Systems and methods for an orthogonal frequency division multiplexing
multipoint-to-point communications system are provided. In one
embodiment, a method comprises establishing communication between a first
remote unit of a plurality of remote units and a host unit, the plurality
of remote units communicatively coupled to the host unit in a
multipoint-to-point configuration; transmitting up to a plurality of
tones from the first remote unit, the up to a plurality of tones
modulated with upstream information using orthogonal frequency division
multiplexing; modulating the up to a plurality of tones using a first
modulation scheme when transmitting a first type of upstream information;
and modulating the up to a plurality of tones using a second modulation
scheme when transmitting a second type of upstream information.