Radio frequency exposure compliance

A method for wireless communications, comprising:

• transmitting a first transmission with a first transmitter operable according to a first radio technology;
• transmitting a second transmission with a second transmitter after completion of the first transmission, the second transmitter operable according to a second radio technology;
• delaying transmission of the second transmission by a predetermined wait time after completion of the first transmission if the first radio technology is a radio frequency (RF) exposure time-averaged technology and the second radio technology is a non-time-averaged RF exposure technology;
• and
• transmitting the second transmission with a limited peak power for a predetermined time period for at least a portion of the second transmission if the first radio technology is a non-time-averaged RF exposure technology and the second radio technology is a time-averaged RF exposure technology,
• wherein transmissions according to the second radio technology are always at or below a specific absorption rate (SAR) limit specified by a regulator for averaging RF exposure for the second radio technology.

A wireless device, comprising:

• multiple transmitters, wherein each of the multiple transmitters is configured to transmit signals according to a respective radio technology of multiple radio technologies, and wherein the multiple radio technologies include a time-averaged radio frequency (RF) exposure technology and a non-time-averaged RF exposure technology;
• and
• a processor coupled to the multiple transmitters, wherein the processor is configured to:
• set a transmission level limit of the non-time-averaged RF exposure technology to a predetermined back-off level during periods when the time-averaged RF exposure technology is active over a transmission time window;
• determine an RF exposure profile for the non-time-averaged RF exposure technology over the transmission time window;
• and
• control transmission of one of the transmitters operable according to the time-averaged RF exposure technology based on the RF exposure profile, wherein
• the processor is further configured to determine the predetermined back-off level based on a relationship 10−x/10 where x is a back-off value in decibels, or
• the processor is configured to set the transmission level limit of the non-time-averaged RF exposure technology to a power level during periods when the time-averaged RF exposure technology is non active over the transmission time window, and the back-off level is equal to the power level reduced by a back-off value.

A method for wireless communications, comprising:

• setting a transmission level limit of a non-time-averaged RF exposure technology to a predetermined back-off level during periods when a time-averaged RF exposure technology is active over a transmission time window;
• determining an RF exposure profile for the non-time-averaged RF exposure technology over the transmission time window;
• and
• controlling transmission of a transmitter operable according to the time-averaged RF exposure technology based on the RF exposure profile,
• wherein the method further comprises
• determining the predetermined back-off level based on the relationship 10−x/10 where x is a back-off value in decibels, or
• setting the transmission level limit of the non-time-averaged RF exposure technology to a power level during periods when the time-averaged RF exposure technology is non active over the transmission time window, and the back-off level is equal to the power level reduced by a back-off value.