Patent ID: 7408873

Claim:
A method for multipoint-to-point communication, the method comprising: receiving at a host a plurality of upstream symbols transmitted from a plurality of remote units; wherein the upstream symbols are transmitted on a plurality of orthogonal carriers modulated using an inverse Fourier transform, and wherein the upstream symbols are demodulated for reception using a Fourier transform; determining respective round trip path delay values associated with each of at least two of the plurality of remote units; wherein determining respective round trip path delay values, determines a round trip path delay value for a remote unit based on a time of reception at the host of a first signal from the remote unit; wherein a time of transmission of the first signal from the remote unit is based on a time of reception at the remote unit of a second signal from the host; transmitting information to each of the at least two remote units based on the respective round trip path delay values determined for each of the at least two remote units; and receiving at the host at least one upstream symbol from each of the at least two remote units at the same time.