Security system, especially passive security system for motor vehicle, has base station that monitors received natural high frequency signal level, detects disturbances for detection of relay position

摘要

The system includes an electronic key with a transmitter and a protected object with a base station with a receiver. The transmitter and receiver are configured to communicate with each other to exchange authentication data. The base station regularly monitors the natural high frequency signal level received by the receiver and detects disturbances in the signal level to enable detection of a relay position (16). AN Independent claim is also included for the following: (a) a communications method implemented by a security system.