Procedures for passive access control

A passive access system comprising:

• a mobile device serving as a transportation vehicle key;
• and
• a transportation vehicle,
• wherein the mobile device and the transportation vehicle each has at least one data communication facility configured for exchanging authorization information,
• wherein the mobile device has an electronic distance measuring facility and the transportation vehicle has a plurality of electronic distance measuring facilities, wherein each electronic distance measuring facility is configured for determining distance between the mobile device and the respective one of the plurality of electronic distance measuring facilities of the transportation vehicle,
• wherein the electronic distance measurement of the distance between the mobile device and each of the plurality of electronic measuring facilities of the transportation vehicle is performed at both the mobile device and each of the plurality of electronic distance measurement facilities of the transportation vehicle,
• wherein the mobile device in cooperation with the transportation vehicle permit an access and/or an interaction to the transportation vehicle only in response to distance of the mobile device from the at least one of the plurality of electronic distance measurement facilities of the transportation vehicle being within a permitted distance, and a deviation of the distances measured by the mobile device and the at least one of the plurality of the electronic distance measurement facilities of the transportation vehicle being zero or less than a predetermined limit value,
• wherein the electronic distance measurement performed at each of the electronic distance measurement facilities at the mobile device and at the transportation vehicle is based on a transit-time measurement of a radio signal transmitted between the mobile device and the transportation vehicle, and
• wherein the distance measuring facility for the mobile device is attached or attachable to the mobile device or integrated into the mobile device during production of the mobile device.

A transportation vehicle having a passive access system, comprising:

• a plurality of electronic distance measuring facilities that determine distance between a mobile device and respective ones of the plurality of the electronic distance measuring facilities of the transportation vehicle,
• wherein the mobile device serves as a key for the transportation vehicle,
• wherein the mobile device and the transportation vehicle each have at least one data communication facility for exchanging authorization information,
• wherein the mobile device includes an electronic distance measuring facility attached or attachable to the mobile device or integrated into the mobile device during production of the mobile device and the transportation vehicle comprises the plurality of electronic distance measuring facilities,
• wherein electronic distance measurement is performed by each of the electronic distance measuring facilities at the mobile device and at the transportation vehicle based on a transit time measurement of a radio signal transmitted therebetween, wherein access and/or an interaction with the transportation vehicle is performed only in response to the distance between the mobile device and at least one of the plurality of electronic distance measuring facilities of the transportation vehicle being within a permitted distance, and a deviation of the distances measured by the plurality of electronic distance measuring facilities being zero or less than a predetermined limit value.