The standard of wireless data transmission between Bluetooth devices, despite the short range, is popular around the world and is actively used to solve many problems. The ease of use of the Bluetooth interface in smartphones, computers and other digital devices has ensured the dynamic development and advancement of technology. Many phone manufacturers even deprive their devices of the 3.5-millimeter headphone jack, teaching users to listen to audio without wires. Modern smartphones support the A2DP Bluetooth standard, which enables the use of wireless headphones or speakers.
How to use A2DP profile in the phone.
What is A2DP profile
The functionality of the phones expands every year, as a result of which the mobile device, besides its main task, has long been able to perform many others. Having discovered the A2DP profile in a smartphone, some users wonder what it is. This is the topic we will reveal. Bluetooth Profile A2DP (Advanced Audio Distribution Profile) is an advanced protocol for wireless audio distribution between devices. The transfer of stereo sound is carried out via Bluetooth in real time. Devices that support A2DP can be divided into two types:
- The transmitter, which can act as a smartphone, tablet, console, Smart-TV, PDA or other device. In this case, the task of the device is to transmit audio.
- Receiver (headphones, portable speaker, radio, etc.), that is, a device that receives audio signal.
The implementation of the technology allows you to transfer high-quality audio files of various formats via Bluetooth wireless connection. Sending a two-channel audio signal via Bluetooth in the original version without compression is impossible due to the bandwidth limitations of this wireless personal area network specification, therefore the digital stream is processed before being sent to the receiving device. The A2DP profile for compression uses various codecs that compress audio content to the size of the Bluetooth channel, while the sound quality remains at a high level due to the algorithms used. Compression in the case of A2DP is performed with minimal loss of quality, which means that the receiver receives stereo sound with high-quality bitrate.
Features of operation
The activation of the Bluetooth connection is provided by the profiles that the device supports, their availability, and the functional capabilities are determined, as well as the range of equipment with which interaction is possible. Often, in conjunction with A2DP, the AVRCP profile is also supported, which provides the device with control over the functionality of the TV, home theater system, car stereo, etc., that is, the performance of remote control functions. It is not enough just to provide communication over the channel; to perform the necessary tasks, both the signal source and the receiver must have the support of the same profiles. Their implementation depends on the design features of the hardware, the specifics, as well as the policies of the manufacturer.
A2DP profile support involves the transfer of stereo audio stream from a signal source to a wireless headset or other audio playback devices and, as mentioned above, a small loss of quality is inevitable due to the peculiarities of Bluetooth technology. Most often, the compression of the transmitted stream is performed using a standard SBC codec or another code, for example, MP3, AAC, etc. For example, the interacting devices agree on the codec with which the signal will be processed (both must support the same) and encoding parameters (bitrate, sampling rate ). Note that if SBC is used, the sound quality will be lower than when encoded using MP3 with standard settings.
The technology provides data transmission in the range of about 10 meters, at a longer distance the signal will be interrupted, interference will occur. This should take into account the presence of obstacles in the form of walls, partitions, etc., so that for the stability of the connection, the interacting devices must be closer to each other. To date, A2DP technology is significantly inferior in quality of transmitted audio to more modern, improved standards AptX and AptX HD, providing almost lossless sound transmission.
The technology is widely used and the A2DP profile can be found in a wide variety of devices, such as smartphones, tablets, PDAs, laptops, speakers, headsets, wireless headphones, speaker systems, Smart TV and other devices with Bluetooth support. You can connect your phone to the radio or any other digital equipment in the presence of A2DP among their characteristics, as well as control playback. The standard supports operating systems Windows, Linux, Mac OS X and mobile OS Android, iOS, Windows Phone, BlackBerry. The ability to transfer audio requires synchronization of devices, for which you need to turn on A2DP Bluetooth on the device and select a receiver, how to do this, we consider below on the example of Android. The compatibility of equipment with A2DP technology allows connecting devices regardless of their model and manufacturer, which is very convenient.
How to connect
To apply the A2DP communication standard, you must activate the corresponding function in the settings of the supporting device. For example, on Android smartphones you will need to turn on Bluetooth. You can do this by accessing the settings (the option is available in the Wireless Networks block) or from the notification curtain opened from the desktop, which will be even faster. If the A2DP profile is supported by the smartphone, it will be activated, while it does not need to be configured. Next you need to turn on the headphones, which must be charged.
The smartphone will detect the device and it must be selected from the list of devices available for connecting via Bluetooth, followed by synchronization. To enjoy the benefits of modern technology A2DP Bluetooth audio transmission, the user does not need to configure anything further, the function is available immediately after activation, provided the communication standard is supported by both devices.