Radio access network node and method thereof

Abstract

To provide improved signaling for mobility related or dual connectivity related procedures.SOLUTION: A first RAN node sends planned path information indicating a plurality of planned locations of a UserEquipment (UE) to a second RAN node in a mobility-related procedure or a dual connectivity-related procedure for the UE.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to wireless communication systems, and more particularly to signaling between radio access network nodes regarding mobility or dual connectivity for wireless terminals. [Background technology]

[0002] 3rd Generation Partnership Project (3GPP®) Release 15 and later supports aerial User Equipment (UE) communications (see, for example, Non-Patent Documents 1-4). As described in Section 23.17 of Non-Patent Document 1, in the current 3GPP specifications, an Evolved Universal Terrestrial Radio Access Network (EUTRAN) based mechanism for providing Long Term Evolution (LTE) connectivity to aerial-capable UEs is supported through the following functionalities: Subscription-based aerial UE identification and authorization; Height reporting in the event that the UE's altitude exceeds a network-configured reference altitude threshold; Interference detection based on measurement reports that is triggered when a set number of cells (i.e., greater than one) simultaneously meet the trigger criteria; Signaling flight path information from the UE to the E-UTRAN, Location information reporting, including the UE's horizontal and vertical velocity.

[0003] Regarding flight path information signaling, E-UTRAN can request the UE to report flight path information including multiple waypoints defined as three-dimensional (3D) locations. If the flight path information is available at the UE, the UE reports up to the number of waypoints configured in the request. If configured in the request and available at the UE, the report can include a timestamp for each waypoint.

[0004] Section 4.3.31 of 3GPP TS 2013-11-14 specifies the following: An eNodeB that supports handling of the aerial UE function uses per-user information provided by the Mobility Management Entity (MME) to determine whether to allow a UE to use the aerial UE function. Support for the aerial UE function is stored in the user's subscription information of the Home Subscriber Server (HSS). The HSS forwards this information to the MME in an Update Location message during attach and tracking area update procedures. A home operator can revoke a user's subscription authorization to operate aerial UEs at any time. An MME that supports the aerial UE function provides the eNodeB with user subscription information regarding aerial UE authorization via an S1 AP Initial Context Setup Request during attach, tracking area update, and service request procedures.

[0005] For S1-based handovers within and between MMEs (intra RAT) or inter-RAT handovers to E-UTRAN, the user's aerial UE subscription information is included in the S1 Application Protocol (S1AP) UE Context Modification Request message sent to the target eNodeB after the handover procedure. On the other hand, for X2-based handovers, the user's aerial UE subscription information is sent to the target eNodeB as follows: If the source eNodeB supports the aerial UE function and the user's aerial UE subscription information is included in the UE context, the source eNodeB must include this information in the X2AP Handover Request message to the target eNodeB. The MME must send the aerial UE subscription information to the target eNodeB in the S1AP Path Switch Request Acknowledge message.

[0006] If the aerial UE subscription information is changed, the updated aerial UE subscription information is included in the S1AP UE Context Modification Request message sent from the MME to the eNodeB.

[0007] Sections 5.3.3, 5.3.5, 5.3.7, and 5.6.5 of Non-Patent Document 3 specify the following: If the UE has flight path information available, the UE shall inform E-UTRTAN of the availability of flight path information in a Radio Resource Control (RRC) connection establishment, RRC connection reconfiguration, or RRC connection re-establishment. Specifically, the UE may include the flightPathInfoAvailable field set to the value true in an RRC Connection Setup Complete message, an RRC Connection Resume Complete message, an RRC Connection Reconfiguration Complete message, and an RRC Connection Reestablishment Complete message.

[0008] The E-UTRTAN can use the UE Information procedure to request the UE to report information. Specifically, the E-UTRTAN can send a UE Information Request message including a flightPathInfoReq field to the UE. The flightPathInfoReq field indicates a FlightPathInfoReportConfig information element (IE). The FlightPathInfoReportConfig IE indicates the maximum number of waypoints that the UE can include in a flight path information report. Furthermore, the FlightPathInfoReportConfig IE optionally indicates whether a timestamp for each waypoint can be reported in the flight path information report if timestamp information is available in the UE. To this end, the FlightPathInfoReportConfig IE includes the maxWayPointNumber and includeTimeStamp fields.

[0009] If the flightPathInfoReq field is present in the UE Information Request message and the UE has available flight path information, the UE includes the flightPathInfoReport field in a UE Information Response message and sends the UE Information Response message to E-UTRTAN. The flightPathInfoReport field contains a FlightPathInfoReport IE. The FlightPathInfoReport IE indicates a sequence of WayPointLocation IEs. The WayPointLocation IE contains a wayPointLocation field and, optionally, a timeStamp field. The wayPointLocation field contains UE location coordinates for Aerial UE operations. Waypoints describe the planned (or scheduled) locations of the UE. The timeStamp field contains waypoint time stamps that indicate the UE's planned locations.

[0010] Non-Patent Document 4 specifies the following: Section 8.2.1.2 states that if the Aerial UE subscription information IE is included in an X2AP Handover Request message received from the source eNB, the target eNB must store this information in the UE context, if supported, and use it as defined in 3GPP TS 36.300 (Non-Patent Document 1). Section 9.1.1.1 states that the Handover Request message optionally includes the Aerial UE subscription information IE. Section 9.2.129 states that the Aerial UE subscription information IE is used by the eNodeB (eNB) to know whether the UE is allowed to use the aerial UE function. In addition, it states that the Aerial UE subscription information IE is an enumerated type and indicates "allowed" or "not allowed."

[0011] 3GPP Release 18 is expected to support similar functions to those described above in order to provide New Radio (NR) communications to aerial UEs (see, for example, Non-Patent Document 5).

[0012] Patent Document 1 describes handover of a mobile station (UE). More specifically, in the handover described in Patent Document 1, a target control device (e.g., a base station, eNodeB) receives a request message from a source control device indicating a target cell as a handover destination of the UE. If the handover request to the target cell is not permitted, the target control device can return a handover acknowledgement message to the source control device indicating another cell that can accept the handover and is different from the target cell. In other words, the target control device informs the source control device via the handover acknowledgement message that it can accept a handover to a cell that is not specified in the handover request message from the source control device. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] International Publication No. 2011 / 018890 [Non-patent literature]

[0014] [Non-Patent Document 1] 3GPP TS 36.300 V17.0.0 (2022-03), "3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 17)", April 2022 [Non-patent document 2] 3GPP TS 23.401 V17.5.0 (2022-06), "3rd Generation Partnership Project; Technical Specification Group Services and System Aspects; General Packet Radio Service (GPRS) enhancements for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) access (Release 17)", June 2022 [Non-Patent Document 3] 3GPP TS 36.331 V17.0.0 (2022-03), "3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specification (Release 17)", April, 2022 [Non-Patent Document 4] 3GPP TS 36.423 V17.1.0 (2022-06), "3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access Network (E-UTRAN); X2 application protocol (X2AP) (Release 17)", June 2022 [Non-Patent Document 5] Nokia, "New WID on NR support for UAV (Uncrewed Aerial Vehicles)", RP-213600, 3GPP TSG-RAN Meeting #94e, December 6-17, 2021 Summary of the Invention [Problem to be solved by the invention]

[0015] The inventors have investigated the mobility of aerial UEs and dual connectivity for aerial UEs and found various problems. One problem is that the current 3GPP specifications do not specify that a source Radio Access Network (RAN) node provides flight path information to a target RAN node in a UE mobility-related procedure. Similarly, the current 3GPP specifications do not specify that a Master Node (MN) provides flight path information to a Secondary Node (SN), or vice versa, in a dual connectivity-related procedure.

[0016] Here, UE mobility may be, but is not limited to, handover or conditional handover. UE mobility may be dual connectivity inter-MN handover, Master Node to eNB / gNB Change, or eNB / gNB to Master Node Change. Dual connectivity-related procedures may be, but are not limited to, an SN addition procedure, a conditional SN addition procedure, an SN change procedure, or a conditional SN change procedure. The (conditional) SN addition procedure may also be referred to as a (conditional) Primary Secondary Cell Group (SCG) Cell (PSCell) addition procedure. Similarly, the (conditional) SN change procedure may also be referred to as a (conditional) inter-SN PSCell change procedure. The above-mentioned dual connectivity-related procedures involve the addition or change of one or more serving cells of a UE, and therefore can be broadly considered to be included in UE mobility. Therefore, as defined herein, the term mobility or mobility-related procedures may refer collectively to handover procedures and the dual connectivity-related procedures described above.

[0017] For example, during handover or conditional handover, a source RAN node (e.g., gNB) or a controller associated with the source RAN node (e.g., Near-Real-Time RAN Intelligent Controller (Near-RT RIC)) is expected to consider the UE's flight path information to determine the target cell, thereby optimizing the handover. However, it may be difficult for the source RAN node to map the three-dimensional location information indicated by the flight path information to the actual coverage of one or more target (candidate) cells, and therefore the flight path information may not be fully utilized. Similar problems exist with dual connectivity. For example, it may be difficult for the MN to map the three-dimensional location information indicated by the flight path information to the actual coverage of one or more candidate PSCells provided by the SN.

[0018] Another issue is that the current 3GPP specifications do not specify that the MN sends aerial UE subscription information to the SN regarding dual connectivity. It may be useful for the SN to use the aerial UE subscription information to decide whether to perform operations related to the aerial UE.

[0019] Another problem is that in the current 3GPP specifications, the execution conditions for conditional mobility are not based on flight path information. In other words, the execution conditions for conditional mobility are not related to the planned flight path of the aerial UE. Flight path information can be taken into consideration to provide execution conditions for conditional mobility suitable for the aerial UE. Here, conditional mobility includes, but is not limited to, conditional handover, conditional PSCell addition (CPA), inter-SN conditional PSCell change (CPC), or inter-SN CPC. Conditional mobility may also be referred to as conditional reconfiguration. CPA, intra-SN CPC, and inter-SN CPC related to dual connectivity may also be referred to as conditional dual connectivity procedures or conditional dual connectivity-related procedures.

[0020] As a further problem, it may be useful to allow handover as described in Patent Document 1, specifically the proposal of an alternative target cell by the target node, only in specific situations or conditions where it is useful, but Patent Document 1 does not provide such specific situations or conditions.

[0021] It should be noted that some or all of the above-described problems may arise not only when flight path information for an aerial UE is used, but also in other cases. For example, these problems may arise when driving path information for a UE implemented in a land-based vehicle is available. A land-based vehicle, also known as a land vehicle or ground vehicle, is a type of vehicle that travels on land or the ground. Driving path information for a land-based vehicle describes planned or scheduled locations of the land-based vehicle. These locations may be two-dimensional (2D) locations. In this specification, the term "planned path information" refers to information, such as flight path information and driving path information, that describes planned or scheduled locations of a UE or a vehicle, air vehicle, mobile robot, or the like, in which the UE is implemented.

[0022] One of the objectives that the embodiments disclosed in this specification aim to achieve is to provide an apparatus, a method, and a program that contribute to solving at least one of the problems, including the problems described above. It should be noted that this objective is only one of the objectives that the embodiments disclosed in this specification aim to achieve. Other objectives or objectives and novel features will become apparent from the description of this specification or the accompanying drawings. [Means for solving the problem]

[0023] A first aspect is directed to a first Radio Access Network (RAN) node including at least one memory and at least one processor coupled to the at least one memory, the at least one processor configured to send planned route information indicating multiple planned positions of a UE to a second RAN node during a mobility-related procedure or a dual connectivity-related procedure for the UE.

[0024] A second aspect is directed to a method performed by a first RAN node, the method including sending planned route information indicating multiple planned positions for a UE to a second RAN node during a mobility-related procedure or a dual connectivity-related procedure for the UE.

[0025] A third aspect is directed to a second RAN node, the second RAN node including at least one memory and at least one processor coupled to the at least one memory, the at least one processor configured to receive, from a first RAN node, planned route information indicating a plurality of planned positions for a UE during a mobility-related procedure or a dual connectivity-related procedure for the UE.

[0026] A fourth aspect is directed to a method performed by a second RAN node, the method including receiving, during a mobility-related procedure or a dual connectivity-related procedure for a UE, planned route information from a first RAN node indicating a plurality of planned positions for the UE.

[0027] A fifth aspect is directed to a RAN node configured to operate as a MN in dual connectivity for a UE, the RAN node including at least one memory and at least one processor coupled to the at least one memory, the at least one processor configured to send planned route information indicating multiple planned positions of the UE to an SN of the dual connectivity.

[0028] A sixth aspect is directed to a method performed by a RAN node configured to act as a mobile node in dual connectivity for a user equipment (UE), the method including sending planned route information indicating multiple planned locations of the UE to a dual connectivity SN.

[0029] A seventh aspect is directed to a RAN node configured to operate as a SN in dual connectivity for a UE, the RAN node including at least one memory and at least one processor coupled to the at least one memory, the at least one processor configured to receive planned route information from the dual connectivity MN indicating multiple planned positions of the UE.

[0030] An eighth aspect is directed to a method performed by a RAN node configured to operate as an SN in dual connectivity for a UE, the method including receiving planned route information from the dual connectivity MN indicating multiple planned locations of the UE.

[0031] A ninth aspect is directed to a RAN node configured to operate as a MN in dual connectivity for a UE, the RAN node including at least one memory and at least one processor coupled to the at least one memory, the at least one processor configured to receive planned route information indicating multiple planned positions of the UE from an SN in the dual connectivity.

[0032] A tenth aspect is directed to a method performed by a RAN node configured to operate as a mobile node in dual connectivity for a user equipment (UE), the method including receiving planned route information from a dual connectivity SN indicating multiple planned locations for the UE.

[0033] An eleventh aspect is directed to a RAN node configured to operate as a SN in dual connectivity for a UE, the RAN node including at least one memory and at least one processor coupled to the at least one memory, the at least one processor configured to send planned route information indicating multiple planned positions of the UE to the dual connectivity MN.

[0034] A twelfth aspect is directed to a method performed by a RAN node configured to operate as an SN in dual connectivity for a UE, the method including sending planned route information indicating multiple planned locations of the UE to the dual connectivity MN.

[0035] A thirteenth aspect is directed to a RAN node configured to operate as a MN in dual connectivity for a UE, the RAN node including at least one memory and at least one processor coupled to the at least one memory, the at least one processor configured to send aerial UE subscription information of the UE or information derived therefrom to a secondary node (SN) of the dual connectivity.

[0036] A fourteenth aspect is directed to a method performed by a RAN node configured to act as a mobile node in dual connectivity for a user equipment (UE), the method including sending aerial UE subscription information of the UE, or information derived therefrom, to a secondary node (SN) of the dual connectivity.

[0037] A fifteenth aspect is directed to a RAN node configured to operate as a SN in dual connectivity for a UE, the RAN node including at least one memory and at least one processor coupled to the at least one memory, the at least one processor configured to receive aerial UE subscription information of the UE or information derived therefrom from the dual connectivity MN.

[0038] A sixteenth aspect is directed to a method performed by a RAN node configured to act as an SN in dual connectivity for a UE, the method including receiving aerial UE subscription information or information derived therefrom for the UE from the dual connectivity MN.

[0039] A seventeenth aspect is directed to a RAN node including at least one memory and at least one processor coupled to the at least one memory, the at least one processor configured to determine one or more execution conditions for conditional mobility of a UE based on planned route information indicating multiple planned positions of the UE.

[0040] An eighteenth aspect is directed to a method performed by a RAN node, the method including determining one or more execution conditions for conditional mobility of a UE based on planned route information indicating multiple planned positions of the UE.

[0041] A nineteenth aspect is directed to a RAN node, the RAN node including at least one memory and at least one processor coupled to the at least one memory, configured to receive a handover request for a UE from a source RAN node, the handover request indicating one or more target cells, and if the handover request message includes one or both of planned route information indicating multiple planned positions of the UE and an explicit indication that an alternative cell proposal is permitted, send a handover request response to the source RAN node indicating other cells that are acceptable for handover and that are different from the one or more target cells.

[0042] A twentieth aspect is directed to a method performed by a RAN node, the method including the steps of: (a) receiving a handover request for the UE from a source RAN node indicating one or more target cells; and (b) if the handover request message includes one or both of planned route information indicating multiple planned locations of the UE and an explicit indication that alternative cell suggestions are allowed, sending a handover request response to the source RAN node indicating other cells that are acceptable for handover and that are different from the one or more target cells.

[0043] A twenty-first aspect is directed to a program, which includes a group of instructions (software code) that, when loaded into a computer, causes the computer to perform the method according to the second, fourth, sixth, eighth, tenth, twelfth, fourteenth, sixteenth, eighteenth, or twentieth aspect. [Effects of the Invention]

[0044] According to the above-described aspects, it is possible to provide an apparatus, a method, and a program that contribute to solving at least one of a plurality of problems including the above-described problem. [Brief explanation of the drawings]

[0045] [Figure 1] 1 is a diagram illustrating an example of the configuration of a wireless communication system according to an embodiment. [Figure 2] 1 is a diagram illustrating an example of the configuration of a wireless communication system according to an embodiment. [Figure 3] 1 is a diagram illustrating an example of the configuration of a wireless communication system according to an embodiment. [Figure 4] FIG. 1 is a diagram illustrating a configuration example of a RAN node according to an embodiment. [Figure 5] FIG. 2 is a sequence diagram illustrating an example of signaling between RAN nodes according to an embodiment. [Figure 6] 10 is a flowchart illustrating an example of an operation of a RAN node according to an embodiment. [Figure 7] 10 is a flowchart illustrating an example of an operation of a RAN node according to an embodiment. [Figure 8] 10 is a flowchart illustrating an example of an operation of a RAN node according to an embodiment. [Figure 9]10 is a flowchart illustrating an example of an operation of a RAN node according to an embodiment. [Figure 10] FIG. 10 is a diagram illustrating an example of the format of a Handover Preparation Information message according to the embodiment. [Figure 11] FIG. 10 is a diagram illustrating an example of a format of a HANDOVER REQUEST message according to the embodiment. [Figure 12] FIG. 10 is a diagram illustrating an example of the format of a CG-ConfigInfo message according to the embodiment. [Figure 13] FIG. 10 is a diagram illustrating an example of the format of an S-NODE ADDITION REQUEST message according to the embodiment. [Figure 14] FIG. 10 is a sequence diagram illustrating an example of dual connectivity-related signaling between RAN nodes according to an embodiment. [Figure 15] FIG. 10 is a sequence diagram illustrating an example of dual connectivity-related signaling between RAN nodes according to an embodiment. [Figure 16] FIG. 10 is a sequence diagram illustrating an example of dual connectivity-related signaling between RAN nodes according to an embodiment. [Figure 17] FIG. 10 is a diagram illustrating an example of the format of an S-NODE ADDITION REQUEST message according to the embodiment. [Figure 18] 10 is a flowchart illustrating an example of an operation of a RAN node according to an embodiment. [Figure 19] FIG. 10 is a sequence diagram illustrating an example of handover-related signaling between RAN nodes according to an embodiment. [Figure 20] FIG. 10 is a sequence diagram illustrating an example of handover-related signaling between RAN nodes according to an embodiment. [Figure 21] FIG. 2 is a block diagram illustrating a configuration example of a RAN node according to the embodiment. [Figure 22] FIG. 2 is a block diagram illustrating an example of the configuration of a UE according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0046] Hereinafter, 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 for clarity of explanation, duplicate explanations will be omitted as necessary.

[0047] The multiple embodiments described below can be implemented independently or in appropriate combination. These multiple embodiments have different novel features. Therefore, these multiple embodiments contribute to solving different purposes or problems and to achieving different effects.

[0048] The following embodiments will be described primarily with respect to the 3GPP Long Term Evolution (LTE) system and the fifth generation mobile communication system (5G system). However, these embodiments may also be applied to other wireless communication systems that support techniques similar to 3GPP mobility-related procedures or dual connectivity-related procedures. Note that, unless otherwise specified, the term LTE used in this specification includes improvements and developments of LTE and LTE-Advanced to enable interworking with the 5G system.

[0049] As used herein, depending on the context, "if" may be construed to mean "when," "at or around the time," "after," "upon," "in response to determining," "in accordance with a determination," or "in response to detecting." These expressions may be construed to have the same meaning, depending on the context.

[0050] First, the configurations and operations of multiple network elements common to multiple embodiments will be described. Figure 1 illustrates an example configuration of a wireless communication system according to multiple embodiments. In the example of Figure 1, the wireless communication system includes RAN node 1, RAN node 2, RAN node 4, and UE 3. Each element (network function) illustrated in Figure 1 can be implemented, for example, as a network element on dedicated hardware, as a software instance running on dedicated hardware, or as a virtualized function instantiated on an application platform.

[0051] RAN node 1 may be a Central Unit (e.g., eNB-CU or gNB-CU) in a cloud RAN (C-RAN) deployment, or may be a combination of a CU and one or more Distributed Units (e.g., eNB-DUs or gNB-DUs). C-RAN is also referred to as a CU / DU split. Furthermore, a CU 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). Thus, RAN node 1 may be a CU-CP or a combination of a CU-CP and a CU-UP. Similarly, each of RAN nodes 2 and 4 may be a CU or a combination of a CU and one or more DUs. Each of RAN nodes 2 and 4 may be a CU-CP or a combination of a CU-CP and a CU-UP.

[0052] Each of RAN nodes 1, 2, and 4 may be an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) node or a Next Generation Radio Access Network (NG-RAN) node. The E-UTRAN node may be an eNB or an en-gNB. The NG-RAN node may be a gNB or an ng-eNB. The en-gNB provides NR user plane and control plane protocol terminations to the UE and acts as an SN for E-UTRA-NR Dual Connectivity (EN-DC). The ng-eNB provides E-UTRA user plane and control plane protocol terminations to the UE and is connected to the 5GC via the NG interface. The Radio Access Technology (RAT) of RAN node 1 may be different from that of RAN nodes 2 and 4.

[0053] RAN node 1 and RAN node 2 communicate with each other via a node-to-node interface (i.e., X2 interface or Xn interface) 103. RAN node 1 and RAN node 2 act as MN and SN of dual connectivity, respectively. Furthermore, RAN node 1 and RAN node 4 communicate with each other via a node-to-node interface (i.e., X2 interface or Xn interface) 105. RAN node 1 and RAN node 4 can act as MN and SN of DC, respectively. A node-to-node interface (i.e., X2 interface or Xn interface) 106 may be established between RAN node 2 and RAN node 4.

[0054] RAN nodes 1, 2, and 4 and UE 3 support inter-SN CPC from the SCG provided by RAN node 2 to the SCG provided by RAN node 4. Therefore, hereinafter, RAN node 1 may be referred to as MN 1, RAN node 2 may be referred to as source SN (S-SN) 2, and RAN node 4 may be referred to as target SN (T-SN) 4, candidate SN 4, or target candidate SN 4. Inter-SN CPC may also be referred to as conditional SN change.

[0055] Inter-SN CPC (or conditional SN change) is an inter-SN PSCell change procedure (or SN change procedure) that is executed only when one or more CPC execution conditions are met or satisfied. After receiving an SN change instruction from MN1, UE3 maintains its connection with source SN2 and source SCG and starts evaluating the execution conditions set by the instruction. Then, UE3 starts accessing target candidate SN4 and the selected candidate PSCell in response to the execution conditions being met.

[0056] An inter-SN CPC can be initiated by the MN1 or the source SN2. An inter-SN CPC initiated by the MN1 is called an MN-initiated inter-SN CPC. On the other hand, an inter-SN CPC initiated by the source SN2 is called an SN-initiated inter-SN CPC. In an MN-initiated inter-SN CPC, the MN1 generates a CPC execution condition. In contrast, in an SN-initiated inter-SN CPC, the source SN2 generates a CPC execution condition and sends it to the MN1. In both the MN-initiated inter-SN CPC and the SN-initiated inter-SN CPC, the target candidate SN4 generates an SCG configuration and sends it to the MN. Then, the MN1 transmits the CPC configuration (e.g., ConditionalReconfiguration IE) including the CPC execution condition and the SCG configuration to the UE3 via an RRC (Connection) Reconfiguration message.

[0057] Although not shown in FIG. 1, multiple candidate cells (i.e., candidate PSCells) provided by multiple candidate SNs 4 may be prepared for inter-SN CPC. In the inter-SN CPC procedure, the UE 3 receives from the MN 1 the configurations of one or more candidate PSCells (i.e., one or more SCG configurations) prepared by one or more candidate SNs and one or more CPC execution conditions associated therewith. More specifically, the configuration of each candidate PSCell is included in an information element (e.g., condRRCReconfig) of the RRC message from the MN 1, and the configurations of one or more candidate PSCells and the associated CPC execution conditions are included in conditional mobility configuration information (e.g., conditionalReconfiguration IE) generated by the MN 1.

[0058] The configuration of each candidate PSCell (i.e., SCG configuration) is generated by the candidate SN (e.g., candidate SN4) that provides (or prepares) this candidate PSCell. The configuration of each candidate PSCell includes at least configuration information for the candidate PSCell. The configuration of each candidate PSCell may further include configuration information for one or more SCells associated with the candidate PSCell (i.e., configured together with or in association with the candidate PSCell). The configuration of each candidate PSCell may be a radio bearer (RB) configuration, a cell group (CG) configuration, an SCG configuration, an SCG radio resource configuration, or any combination thereof. More specifically, the configuration of each candidate PSCell may be an SN RRC Reconfiguration message generated by the candidate SN (e.g., candidate SN4) that provides (or prepares) this candidate PSCell. Some or all of the configurations of one or more candidate PSCells are included in the CPC configuration sent from MN1 to UE3. The CPC configuration of an Inter-SN CPC includes a list of one or more MN RRC Reconfiguration messages and associated execution conditions. Each MN RRC Reconfiguration message contains the configuration of a candidate PSCell received from a candidate SN (e.g., one or any combination of RB configuration, CG configuration, SCG configuration, SCG radio resource configuration, and SN RRC Reconfiguration messages).

[0059] On the other hand, the CPC execution condition is generated by the MN1 in the case of MN-initiated inter-SN CPC, and is generated by the source SN2 in the case of SN-initiated inter-SN CPC. The CPC execution condition may consist of one or more trigger conditions. The conditions or criteria for triggering a CPC event may be similar to those for a measurement report event, and may be, for example, CondEvent B1, CondEvent A3, CondEvent A4, or CondEvent A5. CondEvent B1 is "Conditional reconfiguration candidate becomes better than absolute threshold". CondEvent A3 is "Conditional reconfiguration candidate becomes amount of offset better than PCell / PSCell". CondEvent A4 is "Conditional reconfiguration candidate becomes better than absolute threshold". CondEvent A5 is "PCell / PSCell becomes worse than absolute threshold1 AND Conditional reconfiguration candidate becomes better than another absolute threshold2". The UE3 evaluates the CPC execution conditions. If the execution condition of one candidate PSCell is satisfied, the UE 3 applies the PSCell configuration (e.g., one or any combination of RB configuration, CG configuration, SCG configuration, SCG radio resource configuration, and SN RRC Reconfiguration message) corresponding to the selected candidate PSCell (i.e., the candidate PSCell whose execution condition is satisfied). If a bearer requiring SCG radio resources is configured, the UE 3 synchronizes to the selected PSCell.If the execution conditions of two or more candidate PSCells are met, the UE 3 may select one of the candidate PSCells and perform the above-mentioned operations.

[0060] UE3 communicates with MN1 and S-SN2 via air interfaces 101 and 102, and provides dual connectivity for the MCG provided by MN1 and the SCG provided by S-SN2. Also, by performing inter-SN CPC, UE3 communicates with MN1 and T-SN4 via air interfaces 101 and 104, and provides dual connectivity for the MCG provided by MN1 and the SCG provided by T-SN4.

[0061] This dual connectivity may be Multi-Radio Dual Connectivity (MR-DC). MR-DC includes E-UTRA-NR Dual Connectivity (EN-DC), NG-RAN E-UTRA-NR Dual Connectivity (NGEN-DC), NR-E-UTRA Dual Connectivity (NE-DC), and NR-NR Dual Connectivity (NR-DC). Accordingly, the MN1 may be a master eNB (in EN-DC), a master ng-eNB (in NGEN-DC), or a master gNB (in NR-DC and NE-DC). Similarly, the S-SN2 and T-SN4 may be an en-gNB (in EN-DC), a secondary ng-eNB (in NE-DC), or a secondary gNB (in NR-DC and NGEN-DC). In EN-DC, the UE3 is connected to an eNB operating as the MN1 and an en-gNB operating as the S-SN2 or T-SN4. In NGEN-DC, UE3 is connected to an ng-eNB operating as MN1 and a gNB operating as S-SN2 or T-SN4. In NE-DC, UE3 is connected to a gNB operating as MN1 and a ng-eNB operating as S-SN2 or T-SN4. In NR-DC, UE3 is connected to one gNB (or gNB-DU) operating as MN1 and another gNB (or gNB-DU) operating as S-SN2 or T-SN4.

[0062] The MCG is a group of serving cells associated with (or provided by) the MN1, and includes an SpCell (i.e., a Primary Cell (PCell)) and optionally one or more Secondary Cells (SCells). On the other hand, the SCG is a group of serving cells associated with (or provided by) the S-SN2 or T-SN4, and includes a Primary SCG Cell (PSCell) and optionally one or more Secondary Cells (SCells). The PSCell is a Special Cell (SpCell) of the SCG, and supports Physical Uplink Control Channel (PUCCH) transmission and contention-based Random Access. Note that in LTE (e.g., LTE-DC and NE-DC), PSCell may be an abbreviation for Primary SCell.

[0063] As used herein, the term "primary SCG cell" and its abbreviation "PSCell" refer to a cell included in a cell group provided by a dual connectivity SN, having an uplink component carrier, and configured with uplink control channel (e.g., PUCCH) resources. Specifically, the term "primary SCG cell" and its abbreviation "PSCell" may refer to the Primary SCG Cell of a cell group provided by an SN supporting 5G NR (e.g., en-gNB in ​​EN-DC, gNB in ​​NGEN-DC, or gNB in ​​NR-DC), or the Primary SC Cell of a cell group provided by an SN supporting E-UTRA (e.g., eNB in ​​LTE DC, or ng-eNB in ​​NE-DC).

[0064] Figure 2 illustrates another exemplary configuration of a wireless communication system according to various embodiments. In the example of Figure 2, the wireless communication system includes RAN node 1, RAN node 2, and UE 3. Each element (network function) illustrated in Figure 2 can be implemented, for example, as a network element on dedicated hardware, as a software instance running on the dedicated hardware, or as a virtualized function instantiated on an application platform.

[0065] 2 may have the same configurations and functions as those in the example of FIG. 1. Specifically, RAN node 1 and RAN node 2 communicate with each other via an inter-node interface (i.e., X2 interface or Xn interface) 103. RAN node 1 and RAN node 2 operate as MN and SN, respectively, for dual connectivity. UE 3 communicates with MN 1 and SN 2 via air interfaces 101 and 102, and performs dual connectivity for MCG and SCG. This dual connectivity may be Multi-Radio Dual Connectivity (MR-DC).

[0066] RAN nodes 1 and 2 and UE 3 support conditional PSCell addition (CPA), which adds an SCG provided by RAN node 2 for UE 3. Therefore, hereinafter, RAN node 1 may be referred to as MN 1, and RAN node 2 may be referred to as candidate SN 2. CPA may also be referred to as conditional SN addition. CPA (or conditional SN addition) is a PSCell addition procedure (or SN addition procedure) that is executed only when a CPA execution condition is met.

[0067] CPA (or conditional SN addition) is a PSCell addition procedure (or SN addition procedure) that is executed only when one or more CPA execution conditions are met or satisfied. After receiving a PSCell addition instruction from MN1, UE3 starts evaluating the execution conditions of one or more candidate PSCells configured by the instruction. Then, in response to the execution condition of any candidate PSCell being met, UE3 starts synchronization with that PSCell. In CPA, MN1 generates the CPA execution condition. Candidate SN2 generates an SCG configuration and sends it to MN1. MN1 sends the CPA configuration (e.g., ConditionalReconfiguration IE), which includes both the CPA execution condition and the SCG configuration, to UE3 via an RRC (Connection) Reconfiguration message.

[0068] Although not shown in Fig. 2, multiple candidate PSCells provided by multiple candidate SNs 2 may be prepared for CPA. In the CPA procedure, the UE 3 receives from the MN 1 configurations of one or more candidate PSCells (i.e., one or more SCG configurations) prepared by one or more candidate SNs and one or more CPA execution conditions associated therewith. More specifically, the configuration of each candidate PSCell is included in an information element (e.g., condRRCReconfig) of the RRC message from the MN 1, and the configurations of one or more candidate PSCells and the associated CPA execution conditions are included in conditional mobility configuration information (e.g., conditionalReconfiguration IE) generated by the MN 1.

[0069] The configuration of each candidate PSCell is generated by a candidate SN (e.g., candidate SN2) that provides (or prepares) this candidate PSCell. The configuration of each candidate PSCell includes at least configuration information for the candidate PSCell. The configuration of each candidate PSCell may further include configuration information for one or more SCells associated with the candidate PSCell (i.e., configured together with or in association with the candidate PSCell). The configuration of each candidate PSCell may be one or any combination of RB configuration, CG configuration, SCG configuration, and SCG radio resource configuration. More specifically, the configuration of each candidate PSCell may be an SN RRC Reconfiguration message generated by a candidate SN (e.g., candidate SN4) that provides (or prepares) this candidate PSCell. Some or all of the configurations of one or more candidate PSCells are included in a CPA configuration sent from MN1 to UE3. The CPA configuration includes a list of one or more MN RRC Reconfiguration messages and associated execution conditions. Each MN RRC Reconfiguration message includes the configuration of the candidate PSCell received from the candidate SN (eg, one or any combination of the RB configuration, CG configuration, SCG configuration, SCG radio resource configuration, and SN RRC Reconfiguration message).

[0070] Meanwhile, the CPA execution condition is generated by the MN 1. The CPA execution condition may consist of one or more trigger conditions. The conditions or criteria for triggering a CPA event may be similar to those for a measurement report event, such as CondEvent A3, CondEvent A4, or CondEvent A5. The UE 3 evaluates the CPA execution conditions. If the execution condition for one candidate PSCell is met, the UE 3 applies the PSCell configuration (i.e., CG configuration, SCG configuration, SCG radio resource configuration, or SN RRC Reconfiguration message) corresponding to the selected candidate PSCell (i.e., the candidate PSCell whose execution condition is met). If a bearer requiring SCG radio resources is configured, the UE 3 synchronizes to the selected PSCell. If the execution conditions for two or more candidate PSCells are met, the UE 3 may select one of the candidate PSCells and perform the above-mentioned operations.

[0071] In addition, the RAN node 2 and the UE 3 support intra-SN CPC, which may also be called SN-initiated Conditional SN Modification without MN involvement. Intra-SN CPC is an intra-SN PSCell change procedure that is executed only when the CPC execution conditions are met.

[0072] In the Intra-SN CPC procedure, UE3 receives from SN2 the configuration of one or more candidate PSCells prepared by SN2 and one or more CPC execution conditions associated with the configuration. The configuration of each candidate PSCell and the associated CPC execution conditions are included in the CPC configuration for intra-SN CPC. SN2 may send these to UE3 via MN1 or may send them to UE3 via a direct signaling radio bearer (i.e., Signaling Radio Bearer 3 (SRB3)) between SN2 and UE3. More specifically, the configuration of each candidate PSCell is an information element (IE) (e.g., condRRCReconfig) of an RRC message from SN2, and the configuration of one or more candidate PSCells and the associated CPC execution conditions are included in conditional mobility configuration information (e.g., conditionalReconfiguration IE) generated by SN2.

[0073] The configuration of each candidate PSCell includes at least configuration information for the candidate PSCell. The configuration of each candidate PSCell may further include configuration information for one or more SCells associated with the candidate PSCell (i.e., configured together with or in association with the candidate PSCell). The configuration of each candidate PSCell may be a radio bearer (RB) configuration, a cell group (CG) configuration, an SCG configuration, an SCG radio resource configuration, or any combination thereof. Specifically, the configuration of each candidate PSCell may be an SN RRC Reconfiguration message generated by the SN2.

[0074] The CPC execution condition for Intra-SN CPC may consist of one or more trigger conditions. The conditions or criteria for triggering a CPC event may be similar to those for a measurement report event, such as CondEvent A3, CondEvent A4, or CondEvent A5. The UE 3 evaluates the CPC execution conditions. If the execution condition for one candidate PSCell is met, the UE 3 detaches from the source PSCell, applies the configuration corresponding to the selected candidate PSCell (i.e., the candidate PSCell whose execution condition is met), and synchronizes with the selected candidate PSCell. If the execution conditions for two or more candidate PSCells are met, the UE 3 may select one of the candidate PSCells and perform the above-mentioned operations.

[0075] FIG. 3 illustrates yet another exemplary configuration of a wireless communication system according to several embodiments. In the example of FIG. 3, the wireless communication system includes a RAN node 6, a RAN node 7, and a UE 3. Each element (network function) illustrated in FIG. 3 can be implemented, for example, as a network element on dedicated hardware, as a software instance running on the dedicated hardware, or as a virtualized function instantiated on an application platform. Each of the RAN nodes 6 and 7 may be an EUTRAN node or an NG-RAN node. The EUTRAN node may be an eNB or an en-gNB. The NG-RAN node may be a gNB or an ng-eNB. The RAT of the RAN node 6 may be different from that of the RAN node 7.

[0076] The RAN node 6 provides at least one cell 61. The RAN node 7 provides one or more cells (e.g., four cells 71 to 74). In the example of FIG. 3, the cell 61 provided by the RAN node 6 is the current serving cell of the UE 3, and the UE 3 is handed over from the cell 61 to one of the cells provided by the RAN node 7. Therefore, hereinafter, the RAN node 6 may be referred to as a source node or a source RAN node, and the RAN node 7 may be referred to as a target node or a target RAN node. The cell 61 is referred to as a source cell. The source node 6, the target node 7, and the UE 3 support conditional handover (CHO). CHO is a handover procedure that is executed only when the CHO execution conditions are met.

[0077] Although not shown in FIG. 3 , multiple candidate target cells provided by multiple candidate target nodes 7 may be prepared for CHO. In the CHO procedure, the UE 3 receives from the source node 6 configurations of one or more candidate target cells prepared by one or more candidate target nodes and one or more associated CHO execution conditions (e.g., condExecutionCond). The configurations of one or more candidate target cells and the associated CHO execution conditions are included in the CHO configuration. More specifically, the configuration of each candidate target cell is an information element (IE) (e.g., condRRCReconfig) in an RRC message from the source node 6, and the configurations of one or more candidate target cells and the associated CHO execution conditions are included in conditional mobility configuration information (e.g., conditionalReconfiguration IE) generated by the source node 6.

[0078] The configuration of each candidate target cell is generated by a candidate target node (e.g., target node 7) that serves (or prepares) this candidate target cell. The configuration of each candidate target cell may be a radio bearer (RB) configuration, a radio resource configuration, or an RRC Reconfiguration message, or any combination thereof, generated by the candidate target node (e.g., target node 7) that serves (or prepares) this candidate target cell.

[0079] Meanwhile, the CHO execution condition is generated by the source node 6. The CHO execution condition may consist of one or more trigger conditions. The conditions or criteria for triggering a CHO event may be similar to those for a measurement report event, e.g., CondEvent A3, CondEvent A4, or CondEvent A5. The UE 3 evaluates the CHO execution conditions. If the execution condition for one candidate target cell is met, the UE 3 detaches from the source node 6, applies the configuration corresponding to the selected candidate target cell (i.e., the candidate target cell whose execution condition is met), and synchronizes with the selected candidate target cell. If the execution conditions for two or more candidate target cells are met, the UE 3 may select one of the candidate target cells and perform the above-mentioned operations.

[0080] The CHO may be a dual connectivity inter-MN handover, a Master Node to eNB / gNB Change, or an eNB / gNB to Master Node Change.

[0081] One or more of the RAN nodes 1, 2, 4, 6, and 7 may have the configuration shown in Figure 4. Each element (network function) shown in Figure 4 may be implemented, for example, as a network element on dedicated hardware, as a software instance running on dedicated hardware, or as a virtualized function instantiated on an application platform. One or more of the RAN nodes 1, 2, 4, 6, and 7 may include, but are not limited to, a CU 41 and one or more DUs 42 as shown in Figure 4. The CU 41 and each DU 42 are connected by an interface 401. A UE 3 is connected to at least one DU 42 via at least one air interface 402.

[0082] The CU41 may be a logical node that hosts the RRC, Service Data Adaptation Protocol (SDAP), and Packet Data Convergence Protocol (PDCP) protocols (or the RRC and PDCP protocols) of the gNB. The DU42 may be a logical node that hosts the Radio Link Control (RLC), Medium Access Control (MAC), and Physical (PHY) layers of the gNB. If the CU41 is a gNB-CU and the DUs42 are gNB-DUs, the interface 401 may be an F1 interface. The CU41 may include a CU-CP and a CU-UP.

[0083] In this specification, the term "conditional mobility" is used. As previously described, conditional mobility is a general term that refers to one or more of, for example, but not limited to, CHO, CPA, intra-SN CPC (or conditional SN modification), and inter-SN CPC (or conditional SN change). Conditional mobility may also be referred to as conditional reconfiguration. CPA, intra-SN CPC, and inter-SN CPC related to dual connectivity may also be referred to as conditional dual connectivity procedures or conditional dual connectivity-related procedures.

[0084] Although the above description with reference to Figures 1 to 3 mainly relates to conditional mobility, the RAN nodes and UEs depicted in these figures naturally also support non-conditional mobility, i.e., normal UE mobility. As already explained, in the definitions herein, the terms mobility or mobility-related procedures may refer collectively to conditional and non-conditional handover procedures and conditional and non-conditional dual connectivity procedures.

[0085] In this specification, the terms MN RRC message, MN RRC (Connection) Reconfiguration message, SN RRC message, and SN RRC Reconfiguration message are used. These terms are used for convenience to distinguish RRC messages generated by an MN from RRC messages generated by an SN. Therefore, the MN RRC message and the MN RRC (Connection) Reconfiguration message may be simply referred to as an RRC message and an RRC Reconfiguration message (or an RRC Connection Reconfiguration message). Similarly, the SN RRC message and the SN RRC Reconfiguration message may be simply referred to as an RRC message and an RRC Reconfiguration message.

[0086] The UE 3 described with reference to FIGS. 1 to 4 may be an aerial UE. An aerial UE refers to a UE that supports aerial UE communication or is capable of aerial communication. The aerial UE may be a UE implemented in an unmanned or uncrewed aerial vehicle (UAV). In this case, the UE 3 may provide the functions and operations described in Non-Patent Documents 1 to 3 that an LTE aerial UE should support. Alternatively, the UE 3 may be an NR aerial UE that provides functions and operations similar to those provided by an LTE aerial UE. Similarly, the RAN (e.g., RAN nodes 1, 2, 4, 6, and 7) may provide the functions and operations described in Non-Patent Documents 1 to 3 that an E-UTRAN should support to provide LTE connectivity to an aerial UE. Alternatively, the RAN may be an NG-RAN that provides functions and operations similar to those provided by an E-UTRAN to support aerial UE communication. For example, the RAN (e.g., RAN nodes 1, 2, 4, 6, or 7) may request the UE 3 to report flight path information including multiple waypoints defined as 3D locations. The UE 3 reports the configured number of waypoints if flight path information is available at the UE 3. The report may include a timestamp for each waypoint if configured in the request and available at the UE 3.

[0087] The embodiments described below provide improved signaling between RAN nodes regarding UE mobility or dual connectivity.

[0088] First Embodiment This embodiment provides an improvement in signaling between RAN nodes in UE mobility related procedures or dual connectivity related procedures. A configuration example of the wireless communication system according to this embodiment may be similar to any of the configuration examples described with reference to Figures 1 to 4.

[0089] FIG. 5 illustrates an example of inter-RAN node signaling. In step 520, the RAN node 501 sends planned route information of the UE 3 to the RAN node 502 in a mobility-related or dual connectivity-related procedure for the UE 3. In other words, the RAN node 501 sends a mobility-related or dual connectivity-related message including the planned route information of the UE 3 to the RAN node 502. The planned route information may be information reported from the UE 3 to the RAN node 501 based on a request from the RAN node 501. Before step 520, the RAN node 501 may receive planned route information from the UE 3. The planned route information indicates planned or intended locations of the UE. These locations may be 3D locations or 2D locations. In one example, the planned route information may relate to an aerial UE (i.e., a UE 3 having an aerial UE function) and may be flight route information including waypoints defined as 3D locations. In another example, the planned path information may describe planned or intended 2D locations of a UE 3 embedded in a land-based vehicle or mobile robot.

[0090] The mobility-related procedure may be a handover procedure or a conditional handover (CHO) procedure. RAN nodes 501 and 502 may be a source RAN node (e.g., RAN node 6) and a target RAN node (e.g., RAN node 7) of the handover or CHO, respectively. In this case, the message in step 520 carrying the planned path information may be a HANDOVER REQUEST message. The planned path information may be included in an inter-node RRC message. More specifically, RAN node 501 may send the planned path information to RAN node 502 via the inter-node RRC message within the HANDOVER REQUEST message. Generally, an inter-node RRC message is an RRC message transmitted between RAN nodes via an inter-node interface such as an X2 interface or an Xn interface.

[0091] The dual connectivity-related procedure may be an SN addition procedure, a conditional SN addition (or CPA) procedure, an SN change procedure, or a conditional SN change (or inter-SN CPC) procedure. RAN nodes 501 and 502 may be an MN and an SN, respectively, in an SN addition procedure or a conditional SN addition procedure. RAN nodes 501 and 502 may be an MN and a target SN, respectively, in an SN change procedure or a conditional SN change procedure. In these cases, the message of step 520 carrying the planned route information may be an S-NODE ADDITION REQUEST message. Alternatively, RAN nodes 501 and 502 may be a source SN and an MN, respectively, in an SN change procedure or a conditional SN change procedure. In this case, the message of step 520 may be an S-NODE CHANGE REQUIRED message.

[0092] According to the signaling described with reference to Figure 5, in a mobility-related or dual connectivity-related procedure for UE3, RAN node 501 provides planned route information for UE3 to another RAN node 502. This allows, for example, RAN node 502 to use the planned route information to optimize a (conditional) handover or (conditional) dual connectivity procedure for UE3.

[0093] The RAN node 502 may use the received planned route information for various purposes. For example, the RAN node 502 may predict or determine the current or future location of the UE 3 taking into account the planned locations of the UE 3 and, optionally, a timestamp for each location. The RAN node 502 may also take into account the location of the UE 3 predicted or determined based on the planned route information in various decisions regarding the mobility of the UE 3. Examples of these uses are described below.

[0094] Figure 6 shows a first example of the operation of the RAN node 502. Step 601 corresponds to step 520 in Figure 5. Specifically, the RAN node 502 receives planned route information indicating multiple planned positions of the UE3 from another RAN node 501 in a mobility-related or dual connectivity-related procedure for the UE3.

[0095] In step 602, the RAN node 502 uses the received planned route information to determine whether to accept a (conditional) handover of the UE 3 to the target cell or a (conditional) SN addition or modification for the UE 3. For example, the RAN node 502 may predict or determine the current or future location of the UE 3, taking into account the planned location of the UE 3 and, optionally, a timestamp for each location. The RAN node 502 may take into account the predicted or determined location of the UE 3 based on the planned route information to determine whether to accept the (conditional) handover requested by the RAN node 501. If the requested (candidate) target cell covers the predicted or determined location of the UE 3, the RAN node 502 may accept the (conditional) handover. Additionally or alternatively, the RAN node 502 may take into account the predicted or determined location of the UE 3 based on the planned route information to determine whether to accept the (conditional) SCG addition or modification requested by the RAN node 501. If the requested (candidate) PSCell covers the predicted or determined location of the UE 3, the RAN node 502 may accept the (conditional) SCG addition or modification.

[0096] Figure 7 shows a second example of the operation of the RAN node 502. Step 701 is similar to step 601 of Figure 6. In step 702, the RAN node 502 uses the received planned route information to determine at least one acceptable cell among one or more target or candidate cells. For example, the RAN node 502 may predict or determine the current or future location of the UE 3 taking into account the planned location of the UE 3 and optionally a timestamp for each location. The RAN node 502 may accept at least one cell that covers or is located around the predicted or determined location of the UE 3.

[0097] Figure 8 shows a third example of the operation of the RAN node 502. Step 801 is similar to step 601 in Figure 6. In step 802, the RAN node 502 uses the planned route information to generate or prepare a configuration for a target cell or a candidate cell. For example, the RAN node 502 may predict or determine a current or future location of the UE 3 taking into account the planned location of the UE 3 and optionally a timestamp for each location. The RAN node 502 may generate a configuration for the target cell or a candidate cell (e.g., a serving cell configuration, an MCG configuration, an SCG configuration) taking into account the predicted or determined location of the UE 3.

[0098] Figure 9 shows a fourth example of the operation of the RAN node 502. Step 901 is similar to step 601 in Figure 6. In step 902, the RAN node 502 uses the planned route information to select a secondary cell for carrier aggregation. In other words, the RAN node 502 uses the planned route information to determine one or more secondary cells (SCells) within the MCG or SCG. For example, the RAN node 502 may predict or determine the current or future location of the UE 3, taking into account the planned location of the UE 3 and optionally a timestamp for each location. The RAN node 502 may select at least one cell that covers or is located around the predicted or determined location of the UE 3 as a secondary cell.

[0099] The following provides some specific examples of messages in step 520. Figure 10 shows an example of the format of a HandoverPreparationInformation message, which is one of the inter-node RRC messages. The HandoverPreparationInformation message can be sent from a source RAN node (e.g., RAN node 6 or 501) to a target RAN node (e.g., RAN node 7 or 502) via a HANDOVER REQUEST message. In the example of Figure 10, the HandoverPreparationInformation message can include a flightPathInfo information element or field 1002 within an AS-Context information element or field 1001. The flightPathInfo information element or field 1002 indicates location coordinates that represent the planned or intended locations of the UE. The flightPathInfo information element or field 1002 optionally indicates a timestamp for each location.

[0100] Figure 11 shows an example of the format of a HANDOVER REQUEST message. In the example of Figure 11, the HANDOVER REQUEST message optionally includes a new information element, "Flight Path Information List." The Flight Path Information List IE includes up to a predetermined maximum number of Flight Path Information Items IEs. The Flight Path Information Items IE includes a Waypoint Location IE and optionally a Time Stamp IE. The Waypoint Location IE indicates the location coordinates of the UE's planned location. The Time Stamp IE indicates a timestamp for each location.

[0101] FIG. 12 shows an example of the format of a CG-ConfigInfo message, which is one of the inter-node RRC messages. The CG-ConfigInfo message can be sent from an MN (e.g., MN1 or RAN node 501) to an SN (e.g., SN2, SN4, or RAN node 502) via an S-NODE ADDITION REQUEST message. In the example of FIG. 12, the CG-ConfigInfo message can include a flightPathInfo information element or field 1201. The flightPathInfo information element or field 1201 indicates location coordinates (1202) that represent the planned or intended locations of the UE. The flightPathInfo information element or field 1201 optionally indicates a timestamp for each location (1203).

[0102] Figure 13 shows an example of the format of an S-NODE ADDITION REQUEST message. In the example of Figure 13, the S-NODE ADDITION REQUEST message optionally includes a new information element, "Flight Path Information List." The Flight Path Information List IE includes up to a predetermined maximum number of Flight Path Information Items IEs. The Flight Path Information Items IE includes a Waypoint Location IE and optionally a Time Stamp IE. The Waypoint Location IE indicates the location coordinates of the UE's planned location. The Time Stamp IE indicates a timestamp for each location.

[0103] The formats shown in Figures 10 to 13 may be modified as appropriate. For example, the names of the information elements or fields shown in Figures 10 to 13 are merely examples and are not limiting.

[0104] When a C-RAN deployment is used, the planned path information may be sent from the source DU of the handover to the target DU via the CU. In this case, the planned path information may be sent from the source DU to the CU and from the CU to the target DU by a HandoverPreparationInformation message similar to that shown in Fig. 10. Alternatively, the planned path information may be sent from the source CU of the handover to the target DU (via the target CU). In this case, the planned path information may be sent from the source CU to the target DU (via the target CU) by a HandoverPreparationInformation message similar to that shown in Fig. 10. Note that the HandoverPreparationInformation may be transmitted enclosed in a DU to CU RRC Information IE from the DU to the CU or a CU to DU RRC Information IE from the CU to the DU.

[0105] <Second embodiment> This embodiment provides improved signaling between RAN nodes related to dual connectivity. An example configuration of the wireless communication system according to this embodiment may be similar to any of the example configurations described with reference to Figures 1, 2 and 4.

[0106] FIG. 14 shows an example of signaling between RAN nodes. In step 1420, the MN 1401 sends planned route information of the UE 3 to the SN 1402. The planned route information may be information reported from the UE 3 to the MN 1401 based on a request from the MN 1401. Before step 1420, the MN 1401 may receive planned route information from the UE 3. The planned route information indicates planned or scheduled locations of the UE. These locations may be 3D locations or 2D locations. In one example, the planned route information may relate to an aerial UE (i.e., a UE 3 having an aerial UE function) and may be flight path information including waypoints defined as 3D locations. In another example, the planned route information may describe planned or scheduled 2D locations of a UE 3 embedded in a land-based vehicle or a mobile robot.

[0107] The message of step 1420 carrying the planned route information may be transmitted in a dual connectivity related procedure. The dual connectivity related procedure may be an SN addition procedure or a conditional SN addition (or CPA) procedure. This (conditional) SN addition procedure may be performed between the MN and the target SN within an SN change procedure. The message of step 1420 carrying the planned route information may be an S-NODE ADDITION REQUEST message. The planned route information may be included in an inter-node RRC message. More specifically, the RAN node 1401 may send the planned route information to the RAN node 1402 via an inter-node RRC message within an S-NODE ADDITION REQUEST message. The formats may be similar to those of the examples described using Figures 12 and 13.

[0108] The message of step 1420 carrying the planned route information may be any other message related to dual connectivity, for example, the message of step 1420 may be an S-NODE MODIFICATION REQUEST or an S-NODE MODIFICATION CONFIRM message.

[0109] 14, the MN 1401 provides the planned route information of the UE 3 to the SN 1402. This allows the SN 1402 to use the planned route information to optimize (conditional) SN addition for the UE 3 or to optimize SCG configuration for the UE 3, for example.

[0110] The SN 1402 may use the received planned route information for various purposes. For example, the SN 1402 may predict or determine the current or future location of the UE 3, taking into account the planned location of the UE 3 and, optionally, a timestamp for each location. The SN 1402 may take into account the location of the UE 3 predicted or determined based on the planned route information in various decisions regarding dual connectivity for the UE 3. These uses may be similar to those described with respect to dual connectivity in the first embodiment.

[0111] 15 shows an example of signaling between RAN nodes. In step 1520, the SN 1502 sends planned route information of the UE 3 to the MN 1501. The planned route information may be information reported from the UE 3 to the SN 1502 based on a request from the SN 1502. Before step 1520, the SN 1502 may receive the planned route information from the UE 3. The definition and examples of the planned route information may be similar to those described with reference to FIG. 14.

[0112] The message of step 1520 carrying the planned route information may be, for example, an S-NODE MODIFICATION REQUEST ACKNOWLEDGE, S-NODE MODIFICATION REQUIRED, or S-NODE CHANGE REQUIRED message. The planned route information may be included in an inter-node RRC message included in these messages. The inter-node RRC message may be, for example, a CG-Config message or a CG-CandidateList message included in an S-NG-RAN node to M-NG-RAN node Container IE.

[0113] 15, in the dual connectivity related procedure for UE 3, SN 1502 provides planned route information of UE 3 to MN 1501. This allows MN 1501 to use the planned route information to optimize dual connectivity for UE 3, or to optimize MCG settings for UE 3, or to optimize mobility (e.g., handover) of UE 3, for example.

[0114] The MN 1501 can use the received planned route information for various purposes. For example, the MN 1501 may predict or determine the current or future location of the UE 3, taking into account the planned location of the UE 3 and optionally a timestamp for each location. The MN 1501 may take into account the location of the UE 3 predicted or determined based on the planned route information in various decisions regarding mobility and dual connectivity for the UE 3.

[0115] For example, the MN 1501 may consider the planned route information or a location of the UE 3 predicted based on the planned route information to determine a target cell for handover of the UE 3. The handover may be an inter-MN handover, a Master Node to eNB / gNB Change, or an eNB / gNB to Master Node Change.

[0116] Additionally or alternatively, the MN 1501 may consider planned route information or a location of the UE 3 predicted based on the planned route information in order to determine an SN addition or change for the UE 3. In other words, the MN 1501 may consider planned route information or a location of the UE 3 predicted based on the planned route information in order to determine a new PSCell or SN for the UE 3. The SN addition or change may be a conditional SN addition or change.

[0117] <Third embodiment> This embodiment provides improved signaling between RAN nodes related to dual connectivity. An example configuration of the wireless communication system according to this embodiment may be similar to any of the example configurations described with reference to Figures 1, 2 and 4.

[0118] 16 shows an example of signaling between RAN nodes. In step 1620, the MN 1601 sends aerial UE subscription information about the UE 3 or information derived therefrom to the SN 1602. The aerial UE subscription information about the UE 3 may be the aerial UE subscription information of the user of the UE 3. The aerial UE subscription information may be information sent from the HSS or Unified Data Management (UDM) of the core network to the MN 1601 via a core network node (e.g., MME or Access and Mobility Management Function (AMF)). The aerial UE subscription information may also be information sent to the MN 1601 from another RAN node in a past handover.

[0119] The aerial UE subscription information indicates a user's subscription authorization to operate aerial UEs. The aerial UE subscription information can be used by the RAN node to know whether the UE3 (or its user) is allowed to use the aerial UE function. The aerial UE subscription information or information derived therefrom sent from the MN 1601 to the SN 1602 in step 1620 may indicate whether the UE3 (or its user) is allowed to use the aerial UE function. Additionally or alternatively, the information may indicate whether the UE3 is an aerial UE. Additionally or alternatively, the information may indicate whether the UE3 supports the aerial UE function.

[0120] The message in step 1620 carrying the aerial UE subscription information may be a dual connectivity related message. The MN 1601 may send the aerial UE subscription information to the SN 1602 in an SN addition procedure. This SN addition procedure may be a conditional SN addition procedure. In this case, the message in step 1620 may be an S-NODE ADDITION REQUEST message. Alternatively, the message in step 1620 may be an S-NODE MODIFICATION REQUEST message.

[0121] 16, the MN 1601 provides the SN 1602 with aerial UE subscription information regarding the UE 3. This allows the SN 1602 to use the aerial UE subscription information to determine whether to perform an operation related to the aerial UE for the UE 3, for example.

[0122] The procedure of Fig. 16 may be modified as follows. The MN 1601 may send flight path information indicating multiple planned positions of the UE 3 to the SN 1602 together with aerial UE subscription information or information derived therefrom. The transmission of the flight path information from the MN 1601 to the SN 1602 may be similar to that described with reference to Fig. 14 in the second embodiment.

[0123] Figure 17 shows an example of the format of an S-NODE ADDITION REQUEST message. In the example of Figure 17, the S-NODE ADDITION REQUEST message optionally includes a new information element, "Aerial UE subscription information." The Aerial UE subscription information IE can be used by the SN to know whether the UE 3 or its user is allowed to use the aerial UE function. The Aerial UE subscription information IE is an enumerated type and may indicate "allowed" or "not allowed."

[0124] In the example of Figure 17, the S-NODE ADDITION REQUEST message optionally includes a new information element "Flight Path Information List", which is similar to that shown in Figure 13.

[0125] <Fourth embodiment> The present embodiment provides an improvement to the operation of RAN nodes with respect to conditional mobility. An example configuration of the wireless communication system according to the present embodiment may be similar to any of the example configurations described with reference to Figures 1 to 4.

[0126] 18 illustrates an example of the operation of a RAN node according to this embodiment. The RAN node determines one or more execution conditions to be provided to a UE 3 for a conditional handover, a conditional SN addition, a conditional SN change (or inter-SN CPC), or a conditional SN modification (or intra-SN CPC). Specifically, the RAN node may be a source RAN node of a conditional handover (e.g., RAN node 6 in FIG. 3), a MN of a conditional SN addition (e.g., MN1 in FIG. 2), a MN of a MN-initiated conditional SN change (e.g., MN1 in FIG. 1), a source SN of a SN-initiated conditional SN change (e.g., SN2 in FIG. 1), or a SN of a conditional SN modification (e.g., SN2 in FIG. 2).

[0127] In step 1801, the RAN node obtains planned route information indicating multiple planned positions of the UE 3. The planned route information may be information reported from the UE 3 to the RAN node based on a request from the RAN node. The RAN node may retrieve the planned route information stored in a memory or storage. The RAN node may also receive the planned route information from another RAN node.

[0128] The planned route information indicates planned or intended locations of the UE. These locations may be 3D or 2D locations. In one example, the planned route information may relate to an aerial UE (i.e., a UE 3 having aerial UE functionality) and may be flight path information including waypoints defined as 3D locations. In another example, the planned route information may describe planned or intended 2D locations of a UE 3 embedded in a land-based vehicle or a mobile robot.

[0129] In step 1802, the RAN node determines one or more execution conditions for the conditional mobility of the UE 3 based on the planned route information.

[0130] The one or more execution conditions may include that the location of the UE 3 is at a reference location, within a set distance from the reference location, or within a reference area. The RAN node may determine the reference location or reference area based on the planned location indicated by the planned route information. The RAN node may predict or determine the current or future location of the UE 3 by taking into account the planned location of the UE 3 and optionally a timestamp for each location. The RAN node may then determine or set the reference location or reference area to correspond to the predicted or determined location of the UE 3.

[0131] Additionally or alternatively, the one or more execution conditions may include the distance between the UE 3 and the reference position of the conditional reconfiguration candidate becoming shorter than a set threshold.

[0132] Additionally or alternatively, the one or more execution conditions may include a scheduled time being reached, which may be associated with a predicted future position of the UE 3 based on the planned route information.

[0133] According to the operation described in this embodiment, the RAN node can determine the execution conditions of the conditional mobility of the UE 3 based on the planned route information of the UE 3. This can contribute to improving the conditional mobility suitable for the UE 3 (e.g., aerial UE) that moves according to the planned route information.

[0134] <Fifth embodiment> This embodiment provides improved handover and conditional handover. An example configuration of the wireless communication system according to this embodiment may be similar to any of the example configurations described with reference to Figures 3 and 4.

[0135] FIG. 19 shows an example of a signaling procedure for handover of UE3. The handover may be a conditional handover. In step 1920, the source RAN node 1901 sends a handover request to the target RAN node 1902. Specifically, the source RAN node 1901 sends a HANDOVER REQUEST message to the target RAN node 1902. The HANDOVER REQUEST message requests handover of UE3 and indicates one or more target cells. The HANDOVER REQUEST message further includes planned route information indicating multiple planned locations of UE3. The planned route information may be information reported from UE3 to the source RAN node 1901 based on a request from the source RAN node 1901. The planned route information indicates the planned or intended locations of the UE. These locations may be 3D locations or 2D locations. In one example, the planned route information may relate to an aerial UE (i.e., a UE 3 having aerial UE capabilities) and may be flight path information including waypoints defined as 3D locations. In another example, the planned route information may describe planned or intended 2D locations of a UE 3 embedded in a land-based vehicle or a mobile robot.

[0136] In step 1940, the target RAN node 1902 selects a target cell. Specifically, the target RAN node 1902 may determine whether the handover request to one or more target cells indicated in the HANDOVER REQUEST message is allowed. If the handover request to the target cell indicated in the HANDOVER REQUEST message is not allowed, the target RAN node 1902 may select another cell different from the target cell indicated in the HANDOVER REQUEST message as an alternative target cell. Alternatively, if there is a cell that is more suitable for accepting UE 3 than the one or more target cells indicated in the HANDOVER REQUEST message, the target RAN node 1902 may select such a cell as an alternative or additional target cell.

[0137] The target RAN node 1902 may select or determine an alternative or additional target cell based on, using, or taking into account planned route information for the UE 3. For example, the target RAN node 1902 may predict or determine a current or future location for the UE 3 taking into account the planned locations of the UE 3 and optionally a timestamp for each location. The target RAN node 1902 may select at least one cell that covers or is located around the predicted or determined location of the UE 3 as an alternative or additional target cell.

[0138] The target RAN node 1902 may select or determine an alternative or additional target cell on the condition that at least the HANDOVER REQUEST message includes planned route information. In other words, if the HANDOVER REQUEST message includes planned route information, the target RAN node 1902 may select or determine an alternative or additional target cell.

[0139] In step 1960, the target RAN node 1902 sends a handover request response to the source RAN node 1901. Specifically, the target RAN node 1902 sends a HANDOVER REQUEST ACKNOWLEDGE message to the source RAN node 1901. The HANDOVER REQUEST ACKNOWLEDGE message indicates one or more alternative or additional target cells that can accept the handover of the UE 3. The HANDOVER REQUEST ACKNOWLEDGE message may indicate identities of the alternative or additional target cells.

[0140] Figure 20 shows a variation of the signaling procedure described with reference to Figure 19. In the example of Figure 20, the HANDOVER REQUEST message of step 2020 includes an explicit indication indicating that an alternative cell proposal is allowed. The name of the indication may be, for example, but not limited to, an Alternative Target Cell Allowed information element. Steps 2020 and 2060 are similar to steps 1940 and 1960 of Figure 19, except that in step 2040, the target RAN node 1902 selects or decides on an alternative or additional target cell, provided that the HANDOVER REQUEST message includes the above-mentioned indication indicating that an alternative cell proposal is allowed.

[0141] According to the handover procedures described with reference to Figures 19 and 20, the target RAN node 1902 can propose alternative or additional target cells only in certain situations or conditions where it would be useful.

[0142] <Other embodiment 1> The UE 3 may perform measurements specified by the network (RAN node) at each location indicated in the planned route information and store the measurement results and the location information of the UE 3 as a log. Alternatively, the UE 3 may store the measurement results and the location information of the UE 3 currently held at each location indicated in the planned route information as a log. The UE 3 may report the stored log to the network. This may be an immediate Minimization of Drive Test (MDT) or a logged MDT. In the case of an immediate MDT, the report may be made by a measurement report procedure. For example, the UE 3 may report the measurement results and the location information of the UE 3 currently held to the network upon arriving at (or remaining at) each location indicated in the planned route information.

[0143] <Other embodiment 2> The RAN node may perform altitude-related beam management. Specifically, the RAN node may associate beam or beam control configurations with altitude (altitude / height). For example, if UE3 is an aerial UE, the RAN node may preconfigure UE3 with beam or beam control configurations according to altitude. UE3 may select a beam or beam control configuration according to its own altitude. The beam control configuration may be a Transmission Configuration Indicator (TCI) state IE, a MeasConfig IE, a BeamFailureRecoveryConfig IE, a BeamFailureRecoveryServingCellConfig IE, or any combination thereof. Furthermore, the TCI state IE may be related to Multiple Transmission and Reception Point (mTRP) operation. For example, the RAN node may preconfigure UE3 with beam or beam control configurations according to altitudes corresponding to TRPs associated with multiple cells based on planned route information. UE3 may select a beam or beam control configuration according to its own altitude. In the above embodiments, each RAN node in a mobility-related procedure or a dual connectivity-related procedure may perform these.

[0144] <Other embodiment 3> The RAN node may perform beam management associated with a waypoint. Specifically, the RAN node may associate a beam or beam control configuration with the waypoint. For example, if UE3 is an aerial UE, the RAN node may preconfigure UE3 with a beam or beam control configuration corresponding to the waypoint. UE3 may select a beam or beam control configuration according to its own 3D position. The beam control configuration may be a TCI state IE, a MeasConfig IE, a BeamFailureRecoveryConfig IE, a BeamFailureRecoveryServingCellConfig IE, or any combination thereof. Furthermore, the TCI state IE may be related to mTRP operation. For example, the RAN node may preconfigure UE3 with a beam or beam control configuration corresponding to each waypoint associated with TRPs associated with multiple cells based on planned route information. UE3 may select a beam or beam control configuration according to its own 3D position. In the above-described embodiment, each RAN node in a mobility-related procedure or a dual connectivity-related procedure may perform these operations.

[0145] <Other embodiment 4> During a mobility-related procedure, the UE 3 may detect a radio link failure (e.g., Radio Link Failure (RLF)) due to deterioration of the radio quality (e.g., Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ)) of the serving cell, and may fail to execute the mobility-related procedure. In this case, the UE 3 attempts to re-establish a radio link (e.g., RRC (connection) re-establishment) with, for example, a cell with the best radio quality or a cell with a high priority. If the UE 3 is an aerial UE, it is preferable that the cell to be re-established (i.e., the RAN node managing the cell) supports aerial UEs. Therefore, the RAN node may share aerial UE support information with other RAN nodes managing neighboring cells (e.g., neighboring cells) of the serving cell. The aerial UE support information may indicate support in each cell (e.g., served cell) or in the RAN node. This information may be transmitted, for example, in Xn Setup Request and Xn Setup Response messages.

[0146] The RAN node may transmit information regarding support for aerial UEs in neighboring cells to the UE 3. Additionally or alternatively, the RAN node may transmit information regarding support for aerial UEs in neighboring frequencies (i.e., frequencies different from that of the serving cell) to the UE 3. The UE 3 may take information regarding support for aerial UEs into account when determining a cell to reconnect to. For example, if reconnection occurs while the UE 3 is performing an aerial function, the UE 3 may preferentially select a cell (or frequency) that supports aerial UEs. Alternatively, the UE 3 may preferentially select a cell (or frequency) that supports aerial UEs, regardless of whether the UE 3 was performing an aerial function when or before the reconnection occurred. Information regarding support for aerial UEs may be transmitted in broadcast information (e.g., any System Information Block (SIB), SIBx) or dedicated signaling (e.g., an RRC message).

[0147] Furthermore, the UE 3 may use the information on aerial UE support during mobility (e.g., cell reselection) in the RRC_IDLE state or the RRC_INACTIVE state. For example, the UE 3 may consider the information on aerial UE support when selecting a target cell for cell reselection in the same manner as in the case of reconnection. Specifically, the UE 3 may preferentially reselect a cell (or frequency) that supports aerial UE. Note that the aerial UE support information and the information on aerial UE support may be aerial function support information and information on aerial function support, respectively, or information equivalent thereto.

[0148] The RAN node may be a CU (e.g., gNB-CU) in a C-RAN deployment, or may be a combination of a CU and one or more DUs (e.g., eNB-DUs or gNB-DUs). When the RAN node is a combination of a CU and one or more DUs, the aerial UE support information may be transmitted from the CU to one or more DUs, or may be transmitted from each of the one or more DUs to the CU. Furthermore, in the latter case, the CU may transmit (transfer) the aerial UE support information received from a DU to one or more other DUs. On the other hand, the information regarding aerial UE support may be transmitted from the CU (via a DU) to the UE, or from the DU (first via the CU) to the UE.

[0149] <Other embodiment 5> When transmitting configuration information regarding a target cell (e.g., a target cell for handover, a target PSCell for dual connectivity) in a mobility-related procedure to the UE 3, the target RAN node may transmit information regarding future candidate cells associated with the planned route information to the UE 3. The information regarding future candidate cells associated with the planned route information may include, for example, information regarding recommended cells for each of one or more waypoints included in the planned route information (e.g., information indicating correspondence between waypoints and cells, or a list thereof). Furthermore, the information regarding recommended cells may include only cells managed by the target RAN node itself, or may also include information regarding cells managed by other RAN nodes owned by the target RAN node. When a radio link re-establishment (e.g., RRC (connection) re-establishment) becomes necessary during the execution of a mobility-related procedure or while the UE 3 is staying in a serving cell (e.g., a source cell, a target cell), the UE 3 may determine a cell to attempt re-establishment to based on the information. For example, the UE 3 may check the waypoint closest to its own position at the time of attempting reconnection, and may preferentially select a cell recommended for that waypoint, or may increase the priority of selecting that cell. This allows the UE 3 to appropriately select a cell to attempt reconnection to.

[0150] Additionally or alternatively, when the RAN node transmits an RRC message (e.g., RRC (Connection) Release) to release a radio connection (e.g., RRC Connection) to move the UE 3 to an RRC_IDLE state or an RRC_INACTIVE state, the RAN node may transmit information of future candidate cells associated with the planned route information to the UE 3. The UE 3 may then use this information for mobility (e.g., cell reselection) in the RRC_IDLE state or the RRC_INACTIVE state.

[0151] <Other embodiment 6> As mentioned above, during mobility-related procedures or while staying in a serving cell, the UE 3 may detect a radio link loss (e.g., RLF) due to degradation of the serving cell's radio quality (e.g., RSRP, RSRQ). Furthermore, the UE 3 may attempt to reconnect the radio link but fail. In these cases, the UE 3 may need to perform emergency operations. For example, if the UE 3 is an aerial UE and its movement is controlled by radio communication with a RAN node, it may need to perform an emergency landing in response to the loss of the radio communication.

[0152] Therefore, information on emergency landing points associated with the planned route information may be transmitted to the UE 3 in advance. The information on emergency landing points associated with the planned route information may indicate or include location information of points where an emergency landing is permitted or recommended, corresponding to each of one or more waypoints. Alternatively, the information on emergency landing points associated with the planned route information may be location information of one or more points within a serving cell or a location registration area (e.g., Tracking Area (TA)) of the UE 3, or associated with the serving cell or location registration area, where an emergency landing is permitted or recommended. If the information on emergency landing points indicates a point within the serving cell or associated therewith, the RAN node providing the serving cell may transmit this information to the UE 3 in advance, for example, by an RRC message, while the UE 3 is staying in the serving cell. On the other hand, if the information on emergency landing points indicates a point within the location registration area of ​​the UE 3 or associated therewith, the core network node (e.g., AMF or MME) may transmit this information to the UE 3 in advance during a location (re)registration procedure (e.g., TA update) of the UE 3.

[0153] The UE 3 may initiate an emergency landing operation if, for example, radio link reconnection fails, and may determine a target point for the emergency landing based on the information on the emergency landing point, thereby enabling the UE 3 to quickly and safely perform an emergency landing when it detects a radio link loss (e.g., RLF) during mobility-related procedures or while staying in a serving cell.

[0154] Next, exemplary configurations of RAN nodes 1, 2, 4, 6, and 7 and UE 3 according to the above-described embodiments will be described below. FIG. 21 is a block diagram showing an exemplary configuration of RAN node 1 according to the above-described embodiment. The configurations of other RAN nodes 2, 4, 6, and 7 may also be similar to the configuration shown in FIG. 21. In addition, the configurations of other RAN nodes described in the above embodiments (e.g., RAN nodes 501, 502, 1401, 1402, 1501, 1502, 1601, 1602, 1901, and 1902) may also be similar to the configuration shown in FIG. 21.

[0155] Referring to FIG. 21 , RAN node 1 includes a Radio Frequency (RF) transceiver 2101, a network interface 2103, a processor 2104, and a memory 2105. The RF transceiver 2101 performs analog RF signal processing for communicating with UEs, including UE 3. The RF transceiver 2101 may include multiple transceivers. The RF transceiver 2101 is coupled to an antenna array 2102 and a processor 2104. The RF transceiver 2101 receives modulation symbol data from the processor 2104, generates a transmit RF signal, and provides the transmit RF signal to the antenna array 2102. The RF transceiver 2101 also generates a baseband receive signal based on the receive RF signal received by the antenna array 2102 and provides the baseband receive signal to the processor 2104. The RF transceiver 2101 may include an analog beamformer circuit for beamforming. The analog beamformer circuit may include, for example, multiple phase shifters and multiple power amplifiers.

[0156] The network interface 2103 is used to communicate with network nodes (e.g., RAN nodes 2 and 4, and control and forwarding nodes of the core network). The network interface 2103 may include, for example, a network interface card (NIC) compliant with the IEEE 802.3 series.

[0157] The processor 2104 performs digital baseband signal processing (data plane processing) and control plane processing for wireless communication. The processor 2104 may include multiple processors. For example, the processor 2104 may include a modem processor (e.g., a Digital Signal Processor (DSP)) that performs digital baseband signal processing and a protocol stack processor (e.g., a Central Processing Unit (CPU) or a Micro Processing Unit (MPU)) that performs control plane processing.

[0158] For example, digital baseband signal processing by the processor 2104 may include signal processing of a Service Data Adaptation Protocol (SDAP) layer, a Packet Data Convergence Protocol (PDCP) layer, a Radio Link Control (RLC) layer, a Medium Access Control (MAC) layer, and a Physical (PHY) layer. Also, control plane processing by the processor 2104 may include processing of Non-Access Stratum (NAS) messages, RRC messages, MAC Control Elements (CE), and Downlink Control Information (DCI).

[0159] The processor 2104 may include a digital beamformer module for beamforming, which may include a Multiple Input Multiple Output (MIMO) encoder and precoder.

[0160] The memory 2105 is configured by a combination of volatile memory and non-volatile memory. The volatile memory is, for example, Static Random Access Memory (SRAM), Dynamic RAM (DRAM), or a combination thereof. The non-volatile memory is, for example, Mask Read Only Memory (MROM), Electrically Erasable Programmable ROM (EEPROM), flash memory, or a hard disk drive, or any combination thereof. The memory 2105 may include storage located remotely from the processor 2104. In this case, the processor 2104 may access the memory 2105 via the network interface 2103 or an I / O interface (not shown).

[0161] The memory 2105 may store one or more software modules (computer programs) 2106 including instructions and data for performing the processing by the RAN node 1 described in the above embodiments. In some implementations, the processor 2104 may be configured to read and execute the software modules 2106 from the memory 2105 to perform the processing by the RAN node 1 described in the above embodiments.

[0162] Note that if the RAN node 1 is a CU (eg, eNB-CU or gNB-CU) or a CU-CP, the RAN node 1 may not include the RF transceiver 2101 (and the antenna array 2102).

[0163] FIG. 22 is a block diagram showing an example configuration of a UE 3. A radio frequency (RF) transceiver 2201 performs analog RF signal processing for communication with a RAN node. The RF transceiver 2201 may include multiple transceivers. The analog RF signal processing performed by the RF transceiver 2201 includes frequency up-conversion, frequency down-conversion, and amplification. The RF transceiver 2201 is coupled to an antenna array 2202 and a baseband processor 2203. The RF transceiver 2201 receives modulation symbol data (or OFDM symbol data) from the baseband processor 2203, generates a transmit RF signal, and provides the transmit RF signal to the antenna array 2202. The RF transceiver 2201 also generates a baseband receive signal based on the receive RF signal received by the antenna array 2202 and provides the baseband receive signal to the baseband processor 2203. The RF transceiver 2201 may include an analog beamformer circuit for beamforming. The analog beamformer circuitry includes, for example, multiple phase shifters and multiple power amplifiers.

[0164] The baseband processor 2203 performs digital baseband signal processing (data plane processing) and control plane processing for wireless communication. Digital baseband signal processing includes (a) data compression / decompression, (b) data segmentation / concatenation, (c) transmission format (transmission frame) generation / decomposition, (d) transmission path coding / decoding, (e) modulation (symbol mapping) / demodulation, and (f) generation of OFDM symbol data (baseband OFDM signal) using Inverse Fast Fourier Transform (IFFT). Meanwhile, control plane processing includes communication management for Layer 1 (e.g., transmit power control), Layer 2 (e.g., radio resource management and hybrid automatic repeat request (HARQ) processing), and Layer 3 (e.g., signaling related to attachment, mobility, and call management).

[0165] For example, digital baseband signal processing by the baseband processor 2203 may include signal processing of an SDAP layer, a PDCP layer, an RLC layer, a MAC layer, and a PHY layer. Also, control plane processing by the baseband processor 2203 may include processing of a Non-Access Stratum (NAS) protocol, an RRC protocol, MAC CEs, and DCIs.

[0166] The baseband processor 2203 may perform MIMO encoding and precoding for beamforming.

[0167] The baseband processor 2203 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 control plane processing may be shared with the application processor 2204, which will be described later.

[0168] The application processor 2204 is also referred to as a CPU, MPU, microprocessor, or processor core. The application processor 2204 may include multiple processors (multiple processor cores). The application processor 2204 executes a system software program (operating system (OS)) and various application programs (e.g., a calling application, a web browser, a mailer, a camera operation application, and a music playback application) read from the memory 2206 or a memory not shown, thereby realizing various functions of the UE3.

[0169] In some implementations, the baseband processor 2203 and the application processor 2204 may be integrated on a single chip, as indicated by the dashed line (2205) in Figure 22. In other words, the baseband processor 2203 and the application processor 2204 may be implemented as a single System on Chip (SoC) device 2205. An SoC device is sometimes called a system Large Scale Integration (LSI) or a chipset.

[0170] The memory 2206 is volatile memory, nonvolatile memory, or a combination thereof. The memory 2206 may include multiple physically independent memory devices. The volatile memory is, for example, SRAM, DRAM, or a combination thereof. The nonvolatile memory is MROM, EEPROM, flash memory, a hard disk drive, or any combination thereof. For example, the memory 2206 may include an external memory device accessible from the baseband processor 2203, the application processor 2204, and the SoC 2205. The memory 2206 may also include an internal memory device integrated within the baseband processor 2203, the application processor 2204, or the SoC 2205. Furthermore, the memory 2206 may include memory within a Universal Integrated Circuit Card (UICC).

[0171] The memory 2206 may store one or more software modules (computer programs) 2207 including instructions and data for performing the processing by the UE 3 described in the above-described embodiments. In some implementations, the baseband processor 2203 or the application processor 2204 may be configured to read and execute the software modules 2207 from the memory 2206, thereby performing the processing by the UE 3 described using the drawings in the above-described embodiments.

[0172] It should be noted that the control plane processing and operations performed by UE3 described in the above embodiment can be realized by elements other than the RF transceiver 2201 and the antenna array 2202, namely, at least one of the baseband processor 2203 and the application processor 2204, and the memory 2206 storing the software module 2207.

[0173] As described with reference to Figures 21 and 22, each of the processors included in the multiple RAN nodes and UEs according to the above-described embodiments can execute one or more programs including instructions for causing a computer to perform the algorithms described with reference to the drawings. The programs include instructions (or software code) that, when loaded into a computer, cause the computer to perform one or more functions described in the embodiments. The programs may be stored on a non-transitory computer-readable medium or a tangible storage medium. By way of example and not limitation, computer-readable media or tangible storage media include random-access memory (RAM), read-only memory (ROM), flash memory, solid-state drive (SSD) or other memory technology, CD-ROM, digital versatile disk (DVD), Blu-ray® disk or other optical disk storage, magnetic cassette, magnetic tape, magnetic disk storage or other magnetic storage device. The programs may also be transmitted on a transitory computer-readable medium or communication medium. By way of example and not limitation, transitory computer-readable media or communication media include electrical, optical, acoustic, or other forms of propagated signals.

[0174] The above-described embodiments are merely examples of application of the technical ideas obtained by the inventors of the present invention. In other words, the technical ideas are not limited to the above-described embodiments, and various modifications are possible.

[0175] For example, some or all of the above embodiments can be described as, but are not limited to, the following supplementary notes.

[0176] (Appendix 1) a first Radio Access Network (RAN) node, at least one memory; at least one processor coupled to the at least one memory and configured to send planned route information indicating a plurality of planned locations of a User Equipment (UE) to a second RAN node during a mobility-related procedure or a dual connectivity-related procedure for the UE; Equipped with First RAN node. (Appendix 2) The planned route information is flight route information indicating a plurality of waypoints defined as three-dimensional locations. 1. The first RAN node of claim 1. (Appendix 3) The UE is a UE having an aerial UE function; 3. The first RAN node of claim 1 or 2. (Appendix 4) the at least one processor is configured to send the planned route information to the second RAN node during the mobility-related procedure; the mobility-related procedure is a handover procedure or a conditional handover procedure. 4. The first RAN node according to any one of Supplementary Note 1 to 3. (Appendix 5) the at least one processor is configured to send the planned route information to the second RAN node during the dual connectivity related procedure; The dual connectivity related procedure is a secondary node (SN) addition procedure, a conditional SN addition procedure, a SN change procedure, or a conditional SN change procedure; 4. The first RAN node according to any one of Supplementary Note 1 to 3. (Appendix 6) the first RAN node and the second RAN node are, respectively, a master node (MN) and an SN in the SN addition procedure or the conditional SN addition procedure, an MN and a target SN in the SN change procedure or the conditional SN change procedure, or a source SN and an MN in the SN change procedure or the conditional SN change procedure; 10. The first RAN node according to claim 5. (Appendix 7) the at least one processor is configured to send the planned route information to the second RAN node during a conditional handover procedure, a conditional secondary node (SN) addition procedure, or a conditional SN change procedure. 4. The first RAN node according to any one of Supplementary Note 1 to 3. (Appendix 8) the at least one processor is configured to send the planned route information to the second RAN node via a HANDOVER REQUEST, an S-NODE ADDITION REQUEST, or an S-NODE CHANGE REQUIRED message; 8. The first RAN node according to any one of Supplementary Note 1 to 7. (Appendix 9) the at least one processor is configured to send the planned route information to the second RAN node via an inter-node Radio Resource Control (RRC) message. 8. The first RAN node according to any one of Supplementary Note 1 to 7. (Appendix 10) the planned route information is used by the second RAN node to determine whether to accept a handover of the UE to a target cell or an addition or change of a secondary node (SN) for the UE. 10. The first RAN node according to any one of Supplementary Note 1 to 9. (Appendix 11) the planned route information is used by the second RAN node to determine at least one acceptable cell among one or more target or candidate cells; 10. The first RAN node according to any one of Supplementary Note 1 to 9. (Appendix 12) the planned route information is used by the second RAN node to generate or prepare a configuration of a target cell or a candidate cell. 10. The first RAN node according to any one of Supplementary Note 1 to 9. (Appendix 13) the planned route information is used by the second RAN node to select a secondary cell for carrier aggregation. 10. The first RAN node according to any one of Supplementary Note 1 to 9. (Appendix 14) 1. A method performed by a first Radio Access Network (RAN) node, comprising: In a mobility-related procedure or a dual connectivity-related procedure for User Equipment (UE), sending planned route information indicating a plurality of planned locations of the UE to a second RAN node. method. (Appendix 15) 1. A program for causing a computer to perform a method for a first Radio Access Network (RAN) node, the program comprising: The method comprises sending planned route information indicating a plurality of planned locations of User Equipment (UE) to a second RAN node during a mobility-related procedure or a dual connectivity-related procedure for the UE. program. (Appendix 16) a second Radio Access Network (RAN) node, at least one memory; at least one processor coupled to the at least one memory and configured to receive, from a first RAN node, planned route information indicating a plurality of planned locations for a User Equipment (UE) during a mobility-related procedure or a dual connectivity-related procedure for the UE; Equipped with Second RAN node. (Appendix 17) The planned route information is flight route information indicating a plurality of waypoints defined as three-dimensional locations. 17. The second RAN node of claim 16. (Appendix 18) The UE is a UE having an aerial UE function; 18. The second RAN node of claim 16 or 17. (Appendix 19) the at least one processor is configured to receive the planned route information from the first RAN node during the mobility-related procedure; the mobility-related procedure is a handover procedure or a conditional handover procedure. 19. The second RAN node according to any one of Supplementary Notes 16 to 18. (Appendix 20) the at least one processor is configured to receive the planned route information from a first RAN node during the dual connectivity related procedure; The dual connectivity-related procedure is a secondary node addition, a conditional secondary node addition, a secondary node change, or a conditional secondary node change. 19. The second RAN node according to any one of Supplementary Notes 16 to 18. (Appendix 21) the first RAN node and the second RAN node are, respectively, a master node (MN) and an SN in the SN addition procedure or the conditional SN addition procedure, an MN and a target SN in the SN change procedure or the conditional SN change procedure, or a source SN and an MN in the SN change procedure or the conditional SN change procedure; 21. The second RAN node of claim 20. (Appendix 22) the at least one processor is configured to receive the planned route information from the first RAN node during a conditional handover procedure, a conditional secondary node (SN) addition procedure, or a conditional SN change procedure. 19. The second RAN node according to any one of Supplementary Notes 16 to 18. (Appendix 23) the at least one processor is configured to receive the planned route information from the first RAN node via a HANDOVER REQUEST, an S-NODE ADDITION REQUEST, or an S-NODE CHANGE REQUIRED message; 23. The second RAN node according to any one of Supplementary Notes 16 to 22. (Appendix 24) the at least one processor is configured to receive the planned route information from the first RAN node via an inter-node Radio Resource Control (RRC) message. 23. The second RAN node according to any one of Supplementary Notes 16 to 22. (Appendix 25) the at least one processor is configured to use the planned route information to determine whether to accept a handover of the UE to a target cell or an addition or change of a secondary node (SN) for the UE. 25. The second RAN node according to any one of Supplementary Notes 16 to 24. (Appendix 26) the at least one processor is configured to use the planned route information to determine at least one acceptable cell among one or more target or candidate cells. 25. The second RAN node according to any one of Supplementary Notes 16 to 24. (Appendix 27) the at least one processor is configured to use the planned route information to generate or prepare a configuration of a target cell or a candidate cell. 25. The second RAN node according to any one of Supplementary Notes 16 to 24. (Appendix 28) the at least one processor is configured to use the planned route information to select a secondary cell for carrier aggregation. 25. The second RAN node according to any one of Supplementary Notes 16 to 24. (Appendix 29) 1. A method performed by a second Radio Access Network (RAN) node, comprising: A method for performing a mobility-related or dual connectivity-related procedure for a User Equipment (UE), comprising receiving, from a first RAN node, planned route information indicating a plurality of planned locations for the UE. method. (Appendix 30) 1. A program for causing a computer to perform a method for a second Radio Access Network (RAN) node, the program comprising: The method comprises receiving, during a mobility-related or dual connectivity-related procedure for User Equipment (UE), planned route information from a first RAN node indicating a plurality of planned locations for the UE; program. (Appendix 31) A Radio Access Network (RAN) node configured to operate as a Master Node (MN) in dual connectivity for User Equipment (UE), comprising: at least one memory; at least one processor coupled to the at least one memory and configured to send planned route information indicating a plurality of planned positions of the UE to a secondary node (SN) of the dual connectivity; Equipped with RAN node. (Appendix 32) The planned route information is flight route information indicating a plurality of waypoints defined as three-dimensional locations. RAN node as described in Supplementary Note 31. (Appendix 33) The UE is a UE having an aerial UE function; 33. The RAN node of claim 31 or 32. (Appendix 34) The UE is a UE implemented in an unmanned or uncrewed aerial vehicle (UAV), 34. The RAN node according to any one of Supplementary Notes 31 to 33. (Appendix 35) the at least one processor is configured to send aerial UE subscription information or information derived therefrom together with the planned route information to the SN; The aerial UE subscription information or information derived therefrom indicates whether the UE or its user is authorized to use an aerial UE function, whether the UE is an aerial UE, or whether the UE supports an aerial UE function; 35. The RAN node according to any one of Supplementary Notes 32 to 34. (Appendix 36) the at least one processor is configured to send the planned route information to the SN in an SN addition procedure; 36. The RAN node according to any one of Supplementary Notes 31 to 35. (Appendix 37) the at least one processor is configured to send the planned route information to the SN via an S-NODE ADDITION REQUEST message; 37. The RAN node according to any one of Supplementary Notes 31 to 36. (Appendix 38) the at least one processor is configured to send the planned route information to the SN via an inter-node Radio Resource Control (RRC) message. 37. The RAN node according to any one of Supplementary Notes 31 to 36. (Appendix 39) 1. A method performed by a Radio Access Network (RAN) node configured to operate as a Master Node (MN) in dual connectivity for User Equipment (UE), comprising: sending planned route information indicating a plurality of planned positions of the UE to a secondary node (SN) of the dual connectivity; method. (Appendix 40) 1. A program for causing a computer to perform a method for a Radio Access Network (RAN) node configured to operate as a Master Node (MN) in dual connectivity for User Equipment (UE), comprising: The method comprises sending planned route information indicating a plurality of planned positions of the UE to the dual connectivity secondary node (SN). program. (Appendix 41) 1. A Radio Access Network (RAN) node configured to operate as a Secondary Node (SN) in dual connectivity for User Equipment (UE), comprising: at least one memory; at least one processor coupled to the at least one memory and configured to receive planned route information indicating a plurality of planned positions of the UE from the dual connectivity master node (MN); Equipped with RAN node. (Appendix 42) The planned route information is flight route information indicating a plurality of waypoints defined as three-dimensional locations. RAN node as described in Supplementary Note 41. (Appendix 43) The UE is a UE having an aerial UE function; 43. The RAN node of claim 41 or 42. (Appendix 44) The UE is a UE implemented in an unmanned or uncrewed aerial vehicle (UAV), 44. The RAN node according to any one of Supplementary Notes 41 to 43. (Appendix 45) the at least one processor is configured to receive aerial UE subscription information or information derived therefrom from the MN along with the planned route information; The aerial UE subscription information or information derived therefrom indicates whether the UE or its user is authorized to use an aerial UE function, whether the UE is an aerial UE, or whether the UE supports an aerial UE function; 45. The RAN node according to any one of Supplementary Notes 42 to 44. (Appendix 46) the at least one processor is configured to receive the planned route information from the MN in an SN addition procedure; 46. ​​The RAN node according to any one of Supplementary Notes 41 to 45. (Appendix 47) The at least one processor is configured to receive the planned route information from a previous mobile node via an S-NODE ADDITION REQUEST message. 47. The RAN node according to any one of Supplementary Notes 41 to 46. (Appendix 48) the at least one processor is configured to receive the planned route information from the MN via an inter-node Radio Resource Control (RRC) message. 47. The RAN node according to any one of Supplementary Notes 41 to 46. (Appendix 49) 1. A method performed by a Radio Access Network (RAN) node configured to operate as a Secondary Node (SN) in dual connectivity for User Equipment (UE), comprising: receiving planned route information indicating a plurality of planned positions of the UE from the dual connectivity master node (MN); method. (Appendix 50) 1. A program for causing a computer to perform a method for a Radio Access Network (RAN) node configured to operate as a Secondary Node (SN) in dual connectivity for User Equipment (UE), the program comprising: The method comprises receiving planned route information indicating a plurality of planned positions of the UE from the dual connectivity master node (MN). program. (Appendix 51) A Radio Access Network (RAN) node configured to operate as a Master Node (MN) in dual connectivity for User Equipment (UE), comprising: at least one memory; at least one processor coupled to the at least one memory and configured to receive planned route information indicating a plurality of planned positions of the UE from a secondary node (SN) of the dual connectivity; Equipped with RAN node. (Appendix 52) The planned route information is flight route information indicating a plurality of waypoints defined as three-dimensional locations. RAN node as defined in Supplementary Note 51. (Appendix 53) The UE is a UE having an aerial UE function; 53. The RAN node of claim 51 or 52. (Appendix 54) 1. A method performed by a Radio Access Network (RAN) node configured to operate as a Master Node (MN) in dual connectivity for User Equipment (UE), comprising: receiving planned route information indicating a plurality of planned locations of the UE from a secondary node (SN) of the dual connectivity; method. (Appendix 55) 1. A program for causing a computer to perform a method for a Radio Access Network (RAN) node configured to operate as a Master Node (MN) in dual connectivity for User Equipment (UE), comprising: The method comprises receiving planned route information indicating a plurality of planned positions of the UE from a secondary node (SN) of the dual connectivity. program. (Appendix 56) 1. A Radio Access Network (RAN) node configured to operate as a Secondary Node (SN) in dual connectivity for User Equipment (UE), comprising: at least one memory; at least one processor coupled to the at least one memory and configured to send planned route information indicating a plurality of planned positions of the UE to the dual connectivity master node (MN); Equipped with RAN node. (Appendix 57) The planned route information is flight route information indicating a plurality of waypoints defined as three-dimensional locations. RAN node as described in Appendix 56. (Appendix 58) The UE is a UE having an aerial UE function; 58. A RAN node as defined in claim 56 or 57. (Appendix 59) 1. A method performed by a Radio Access Network (RAN) node configured to operate as a Secondary Node (SN) in dual connectivity for User Equipment (UE), comprising: sending planned route information indicating a plurality of planned positions of the UE to the dual connectivity master node (MN); method. (Appendix 60) 1. A program for causing a computer to perform a method for a Radio Access Network (RAN) node configured to operate as a Secondary Node (SN) in dual connectivity for User Equipment (UE), the program comprising: The method comprises sending planned route information indicating a plurality of planned positions of the UE to the dual connectivity master node (MN); program. (Appendix 61) A Radio Access Network (RAN) node configured to operate as a Master Node (MN) in dual connectivity for User Equipment (UE), comprising: at least one memory; at least one processor coupled to the at least one memory and configured to send aerial UE subscription information or information derived therefrom regarding the UE to the dual connectivity secondary node (SN); Equipped with RAN node. (Appendix 62) The aerial UE subscription information or information derived therefrom indicates whether the UE or its user is authorized to use an aerial UE function, whether the UE is an aerial UE, or whether the UE supports an aerial UE function; RAN node as described in Supplementary Note 61. (Appendix 63) The at least one processor is configured to send the aerial UE subscription information or information derived therefrom to the SN in an SN addition procedure. 63. The RAN node of claim 61 or 62. (Appendix 64) the at least one processor is configured to send the aerial UE subscription information or information derived therefrom to the SN via an S-NODE ADDITION REQUEST message; 64. The RAN node according to any one of Supplementary Notes 61 to 63. (Appendix 65) the at least one processor is configured to send flight path information indicating a plurality of planned positions of the UE together with the aerial UE subscription information or information derived therefrom to the SN; 65. The RAN node according to any one of Supplementary Notes 61 to 64. (Appendix 66) 1. A method performed by a Radio Access Network (RAN) node configured to operate as a Master Node (MN) in dual connectivity for User Equipment (UE), comprising: sending aerial UE subscription information or information derived therefrom about the UE to the dual connectivity secondary node (SN); method. (Appendix 67) 1. A program for causing a computer to perform a method for a Radio Access Network (RAN) node configured to operate as a Master Node (MN) in dual connectivity for User Equipment (UE), comprising: The method comprises sending aerial UE subscription information or information derived therefrom to a secondary node (SN) of the dual connectivity. program. (Appendix 68) 1. A Radio Access Network (RAN) node configured to operate as a Secondary Node (SN) in dual connectivity for User Equipment (UE), comprising: at least one memory; at least one processor coupled to the at least one memory and configured to receive aerial UE subscription information or information derived therefrom regarding the UE from the dual connectivity master node (MN); Equipped with RAN node. (Appendix 69) The aerial UE subscription information or information derived therefrom indicates whether the UE or its user is authorized to use an aerial UE function, whether the UE is an aerial UE, or whether the UE supports an aerial UE function; 68. A RAN node as described in Appendix 68. (Appendix 70) The at least one processor is configured to receive the aerial UE subscription information or information derived therefrom from the MN in an SN addition procedure. 69. The RAN node of claim 68. (Appendix 71) the at least one processor is configured to receive the aerial UE subscription information or information derived therefrom from the MN via an S-NODE ADDITION REQUEST message. 71. The RAN node of any one of Supplementary Notes 68 to 70. (Appendix 72) the at least one processor is configured to receive from the MN flight path information indicating a plurality of planned positions of the UE along with the aerial UE subscription information or information derived therefrom. 72. The RAN node of any one of Supplementary Notes 68 to 71. (Appendix 73) 1. A method performed by a Radio Access Network (RAN) node configured to operate as a Secondary Node (SN) in dual connectivity for User Equipment (UE), comprising: receiving aerial UE subscription information or information derived therefrom relating to the UE from the dual connectivity master node (MN); method. (Appendix 74) 1. A program for causing a computer to perform a method for a Radio Access Network (RAN) node configured to operate as a Secondary Node (SN) in dual connectivity for User Equipment (UE), the program comprising: The method comprises receiving aerial UE subscription information or information derived therefrom from the dual connectivity master node (MN). program. (Appendix 75) A Radio Access Network (RAN) node, comprising: at least one memory; at least one processor coupled to the at least one memory and configured to determine one or more execution conditions for conditional mobility of a User Equipment (UE) based on planned route information indicating a plurality of planned positions of the UE; Equipped with RAN node. (Appendix 76) The planned route information is flight route information indicating a plurality of waypoints defined as three-dimensional locations. 7. The RAN node of claim 75. (Appendix 77) The UE is a UE having an aerial UE function; 77. The RAN node of claim 75 or 76. (Appendix 78) The one or more execution conditions include the UE being located at a reference position, being within a set distance from a reference position, or being within a reference area. 78. The RAN node of any one of Supplementary Notes 75 to 77. (Appendix 79) The one or more execution conditions include a scheduled time being reached. 79. The RAN node of any one of Supplementary Notes 75 to 78. (Appendix 80) The conditional mobility is a conditional handover, a conditional Primary Secondary Cell Group (SCG) Cell (PSCell) addition, a conditional intra-Secondary Node (SN) PSCell change, or an inter-SN conditional PSCell change. 80. The RAN node of any one of Supplementary Notes 75 to 79. (Appendix 81) The RAN node is a source node of a conditional handover, a master node (MN) of a conditional PSCell addition, a SN of an intra-SN conditional PSCell change, a source SN of an SN-initiated inter-SN conditional PSCell change, or a MN of an MN-initiated inter-SN conditional PSCell change. 80. The RAN node of claim 80. (Appendix 82) 1. A method performed by a Radio Access Network (RAN) node, comprising: determining one or more execution conditions for conditional mobility of a User Equipment (UE) based on planned route information indicating a plurality of planned positions of the UE; method. (Appendix 83) 1. A program for causing a computer to perform a method for a radio access network (RAN) node, comprising: The method comprises determining one or more execution conditions for conditional mobility of a User Equipment (UE) based on planned route information indicating a plurality of planned positions of the UE. program. (Appendix 84) A Radio Access Network (RAN) node, comprising: at least one memory; coupled to the at least one memory; and receiving a User Equipment (UE) handover request from a source RAN node indicating one or more target cells; if the handover request includes one or both of planned route information indicating multiple planned locations of the UE and an explicit indication that alternative cell suggestions are allowed, sending a handover request response to the source RAN node indicating other cells that are acceptable for handover and that are different from the one or more target cells; at least one processor configured to Equipped with RAN node. (Appendix 85) the at least one processor is configured to send the handover request response to the source RAN node indicating the other cell, at least on the condition that the handover request includes planned route information indicating multiple planned locations of the UE. RAN node as described in Appendix 84. (Appendix 86) the at least one processor is configured to determine the other cell that is capable of accepting handover based on the planned route information. 86. The RAN node of claim 84 or 85. (Appendix 87) The planned route information is flight route information indicating a plurality of waypoints defined as three-dimensional locations. 87. The RAN node of any one of Supplementary Notes 84 to 86. (Appendix 88) the handover request is a conditional handover request. 88. The RAN node of any one of Supplementary Notes 84 to 87. (Appendix 89) 1. A method performed by a Radio Access Network (RAN) node, comprising: receiving a handover request for a User Equipment (UE) from a source RAN node indicating one or more target cells; and if the handover request includes one or both of planned route information indicating multiple planned locations of the UE and an explicit indication that alternative cell suggestions are allowed, sending a handover request response to the source RAN node indicating other cells that are acceptable for handover and that are different from the one or more target cells; A method comprising: (Appendix 90) A program for causing a computer to perform a method for a Radio Access Network (RAN) node, comprising: The method comprises: receiving a handover request for a User Equipment (UE) from a source RAN node indicating one or more target cells; and if the handover request includes one or both of planned route information indicating multiple planned locations of the UE and an explicit indication that alternative cell suggestions are allowed, sending a handover request response to the source RAN node indicating other cells that are acceptable for handover and that are different from the one or more target cells; A program that includes: (Appendix 91) A Radio Access Network (RAN) node, comprising: at least one memory; at least one processor coupled to the at least one memory and configured to transmit information regarding support of aerial user equipment (UE) in neighboring cells or neighboring frequencies to the UE; Equipped with RAN node. (Appendix 92) User Equipment (UE), at least one memory; at least one processor coupled to the at least one memory and configured to receive information from a Radio Access Network (RAN) node regarding support for aerial UEs in neighboring cells or neighboring frequencies; Equipped with UE. (Appendix 93) the at least one processor is configured to determine, based on the information, a cell to which a reconnection to the wireless link is to be attempted when a reconnection of the wireless link is necessary. UE as described in Appendix 92. (Appendix 94) the at least one processor is configured to take the information into account in cell reselection in a Radio Resource Control (RRC)_IDLE state or an RRC_INACTIVE state. 94. The UE described in Appendix 92 or 93. (Appendix 95) A Radio Access Network (RAN) node, comprising: at least one memory; at least one processor coupled to the at least one memory and configured to transmit to the User Equipment (UE) information of one or more future candidate cells associated with planned route information indicating a plurality of planned locations of the UE; Equipped with RAN node. (Appendix 96) the information of the one or more future candidate cells indicates information of a recommended cell at each of a plurality of locations included in the planned route information; RAN node as described in Appendix 95. (Appendix 97) User Equipment (UE), at least one memory; at least one processor coupled to the at least one memory and configured to receive, from a Radio Access Network (RAN) node, information of one or more future candidate cells associated with planned route information indicating a plurality of planned positions of the UE; Equipped with UE. (Appendix 98) the information of the one or more future candidate cells indicates information of a recommended cell at each of a plurality of locations included in the planned route information; UE as described in Appendix 97. (Appendix 99) the at least one processor is configured to determine, when a reconnection of a wireless link is necessary, a cell to which to attempt reconnection based on information of the one or more future candidate cells. 97 or 98. (Appendix 100) the at least one processor is configured to consider information of the one or more future candidate cells in cell reselection in a Radio Resource Control (RRC)_IDLE state or an RRC_INACTIVE state. 97 or 98. (Appendix 101) a network node, at least one memory; at least one processor coupled to the at least one memory and configured to transmit, to the User Equipment (UE), information on emergency landing points associated with planned route information indicating a plurality of planned positions of the UE; Equipped with Network node. (Appendix 102) the emergency landing point information indicates location information of one or more points where emergency landings are permitted or recommended corresponding to each of the plurality of planned locations; 102. The network node of claim 101. (Appendix 103) The emergency landing point information indicates location information of one or more points within a serving cell of the UE or a location registration area of ​​the UE, or associated with the serving cell or the location registration area, where an emergency landing is permitted or recommended. 102. The network node of claim 101. (Appendix 104) the network node is a Radio Access Network (RAN) node or a core network node; A network node according to any one of appendices 101 to 103. (Appendix 105) User Equipment (UE), at least one memory; at least one processor coupled to the at least one memory and configured to receive, from a Radio Access Network (RAN) node or a core network node via the RAN node, information of an emergency landing point associated with planned route information indicating a plurality of planned positions of the UE; Equipped with UE. (Appendix 106) the emergency landing point information indicates location information of one or more points where emergency landings are permitted or recommended corresponding to each of the plurality of planned locations; 1. The UE described in Appendix 105. (Appendix 107) The emergency landing point information indicates location information of one or more points within a serving cell of the UE or a location registration area of ​​the UE, or associated with the serving cell or the location registration area, where an emergency landing is permitted or recommended. 1. The UE described in Appendix 105. (Appendix 108) the at least one processor is configured to determine a target location for an emergency landing attempt based on information about the emergency landing point. 108. The UE according to any one of appendices 105 to 107.

[0177] This application claims priority based on Japanese Patent Application No. 2022-118616, filed on July 26, 2022, the disclosure of which is incorporated herein in its entirety. [Explanation of symbols]

[0178] 1 Master Node (MN) 2. Source Secondary Node (S-SN) 3. User Equipment (UE) 4. Target Secondary Node (T-SN) 6 Source RAN Node 7 Target RAN Node 2104 processor 2105 memory 2106 Modules 2203 Baseband Processor 2204 Application Processor 2206 memory 2207 Modules

Claims

1. a first Radio Access Network (RAN) node, means for sending planned route information indicating a plurality of planned positions of a User Equipment (UE) to a second RAN node during a mobility-related procedure or a dual connectivity-related procedure for the UE; First RAN node.

2. the planned route information is flight route information indicating a plurality of waypoints defined as three-dimensional locations; The first RAN node of claim 1.

3. the sending means is configured to send the planned route information to the second RAN node during the mobility-related procedure; the mobility-related procedure is a handover procedure or a conditional handover procedure. The first RAN node according to claim 1 or 2.

4. 1. A method performed by a first Radio Access Network (RAN) node, comprising: In a mobility-related procedure or a dual connectivity-related procedure for a User Equipment (UE), sending planned route information indicating a plurality of planned positions of the UE to a second RAN node. method.

5. 1. A program for causing a computer to perform a method for a first Radio Access Network (RAN) node, the program comprising: The method comprises sending planned route information indicating a plurality of planned locations of User Equipment (UE) to a second RAN node during a mobility-related procedure or a dual connectivity-related procedure for the UE. program.

6. a second Radio Access Network (RAN) node, a means for receiving, during a mobility-related procedure or a dual connectivity-related procedure for a User Equipment (UE), from a first RAN node, planned route information indicating a plurality of planned positions for the UE; Second RAN node.

7. 1. A Radio Access Network (RAN) node configured to operate as a Master Node (MN) in dual connectivity for User Equipment (UE), comprising: means coupled to the at least one memory and configured to send planned route information indicating a plurality of planned positions of the UE to the dual connectivity secondary node (SN); RAN node.

8. 1. A Radio Access Network (RAN) node configured to operate as a Secondary Node (SN) in dual connectivity for User Equipment (UE), comprising: means for receiving planned route information indicating a plurality of planned positions of the UE from the dual connectivity master node (MN); RAN node.

9. 1. A Radio Access Network (RAN) node configured to operate as a Master Node (MN) in dual connectivity for User Equipment (UE), comprising: means for receiving planned route information indicating a plurality of planned positions of the UE from a secondary node (SN) of the dual connectivity; RAN node.

10. 1. A Radio Access Network (RAN) node configured to operate as a Secondary Node (SN) in dual connectivity for User Equipment (UE), comprising: means for sending planned route information indicating a plurality of planned positions of the UE to the dual connectivity master node (MN); RAN node.

Images