SAP
(SIM Access Profile)
A Bluetooth profile (mode) that enables a phone to securely share its SIM card information with another device.
This is typically used for advanced car kit systems, where the car's infotainment system will have its own cellular radio and antenna, but connect to the user's phone via Bluetooth and use the phone's SIM card. This allows the performance benefits of a dedicated radio and antenna for the car, with the convenience of a single phone number and account, tied to one phone that can stay in the user's pocket.
See: Bluetooth