Using the expected time to be served as handover target cell selection criterion in a non-terrestrial network
A method is performed by a wireless device in a connected mode. The method includes obtaining, by the wireless device, information that includes an expected time for the wireless device in the connected mode to be served in at least one cell. The at least one cell includes a serving cell currently serving the wireless device and/or at least one target cell associated with a conditional handover procedure. The wireless device performs the conditional handover procedure based on the information.
1 . A method performed by a wireless device in a connected mode, the method comprising:
obtaining information comprising an expected time for the wireless device in the connected mode to be served in at least one cell, the at least one cell comprising a serving cell currently serving the wireless device and/or at least one target cell associated with a conditional handover procedure; and
based on the information, performing the conditional handover procedure when:
the expected time to be served in the at least one cell comprising the serving cell is less than or equal to a threshold, and
the expected time to be served in the at least one target cell is equal to or greater than the threshold.
2 . The method of claim 1 , wherein obtaining the information comprises receiving at least a portion of the information from a network node in broadcast information or system information.
3 . The method of claim 1 , wherein performing the conditional handover procedure comprises selecting, based at least in part on the information, the target cell for handover of the wireless device.
4 . The method of claim 3 wherein:
the at least one cell comprises a plurality of target cells, and
selecting the target cell comprises selecting, from the plurality of target cells, the target cell associated with a highest expected time to be served for the wireless device.
5 . The method of claim 1 , further comprising transmitting the information to a network node.
6 . The method of claim 5 , wherein transmitting the information to the network node comprises at least one of:
transmitting the information in a measurement report comprising at least one measurement associated with one of the plurality of target cells;
transmitting the information with assistance information;
transmitting the information after the network node receives a request for the information from the network node; and
transmitting the information to the network node in response to determining that the expected time for a wireless device to be served in the at least one cell is equal to or exceeds a threshold.
7 . A method performed by a network node, the method comprising:
transmitting, to a wireless device, information comprising:
an expected time for the wireless device in a connected mode to be served in a serving cell currently serving the wireless device, and
an expected time for the wireless device to be to be served in at least one target cell associated with a conditional handover procedure.
8 . A wireless device adapted to:
obtain information comprising an expected time for the wireless device in the connected mode to be served in at least one cell, the at least one cell comprising a serving cell currently serving the wireless device and/or at least one target cell associated with a conditional handover procedure; and
based on the information, perform the conditional handover procedure when:
the expected time to be served in the at least one cell comprising the serving cell is less than or equal to a threshold, and
the expected time to be served in the at least one target cell is equal to or greater than the threshold.
9 . The wireless device of claim 8 , wherein when obtaining the information the wireless device is adapted to receive at least a portion of the information from a network node in broadcast information or system information.
10 . The wireless device of claim 8 , wherein when performing the conditional handover procedure the wireless device is adapted to select, based at least in part on the information, the target cell for handover of the wireless device.
11 . The wireless device of claim 10 , wherein:
the at least one cell comprises a plurality of target cells, and
when selecting the target cell the wireless device is adapted to select, from the plurality of target cells, the target cell associated with a highest expected time to be served for the wireless device.
12 . The wireless device of claim 8 , wherein the wireless device is adapted to transmit the information to a network node.
13 . The wireless device of claim 12 , wherein when transmitting the information to the network node the wireless device is adapted to perform at least one of:
transmitting the information in a measurement report comprising at least one measurement associated with one of the plurality of target cells;
transmitting the information with assistance information;
transmitting the information after the network node receives a request for the information from the network node; and
transmitting the information to the network node in response to determining that the expected time for a wireless device to be served in the at least one cell is equal to or exceeds a threshold.
14 . The wireless device of claim 8 , wherein:
when performing the conditional handover procedure based on the information the wireless device is adapted to determine that the expected time for the wireless device to be served in the at least one cell is equal to or exceeds a threshold, and
the threshold is associated with a trigger condition for the conditional handover procedure.
15 . The wireless device of claim 14 , wherein the trigger condition comprises one of a plurality of conditions for the conditional handover procedure.
16 . The wireless device of claim 15 , wherein the plurality of conditions for the conditional handover procedure comprises at least one condition associated with a channel quality and/or cell quality.
17 . A network node adapted to:
transmit, to a wireless device, information comprising:
an expected time for the wireless device in a connected mode to be served in a serving cell currently serving the wireless device, and
an expected time for the wireless device to be to be served in at least one target cell associated with a conditional handover procedure.
18 . The network node of claim 17 , wherein the network node is associated with the serving cell.
19 . The network node of claim 17 , wherein the network node is associated with the target cell.
20 . The network node of claim 17 , wherein the information is transmitted to the wireless device in broadcast information or system information.
21 . The network node of claim 17 , wherein the network node is adapted to obtain at least a portion of the information from the wireless device.
22 . The network node of claim 17 , wherein the network node is adapted to:
select, based at least in part on the information, the target cell for handover of the wireless device; and
wherein the information transmitted to the wireless device indicates the target cell for the conditional handover procedure.
23 . The network node of claim 22 , wherein the target cell is selected for handover when the expected time to be served in the at least one cell comprising the serving cell is less than or equal to a threshold and the expected time to be served in the target cell is equal to or greater than threshold, the threshold being associated with a trigger condition for the conditional handover procedure.
24 . The network node of claim 23 , wherein:
the trigger condition comprises one of a plurality of conditions for the conditional handover procedure, and
at least one condition of the plurality of conditions is associated with a channel quality and/or cell quality.