Comment Re:Not really "a radio" (Score 5, Informative) 93
Wi-Fi and 802.15.4/Bluetooth Classic/BLE use different modulation schemes so they are entirely different transceivers even though they almost operate entirely within the same ISM band. Bluetooth's frequency band is actually slightly larger than 2.4 GHz Wi-Fi for FCC/IC regions.
For single package/chip components that support both 2.4 GHz Wi-Fi and Bluetooth have two dedicated radio transceivers that will operate in co-existence mode when both are enabled for transmit, however both may receive at the same time.
It's the reason why turning off Bluetooth tends to have little to no impact on battery life. It's not a separate radio, it's just a software switch that says "ignore Bluetooth packets" and the hardware remains powered up for WiFi.
The whole reason for Bluetooth, and even more so for Bluetooth Low Energy, is a low-power personal area network (PAN). So turning it off I would expect it to show little to no power usage impact for say a mobile phone or tablet that mostly communicates over Wi-Fi or cellular network. Now days we have BLE beacons used for tracking items that lasts for years on a single coin cell battery.