Radio frequency exposure compliance for transitions between exposure control schemes

1 . A method of wireless communication by a wireless device, the method comprising:

obtaining radio frequency (RF) exposure information associated with a first RF exposure control scheme, wherein the RF exposure information associated with the RF exposure control scheme includes a length of a time-averaging window for the first RF exposure control scheme, and wherein the first RF exposure control scheme is associated with one or more first radios;

transitioning to transmitting a first signal via one or more second radios associated with a second RF exposure control scheme;

during a duration corresponding to the length of the time-averaging window for the first RF exposure control scheme, transmitting the first signal via the one or more second radios associated with the second RF exposure control scheme at a reduced RF exposure level based at least in part on the RF exposure information, wherein the one or more first radios are different than the one or more second radios; and

after the duration corresponding to the length of the time-averaging window for the first RF exposure control scheme, transmitting via the one or more second radios at an RF exposure level according to the second RF exposure scheme.

2 . The method of claim 1 , wherein the first RF exposure control scheme is associated with a different radio access technology than the second RF exposure control scheme.

3 . The method of claim 1 , wherein the first RF exposure control scheme applies a different mode of RF exposure compliance than the second RF exposure control scheme.

4 . The method of claim 1 , wherein the RF exposure information includes on-off information of the one or more first radios associated with the first RF exposure control scheme.

5 . The method of claim 4 , wherein the on-off information indicates:

a first time corresponding to when the one or more first radios associated with the first RF exposure control scheme were operating,

a second time corresponding to when the one or more first radios associated with the first RF exposure control scheme were not operating, or

a combination thereof.

6 . The method of claim 4 , further comprising:

determining, based on the on-off information of the one or more first radios associated with the first RF exposure control scheme, a duration that the one or more first radios associated with the first RF exposure control scheme were operating;

assuming an exposure level at which the one or more first radios were operating during the determined duration that the one or more first radios associated with the first RF exposure control scheme were operating; and

determining the reduced RF exposure level based at least in part on the assumed exposure level.

7 . The method of claim 6 , wherein the exposure level is a maximum exposure level that satisfies a time-averaged RF exposure limit for the determined duration that the one or more first radios associated with the first RF exposure control scheme were operating.

8 . The method of claim 1 , further comprising:

when the RF exposure information indicates the wireless device is transmitting in a standalone mode via the one or more second radios associated with the second RF exposure control scheme, determining the reduced RF exposure level to be in compliance with an exposure margin associated with the second RF exposure control scheme;

when the RF exposure information indicates the wireless device transitioned from transmitting via the one or more first radios associated with the first RF exposure control scheme to transmitting via the one or more second radios associated with the second RF exposure control scheme, determining the reduced RF exposure level to be in compliance with a first control level;

when the RF exposure information indicates the wireless device transitioned from transmitting via the one or more first radios associated with the first RF exposure control scheme to transmitting via the one or more first radios associated with the first RF exposure control scheme and the one or more second radios associated with the second RF exposure control scheme, determining the reduced RF exposure level to be in compliance with a second control level, wherein the second control level is less than the first control level; and

when the RF exposure information indicates the wireless device transitioned from transmitting via the one or more first radios associated with the first RF exposure control scheme and the one or more second radios associated with the second RF exposure control scheme to transmitting via the one or more second radios associated with the second RF exposure control scheme, determining the reduced RF exposure level to be in compliance with the first control level.

9 . The method of claim 1 , wherein the RF exposure information includes a time variation of RF exposure used by the first RF exposure control scheme over a past time-averaging time window.

10 . The method of claim 1 , wherein the RF exposure information includes an indication of an RF exposure margin used by the first RF exposure control scheme.

11 . The method of claim 1 , wherein the RF exposure information includes an indication of a first limit for transmitting via the one or more second radios associated with the second RF exposure control scheme.

12 . The method of claim 11 , wherein the first limit is a remaining RF exposure margin determined as a difference of a value and an RF exposure margin used by the first RF exposure control scheme.

13 . The method of claim 11 , further comprising:

determining a smallest value among the first limit and a second RF exposure margin associated with the second RF exposure control scheme; and

determining the reduced RF exposure level based at least in part on the smallest value.

14 . The method of claim 1 , further comprising:

obtaining a first maximum time-averaged transmit power level, a second maximum time-averaged transmit power level, and a scaling factor, wherein the second maximum time-averaged transmit power level is less than the first maximum time-averaged transmit power level; and

determining the reduced RF exposure level based at least in part on the RF exposure information, the first maximum time-averaged transmit power level, the second maximum time-averaged transmit power level, and the scaling factor.

15 . The method of claim 14 , further comprising:

determining a first control level as a product of the first maximum time-averaged transmit power level and the scaling factor;

determining a second control level as a product of the second maximum time-averaged transmit power level and the scaling factor; and

determining the reduced RF exposure level further based at least in part on the first control level or the second control level in response to transitioning from operating with at least the one or more first radios associated with the first RF exposure control scheme to operating with at least the one or more second radios associated with the second RF exposure control scheme.

16 . The method of claim 1 , further comprising:

obtaining additional RF exposure information associated with one or more third RF exposure control schemes; and

determining the reduced RF exposure level based at least in part on the RF exposure information and the additional RF exposure information.

17 . The method of claim 1 , further comprising:

determining updated RF exposure information for the one or more first radios based at least in part on the RF exposure information;

providing the one or more first radios with the updated RF exposure information; and

transmitting a second signal via the one or more first radios associated with the first RF exposure control scheme at a second transmit power based at least in part on the updated RF exposure information.

18 . The method of claim 17 , wherein determining the updated RF exposure information comprises determining the updated RF exposure information in accordance with the second RF exposure control scheme.

19 . The method of claim 18 , further comprising:

detecting that the second RF exposure control scheme or the one or more second radios are offline;

determining a third transmit power for the one or more first radios in accordance with the first RF exposure control scheme in response to detecting that the second RF exposure control scheme or the one or more second radios are offline; and

transmitting a third signal via the one or more first radios at the third transmit power.

20 . An apparatus for wireless communication, the apparatus comprising:

memory storing computer-executable code; and

one or more processors coupled to the memory, the one or more processors being configured to, individually or collectively, execute the computer-executable code and cause the apparatus to:

obtain radio frequency (RF) exposure information associated with a first RF exposure control scheme, wherein the RF exposure information associated with the RF exposure control scheme includes a length of a time-averaging window for the first RF exposure control scheme, and wherein the first RF exposure control scheme is associated with one or more first radios;

transition to transmitting a first signal via one or more second radios associated with a second RF exposure control scheme;

during a duration corresponding to the length of the time-averaging window for the first RF exposure control scheme, control transmission of the first signal via the one or more second radios associated with the second RF exposure control scheme at a reduced RF exposure level based at least in part on the RF exposure information, wherein the one or more first radios are different than the one or more second radios; and

after the duration corresponding to the length of the time-averaging window for the first RF exposure control scheme, transmit via the one or more second radios at an RF exposure level according to the second RF exposure scheme.

21 . The apparatus of claim 20 , wherein the RF exposure information includes on-off information of the one or more first radios associated with the first RF exposure control scheme.

22 . The apparatus of claim 20 , wherein the RF exposure information includes an indication of an RF exposure margin used by the first RF exposure control scheme.

23 . An apparatus for wireless communication, the apparatus comprising:

means for obtaining radio frequency (RF) exposure information associated with a first RF exposure control scheme, wherein the RF exposure information associated with the RF exposure control scheme includes a length of a time-averaging window for the first RF exposure control scheme, and wherein the first RF exposure control scheme is associated with one or more first radios;

means for transitioning to transmitting a first signal via one or more second radios associated with a second RF exposure control scheme;

means for, during a duration corresponding to the length of the time-averaging window for the first RF exposure control scheme, transmitting the first signal via the one or more second radios associated with the second RF exposure control scheme at a reduced RF exposure level based at least in part on the RF exposure information, wherein the one or more first radios are different than the one or more second radios; and

means for, after the duration corresponding to the length of the time-averaging window for the first RF exposure control scheme, transmitting via the one or more second radios at an RF exposure level according to the second RF exposure scheme.