Bluetooth Profiles and Versions in Headphones

Wireless Headphones are a favorite go-to for many users due to their ease of use and convenience, sound quality, price, and creative designs. The manufacture of wireless headphones has created a variety of options and Bluetooth Technologies for individuals to choose from in recent years. However, once wireless headphones are mentioned, the first thing that comes to mind is “Bluetooth Headphones.” This is because one of the most common forms of wireless headphones is Bluetooth Headphones.

Bluetooth is simply based on a short distance wireless signal exchange technology. For a Bluetooth exchange to occur, both devices must be compatible with each other and have a Bluetooth profile. This is the basis of many Bluetooth Headphones, as compatibility is the foundation of any Bluetooth exchange. This is brought about by two things, the Bluetooth Profile as well as the Bluetooth Version of both devices in use. This is why you must know the Bluetooth profile and versions of your device before going ahead to buy that particular headphone.

The synergy of communication through Bluetooth enabled by profiles
The synergy of communication through Bluetooth enabled by Bluetooth profiles | Source: Unsplash

1. Bluetooth Profiles

I used to think it was only the Bluetooth Version that can pose problems in a signal exchange between devices until some years ago. A Bluetooth profile is a specification used to connect both devices. Bluetooth Profiles usually specify the functionality of the device, as well as its features and the features of the connecting device. Different functions are determined by different profiles, and data transfer is enabled by these profiles as they give the exchanging devices the information on how best to transfer data in the easiest way possible. The 3 basic functions of Bluetooth Profiles are:

  • Format Dependency
  • Type of Bluetooth Protocol needed for the task
  • Suggested User Interface formats

There are over 27 different profiles, but the majority of them are classified under smaller groups of Bluetooth Profiles. Some of these profiles include:

1.1 Advanced Audio Distribution Profile

This is more popularly known as A2DP, and it is the profile that allows the seamless flow and transmission of audio sounds, especially high-quality stereo audio. It is designed for multimedia as well, and it is usually the profile that the exchange between Bluetooth Headphones and Car Stereo depends on. This profile improved Bluetooth transfer as before the A2DP was developed, the level of Bluetooth audio exchange was limited to mainly phone calls.

Now, the A2DP also allows you to stream music from a mobile device to the headset. The wireless transmission between devices, as defined by A2DP, is divided into 2; Source (SRC) and Sink (SNK). The SRC device acts as the source of the audio that is delivered to the device that acts as the sink. The SNK device is the receiver of the audio stream from the SRC. 

1.2 Audio/Video Remote Control Profile

This profile is commonly called AVRCP, and as the name implies, it is the profile that controls the functionality of the device remote control, e.g., Playing and Pausing music.

Some headphones are manufactured with dual functionality buttons, where the power and volume buttons also double as remote control buttons. This is where the AVRCP is useful. It sends commands from the Controller (usually the Bluetooth Headphones) to the receiver/target device (e.g., the music player). The Controller detects an action by the user (probably a button press), translating it into a signal transmitted to the receiving device.

AVRCP controls the scope of the Digital Interface Command of the Audio/Video control to be used through a command format for the control messages, and this format is transported to the Transport Protocol of the Audio/Video Control, known as AVCTP. This feature can also be used in Infrared mode, thereby giving a wide range of communication modes.

1.3 File Transfer Profile (FTP)

This profile allows the exchange and transfer of files between devices wirelessly. The devices involved in FTP are usually divided into two; Client (which is basically the device from which the file is being transferred that pushes or pulls the files from the server) and server (which is the recipient device that is usually remote from the Client).

1.4 Hands-Free Profile

This profile, commonly known as HFP, is the profile that allows you to enjoy the hands-free function on your device when driving. This is very important for calls and other in-vehicle equipment. This profile also allows for remote control. This profile defines two major functions

i)  Audio Gateway (AG): The audio gateway provides connectivity to the voice data source, usually the mobile phone.

ii) Hands-Free Unit (HF): The HF Unit is the device that is the audio input and output outlet for the Audio Gateway.

The HFP uses a voice codec for voice transmission, and this feature determines a lot of the voice control features, including volume.

1.5 Headset Profile (HSP)

This is the profile that comes in all Bluetooth Headphones. It basically gives the ability to ring out, answer, and end calls as well as adjust the volume. HSP is the profile that enables all Bluetooth headphones to communicate with Bluetooth enabled devices. It is similar to the HFP in its functions, which include;

i)  Audio Gateway (AG): The Audio Gateway is the source of audio input and output. It is usually a mobile device, PC or a car stereo.

ii) Headset: This is the device that ensures the audio input and output are connected to the AG through Bluetooth.

1.6 Secure Simple Pairing Profile (SSP)

This profile ensures that the devices involved in the exchange connect securely, both the headset and the phone or car kit.

1.7 Human Interface Device Profile (HID) and Device ID Profile

The Device ID Profile (DIP) is the profile that identifies the connection range and devices outside the connection range. DIP identifies the product ID, the product version, the manufacturer as well as the version of the Device ID to be identified. The DIP is the profile that identifies the devices to be connected to.
The Human Interface Device Profile (HID) profile allows other devices to be supported, such as keyboards, mouse, some gaming controllers, e.g., PlayStation controllers. The HID defines 2 major functions;

i) Host: This is the device that uses the Human Interface Device, usually a PC or Laptop.

ii) Human Interface Device (HID): This is the device providing the data input and output to and from the device. This is usually a keyboard or a mouse.

Airpods 2.0 - Benefits of Bluetooth 5.0
Airpods 2.0 – Bluetooth 5.0 Version | Source: Unsplash

2. Bluetooth Versions

The earliest versions of Bluetooth technology are the Bluetooth 1.0 and 1.1, but they offered relatively obsolete capabilities and had problems with deployment and compatibility. However, there has been a timeline of different versions from the early 2000s. Further versions between 2003 and 2014 include versions 1.2, 2.0, 2.1, 3.0+ High Speed. However, in headphones, the more recent versions of Bluetooth technology is in use, and they include versions 4.0, 4.1, 4.2, and most recently, 5.0.

2.1 Bluetooth 4.0

This version is an improvement on the widely used Bluetooth 3.0+ HS (it has a high-speed capability of 3.0 though), and it is a Low Energy Bluetooth technology that reduces power consumption for device accessories, though not for wireless headphones. The Bluetooth 4.0 allows the user to control the functionality of the device using headphones and even smartwatches.

2.2 Bluetooth 4.1

The Bluetooth 4.1 version has an enhanced anti-jamming protection feature and an integrated LTE band filter as a development over the Bluetooth 4.0 feature. Devices with Bluetooth 4.1 version looks for a channel with less interference and a slightly different frequency and connects with it. There is also no distinction between devices involved in the pairing using Bluetooth 4.1, and pairing can occur without interruption for up to 3 minutes with this version.

2.3 Bluetooth 4.2

The major distinction in this version over the other Bluetooth 4 versions is the inclusion of new features for the Internet of things. A device with Bluetooth 4.2 version usually has support that has a uniquely assigned IP address.

2.4 Bluetooth 5.0

This is the most recent version of Bluetooth technology that is widely used in headphones manufactured in recent times. The Bluetooth 5.0 has an Advanced Low Energy Technology and is better suited for the Internet of things. It has twice the bandwidth of Bluetooth 4.2, and the range is up to four times greater than Bluetooth 4.2. There is an added feature for the Bluetooth 5.0 called the Slot Availability Masking (SAM), which is simply a feature that helps identify and prevent interfering bands to ensure a smooth exchange. In the Bluetooth 5.0 version, the physical location of the devices in a room up to 1 meter can be introduced to provide a more reliable connection. Improved caching with this version also helps with pairing devices faster.

There is an eightfold increase in throughput with the Bluetooth 5.0 version, although this version has backward compatibility with devices. For example, if the device you want to use in pairing with your wireless headphones is an older version of Bluetooth, say Bluetooth 4.2; the headphones will connect to your device on a 4.2 band, rather than a 5.0 connection. Now, the connection will be seamless, but because of the bandwidth difference, you are more likely to experience interruptions in music playing and another audio usage. Wi-Fi signals and other mobile signals can further cause interruptions due to this difference in bandwidth.

To know the Bluetooth version, the wireless headphone you want to buy uses, check the product packaging. Most manufacturers write the version of Bluetooth in use on the pack of the headphones. It is also advisable that you check the Bluetooth version your mobile device uses before making the headphone purchase, as this will give you an idea of the best version to buy that will be compatible with the headphones.

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