Change of tracking area code for wireless networks
Methods, systems, and devices for wireless communications are described. In some non-terrestrial networks, the movement of satellites may result in the movement of cell coverage. A user equipment (UE) may experience changing cell coverage due to the movement of cell coverage, even if the UE is stationary. A UE may be configured to determine a cell is serving two or more earth-fixed tracking areas, determine whether to monitor paging resources of a first earth-fixed tracking area or a second earth-fixed tracking area, and monitor the selected paging resources. In some aspects, the UE may determine that a cell serves two or more earth-fixed tracking areas based on a received control message including multiple tracking area indicators. In some aspects, the UE may determine which paging resources to monitor based on a geographic position of the UE.
1. A method for wireless communication at a user equipment (UE), comprising:
receiving system information that includes an indication that a first cell of a non-terrestrial network is associated with a first tracking area indicator and a second tracking area indicator;
determining, based at least in part on the system information, that the first cell serves a first earth-fixed tracking area associated with the first tracking area indicator and a second earth-fixed tracking area associated with the second tracking area indicator; and
monitoring paging resources associated with the first earth-fixed tracking area based at least in part on determining that the first cell serves the first earth-fixed tracking area and the second earth-fixed tracking area.
2. The method of claim 1 , further comprising:
determining a terrestrial location of the UE; and
determining that the UE is positioned within the first earth-fixed tracking area based at least in part on determining the terrestrial location of the UE, wherein monitoring the paging resources associated with the first earth-fixed tracking area is based at least in part on determining that the UE is positioned within the first earth-fixed tracking area.
3. The method of claim 1 , further comprising:
determining that the UE was associated with the first earth-fixed tracking area prior to the first cell serving the first earth-fixed tracking area and the second earth-fixed tracking area, wherein monitoring the paging resources associated with the first earth-fixed tracking area is based at least in part on determining that the UE was associated with the first earth-fixed tracking area.
4. The method of claim 1 , wherein one of the first tracking area indicator or the second tracking area indicator comprises a temporary tracking area indicator or shorter validity indicator.
5. The method of claim 4 , further comprising:
determining a paging message for the first earth-fixed tracking area based at least in part on whether the first earth-fixed tracking area comprises the temporary tracking area indicator, wherein monitoring the paging resources of the first earth-fixed tracking area is based at least in part on determining the paging message.
6. The method of claim 4 , wherein the second earth-fixed tracking area comprises the temporary tracking area indicator, the method further comprising:
identifying that a validity time associated with the temporary tracking area indicator is less than or equal a threshold validity time, wherein monitoring the paging resources associated with the first earth-fixed tracking area is based at least in part on the validity time being less than or equal to the threshold validity time.
7. The method of claim 4 , further comprising:
receiving, via the system information, an indication of boundary information associated with an earth-fixed tracking area associated with the temporary tracking area indicator, wherein monitoring the paging resources associated with the first earth-fixed tracking area is based at least in part on the boundary information.
8. The method of claim 4 , further comprising:
receiving a master information block message comprising one or more fields associated with temporary tracking area indicators, wherein the one or more fields indicate whether the system information includes data associated with the temporary tracking area indicator.
9. The method of claim 4 , further comprising:
identifying a validity time associated with the temporary tracking area indicator based at least in part on receiving the system information; and
removing the temporary tracking area indicator from a tracking area indicator list of the UE upon expiration of the validity time associated with the temporary tracking area indicator.
10. The method of claim 9 , further comprising:
storing the temporary tracking area indicator and one of the first tracking area indicator or the second tracking area indicator in the tracking area indicator list of the UE based at least in part on receiving the system information, wherein removing the temporary tracking area indicator from the tracking area indicator list is based at least in part on storing the temporary tracking area indicator and one of the first tracking area indicator or the second tracking area indicator in the tracking area indicator list.
11. The method of claim 4 , wherein the second tracking area indicator comprises the temporary tracking area indicator, the method further comprising:
identifying that the UE was associated with the first cell serving the first earth-fixed tracking area and the second earth-fixed tracking area; and
identifying that the UE is associated with the first earth-fixed tracking area based at least in part on identifying that the UE was associated with the first cell, wherein monitoring the paging resources is based at least in part on determining that the UE is associated with the first earth-fixed tracking area.
12. The method of claim 4 , wherein the second tracking area indicator comprises the temporary tracking area indicator, the method further comprising:
identifying that the UE was not associated with the first cell serving the first earth-fixed tracking area and the second earth-fixed tracking area; and
identifying that the UE is associated with the first earth-fixed tracking area based at least in part on identifying that the UE was not associated with the first cell, wherein monitoring the paging resources is based at least in part on determining that the UE is associated with the first earth-fixed tracking area.
13. The method of claim 1 , wherein:
the first tracking area indicator is indicated via a first tracking area indicator field of the system information, and
the second tracking area indicator is indicated via a second tracking area indicator field of the system information.
14. The method of claim 1 , wherein determining that the first cell serves the first earth-fixed tracking area and the second earth-fixed tracking area comprises:
determining that a tracking area indicator included in a control message is associated with the first earth-fixed tracking area and a temporary tracking area indicator included in the control message is associated with the second earth-fixed tracking area of the non-terrestrial network.
15. The method of claim 1 , further comprising:
reporting the first earth-fixed tracking area and the second earth-fixed tracking area to a non-access stratum of the UE.
16. The method of claim 12 , further comprising:
determining whether to perform a registration update based at least in part on the first tracking area indicator and the second tracking area indicator.
17. The method of claim 1 , wherein monitoring the paging resources associated with the first earth-fixed tracking area comprises:
monitoring a paging message associated with the first earth-fixed tracking area using a first paging radio network temporary identifier that is different than a second paging radio network temporary identifier associated with the second earth-fixed tracking area.
18. The method of claim 1 , further comprising:
receiving a system information broadcast message associated with the first cell that indicates a paging radio network temporary identifier associated with the first earth-fixed tracking area and a temporary paging radio network temporary identifier associated with the second earth-fixed tracking area; and
monitoring a paging message associated with the first earth-fixed tracking area using the paging radio network temporary identifier associated with the first earth-fixed tracking area.
19. The method of claim 1 , further comprising:
receiving a downlink control information that includes an indication of whether a paging message is associated with the first earth-fixed tracking area or is associated with the second earth-fixed tracking area, wherein monitoring the paging resources associated with the first earth-fixed tracking area is based at least in part on receiving the downlink control information.
20. The method of claim 19 , wherein the downlink control information includes a first value of the indication for the paging message being associated with the first earth-fixed tracking area or a second value of the indication for the paging message being associated with the second earth-fixed tracking area.
21. The method of claim 19 , further comprising:
determining that a first paging message is associated with the first earth-fixed tracking area and that a second paging message is associated with the second earth-fixed tracking area based at least in part on receiving the downlink control information.
22. The method of claim 19 , wherein the downlink control information includes a first value of the indication for the paging message being associated with the first earth-fixed tracking area, a second value of the indication for the paging message being associated with the second earth-fixed tracking area, or a third value of the indication for the paging message being associated with both the first earth-fixed tracking area and the second earth-fixed tracking area.
23. The method of claim 1 , further comprising:
determining the paging resources associated with the first earth-fixed tracking area and second paging resources associated with the second earth-fixed tracking area are the same.
24. The method of claim 1 , further comprising:
selecting to communicate with the first cell of the non-terrestrial network, wherein monitoring the paging resources associated with the first earth-fixed tracking area is based at least in part on selecting to communicate with the first cell.
25. A method for wireless communication at a base station, comprising:
transmitting, to a user equipment (UE), system information that includes an indication that a first cell of a non-terrestrial network is associated with a first tracking area indicator and a second tracking area indicator;
determining, based at least in part on the system information, that the first cell serves a first earth-fixed tracking area associated with the first tracking area indicator and a second earth-fixed tracking area associated with the second tracking area indicator; and
transmitting one or more first paging messages associated with the first earth-fixed tracking area and one or more second paging messages associated with the second earth-fixed tracking area based at least in part on determining that the first cell serves the first earth-fixed tracking area and the second earth-fixed tracking area.
26. The method of claim 25 , wherein one of the first tracking area indicator or the second tracking area indicator comprises a temporary tracking area indicator or a shorter validity indicator.
27. The method of claim 26 , further comprising:
transmitting, to the UE via the system information, a validity time associated with the temporary tracking area indicator.
28. The method of claim 26 , wherein the second earth-fixed tracking area comprises the temporary tracking area indicator, the method further comprising:
identifying that a validity time associated with the temporary tracking area indicator is less than or equal a threshold validity time, wherein transmitting the one or more first paging messages is based at least in part on the validity time being less than or equal to the threshold validity time.
29. An apparatus for wireless communication at a user equipment (UE), comprising:
a processor,
memory coupled with the processor; and
instructions stored in the memory and executable by the processor to cause the apparatus to:
communicate with a first cell of a non-terrestrial network;
determine that the first cell serves a first earth-fixed tracking area and a second earth-fixed tracking area; and
monitor paging resources associated with the first earth-fixed tracking area based at least in part on determining that the first cell serves the first earth-fixed tracking area and the second earth-fixed tracking area.
30. An apparatus for wireless communication at a base station, comprising:
a processor,
memory coupled with the processor; and
instructions stored in the memory and executable by the processor to cause the apparatus to:
communicate with a user equipment (UE) via a first cell of a non-terrestrial network;
determine that the first cell serves a first earth-fixed tracking area and a second earth-fixed tracking area; and
transmit one or more first paging messages associated with the first earth-fixed tracking area and one or more second paging messages associated with the second earth-fixed tracking area based at least in part on determining that the first cell serves the first earth-fixed tracking area and the second earth-fixed tracking area.