Method and apparatus for performing conditional cell change based on channel occupancy in wireless communication system
A method and apparatus for performing a conditional mobility based on a congestion level in a wireless communication system is provided. That is, the congestion level may be considered as mobility triggering condition of the conditional mobility. A wireless device performs a congestion level measurement, and receives a conditional mobility configuration associated with multiple target cells from a serving node. The conditional mobility configuration includes a threshold for the congestion level. The wireless device performs a mobility towards one target cell among the multiple target cells based on a result of the congestion level measurement and the threshold for the congestion level.
1. A method performed by a wireless device in a wireless communication system, the method comprising:
performing a congestion level measurement to evaluate channel occupancy;
receiving a conditional mobility configuration associated with multiple target cells from a serving node,
wherein the conditional mobility configuration includes (1) information on a threshold for the channel occupancy and (2) information on a time-to-trigger; and
performing a mobility towards one target cell among the multiple target cells based on a condition related to the conditional mobility configuration, which is based on the channel occupancy and the threshold, being met for a duration determined by the time-to-trigger.
2. The method of claim 1 , wherein the congestion level measurement is performed on at least one of a serving frequency and/or a target frequency.
3. The method of claim 1 , wherein the condition related to the conditional mobility configuration is met, based on (1) a channel occupancy of a target frequency being lower than the threshold for the channel occupancy and (2) a quality of the one target cell on the target frequency being higher than a threshold for cell quality.
4. The method of claim 1 , wherein the condition related to the conditional mobility configuration is met, based on (1) channel occupancies of all target frequencies, which includes a target frequency and does not include a serving frequency, are higher than the threshold for the channel occupancy and (2) a quality of the one target cell on the serving frequency being higher than a threshold for cell quality.
5. The method of claim 1 , wherein the condition related to the conditional mobility configuration is met, based on (1) a channel occupancy of a serving frequency being higher than the threshold for the channel occupancy and (2) a quality of the one target cell on the target frequency other than the serving frequency is higher than a threshold for cell quality.
6. The method of claim 1 , wherein the condition related to the conditional mobility configuration is met, based on (1) a channel occupancy of a serving frequency being lower than the threshold for the channel occupancy and (2) a quality of the one target cell on the serving frequency is higher than a threshold for cell quality.
7. The method of claim 1 , wherein the congestion level measurement includes a received signal strength indicator (RSSI) measurement to evaluate the channel occupancy.
8. The method of claim 1 , wherein the mobility includes a handover to the one target cell and/or a cell addition of the one target cell.
9. The method of claim 1 , wherein the conditional mobility configuration associated with multiple target cells includes mobility commands associated with multiple target cells.
10. The method of claim 9 , further comprising applying a mobility command associated with the one target cell among mobility commands associated with the multiple target cells.
11. The method of claim 1 , wherein the wireless device is in communication with at least one of a user equipment, a network, and/or autonomous vehicles other than the wireless device.
12. A wireless device in a wireless communication system, the wireless device comprising:
a memory;
a transceiver; and
a processor, operably coupled to the memory and the transceiver,
wherein the wireless device is configured to:
perform, via the processor and the transceiver, a congestion level measurement to evaluate channel occupancy,
receive, via the transceiver, a conditional mobility configuration associated with multiple target cells from a serving node,
wherein the conditional mobility configuration includes (1) information on a threshold for the channel occupancy and (2) information on a time-to-trigger, and
perform a mobility towards one target cell among the multiple target cells based on a condition related to the conditional mobility configuration, which is based on the channel occupancy and the threshold, being met for a duration determined by the time-to-trigger.
13. A processor for a wireless device in a wireless communication system, wherein the processor is configured to:
perform a congestion level measurement to evaluate channel occupancy,
control the wireless device to receive a conditional mobility configuration associated with multiple target cells from a serving node,
wherein the conditional mobility configuration includes (1) information on a threshold for the channel occupancy and (2) information on a time-to-trigger, and
perform a mobility towards one target cell among the multiple target cells based on a condition related to the conditional mobility configuration, which is based on the channel occupancy and the threshold, being met for a duration determined by the time-to-trigger.