Techniques for controlling specific absorption rate of radio energy transmission

1. A radio device, comprising:

a plurality of radio entities configured to transmit radio energy; and

a controller configured to control the radio energy transmission of the plurality of radio entities to comply with a predefined Specific Absorption Rate (SAR) requirement, to assign time quotas to the plurality of radio entities over multiple time windows,

wherein the controller is configured to enable at least two radio entities of the plurality of radio entities operating concurrently based on a shared SAR transmission power restriction which allows the at least two radio entities transmitting concurrently up to a 100% duty cycle without violating the SAR requirement.

2. The radio device of claim 1 ,

wherein the controller is further configured to enable at least one radio entity of the plurality of radio entities operating in stand-alone mode based on a stand-alone SAR transmission power restriction which allows the at least one radio entity transmitting up to the 100% duty cycle without violating the SAR requirement.

3. The radio device of claim 1 ,

wherein the shared SAR transmission power restriction is based on a SAR budgeting scheme.

4. The radio device of claim 1 ,

wherein the shared SAR transmission power restriction is configured to restrict cumulative transmission times of the at least two radio entities within a specific time window to predefined quotas.

5. The radio device of claim 4 ,

wherein the predefined quotas are specified as percentage values of the specific time window.

6. The radio device of claim 4 ,

wherein the specific time window is less than a period over which the SAR requirement is defined.

7. The radio device of claim 4 ,

wherein the controller is configured to assign transmission power quotas to the plurality of radio entities.

8. The radio device of claim 1 ,

wherein the controller is configured to stop an ongoing transmission of at least one radio entity in order to allow at least another radio entity to commence transmitting and still meeting the SAR requirement.

9. A radio device, comprising:

a plurality of radio entities configured to transmit radio energy;

a concurrency detection circuit configured to detect concurrent transmissions of at least two radio entities of the plurality of radio entities; and

a transmission arbitration circuit configured to disable transmission of at least one radio entity of the at least two concurrently transmitting radio entities based on a concurrency criterion based in time quotas assigned to the plurality of radio entities over multiple time windows.

10. The radio device of claim 9 ,

wherein the concurrency criterion is based on a Specific Absorption Rate, SAR, requirement.

11. The radio device of claim 9 ,

wherein the concurrency detection circuit is configured to count concurrent transmissions of the at least two radio entities within a measurement interval.

12. The radio device of claim 9 ,

wherein the concurrency detection circuit is configured to relate to a Tx power weighted list of concurrent transmissions of the at least two radio entities within a measurement interval.

13. The radio device of claim 12 ,

wherein the concurrency detection circuit is configured to indicate a concurrency allowance to the transmission arbitration circuit if the counted concurrent transmissions are below a threshold.

14. The radio device of claim 13 ,

wherein the transmission arbitration circuit is configured to disable transmission of the at least one radio entity of the at least two concurrently transmitting radio entities if the concurrency detection circuit stops indicating concurrency allowance.

15. The radio device of claim 9 ,

wherein the transmission arbitration circuit is configured to disable transmission of the at least one radio entity of the at least two concurrently transmitting radio entities based on priorities of the at least two concurrently transmitting radio entities.

16. The radio device of claim 15 ,

wherein the priorities are based on strict priority to one of the radio entities, strict priority based on access category and/or Round Robin between the radio entities.

17. A method for controlling radio energy transmission of a plurality of radio entities to comply with a predefined Specific Absorption Rate, SAR, requirement, the method comprising:

enabling at least two radio entities of the plurality of radio entities operating concurrently based on a shared SAR transmission power restriction which allows the at least two radio entities transmitting concurrently up to a 100% duty cycle without violating the SAR requirement; and

assigning time quotas to the plurality of radio entities over multiple time windows.

18. The method of claim 17 , comprising:

enabling at least one radio entity of the plurality of radio entities operating in stand-alone mode based on a stand-alone SAR transmission power restriction which allows the at least one radio entity transmitting at a up to the 100% duty cycle without violating the SAR requirement.

19. The method of claim 17 ,

wherein the shared SAR transmission power restriction is based on a SAR budgeting scheme.

20. The method of claim 17 , comprising:

restricting cumulative transmission times of the at least two radio entities within a specific time window to predefined quotas.

21. The method of claim 20 ,

wherein the predefined quotas are specified as percentage values of the specific time window.

22. The method of claim 20 ,

wherein the specific time window is less than a period over which the SAR requirement is defined.