SDP is the Bluetooth Service Discovery Protocol. Dialling and control is the commands and procedures used for automatic dialling and control over the asynchronous serial link provided by the lower layers. The modem emulation layer shown a bove is the entity emulating the modem, and the modem driver is the driver software in the data terminal. For these protocols, all requirements stated in the Serial Port Profile apply except in those cases where this profile explicitly states deviations. This is the device that provides facsimile services.
Typical devices acting as gateway are cellular phones and modems.
This is the device that uses the facsimile services of the gateway. Typical devices acting as data terminals are laptops and desktop PCs. In the rest of this document, these terms are only used to designate these roles. This profile requires support for one-slot packets only. This means that this profile ensures that data rates up to 128 Kbps can be used.