To enable a method and a system, having at least one base station and/or one data carrier, for transmitting signals between the base station and a number of mobile data carriers operating in the crypto mode or in the plain mode, wherein [a] the base station emits at least one command signal and/or data signal that is provided with at least one identifying pattern, [b] at least one of the data carriers receives the command signal and/or data signal emitted by the base station that is provided with the identifying pattern, [c] at least one of the data carriers that receive the command signal and/or data signal transmits to the base station a response signal that is a response to the command signal and/or data signal, and [d] the base station receives the response signal transmitted by the data carrier.