Bluetooth protocol is to determine what kind of function the device can have a technology, the more protocols supported by the device the more comprehensive the functionality of the current Bluetooth devices, there are some major support agreements as follows:
HFP (Hands-free Profile) Hands-free protocol: Bluetooth devices can control the phone, such as answering, hanging up, rejecting, voice dialing and so on.
HSP (Headset Profile) Device Protocol: Represents the headset features that provide the basic functionality required for communication between the headset and the headset. When connected and configured, the headset can be used as the audio input and output interface for remote devices. This is the most commonly used configuration, support Bluetooth headset and mobile phone use, the typical scenario is to use a wireless headset to connect with the phone.