Understanding Bluetooth Profiles: HFP, HSP, A2DP, AVRCP, PBAP, MAP

Bluetooth profiles are standardized sets of protocols that define how Bluetooth devices communicate and interact with each other for specific purposes. We will explore a list of Bluetooth profiles, including HSP, HFP, A2DP, PBAP, AVRCP, and MAP, and the differences between them.

Key features of Bluetooth technology:

• Bluetooth operates at the 2.4 GHz ISM band.
• It covers a range of about 10 to 100 meters.
• It is an interference-tolerant system as it supports AFH (Adaptive Frequency Hopping) capability.
• It provides reliable and secure wireless connectivity.
• It consumes low power.
• It is interoperable with various vendor devices.
• It supports different operating systems such as Windows, Linux, Android, iOS, etc.
• The Bluetooth standard has been maintained and developed by the Bluetooth SIG.
• The different versions of Bluetooth standards are Bluetooth Classic, Bluetooth Low Energy (i.e., Bluetooth Smart), and Bluetooth High Speed.

Bluetooth Profiles List

Bluetooth profiles serve various communication and entertainment needs. They ensure compatibility and smooth interactions between different Bluetooth-enabled devices. The choice of profile depends on the intended use case, such as making calls, listening to music, controlling media playback, or accessing contact and message data.

Let’s understand each of these profiles one by one.

HFP Bluetooth Profile

HFP is designed for hands-free calling in vehicles and headsets. It allows for voice calls and audio streaming. It provides call control functions such as answer, end, and reject calls.

• HFP stands for Hands-Free Profile.
• It enables voice transmission between a mobile phone and a wireless headset in order to provide comfort while driving or during exercise.
• Audio is transmitted over a synchronous SCO channel. A separate data channel is used to control the audio stream.
• Other features include support for mono audio, sampling rates from 8 KHz to 16 KHz, and an audio delay of about 20 to 30 ms.
• The HFP Bluetooth profile supports audio codecs such as CVSD and mSBC.
• AT commands are used to control the mobile phone.

HSP Bluetooth Profile

It enables voice transmission between a mobile phone and a wireless Bluetooth headset. The primary use case is mono voice calls using Bluetooth headsets. It supports limited audio streaming capabilities and is often used in mono Bluetooth headsets.

• HSP stands for Headset Profile.
• Audio is transmitted over a synchronous SCO channel.
• It has become obsolete due to the availability of the HFP profile.
• Other features of the HSP Bluetooth profile are mono audio, 8 KHz sampling, audio delay of 20 to 30 ms, and CVSD codec, etc.

A2DP Bluetooth Profile

A2DP stands for Advanced Audio Distribution Profile. It enables stereo audio streaming between a music player (as source) and speakers/headphones (as sink).

It provides high-quality audio streaming (stereo). It is ideal for music playback from devices to Bluetooth audio output devices.

AVRCP Bluetooth Profile

• AVRCP stands for Audio/Video Remote Control Profile.
• It enables an audio sink to control the audio sources’ music player and streaming status.
• It uses a data channel to transmit control information between the audio controller and target.
• AVRCP v 1.5 enables advanced features like media browsing, audio player, and playlist management.
• Other features of the AVRCP Bluetooth profile are as follows:
  • Content browsing (artists, songs, etc.)
  • Content searching
  • Audio player management
  • Enables audio stream status control
  • Enables transmission of track, title, and other media information
  • Playlist management, etc.

PBAP Bluetooth Profile

PBAP provides access to contact and address book information stored on a mobile device, typically used in car infotainment systems for accessing phone contacts and caller ID information.

• PBAP stands for Phone Book Access Profile.
• This profile enables the exchange of phone book objects between, for example, a smartphone and a car kit.
• It uses a data channel to transmit vCARDS over a Bluetooth connection.
• The other features of the PBAP Bluetooth profile are:
  • Download phone book items
  • Access call history
  • Access subscriber number information, etc.

MAP Bluetooth Profile

MAP stands for Message Access Profile. MAP allows access to text messages and email data on a paired device, often used in car infotainment systems for hands-free access to messages and emails. The primary use case is accessing text messages and email data while driving through the car’s infotainment system.

• This profile enables the exchange of messages between a smartphone and a car kit.
• It uses a data channel to transmit SMS and email notifications and messages over Bluetooth.
• The other features of the MAP Bluetooth profile are as follows:
  • SMS and email notifications
  • Download of messages
  • Upload of messages
  • Browsing message folders
• Bluetooth MAP Version specifications are developed to allow the exchange of messages between devices. It is mostly used for automotive hands-free use.

Conclusion

The following table summarizes the difference between the HSP, HFP, A2DP, PBAP, AVRCP, and MAP Bluetooth profile versions.

These profiles ensure seamless communication and interaction between various Bluetooth-enabled devices, catering to a wide range of applications, from hands-free calling and audio streaming to media control and data access.