Bluetooth – how does it work?
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 such as IBM and HP) founded the Infrared Data Association with the aim of laying the foundations for a data transfer standard using infrared. These efforts were not really successful, mainly because such data transmission requires a line of sight between the sender and receiver.
However, some of the insights gained were incorporated into the development of the Bluetooth transmission standard, which uses radio waves instead of infrared light.
Today, Bluetooth technology enables us to connect a variety of devices wirelessly.
As convenient as this is in theory, the actual use of Bluetooth devices can often be tricky. And that's why – as you've probably guessed – the following pages are devoted to the basics of Bluetooth use, some advanced topics, and common problems and their solutions.
Turning on and off
settings
To use a Bluetooth device with your smartphone, you must first turn on the Bluetooth function on your smartphone. You can do this easily in your smartphone's settings.
Switching on
Swipe down from the top of the screen and tap and hold the ‘Bluetooth’ field. In the window that appears, you can ‘Pair new device’.
Switching off
If you don't need Bluetooth, don't hesitate to switch it off. This saves battery and also serves your own safety.
Bluetooth versions
Bluetooth 1 to 3
The specifications for Bluetooth version 1.0 were published in 1999. The most important innovation in version 2.0 (from 2004) is the approximately threefold increase in transmission speed.
Bluetooth version 3.0 was released in 2009, allowing data to be transferred in parallel via WLAN for even higher speeds.
The various versions are backward compatible in principle, so you can connect newer and older devices with each other.
Bluetooth 4
A new feature of Bluetooth version 4.0 (released 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 mode 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: low-energy transmissions now offer greater range and higher speeds. In addition, there is an optional error correction feature that increases connection stability.
New in 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 devices
Basically two steps
The second requirement for using a Bluetooth device is to pair the device with your 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. Putting the Bluetooth device into pairing mode – usually by pressing and holding a special button.
2. Select this Bluetooth device on your smartphone (from a list of available Bluetooth devices).
Device list
You can access this list of available devices by opening the Bluetooth window in your smartphone's settings (see section ‘Switching on and off’) and, if necessary, tapping the ‘Bluetooth’ button again.
Speaker or over-ear headset
Using the specific example of a Bluetooth speaker (or over-ear headset): either press and hold a special button on the speaker (or the power button) until the speaker signals (usually by means of a flashing LED) that it is in pairing mode. You can then select the loudspeaker from the Bluetooth device list on your smartphone.
Enter 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 your smartphone. This code is either displayed on the Bluetooth device or can be found in the device's instructions.
Switch on Bluetooth
For devices (such as car radios and blood glucose meters) that do not use Bluetooth continuously, you must switch on the Bluetooth function via a menu on the device before pairing. Details can be found in the manual for the respective device.
Simply select
Once a Bluetooth device has been paired with your smartphone, you can select it from the list of paired Bluetooth devices on your smartphone to use it.
Areas of application
Audio transmission
Bluetooth devices are almost ubiquitous today. One of the most common uses is connecting smartphones to speakers, over-ear headsets or car radios. Even though there are good reasons to lament the increasing disappearance of the jack socket for connecting headphones, it is undeniably extremely practical to be able to listen to music on headphones or loudspeakers without having to fiddle around with cables.
Data transfers
A second common application for Bluetooth technology is the transfer of many types of data. 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, conveniently, quickly and without consuming much energy.
Industry
Production facilities in factories are also networked via Bluetooth to automate manufacturing processes.
Limitations
Bluetooth is a short-range wireless technology. In addition, the achievable data transfer rates are relatively low. Bluetooth connections are therefore not well suited for large networks or for transferring large amounts of data.
Remote controls
Remote controls for game consoles and video and audio devices (such as streaming boxes) also frequently rely on Bluetooth technology. The advantage over good old infrared technology is that with a Bluetooth remote control, you no longer have to aim to ensure that the device receives the control commands.