Method and apparatus for acquiring system information

1. A method for acquiring system information (SI) performed by a user equipment (UE), the method comprising:

performing a first set of operations after determining that the UE is in a radio resource control (RRC)_CONNECTED state with an active bandwidth part (BWP) not configured with a common search space (CSS) with a field searchSpaceOtherSystemInformation, the first set of operations comprising:

transmitting, to a cell, a first RRC message to request a required system information block (SIB) and starting a timer, after determining that (i) the required SIB is supported by the cell, (ii) the UE is allowed to request a SIB on-demand, and (iii) the timer is not running, and

receiving, from the cell, an RRCReconfiguration message including the required SIB; and

performing a second set of operations after determining that the UE is in the RRC_CONNECTED state with the active BWP configured with the CSS with the field searchSpaceOtherSystemInformation, the second set of operations comprising:

transmitting, to the cell, the first RRC message to request the required SIB and starting the timer, after determining that (i) the required SIB is not being broadcast in the cell, (ii) the UE is allowed to request the SIB on-demand, and (iii) the timer is not running; and

monitoring the CSS to acquire the required SIB.

2. The method of claim 1 , further comprising:

receiving, from the cell, a system information block type 1 (SIB1),

wherein the SIB1 indicates whether the required SIB is supported by the cell.

3. The method of claim 2 , wherein the SIB1 further indicates whether the required SIB is being broadcast in the cell.

4. The method of claim 1 , wherein the first set of operations further comprises:

monitoring a configured UE-specific search space in the active BWP for the reception of the RRCReconfiguration message after transmitting the first RRC message.

5. The method of claim 1 , wherein monitoring the CSS comprises:

monitoring the CSS for a downlink control information (DCI) format with cyclic redundancy check (CRC) scrambled by a system information radio network temporary identifier (SI-RNTI) to derive a resource for reception of the required SIB after transmitting the first RRC message.

6. The method of claim 1 , wherein the second set of operations further comprises:

stopping monitoring the CSS during an SI time window after acquiring the required SIB.

7. The method of claim 1 , further comprising:

receiving a second RRC message including an indicator that indicates whether the UE is allowed to request the SIB on-demand.

8. The method of claim 1 , further comprising:

stopping the timer after receiving the required SIB; and

receiving a second RRC message that indicates an initial value of the timer before transmitting the first RRC message,

wherein the UE is not allowed to transmit the first RRC message to request another SIB when the timer is running.

9. The method of claim 1 , wherein the first RRC message indicates at least one of a list of requested SIBs with ENUMERATED format or a list of requested positioning SIBs (posSIBs) with the ENUMERATED format.

10. The method of claim 1 , further comprising:

sending, by a radio link control (RLC) acknowledged mode (AM) entity of the UE, an RLC AM protocol data unit (PDU) that includes the first RRC message to a medium access control (MAC) entity of the UE in an uplink dedicated control channel (UL-DCCH) over signaling radio bearer 1 (SRB1).

11. A user equipment (UE) comprising:

one or more processors; and

at least one memory coupled to at least one of the one or more processors, wherein the at least one memory stores one or more computer-executable instructions that, when executed by the at least one of the one or more processors, cause the UE to:

perform a first set of operations after determining that the UE is in a radio resource control (RRC)_CONNECTED state with an active bandwidth part (BWP) not configured with a common search space (CSS) with a field searchSpaceOtherSystemInformation, the first set of operations comprising:

transmitting, to a cell, a first RRC message to request a required system information block (SIB) and starting a timer, after determining that (i) the required SIB is supported by the cell, (ii) the UE is allowed to request a SIB on-demand, and (iii) the timer is not running, and

receiving, from the cell, an RRCReconfiguration message including the required SIB; and

perform a second set of operations after determining that the UE is in the RRC_CONNECTED state with the active BWP configured with the CSS with the field searchSpaceOtherSystemInformation, the second set of operations comprising:

transmitting, to the cell, the first RRC message to request the required SIB and starting the timer, after determining that (i) the required SIB is not being broadcast in the cell, (ii) the UE is allowed to request the SIB on-demand, and (iii) the timer is not running; and

monitoring the CSS to acquire the required SIB.

12. The UE of claim 11 , wherein the one or more computer-executable instructions, when executed by the at least one of the one or more processors, further cause the UE to:

receive, from the cell, a system information block type 1 (SIB1),

wherein the SIB1 indicates whether the required SIB is supported by the cell.

13. The UE of claim 12 , wherein the SIB1 further indicates whether the required SIB is being broadcast in the cell.

14. The UE of claim 11 , wherein the first set of operations further comprises:

monitoring a configured UE-specific search space in the active BWP for the reception of the RRCReconfiguration message after transmitting the first RRC message.

15. The UE of claim 11 , wherein monitoring the CSS comprises:

monitoring the CSS for a downlink control information (DCI) format with cyclic redundancy check (CRC) scrambled by a system information radio network temporary identifier (SI-RNTI) to derive a resource for the reception of the required SIB after transmitting the first RRC message.

16. The UE of claim 11 , wherein the second set of operations further comprises:

stopping monitoring the CSS during a system information (SI) time window after acquiring the required SIB.

17. The UE of claim 11 , wherein the computer-executable program, when executed by the at least one of the one or more processors, further causes the UE to:

receive a second RRC message including an indicator that indicates whether the UE is allowed to request the SIB on-demand.

18. The UE of claim 11 , wherein the one or more computer-executable instructions, when executed by the at least one of the one or more processors, further cause the UE to:

stop the timer after receiving the required SIB; and

receive a second RRC message that indicates an initial value of the timer before transmitting the first RRC message,

wherein the UE is not allowed to transmit the first RRC message to request another SIB when the timer is running.

19. The UE of claim 11 , wherein the first RRC message indicates at least one of a list of requested SIBs with ENUMERATED format or a list of requested positioning SIBs (posSIBs) with the ENUMERATED format.

20. The UE of claim 11 , wherein the one or more computer-executable instructions, when executed by the at least one of the one or more processors, further cause the UE to:

send, by a radio link control (RLC) acknowledged mode (AM) entity of the UE, an RLC AM protocol data unit (PDU) that includes the first RRC message to a medium access control (MAC) entity of the UE in an uplink dedicated control channel (UL-DCCH) over signaling radio bearer 1 (SRB1).