Configuration for conditional cell operation

Abstract

The present disclosure relates, among other things, to a user equipment configured to support dual connectivity operation towards a primary 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, the instructions, when executed by the at least one processor, cause the user equipment to obtain transition information from the primary node, the transition information configuring the user equipment to at least partially reuse a configuration related to a first conditional cell operation with respect to the one or more secondary nodes, for subsequent second condition cell operation with respect to 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 a radio access network defined by 3rd Generation Partnership Project (3GPP) standards such as the 5G standard (which is also referred to as New Radio (NR)). Background Art

[0002] Dual-connectivity (DC) is an operation 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 acts as a master node (MN), while the other node acts as a secondary node (SN). The MN and the SN are connected via a network interface, and at least the MN is connected to the core network. A master cell group (MCG) is a group of at least one serving cell associated with the MN, and a secondary cell group (SCG) is a group of at least one serving cell associated with the SN. The master cell group includes at least one primary cell (PCell). The secondary cell group also includes at least one primary cell or primary-secondary cell (PSCell) of the secondary cell group. The corresponding primary cell can be understood as the cell on which the UE establishes a connection or initial access to the corresponding cell group (see, for example, References [1], [2]).

[0003] For example, there are different operations for adding, modifying, releasing, or changing the corresponding secondary node or PSCell. These operations may be necessary, for example, because the UE is moving and may leave or enter the coverage area of the corresponding cell or node. These operations can also be implemented as conditional operations by configuring the UE with specific configurations for these operations, but the UE will only perform the operation (such as connecting to another secondary node or cell) when a certain execution condition provided in the configuration and monitored by the UE is satisfied. For example, conditional PSCell addition (CPA) is defined as the addition of a PSCell performed by the UE when the (multiple) execution conditions are met. The UE starts evaluating the (multiple) execution conditions after receiving the CPA configuration, and stops evaluating the (multiple) execution conditions once the PSCell addition or PCell change is triggered. Similarly, conditional PSCell change (CPC) is defined as the change of a PSCell performed by the UE when the (multiple) execution conditions are met. The UE starts evaluating the (multiple) execution conditions after receiving the CPC configuration, and stops evaluating the (multiple) execution conditions once the PSCell change or PCell change is triggered. Generally, the UE is provided with multiple prepared candidate secondary nodes or PSCs for the corresponding operation, and then the UE will establish a connection with one of the nodes or change from the previous secondary node or PSC to that node for dual-connectivity operation. Then the configurations for the remaining or unused candidate secondary nodes or PSCs are released. SUMMARY OF THE INVENTION

[0004] For example, consider the case of SN or PSCell addition, and assume that an SN or PSCell is successfully added during a conditional PSCell addition (CPA) procedure. Then, the CPA configuration of other candidate PSCs is released at the UE, and the configured or reserved resources are also deconfigured or cancelled in other candidate PSCs that the UE has not selected or connected to. Therefore, for subsequent PSCell changes (after the first successful CPA), a conditional reconfiguration and preparation of the target SN needs to be initiated again (but this time it is a change procedure CPC instead of an addition procedure CPA). To this end, a CPC configuration needs to be requested from the candidate target cell, and CPC conditions need to be configured, which results in latency and signaling overhead.

[0005] Similarly, considering the case of a conditional PSCell change (CPC) initiated by an SN, the UE can be configured with a CPC configuration and can monitor the corresponding conditions, but a failure (such as a synchronization failure) may occur before the actual change is executed. In this case, an SN release message will be initiated, which releases the serving or source secondary node, and causes all prepared PSCs at the target SN to be cancelled, and initiates the release of the entire SCG configuration and the associated UE context at the target SN.

[0006] Either case results in latency and increased signaling overhead because subsequent preparation for conditional PSCell addition or change to another target SN is required.

[0007] Accordingly, some embodiments of the present disclosure may provide an improved method of configuring (subsequent) conditional cell operations. Some embodiments of the present disclosure may have the effect of reducing the latency and / or signaling overhead of subsequent preparation for conditional PSCell addition or change to another target SN. Some embodiments of the present disclosure may have the effect of faster SN addition immediately after an SN release. Some embodiments of the present disclosure may have the effect of faster PSCell change to another SN immediately after an SN addition. Some embodiments of the present disclosure may have the effect of reusing or converting configurations for conditional cell operations.

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

[0010] According to each exemplary aspect, a corresponding method is also disclosed.

[0011] Thus, according to a first exemplary aspect, a method performed by a user equipment configured to support dual connectivity operation towards a master node and a secondary node of a radio access network is also disclosed. The method may at least include obtaining conversion information from the master node. The conversion information may configure the user equipment to at least partially reuse a configuration related to a first conditional cell operation regarding one or more secondary nodes for a subsequent second conditional cell operation regarding the 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 a secondary node of the radio access network may be configured to support dual connectivity operation towards a user equipment. The method may at least include providing conversion information to the user equipment. The conversion information may configure the user equipment to at least partially reuse a configuration related to a first conditional cell operation regarding one or more secondary nodes for a subsequent second conditional cell operation regarding the one or more secondary nodes.

[0013] The user equipment can be a fixed device or a mobile device. Specifically, the user equipment can be a mobile device, such as a smart phone, a tablet computer, a wearable device, a smart watch, a low-power device, an IoT device, an IIoT device, a vehicle, a truck, a drone, an aircraft, etc. The user equipment can be particularly capable of communicating with one or more other user equipments (transmitting and receiving signals and / or data to / from one or more other user equipments). Additionally or alternatively, the user equipment can be particularly capable of communicating with at least one master node of a radio access network (transmitting and receiving signals and / or data to / from one or more other user nodes), where the master node is configured to support dual-connectivity operation towards a secondary node and the user equipment of the radio access network. Additionally or alternatively, the user equipment can be particularly capable of communicating with at least one secondary node of a radio access network (transmitting and receiving signals and / or data to / from one or more other user equipments), where the secondary node is configured to support dual-connectivity operation towards the master node and the user equipment of the radio access network. Generally, the user equipment can also 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) can be understood as a wireless communication station installed in a fixed or mobile location, and can particularly be or include an entity of a radio access network of a wireless communication system. For example, a radio node can be, include, or be part of a base station of any generation of a wireless communication network of the 3GPP standard (e.g., gNB, ng-eNB, eNodeB, NodeB, BTS, etc.). Generally, a radio node can be or include a hardware or software component that implements specific functionality. In one example, a radio node can be or include a Location Management Function (LMF). In one example, a radio node can be an entity defined by the 3GPP 5G or NR standard (also referred to as gNB). In one example, a radio node can be or include a gNB-CU-CP node. Thus, although a radio node can be understood to be implemented in a single device or module or as a single device or module, a radio node can also be implemented across multiple devices or modules or include multiple devices or modules. As such, a radio node can particularly be implemented in a fixed device or as a fixed device. Multiple radio nodes can particularly establish a wireless communication system or network, which can particularly be an NR or 5G system or any other wireless communication system defined by past or future standards (especially successor standards of the current 3GPP standards). Particularly, multiple radio nodes (e.g., a master node and one or more secondary nodes) can be configured to support dual-connectivity operation towards one or more user equipments. A radio node can be capable of communicating directly and / or indirectly with other radio nodes or user equipments.

[0015] The components or functionality of any disclosed device or apparatus (i.e., any user equipment and any radio node) can be implemented in hardware and / or software. Generally, the described apparatus may include components for performing or causing the described functions. They may include one or more modules or units providing the corresponding functionality. For example, they may include at least one processor for executing computer program code to perform the desired function, at least one memory storing the program code, or both. Alternatively, they may include circuitry, for example implemented in a chipset or a chip such as an integrated circuit, designed to implement the desired function. Generally, these components may include, for example, one or more processing components or processors.

[0016] The master node may, for example, implement CU-CP and / or CP-UP functionality. This functionality may also be implemented using specific components configured to perform corresponding specific tasks, such as a layer 3 component for performing layer 3 operations, a layer 2 component for performing layer 2 operations, etc. The master node may include, for example, a conversion component configured to provide conversion information to the user equipment, the conversion information configuring the user equipment to at least partially reuse a configuration related to first conditional cell operation regarding one or more secondary nodes for subsequent second conditional cell operation regarding one or more secondary nodes.

[0017] Similarly, the user equipment may include specific components for performing specific tasks, such as an obtaining component configured to obtain conversion information from the master node, the conversion information configuring the user equipment to at least partially reuse a configuration related to first conditional cell operation regarding one or more secondary nodes for subsequent second conditional cell operation regarding one or more secondary nodes.

[0018] Thus, according to the corresponding exemplary aspects of the present disclosure, corresponding apparatuses (i.e., terminal devices and network devices) are also disclosed in each case, which include components for causing the corresponding apparatus to at least perform the methods according to the corresponding aspects of the present disclosure.

[0019] However, any of the above-disclosed exemplary aspects may generally be performed by an apparatus, which may be a module or a component of a device, such as a chip. The disclosed apparatus may include the disclosed components, such as components, processors, memories, or may also include one or more additional components.

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

[0021] In each case, the computer program can be stored on a computer-readable storage medium, in particular a tangible and / or non-transitory medium. The computer-readable storage medium can be, for example, a disk or a memory, etc. The computer program can be stored in the computer-readable storage medium in the form of instructions encoding the computer-readable storage medium. The computer-readable storage medium can be used to participate in the operation of a device, such as an internal or external memory, for example the read-only memory (ROM) or hard disk of a computer, or for distributing the program, such as an optical disc.

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

[0023] Similarly, according to a second exemplary aspect, among other things, a non-transitory computer-readable medium including program instructions is disclosed, the program instructions, when executed by a master node of a radio access network, the master node and the secondary node of which are configured to support dual-connectivity operation towards a user equipment, cause the master node to provide the user equipment with transition information, the transition information configuring the user equipment to at least partially reuse a configuration related to a first conditional cell operation regarding one or more secondary nodes for a subsequent second conditional cell operation regarding the one or more secondary nodes.

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

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

[0026] Generally, the connection of a user equipment is considered to be towards a cell, and the cell is provided by the corresponding node. Thus, the terms node and its associated cell may be used interchangeably in the present disclosure. In the context of dual connectivity, a user equipment typically has (or attempts to obtain) a connection to (at least) two different cells, namely the primary cell (PCell) of the (serving or source) primary node and the primary secondary cell (i.e., the primary cell of the secondary cell group) (PSCell) of the (serving or source) secondary node. Thus, conditional cell operation with respect to the secondary node is related to the PSCell of the target secondary node (e.g., the one to which the user equipment is to be switched or added). Where the source secondary node (to which the user equipment is already connected or from which it is being switched) is typically different from the target secondary node (to which one of the nodes is to be added or switched).

[0027] Cell operation can be particularly understood as an operation or process performed on the secondary node or cell (e.g., PSCell). Cell operation can particularly include or be the addition, change, release, modification of the secondary node or cell (e.g., PSCell). In the process of adding a secondary node or cell, the UE can add a secondary node or a primary secondary cell in addition to the primary node or primary cell. In the process of changing a secondary node or cell, the UE can change from the source secondary node (S-SN) or the serving primary secondary cell (serving PSCell) to the target secondary node (T-SN) or the target primary secondary cell (target PSCell). For example, conditional cell operation can be conditional PSCell addition (CPA) or conditional PSCell change (CPC), which can also be collectively referred to as conditional PSCell addition or change (CPAC).

[0028] Transition information can generally be understood as any information that enables a user equipment to at least partially reuse the configuration related to a first conditional cell operation for a subsequent second conditional cell operation. Transition information can, for example, include information on how to use, update, and / or modify the configuration related to the first conditional cell operation so that it can be used for the subsequent second conditional cell operation. Transition information can be understood as configuring the user equipment for a subsequent second conditional cell operation based on the configuration of the first conditional cell operation. Thus, transition information can be regarded as or referred to as "configuration information" for conditional cell operation. Transition information can be understood as aligning the configuration related to the first conditional cell operation of the user equipment so that it can be reused for the subsequent second conditional cell operation. Thus, transition information can be understood as or referred to as "alignment information". The potential content or information contained in transition information will be described in more detail below.

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

[0030] Since the configuration related to the first conditional cell operation involves one or more secondary nodes, the configuration can be understood to include multiple (individual) configurations, e.g., each of the one or more secondary nodes has a configuration. For example, these individual configurations can be maintained, modified, and / or reused individually.

[0031] One or more secondary nodes can include candidate secondary nodes, which can be secondary nodes that the user equipment can use for dual connectivity. The secondary node can provide a candidate primary secondary cell (PSCell) or be associated with a candidate primary secondary cell (PSCell). For example, if the conditions are met, the user equipment can (attempt to) establish a connection with the corresponding secondary node or PSCell by means of the corresponding conditional cell operation that has been configured with the corresponding configuration. Typically, the UE only selects one of the candidate cells or nodes for the corresponding cell operation (e.g., to be added or changed).

[0032] Typically, the user equipment can receive a configuration for conditional cell operation, e.g., in a higher layer configuration message, such as an RRC configuration message, e.g., RRCReconfiguration. The configuration related to a certain conditional cell operation can particularly include information about one or more conditions to be met. These conditions can be referred to as execution conditions. The user equipment will use this configuration to monitor whether one or more conditions are met. If the (multiple) conditions are met, the user equipment will apply or execute the configuration, thereby performing the corresponding operation (e.g., cell addition or cell change).

[0033] One or more secondary nodes of the first conditional cell operation can be at least partially the same as one or more secondary nodes of the second conditional cell operation. In one example, only a part of the one or more secondary nodes related to the first conditional cell operation can be reused for the second conditional cell operation. In one example, all nodes of the one or more secondary nodes related to the first conditional cell operation can be reused for the second conditional cell operation.

[0034] The reuse of at least a part of the configuration information is particularly understood to mean that the configuration (or a part thereof) for at least one of one or more secondary nodes or secondary cells can be reused. For example, the configuration regarding all or some specific secondary cells or nodes can be reused. However, the transition information can modify or update the configuration related to the first conditional cell operation. For example, the transition information can include information on a list of candidate secondary nodes or cells for modifying or updating the configuration upon reuse. For example, the transition information can include information on one or more execution conditions for modifying or updating one or more candidate secondary nodes or cells.

[0035] In one example, the configuration related to the first conditional cell operation can include the configuration of at least two prepared candidate primary secondary cells (PSCells) for at least one (e.g., target) secondary node. A prepared primary secondary cell can be understood as a cell (or the associated secondary node) that has been informed of its potential use as a primary secondary cell or secondary node. For example, the secondary node may have received an SN addition request from the primary node to prepare the corresponding secondary node or the associated cell. For example, the secondary node may have obtained UE context information for the corresponding user equipment.

[0036] Similarly, the configuration related to the second conditional cell operation (which is at least partially based on or derived from the configuration related to the first conditional cell operation) can include the configuration of at least two prepared candidate primary secondary cells (PSCells) for at least one (e.g., target) secondary node.

[0037] In one example, the user equipment can be configured to establish a connection for a dual connection of a primary cell (PCell) towards the primary node and a primary secondary cell (PSCell) of a secondary node. To establish or maintain the dual connection, the user equipment is provided with the corresponding configuration for the conditional cell operation of the secondary node or the primary secondary cell.

[0038] It will also be more apparent from the additional examples provided herein that the described aspects can allow for an improved method for subsequent second conditional cell operations after a first (successful or unsuccessful) first conditional cell operation regarding one or more secondary nodes. More specifically, since the user equipment can at least partially reuse the configuration regarding the first conditional cell operation for the second conditional cell operation or convert the configuration regarding the first conditional cell operation into the second conditional cell operation, the user equipment can be configured for the second conditional cell operation quickly and efficiently. This can have the effect of reducing the latency and / or signaling overhead for subsequent prepared conditional PSCell addition or change to other target SNs.

[0039] In one example, the first conditional cell operation is a conditional cell change, in particular a conditional PSCell change (CPC), and wherein the subsequent second conditional cell operation is a conditional cell addition, in particular a conditional PSCell addition (CPA). As described above, there may be cases where the CPC has been successfully configured (and the user equipment is monitoring the conditions provided in the CPC configuration) but has not been successfully executed or completed. Instead, there may be a connection failure (such as a synchronization failure) 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 method may have the effect of a faster SN addition immediately after the SN release, because the configuration initially provided to the user equipment for the CPC process can be converted, based on the conversion information, into a configuration for, for example, CPA and reused for CPA without additional delay or signaling.

[0040] In one example, the first conditional cell operation is a conditional cell addition, in particular a conditional PSCell addition (CPA), wherein the subsequent second conditional cell operation is a conditional cell change, in particular a conditional PSCell change (CPC). For example, the CPA may be successfully configured and executed. Instead of releasing other candidate secondary nodes or PSCs that have not been used for CPA, the configurations of these other candidate secondary nodes or PSCs can be converted, based on the conversion information, into a configuration for CPC and reused for CPC without additional delay or signaling, thus allowing for a faster change of the PSCell to another SN immediately after the SN addition.

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

[0042] In one example, the configuration related to the first conditional cell operation regarding one or more secondary nodes may be obtained in a first configuration message (such as an RRCReconfiguration). Then, the user equipment may use the configuration related to the first conditional cell operation and monitor whether the corresponding execution conditions are met. The first conditional cell operation may have been completed or may not have been completed. However, the UE may subsequently obtain the conversion information in a subsequent second configuration message. The user equipment may then use the conversion information to obtain the configuration related to the subsequent second conditional cell operation. The user equipment may then replace the previous configuration and instead use the thus obtained configuration related to the subsequent second conditional cell operation and monitor whether the corresponding execution conditions are met.

[0043] In one example, the configuration related to the first conditional cell operation regarding one or more secondary nodes and the transition information can be obtained in a common configuration message. The user equipment can first use the configuration related to the first conditional cell operation and monitor whether the corresponding execution conditions are met. As described in more detail below, the transition information can indicate to maintain or not release the configuration regarding other candidate secondary nodes. In contrast, after the first conditional cell operation is completed, the UE can then directly use the configuration related to the subsequent second conditional cell operation that is also received together with the common configuration message.

[0044] In one example, the described first configuration message, second configuration message, and / or common configuration message can each be a higher layer message, particularly an RRCReconfiguration message. For example, each corresponding message can include one or more RRCReconfigurations for the corresponding conditional cell operation.

[0045] In different examples, the transition information can include one or more of the following information.

[0046] For example, the transition information can include an indication to maintain the configuration related to the source secondary node S-SN or serving secondary cell group SCG for the reuse of the configuration for the subsequent second conditional cell operation. For example, in the case of at least partially reusing the CPC configuration for the CPA operation, the transition information can include an indication to not release the configuration related to the S-SN or SCG, but to facilitate the configuration used for the CPA.

[0047] For example, the transition information can include an indication for maintaining the configuration related to one or more target secondary nodes T-SN or target secondary cell group SCG for the reuse of the configuration for the subsequent second conditional cell operation.

[0048] The indication to maintain the configuration can be an implicit or explicit indication. In one example, the indication can be a bit or flag indicating to maintain or not release one or more (or all) configurations. In one example, the indication for maintaining the configuration can be achieved by not including the corresponding SN, SCG, or PSCell (e.g., their corresponding IDs) related to the configuration in the release list.

[0049] In one example, the transition information can include information indicating an updated measurement gap for the reuse of the configuration for the subsequent second conditional cell operation. For example, the configuration related to the first conditional cell operation can include a first measurement gap. The transition information can include a second measurement gap to be used for the subsequent second conditional cell operation.

[0050] In one example, the conversion information may include information that indicates one or more updated execution conditions for the reused configuration for subsequent second conditional cell operations. For example, the configuration related to the first conditional cell operation may include one or more first execution conditions. The conversion information may include one or more second execution conditions to be used for subsequent second conditional cell operations.

[0051] In one example, the conversion information may include an indication for maintaining the configuration related to one or more remaining secondary nodes after successful execution of a first conditional cell operation towards a secondary node for the reuse of the configuration for subsequent second conditional cell operations. To this end, as described above, the conversion information may particularly include a flag indicating not to release other or remaining secondary nodes. For example, in the case of at least partially reusing the CPA configuration for CPC operations, the conversion information may include a flag indicating not to release other secondary nodes after (successful) SN addition.

[0052] In one example, the conversion information may include information that indicates one or more execution conditions to be used for the first conditional cell operation and one or more execution conditions to be used for subsequent second conditional cell operations. One or more execution conditions to be used for subsequent second conditional cell operations may be used to (at least partially) replace one or more execution conditions for the first conditional cell operation.

[0053] In one example, the user equipment may also start evaluating one or more execution conditions based on the configuration related to the first conditional cell operation in response to obtaining the configuration related to the first conditional cell operation. In one example, the user equipment may obtain the conversion information before one or more execution conditions based on the configuration related to the first conditional cell operation are satisfied or before the execution of the first conditional cell operation is completed. This may be due to a connection failure regarding the serving SN or SCG, and thus this may indicate a need to release to the master node. In response, the master node may provide the conversion information to the user equipment so that the already configured conditional cell operation can be reused instead of being released. In one example, the user equipment may start evaluating one or more execution conditions based on the reuse configuration of the second conditional cell operation in response to obtaining the conversion information. Thus, the user equipment may, for example, quickly re-add any source or target secondary nodes from a previous unsuccessful conditional cell operation.

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

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

[0056] In one example, the configuration related to the first conditional cell operation includes a complete configuration or an incremental configuration of the first conditional cell operation. The corresponding configuration (e.g., a complete RRC configuration or an incremental RRC configuration) may first be sent from the corresponding secondary node to the master node. Then, the master node may provide the corresponding configuration to the user equipment. In the case of an incremental configuration, the user equipment may construct a complete configuration by combining the incremental configuration with a reference configuration.

[0057] In one example, the user equipment may also determine whether the configuration reused for a subsequent second conditional cell operation is related to more than a predetermined number of candidate secondary cells. 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 configuration reused for a subsequent second conditional cell operation is related to more than a predetermined number of candidate secondary cells, the user equipment may remove one or more candidate secondary cells from the configuration reused 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 also obtain an indication for releasing a source secondary node S-SN from the source secondary node, and in response to the indication for releasing the source secondary node, provide the conversion information to the user equipment. When receiving an indication for releasing the S-SN (e.g., SNReleaseRequired), the source secondary node may provide updated information (e.g., regarding execution conditions and / or measurement gaps) to the master node (e.g., in a ReleaseRequired message) to be used for the secondary node - after being released and when the secondary node becomes a candidate for subsequent secondary condition cell operation. Thus, in one example, the indication for releasing the source secondary node may include information indicating the updated measurement gap re-used for the configuration of subsequent secondary condition cell operation. Thus, in one example, the indication for releasing the source secondary node may additionally or alternatively include information indicating the updated execution conditions re-used for the configuration of subsequent secondary condition cell operation. This information may be used or forwarded by the master node in the conversion information.

[0059] In one example, the master node may also update one or more execution conditions, which are indicated to the user equipment as part of the conversion information re-used for the configuration of subsequent secondary condition cell operation. As described above, the master node may update one or more execution conditions based on information received from one or more corresponding secondary nodes, which may be candidate nodes for subsequent secondary condition cell operation.

[0060] In one example, the master node may also avoid releasing configurations related to one or more target secondary nodes, target secondary cell groups, and / or primary-secondary cells to be re-used for subsequent secondary condition cell operation.

[0061] Any of the described examples may equally apply to any of the described aspects. Specifically, the disclosure of method steps should also be regarded as the disclosure of components for performing the corresponding method steps. Similarly, the disclosure of components for performing method steps should also be regarded as the disclosure of the method steps themselves. However, it should be understood that the presentation of the embodiments disclosed herein is merely exemplary and not restrictive.

[0062] Other features of the present disclosure will be apparent from the following detailed description in conjunction with the accompanying drawings. However, it should be understood that the drawings are only designed for illustrative purposes and not as a definition of the limitations 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 are only used to conceptually illustrate the structures and processes described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Some example embodiments will now be described with reference to the accompanying drawings, wherein

[0064] Figures 1a - 1d A first exemplary embodiment according to different aspects of the present disclosure is shown in a signaling flow chart;

[0065] Figures 2a - 2d A second exemplary embodiment according to different aspects of the present disclosure is shown in a signaling flow chart;

[0066] Figures 3a - 3b A third exemplary embodiment according to different aspects of the present disclosure is shown in a signaling flow chart;

[0067] Figure 4 An example embodiment of a user equipment according to a first aspect is shown in a schematic block diagram;

[0068] Figure 5 An example embodiment of a radio node (such as a master node or a secondary node) according to a second aspect is shown in a schematic diagram;

[0069] Figure 6 Examples of tangible and non - transitory computer - readable storage media according to different aspects are shown in schematic diagrams; and

[0070] Figure 7 A radio environment in which example embodiments of the present disclosure can be implemented is shown schematically and by way of example. Detailed Description

[0071] The following description is for deepening the understanding of the present disclosure and should be understood as supplementary and read in conjunction with the description of the example embodiments of the present disclosure provided in the above - mentioned aspects section of this specification.

[0072] The following refers to Figure 7 , and describes an example radio environment in which the present disclosure can be applied. Although the specific radio system in the following examples is a 5G system, this should only be regarded as a non - restrictive example.

[0073] Figure 7 A user equipment (UE) 701 is shown schematically and by way of example as an example of a UE according to a first exemplary aspect. Figure 7 A master node (MN) 702 is also shown as an example of an MN according to a second exemplary aspect. Figure 7Examples of SN, source secondary node (S-SN) 703, first target secondary node (T-SN1) 704, and second target secondary node (T-SN2) 705 are also illustrated. MN 702, S-SN 703, T-SN1 704, and T-SN2 705 can together establish a wireless communication system or network to serve the geographical area where UE 701 is located. UE 701, MN 702, and SN 703, 704, 705 can operate in a dual-connectivity mode.

[0074] UE 701 can be connected to MN 702 and one or more SNs 703, 704, 705 via a radio link (not shown), which can correspond to, for example, the 5G / NR Uu interface. MN 702 can be connected to one or more SNs 703, 704, 705 via a radio link (not shown), which can correspond to, for example, the 5G / NR Xn interface. The radio link can enable the transmission and / or reception of information and / or signals between the respective devices.

[0075] MN 702 can provide one or more secondary cells (SCells) of a primary cell (PCell) and / or a master cell group (MCG). Any secondary node 703, 704, 705 can provide one or more secondary cells (SCells) of a primary secondary cell (PSCell) and a secondary cell group (SCG).

[0076] At some point in time, as indicated by arrow 770, UE 701 moves from a first location to a second location. At the first location, the UE may have been served by the PSCell of the source secondary node S-SN 703, which may have been added via conditional PSCell addition (CPA). The PSCell associated with the target secondary node T-SN1 704 may be serving the UE at the second location. Therefore, during the movement of UE 701 along arrow 770, a conditional PSCell change (CPC) of UE 701 from S-SN 703 to T-SN1 704 may have been performed.

[0077] For the sake of general understanding, the two cases of the above-mentioned conditional PSCell change and conditional PSCell addition will be explained in more detail below. This will become apparent and be explained in more detail later with respect to Figures 1a - 1d 、 Figures 2a - 2d 、 Figures 3a - 3b It will become apparent and be explained in more detail that various aspects of the present disclosure can be advantageously applied to these exemplary scenarios

[0078] Conditional PSCell Change (CPC) between SNs is specified in Rel-17, where the procedure can be initiated by 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:

[0079] - The SN-initiated CPC can be initiated by the source SN to modify an existing CPC configuration or trigger the release of the target SN by cancelling all prepared PSCells and releasing the CPC-related UE context at the target SN.

[0080] - In the SN-initiated CPC, the source SN proposes PSCell candidates, determines the CPC execution conditions, and may also include SCG measurement configuration for the CPC. The target SN determines the list of PSCells to be prepared and sends the list of PSCell IDs together with a full or incremental RRC configuration indication to the MN.

[0081] - For example, in the case where the target SN does not prepare all the proposed PSCells, the MN can indicate to the source SN the candidate PSCells accepted by the target SN via the "SN Modification Request" message. The source SN can provide the updated measurement configuration and execution conditions to the MN via the "SN Modification Request Acknowledge" message.

[0082] - The MN reconfigures the UE with the CPC configuration and the associated execution conditions. The UE applies the RRC configuration and stores the CPC configuration provided that it complies with the received configuration (otherwise the reconfiguration failure procedure is executed).

[0083] - The source SN can also trigger an update of the CPC execution conditions and the corresponding SCGmeasConfig for the CPC via the "SN Modification Required" message, enabling the MN to reconfigure the UE.

[0084] - The UE starts to evaluate the execution conditions. If the execution conditions of a candidate PSCell are met, the UE applies the "RRCReconfiguration" message corresponding to the selected candidate PSCell and sends an "RRCReconfiguration complete" message including the information of the selected PSCell to the MN.

[0085] reconfiguration complete) message.

[0086] - The MN triggers the SN Release procedure initiated by the MN to notify the source SN to stop providing user data to the UE, and triggers the Xn-U address indication procedure to notify the source SN of the address of the selected target SN for data forwarding.

[0087] - The MN also notifies the target SN of the successful RRC connection reconfiguration via the "SN Reconfiguration complete" message. Subsequently, the MN sends a "SN Release Request" message to cancel the CPC (if configured) in other target candidate SNs.

[0088] - After the "RRCReconfiguration complete" message, the UE synchronizes to the target SN (random access procedure).

[0089] However, when the SN-initiated CPC is configured, for example, the SN release message initiated due to synchronization failure will cause the cancellation of all prepared PSCells at the target SN and initiate the release of the entire SCG configuration and related UE context at the target SN.

[0090] Note that there may be a time gap between the CPC configuration and conditions configured at the UE and the UE triggering RRCReconfigurationComplete for the target PSCell (when the CPC conditions are met). During this period, there is an opportunity to trigger the SN-initiated SN Release procedure.

[0091] Also note that in the case of an SN-initiated release (i.e., "SN Release Required"), there is no defined rejection message in 38.423 (Section 8.3.7.3 - unsuccessful operation is "Not applicable"). In addition, when this SN-initiated release is triggered, the actual SN change procedure (CPC execution) may not have been triggered yet.

[0092] Conditional PSCell addition (CPA) is also specified in Rel-17, and this procedure is initiated by the MN. See Section 10.2 of [2], Figure 10.2.2-2. The steps of the CPA procedure can be described as follows:

[0093] - To configure CPA for the UE, the MN requests the target candidate SN to allocate resources. The MN indicates the requested SCG configuration information and provides the candidate cells recommended by the MN via the latest measurement results for the SN to select and configure (multiple) SCG cells.

[0094] - If the SN can accept the resource request, it will allocate the corresponding resources and convey the (multiple) PSCell configurations to the MN.

[0095] - MN reconfigures the UE using the CPA configuration and the associated execution conditions. The UE applies the RRC configuration and stores the CPA configuration provided that it complies with the received configuration (otherwise, the reconfiguration failure procedure is executed).

[0096] - The UE starts to evaluate the execution conditions. If the execution conditions of a 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

[0097] information to MN.

[0098] - MN notifies the SN about the successful RRC connection reconfiguration via the "SN Reconfiguration complete" message. Subsequently, MN

[0099] transmits an "SN Release Request" message to cancel the CPA in other target candidate SNs (if configured).

[0100] - After the "RRC reconfiguration complete" message, the UE synchronizes to the target SN (random access procedure).

[0101] - For the detailed flowchart, see "Figure 10.2.2-2: Conditional secondary node addition procedure" in TS 37.340.

[0102] However, after a successful SN addition, the CPA configuration of other remaining candidate PSCells is released at the UE, and the CPA in other candidate PSCells is cancelled. Therefore, for additional PSCell changes (after the said successful CPA), the conditional reconfiguration and preparation of the target SN need to be initiated again (but this time the CPC should be configured instead of the CPA). That is, the (multiple) CPC configurations need to be requested from the candidate target cells, and the CPC conditions need to be configured, which results in latency and signaling overhead.

[0103] Therefore, after the SN-initiated inter-SN CPC is successfully configured at the UE, if a source SN release is initiated (e.g., due to a synchronization failure), the prepared PSCell at the target SN will be cancelled, and the entire SCG configuration at the UE will be released. Since the conditional PSCell addition is subsequently prepared, this results in latency and increased signaling overhead.

[0104] Similarly, after successfully adding an SN via CPA, the prepared PSCell at other candidate SNs will be cancelled, and the configurations of other candidate SNs at the UE will be released. This results in delays and increased signaling overhead when subsequently preparing to change the conditional PSCell to another target SN.

[0105] Now turn to Figures 1a - 1d , where a first exemplary embodiment in accordance with different aspects of the present disclosure is shown in a signaling flow diagram.

[0106] In conjunction with Figures 1a - 1d The method illustrated can be regarded as a conversion from CPC configuration to CPA configuration and can be summarized as follows: In response to a conditional SN change initiated by the source SN, the target SN includes a complete RRC configuration in the "SgNB Addition RequestAcknowledge" message. The "SN ReleaseRequired" message from the source SN to the MN can update some of the CPC execution conditions to CPA conditions. The MN does not initiate the release of the source SN and target SN configurations; instead, it should use the existing target SN CPC configuration for CPA. The MN reconfigures the UE with the newly prepared CPA configuration and the updated execution conditions. After successfully reconfiguring the updated CPA configuration, the UE starts to evaluate the configured CPA conditions.

[0107] More specifically, the source SN initiates the conditional SN change process by sending a "SN Change Required" message (action 101). The MN requests the (multiple) target SNs to allocate a complete configuration for the UE by indicating this in the "SN Addition Request" (action 102). The candidate target SN responds with a "SN Addition RequestAck", which includes the complete RRC configuration for the prepared PSCell (action 103).

[0108] The MN sends an RRC reconfiguration message ("RRCReconfiguration*") to the UE, which includes an MN RRC reconfiguration message ("RRCReconfiguration**"), a CPC configuration (i.e., a list of "RRCReconfiguration***" messages), and associated execution conditions. The "RRCReconfiguration***" message contains the RRCReconfiguration**** received from the candidate SN (with a complete configuration) and possibly an MCG configuration (action 104).

[0109] The UE application excludes the RRC configuration configured by CPC (in RRCReconfiguration*), stores the CPC configuration, and replies to the MN using the RRC reconfiguration complete message (“RRCReconfigurationComplete*”) (Action 105). Therefore, the UE is configured with the configuration for CPC as the first conditional cell operation.

[0110] The MN notifies the source SN of “RRCReconfigutationComplete**” for the source SN via the “SN Change Confirm” (SN change confirmation) message (Action 106).

[0111] After initiating the SN release to the MN (e.g., due to a synchronization failure), the SN updates the CPA condition and optionally updates the MeasGap configuration in “SNReleaseRequired” (SN release required) (Action 107). The MN confirms this situation to the SN using the “SNReleaseConfirm” (SN release confirmation) message (Action 108). After receiving the “SNReleaseRequired” message, the MN updates the CPC condition / measurement event to the CPA condition / measurement event. The MN avoids releasing the complete configuration of the prepared target SN's PSCell from the UE.

[0112] The MN sends “RRCReconfiguration” to the UE (Action 109). The “RRCReconfiguration” message can be regarded as or include the conversion information described herein. More specifically, this message contains the updated condition for CPA and instructs the UE to promote the source SCG of CPC for CPA. Since the release list does not contain the candidate PSCell ID, the UE obtains an indication for maintaining the configuration of the corresponding PSCell. The “RRCReconfiguration” message also includes the updated measurement gap and configuration. Therefore, the UE is configured to reuse the configuration originally provided for CPC for subsequent second conditional cell operation, i.e., CPA in this case. The UE confirms the reconfiguration to the MN by sending the “RRCReconfigurationComplete” message (Action 110).

[0113] The MN triggers the Xn-U address indication procedure to notify the source SN of the address of the selected target SN and starts the late data forwarding (if applicable) (Actions 10a - 10c).

[0114] As a result, the UE re-uses the full configuration of the PSCell for CPA (which is received as part of the CPC configuration). The UE retains the serving SCG configuration that will be used for CPA. The UE starts evaluating the CPA conditions immediately after the SN release.

[0115] Thereafter, the S-SN sends a "SN Status Transfer" message to the MN to inform the PDCP SN. Data forwarding 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).

[0116] The handover behavior from the T-SN of CPC to the T-SN of CPA may be triggered by a release. To this end, relevant releases may be indicated to the target using corresponding signals (e.g., indicating to all target SNs). Then, the handover from the T-SN of CPC to the S-SN of CPA may occur only for the T-SN. The handover from the T-SN of CPC to the T-SN of CPA occurs among other potential T-SNs and S-SNs.

[0117] When the CPA conditions for the T-SN are met, the UE applies the "RRCReconfiguration" message ("RRCReconfiguration**") corresponding to the selected candidate PSCell and sends an MN RRC reconfiguration complete message ("RRCReconfigurationComplete**") to the MN, which includes an NR RRC reconfiguration complete message ("RRCReconfigurationComplete***") for the selected candidate PSCell and the selected PSCell information (action 114).

[0118] The MN notifies the SN via a "SNReconfigurationComplete" message (including the "RRCReconfigurationComplete***" response message) that the UE has successfully completed the reconfiguration process (action 115).

[0119] Note: When configured to operate using this feature, the MN does not send an SN release request message to cancel CPA in other target candidate SNs.

[0120] The UE uses the T-SN to perform the random access procedure (Action 116). The MN sends a "SN Status Transfer" message to the T-SN (Action 117). Data forwarding from the UPF to the MN and then from the MN to the T-SN is performed. The MN sends a "PDU Session Modification Indication" message to the AMF (Action 118). A "Bearer Modification" process 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. The AMF sends a "PDU Session Modification Confirmation" message to the MN (Action 120).

[0121] Among other things, the following advantages of the proposed solution can be identified:

[0122] - After SN release, the SN is added more quickly and immediately.

[0123] - The CPC configuration is reused as the CPA configuration, which greatly reduces the signaling overhead and latency of re-initiation of preparation.

[0124] - The serving SCG configuration is promoted to a candidate cell for CPA.

[0125] Now turning to Figures 2a - 2d , a second exemplary embodiment according to different aspects of the present disclosure is shown in the signaling flow diagram.

[0126] Similar to the embodiment of Figures 1a - 1d , the method illustrated in conjunction with Figures 2a - 2d can also be regarded as the conversion of the CPC configuration to the CPA configuration, and can be summarized as follows: The target SN includes the incremental RRC configuration in the "SgNB Addition Request Acknowledge" message (compared with the complete RRC configuration in the embodiment of Figures 1a - 1d ). The "SN Release Required" message from the source SN to the MN can convert the CPC condition to the CPA condition. The MN will not initiate the release of the source SN and target SN configurations. Instead, the MN should allow the UE to reconstruct the CPA configuration using the complete RRC configuration of the source SN and the incremental configuration of the target SN. The MN can reconfigure the UE with the updated execution conditions for CPA (and if necessary, also with the updated measurement gaps for target SN measurement). The UE starts to evaluate the configured CPA conditions.

[0127] Operation 201 corresponds to Operation 101.

[0128] Then, by indicating this in the "SN Addition Request" (action 202), the MN requests that the (multiple) target SNs allocate an incremental configuration for the UE. The candidate target SNs respond using "SN Addition Request Ack", which includes the incremental RRC configuration (action 203). The MN sends an RRC reconfiguration message ("RRCreconfiguration*") to the UE, which includes the CPC configuration (i.e., the list of "RRCReconfiguration***" messages) and the associated execution conditions. The "RRCReconfiguration***" message contains the "RRCReconfiguration****" (with incremental configuration) received from the candidate SNs and possibly the MCG configuration.

[0129] Operations 205 - 208 correspond to operations 105 - 108. Contrary to the example in Figures 1a - 1d , the UE then constructs a complete configuration of the CPA configuration for the candidate target SNs from the stored source SCG configuration and the incremental configuration from the respective target SNs. Operations 210 - 220 again correspond to operations 110 - 120.

[0130] The following advantages of the proposed solution can be identified:

[0131] - After an SN release, the SN can be added immediately more quickly.

[0132] - The CPC configuration is reused as the CPA configuration, thus reducing the signaling overhead and latency for re - initiating CPA preparation.

[0133] - The serving SCG configuration is promoted to a candidate cell for CPA.

[0134] - The complete configuration of the candidate cell is constructed by referring to the incremental configuration received from the respective candidate cells as part of the CPC process and the serving SCG configuration.

[0135] Now turning to Figures 3a - 3b , a third exemplary embodiment in accordance with different aspects of the present disclosure is shown in the signaling flow diagram.

[0136] In combination with Figures 3a - 3bThe method illustrated can be regarded as the conversion of the CPA configuration to the CPC configuration and can be summarized as follows: The candidate SN includes the configuration of the prepared PSCell in the "SgNB Addition Request Acknowledge" message as part of the CPA preparation process. The MN configures the CPA and CPC conditions for the candidate cells. The MN includes a flag in the "RRCReconfiguration*" message to indicate that the configuration of other candidate SNs is not released after a successful conditional PSCell addition. Even after the execution of the CPA, the CPA configuration for other SNs should be used as the CPC configuration. After the RACH for the addition of SN1 is successful, the UE starts to measure and check the CPC conditions for the PSCell change.

[0137] More specifically, the MN decides to configure the CPA for the UE. The MN requests the target candidate SN to allocate resources by sending a "SGNB Addition Request" message (action 301). The target candidate SN allocates the corresponding resources and sends the corresponding configuration in the "SGNB Addition Request Ack" message (action 302). For the SN terminated bearer using the MCG resources, the MN provides the Xn-U DLTNL address information to the target candidate SN in the "Xn-U Address Indication" message (action 302a).

[0138] The MN sends an RRC reconfiguration message ("RRC Reconfiguration*") to the UE, which includes the CPA configuration (i.e., the list of "RRC Reconfiguration**" messages) and the associated execution conditions. The corresponding "RRC Reconfiguration**" message contains the "RRCReconfiguration***" received from the candidate SN and possibly the MCG configuration. The MN configures the CPC and CPA conditions for all candidate SNs. The MN includes a flag in the "RRCReconfiguration*" message to indicate that the UE does not release the configuration of other candidate SNs after the SN addition (action 303).

[0139] The UE applies the RRC configuration excluding the CPA configuration (in the "RRCreconfiguration*" message), stores the CPA configuration and replies to the MN with an RRC reconfiguration complete message ("RRCReconfigurationComplete*") without any NRSN RRC response message (action 304).

[0140] The UE starts to evaluate the CPA execution conditions. If the CPA execution conditions of a candidate PSCell are met, the UE applies the RRC reconfiguration message ("RRCReconfiguration**") corresponding to the selected candidate PSCell, and sends an MN RRC reconfiguration complete message ("RRCReconfigurationComplete**") to the MN, which includes an NR RRC reconfiguration complete message ("RRCReconfigurationComplete***") for the selected candidate PSCell and the selected PSCell information (action 305).

[0141] The MN notifies the SN via the "SNReconfigurationComplete" message (including the "RRCReconfigurationComplete***" response message) that the UE has successfully completed the reconfiguration process (action 306). Note: The UE performs synchronization towards the selected PSCell indicated in the "RRCReconfiguration**" message and performs a random access procedure towards the SCG. The UE will start to measure and check whether the CPC conditions for the PSCell change are met.

[0142] The MN sends an SN status transfer to notify the PDCP SN (action 307). Note that data forwarding will start from the UPF to the MN and then from the MN to SN1.

[0143] 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). Please note that the end marker is sent from the UPF to the MN and then from the MN to SN1. Then, the DL data will be sent directly from the UPF to SN1.

[0144] Please note that at the UE, the CPA configurations for other SNs have complete configurations, so these CPA configurations can also be used as CPC configurations. After the RACH addition for SN1 is successful, the UE will start to measure and check the CPC conditions for the PSCell change.

[0145] After the CPC conditions for SN2 are satisfied, the PSCell change process for SN2 can be started by sending "RRCReconfigurationComplete" towards MN (action 311). A "SNReconfigurationComplete" message is sent from MN to SN2 (action 312).

[0146] Among other things, the following advantages of the proposed solution can be identified:

[0147] - The PSCell change to SN2 will be faster (i.e., it can be done immediately after the SN addition).

[0148] - After the PSCell addition, no additional configuration of the CPC (or message exchange towards the candidate SN) is required, which reduces the signaling overhead and latency for initiating the CPC after the CPA.

[0149] Now turning to Figure 4 , a block diagram of an example embodiment of a UE 400 according to a first aspect is shown. For example, the UE 400 can be one or a part of a smart phone, a tablet computer, a laptop computer, a smart watch, a smart bracelet, an IoT device, or a vehicle.

[0150] The UE 400 includes a processor 401. The processor 401 can represent a single processor or two or more processors, for example, 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 execute one or more embodiments or portions thereof of the method according to the present disclosure) and interfaces with a main memory 403. The program memory 402 can also contain an operating system for the processor 401. Some or all of the memories 402 and 403 can also be included in the processor 401.

[0151] One or both of the main memory and the program memory of the processor (e.g., the program memory 402 and the main memory 403) can be fixedly connected to the processor (e.g., the processor 401) or at least partially removable from the processor, e.g., in the form of a memory card or a memory stick.

[0152] The program memory (e.g., program memory 402) can be, for example, a non-volatile memory. For example, it can be any one (or part) of FLASH memory (or a part thereof), ROM, PROM, EPROM, MRAM, or FeRAM, or a hard disk (or a part thereof), to name just a few. For example, the program memory can, for example, include a first memory part that is fixedly installed and a removable second memory part, for example, in the form of a removable SD memory card.

[0153] The main memory (e.g., main memory 403) can be, for example, a volatile memory. For example, it can be a DRAM memory, which is just a non-limiting example. For example, it can be used as the working memory of the processor 401 when executing the operating system, applications, programs, etc.

[0154] The processor 401 can also control the communication interface 404 (e.g., a radio interface), which is configured to receive and / or transmit data and / or information. For example, the communication interface 404 can be configured to transmit and / or receive radio signals from a radio node (such as a master node or a secondary node), particularly as described herein. It should be understood that any computer program code-based processing required to receive and / or evaluate radio signals can be stored in the own memory of the communication interface 404 and executed by the own processor of the communication interface 404, and / or can be stored in, for example, the memory 403 and, for example, executed by the processor 401.

[0155] The communication interface 404 can be particularly configured to communicate according to a cellular communication system (such as 2G / 3G / 4G / 5G or a future generation cellular communication system). The UE 400 can use the radio interface 404 to communicate with a radio node (such as a master node or a secondary node), particularly as described herein.

[0156] For example, the communication interface 404 can also include a BLE and / or Bluetooth radio interface, including a BLE transmitter, receiver, or transceiver. For example, the radio interface 404 can additionally or alternatively include a WLAN radio interface, which at least includes a WLAN transmitter, receiver, or transceiver.

[0157] The components 402, 403, and 404 of the UE 400 can be connected to the processor 401, for example, by means of one or more serial and / or parallel buses.

[0158] It should be understood that the UE 400 can include various other components. For example, the UE 400 can optionally include a user interface (e.g., a touch display, keyboard, touchpad, display, etc.).

[0159] Figure 5It is a block diagram of an example embodiment of a radio node 500, such as a master node 500 or a secondary node 500. For example, the radio node 500 may be configured to schedule and / or transmit signals to the UE 400 and / or one or more other radio nodes 500, as described above.

[0160] The radio node 500 includes a processor 501. The processor 501 may represent a single processor or two or more processors, for example, at least partially coupled, such as via a bus. The processor 501 executes program code stored in the program memory 502 (e.g., program code that causes the radio node 500 to perform one or more embodiments or portions thereof of the methods according to the present disclosure alone, together with the UE 400, and / or together with one or more other radio nodes 500 when executed on the processor 501) and interfaces with the main memory 503.

[0161] The program memory 502 may also include an operating system for the processor 501. Some or all of the memories 502 and 503 may also be included in the processor 501.

[0162] In addition, the processor 501 may control the communication interface 504, which is configured, for example, to communicate according to a cellular communication system, such as a 2G / 3G / 4G / 5G cellular communication system. The communication interface 504 of the radio node 500 may be implemented by, for example, a radio head and may be provided for communication between a network device and a terminal device.

[0163] The components 502, 503, and 504 of the radio node 500 may be connected to the processor 501, for example, by means of one or more serial and / or parallel buses.

[0164] It should be understood that the radio node 500 may include various other components.

[0165] Figure 6 It is a schematic illustration of an example of a tangible and non-transitory computer-readable storage medium according to the present disclosure, which may be used, for example, to implement Figure 4 the memory 402 of Figure 5 or Figure 6 the memory 502 of

[0166] Any connection presented in the described embodiments should be understood as the components involved being operably coupled. Thus, the connection can be direct or indirect, with any number or combination of intermediate elements, and there may only be a functional relationship between the components.

[0167] In addition, as used herein, the term "circuitry" refers to any of the following:

[0168] (a) A pure hardware circuit implementation (such as an implementation only in analog and / or digital circuitry);

[0169] (b) A combination of circuitry and software (and / or firmware), such as:

[0170] (i) A combination of (one or more) processors, or

[0171] (ii) (One or more) processors / software (including digital signal processors), portions of software and memory, which together cause a device (such as a mobile phone) to perform various functions); and

[0172] (c) Circuitry that requires software or firmware to operate, such as (one or more) microprocessors or a portion of (one or more) microprocessors, even if the software or firmware is not physically present.

[0173] This definition of "circuitry" applies to all uses of the term herein, including all uses in any claims. As a further example, as used herein, the term "circuitry" also encompasses an implementation of only one processor (or more processors) or a portion of a processor and its (or their) accompanying software and / or firmware. The term "circuitry" also encompasses, for example, a baseband integrated circuit or an application processor integrated circuit of a mobile phone.

[0174] Any processor mentioned herein, particularly but not limited to Figure 4 and processors 401 and 501 in it5, can be any suitable type of processor. Any processor can include but is not limited to one or more microprocessors, one or more processors with (one or more) accompanying digital signal processors, one or more processors without (one or more) accompanying digital signal processors, one or more dedicated 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 relevant structure / hardware has been programmed to perform the described functions.

[0175] In addition, any action or step described or illustrated herein can be implemented using executable instructions in a general or special-purpose processor and stored on a computer-readable storage medium (such as a disk, memory, etc.) for execution by such a processor. The reference to "computer-readable storage medium" should be understood to cover dedicated circuits such as FPGAs, ASICs, signal processing devices, and other devices.

[0176] 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 the list of two or more elements is joined by "and" or "or", means at least any one element, or at least any two or more elements, or at least all elements.

[0177] The phrase "A, or B, or C, or combinations thereof" or "at least one of A, B, and C" can be understood to be non-exhaustive and to include at least the following: (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 and B and C.

[0178] It should be understood that the embodiments disclosed herein are merely exemplary, and any feature presented for a particular exemplary embodiment can be used alone with any aspect of the present disclosure, or in combination with any feature presented for the same or another particular exemplary embodiment and / or in combination with any other feature not mentioned. It should also be understood that any feature presented for an exemplary embodiment in a particular category can also be used in a corresponding manner in any other category of exemplary embodiments.

[0179] Abbreviations

[0180] 3GPP Third Generation Partnership Project

[0181] AMF Access and Mobility Management Function

[0182] CHO Conditional Handover

[0183] CPAC Conditional PSCell Addition or Change

[0184] CPC Conditional PSCell Change

[0185] CPA Conditional PSCell Addition

[0186] DC Dual Connectivity

[0187] LMF Location Management Function

[0188] MCG Master Cell Group

[0189] MN Master Node

[0190] NAS Non-Access Stratum

[0191] NR New Radio

[0192] PCell Primary Cell of the Primary Cell Group

[0193] PSCell Primary Cell of the Secondary Cell Group (SCG), Primary SCG Cell

[0194] RACH Random Access Channel

[0195] SCG Secondary Cell Group

[0196] SN Secondary Node

[0197] S-SN Source Secondary Node

[0198] RRC Radio Resource Control

[0199] T-SN Target Secondary Node

[0200] UE User Equipment

[0201] UPF User Plane Function

[0202] References

[0203] [1] 3GPP TS 36.300 V17.1.0 "Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Phase 2 (Release 17)", June 2022.

[0204] [2] 3GPP TS 37.340 V17.1.0 "Evolved Universal Terrestrial Radio Access (E-UTRA) and NR; Multi-connectivity; Phase 2 (Release 17)", June 2022.

Claims

1. A user equipment configured to support dual-connectivity operation towards 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 which, when executed by the at least one processor, cause the user equipment to: - obtain conversion information from the master node, the conversion information configuring the user equipment to at least partially reuse a configuration related to first conditional cell operation regarding one or more secondary nodes for subsequent second conditional cell operation regarding the one or more secondary nodes.

2. The user equipment according to claim 1, wherein the configuration related to the first conditional cell operation comprises: configuration of at least two prepared candidate primary-secondary cells (PSCells) for at least one target secondary node.

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

4. The user equipment according to claim 1, wherein one of the following exists: - the first conditional cell operation is a conditional cell change, in particular a conditional PSCell change (CPC), and wherein the subsequent second conditional cell operation is a conditional cell addition, in particular a conditional PSCell addition (CPA); or - the first conditional cell operation is a conditional cell addition, in particular a conditional PSCell addition (CPA), and wherein the subsequent second conditional cell operation is a conditional cell change, in particular a conditional PSCell change (CPC).

5. The user equipment according to claim 1 or 2, further caused to: - obtain the configuration related to the first conditional cell operation regarding one or more secondary nodes from the master node; wherein the configuration related to the first conditional cell operation regarding one or more secondary nodes is obtained in a first configuration message, and wherein the conversion information is obtained in a subsequent second configuration message; or wherein the configuration related to the first conditional cell operation regarding one or more secondary nodes and the conversion information are obtained in a common configuration message.

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

7. The user equipment according to any one of the preceding claims, wherein the conversion information comprises one or more of the following: - an indication to maintain a configuration related to a source secondary node (S-SN) or a serving secondary cell group (SCG) for reuse of the configuration for the subsequent second conditional cell operation; - an indication to maintain a configuration related to one or more target secondary nodes (T-SN) or target secondary cell groups (SCG) for reuse of the configuration for the subsequent second conditional cell operation; - Information indicating an updated measurement gap for reuse of the configuration for the subsequent second conditional cell operation; - Information indicating one or more execution conditions for the update, the one or more execution conditions for reuse of the configuration for the subsequent second conditional cell operation; - An indication to maintain the configuration related to one or more remaining secondary nodes after successful execution of the first conditional cell operation towards one secondary node for reuse of the configuration for the subsequent second conditional cell operation; and / or - Information indicating one or more execution conditions to be used for the first conditional cell operation and one or more execution conditions to be used for the subsequent second conditional cell operation.

8. The user equipment according to any one of the preceding claims, wherein the user equipment is further caused to: - In response to obtaining the configuration related to the first conditional cell operation, start evaluating one or more execution conditions based on the configuration related to the first conditional cell operation; - Obtain the conversion information before one or more execution conditions based on the configuration related to the first conditional cell operation are satisfied or before the execution of the first conditional cell operation is completed; - In response to obtaining the conversion information, start evaluating one or more execution conditions based on the reused configuration for the second conditional cell operation.

9. The user equipment according to any one of claims 1 to 7, wherein the user equipment is further caused to: - In response to obtaining the configuration related to the first conditional cell operation, start evaluating one or more execution conditions based on the configuration related to the first conditional cell operation; - Determine whether one or more execution conditions for the configuration related to the first conditional cell operation are satisfied; - In the case where it is determined that one or more execution conditions for the configuration related to the first conditional cell operation are satisfied, apply the configuration related to the first conditional cell operation and start evaluating one or more execution conditions based on the reused configuration for the second conditional cell operation.

10. The user equipment according to claim 8 or 9, wherein the user equipment is further caused to: - Determine whether one or more execution conditions for the reused configuration for the second conditional cell operation are satisfied; - In the case where it is determined that one or more execution conditions for the reused configuration for the second conditional cell operation are satisfied, apply the reused configuration for the second conditional cell operation.

11. The user equipment according to any one of the preceding claims, wherein the configuration related to the first conditional cell operation comprises: The complete configuration or incremental configuration of the first conditional cell operation.

12. The user equipment according to any one of the preceding claims, wherein the user equipment is further caused to: - Determine whether the configuration for the subsequent second conditional cell operation to be reused is related to the number of candidate secondary cells exceeding a predetermined number; and - In the case where it is determined that the configuration for the subsequent second conditional cell operation to be reused is related to the number of candidate secondary cells exceeding the predetermined number, remove one or more candidate secondary cells from the configuration for the subsequent second conditional cell operation to be reused.

13. A method performed by a user equipment configured to support dual connectivity operation towards a master node and a secondary node of a radio access network, wherein the method at least comprises the following operations: - Obtain conversion information from the master node, the conversion information configuring the user equipment to at least partially reuse a configuration related to a first conditional cell operation regarding one or more secondary nodes for a subsequent second conditional cell operation regarding the one or more secondary nodes.

14. A non-transitory computer-readable medium comprising program instructions which, when executed by a user equipment configured to support dual connectivity operation towards a master node and a secondary node of a radio access network, cause the user equipment to: - Obtain conversion information from the master node, the conversion information configuring the user equipment to at least partially reuse a configuration related to a first conditional cell operation regarding one or more secondary nodes for a subsequent second conditional cell operation regarding the one or more secondary nodes.

15. A master node of a radio access network, the master node and the secondary node of the radio access network being configured to support dual connectivity operation towards a user equipment, the master node comprising at least one processor and at least one memory, the at least one memory storing instructions which, when executed by the at least one processor, cause the master node to: - Provide conversion information to the user equipment, the conversion information configuring the user equipment to at least partially reuse a configuration related to a first conditional cell operation regarding one or more secondary nodes for a subsequent second conditional cell operation regarding the one or more secondary nodes.

16. The master node according to claim 15, further being caused to: - Obtain an indication to release the source secondary node S-SN from the source secondary node, wherein in response to the indication to release the source secondary node, the conversion information is provided to the user equipment.

17. The master node according to claim 15 or 16, wherein the indication to release the source secondary node comprises one or more of the following: - Information indicating an updated measurement gap for reusing the configuration for the subsequent second conditional cell operation; - Information indicating an updated execution condition for reusing the configuration for the subsequent second conditional cell operation; 18. The master node according to any one of claims 15 to 17, further being caused to one or more of the following: - Update one or more execution conditions, the one or more execution conditions being indicated to the user equipment as part of the conversion information for reuse of the configuration for the subsequent second conditional cell operation; - Avoid releasing configurations related to one or more target secondary nodes, target secondary cell groups, and / or primary-secondary cells to be reused for the subsequent second conditional cell operation.

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 operation towards a user equipment, wherein the method at least comprises the following operations: - Provide the user equipment with conversion information that configures the user equipment to at least partially reuse configurations related to first conditional cell operation regarding one or more secondary nodes for subsequent second conditional cell operation regarding the one or more secondary nodes.

20. A non-transitory computer-readable medium comprising program instructions, which when executed 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 operation towards a user equipment, the program instructions cause the master node to: - Provide the user equipment with conversion information that configures the user equipment to at least partially reuse configurations related to first conditional cell operation regarding one or more secondary nodes for subsequent second conditional cell operation regarding the one or more secondary nodes.

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