• BT off
  This is the power consumption of the phone with Bluetooth off. Since all the other air interfaces are off and the backlight of the display as well, this represents the minimum consumption of the phone when is not doing anything.
• BT on
  We have measured the power consumption of the phone with only Bluetooth on and everything else inactive.
• BT connected+idle
  This is the power consumption of a phone connected to another one but not sending nor receiving data.
• BT discovery
  This is the power consumption when a mobile phone is performing a device discovery. This procedure can take a longer time according to the number of the devices in the range, but the power levels are the same. Therefore the energy depends on the duration of the discovery.
• BT Receiving
  This is the power consumption of a phone receiving data using an RFCOMM protocol.
• BT Sending
  This is the power consumption of a phone sending data using an RFCOMM protocol.

In Figure below values for power consumption of the phone when Bluetooth is switched off and when it is turned on and in idle mode are shown. By comparing the two values, is possible to note that having Bluetooth on will increase the power consumption by only 3 mW. This goes against the common idea that Bluetooth has a very high power consumption when turned on.