Abstract: A serving call session control function unit (S-CSCF) is provided within an IMS-based service communication system in order to register a user of a mobile communication terminal for communication service in a mobile communication system. The IMS-based service communication system has several call session control function units and at least one interrogation call session control function unit (I-CSCF). The mobile communication system is equipped with at least one policy decision point unit (PDP). To select a suitable S-CSCF unit, user information is first determined using a user context server unit that is assigned to the policy decision point unit and network information is determined using a network context server unit. The user information and network information are interlinked in the policy decision point unit (PDP) and user-specific and/or network-specific selection criteria are derived from said information and are taken into consideration to select a suitable S-CSCF unit.

Abstract: An operational method interfaces a second communication network containing an access node with a first communication network encompassing a contact node. In a first step, an access node reads or receives an identity which is specific for the second communication network and is stored in a storage medium of a memory node. Then an interfacing message containing the identity that is specific for the second communication network is transmitted from the access node to the contact node, which is defined by an address stored in the storage medium. A packet data service to the access node is supplied by the contact node such that the second communication network is interfaced with the first communication network. An assembly and a storage medium are provided for interfacing the second communication network with the first communication network.

Abstract: A serving call session control function unit (S-CSCF) is provided within an IMS-based service communication system in order to register a user of a mobile communication terminal for communication service in a mobile communication system. The IMS-based service communication system has several call session control function units and at least one interrogation call session control function unit (I-CSCF). The mobile communication system is equipped with at least one policy decision point unit (PDP). To select a suitable S-CSCF unit, user information is first determined using a user context server unit that is assigned to the policy decision point unit and network information is determined using a network context server unit. The user information and network information are interlinked in the policy decision point unit (PDP) and user-specific and/or network-specific selection criteria are derived from said information and are taken into consideration to select a suitable S-CSCF unit.

Abstract: An operational method interfaces a second communication network containing an access node with a first communication network encompassing a contact node. In a first step, an access node reads or receives an identity which is specific for the second communication network and is stored in a storage medium of a memory node. Then an interfacing message containing the identity that is specific for the second communication network is transmitted from the access node to the contact node, which is defined by an address stored in the storage medium. A packet data service to the access node is supplied by the contact node such that the second communication network is interfaced with the first communication network. An assembly and a storage medium are provided for interfacing the second communication network with the first communication network.

Abstract: By signalling information for establishing the push-to-talk communication of a first terminal with a switching node in a mobile telecommunications network, establishing a usable link with the switching node from the first terminal and then establishing a usable link with at least one other terminal from the switching node, a push-to-talk connection is established.

Abstract: A (mobile) transceiver can be switched into different equipment states, and is provided with an equipment state in which supplementary functions (appointment calendar, games, etc.)—which do not require any transmission via a radio interface of the transceiver—can be executed without any transmission of the transceiver via the radio interface. In particular, there is no transmission of a signal or organizational data which is normally automatically transmitted when a transceiver is activated or in a standby or a ready-to-receive state.