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What ist Bluetooth?

Wireless data transfer

Bluetooth allows data to be transmitted wirelessly between devices such as Bluetooth headphones and a smartphone.


Bluetooth is an industry standard developed in the 1990s in accordance with IEEE 802.15.1. Incidentally, it was named after the Danish King Harald Bluetooth. The Bluetooth symbol is made up of the runes ᚼ (h) and ᛒ (b), which were the initials of Harald Bluetooth. 
The data transfer rate ranges from 732.2 Kbit/s (V 1.2) to 50 Mbit/s with Bluetooth 5.X. The latest version is Bluetooth 6, which was released in September 2024 with new features and functions. Devices with the latest standard are expected in 2025.

Bluetooth versions at a glance


Bluetooth 1.0  Enthielt Sicherheitsprobleme durch Bluetooth Hardware Device Address Transmission (BD_ADDR), maximale Datenübertragungsrate von 732,2 Kbit/s 
Bluetooth 1.1 Ermöglicht eine Datenübertragungsrate von 732,2 Kbit/s
Bluetooth 1.2 Ermöglicht eine stabilere Datenübertragung als Version 1.1 und eine Datenübertragungsrate von 732,2 Kbit/s
Bluetooth 2.0 + EDR Ermöglicht mit der EDR (Enhanced Data Rate) eine maximale Datenübertragungsrate von 2,1 Mbit/s
Bluetooth 2.1 + EDR Datenübertragungsrate wie die Version 2.0, besitzt jedoch verbesserte Technik zur Verbindung von Bluetooth-fähigen Geräten
Bluetooth 3.0 + HS Ermöglicht eine Datenübertragungsrate von maximal 24 Mbit/s (bei Nutzung eines zusätzlichen Highspeed (HS) Kanals auf Basis von WLAN und UWB (Ultra Wide Band))
Bluetooth 4.0 Sehr stromsparend, nicht vollständig abwärtskompatibel, ermöglicht Datenübertragungsraten bis zu 732,2 Kbit/s
Bluetooth 5 Reichweite wurde vervierfacht, maximale Datenübertragungsrate von 2 Mbit/s, es können bis zu acht Geräte gleichzeitig verbunden werden. Vollständig abwärtskompatibel zu Bluetooth 4.0
Bluetooth 5.1  Verbesserte Ortung mit Direction Finding ermöglicht eine präzisere Positionsbestimmung durch Winkelmessung.
Bluetooth 5.2 Führte Enhanced Attribute Protocol (EATT) für effizienteres Multi-Device-Handling ein und brachte Verbesserungen bei der Audioqualität mit LE Audio.
Bluetooth 5.3 Reduzierte den Energieverbrauch durch bessere Steuerung der Übertragungseinstellungen und verbesserte die Robustheit in überfüllten Frequenzbereichen.
Bluetooth 5.4 Optimierte die IoT-Kompatibilität durch Unterstützung für größere Netzwerke und bessere Sicherheitsfeatures für industrielle Anwendungen.
Bluetooth 6  Bluetooth 6 wird voraussichtlich energieeffizienter, schneller und präziser in der Ortung sein.

Bluetooth 4.0: Connect accessories in an energy-saving way


Bluetooth 4.0 has been available since around 2011, but has only been usable on Android-based devices since 2013. Compared to the previous versions, version 4.0 consumes significantly less energy. With Bluetooth 4.0, the connection between devices, such as a Bluetooth keyboard or a Bluetooth headset, is also established more quickly and is maintained over a distance of up to 100 metres. One disadvantage is the lack of downward compatibility of the new protocols. Although Bluetooth 4.0, like all previous standards, operates on the 2.4 GHz frequency, it uses 40 radio channels of 2 MHz each. However, older Bluetooth accessories do not support this radio channel distribution.

Although the data rate of Bluetooth 4.0 is theoretically one Mbit/s, the standard is not suitable for transferring larger files. Bluetooth 4.0 is designed so that the devices only wake up briefly to transfer information quickly. The devices then switch back to a power-saving deep sleep. This information includes values such as pulse rate or blood sugar levels. The standard is therefore particularly suitable for Bluetooth accessories in the health, sports and smart home categories.

The Bluetooth devices must also support GATT (General Agreement on Tariffs and Trade), which is a Generic Attribute Profile. Up to Bluetooth standard 4.0, devices used GAP (Generic Access Profile). With versions 4.1 and 4.2, faster data transmission, more security and even greater energy savings were achieved.

Bluetooth 5: Use more range or higher data transmission


Unlike its predecessors, the Bluetooth standard is not called 5.0, but simply Bluetooth 5. The Bluetooth Special Interest Group (SIG) decided on this name change when it was introduced at the end of December 2016, heralding a completely new era in the wireless transmission of data.

SIG has quadrupled the range, doubled the speed of low-energy connections and simultaneously increased the capacity of connectionless data transmissions by a factor of eight. With Bluetooth 5, it is therefore possible to transfer data between two compatible devices at a distance of up to 240 metres. However, the further the distance, the lower the data transfer rate. While up to 500 Kbit/s can be transmitted at 120 metres, the rate is only 128 Kbit/s at 240 metres. You therefore benefit from either a higher speed or greater range. The range has an advantage when using Bluetooth headphones or loudspeakers in your home. The connection is not interrupted when you move to another room. Bluetooth 5 also allows you to connect up to eight devices simultaneously and is fully backwards compatible with Bluetooth 4.0.

In the following years, the Bluetooth standards were further improved with versions 5.1 to 5.4. Bluetooth 5.1 introduced Direction Finding, which enabled more precise positioning through angle measurement - an important advance for location services. Bluetooth 5.2 introduced LE Audio, which significantly improved audio quality and enabled more efficient handling of multiple devices thanks to the Enhanced Attribute Protocol (EATT). Bluetooth 5.3 optimised energy consumption through finer control of transmission settings and improved performance in crowded frequency ranges. Finally, Bluetooth 5.4 focused on IoT compatibility, increased capacity for larger networks and improved security features, especially for industrial applications.

Bluetooth 6

Bluetooth 6 wird voraussichtlich Verbesserungen in Energieeffizienz, höhere Datengeschwindigkeiten und eine noch präzisere Ortungsgenauigkeit bringen, ideal für IoT- und Smart-Home-Anwendungen. Zudem sind erweiterte Sicherheitsfeatures und Optimierungen für größere Netzwerke im Gespräch, um die Leistung und Zuverlässigkeit in industriellen und öffentlichen Umgebungen weiter zu steigern.

Bluetooth accessories: The most important profiles and their functions

The profiles in Bluetooth are of central importance. They define the structure and content of a specific communication depending on the application. The Bluetooth profiles allow Bluetooth accessories to work together at application level and therefore guarantee that Bluetooth devices from different manufacturers can work together. A typical example is communication between a mobile phone and a Bluetooth headset. Both devices do not have to come from the same manufacturer. Rules and protocols are defined in a profile. This gives the user the advantage of not having to manually synchronise the devices. In addition, Bluetooth allows several profiles at the same time. A profile limits the device to the functions required for the specific application, which keeps it small and energy-efficient. This means that the device only needs to have a small range of functions and does not need to be able to handle every conceivable function.
GAP Generic Access Profile - Basic procedure for authentication and establishing a connection
A2DP Advanced Audio Distribution Profile - Wireless stereo connection for speakers or Bluetooth headphones
SCO Synchronous Connection-Oriented Link - access to both the microphone and the headphones of a Bluetooth headset
PBAP Phonebook Access Profile - Access to phonebook (read only)
DUNP Dial-Up Networking Profile - Dial-up via GSM, UMTS, analogue modem or ISDN into a network, for example for Internet access
HFP Hands Free Profile - manufacturer-independent communication between mobile phone and hands-free system
BIP Basic Imaging - Image transmission
BPP Basic Printing Profile - Printing via the parallel interface
SAP SIM Access Profile - SIM card access
GAVDP Generic AV Distribution - Audio and video transmission
AVRCP Audio Video Remote Control - Audio/video remote control

High-quality Bluetooth products for perfect sound

InLine® Bluetooth 5.3 audio receiver with 96 watt amplifier

The InLine audio receiver combines a compact design with high-quality signal transmission and maximum performance for the demanding audio user. Audio signals are transmitted in the highest quality wirelessly via Bluetooth 5.3 or wired via RCA stereo to the receiver, amplified with up to 96 watts and then passed on to two passive stereo speakers. Up to 2 devices can be connected simultaneously via Bluetooth. Volume, bass and treble are intuitively adjusted via 3 controls. Make the InLine Audio Receiver the control center of your mini HiFi system and look forward to a fast connection, high range, intuitive operation and first-class sound quality.


  • Bluetooth: Version 5.3 with aptX HD
  • Bluetooth chipset: ATS2853
  • Supported codecs: SBC, AAC
  • Bluetooth range: up to 20 metres / 60 feet
  • Inputs: 2x Bluetooth, 1x line-in stereo (2x RCA jack)
  • Output: Loudspeaker connection stereo
  • Power supply: 24V DC / 4.0 A via supplied USB power adapter
  • Total harmonic distortion (THD): =0.5%
  • Frequency range: 20Hz - 20kHz
  • Signal to noise ratio (SNR): =98dB
  • Input sensitivity: = 1V
  • Dimensions: approx. 14.8 x 11 x 4 cm (without antenna)
  • Housing: aluminium
  • Colour: Black
Item no.: 99209L

InLine® Bluetooth 5.1 HiFi Receiver & USB DAC, with LCD

The Bluetooth 5.1 HiFi Audio Receiver from InLine transmits audio signals in highest quality (96kHz / 24-bit) either via Bluetooth e.g. from a smartphone or as DAC via USB-C e.g. from a PC to a HiFi music system or active speakers. For audio output, a RCA stereo or an optical Toslink connection is available. The receiver features a volume control, 7 preset equalizer profiles and an OLED display. A fast connection, intuitive operation and high range complement the excellent signal transmission. This makes the InLine Audio Receiver the perfect accessory for older AV receivers.


  • Bluetooth: Version 5.1 with aptX HD
  • Bluetooth chipset: Qualcomm QCC5125
  • Supported codecs: LDAC, aptX, aptX-LL, aptX HD, AAC, SBC
  • Bluetooth range: up to 30 meters
  • Input: Bluetooth, USB-C audio
  • Outputs: Toslink optical, 2x RCA analog stereo
  • Power supply: 5V DC / 0.08A via included USB power adapter
  • RCA output: 1.8 Vrms / 0dB
  • Total harmonic distortion + noise (THD+N): B-weighted: 0.02%/1KHz 0dB
  • Signal to noise ratio (SNR): -114dB
  • Dynamic range: -115dB
  • Crosstalk: -114dB
  • Equalizer modes: POP, BASS, CLASSIC, DANCE, JAZZ, ROCK, NORMAL
  • Dimensions: approx. 8.89 x 7.62 x 2.54 cm (without antenna)
  • D/A converter: ES9018K2M SABRE32
  • PCM support: 96kHz / 24-bit
  • OLED display: 1" monochrome
  • Housing: Aluminum
  • Color: Black

Technical features power supply:

  • Input voltage: 100-240V AC
  • Input AC frequency: ~50/60 Hz
  • Output voltage: 5.0 V DC
  • Output current: max. 1.0 A
  • Output power: 5.0 W
  • Average active efficiency: 73.9 %
  • No-load power consumption: 0.06 W
Item no.: 99209M

InLine® Bluetooth Audio Transceiver, Receiver/Transmitter, BT 5.0, aptX
The InLine Bluetooth Audio Transceiver is a sleek and compact Bluetooth audio transmitter that seamlessly streams Hi-Fi digital audio wirelessly from your TV or wired music system to your favourite pair of Bluetooth headphones or speakers. Also it´s a Hi-Fi Bluetooth music receiver that streams high quality audio wirelessly from any Bluetooth enabled smartphone, computer or tablet to any music system or powered speakers. With aptX low latency, the audio signals are transmitted with minimal delay to achieve the best possible synchronicity between audio and video content.
  • Bluetooth version 5.0 with aptX low latency
  • Supported codecs: aptX low latency, aptX, AAC, SBC
  • Bluetooth profiles: A2DP
  • Bluetooth range: Up to 10 meters
  • Output signal connections: TOSLINK digital optical OUT, 3.5mm AUX OUT
  • Input signal connections: TOSLINK digital optical IN, 3.5 mm AUX IN
  • Input power: 5V DC, 500 mA (requires an USB-C port as power source)
  • Latency: only ~ 40ms
  • supports multipoint streaming for simultaneous playback to two Bluetooth headphones / speakers
  • Mounting options: Sticky gel mounting strips, hook-and-loop tape
  • Dimensions: 10.4x2.3x2.0 cm
Delivery content:
  • InLine Bluetooth Audio Transceiver
  • TOSLINK digital optical audio cable (1.5m)
  • 3.5mm AUX audio cable (1.5m)
  • 3.5mm to RCA adapter cable (0.2m)
  • USB C cable (0.8m)
  • Sticky gel mounting strips
  • Manual
Item no.: 99151I

InLine® woodwoom, Bluetooth walnut wooden speaker, 52mm
Simply set it up, connect and go! The woodwoom works with any Bluetooth device. Enjoy impressive sound for more listening experience with a distance of up to 10 meters and up to 7 hours of play time. The lithium-ion battery is rechargeable via USB.
  • Bluetooth specification: 3.0
  • Transmission distance: up to 10m
  • Frequency: 150Hz - 20kHz
  • 52mm speaker, 3W
  • Lithium battery, 600mAh, 3.7V
  • Charging time: about 3-5h
  • Input power: USB +5 V, max. 1A
  • Real wooden case
  • Dimensions: Ø: 75mm x H: 73mm
  • Weight: 250g
In its new product range "woodline" InLine presents gadgets with bodies or details of real wood. The Bluetooth / induction speaker, Power Banks, stylus or headphones with loving applications of real walnut wood looks attractive and feels great for hand and ear.
Item no.: 55380H

InLine® Airplane Bluetooth Audio Transmitter, BT 5.0, aptX HD/LL
The InLine Bluetooth Flight Audio Adapter transmits the audio signals of the board entertainment wirelessly via Bluetooth in highest quality to your favourite headphones, no matter if in-ear, on-ear or over-ear. The adapter is compatible with the most common one-, two- and three-pin systems and also has a USB port. The power supply is also ensured over long distances by a battery and charging case. Furthermore, the Bluetooth Flight Audio Adapter can easily be used as a battery-operated Bluetooth transmitter on audio sources with 3.5mm stereo jack output. This allows you to stream Bluetooth audio to your headphones when you are away from the aircraft.
  • Bluetooth: Version 5.0 with aptX HD, aptX Low Latency
  • Supported codecs: aptX, aptX HD, aptX LL, SBC, AAC
  • Bluetooth profiles: A2DP and AVRCP, GAIA, HSP und HFP
  • Bluetooth range: Up to 20 meters
  • Input: 2x 3.5mm Audio plugs, 1x USB Type-C (when connected to a PC)
  • Outputs: Bluetooth / Can be used with 1 or 2 Bluetooth headphones simultaneously
  • USB Audio Audio sampling rate: 48kHz / 16-bit / Compatible with Windows, MacOS, Linux / no driver installation necessary
  • Rechargeable battery: Flight Audio Adapter: 180mAh / Charging case: 900mAh
  • Input Power: Flight Audio Adapter: USB Type-C DC5V 500mA / Charging Case: USB Type-C DC5V 500mA (requires an optional USB power adapter)
  • Battery runtime: up to 6h / up to 30h with charging case
  • Operating temperature: -10°C - 45°C
  • Storage temperature: -20°C - 60°C
  • Supported sample rate: =48 kHz
  • Enclosure: plastic
  • Colour: black
  • Dimensions Adapter: 5x3.9x1.5 cm
  • Dimensions Charging-Case: 8x5x3,1 cm
  • Weight Adapter: 20g
  • Weight Charging-Case: 60g
SCOPE OF DELIVERY:
  • 1x InLine Bluetooth Flight Audio Adapter
  • 1x Charging-Case
  • 1x USB Type-A to USB Type-C cable 1m
  • 1x Operating instructions
Item no.: 99160I