Systems for multiple use subchannels are provided. In one embodiment, a
bidirectional communication system comprises: a first remote for
communicating with a host using orthogonal frequency division
multiplexing (OFDM), the host communicatively coupled to a plurality of
remotes in a multipoint-to-point configuration; wherein the first remote
is configured to transmit up to a plurality of tones modulated with
upstream information using OFDM; the first remote including a modulator
for modulating the up to a plurality of tones with upstream information
using OFDM, wherein the modulator is configured to adjust a carrier
frequency of the plurality of tones such that when any tones are
transmitted from the first remote and at least one other remote of the
plurality of remotes, the orthogonality of the tones when received at the
host is improved; and wherein both control data and payload data are
transmitted on a first tone of the plurality of tones.