Abstract: In a method for operating a computer system connected to a telecommunication network and provided with a data memory for storing communication data, a data trace is compiled from parameters selected from time, at least one position designation, and at least one content. A communication data set together with the data trace is stored as a data set that is retrievable by authorized persons.

Abstract: In a method for operating a computer system connected to a telecommunication network and provided with a data memory for storing communication data, a data trace is compiled from parameters selected from time, at least one position designation, and at least one content. A communication data set together with the data trace is stored as a data set that is retrievable by authorized persons.

Abstract: A method for communication over a telecommunications network includes selecting a public telecommunication station located in the vicinity of a mobile telephone. The public telecommunication station is used by the mobile telephone as an access point to the telecommunications network.

Abstract: An authorization control system controlling who may use a device, includes a device for storing personal code data, a signal provider for outputting signals representing the personal code data, a signal delivery interface for receiving signals representing the personal code data, and adapted for wear by a user in proximity to a body of the user, a signal receive interface means, connected to the device, for receiving the signal from the signal delivery interface, a signal processing device, connected to the signal receive delivery interface, for determining a user's authorization for using the device by evaluating the signals and outputting a signal indicative of an evaluation result, a control device connected to the signal processing device, and an actuator for the device coupled to the control device, for allowing the user to use the device based on an output of the control device. Thus, the system allows a person to use the device only after the person has completed a successful authorization check.