A head end controller is described. The head end controller controls a plurality of service units in a telecommunications system with a multi-carrier transmission scheme. The head end controller includes a logic circuit that generates control messages for the plurality of service units. Each service...http://www.google.com/patents/US7310522?utm_source=gb-gplus-sharePatent US7310522 - Systems for synchronous multipoint-to-point orthogonal frequency division multiplexing communication
