Emitted power from consumer devices is required to meet a specific absorption rate (SAR) limit. Since SAR limits apply to the total transmitted power, mobile devices that have multiple radios limit transmit power on each radio based on the on/off status of other radios. For example, if cellular is enabled, then the maximum power available to WiFi is reduced. Such an approach does not account for the actual instantaneous power transmitted by a radio. For example, the cellular radio may be transmitting well below its maximum power when proximate to a base station. In such a case, the WiFi (or Bluetooth) radios can safely transmit power at relatively high levels while staying with the SAR limit.
The techniques of this disclosure calculate the maximum transmissible power of a radio based, e.g., on the actual power transmitted by other radios; on the priority of different radios; on the scheduling of packets within each radio; etc. The techniques thereby can achieve a higher per-radio transmit power, e.g., higher link throughput, while operating within the SAR limit.
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Jiang, Qi; Husted, Paul; Mehta, Srenik; and Jindal, Nihar, "Transmit power setting based on dynamic SAR", Technical Disclosure Commons, (January 14, 2019)