Systems and methods for round-trip-delay adjustment in a multipoint-to-point orthogonal frequency division multiplexing () system are provided. In one embodiment, a method for a remote unit to request bandwidth in an Orthogonal Frequency Division Multiplexing () multi-point to point system comprises: transmitting a signal from a remote unit having a request for bandwidth to a host unit on a first tone, the signal from the remote unit configured to combine with a signal from at least one other remote unit on a different tone to form a coherent waveform; determining when a collision has occurred on the first tone between the signal transmitted by the remote unit and a signal from at least one other remote unit; and when a collision occurs, re-transmitting the request for bandwidth on the first tone.