Method and apparatus for performing cell (re)selection in wireless communication systems

1. A User Equipment (UE), comprising:

one or more non-transitory computer-readable media storing computer-executable instructions; and

at least one processor coupled to the one or more non-transitory computer-readable media, and configured to execute the computer-executable instructions to:

receive first other system information from a base station, wherein other system information comprises system information other than minimum system information broadcast by the base station;

determine whether a Supplementary Uplink (SUL)-related factor is present in the first other system information;

transmit a Radio Resource Control (RRC) system information request message to the base station in response to determining that the SUL-related factor is absent in the first other system information;

determine a minimum required received level based on the SUL-related factor in a case that the UE receives the SUL-related factor in second other system information from the base station; and

determine a cell selection criterion based on the minimum required received level.

2. The UE of claim 1 , wherein the at least one processor is further configured to execute the computer-executable instructions to:

receive the SUL-related factor in intra-frequency cell reselection information in a System Information Block 2 (SIB2) of the second other system information from the base station.

3. The UE of claim 2 , wherein the at least one processor is further configured to execute the computer-executable instructions to:

perform an intra-frequency cell reselection procedure based on the cell selection criterion.

4. The UE of claim 1 , wherein the at least one processor is further configured to execute the computer-executable instructions to:

receive the SUL-related factor in inter-frequency cell reselection information in a System Information Block 4 (SIB4) of the second other system information from the base station.

5. The UE of claim 4 , wherein the at least one processor is further configured to execute the computer-executable instructions to:

perform an inter-frequency cell reselection procedure based on the cell selection criterion.

6. The UE of claim 1 , wherein the at least one processor is further configured to execute the computer-executable instructions to:

receive the SUL-related factor in inter-Radio Access Technology (inter-RAT) cell reselection information in the second other system information from the base station.

7. The UE of claim 6 , wherein the at least one processor is further configured to execute the computer-executable instructions to:

perform an inter-RAT cell reselection procedure based on the cell selection criterion.

8. A method performed by User Equipment (UE) for wireless communications, the method comprising:

receiving first other system information from a base station, wherein other system information comprises system information other than minimum system information broadcast by the base station;

determining whether a Supplementary Uplink (SUL)-related factor is present in the first other system information;

transmitting a Radio Resource Control (RRC) system information request message to the base station in response to determining that the SUL-related factor is absent in the first other system information;

determining a minimum required received level based on the SUL-related factor in a case that the UE receives the SUL-related factor in second other system information from the base station; and

determining a cell selection criterion based on the minimum required received level.

9. The method of claim 8 , further comprising:

receiving the SUL-related factor in intra-frequency cell reselection information in a System Information Block 2 (SIB2) of the second other system information from the base station.

10. The method of claim 9 , further comprising:

performing an intra-frequency cell reselection procedure based on the cell selection criterion.

11. The method of claim 8 , further comprising:

receiving the SUL-related factor in inter-frequency cell reselection information in a System Information Block 4 (SIB4) of the second other system information from the base station.

12. The method of claim 11 , further comprising:

performing an inter-frequency cell reselection procedure based on the cell selection criterion.

13. The method of claim 8 , further comprising:

receiving the SUL-related factor in inter-Radio Access Technology (inter-RAT) cell reselection information in the second other system information from the base station.

14. The method of claim 13 , further comprising:

performing an inter-RAT cell reselection procedure based on the cell selection criterion.

15. A base station, comprising:

one or more non-transitory computer-readable media storing computer-executable instructions; and

at least one processor coupled to the one or more non-transitory computer-readable media, and configured to execute the computer-executable instructions to:

transmit first other system information to a User Equipment (UE), causing the UE to determine whether a Supplementary Uplink (SUL)-related factor is present in the first other system information, wherein other system information comprises system information other than minimum system information broadcast by the base station;

cause the UE to transmit a Radio Resource Control (RRC) system information request message to the base station by not including the SUL-related factor in the first other system information;

receive the RRC system information request message from the UE;

transmit second other system information comprising the SUL-related factor to the UE in response to receiving the RRC system information request message; and

cause the UE to determine, based on the SUL-related factor, a minimum required received level for determining a cell selection criterion.

16. The base station of claim 15 , wherein the SUL-related factor is transmitted in intra-frequency cell reselection information in the second other system information.

17. The base station of claim 16 , wherein the second other system information comprises a System Information Block 2 (SIB2) that includes the intra-frequency cell reselection information.

18. The base station of claim 15 , wherein the SUL-related factor is transmitted in inter-frequency cell reselection information in the second other system information.

19. The base station of claim 18 , wherein the second other system information comprises a System Information Block 4 (SIB4) that includes the inter-frequency cell reselection information.

20. The base station of claim 15 , wherein the SUL-related factor is transmitted in inter-Radio Access Technology (inter-RAT) cell reselection information in the second other system information.