Network Node, Communication Device, and Method for Processing a Multi-Hop Configuration in a Wireless Communication Network

Abstract

In a wireless communication network (500), a network node and a method thereof are provided for handling a multi-hop configuration of conditional primary-secondary cell change or primary-secondary cell group cell change (CPC) for communication devices (530, 531) configured with a dual connection of a master cell group (MCG) managed by a first network node (511) and a secondary cell group (SCG) managed by a second network node (512). Different solutions for enabling a multi-hop CPC configuration and implementations of these solutions are disclosed from the perspectives of the first network node (511), the second network node (512), the target candidate network node, and the communication devices (530, 531).

Description

Technical Field

[0001] The present embodiment relates to network nodes, communication devices, and methods therein. In particular, it relates to the processing of a multi-hop conditional primary secondary cell (PSCell) or primary secondary cell group change (CPC) configuration for a communication device operating in dual connectivity with a master cell group (MCG) and a secondary cell group (SCG) in a wireless communication network.

Background Art

[0002] In a typical wireless communication network, a wireless device, also known as a wireless communication device, mobile station, station (STA), and / or user equipment (UE), communicates with one or more core networks (CNs) via a radio access network (RAN). The RAN covers a geographical area that is divided into service areas or cell areas that can be referred to as beams or beam groups, and each service area or cell area is served by a wireless access node, such as a Wi-Fi access point or a radio base station (RBS), which may be denoted as, for example, "NodeB" or "eNodeB" or "gNB" depending on the network. A service area or cell area is a geographical area where wireless coverage is provided by a wireless network node. The wireless network node communicates with wireless devices within the range of the wireless network node via an air interface operating at a radio frequency.

[0003] The Universal Mobile Telecommunications System (UMTS) is a third-generation (3G) communication network developed from the second-generation (2G) GSM (Global System for Mobile Communication). The fourth-generation (4G) network or Long Term Evolution (LTE)The standardization of the evolved packet system (EPS), also known as such, has been completed within the 3rd Generation Partnership Project (3GPP), and this work continues in the next 3GPP release, such as the specification of the 5th Generation (5G) New Radio (NR) network. and future releases It continues in the following.

[0004] 3GPP Dual Connectivity In 3GPP Release 12, dual connectivity (DC) of LTE functions was introduced, enabling the UE to connect to two cell groups, each controlled by an eNB, an LTE access node called the master eNB (MeNB) and the secondary eNB (SeNB). The UE still has only one radio resource control (RRC) connection to the network. In 3GPP, the dual connection (DC) solution has since evolved and is now also specified between NR and between LTE and NR. With the introduction of 5G, the term multi-radio dual connectivity (MR-DC) (see also 3GPP TS37.340) was defined as an umbrella term for all dual connection options that include at least one NR access node. Using the generalized term for MR-DC, the UE is connected to a master cell group (MCG) controlled by a master node (MN) and a secondary cell group (SCG) controlled by a secondary node (SN).

[0005] Furthermore, in MR-DC, when dual connectivity is configured for the UE, carrier aggregation can also be used in the same way in each of the two cell groups of MCG and SCG. In this case, within the MCG controlled by the master node (MN), the UE can use one primary cell (Pcell) and one or more secondary cells (SCells). And within the SCG controlled by the secondary node (SN), the UE can use one primary SCell (PSCell) (also known as the primary SCG cell in NR) and one or more SCells. In the case of this combination, that is, the dual connectivity combined with carrier aggregation in MR-DC is shown in FIG. 1, where the master node (MN) 110, secondary node (SN) 120, UE 130, master cell group (MCG) 140, secondary cell group (SCG) 150, primary cell (PCell) 160 within MCG 140, primary SCell (PSCell) 170 within SCG 150, and a plurality of SCells are shown. In NR, the primary cell of the master cell group or secondary cell group is also called a special cell (SpCell). Therefore, the SpCell within the MCG is the PCell, and the SpCell within the SCG is the PSCell.

[0006] Regardless of the presence or absence of interaction with LTE, also known as evolved universal terrestrial radio access (E-UTRA) and evolved packet core (EPC), there are various ways to deploy a 5G network. In principle, NR and LTE can be introduced without interaction shown as NR stand-alone (SA) operation, also known as Option 2. That is, the gNB of NR is connected to the 5G core network (5GC), and the eNB of LTE can be connected to the EPC without an interconnection between the two (also known as Option 1).

[0007] On one hand, the first supported version of NR uses a dual connection known as Option 3, also known as evolved Universal Terrestrial Radio Access Network-NR (E-UTRAN-NR) Dual Connectivity (EN-DC) as shown in Figure 2. In such a deployment, a dual connection between NR and LTE is applied, and the UE210 is connected to both an LTE access node (LTE MeNB) 220 with an LTE radio interface ( LTE Uu ) 221 and an NR access node (NR SgNB) 230 with an NR radio interface (NR Uu) 231. Further, in EN-DC, the LTE access node operates as the master node, in which case it is known as the master eNB (MeNB) that controls the master cell group (MCG), and the NR access node operates as the secondary node, in which case it is also known as the secondary gNB (SgNB) that controls the secondary cell group (SCG). In this case, the SgNB, which is NR, may not have a control plane connection to the core network (EPC240) and is instead provided by the MeNB. This is also referred to as "non-standalone NR", abbreviated as "NSA NR". In this case, the functions of the NR cell are limited and are used for connected mode UEs as boosters and / or diversity legs, but note that UEs in RRC_IDLE that are powered on but do not have an established RRC connection cannot camp on these NR cells.

[0008] With the introduction of 5GC, other options may also become available. As described above, Option 2 supports a standalone NR configuration where the gNB is connected to 5GC. Similarly, LTE can also be connected to 5GC using Option 5, also known as eLTE, E-UTRA / 5GC, or LTE / 5GC, and the node is also called an ng-eNB. In these cases, both NR and LTE are considered part of the NG-RAN, and both the ng-eNB and the gNB can be called NG-RAN nodes.

[0009] There are also other variations of the dual connection between LTE and NR, standardized as part of the NG-RAN connected to 5GC. Under the umbrella of MR-DC, there are the following. · EN-DC (Option 3): LTE is the master node and NR is the secondary node, and as shown in Figure 2, the EPC CN is used. · NE-DC (Option 4): NR is the master node and LTE is the secondary node, and 5GCN is used. · NGEN-DC (Option 7): LTE is the master node and NR is the secondary node, and 5GCN is used. · NR-DC (variant of Option 2): It is a dual connection where both the master node (MN) controlling the MCG and the secondary node (SN) controlling the SCG use the NR 5GCN, as shown in Figure 3.

[0010] 3GPP Release-16 Conditional PSCell Change (CPC) The solution for the CPC procedure was also standardized in Release 16. Therein, a UE operating in a Multi-Radio Dual Connection (MR-DC) receives, in a conditional reconfiguration, one or more RRC reconfigurations (e.g., RRCReconfiguration message) including the SCG configuration, such as the secondaryCellGroup of the information element (IE) CellGroupConfig, together with reconfigurationWithSync that is stored associated with execution conditions (conditions such as A3 / A5 event configurations). As a result, one of the stored messages is applied only when the execution conditions associated with the serving PSCell are met, for example, when the UE finds an adjacent cell better than the current SpCell of the SCG. In 3GPP Rel-16, only intra-SN CPC without the involvement of the MN is standardized, that is, when the candidate for the target PSCell is within the current serving SN.

[0011] Similar to conditional handover, random access is performed on the target PSCell, and if the UE is configured with CPC, the UE releases all stored conditional reconfigurations.

[0012] Conditional PSCell Addition (CPA) and Inter-SN CPC in 3GPP Rel-17: In 3GPP Rel-17, solutions for CPA and Inter-SN CPC are being considered and introduced. The CPA procedure is used to add a PSCell / SCG to the configuration of a UE that is currently configured with only MCG when the associated execution conditions are met. CPA is initiated by the MN by requesting the SCG configuration provided as part of the conditional reconfiguration for the UE from the candidate of the target SN (T-SN) and sending it to the UE with the associated execution conditions in the conditional reconfiguration.

[0013] Inter-SN CPC can be initiated by the MN or the source SN (S-SN), and the signaling towards the source SN and the candidate of the target SN, as well as the signaling towards the UE, are both processed by the MN in either case. As shown in the signaling flow of Figure 4 showing Inter-SN CPC in 3GPP Rel-17, one of the possible signaling sequences for configuring Inter-SN CPC is initiated by the source SN.

[0014] Also, in Rel-17 Conditional PSCell Change (CPC) / Conditional PSCell Addition (CPA), when completing random access to the target PSCell, a UE configured with CPC / CPA needs to release the CPC / CPA configuration.

[0015] NR-DC that selectively activates a cell group (at least SCG) via L3 extensions in 3GPP Rel-18: In 3GPP Rel-18, RP-213565 (New WI: Further NR Mobility Enhancements, MediaTek, 3GPP TSG RAN Meeting #94e (December 6 - 17, 2021) in the work item description Work has started on introducing extensions for different mobility procedures. One of the current objectives is to "specify the mechanisms and procedures for NR-DC with selective activation of cell groups (at least SCG) by L3 extensions", which includes "enabling subsequent cell group changes without reconfiguring and restarting CPC / CPA after changing the CG".

[0016] Therefore, after the first cell group change, subsequent cell group changes should be possible without reconfiguring or restarting the conditional PSCell change (CPC) or conditional PSCell addition (CPA). This is done to reduce the interruption time and signaling overhead of SCG changes, especially when frequently changing the SCG while operating in NR frequency range 2 (FR2), compared to the case in previous releases where these configurations were released when the UE completed random access to the target PSCell. Start

[0017] Full Configuration and Delta Configuration: As part of the mobility preparation to the target node, the source node sends the current UE configuration to the target node. The target node prepares the target configuration of the UE based on the current configuration and the capabilities of the target node and the UE. The target configuration is sent from the target node to the source node and then sent to the UE in RRCReconfiguration. As a reasonable option, the target configuration can also be provided as a so-called delta configuration that only shows the difference from the current configuration of the UE in the source cell.

[0018] ​However, in some cases, for example, when the target node does not support some of the functions supported by the source node, or when the target node cannot recognize something in the current configuration of the UE, the target node triggers a full configuration. A full configuration means that the UE clears the current configuration and creates a new configuration from scratch. This is further described in section 5.3.5.11 of TS38.331 V16.7.0 and is referred to as "full configuration" or "fullConfig".

[0019] When building the delta configuration is complex, or when the network node prefers to signal the entire UE target configuration instead of signaling the delta configuration towards the source cell, it is also possible to use the full configuration during mobility.

[0020] Hereinafter, the terms "communication device" and "UE" are used interchangeably. The terms "network node", "gNB", "eNB", "gNodeB" are used interchangeably.

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0021] As part of the development of this embodiment, first, the problems are identified and first explained.

[0022] According to the 3GPP Rel-17 solution, CPC is composed of "one-hop destination". That is, a UE operating in MR-DC with cell A configured as the source cell can receive one or more RRC reconfigurations for one or more target cells such as cell B or cell C. However, the existing solution does not support the "multi-hop destination" CPC configuration. Therefore, in the existing 3GPP Rel-17 solution, only the reconfiguration of CPC or subsequent cell group changes involving re- Start are possible. In the case of frequent SCG changes that may occur when operating in NR FR2, a lot of interruption time and signaling overhead may occur.

[0023] Therefore, it is an object of the present embodiment to provide an improved method for handling a multi-hop CPC configuration of a UE or a communication device.

Means for Solving the Problem

[0024] The present embodiment includes different solutions for configuring a UE with a CPC configuration including a configuration of a target candidate PSCell including an SCG configuration and an MCG configuration, which is applied when a first CPC execution condition is satisfied, and the configuration for the target candidate PSCell also includes at least one embedded CPC configuration valid in its new PSCell.

[0025] Specifically, the solutions address the following aspects: - Actions that the MN needs to perform, - Actions that the source SN needs to perform, - Actions that the target candidate SN needs to perform, - Actions that the UE needs to perform, - Contents of conditional reconfiguration, such as including information related to multiple CPC hops or a single CPC hop, - Signaling when the MN is involved in the CPC configuration, - Signaling when the MN is not involved in the CPC configuration, - Signaling when the CPC of each hop is initiated by the MN, - Signaling when the CPC of each hop is initiated by the SN, - Signaling when the MN initiates in one hop and the SN initiates in another hop in the CPC configuration, - Signaling in the case of an inter-CPC multi-hop configuration, - Signaling in the case of an intra-CPC multi-hop configuration, - Signaling in the case of a hybrid, for example, an inter-intra or intra-inter CPC multi-hop configuration

[0026] According to one aspect of this embodiment, the object is achieved by a first network node and its method for handling the multi-hop CPC of a communication device composed of a dual connection between an MCG managed by a first network node and an SCG managed by a second network node in a wireless communication network. The first network node transmits a request for CPC to the second network node or a first target candidate secondary node (SN), and receives a message from the second network node or the first target candidate SN in response to the request for CPC. The message may include one or more of the following information: i. An indication indicating that the CPC configuration is a multi-hop CPC configuration, ii. An indication regarding whether it is time-critical to configure the first CPC of ; iii. An indication regarding the number of hops it is configured for; iv. Identifiers of one or more target candidate primary secondary cells (PSCells) for the second-hop CPC configuration, v. Identifiers of one or more target candidate secondary nodes (T-SN2) associated with one or more target candidate PSCs.

[0027] The first network node configures the multi-hop CPC of the communication devices 530, 531 based on the received message.

[0028] According to one aspect of this embodiment, the object is achieved by a second network node and its method for handling the multi-hop CPC of a communication device composed of a dual connection between an MCG managed by a first network node and an SCG managed by a second network node in a wireless communication network. The second network node transmits a request for CPC to the first network node or the communication device. The request for CPC may include one or more of the following information: · An indication indicating permission for multi-hop CPC; · Indication showing the maximum number of allowed CPC hops; · Configuration of the first hop intra-SN CPC; · Configuration of subsequent hop intra-SN CPC; · Configuration of the second hop inter-SN CPC to another target candidate SN; · Indication showing whether the next CPC hop configuration is permitted.

[0029] According to one aspect of the present embodiment, the object is achieved by a first target candidate secondary node and its method for processing the multi-hop CPC of a communication device configured by a dual connection between an MCG managed by a first network node and an SCG managed by a second network node in a wireless communication network. The first target candidate secondary node receives a CPC request from the first network node, constructs the first hop CPC, includes the information of the second hop CPC, or constructs the first hop CPC and starts the construction of the second hop CPC for the second candidate secondary node (T-SN2), constructs the multi-hop CPC, and sends a response message to the first network node. The response message may include one or more of the following information: i. An indication showing that it is a multi-hop CPC configuration, ii. Identifiers of one or more target candidate cells for the CPC configuration of the next or subsequent hops, iii. Identifiers of one or more target candidate SNs associated with one or more target candidate cells.

[0030] According to one aspect of the present embodiment, the object is achieved by a communication device and its method for processing the multi-hop CPC configuration. The communication device is configured by a dual connection between an MCG managed by a first network node and an SCG managed by a second network node in a wireless communication network.

[0031] According to some embodiments, a communication device may receive a reconfiguration message from a first network node or a second network node (512). The reconfiguration message includes information regarding the configuration of a first-hop CPC and encapsulated information regarding future CPC hops. The communication device may evaluate the execution conditions of a CPC candidate based on the content of the reconfiguration message and may send a completion message to the first network node or the second network node in response to the reconfiguration message. After executing the first-hop CPC, the communication device may evaluate the execution conditions of the first-hop CPC candidate and may evaluate the execution conditions of CPC candidates for future hops such as the second hop.

[0032] According to some embodiments, a communication device may receive a first reconfiguration message from a first network node. The first reconfiguration message includes information regarding the first-hop CPC configuration. The communication device may evaluate the execution conditions of a CPC candidate based on the content of the first reconfiguration message. The communication device may receive a second reconfiguration message from the first network node. The second reconfiguration message includes information regarding the second-hop CPC configuration. After executing the first-hop CPC, the communication device may evaluate the execution conditions of a CPC candidate based on the content of the second reconfiguration message and may send a reconfiguration completion message to the first network node in response to the second reconfiguration message.

[0033] According to some embodiments, a communication device may receive a first reconfiguration message from a first network node. The first reconfiguration message includes information regarding the first-hop CPC configuration. The communication device may receive a second reconfiguration message from the first network node. The second reconfiguration message includes information regarding the second-hop CPC configuration and an indication indicating that the CPC configuration is applicable to the second CPC hop. The communication device may evaluate the execution conditions of the first-hop CPC candidate based on the content of the first reconfiguration message. After executing the first-hop CPC, the communication device may evaluate the execution conditions of the second-hop CPC candidate based on the content of the second reconfiguration message and may send a completion message to the first network node.

[0034] Embodiments of this specification include various solutions for enabling a multi-hop CPC configuration, and the meaning of these solutions will be described from the perspectives of the MN, source SN, T-SN, and UE.

[0035] According to the embodiments of this specification, it becomes possible to support frequent SCG changes without reconfiguring or re- Start doing the CPC, and the interruption time perceived by the UE can be minimized.

[0036] Therefore, the embodiments of this specification provide an improved method for handling the multi-hop CPC configuration of a communication device configured with dual connectivity.

[0037] Examples of the embodiments of this specification will be described in more detail with reference to the accompanying drawings.

Brief Description of the Drawings

[0038]

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DETAILED DESCRIPTION OF THE INVENTION

[0039] This embodiment refers to, for example, a first network node operating as a master node (MN) having a master cell group (MCG) configured in a UE, and the MN can be a gNodeB, or a central unit gNodeB (CU-gNB), or an eNodeB, or a central unit eNodeB (CU-eNB), or any network node and / or network function.

[0040] This embodiment also refers to, for example, a second network node operating as a secondary node (SN), or a source secondary node (S-SN), having a secondary cell group (SCG) pre-configured in the UE, i.e., not connected to the UE, and the SN can be, for example, a gNodeB, or a central unit gNodeB (CU-gNB), or an eNodeB, or a central unit eNodeB (CU-eNB), or any network node and / or network function. Note that the MN, S-SN, and T-SN can be from the same or different radio access technologies and can be associated with different core network nodes.

[0041] In this description, the "Secondary Node (SN)" or the target SN is often referred to. This is equivalent to saying that it is a network node associated with the target candidate SN or the configured target candidate PSCell. When the UE connects to its cell, if the cell is associated with that node, the transmission and reception with the UE will be processed by that node.

[0042] In this description, it is described that the cell exists within the node, for example, the target candidate cell exists within the S-SN or T-SN. This is the same as saying that the cell is managed by the node, or the cell is associated with the node, or the cell belongs to the node, or the cell is of the node.

[0043] "MN starts CPC" corresponds to the procedure for the MN of the UE configured with MR-DC to determine to configure the CPC. The MN provides, via the latest measurement results, the candidate cells recommended by the MN and the upper limit of the number of PSCells for the SN to select and configure the SCG cell. The SN determines the list of PSCells to be prepared from the list of cells indicated in the measurement results shown by the MN, and for each prepared PSCell, determines another SCG SCell, and includes in the SgNB addition request confirmation response message, together with the prepared PSCell ID, an NR RRC configuration message, for example, RRCReconfiguration, to provide the MN with the newly corresponding SCG radio resource configuration. If transfer is required, the target SN provides the MN with a transfer address. The target SN includes an indication of a full or delta RRC configuration. The target SN can accept or reject each of the candidate cells proposed by the MN, that is, it cannot present alternative candidates.

[0044] "SN start CPC" corresponds to the procedure for the source SN of a UE composed of MR-DC to determine to configure the CPC. Once determined, the source SN selects one or more target candidate cells, e.g., a target candidate PSCell, based on, for example, the reported measurement values. At least one cell is associated with the source SN, and at least another cell is associated with the adjacent SN. If all target candidate cells are associated with the source SN, it can be said to be "SN start intra-SN CPC", which is called the Release 16 solution. be possible If at least one target candidate cell is associated with the adjacent SN, it can be said to be "SN start inter-SN CPC", which can be called the Release 17 solution.

[0045] In this document, the candidate SN, or SN candidate, or SN refers to a network node (e.g., gNodeB) that can create an RRC reconfiguration message with the SCG configuration (e.g., RRCReconfiguration ** ) prepared during the CPA procedure and provided to and stored by the UE together with the execution conditions. The UE applies the message only when the execution conditions are met. The candidate SN is associated with one or more PSCell candidate cells that can be configured for the UE. Then, the UE can execute the conditions and access one of these candidate cells associated with the SN or the candidate SN that becomes the SN after execution (i.e., when the execution conditions are satisfied).

[0046] In this document, the adjacent SN and the source SN are referred to as different entities, but both can be target candidate SNs for the CPC.

[0047] In this embodiment, the subsequent CPC configuration is referred to as the next-hop CPC configuration. In particular, the CPC defined in Rel-17 is referred to as the "first-hop" CPC, and each subsequent CPC is referred to as the "next-hop" CPC.

[0048] The configuration of CPC can be carried out using the same information elements (IEs) as conditional handover and may be called conditional configuration or conditional reconfiguration at a certain point. The principle of configuration is the same as that of trigger / execution condition configuration and the reconfiguration message applied when the trigger condition is met. Configuration IEs in TS38.331: -ConditionalReconfiguration IE ConditionalReconfiguration is used to add, modify and release the configuration of conditional configuration. ConditionalReconfiguration information element

[0049]

Table 1

[0050]

Table 2

[0051] -CondConfigId IE CondConfigId is used to identify the CHO or CPC configuration. CondConfigId information element

[0052]

Table 3

[0053] -CondConfigToAddModList IE CHO-ConfigToAddModList is related to the list of conditional configurations to be added or modified and includes cho-ConfigId, associated condExecutionCond and condRRCReconfig for each entry. CondConfigToAddModList information element

[0054]

Table 4

[0055]

Table 5

[0056] This embodiment generally relates to a wireless communication network. FIG. 5 shows an overview of a communication network 500. The communication network 500 can be a wireless communication network including one or more RANs and one or more CNs. The communication network 500 can use one or more different technologies. To describe some possible implementations, WiFi, Long Term Evolution (LTE), LTE-Advanced, NR, Wideband Code Division Multiple Access (WCDMA (registered trademark)), Global System for Mobile Communications / Enhanced Data Rate for GSM Evolution (GSM / EDGE), Worldwide Interoperability for Microwave Access (WiMax), or Ultra Mobile Broadband (UMB) can be used.

[0057] In the wireless communication network 500, one or more wireless communication devices 530, 531 such as a UE, a mobile station, or a wireless terminal communicate with one or more core networks (CNs) via one or more radio access networks (RANs). Those skilled in the art understand that "wireless communication device" means any terminal such as a smartphone, laptop, mobile phone, sensor, repeater, mobile tablet, or small base station communicating within a cell, wireless communication terminal, user equipment, machine type communication (MTC) device, device-to-device (D2D) terminal or node.

[0058] The network node operates in a wireless communication network 500, such as a first network node 511 and a second network node 512. The first and second network nodes 511, 512 may be any of RAN nodes such as gNB, eNB, en-gNB, ng-eNB, gNB. The first network node 511 provides wireless coverage over a geographical area, which may also be referred to as a beam or beam group that covers a service area of a first radio access technology (RAT) such as 5G, LTE, Wi-Fi, etc., area service area 11. The second network node 512 provides wireless coverage over a geographical area, which may also be referred to as a beam or beam group that covers a service area of a first or second radio access technology (RAT) such as 5G, LTE, Wi-Fi, etc., area service area 12. It should be noted that the network node may be a RAN node, a CN node, or an OAM node.

[0059] Depending on the radio access technology being used and the terms used, the first and second network nodes 511 and 512 may be, for example, a wireless local area network (WLAN) access point, or an access point station (AP STA), or an access controller, or, for example, a Node B, an evolved Node B (eNB, e-node B), a gNB, a base transceiver station, a radio remote unit, an access point base station, a base station router, a transmitting device of a radio base station, a stand-alone Lon access point such as a radio base station, or, for example, the first and second network nodes 511, 512 respectively served by the service area It may be a transmission and reception point, such as any other network unit in the wireless device that can communicate with the wireless device within the service. The first and second network nodes 511, 512 may sometimes be referred to as source and target network nodes respectively, and can communicate with the wireless communication devices 530, 531 in downlink (DL) transmission to the wireless communication devices 530, 531 and uplink (UL) transmission from the wireless communication devices 530, 531.

[0060] The first and second network nodes 511 and 512 can each be either a master node (MN) having a cell group MCG or a secondary node (SN) having a cell group SCG, as shown in FIG. 1.

[0061] In this specification, terms such as SCG and PSCell are described as one of the cells associated with the SCG. This is, for example, the PSCell defined in the NR specification (e.g., RRC TS38.331), defined as the special cell (SpCell) of the SCG, or defined as the primary SCG cell (PSCell) as follows: - Secondary cell group: For a UE with a configured dual connection, a subset of serving cells composed of a PSCell and zero or more secondary cells (SCells). - Special cell: In the case of dual connection operation, the term special cell refers to the PC of the MCG ell or the PS of the SCG Cell and in other cases, the term special cell refers to the PC ell - Primary SCG cell (PSCell): In the case of dual connection operation, the SCG cell where the UE performs random access when executing a reconfiguration procedure involving synchronization.

[0062] This embodiment includes different methods for the network to configure a multi-hop CPC. These methods differ in the sequence of messages exchanged between the MN, S-SN, T-SN, and UE, and the way the multi-hop CPC configuration is communicated to the UE, e.g., in the CPC within the CPC or individual reconfiguration messages. In this specification, solutions will be described from the perspectives of the MN, S-SN, T-SN, and UE as described below.

[0063] The configuration of the multi-hop CPC differs depending on whether the CPC hop is inter or intra and whether it starts with the MN or the SN.

[0064] ​a) In the first embodiment, the multi-hop CPC configuration starts with the MN. In this embodiment, there are cases that differ depending on the type of the first CPC configuration and the subsequent CPC configuration, that is, inter or intra: i. An inter-inter configuration where each subsequent hop CPC configuration is an inter-CPC configuration. ii. An inter-intra configuration where the "first hop" is an inter-CPC configuration and the subsequent hop is an intra-CPC configuration. iii. An intra-inter configuration where the "first hop" is an intra-CPC configuration and the subsequent hop is an inter-CPC configuration. iv. An intra-intra configuration where the "first hop" is an intra-CPC configuration and the subsequent hop is also an intra-CPC configuration.

[0065] b) In the second embodiment, the multi-hop CPC configuration starts with the SN, that is, each SN determines whether to start the configuration of the subsequent hop CPC at the first hop S-SN and each subsequent hop T-SN. In this embodiment, there are cases that differ depending on the type of the first and subsequent CPC configurations, that is, inter or intra: i. An inter-inter configuration where each subsequent hop CPC configuration is an inter-CPC configuration. ii. An inter-intra configuration where the "first hop" is an inter-CPC configuration and the subsequent hop is an intra-CPC configuration. iii. An intra-inter configuration where the "first hop" is an intra-CPC configuration and the subsequent hop is an inter-CPC configuration. iv. An intra-intra configuration where the "first hop" is an intra-CPC configuration and the subsequent hop is also an intra-CPC configuration. Here, there are two possible sub-cases: · The case where the MN is involved, and the multi-hop CPC configuration is communicated to the UE via the MN · The case where the MN is not involved, and the S-SN directly provides the information regarding the multi-hop CPC configuration to the UE

[0066] c) In the third embodiment, the multi-hop CPC configuration is MN-SN initiated, i.e., the first-hop CPC is MN initiated and the subsequent-hop CPCs are SN initiated. In this embodiment, there are cases that differ depending on the type of the first and subsequent CPC configurations, i.e., inter or intra: i. An inter-inter configuration where each subsequent-hop CPC configuration is an inter-CPC configuration. ii. An inter-intra configuration where the "first hop" is an inter-CPC configuration and the next hop is an intra-CPC configuration. iii. An intra-inter configuration where the "first hop" is an intra-CPC configuration and the next hop is an inter-CPC configuration.

[0067] Master node embodiments and actions: In relation to the multi-hop CPC configuration, the MN can perform the following actions.

[0068] a. Send a SN addition request for the CPC to the target candidate SN (e.g., T-SN1). i. In one option, this is triggered by the MN itself (MN-initiated CPC). ii. In one option, this is triggered by S-S to N Thus triggered (SN-initiated CPC). That is, the S-SN sends the MN a SN change requirement to request a CPC, and the MN triggers a SN addition request to T-SN1.

[0069] b. In response to the SN addition request, receive a SN addition request Ack from T-SN1 including the following: i) An indication that it is a multi-hop CPC, ii) Identifiers of one or more target candidate PSCells for the second-hop CPC configuration, iii) Identifiers of one or more target candidate SNs (e.g., T-SN2) associated with one or more target candidate PSCells.

[0070] c. Trigger the SN addition procedure of CPC for one or more target candidate SNs indicated by T-SN1 for one or more target candidate PSCs of the second-hop CPC configuration, for example, for T-SN2.

[0071] d. For one or more target candidate PSCs of the second-hop CPC configuration, trigger the SN release or S CG deactivation procedure for one or more target candidate SNs indicated by T-SN1, for example, for T-SN2.

[0072] e. In the case of the MN-initiated intra-CPC first-hop configuration, send the SN modification request to S-SN.

[0073] f. In the case of the MN-initiated inter-CPC configuration, send the data transfer address indication to the SN, for example, S-SN for the first hop and T-SN for subsequent hops.

[0074] g. In the case of the S-SN-initiated inter-CPC first-hop configuration, receive the need for SN change from S-SN.

[0075] h. In the case of the S-SN-initiated intra-CPC first-hop configuration, receive the need for SN modification from S-SN.

[0076] Some exemplary embodiments for the MN are described below:

[0077] Embodiment 1: A method of triggering the SN addition procedure of CPC for one or more target candidate SNs indicated by the MN or T-SN1 for one or more target candidate PSCs in the second hop, wherein the MN sends a CPC SN addition request including an indication indicating that it is the second-hop CPC to T-SN2; In response thereto, the MN receives an SN addition request Ack including at least one SCG configuration associated with at least one of the one or more target candidate PSCells requested by the MN.

[0078] Embodiment 2: The MN may send an SN addition request of the CPC to T-SN2 after execution of the CPC for the current hop for T-SN1. In this case, the multi-hop CPC becomes a conventional single-hop CPC, that is, each CPC is continuously triggered only when the previous CPC has been executed.

[0079] Embodiment 3: The MN may send an SN addition request of the CPC to T-SN2 before execution of the current hop CPC for T-SN1. In this case, there are different options for the MN to transmit a multi-hop CPC configuration to the UE as part of an RRC reconfiguration message.

[0080] Option 1: The MN may wait to receive information regarding the SCG configuration of the CPC for the next k hops before sending an RRC reconfiguration message to the UE. In this case, the MN sends an RRC reconfiguration message including the CPC within the CPC configuration to the UE, that is, the information regarding the next-hop CPC is encapsulated in the information regarding the previous-hop CPC. For example, in the case of a two-hop inter-CPC, the MN waits to receive an SN addition request Ack including at least one SCG configuration for the second-hop CPC from T-SN2. Upon receiving such an SN addition request ACK, the MN creates an RRC reconfiguration message including information regarding both the first-hop and second-hop CPCs and sends this RRC reconfiguration message to the UE.

[0081] Option 2: As soon as MN obtains information about the first-hop CPC, it may send a first RRC reconfiguration message to the UE. Thereafter, MN may initiate the configuration of the next-hop CPC. For example, if the second-hop CPC is an inter-CPC, MN may trigger the SN addition procedure for CPC to T-SN2. When receiving information about the SCG configuration of the next-hop CPC, for example, when receiving an SN addition request Ack from T-SN2, MN may do the following.

[0082] a) Create a new RRC reconfiguration message containing information about the CPC configurations of both the first hop (such as T-SN1) and subsequent hops (such as T-SN2), and send this RRC reconfiguration message to the UE. This RRC reconfiguration message has the same structure as the RRC reconfiguration message described in Option 1, including the encapsulated CPC within the CPC configuration.

[0083] b) Create a new RRC reconfiguration message containing only information about the CPC configuration of the next hop (for example, T-SN2), and send this RRC reconfiguration message to the UE. This RRC reconfiguration message needs to include an indicator indicating that the content of the CPC configuration is related to the future next-hop CPC configuration, that is, it is necessary to clarify to the UE that the CPC configuration included in this message applies to the second hop rather than the first hop.

[0084] c) Store the information about the next-hop CPC, such as the CPC configuration information received in the SN addition request Ack from T-SN2, wait for the execution of the first-hop CPC, and after the execution of the first-hop CPC, that is, immediately after T-SN1 becomes the SN in the inter-CPC example, send an RRC reconfiguration message containing information about the next-hop CPC.

[0085] Embodiment 4: Determine Embodiment 2 or 3 based on the indication from the S-SN. When determining when and how to communicate the multi-hop CPC configuration to the UE, i.e., which of the above options to select for creating and sending the RRC reconfiguration message, the MN needs to consider the indication sent from the S-SN regarding whether it is time-critical to configure the first-hop CPC as early as possible and how many hops ahead configuration the S-SN desires. For example, if the S-SN indicates that the configuration of the first-hop CPC needs to be sent to the UE as early as possible, the MN may decide to select a solution among those shown in Option 2 of Embodiment 3 that does not delay the communication of the first-hop CPC configuration to the UE.

[0086] Embodiment 5: Trigger the SN release or SCG deactivation procedure for one or more target candidate SNs, e.g., T-SN2, indicated by the MN or T-SN1. The MN may trigger the SN release procedure due to MN change (handover), and the target MN may trigger the SN addition procedure described above to add a CPC hop. The MN may trigger the SCG deactivation procedure due to, for example, temporary inoperability of the SCG due to overheating.

[0087] Embodiment 6: The SN addition request may include an indication of which hop, e.g., the first, second, third, etc. Based on that indication, it can be determined whether to accept the requested candidate SN, and if accepted, how to set its timer and when to expect the UE to potentially arrive.

[0088] Embodiment 7: The SN addition request includes an indication regarding the maximum number of hops supported by the UE, along with previous information, and subsequent candidates can know to what extent multi-hop can be configured. This information can be provided from the UE to the network, for example, by reporting the ability indicating the maximum number of hops supported by the UE. Alternatively, the UE can indicate the preferred number of hops to the network, for example, via UE assistance information.

[0089] Note: Further involvement of the MN may depend on the selection of the solution for the multi-hop CPC configuration. For example, when the CPC within the CPC is configured as a legacy Rel-17 CPC, i.e., in Option 1 of Embodiment 3, the CPC is part of the conditional reconfiguration of the MCG configuration, i.e., generated by the MN, and the messages actually applied are also generated by the MN and include the MCG part. Therefore, when the MN receives the SCG configuration for the second-hop RRCReconfiguration ** (hop2), it can generate the RRCReconfiguration ** (hop1) including the RRCReconfiguration**(hop2). Next, the MN generates the CPC configuration within the RRCReconfiguration ** (hop1), and the CPC configuration includes the target candidate cell of the RRCReconfiguration ** (hop2). Since all are related to a single MN, if the MN is changed, these are no longer valid and need to be cancelled and / or modified.

[0090] Embodiments and actions of the S-SN: Regarding the configuration of the multi-hop CPC, the S-SN may perform the following actions.

[0091] a. In the case of SN-initiated inter-CPC, send to the MN the need for SN change of the CPC, including an indication of permitting multi-hop CPC with T-SN1 as the target candidate and the maximum number of hops permitted. For example, if it is not time-critical to configure the first hop as soon as possible, the SN may permit the configuration of multi-hop CPC.

[0092] b. In the case of SN-initiated intra-CPC, send to the MN the need for SN correction of the CPC. In the SN correction required message, S-SN includes the configuration of the intra-CPC of the first hop, but may include the configuration of the intra-CPC of subsequent hops, or may indicate the desire to configure the inter-CPC of the second hop, for example, T-SN1 as the target candidate. If S-SN indicates the desire to configure the inter-CPC of the second hop with, for example, T-SN1 as the target candidate, it can also indicate to the MN whether to permit the configuration of the next hop, and if permitted, what the maximum number of permitted hops is.

[0093] Note: "Permit" means that the node where S-SN makes a decision to configure multi-hop CPC is not. This decision is made by each requested target candidate SN, but there are different options for configuring multi-hop: In one option, the MN supports the configuration of the second hop as described above for each target candidate SN; In another option, each target candidate SN can directly request other candidates to configure CPC; In yet another option, each target candidate SN can configure its own cell as the target candidate at the second hop.

[0094] Embodiments and actions of the first target candidate T-SN1: Regarding the configuration of multi-hop CPC, T-SN1 may perform the following actions.

[0095] a. Receive a request for adding the first SN of the CPC from the MN. i. In one option, this is triggered by the MN itself (MN-initiated CPC). ii. In one option, this is S-S to N and thus triggered (SN-initiated CPC). That is, S-SN sends to the MN the need for an SN change that requires a CPC, and the MN triggers a request to add an SN to T-SN1.

[0096] b. For example, in the case of an inter-CPC hop, it is determined to configure a multi-hop CPC for the second target candidate SN2 (T-SN2).

[0097] c. In response to the first SN addition request of the CPC, respond to the MN with an SN addition request Ack that includes the following: i) An indication that it is a multi-hop CPC, ii) Identifiers of one or more target candidate PSCells for the second-hop CPC configuration, iii) Identifiers of one or more target candidate SNs (e.g., T-SN2) associated with one or more target candidate PSCells.

[0098] d. Receive from the MN a message confirming that the second-hop CPC configuration has been successfully completed, for example, a message similar to the SN change confirmation in the case of an inter-CPC.

[0099] UE embodiments and actions: In relation to the multi-hop CPC configuration, the UE can perform the following actions.

[0100] a. Receive an RRC reconfiguration message, and the following cases can be distinguished.

[0101] i. The UE may receive information regarding the configuration related to the first-hop CPC and encapsulated information regarding future hops, i.e., an RRC reconfiguration message including the in-CPC CPC configuration. If the UE has received a configuration including only the information regarding the first-hop CPC before receiving the in-CPC CPC configuration, the UE needs to "rewrite" this previous message and apply the latest first-hop CPC configuration indicated by the RRC reconfiguration message including the in-CPC CPC configuration.

[0102] ii. The UE may receive the RRC reconfiguration messages for each hop individually. For example, the UE may first receive an RRC reconfiguration message including only the information regarding the first-hop CPC configuration. Then, the UE may receive an RRC reconfiguration message including only the information regarding the second-hop CPC configuration.

[0103] In one option, the UE may receive the RRC reconfiguration message for the second hop before the execution conditions for the first hop are satisfied. In this case, the RRC reconfiguration message for the second hop needs to include a clear indication that the received CPC configuration is applicable to the second hop instead of the first hop.

[0104] In another option, the UE may be able to receive the RRC reconfiguration message for the second hop immediately after applying the CPC configuration of the first-hop CPC, for example, immediately after T-SN1 becomes S-SN in the case of inter-CPC. In this case, the RRC reconfiguration message for the second hop does not need to include an indication regarding the hop number to which the configuration is applied.

[0105] b. Evaluate the execution conditions of the CPC candidates in the order specified by the content of the RRC reconfiguration message, i.e., first evaluate the execution conditions of the candidates for the first hop, and then evaluate the execution conditions of the candidates for the second hop after the execution of the first-hop CPC, and so on. For example, if the UE receives the in-CPC CPC configuration, the UE only performs the evaluation of the execution conditions for the conditional reconfiguration of the "first hop". That is, the CPC configuration of the "second hop" is stored but the evaluation of the execution conditions is not performed.

[0106] c. In the case of an SN-initiated intra-intra multi-hop CPC configuration not involving the MN, an RRC reconfiguration complete message is transmitted as a response to the RRC reconfiguration message sent by the MN or S-SN.

[0107] The multi-hop CPC solution is intended to support the CPC configurations of multiple hop destinations. However, it is important to note that unless the UE's movement path is known to the network in advance, each subsequent hop configuration may be less likely to occur than the previous one. Examples of scenarios where the UE's movement route is known to the network in advance include the movement of a train, that is, a UE inside a train moving in a direction known to the network.

[0108] Also, in this embodiment, the first conditional reconfiguration is a conditional handover (CHO), and subsequent conditional reconfigurations are also made possible with options consisting of a one-hop or multi-hop CPC configuration.

[0109] Below, signal examples of various solutions for the multi-hop CPC configuration will be described.

[0110] Figures 6(a), (b), and (c) show examples of signaling in the MN-initiated multi-hop CPC configuration, inter-inter SN case, where (a) is the CPC within the CPC, (b) is the second-hop CPC before the execution of the first-hop CPC, and (c) is the second-hop CPC immediately after the execution of the first-hop CPC.

[0111] New and / or modified messages: · SN addition request * (See Figures 6(a), (b), and (c)) is changed so that it becomes clear that T-SN2 is a "second-hop" CPC candidate.

[0112] This can be done, for example, by adding a new IE of the container CG-ConfigInfo to the S-NODE addition request, and the new container includes the target candidate configuration of the first CPC configuration created by T-SN1.

[0113] Another option is to add an indication indicating that the request is a "second hop" CPC candidate. The configuration used by T-SN2 when creating the target candidate configuration may be included in the existing CG-ConfigInfo or in the new IE of the new container. · RRC reconfiguration in Fig. 6(a) * and RRC reconfiguration completion * are extended to include encapsulated information about the first hop and second hop CPCs, i.e., information about the CPC within the CPC. · RRC reconfiguration in Fig. 6(b) * and RRC reconfiguration completion * can be changed in two different ways: Option 1: Include encapsulated information about the first hop and second hop CPCs, i.e., information about the CPC within the CPC. Option 2: Include information about the second hop CPC such that it is clear that it is information about the future CPC to be applied at the second hop rather than the first hop.

[0114] Figs. 7(a) and (b) show examples of signaling in the case of MN-initiated multi-hop CPC configuration, inter-intra SN, where (a) is the CPC within the CPC and (b) is the second hop CPC immediately after the first hop CPC execution.

[0115] New and / or modified messages: · SN addition request * (see Figs. 7(a) and (b)) is extended to include information about both the inter-"first hop" CPC and the subsequent intra-"second hop" CPC.

[0116] This can be done, for example, by adding a new IE of the container CG-ConfigInfo to the S-NODE addition request, and the new container contains the target candidate configuration of the first CPC configuration created by T-SN1.

[0117] Another option is to add an indication indicating that the request is a "second hop" CPC candidate. The configuration used by the second-hop T-SN1 when creating the target candidate configuration may be included in the existing CG-ConfigInfo or in the new IE of the new container. · SN addition request confirmation response * is extended to include the configuration information of both the "first hop" CPC and the subsequent "second hop" CPC.

[0118] This can be done, for example, by adding a new IE of the container CG-ConfigInfo or CG-CandidateList to the S-NODE addition request, and the new container contains the target candidate configuration of the first CPC configuration created by T-SN1.

[0119] Another option is to add an indication indicating that the request is a "second hop" CPC candidate. The configuration used by the second-hop T-SN1 when creating the target candidate configuration may be included in the existing CG-ConfigInfo or CG-CandidateList or in the new IE of the new container.

[0120] The request for an additional cell as a CPC candidate can be used to propose a CPC candidate at the same "hop level" as other candidates configured by T-SN1. · RRC reconfiguration in Figure 7(a) * and RRC reconfiguration completion * are extended to include encapsulated information regarding the first-hop and second-hop CPCs, i.e., information regarding the CPCs within the CPC.

[0121] Figures 8(a), (b), and (c) show examples of signaling in the MN start multi-hop CPC configuration, intra-inter SN cases, where (a) is the CPC within the CPC, (b) is the second-hop CPC before the first-hop CPC execution, and (c) is the second-hop CPC immediately after the first-hop CPC execution.

[0122] New and / or modified messages: · SN addition request * (Figure 8(a) 、 (b) and (c) (reference) is changed so that it becomes clear that T-SN1 is a "second-hop" CPC candidate.

[0123] This can be done, for example, by adding a new IE of the container CG-ConfigInfo to the S-NODE addition request, and the new container includes the target candidate configuration of the second CPC configuration created by T-SN1.

[0124] Another option is to add an indication indicating that the request is a "second-hop" CPC candidate. The configuration used by the second-hop T-SN1 when creating the target candidate configuration may be included in the existing CG-ConfigInfo or in the new IE of the new container. · RRC reconfiguration in Figure 8(a) * and RRC reconfiguration completion * are extended to include encapsulated information regarding the first-hop and second-hop CPCs, i.e., information regarding the CPC within the CPC. · RRC reconfiguration in Figure 8(b) * and RRC reconfiguration completion * can be changed in two different ways: Option 1: Include encapsulated information regarding the first-hop and second-hop CPCs, i.e., information regarding the CPC within the CPC. Option 2: Include information regarding the second-hop CPC so that it becomes clear that it is information regarding the future CPC to be applied at the second-hop rather than the first-hop.

[0125] Figures 9(a) and (b) show examples of signaling in the case of an MN start multi-hop CPC configuration, an intra-intra SN, where (a) is the CPC within the CPC and (b) is the second-hop CPC immediately after the execution of the first-hop CPC.

[0126] New and / or modified messages: · SN addition request * (See Figures 9(a) and (b)) is extended to include information on both the intra "first-hop" CPC and the subsequent intra "second-hop" CPC.

[0127] This can be done, for example, by adding a new IE of the container CG-ConfigInfo to the S-NODE addition request, and the new container includes the target candidate configuration of the second CPC configuration created by the S-SN.

[0128] Another option is to add an indication indicating that the request is a "second-hop" CPC candidate. The configuration used by the second-hop S-SN when creating the target candidate configuration may be included in the existing CG-ConfigInfo or in the new IE of the new container. · SN addition request confirmation response * is extended to include the configuration information of both the "first-hop" CPC and the subsequent "second-hop" CPC.

[0129] This can be done, for example, by adding a new IE of the container CG-ConfigInfo or CG-CandidateList to the S-NODE addition request, and the new container includes the target candidate configuration of the first CPC configuration created by the S-SN.

[0130] Another option is to add an indication that the request is a "second hop" CPC candidate. The configuration used by the S-SN of the second hop when creating the target candidate configuration may be included in the existing CG-ConfigInfo or CG-CandidateList, or may be included in a new IE of a new container.

[0131] The request for an additional cell as a CPC candidate is the same as other candidates configured by the S-SN "hop level" of and can also be used to propose a CPC candidate. · RRC Reconfiguration of Figure 9(a) * and RRC Reconfiguration Complete * are extended to include information about multiple CPC configuration hops, i.e., information about CPCs within the CPC.

[0132] Figures 10(a), (b) and (c) show examples of signaling in the SN start multi-hop CPC configuration, inter-inter SN case, where (a) is the CPC within the CPC, (b) is the second hop CPC before the first hop CPC execution, and (c) is the second hop CPC immediately after the first hop CPC execution.

[0133] New and / or modified messages: · SN Change Required (T-SN1) * (see Figures 10(a), (b) and (c)) is extended to include whether the configuration of multiple CPC hops is permitted and, if so, the maximum number of hops permitted. · SN Add Request Confirmation Response * (see Figures 10(a), (b) and (c)) is extended to also include a subsequent inter-CPC start indication for T-SN2 (i.e., includes information similar to the SN change request message). · SN Add Procedure * (see Figures 10(a), (b) and (c)) is changed so that it is clear that T-SN2 is a CPC candidate for the "second hop". · Subsequent CPC Confirmation *(See FIGS. 10(a), (b), and (c)) is the answer to the SN change request sent in the SN addition request confirmation response * message (e.g., similar to SN change confirmation). · The RRC reconfiguration in FIG. 10(a) * and RRC reconfiguration complete * are extended to include information on multiple CPC configuration hops (i.e., information on CPCs within the CPC). · The RRC reconfiguration in FIG. 10(b) * and RRC reconfiguration complete * can be changed in two different ways: Option 1: Include information on the encapsulated first and second hop CPCs (i.e., information on CPCs within the CPC). Option 2: Include information on the second hop CPC such that it becomes clear that it is information on the future CPC to be applied at the second hop rather than the first hop.

[0134] FIGS. 11(a) and (b) show examples of SN start multi-hop CPC configurations and signaling in the case of inter-intra SN, where (a) is the CPC within the CPC and (b) is the second hop CPC immediately after the first hop CPC execution.

[0135] New and / or modified messages: · SN change required (T-SN1) * (See FIGS. 11(a) and (b)) is extended to include whether the configuration of multiple CPC hops is permitted and, if so, the maximum number of hops permitted. · SN addition request confirmation response * (See FIGS. 11(a) and (b)) is extended to include information on both the inter-"first hop" CPC initiated by the S-SN and the "second hop" intra-CPC initiated by the subsequent T-SN1. · Subsequent CPC confirmation * (See FIGS. 11(a) and (b)) is the SN addition request confirmation response *This is the response to T-SN1 regarding the subsequent CPC of the "second hop" started with · RRC reconfiguration in Fig. 11(a) * and RRC reconfiguration completion * are extended to include information on multiple CPC configuration hops (i.e., information on CPCs within the CPC).

[0136] Figs. 12(a), (b), and (c) show examples of signaling in the SN start multi-hop CPC configuration, in intra-inter SN cases, where (a) is the CPC within the CPC, (b) is the second hop CPC before the first hop CPC execution, and (c) is the second hop CPC immediately after the first hop CPC execution.

[0137] New and / or modified messages: · SN modification required * (See Figs. 12(a), (b), and (c)) are changed to include the "first hop" intra-CPC start indication and the subsequent "second hop" inter-CPC start indication. · SN addition procedure * (See Figs. 12(a), (b), and (c)) is changed to clarify that it is a two-hop is the PC candidate. pro C · SN modification confirmation (See Figs. 12(a) and (b)) is made to confirm both the "first hop" intra-CPC and the "second hop" inter-CPC. * extension done. · RRC reconfiguration in Fig. 12(a) * and RRC reconfiguration completion * are extended to include information on multiple CPC configuration hops (i.e., information on CPCs within the CPC). · RRC reconfiguration in Fig. 12(b) * and RRC reconfiguration completion * can be changed in two different ways: Option 1: Include encapsulated information on the first hop and second hop CPCs (i.e., information on CPCs within the CPC).​ Option 2: Include information regarding the second-hop CPC such that it becomes clear that the information regarding the future CPC to be applied is for the second hop, rather than the first hop.

[0138] Figures 13(a) and (b) show examples of signaling for an SN-initiated multi-hop CPC configuration, in the case of an intra-intra SN, where (a) is the CPC within the CPC, and (b) is the second-hop CPC immediately after the first-hop CPC execution.

[0139] New and / or modified messages: · SN modification required * (See Figures 13(a) and (b)) is modified to include a "first-hop" intra-CPC start indication and a "second-hop" intra-CPC start indication. · SN modification confirmation in Figure 13(a) * is made to confirm both the "first-hop" intra-CPC and the "second-hop" intra-CPC extension are made. · RRC reconfiguration in Figure 13(a) * and RRC reconfiguration completion * are extended to include information regarding multiple CPC configuration hops (i.e., information regarding the CPC within the CPC).

[0140] Figure 14 shows an example of signaling for an SN-initiated multi-hop CPC configuration, in the case of an MN-non-participating intra-intra SN case.

[0141] New and / or modified messages: · Figure 1 of 4 RRC reconfiguration * and RRC reconfiguration completion * are extended to include information regarding multiple CPC configuration hops (i.e., information regarding the CPC within the CPC).

[0142] Figures 15(a), (b), and (c) show examples of signaling in the MN-SN start multi-hop CPC configuration, the inter-inter-SN case, where (a) is the CPC within the CPC, (b) is the second-hop CPC before the execution of the first-hop CPC, and (c) is the second-hop CPC immediately after the execution of the first-hop CPC.

[0143] New and / or modified messages: · SN addition request confirmation response * (See Figures 15(a), (b), and (c)) is extended to also include the subsequent inter-CPC start indication for T-SN2 (i.e., SN change required requirements and including similar information). · SN addition procedure * (See Figures 15(a), (b), and (c)) is changed so that it is clear that T-SN2 is a CPC candidate for the "second hop". · Subsequent CPC confirmation * (See Figures 15(a), (b), and (c)) is the answer to the SN change request sent by T-SN1 in the SN addition request confirmation response * message (e.g., similar to SN change confirmation). · RRC reconfiguration in Figure 15(a) * and RRC reconfiguration complete * are extended to include information regarding multiple CPC configuration hops (i.e., information regarding the CPC within the CPC). · RRC reconfiguration in Figure 15(b) * and RRC reconfiguration complete * can be changed in two different ways: Option 1: Include encapsulated information regarding the first-hop and second-hop CPCs (i.e., information regarding the CPC within the CPC), Option 2: Include information regarding the second-hop CPC so that it is clear that it is information regarding the future CPC to be applied at the second-hop rather than the first-hop.

[0144] Figures 16(a) and (b) show examples of signaling in the MN-SN-initiated multi-hop CPC configuration, in the case of inter-intra SN, where (a) is the CPC within the CPC, and (b) is the second-hop CPC immediately after the execution of the first-hop CPC.

[0145] New and / or modified messages: · SN addition request confirmation response * (See Figures 16(a) and (b)) is extended to include information on both the inter-"first-hop" CPC initiated by the MN and the intra-"second-hop" CPC initiated by the subsequent T-SN1. · Subsequent CPC confirmation * (See Figures 16(a) and (b)) is the response of T-SN1 to the SN change request sent in the * SN addition request confirmation response message (e.g., similar to SN change confirmation). · RRC reconfiguration in Figure 16(a) * and RRC reconfiguration complete * are extended to include information on multiple CPC configuration hops (i.e., information on the CPC within the CPC).

[0146] Figures 17(a), (b), and (c) show examples of signaling in the MN-SN-initiated multi-hop CPC configuration, in the intra-inter SN case, where (a) is the CPC within the CPC, (b) is the second-hop CPC before the execution of the first-hop CPC, and (c) is the second-hop CPC immediately after the execution of the first-hop CPC.

[0147] New and / or modified messages: · SN modification request confirmation response * (See Figures 17(a), (b), and (c)) is extended to include information on both the intra-"first-hop" CPC initiated by the MN and the inter-"second-hop" CPC initiated by the subsequent S-SN. · SN addition procedure * (See Figures 17(a), (b), and (c)) is modified to clarify that T-SN1 is a second-hop CPC candidate. · Subsequent CPC confirmation* (see FIGS. 17(a), (b) and (c)) is an answer to the SN change request sent by the SN modification Request Confirmation Response * message (for example, similar to SN change confirmation). · RRC Reconfiguration in FIG. 17(a) * and RRC Reconfiguration Complete * is extended to include information about multiple CPC configuration hops, that is, information about the CPCs within the CPC. · RRC Reconfiguration in FIG. 17(b) * and RRC Reconfiguration Complete * can be changed in two different ways: Option 1: Include information about the encapsulated first-hop and second-hop CPCs (that is, information about the CPCs within the CPC). Option 2: Include information about the second-hop CPC so that it is clear that it is information about the future CPC to be applied at the second hop rather than the first hop.

[0148] Example regarding the update of ASN and procedures in the case of the in-CPC CPC solution: The following example shows part of the changes to the implementation of TS38.331 required to configure a multi-hop CPC.

[0149] -CondReconfigToAddModList The IE CondReconfigToAddModList is related to the list of conditional reconfigurations to be added or modified, and each entry has condExecutionCond / condExecutionCondSCG and condRRCReconfig associated with condReconfigId.

[0150] [Table 6]

[0151] [Table 7]

[0152]

Table 8

[0153] - Reception of RRCReconfiguration by UE When receiving RRCReconfiguration or executing conditional reconfiguration (CHO, CPA or CPC), the UE shall perform the following actions. 1> If RRCReconfiguration is not received within mrdc-SecondaryCellGroup nor within E-UTRA nor within RRCConnectionReconfiguration nor within RRCConnectionResume: 2> If the scg-State is included in the RRCReconfiguration: 3> Execute SCG deactivation as specified in 5.3.5.13b; 2> Otherwise: 3> Execute SCG activation as specified in 5.3.5.13a. Editor's Note: The way to ensure that the notification to MAC is processed only when the SCG configuration is being processed is FFS if included 1> If RRCReconfiguration is applied by executing conditional reconfiguration during cell selection while timer T311 is running as defined in 5.3.7.3: 2> If the RRCReconfiguration contains keepConditional: 3> If there are other entries in VarConditionalReconfig that triggered this conditional reconfiguration, keep them all; 2> Otherwise: If there are any entries in VarConditionalReconfig, delete them all; ...

[0154] Example of the structure of the RRC reconfiguration message: Figures 18(a) and (b) show examples of the structure of the RRC reconfiguration message in the case of an in-CPC solution with a multi-hop CPC configuration. In particular, in this example, it shows the in-CPC encapsulation within the RRC reconfiguration message sent to the UE.

[0155] Implementation example in XnAP TS38.423: 9.1.2.1 S-Node Addition Request This message is sent from the M-NG-RAN node to the S-NG-RAN node to request the preparation of resources for the dual-connection operation of a specific UE. Direction: M-NG-RAN node → S-NG-RAN node

[0156] [Table 9]

[0157] [Table 10]

[0158] [Table 11]

[0159] [Table 12]

[0160] [Table 13]

[0161] [Table 14]

[0162] 9.1.2.2 S-Node Addition Request Confirmation Response This message is sent by the S-NG-RAN node to confirm to the M-NG-RAN node about the preparation for S-NG-RAN node addition. Direction: S-NG-RAN node → M-NG-RAN node

[0163]

Table 15

[0164]

Table 16

[0165]

Table 17

[0166] According to this embodiment, a method executed at the first network node 511 for processing a multi-hop configuration of conditional primary-secondary cell change or primary-secondary cell group cell change (CPC) of communication devices 530, 531 is described with reference to FIG. 19. The communication devices 530, 531 are configured to have a dual connection between a master cell group (MCG) managed by the first network node 511 and a secondary cell group (SCG) managed by the second network node 512 in the wireless communication network 500. The method includes the following actions that may be executed in any suitable order.

[0167] Action 1900 This action is optional. The first network node 511 may receive a need for SN change from the second network node 512 when the inter-SN-CPC first-hop configuration is initiated by the second network node 512.

[0168] The first network node 511 may receive a need for SN correction from the second network node 512 when the intra-SN-CPC first-hop configuration is initiated by the second network node 512.

[0169] Action 1910 The first network node 511 transmits a CPC request to the second network node 512 or the first target candidate secondary node T-SN1. The CPC request may include · Part of the configuration applied in the first-hop configuration or the first-hop CPC, and · An indication of which CPC hop is requested, and · An indication of the maximum number of CPC hops supported by the communication device, and may include one or more of the above information.

[0170] Action 1920 In response to the CPC request, the first network node 511 receives a message from the second network node 512 or the first target candidate SN (T-SN1). The message includes i. An indication that the CPC configuration is a multi-hop CPC configuration, and ii. An indication of whether it is time-critical to configure the first-hop CPC, and ii. An indication of the number of hops ahead where it is configured, and iii. Identifiers of one or more target candidate primary secondary cells (PSCell) for the second-hop CPC configuration, and iv. Identifiers of one or more target candidate secondary nodes (T-SN2) associated with one or more target candidate PSCell, It may include one or more pieces of information among them.

[0171] Action 1930 Based on the received message, the first network node 511 configures a multi-hop CPC for the communication devices 530, 531. This can be implemented by creating a reconfiguration message including information about both the first-hop CPC configuration and the next-hop CPC configuration, and sending this reconfiguration message to the communication devices 530, 531.

[0172] Based on the received message, the first network node 511 may configure the multi-hop CPC of the communication devices 530, 531 in any one of the following ways: · Create a first reconfiguration message including information about the first-hop CPC configuration, send the first reconfiguration message to the communication device, then create a second reconfiguration message including information about the next-hop CPC configuration, and send this second reconfiguration message to the communication device. · Create a first reconfiguration message including information about the first-hop CPC configuration, send the first reconfiguration message to the communication device, store the information about the next-hop CPC configuration, and after the execution of the first-hop CPC, send a second reconfiguration message including information about the next-hop CPC configuration to the communication device.

[0173] According to some embodiments, the method may further include Furthermore the following actions.

[0174] Action 1940 The first network node 511 triggers the SN addition procedure of the CPC for one or more target candidate SNs indicated by the second network node 512 or the first target candidate SN T-SN1 for one or more target candidate PSCs in the second-hop CPC configuration.

[0175] The first network node 511 may trigger the SN addition procedure for the CPC by sending a SN addition request for the CPC that includes an indication that it is the second-hop CPC to the second target candidate SN (T-SN2), and receiving a SN addition request Ack that includes at least one SCG configuration associated with at least one of the one or more target candidate PSCs requested by the first network node 511. The transmission of the SN addition request for the CPC to the second target candidate SN (T-SN2) may be performed before or after the execution of the first-hop CPC for the first target candidate SN (T-SN1).

[0176] Action 1950 The first network node 511 sends a SN modification request to the second network node 512 when the intra-SN-CPC first-hop configuration is initiated by the first network node 511.

[0177] The first network node 511 sends a data transfer address indication to the second network node 512 or the first target candidate SN (T-SN1) when the inter-SN-CPC configuration is initiated by the first network node 511.

[0178] The first network node 511 sends a SN addition request to the first target candidate SN (T-SN1) when the inter-SN-CPC first-hop configuration is initiated by the first network node 511.

[0179] Action 1960 The first network node 511 triggers a SN release or SCG deactivation procedure for one or more target candidate SNs indicated by the second network node 512 or the first target candidate SN (T-SN1) for one or more target candidate PSCs in the second-hop CPC configuration.

[0180] According to this embodiment, a method executed at a second network node 512 to handle a multi-hop configuration of conditional primary-secondary cell change or primary-secondary cell group cell change (CPC) of communication devices 530, 531 is described with reference to FIG. 20. The communication devices 530, 531 are configured to have a dual connection with a master cell group (MCG) managed by a first network node 511 and a secondary cell group (SCG) managed by a second network node 512 in a wireless communication network 500. The method includes the following actions that may be executed in any suitable order.

[0181] Action 2010 The second network node 512 transmits a request for CPC to the first network node 511 or the communication device 530. The request for CPC may include one or more of the following information. · An indication indicating permission for multi-hop CPC; · An indication indicating the maximum number of permitted CPC hops; · The configuration of the first-hop intra-SN CPC; · The configuration of subsequent-hop intra-SN CPC; · The configuration of the second-hop inter-SN CPC to another target candidate SN; · An indication indicating whether the next CPC hop configuration is permitted.

[0182] The request for CPC may be any one of the following messages. · An SN change required message transmitted to the first network node 511 when the second network node 512 determines to configure an inter-SN CPC for a first target candidate SN (T-SN1); · The second network node 512 performs an intra-SN CPC by Configuration when doingA SN modification required message that is determined and sent to the first network node 511 when starting a second-hop intra-SN CPC configuration or an inter-SN CPC configuration for the first target candidate SN (T-SN1); · A reconfiguration message that is sent to the communication device 530 when the second network node 512 determines to modify the first-hop intra-CPC to include the configuration of the second-hop intra-CPC.

[0183] According to this embodiment, a method executed at the first target candidate secondary node (T-SN1) for processing a multi-hop configuration of conditional primary secondary cell change or primary secondary cell group cell change (CPC) of the communication devices 530 and 531 is described with reference to FIG. 21. The communication devices 530 and 531 are configured to have a dual connection between a master cell group (MCG) managed by the first network node 511 and a secondary cell group (SCG) managed by the second network node 512 in the wireless communication network 500. The method includes the following actions that may be executed in any suitable order.

[0184] Action 2110 The first target candidate secondary node (T-SN1) receives a CPC request from the first network node 511.

[0185] Action 2120 The first target candidate secondary node (T-SN1) configures a multi-hop CPC by configuring the first-hop CPC and including information on the second-hop CPC, or by configuring the first-hop CPC and starting the configuration of the second-hop CPC for the second target candidate secondary node (T-SN2).

[0186] Action 2130 The first target candidate secondary node (T-SN1) transmits a response message to the first network node 511. The response message may include one or more of the following information. iv. An indication that it is a multi-hop CPC configuration, v. Identifiers of one or more target candidate cells for the CPC configuration of the next or subsequent hop, vi. Identifiers of one or more target candidate SNs associated with one or more target candidate cells.

[0187] The method may further include the following actions.

[0188] Action 2140 The first target candidate secondary node (T-SN1) may receive from the first network node 511 a message confirming the completion of the second-hop CPC configuration.

[0189] According to some embodiments, a first method executed in communication devices 530, 531 to handle a multi-hop configuration of conditional primary-secondary cell change or primary-secondary cell group cell change (CPC) of communication devices 530, 531 is described with reference to FIG. 22. Communication devices 530, 531 are configured to have a dual connection with a master cell group (MCG) managed by a first network node 511 and a secondary cell group (SCG) managed by a second network node 512 in a wireless communication network 500. The method includes the following actions, which may be executed in any suitable order.

[0190] Action 2210 Communication devices 530, 531 receive a reconfiguration message from the first network node 511 or the second network node 512. The reconfiguration message includes information regarding the configuration of the first-hop CPC and encapsulated information regarding future CPC hops.

[0191] Action 2220 The communication devices 530, 531 evaluate the execution conditions of the CPC candidates based on the content of the reconfiguration message. The communication devices 530, 531 may evaluate the execution conditions of the first-hop CPC candidates and, after the execution of the first-hop CPC, evaluate the execution conditions of future CPC hops such as the second-hop CPC candidates.

[0192] Action 2230 The communication devices 530, 531 transmit a completion message to the first network node 511 or the second network node 512 in response to the reconfiguration message.

[0193] According to some embodiments, a second method executed in the communication devices 530, 531 for handling a multi-hop configuration of conditional primary-secondary cell change or primary-secondary cell group cell change (CPC) of the communication devices 530, 531 is described with reference to FIG. 23. The communication devices 530, 531 are configured to have a dual connection between a master cell group (MCG) managed by the first network node 511 and a secondary cell group (SCG) managed by the second network node 512 in the wireless communication network 500. The method includes the following actions that may be executed in any suitable order.

[0194] Action 2310 The communication devices 530, 531 receive a first reconfiguration message from the first network node 511. The first reconfiguration message includes information regarding the first-hop CPC configuration.

[0195] Action 2320 The communication devices 530, 531 evaluate the execution conditions of the CPC candidates based on the content of the first reconfiguration message.

[0196] Action 2330 The communication devices 530, 531 receive a second reconfiguration message from the first network node 511. The second reconfiguration message includes information regarding the second-hop CPC configuration.

[0197] Action 2330 After the execution of the first-hop CPC, the communication devices 530, 531 evaluate the execution conditions of the CPC candidates based on the content of the second reconfiguration message.

[0198] Action 2330 In response to the second reconfiguration message, the communication devices 530, 531 send a reconfiguration completion message to the first network node 511.

[0199] According to some embodiments, a third method executed in the communication devices 530, 531 for processing a multi-hop configuration of conditional primary-secondary cell change or primary-secondary cell group cell change (CPC) in the communication devices 530, 531 is described with reference to FIG. 24. The communication devices 530, 531 are configured to have a dual connection with a master cell group (MCG) managed by the first network node 511 and a secondary cell group (SCG) managed by the second network node 512 in the wireless communication network 500. The method includes the following actions that can be executed in any suitable order.

[0200] Action 2410 The communication devices 530, 531 receive a first reconfiguration message from the first network node 511. The first reconfiguration message includes information regarding the first-hop CPC configuration.

[0201] Action 2420 The communication devices 530, 531 receive a second reconfiguration message from the first network node (511). The second reconfiguration message includes information regarding the second-hop CPC configuration and an indication indicating that the CPC configuration is applied to the second CPC hop.

[0202] Action 2430 The communication devices 530 and 531 evaluate the execution conditions of the first-hop CPC candidate based on the content of the first reconfiguration message.

[0203] Action 2431 After the execution of the first-hop CPC, the communication devices 530 and 531 evaluate the execution conditions of the second-hop CPC candidate based on the content of the second reconfiguration message.

[0204] Action 2440 The communication devices 530 and 531 send a completion message to the first network node 511.

[0205] FIG. 25 is a schematic block diagram showing an exemplary embodiment of a network node that can be the first network node 511, the second network node, or the first target candidate secondary node (T-SN1).

[0206] To execute the method in the first network node 511, the second network node 512, and the first target candidate secondary node (T-SN1), the first network node 511, the second network node 512, and the first target candidate secondary node (T-SN1) may include modules as shown in FIG. 25. The first network node 511, the second network node 512, and the first target candidate secondary node (T-SN1) may include a receiving module 2510, a transmitting module 2520, a determining module 2530, a processing module 2540, a memory 2550, and the like.

[0207] The network nodes 511 and 512 are MN, S-SN, and target candidate T-SN1, and are configured to execute any one of the actions described above with respect to MN, S-SN, and target candidate T-SN1.

[0208] The method according to this embodiment can be implemented via one or more processors such as processor 1960 in network nodes 511, 512, together with computer program code for performing the functions and actions of this embodiment. The above-described program code can be provided as a computer program product in the form of a computer-readable medium or data carrier 2580 carrying computer program code 2570, such as shown in FIG. 25 for example, for executing this embodiment when loaded into network nodes 511, 512. One form of such a carrier is a CD ROM. However, other data carriers such as memory sticks are also possible. The computer program code can also be provided as pure program code on a server or in the cloud and downloaded to network nodes 511, 512.

[0209] FIG. 26 shows an exemplary embodiment of a communication device 530 in which the method executed by the communication device 530 can be implemented. The communication device 530 is composed of modules as shown in FIG. 26. The communication device 530 includes a receiving module 2610, a transmitting module 2620, a determination module 2630, a processing module 2640, a memory 2650, and the like. The communication device 530 is configured to execute any one of the method actions described above with respect to the UE.

[0210] The method according to this embodiment can be implemented via one or more processors, such as processor 2660 in UE 530, together with computer program code for performing the functions and actions of this embodiment. The above-mentioned program code can be provided as a computer program product in the form of a computer-readable medium or data carrier 2680 carrying computer program code 2670, such as that shown in FIG. 26 for example, for executing this embodiment when loaded into UE 530. One form of such a carrier is a CD ROM. However, other data carriers such as a memory stick are also possible. The computer program code can also be provided as pure program code on a server or in the cloud and downloaded to communication device 530.

Claims

1. A method executed at the first network node (511) to process a multi-hop configuration of conditional primary-secondary cell change or conditional primary-secondary cell group change (CPC) for a communication device (530, 531) configured with a dual connection of a master cell group (MCG) managed by the first network node (511) of a wireless communication network (500) and a secondary cell group (SCG) managed by a second network node (512), comprising: sending (1910) a request for CPC to the second network node (512) or a first target candidate secondary node (S N) (T-S N1); receiving (1920) a message from the second network node (512) or the first target candidate S N (T-S N1) in response to the request for CPC, the message comprising: vi. an indication that the CPC configuration is a multi-hop CPC configuration; vii. an indication as to whether it is time-critical to configure a first-hop CPC; viii. an indication of the hop number at which it is configured; ix. identifiers of one or more target candidate primary-secondary cells (P S Cells) for a second-hop CPC configuration; x. identifiers of one or more target candidate secondary nodes (T-S N2) associated with the one or more target candidate P S Cells; and including one or more of the information; configuring (1930) a multi-hop CPC of the communication device (530, 531) based on the received message; A method comprising the above steps.

2. The method according to claim 1, wherein the request for CPC comprises: part of a configuration applied in a first-hop configuration or a first-hop CPC; an indication of which CPC hop is requested; an indication of the maximum number of CPC hops supported by the communication device; and including one or more of the above information. A method comprising the above steps.

3. The method according to claim 1 or 2, wherein: Configuring (1930) the multi-hop CPC of the communication device (530, 531) based on the received message includes creating a reconfiguration message including information on both the first-hop CPC configuration and the next-hop CPC configuration, and transmitting this reconfiguration message to the communication device.

4. The method according to any one of claims 1 to 3, further comprising triggering (1940) an SN addition procedure for the CPC for the one or more target candidate PSCells in the second-hop CPC configuration for the one or more target candidate SNs indicated by the second network node (512) or the first target candidate SN (T-SN1).

5. The method according to any one of claims 1 to 4, further comprising triggering (1960) an SN release or SCG deactivation procedure for the one or more target candidate SNs indicated by the second network node (512) or the first target candidate SN (T-SN1) for the one or more target candidate PSCells in the second-hop CPC configuration.

6. The method according to claim 1 or 2, Configuring (1930) the multi-hop CPC of the communication device (530, 531) based on the received message includes - creating a first reconfiguration message including information on the first-hop CPC configuration, transmitting the first reconfiguration message to the communication device, then creating a second reconfiguration message including information on the next-hop CPC configuration, and transmitting this second reconfiguration message to the communication device; - creating a first reconfiguration message including information on the first-hop CPC configuration, transmitting the first reconfiguration message to the communication device, then storing information on the next-hop CPC configuration, and after execution of the first-hop CPC, transmitting a second reconfiguration message including the information on the next-hop CPC configuration to the communication device; including any one of the above.

7. The method according to any one of claims 1 to 6, further comprising transmitting (1950) an SN modification request to the second network node (512) when the intra-SN-CPC first-hop configuration is initiated by the first network node (511).

8. The method according to any one of claims 1 to 6, further comprising: when the inter-SN-CPC configuration is initiated by the first network node (511), transmitting (1950) a data transfer address indication to the second network node (512) or the first target candidate SN (T-SN1).

9. The method according to any one of claims 1 to 6, further comprising: when the inter-SN-CPC first hop configuration is initiated by the first network node (511), transmitting (1950) an SN addition request to the first target candidate SN (T-SN1).

10. The method according to any one of claims 1 to 6, further comprising: when the inter-SN-CPC first hop configuration is initiated by the second network node (512), receiving (1900) a need for SN change from the second network node (512).

11. The method according to any one of claims 1 to 6, further comprising: when the intra-SN-CPC first hop configuration is initiated by the second network node (512), receiving (1900) a need for SN modification from the second network node (512).

12. The method according to claim 4, wherein triggering the SN addition procedure of the CPC comprises transmitting an SN addition request of the CPC including an indication indicating that it is a second hop CPC to the second target candidate SN (T-SN2), and receiving an SN addition request Ack including at least one SCG configuration associated with at least one of the one or more target candidate PSCells requested by the first network node (511).

13. The method according to claim 12, wherein transmitting the SN addition request of the CPC to the second target candidate SN (T-SN2) is performed after performing the first hop CPC for the first target candidate SN (T-SN1).

14. The method according to claim 12, wherein transmitting the SN addition request of the CPC to the second target candidate SN (T-SN2) is performed before performing the first hop CPC for the first target candidate SN (T-SN1).

15. ​ A method executed at the second network node (512) for processing a multi-hop configuration of conditional primary-secondary cell change or conditional primary-secondary cell group cell change (CPC) for a communication device (530, 531) configured with a dual connection between a master cell group (MCG) managed by a first network node (511) of a wireless communication network (500) and a secondary cell group (SCG) managed by a second network node (512), the method comprising: sending (2010) a request for CPC to the first network node (511) or the communication device (530), the request for CPC comprising: - an indication indicating permission for multi-hop CPC; - an indication indicating the maximum number of allowed CPC hops; - a configuration of first-hop intra-SN CPC; - a configuration of subsequent-hop intra-SN CPC; - a configuration of second-hop inter-SN CPC to another target candidate SN; - an indication indicating whether a next CPC hop configuration is allowed; and comprising one or more of the above information. **Claim 16** The method according to claim 15, wherein the request for CPC is - an SN change required message sent to the first network node (511) when the second network node (512) determines to configure an inter-SN CPC for a first target candidate SN (T-SN1); - an SN modification required message sent to the first network node (511) when the second network node (512) determines a configuration of intra-SN CPC and starts a configuration of second-hop intra-SN CPC or inter-SN CPC for the first target candidate SN (T-SN1); - a reconfiguration message sent to the communication device (530) when the second network node (512) determines to modify the first-hop intra-SN CPC to include a configuration of second-hop intra-CPC; and is any one of the above messages. **Claim 17** A method executed at a first target candidate secondary node (T-SN1) for processing a multi-hop configuration of conditional primary-secondary cell change or conditional primary-secondary cell group cell change (CPC) for a communication device (530, 531) configured with a dual connection of a master cell group (MCG) managed by a first network node (511) of a wireless communication network (500) and a secondary cell group (SCG) managed by a second network node (512), comprising: Receiving (2110) a request for CPC from the first network node (511); Configuring a multi-hop CPC by configuring a first-hop CPC and including information regarding a second-hop CPC, or by configuring a first-hop CPC and initiating a configuration for a second-hop CPC for a second candidate secondary node (T-SN2) (2120); Transmitting (2130) a response message to the first network node (511); Including; The response message includes: vii. An indication indicating that it is a multi-hop CPC configuration; viii. Identifiers of one or more target candidate cells for a next-hop CPC configuration or a CPC configuration of subsequent hops; ix. Identifiers of one or more target candidate SNs associated with the one or more target candidate cells; A method including one or more of the above information.

18. The method according to claim 17, further comprising: Receiving (2140) from the first network node (511) a message confirming completion of the second-hop CPC configuration.

19. A method executed at a communication device (530, 531) for processing a multi-hop configuration of conditional primary-secondary cell change or conditional primary-secondary cell group cell change (CPC), wherein the communication device (530, 531) is configured with a dual connection of a master cell group (MCG) managed by a first network node (511) of a wireless communication network (500) and a secondary cell group (SCG) managed by a second network node (512), and the method comprises: Receiving (2210) a reconfiguration message from the first network node (511) or the second network node (512), the reconfiguration message including information regarding the configuration of a first-hop CPC and encapsulated information regarding future CPC hops, Evaluating (2220) the execution conditions of CPC candidates based on the content of the reconfiguration message, Transmitting (2230) a completion message to the first network node (511) or the second network node (512) in response to the reconfiguration message, A method comprising.

20. The method according to claim 19, wherein Evaluating (2220) the execution conditions of CPC candidates includes evaluating the execution conditions of candidates for the first-hop CPC and evaluating the execution conditions of future CPC hops such as the second-hop CPC candidate after execution of the first-hop CPC.

21. A method executed in a communication device (530, 531) for handling a multi-hop configuration of conditional primary-secondary cell change or conditional primary-secondary cell group cell change (CPC), the communication device (530, 531) being configured with a dual connection between a master cell group (MCG) managed by a first network node (511) of a wireless communication network (500) and a secondary cell group (SCG) managed by a second network node (512), the method comprising: Receiving (2310) a first reconfiguration message from the first network node (511), the first reconfiguration message including information regarding the configuration of a first-hop CPC, Evaluating (2320) the execution conditions of CPC candidates based on the content of the first reconfiguration message, Receiving (2330) a second reconfiguration message from the first network node (511), the second reconfiguration message including information regarding the configuration of a second-hop CPC, After execution of the first-hop CPC, Evaluating (2340) the execution conditions of CPC candidates based on the content of the second reconfiguration message, Transmitting (2350) a reconfiguration completion message to the first network node (511) in response to the second reconfiguration message, A method comprising.

22. A method executed in a communication device (530, 531) for processing a multi-hop configuration of conditional primary-secondary cell change or conditional primary-secondary cell group cell change (CPC), wherein the communication device (530, 531) is configured with a dual connection between a master cell group (MCG) managed by a first network node (511) of a wireless communication network (500) and a secondary cell group (SCG) managed by a second network node (512), the method comprising: Receiving (2410) a first reconfiguration message from the first network node (511), the first reconfiguration message including information regarding a configuration of a first-hop CPC; Receiving (2420) a second reconfiguration message from the first network node (511), the second reconfiguration message including information regarding a configuration of a second-hop CPC and an indication indicating that the CPC configuration is applicable to the second CPC hop; Evaluating (2430) execution conditions of candidates for the first-hop CPC based on the content of the first reconfiguration message; After execution of the first-hop CPC, Evaluating (2431) execution conditions of candidates for the second-hop CPC based on the content of the second reconfiguration message; Transmitting (2440) a completion message to the first network node (511); A method comprising.

23. A first network node (511) configured to execute the method according to any one of claims 1 to 14.

24. A second network node (512) configured to execute the method according to any one of claims 15 to 16.

25. A first target candidate secondary node (T-SN1) configured to execute the method according to any one of claims 17 to 18.

26. A communication device (530, 531) configured to execute the method according to any one of claims 19 to 22.

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