Patent ID: 6034953
Filing Date: 2000-03-07
Classification: H04Q

Abstract:
A system for interfacing a plurality of telephones to an integrated services digital network (ISDN) line of a telecommunications network, comprising:a plurality of line interface units connected to respective telephones, and a distribution line;a communications controller interconnecting the distribution line and the ISDN line;wherein the communications controller includes:means for transmitting digital data frames on the distribution line, each frame having a frame start and a plurality of control channels and voice channels of which respective voice and control channels are associated with respective line interface units,means for instructing each line interface unit on the control channel of that unit, to issue ringing voltage, dial tone, busy tone or ringing tone, andmeans for selectively coupling the voice channels to the ISDN line such that at least two voice channels can share a bearer channel; andwherein each line interface unit includes:means for detecting the frame start and identifying the voice and control channels of that unit,means for informing the communications controller, on the control channel, of switch-hook status of the connected telephone, a dialed directory number or dual tone multi-frequency (DTMF) digits collected, andmeans for coupling outbound and inbound voice signals, respectively, between the connected telephone and the voice channel.