Dual Connection

Abstract

A method, apparatus, and computer program are provided for causing a master node operating with a dual connection to a user equipment together with a first secondary node to determine that a primary cell of a secondary cell group will switch from a first cell serving the user equipment, the first cell being provided by the first secondary node, determine at least one measurement configuration for a second cell provided by a second secondary node that will remain valid after or during a period when the primary cell of the secondary cell group serving the user equipment switches from the first cell to the second cell, and provide the at least one measurement configuration to the user equipment.

Description

[Technical Field]

[0001] The examples described herein relate generally to apparatus, methods, and computer programs, and more particularly (but without limitation) to apparatus, methods, and computer programs for network devices. [Background technology]

[0002] A communication system can be thought of as a facility that enables communication sessions between two or more entities, such as communication devices, base stations, and / or other nodes, by providing carriers between the various entities involved in the communication path.

[0003] The communication system may be a wireless communication system. Examples of wireless systems include public land mobile networks (PLMNs) operating according to wireless standards such as those provided by 3GPP, satellite-based communication systems, and various wireless local networks such as wireless local area networks (WLANs). Wireless systems can typically be divided into cells, and are therefore often referred to as cellular systems.

[0004] Communication systems and associated devices typically operate according to a given standard or specification that defines what the various entities associated with the system are allowed to do and how to achieve this. The communication protocols and / or parameters used for connectivity are also typically defined. An example of a standard is the so-called 5G standard. Summary of the Invention [Means for solving the problem]

[0005] According to a first aspect, there is provided a method for a master node operating with dual connections to user equipment together with a first secondary node, the method comprising: determining a primary cell of a secondary cell group to switch from a first cell serving the user equipment, the first cell being provided by the first secondary node; determining at least one measurement configuration for a second cell provided by the second secondary node, the measurement configuration remaining valid after or during a period when the primary cell of the secondary cell group serving the user equipment switches from the first cell to the second cell; and providing the at least one measurement configuration to the user equipment.

[0006] Determining the at least one measurement configuration may include: identifying a measurement configuration provided by the first secondary node to be applied by the user equipment after the user equipment switches from the first cell to the second cell; and setting the identified measurement configuration as the at least one measurement configuration.

[0007] Determining at least one measurement configuration may include: determining, for a measurement configuration associated with the first secondary node, a range of first measurement identifier values ​​reserved for use by the first secondary node; providing the range of first measurement identifier values ​​to the second secondary node; and receiving at least one measurement configuration from the second secondary node, wherein the at least one measurement configuration does not include any measurement identifier having an associated value that is within the range of first measurement identifier values.

[0008] Determining at least one measurement configuration may include: determining a range of first measurement identifier values ​​reserved for use by the first secondary node for an associated measurement configuration; providing the first measurement identifier value range and the associated measurement configuration to the second secondary node; and receiving at least one measurement configuration from the second secondary node, wherein the at least one measurement configuration includes at least one measurement identifier having an associated value that is within the range of first measurement identifier values.

[0009] The determining that the first cell ceases to operate as a primary cell of a secondary cell group for the user equipment may include receiving an indication to this effect from the first secondary cell, and the determining the range of first measurement identifier values ​​includes receiving the range of first measurement identifier values ​​from the first secondary node.

[0010] The determining that the first cell will cease to operate as a primary cell of a secondary cell group for the user equipment may be made without receiving an indication to this effect from the first secondary cell, and the determining the range of first measurement identifier values ​​includes generating the range of first measurement identifier values.

[0011] According to a second aspect, there is provided a method for a first secondary node operating with a dual connection to a user equipment together with a master node, the method comprising: determining that a primary cell of a secondary cell group switches from a first cell serving the user equipment, the first cell being provided by the first secondary node; and signaling an indication to the master node that the first cell will cease to operate as a primary cell of the secondary cell group, the indication including a range of first measurement identifier values ​​reserved for use by the first secondary node for a measurement configuration associated with the first secondary node.

[0012] According to a third aspect, there is provided a method for a second secondary node, the method comprising: receiving an indication from a master node that a primary cell of a secondary cell group switches from a first cell serving a user equipment, the first cell being provided by the first secondary node, the indication including a range of first measurement identifier values ​​reserved for use by the first secondary node for measurement configurations associated with the first secondary node; generating at least one measurement configuration for use by the user equipment when the user equipment starts using the cell provided by the second secondary node as a primary cell of the secondary cell group, and signaling the generated at least one measurement configuration to the master node.

[0013] The generating may include generating at least one measurement configuration that includes a measurement identifier value that is outside the range of first measurement identifier values.

[0014] The generating may include generating at least one measurement configuration that includes a measurement identifier value within a first range of measurement identifier values.

[0015] After signaling the generated at least one measurement configuration to the master node, the method may include: generating at least one second cell measurement configuration to be applied by the user equipment when the primary cell of the secondary cell group is provided by a second cell that is provided by a second secondary cell; and signaling the generated at least one second cell measurement configuration to the user equipment when the primary cell of the secondary cell group is provided by the second cell.

[0016] According to a fourth aspect, there is provided a method for a user equipment configured to operate with a dual connection to a master node and a first secondary node, the method comprising: maintaining a data connection with a first cell provided by a first secondary node by using the first cell as a primary cell of a secondary cell group; receiving from the master node at least one measurement configuration that can be applied by the user equipment if the user equipment decides to switch a primary cell of the user equipment of the secondary cell group from the first cell to a second cell provided by a second secondary node; switching the primary cell of the secondary cell group from the first cell to the second cell; and performing measurements in the second cell in accordance with the received at least one measurement configuration.

[0017] The method may include: receiving at least one secondary cell measurement configuration from a second secondary node that is applied when the primary cell of the secondary cell group is the second cell; stopping performing measurements in accordance with the received at least one measurement configuration; and starting performing measurements in the second cell in accordance with the received at least one secondary cell measurement configuration.

[0018] The at least one measurement configuration may be independent of a second measurement configuration associated with a second secondary cell.

[0019] The method may include: receiving a first measurement configuration associated with a first secondary cell; and applying, for the user equipment, the first measurement configuration only when a primary cell of the secondary cell group is provided by the first cell.

[0020] The method includes: using, for a user equipment, at least one measurement configuration when a primary cell of a secondary cell group is provided by a first cell.

[0021] The method may include: generating a measurement configuration variable; and storing the measurement configuration variable for use while a primary cell of the secondary cell group is provided by the second cell.

[0022] The method may include: receiving an indication to release stored measurement configuration variables from a secondary cell currently serving the cell acting as a primary cell of the secondary cell group for the user equipment.

[0023] The method may include: receiving, from a second secondary node, at least one secondary cell measurement configuration to be applied by the user equipment when the second cell is operating as a primary cell of a secondary cell group for the user equipment; and applying the received at least one measurement configuration in addition to a measurement configuration provided by the secondary node.

[0024] The method may include: indicating, as part of a persistent measurement configuration configured by the master node, measurement objects and measurement identifiers that apply to the measurement configuration.

[0025] According to a fifth aspect, there is provided an apparatus for a master node operating with dual connectivity to user equipment together with a first secondary node, the apparatus comprising: means for determining that a primary cell of a secondary cell group switches from a first cell serving the user equipment, the first cell being provided by the first secondary node; determining at least one measurement configuration for a second cell provided by the second secondary node, the measurement configuration remaining valid after or during a period during which the primary cell of the secondary cell group serving the user equipment switches from the first cell to the second cell; and providing the at least one measurement configuration to the user equipment.

[0026] The determining means for determining at least one measurement configuration may comprise means for: identifying a measurement configuration provided by a first secondary node to be applied by the user equipment after the user equipment switches from the first cell to the second cell; and setting the identified measurement configuration as the at least one measurement configuration.

[0027] The determining means for determining at least one measurement configuration may comprise means for: determining, for a measurement configuration associated with a first secondary node, a range of first measurement identifier values ​​reserved for use by the first secondary node; providing the range of first measurement identifier values ​​to a second secondary node; and receiving at least one measurement configuration from the second secondary node, wherein the at least one measurement configuration does not include any measurement identifier having an associated value that is within said range of first measurement identifier values.

[0028] The determining means for determining at least one measurement configuration may comprise means for determining, for an associated measurement configuration, a range of first measurement identifier values ​​reserved for use by the first secondary node; providing the first measurement identifier value range and the associated measurement configuration to the second secondary node; and receiving at least one measurement configuration from the second secondary node, the at least one measurement configuration including at least one measurement identifier having an associated value that is within the range of first measurement identifier values.

[0029] The determining means for determining that the first cell ceases to act as a primary cell of a secondary cell group for the user equipment may comprise means for receiving an indication to this effect from the first secondary cell, and determining the range of first measurement identifier values ​​comprises receiving the range of first measurement identifier values ​​from the first secondary node.

[0030] The determining means for determining that the first cell will cease to operate as a primary cell of a secondary cell group for the user equipment may be performed without receiving an indication to this effect from the first secondary cell, and determining a first measurement identifier value range includes generating a first measurement identifier value range.

[0031] According to a sixth aspect, there is provided an apparatus for a first secondary node operating with a dual connection to a user equipment together with a master node, the apparatus comprising: means for determining that a primary cell of a secondary cell group switches from a first cell serving the user equipment, the first cell being served by the first secondary node; and signaling to the master node an indication that the first cell ceases to operate as a primary cell of the secondary cell group, the indication including a range of first measurement identifier values ​​reserved for use by the first secondary node for a measurement configuration associated with the first secondary node.

[0032] According to a seventh aspect, there is provided an apparatus for a second secondary node, the apparatus comprising: means for receiving from a master node an indication that a primary cell of a secondary cell group switches from a first cell serving a user equipment, the first cell being provided by the first secondary node; the indication including a range of first measurement identifier values ​​reserved for use by the first secondary node for measurement configurations associated with the first secondary node; generating at least one measurement configuration for use by the user equipment when the user equipment starts using the cell provided by the second secondary node as a primary cell of the secondary cell group; and signaling the generated at least one measurement configuration to the master node.

[0033] The generating means may comprise: means for generating at least one measurement configuration including a measurement identifier value that is outside a range of first measurement identifier values.

[0034] The generating means may comprise: means for generating at least one measurement configuration including a measurement identifier value within a first range of measurement identifier values.

[0035] After signaling the generated at least one measurement configuration to the master node, the apparatus may comprise means for: generating at least one second cell measurement configuration to be applied by a user equipment when a primary cell of a secondary cell group is provided by a second cell provided by a second secondary cell; and signaling the generated at least one second cell measurement configuration to a user equipment when a primary cell of a secondary cell group is provided by a second cell.

[0036] According to an eighth aspect, there is provided an apparatus for user equipment configured to operate with dual connection to a master node and a first secondary node, the apparatus comprising: means for: maintaining a data connection with a first cell provided by a first secondary node by using the first cell as a primary cell of a secondary cell group; receiving from the master node at least one measurement configuration that can be applied by the user equipment when the user equipment decides to switch the primary cell of the user equipment of the secondary cell group from the first cell to a second cell provided by a second secondary node; and means for switching the primary cell of the secondary cell group from the first cell to the second cell and performing measurements on the second cell in accordance with the received at least one measurement configuration.

[0037] The apparatus may comprise means for: receiving at least one secondary cell measurement configuration from a second secondary node to be applied when a primary cell of a secondary cell group is the second cell; stopping performing measurements in accordance with the received at least one measurement configuration; and starting performing measurements in the second cell in accordance with the received at least one secondary cell measurement configuration.

[0038] The at least one measurement configuration may be independent of a second measurement configuration associated with a second secondary cell.

[0039] The apparatus may comprise means for: receiving a first measurement configuration associated with a first secondary cell; and applying, for a user equipment, the first measurement configuration only when a primary cell of the secondary cell group is provided by the first cell.

[0040] The apparatus may comprise: means for using, for a user equipment, at least one measurement configuration when a primary cell of a secondary cell group is provided by a first cell.

[0041] The apparatus may comprise: means for generating a measurement configuration variable and storing the measurement configuration variable for use while a primary cell of the secondary cell group is provided by the second cell.

[0042] The apparatus may comprise means for: receiving an indication to release stored measurement configuration variables from a secondary cell currently serving a cell operating as a primary cell of a secondary cell group for the user equipment.

[0043] The apparatus may comprise means for: receiving, from a second secondary node, at least one secondary cell measurement configuration to be applied by the user equipment when the second cell is operating as a primary cell of a secondary cell group for the user equipment; and applying the received at least one measurement configuration in addition to the measurement configuration provided by the secondary node.

[0044] The apparatus may comprise: means for indicating, as part of a persistent measurement configuration configured by the master node, measurement objects and measurement identifiers that apply to the measurement configuration.

[0045] According to a ninth aspect, there is provided an apparatus for a master node operating with dual connections to user equipment together with a first secondary node, the apparatus comprising: at least one processor; and at least one memory containing code that, when executed by the at least one processor, causes the apparatus to: determine that a primary cell of a secondary cell group will switch from a first cell serving the user equipment, the first cell being provided by the first secondary node; determine at least one measurement configuration for a second cell provided by the second secondary node, that will remain valid after or during a period when the primary cell of the secondary cell group serving the user equipment switches from the first cell to the second cell; and provide the at least one measurement configuration to the user equipment.

[0046] Determining the at least one measurement configuration may include: identifying a measurement configuration provided by the first secondary node to be applied by the user equipment after the user equipment switches from the first cell to the second cell; and setting the identified measurement configuration as the at least one measurement configuration.

[0047] Determining at least one measurement configuration may include: determining, for a measurement configuration associated with the first secondary node, a range of first measurement identifier values ​​reserved for use by the first secondary node; providing the range of first measurement identifier values ​​to the second secondary node; and receiving at least one measurement configuration from the second secondary node, wherein the at least one measurement configuration does not include any measurement identifier having an associated value that is within the range of first measurement identifier values.

[0048] Determining at least one measurement configuration may include: determining a range of first measurement identifier values ​​reserved for use by the first secondary node for an associated measurement configuration; providing the first measurement identifier value range and the associated measurement configuration to the second secondary node; and receiving at least one measurement configuration from the second secondary node, the at least one measurement configuration including at least one measurement identifier having an associated value that is within the range of first measurement identifier values.

[0049] The determining that the first cell ceases to operate as a primary cell of a secondary cell group for the user equipment may include receiving an indication to this effect from the first secondary cell, and the determining the range of first measurement identifier values ​​includes receiving the range of first measurement identifier values ​​from the first secondary node.

[0050] The determining that the first cell will cease to operate as a primary cell of a secondary cell group for the user equipment may be made without receiving an indication to this effect from the first secondary cell, and the determining the range of first measurement identifier values ​​includes generating the range of first measurement identifier values.

[0051] According to a tenth aspect, there is provided an apparatus for a first secondary node operating together with a master node with dual connectivity to user equipment, the apparatus comprising: at least one processor; and at least one memory including code that, when executed by the at least one processor, causes the apparatus to: determine that a primary cell of a secondary cell group switches from a first cell serving the user equipment, the first cell being provided by the first secondary node; and signal an indication to the master node that the first cell ceases to operate as a primary cell of the secondary cell group, the indication including a range of first measurement identifier values ​​reserved for use by the first secondary node for a measurement configuration associated with the first secondary node.

[0052] According to an eleventh aspect, there is provided an apparatus for a second secondary node, the apparatus comprising: at least one processor; and at least one memory including code that, when executed by the at least one processor, causes the apparatus to: receive an indication from a master node that a primary cell of a secondary cell group will switch from a first cell serving a user equipment, the first cell being provided by the first secondary node, the indication including a first measurement identifier value range reserved for use by the first secondary node for a measurement configuration associated with the first secondary node; generate at least one measurement configuration for use by the user equipment when the user equipment starts using the cell provided by the second secondary node as a primary cell of the secondary cell group; and signal the generated at least one measurement configuration to the master node.

[0053] The generating may include: generating at least one measurement configuration that includes a measurement identifier value that is outside of a first range of measurement identifier values.

[0054] The generating may include: generating at least one measurement configuration that includes a measurement identifier value that is within a first range of measurement identifier values.

[0055] After signaling the generated at least one measurement configuration to the master node, the device may be caused to: generate at least one second cell measurement configuration to be applied by a user equipment when a primary cell of a secondary cell group is provided by a second cell that is provided by a second secondary cell; and signal the generated at least one second cell measurement configuration to a user equipment when a primary cell of a secondary cell group is provided by a second cell.

[0056] According to a twelfth aspect, there is provided an apparatus for user equipment configured to operate with dual connection to a master node and a first secondary node, the apparatus comprising: at least one processor; and at least one memory containing code that, when executed by the at least one processor, causes the apparatus to: maintain a data connection with a first cell provided by the first secondary node by using the first cell as a primary cell of a secondary cell group; receive from the master node at least one measurement configuration that can be applied by the user equipment when the user equipment decides to switch the primary cell of the user equipment of the secondary cell group from the first cell to a second cell provided by a second secondary node; switch the primary cell of the secondary cell group from the first cell to the second cell; and perform measurements in the second cell in accordance with the received at least one measurement configuration.

[0057] The device may receive from a second secondary node at least one secondary cell measurement configuration that applies when a primary cell of a secondary cell group is the second cell; stop performing measurements in accordance with the received at least one measurement configuration; and start performing measurements in the second cell in accordance with the received at least one secondary cell measurement configuration.

[0058] The at least one measurement configuration may be independent of a second measurement configuration associated with a second secondary cell.

[0059] The device: receives a first measurement configuration associated with a first secondary cell; and can cause the first measurement configuration to be applied for the user equipment only when the primary cell of the secondary cell group is provided by the first cell.

[0060] The apparatus may: be caused to use, for the user equipment, at least one measurement configuration when a primary cell of the secondary cell group is provided by the first cell.

[0061] The apparatus may be caused to: generate a measurement configuration variable and store the measurement configuration variable for use while a primary cell of the secondary cell group is provided by the second cell.

[0062] The apparatus may be caused to: receive an indication to release stored measurement configuration variables from a secondary cell currently serving the cell acting as a primary cell of a secondary cell group for the user equipment.

[0063] The apparatus: receives, from a second secondary node, at least one secondary cell measurement configuration to be applied by the user equipment when the second cell is operating as a primary cell of a secondary cell group for the user equipment; and can apply the received at least one measurement configuration in addition to the measurement configuration provided by the secondary node.

[0064] The device may be made to indicate the measurement objects and measurement identifiers applied to the measurement configuration as part of the persistent measurement configuration configured by the master node.

[0065] According to a thirteenth aspect, there is provided an apparatus for a master node operating with dual connectivity to user equipment together with a first secondary node, the apparatus comprising: a determining circuit for determining that a primary cell of a secondary cell group switches from a first cell serving the user equipment, the first cell being provided by the first secondary node; a determining circuit for determining, when a primary cell of the secondary cell group serving the user equipment switches from the first cell to the second cell, at least one measurement configuration for a second cell provided by the second secondary node that will remain valid after or during a period of time; and a providing circuit for providing the at least one measurement configuration to the user equipment.

[0066] The determination circuit for determining at least one measurement configuration may include a circuit for: identifying that a measurement configuration provided by a first secondary node is to be applied by the user equipment after the user equipment switches from a first cell to a second cell; and setting the identified measurement configuration as the at least one measurement configuration.

[0067] The determination circuit for determining at least one measurement configuration may include circuitry for: determining, for a measurement configuration associated with a first secondary node, a range of first measurement identifier values ​​reserved for use by the first secondary node; providing the range of first measurement identifier values ​​to a second secondary node; and receiving at least one measurement configuration from the second secondary node, wherein the at least one measurement configuration does not include any measurement identifier having an associated value that is within the range of first measurement identifier values.

[0068] The determination circuit for determining at least one measurement configuration may include circuitry for: determining a range of first measurement identifier values ​​reserved for use by the first secondary node for an associated measurement configuration; providing the range of first measurement identifier values ​​and the associated measurement configuration to the second secondary node; and receiving at least one measurement configuration from the second secondary node, the at least one measurement configuration including at least one measurement identifier having an associated value that is within the range of first measurement identifier values.

[0069] The decision circuit for deciding to stop the first cell from operating as a primary cell of a secondary cell group for the user equipment may include circuitry for receiving an indication to this effect from the first secondary cell, and determining the range of first measurement identifier values ​​includes receiving the range of first measurement identifier values ​​from the first secondary node.

[0070] The decision circuit for determining that the first cell will cease to operate as a primary cell of a secondary cell group for the user equipment may be made without receiving an indication to this effect from the first secondary cell, and determining the range of first measurement identifier values ​​includes generating the range of first measurement identifier values.

[0071] According to a fourteenth aspect, there is provided an apparatus for a first secondary node operating together with a master node with dual connectivity to user equipment, the apparatus comprising: a decision circuit for determining that a primary cell of a secondary cell group switches from a first cell serving the user equipment, the first cell being provided by the first secondary node; and a signaling circuit for signaling an indication to the master node that the first cell will cease to operate as a primary cell of the secondary cell group, the indication including a range of first measurement identifier values ​​reserved for use by the first secondary node for a measurement configuration associated with the first secondary node.

[0072] According to a fifteenth aspect, an apparatus for a second secondary node is provided, the apparatus comprising: a receiving circuit for receiving an indication from a master node that a primary cell of a secondary cell group switches from a first cell serving a user equipment, the first cell being provided by the first secondary node, the indication including a range of first measurement identifier values ​​reserved for use by the first secondary node for a measurement configuration associated with the first secondary node; a generating circuit for generating at least one measurement configuration for use by the user equipment when the user equipment starts using a cell provided by the second secondary node as a primary cell of the secondary cell group; and a signaling circuit for signaling the generated at least one measurement configuration to the master node.

[0073] The generating circuitry for generating may comprise: circuitry for generating at least one measurement configuration that includes a measurement identifier value that is outside a range of first measurement identifier values.

[0074] The generating circuitry for generating may comprise circuitry for generating at least one measurement configuration that includes a measurement identifier value within a first range of measurement identifier values.

[0075] After signaling the generated at least one measurement configuration to the master node, the apparatus may include: a generating circuit for generating at least one second cell measurement configuration to be applied by a user equipment when a primary cell of a secondary cell group is provided by a second cell provided by a second secondary cell; and a signaling circuit for signaling the generated at least one second cell measurement configuration to a user equipment when a primary cell of a secondary cell group is provided by the second cell.

[0076] According to a sixteenth aspect, there is provided an apparatus for user equipment configured to operate with dual connection to a master node and a first secondary node, the apparatus comprising: a maintaining circuit for maintaining a data connection with a first cell provided by a first secondary node by using the first cell as a primary cell of a secondary cell group; a receiving circuit for receiving from the master node at least one measurement configuration that can be applied by the user equipment when the user equipment decides to switch a primary cell of the user equipment of the secondary cell group from the first cell to a second cell provided by a second secondary node; a switching circuit for switching the primary cell of the secondary cell group from the first cell to the second cell; and an executing circuit for performing measurements in the second cell in accordance with the received at least one measurement configuration.

[0077] The apparatus may include: a receiving circuit for receiving at least one secondary cell measurement configuration to be applied from a second secondary node when a primary cell of a secondary cell group is the second cell; a stopping circuit for stopping the performing of measurements in accordance with the received at least one measurement configuration; and a starting circuit for starting the performing of measurements in the second cell in accordance with the received at least one secondary cell measurement configuration.

[0078] The at least one measurement configuration may be independent of a second measurement configuration associated with a second secondary cell.

[0079] The apparatus may include: a receiving circuit for receiving a first measurement configuration associated with a first secondary cell; and applying, for the user equipment, the first measurement configuration only when a primary cell of the secondary cell group is provided by the first cell.

[0080] The apparatus may comprise: a usage circuit for using, for a user equipment, at least one measurement configuration when a primary cell of a secondary cell group is provided by a first cell.

[0081] The apparatus may comprise: a generating circuit for generating a measurement configuration variable and storing the measurement configuration variable for use while a primary cell of the secondary cell group is provided by the second cell.

[0082] The apparatus may include a receiving circuit for receiving an indication to release stored measurement configuration variables from a secondary cell currently serving the cell operating as a primary cell of a secondary cell group for user equipment.

[0083] The apparatus may include: a receiving circuit for receiving, from a second secondary node, at least one secondary cell measurement configuration to be applied by the user equipment when the second cell is operating as a primary cell of a secondary cell group for the user equipment; and an applying circuit for applying the received at least one measurement configuration in addition to a measurement configuration provided by the secondary node.

[0084] The apparatus may include: a display circuit for indicating, as part of a persistent measurement configuration configured by the master node, measurement objects and measurement identifiers that apply to the measurement configuration.

[0085] According to a seventeenth aspect, there is provided a non-transitory computer-readable medium comprising program instructions to cause an apparatus for a master node operating with dual connectivity to user equipment together with a first secondary node to at least: determine a primary cell of a secondary cell group to switch from a first cell serving the user equipment, the first cell being provided by the first secondary node; determine at least one measurement configuration for a second cell provided by the second secondary node, the measurement configuration remaining valid after or during a period when the primary cell of the secondary cell group serving the user equipment switches from the first cell to the second cell; and provide the at least one measurement configuration to the user equipment.

[0086] Determining the at least one measurement configuration may include: identifying a measurement configuration provided by a first secondary node to be applied by the user equipment after the user equipment switches from the first cell to the second cell; and setting the identified measurement configuration as the at least one measurement configuration.

[0087] Determining at least one measurement configuration may include: determining, for a measurement configuration associated with the first secondary node, a range of first measurement identifier values ​​reserved for use by the first secondary node; providing the range of first measurement identifier values ​​to the second secondary node; and receiving at least one measurement configuration from the second secondary node, wherein the at least one measurement configuration does not include any measurement identifier having an associated value that is within the range of first measurement identifier values.

[0088] Determining at least one measurement configuration may include: determining a range of first measurement identifier values ​​reserved for use by the first secondary node for an associated measurement configuration; providing the first measurement identifier value range and the associated measurement configuration to the second secondary node; and receiving at least one measurement configuration from the second secondary node, the at least one measurement configuration including at least one measurement identifier having an associated value that is within the range of first measurement identifier values.

[0089] The determining that the first cell ceases to operate as a primary cell of the user equipment's secondary cell group may include receiving an indication to this effect from the first secondary cell, and the determining the range of first measurement identifier values ​​includes receiving the range of first measurement identifier values ​​from the first secondary node.

[0090] The determining that the first cell will cease to operate as a primary cell of a secondary cell group for the user equipment may be made without receiving an indication to this effect from the first secondary cell, and the determining the range of first measurement identifier values ​​includes generating the range of first measurement identifier values.

[0091] According to an eighteenth aspect, provided is a non-transitory computer-readable medium comprising program instructions to cause an apparatus for a first secondary node operating with a dual connection to a user equipment together with a master node to at least: determine a primary cell of a secondary cell group to switch from a first cell serving the user equipment, the first cell being provided by the first secondary node; and signal an indication to the master node that the first cell will cease operating as a primary cell of the secondary cell group, the indication including a range of first measurement identifier values ​​reserved for use by the first secondary node for a measurement configuration associated with the first secondary node.

[0092] According to a nineteenth aspect, there is provided a non-transitory computer-readable medium comprising program instructions to cause an apparatus for a second secondary node to at least: receive an indication from a master node that a primary cell of a secondary cell group switches from a first cell serving a user equipment, the first cell being provided by the first secondary node, and the indication including a range of first measurement identifier values ​​reserved for use by the first secondary node for a measurement configuration associated with the first secondary node; generate at least one measurement configuration for use by the user equipment when the user equipment starts using the cell provided by the second secondary node as a primary cell of the secondary cell group; and signal the generated at least one measurement configuration to the master node.

[0093] The generating may include: generating at least one measurement configuration that includes a measurement identifier value that is outside of a first range of measurement identifier values.

[0094] The generating may include: generating at least one measurement configuration that includes a measurement identifier value that is within a first range of measurement identifier values.

[0095] After signaling the generated at least one measurement configuration to the master node, the device may be configured to: generate at least one second cell measurement configuration to be applied by a user equipment when a primary cell of a secondary cell group is provided by a second cell that is provided by a second secondary cell; and signal the generated at least one second cell measurement configuration to a user equipment when a primary cell of a secondary cell group is provided by a second cell.

[0096] According to a twentieth aspect, there is provided a non-transitory computer-readable medium comprising program instructions to cause an apparatus for user equipment configured to operate with dual connection to a master node and a first secondary node to at least: maintain a data connection with a first cell provided by the first secondary node by using the first cell as a primary cell of a secondary cell group, and receive from the master node at least one measurement configuration that can be applied by the user equipment if the user equipment decides to switch the primary cell of the user equipment of the secondary cell group from the first cell to a second cell provided by a second secondary node; switch the primary cell of the secondary cell group from the first cell to the second cell; and perform measurements in the second cell in accordance with the received at least one measurement configuration.

[0097] The device may receive at least one secondary cell measurement configuration to be applied from a second secondary node when the primary cell of the secondary cell group is the second cell; stop performing measurements in accordance with the received at least one measurement configuration; and start performing measurements in the second cell in accordance with the received at least one secondary cell measurement configuration.

[0098] The at least one measurement configuration may be independent of a second measurement configuration associated with a second secondary cell.

[0099] The device: receives a first measurement configuration associated with a first secondary cell; and can cause the first measurement configuration to be applied for the user equipment only when the primary cell of the secondary cell group is provided by the first cell.

[0100] The apparatus may: be caused to use, for the user equipment, at least one measurement configuration when a primary cell of the secondary cell group is provided by the first cell.

[0101] The apparatus may be caused to: generate a measurement configuration variable and store the measurement configuration variable for use while a primary cell of a secondary cell group is provided by a second cell.

[0102] The apparatus may be caused to: receive an indication to release stored measurement configuration variables from a secondary cell currently serving the cell acting as a primary cell of a secondary cell group for the user equipment.

[0103] The apparatus: receives, from a second secondary node, at least one secondary cell measurement configuration to be applied by the user equipment when the second cell is operating as a primary cell of a secondary cell group for the user equipment; and can apply the received at least one measurement configuration in addition to the measurement configuration provided by the secondary node.

[0104] The device may be made to indicate the measurement objects and measurement identifiers applied to the measurement configuration as part of the persistent measurement configuration configured by the master node.

[0105] According to a twenty-first aspect, there is provided a computer program product stored on a medium capable of causing an apparatus to perform any method as described herein.

[0106] According to a twenty-second aspect, there is provided an electronic device which may comprise an apparatus as described herein.

[0107] According to a twenty-third aspect, there is provided a chipset that may comprise an apparatus as described herein.

[0108] Some examples will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0109] [Figure 1A] 1 is a schematic diagram of a 5G system. [Figure 1B] 1 is a schematic diagram of a 5G system. [Figure 2] FIG. 1 is a schematic diagram of a network device. [Figure 3] FIG. 1 is a schematic diagram of a user equipment. [Figure 4] 1 is a schematic diagram of a non-volatile memory medium that stores instructions that, when executed by a processor, cause the processor to perform one or more of the steps of some example methods. [Figure 5] FIG. 1 is a schematic diagram of a network. [Figure 6] FIG. 1 illustrates call signaling. [Figure 7A] FIG. 1 illustrates an exemplary measurement configuration. [Figure 7B] FIG. 1 illustrates an exemplary measurement configuration. [Figure 8] FIG. 1 illustrates call signaling. [Figure 9] FIG. 1 illustrates exemplary call signaling. [Figure 10] FIG. 1 illustrates exemplary call signaling. [Figure 11] FIG. 1 illustrates exemplary call signaling. [Figure 12] 10A-10C illustrate operations that may be performed by the devices described herein. [Figure 13]10A-10C illustrate operations that may be performed by the devices described herein. [Figure 14] 10A-10C illustrate operations that may be performed by the devices described herein. [Figure 15] 10A-10C illustrate operations that may be performed by the devices described herein. DETAILED DESCRIPTION OF THE INVENTION

[0110] In the following example description, certain aspects are described with reference to mobile communication devices capable of communicating via a wireless cellular system and a mobile communication system serving such mobile communication devices. For brevity and clarity, such aspects are described below with reference to a 5G wireless communication system. However, it will be understood that such aspects are not limited to 5G wireless communication systems and may, for example, also be applied to other wireless communication systems (e.g., current 6G proposals).

[0111] Before describing examples in detail, certain general principles of 5G wireless communication systems will be briefly described with reference to Figures 1A and 1B.

[0112] 1A illustrates a schematic diagram of a 5G system (5GS) 100. The 5GS may include a user equipment (UE) 102 (which may also be referred to as a communication device or terminal), a 5G access network (AN) (which may be a 5G Radio Access Network (RAN) or any other type of 5G AN, such as a Non-3GPP Interworking Function (N3IWF) / Trusted Non-3GPP Gateway Function (TNGF) for untrusted / trusted non-3GPP access, or a Wireline Access Gateway Function (W-AGF) for wireline access) 104, a 5G core (5GC) 106, one or more application functions (AFs) 108, and one or more data networks (DNs) 110.

[0113] A 5G RAN may include one or more gNodeB (gNB) distributed unit functions connected to one or more gNodeB (gNB) central unit functions. The RAN may comprise one or more access nodes.

[0114] The 5GC 106 may include one or more Access and Mobility Management Functions (AMF) 112, one or more Session Management Functions (SMF) 114, one or more Authentication Server Functions (AUSF) 116, one or more Unified Data Management (UDM) functions 118, one or more User Plane Functions (UPF) 120, one or more Unified Data Repository (UDR) functions 122, one or more Network Repository Functions (NRF) 128, and / or one or more Network Exposure Functions (NEF) 124. The role of the NEF is to securely expose network services (e.g., voice, data connectivity, billing, subscriber data, etc.) to third parties. While the NRF 128 is not depicted with an interface, this is for clarity and it is understood that the NRF 128 may have multiple interfaces with other network functions.

[0115] The 5GC 106 also includes a network data analysis function (NWDAF) 126. The NWDAF is responsible for providing network analysis information in response to requests from one or more network functions or devices within the network. Network functions may also subscribe to the NWDAF 126 to receive information therefrom. Thus, the NWDAF 126 is also configured to receive and store network information from one or more network functions or devices within the network. Data collection by the NWDAF 126 may be based on at least one subscription to events provided by at least one network function.

[0116] The network may further comprise a management data analysis service (MDAS) producer, or MDAS Management Service (MnS) producer. The MDAS MnS producer may provide data analysis at the management plane, taking into account parameters including, for example, load levels and / or resource utilization. For example, an MDAS MnS producer in a network function (NF) may collect load-related performance data of the NF, such as the resource usage status of the NF. Analysis of the collected data may provide a prediction of resource usage information in a predefined future time window. This analysis may also recommend appropriate actions, such as, for example, resource scaling, admission control, traffic load balancing, etc.

[0117] Figure 1B illustrates a schematic diagram of 5GC as expressed in current 3GPP specifications. This architecture is intended to illustrate potential components that may be included in a core network, and it will be understood that the principles currently described are not limited to core networks that include only the components described.

[0118] 1B illustrates a 5G Core 106' comprising a UPF 120' connected to an SMF 114' over an N4 interface. The SMF 114' is connected to each of a UDM 122', a NEF 124', an NWDAF 126', an AF 108', a Policy Control Function (PCF) 130', an AMF 112', and a Charging Function 132' over an interconnection medium that also connects these network functions to each other. The 5G Core 106' further includes a Network Repository Function (NRF) 133' and a Network Function 134' that connect to the interconnection medium.

[0119] The NG-Radio Access Network (NG-RAN) supports Multi-Radio Dual Connectivity (MR-DC) operations, whereby a UE in RRC_CONNECTED is connected via a non-ideal backhaul and configured to utilize radio resources provided by two different schedulers located in two different NG-RAN nodes, one providing New Radio (NR) access and the other providing Evolved UMTS Terrestrial Radio Access Network (E-UTRA) or NR access. One of these nodes (the master node (MN)) may establish a UE context in a secondary node (SN) to provide the UE with resources from the SN. Exemplary MR-DC operations include a Conditional Primary Cell (PSCell) Change (CPC) of the secondary cell group and a Conditional PSCell Addition (CPA).

[0120] Dual connectivity may be considered to be a mode of operation of a user equipment in a radio resource control (RCC) connected mode (RCC_CONNECTED mode) configured with a master cell group (MCG) and a secondary cell group (SCG). For example, dual connectivity may refer to when one UE has two radio connections with two access points, e.g., one macrocell EnodeB (eNB) and one small cell EnodeB.

[0121] A master cell group may comprise a single cell. A master cell group may comprise multiple cells. A master cell / master cell group may provide a control plane connection between a UE and a core network. A secondary cell group may comprise a single cell. A secondary cell group may comprise multiple cells. A secondary cell / secondary cell group may provide a user plane (e.g., data) connection between a UE and the core. At any time, one (i.e., a single) cell of a secondary cell group may be designated as the primary secondary cell of the secondary cell group. A primary secondary cell (PSCell) of a secondary cell group operates on a primary frequency and may be the cell from which a UE performs an initial RRC connection establishment procedure or initiates an RRC connection re-establishment procedure, or may be the cell designated as the primary cell in a handover procedure. A PSCell may provide a measurement configuration to a UE to configure the UE to perform measurements on different frequencies. Non-PSCells (if available) of a secondary cell group may provide additional resources for carrier aggregation.

[0122] CPC is a PSCell change procedure that is executed only when the PSCell execution conditions are met.

[0123] More specifically, when the MN configures the UE with CPC for the source PSCell using an RRCReconfiguration message, the UE maintains connection with the source PSCell after receiving the CPC configuration and starts evaluating the CPC execution conditions of the candidate PSCells included in the RRCReconfiguration message. The network can configure the UE with up to eight candidate PSCell configurations with associated execution conditions. If at least one CPC candidate PSCell satisfies the corresponding CPC execution condition, the UE detaches from the source PSCell, applies the corresponding configuration stored for the selected candidate PSCell, and synchronizes to that candidate PSCell. The UE completes the CPC execution procedure by signaling an embedded RRCReconfigurationComplete message to the MN for forwarding to the new PSCell (i.e., the selected candidate PSCell) or by sending an RRCReconfigurationComplete message directly to the new PSCell.

[0124] 3GPP refers to a group of organizations that develops and releases various standardized communications protocols. 3GPP advances and publishes documents related to the system in "Release" stages (e.g., Release 15, Release 16, etc.).

[0125] 3GPP Release 16 specified conditional PSCells for intra-Secondary Node (SN) scenarios. In particular, Release 16 introduced conditional NR PSCell addition / modification for any architecture option using NR PSCells, but limited to intra-SN modifications without master node (MN) involvement.

[0126] CPC has been extended for inter-SN scenarios in Release 17. Inter-SN CPC can be initiated by the master node (MN) and / or by the SN.

[0127] An SN initiated CPC is illustrated with respect to FIG.

[0128] FIG. 6 illustrates example signaling between a UE 601, a master node 602, a source SN 603, a first target SN 604, and a second target 605.

[0129] During 6001, the source SN 603 signals to the MN 602. This signaling may indicate that an SN and / or SgNB change is requested by the source SN 603. This signaling may include at least one identifier of at least one target SN (e.g., a first and second target SN) targeted for preparing a target PSCell. The source SN 603 may include, in the signaling of 6001, a list of PSCells to be prepared by each target SN and / or provide CPC execution conditions for each listed target PSCell. The CPC execution conditions refer to measurement identifiers in the measurement configuration provided by the initiating node (the source SN in this case). In general, the measurement configuration may be considered to be used by the UE to configure parameters of cell measurements made by the UE.

[0130] During 6002 and 6003, the MN 602 signals each of the target SNs included in the signaling of 6001.

[0131] During 6002, the MN 602 signals the first target SN 604. This 6002 signaling may include a request to add the first target SN 604. The 6002 add request may request that the first target SN determine a list of PSCells to prepare (considering the maximum number indicated by the MN in the add request), and that for each PSCell to be prepared, the first target SN determine a Secondary Cell Group (SCG) Secondary Cell (SCell) and provide the corresponding SCG radio resource configuration to the MN in an NR RRC Reconfiguration message. The first target SN 604 can accept or reject each of the candidate cells listed in the measurement results indicated by the MN; i.e., the first target SN 604 cannot configure any alternative candidates.

[0132] During 6003, the MN 602 signals the second target SN 605. This 6003 signaling may include a request to add the second target SN 604. The 6003 add request may request that the second target SN determine a list of PSCells to prepare (considering the maximum number indicated by the MN in the add request), and that for each prepared PSCell, the second target SN determine a Secondary Cell Group (SCG) Secondary Cell (SCell) and provide the corresponding SCG radio resource configuration to the MN in an NR RRCReconfiguration message. The second target SN 605 can accept or reject each of the candidate cells listed in the measurement results indicated by the MN; i.e., the second target SN 605 cannot configure any alternative candidates.

[0133] During 6004 and 6005, the first and second target SNs respectively determine candidate target PSCells to prepare.

[0134] During 6006, the first target SN responds to the signaling of 6002. This response may include an acknowledgement of the request of 6002. This signaling may include at least one identifier of the prepared target cells of 6004, as well as a respective CPC configuration for each target cell prepared during 6004. Thus, this signaling of 6006 may include configuration information for any PSCells prepared by the first target SN 604.

[0135] During 6007, the second target SN responds to the signaling of 6003. This response may include an acknowledgement of the request of 6003. This signaling may include at least one identifier of the prepared target cells of 6005, as well as a respective CPC configuration for each target cell prepared during 6005. Thus, this 6007 signaling may include configuration information for any PSCells prepared by the second target SN 605.

[0136] During 6008, the MN 602 signals to the UE 601. This signaling in 6008 may include a conditional (re)configuration of the UE including the CPC configurations of the candidate target PSCells received during 6006 and 6007. The signaling in 6008 may include the CPC execution conditions received during 6006 and 6007. In other words, the MN 602 may provide the UE with a list of CPA configurations, i.e., RRCConnectionReconfiguration messages, and associated execution conditions, where each RRCConnectionReconfiguration* message includes the SCG configuration in the RRCReconfiguration** messages received from the first and second target SN nodes.

[0137] During 6009, the UE 601 signals to the MN 602. This 6009 signaling may include an acknowledgment of the signaling of 6008. This 6009 signaling may include an indication that the conditional (re)configuration of the UE 601 is complete.

[0138] During 6010, the MN 602 signals to the source SN 603. This 6010 signaling may indicate that the UE 601 is preparing to change SN from the source SN to at least one of the target SNs.

[0139] During 6011, the UE 601 evaluates the CPC execution conditions of the prepared target PSCell received during 6008 to determine whether at least one CPC execution condition is met.

[0140] During 6012, the UE 601 determines that at least one CPC execution condition is satisfied. For purposes of this example, it is assumed that the at least one CPC execution condition that is satisfied is for a PSCell candidate in the first target SN 604.

[0141] During 6013, in response to the positive determination of 6012, the UE 601 signals to the MN 602. This signaling of 6013 may indicate that the at least one CPC execution condition of the PSCell candidate in the first target SN 604 is satisfied. The signaling of 6013 may include an embedded RRC_ReconfigurationComplete message indicating that the radio resource control of the UE has been successfully reconfigured.

[0142] During 6014, the MN 602 signals to the first target node SN 604. This 6014 signaling may include an RRC_ReconfigurationComplete message. The 6014 signaling may indicate to the first target SN 604 that the UE 601 will use at least one of the target PSCells prepared by the first target SN 604.

[0143] During 6015, the UE completes a random access to access the prepared target PSCell associated with the fulfilled execution criteria of 6012.

[0144] In accordance with the objectives of 3GPP Release 17, the entity initiating the CPC procedure is responsible for determining a list of target PSCells that can be prepared with the corresponding CPC execution conditions.

[0145] However, the target SN cannot prepare more PSCells than the maximum number of PSCells determined (and transmitted) by the initiating node (Source SN). Similarly, in an SN-initiated inter-SN CPC, the source SN is responsible for setting the execution conditions for each target PSCell that can possibly be prepared.

[0146] Figure 7A illustrates an example in which a source SN prepares three CPCs for a UE. In particular, Figure 7A illustrates the CPC configuration prepared by the source SN for an SN-initiated inter-SN conditional PSCell change.

[0147] In the example of Figure 7A, the UE is currently served by PSCell0-1 (the first index 0 indicates the identifier of the SN that controls the PSCell currently serving the UE, and the second index 1 indicates the identifier of the PSCell in the SN. In other words, PSCell1 of SN0 (i.e., the source SN) is shown as PSCell0-1).

[0148] A radio access network (RAN) node controlling the UE's serving PSCell0-1 may trigger the preparation of three target PSCells, each associated with a respective CPC configuration: CPC1-1 represents the configuration of the prepared target PSCell1-1 from SN1 (i.e., the first SN), CPC2-1 represents the configuration of the prepared target PSCell2-1 from SN2 (i.e., the second SN), and CPC2-2 represents the configuration of PSCell2-2 from SN2. SN0 specifies the CPC execution conditions for each prepared target cell and provides measurement configurations for evaluating the CPC execution conditions.

[0149] The parameters of the CPC execution condition can be set differently for each prepared target cell. This is because the radio conditions between the source PSCell0-1 and the prepared target PSCell may be different, and the CPC1-1 execution condition used by the UE to decide CPC execution from PSCell0-1 to PSCell1-1 may be different from the CPC execution condition used to decide the change from PSCell0-1 to PSCell2-1 or from PSCell0-1 to PSCell2-2. From the viewpoint of mobility robustness and configuration flexibility, the parameters of the CPC execution condition can be configured to be specific to the source and target PSCell pair.

[0150] Furthermore, as mentioned above, the measurement configuration is set by the SN0 in an SN-initiated conditional PSCell change procedure. This means that other network nodes are not aware of the measurement configuration and / or CPC execution set by the SN0 for the target PSCell. Even when the MN is on the same radio access technology as the source SN, the MN is not configured to decode the configuration sent by the SN.

[0151] 3GPP Release 17 further mandates that once the CPC procedure is successfully executed, the UE shall release all stored CPC configurations (see, for example, 3GPP TS37.340). This means that after successfully executing the CPC procedure after the execution procedure is satisfied, the UE shall release all stored conditional reconfigurations.

[0152] 3GPP Release 18 set a new goal to specify New Radio Dual Connectivity (NR-DC) mechanisms and procedures that enable selective activation of cell groups via Layer 3 (i.e., network layer) enhancements to enable subsequent cell group changes after changing cell groups without reconfiguration and restart of Conditional PSCell Change (CPC) and / or Conditional PSCell Addition (CPA).

[0153] The new goal is to change the SCG without reconfiguring it and restart the CPC / CPA preparation, which implicitly indicates that the preconfigured CPC configuration should be maintained even after the CPC execution.

[0154] Maintaining the CPC configuration after the CPC has been run presents several challenges.

[0155] For example, after a UE performs CPC for one of the target PSCells for which it is configured, the UE needs to maintain other CPC configurations received for other target PSCells. This is illustrated in Figure 7B, which illustrates the configurations maintained by the UE after CPC execution.

[0156] In FIG. 7B, it is assumed that the UE has performed CPC for PSCell1-1, and SN1 becomes the serving SN for PSCell1-1.

[0157] After this change, SN1 does not recognize the other prepared target PSCells (because they were prepared by SN0, the original source SN). Therefore, SN1 cannot maintain a list of prepared target cells (e.g., for adding, releasing, and updating PSCell operations) and cannot initiate early data transfer to the target PSCells. Early data transfer involves sending the UE's data to candidate cells before any of the candidate cells provide a data connection to the UE. In this way, the candidate cells can have data prepared for the UE if the UE switches to them.

[0158] Furthermore, in the simplest extension to enable the above objectives for Release 18, the UE may attempt to retain and use the CPC configuration defined in Release 17 for future SN cell changes. This may require the UE to continue evaluating the CPC execution conditions configured by the previous SN0 before CPC execution towards SN1. These conditions are defined by and relevant to SN0 (i.e., the CPC execution conditions configured by SN0 are for CPC from source PSCell0-1 to target PSCell2-1 and PSCell2-2).

[0159] However, after CPC execution to SN1, these CPC execution conditions evaluated by the UE may not necessarily be convenient / optimal to decide to change from the new serving PSCell1-1 (controlled by SN1) to other target PSCell2-1 and PSCell2-2, which may affect the robustness of the CPC change and result in failure.

[0160] Similarly, CPC conditions are tied to measurement identifiers that are not known by the new serving PSCell, so the serving PSCell may reconfigure the UE and overwrite some of these measurement identifiers, so that the UE no longer has valid conditions for triggering CPC.

[0161] Conditional Handover (CHO) is a conditional cell change in the Master Cell Group. In the case of dual connectivity, the configuration for enabling CHO can be maintained by the source gNB or the Master Node. After CHO execution, the CHO configuration can be maintained. To achieve this, a CHO Request indicating a list of candidate cells and a CHO Request ACK containing a set of CHO execution conditions to be applied by the UE after CHO execution are provided.

[0162] This signaling is illustrated with respect to Figure 8, which illustrates the UE applying CHO condition set #2 for cell 2 and CHO condition set #3 for cell 3 before and after performing CHO to cells 2 and 3, respectively. CHO execution condition set #2 for cell 2 includes CHO execution conditions from cell 2 to cell 1 and from cell 2 to cell 3. The same logic applies to CHO execution condition set #3, i.e., includes CHO execution conditions from cell 3 to cell 1 and from cell 3 to cell 2.

[0163] However, this procedure is specified for the CHO of the MCG and is not applicable when the SN is a Secondary Cell Group (SCG) considered in dual connectivity.

[0164] Furthermore, in this example of Figure 8, the target gNB that controls the prepared target cell provides the CHO execution conditions to other prepared target cells during CHO preparation, which generates high signaling overhead every time a new cell is prepared by the source gNB or every time a prepared cell is released or replaced, because in each of these cases the source gNB needs to fetch an updated set of CHO execution conditions from each prepared target gNB.

[0165] In another mechanism, the source MN notifies the target SN of the prepared cell after executing CPC. However, it takes time to notify the target SN of the prepared cell, and the target SN takes some time to reconfigure the UE to the CPC execution condition, and radio failure may occur during that time because the UE does not have the configuration for CPC. Furthermore, additional signaling is performed every time the UE executes CPC, which adds signaling overhead to the system.

[0166] In another mechanism, the source MN notifies the target SN about each provision during CPC provisioning. However, every time a (new) SN is added (e.g., provisioned) or changed, all other target SNs need to be notified and involved. This uses a lot of Xn signaling and additional delay for each new provision or change, adding signaling overhead to the system.

[0167] The following aims to address at least one of the above problems.

[0168] The following discloses a new mechanism that allows the UE to maintain a persistent measurement configuration after an RRC Reconfiguration operation due to a change in the PSCell. By maintaining the measurement configuration, the UE can subsequently switch cells using this persistent measurement configuration. The following further provides network tools for maintaining the persistent measurement configuration.

[0169] Below, three examples are discussed to illustrate the present disclosure.

[0170] In a first example, the source SN indicates to the target SN (e.g., via the source MN) the measurement identifier range associated with the persistent CPC configuration. The target SN does not use this measurement identifier range for the initial CPC configuration in its own measurement configuration. The source MN further provides the UE with a delta measurement configuration to be applied to the target measurement configuration after the target cell configuration is applied. The UE applies this measurement configuration immediately after CPC execution. The UE may further retain this measurement configuration for applying subsequent CPCs. The UE may indicate to the target SN that the persistent measurement configuration is being used. This may be indicated, for example, by providing a measurement configuration including a measurement identifier, a measurement object, and a reporting configuration for the persistent CPC configuration.

[0171] In general, measurement configuration may configure the UE regarding: when to make measurements, what to measure (i.e., measurement objects), how to evaluate when to report measurements, and what to include in measurement reports.

[0172] As mentioned above, a measurement object may be considered as an object on which a UE performs measurements. For example, for intra-frequency and inter-frequency measurements, the measurement object may be a single carrier frequency. For inter-RAT measurements, the measurement object may be a set of cells on a single carrier frequency. For inter-RAT measurements, the measurement object may be a set of carrier frequencies.

[0173] Each reporting configuration may include at least one Reporting Criterion and a Reporting Format. The Reporting Criterion is the criteria that triggers the UE to send a measurement report (which may be periodic or a single event description). The Reporting Format may specify the amount and associated information that the UE includes in the measurement report (e.g., the number of cells to report).

[0174] The measurement identifier links a measurement object to its respective reporting configuration. By configuring multiple measurement identifiers, it is possible to link multiple measurement objects to the same reporting configuration or multiple reporting configurations to the same measurement object. The measurement identifier can be used as a reference number in the measurement report.

[0175] The target SN may reconfigure the persistent CPC configuration in response to receiving this persistent measurement configuration.

[0176] This is further illustrated with respect to FIG.

[0177] 9 illustrates signaling that may occur between a UE 901, a source MN 902, a source SN 903, a first target SN 904, and a second target SN 905. The source SN 903 may be labeled as SN-0 and may be configured to provide PSCells 0-1. The first target SN 904 may be labeled as SN-1 and may be configured to provide PSCells 1-1. The second target SN 905 may be labeled as SN-2 and may be configured to provide PSCells 2-1 and / or 2-2.

[0178] During 9001, the source SN 903 signals to the source MN 902. This 9001 signaling may request an SN change. This 9001 signaling may include associations between PSCells and respective measurement identifiers provided by the first and second target SNs. For example, the 9001 signaling may indicate that PSCell1-1 is associated with a first measurement identifier, PSCell2-1 is associated with a second measurement identifier, and PSCell2-2 is associated with a third measurement identifier. In contrast to conventional systems, the 9001 SN change request may include a range of measurement identifiers (e.g., first to eighth measurement identifiers) associated with the first CPC. In other words, the Source SN 903 may indicate a measurement configuration including the measurement identifier range to the source MN 902. The measurement identifier range may be considered to form a set of measurement identifier values ​​(which may include two or more measurement identifier values) used for the CPC and remaining valid after the CPC execution. This measurement identifier range may indicate only the measurement identifiers of the CPCs available at the time of SN addition, or may indicate the measurement identifiers of future CPCs. This measurement identifier range may include a range of measurement identifiers that can be configured and deconfigured by the source SN.

[0179] During 9002, the source MN 902 signals to the first target SN 904. This 9002 signaling may include a request to add an SN. This 9002 signaling may include an indication of a measurement identifier range.

[0180] In response to the measurement identifier range information received from the source MN 902 during 9002, the first target SN 904 does not configure a measurement identifier in the measurement identifier range included in the signaling received during 9002 as part of the measurement configuration of the first target SN 904.

[0181] During 9003, the first target SN 904 responds to the signaling of 9002. This response of 9003 may include an acknowledgment. This response of 9003 may include an acknowledgment of the 9002 SN addition request.

[0182] The signaling of 9003 may include a measurement configuration having a measurement identifier value different from those included in the measurement identifier range indicated in 9002.

[0183] During 9004, the source MN 902 signals to the second target SN 905. This 9004 signaling may include a request to add an SN. This 9004 signaling may include an indication of the measurement identifier range.

[0184] In response to receiving the measurement identifier range information from the source MN 902 during 9004, the second target SN 905 does not configure a measurement identifier in the measurement identifier range included in the signaling received during 9004 as part of the measurement configuration of the second target SN 905.

[0185] During 9005, the second target SN 905 responds to the signaling of 9004. This response of 9005 may include an acknowledgment. This response of 9005 may include an acknowledgment of the 9004 SN addition request.

[0186] The signaling of 9005 may include a measurement configuration having a measurement identifier value different from those included in the range of measurement identifiers shown in 9004.

[0187] The indication of the measurement range may indicate a range of measurement identifiers that will not be used (at least initially) by the first and second target SNs 904, 905. The measurement range is provided by the source SN controlling the serving PSCell 903 during 9001 and provided to the first and second target SNs during 9002 and 9004, respectively. It will be understood that although these measurement identifiers are not used as part of the measurement configuration provided by the first and second target SNs during 9003 and 9005, the first and / or second target SNs may use these measurement identifiers at a later time.

[0188] During 9006, the source MN 902 signals to the UE 901. The signaling at 9006 may include an RRC reconfiguration request message to cause the UE to reconfigure itself. The signaling at 9006 may include a new measurement configuration information element. Here, the new measurement configuration may be labeled as "measIdtoAddModListAfterCPC." The "measIdToAddModListAfterCPC" measurement configuration may be considered to include a measurement configuration that includes measurement objects and measurement identifiers related to condition configurations that are maintained after CPC execution.

[0189] The new measurement configuration may include the CPC configuration received from the first and second target nodes in 9003 and 9005. The new measurement configuration may include the measurement configuration indicated by the source SN. The signaling in 9006 may indicate to the UE 901 to apply the signaled configuration associated with a specific CPC performance criterion when the specific CPC performance criterion is met. In other words, the signaling in 9006 may indicate to the UE 901 to apply the signaled configuration associated with the CPC performance criterion of the target cell after switching from the source cell to the target cell.

[0190] Upon receiving the signaling of 9006, the UE may evaluate multiple measurement configurations associated with each identifier to determine whether to perform CPC for different PSCells. For example, the UE may evaluate "measID1" to determine CPC for PSCell1-1, "measID2" to determine CPC for PSCell2-2, and / or "measID3" to determine CPC for PSCell2-2. This evaluation may be performed regardless of the ID of the serving PSCell. The remaining measurement identifiers included in the measurement range identifier (e.g., MeasID4-8) may be reserved when a new PSCell is prepared.

[0191] During 9007, the UE acknowledges the signaling of 9006. This signaling of 9007 may acknowledge receipt of the new configuration. The signaling of 9007 may include an RRCReconfigurationComp message.

[0192] During 9008, the UE 901 determines that at least one CPC condition for one of the PSCells is satisfied. For example, in this case, the UE may determine that a CPC condition for PSCell1-1 in SN-1 is met and decides to initiate a PSCell change procedure for SN-1. The UE decides to apply the measurement configuration of PSCell1-1.

[0193] During 9009, the UE 901 applies measIdToAddModListAfterCPC and adds it to the measurement configuration of PSCell1-1.

[0194] During 9010, the UE 901 signals to the source MN 902. This signaling 9010 may include an indication that the UE 901 has completed the PSCell change procedure. The signaling 9010 may indicate that the UE 901 has completed the RRC reconfiguration. For example, the signaling 9010 may include an RRCReconfiguration complete signaling operation. The signaling 9010 may include an indication to the effect that the UE 901 applies the measurement configuration configured by the source MN 902 during 9006.

[0195] In one example, during 9010, the UE 901 reports only the measurement ID of the configuration used for the PSCell change (i.e., in this example, MeasID1 of the CPC from PSCell0-1 to PSCell1-1). This is because if the UE is already in PSCell1-1, the measurement configuration given in MeasID1 cannot be used by the UE, and the new serving PScell ​​(e.g., PSCell1-1) can reuse the measurement identifier associated with this PSCell. For measurement configurations of other CPCs, the UE 901 may reuse the measurement identifier configured by the source SN, and the target SN does not reconfigure the UE.

[0196] During 9011, the source MN 902 signals to the source SN 903. This 9011 signaling may indicate that the SN of the UE 901 has changed.

[0197] In 9012, the source MN 902 signals to the first target node 904. This signaling in 9012 may include an indication that SN reconfiguration has been completed by the UE for PSCell1-1. This signaling in 9012 may include the measurement identifier and object of the CP signaled by the UE 901 in 9010.

[0198] During 9013, the UE 901 may signal to the first target node 904. This signaling of 9013 may be a Random Access Channel procedure to access PSCell1-1.

[0199] During step 9014, the source MN 902, the source SN 903, and the first target SN 904 perform user plane procedures. The user plane procedures may be considered to include data plane communications of the UE. The data plane is related to applications used by the UE for various services. Thus, the user plane is initiated / established between the UE 901 and a network entity to receive and / or provide services. Step 9014 is performed to avoid service interruptions to the UE 901 when at least one cell providing a data connection to the UE 901 is changed.

[0200] During 9015, the source MN 902 signals to the source SN 903. This signaling of 9015 may instruct the source MN 902 to release any UE context held by the source SN 903 for the UE 901.

[0201] In the example of Figure 9, the source SN 903 determines and provides the measurement identifier range 1 to 8 to the source MN, although it will be appreciated that another entity may determine this range. For example, the source MN may determine the measurement identifiers 1 to 8 for the CPC on behalf of the source SN during 9002. This may be particularly useful if the CPC is initiated by the MN.

[0202] A second example is illustrated with respect to Figure 10. In this example of Figure 10, the source MN indicates a measurement configuration for a persistent CPC configuration to the target SN. The measurement may include, for example, a measurement identifier, an object, and a reporting configuration for the persistent CPC configuration. The target SN may integrate this information into the measurement configuration of the target SN. Once the measurement configuration becomes part of the measurement configuration of the target SN, the UE may apply this measurement configuration and immediately begin evaluating the conditions for subsequent CPCs.

[0203] In other words, in this second example, the source measurement configuration for CPC survival continues after execution from the UE side. Since the target SN already knows these measurement IDs during preparation, the target SN can ensure that these measurement identifiers are not assigned for new measurement configurations with different purposes.

[0204] 10 illustrates signaling that may occur between a UE 1001, a source MN 1002, a source SN 1003, a first target SN 1004, and a second target SN 1005. The source SN 1003 may be labeled as SN-0 and may be configured to provide PSCells 0-1. The first target SN 1004 may be labeled as SN-1 and may be configured to provide PSCells 1-1. The second target SN 1005 may be labeled as SN-2 and may be configured to provide PSCells 2-1 and 2-2.

[0205] During 10001, the source SN 1003 signals to the source MN 1002. This 10001 signaling may include an indication that a change in SN is requested. Receipt of this signal by the source MN 1002 may initiate an SN-initiated Conditional PSCell change procedure. This 10001 signaling may include a list of PSCells and measurement configurations (including measurement objects and reporting configurations configured in the UE for CPC).

[0206] For example, the 10001 signaling may associate: PSCell1-1 with the measurement identifier measID1, PSCell2-1 with the measurement identifier measID2, PSCell2-2 with the measurement identifier measID3, and PSCell0-1 with the measurement identifier measID4. The 10001 signaling may include the range of measurement identifiers (i.e., measID1-4 in this example) that are associated with the CPC.

[0207] During 10002, the source MN signals to the first target SN 1004. This 10002 signaling may include an SN addition request. This 10002 signaling may include an indication of the prepared PSCell. The 10002 signaling may include an indication that measurement identifiers MeasID1 to 4 range are associated with the CPCs configured in the UE 1001. The 10002 signaling may include measurement objects associated with these measurement identifiers.

[0208] During 10003, the first target SN 1004 integrates the measurement identifier (and any associated measurement object) received during 10002 into its own measurement configuration.

[0209] During 10004, the first target SN 1004 signals to the source MN 1002. The signaling of 10004 may acknowledge the SN addition request of 10002. The signaling of 1007 may include an indication of the integration of 10003.

[0210] During 10005, the source MN signals to the second target SN 1005. This 10005 signaling may include an SN addition request. This 10005 signaling may include an indication of the prepared PSCell. The 10005 signaling may include an indication that the range of measurement identifiers MeasID1 to 4 are associated with the CPCs configured in the UE 1001. The 10005 signaling may include measurement objects associated with these measurement identifiers.

[0211] During 10006, the second target SN 1005 integrates the measurement identifier (and any associated measurement object) received during 10005 into its own measurement configuration of the first target SN.

[0212] During 10007, the second target SN 1005 signals to the source MN 1002. The signaling of 10007 may acknowledge the SN addition request of 10005. The signaling of 1007 may include an indication of integration of 10006.

[0213] In 10008, the source MN 1002 signals to the UE 1001. This signaling in 10008 may include an instruction to the UE 1001 to perform RRC reconfiguration. The signaling in 10008 may include an RRCReconfiguration message. The signaling in 10008 may include, in 10004 and 10007, the CPC configurations received from the first and second target SNs.

[0214] During 10009, the UE 1001 signals to the source MN 1002. This signaling of 10009 may indicate to the source MN 1002 that the UE has reconfigured the measurement object according to the signaling of 10008.

[0215] During 10010, the UE 1001 monitors the CPC execution conditions configured by the PSCells 0-1 (i.e., configured by the source SN 1003).

[0216] During 10011, the UE 1001 determines that the CPC conditions for PSCell1-1 in the first target SN 1004 are met and that as a result the UE needs to perform CPC for the first target SN 1004.

[0217] 10012 to 10017 relate to the completion of the CPC procedure.

[0218] During 10012, the UE 1001 signals to the source MN 1002. This signaling of 10012 may indicate that the UE 1001 is applying the measurement configuration of the PSCell1-1. This signaling may be indicated via an RRC reconfiguration signal.

[0219] During 10013, the source MN 1002 signals to the source SN 1003. This signaling of 10013 may indicate that the SN for the UE 1001 has changed.

[0220] During 10014, the source MN 1002 signals to the first target node 1004. This signaling of 10014 may include an indication that the SN reconfiguration of PSCell1-1 has been completed by the UE.

[0221] During 10015, the UE 1001 may signal to the first target node 1004. This signaling of 10015 may be a Random Access Channel procedure to access the PSCell1-1.

[0222] During 10016, the source MN 1002, the source SN 1003, and the first target SN 1004 perform user plane procedures. The user plane procedures may be as discussed above.

[0223] During 10017, the source MN 1002 signals to the source SN 1003. This signaling of 10017 may instruct the source MN 1002 to release any UE context held by the source SN 1003 for the UE 1001.

[0224] In the example of Figure 10, the source SN 1003 determines and provides the measurement identifier range 1 to 8 to the source MN, but it will be appreciated that another entity may determine this range. For example, the source MN may determine the measurement identifiers 1 to 8 for the CPC in 10002 on behalf of the source SN. This may be particularly useful if the CPC is initiated by the MN.

[0225] A third example is described in connection with FIG.

[0226] In this third example, the source MN provides the UE with a cell-independent measurement configuration that is applied immediately and retained throughout the cell change. This means that in this example, a new measurement configuration for selective activation or CPC survival is described. The UE may refer to this measurement configuration for CPC execution instead of the measurement configuration of the master cell group and / or the secondary cell group.

[0227] After CPC, the UE releases the source SN configuration while maintaining the cell-independent measurement configuration. Since the measurement configuration is maintained after CPC, the UE can apply this measurement configuration for subsequent CPC. The handed-over Target SN can release or reconfigure the cell-independent measurement configuration. The existence of the cell-independent measurement configuration can be part of the UE context.

[0228] 11 illustrates signaling that may occur between a UE 1101, a source MN 1102, a source SN 1103, a first target SN 1104, and a second target SN 1105. The source SN 1103 may be labeled as SN-0 and may be configured to provide PSCells 0-1. The first target SN 1104 may be labeled as SN-1 and may be configured to provide PSCells 1-1. The second target SN 1105 may be labeled as SN-2 and may be configured to provide PSCells 2-1 and 2-2.

[0229] During 11001, the source SN 1103 signals to the source MN 1102. This 11001 signaling may include an indication that an SN change is requested. Receipt of this signaling by the source MN 1102 may initiate an SN-initiated Conditional PSCell change procedure. This 1001 signaling may include multiple respective associations between PSCells and measurement identifiers.

[0230] For example, signaling 11001 may associate: PSCell1-1 with measurement identifier measID1, PSCell2-1 with measurement identifier measID2, PSCell2-2 with measurement identifier measID3, and PSCell0-1 with measurement identifier measID4.

[0231] During 11002, the source MN signals the first target SN 1104. This 11002 signaling may include an SN addition request.

[0232] During 11003, the first target SN 1104 signals to the source MN 1102. The signaling of 11003 may acknowledge the SN addition request of 11002.

[0233] During 11004, the source MN 1102 signals to the second target SN 1105. This signaling of 11004 may include an SN addition request.

[0234] During 11005, the second target SN 1105 signals to the source MN 1102. The signaling of 11005 may acknowledge the SN addition request of 11005.

[0235] During 11006, the source MN 1102 signals to the UE 1101. This signaling at 11006 may include an instruction to cause the UE 1101 to perform RRC reconfiguration. The signaling at 11006 may include an RRCReconfiguration message. The signaling at 11006 may include an instruction to retain the measurement configuration previously provided by the serving PSCell.

[0236] During 11007, the UE 1101 signals to the source MN 1102. This signaling of 11007 may indicate to the source MN 1102 that the UE has reconfigured the measurement object according to the signaling of 11006.

[0237] During 11008, the UE 1101 monitors the CPC execution conditions configured by PSCell0-1 (i.e., configured by the source SN 1103).

[0238] During 11009, the UE 1001 determines that the CPC condition for PSCell1-1 in the first target SN 1104 is met, and as a result, the UE determines that it needs to perform CPC for the first target SN 1104.

[0239] During 11010, the UE 1001 decides to retain the PSCell measurement configuration variable.

[0240] For example, the measurement configuration of the UE is part of the cell group configuration. The UE maintains the measurement configuration as a "measurement configuration variable." After the UE changes the cell group, the UE typically deletes the cell group configuration and deletes variables related to the cell group configuration. Therefore, the measurement configuration variable is typically one of the variables deleted after the cell group change. However, on the contrary, during 11010, the UE 1001 maintains the PSCell measurement configuration variable upon cell change.

[0241] 11011 to 11018 relate to the CPC procedure to be completed.

[0242] During 11011, the UE 1101 signals to the source MN 1102. This signaling in 11012 may indicate that the UE 1101 is applying the measurement configuration of the serving PS cell. This signaling may be indicated via an RRC reconfiguration signal.

[0243] During 11012, the source MN 1102 signals to the source SN 1103. This 11012 signaling may indicate that the SN for the UE 1101 has changed.

[0244] During 11013, the source MN 1102 signals to the first target node 1104. This signaling of 11013 may include an indication that the SN reconfiguration for PSCell1-1 has been completed by the UE.

[0245] During 11014, the UE 1101 may signal to the first target node 1104. This signaling of 11014 may be a Random Access Channel procedure to access the PSCell1-1.

[0246] During 11015, the source MN 1102, the source SN 1103, and the first target SN 1104 perform a user plane procedure. This user plane procedure may be as described above.

[0247] During 11016, the source MN 1102 signals to the source SN 1103. This signaling at 11016 may instruct the source MN 1102 to release any UE context held by the source SN 1103 for the UE 1101.

[0248] During 11017, the first target SN 1104 signals to the UE 1101. This 11017 signaling may include an instruction to the UE 1101 to release temporary configuration variables. The 1104 signaling may include a new measurement CPC configuration specific to the first target SN 1104. The 11017 signaling may include RRCReconfiguration signaling, which may cause the UE to perform an RRC reconfiguration upon receiving the signaling.

[0249] During 11018, the UE 1101 signals to the first target SN 1104. This signaling at 11018 may indicate that the UE has reconfigured RRC operation based on the RRC configuration provided at 11017. The signaling at 11018 may include an RRCReconfiguration complete operation.

[0250] 12 through 15 illustrate the above aspects by illustrating example operations that may be performed by the devices described herein. These aspects highlight features of the above examples, and thus it will be understood that certain features of the above examples may be combined with the following operations.

[0251] FIG. 12 illustrates operations that may be performed by a master node operating with dual connections to user equipment along with a first secondary node.

[0252] During 1201, the master node determines that a primary cell of a secondary cell group will switch from a first cell serving the user equipment, the first cell being provided by a first secondary node.

[0253] During 1202, the master node determines at least one measurement configuration for a second cell provided by a second secondary node that will remain valid after or during a period when a primary cell of a secondary cell group serving the user equipment switches from the first cell to the second cell.

[0254] During 1203, the master node provides at least one measurement configuration to the user equipment.

[0255] Determining the at least one measurement configuration may include: identifying a measurement configuration provided by the first secondary node to be applied by the user equipment after the user equipment switches from the first cell to the second cell; and setting the identified measurement configuration as the at least one measurement configuration.

[0256] Determining at least one measurement configuration may include: determining, for a measurement configuration associated with the first secondary node, a range of first measurement identifier values ​​reserved for use by the first secondary node; providing the range of first measurement identifier values ​​to the second secondary node; and receiving at least one measurement configuration from the second secondary node, wherein the at least one measurement configuration does not include any measurement identifier having an associated value that is within the range of first measurement identifier values.

[0257] Determining at least one measurement configuration may include: determining a range of first measurement identifier values ​​reserved for use by the first secondary node for an associated measurement configuration; providing the first measurement identifier value range and the associated measurement configuration to the second secondary node; and receiving at least one measurement configuration from the second secondary node, the at least one measurement configuration including at least one measurement identifier having an associated value that is within the range of first measurement identifier values.

[0258] The determining that the first cell ceases to operate as a primary cell of a secondary cell group for the user equipment may include receiving an indication to this effect from the first secondary cell, and the determining the range of first measurement identifier values ​​includes receiving the range of first measurement identifier values ​​from the first secondary node.

[0259] The determining that the first cell will cease to operate as a primary cell of a secondary cell group for the user equipment may be made without receiving an indication to this effect from the first secondary cell, and the determining the range of first measurement identifier values ​​includes generating the range of first measurement identifier values.

[0260] 13 illustrates operations that may be performed by a first secondary node operating with a master node and dual connections to user equipment. The master node may be the master node of FIG. 12. The first secondary node may be the first secondary node discussed in connection with FIG. 12.

[0261] During 1301, a first secondary node determines that a primary cell of a secondary cell group will switch from a first cell serving the user equipment, the first cell being provided by the first secondary node.

[0262] During 1302, the first secondary node signals an indication to the master node that the first cell will cease to operate as a primary cell of the secondary cell group, the indication including a range of first measurement identifier values ​​reserved for use by the first secondary node for a measurement configuration associated with the first secondary node.

[0263] 14 illustrates an example of an operation that may be performed by a second secondary node. Hereinafter, the master node may be the master node of FIG. 12. The first secondary node may be the first secondary node discussed in connection with FIG. 13.

[0264] During 1401, a second secondary node receives an indication from the master node that a primary cell of a secondary cell group switches from a first cell serving a user equipment, the first cell being provided by the first secondary node, and the indication includes a range of first measurement identifier values ​​reserved for use by the first secondary node for a measurement configuration associated with the first secondary node.

[0265] During 1402, the second secondary node generates at least one measurement configuration for use by the user equipment when the user equipment starts using a cell provided by the second secondary node as a primary cell of the secondary cell group.

[0266] During 1403, the second secondary node signals the generated at least one measurement configuration to the master node.

[0267] The generating may include generating at least one measurement configuration that includes a measurement identifier value that is outside the range of first measurement identifier values.

[0268] The generating may include generating at least one measurement configuration that includes a measurement identifier value within a first range of measurement identifier values.

[0269] After signaling the generated at least one measurement configuration to the master node, the second secondary node may: generate at least one second cell measurement configuration to be applied by the user equipment when the primary cell of the secondary cell group is provided by a second cell that is provided by the second secondary cell; and signal the generated at least one second cell measurement configuration to the user equipment when the primary cell of the secondary cell group is provided by the second cell.

[0270] 15 illustrates example operations that may be performed by user equipment configured to operate with a dual connection to a master node and a first secondary node. The user equipment, master node, first secondary node, and second secondary node discussed in connection with FIG. 51 may correspond to the entities described in connection with FIGS. 12 through 14.

[0271] During 1501, the user equipment maintains a data connection with a first cell provided by a first secondary node by using the first cell as a primary cell of a secondary cell group.

[0272] During 1502, the user equipment receives from a master node (e.g., the master node) at least one measurement configuration that can be applied by the user equipment when the user equipment decides to switch the primary cell of the user equipment in the secondary cell group from the first cell to a second cell provided by a second secondary node.

[0273] During 1503, the user equipment switches the primary cell of the secondary cell group from a first cell to a second cell.

[0274] During 1504, the user equipment performs measurements in the second cell according to the received at least one measurement configuration.

[0275] The user equipment may: receive from a second secondary node at least one secondary cell measurement configuration that applies when the primary cell of the secondary cell group is the second cell; stop performing measurements in accordance with the received at least one measurement configuration; and start performing measurements in the second cell in accordance with the received at least one secondary cell measurement configuration.

[0276] The at least one measurement configuration may be independent of a second measurement configuration associated with a second secondary cell.

[0277] The user equipment: receives a first measurement configuration associated with a first secondary cell; and may apply the first measurement configuration only when the primary cell of the user equipment's secondary cell group is provided by the first cell.

[0278] The user equipment may use at least one measurement configuration when, for the user equipment, a primary cell of the secondary cell group is provided by the first cell.

[0279] The user equipment may generate measurement configuration variables and store the measurement configuration variables for use while the primary cell of the secondary cell group is provided by the second cell.

[0280] The user equipment may receive an indication to release stored measurement configuration variables from a secondary cell currently serving the user equipment with the cell acting as a primary cell of the secondary cell group.

[0281] The user equipment may receive from the second secondary node at least one secondary cell measurement configuration to be applied by the user equipment when the second cell is operating as a primary cell of the secondary cell group for the user equipment; and may apply the received at least one measurement configuration in addition to the measurement configuration provided by the secondary node.

[0282] The user equipment may indicate the measurement objects and measurement identifiers that apply to the measurement configuration as part of the persistent measurement configuration configured by the master node, which may be indicated to the second secondary node via a transmission to the second secondary node.

[0283] FIG. 2 illustrates an example of a controller for a communication system coupled to and / or controlling a station of an access system, such as a base station, a RAN node such as a gNB, a central unit of a cloud architecture, a node of a core network such as an MME or S-GW, a scheduling entity such as a spectrum management entity, or a server or host such as an apparatus hosting an NRF, NWDAF, AMF, SMF, UDM / UDR, etc. The controller may be integrated into a node or module of the core network or RAN, or may be external. In some examples, a base station comprises a separate controller unit or module. In other examples, the controller can be another network element such as a radio network controller or a spectrum controller. The controller 200 can be configured to provide control over communications in a service area of ​​the system. The apparatus 200 comprises at least one memory 201, at least one data processing unit 202, 203, and an input / output interface 204. The controller can be coupled to a receiver and a transmitter of the apparatus via the interface. The receiver and / or transmitter can be implemented as a radio front end or a remote radio head. For example, the controller 200 or processor 201 may be configured to execute appropriate software code to provide control functionality.

[0284] Possible wireless communication devices are described in further detail with reference to FIG. 3, which illustrates a schematic, partial cross-sectional view of a communication device 300. Such communication devices are often referred to as user equipment (UE) or terminals. A suitable mobile communication device may be provided by any device capable of transmitting and receiving wireless signals. Non-limiting examples include a mobile station (MS) or mobile device, such as a mobile phone or a so-called "smartphone," a computer equipped with a wireless interface card or other wireless interface capabilities (e.g., a USB dongle), a personal digital assistant (PDA) or tablet equipped with wireless communication capabilities, or any combination thereof. Mobile communication devices may provide data communications for transmitting communications such as voice, electronic mail (email), text messages, multimedia, and the like. Thus, users may be offered and provided with various services via the communication device. Non-limiting examples of these services include two-way or multi-way calls, data communication or multimedia services, or simply access to a data communication network system such as the Internet. Users may also be provided with broadcast or multicast data. Non-limiting examples of content include downloads, television or radio programs, videos, advertisements, various alerts, and other information.

[0285] A wireless communication device may be, for example, a mobile device, which is a device that is not fixed to a particular location, or may be a fixed device. A wireless device may or may not require human interaction for communication. As described herein, the term UE or "user" is used to refer to any type of wireless communication device.

[0286] The wireless device 300 may receive signals over the air or wireless interface 307 via suitable equipment for reception and may transmit signals via suitable equipment for transmitting wireless signals. In Figure 3, a transceiver unit is shown schematically by block 306. The transceiver unit 306 may be provided, for example, by a radio unit and an associated antenna arrangement. The antenna arrangement may be configured internal or external to the wireless device.

[0287] A wireless device typically includes at least one data processing entity 301, at least one memory 302, and possible other components 303 for use in software- and hardware-assisted execution of the tasks it is designed to perform, such as accessing and controlling communications with access systems and other communication devices. Data processing, storage, and other related controls may be provided within a suitable circuit board and / or chipset. This feature is indicated by reference numeral 304. A user may control the operation of the wireless device by means of a suitable user interface, such as a keypad 305, voice commands, a touchscreen or pad, or a combination thereof. A display 308, a speaker, and a microphone may also be provided. Additionally, a wireless communication device may include suitable connectors (wired or wireless) to other devices and / or for connecting external accessories, such as, for example, hands-free equipment.

[0288] FIG. 4 illustrates a schematic diagram of non-volatile memory media 400a (e.g., a computer disk (CD) or a digital versatile disk (DVD)) and 400b (e.g., a universal serial bus (USB) memory stick) that store instructions and / or parameters 402 that, when executed by a processor, enable the processor to perform one or more of the method steps of FIG. 12 and / or FIG. 13 and / or FIG. 14 and / or FIG. 15 and / or other previously described methods.

[0289] As provided herein, various aspects are described in the detailed description of examples and in the claims. Generally, some examples may be implemented in hardware or special-purpose circuits, software, logic, or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device, but examples are not limited thereto. While various examples may be illustrated and described as block diagrams, flowcharts, or using other graphical representations, it is well understood that these blocks, apparatus, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, special-purpose circuits or logic, general-purpose hardware or controllers, or other computing devices, or combinations thereof, as non-limiting examples.

[0290] These examples may be implemented by computer software stored in a memory and executable by at least one data processor of the participating entities, or by hardware, or by a combination of software and hardware. Further in this regard, it should be noted that, for example, Figures 12 and / or 13 and / or 14 and / or 15 and / or other procedures described above may represent program steps, or interconnected logic circuits, blocks, and functions, or a combination of program steps and logic circuits, blocks, and functions. Software may be stored on physical media, such as memory chips or blocks implemented within a processor, magnetic media (such as hard disks or floppy disks), and optical media (such as DVDs and their data variants, CDs, etc.).

[0291] The memory may be of any type suitable for the local technology environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed and removable memory, etc. The data processor may be of any type suitable for the local technology environment and may include, by way of non-limiting examples, one or more of a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (AStudyItemC), a gate-level circuit, and a processor based on a multi-core processor architecture.

[0292] Additionally or alternatively, some examples may be implemented using circuitry that may be configured to perform one or more of the functions and / or method steps described above, and that may be provided within a base station and / or a communication device and / or a core network entity.

[0293] As used herein, the term "circuit" refers to: (a) hardware-only circuit implementations (e.g., analog and / or digital-only implementations); (b)For example: (i) a combination of analog and / or digital hardware circuitry and software / firmware; and (ii) any portion of hardware processors (including digital signal processors), software, and memory with software that work together to cause an apparatus, such as a communications device or base station, to perform the various functions previously described; (c) Hardware circuitry and / or processors, such as microprocessors or portions of microprocessors, that require software (e.g., firmware) to operate, but that may not be present when this software is not required for operation. It may refer to one or more or all of:

[0294] This definition of circuit applies to all uses of the term in this application, including any claims. As a further example, the term circuit as used herein covers implementations of only a hardware circuit or processor(s), or of portions of a hardware circuit or processor and its(their) accompanying software and / or firmware. The term circuit also covers, for example, integrated devices.

[0295] The above description has provided a complete and informative description of several examples, by way of non-limiting example. However, various modifications and adaptations will become apparent to those skilled in the art in view of the foregoing description, when read in conjunction with the accompanying drawings and claims. However, all such and similar modifications of the present teachings will still fall within the scope of the claims.

[0296] Although different examples have been described above using radio access architectures based on Evolved Long Term Evolution (LTE Advanced, LTE-A) or New Radio (NR, 5G) as examples of access architectures to which the described techniques can be applied, the examples are not limited to such architectures. By appropriately adjusting parameters and procedures, these examples may also be applied to other types of communication networks with appropriate means. Some examples of other suitable system options are Universal Mobile Telecommunications System (UMTS) Radio Access Network (UTRAN), Wireless Local Area Network (WLAN or WiFi), Worldwide Interoperability for Microwave Access (WiMAX), Bluetooth®, Personal Communications Services (PCS), ZigBee®, Wideband Code Division Multiple Access (WCDMA), systems using Ultra-Wideband (UWB) technology, sensor networks, Mobile Ad Hoc Networks (MANETs), and Internet Protocol Multimedia Subsystem (IMS), or any combination thereof.

[0297] 5 depicts an example of a simplified system architecture illustrating only some elements and functional entities, which are all logical units, and their implementation may differ from those illustrated. The connections illustrated in FIG. 5 are logical connections, and the actual physical connections may differ. It is clear to those skilled in the art that a system typically includes other functions and structures in addition to those illustrated in FIG. 5.

[0298] However, the example is not limited to the system given as an example, and a person skilled in the art can apply this solution to other communication systems with the required characteristics.

[0299] The example of Figure 5 illustrates a portion of an exemplary radio access network. For example, the radio access network may support sidelink communications, which are described in more detail below.

[0300] FIG. 5 illustrates devices 500, 502. The devices 500, 502 are configured to wirelessly connect over one or more communication channels with a node 504. The node 504 is further connected to a core network 506. In one example, the node 504 may be an access node, such as an (e / g)NodeB, serving devices in a cell. In one example, the node 504 may be a non-3GPP access node. The physical link from the device to the (e / g)NodeB is referred to as the uplink or reverse link, and the physical link from the (e / g)NodeB to the device is referred to as the downlink or forward link. It should be appreciated that the (e / g)NodeB or their functionality may be implemented using any node, host, server, access point, or other entity suitable for such use.

[0301] A communication system typically comprises one or more (e / g)NodeBs, which may be configured to communicate with each other via wired or wireless links designed for that purpose. These links may be used for signaling purposes. An (e / g)NodeB is a computing device configured to control the radio resources of the communication system to which it is coupled. A NodeB may also be referred to as a base station, an access point, or any other type of interface device, including a relay station, capable of operating in a wireless environment. An (e / g)NodeB includes or is coupled to a transceiver. A connection is provided from the transceiver of the (e / g)NodeB to an antenna unit that establishes a bidirectional wireless link with the device. The antenna unit may comprise multiple antennas or antenna elements. The (e / g)NodeB is further connected to a core network 506 (CN or Next Generation Core NGC). Depending on the deployed technology, the (e / g)NodeB is connected to a Serving and Packet Data Network Gateway (S-GW+P-GW) or User Plane Function (UPF) for routing and forwarding user data packets and providing connectivity of devices to one or more external packet data networks, and to a Mobile Management Entity (MME) or Access Mobility Management Function (AMF) for controlling device access and mobility.

[0302] Examples of devices include subscriber units, user devices, user equipment (UE), user terminals, terminal devices, mobile stations, and mobile devices.

[0303] A device generally refers to a mobile or fixed device (e.g., a portable or non-portable computing device), including wireless mobile communication devices that operate with or without a Universal Subscriber Identity Module (USIM), including, but not limited to, the following types of devices: mobile phones, smartphones, personal digital assistants (PDAs), handsets, devices that use wireless modems (such as alarms or measurement devices), laptop and / or touchscreen computers, tablets, game consoles, notebooks, and multimedia devices. It should be recognized that a device may also be almost exclusively an uplink-only device, an example of which is a camera or video camera that loads images or video clips onto a network. A device may also be capable of operating in an Internet of Things (IoT) network, a scenario in which objects are provided with the ability to transfer data over a network without the need for human-to-human or human-to-computer interaction, such as those used in smart power grids and connected vehicles. A device may also utilize the cloud. In some applications, a device may comprise a user-portable device with wireless components (such as a watch, earphones, or glasses), and computations are performed in the cloud.

[0304] This device illustrates one type of device to which resources over the air interface are allocated and assigned, and therefore any functionality described herein with respect to the device may be implemented using a corresponding device, such as a relay node. An example of such a relay node is a Layer 3 relay (self-backhaul relay) to a base station. The device (or, in some examples, a Layer 3 relay node) is configured to perform one or more of the user equipment functions.

[0305] The various techniques described herein may also be applied to cyber-physical systems (CPSs), which are systems of collaborative computational elements that control physical entities. CPSs may enable the implementation and utilization of a large number of interconnected information and communication technology (ICT) devices (sensors, actuators, processors, microcontrollers, etc.) embedded in physical objects in different locations. Mobile cyber-physical systems are a subcategory of cyber-physical systems because the physical systems in question are inherently mobile. Examples of mobile physical systems include mobile robots and electronic devices carried by humans or animals.

[0306] Additionally, although the device is depicted as a single entity, different units, processors, and / or memory units (not all of which are shown in FIG. 5) may be implemented.

[0307] 5G will enable the use of many more base stations or nodes than LTE (the so-called small cell concept), including multiple input-multiple output (MIMO) antennas and macro sites that operate in conjunction with smaller stations and employ various radio technologies depending on service needs, use cases, and / or available spectrum. 5G mobile communications will support a wide range of use cases and related applications, including video streaming, augmented reality, different data sharing techniques, and various forms of machine-type applications (e.g., vehicle safety, different sensors, and (massive) machine-type communications (mMTC) involving real-time control). 5G is expected to have multiple air interfaces, e.g., below 6 GHz or above 24 GHz, cmWave, and mmWave, and to be integrable with existing legacy radio access technologies such as LTE. At least initially, integration with LTE could be implemented as a system in which macro coverage is provided by LTE and 5G air interface access is provided by small cells through aggregation to LTE. In other words, 5G is planned to support both inter-RAT interoperability (e.g., LTE-5G) and inter-RI interoperability (operability between air interfaces, such as below 6 GHz - cmWave, above 6 GHz or 24 GHz - cmWave and mmWave). One of the concepts being considered for use in 5G networks is network slicing, where multiple independent and dedicated virtual sub-networks (network instances) can be created within the same infrastructure to run services with different requirements regarding latency, reliability, throughput, and mobility.

[0308] The LTE network architecture is fully distributed in the radio and fully centralized in the core network. Low-latency applications and services in 5G require content to be closer to the radio, leading to local breakout and multi-access edge computing (MEC). 5G enables analytics and knowledge generation at the source of data. This approach must leverage resources that may not be continuously connected to the network, such as laptops, smartphones, tablets, and sensors. MEC provides a distributed computing environment for hosting applications and services. It also has the ability to store and process content closer to cellular subscribers, resulting in faster response times. Edge computing covers a wide range of technologies including wireless sensor networks, mobile data acquisition, mobile signature analysis, collaborative distributed peer-to-peer ad-hoc networking and processing (which can also be categorized as local cloud / fog computing and grid / mesh computing), dew computing, mobile edge computing, cloudlets, distributed data storage and retrieval, autonomous self-healing networks, remote cloud services, augmented and virtual reality, data caching, Internet of Things (where massive connectivity and / or latency are critical), and critical communications (autonomous vehicles, road safety, real-time analytics, time-critical control, healthcare applications).

[0309] The communications system may also communicate with or use services provided by other networks 512, such as the public switched telephone network, or a VoIP network, or the Internet, or a private network. The communications network may also be capable of supporting the use of cloud services; for example, at least some of the core network operations may be performed as cloud services (depicted in FIG. 5 by "cloud" 514). When performed away from the core network, this may also be referred to as Edge Computing. The communications system may also comprise a central control entity, etc., that provides facilities for networks of different operators to cooperate, for example in spectrum sharing.

[0310] Edge computing technologies can be introduced into the Radio Access Network (RAN) by utilizing Network Functions Virtualization (NFV) and Software-Defined Networking (SDN). Using edge cloud technologies can mean that access node operations are performed at least in part on a server, host, or node operatively coupled to a remote radio head or base station comprising the radio components. It is also possible for node operations to be distributed across multiple servers, nodes, or hosts. Application of the cloudRAN architecture allows RAN real-time functions to be performed at or near the remote antenna site (distributed unit, DU 508) and non-real-time functions to be performed in a centralized manner (centralized unit, CU 510).

[0311] It should also be understood that the distribution of load between core network operations and base station operations may be different from that in LTE and may even not exist in some cases. Some other technology advancements that will likely be used are Big Data and all-IP, which could change the way networks are built and managed. 5G (or New Radio, NR) networks will be designed to support multiple tiers where Edge Computing servers can be placed between the core and base stations or Node Bs (gNBs). One example of Edge Computing is MEC, as defined by the European Telecommunications Standards Institute. It should be recognized that MEC (and other Edge Computing protocols) can also be applied to 4G networks.

[0312] 5G may also utilize satellite communications to extend or complement 5G service coverage, for example by providing backhaul. Possible use cases include providing service continuity for machine-to-machine (M2M) or Internet of Things (IoT) devices, or passengers on board vehicles, Mobile Broadband (MBB), or ensuring service availability for critical communications and future rail, maritime, and aviation communications. Satellite communications may utilize not only geostationary orbit (GEO) satellite systems, but also low-earth orbit (LEO) satellite systems, especially megaconstellations (systems with hundreds of (nano)satellites). Each satellite in a megaconstellation may cover multiple satellite-enabled network entities, creating ground cells. Ground cells may be created through terrestrial relay nodes or by gNBs located on the ground or satellites.

[0313] The depicted system is only a partial example of a radio access system; in reality, the system may include multiple (e / g)NodeBs, a device may have access to multiple radio cells, and the system may also include other devices such as physical layer relay nodes or other network elements. At least one of the (e / g)NodeBs may be a home (e / g)NodeB. In addition, a geographical area of ​​a wireless communication system may be provided with multiple radio cells as well as multiple different types of radio cells. Radio cells may be macrocells (or umbrella cells), which are large cells typically reaching tens of kilometers in diameter, or smaller cells such as microcells, femtocells, and picocells. The (e / g)NodeB in FIG. 5 may provide any of these cell types. A cellular radio system may be implemented as a multi-layer network including multiple types of cells.

Claims

1. 1. A method for a master node operating with dual connections to user equipment together with a first secondary node, comprising: determining a primary cell of a secondary cell group to switch from a first cell serving the user equipment, the first cell being provided by a first secondary node; determining at least one measurement configuration for a second cell provided by a second secondary node that remains valid after or during a period when a primary cell of a secondary cell group serving the user equipment switches from the first cell to the second cell; providing at least one measurement configuration to a user equipment; A method comprising:

2. determining at least one measurement configuration; identifying a measurement configuration provided by a first secondary node to be applied by the user equipment after the user equipment switches from the first cell to the second cell; setting the identified measurement configuration as at least one measurement configuration; The method of claim 1 , comprising:

3. determining at least one measurement configuration; determining, for a measurement configuration associated with the first secondary node, a range of first measurement identifier values ​​reserved for use by the first secondary node; providing the first measurement identifier value range to a second secondary node; receiving at least one measurement configuration from a second secondary node; 2. The method of claim 1, wherein at least one measurement configuration does not include any measurement identifiers having associated values ​​that are within the range of first measurement identifier values.

4. determining at least one measurement configuration; determining a range of first measurement identifier values ​​reserved for use by the first secondary node for the associated measurement configuration; providing the first measurement identifier value range and associated measurement configuration to a second secondary node; receiving at least one measurement configuration from a second secondary node; 2. The method of claim 1, wherein at least one measurement configuration includes at least one measurement identifier having an associated value that is within the range of first measurement identifier values.

5. 5. The method of claim 3 or 4, wherein determining that a first cell ceases to act as a primary cell of a secondary cell group for a user equipment comprises receiving an indication to this effect from a first secondary cell, and wherein determining a range of first measurement identifier values ​​comprises receiving the range of first measurement identifier values ​​from a first secondary node.

6. 5. The method of claim 3, wherein the determining that the first cell ceases to act as a primary cell of a secondary cell group for the user equipment is made without receiving an indication to this effect from the first secondary cell, and wherein the determining a first measurement identifier value range comprises generating a first measurement identifier value range.

7. 1. A method for a first secondary node operating with a master node and with dual connections to user equipment, comprising: determining a primary cell of a secondary cell group to switch from a first cell serving the user equipment, the first cell being provided by a first secondary node; signaling an indication to the master node that the first cell will cease to operate as a primary cell of the secondary cell group; wherein the indication includes a range of first measurement identifier values ​​reserved for use by the first secondary node for a measurement configuration associated with the first secondary node.

8. A method for a second secondary node, comprising: receiving an indication from the master node that a primary cell of a secondary cell group will switch from a first cell serving the user equipment, the first cell being provided by a first secondary node, the indication including a range of first measurement identifier values ​​reserved for use by the first secondary node for a measurement configuration associated with the first secondary node; generating at least one measurement configuration for use by the user equipment when the user equipment starts to use a cell provided by the second secondary node as a primary cell of the secondary cell group; signaling the generated at least one measurement configuration to a master node; A method comprising:

9. The method of claim 8 , wherein generating comprises generating at least one measurement configuration that includes a measurement identifier value that is outside of a range of first measurement identifier values.

10. The method of claim 8 , wherein generating comprises generating at least one measurement configuration that includes a measurement identifier value that is within a first range of measurement identifier values.

11. After said signaling the generated at least one measurement configuration to a master node, generating at least one second cell measurement configuration to be applied by the user equipment when a primary cell of the secondary cell group is provided by a second cell provided by a second secondary cell; signaling the generated at least one second cell measurement configuration to a user equipment when a primary cell of a secondary cell group is provided by a second cell; 11. The method of any one of claims 8 to 10, comprising:

12. 1. A method for a user equipment configured to operate with a dual connection to a master node and a first secondary node, comprising: maintaining a data connection with the first cell provided by the first secondary node by using the first cell as a primary cell of a secondary cell group; receiving from the master node at least one measurement configuration that can be applied by the user equipment when the user equipment decides to switch a primary cell of the user equipment of a secondary cell group from a first cell to a second cell provided by a second secondary node; Switching the primary cell of a secondary cell group from a first cell to a second cell; performing measurements in the second cell according to the received at least one measurement configuration; A method comprising:

13. receiving, from a second secondary node, at least one secondary cell measurement configuration to be applied when a primary cell of the secondary cell group is the second cell; ceasing said performing measurements in accordance with the received at least one measurement configuration; initiating measurements in the second cell according to the received at least one secondary cell measurement configuration; 13. The method of claim 12, comprising:

14. 14. The method of claim 12 or 13, wherein at least one measurement configuration is independent of a second measurement configuration associated with a second secondary cell.

15. receiving a first measurement configuration associated with a first secondary cell; applying the first measurement configuration for the user equipment only when a primary cell of the secondary cell group is provided by the first cell; 14. The method of claim 12 or 13, further comprising:

16. 14. The method of claim 12 or 13, comprising using at least one measurement configuration when, for the user equipment, a primary cell of a secondary cell group is provided by the first cell.

17. 14. A method according to claim 12 or 13, comprising generating a measurement configuration variable and storing the measurement configuration variable for use while a primary cell of a secondary cell group is provided by the second cell.

18. 20. The method of claim 17, comprising receiving an indication to release stored measurement configuration variables from a secondary cell currently serving the user equipment with the cell acting as a primary cell of a secondary cell group.

19. receiving, from a second secondary node, at least one secondary cell measurement configuration to be applied by the user equipment when the second cell acts as a primary cell of a secondary cell group for the user equipment; applying the received at least one measurement configuration in addition to the measurement configuration provided by the secondary node; 14. The method of claim 12 or 13, comprising:

20. 14. The method of claim 12 or 13, comprising indicating measurement objects and measurement identifiers that apply to the measurement configuration as part of a persistent measurement configuration configured by the master node.

21. 10. A computer program comprising instructions which, when executed by an apparatus, cause the apparatus to perform a method according to any one of claims 1 to 6, or to perform a method according to claim 7, or to perform a method according to any one of claims 8 to 11, or to perform a method according to any one of claims 12 to 20.

22. 1. An apparatus for a master node operating with dual connections to user equipment together with a first secondary node, comprising: at least one processor; and at least one memory containing code, the code, when executed by the at least one processor, causing the apparatus to: determining that a primary cell of a secondary cell group is to switch from a first cell serving the user equipment, the first cell being provided by a first secondary node; determining at least one measurement configuration for a second cell provided by a second secondary node, the measurement configuration remaining valid after or during a period when a primary cell of a secondary cell group serving the user equipment switches from the first cell to the second cell; An apparatus that causes at least one measurement configuration to be provided to a user equipment.

23. 1. An apparatus for a first secondary node operating with a master node and with dual connections to user equipment, comprising: at least one processor; and at least one memory containing code, the code, when executed by the at least one processor, causing the apparatus to: determining that a primary cell of a secondary cell group is to switch from a first cell serving the user equipment, the first cell being provided by a first secondary node; 1. An apparatus for signaling an indication to a master node that a first cell will cease to operate as a primary cell of a secondary cell group, the indication including a range of first measurement identifier values ​​reserved for use by the first secondary node for a measurement configuration associated with the first secondary node.

24. 1. An apparatus for a second secondary node, comprising: at least one processor; and at least one memory containing code, the code, when executed by the at least one processor, causing the apparatus to: receiving an indication from the master node that a primary cell of a secondary cell group will switch from a first cell serving the user equipment, the first cell being provided by a first secondary node, the indication including a range of first measurement identifier values ​​reserved for use by the first secondary node for a measurement configuration associated with the first secondary node; generating at least one measurement configuration for use by the user equipment when the user equipment starts to use the cell provided by the second secondary node as a primary cell of the secondary cell group; An apparatus for signaling the generated at least one measurement configuration to a master node.

25. 1. An apparatus for user equipment configured to operate with dual connectivity to a master node and a first secondary node, comprising: at least one processor; and at least one memory containing code, the code, when executed by the at least one processor, causing the apparatus to: maintaining a data connection with the first cell provided by the first secondary node by using the first cell as a primary cell of a secondary cell group; receiving from the master node at least one measurement configuration that can be applied by the user equipment when the user equipment decides to switch a primary cell of the user equipment of the secondary cell group from the first cell to a second cell provided by a second secondary node; Switching the primary cell of a secondary cell group from a first cell to a second cell; The apparatus causes measurements to be made in the second cell according to the received at least one measurement configuration.

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