Abstract: In cases when a called participant (Tln-B) is not registered on a packet orientated network (IP-N), a call-back request made by a calling subscriber (Tln-A) is transmitted automatically to a substitutional device (ST-B) which is disposed in a network (IP-N) and assigned to the called subscriber (Tln-B). Preferably, the call-back request is stored in a separate data base (DB-B). As soon as the called subscriber (Tln-B) is registered in the network (IP-N), the call-back request is transmitted to the called subscriber (Tln-B) who carries out said request.

Abstract: Communication connections in a communication system with a communication terminal are assigned to a first communication device, which can be registered at a second communication device, and used in a packet-oriented network by way of which the communication terminal is connected to the first and the second communication devices. As a consequence of a registration performed by a subscriber the communication terminal is signed off from the first communication device and is assigned to the second communication device. In the case of a communication connection initialized at the communication terminal a check is carried out to determine whether the initiated communication connection to a destination device defined by a subscriber number reserved in the communication system is to be realized.

Abstract: A method for operating a wireless telephone system to provide emergency service for a wireless telephone operating in the wireless telephone system. In the present invention, the wireless telephone system receives a request to connect the wireless phone to a predetermined telephone number from the wireless telephone. The telephone system then queries the wireless telephone for a unique identifying number identifying the wireless telephone. The unique identifying number enables the wireless telephone system to connect the wireless telephone to the wireless telephone system. The wireless telephone system maintains a set of direct inward dialing numbers (DIDs) that are used exclusively for emergency calls. Each of the DID allows a caller outside of the wireless telephone system to direct a call to a telephone within the wireless telephone system. The emergency call is assigned one of these DIDs and that DID is linked to the unique identifying number of the telephone placing the emergency call.