System information requesting method, corresponding user equipment, and computer-readable medium

1. A method for providing System Information (SI), the method comprising:

transmitting information about first associations between a plurality of preamble sequences and a plurality of pieces of SI, and about second associations between the pieces of SI and a plurality of system information blocks (SIBs);

receiving a preamble from a user equipment (UE), wherein the preamble includes one of the preamble sequences;

identifying one of the SIBs based on the one of the preamble sequences, the first associations, and the second associations, wherein the one of the SIBs is included in one of the pieces of SI associated with the one of the preamble sequences; and

transmitting the one of the SIBs to the UE.

2. The method of claim 1 , wherein the one of the pieces of SI is required by a Radio Resource Control (RRC) layer of the UE.

3. The method of claim 1 , wherein the one of the preamble sequences is used for acquiring SI or for handover.

4. The method of claim 1 , wherein the one of the preamble sequences indicates an SI request.

5. The method of claim 1 , wherein:

the one of the SIBs is a first SIB, wherein the first SIB is a first one of the SIBs;

the one of the pieces of SI is associated with the first SIB and a second SIB, wherein the second SIB is a second one of the SIBs; and

the first SIB and the second SIB have a same scheduling period.

6. The method of claim 1 , wherein identifying the one of the SIBs based on the one of the preamble sequences, the first associations, and the second associations comprises:

determining the one of the pieces of SI based on the one of the preamble sequences and the first associations; and

selecting the one of the SIBs based on the one of the pieces of SI and the second associations.

7. The method of claim 1 , wherein the one of the preamble sequences is selected based on a piece of SI required by the UE, the first associations, and the second associations.

8. A base station (BS), comprising:

a memory storing instructions; and

at least one processor configured to execute the instructions to cause the BS to:

transmit information about first associations between a plurality of preamble sequences and a plurality of pieces of SI, and about second associations between the pieces of SI and a plurality of system information blocks (SIBs);

receive a preamble from a user equipment (UE), wherein the preamble includes one of the preamble sequences;

identify one of the SIBs based on the one of the preamble sequences, the first associations, and the second associations, wherein the one of the SIBs is included in one of the pieces of SI associated with the one of the preamble sequences; and

transmit the one of the SIBs to the UE.

9. The BS of claim 8 , wherein the one of the pieces of SI is required by a Radio Resource Control (RRC) layer of the UE.

10. The BS of claim 8 , wherein the one of the preamble sequences is used for acquiring SI or for handover.

11. The BS of claim 8 , wherein the one of the preamble sequences indicates an SI request.

12. The BS of claim 8 , wherein:

the one of the SIBs is a first SIB, wherein the first SIB is a first one of the SIBs;

the one of the pieces of SI is associated with the first SIB and a second SIB, wherein the second SIB is a second one of the SIBs; and

the first SIB and the second SIB have a same scheduling period.

13. The BS of claim 8 , wherein the at least one processor is configured to execute the instructions to cause the BS to identify the one of the SIBs based on the one of the preamble sequences, the first associations, and the second associations by:

determining the one of the pieces of SI based on the one of the preamble sequences and the first associations; and

selecting the one of the SIBs based on the one of the pieces of SI and the second associations.

14. The BS of claim 8 , wherein the one of the preamble sequences is selected based on a piece of SI required by the UE, the first associations, and the second associations.

15. A user equipment (UE), comprising:

a memory storing instructions; and

a processor configured to execute the instructions to cause the UE to:

trigger a medium access control (MAC) layer to initiate a random access procedure for transmitting a preamble, wherein the preamble corresponds to a piece of system information (SI), wherein the piece of SI is required by a radio resource control (RRC) layer of the UE;

receive, in the RRC layer, an indication from the MAC layer;

acquire, in the RRC layer, the piece of SI required by the RRC layer of the UE when the indication is received from the MAC layer;

receive information about a plurality of preamble sequences, a plurality of pieces of SI, and a plurality of system information blocks (SIBs), wherein:

a first one of the pieces of SI is required by the UE,

a second one of the pieces of SI is associated with two of the SIBs, and

the two of the SIBs have a same scheduling period;

select one of the preamble sequences based on the information and the first one of the pieces of SI required by the UE; and

transmit the selected one of the preamble sequences as the preamble to a base station.

16. The UE according to claim 15 , wherein the processor is further configured to execute the instructions to cause the UE to:

determine, in the MAC layer, whether the one of the preamble sequences is used for acquiring SI or for handover.

17. The UE according to claim 15 , wherein the indication comprises an acknowledgement for an SI request.