Reporting power headroom for aggregated carriers

1. A method at an access node for a wireless telecommunications system, the method comprising:

receiving, from a user agent (UA), power headroom-related information for a number of aggregated carriers, the power headroom-related information including a bitmap,

wherein each bit in the bitmap corresponds to one of the aggregated carriers, one value in the bitmap indicating that the power headroom-related information for a corresponding carrier is being transmitted, and another value in the bitmap indicating that the power headroom-related information for a corresponding carrier is not being transmitted, and

wherein the power headroom-related information comprises one of power headroom and path loss information for at least one of the aggregated carriers.

2. The method of claim 1 , wherein the power headroom-related information is received for a representative carrier in a frequency band, the representative carrier being one of the aggregated carriers, and wherein the representative carrier is selected based on a rule known by the access node and the UA from which the access node receives the power headroom-related information.

3. The method of claim 1 , wherein the power headroom-related information is received as a result of one of:

a difference in path loss between consecutive measurements of path loss for one of the carriers exceeding a threshold;

a transmission on a carrier's physical uplink shared channel being scheduled; and

a power headroom for a carrier exceeding a threshold.

4. The method of claim 1 , wherein a physical uplink control channel (PUCCH) related power headroom is received when power headroom reporting is triggered and a physical uplink shared channel (PUSCH) resource is scheduled.

5. The method of claim 4 , wherein, when the PUCCH is received in the same subframe in which the PUCCH related power headroom is reported, the PUCCH related power headroom is calculated based on an actual transmit power of the PUCCH.

6. An access node, for a wireless telecommunications system, comprising a memory device and a processor configured to execute instructions stored on the memory device such that when executed, cause the access node to:

receive, from a user agent (UA), power headroom-related information for a number of aggregated carriers, the power headroom-related information including a bitmap,

wherein each bit in the bitmap corresponds to one of the aggregated carriers, one value in the bitmap indicating that the power headroom-related information for a corresponding carrier is being transmitted, and another value in the bitmap indicating that the power headroom-related information for a corresponding carrier is not being transmitted, and

wherein the power headroom-related information comprises one of power headroom and path loss information, for at least one of the aggregated carriers.

7. The access node of claim 6 , wherein the power headroom-related information is received for a representative carrier in a frequency band, the representative carrier being one of the aggregated carriers, and wherein the representative carrier is selected based on a rule known by the access node and the UA from which the access node receives the power headroom-related information.

8. The access node of claim 6 , wherein the power headroom-related information is received as a result of one of:

a difference in path loss between consecutive measurements of path loss for one of the carriers exceeding a threshold;

a transmission on a carrier's physical uplink shared channel being scheduled; and

a power headroom for a carrier exceeding a threshold.

9. The access node of claim 6 , wherein a physical uplink control channel (PUCCH) related power headroom is received when power headroom reporting is triggered and a physical uplink shared channel (PUSCH) resource is scheduled.

10. The access node of claim 9 , wherein, when the PUCCH is received in the same subframe in which the PUCCH related power headroom is reported, the PUCCH related power headroom is calculated based on an actual transmit power of the PUCCH.

11. A non-transitory computer-readable medium containing instructions which, when executed by an access node, for a wireless telecommunications system, cause the access node to:

receive, from a user agent (UA), power headroom-related information for a number of aggregated carriers, the power headroom-related information including a bitmap,

wherein each bit in the bitmap corresponds to one of the aggregated carriers, one value in the bitmap indicating that the power headroom-related information for a corresponding carrier is being transmitted, and another value in the bitmap indicating that the power headroom-related information for a corresponding carrier is not being transmitted, and

wherein the power headroom-related information comprises one of power headroom and path loss information, for at least one of the aggregated carriers.

12. The non-transitory computer-readable medium of claim 11 , wherein the power headroom-related information is received for a representative carrier in a frequency band, the representative carrier being one of the aggregated carriers, and wherein the representative carrier is selected based on a rule known by the access node and the UA from which the access node receives the power headroom-related information.

13. The non-transitory computer-readable medium of claim 11 , wherein the power headroom-related information is received as a result of one of:

a difference in path loss between consecutive measurements of path loss for one of the carriers exceeding a threshold;

a transmission on a carrier's physical uplink shared channel being scheduled; and

a power headroom for a carrier exceeding a threshold.

14. The non-transitory computer-readable medium of claim 11 , wherein a physical uplink control channel (PUCCH) related power headroom is received when power headroom reporting is triggered and a physical uplink shared channel (PUSCH) resource is scheduled.

15. The non-transitory computer-readable medium of claim 14 , wherein, when the PUCCH is received in the same subframe in which the PUCCH related power headroom is reported, the PUCCH related power headroom is calculated based on an actual transmit power of the PUCCH.

16. A method at a user agent (UA), comprising:

transmitting, to an access node for a wireless telecommunications system, power headroom-related information for a number of aggregated carriers, the power headroom-related information including a bitmap,

wherein the power headroom-related information comprises one of power headroom and path loss information, for at least one of the aggregated carriers, and

wherein each bit in the bitmap corresponds to one of the aggregated carriers, one value in the bitmap indicating that the power headroom-related information for a corresponding carrier is being transmitted, and another value in the bitmap indicating that the power headroom-related information for a corresponding carrier is not being transmitted.

17. The method of claim 16 , wherein the UA transmits the power headroom-related information to the access node as a result of one of:

a difference in path loss between consecutive measurements of path loss for one of the carriers exceeding a threshold;

a transmission on a carrier's physical uplink shared channel being scheduled; and

a power headroom for a carrier exceeding a threshold.

18. A user agent (UA) comprising a memory device and a processor configured to execute instructions stored on the memory device such that when executed, cause the UA to:

transmit, to an access node for a wireless telecommunications system, power headroom-related information for a number of aggregated carriers, the power headroom-related information including a bitmap,

wherein the power headroom-related information comprises one of power headroom and path loss information, for at least one of the aggregated carriers, and

wherein each bit in the bitmap corresponds to one of the aggregated carriers, one value in the bitmap indicating that the power headroom-related information for a corresponding carrier is being transmitted, and another value in the bitmap indicating that the power headroom-related information for a corresponding carrier is not being transmitted.

19. The UA of claim 18 , wherein the UA transmits the power headroom-related information to the access node as a result of one of:

a difference in path loss between consecutive measurements of path loss for one of the carriers exceeding a threshold;

a transmission on a carrier's physical uplink shared channel being scheduled; and

a power headroom for a carrier exceeding a threshold.

20. The UA of claim 18 , wherein the UA receives information, from the access node, about a specified set of carriers for which the power headroom-related information is to be reported.