Dual connectivity
A method, apparatus, and computer program for causing a master node operating with dual connectivity to a user equipment with a first secondary node to: determine that a primary cell of a secondary cell group is to switch from a first cell serving the user equipment, wherein the first cell is provided by the first secondary node; determine, for a second cell provided by a second secondary node, at least one measurement configuration that will remain valid after or during a time 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.
1 . A method for a user equipment configured to operate with dual connectivity to a master node and a first secondary node, the method comprising:
maintaining data connectivity with a 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, a measurement configuration information comprising:
a first measurement configuration associated with the first secondary node;
applying the first measurement configuration only when the primary cell of the secondary cell group for the user equipment is being provided by the first cell;
wherein the measurement configuration information further comprises at least one measurement configuration comprising a measurement identifier for evaluating a subsequent conditional primary cell of secondary cell group change (subsequent CPC) execution condition configured to be applied by the user equipment after the user equipment switches the user equipment's primary cell of the secondary cell group from the first cell to a second cell provided by a second secondary node;
switching said primary cell of the secondary cell group from the first cell to the second cell; and
after switching said primary cell, performing measurements in the second cell in accordance with the received at least one measurement configuration for evaluating the subsequent CPC execution condition.
2 . A method as claimed in claim 1 , comprising:
receiving, from the second secondary node, at least one secondary cell measurement configuration to be applied when the primary cell of the secondary cell group is the second cell;
stopping said performing measurements in accordance with the received at least one measurement configuration; and
initiating performing measurements in the second cell in accordance with the received at least one secondary cell measurement configuration.
3 . A method as claimed in claim 1 , wherein the at least one measurement configuration is independent of a second measurement configuration association with the second secondary node.
4 . A method as claimed in claim 1 , comprising using the at least one measurement configuration when the primary cell of the secondary cell group for the user equipment is being provided by the first cell.
5 . A method as claimed in claim 1 , comprising:
generating a measurement configuration variable and storing the measurement configuration variable for use while the primary cell of the secondary cell group is being provided by the second cell.
6 . A method as claimed in claim 1 , comprising receiving an indication to release the stored measurement configuration variable from the secondary cell currently providing a cell acting as a primary cell of a secondary cell group for the user equipment.
7 . A method as claimed in claim 1 , comprising:
receiving, from the second secondary node, at least one secondary cell measurement configuration to be applied by the user equipment when the second cell is acting as the primary cell of the 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 second secondary node.
8 . A method as claimed in claim 1 , comprising indicating measurement objects and measurement identifiers applied in the measurement configurations as part of a persistent measurement configuration configured by the master node.
9 . A user equipment configured to operate with dual connectivity to a master node and a first secondary node, the user equipment comprising: at least one processor; and at least one memory comprising code that, when executed by the at least one processor, causes the user equipment to:
maintain data connectivity 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, a measurement configuration information comprising:
a first measurement configuration associated with the first secondary node;
apply the first measurement configuration only when the primary cell of the secondary cell group for the user equipment is being provided by the first cell;
wherein the measurement configuration information further comprises at least one measurement configuration comprising a measurement identifier for evaluating a subsequent conditional primary cell of secondary cell group change (subsequent CPC) execution condition configured to be applied by the user equipment after the user equipment switches the user equipment's primary cell of the secondary cell group from the first cell to a second cell provided by a second secondary node;
switch said primary cell of the secondary cell group from the first cell to the second cell; and
after switching said primary cell, perform measurements in the second cell in accordance with the received at least one measurement configuration for evaluating the subsequent CPC execution condition.