Configuration for conditional cell operation

Abstract

The present disclosure relates, inter alia, to a user equipment configured to support dual connectivity operation to a master node and a secondary node of a radio access network, the user equipment comprising at least one processor and at least one memory, the at least one memory storing instructions that, when executed by the at least one processor, cause the user equipment to obtain, from the master node, transformation information that configures the user equipment to at least partially reuse configuration associated with a first conditional cell operation with one or more secondary nodes for a subsequent second conditional cell operation with the one or more secondary nodes.

Description

[Technical Field]

[0001] The present disclosure relates to, but is not limited to, dual connectivity operation in the context of radio access networks defined by 3rd Generation Partnership Project (3GPP®) standards, such as the 5G standard also known as New Radio (NR). [Background technology]

[0002] Dual Connectivity (DC) is an operating mode in which a user equipment (UE) capable of multiple transmissions and receptions is configured to utilize resources provided by two different radio nodes. One node functions as a master node (MN) and the other node functions as a secondary node (SN). The MN and SN are connected via a network interface, and at least the MN is connected to a core network. A master cell group (MCG) is a group of at least one serving cell associated with an MN, and a secondary cell group (SCG) is a group of at least one serving cell associated with an SN. The master cell group comprises at least one primary cell (PCell). The secondary cell group also comprises at least one primary or primary secondary cell (PSCell) of the secondary cell group. Each primary cell can be understood to be the cell from which the UE establishes connection or initial access to the respective cell group (see, for example, References [1] and [2]).

[0003] There are various operations for, for example, adding, modifying, releasing, or changing the respective secondary node or PSCell. These operations may be necessary, for example, because the UE is moving and may move in and out of the coverage area of ​​the respective cell or node. By configuring the UE with a specific configuration for such an operation, it is also possible to implement these operations as conditional operations, but the UE will only perform the operation (e.g., connect to another secondary node or cell) if certain execution conditions provided in the configuration and monitored by the UE are met. For example, conditional PSCell addition (CPA) is defined as a PSCell addition performed by the UE when the execution conditions are met. The UE starts evaluating the execution conditions when it receives a CPA configuration and stops evaluating the execution conditions when a PSCell addition or PCell change is triggered. Similarly, conditional PSCell change (CPC) is defined as a PSCell change performed by the UE when the execution conditions are met. The UE starts evaluating the execution conditions when it receives a CPC configuration and stops evaluating the execution conditions when a PSCell change or PCell change is triggered. Typically, a UE is provided with multiple candidate secondary nodes or PSCells prepared for each operation, and the UE then establishes a connection to one of them or changes from the previous secondary node or PSCell for dual connection operation, and the configuration of the remaining or unused candidate secondary nodes or PSCells is then released. Summary of the Invention [Problem to be solved by the invention]

[0004] For example, consider the case of SN or PSCell addition. Assuming that the SN or PSCell is successfully added in a conditional PSCell addition (CPA) procedure, the CPA configurations of other candidate PSCells are released in the UE, and the configurations or reserved resources of other candidate PSCells that are not selected or connected by the UE are also canceled. Therefore, for a subsequent PSCell change (after the first CPA is successful), a conditional reconfiguration and preparation of the target SN needs to be initiated again (but this time it is a modification procedure (CPC) instead of an addition procedure (CPA)). This requires that a CPC configuration is requested from the candidate target cell and that CPC conditions need to be configured, which causes delays and signaling overhead.

[0005] Similarly, considering the case of a conditional PSCell change (CPC) initiated by the SN, the UE may be configured with the CPC configuration and may monitor the respective conditions, but a failure (e.g., synchronization failure) may occur before the actual change is performed. In that case, an SN release message is initiated, resulting in the release of the serving or source secondary node, the cancellation of all prepared PSCells in the target SN, and the release of the entire SCG configuration and associated UE context in the target SN.

[0006] In both cases, the subsequent preparations required for conditional PSCell addition or changes to other target SNs will be delayed and signaling overhead will increase.

[0007] Therefore, certain embodiments of the present disclosure may provide improved techniques for configuring (subsequent) conditional cell operation. Certain embodiments of the present disclosure may have the effect of reducing delay and / or signaling overhead for subsequent preparation of a conditional PSCell addition or a change to another target SN. Certain embodiments of the present disclosure may have the effect of making SN addition faster immediately after SN release. Certain embodiments of the present disclosure may have the effect of making PSCell changes to further SNs faster immediately after SN addition. Certain embodiments of the present disclosure may have the effect of reusing or converting configurations for conditional cell operation. [Means for solving the problem]

[0008] According to a first exemplary aspect, a user equipment is disclosed. The user equipment may be configured to support dual-attach operation to a master node and a secondary node of a radio access network. The user equipment may include at least one processor and at least one memory. The at least one memory may store instructions that, when executed by the at least one processor, cause the user equipment to obtain translation information from the master node. The translation information may configure the user equipment to at least partially reuse configuration associated with a first conditional cell operation with one or more secondary nodes for a subsequent second conditional cell operation with one or more secondary nodes.

[0009] According to a second exemplary aspect, a master node of a radio access network is disclosed. The master node and secondary nodes of the radio access network may be configured to support dual-attach operation to a user equipment. The master node may comprise at least one processor and at least one memory. The at least one memory may store instructions that, when executed by the at least one processor, cause the master node to provide translation information to the user equipment. The translation information may configure the user equipment to at least partially reuse configuration associated with a first conditional cell operation with one or more secondary nodes for a subsequent second conditional cell operation with one or more secondary nodes.

[0010] According to each of the exemplary aspects, a respective method is also disclosed.

[0011] Thus, according to a first exemplary aspect, a method performed by a user equipment configured to support dual-attach operation to a master node and a secondary node of a radio access network is also disclosed. The method may comprise at least obtaining translation information from the master node. The translation information may configure the user equipment to at least partially reuse configuration associated with a first conditional cell operation with one or more secondary nodes for a subsequent second conditional cell operation with one or more secondary nodes.

[0012] Thus, according to a second exemplary aspect, a method performed by a master node of a radio access network is also disclosed. The master node and secondary nodes of the radio access network may be configured to support dual-attach operation to a user equipment. The method may comprise at least providing translation information to the user equipment. The translation information may configure the user equipment to at least partially reuse configuration associated with a first conditional cell operation with one or more secondary nodes for a subsequent second conditional cell operation with one or more secondary nodes.

[0013] The user equipment may be a fixed device or a mobile device. In particular, the user equipment may be a mobile device such as a smartphone, a tablet, a wearable, a smartwatch, a low-power device, an IoT device, an IIoT device, a vehicle, a truck, a drone, or an airplane. The user equipment may, in particular, be capable of communicating with (transmitting and receiving signals and / or data from) one or more other user equipments. Additionally or alternatively, the user equipment may, in particular, be capable of communicating with (transmitting and receiving signals and / or data from) at least one master node of a radio access network, the master node being configured to support dual-connection operation to a secondary node of the radio access network and to the user equipment. Additionally or alternatively, the user equipment may, in particular, be capable of communicating with (transmitting and receiving signals and / or data from) at least one secondary node of the radio access network, the secondary node being configured to support dual-connection operation to a master node of the radio access network and to the user equipment. In general, the user equipment may be any device capable of communicating with a communication network and / or another user equipment.

[0014] A radio node (e.g., a master node or a secondary node) may be understood as a wireless communication station installed at a fixed or mobile location, and in particular, may be or comprise an entity of a radio access network of a wireless communication system. For example, a radio node may be, comprise, or be part of a base station of a wireless communication network of any generation of 3GPP standards (e.g., gNB, ng-eNB, eNodeB, NodeB, BTS, etc.). In general, a radio node may be or comprise hardware or software components that perform a specific function. In one example, a radio node may be or comprise a Location Management Function (LMF). In one example, a radio node may be an entity defined by the 3GPP 5G or NR standards (also referred to as gNB). In one example, a radio node may be or comprise a gNB-CU-CP node. Thus, although a radio node may be implemented in or be understood to be a single device or module, a radio node may be implemented across or comprise multiple devices or modules. Thus, a radio node may be implemented in or be a fixed device, among other things. Multiple radio nodes may establish a wireless communication system or network, which may be an NR or 5G system, among other things, or any other wireless communication system defined by past or future standards, among other things, successors of current 3GPP standards. In particular, multiple radio nodes, e.g., a master node and one or more secondary nodes, may be configured to support dual connection operation to one or more user equipment. The radio nodes may communicate directly and / or indirectly with other radio nodes or user equipment.

[0015] Any means or functions of the disclosed devices or apparatus (i.e., any of the user equipment and any wireless node) can be implemented in hardware and / or software. In general, the described apparatuses may comprise means for performing or causing the described functions. They may comprise one or more modules or units providing the respective functions. They may comprise, for example, at least one processor for executing computer program code to perform the required functions, at least one memory for storing the program code, or both. Alternatively, they may comprise circuitry designed to perform the required functions, for example, embodied in a chipset or chip such as an integrated circuit. In general, means may comprise, for example, one or more processing means or processors.

[0016] The master node may perform, for example, CU-CP and / or CP-UP functions. The functions may be performed using specific means configured to perform respective specific tasks, such as, for example, Layer 3 means for performing Layer 3 operations, Layer 2 means for performing Layer 2 operations, etc. The master node may include, for example, conversion means configured to provide conversion information to a user equipment to configure the user equipment to at least partially reuse configuration associated with a first conditional cell operation with one or more secondary nodes for a subsequent second conditional cell operation with one or more secondary nodes.

[0017] Similarly, the user equipment may include specific means for performing a specific task, e.g., obtaining means configured to obtain from the master node transformation information that configures the user equipment to at least partially reuse configuration associated with a first conditional cell operation with one or more secondary nodes for a subsequent second conditional cell operation with one or more secondary nodes.

[0018] Thus, according to each exemplary aspect of the present disclosure, there is also disclosed a respective apparatus (i.e., a terminal device and a network device) that in each case comprises means for causing the respective apparatus to perform at least a method according to each aspect of the present disclosure.

[0019] However, any of the exemplary aspects disclosed above may generally be performed by an apparatus, which may be a module or component of a device, e.g., a chip. The disclosed apparatus may include the disclosed components, e.g., means, processor, memory, or may further include one or more additional components.

[0020] According to exemplary aspects of the present disclosure, in each case there is also disclosed a computer program which, when executed by a processor of a device, causes said device to perform a method according to the respective aspect.

[0021] The computer program may in each case be stored on a computer-readable storage medium, in particular a tangible and / or non-transitory medium. The computer-readable storage medium may be, for example, a disk or a memory. The computer program may be stored on the computer-readable storage medium in the form of instructions that encode the computer-readable storage medium. The computer-readable storage medium may be intended for participating in the operation of a device, such as, for example, an internal or external memory, such as a computer read-only memory (ROM) or a hard disk, or may be intended for distribution of the program, such as an optical disk.

[0022] Thus, according to a first exemplary aspect, a non-transitory computer-readable medium is disclosed comprising, among other things, program instructions that, when executed by user equipment configured to support dual-connection operation to a master node and a secondary node of a radio access network, cause the user equipment to obtain, from the master node, transformation information that configures the user equipment to at least partially reuse configuration associated with a first conditional cell operation with one or more secondary nodes for a subsequent second conditional cell operation with the one or more secondary nodes.

[0023] Similarly, according to a second exemplary aspect, a non-transitory computer-readable medium is disclosed comprising, among other things, program instructions that, when executed by a master node of a radio access network, the master node and secondary nodes of the radio access network being configured to support dual connect operation to a user equipment, cause the master node to provide transformation information to the user equipment that configures the user equipment to at least partially reuse configuration associated with a first conditional cell operation with one or more secondary nodes for a subsequent second conditional cell operation with the one or more secondary nodes.

[0024] The user equipment may have established a connection with (at least) a master node. The master node may serve a master cell group (MCG). The user equipment may have a connection to a primary cell (PCell) of the master cell group. For example, the user equipment and the master node or the PCell may communicate using an RRC signaling connection.

[0025] The user equipment may have established or may be about to establish a connection with a secondary node. The secondary node may provide or be part of a secondary cell group (SCG). The user equipment may have or establish a connection to a primary cell (PSCell) of the secondary cell group. For example, the user equipment and the secondary node or PSCell may communicate using an RRC signaling connection.

[0026] Generally, a user equipment connection is considered to be toward a cell, which is provided by a respective node. Therefore, in this disclosure, the terms node and its associated cell may be used interchangeably. In the context of dual connectivity, a user equipment typically has a connection to (or attempts to gain a connection to) (at least) two different cells: a primary cell, PCell, of a (serving or source) master node, and a primary secondary cell (i.e., a primary cell of a secondary cell group) PSCell of a (serving or source) secondary node. Therefore, conditional cell operations with respect to the secondary node relate to (e.g., switching to or being added to) the PSCell of the target secondary node. Here, the source secondary node (the node to which the user equipment is already connected or from which it switches) is typically different from the target secondary node (one of which it will be added or switching to).

[0027] A cell operation may be understood to be, among other things, an operation or procedure performed with respect to a secondary node or cell (e.g., a PSCell). A cell operation may comprise or be, among other things, an addition, change, release, or modification of a secondary node or cell (e.g., a PSCell). In a secondary node or cell addition procedure, a UE may add a secondary node or primary secondary cell in addition to a master node or primary cell. In a secondary node or cell change procedure, a UE may change from a source secondary node, S-SN, or serving primary secondary cell, or serving PSCell to a target secondary node, T-SN, or target primary secondary cell, or target PSCell. For example, a conditional cell operation may be a conditional PSCell addition (CPA) or a conditional PSCell change (CPC), which may collectively be referred to as a conditional PSCell addition or change (CPAC).

[0028] Conversion information may generally be understood to be any information that enables a user equipment to at least partially reuse a configuration associated with a first conditional cell operation for a subsequent second conditional cell operation. Conversion information may comprise, for example, information regarding how to use, update, and / or modify a configuration associated with a first conditional cell operation so that it can be used for the subsequent second conditional cell operation. Conversion information may be understood to configure a user equipment for a subsequent second conditional cell operation based on the configuration of the first conditional cell operation. Thus, conversion information may be viewed as “configuration information” for a conditional cell operation and may be referred to as “configuration information.” Conversion information may be understood to adjust a configuration associated with a first conditional cell operation of a user equipment so that it can be reused for a subsequent second conditional cell operation. Thus, conversion information may be understood to be “alignment information” and may be referred to as “alignment information.” Potential content or information comprised by conversion information is described in more detail below.

[0029] The configuration related to the first conditional cell operation may have been previously received by the user equipment from the master node (e.g., in a previous message). However, the configuration and conversion information related to the first conditional cell operation may be obtained together from the master node (e.g., in a common message).

[0030] Because the configuration associated with the first conditional cell operation relates to one or more secondary nodes, the configuration may be understood to comprise multiple (separate) configurations, e.g., one for each of the one or more secondary nodes. For example, these individual configurations may be individually maintained, modified, and / or reused.

[0031] The one or more secondary nodes may comprise candidate secondary nodes, which may be secondary nodes usable by the user equipment for dual connectivity. The secondary node may provide or be associated with a candidate primary secondary cell, PSCell. For example, if a condition is met, the user equipment may establish (attempt to establish) a connection to the respective secondary node or PSCell according to the respective conditional cell operation configured with the respective configuration. Typically, only one of the candidate cells or candidate nodes is selected by the UE for the respective cell operation (e.g., to be added to or changed to).

[0032] In general, a configuration for a conditional cell operation may be received by a user equipment, for example, in an RRC configuration message, e.g., a higher layer configuration message such as RRCReconfiguration. A configuration related to a particular conditional cell operation may comprise, among other things, information about one or more conditions to be met. These conditions may be referred to as execution conditions. The user equipment uses the configuration to monitor whether one or more conditions are met. If a condition is met, the user equipment applies or executes the configuration, thereby performing the respective operation (e.g., cell addition or cell change).

[0033] One or more secondary nodes of the first conditional cell operation may be at least partially the same as one or more secondary nodes of the second conditional cell operation. In one example, only a portion of the one or more secondary nodes associated with the first conditional cell operation may be reused for the second conditional cell operation. In one example, all of the one or more secondary nodes associated with the first conditional cell operation may be reused for the second conditional cell operation.

[0034] Reusing at least a portion of the configuration information is understood to mean, in particular, that the configuration (or a portion thereof) of at least one of one or more secondary nodes or secondary cells may be reused. For example, the configurations for all or some specific secondary cells or nodes may be reused. However, the conversion information may modify or update the configuration related to the first conditional cell operation. For example, the conversion information may comprise information for modifying or updating the list of candidate secondary nodes or cells for the configuration upon reuse. For example, the conversion information may comprise information for modifying or updating one or more execution conditions of one or more candidate secondary nodes or cells.

[0035] In one example, the configuration associated with the first conditional cell operation may comprise the configuration of at least two prepared candidate primary secondary cells, PSCells, of at least one (e.g., target) secondary node. The prepared primary secondary cells may be understood as cells (or associated secondary nodes) being notified of their potential use as primary secondary cells or secondary nodes. For example, the secondary nodes may have received an SN Addition Request from the master node, resulting in the preparation of the respective secondary nodes or associated cells. For example, the secondary nodes may have obtained UE context information for the respective user equipment.

[0036] Similarly, the configuration associated with the second conditional cell operation (based at least in part on or derived from the configuration associated with the first conditional cell operation) may comprise configuration of at least two prepared candidate primary secondary cells, PSCells, of at least one (e.g., target) secondary node.

[0037] In one example, a user equipment may be configured to establish a dual connectivity connection to a primary cell, PCell, of a master node and a primary secondary cell, PSCell, of a secondary node. To establish or maintain the dual connectivity connection, the user equipment is provided with respective configurations for conditional cell operation with respect to the secondary node or the primary secondary cell.

[0038] As will become apparent from further examples provided herein, the described aspects may also enable improved approaches for subsequent second conditional cell operation after a first (successful or unsuccessful) first conditional cell operation with one or more secondary nodes. More specifically, because the user equipment can at least partially reuse or convert its configuration for the first conditional cell operation for / to the second conditional cell operation, the user equipment is quickly and efficiently configured for the second conditional cell operation. This may have the effect of reducing delay and / or signaling overhead for subsequent preparation of a conditional PSCell addition or other target SN change.

[0039] In one example, the first conditional cell operation is a conditional cell change, specifically a conditional PSCell change, CPC, and the subsequent second conditional cell operation is a conditional cell addition, specifically a conditional PSCell addition, CPA. As mentioned above, it may be the case that CPC is successfully configured (and the user equipment is monitoring the conditions defined in the CPC configuration) but has not yet been successfully executed or completed. Alternatively, a connection failure (e.g., a synchronization failure) may occur between the user equipment and the serving secondary node, resulting in the release of the connection to the secondary node. In this example, the described approach may have the effect of making SN addition immediately after SN release faster, since the configuration initially provided to the user equipment for the CPC procedure can be converted, e.g., into a configuration for CPA, based on the conversion information, and reused for CPA without additional delay or signaling.

[0040] In one example, the first conditional cell operation is a conditional cell addition, particularly a conditional PSCell addition, CPA, and the subsequent second conditional cell operation is a conditional cell change, particularly a conditional PSCell change, CPC. For example, CPA may be configured and executed normally. Instead of releasing other candidate secondary nodes or PSCells not used for CPA, the configurations of these other candidate secondary nodes or PSCells can be converted to the configuration of the CPC based on the conversion information and reused for the CPC without additional delay or signaling, thereby enabling faster PSCell changes to additional SNs immediately after the SN addition.

[0041] In one example, the user equipment may further obtain the configuration related to the first conditional cell operation with respect to one or more secondary nodes from the master node. For example, the user equipment may receive a higher layer message, e.g., an RRC message such as an RRCReconfiguration message.

[0042] In one example, a configuration related to the first conditional cell operation for one or more secondary nodes may be obtained in a first configuration message (e.g., RRCReconfiguration). The user equipment may then use the configuration related to the first conditional cell operation to monitor whether a respective execution condition is met. The first conditional cell operation may be completed or may not yet be completed. The UE may then obtain conversion information in a subsequent second configuration message. The user equipment may then use the conversion information to obtain a configuration related to a subsequent second conditional cell operation. The user equipment may then replace the previous configuration and instead use the so-derived configuration related to the subsequent second conditional cell operation to monitor whether a respective execution condition is met.

[0043] In one example, the configuration associated with the first conditional cell operation for one or more secondary nodes and the conversion information may be obtained in a common configuration message. First, the user equipment may use the configuration associated with the first conditional cell operation and monitor whether respective execution conditions are met. As described in more detail below, the conversion information may indicate whether to maintain or not release configurations for other candidate secondary nodes. Rather, after the first conditional cell operation is completed, the UE may directly use the configuration associated with a subsequent second conditional cell operation, also received with the common configuration message.

[0044] In one example, each of the described first, second, and / or common configuration messages may be a higher layer message, in particular an RRCReconfiguration message, each of which may comprise, for example, one or more RRCReconfiguration messages for a respective conditional cell operation.

[0045] In various examples, the conversion information may comprise one or more of the following information:

[0046] For example, the conversion information may comprise instructions to maintain a configuration associated with a source secondary node, S-SN, or serving secondary cell group, SCG, for said reuse of configuration for a subsequent second conditional cell operation. For example, in the case of at least partially reusing a CPC configuration for CPA operation, the conversion information may comprise instructions to promote the use of the configuration associated with the S-SN or SCG for CPA, rather than releasing the configuration.

[0047] For example, the conversion information may comprise instructions to maintain configurations associated with one or more target secondary nodes, T-SNs or target secondary cell groups, SCGs, for said reuse of configurations for subsequent second conditional cell operation.

[0048] The instruction to keep a configuration may be an implicit instruction or an explicit instruction. In one example, the instruction may be a bit or flag indicating to keep or not release one or more (or all) configurations. In one example, the instruction to keep a configuration may be implemented by not including each SN, SCG, or PSCell to which the configuration is associated (e.g., their respective IDs) in the release list.

[0049] In one example, the conversion information may comprise information indicating an updated measurement gap for the reuse of the configuration for a subsequent second conditional cell operation. For example, the configuration associated with the first conditional cell operation may comprise a first measurement gap. The conversion information may comprise a second measurement gap to be used for the subsequent second conditional cell operation.

[0050] In one example, the conversion information may comprise information indicating one or more updated execution conditions for the reuse of the configuration for a subsequent second conditional cell operation. For example, the configuration associated with a first conditional cell operation may comprise one or more first execution conditions. The conversion information may comprise one or more second execution conditions to be used for the subsequent second conditional cell operation.

[0051] In one example, the conversion information may comprise instructions for maintaining configurations associated with one or more remaining secondary nodes after a first conditional cell operation to one secondary node has been successfully performed, for the reuse of the configurations for a subsequent second conditional cell operation. To this end, as described above, the conversion information may comprise a flag indicating, among other things, not to release other or remaining secondary nodes. For example, in the case of at least partially reusing the CPA configuration for a CPC operation, the conversion information may comprise a flag for not releasing other secondary nodes after the SN addition (success).

[0052] In one example, the conversion information may comprise information indicating one or more execution conditions to be used for a first conditional cell operation and one or more execution conditions to be used for a subsequent second conditional cell operation, where the one or more execution conditions to be used for the subsequent second conditional cell operation may be used to (at least partially) replace the one or more execution conditions of the first conditional cell operation.

[0053] In one example, in response to acquiring the configuration related to the first conditional cell operation, the user equipment may further begin evaluating one or more execution conditions based on the configuration related to the first conditional cell operation. In one example, the user equipment may acquire conversion information before one or more execution conditions based on the configuration related to the first conditional cell operation are satisfied or before execution of the first conditional cell operation is completed. This may be due to a connection failure with the serving SN or SCG and may therefore indicate to the master node that release is necessary. In response, the master node may provide conversion information to the user equipment so that, among other things, an already configured conditional cell operation may be reused rather than released. In one example, in response to acquiring the conversion information, the user equipment may begin evaluating one or more execution conditions based on the reused configuration for the second conditional cell operation. Thus, the user equipment may be able to quickly re-add, for example, either a source secondary node or a target secondary node from a previous failed conditional cell operation.

[0054] In one example, in response to obtaining the configuration associated with the first conditional cell operation, the user equipment may further begin evaluating one or more execution conditions based on the configuration associated with the first conditional cell operation. The user equipment may then determine whether the one or more execution conditions of the configuration associated with the first conditional cell operation are satisfied. If the user equipment determines that the one or more execution conditions of the configuration associated with the first conditional cell operation are satisfied, the user equipment may execute or apply the configuration associated with the first conditional cell operation and begin evaluating one or more execution conditions based on the reused configuration for the second conditional cell operation.

[0055] In one example, the user equipment may further determine whether one or more execution conditions of the reused configuration for the second conditional cell operation are met. If the user equipment determines that the one or more execution conditions of the reused configuration for the second conditional cell operation are met, the user equipment may execute or apply the reused configuration for the second conditional cell operation.

[0056] In one example, the configuration associated with the first conditional cell operation comprises a full configuration or a delta configuration for the first conditional cell operation. Each configuration (e.g., a full RRC configuration or a delta RRC configuration) may first be transmitted from each secondary node to the master node. The master node may then provide each configuration to the user equipment. In the case of a delta configuration, the user equipment can combine the delta configuration with the full configuration of the reference configuration.

[0057] In one example, the user equipment may further determine whether the reused configuration for the subsequent second conditional cell operation is associated with a number of candidate secondary cells that exceeds a predetermined number. The predetermined number may be, for example, between 2 and 20. In one example, the predetermined number is 8. If the user equipment determines that the number of candidate secondary cells associated with the reused configuration for the subsequent second conditional cell operation exceeds the predetermined number, the user equipment may remove one or more candidate secondary cells from the reused configuration for the subsequent second conditional cell operation. For example, the user equipment may remove the last target candidate cell configuration.

[0058] In one example, the master node may further obtain an instruction to release the source secondary node, S-SN, from the source secondary node, and the conversion information is provided to the user equipment in response to the instruction to release the source secondary node. Upon receiving an instruction to release the S-SN (e.g., SN Release Required), the source secondary node may provide the master node (e.g., in the Release Required message) with updated information regarding, for example, the performance conditions and / or measurement gaps to be used for this secondary node after being released and when becoming a candidate for subsequent second conditional cell operation. Thus, in one example, the instruction to release the source secondary node may comprise information indicating updated measurement gaps for the reuse of configuration for subsequent second conditional cell operation. Thus, in one example, the instruction to release the source secondary node may additionally or alternatively comprise information indicating updated performance conditions for the reuse of configuration for subsequent second conditional cell operation. This information may be used by the master node in the conversion information or may be forwarded.

[0059] In one example, the master node may further update one or more execution conditions indicated to the user equipment as part of the conversion information for the reuse of the configuration for the subsequent second conditional cell operation. As described above, the master node may update one or more execution conditions based on information received from one or more respective secondary nodes that may be candidate nodes for the subsequent second conditional cell operation.

[0060] In one example, the master node may further refrain from releasing configurations associated with one or more target secondary nodes, target secondary cell groups, and / or primary secondary cells that are reused for a subsequent second conditional cell operation.

[0061] Any of the described examples may be similarly applied to any of the described aspects. In particular, the disclosure of a method step shall also be considered as a disclosure of a means for performing the respective method step. Similarly, the disclosure of a means for performing a method step shall also be considered as a disclosure of the method step itself. However, it should be understood that the presentation of the embodiments disclosed herein is merely illustrative and non-limiting.

[0062] Other features of the present disclosure will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It should be understood, however, that the drawings are designed for illustrative purposes only and do not define the limits of the present disclosure, for which reference should be made to the appended claims. It should also be understood that the drawings are not drawn to scale and that they are intended only to conceptually illustrate the structures and procedures described herein.

[0063] Some example embodiments will now be described with reference to the accompanying drawings. [Brief explanation of the drawings]

[0064] [Figure 1a]1 illustrates, in a signaling flow chart, a first exemplary embodiment according to different aspects of the present disclosure. [Figure 1b] 1 illustrates, in a signaling flow chart, a first exemplary embodiment according to different aspects of the present disclosure. [Figure 1c] 1 illustrates, in a signaling flow chart, a first exemplary embodiment according to different aspects of the present disclosure. [Figure 1d] 1 illustrates, in a signaling flow chart, a first exemplary embodiment according to different aspects of the present disclosure. [Figure 2a] FIG. 10 illustrates, in a signaling flow chart, a second exemplary embodiment according to different aspects of the present disclosure. [Figure 2b] FIG. 10 illustrates, in a signaling flow chart, a second exemplary embodiment according to different aspects of the present disclosure. [Figure 2c] FIG. 10 illustrates, in a signaling flow chart, a second exemplary embodiment according to different aspects of the present disclosure. [Figure 2d] FIG. 10 illustrates, in a signaling flow chart, a second exemplary embodiment according to different aspects of the present disclosure. [Figure 3a] FIG. 10 illustrates, in a signaling flow chart, a third exemplary embodiment according to different aspects of the present disclosure. [Figure 3b] FIG. 10 illustrates, in a signaling flow chart, a third exemplary embodiment according to different aspects of the present disclosure. [Figure 4] 1 shows, in a schematic block diagram, an exemplary embodiment of a user equipment according to a first aspect; [Figure 5] FIG. 1 shows, in a schematic diagram, an exemplary embodiment of a wireless node, such as a master node or a secondary node, according to a second aspect. [Figure 6] 1A-1C illustrate, in schematic diagrams, examples of tangible and non-transitory computer-readable storage media, according to different aspects. [Figure 7]FIG. 1 is a schematic diagram illustrating an exemplary wireless environment in which exemplary embodiments of the present disclosure may be implemented. DETAILED DESCRIPTION OF THE INVENTION

[0065] The following description will aid in the understanding of the present disclosure and is intended to complement and be read in conjunction with the description of exemplary embodiments of the present disclosure set forth in the Summary section herein above.

[0066] An example of a wireless environment to which the present invention may be applied will now be described with reference to Figure 7. The specific wireless system in the following example is a 5G system, but this is only a non-limiting example.

[0067] FIG. 7 illustratively illustrates a user equipment (UE) 701 as an example of a UE according to a first exemplary aspect. FIG. 7 further illustrates a master node (MN) 702 as an example of an MN according to a second exemplary aspect. FIG. 7 further illustrates example SNs: a source secondary node (S-SN) 703, a first target secondary node (T-SN1) 704, and a second target secondary node (T-SN2) 705. The MN 702, S-SN 703, T-SN1 704, and T-SN2 705 may together establish a wireless communication system or network serving the geographic area in which the UE 701 is located. The UE 701, MN 702, and SNs 703, 704, 705 may operate in a dual connectivity mode.

[0068] The UE 701 may be connected to the MN 702 and one or more of the SNs 703, 704, 705 by wireless links (not shown), which may correspond to, for example, a 5G / NR Uu interface. The MN 702 may be connected to one or more of the SNs 703, 704, 705 by wireless links (not shown), which may correspond to, for example, a 5G / NR Xn interface. The wireless links may enable transmission and / or reception of information and / or signals between the respective devices.

[0069] The MN 702 may provide a primary cell (PCell) and / or one or more secondary cells (SCells) of a master cell group (MCG). Any of the secondary nodes 703, 704, 705 may provide a primary secondary cell (PSCell) and one or more secondary cells (SCells) of a secondary cell group (SCG).

[0070] At some point, the UE 701 moves from a first location to a second location, as indicated by arrow 770. At the first location, the UE may have been served by a PSCell of a source secondary node S-SN 703, which may have been added by a conditional PSCell addition (CPA). A PSCell associated with a target secondary node T-SN1 704 may be serving the UE at the second location. Thus, during the UE 701's movement along arrow 770, a conditional PSCell change (CPC) of the UE 701 from S-SN 703 to T-SN1 704 may have been performed.

[0071] In the following, the above two scenarios of conditional PSCell modification and conditional PSCell addition will be described in more detail for a better general understanding. As will become clear and explained in more detail later with respect to Figures 1a-1d, 2a-2d, and 3a-3b, aspects of the present disclosure may be advantageously employed in these exemplary scenarios.

[0072] Inter-SN conditional PSCell change (CPC) is specified in Rel-17 and the procedure can be initiated by either the MN or the SN. See, for example, Section 10.5.2, Figure 10.5.2-4 of [2]. The steps of the SN-initiated inter-SN CPC procedure can be described as follows: - SN-initiated CPC may be initiated by the source SN to modify an existing CPC configuration or to trigger the release of the target SN by canceling all prepared PSCells and releasing CPC-related UE contexts in the target SN. - In an SN-initiated CPC, the source SN proposes PSCell candidates, determines the CPC execution conditions, and may also include the SCG measurement configuration for the CPC. It is the target SN that determines the list of PSCells to prepare and includes the list of PSCell IDs in the MN along with instructions for full RRC configuration or delta RRC configuration. For example, if the target SN has not prepared all proposed PSCells, the MN may indicate the candidate PSCells accepted by the target SN to the source SN via an "SN Modification Request" message. The source SN may provide the MN with updated measurement configuration and execution conditions via an "SN Modification Request Acknowledge" message. - The MN reconfigures the UE with the CPC configuration and associated execution conditions. If the UE complies with the received configuration, it applies the RRC configuration and stores the CPC configuration (if not, it performs a reconfiguration failure procedure). - The source SN may further trigger an update of the CPC execution conditions and the corresponding SCG measConfig of the CPC via the "SN Modification Required" message, allowing the MN to reconfigure the UE. - The UE starts evaluating the execution conditions. If the execution conditions for one candidate PSCell are met, the UE applies the "RRCReconfiguration" message corresponding to the selected candidate PSCell and sends an "RRCReconfiguration Complete" message including the selected PSCell information to the MN. - The MN triggers an MN-initiated SN release procedure to notify the source SN to stop providing user data to the UE, and the address of the target SN selected for data forwarding. Trigger an Xn-U Address Indication procedure to notify the source SN. The MN also notifies the target SN of the success of the RRC connection reconfiguration via the "SN Reconfiguration Complete" message. The MN then sends an "SN Release Request" message to cancel the CPC in other target candidate SNs, if configured. - Following the "RRCReconfiguration Complete" message, the UE synchronizes to the target SN (Random Access Procedure).

[0073] However, if an SN-initiated CPC is configured, an SN release message initiated, for example due to a synchronization failure, will result in the cancellation of all prepared PSCells in the target SN and will initiate the release of the entire SCG configuration and associated UE contexts in the target SN.

[0074] Please note that there may be a time lag between the CPC configuration and conditions configured in the UE and the UE triggering RRCReconfigurationComplete for the target PSCell (if the CPC conditions are met), during which an SN initiated SN release procedure may be triggered.

[0075] Furthermore, please note that in case of SN initiated release (i.e. "SN release requested"), there is no rejection message defined in 38.423 (section 8.3.7.3. - Unsuccessful Operation is "Not applicable"). Also, when this SN initiated release is triggered, the actual SN change procedure (CPC execution) may not have been triggered yet.

[0076] Conditional PSCell Addition (CPA) is also specified in Rel-17, and the procedure is initiated by the MN. See section 10.2, Figure 10.2.2-2 of [2]. The steps of the CPA procedure can be described as follows: - To configure the UE's CPA, the MN requests resource allocation from the target candidate SN. The MN indicates the requested SCG configuration information and also provides the candidate cells proposed by the MN via the latest measurement results so that the SN can select and configure SCG cells. - If the SN can grant the resource request, it allocates the respective resources and communicates the PSCell configuration to the MN. The MN reconfigures the UE with the CPA configuration and associated execution conditions. If the UE complies with the received configuration, it applies the RRC configuration and stores the CPA configuration (if not, it performs a reconfiguration failure procedure). - The UE starts evaluating the execution conditions. If the execution conditions for one candidate PSCell are met, the UE applies the "RRCReconfiguration" message corresponding to the selected candidate PSCell and sends an "RRC Reconfiguration Complete" message including the selected PSCell information to the MN. - The MN notifies the SN of the success of the RRC connection reconfiguration via the "SN reconfiguration complete" message. The MN then sends an "SN release request" message to cancel the CPA in other target candidate SNs, if configured. - Following the "RRC reconfiguration complete" message, the UE synchronizes to the target SN (random access procedure). - For a detailed flow diagram, see "Figure 10.2.2-2: Conditional Secondary Node Addition procedure" in TS 37.340.

[0077] However, after a successful SN addition, the CPA configurations of other remaining candidate PSCells are released in the UE, and CPA in other candidate PSCells is cancelled. Therefore, for further PSCell changes (after the successful CPA), conditional reconfiguration and target SN preparation needs to be initiated again (but this time CPC should be configured instead of CPA). That is, CPC configuration needs to be requested from the candidate target cell, and CPC conditions need to be configured, which causes delay and signaling overhead.

[0078] Therefore, after successful configuration of SN-initiated inter-SN CPC in the UE, if the release of the source SN is initiated (e.g., due to a synchronization failure), the prepared PSCell in the target SN is cancelled and the entire SCG configuration in the UE is released, which causes delays and increased signaling overhead due to the subsequent preparation of conditional PSCell additions.

[0079] Similarly, if the CPA SN addition is successful, the prepared PSCells in other candidate SNs are cancelled and the configuration of the other candidate SNs in the UE is released, which causes delays in the subsequent preparation of conditional PSCell changes to other target SNs and increases signaling overhead.

[0080] 1a-1d, a signaling flow chart illustrates a first exemplary embodiment according to different aspects of the present disclosure.

[0081] The approach shown in relation to Figures 1a-1d may be considered as a conversion from a CPC configuration to a CPA configuration and may be summarized as follows: In response to a source SN initiated conditional SN change, the target SN includes the complete RRC configuration in the "SgNB Addition Request Acknowledge" message. A "SN Release Requested" message from the source SN to the MN may update some of the CPC execution conditions to CPA conditions. The MN shall not initiate the release of the source SN and target SN configurations, but instead use the existing target SN CPC configuration for CPA. The MN shall reconfigure the UE with the newly prepared CPA configuration and the updated execution conditions. Upon successful reconfiguration of the updated CPA configuration, the UE starts evaluating the configured CPA conditions.

[0082] More specifically, the source SN initiates the conditional SN change procedure by sending an "SN Change Required" message (action 101). The MN requests the target SN to allocate the full configuration of the UE by specifying this in an "SN Addition Request" (action 102). The candidate target SN replies with an "SN Addition Request Ack" containing the full RRC configuration of the prepared PSCell (action 103).

[0083] The MN sends an RRC reconfiguration message ("RRCReconfiguration**") to the UE, including the MN RRC reconfiguration message ("RRCReconfiguration***"), the CPC configuration (i.e., a list of "RRCReconfiguration***" messages), and the associated execution conditions, where the "RRCReconfiguration***" message includes the RRCReconfiguration**** (including the complete configuration) received from the candidate SN and possibly the MCG configuration (action 104).

[0084] The UE applies the RRC configuration (in RRCReconfiguration*) except for the CPC configuration, stores the CPC configuration, and responds to the MN with an RRC reconfiguration complete message ("RRCReconfigurationComplete*") (action 105). Thus, the UE is configured with the CPC configuration as the first conditional cell operation.

[0085] The MN notifies the source SN of an "RRCReconfigurationComplete**" for the source SN via an "SN Change Confirm" message (action 106).

[0086] Upon initiating the SN release to the MN (e.g. due to synchronization failure), the SN may update the CPA condition and update the MeasGap configuration in "SNReleaseRequired" (action 107). The MN confirms this to the SN using an "SN Release Confirm" message (action 108). Upon receiving the "SN Release Requested" message, the MN updates the CPC condition / measurement event to a CPA condition / measurement event. The MN refrains from releasing the complete configuration of the prepared target SN's PSCell from the UE.

[0087] The MN sends an "RRCReconfiguration" to the UE (action 109). The "RRCReconfiguration" message can be considered to be or comprise transformation information, as described herein. More specifically, this message contains the updated conditions for the CPA and instructs the UE to promote the source SCG of the CPC for use in the CPA. Since the release list does not include candidate PSCell IDs, the UE obtains instructions to maintain the configuration of the respective PSCell. The "RRCReconfiguration" message also comprises updated measurement gaps and configurations. Thus, the UE is configured to reuse the configuration originally provided for the CPC for a subsequent second conditional cell operation, i.e., in this case, for the CPA. The UE confirms the reconfiguration to the MN by sending an "RRCReconfigurationComplete" message (action 110).

[0088] The MN triggers the Xn-U address indication procedure to inform the source SN of the address of the selected target SN and initiates a deferred data transfer if applicable (actions 10a-10c).

[0089] As a result, the UE reuses the complete configuration of the PSCell for CPA (received as part of the CPC configuration). The UE retains the serving SCG configuration used for CPA. The UE starts evaluating the CPA conditions immediately after SN release.

[0090] Afterwards, an "SN Status Transfer" message is sent from the S-SN to the MN to inform the PDCP SN. Data transfer occurs from the UPF to the S-SN and then from the S-SN to the MN. A "Secondary RAT Data Usage Report" is sent from the S-SN to the MN. A "UE Context Release" message is sent from the MN to the SN (actions 111, 112, 113).

[0091] The action of switching from the CPC's T-SN to the CPA's T-SN may be triggered by the release. To this end, the target may be instructed about the release using a respective signal, e.g., an instruction to all target SNs. The switch from the CPC's T-SN to the CPA's S-SN may then occur only for the T-SN. The switch from the CPC's T-SN to the CPA's T-SN also occurs for other potential T-SNs and S-SNs.

[0092] If the CPA condition of the T-SN is met, the UE applies an “RRCReconfiguration” message (“RRCReconfiguration**”) corresponding to the selected candidate PSCell and sends an MN RRC reconfiguration complete message (“RRCReconfigurationComplete**”) containing the NR RRC reconfiguration complete message (“RRCReconfigurationComplete***”) of the selected candidate PSCell and the selected PSCell information to the MN (action 114).

[0093] The MN informs the SN that the UE has successfully completed the reconfiguration procedure via an "SNReconfigurationComplete" message containing an "RRCReconfigurationComplete***" response message (action 115).

[0094] NOTE: When configured to operate with this feature, the MN will not send an SN Release Request message to cancel CPA in other target candidate SNs.

[0095] The UE performs a random access procedure with the T-SN (action 116). An "SN Status Transfer" message is sent from the MN to the T-SN (action 117). Data transfer is performed from the UPF to the MN and then from the MN to the T-SN. A "PDU Session Modification Indication" message is sent from the MN to the AMF (action 118). A "Bearer Modification" procedure is performed between the AMF and the UPF (action 119). An End Marker is sent from the UPF to the MN and then from the MN to the T-SN. A "PDU Session Modification Confirmation" message is sent from the AMF to the MN (action 120).

[0096] Among others, the following advantages of the proposed solution can be identified: - SNs will be added more quickly immediately after SN release. - The CPC configuration is reused as the CPA configuration, which significantly reduces the signaling overhead and delay when resuming provisioning. - The serving SCG configuration is promoted as a candidate cell for CPA.

[0097] 2a-2d, a second exemplary embodiment according to a different aspect of the present disclosure is illustrated in a signaling flow chart.

[0098] Similar to the embodiment of Figures 1a-1d, the approach shown in connection with Figures 2a-2d may also be considered a conversion from a CPC configuration to a CPA configuration and may be summarized as follows: The target SN includes a delta RRC configuration in the "SgNB Addition Request Confirm" message (compared to a full RRC configuration in the embodiment of Figures 1a-1d). The CPC state may be converted to a CPA state by an "SN Release Requested" message from the source SN to the MN. The MN shall not initiate the release of the source SN and target SN configurations. Instead, the MN shall allow the UE to reconfigure the CPA configuration using the full RRC configuration of the source SN and the delta configuration of the target SN. The MN may reconfigure the UE with updated execution conditions for CPA (and, if necessary, updated measurement gaps for target SN measurements). The UE begins evaluating the configured CPA conditions.

[0099] Action 201 corresponds to action 101.

[0100] The MN then requests the target SN to allocate the UE's delta configuration by indicating this in an "SN Addition Request" (action 202). The candidate target SN replies with an "SN Addition Request Ack" containing the delta RRC configuration (action 203). The MN sends the UE an RRC reconfiguration message ("RRCReconfiguration*") containing the CPC configuration (i.e., a list of "RRCReconfiguration***" messages) and associated execution conditions. Here, the "RRCReconfiguration***" message contains the "RRCReconfiguration****" (containing the delta configuration) received from the candidate SN and possibly the MCG configuration.

[0101] Actions 205-208 correspond to actions 105-108. In contrast to the example of Figures 1a-1d, the UE then builds a complete configuration of the CPA configurations of the candidate target SNs from the stored source SCG configuration and the delta configurations from the respective target SNs. Actions 210-220 again correspond to actions 110-120.

[0102] Among others, the following advantages of the proposed solution can be identified: - SNs will be added more quickly immediately after SN release. - The CPC configuration is reused as the CPA configuration, which reduces the signaling overhead and delay of restarting the CPA preparation. - The serving SCG configuration is promoted as a candidate cell for CPA. - The complete configuration of the candidate cells is constructed by referencing the serving SCG configuration and delta configuration received from each candidate cell as part of the CPC procedure.

[0103] 3a-3b, a signaling flow chart illustrates a third exemplary embodiment according to different aspects of the present disclosure.

[0104] The approach shown in relation to Figures 3a-3b may be considered as a conversion from a CPA configuration to a CPC configuration and may be summarized as follows: The candidate SN includes the prepared PSCell configuration in the "SgNB Addition Request Confirm" message as part of the CPA preparation procedure. The MN configures both CPA and CPC conditions for the candidate cell. The MN includes a flag in the "RRCReconfiguration*" message indicating that the configurations of other candidate SNs should not be released after the conditional PSCell addition is successful. Even after CPA is performed, the CPA configurations of other SNs are used as CPC configurations. The UE starts measurements immediately after the successful RACH of the SN addition and checks the CPC conditions for the PSCell change.

[0105] More specifically, the MN decides to configure CPA for the UE. The MN requests allocation of resources from the target candidate SN by sending an "SGNB Addition Request" message (action 301). The target candidate SN allocates the respective resources and sends the respective configuration in an "SGNB Addition Request Ack" message (action 302). For SN-terminated bearers using MCG resources, the MN provides Xn-U DL TNL address information to the target candidate SN in an "Xn-U Address Indication" message (action 302a).

[0106] The MN sends an RRC reconfiguration message ("RRCReconfiguration*") containing the CPA configuration (i.e., a list of "RRCReconfiguration**" messages) and associated execution conditions to the UE, where each "RRCReconfiguration**" message contains the "RRCReconfiguration***" received from the candidate SN and possibly the MCG configuration. The MN configures both the CPC and CPA conditions for all candidate SNs. The MN includes a flag in the "RRCReconfiguration*" message that indicates to the UE that it will not release the configurations of other candidate SNs after the SN addition (action 303).

[0107] The UE applies the RRC configuration (in the "RRC Reconfiguration*" message) except for the CPA configuration, stores the CPA configuration, and responds to the MN with an RRC Reconfiguration Complete message ("RRCReconfigurationComplete*") without an NR SN RRC Response message (action 304).

[0108] The UE starts evaluating the CPA execution conditions. If the CPA execution conditions for one candidate PSCell are met, the UE applies an RRC reconfiguration message ("RRC Reconfiguration**") corresponding to the selected candidate PSCell and sends an NR RRC reconfiguration complete message ("RRCReconfigurationComplete***") for the selected candidate PSCell and an MN RRC reconfiguration complete message ("RRCReconfigurationComplete**") containing the selected PSCell information to the MN (action 305).

[0109] The MN informs the SN that the UE has successfully completed the reconfiguration procedure via an "SN ReconfigurationComplete" message containing an "RRCReconfigurationComplete***" response message (action 306). Note that the UE performs synchronization to the selected PSCell indicated in the "RRCReconfiguration**" message and performs a random access procedure to the SCG. The UE starts measurements and checks whether the CPC conditions for the PSCell change are met.

[0110] The MN sends an SN Status Transfer to notify the PDCP SN (action 307). Note that data transfer is initiated from the UPF to the MN and then from the MN to SN1.

[0111] The MN sends a "PDU Session Modification Indication" to the AMF. The AMF sends a "Bearer Modification" to the UPF. The AMF sends a "PDU Session Modification Confirmation" to the MN (actions 308-310). Note that the end marker is sent from the UPF to the MN and then from the MN to SN1. DL data is then sent directly from the UPF to SN1.

[0112] Note that in the UE, the CPA configurations of other SNs have complete configurations, and therefore, those CPA configurations can also be used as CPC configurations. The UE starts measurements immediately after the RACH success of SN1 addition and checks the CPC conditions for PSCell change.

[0113] Once the CPC conditions of SN2 are met, the PSCell change procedure of SN2 can be initiated by sending "RRCReconfigurationComplete**" towards the MN (action 311). An "SN ReconfigurationComplete" message is sent from the MN to SN2 (action 312).

[0114] Among others, the following advantages of the proposed solution can be identified: - PSCell change to SN2 is faster (i.e. it can be done immediately after SN addition). - After PSCell addition, there is no need to have additional configuration for CPC (or message exchange to candidate SNs), thereby reducing the signaling overhead and delay of CPC initiation after CPA.

[0115] 4, there is shown a block diagram of an exemplary embodiment of a UE 400 according to a first aspect. For example, the UE 400 may be any of a smartphone, a tablet computer, a notebook computer, a smart watch, a smart band, an IoT device, and / or a vehicle.

[0116] The UE 400 comprises a processor 401. The processor 401 may represent a single processor or two or more processors, e.g., at least partially coupled, e.g., via a bus. The processor 401 executes program code stored in a program memory 402 (e.g., program code that, when executed on the processor 401, causes the UE 400 connected to the wireless node 500 to perform one or more, or portions thereof, of the method embodiments according to the present disclosure) and interfaces with a main memory 403. The program memory 402 may also include an operating system for the processor 401. Some or all of the memories 402 and 403 may also be included in the processor 401.

[0117] One or both of the main memory and program memory of a processor (e.g., program memory 402 and main memory 403) may be permanently connected to the processor (e.g., processor 401) or may be at least partially removable from the processor, for example in the form of a memory card or memory stick.

[0118] The program memory (e.g., program memory 402) may be, for example, a non-volatile memory. To name a few, the program memory may be, for example, a flash memory (or a portion thereof), a ROM, a PROM, an EPROM, an MRAM, or an FeRAM (or a portion thereof), or a hard disk (or a portion thereof). For example, the program memory may comprise, for example, a first memory section that is fixedly installed and a second memory section that is removable, for example in the form of a removable SD memory card.

[0119] The main memory (e.g., main memory 403) may be, for example, a volatile memory. The main memory may be, for example, a DRAM memory, as a non-limiting example. The main memory may be used, for example, as a working memory for the processor 401 when executing an operating system, applications, programs, etc.

[0120] The processor 401 may further control a communication interface 404 (e.g., a wireless interface) configured to receive and / or transmit data and / or information. For example, the communication interface 404 may be configured to transmit and / or receive wireless signals from a wireless node, such as a master node or a secondary node, as described herein, among others. It should be understood that any computer program code-based processing necessary for receiving and / or evaluating the wireless signals may be stored in a memory of the communication interface 404 and executed by a processor of the communication interface 404, and / or it may be stored in, for example, the memory 403 and executed by, for example, the processor 401.

[0121] The communication interface 404 may be configured to communicate in accordance with a cellular communication system, such as 2G / 3G / 4G / 5G, or a future generation cellular communication system, among others. The UE 400 may use the wireless interface 404 to communicate with a wireless node, such as a master node or a secondary node, among others, as described herein.

[0122] For example, the communication interface 404 may further comprise a BLE and / or Bluetooth wireless interface including a BLE transmitter, receiver, or transceiver. For example, the wireless interface 404 may additionally or alternatively comprise a WLAN wireless interface including at least a WLAN transmitter, receiver, or transceiver.

[0123] Components 402, 403, and 404 of UE 400 may be connected to processor 401 by, for example, one or more serial and / or parallel buses.

[0124] It should be appreciated that the UE 400 may include various other components. For example, the UE 400 may optionally include a user interface (e.g., a touch-sensitive display, a keyboard, a touchpad, a display, etc.).

[0125] 5 is a block diagram of an example embodiment of a wireless node 500, such as a master node 500 or a secondary node 500. For example, the wireless node 500 may be configured to schedule and / or transmit signals to the UE 400 and / or one or more additional wireless nodes 500, as described above.

[0126] The wireless node 500 comprises a processor 501. The processor 501 may represent a single processor or two or more processors, e.g., at least partially coupled, e.g., via a bus. The processor 501 executes program code stored in a program memory 502 (e.g., program code that, when executed on the processor 501, causes the wireless node 500, alone, in conjunction with a UE 400, and / or in conjunction with one or more further wireless nodes 500, to perform one or more, or portions of, embodiments of methods according to the present disclosure) and interfaces with a main memory 503.

[0127] Program memory 502 may also include an operating system for processor 501. Some or all of memories 502 and 503 may also be included in processor 501.

[0128] Furthermore, the processor 501 may control a communication interface 504 configured to communicate according to a cellular communication system, such as a 2G / 3G / 4G / 5G cellular communication system, for example. The communication interface 504 of the wireless node 500 may be realized by, for example, a radio head and may be provided for communication between a network device and a terminal device.

[0129] Components 502, 503, and 504 of wireless node 500 may be connected to processor 501 by, for example, one or more serial and / or parallel buses.

[0130] It should be appreciated that the wireless node 500 may include various other components.

[0131] Figure 6 is a schematic diagram of example tangible and non-transitory computer-readable storage media according to the present disclosure that may be used, for example, to implement memory 402 of Figure 4 or memory 502 of Figure 5. To this end, Figure 6 illustrates a flash memory 600, which may be soldered or glued to, for example, a printed circuit board, a solid-state drive 601 comprising multiple memory chips (e.g., flash memory chips), a magnetic hard drive 602, a Secure Digital (SD) card 603, a Universal Serial Bus (USB) memory stick 604, an optical storage medium 605 (e.g., a CD-ROM or DVD), and a magnetic storage medium 606.

[0132] Connections presented in the described embodiments are to be understood in terms of the associated components being operatively coupled. As such, connections may be direct or indirect, with any number or combination of intervening elements, and may only have a functional relationship between the components.

[0133] Furthermore, the term "circuit" as used in this text refers to either: (a) a hardware-only circuit implementation (e.g., an analog and / or digital-only implementation); (b) A combination of circuitry and software (and / or firmware) that: (i) a combination of processors; or (ii) sections of processors / software (including digital signal processors), software, and memory that work together to cause a device, such as a mobile phone, to perform various functions; and (c) A microprocessor, or a section of a microprocessor, or any circuitry that requires software or firmware for its operation even when the software or firmware is not physically present.

[0134] This definition of "circuit" applies to all uses of the term in this text, including any claims. As a further example, the term "circuit" as used in this text also covers simply a processor (or processors) or part of a processor and its (or their) accompanying software and / or firmware implementation. The term "circuit" also covers, for example, a baseband integrated circuit or an application processor integrated circuit in a mobile phone.

[0135] Any processors referred to in this text are not limited to processor 401 of Figure 4 and processor 501 of Figure 5 specifically, but may be any suitable type of processor. Any processor may comprise, but is not limited to, one or more microprocessors, one or more processors with digital signal processors, one or more processors without digital signal processors, one or more special purpose computer chips, one or more field programmable gate arrays (FPGAs), one or more controllers, one or more application specific integrated circuits (ASICs), or one or more computers. The associated structure / hardware is programmed to perform the described functions.

[0136] Additionally, any of the actions or steps described or illustrated herein may be performed using executable instructions in a general-purpose or special-purpose processor and stored on a computer-readable storage medium (e.g., disk, memory, etc.) for execution by such a processor. References to a "computer-readable storage medium" should be understood to encompass specialized circuitry such as FPGAs, ASICs, signal processing devices, and other devices.

[0137] As used herein, "at least one of the following <list of two or more elements>" and "at least one of <list of two or more elements>" and similar phrases where a list of two or more elements is joined by "and" or "or" mean at least any of the elements, or at least two or more of any of the elements, or at least all of the elements.

[0138] The phrase "A, or B, or C, or combinations thereof" or "at least one of A, B, and C" is not exhaustive and may be understood to include at least (i) A, or (ii) B, or (iii) C, or (iv) A and B, or (v) A and C, or (vi) B and C, or (vii) A, B, and C.

[0139] It will be understood that the embodiments disclosed herein are exemplary only, and that any feature presented with respect to a particular exemplary embodiment may be used with any aspect of the disclosure by itself, or in combination with any feature presented with the same or another particular exemplary embodiment, and / or in combination with any other feature not mentioned. Furthermore, it will be understood that any feature presented with exemplary embodiments in a particular category may be used in a corresponding manner with exemplary embodiments in any other category.

[0140] Abbreviation 3GPP 3rd Generation Partnership Project AMF Access and Mobility Management Functions CHO Conditional Handover CPAC Conditional PSCell Addition or Change CPC Conditional PSCell Change CPA conditional PSCell addition DC Dual Connection LMF location management function MCG Master Cell Group MN Master Node NAS non-access layer NR New Radio PCell Primary cell of the master cell group PSCell Primary cell of a Secondary Cell Group (SCG), Primary SCG cell RACH Random Access Channel SCG Secondary Cell Group SN Secondary Node S-SN Source Secondary Node RRC Radio Resource Control T-SN Target Secondary Node UE User Equipment UPF User Plane Function

[0141] References [1]3GPP TS 36.300 V 17.1.0 "Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access network (E-UTRAN); Overall description; Stage 2 (Release 17)", June 2022. [2]3GPP TS 37.340 V17.1.0 "Evolved Universal Terrestrial Radio Access (E-UTRA) and NR; Multi-connectivity; Stage 2 (Release 17)", June 2022.

Claims

1. 1. A user equipment configured to support dual connectivity operation to a master node and a secondary node of a radio access network, the user equipment comprising: at least one processor and at least one memory, the at least one memory, when executed by the at least one processor, causing the user equipment to: storing instructions to cause a user equipment to obtain, from the master node, transformation information that configures the user equipment to at least partially reuse configuration associated with a first conditional cell operation with one or more secondary nodes for a subsequent second conditional cell operation with the one or more secondary nodes.

2. 2. The user equipment of claim 1, wherein the configuration associated with the first conditional cell operation comprises configuration of at least two prepared candidate primary secondary cells, PSCells, of at least one target secondary node.

3. 3. The user equipment of claim 1 or 2, wherein the user equipment is configured to establish a dual connectivity connection to a primary cell, PCell, of the master node and a primary secondary cell, PSCell, of the secondary node.

4. the first conditional cell operation is a conditional cell change, in particular a conditional PSCell change, CPC, and the subsequent second conditional cell operation is a conditional cell addition, in particular a conditional PSCell addition, CPA, or said first conditional cell operation is a conditional cell addition, in particular a conditional PSCell addition, CPA, and said subsequent second conditional cell operation is a conditional cell change, in particular a conditional PSCell change, CPC. The user equipment of claim 1 .

5. further adapted to obtain from the master node the configuration related to the first conditional cell operation for one or more secondary nodes; The configuration related to the first conditional cell operation for one or more secondary nodes is obtained in a first configuration message, and the conversion information is obtained in a subsequent second configuration message; or 3. The user equipment of claim 1, wherein the configuration and conversion information related to the first conditional cell operation for one or more secondary nodes is obtained in a common configuration message.

6. 6. The user equipment of claim 5, wherein the first, second and / or common configuration message is a higher layer message, in particular an RRCReconfiguration message.

7. The conversion information is - an instruction to maintain configurations related to a source secondary node, S-SN or serving secondary cell group, SCG, for said reuse of said configurations for said subsequent second conditional cell operation; instructions to maintain configurations associated with one or more target secondary nodes, T-SNs or target secondary cell groups, SCGs, for said reuse of said configurations for said subsequent second conditional cell operation; - information indicating an updated measurement gap for the reuse of the configuration for the subsequent second conditional cell operation; - information indicating one or more updated execution conditions for said reuse of said configuration for said subsequent second conditional cell operation; instructions to maintain the configuration associated with one or more remaining secondary nodes for the reuse of the configuration for the subsequent second conditional cell operation after the first conditional cell operation for one secondary node has been successfully performed; and / or - information indicating one or more execution conditions to be used for said first conditional cell operation and one or more execution conditions to be used for said subsequent second conditional cell operation; A user equipment according to any one of claims 1 to 6, comprising one or more of:

8. The user equipment: initiating, in response to obtaining the configuration associated with the first conditional cell operation, evaluating one or more execution conditions based on the configuration associated with the first conditional cell operation; obtaining the conversion information before the one or more execution conditions based on the configuration associated with the first conditional cell operation are satisfied or before the execution of the first conditional cell operation is completed; initiating evaluation of one or more execution conditions based on the reused configuration for the second conditional cell operation in response to obtaining the transformation information; A user equipment according to any one of claims 1 to 7, further adapted to:

9. The user equipment: initiating, in response to obtaining the configuration associated with the first conditional cell operation, evaluating one or more execution conditions based on the configuration associated with the first conditional cell operation; determining whether the one or more execution conditions of the configuration associated with the first conditional cell operation are satisfied; and if it is determined that the one or more execution conditions of the configuration associated with the first conditional cell operation are satisfied, applying the configuration associated with the first conditional cell operation and initiating evaluation of one or more execution conditions based on the reused configuration for the second conditional cell operation; A user equipment according to any one of claims 1 to 7, further adapted to:

10. The user equipment: determining whether the one or more execution conditions of the reused configuration for the second conditional cell operation are satisfied; and applying the reused configuration for the second conditional cell operation if it is determined that the one or more execution conditions of the reused configuration for the second conditional cell operation are satisfied; and 10. A user equipment according to claim 8 or 9, further adapted to:

11. 11. The user equipment of any one of claims 1 to 10, wherein the configuration associated with the first conditional cell operation comprises a full configuration or a delta configuration for the first conditional cell operation.

12. The user equipment: determining whether the reused configuration for the subsequent second conditional cell operation is associated with a number of candidate secondary cells that exceeds a predetermined number; removing one or more candidate secondary cells from the reused configuration for the subsequent second conditional cell operation if it is determined that the number of candidate secondary cells to which the reused configuration for the subsequent second conditional cell operation is associated exceeds the predetermined number; A user equipment according to any one of claims 1 to 11, further adapted to:

13. 1. A method performed by a user equipment configured to support dual connectivity operation to a master node and a secondary node of a radio access network, the method comprising at least: obtaining, from the master node, transformation information that configures the user equipment to at least partially reuse configuration associated with a first conditional cell operation with one or more secondary nodes for a subsequent second conditional cell operation with the one or more secondary nodes.

14. When executed by a user equipment configured to support dual connectivity operation to a master node and a secondary node of a radio access network, the method causes the user equipment to: a non-transitory computer-readable medium comprising program instructions for causing the user equipment to obtain, from the master node, conversion information that configures the user equipment to at least partially reuse configuration associated with a first conditional cell operation with one or more secondary nodes for a subsequent second conditional cell operation with the one or more secondary nodes.

15. A master node of a radio access network, wherein the master node and a secondary node of the radio access network are configured to support dual connection operations to a user equipment, the master node comprising at least one processor and at least one memory, the at least one memory, when executed by the at least one processor, providing the master node with at least: a master node of a radio access network storing instructions to cause the user equipment to provide transformation information that configures the user equipment to at least partially reuse configurations associated with a first conditional cell operation with respect to one or more secondary nodes for a subsequent second conditional cell operation with respect to the one or more secondary nodes.

16. 16. The master node of claim 15, further adapted to obtain, from a source secondary node, an instruction to release the source secondary node, S-SN, and wherein, in response to the instruction to release the source secondary node, the conversion information is provided to the user equipment.

17. The instruction to release the source secondary node comprises: - information indicating an updated measurement gap for the reuse of the configuration for the subsequent second conditional cell operation; - information indicating updated execution conditions for said reuse of said configuration for said subsequent second conditional cell operation; 17. The master node of claim 15 or 16, comprising one or more of:

18. updating one or more execution conditions indicated to the user equipment as part of the transformation information for the reuse of the configuration for the subsequent second conditional cell operation; refraining from releasing configurations associated with one or more target secondary nodes, target secondary cell groups, and / or primary secondary cells that are reused for said subsequent second conditional cell operation; The master node of any one of claims 15 to 17, further adapted to perform one or more of the following:

19. A method performed by a master node of a radio access network, the master node and a secondary node of the radio access network being configured to support dual connectivity operations to user equipment, the method comprising at least: providing to the user equipment transformation information that configures the user equipment to at least partially reuse configuration associated with a first conditional cell operation with one or more secondary nodes for a subsequent second conditional cell operation with the one or more secondary nodes.

20. The program instructions, when executed by a master node of a radio access network, wherein a master node and a secondary node of the radio access network are configured to support dual connectivity operations to user equipment, cause the master node to: a non-transitory computer-readable medium comprising program instructions that cause the user equipment to provide conversion information that configures the user equipment to at least partially reuse configuration associated with a first conditional cell operation with one or more secondary nodes for a subsequent second conditional cell operation with the one or more secondary nodes;

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