Patent ID: 6275990
Filing Date: 2001-08-14
Classification: G06F,H03M,H04B,H04H,H04J,H04K,H04L,H04M,H04N,H04W,Y02D

Abstract:
A bidirectional multipoint-to-point communications system for sending payload information over a distribution network, comprising:a head-end tenninal coupled to the distribution network for transmitting downstream control messages and downstream payload information in a first frequency band, and for receiving upstream control messages and upstream payload information in a second frequency band, the head-end terminal including:a head-end controller for sending the payload data to and from an external communications network and for producing and processing the control messages at the head-end terminal,a head-end multicarrier transmitting modem coupled to the head-end controller for modulating the downstream payload information and the downstream control messages onto multiple orthogonal downstream carriers spread throughout substantially all of the first frequency band on the distribution network,a head-end multicarrier receiving modem coupled to the head-end controller for demodulating multiple orthogonal upstream carriers spread throughout substantially all of the second frequency band and carrying the upstream payload information and control messages on the distribution network;a plurality of service units physically remote from each other and from the head-end tenninal, each of the remote service units receiving the downstream control messages and downstream payload information over only a portion of the first frequency band, and each of the remote service units transmitting only a portion of the upstream control messages and upstream payload information, each of the remote service units including:a service-unit controller for transferring a portion of the payload data to and from user equipment and for producing and processing the control messages at the remote service unit,a service-unit multicarrier receiving modem coupled to the distribution network for demodulating only a portion of the multiple downstream orthogonal carriers, containing the portion of the the payload information and at least some of the control messages from the head-end transmitting modem,a service-unit multicarrier transmitting modem coupled to the service-unit controller for modulating the portion of the upstream payload information and some of the upstream control messages onto multiple orthogonal upstream carriers in only a portion of the second frequency band on the distribution network.