Bluetooth protocol HFP, HSP, A2DP, AVRCP, OPP, PBAP
Introduction:
HSP (Hand Phone Profile) – Provides the basic functions required for communication between a cell phone (mobile phone) and the headset.
HFP (Hands-Free Profile) – An extension of the HSP that was originally only used to control a mobile phone from a fixed in-vehicle hands-free.
A2DP (Advanced Audio Distribution Profile) – Allows the transmission of stereo audio signals. (Much better quality than mono encryption used for HSP and HFP
many)
AVRCP (Audio/Video Remote Control Profile) – used to send data from a controller (such as a stereo headset) to a target device (such as a computer with Media Player)
Send commands (such as skip forward, pause, and play).
Detailed introduction:
HFP
HFP (Hands-freeProfile), allows Bluetooth devices to control the phone, such as answering, hanging up, rejecting, voice dialing, etc. The rejection and voice dialing depend on whether the Bluetooth headset and the phone are
support.
HSP
HSP describes how a Bluetooth headset communicates with a computer or other Bluetooth device such as a cell phone. Once connected and configured, the headset can act as an audio input and output interface for the remote device.
This is the most commonly used configuration for use with currently popular Bluetooth headsets and mobile phones. It relies on audio encoded at 64 kbit/s in CVSD or PCM as well as AT commands from
A subset of GSM07.07, including minimal control of the ability to ring, answer incoming calls, hang up and adjust volume.
A typical usage scenario is using a wireless headset to connect to a mobile phone.
Several types of devices that may use HSP: headsets, cell phones, PDAs, PCs, laptops.
A2DP
The full name of A2DP is the AdvancedAudio Distribution Profile Bluetooth audio transmission model agreement! A2DP can use the chip in the headset to stack data to achieve high sound quality.
clarity. Headphones with A2DP are Bluetooth stereo headphones. The sound can reach 44.1kHz, and the general earphone can only reach 8kHz. If your phone supports Bluetooth, just install
Load the A2DP protocol, you can use the A2DP headset. There are also consumers who see that the technical parameters mention Bluetooth V1.0V1.1 V1.2 V2.0 - these refer to the technical version of Bluetooth, which refers to
The speed of transmission over Bluetooth, whether they support A2DP depends on whether the Bluetooth product manufacturer uses this technology
AVRCP
AVRCP (Audio/VideoRemote Control Profile), which is the audio/video remote control specification.
AVRCP is designed to provide a standard interface for controlling TVs, Hi-Fi devices, etc. This profile is used to allow a single remote control device (or other device) to control all users
input A/V equipment. It can be used with A2DP or VDP.
AVRCP defines how to control the characteristics of streaming media. Includes pause, stop, start playback, volume control, and other types of remote control operations. AVRCP defines two angles
color, that is, the controller and the target device. The controller is usually the remote control device, and the target device is the device whose characteristics can be changed. In AVRCP, the controller will detect the user
Actions are translated into A/V control signals, which are then transmitted to remote Bluetooth devices. For "Walkman" type media players, the control device can be one that allows skipping of tracks
headset, and the target device is the actual player. The available functions of a conventional infrared remote control can be implemented in this protocol.
The AVRCP protocol specifies the application range of the AV/C digital interface command set (AV/C command set, defined by the 1394 industry association), achieving simplified implementation and easy operability. this agreement
The AV/C device mode and command format are used for control messages, which can be transmitted via the Audio/Video Control Transport Protocol (AVCTP).
UP
The Bluetooth communication program part needs to use the OPP Profile for the transmission of data objects between devices: Object Push Profile is subdivided into OPPC (client) and
OPPS (server) side profile, the difference between these two profiles is that only the client side can initiate the process of data transmission, but in the scenario where the accessory device communicates with the mobile phone, the existing mobile phone
Initiating a data transmission request also requires the device side to initiate a transmission request, so two profiles, OPPC and OPPS, must be implemented in the device.
PBAP
PhonebookAccess Profile