This profile is used to allow car hands-free kits to communicate with mobile phones in the car. It commonly uses Synchronous Connection Oriented link (
SCO) to carry a
monaural audio channel with
continuously variable slope delta modulation or
pulse-code modulation, and with logarithmic
a-law or
μ-law quantization. Version 1.6 adds optional support for wide band speech with the mSBC codec, a 16 kHz monaural configuration of the
SBC codec mandated by the
A2DP profile. Version 1.7 adds indicator support to report such things as headset battery level. Version 1.9 adds
LC3-SWB codec. In 2002
Audi, with the
Audi A8, was the first motor vehicle manufacturer to install Bluetooth technology in a car, enabling the passenger to use a wireless in-car phone. The following year
DaimlerChrysler and
Acura introduced Bluetooth technology integration with the audio system as a standard feature in the third-generation
Acura TL in a system dubbed HandsFree Link (HFL). Later,
BMW added it as an option on its
1 Series,
3 Series,
5 Series,
7 Series and
X5 vehicles. Since then, other manufacturers have followed suit, with many vehicles, including the
Toyota Prius (since 2004), 2007
Toyota Camry, 2006
Infiniti G35, and the
Lexus LS 430 (since 2004). Several
Nissan models (
Versa, X-Trail) include a built-in Bluetooth for the Technology option.
Volvo started introducing support in some vehicles in 2007, and as of 2009 all Bluetooth-enabled vehicles support HFP. Many car audio consumer electronics manufacturers like Kenwood, JVC, Sony, Pioneer and Alpine build car audio receivers that house Bluetooth modules all supporting various HFP versions. Bluetooth car kits allow users with Bluetooth-equipped cell phones to make use of some of the phone's features, such as making calls, while the phone itself can be left in the user's pocket or hand bag. Companies like
Visteon Corp.,
Peiker acustic, RAYTEL ,
Parrot SA,
Novero, Dension, S1NN and Motorola manufacture Bluetooth hands-free car kits for well-known brand car manufacturers. Most Bluetooth headsets implement both Hands-Free Profile and Headset Profile, because of the extra features in HFP for use with a mobile phone, such as last number redial, call waiting and voice dialing. The mobile phone side of an HFP link is Audio Gateway or HFP Server. The automobile side of HFP link is Car Kit or HFP Client. == Human Interface Device Profile (HID) ==