Abstract: A method for determining a protection zone with a protection radius about a wireless communication object transponder, wherein the method includes a) ascertaining a first indefinite position of the object transponder using a first locating system, b) ascertaining at least two definite anchor object distances between the object transponder and at least two anchor gateways with respective known positions via a definite distance measuring device using a two-way ranging method, and c) ascertaining the protection radius using a failsafe computing device which receives the first indefinite position from the first locating system and the at least two definite anchor object distances from the distance measuring device and determines the protection radius therefrom using the known positions of the at least two anchor gateways.

Abstract: A method for determining a definite safe distance between a wirelessly communicating object transponder and at least one anchor gateway in accordance with a two-way ranging method, wherein transmission and reception timestamps are detected for each communication message via the transponder and the at least one anchor gateway, each of the timestamps from the transponder and the at least one anchor gateway together with at least one respective piece of timestamp monitoring information are transmitted to a failsafe computing device, at least one check is implemented via the failsafe computing device, and the definite safe distance is determined via the failsafe computing device aided by the checked timestamps, where timestamp errors occurring during the detection of the timestamps are caused solely by the transponder or alternatively solely the one anchor gateway.