Devices and methods employing predictive back-off estimation schemes for SAR compliance

1. A device comprising a processor configured to:

estimate a congestion level of a communication channel, wherein the congestion level indicates an availability for transmissions over at least one time period;

determine a projected time back-off for an ensuing packet transmission based on the congestion level; and

determine whether to apply a transmission back-off based on the projected time back-off and a transmission energy budget based on at least one time-averaging specific absorption rate (TAS) parameter to regulate a radiation exposure.

2. The device of claim 1 , wherein the congestion level is estimated by at least one of:

estimating an average total back-off time for a number of packets waiting to be transmitted;

estimating a quantity of frames received from a network access node that are allocated for other wireless devices;

estimating a change in the number of packets waiting to be transmitted over time;

and/or decreasing a transmission rate of data packets and measuring a change in packet error rate (PER) based on the decreased transmission rate.

3. The device of claim 1 , wherein the projected time back-off is additionally based on at least one of:

a congestion estimation error indicating error margins in the congestion estimation, wherein the error margins factor into account a time-averaging window; or

a future estimation maximum time indicating an impact the at least one TAS parameter will have in upcoming energy estimations.

4. The device of claim 3 , wherein determining the projected time back-off comprises determining a minimum of:

a difference between the congestion level and the congestion estimation error; and

the future estimation maximum time.

5. The device of claim 1 , wherein the processor is configured to add the projected time back-off to a transmission energy budget to increase transmission energy available at a current time, wherein the transmission energy budget comprises an energy available for transmissions over a time window.

6. The device of claim 5 , wherein the least one TAS parameter to regulate the radiation exposure is to regulate the radiation exposure to a user, wherein at least one of the at least one TAS parameters comprises the time window or an average transmission power limit.

7. The device of claim 1 , wherein the projected time back-off adds energy to the transmission energy budget, wherein the transmission energy budget comprises an energy available for transmissions over a time window.

8. The device of claim 1 , wherein the processor is configured to determine whether a conversion of the transmission back-off is required if the transmission back-off comprises a requested power back-off, wherein the requested power back-off is converted into an equivalent requested time back-off based on an estimated energy saving for a packet duration over the air (OTA) that the requested power back-off would introduce.

9. The device of claim 8 , wherein the processor is configured to determine the equivalent requested time back-off based on a current transmission power, a target transmission power which would be induced by the requested power back-off, and the packet duration OTA.

10. A method comprising:

estimating a congestion level of a communication channel, wherein the congestion level indicates an availability for transmissions over at least one time period;

determining a projected time back-off for an ensuing packet transmission based on the congestion level; and

determining whether to apply a transmission back-off based on the projected time back-off and a transmission energy budget based on at least one time-averaging specific absorption rate (TAS) parameter to regulate a radiation exposure.

11. The method of claim 10 , further comprising estimating the congestion level by at least one of:

estimating an average total back-off time for a number of packets waiting to be transmitted;

estimating a quantity of frames received from a network access node that are allocated for other wireless devices;

estimating a change in the number of packets waiting to be transmitted over time; and/or

decreasing a transmission rate of data packets and measuring a change in packet error rate (PER) based on the decreased transmission rate.

12. The method of claim 10 , wherein the projected time back-off is additionally based on at least one of:

a congestion estimation error indicating error margins in the congestion estimation, wherein the error margins factor into account a time-averaging window; or

a future estimation maximum time indicating an impact the at least one of the TAS parameters will have in upcoming energy estimations.

13. The method of claim 12 , further comprising determining the projected time back-off by determining a minimum of:

a difference between the congestion level and the congestion estimation error; and

the future estimation maximum time.

14. The method of claim 10 , further comprising adding the projected time back-off to a transmission energy budget to increase transmission energy available at a current time, wherein the transmission energy budget comprises an energy available for transmissions over a time window.

15. The method of claim 14 , wherein the least one TAS parameter to regulate the radiation exposure is to regulate the radiation exposure to a user, wherein at least one of the at least one TAS parameters comprises the time window or an average transmission power limit.

16. The method of claim 10 , further comprising:

determining whether a conversion of the transmission back-off is required if the transmission back-off comprises a requested power back-off; and

converting the requested power back-off into an equivalent requested time back-off based on an estimated energy saving for a packet duration over the air (OTA) that the requested power back-off would introduce.

17. The method of claim 16 , further comprising:

determining the equivalent requested time back-off based on a current transmission power, a target transmission power which would be induced by the requested power back-off, and the packet duration OTA.

18. One or more non-transitory computer readable storage mediums with instructions stored thereon that, when executed by a processor of a device, cause the device to:

estimate a congestion level of a communication channel, wherein the congestion level indicates an availability for transmissions over at least one time period;

determine a projected time back-off for an ensuing packet transmission based on the congestion level; and

determine whether to apply a transmission back-off based on the projected time back-off and a transmission energy budget based on at least one time-averaging specific absorption rate (TAS) parameter to regulate a radiation exposure.

19. The one or more non-transitory computer readable storage mediums of claim 18 , further comprising instructions to cause the device to estimate the congestion level by at least one of:

estimating an average total back-off time for a number of packets waiting to be transmitted;

estimating a quantity of frames received from a network access node that are allocated for other wireless devices;

estimating a change in the number of packets waiting to be transmitted over time; and/or

decreasing a transmission rate of data packets and measuring a change in packet error rate (PER) based on the decreased transmission rate.

20. The one or more non-transitory computer readable storage mediums of claim 18 , further comprising instructions to cause the device to:

add the projected time back-off to a transmission energy budget to increase transmission energy available at a current time, wherein the transmission energy budget comprises an energy available for transmissions over a time window.