Patent ID: 6925072

Claim:
A method for sending control information between a control unit and at least one of a plurality of cascaded units (CU) comprising: generating an down link message of a predetermined length comprising a Cu identifier and control information, wherein said CU identifier corresponds to a designated Cu; sending said downlink message to said designated CU using a common control channel over a time-multiplexed communications link, said common control channel comprising a plurality of consecutive timeslots of a time-multiplexed frame; and processing said downlink message at said designated CU; wherein generating said downlink message comprises: generating said downlink message in a Link Access Procedure on D-channel (LAPD) format using High Level Data Link Control (HDLC) frames, said HDLC frame including an address field having a Service Access Point Identifier (SAPI) location for transmitting said CU identifier; and placing said CU identifier in said SAPI location.