Techniques and apparatuses for search, measurement, and icon display in new radio non-standalone mode

1. A method of wireless communication performed by a user equipment (UE), comprising:

camping on a cell of a first radio access technology (RAT);

performing a cell search for a second RAT while camped on the cell of the first RAT, wherein the second RAT operates in a non-standalone (NSA) mode with the first RAT; and

presenting, for display, an indication of whether the second RAT is available in the cell based at least in part on performing the cell search for the second RAT;

wherein a periodic search and measurement associated with the second RAT is performed in the cell when the second RAT is determined to be available in the cell; and

wherein a timer that triggers an iteration of the periodic search and measurement is configured with a different duration based at least in part on whether the second RAT is:

determined to be available in the cell, or

has not yet been determined to be available or unavailable in the cell.

2. The method of claim 1 , wherein the first RAT is a Long Term Evolution RAT used to anchor a network connection associated with the UE on a master cell group and the second RAT is a New Radio RAT used to add at least one carrier to the network connection on a secondary cell group.

3. The method of claim 1 , wherein a cell global identity of the cell is stored in a first list when the second RAT is determined to be available in the cell, or is stored in a second list when the second RAT is determined to be unavailable in the cell,

wherein the first list identifies one or more cells of the first RAT in which the second RAT is available, and

wherein the second list identifies one or more cells of the first RAT in which the second RAT is unavailable.

4. The method of claim 3 , wherein an icon indicating availability of the second RAT is displayed when the cell on which the UE is camped is identified in the first list, and is not displayed when the cell on which the UE is camped is identified in the second list.

5. The method of claim 1 , wherein the second RAT is determined to be available in the cell when the cell search detects at least one available cell of the second RAT, or wherein the second RAT is determined to be unavailable in the cell when a configured number of cell searches fail to detect at least one available cell of the second RAT.

6. The method of claim 1 , wherein the second RAT is determined to be available or unavailable based at least in part on:

the cell search for the second RAT,

whether system information is received that indicates that the second RAT is available in the cell,

whether system information is received that indicates one or more available frequencies of the second RAT in the cell,

whether one or more measurement objects associated with the second RAT are received in the cell,

a determination of whether the cell is associated with one or more restrictions relating to the second RAT in the cell, or

some combination thereof.

7. The method of claim 6 , wherein the determination of whether the cell is associated with the one or more restrictions is based at least in part on one or more of:

whether an indication that the second RAT is restricted in the cell is included in an attach accept message or a tracking area update accept message,

whether the UE is in a limited service mode or a barred cell,

whether the UE is in an out of service state or a radio link failure state,

whether the UE is camped on a 2G or a 3G cell,

whether an indication is received that the second RAT is operating in only a standalone mode in the cell, or

some combination thereof.

8. The method of claim 1 , wherein the periodic search and measurement associated with the second RAT is not performed in the cell when the second RAT is determined to be unavailable in the cell.

9. A method of wireless communication performed by a user equipment (UE), comprising:

camping on a cell of a first radio access technology (RAT);

performing a cell search for a second RAT while camped on the cell of the first RAT, wherein the second RAT operates in a non-standalone (NSA) mode with the first RAT; and

presenting, for display, an indication of whether the second RAT is available in the cell based at least in part on performing the cell search for the second RAT;

wherein a periodic search and measurement associated with the second RAT is performed in the cell when the second RAT is determined to be available in the cell; and

wherein a timer that triggers an iteration of the periodic search and measurement is suspended based at least in part on a determination that a display of the UE is off, or wherein the timer is resumed based at least in part on a determination that the display is on.

10. The method of claim 9 , wherein a duration of the timer that triggers the iteration of the periodic search and measurement is modified based at least in part on a result of a prior iteration of the periodic search and measurement, or wherein the duration of the timer is configured based at least in part on a data rate associated with the UE.

11. The method of claim 9 , wherein an iteration of the periodic search and measurement is terminated based at least in part on detection of at least one cell of the second RAT with a signal parameter that satisfies a threshold.

12. The method of claim 1 , wherein one or more frequencies on which the second RAT is available in the cell are stored in a frequency list, and wherein the one or more frequencies are identified based at least in part on:

the cell search for the second RAT,

system information that indicates at least one available frequency of the second RAT in the cell,

one or more measurement objects that are associated with the second RAT and are received in the cell, or

some combination thereof.

13. The method of claim 12 , wherein the one or more frequencies are stored on a per-tracking area identity basis and are stored based at least in part on a tracking area identity associated with the cell.

14. The method of claim 12 , wherein the one or more frequencies are sorted in the frequency list based at least in part on one or more measured signal parameters corresponding to the one or more frequencies.

15. The method of claim 14 , wherein an iteration of a periodic search and measurement associated with the second RAT is performed according to a sequence in which the one or more frequencies are sorted in the frequency list.

16. The method of claim 14 , wherein the indication of whether the second RAT is available includes a signal strength indicator that is displayed based at least in part on the one or more measured signal parameters.

17. The method of claim 1 , wherein the indication of whether the second RAT is available is displayed differently based at least in part on at least one of:

a data rate associated with the UE,

whether system information is received that identifies one or more frequencies on which the second RAT is available in the cell, or

a combination thereof.

18. A method of wireless communication performed by a user equipment (UE), comprising:

camping on a cell of a first radio access technology (RAT);

performing a cell search for a second RAT while camped on the cell of the first RAT, wherein the second RAT operates in a non-standalone (NSA) mode with the first RAT; and

presenting, for display, an indication of whether the second RAT is available in the cell based at least in part on performing the cell search for the second RAT;

wherein the indication of whether the second RAT is available is displayed differently based at least in part on at least one of:

a data rate associated with the UE,

whether system information is received that identifies one or more frequencies on which the second RAT is available in the cell, or

a combination thereof; and

wherein the indication:

includes a signal strength indicator when the system information is received; and

does not include a signal strength indicator when the system information is not received.

19. A user equipment (UE) for wireless communication, comprising:

a memory; and

one or more processors coupled to the memory, the memory and the one or more processors configured to:

camp on a cell of a first radio access technology (RAT);

perform a cell search for a second RAT while camped on the cell of the first RAT, wherein the second RAT operates in a non-standalone mode with the first RAT; and

present, for display, an indication of whether the second RAT is available in the cell based at least in part on performing the cell search for the second RAT;

wherein a cell global identity of the cell is stored in:

a first list when the second RAT is determined to be available in the cell, or

a second list when the second RAT is determined to be unavailable in the cell,

wherein the first list identifies one or more cells of the first RAT in which the second RAT is available, and

wherein the second list identifies one or more cells of the first RAT in which the second RAT is unavailable;

wherein an icon indicating availability of the second RAT is displayed when the cell on which the UE is camped is identified in the first list, and is not displayed when the cell on which the UE is camped is identified in the second list.

20. The UE of claim 19 , wherein a periodic search and measurement associated with the second RAT is not performed in the cell when the second RAT is determined to be unavailable in the cell, or wherein the periodic search and measurement associated with the second RAT is performed in the cell when the second RAT is determined to be available in the cell.

21. An apparatus for wireless communication, comprising;

means for camping on a cell of a first radio access technology (RAT);

means for performing a cell search for a second RAT while camped on the cell of the first RAT, wherein the second RAT operates in a non-standalone mode with the first RAT; and

means for presenting, for display, an indication of whether the second RAT is available in the cell based at least in part on performing the cell search for the second RAT;

wherein a periodic search and measurement associated with the second RAT is performed in the cell when the second RAT is determined to be available in the cell; and

wherein a timer that triggers an iteration of the periodic search and measurement is configured with a different duration based at least in part on whether the second RAT is:

determined to be available in the cell, or

has not yet been determined to be available or unavailable in the cell.

22. The apparatus of claim 21 , wherein a cell global identity of the cell is stored in a first list when the second RAT is determined to be available in the cell, or is stored in a second list when the second RAT is determined to be unavailable in the cell,

wherein the first list identifies one or more cells of the first RAT in which the second RAT is available, and

wherein the second list identifies one or more cells of the first RAT in which the second RAT is unavailable.

23. The apparatus of claim 21 , wherein the periodic search and measurement associated with the second RAT is not performed in the cell when the second RAT is determined to be unavailable in the cell.

24. A user equipment (UE) for wireless communication, comprising:

a memory; and

one or more processors coupled to the memory, the memory and the one or more processors configured to:

camp on a cell of a first radio access technology (RAT);

perform a cell search for a second RAT while camped on the cell of the first RAT, wherein the second RAT operates in a non-standalone mode with the first RAT; and

present, for display, an indication of whether the second RAT is available in the cell based at least in part on performing the cell search for the second RAT;

wherein a periodic search and measurement associated with the second RAT is performed in the cell when the second RAT is determined to be available in the cell; and

wherein a timer that triggers an iteration of the periodic search and measurement is configured with a different duration based at least in part on whether the second RAT is:

determined to be available in the cell, or

has not yet been determined to be available or unavailable in the cell.

25. The UE of claim 24 , wherein one or more frequencies on which the second RAT is available in the cell are stored in a frequency list, and wherein the one or more frequencies are identified based at least in part on:

the cell search for the second RAT,

system information that indicates at least one available frequency of the second RAT in the cell,

one or more measurement objects that are associated with the second RAT and are received in the cell, or

some combination thereof.

26. The UE of claim 25 , wherein the one or more frequencies are stored on a per-tracking area identity basis and are stored based at least in part on a tracking area identity associated with the cell.

27. The UE of claim 25 , wherein the one or more frequencies are sorted in the frequency list based at least in part on one or more measured signal parameters corresponding to the one or more frequencies.

28. A user equipment (UE) for wireless communication, comprising:

a memory; and

one or more processors coupled to the memory, the memory and the one or more processors configured to:

camp on a cell of a first radio access technology (RAT);

perform a cell search for a second RAT while camped on the cell of the first RAT, wherein the second RAT operates in a non-standalone mode with the first RAT; and

present, for display, an indication of whether the second RAT is available in the cell based at least in part on performing the cell search for the second RAT;

wherein the indication of whether the second RAT is available is displayed differently based at least in part on at least one of:

a data rate associated with the UE,

whether system information is received that identifies one or more frequencies on which the second RAT is available in the cell, or

a combination thereof; and

wherein the indication:

includes a signal strength indicator when the system information is received; and

does not include a signal strength indicator when the system information is not received.

29. The UE of claim 28 , wherein the first RAT is a Long Term Evolution RAT used to anchor a network connection associated with the UE on a master cell group and the second RAT is a New Radio RAT used to add at least one carrier to the network connection on a secondary cell group.

30. The UE of claim 28 , wherein the second RAT is determined to be available in the cell when the cell search detects at least one available cell of the second RAT, or wherein the second RAT is determined to be unavailable in the cell when a configured number of cell searches fail to detect at least one available cell of the second RAT.