A bidirectional communication system is provided. The system includes a first remote unit for communicating with a host unit using orthogonal frequency division multiplexing. The host unit is communicatively coupled to a plurality of remote units in a multipoint-to-point configuration. The first remote unit is configured to transmit up to a plurality of tones and the first remote unit includes a modulator for modulating the plurality of tones with upstream information using orthogonal frequency division multiplexing such that when any tones are transmitted from the first remote unit and at least one other remote unit of the plurality of remote units, the tones are substantially orthogonal when received at the host unit.