You are not the only one who is fed up with the tangle of cables that almost inevitably surrounds digital devices: As early as 1993, several dozen companies (including big names like IBM and HP) founded the Infrared Data Association - with the aim of laying the foundations for a data transmission standard via infrared. These efforts were not really successful. Mainly because a line-of-sight connection between transmitter and receiver is necessary for such data transmission.

However, some of the knowledge gained was incorporated into the development of the Bluetooth transmission standard, which uses radio waves instead of infrared light.
Today, this Bluetooth technology enables us to connect a multitude of devices wirelessly.

As convenient as this is in theory, the actual use of Bluetooth devices can often be tricky. And that's why - you probably guessed it - the following pages are dedicated to the basics of Bluetooth use, some advanced topics as well as common problems and their solutions.

Switch on and off

To use a Bluetooth device together with your smartphone, you must first switch on the Bluetooth function on your smartphone. You can do this easily in the settings of your smartphone.

Switch on
Swipe down from the top edge of the screen and tap and hold the "Bluetooth" field. In the following window, you can "pair a new device".

Switch off
If you do not need Bluetooth, do not hesitate and switch it off. This saves battery and is also for your own safety.


Bluetooth Versions

Bluetooth 1 to 3
The specifications for Bluetooth version 1.0 were published in 1999. The most important innovation of version 2.0 (from 2004) is the approximately three times higher transmission speed.
In 2009, Bluetooth version 3.0 was released, which allows data to be transmitted in parallel via WLAN for even higher speed.
The various versions are in principle backwards compatible, so that you can connect newer and older devices with each other.

Bluetooth 4
A new feature of Bluetooth version 4.0 (published in 2010) is the Bluetooth Low Energy variant, which consumes less power (see section "Internet of Things").
Bluetooth 4.x supports both the "classic" transmission type and low-energy transmissions. However, these two transmission rates are not compatible with each other, and not every Bluetooth 4 device automatically supports Bluetooth Low Energy.

Bluetooth 5
Bluetooth version 5 (released in 2016) focuses on the Internet of Things: longer ranges and higher speeds are now possible with low-energy transmissions. In addition, there is an optional error correction that increases the stability of the connections.
New to version 5.1 (from 2019) are improved location functions that allow the position of devices to be determined with an accuracy of up to ten centimetres.

Pairing the devices

In principle, two steps
The second requirement for using a Bluetooth device: pairing the device with the smartphone.
The specific steps for establishing such a pairing depend on the Bluetooth device used. In principle, however, the following two steps are necessary:
1. put the Bluetooth device into pairing mode - usually by pressing a special button for a longer time. 2. select this Bluetooth device.
2. selecting this Bluetooth device on the smartphone (from a list of available Bluetooth devices).

Device list
You can access this list of available devices by opening the Bluetooth window in the settings of the smartphone (see section "Switching on and off") - and, if necessary, tapping the "Bluetooth" button again.

Loudspeaker or headphones
Using the specific example of a Bluetooth loudspeaker (or headphones): Either press and hold a special button on the loudspeaker (or the power button) until the loudspeaker signals (usually by a flashing LED) that it is in pairing mode. You can then select the loudspeaker on the smartphone in the Bluetooth device list.

Entering the code
Depending on the Bluetooth device, pairing can be a little more complicated. In this case, it is advisable to take a look at the instructions. For example, it is often necessary to enter a code on the smartphone. This code is either displayed by the Bluetooth device. Or you can find it in the instructions for the device.

Switching on Bluetooth
For devices (such as car radios and blood glucose meters) that do not use Bluetooth all the time, you must switch on the Bluetooth function via a menu on the device before pairing. You can find details on this in the instructions for the respective device.

Simply select
Once a Bluetooth device is paired with the smartphone, it is sufficient to select this device on the smartphone in the list of paired Bluetooth devices to use it.

Areas of application

Audio transmissions
Bluetooth devices are almost ubiquitous today. One of the most common uses is to connect smartphones to speakers, headphones or car radios. Although there are good reasons to lament the increasing disappearance of the jack socket for connecting headphones, it is undeniably extremely practical to let music sound in headphones or on speakers without having to fiddle with cables.

Data transmission
A second common use for Bluetooth technology is the transfer of data of many kinds. No matter whether you want to manually send measurement data from a blood glucose meter to your smartphone, automatically synchronise data between a smartwatch and a smartphone or use a printer from your smartphone: Bluetooth makes it possible wirelessly, comfortably, quickly and without much energy consumption.

Production plants in factories are also networked with each other via Bluetooth to automate manufacturing processes.

Bluetooth is a radio technology for short distances. In addition, the achievable data transmission rates are relatively low. Bluetooth connections are therefore not well suited for large-area networks or for transmitting large amounts of data.

Remote controls
Remote controls for game consoles as well as for video and audio devices (such as streaming boxes) also often rely on Bluetooth technology. The advantage here compared to good old infrared technology: with a Bluetooth remote control, you no longer have to aim to ensure that the device receives the control commands.