More about Bluetooth SSP Mode
SSP is required for devices using Bluetooth v 2.1 and later. Bluetooth v 2.0 and earlier devices use Legacy Pairing.
APx provides four SSP (Secure Simple Pairing) options. You must choose the option that is appropriate for the Bluetooth device you are testing.
Man-in-the-middle (MITM)
Man-in-the-middle or MITM is the term used in Bluetooth technology to refer to Secure Simple Pairing mechanisms that require human interaction. One device may display a PIN, for example, and the user may be required to enter the same PIN using a keyboard on a second device. MITM methods add security to the pairing process.
APx SSP Modes
This mode is used in Bluetooth device relationships that require little security, such as headsets. User interaction is not required.
Numeric Comparison, Display Only
Some Bluetooth devices have only a display screen to interact with a user; an example is a car kit (car stereo head unit). Use this mode when APx is playing the role of such a device.
A use case would be testing a smart phone. APx would be an A2DP Sink, HFP with a display only (the car kit), and the DUT would be the smart phone. The phone would initiate pairing, and APx would display the PIN transmitted from the phone. The user would confirm (using a button on the phone) that the PIN displayed in APx matched the PIN on the phone.
Numeric Comparison, Display+Buttons
Some Bluetooth devices have a display screen and one or more buttons to interact with a user; the button may be used for a binary (Yes/No) response to a query. An example is a smart phone. Use this mode when APx is playing the role of such a device.
A use case would be testing a car kit. APx would be an A2DP Source, HFP Hands-Free with a display and buttons (the smart phone), and the DUT would be the car kit. APx would initiate pairing and transmit a PIN to the DUT. The DUT would display the PIN, and the user would confirm (using a button in the APx prompt dialog) that the PIN in the DUT display and the APx PIN matched.
Numeric Comparison, Keyboard
Some Bluetooth devices have a numeric or alphanumeric keyboard to interact with the user. An example is a computer used as an audio source, distributing iTunes audio to a home entertainment system. Use this mode when APx is playing the role of such a device.
There are not obvious use cases in audio test for this mode, which is include in APx for completeness. A non-audio test use case would be pairing a Bluetooth keyboard to a tablet computer. The computer would display a PIN, and the user would enter a PIN (using the keyboard) that matches the PIN on the tablet screen.
Legacy Pairing
Bluetooth v2.1 and later devices (such as APx) are permitted to use Legacy Pairing modes when pairing with a Bluetooth v2.0 or earlier device.
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