Bluetooth vs. Wi-Fi Power Consumption

Bluetooth devices typically have low power consumption while Wi-Fi uses much more electrical power. In part, this is due to the broadcast range of the two technologies. Both Bluetooth and Wi-Fi devices announce themselves by emitting a signal with a frequency of 2.4 gigahertz. Bluetooth devices emit a signal that travels for about 30 feet, while Wi-Fi signals travel about ten times as far. Wi-Fi devices need more power to generate a stronger signal.

Rahul Balani of the Electrical Engineering Department at the University of California, Los Angeles, has run extensive tests to measure the power consumption of Bluetooth versus Wi-Fi. His results indicate that in some cases, Bluetooth uses less than 3 percent of the power required by Wi-Fi for the same tasks. For example, sending data at the rate of 75 bytes per second over Wi-Fi requires approximately 80 milliwatts of electrical power. Sending data at the same rate over Bluetooth consumes only 2 milliwatts.

Even though Wi-Fi may use as much as 40 times the power of Bluetooth in some applications, this difference may not be important to some users. Electrical power is inexpensive enough that even the larger draw of Wi-Fi may be considered insignificant. This is not true for computer users who live off the electrical grid and must generate their own electrical power using solar cells or wind turbine technology. Such users are very likely to prefer Bluetooth over Wi-Fi because generating extra power at the home site requires expensive infrastructure.

In addition to using less power, Bluetooth is also easy to set up and use. The system seamlessly connects to devices and can include up to seven in a single network. Wi-Fi requires users to have more technical knowledge. Setting up a system is difficult enough that some users hire a network technician.