Bluetooth LE (Low Energy): This is the difference to normal Bluetooth

You have probably stumbled across Bluetooth Low Energy. You can find out what this is all about in this practical tip.

What is Bluetooth Low Energy?

Bluetooth Low Energy is a radio standard that enables Bluetooth connections with low transmission power and low power consumption.

• The Bluetooth LE technology can be found, for example, in fitness trackers, sensors or toys.
• The main advantage is that a Bluetooth connection can be established in a relatively energy-saving manner and only a little (~ 10 mW) transmission power is required.
• The disadvantage, however, is that Bluetooth Low Energy is usually somewhat slower than classic Bluetooth and the range is limited to around 10 - 40 m due to the reduced transmission power.
• Bluetooth LE is also only partially backwards compatible. Connections can only be established if the remote station also supports Bluetooth Low Energy. However, support is usually available from Bluetooth 4.
• Smartphones and PCs usually have both a normal Bluetooth interface (BR / EDR controller) and Bluetooth low-energy support (LE controller). In the case of pure BLE devices, there is only support for the energy-saving version.

Bluetooth LE: roles

Bluetooth Low Energy has different roles that a device can assume. A device can be either Observer, Broadcaster, Peripheral or Central.

• Observer are - as the name suggests - devices that only receive data. The counterpart here are the broadcasters, which only send data.
• Peripheral devices act as slaves and can send connection requests. Central devices, in turn, only act as masters and do not send out connection requests. Mobile phones and PCs can mostly work as masters and slaves.

Status at Bluetooth Low Energy

In addition, Bluetooth low-energy devices can switch between different states.

• If there is no connection, the Bluetooth module is in standby status and consumes hardly any power.
• With the advertising status, the device sends out packets that allow other devices to receive transmitted data or to find the device. The other devices are in scanner status and search for packages without establishing a connection.
• If a connection is established, the device is in the initiating status. With an active connection it is in the connection status. Then data can be exchanged as normal between two devices (private).

In the next practical tip, you will learn how to activate Bluetooth on your laptop.