Wireless communication between wideband ENB and narrowband UE

1. A method of wireless communication at a base station, comprising:

performing a dual clear channel assessment (CCA) procedure for a frame prior to transmitting a transmission, wherein the dual CCA procedure comprises CCA followed by a first extended CCA (eCCA) when the CCA is unsuccessful;

transmitting the transmission during the frame when at least one CCA procedure of the dual CCA procedure is successful;

refraining from transmitting during the frame when both CCA procedures of the dual CCA procedure are unsuccessful; and

when the CCA and the first eCCA of the dual CCA procedure are unsuccessful:

waiting until a next CCA location at a next frame boundary following the frame in which the CCA and the first eCCA are performed; and

performing a second eCCA at the next CCA location prior to transmitting the transmission, wherein the second eCCA comprises a next eCCA following the dual CCA procedure and is performed at the next CCA location without performing a new CCA at the next CCA location.

2. The method of claim 1 , wherein performing the dual CCA procedure comprises:

performing the CCA for a first period of time; and

performing the first eCCA for a second period of time following the CCA, when the CCA is unsuccessful.

3. The method of claim 2 , wherein the second period of time is longer than the first period of time.

4. The method of claim 1 , further comprising:

transmitting a reservation signal when the CCA is successful; and

transmitting the transmission following the reservation signal.

5. The method of claim 1 , further comprising:

transmitting a reservation signal when the first eCCA or the second eCCA is successful; and

transmitting the transmission following the reservation signal.

6. The method of claim 1 , wherein a first transmission time corresponding to the CCA is independent of a first duration of the CCA and a second transmission time corresponding to the first eCCA or the second eCCA is based on a second duration of the first eCCA or the second eCCA.

7. The method of claim 1 , wherein the dual CCA procedure is performed when the base station transmitted on a previous frame or prior to the base station transmitting the frame as a first frame on a frequency.

8. The method of claim 1 , wherein the wireless communication comprises enhanced machine type communication (eMTC).

9. An apparatus for wireless communication at a base station comprising:

means for performing a dual clear channel assessment (CCA) procedure for a frame prior to transmitting a transmission, wherein the dual CCA procedure comprises CCA followed by a first extended CCA (eCCA) when the CCA is unsuccessful;

means for transmitting the transmission during the frame when at least one CCA procedure of the dual CCA procedure is successful; and

means for refraining from transmitting during the frame when both CCA procedures of the dual CCA procedure are unsuccessful, wherein when the CCA and the first eCCA of the dual CCA procedure are unsuccessful:

the means for refraining waits until a next CCA location at a next frame boundary following the frame in which the CCA and the first eCCA are performed, and

the means for performing a dual CCA procedure performs a second eCCA at the next CCA location prior to transmitting the transmission, wherein the second eCCA comprises a next eCCA following the dual CCA procedure and is performed at the next CCA location without performing a new CCA at the next CCA location.

10. The apparatus of claim 9 , wherein the means for performing the dual CCA procedure performs the CCA for a first period of time and performs the first eCCA for a second period of time following the CCA, when the CCA is unsuccessful.

11. The apparatus of claim 10 , wherein the second period of time is longer than the first period of time.

12. The apparatus of claim 9 , wherein the means for transmitting transmits a reservation signal when the CCA is successful and transmits the transmission following the reservation signal.

13. The apparatus of claim 9 , wherein the means for transmitting transmits a reservation signal when the first eCCA or the second eCCA is successful and transmits the transmission following the reservation signal.

14. The apparatus of claim 9 , wherein a first transmission time corresponding to the CCA is independent of a first duration of the CCA and a second transmission time corresponding to the first eCCA or the second eCCA is based on a second duration of the first eCCA or the second eCCA.

15. The apparatus of claim 9 , wherein the dual CCA procedure is performed when the base station transmitted on a previous frame or prior to the base station transmitting the frame as a first frame on a frequency.

16. The apparatus of claim 9 , wherein the wireless communication comprises enhanced machine type communication (eMTC).

17. An apparatus for wireless communication at a base station comprising:

a memory; and

at least one processor coupled to the memory and configured to:

perform a dual clear channel assessment (CCA) procedure for a frame prior to transmitting a transmission, wherein the dual CCA procedure comprises CCA followed by a first extended CCA (eCCA) when the CCA is unsuccessful;

transmit the transmission during the frame when at least one CCA procedure of the dual CCA procedure is successful;

refrain from transmitting during the frame when both CCA procedures of the dual CCA procedure are unsuccessful; and

when the CCA and the first eCCA of the dual CCA procedure are unsuccessful:

wait until a next CCA location at a next frame boundary following the frame in which the CCA and the first eCCA are performed; and

perform a second eCCA at the next CCA location prior to transmitting the transmission, wherein the second eCCA comprises a next eCCA following the dual CCA procedure and is performed at the next CCA location without performing a new CCA at the next CCA location.

18. The apparatus of claim 17 , wherein performing the dual CCA procedure comprises:

performing the CCA for a first period of time; and

performing the first eCCA for a second period of time following the CCA, when the CCA is unsuccessful.

19. The apparatus of claim 18 , wherein the second period of time is longer than the first period of time.

20. The apparatus of claim 17 , wherein the at least one processor is further configured to:

transmit a reservation signal when the CCA is successful; and

transmit the transmission following the reservation signal.

21. The apparatus of claim 17 , wherein the at least one processor is further configured to:

transmit a reservation signal when the first eCCA or the second eCCA is successful; and

transmit the transmission following the reservation signal.

22. The apparatus of claim 17 , wherein a first transmission time corresponding to the CCA is independent of a first duration of the CCA and a second transmission time corresponding to the first eCCA or the second eCCA is based on a second duration of the first eCCA or the second eCCA.

23. The apparatus of claim 17 , wherein the dual CCA procedure is performed when the base station transmitted on a previous frame or prior to the base station transmitting the frame as a first frame on a frequency.

24. The apparatus of claim 17 , wherein the wireless communication comprises enhanced machine type communication (eMTC).

25. A non-transitory computer-readable medium storing computer executable code for wireless communication at a base station, comprising code to:

perform a dual clear channel assessment (CCA) procedure for a frame prior to transmitting a transmission, wherein the dual CCA procedure comprises CCA followed by a first extended CCA (eCCA) when the CCA is unsuccessful;

transmit the transmission during the frame when at least one CCA procedure of the dual CCA procedure is successful;

refrain from transmitting during the frame when both CCA procedures of the dual CCA procedure are unsuccessful; and

when the CCA and the first eCCA of the dual CCA procedure are unsuccessful:

wait until a next CCA location at a next frame boundary following the frame in which the CCA and the first eCCA are performed; and

perform a second eCCA at the next CCA location prior to transmitting the transmission, wherein the second eCCA comprises a next eCCA following the dual CCA procedure and is performed at the next CCA location without performing a new CCA at the next CCA location.

26. The non-transitory computer-readable medium of claim 25 , wherein performing the dual CCA procedure comprises:

performing the CCA for a first period of time; and

performing the first eCCA for a second period of time following the CCA, when the CCA is unsuccessful.

27. The non-transitory computer-readable medium of claim 26 , wherein the second period of time is longer than the first period of time.

28. The non-transitory computer-readable medium of claim 25 , further comprising code to:

transmit a reservation signal when the CCA is successful; and

transmit the transmission following the reservation signal.

29. The non-transitory computer-readable medium of claim 25 , further comprising code to:

transmit a reservation signal when the first eCCA or the second eCCA is successful; and

transmit the transmission following the reservation signal.

30. The non-transitory computer-readable medium of claim 25 , wherein a first transmission time corresponding to the CCA procedure is independent of a first duration of the CCA and a second transmission time corresponding to the first eCCA or the second eCCA is based on a second duration of the first eCCA or the second eCCA.

31. The non-transitory computer-readable medium of claim 25 , wherein the dual CCA procedure is performed when the base station transmitted on a previous frame or prior to the base station transmitting the frame as a first frame on a frequency.

32. The non-transitory computer-readable medium of claim 25 , wherein the wireless communication comprises enhanced machine type communication (eMTC).

33. The method of claim 1 , further comprising transmitting the transmission during the frame when the second eCCA is successful.

34. The apparatus of claim 9 , wherein the means for transmitting transmits the transmission during the frame when the second eCCA is successful.

35. The apparatus of claim 17 , wherein the at least one processor is further configured to transmit the transmission during the frame when the second eCCA is successful.

36. The non-transitory computer-readable medium of claim 25 , further comprising code to transmit the transmission during the frame when the second eCCA is successful.