Abstract: A method for determining an access authorization to a transportation vehicle, wherein an internal authorization device emits a request signal into an environment of the transportation vehicle depending on a predefined triggering event. The authorization device checks the response signal received for at least one request condition. Based on the at least one request condition, access to the transportation vehicle is granted. Concurrently, the transportation vehicle-internal authorization device forwards the request signal to a transportation vehicle-internal key processing unit which calculates a comparison response signal and forwards the signal to the authorization device. The authorization device determines a time difference between a time of receipt of the response signal from the environment of the transportation vehicle and a time of receipt of the comparison response signal.

Abstract: A method for determining an access authorization to a transportation vehicle, wherein an internal authorization device emits a request signal into an environment of the transportation vehicle depending on a predefined triggering event. The authorization device checks the response signal received for at least one request condition. Based on the at least one request condition, access to the transportation vehicle is granted. Concurrently, the transportation vehicle-internal authorization device forwards the request signal to a transportation vehicle-internal key processing unit which calculates a comparison response signal and forwards the signal to the authorization device. The authorization device determines a time difference between a time of receipt of the response signal from the environment of the transportation vehicle and a time of receipt of the comparison response signal.