The present disclosure relates to wireless communication systems, particularly to the mobility of wireless terminals.
Background technology
[0002]
Non-Patent Documents 1 and 2 disclose conditional handover (CHO) discussed in 3GPP. In some implementations for CHO, the source radio access network (RAN) node (eg, eNodeB (eNB)) issues a handover command containing the conditions for performing the handover (eg, threshold) to the wireless terminal (eg). , User Equipment (UE)). The wireless terminal maintains the connection with the source RAN node even after receiving the handover command, and starts accessing the target RAN node as soon as the condition (configured condition) set by the handover command is satisfied. That is, conditional handover (CHO) is existing in that the wireless terminal starts accessing the target cell not in response to the reception of the handover command but in response to the satisfaction of the condition set by the handover command. It is different from the handover of.
[0003]
CHO can increase the reliability of delivery of the handover command to the UE by early event triggering (that is, lowering the threshold value that triggers the measurement report by the wireless terminal). As a result, the CHO can reduce the handover failure rate.
[0004]
In CHO, the settings of a plurality of candidate target cells may be sent to the wireless terminal. Candidate target cells may be referred to as potential target cells. For example, the wireless terminal receives a handover command including the setting of a plurality of candidate target cells and the CHO execution threshold value from the source RAN node (e.g., eNB). Then, the wireless terminal measures a plurality of set candidate target cells, and starts access to the candidate cell when the measurement in any of the candidate target cells satisfies the CHO execution threshold value.
Prior art literature
Non-patent literature
[0005]
Non-Patent Document 1: Intel Corporation, “Discussion of conditional handover”, R2-1816691, 3GPP TSG RAN WG2 Meeting # 104, Spokane, WA, USA, November 12-16, 2018
Non-Patent Document 2: MediaTek Inc., “Conditional Handover Procedures”, R2-1816959, 3GPP TSG RAN WG2 Meeting # 104, Spokane, WA, USA, November 12-16, 2018
Outline of the invention
Problems to be solved by the invention
[0006]
The inventors have performed a conditional mobility operation similar to the conditional handover in the cell of the primary cell (Primary SCG Cell (PSCell)) of the secondary cell group (SCG) of the dual connectivity (DC). We considered applying it to the change (PSCell change) and found various issues.
[0007]
PSCell is, in other words, SCG's Special Cell (SpCell). The UE randomly accesses the PSCell when performing the handover procedure (or Reconfiguration with Sync procedure). An SCG is a group of serving cells associated with a DC's Secondary Node (SN), a SpCell (ie, PSCell) and optionally one or more secondary cells (SCG). Includes Secondary Cells (SCells).
[0008]
The PSCell Change procedure is an example of a procedure that involves a Reconfiguration with sync procedure. For this reason, conditional PSCell Change can also be called conditional Reconfiguration with sync (for PSCell change).
[0009]
As an example, consider the case where SN uses the SN initiated SN Modification with MN involvement procedure for PS Cell change. In this case, the RRC signaling between the SN and UE for conditional mobility (ie, conditional PSCell change) is the Signaling Radio Bearer (SRB) of the Master Cell Group (MCG). )) Sent via (eg, SRB1). An MCG is a group of serving cells provided by a master node (MN) of a DC. In this case, it is not clear how the SN knows that the execution condition of the conditional PSCell change is satisfied (or the start of conditional mobility).
[0010]
One of the objectives to be achieved by the embodiments disclosed herein contributes to enabling the SN to know the fulfillment of the execution condition of the conditional PSCell change (or the start of the conditional PSCell change). To provide equipment, methods, and programs to do so. It should be noted that this object is only one of the purposes that the embodiments disclosed herein seek to achieve. Other objectives or issues and novel features will be apparent from the description or accompanying drawings herein.
Means to solve problems
[0011]
In the first aspect, the radio access network node comprises at least one memory and at least one processor coupled to said at least one memory. The at least one processor is configured to operate as a dual connectivity secondary node for a wireless terminal. The at least one processor sends a first Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell, said dual connectivity. It is configured to transmit to the wireless terminal via the master node of. Further, the at least one processor is configured to receive a second RRC message sent from the wireless terminal from the wireless terminal via the master node in response to the establishment of the execution condition.
[0012]
In the second aspect, the wireless terminal includes at least one memory and at least one processor coupled to the at least one memory. The at least one processor is configured to perform dual connectivity of the master cell group associated with the master node and the secondary cell group associated with the secondary node. The at least one processor sends a first Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell to the master node. It is configured to receive from the secondary node via. Further, the at least one processor is configured to transmit a second RRC message from the radio terminal to the secondary node via the master node in response to the establishment of the execution condition.
[0013]
In the third aspect, the method for radio access network nodes is
(A) Acting as a dual connectivity secondary node for wireless terminals,
(B) A first Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is sent to the master node of the dual connectivity. Sending to the wireless terminal via, and
(C) Receiving a second RRC message sent from the wireless terminal from the wireless terminal via the master node in response to the satisfaction of the execution condition.
including.
[0014]
In the fourth aspect, the method for wireless terminals is:
(A) Perform dual connectivity of the master cell group associated with the master node and the secondary cell group associated with the secondary node.
(B) The first Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is sent via the master node. Receiving from the secondary node and
(C) In response to the satisfaction of the execution condition, the second RRC message is transmitted from the wireless terminal to the secondary node via the master node.
including.
[0015]
In a fifth aspect, the radio access network node comprises at least one memory and at least one processor coupled to said at least one memory. The at least one processor is configured to operate as a dual connectivity secondary node for a wireless terminal. The dual connectivity is such that at least one processor sends a first Radio Resource Control (RRC) message indicating the conditions for performing a conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell. It is configured to transmit to the wireless terminal via the master node of. Further, the at least one processor displays the execution or start display of the conditional primary cell change sent from the wireless terminal in response to the establishment of the execution condition of the first secondary cell or the secondary cell group. It is configured to receive directly from the wireless terminal in any of the secondary cells.
[0016]
In the sixth aspect, the wireless terminal includes at least one memory and at least one processor coupled to the at least one memory. The at least one processor is configured to perform dual connectivity of the master cell group associated with the master node and the secondary cell group associated with the secondary node. The at least one processor sends a first Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell to the master node. It is configured to receive from the secondary node via. Further, the at least one processor displays the execution or start of the conditional primary cell change in the secondary cell of either the first cell or the secondary cell group in response to the establishment of the execution condition. It is configured to send directly to the secondary node.
[0017]
In the seventh aspect, the method for radio access network nodes is:
(A) Acting as a dual connectivity secondary node for wireless terminals,
(B) A first Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is sent to the master node of the dual connectivity. Send to the wireless terminal via Believe and
(C) The display of the execution or start of the conditional primary cell change sent from the wireless terminal in response to the establishment of the execution condition is displayed in the secondary cell of either the first cell or the secondary cell group. Receiving directly from a wireless terminal,
including.
[0018]
In the eighth aspect, the method for wireless terminals is:
(A) Perform dual connectivity of the master cell group associated with the master node and the secondary cell group associated with the secondary node.
(B) The first Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is sent via the master node. Receiving from the secondary node and
(C) In response to the fulfillment of the execution condition, the display of the execution or start of the conditional primary cell change is directly displayed to the secondary node in the secondary cell of either the first cell or the secondary cell group. To send to
including.
[0019]
In the ninth aspect, the program provides a set of instructions (software code) for causing the computer to perform the method according to the third, fourth, seventh, or eighth aspect described above when the program is read by the computer. include.
The invention's effect
[0020]
According to the above aspect, it is possible to provide a device, a method, and a program that contribute to making it possible for the SN to know the establishment of the execution condition of the conditional PSCell change (or the start of the conditional PSCell change).
A brief description of the drawing
[0021]
FIG. 1 is a diagram showing a configuration example of a wireless communication network according to the first embodiment.
FIG. 2 is a sequence diagram showing an example of signaling according to the first embodiment.
FIG. 3 is a flowchart showing an example of processing performed by the secondary node according to the first embodiment.
FIG. 4 is a flowchart showing an example of processing performed by the wireless terminal according to the first embodiment.
FIG. 5 is a diagram showing a configuration example of a secondary node according to a second embodiment.
FIG. 6 is a sequence diagram showing an example of signaling according to the second embodiment.
FIG. 7 is a sequence diagram showing an example of signaling according to the third embodiment.
FIG. 8 is a block diagram showing a configuration example of a secondary node according to some embodiments.
FIG. 9 is a block diagram showing a configuration example of a wireless terminal according to some embodiments.
Embodiment for carrying out the invention
[0022]
In the following, specific embodiments will be described in detail with reference to the drawings. In each drawing, the same or corresponding elements are designated by the same reference numerals, and duplicate explanations are omitted as necessary for the sake of clarity of explanation.
[0023]
The plurality of embodiments described below can be implemented independently or in combination as appropriate. These plurality of embodiments have novel features that differ from each other. Therefore, these plurality of embodiments contribute to solving different purposes or problems, and contribute to different effects.
[0024]
The plurality of embodiments shown below will be described mainly for the 3GPP Long Term Evolution (LTE) system and the 5th generation mobile communication system (5G system). However, these embodiments may be applied to other wireless communication systems that support dual connectivity. The term LTE as used herein includes improvements and developments of LTE and LTE-Advanced to enable interworking with the 5G System, unless otherwise noted. In addition to NR (New Radio), the 5G System also includes a network configuration in which LTE eNodeB (eNB) connects to the 5G core network (5GC). LTE eNB at this time is also called Next generation (ng) -eNB. ng-eNB is also called eNB / 5GC because it is an eNB connected to 5GC.
[0025]

FIG. 1 shows a configuration example of a wireless communication network according to this embodiment. The wireless communication network according to the present embodiment includes a master node (MN) 1 and a secondary node (SN) 2. MN1 and SN2 communicate with each other via the inter-node interface 103. UE3 communicates with MN1 and SN2 via air interfaces 101 and 102 to perform dual connectivity of master cell group (MCG) and secondary cell group (SCG). An MCG is a group of serving cells associated with (or provided with) MN1 and is a SpCell (ie, Primary Cell (PCell)) and optionally one or more secondary cells (ie, Primary Cell (PCell)). Includes Secondary Cells (SCells). An SCG, on the other hand, is a group of serving cells associated with (or provided with) SN2, the SCG's primary cell (ie, the Primary SCG Cell (PSCell)) and optionally 1 or Includes more secondary cells (SCells). PSCell is SCG's Special Cell (SpCell).
[0026]
Each of MN1 and SN2 may be an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (EUTRAN) node or an NG-RAN (Next generation Radio Access Network) node. The EUTRAN node may be eNB or en-gNB. The NG-RAN node may be gNB or ng-eNB. The Radio Access Technology (RAT) of MN1 may be different from that of SN2.
[0027]
DC may be Multi-Radio Dual Connectivity (MR-DC). MR-DC is Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (E-UTRA)-NR Dual Connectivit (EN-DC), NR-E-UTRA DC (NE-DC), NG-RAN EN-DC ( Includes NGEN-DC) and NR-NR DC (NR DC).
[0028]
FIG. 2 shows an example of signaling for a conditional primary cell change (that is, a conditional PSCell Change) of a primary cell (i.e., PSCell) in a secondary cell group. As already mentioned, conditional PSCell Change can also be called conditional Reconfiguration with sync (for PSCell change). FIG. 2 shows a case where MN1 (e.g., Master eNB (MeNB)) is involved in PS Cell Change in MR-DC. That is, in the example of FIG. 2, the RRC signaling transmitted between SN2 (eg, Secondary gNB (SgNB)) and UE3 for PSCell Change is SRB (eg, SRB1) in the MCG provided by MN1. To use.
[0029]
Prior to the procedure in FIG. 2, SN2 generated an RRC message (eg, RRCReconfiguration message) containing measurement settings (eg, MeasConfig) including report settings (eg, ReportConfig) for conditional PSCell Change. This may be transmitted to UE3 via the MCG SRB provided by MN1. The measurement settings for conditional PSCell Change allow for early event triggering (ie, lowering the threshold that triggers measurement reporting by UE3) for conditional PSCell Change decisions. Further, the UE3 may send a measurement report to the SN2 via the MN1. SN2 may determine a conditional PSCell Change to change the PSCell of UE3 from the current cell to another SCG cell or another cell of SN2 based on the received measurement report.
[0030]
In step 201, SN2 sends an SN MODIFICATION REQUIRED message including an RRC message (e.g., RRC Reconfiguration message) of SN RAT (e.g., NR) generated by SN2 to MN1. The RRC message contains a condition for starting (or executing) a conditional PSCell change (or conditional Reconfiguration with sync for PSCell change). Conditions for starting (or executing) a conditional PS Cell change include, for example, a threshold and a corresponding time-to-trigger (TTT). Alternatively, the condition for starting (or executing) a conditional PSCell change may be the reception of an explicit execution instruction (e.g., predetermined signaling) from the network. In this case, the reception by UE3 of the setting (eg, radio parameter) used for receiving the execution instruction implies to UE3 that the start (or execution) condition of the conditional PSCell change is the reception of the execution instruction. It may be shown as a target. In other words, when UE3 receives the setting (eg, radio parameter), it determines that the start (or execution) condition of the conditional PSCell change associated with it is the reception of the execution instruction (eg, predetermined signaling). (Or understand).
[0031]
Further, the RRC message may include a condition (e.g., offset) in which UE3 exits the conditional PSCell change, and a value of the validity timer. The value of the valid timer may indicate how long the resource of the candidate target cell (that is, the cell that is a candidate for the changed PSCell) is valid. Alternatively, the value of the valid timer may indicate the period (hours) during which access to the candidate target cell is permitted, or the period (hours) during which the setting for conditional PSCell change is valid.
[0032]
If data forwarding and / or SN security key changes need to be applied, MN1 will perform the MN initiated SN Modification procedure and use the forwarding address and / or new SN security key information with the SN Modification Request message. It may be applied to SN2. In response, the SN2 may generate an RRC message (e.g., RRC Reconfiguration message) again and send it to the MN1 using the SN Modification Request Acknowledge message.
[0033]
In step 202, MN1 performs an RRC reconfiguration procedure (eg, LTE RRC Connection Reconfigurtion procedure) of MN RAT (eg, LTE) via MCG SRB, and forwards the RRC message of SN RAT received from SN2 to UE3. .. MN1 carries the SN RAT RRC message received from SN2 (e). .g., LTE RRC Connection Reconfigurtion message) may be sent to UE3 via MCG SRB.
[0034]
UE3 maintains the current (that is, before the change) PSCell setting even after receiving the SN RAT RRC message (step 202), and uses the PSCell. UE3 responds to the execution condition of the conditional PS Cell change (ie, conditional Reconfiguration with sync) set by the RRC message of SN RAT (step 202) (step 203), and causes the SN RAT addressed to SN2. An MN RAT RRC response message (eg, LTE RRC Connection Reconfigurtion Complete message) including an RRC response message (eg, NR RRC Reconfiguration Complete message) is sent to MN1 (step 204). Then, UE3 applies the new PSCell setting and starts access to the target PSCell (i.e., random access procedure).
[0035]
In step 205, MN1 responds to SN2 with an SN MODIFICATION CONFIRM message. The SN MODIFICATION CONFIRM message includes the SN RAT RRC response message (e.g., RRC Reconfiguration Complete message) received from UE3.
[0036]
In the procedure of FIG. 2, UE3 operates to send an RRC response message (e.g., RRC Reconfiguration Complete message) addressed to SN2 to SN2 via MN1 in response to the execution condition of conditional PSCell change being satisfied. As a result, the RRC response message can also be used to report the start (execution) of the conditional PSCell change to the SN2. Upon receiving the RRC response message, SN2 can detect the start of a conditional PSCell change.
[0037]
The SN2 may stop the downlink data transfer to the UE3 via the PSCell before the change in response to the reception of the RRC response message from the UE3. In other words, the RRC response message from UE3 may trigger SN2 to stop the downlink data transfer to UE3 via the PSCell before the change. This causes SN2 to be for UE3 in the current (ie, before) PSCell (and other current SCG serving cells (ie SCG SCell (s))) until just before the start (or execution) of the conditional PSCell change. Data transmission (downlink, uplink, or both) can be continued.
[0038]
In the procedure of FIG. 2, UE3 may change the PSCell to one cell selected from a plurality of candidate target cells (that is, cells that are candidates for the changed PSCell). For example, in step 203 of FIG. 2, the UE 3 may determine that the execution condition of the conditional PS Cell change is satisfied for any one of the plurality of target cells. UE3 then includes information in the SN RAT RRC response message (step 204) addressed to SN2 that explicitly or implicitly indicates the selected candidate target cell (ie, the cell where the conditional PSCell Change was triggered). May be.
[0039]
FIG. 3 is a flowchart showing an example of the operation of SN2. In step 301, the SN2 sends an RRC message indicating the execution condition of the conditional PSCell change to the UE3 via the MN1. In step 302, the SN2 receives the RRC response message sent from the UE3 via the MN1 in response to the fulfillment of the execution condition of the conditional PSCell change.
[0040]
After step 302, the SN2 may stop the downlink data transfer to the UE3 via the PSCell before the change in response to the reception of the RRC response message from the UE3.
[0041]
FIG. 4 is a flowchart showing an example of the operation of UE3. In step 401, UE3 receives an RRC message indicating the execution condition of the conditional PSCell change from SN2 via MN1. In step 402, UE3 sends an RRC response message to SN2 via MN1 in response to the fulfillment of the execution condition of the conditional PSCell change. The RRC response message may include information that explicitly or implicitly indicates the selected candidate target cell (ie, the cell where the conditional PSCell Change was triggered).
[0042]
According to the operation of MN1, SN2, and UE3 described in the present embodiment, the execution condition of the conditional PSCell change in which the RRC signaling between SN2 and UE3 is performed via MN1 is satisfied (or the conditional PSCell change). It is possible for SN2 to know the start of).
[0043]
In this embodiment, UE3 may further operate as follows. UE3 did not perform a conditional PSCell change due to this if the exit condition (eg, offset) was met or the aforementioned validity timer expired. (Non-execution) or termination information indicating failure may be transmitted to SN2 via MN1. For example, the UE 3 may operate as follows instead of the operation of step 204 in FIG. UE3 responds to the SN RAT RRC message (eg, NR) if the above-mentioned conditional PSCell change exit condition (eg, offset) is satisfied or if the above-mentioned validity timer expires. An RRC message (eg, LTE RRC Connection Reconfiguration Complete message) of MN RAT including RRC Reconfiguration Complete) may be sent to MN1 (eg MeNB). In this case, the MN RAT RRC message or the SN RAT RRC message contained therein may include termination information indicating the failure or failure of the conditional PSCell change. The MN1 may send the RRC message of the SN RAT received from the UE3 to the SN2 (e.g. SgNB). Upon receiving (in response to) this SN RAT RRC message from MN1, SN2 may release the prepared candidate target cell settings and resources.
[0044]
The termination information may further include information (eg, cause) for distinguishing whether the failure or failure of the conditional PSCell change is due to the establishment of the exit condition or the expiration of the valid timer.
[0045]
When there are multiple candidate target cells and at least one of the exit condition or the value of the valid timer is set for each cell, UE3 satisfies the exit condition (or the valid timer) for all the candidate target cells. May be sent in response to an SN RAT RRC message containing exit information. Alternatively, the UE 3 may send an SN RAT RRC message containing exit information in response to satisfying the exit condition (or the valid timer has expired) for any of the candidate target cells. In the latter case, UE3 indicates information indicating a candidate target cell that meets the exit condition (or the valid timer has expired) (the first one, or multiple cells that meet the condition simultaneously or almost (substantially) simultaneously). May be included in the SN RAT RRC message.
[0046]

This embodiment provides a specific example of the conditional PS Cell change described in the first embodiment. The configuration example of the wireless communication network according to the present embodiment may be the same as the example shown in FIG. However, in this embodiment, cloud RAN (C-RAN) deployment is applied to SN2. In C-RAN, a RAN node (e.g., eNB, or NR gNodeB (gNB)) is composed of a Central Unit (CU) and one or more Distributed Units (DUs). C-RAN is sometimes called Centralized RAN or CU-DU split architecture.
[0047]
FIG. 5 shows a configuration example of SN2 according to the present embodiment. SN2 in FIG. 5 includes CU21 and one or more DUs22. The CU 21 and each DU 22 are connected by an interface 501. The UE 3 is connected to at least one DU 22 via at least one air interface 502.
[0048]
CU21 may be a logical node hosting gNB's Radio Resource Control (RRC), Service Data Adaptation Protocol (SDAP), and Packet Data Convergence Protocol (PDCP) protocols (or gNB's RRC and PDCP protocols). The DU22 may be a logical node hosting the gNB's Radio Link Control (RLC), Medium Access Control (MAC), and Physical (PHY) layers. If CU21 is gNB-CU and DUs22 is gNB-DUs, interface 501 may be an F1 interface.
[0049]
CU21 may include a Control Plane (CP) Unit (e.g., gNB-CU-CP) and one or more User Plane (UP) Units (e.g., gNB-CU-UP).
[0050]
FIG. 6 shows an example of the intra-CU inter-DU conditional PSCell Change procedure. As already mentioned, conditional PSCell Change can also be called conditional Reconfiguration with sync (for PSCell change). FIG. 6 shows a case where MN1 (e.g., Master eNB (MeNB)) is involved in PS Cell Change in MR-DC. In the example of FIG. 6, the PSCell for UE3 is changed from the cell of the source DU22A to the cell of the target DU22B. The RRC signaling transmitted between SN2 (i.e., CU21) and UE3 for PSCell Change uses the SRB in the MCG provided by MN1.
[0051]
Prior to the procedure in FIG. 6, the SN2 (ie, CU21) contains an RRC message (eg, RRC Reconfiguration message) that includes a measurement setting (eg, MeasConfig) that includes a report setting (eg, ReportConfig) for conditional PSCell Change. ) May be generated and sent to UE3 via the MCG SRB provided by MN1. The measurement settings for conditional PSCell Change allow for early event triggering (ie, lowering the threshold that triggers measurement reporting by UE3) for conditional PSCell Change decisions. Further, UE3 may send a measurement report to SN2 (i.e., CU21) via MN1. SN2 (i.e., CU21) received the measurement Based on the regular report, a conditional PSCell Change may be determined to change the PSCell of UE3 from the cell under the current SN to the cell under another SN.
[0052]
In step 601 the CU 21 sends a UE CONTEXT SETUP REQUEST message to the target DU22B to create a UE context and set up one or more bearers. The UE CONTEXT SETUP REQUEST message may request the target DU22B to set the radio resource of PSCell (e.g., CellGroupConfig). The "CG-ConfigInfo" information element contained in the "CU to DU RRC Information" information element in the UE CONTEXT SETUP REQUEST message may be used to indicate that it is a conditional PS Cell change request. Alternatively, a new information element may be defined in the UE CONTEXT SETUP REQUEST message to indicate that it is a conditional mobility request.
[0053]
In step 602, the target DU22B responds to the CU21 with a UE CONTEXT SETUP RESPONSE message. The target DU22B may determine whether or not the conditional PSCell Change is acceptable in response to the reception of the conditional PSCell Change request. The target DU22B may include an information element in the UE CONTEXT SETUP RESPONSE message (step 602) indicating whether or not the conditional PSCell Change is acceptable.
[0054]
In step 603, CU21 sends an SN MODIFICATION REQUIRED message including an RRC message (e.g., RRC Reconfiguration message) generated by CU21 to MN1. The RRC message includes conditions (e.g., thresholds and TTTs) for the start (or execution) of a conditional PSCell change (or conditional Reconfiguration with sync for PSCell change). In addition, the RRC message may include a condition (e.g., offset) that UE3 exits the conditional PSCell change, and a value for the validity timer. The value of the valid timer may indicate how long the resource of the candidate target cell (that is, the cell that is a candidate for the changed PSCell) is valid. Alternatively, the value of the valid timer may indicate the period (hours) during which access to the candidate target cell is permitted, or the period (hours) during which the setting for conditional PSCell change is valid.
[0055]
More specifically, the CU 21 may determine the start condition of the conditional PSCell change and include it in the CG-ConfigInfo information element or the new information element included in the UE CONTEXT SETUP REQUEST message (step 601). .. Then, the target DU22B may generate a radio resource setting (e.g., CellGroupConfig) including the start condition of the conditional PS Cell change, and include this in the UE CONTEXT SETUP RESPONSE message (step 602). Further, the CU 21 may generate an RRC message (e.g., NR RRCReconfiguraion message) including the received radio resource setting (e.g., CellGroupConfig) and include it in the SN MODIFICATION REQUIRED message (step 603). In step 601 the CU 21 may transmit to the DU22B either or both of the condition that the UE3 leaves the conditional PSCell change and the value of the valid timer, together with the condition for starting the conditional PSCell change. Then, the DU 22B may include them in the radio resource setting (e.g., CellGroupConfig) including the start condition of the conditional PS Cell change, and transmit this to the CU 21.
[0056]
Alternatively, the CU 21 may determine the start condition for the conditional PSCell change and include it in the new information element in the SN MODIFICATION REQUIRED message (step 603). The CU 21 may further include one or both of the condition that UE3 leaves the conditional PSCell change and the value of the active timer in the message.
[0057]
Further, instead of this, the target DU22B may determine the start condition of the conditional PS Cell change. In this case, the target DU22B determines the start condition of the conditional PSCell change in response to the conditional PSCell change request (step 601), and sets the determined start condition as the CellGroupConfig information element in the UE CONTEXT SETUP RESPONSE message (step 602). Alternatively, it may be included in a new information element. The CU 21 may then generate an RRC message containing a CellGroupConfig information element containing a conditional PSCell change start condition or a new information requirement, which may be included in the SN MODIFICATION REQUIRED message (step 603). The DU22 may further determine one or both of the conditions under which the UE3 leaves the conditional PSCell change and / or the values ​​of the active timer, which may be included in the RRC message to the CU21.
[0058]
If data forwarding and / or SN security key changes need to be applied, MN1 will perform the MN initiated SN Modification procedure and use the forwarding address and / or new SN security key information with the SN Modification Request message. It may be applied to SN2 (ie, CU21).
[0059]
In step 604, the CU 21 sends a UE CONTEXT MODIFICATION REQUEST message to the source DU22A. The message contains a conditional PS Cell change indication.
[0060]
In step 605, the source DU22A responds to the CU21 with a UE CONTEXT MODIFICATION RESPONSE message.
[0061]
In step 606, MN1 performs an RRC (Connection) Reconfigurtion procedure via MCG SRB, and forwards the RRC message received from CU21 to UE3. The MN1 may send an RRC (Connection) Reconfigurtion message carrying an RRC message received from the CU 21 to the UE 3 via the MCG SRB.
[0062]
UE3 maintains the setting of the PSCell before the change even after receiving the RRC message (step 606), and uses the PSCell before the change provided by the source DU22A. UE3 applies the new PSCell setting according to the execution condition of the conditional PSCell change (ie, conditional Reconfiguration with sync) set by the RRC message (step 606) (step 607), and applies the new PSCell setting to SN2. An RRC (Connection) Reconfigurtion Complete message containing an RRC response message addressed to (ie, CU21) is sent to MN1 (step 608). Then, UE3 starts access (i.e., random access procedure) to the changed PSCell (i.e., cell provided by the target DU22B) (step 610).
[0063]
In step 609, MN1 responds to SN2 (i.e., CU21) with an SN MODIFICATION CONFIRM message. The SN MODIFICATION CONFIRM message includes an RRC response message message received from UE3.
[0064]
In the procedure of FIG. 6, UE3 operates to send an RRC response message addressed to SN2 (ie, CU21) to SN2 (ie, CU21) via MN1 in response to the execution condition of the conditional PSCell change being satisfied. do. Thereby, the RRC response message can also be used to report the start (execution) of the conditional PSCell change to the SN2 (i.e., CU21). The SN2 (i.e., CU21) can detect the start of a conditional PSCell change by receiving the RRC response message.
[0065]
The SN2 (i.e., CU21) may stop the downlink data transfer to the UE3 via the source DU22A in response to the reception of the RRC response message from the UE3. In other words, the RRC response message from UE3 may trigger SN2 (i.e., CU21) to stop the downlink data transfer to UE3 via the PSCell before the change. As a result, SN2 (ie, CU21) is for UE3 in the PSCell before the change (and other serving cells of the current SCG (ie SCG SCell (s))) until just before the start (or execution) of the conditional PSCell change. Data transmission (downlink, uplink, or both) can be continued.
[0066]
Note that the SN2 (ie, CU21) responds to the reception of the control message indicating the downlink data that has not been transmitted to the UE3 from the source DU22A before receiving the RRC response message from the UE3, and the source DU22A. You may stop the downlink data transfer to UE3 via. The control data may be a message (or frame, or Protocol Data Unit (PDU)) transmitted to the CU 21 to indicate downlink data that has not been transmitted to the UE 3. More specifically, the control message may be a DOWNLINK DATA DELIVERY STATUS (DDDS) frame. The DDDS frame may be a GTP-U (or F1-U) PDU.
[0067]
According to the operations of MN1, SN2 (CU21, source DU22A, and target DU22B) and UE3 described in this embodiment, conditional PSCell modification in which RRC signaling between SN2 and UE3 is performed via MN1. It is possible for SN2 to know that the execution condition is satisfied (or the start of conditional PSCell change). Although this embodiment has been described by taking the intra-CU inter-DU conditional PSCell Change procedure as an example, it can also be applied to or reused for the intra-CU intra-DU conditional PSCell Change procedure.
[0068]
In the present embodiment, as described in the first embodiment, the UE 3 will exit the conditional PSCell change (exit) if the condition (eg, offset) is satisfied or the validity timer described above has expired. If so, the termination information indicating that the conditional PSCell change was not performed (non-execution) or failed due to this may be transmitted to the SN2 (ie, CU21) via the MN1. For example, the UE 3 may operate as follows instead of the operation of step 608 in FIG. UE3 exits the conditional PSCell change mentioned above (e.g., If offset) is satisfied or the above-mentioned validity timer expires, an RRC (Connection) Reconfigurtion Complete message containing an RRC response message addressed to SN2 (ie, CU21) is sent to MN1 accordingly. May be good. In this case, the RRC (Connection) Reconfigurtion Complete or the included RRC response message addressed to SN2 (i.e., CU21) may include termination information indicating the failure or failure of the conditional PSCell change. Further, the CU 21 may send information to the target DU22B indicating that the conditional PS Cell change to the cell of the target DU22B has not been performed (or has failed). The CU 21 may send the information by CU To DU RRC Information IE or F1AP new IE. In response, the target DU22B may release the prepared candidate target cell settings and resources.
[0069]

The present embodiment provides another example of signaling for conditional PSCell Change. The configuration example of the wireless communication network according to the present embodiment may be the same as the example shown in FIG.
[0070]
In this embodiment, the SN2 sends an RRC message indicating the execution condition of the conditional PSCell change to the UE3 via the MN1. On the other hand, the SN2 displays the current (that is, before the change) PSCell (or SCG SCell) of the execution (or start) of the conditional PSCell change sent from the UE3 in response to the fulfillment of the execution condition of the conditional PSCell change. Receives directly from UE3 in.
[0071]
In this embodiment, the UE3 receives an RRC message indicating the execution condition of the conditional PSCell change from the SN2 via the MN1. On the other hand, in response to the fulfillment of the execution condition of the conditional PSCell change, the UE3 displays the execution (or start) of the conditional PSCell change directly to the SN2 in the current (that is, before the change) PSCell (or SCG SCell). To send.
[0072]
According to the operation of MN1, SN2, and UE3 described in the present embodiment, the execution condition of the conditional PSCell change in which the RRC signaling between SN2 and UE3 is performed via MN1 is satisfied (or the conditional PSCell change). It is possible for SN2 to know the start of).
[0073]
Further, in the present embodiment, the display of the execution (or start) of the conditional PSCell change is directly transmitted from the UE3 to the SN2 without going through the MN1. This avoids the delay caused by going through the MN1 and thus reduces the delay in sending the display from the UE3 to the SN2.
[0074]
The display of the execution (or start) of the conditional PSCell change may be transmitted using the signaling of the layer lower than the RRC layer. More specifically, the display may be transmitted using signaling at the MAC layer or the physical layer. The display may be Uplink Control Information (UCI) transmitted on the Physical Uplink Control Channel (PUCCH). Alternatively, the display may be a MAC Control Element (CE).
[0075]
Sending an indication of the execution (or initiation) of conditional mobility using signaling in layers below the RRC layer (eg, MAC layer, physical layer) is SN initiated SN Modification with MN involvement for conditional PSCell Change. This is especially useful in cases where the procedure is used. SN initiated SN Modification with MN involvement provides RRC signaling for conditional mobility (e.g., conditional PSCell change).
Sent via MCG SRB. Therefore, the transmission of RRC signaling from UE3 to SN2 causes a delay due to passing through MN1. In contrast, MAC or physical layer signaling from UE3 to SN2 can be transmitted directly to SN2 via the physical channel of the cell provided by SN2. Therefore, UE3 delays sending the display from UE3 to SN2 by transmitting a display of conditional mobility execution using signaling from layers below the RRC layer (eg, MAC layer, physical layer). Can be reduced.
[0076]
The SN2 may predetermine the setting of the radio resource used for displaying the execution (or start) of the conditional PSCell change, and notify the UE3 of this. The notification may be transmitted by RRC layer signaling performed via MN1.
[0077]
If there are multiple candidate target cells, the execution (or start) display of the conditional PSCell change explicitly or implicitly indicates the selected candidate target cell (that is, the candidate target cell for which the PSCell Change was triggered). Information may be included.
[0078]
The signaling of the present embodiment is not limited to this, but may be performed according to, for example, FIG. FIG. 7 shows an example of signaling for a conditional PS Cell Change. In the example of FIG. 7, MN1 (e.g., Master eNB (MeNB)) is involved in PS Cell Change in MR-DC. That is, in the example of FIG. 2, the RRC signaling transmitted between SN2 (eg, Secondary gNB (SgNB)) and UE3 for PSCell Change is SRB (eg, SRB1) in the MCG provided by MN1. To use.
[0079]
The processing of steps 701 and 702 in FIG. 7 is the same as that of steps 201 and 202 of FIG.
[0080] [0080]
In step 703, UE3 transmits an RRC message (e.g., LTE RRC Connection Reconfiguration Complete message) of MN RAT including an RRC response message (e.g., NR RRC Reconfiguration Complete message) of SN RAT addressed to SN2 to MN1.
[0081]
In step 704, MN1 responds to SN2 with an SN MODIFICATION CONFIRM message. The SN MODIFICATION CONFIRM message includes the SN RAT RRC response message (e.g., RRC Reconfiguration Complete message) received from UE3.
[0082]
UE3 maintains the current (that is, before the change) PSCell setting even after receiving the RRC message (step 702), and uses the PSCell. UE3 responds to the execution condition of the conditional PSCell change (ie, conditional Reconfiguration with sync) set by the RRC message of SN RAT (step 702) (step 705), and performs the conditional mobility (ie, conditional reconfiguration with sync). A display (or report) indicating the execution or start of a conditional PSCell Change) is sent directly to the SN2 in the current PSCell (or SCG SCell). As mentioned above, the transmission of the display (or report) may use signaling in a layer below the RRC layer (e.g., MAC layer, physical layer). Then, UE3 applies the new PSCell setting and starts access to the target PSCell (i.e., random access procedure).
[0083]
The SN2 may stop the downlink data transfer to the UE3 via the PSCell before the change in response to the reception of the display (or report) (step 706). In other words, the display (or report) from UE3 (step 706) may trigger SN2 to stop the downlink data transfer to UE3 via the PSCell before the change. This causes the SN2 to transmit data (downlink or uplink) for the UE3 in the current (that is, before the change) PSCell (and SCG SCell (s)) until just before the start (or execution) of the conditional PSCell change. , Or both) can be continued.
[0084]
In some implementations, the C-RAN configuration is applied to SN2 (eg, gNB), where SN2 (eg, gNB) is CU (eg, gNB-CU) and one or more DU (eg, gNB-DU). ) May be included. The conditional PSCell change in this embodiment may be applied to a PSCell change (e.g., intra-gNB-CU inter-gNB-DU PSCell change) between different DUs of SN2. In this case, UE3 will perform conditional mobility (ie, conditional PSCell Change) according to the execution condition of conditional PSCell change (ie, conditional Reconfiguration with sync) set by the RRC message of SN RAT. A display (or report) indicating execution or start may be sent directly to the source DU (eg, gNB-DU) in the current PSCell. The source DU (eg, gNB-DU) responds to the receipt of the indication (or report) to the CU (eg, gNB-CU) that conditional mobility has been performed or started in the UE. You may notify. The source DU (eg, gNB-DU) may make the notification in IE of the F1 message, or the RRC information (eg) contained in the RRC container (eg, DU To CU RRC Information) from CU to DU. , IE, message).
[0085]
Subsequently, in the following, configuration examples of MN1, SN2, SN2 and UE3 according to the above-mentioned plurality of embodiments will be described. FIG. 8 is a block diagram showing a configuration example of SN2 according to the above-described embodiment. The configuration of MN1 may be similar to the configuration shown in FIG. Referring to FIG. 8, SN2 includes a Radio Frequency transceiver 801, a network interface 803, a processor 804, and a memory 805. The RF transceiver 801 performs analog RF signal processing to communicate with UEs including UE3. The RF transceiver 801 may include a plurality of transceivers. The RF transceiver 801 is coupled with the antenna array 802 and the processor 804. The RF transceiver 801 receives the modulation symbol data from the processor 804, generates a transmit RF signal, and supplies the transmit RF signal to the antenna array 802. Further, the RF transceiver 801 generates a baseband reception signal based on the received RF signal received by the antenna array 802, and supplies the baseband reception signal to the processor 804. The RF transceiver 801 may include an analog beamformer circuit for beamforming. The analog beamformer circuit includes, for example, a plurality of phase shifters and a plurality of power amplifiers.
[0086]
The network interface 803 is used to communicate with network nodes (e.g., MN1, as well as control and transfer nodes of the core network). The network interface 803 is, for example, a network compliant with the IEEE 802.3 series. It may include a client interface card (NIC).
[0087]
The processor 804 performs digital baseband signal processing (data plane processing) and control plane processing for wireless communication. Processor 804 may include a plurality of processors. For example, the processor 804 may include a modem processor (eg, Digital Signal Processor (DSP)) that performs digital baseband signal processing and a protocol stack processor (eg, Central Processing Unit (CPU) or Micro Processing Unit (eg, Central Processing Unit (CPU)) that performs control plane processing. MPU)) may be included. Processor 804 may include a digital beamformer module for beamforming. The digital beamformer module may include a Multiple Input Multiple Output (MIMO) encoder and precoder.
[0088]
The memory 805 is composed of a combination of a volatile memory and a non-volatile memory. Volatile memory is, for example, Static Random Access Memory (SRAM) or Dynamic RAM (DRAM) or a combination thereof. Non-volatile memory can be masked Read Only Memory (MROM), Electrically Erasable Programmable ROM (EEPROM), flash memory, or hard disk drive, or any combination thereof. Memory 805 may include storage located away from processor 804. In this case, processor 804 may access memory 805 via network interface 803 or an I / O interface (not shown).
[0089]
The memory 805 may store one or more software modules (computer programs) 806 including instruction groups and data for performing processing by the SN2 described in the plurality of embodiments described above. In some implementations, the processor 804 may be configured to read the software module 806 from the memory 805 and execute it to perform the processing of the SN2 described in the embodiments described above.
[0090]
When the SN2 is a CU (e.g., eNB-CU or gNB-CU), the SN2 does not have to include the RF transceiver 801 (and the antenna array 802).
[0091]
FIG. 9 is a block diagram showing a configuration example of UE3. Radio Frequency (RF) transceiver 901 performs analog RF signal processing to communicate with MN1 and SN2. The RF transceiver 901 may include a plurality of transceivers. The analog RF signal processing performed by the RF transceiver 901 includes frequency up-conversion, frequency down-conversion, and amplification. The RF transceiver 901 is coupled with the antenna array 902 and the baseband processor 903. The RF transceiver 901 receives modulation symbol data (or OFDM symbol data) from the baseband processor 903, generates a transmit RF signal, and supplies the transmit RF signal to the antenna array 902. Further, the RF transceiver 901 generates a baseband reception signal based on the received RF signal received by the antenna array 902, and supplies the baseband reception signal to the baseband processor 903. The RF transceiver 901 may include an analog beamformer circuit for beamforming. The analog beamformer circuit includes, for example, a plurality of phase shifters and a plurality of power amplifiers.
[0092]
The baseband processor 903 performs digital baseband signal processing (data plane processing) and control plane processing for wireless communication. Digital baseband signal processing includes (a) data compression / restoration, (b) data segmentation / concatenation, (c) transmission format (transmission frame) generation / decomposition, and (d) transmission path coding / decoding. , (E) Modulation (symbol mapping) / demodulation, and (f) Generation of OFDM symbol data (baseband OFDM signal) by Inverse Fast Fourier Transform (IFFT). On the other hand, the control plane processing includes layer 1 (eg, transmission power control), layer 2 (eg, radio resource management, and hybrid automatic repeat request (HARQ) processing), and layer 3 (eg, attach, mobility, and call management). Includes communication management (signaling regarding).
[0093]
For example, digital baseband signal processing by the baseband processor 903 includes signal processing for the Service Data Adaptation Protocol (SDAP) layer, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, MAC layer, and PHY layer. It may be included. Further, the control plane processing by the baseband processor 903 may include the processing of the Non-Access Stratum (NAS) protocol, the RRC protocol, and the MAC CE.
[0094]
The baseband processor 903 may perform MIMO encoding and precoding for beamforming.
[0095]
The baseband processor 903 may include a modem processor (e.g., DSP) that performs digital baseband signal processing and a protocol stack processor (e.g., CPU or MPU) that performs control plane processing. In this case, the protocol stack processor that performs the control plane processing may be shared with the application processor 904 described later.
[0096]
The application processor 904 is also called a CPU, MPU, microprocessor, or processor core. The application processor 904 may include a plurality of processors (a plurality of processor cores). The application processor 904 is a system software program (Operating System (OS)) read from memory 906 or a memory (not shown) and various application programs (eg, call application, web browser, mailer, camera operation application, music playback). By executing the application), various functions of UE3 are realized.
[0097]
In some implementations, the baseband processor 903 and the application processor 904 may be integrated on one chip, as shown by the dashed line (905) in FIG. In other words, the baseband processor 903 and application processor 904 may be implemented as one System on Chip (SoC) device 905. SoC devices are sometimes referred to as system Large Scale Integration (LSI) or chipsets.
[0098]
The memory 906 is a volatile memory, a non-volatile memory, or a combination thereof. The memory 906 may include a plurality of physically independent memory devices. Volatile memory is, for example, SRAM or DRAM or a combination thereof. Non-volatile memory can be MROM, EEPROM, flash memory, or a hard disk drive, or any combination thereof. For example, memory 906 may include external memory devices accessible from baseband processor 903, application processor 904, and SoC 905. The memory 906 may include an internal memory device integrated in the baseband processor 903, the application processor 904, or the SoC 905. Further, the memory 906 may include a memory in a Universal Integrated Circuit Card (UICC).
[0099]
The memory 906 may store one or more software modules (computer programs) 907 including instruction groups and data for performing processing by the UE 3 described in the plurality of embodiments described above. In some implementations, the baseband processor 903 or application processor 904 is configured to read the software module 907 from memory 906 and execute it to perform the processing of UE3 described with reference to the drawings in the above embodiments. May be done.
[0100]
It should be noted that the control plane processing and operation performed by the UE 3 described in the above-described embodiment is performed by other elements other than the RF transceiver 901 and the antenna array 902, that is, at least one of the baseband processor 903 and the application processor 904, and the software module 907. It can be realized by the memory 906 that stores the above.
[0101]
As described with reference to FIGS. 8 and 9, each of the processors included in the MN1, SN2, and UE3 according to the above-described embodiment provides instructions for causing the computer to perform the algorithm described with reference to the drawings. Execute one or more programs including. This program can be stored and supplied to a computer using various types of non-transitory computer readable medium. Non-temporary computer-readable media include various types of tangible storage media. Examples of non-temporary computer readable media are magnetic recording media (eg flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (eg magneto-optical disks), Compact Disc Read Only Memory (CD-ROM), CD- Includes R, CD-R / W, semiconductor memory (eg, mask ROM, Programmable ROM (PROM), Erasable PROM (EPROM), flash ROM, Random Access Memory (RAM)). The program may also be supplied to the computer by various types of transient computer readable medium. Examples of temporary computer-readable media include electrical, optical, and electromagnetic waves. The temporary computer-readable medium can supply the program to the computer via a wired communication path such as an electric wire and an optical fiber, or a wireless communication path.
[0102]

The above-described embodiments may be implemented independently, or the whole embodiment or a part thereof may be combined as appropriate. For example, the third embodiment can be implemented independently of the first and second embodiments, and contributes to solving a purpose or problem different from that of the first and second embodiments. It contributes to the effect different from that of the first and second embodiments.
[0103]
Functions described as Conditional PSCell change in the above embodiments are referred to as pre-conditioned PSCell change, prepared PSCell change, delayed PSCell change, and the like. You may.
[0104]
In the above embodiment, UE3 is an RRC message (e.g., NR) of SN RAT (e.g., NR) received by an RRC message (e.g., LTE RRCConnectionReconfiguration) of MN RAT (e.g., LTE). The generation and transmission of the RRC message (e.g., RRCReconfigurationComplete) in response to NR RRCReconfiguration) may be executed as follows. When the RRC layer of MN RAT of UE3 detects that the RRC message of SN RAT is included in the RRC message of MN RAT, it passes it to the RRC layer of SN RAT. When the RRC layer of the SN RAT of UE3 decodes the RRC message of the SN RAT and detects that it is a conditional PSCell change, it determines whether or not the execution condition for the conditional PSCell change is satisfied. The RRC layer of SN RAT generates a response RRC message (e.g., RRCReconfigurationComplete) of SN RAT and passes it to the RRC layer of MN RAT when the execution condition for conditional PSCell change is satisfied. The RRC layer of MN RAT generates an RRC message (e.g., RRCConnectionReconfigurationComplete) of MN RAT including a response RRC message passed from the RRC layer of SN RAT, and sends this to MN1. Then, MN1 transfers the response RRC message of SN RAT to SN2.
[0105]
On the other hand, in the RRC layer of SN RAT of UE3, the conditional PSCell change did not end successfully when the condition to exit the conditional PSCell change was met or the validity timer expired. A response RRC message (eg, RRCReconfigurationComplete) containing information indicating may be generated and passed to the RRC layer of MN RAT. The RRC layer of MN RAT generates an RRC message (e.g., RRCConnectionReconfigurationComplete) of MN RAT including a response RRC message passed from the RRC layer of SN RAT, and sends this to MN1. Then, MN1 transfers the response RRC message of SN RAT to SN2. When there are multiple candidate target cells (that is, when there are multiple candidates for the target PSCell), the RRC layer of SN RAT is when the condition for leaving the conditional PSCell change for any one candidate target cell is satisfied. This operation may be performed when the valid timer has expired. Alternatively, the RRC layer of the SN RAT may perform this operation when the conditions for leaving the conditional PSCell change for all candidate target cells are met or when the valid timer expires.
[0106]
In the conditional PSCell change in the above-described embodiment, the UE 3 may handle the timer T30x related to the conditional PS Cell change as follows. In a normal PS Cell change, the UE 3 starts the timer T304 when it receives an RRC message (e.g., RRC Reconfiguration including reconfigurationWithSync) instructing the PS Cell change. Instead, in conditional PSCell change, UE3 does not have to start the timer T30x immediately even if it receives an RRC message (eg, RRC Reconfiguration including reconfigurationWithSync for Conditional PSCell change) instructing conditional PSCell change. .. When the condition of conditional PSCell change for a candidate target cell is satisfied, UE3 starts the timer T30x corresponding to the candidate target cell. Then, the UE 3 stops the timer T30x when the random access in the candidate target cell (e.g., SpCell) is successful. The conventional T304 may be used as the T30x, or a new timer may be specified as the T30x.
[0107]
The wireless terminal (User Equipment (UE)) in the present specification is an entity connected to a network via a wireless interface. The wireless terminal (UE) of the present specification is not limited to a dedicated communication device, and is any device as follows having the communication function of the wireless terminal (UE) described in the present specification. You may.
[0108]
"User equipment (UE)" (as a word used in 3GPP), "mobile station", "mobile terminal", "mobile device", and "mobile device" The terms "wireless device" are generally intended to be synonymous with each other. The UE may be a stand-alone mobile station such as a terminal, mobile phone, smartphone, tablet, cellular IoT terminal, IoT device, and the like. The terms "UE" and "wireless terminal" also include devices that are stationary for extended periods of time.
[0109]
UE is, for example, production equipment / manufacturing equipment and / or energy related machinery (for example, boilers, engines, turbines, solar panels, wind power generators, hydroelectric generators, thermal power generators, nuclear power generators, storage batteries, nuclear systems, etc. Nuclear-related equipment, heavy electrical equipment, pumps including vacuum pumps, compressors, fans, blowers, hydraulic equipment, pneumatic equipment, metal processing machines, manipulators, robots, robot application systems, transport equipment, lifting equipment, cargo handling equipment, etc. Textile machinery, sewing machinery, printing machinery, printing-related machinery, paperworking machinery, chemical machinery, mining machinery, mining-related machinery, construction machinery, construction-related machinery, agricultural machinery and / or equipment, forestry machinery and / or equipment, fishing Machines and / or equipment, safety and / or environmental protection equipment, tractors, power transmissions, and / or application systems of any equipment or machine mentioned above).
[0110]
UE is, for example, transportation equipment (for example, vehicles, automobiles, two-wheeled vehicles, bicycles, trains, buses, rear cars, rickshaws, ships and other watercraft, airplanes, rockets, artificial satellites, drones, balloons, etc.) There may be.
[0111]
The UE may be, for example, an information communication device (for example, a computer and related devices, a communication device and related devices, electronic components, etc.).
[0112]
UEs are, for example, commercial and service equipment, vending machines, automatic service machines, office machinery and equipment, consumer electrical and electronic machinery (eg audio equipment, speakers, radios, video equipment, televisions, etc.). You may.
[0113]
The UE may be, for example, an electronic application system or an electronic application device (for example, an X-ray device, a particle accelerator, a radioactive material application device, a sound wave application device, an electromagnetic application device, a power application device, etc.).
[0114]
UEs are, for example, light bulbs, lighting, weighing machines, analyzers, testing machines and measuring machines (for example, smoke alarms, personal alarm sensors, motion sensors, wireless tags, etc.), watches or clocks, physics and chemistry machines, etc. It may be an optical machine, a medical device and / or a medical system, a weapon, a clockwork tool, or a hand tool.
[0115]
The UE is, for example, a personal digital assistant or device with wireless communication capabilities (for example, an electronic device to which or is configured to install or insert a wireless card, wireless module, etc. (eg, personal computer, electronic measuring instrument, etc.)). ) May be.
[0116]
The UE may be, for example, a device or a part thereof that provides the following applications, services, and solutions in the "Internet of Things (IoT)" using wired or wireless communication technology. IoT devices (or things) include suitable electronics, software, sensors, network connections, etc. that allow devices to collect and exchange data with each other and with other communication devices. The IoT device may be an automated device that complies with software directives stored in internal memory. IoT devices may operate without the need for human supervision or response. The IoT device may remain inactive for a long period of time and / or for a long period of time. IoT devices can be implemented as part of a stationary device. IoT devices can be embedded in non-stationary devices (eg vehicles) or attached to animals or people that are monitored / tracked. IoT technology can be implemented on any communication device that can be connected to a communication network that sends and receives data regardless of human input control or software instructions stored in memory. IoT devices are sometimes referred to as Machine Type Communication (MTC) devices, or Machine to Machine (M2M) communication devices, Narrow Band-IoT (NB-IoT) UEs.
[0117]
The UE may support one or more IoT or MTC applications.
[0118]
Some examples of MTC applications are listed in the list shown in 3GPP TS22.368 V13.2.0 (2017-01-13) Annex B (whose content is incorporated herein by reference). This list is not exhaustive and shows an example MTC application. In this list, the Service Areas for MTC applications are Security, Tracking & Tracing, Payment, Health, Remote Maintenance / Control, Includes Metering and Consumer Devices.
[0119]
Examples of security MTC applications are Surveillance systems, Landline Backup for landline, Control of physical access (eg to buildings), and vehicles. / Includes Car / driver security.
[0120]
Examples of MTC applications for tracking and tracing are Fleet Management, Order Management, Telematics Insurance: Pay as you drive (PAYD), Asset Tracking, Navigation. Includes Navigation, Traffic information, Road tolling, and Road traffic optimisation / steering.
[0121]
Examples of MTC applications for payments include point of sale (POS), vending machines, and Gaming machines.
[0122]
Ken Examples of MTC applications for Yasushi are Monitoring vital signs, Supporting the aged or handicapped, Web Access Telemedicine points, and Remote diagnostics. including.
[0123]
Examples of MTC applications for remote maintenance / control are Sensors, Lighting, Pumps, Valves, Elevator control, Vending machine control, and vehicles. Includes Vehicle diagnostics.
[0124]
Examples of MTC applications related to weighing are Power and Gas.
Includes Water, Heating, Grid control, and Industrial metering.
[0125]
Examples of MTC applications for consumer devices include digital photo frames, digital cameras, and ebooks.
[0126]
Applications, services, and solutions include, for example, MVNO (Mobile Virtual Network Operator) services / systems, disaster prevention wireless services / systems, and on-site wireless telephone (PBX (Private Branch eXchange)) services. / System, PHS / Digital Cordless Telephone Service / System, Point of sales (POS) System, Advertisement Transmission Service / System, Multimedia Broadcast and Multicast Service (MBMS) Service / System, V2X (Vehicle to Everything: Vehicle-to-Vehicle Communication) And road-to-vehicle / pedestrian communication) services / systems, in-train mobile wireless services / systems, location information-related services / systems, disaster / emergency wireless communication services / systems, IoT (Internet of Things) services / systems , Community service / system, video distribution service / system, Femto cell application service / system, VoLTE (Voice over LTE) service / system, wireless tag service / system, billing service / system, radio on-demand service / system, roaming service / System, user behavior monitoring service / system, communication carrier / communication NW selection service / system, function restriction service / system, PoC (Proof of Concept) service / system, personal information management service / system for terminals, display / video for terminals It may be a service / system, a non-communication service / system for terminals, an ad hoc NW / DTN (Delay Tolerant Networking) service / system, or the like.
[0127]
The UE category described above is merely an application example of the technical idea and embodiment described in the present specification. The UEs herein are not limited to these examples, and one of ordinary skill in the art may make various modifications to them.
[0128]
Furthermore, the above-described embodiment is merely an example relating to the application of the technical idea obtained by the inventor of the present invention. That is, the technical idea is not limited to the above-described embodiment, and it goes without saying that various changes can be made.
[0129]
For example, some or all of the above embodiments may be described as in the following appendix, but are not limited to the following.
[0130]
(Appendix 1)
At least one memory and
With at least one processor coupled to the at least one memory,
Equipped with
The at least one processor is
Operates as a dual connectivity secondary node for wireless terminals,
The first Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is sent through the master node of the dual connectivity. Send to wireless terminal,
The second RRC message sent from the wireless terminal in response to the establishment of the execution condition is received from the wireless terminal via the master node.
Is configured as
Radio access network node.
[0131]
(Appendix 2)
The at least one processor is configured to detect the start of the conditional primary cell change upon receiving the second RRC message.
The radio access network node according to Appendix 1.
[0132]
(Appendix 3)
The at least one processor is configured to stop downlink data transfer to the wireless terminal in the serving cell of the secondary cell group in response to receiving the second RRC message.
The radio access network node according to Appendix 1 or 2.
[0133]
(Appendix 4)
The radio access network node is the central unit of the base station.
The at least one processor is configured to stop downlink data transfer to the radio terminal via the first distributed unit providing the first cell in response to receiving the second RRC message. NS,
The radio access network node according to any one of Supplementary note 1 to 3.
[0134]
(Appendix 5)
The at least one processor further responds to receiving a control message from the first distributed unit indicating downlink data that has not been transmitted to the radio terminal prior to receiving the second RRC message. Then, the downlink data transfer to the wireless terminal via the first distributed unit is configured to be stopped.
The radio access network node according to Appendix 4.
[0135]
(Appendix 6)
The control message is a DOWNLINK DATA DELIVERY STATUS frame,
The radio access network node according to Appendix 5.
[0136]
(Appendix 7)
It is a wireless terminal
At least one memory and
With at least one processor coupled to the at least one memory,
Equipped with
The at least one processor is
Perform dual connectivity of the master cell group associated with the master node and the secondary cell group associated with the secondary node.
A first Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is sent from the secondary node via the master node. Receive and
In response to the establishment of the execution condition, a second RRC message is transmitted from the wireless terminal to the secondary node via the master node.
Is configured as
Wireless terminal.
[0137]
(Appendix 8)
The second RRC message triggers the secondary node to stop the downlink data transfer to the wireless terminal in the serving cell of the secondary cell group.
The wireless terminal described in Appendix 7.
[0138]
(Appendix 9)
A method for radio access network nodes
Acting as a dual connectivity secondary node for wireless terminals,
The first Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is sent through the master node of the dual connectivity. Sending to a wireless terminal and
Receiving a second RRC message sent from the wireless terminal from the wireless terminal via the master node in response to the establishment of the execution condition.
How to prepare.
[0139]
(Appendix 10)
It is a method for wireless terminals,
Perform dual connectivity of the master cell group associated with the master node and the secondary cell group associated with the secondary node,
A first Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is sent from the secondary node via the master node. To receive and
In response to the fulfillment of the execution condition, the second RRC message is transmitted from the wireless terminal to the secondary node via the master node.
How to prepare.
[0140]
(Appendix 11)
A program that lets a computer do the method for a radio access network node,
The above method is
Acting as a dual connectivity secondary node for wireless terminals,
The first Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is sent through the master node of the dual connectivity. Sending to a wireless terminal and
Receiving a second RRC message sent from the wireless terminal from the wireless terminal via the master node in response to the establishment of the execution condition.
To prepare
program.
[0141]
(Appendix 12)
It is a program to make a computer do the method for wireless terminals.
The above method is
Perform dual connectivity of the master cell group associated with the master node and the secondary cell group associated with the secondary node,
A first Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is sent from the secondary node via the master node. To receive and
In response to the fulfillment of the execution condition, the second RRC message is transmitted from the wireless terminal to the secondary node via the master node.
To prepare
program.
[0142]
(Appendix 13)
At least one memory and
With at least one processor coupled to the at least one memory,
Equipped with
The at least one processor is
Operates as a dual connectivity secondary node for wireless terminals,
A Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is sent to the wireless terminal via the master node of the dual connectivity. Send and
The display of the execution or start of the conditional primary cell change sent from the wireless terminal in response to the establishment of the execution condition is displayed from the wireless terminal in the secondary cell of either the first cell or the secondary cell group. Receive directly,
Is configured as
Radio access network node.
[0143]
(Appendix 14)
The display is transmitted using signaling in a layer below the RRC layer.
The radio access network node according to Appendix 13.
[0144]
(Appendix 15)
The signaling is a medium access control (MAC) layer or physical layer signaling.
Radio a. Access network node.
[0145]
(Appendix 16)
It is a wireless terminal
At least one memory and
With at least one processor coupled to the at least one memory,
Equipped with
The at least one processor is
Perform dual connectivity of the master cell group associated with the master node and the secondary cell group associated with the secondary node.
A Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is received from the secondary node via the master node.
In response to the fulfillment of the execution condition, an indication of execution or start of the conditional primary cell change is transmitted directly to the secondary node in either the secondary cell of the first cell or the secondary cell group. ,
Is configured as
Wireless terminal.
[0146]
(Appendix 17)
The at least one processor is configured to transmit the display using signaling in a layer below the RRC layer.
The wireless terminal according to Appendix 16.
[0147]
(Appendix 18)
The signaling is a medium access control (MAC) layer or physical layer signaling.
The wireless terminal according to Appendix 17.
[0148]
(Appendix 19)
The secondary node includes a central unit and one or more distributed units.
The at least one processor is configured to receive the RRC message from the central unit via the master node.
The at least one processor is configured to transmit the indication in the first cell to one of the one or more distributed units.
The wireless terminal according to any one of Supplementary Provisions 16 to 18.
[0149]
(Appendix 20)
A method for radio access network nodes
Acting as a dual connectivity secondary node for wireless terminals,
A Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is sent to the wireless terminal via the master node of the dual connectivity. Sending and
The display of the execution or start of the conditional primary cell change sent from the wireless terminal in response to the establishment of the execution condition is displayed from the wireless terminal in the secondary cell of either the first cell or the secondary cell group. To receive directly,
How to prepare.
[0150]
(Appendix 21)
It is a method for wireless terminals,
Perform dual connectivity of the master cell group associated with the master node and the secondary cell group associated with the secondary node,
To receive a Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell from the secondary node via the master node. ,as well as
In response to the fulfillment of the execution condition, an indication of execution or start of the conditional primary cell change is transmitted directly to the secondary node in either the secondary cell of the first cell or the secondary cell group. matter,
How to prepare.
[0151]
(Appendix 22)
A program that lets a computer do the method for a radio access network node,
The above method is
Acting as a dual connectivity secondary node for wireless terminals,
A Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is sent to the wireless terminal via the master node of the dual connectivity. Sending and
The display of the execution or start of the conditional primary cell change sent from the wireless terminal in response to the establishment of the execution condition is displayed from the wireless terminal in the secondary cell of either the first cell or the secondary cell group. To receive directly,
To prepare
program.
[0152]
(Appendix 23)
It is a program to make a computer do the method for wireless terminals.
The above method is
Perform dual connectivity of the master cell group associated with the master node and the secondary cell group associated with the secondary node,
To receive a Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell from the secondary node via the master node. ,as well as
In response to the fulfillment of the execution condition, an indication of execution or start of the conditional primary cell change is transmitted directly to the secondary node in either the secondary cell of the first cell or the secondary cell group. matter,
To prepare
program.
[0153]
This application claims priority based on Japanese application Japanese Patent Application No. 2019-003563 filed on January 11, 2019, and incorporates all of its disclosures herein.
Description of the sign
[0154]
1 Master Node (MN)
2 Secondary node (SN)
3 User Equipment (UE)
21 Central Unit (CU)
22 Distributed Unit (DU)
804 processor
805 memory
806 modules
903 baseband processor
904 application processor
906 memory
907 modules
The scope of the claims
[Claim 1]
At least one memory and
With at least one processor coupled to the at least one memory,
Equipped with
The at least one processor is
Operates as a dual connectivity secondary node for wireless terminals,
The first Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is sent through the master node of the dual connectivity. Send to wireless terminal,
The second RRC message sent from the wireless terminal in response to the establishment of the execution condition is received from the wireless terminal via the master node.
Is configured as
Radio access network node.
[Claim 2]
The at least one processor is configured to detect the start of the conditional primary cell change upon receiving the second RRC message.
The radio access network node according to claim 1.
[Claim 3]
The at least one processor is configured to stop downlink data transfer to the wireless terminal in the serving cell of the secondary cell group in response to receiving the second RRC message.
The radio access network node according to claim 1 or 2.
[Claim 4]
The radio access network node is the central unit of the base station.
The at least one processor is configured to stop downlink data transfer to the radio terminal via the first distributed unit providing the first cell in response to receiving the second RRC message. NS,
The radio access network node according to any one of claims 1 to 3.
[Claim 5]
The at least one processor further responds to receiving a control message from the first distributed unit indicating downlink data that has not been transmitted to the radio terminal prior to receiving the second RRC message. Then, the downlink data transfer to the wireless terminal via the first distributed unit is configured to be stopped.
The radio access network node according to claim 4.
[Claim 6]
The control message is a DOWNLINK DATA DELIVERY STATUS frame,
The radio access network node according to claim 5.
[Claim 7]
It is a wireless terminal
At least one memory and
With at least one processor coupled to the at least one memory,
Equipped with
The at least one processor is
Perform dual connectivity of the master cell group associated with the master node and the secondary cell group associated with the secondary node.
A first Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is sent from the secondary node via the master node. Receive and
In response to the establishment of the execution condition, a second RRC message is transmitted from the wireless terminal to the secondary node via the master node.
Is configured as
Wireless terminal.
[Claim 8]
The second RRC message triggers the secondary node to stop the downlink data transfer to the wireless terminal in the serving cell of the secondary cell group.
The wireless terminal according to claim 7.
[Claim 9]
A method for radio access network nodes
Acting as a dual connectivity secondary node for wireless terminals,
The first Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is sent through the master node of the dual connectivity. Sending to a wireless terminal and
Receiving a second RRC message sent from the wireless terminal from the wireless terminal via the master node in response to the establishment of the execution condition.
How to prepare.
[Claim 10]
It is a method for wireless terminals,
Perform dual connectivity of the master cell group associated with the master node and the secondary cell group associated with the secondary node,
A first Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is sent from the secondary node via the master node. To receive and
In response to the fulfillment of the execution condition, the second RRC message is transmitted from the wireless terminal to the secondary node via the master node.
How to prepare.
[Claim 11]
A non-temporary computer-readable medium containing a program that allows a computer to perform methods for radio access network nodes.
The above method is
Acting as a dual connectivity secondary node for wireless terminals,
The first Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is sent through the master node of the dual connectivity. Sending to a wireless terminal and
Receiving a second RRC message sent from the wireless terminal from the wireless terminal via the master node in response to the establishment of the execution condition. To prepare
Non-temporary computer-readable medium.
[Claim 12]
A non-temporary computer-readable medium containing a program that allows a computer to perform methods for wireless terminals.
The above method is
Perform dual connectivity of the master cell group associated with the master node and the secondary cell group associated with the secondary node,
A first Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is sent from the secondary node via the master node. To receive and
In response to the fulfillment of the execution condition, the second RRC message is transmitted from the wireless terminal to the secondary node via the master node.
To prepare
Non-temporary computer-readable medium.
[Claim 13]
At least one memory and
With at least one processor coupled to the at least one memory,
Equipped with
The at least one processor is
Operates as a dual connectivity secondary node for wireless terminals,
A Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is sent to the wireless terminal via the master node of the dual connectivity. Send and
The display of the execution or start of the conditional primary cell change sent from the wireless terminal in response to the establishment of the execution condition is displayed from the wireless terminal in the secondary cell of either the first cell or the secondary cell group. Receive directly,
Is configured as
Radio access network node.
[Claim 14]
The display is transmitted using signaling in a layer below the RRC layer.
The radio access network node according to claim 13.
[Claim 15]
The signaling is a medium access control (MAC) layer or physical layer signaling.
The radio access network node according to claim 14.
[Claim 16]
It is a wireless terminal
At least one memory and
With at least one processor coupled to the at least one memory,
Equipped with
The at least one processor is
Perform dual connectivity of the master cell group associated with the master node and the secondary cell group associated with the secondary node.
A Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is received from the secondary node via the master node.
In response to the fulfillment of the execution condition, an indication of execution or start of the conditional primary cell change is transmitted directly to the secondary node in either the secondary cell of the first cell or the secondary cell group. ,
Is configured as
Wireless terminal.
[Claim 17]
The at least one processor is configured to transmit the display using signaling in a layer below the RRC layer.
The wireless terminal according to claim 16.
[Claim 18]
The signaling is a medium access control (MAC) layer or physical layer signaling.
The wireless terminal according to claim 17.
[Claim 19]
The secondary node includes a central unit and one or more distributed units.
The at least one processor is configured to receive the RRC message from the central unit via the master node.
The at least one processor is configured to transmit the indication to one of the one or more distributed units in either the first cell or the secondary cell of the secondary cell group.
The wireless terminal according to any one of claims 16 to 18.
[Claim 20]
A method for radio access network nodes
Acting as a dual connectivity secondary node for wireless terminals,
A Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is sent to the wireless terminal via the master node of the dual connectivity. Sending and
The display of the execution or start of the conditional primary cell change sent from the wireless terminal in response to the establishment of the execution condition is displayed from the wireless terminal in the secondary cell of either the first cell or the secondary cell group. To receive directly,
How to prepare.
[Claim 21]
It is a method for wireless terminals,
Perform dual connectivity of the master cell group associated with the master node and the secondary cell group associated with the secondary node,
To receive a Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell from the secondary node via the master node. ,as well as
In response to the fulfillment of the execution condition, an indication of execution or start of the conditional primary cell change is transmitted directly to the secondary node in either the secondary cell of the first cell or the secondary cell group. matter,
How to prepare.
[Claim 22]
A non-temporary computer-readable medium containing a program that allows a computer to perform methods for radio access network nodes.
The above method is
Acting as a dual connectivity secondary node for wireless terminals,
A Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell is sent to the wireless terminal via the master node of the dual connectivity. Sending and
The display of the execution or start of the conditional primary cell change sent from the wireless terminal in response to the establishment of the execution condition is displayed from the wireless terminal in the secondary cell of either the first cell or the secondary cell group. To receive directly,
To prepare
Non-temporary computer-readable medium.
[Claim 23]
A non-temporary computer-readable medium containing a program that allows a computer to perform methods for wireless terminals.
The above method is
Perform dual connectivity of the master cell group associated with the master node and the secondary cell group associated with the secondary node,
To receive a Radio Resource Control (RRC) message indicating the execution condition of the conditional primary cell change of the primary cell of the secondary cell group from the first cell to the second cell from the secondary node via the master node. ,as well as
In response to the fulfillment of the execution condition, an indication of execution or start of the conditional primary cell change is transmitted directly to the secondary node in either the secondary cell of the first cell or the secondary cell group. matter,
To prepare
Non-temporary computer-readable medium.