change may mean at least one of addition (addition) and change (change) of SCell.

In addition, the wireless communication system 10 may support the conditional PSCell change procedure between SNs. Specifically, MN-led conditional inter-SN PSCell change and / or SN-led SN-initiated conditional inter-SN PSCell change may be supported.

(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 configuration of the eNB 100A and UE 200 will be described.

(2.1) eNB100A
FIG. 2 is a functional block configuration diagram of the eNB 100A. As shown in FIG. 2, the eNB 100A includes a wireless communication unit 110, an RRC processing unit 120, a DC processing unit 130, and a control unit 140. The gNB100B may also have the same function as the eNB100A, except that it supports NR.

The wireless communication unit 110 transmits a downlink signal (DL signal) according to LTE. Further, the wireless communication unit 110 receives the uplink signal (UL signal) according to LTE.

The RRC processing unit 120 executes various processes in the radio resource control layer (RRC). Specifically, the RRC processing unit 120 can transmit the RRC Reconfiguration to the UE 200. Further, the RRC processing unit 120 can receive the RRC Reconfiguration Complete, which is a response to the RRC Reconfiguration, from the UE 200.

In this embodiment, the eNB 100A supports LTE, but in this case, the name of the RRC message may be RRCConnectionReconfiguration or RRCConnectionReconfigurationComplete.

Further, in the present embodiment, the RRC processing unit 120 can receive SCG failure information regarding conditional PSCell addition / change by UE200. In the present embodiment, the RRC processing unit 120 constitutes a receiving unit that receives failure information of the secondary cell group regarding the procedure for adding / changing the secondary cell by the terminal.

Specifically, the SCG failure information may include any of the following information.

-Identification information of the target PSCell formed by the target secondary node (T-SN) where conditional PSCell addition / change failed (for example, NR Physical Cell ID (PCI), NR Cell Global Identifier (CGI))
-Quality information between the serving cell of UE200 and neighboring cells of the serving cell-RACH (Random Access Channel) information used Note that the identification information of the target PSCell is not PCI / CGI, but information that can identify the PSCell (gNB ID). May be called) may be used. Further, two or more pieces of information on the identification information of the PSCell for which conditional PSCell addition / change has failed may be included.

The quality information may be, for example, the quality (for example, Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ)) included in the measurement report (Measurement Report) specified in 3GPP TS38.331.

The RACH information may be, for example, any of the following information specified in 3GPP TS38.331.

・ RA-InformationCommon-r16
-2-step RACH info (msgA-SubcarrierSpacing, msgA-RO-FrequencyStart, msgA-RO-FDM, ssb-Index, CSIRS-index, numberOfPreamblesSentOnSSB, numberOfPreamblesSentOnCSI-RS, contentionDetected or not, dlRSRPAboveThreshold
The DC processing unit 130 executes processing related to dual connectivity, specifically, Multi-RAT Dual Connectivity (MR-DC). In this embodiment, since the eNB 100A supports LTE and the gNB 100B supports NR, the DC processing unit 130 may execute processing related to E-UTRA-NR Dual Connectivity (EN-DC). As described above, the type of DC is not limited, and for example, NR-E-UTRA Dual Connectivity (NE-DC) or NR-NR Dual Connectivity (NR-DC) may be supported.

The DC processing unit 130 can send and receive messages specified in 3GPP TS37.340 and execute processing related to DC setting and release between eNB100A, gNB100B and UE200.

The control unit 140 controls each functional block constituting the eNB 100A. In particular, in the present embodiment, control regarding the addition or modification of the secondary node is executed.

Specifically, the control unit 140 can determine whether or not to execute conditional PSCell addition / change (CPA / CPC) based on the measurement report (Measurement Report) from the UE 200.

When the control unit 140 determines the CPA / CPC, the control unit 140 may send an SN Addition Request to the target secondary node (T-SN). Further, the control unit 140 may receive the SN Addition Request Ack, which is a response to the SN Addition Request, from the T-SN.

Further, the control unit 140 receives not only the CPA / CPC but also the SN change required from the S-SN when the source / secondary node (S-SN) determines the SN-initiated conditional inter-SN PSCell change (CPC). You may. Further, the control unit 140 may send an SN Addition Request to the T-SN in response to the SN change required.

In the present 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), PBCH (Physical Broadcast Channel) and the like.

The data channels include PDSCH (Physical Downlink Shared Channel) and PUSCH (Physical Uplink Shared Channel).

The reference signal includes Demodulation reference signal (DMRS), Sounding Reference Signal (SRS), Phase Tracking Reference Signal (PTRS), Channel State Information-Reference Signal (CSI-RS), and the like. Includes channels and reference signals. Further, the data may mean data transmitted via a data channel.

Further, when the RRC processing unit 120 receives the SCG failure information (failure information), the control unit 140 transfers data related to the UE 200 to another candidate PSCell (candidate secondary cell) other than the failed PSCell (secondary cell). You may start.

Specifically, the control unit 140 may immediately start data forwarding regarding the UE 200 to the SN forming the candidate PS Cell as soon as the SCG failure information is received, or a predetermined time after receiving the SCG failure information. The data transfer may be started within. The data transfer relating to the UE 200 may be uplink (UL) data from the UE 200 or downlink (DL) data to the UE 200.

Further, the control unit 140 transfers data related to the UE 200 to another candidate PS Cell (candidate secondary cell) in which the random access procedure (RA procedure) by the UE 200 is successful, based on the received SCG failure information (failure information). You may start.

Specifically, the control unit 140 implied based on the identification information of the target PSCell that succeeded in the RA procedure (which may be interpreted as RACH transmission) accompanying the conditional PSCell addition / change included in the SCG failure information. Data transfer related to the UE 200 may be started intentionally (or explicitly).

(2.2) UE200
FIG. 3 is a functional block configuration diagram of the UE 200. As shown in FIG. 3, the UE 200 includes a wireless communication unit 210, an RRC processing unit 220, a DC processing unit 230, and a control unit 240.

The wireless communication unit 210 transmits an uplink signal (UL signal) according to LTE or NR. Further, the wireless communication unit 210 receives the downlink signal (DL signal) according to LTE. That is, the UE200 can access the eNB100A (E-UTRAN20) and gNB100B (NGRAN30), and can support dual connectivity (specifically, EN-DC).

The RRC processing unit 220 executes various processes in the radio resource control layer (RRC). Specifically, the RRC processing unit 220 can send and receive messages of the radio resource control layer.

The RRC processing unit 220 can receive the RRC Reconfiguration from the network, specifically, E-UTRAN20 (or NGRAN30). Further, the RRC processing unit 220 can transmit the RRC Reconfiguration Complete, which is a response to the RRC Reconfiguration, to the network.

When the conditional PSCell addition / change fails, the RRC processing unit 220 can transmit the identification information of the target PSCell (secondary cell) in which the conditional PSCell addition / change fails, and the quality information between the serving cell and the neighboring cell. In the present embodiment, the RRC processing unit 220 constitutes a transmission unit that transmits identification information and quality information.

As described above, the identification information of the target PSCell may be PCI / CGI or the like, and the quality information between the serving cell and the neighboring cell may be the quality included in the Measurement Report.

The identification information and quality information may be included in SCG failure information, specifically, SCG failure information. Also, as mentioned above, the RACH information used may be included. That is, if the UE 200 executes the RA procedure for another selected target PSCell before the UE 200 transmits the SCG failure information, the RRC processing unit 220 may transmit the SCG failure information including the information about the RA procedure.

The identification information and quality information may be transmitted when the timer T304 for the secondary cell group (SCG) has expired.

Timer T304 is started when an RRC Reconfiguration message containing reconfigurationWithSync is received, or when a conditional reconfiguration (conditional PSCell addition / change) is executed, that is, when a stored RRC Reconfiguration message containing reconfigurationWithSync is applied. It may be stopped when random access is completed normally in the corresponding Special Cell (SpCell).

In addition, the RRC processing unit 220 sends SCG failure information regarding conditional PSCell addition / change. In the present embodiment, the RRC processing unit 220 constitutes a transmission unit for transmitting failure information.

Specifically, the RRC processing unit 220 sends SCG failure information to MN (for example, eNB100A). The RRC processing unit 220 may transmit SCG failure information to the SN.

Further, when the RA procedure (RACH transmission) fails twice (or more), the RRC processing unit 220 determines the identification information of the failed target PSCell and the quality information between the serving cell and the neighboring cell (further, use). The SCG failure information including the RACH information may be included) may be sent.

The DC processing unit 230 executes processing related to dual connectivity, specifically, MR-DC. As described above, in the present embodiment, the DC processing unit 230 may execute the processing related to EN-DC, but may correspond to NE-DC and / or NR-DC.

The DC processing unit 230 accesses each of the eNB 100A and gNB 100B, and has a plurality of layers including RRC (medium access control layer (MAC), radio link control layer (RLC), and packet data convergence protocol layer (. PDCP) etc.) can be executed.

The control unit 240 controls each functional block constituting the UE 200. In particular, in the present embodiment, the control unit 240 controls the execution of conditional PSCell addition / change.

Specifically, the control unit 240 can execute the RA procedure for another selected target PSCell (secondary cell) when the conditional PSCell addition / change fails. Further, when another selected target PSCell is included in the candidate PSCell, the control unit 240 may directly apply (apply) RRC Reconfiguration to the candidate PSCell and transmit RACH.

Further, when the conditional PSCell addition / change fails, the control unit 240 may execute the RA procedure for the selected target PSCell (secondary cell) before transmitting the SCG failure information.

Specifically, when the T304 of SCG has expired, the control unit 240 selects another targetPSCell first before sending the SCGfailure information, and if the selected targetPSCell is included in the candidatePSCell, the control unit 240 directly selects the candidatePSCell. RRC Reconfiguration may be applied to PSCell and RACH may be transmitted.

(3) Operation of 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 a conditional secondary cell (secondary node) (conditional PSCell addition / change) will be described.

(3.1) Conventional operation example and problem FIG. 4 shows an example of a communication sequence according to a conventional conditional PSCell addition procedure.

As shown in FIG. 4, in the conditional PSCell addition (CPA), the MN (eNB100A) determines whether or not CPA is possible (necessity) based on the Measurement Report from UE200 (step 2).

Here, when MN is eNB and SN is gNB, UE200 monitors the execution condition, and if there is a targetPSCell that satisfies the execution condition, UE200 requests MN to reset the RRC of the targetPSCell ( RRC Reconfiguration Complete is returned to MN for (apply) (steps 7 and 8).

After that, the setting between MN and T-SN1 is executed (steps 9 and 10), and the data transfer to T-SN1 (and UPF40) is started (step 11). The UE200 then sends RACH to T-SN1 and executes the RA procedure with T-SN1 (step 12). UE200 may send SCG failure information to MN.

Here, the UE200 may select another targetPSCell (which may be interpreted as a targetPSCell) if the RACH with the targetPSCell fails. However, the UE200 cannot cooperate with MN or the like when selecting another target PSCell, and cannot efficiently select another target PS Cell.

Such a problem is the same for conditional PSCell change (CPC). FIG. 5 shows an example of a communication sequence according to a conventional conditional PSCell change procedure (conditional PSCell change).

As shown in FIG. 5, in conditional PSCell change (CPC), S-SN determines whether or not CPC is possible (necessity) based on the Measurement Report from UE200 (step 2).

Even in CPC, UE200 sends RACH to T-SN1 and executes the RA procedure with T-SN1 (step 14).

Similar to CPA, UE200 may select another targetPSCell (which may be interpreted as candidate PSCell) if RACH with targetPSCell fails. However, the UE200 cannot cooperate with MN or the like when selecting another target PSCell, and cannot efficiently select another target PS Cell.

In this way, at present, at the time of conditional PSCell addition / change, UE200 may select another candidate PSCell after RACH with T-SN1 fails, but the operation of UE200 and data transfer after that. The timing of is not clear. An operation example that can solve such a problem will be described below.

(3.2) Operation example 1
FIG. 6 shows an example of a communication sequence according to the conditional PSCell addition procedure according to the operation example 1. In this operation example, the timing of data transfer is improved as compared with the above-mentioned conventional example, and the content of SCG failure information is also added.

Specifically, as shown in FIG. 6, when the timer T304 (T304 of SCG) for SCG has expired, the UE200 has the identification information (PCI / CGI) of the target PSCell for which the conditional PSCell addition has failed, the serving cell, and the corresponding cell. Quality information (eg, RSRP / RSRQ, etc.) of the serving cell with neighboring cells and information on the RACH used may be transmitted to the MN (step 13).

The information may be transmitted to the MN in the form included in the SCG failure information. Also, as mentioned above, the RACH information used is not always essential.

When the MN receives the SCG failure information (step 13), it sends an SN Status Transfer to the T-SN2 (step 14), and data is sent to the remaining candidate PSCell excluding the target PSCell for which the conditional PSCell addition failed. The transfer may be started (step 15).

UE200 can select another targetPSCell, and if the selected targetPSCell is a candidatePSCell, directly request the candidatePSCell to reset the RRC and execute the RA procedure including sending RACH. Good (step 16).

In addition, when the RACH transmission fails, the UE200 includes the ID of the failed targetPSCell, the quality information between the serving cell and the neighboring cell of the serving cell, and the RACH information used (optional) in the SCG failure information. It may be transmitted to MN (step 17).

Similarly, if the RACH transmission is successful, the UE200 includes the ID of the successful targetPSCell, the quality information between the serving cell and the neighboring cell of the serving cell, and the RACH information used (optional) in the SCG failure information. May be sent to MN.

(3.3) Operation example 2
FIG. 7 shows a communication sequence example (No. 1) according to the conditional PSCell addition procedure according to the operation example 2.

FIG. 8 shows a communication sequence example (No. 2) according to the conditional PSCell addition procedure (conditional PSCell addition) according to the operation example 2.

In this operation example as well, the timing of data transfer is improved and the contents of SCG failure information are added as compared with the above-mentioned conventional example. FIG. 7 shows an operation example in which the first RACH associated with the conditional PSCell addition fails and the second RACH succeeds. On the other hand, FIG. 8 shows an operation example in which both the first and second RACHs associated with the conditional PSCell addition fail.

As shown in FIG. 7 or 8, when the UE200 has expired the timer T304 (T304 of SCG) for SCG, the UE200 first selects another targetPSCell before transmitting the SCG failure information. If the selected target PSCell is a candidate PSCell, the RRC reset may be directly requested from the candidate PSCell and the RA procedure including the transmission of RACH may be executed (step 12).

If the RACH fails multiple times, the UE200 will send the failed targetPSCell ID, quality information between the serving cell and neighboring cells of the serving cell, and RACH information used (optional) to SCG failure information. It may be included and sent to MN.

In connection with the operation of the UE200, the network (for example, MN) stops accessing another targetPSCell (RACH) when the RACH to the targetPSCell (candidatePSCell) fails a predetermined number of times in a row. , SCG failure information may be sent to UE200 in advance. Further, instead of (or in combination with) a predetermined number of times, the access may be stopped when the timer expires.

Alternatively, the network may send an explicit instruction to the UE200 to stop access to another targetPSCell (candidatePSCell). The UE200 may suspend access to another targetPSCell (candidatePSCell) and send SCG failure information to the MN in response to the instruction.

Note that the above-mentioned settings and instructions may be executed by RRC signaling or lower layer signaling.

In the UE200, for example, when the RACH transmission to the second target PSCell is successful, the target PS Cell in which the RACH transmission is successful and the ID of the first target PS Cell in which the RACH transmission is unsuccessful, the serving cell at each time point and the vicinity of the serving cell. Quality information with the cell and RACH information used (optional) may be included in the SCG failure information and sent to the MN.

In addition, the UE 200 may include an explicit instruction in the SCG failure information indicating that the data transfer is started for the target PS Cell for which the RACH transmission is successful. In this case, the MN may start data transfer regarding the UE 200 when the SCG failure information is received.

Alternatively, the MN may implicitly start data transfer regarding the UE 200 to the target PS Cell that has succeeded in RACH transmission included in the SCG failure information, without such an explicit instruction.

(4) Action / Effect According to the above-described embodiment, the following action / effect can be obtained. Specifically, when the conditional PSCell addition / change fails, the UE 200 can transmit the identification information of the target PSCell (secondary cell) in which the conditional PSCell addition / change fails, and the quality information between the serving cell and the neighboring cell.

The UE200 can also execute the RA procedure for the selected target PSCell before sending the SCG failure information when the conditional PSCell addition / change fails.

Furthermore, in response to such an operation of the UE200, the MN, that is, the radio base station, when the SCG failure information is received, starts data transfer regarding the UE200 to another candidate PSCell other than the failed target PSCell. Alternatively, based on the SCG failure information, data transfer related to the UE 200 can be started to another candidate PS Cell in which the RA procedure (RACH transmission) by the UE 200 is successful.

Therefore, the network including MN can optimize the SCG mobility parameter and / or RACH parameter based on the information reported from UE200 by SCG failure information. In addition, this can reduce the failure of conditional PSCell addition / change.

In this embodiment, the UE 200 can execute the RA procedure for another selected target PSCell (secondary cell) when the conditional PSCell addition / change fails. Therefore, even if conditionalPSCell addition / change fails, it is possible to quickly realize a change to another targetPSCell.

In the present embodiment, when the UE 200 executes the RA procedure for another selected target PSCell before transmitting the SCG failure information, the UE 200 can transmit the SCG failure information including the information about the RA procedure. Therefore, the network may further optimize the SCG mobility parameter and / or the RACH parameter based on the information about the RA procedure reported by the UE 200 by the SCG failure information.

(5) Other Embodiments Although the contents of the present invention have been described above with reference to the examples, the present invention is not limited to these descriptions, and various modifications and improvements are possible. It is obvious to the trader.

For example, in the above-described embodiment, EN-DC in which MN is eNB and SN is gNB has been described as an example, but as described above, it may be another DC. Specifically, MN may be gNB and SN may be gNB, or MN may be gNB and SN may be NE-DC.

Further, in the above-described embodiment, the conditional PSCell addition / change has been mainly described as an example, but as described above, the conditional PSCell change procedure (MN-initiated conditional inter-SN PSCell change / SN-initiated conditional inter). -The same operation may be applied to SNPSCellchange).

Further, the block configuration diagram (FIGS. 2 and 3) used in the explanation of the above-described embodiment shows the block of the functional unit. These functional blocks (components) are realized by any combination of at least one of hardware and software. Further, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one physically or logically coupled device, or two or more physically or logically separated devices can be directly or indirectly (eg, for example). , Wired, wireless, etc.) and may be realized using these plurality of devices. The functional block may be realized by combining the software with the one device or the plurality of devices.

Functions include judgment, decision, judgment, calculation, calculation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, solution, selection, selection, establishment, comparison, assumption, expectation, and assumption. Broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, assigning, etc., but limited to these I can't. For example, a functional block (configuration unit) that makes transmission function is called a transmitting unit (transmitting unit) or a transmitter (transmitter). In each case, as described above, the realization method is not particularly limited.

Further, the above-mentioned eNB100A, gNB100B and UE200 (the device) may function as a computer for processing the wireless communication method of the present disclosure. FIG. 9 is a diagram showing an example of the hardware configuration of the device. As shown in FIG. 9, the device may be configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

In the following explanation, the word "device" can be read as a circuit, device, unit, etc. The hardware configuration of the device may be configured to include one or more of each of the devices shown in the figure, or may be configured not to include some of the devices.

Each functional block of the device (see FIG. 2.3) is realized by any hardware element of the computer device or a combination of the hardware elements.

In addition, each function in the device is such that the processor 1001 performs an operation by loading predetermined software (program) on the hardware such as the processor 1001 and the memory 1002, and controls the communication by the communication device 1004, or the memory. It is realized by controlling at least one of reading and writing of data in 1002 and storage 1003.

Processor 1001 operates, for example, an operating system to control the entire computer. The processor 1001 may be configured by a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, and the like.

Further, the processor 1001 reads a program (program code), a software module, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002, and executes various processes according to these. As the program, a program that causes a computer to execute at least a part of the operations described in the above-described embodiment is used. Further, the various processes described above may be executed by one processor 1001 or may be executed simultaneously or sequentially by two or more processors 1001. Processor 1001 may be implemented by one or more chips. The program may be transmitted from the network via a telecommunication line.

The memory 1002 is a computer-readable recording medium, and is composed of at least one such as ReadOnlyMemory (ROM), ErasableProgrammableROM (EPROM), Electrically ErasableProgrammableROM (EEPROM), and RandomAccessMemory (RAM). May be done. The memory 1002 may be referred to as a register, a cache, a main memory (main storage device), or the like. The memory 1002 can store a program (program code), a software module, or the like that can execute the method according to the embodiment of the present disclosure.

The storage 1003 is a computer-readable recording medium, for example, an optical disk such as Compact Disc ROM (CD-ROM), a hard disk drive, a flexible disk, an optical magnetic disk (for example, a compact disk, a digital versatile disk, or a Blu-ray). It may consist of at least one (registered trademark) disk), smart card, flash memory (eg, card, stick, key drive), floppy (registered trademark) disk, magnetic strip, and the like. Storage 1003 may be referred to as auxiliary storage. The recording medium described above may be, for example, a database, server or other suitable medium containing at least one of the memory 1002 and the storage 1003.

The communication device 1004 is hardware (transmission / reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, a communication module, or the like.

The communication device 1004 includes, for example, a high frequency switch, a duplexer, a filter, a frequency synthesizer, etc. in order to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). It may be composed of.

The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that accepts an input from the outside. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, etc.) that outputs to the outside. The input device 1005 and the output device 1006 may have an integrated configuration (for example, a touch panel).

In addition, each device such as the processor 1001 and the memory 1002 is connected by the bus 1007 for communicating information. Bus 1007 may be configured using a single bus or may be configured using different buses for each device.

Furthermore, the device includes hardware such as a microprocessor, a digital signal processor (Digital Signal Processor: DSP), an ApplicationSpecific Integrated Circuit (ASIC), a ProgrammableLogicDevice (PLD), and a FieldProgrammableGateArray (FPGA). The hardware may implement some or all of each functional block. For example, processor 1001 may be implemented using at least one of these hardware.

Further, the notification of information is not limited to the embodiment / embodiment described in the present disclosure, and may be performed by using another method. For example, information notification includes physical layer signaling (eg Downlink Control Information (DCI), Uplink Control Information (UCI), higher layer signaling (eg RRC signaling, Medium Access Control (MAC) signaling, Master Information Block). (MIB), System Information Block (SIB)), other signals or combinations thereof. RRC signaling may also be referred to as an RRC message, eg, RRC Connection Setup. ) Message, RRC Connection Reconfiguration message, etc. may be used.

Each aspect / embodiment described in the present disclosure includes LongTermEvolution (LTE), LTE-Advanced (LTE-A), SUPER3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system ( 5G), FutureRadioAccess (FRA), NewRadio (NR), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UltraMobileBroadband (UMB), IEEE802.11 (Wi-Fi (registered trademark)) , IEEE802.16 (WiMAX®), IEEE802.20, Ultra-WideBand (UWB), Bluetooth®, and other systems that utilize appropriate systems and at least one of the next-generation systems extended based on them. It may be applied to one. In addition, a plurality of systems may be applied in combination (for example, a combination of at least one of LTE and LTE-A and 5G).

The order of the processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in the present disclosure may be changed as long as there is no contradiction. For example, the methods described in the present disclosure present elements of various steps using exemplary order, and are not limited to the particular order presented.

In some cases, the specific operation performed by the base station in this disclosure may be performed by its upper node (upper node). In a network consisting of one or more network nodes having a base station, various operations performed for communication with the terminal are the base station and other network nodes other than the base station (eg, MME or). It is clear that it can be done by at least one of (but not limited to, S-GW, etc.). Although the case where there is one network node other than the base station is illustrated above, it may be a combination of a plurality of other network nodes (for example, MME and S-GW).

Information and signals (information, etc.) can be output from the upper layer (or lower layer) to the lower layer (or upper layer). Input / output may be performed via a plurality of network nodes.

The input / output information may be stored in a specific location (for example, memory) or may be managed using a management table. I / O information can be overwritten, updated, or added. The output information may be deleted. The entered information may be transmitted to other devices.

The determination may be made by a value represented by 1 bit (0 or 1), by a boolean value (Boolean: true or false), or by comparing numerical values (for example, a predetermined value). It may be done by comparison with the value).

Each aspect / embodiment described in the present disclosure may be used alone, in combination, or may be switched and used according to the execution. Further, the notification of predetermined information (for example, the notification of "being X") is not limited to the explicit one, but is performed implicitly (for example, the notification of the predetermined information is not performed). May be good.

Software, whether called software, firmware, middleware, microcode, hardware description language, or other names, instructions, instruction sets, codes, code segments, program codes, programs, subprograms, software modules. , Applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, features, etc. should be broadly interpreted.

Further, software, instructions, information, etc. may be transmitted and received via a transmission medium. For example, a website, where the software uses at least one of wired technology (coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), etc.) and wireless technology (infrared, microwave, etc.). When transmitted from a server or other remote source, at least one of these wired and wireless technologies is included within the definition of transmission medium.

The information, signals, etc. described in this disclosure may be represented using any of a variety of different techniques. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description are voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any of these. It may be represented by a combination of.

The terms described in the present disclosure and the terms necessary 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 be a signal (signaling). Also, the signal may be a message. Further, the component carrier (CC) may be referred to as a carrier frequency, a cell, a frequency carrier, or the like.

The terms "system" and "network" used in this disclosure are used interchangeably.

Further, the information, parameters, etc. described in the present disclosure may be expressed using an absolute value, a relative value from a predetermined value, or another corresponding information. It may be represented. For example, the radio resource may be one indicated by an index.

The names used for the above parameters are not limited in any respect. Further, mathematical formulas and the like using these parameters may differ from those expressly disclosed in this disclosure. Since various channels (eg, 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 in any respect limited names. is not.

In this disclosure, "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", "cell group", " Terms such as "carrier" and "component carrier" may be used interchangeably. Base stations are sometimes referred to by terms such as macrocells, small cells, femtocells, and picocells.

A base station can accommodate one or more (eg, three) cells (also called sectors). When a base station accommodates multiple cells, the entire base station coverage area can be divided into multiple smaller areas, each smaller area being a base station subsystem (eg, a remote radio for indoor use). Communication services can also be provided by Head: RRH).

The term "cell" or "sector" refers to a base station that provides communication services in this coverage, and part or all of the coverage area of at least one of the base station subsystems.

In the present disclosure, terms such as "Mobile Station (MS)", "user terminal", "user equipment (UE)", and "terminal" may be used interchangeably. ..

Mobile stations can be used by those skilled in the art as subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobile terminals, wireless. It may also be referred to as a terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable term.

At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, or the like. At least one of the base station and the mobile station may be a device mounted on the mobile body, a mobile body itself, or the like. The moving body may be a vehicle (eg, car, airplane, etc.), an unmanned moving body (eg, drone, self-driving car, etc.), or a robot (manned or unmanned). ) May be. It should be noted that at least one of the base station and the mobile station includes a device that does not necessarily move during communication operation. For example, at least one of a base station and a mobile station may be an Internet of Things (IoT) device such as a sensor.

Further, the base station in the present disclosure may be read as a mobile station (user terminal, the same shall apply hereinafter). For example, communication between a base station and a mobile station has been replaced with communication between a plurality of mobile stations (for example, it may be called Device-to-Device (D2D), Vehicle-to-Everything (V2X), etc.). Each aspect / embodiment of the present disclosure may be applied to the configuration. In this case, the mobile station may have the functions of the base station. Further, words such as "up" and "down" may be read as words corresponding to communication between terminals (for example, "side"). For example, the upstream channel, the downstream channel, and the like may be read as a side channel.

Similarly, the mobile station in the present disclosure may be read as a base station. In this case, the base station may have the functions of the mobile station.
The radio frame may be composed of one or more frames in the time domain. Each one or more frames in the time domain may be referred to as a subframe. Subframes may further be composed of one or more slots in the time domain. The subframe may have a fixed time length (eg, 1 ms) that does not depend on numerology.

The numerology may be a communication parameter that applies to at least one of the transmission and reception of a signal or channel. Numerology includes, for example, SubCarrier Spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (Transmission Time Interval: TTI), number of symbols per TTI, wireless frame configuration, transmission / reception. It may indicate at least one of a specific filtering process performed by the machine in the frequency domain, a specific windowing process performed by the transmitter / receiver in the time domain, and the like.

The slot may be composed of one or more symbols (Orthogonal Frequency Division Multiplexing (OFDM) symbol, Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol, etc.) in the time area. The slot may be a unit of time based on numerology.

The slot may include a plurality of mini slots. Each minislot may be composed of one or more symbols in the time domain. Further, the mini-slot may be referred to as a sub-slot. A minislot may consist of a smaller number of symbols than the slot. PDSCH (or PUSCH) transmitted in time units larger than the minislot may be referred to as PDSCH (or PUSCH) mapping type A. The PDSCH (or PUSCH) transmitted using the minislot may be referred to as PDSCH (or PUSCH) mapping type B.

Wireless frames, subframes, slots, mini slots and symbols all represent time units when transmitting signals. The radio frame, subframe, slot, minislot and symbol may use different names corresponding to each.

For example, one subframe may be referred to as a transmission time interval (TTI), a plurality of consecutive subframes may be referred to as TTI, and one slot or one minislot may be referred to as TTI. That is, at least one of the subframe and TTI may be a subframe (1ms) in existing LTE, a period shorter than 1ms (eg, 1-13 symbols), or a period longer than 1ms. May be. The unit representing TTI may be called a slot, a mini slot, or the like instead of a subframe.

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

TTI may be a transmission time unit such as a channel-encoded data packet (transport block), a code block, or a code word, or may be a processing unit such as scheduling or link adaptation. When a TTI is given, the time interval (for example, the number of symbols) to which the transport block, code block, code word, etc. are actually mapped may be shorter than the TTI.

When one slot or one mini slot is called TTI, one or more TTIs (that is, one or more slots or one or more mini slots) may be the minimum time unit for scheduling. Further, the number of slots (number of mini-slots) constituting the minimum time unit of the scheduling may be controlled.

TTI with a time length of 1 ms may be called normal TTI (TTI in LTE Rel.8-12), normal TTI, long TTI, normal subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a normal TTI may be referred to as a shortened TTI, a short TTI, a partial TTI (partial or fractional TTI), a shortened subframe, a short subframe, a minislot, a subslot, a slot, and the like.

The long TTI (for example, normal TTI, subframe, etc.) may be read as a TTI having a time length of more than 1 ms, and the short TTI (for example, shortened TTI, etc.) may be read as a TTI less than the TTI length of the long TTI and 1 ms. It may be read as a TTI having the above TTI length.

The resource block (RB) is a resource allocation unit in the time domain and the frequency domain, and may include one or a plurality of continuous subcarriers in the frequency domain. The number of subcarriers contained in RB may be the same regardless of numerology, and may be, for example, 12. The number of subcarriers contained in the RB may be determined based on numerology.

Further, the time domain of RB may include one or more symbols, and may have a length of 1 slot, 1 mini slot, 1 subframe, or 1 TTI. Each 1TTI, 1 subframe, etc. may be composed of one or a plurality of resource blocks.

One or more RBs are physical resource blocks (Physical RB: PRB), sub-carrier groups (Sub-Carrier Group: SCG), resource element groups (Resource Element Group: REG), PRB pairs, RB pairs, etc. May be called.

Further, the resource block may be composed of one or a plurality of resource elements (ResourceElement: RE). For example, 1RE may be a radio resource area of 1 subcarrier and 1 symbol.

Bandwidth Part (BWP) (which may also be called partial bandwidth) may represent a subset of consecutive common resource blocks for a neurology in a carrier. good. Here, the common RB may be specified by the index of the RB with respect to the common reference point of the carrier. PRBs may be defined in a BWP and numbered within that BWP.

BWP may include BWP for UL (UL BWP) and BWP for DL (DL BWP). One or more BWPs may be set in one carrier for the UE.

At least one of the configured BWPs may be active, and the UE may not expect to send or receive a given signal / channel outside the active BWP. In addition, "cell", "carrier" and the like in this disclosure may be read as "BWP".

The above-mentioned structures such as wireless frames, subframes, slots, mini slots and symbols are merely examples. For example, the number of subframes contained in a radio frame, the number of slots per subframe or radioframe, the number of minislots contained within a slot, the number of symbols and RBs contained in a slot or minislot, included in RB. The number of subcarriers, as well as the number of symbols in the TTI, the symbol length, the cyclic prefix (CP) length, and other configurations can be changed in various ways.

The terms "connected", "coupled", or any variation thereof, mean any direct or indirect connection or connection between two or more elements and each other. It can include the presence of one or more intermediate elements between two "connected" or "joined" elements. The connection or connection between the elements may be physical, logical, or a combination thereof. For example, "connection" may be read as "access". As used in the present disclosure, the two elements use at least one of one or more wires, cables and printed electrical connections, and, as some non-limiting and non-comprehensive examples, the radio frequency domain. Can be considered to be "connected" or "coupled" to each other using electromagnetic energy having wavelengths in the microwave and light (both visible and invisible) regions.

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

The statement "based on" used in this disclosure does not mean "based on" unless otherwise stated. In other words, the statement "based on" means both "based only" and "at least based on".

The "means" in the configuration of each of the above devices may be replaced with a "part", a "circuit", a "device", or the like.

Any reference to elements using designations such as "first" and "second" as used in this disclosure does not generally limit the quantity or order of those elements. These designations can be used in the present disclosure as a convenient way to distinguish between two or more elements. Therefore, references to the first and second elements do not mean that only two elements can be adopted there, or that the first element must somehow precede the second element.

When "include", "including" and variations thereof are used in the present disclosure, these terms are as inclusive as the term "comprising". Is intended. Moreover, the term "or" used in the present disclosure is intended to be non-exclusive.

In the present disclosure, if articles are added by translation, for example, a, an and the in English, the disclosure may include the plural nouns following these articles.

The terms "determining" and "determining" used in this disclosure may include a wide variety of actions. "Judgment" and "decision" are, for example, judgment (judging), calculation (calculating), calculation (computing), processing (processing), derivation (deriving), investigation (investigating), search (looking up, search, inquiry). It may include (eg, searching in a table, database or another data structure), ascertaining as "judgment" or "decision". Also, "judgment" and "decision" are receiving (for example, receiving information), transmitting (for example, transmitting information), input (input), output (output), and access. It may include (for example, accessing data in memory) to be regarded as "judgment" or "decision". In addition, "judgment" and "decision" are considered to be "judgment" and "decision" when the things such as solving, selecting, choosing, establishing, and comparing are regarded as "judgment" and "decision". Can include. That is, "judgment" and "decision" may include considering some action as "judgment" and "decision". Further, "judgment (decision)" may be read as "assuming", "expecting", "considering" and the like.

In the present disclosure, the term "A and B are different" may mean "A and B are different from each other". The term may mean that "A and B are different from C". Terms such as "separate" and "combined" may be interpreted in the same way as "different".

Although the present disclosure has been described in detail above, it is 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 may be implemented as amendments and modifications without departing from the spirit and scope of the present disclosure as determined by the description of the scope of claims. Therefore, the description of this disclosure is for purposes of illustration and does not have any limiting meaning to this disclosure.

10 Wireless communication system 20 E-UTRAN
30 NG RAN
40 UPF
100A eNB
100B gNB
110 Wireless communication unit 120 RRC processing unit 130 DC processing unit 140 Control unit 200 UE
210 Wireless communication unit 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

Claims

A control unit that controls the execution of secondary cell addition / modification procedures,
A terminal including a transmission unit that transmits identification information of a secondary cell in which the addition / modification procedure has failed and quality information between a serving cell and a neighboring cell when the addition / modification procedure fails.
The terminal according to claim 1, wherein the control unit executes a random access procedure for another selected secondary cell.
A receiver that receives failure information of the secondary cell group related to the procedure for adding / changing secondary cells by the terminal, and
A radio base station including a control unit that starts data transfer regarding the terminal to another candidate secondary cell other than the failed secondary cell when the failure information is received.
A control unit that controls the execution of secondary cell addition / modification procedures,
It is equipped with a transmitter that transmits failure information of the secondary cell group related to the addition / modification procedure.
The control unit is a terminal that, when the addition / modification procedure fails, executes a random access procedure for another selected secondary cell before transmitting the failure information.
The terminal according to claim 4, wherein the transmission unit transmits the failure information including information on the random access procedure.
A receiver that receives failure information of the secondary cell group related to the procedure for adding / changing secondary cells by the terminal, and
A radio base station including a control unit that initiates data transfer relating to the terminal to another candidate secondary cell in which the random access procedure by the terminal has succeeded based on the failure information.