Meaning
Power control methods that calculate the electromagnetic exposure of a user over a moving window of time allow for higher peak transmit powers. With time averaged sar, the device does not run at a fixed maximum power but instead balances periods of high power with periods of lower power. This approach improves the connection speed during burst transmissions while remaining compliant with exposure limits.
Monitoring Algorithm
Control firmware tracks the transmit power of each active antenna in real time and calculates the rolling average. When the average exposure approaches the regulatory limit, the algorithm commands the radio to lower its power. This continuous monitoring ensures that the safety limit is never exceeded over any defined time window.
Window Duration
Regulatory agencies define the window duration used for the average calculation, which is typically six minutes for frequencies below six gigahertz. This timeframe is based on the thermal response of human tissue to electromagnetic heating. This standard window allows manufacturers to optimize their power control strategies for different use cases.
Device Qualification
Demonstrating compliance requires a dynamic test setup that can simulate changing network conditions and record the corresponding power output. The test laboratory uses a continuous power logging system to verify that the averaging algorithm responds correctly to sudden power spikes. This testing confirms that the rolling average remains below the legal limit under all scenarios, which is required before the device can be certified for the consumer market.