Passive Entry Passive Start (PEPS) is a phone-as-a-key method for radio-controlled authentication of motor vehicle access applications. The PEPS method makes it possible to open car doors and start the motor vehicle via the smartphone
. Radio keys of 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. Unique authentication is performed with these radio signals, which are used to exchange key access codes between the key and the vehicle. Since the aforementioned radio technologies are not supported by smartphones, the smartphone-based PEPS technology works with the energy-saving Bluetooth Low Energy
(BLE).Smart Key Module, which is installed inside the car and takes over 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. Through 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.