Passive Entry Passive Start (PEPS) is a phone-as-a-key method for radio-controlled authentication of automotive access applications. The PEPS method allows car doors to be opened and the motor vehicle to be started via the smartphone.
Radio keys from traditional PEPS systems transmit their radio signals in the ISM bands at 130 kHz and in the UHF range at 868 MHz or even on ultra-wideband. These radio signals, which are used to exchange key access codes between the key and the vehicle, are used for unique authentication. Since the aforementioned radio technologies are not supported by smartphones, the smartphone-based PEPS technology uses the energy-saving Bluetooth Low Energy( BLE).
Phone-as-a-key methods work with an exchange of key codes. Communication between the smartphone and the motor vehicle takes place via a smart key module installed inside the car, which handles central communication control. If the exchanged key codes match the expected values and the key is near the vehicle, the driver can open the car door. Using additional peripheral key nodes connected to the smart key module, the PEPS system determines whether the smartphone is inside or outside the vehicle, and at what distance the smartphone is from the vehicle. If it is inside the vehicle, it warns the driver if he has forgotten it in the car. On the other hand, the vehicle cannot be started if the key is outside the vehicle.