System comprising a door, a door lock and a radio key

Abstract

The invention relates to a system comprising a door, in particular of a vehicle, having a door lock, a door control module that has a transmission/reception unit at the door side or is connected thereto, and having a key that is associated with the door lock and that has a transmission/reception unit at the key side, wherein the transmission/reception unit at the door side and the transmission/reception unit at the key side are configured for radio communication. The time of flight of a radio signal transmitted by the transmission/reception unit at the door side and reflected by the transmission/reception unit at the key side can be determined by means of the transmission/reception unit at the door side. Alternatively, the time of flight of a radio signal transmitted by the transmission/reception unit at the key side and reflected by the transmission/reception unit at the door side can be determined by means of the transmission/reception unit at the key side.

Dependencies are inferred from the claim text.