Method for preserving the anonymity of a calling subscriber in communications switching systems

摘要

In communications switching systems which can transmit data identifying a calling subscriber to the terminal of a called subscriber in order to display it there, a calling subscriber is intended to be able to decide for himself whether or not the data should reach the called station. By means of a special operating procedure on the terminal of a calling subscriber, a code is formed and initially stored in the terminal. When the connection line is seized in an outgoing direction, this code is transmitted to the exchange before dialling is completed and with it the forwarding of data identifying the calling subscriber to the called terminal is prevented. The forwarding of data to the called terminal can even be prevented if a call diversion takes place. The operating procedures required to activate this facility in different variants can also be carried out from a different terminal or from a central operator's position. A calling subscriber can decide for himself in which instances his anonymity should be preserved. The facility can be activated on a connection-related and/or time-dependent basis.