Specifications

Windows Embedded Automotive 7 Deep Dive: Phone Core and Media Core 21
bit mask for 16 tunable settings. Microsoft does not recommend changing the settings, as this
typically results in degraded audio quality.
Two additional registry keys hold AEC/NS configuration settings:
• HKEY_LOCAL_MACHINE\Software\Microsoft\Automotive\HFP\SendNRECSetting
• HKEY_LOCAL_MACHINE\Software\Microsoft\Automotive\HFP\NoiseSuppressSetting
Table 6 lists the key values that can be configured for each registry key.
Note: The first three values in the following table define whether or not the AT+NREC=0
command is sent to the phone’s audio gateway (AG). This HFP command turns off noise
reduction and echo cancellation on a phone.
Table 6: AEC/NS registry key values
HKEY_LOCAL_MACHINE\Software\Microsoft\Automotive\HFP\SendNRECSetting
HKEY_LOCAL_MACHINE\Software\Microsoft\Automotive\HFP\NoiseSuppressSetting
Key Value
Description
ALLOW_NREC_REGISTRY_OVERRIDE
The Hands-Free Profile Service (HFPSvc) sends the AT+NREC=0 command
to the phone’s AG unless the PHONESPECIFIC_SKIP_AT registry setting is
active for this phone manufacturer/model. This is the default setting.
ALWAYS_SEND_NREC
The HFPSvc always sends the AT+NREC=0 command to any AG.
NEVER_SEND_NREC
The HFPSvc never sends the AT+NREC=0 command to any AG.
USE_NS_UNLESS_NO_NREC
The HFPSvc enables AEC/NS unless the AT+NREC=0 command fails or is
blocked from being sent by the HFP\SendNRECSetting command. This is a
default setting.
ALWAYS_USE_NS
The HFPSvc always enables AEC/NS, independent of the
HFP\SendNRECSetting command.
NEVER_USE_NS
The HFPSvc always disables AEC/NS, independent of the
HFP\SendNRECSetting command.
Supported Bluetooth Profiles
Phone Core supports the Bluetooth Core 2.1+EDR specification with Secure Simple Pairing (SSP).
You can find the complete specification at
http://www.bluetooth.com/English/Technology/Building/Pages/Specification.aspx.
Phone Core supports the following Bluetooth profiles:
• Generic Object Exchange Profile (GOEP) 1.1
• Object Push Profile (OPP) 1.1