Radio unlicensed (NR-U) idle mode operations

1. An apparatus of a user equipment (UE), comprising:

one or more processors configured to:

perform cell re-selection associated with a selected public land mobile network (PLMN) in New Radio (NR) unlicensed (NR-U) idle mode, wherein performing the cell re-selection in NR-U idle mode comprises to:

determine a best cell associated with the selected PLMN based on one or more measurements, wherein at least one of the one or more measurements comprises a channel occupancy measurement;

camp on the best cell; and

periodically search for cells that are determined to be better than the best cell based on the one or more measurements; and

a memory configured to store information associated with performing the cell re-selection.

2. The apparatus of claim 1 , wherein determining the best cell associated with the selected PLMN comprises to:

identify a candidate cell of a plurality of cells that is strongest based on the one or more measurements;

analyze PLMN information associated with the candidate cell to thereby determine a particular PLMN associated with the candidate cell from a plurality of PLMNs;

determine that the candidate cell is not associated with the selected PLMN based on the analyzed PLMN information; and

in response to determining that the candidate cell is not associated with the selected PLMN, determine the best cell that is associated with the selected PLMN based on the one or more measurements.

3. The apparatus of claim 1 , wherein the channel occupancy measurement is performed within a specified duration.

4. The apparatus of claim 1 , wherein the one or more measurements include one or more of a synchronization signal reference signal received power (SS-RSRP) and synchronization signal reference signal received quality (SS-RSRQ).

5. The apparatus of claim 1 , wherein the one or more processors are further configured to determine whether the best cell fulfills a cell selection criterion during camping.

6. The apparatus of claim 5 , wherein the one or more processors are further configured to, in response to determining that the best cell does not fulfill the cell selection criterion, measure one or more neighbor cells regardless of any measurement rules that limit measurement activities of the UE.

7. The apparatus of claim 1 , wherein searching for cells that are determined to be better than the best cell based on the one or more measurements comprises evaluating neighbor cells to the best cell.

8. The apparatus of claim 7 , wherein evaluating the neighbor cells includes consideration of at least one of cell detection time, measurement interval, and cell evaluation time.

9. The apparatus of claim 7 , wherein the one or more processors are further configured to monitor intra-frequency carriers, inter-frequency carriers, frequency-division duplexing (FDD) evolved universal mobile telecommunications system (UMTS) terrestrial radio access (E-UTRA) inter-radio access technology (RAT) carriers, and time-division duplexing (TDD) E-UTRA inter-RAT carriers.

10. A method of a user equipment (UE) performing cell re-selection, the method comprising:

performing cell re-selection associated with a selected public land mobile network (PLMN) in New Radio (NR) unlicensed (NR-U) idle mode, wherein performing cell re-selection in NR-U idle mode comprises:

determining a best cell associated with the selected PLMN based on one or more measurements, wherein at least one of the one or more measurements comprises a channel occupancy measurement;

camping on the best cell; and

periodically searching for cells that are determined to be better than the best cell based on the one or more measurements.

11. The method of claim 10 , wherein determining the best cell associated with the selected PLMN further comprises:

identifying a candidate cell of a plurality of cells that is strongest based on the one or more measurements;

analyzing PLMN information associated with the candidate cell to thereby determine a particular PLMN associated with the candidate cell from a plurality of PLMNs;

determining that the candidate cell is not associated with the selected PLMN based on the analyzed PLMN information; and

in response to determining that the candidate cell is not associated with the selected PLMN, determining the best cell that is associated with the selected PLMN based on the one or more measurements.

12. The method of claim 10 , wherein the channel occupancy measurement is performed within a specified duration.

13. The method of claim 10 , wherein the one or more measurements include one or more of a synchronization signal reference signal received power (SS-RSRP), a synchronization signal reference signal received quality (SS-RSRQ), or a signal to interference and noise ratio (SINR).

14. The method of claim 10 , further comprising determining whether the best cell fulfills a cell selection criterion during camping.

15. The method of claim 14 , further comprising, in response to determining that the best cell does not fulfill the cell selection criterion, measuring one or more neighbor cells regardless of any measurement rules that limit measurement activities of the UE.

16. The method of claim 10 , wherein searching for cells that are determined to be better than the best cell based on the one or more measurements comprises evaluating neighbor cells to the best cell.

17. The method of claim 16 , wherein evaluating the neighbor cells includes consideration of at least one of cell detection time, measurement interval, and cell evaluation time.

18. The method of claim 16 , further comprising monitoring intra-frequency carriers, inter-frequency carriers, frequency-division duplexing (FDD) evolved universal mobile telecommunications system (UMTS) terrestrial radio access (E-UTRA) inter-radio access technology (RAT) carriers, and time-division duplexing (TDD) E-UTRA inter-RAT carriers.

19. An apparatus of a user equipment (UE), comprising:

one or more processors configured to:

select a public land mobile network (PLMN), wherein selecting the PLMN includes performing registration on the PLMN; and

perform cell selection in New Radio (NR) unlicensed (NR-U) idle mode, wherein performing cell selection in NR-U idle mode comprises to:

determine a best cell of a plurality of cells based on one or more measurements, wherein at least one of the one or more measurements comprises a channel occupancy measurement;

analyze PLMN information associated with the best cell to thereby determine a particular PLMN associated with the best cell from a plurality of PLMNs;

determine that the best cell is not associated with the selected PLMN based on the analyzed PLMN information;

in response to determining that the best cell is not associated with the selected PLMN, determine a next best cell associated with the selected PLMN based on the one or more measurements; and

camp on the next best cell; and

a memory configured to store information associated with performing cell selection.

20. The apparatus of claim 19 , wherein the one or more measurements comprise at least one of reference signal received power (RSRP) and reference signal received quality (RSRQ).