21-02-2011, 03:25 PM
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Bluetooth
A Bluetooth profile is a wireless interface specification for Bluetooth-based communication between devices. In order to use Bluetooth technology, a device must be compatible with the subset of Bluetooth profiles necessary to use the desired services. A Bluetooth profile resides on top of the Bluetooth Core Specification and (optionally) additional protocols. While the profile may use certain features of the core specification, specific versions of profiles are rarely tied to specific versions of the core specification. For example, there are HFP 1.5 implementations using both Bluetooth 2.0 and Bluetooth 1.2 core specifications.
The way a device uses Bluetooth technology depends on its profile capabilities. The profiles provide standards which manufacturers follow to allow devices to use Bluetooth in the intended manner.
At a maximum, each profile specification contains information on the following topics:
• Dependencies on other formats
• Suggested user interface formats
• Specific parts of the Bluetooth protocol stack used by the protocol. To perform its task, each profile uses particular options and parameters at each layer of the stack. This may include an outline of the required service record, if appropriate.
Advanced Audio Distribution Profile (A2DP)
This profile defines how high quality audio (stereo or mono) can be streamed from one device to another over a Bluetooth connection.[1] For example, music can be streamed from a mobile phone to a wireless headset or car audio or from a laptop/desktop to a wireless headset.
A2DP was initially used in conjunction with an intermediate Bluetooth transceiver that connects to a standard audio output jack, encodes the incoming audio to a Bluetooth-friendly format, and sends the signal wirelessly to Bluetooth headphones that decode and play the audio. Bluetooth headphones, especially the more advanced models, often come with a microphone and support for the Headset (HSP), Hands-Free (HFP) and Audio/Video Remote Control (AVRCP) profiles.
A2DP is designed to transfer a uni-directional 2-channel stereo audio stream, like music from an MP3 player, to a headset or car radio.[2] This profile relies on AVDTP and GAVDP. It includes mandatory support for the low-complexity SBC codec (not to be confused with Bluetooth's voice-signal codecs such as CVSDM), and supports optionally: MPEG-1 , MPEG-2, MPEG-4, AAC, and ATRAC, and is extensible to support manufacturer-defined codecs, such as apt-X. Some Bluetooth stacks enforce the SCMS-T digital rights management (DRM) scheme. In these cases, it is impossible to connect certain A2DP headphones for high quality audio.
Operating systems
• Android: Supported in version 1.5.
• BlackBerry: Supports A2DP in Operating System 4.2.
• iPhone and iPod Touch: All iPhones support HFP and PBAP. Version 3.0 of the operating system added support for A2DP, limited AVRCP and PAN for iPhone 3G/3GS and iPod Touch 2nd/3rd generation only. iPod Touch 2g is now compatible with headsets that use the PAN profile. Original iPhone (iPhone 2G) bluetooth chip can provide A2DP as well, but Apple decided not to enable it. However, A2DP can be enabled in a jailbroken iPhone 2G by a special utility.
• Linux: Initial A2DP support was added to BlueZ in version 3.15. The instructions to set up A2DP can be found in the BlueZ Wiki; Since Ubuntu 10.10 setting up a A2DP is as easy as pairing your computer with the bluetooth device and selecting this device as sound in- and/or output in the sound preferences.
• Mac OS X: As of version 10.5, Mac OS X includes native support for A2DP on Bluetooth-equipped Macs. Version 10.4 does not support A2DP, but can be hacked to enable limited functionality.
• Motorola P2K: Motorola L9 running on P2K supports A2DP Profile.
• Nucleus : All Mediatek 6225+ Chipsets supports A2DP Profile.
• Palm OS: A2DP not supported, but can be implemented with third-party applications.
• Palm webOS: A2DP supported by Palm Pre.
• Symbian Series60: Devices running Series60 3rd Edition FP1 (S60v3.1/Symbian 9.1) and newer support A2DP
• UIQ: UIQ 3.0 (Symbian 9.1) and newer support A2DP.
• Windows Mobile (previously Pocket PC): Version 4.0 and newer via Widcomm third party add on. Version 5.0 and newer (with AKU 2.0), thus far based on the Windows CE 5.0 kernel, fully support A2DP if an appropriate device is present.
• Windows XP: Does not natively support A2DP, but newer Bluetooth USB dongles and built-in adapters include drivers with A2DP support.
• Windows Vista: Does not support A2DP natively, but third-parties can provide A2DP profile support without entirely replacing Microsoft's stack. Service Pack 2 adds Bluetooth 2.1 capabilities such as simplified pairing.
• Windows 7: A2DP working on Windows 7 beta releases. Windows 7 Release Candidate and final release no longer includes a Bluetooth audio-class driver. A2DP support is provided entirely by third-party Bluetooth software.
Audio/Video Remote Control Profile (AVRCP)
This profile is designed to provide a standard interface to control TVs, Hi-fi equipment, etc. to allow a single remote control (or other device) to control all of the A/V equipment to which a user has access. It may be used in concert with A2DP or VDP.
It has the possibility for vendor-dependent extensions.
AVRCP has several versions with significantly increasing functionality:
Bluetooth
A Bluetooth profile is a wireless interface specification for Bluetooth-based communication between devices. In order to use Bluetooth technology, a device must be compatible with the subset of Bluetooth profiles necessary to use the desired services. A Bluetooth profile resides on top of the Bluetooth Core Specification and (optionally) additional protocols. While the profile may use certain features of the core specification, specific versions of profiles are rarely tied to specific versions of the core specification. For example, there are HFP 1.5 implementations using both Bluetooth 2.0 and Bluetooth 1.2 core specifications.
The way a device uses Bluetooth technology depends on its profile capabilities. The profiles provide standards which manufacturers follow to allow devices to use Bluetooth in the intended manner.
At a maximum, each profile specification contains information on the following topics:
• Dependencies on other formats
• Suggested user interface formats
• Specific parts of the Bluetooth protocol stack used by the protocol. To perform its task, each profile uses particular options and parameters at each layer of the stack. This may include an outline of the required service record, if appropriate.
Advanced Audio Distribution Profile (A2DP)
This profile defines how high quality audio (stereo or mono) can be streamed from one device to another over a Bluetooth connection.[1] For example, music can be streamed from a mobile phone to a wireless headset or car audio or from a laptop/desktop to a wireless headset.
A2DP was initially used in conjunction with an intermediate Bluetooth transceiver that connects to a standard audio output jack, encodes the incoming audio to a Bluetooth-friendly format, and sends the signal wirelessly to Bluetooth headphones that decode and play the audio. Bluetooth headphones, especially the more advanced models, often come with a microphone and support for the Headset (HSP), Hands-Free (HFP) and Audio/Video Remote Control (AVRCP) profiles.
A2DP is designed to transfer a uni-directional 2-channel stereo audio stream, like music from an MP3 player, to a headset or car radio.[2] This profile relies on AVDTP and GAVDP. It includes mandatory support for the low-complexity SBC codec (not to be confused with Bluetooth's voice-signal codecs such as CVSDM), and supports optionally: MPEG-1 , MPEG-2, MPEG-4, AAC, and ATRAC, and is extensible to support manufacturer-defined codecs, such as apt-X. Some Bluetooth stacks enforce the SCMS-T digital rights management (DRM) scheme. In these cases, it is impossible to connect certain A2DP headphones for high quality audio.
Operating systems
• Android: Supported in version 1.5.
• BlackBerry: Supports A2DP in Operating System 4.2.
• iPhone and iPod Touch: All iPhones support HFP and PBAP. Version 3.0 of the operating system added support for A2DP, limited AVRCP and PAN for iPhone 3G/3GS and iPod Touch 2nd/3rd generation only. iPod Touch 2g is now compatible with headsets that use the PAN profile. Original iPhone (iPhone 2G) bluetooth chip can provide A2DP as well, but Apple decided not to enable it. However, A2DP can be enabled in a jailbroken iPhone 2G by a special utility.
• Linux: Initial A2DP support was added to BlueZ in version 3.15. The instructions to set up A2DP can be found in the BlueZ Wiki; Since Ubuntu 10.10 setting up a A2DP is as easy as pairing your computer with the bluetooth device and selecting this device as sound in- and/or output in the sound preferences.
• Mac OS X: As of version 10.5, Mac OS X includes native support for A2DP on Bluetooth-equipped Macs. Version 10.4 does not support A2DP, but can be hacked to enable limited functionality.
• Motorola P2K: Motorola L9 running on P2K supports A2DP Profile.
• Nucleus : All Mediatek 6225+ Chipsets supports A2DP Profile.
• Palm OS: A2DP not supported, but can be implemented with third-party applications.
• Palm webOS: A2DP supported by Palm Pre.
• Symbian Series60: Devices running Series60 3rd Edition FP1 (S60v3.1/Symbian 9.1) and newer support A2DP
• UIQ: UIQ 3.0 (Symbian 9.1) and newer support A2DP.
• Windows Mobile (previously Pocket PC): Version 4.0 and newer via Widcomm third party add on. Version 5.0 and newer (with AKU 2.0), thus far based on the Windows CE 5.0 kernel, fully support A2DP if an appropriate device is present.
• Windows XP: Does not natively support A2DP, but newer Bluetooth USB dongles and built-in adapters include drivers with A2DP support.
• Windows Vista: Does not support A2DP natively, but third-parties can provide A2DP profile support without entirely replacing Microsoft's stack. Service Pack 2 adds Bluetooth 2.1 capabilities such as simplified pairing.
• Windows 7: A2DP working on Windows 7 beta releases. Windows 7 Release Candidate and final release no longer includes a Bluetooth audio-class driver. A2DP support is provided entirely by third-party Bluetooth software.
Audio/Video Remote Control Profile (AVRCP)
This profile is designed to provide a standard interface to control TVs, Hi-fi equipment, etc. to allow a single remote control (or other device) to control all of the A/V equipment to which a user has access. It may be used in concert with A2DP or VDP.
It has the possibility for vendor-dependent extensions.
AVRCP has several versions with significantly increasing functionality:
