Feedback for a system information request

1. An apparatus comprising:

a transmitter that transmits information indicating a request for system information, wherein the request for the system information comprises a request for system information that is only provided on-demand, the transmitted information comprises a physical random access channel preamble of a set of physical random access channel preambles that indicates the request for the on-demand system information, and each physical random access channel preamble of the set of physical random access channel preambles indicates specific system information; and

a processor that monitors, during a predetermined time period, for a feedback response acknowledging reception of the request for the system information, wherein the feedback response is part of a random access response message and comprises only a medium access control subheader without a medium access control payload for a random access response, and the medium access control subheader comprises a physical random access channel preamble identifier corresponding to the physical random access channel preamble.

2. The apparatus of claim 1 , further comprising a receiver that receives a system information block 1 containing scheduling information for the reception of system information messages.

3. The apparatus of claim 2 , further comprising, in response to receiving the feedback response, the receiver acquires the system information messages based on the scheduling information for the system information messages in the system information block 1 .

4. The apparatus of claim 1 , further comprising, in response to not receiving the feedback response:

the transmitter retransmits information indicating the request for the system information; and

the processor monitors, during the predetermined time period, for the feedback response indicating that the request for the system information was received.

5. The apparatus of claim 4 , wherein the transmitter retransmits the information using increased power.

6. The apparatus of claim 4 , wherein the transmitter repeats retransmitting information indicating the request for the system information up to a predetermined number of times.

7. The apparatus of claim 1 , wherein a radio network temporary identifier is used to indicate the feedback response.

8. The apparatus of claim 1 , wherein the feedback response is transmitted on a physical downlink shared channel.

9. The apparatus of claim 1 , wherein the request for system information that is only provided on-demand comprises information indicating a request for system information messages.

10. The apparatus of claim 1 , wherein the physical random access channel preamble is configured for an on-demand system information request and indicates the on-demand system information request for at least one system information message.

11. A method comprising:

transmitting information indicating a request for system information, wherein the request for the system information comprises a request for system information that is only provided on-demand, the transmitted information comprises a physical random access channel preamble of a set of physical random access channel preambles that indicates the request for the on-demand system information, and each physical random access channel preamble of the set of physical random access channel preambles indicates specific system information; and

monitoring, during a predetermined time period, for a feedback response acknowledging reception of the request for the system information, wherein the feedback response is part of a random access response message and comprises only a medium access control subheader without a medium access control payload for a random access response, and the medium access control subheader comprises a physical random access channel preamble identifier corresponding to the physical random access channel preamble.

12. The method of claim 11 , further comprising receiving a system information block 1 containing scheduling information for the reception of system information messages.

13. The method of claim 12 , further comprising, in response to receiving the feedback response, acquiring the system information messages based on the scheduling information for the system information messages in the system information block 1 .

14. The method of claim 11 , further comprising, in response to not receiving the feedback response:

retransmitting information indicating the request for the system information; and

monitoring, during the predetermined time period, for the feedback response indicating that the request for the system information was received.

15. The method of claim 14 , wherein retransmitting the information indicating the request for the system information comprises retransmitting the information using increased power.

16. The method of claim 14 , wherein retransmitting information indicating the request for the system information comprises repeating retransmitting information indicating the request for the system information up to a predetermined number of times.

17. The method of claim 11 , wherein a radio network temporary identifier is used to indicate the feedback response.

18. The method of claim 11 , wherein the feedback response is transmitted on a physical downlink shared channel.

19. The method of claim 11 , wherein the request for system information that is only provided on-demand comprises information indicating a request for system information messages.

20. The method of claim 11 , wherein the physical random access channel preamble is configured for an on-demand system information request and indicates the on-demand system information request for at least one system information message.

21. An apparatus comprising:

a receiver that receives information indicating a request for system information, wherein the request for the system information comprises a request for system information that is only provided on-demand, the received information comprises a physical random access channel preamble of a set of physical random access channel preambles that indicates the request for the on-demand system information, and each physical random access channel preamble of the set of physical random access channel preambles indicates specific system information; and

a transmitter that transmits a feedback response acknowledging reception of the request for the system information, wherein the feedback response is part of a random access response message and comprises only a medium access control subheader without a medium access control payload for a random access response, and the medium access control subheader comprises a physical random access channel preamble identifier corresponding to the physical random access channel preamble.

22. The apparatus of claim 21 , further comprising the transmitter transmitting a system information block 1 containing scheduling information for the reception of system information messages.

23. The apparatus of claim 22 , further comprising the transmitter transmitting the system information messages based on the scheduling information for the system information messages in the system information block 1 .

24. The apparatus of claim 21 , wherein a radio network temporary identifier is used to indicate the feedback response.

25. The apparatus of claim 21 , wherein the feedback response is transmitted on a physical downlink shared channel.

26. The apparatus of claim 21 , wherein the request for system information that is only provided on-demand comprises information indicating a request for system information messages.

27. The apparatus of claim 21 , wherein the physical random access channel preamble is configured for an on-demand system information request and indicates the on-demand system information request for at least one system information message.

28. A method comprising:

receiving information indicating a request for system information, wherein the request for the system information comprises a request for system information that is only provided on-demand, the received information comprises a physical random access channel preamble of a set of physical random access channel preambles that indicates the request for the on-demand system information, and each physical random access channel preamble of the set of physical random access channel preambles indicates specific system information; and

transmitting a feedback response acknowledging reception of the request for the system information, wherein the feedback response is part of a random access response message and comprises only a medium access control subheader without a medium access control payload for a random access response, and the medium access control subheader comprises a physical random access channel preamble identifier corresponding to the physical random access channel preamble.

29. The method of claim 28 , further comprising transmitting a system information block 1 containing scheduling information for the reception of system information messages.

30. The method of claim 29 , further comprising transmitting the system information messages based on the scheduling information for the system information messages in the system information block 1 .

31. The method of claim 28 , wherein a radio network temporary identifier is used to indicate the feedback response.

32. The method of claim 28 , wherein the feedback response is transmitted on a physical downlink shared channel.

33. The method of claim 28 , wherein the request for system information that is only provided on-demand comprises information indicating a request for system information messages.

34. The method of claim 28 , wherein the physical random access channel preamble is configured for an on-demand system information request and indicates the on-demand system information request for at least one system information message.