Bidirectional communication apparatus for reducing transmitted data

Abstract

One of a plurality of subscribers connecting via a communications line a signal line and switching units, each accommodating a subscriber line connected to a terminal, etc., lowers the communication quality of the communications to reduce the cost of communications. A calling or called subscriber issues to a switching unit an instruction to lower the communication quality. A control unit in one of the switching unit receives the instruction, analyzes a method of lowering the communication quality and determining a switching unit for performing it, generates a control signal indicating that the communication quality should be lowered, and sends via a signal line the control signal to the switching unit determined to be used for lowering the communication quality. After receiving the control signal, a polishing unit in that switching unit lowers the communication quality by discarding a part of communication contents of the communications according to the control signal, or lowering the priority of the communication contents. Thus, communications fees can be greatly reduced.

Dependencies are inferred from the claim text.