LINE INTERFACE FOR COMBINING VOICE BAND SIGNAL AND XDSL SIGNAL ON TWISTED-PAIR COPPER LINE

PROBLEM TO BE SOLVED: To provide a line interface (30) operated at a low feed voltage that couples a broadband XDSL signal and a voice band telephone signal on a twisted-pair copper line. SOLUTION: In the line interface (30) where the voice-band signal carries a DC feed for a user telephone and also a voice signal, a ring signal, the XDSL signal, and the voice signal are coupled to at least one primary winding of a line transformer, and at least a secondary winding (40) pilots a twisted-pair telephone line (41), the secondary winding (40) is DC-coupled with the line (41) and the ring and feed signals are injected into the telephone line (41) by a circuit (43) arranged in parallel with the secondary winding (40). COPYRIGHT: (C)2003,JPO