Random access procedure for machine type communication

1. A method, comprising:

transmitting a physical random access channel (PRACH) preamble on a first time-frequency resource;

monitoring a second time-frequency resource for a first downlink (DL) grant scheduling a random access response (RAR) corresponding to the transmitted PRACH preamble on a third time-frequency resource;

receiving the RAR on the third time-frequency resource;

transmitting a connection request message on a fourth time-frequency resource, wherein the fourth time-frequency resource is determined based on the RAR;

determining a fifth time-frequency resource based on a time-frequency resource index, wherein the RAR includes the time-frequency resource index; and

monitoring the fifth time-frequency resource for a second DL grant scheduling a contention resolution message.

2. The method of claim 1 , wherein the time-frequency resource index comprises a time-delay index.

3. The method of claim 2 , further comprising:

initiating a contention resolution timer after an amount of delay based on the time-delay index.

4. The method of claim 2 , wherein the time-delay index indicates a number of subframes, and wherein the fifth time-frequency resource starts at least the indicated number of subframes after a last subframe in the fourth time-frequency resource.

5. The method of claim 4 , wherein the second and fifth time-frequency resources have the same frequency resource.

6. The method of claim 1 , wherein the time-frequency resource index comprises a frequency index, and wherein the frequency resource of the fifth time-frequency resource is indicated by the frequency index.

7. The method of claim 6 , wherein the time-frequency resource index comprises a time-delay index, wherein the time-delay index indicates a number of subframes, and wherein the fifth time-frequency resource starts at least the indicated number of subframes after a last subframe in the fourth time-frequency resource.

8. The method of claim 1 , wherein the RAR includes a field containing the time-frequency index.

9. A device comprising:

a radio transceiver that communicates over a mobile telecommunications network; and

a processor configured to:

control the radio transceiver to transmit a physical random access channel (PRACH) preamble on a first time-frequency resource;

monitor a second time-frequency resource for a first downlink (DL) grant scheduling a random access response (RAR) corresponding to the transmitted PRACH preamble on a third time-frequency resource;

control the radio transceiver to receive the RAR on the third time-frequency resource;

control the radio transceiver to transmit a connection request message on a fourth time-frequency resource, wherein the fourth time-frequency resource is determined based on the RAR;

determine a fifth time-frequency resource based on a time-frequency resource index, wherein the RAR includes the time-frequency resource index; and

monitor the fifth time-frequency resource for a second DL grant scheduling a contention resolution message.

10. The device of claim 9 , wherein the time-frequency resource index comprises a time-delay index.

11. The device of claim 10 , wherein the processor is further configured to:

initiate a contention resolution timer after an amount of delay based on the time-delay index.

12. The device of claim 10 , wherein the time-delay index indicates a number of subframes, and wherein the fifth time-frequency resource starts at least the indicated number of subframes after a last subframe in the fourth time-frequency resource.

13. The device of claim 12 , wherein the second and fifth time-frequency resources have the same frequency resource.

14. The device of claim 9 , wherein the time-frequency resource index comprises a frequency index, and wherein the frequency resource of the fifth time-frequency resource is indicated by the frequency index.

15. The device of claim 14 , wherein the time-frequency resource index comprises a time-delay index, wherein the time-delay index indicates a number of subframes, and wherein the fifth time-frequency resource starts at least the indicated number of subframes after a last subframe in the fourth time-frequency resource.

16. The device of claim 9 , wherein the RAR includes a field containing the time-frequency index.

17. A method, comprising:

receiving at least one physical random access channel (PRACH) preamble on a first time-frequency resource;

determining a time-frequency resource index;

transmitting a first downlink (DL) grant on a second time-frequency resource, the first DL grant scheduling a random access response (RAR) corresponding to the received PRACH preamble on a third time-frequency resource, wherein the RAR comprises the time-frequency resource index;

receiving a connection request message on a fourth time-frequency resource, wherein the fourth time-frequency resource is determined based on the RAR; and

transmitting a second DL grant on a fifth time-frequency resource, the second DL grant scheduling a contention resolution message, wherein the fifth time-frequency resource is based on the time-frequency resource index.

18. The method of claim 17 , wherein the time-frequency resource index comprises a frequency index, and wherein the frequency resource of the fifth time-frequency resource is indicated by the frequency index.

19. The method of claim 17 , wherein the time-frequency resource index comprises a time-delay index, wherein the time-delay index indicates a number of subframes, and wherein the fifth time-frequency resource starts at least the indicated number of subframes after a last subframe in the fourth time-frequency resource.

20. The method of claim 17 , wherein the RAR includes a field containing the time-frequency index.