Abstract: Telephone terminals directly implement an automatic call back feature by establishing a logical channel between two telephone terminals when a calling telephone terminal is unable to complete a call to a called telephone terminal. Via the logical link, the called telephone terminal communicates to the calling telephone terminal any change in state that is related to its ability to receive a call. When both telephone terminals are idle, the calling telephone terminal recalls the called telephone terminal to set up a call. The logical link is established on user-user temporary signaling or D channel facilities of ISDN links. Since the interconnecting networks are not part of providing the automatic call back service, the telephone terminals can be interconnected by any combination of telephone networks that provide ISDN service.

Abstract: Allowing for pre-location of authentication information to a switching node before a mobile telephone starts to register on that switching node. Where the switching node is part of a mobile telecommunication system having a plurality of switching nodes. The pre-location of authentication information allows the authentication information to be distributed to switching nodes in a distributed telecommunication switching system before peak traffic conditions arise. A user of a mobile telephone can directly specify the time and place for the pre-location of authentication information, or the switching node to which the mobile telephone is assigned can statistically determine the other switching nodes to which authentication information will be pre-located and the day and time of the pre-location.

Abstract: Continuously varying the type of media used during a multimedia communication conference call by a telecommunications terminal. In response to inputs from a user, a telecommunication terminal can vary the type of media by increasing, decreasing, or changing the bandwidth of the call. Further, a telecommunication terminal controlling the multimedia communication conference call is informed of changes being made by the telecommunication terminal on the conference call and informs the remaining telecommunication terminals of changes in participation of the telecommunication terminal.

Abstract: Automatically reducing communication bandwidth to coincide with the state of a communication call by a communication terminal. If a first telecommunication terminal puts a second telecommunication terminal on hold, the first telecommunication terminal transmits a transport message that reduces the bandwidth of the call to a low speed data link. When the first telecommunication terminal wishes to again be in communication with the second telecommunication terminal, a transport message is utilized to restore the communication bandwidth. If a first communication terminal calls a second communication terminal and the second communication terminal is busy, the first communication terminal reduces the bandwidth of the communication call to that of a low speed data link. When the second telecommunication terminal becomes idle, the second terminal sends a message to the first terminal indicating the idle state.

Abstract: Establishing a multimedia telecommunication conference call with reduced bandwidth if not all participants are available to be part of the conference call by telecommunication terminals. When one telecommunication terminal is initiating a conference call, the initiating telecommunication terminal first establishes low speed data links with each of the other telecommunications terminals that are to be part of the conference. When all users of the other telecommunication terminals are ready for the conference, the other telecommunication terminals signal the initiating telecommunication terminal which then adds the necessary bandwidth to the conference call to establish the multimedia telecommunication conference call. Since the conference call is already set up, the initiating telecommunication terminal only has to add the necessary bandwidth to conference call. Each participant in the telecommunication conference call designates when they are ready to have the conference call start.