Eli5: How do cell phone waves make it back to the tower from my phone?

Question

The cell towers are heavily powered so the signals go out but how does my phone with a much smaller power source transmit the data back to the tower?

In: 4

Answer 1

This is why my phone’s battery has 78 hours standby but only 23 hours talk time: it boosts the signal to reach the tower.

Having an electromagnetic source so close to the brain causes concern for some, so phones are rated with an SAR – Specific Absorption Rate, in watts per kg.