Time division multiplex system with conference link

A time division multiplex system including a plurality of subscriber links each for connection to a subscriber line, the subscriber links including a switching network having an in-gate and an out-gate for each subscriber line for accessing it to a common transmission highway, and a common control for controlling the in-gates to sequentially connect a calling subscriber link to the common transmission highway in time-slots allotted to the called subscriber links and for controlling the out-gates to connect a called subscriber link to the common transmission highway in the time-slot of the calling subscriber, the improvement wherein the system further includes a conference link to the common transmission highway, the conference link including a plurality of incoming conference lines and a plurality of outgoing conference lines for effecting at least one conference connection between a plurality of the subscriber lines, a switching network including an in-gate in each incoming conference line and an out-gate in each outgoing conference line for accessing the lines to the common transmission highway, the common control including means for controlling the conference in-gates for sequentially connecting the incoming conference lines to the common transmission highway in specific time-slots allotted to them, and controlling the conference out-gates to connect a called outgoing conference line to the common transmission highway in the time-slot of a calling conferee subscriber, said means for controlling being comprised of a cyclic memory and means for recording therein the address of the called subscriber link or outgoing conference line in relation to the time-slot of the calling subscriber, and for recording therein the address of the calling subscriber link in relation to the time-slot of the called subscriber line or incoming conference line.