A data communication framing scheme of a bit stream that is divided among a plurality of discrete physical frames, each physical frame is of a definite number of symbols in duration, each symbol is associated with at least one sub-carrier in a plurality of sub-carriers, the physical frame is partitioned in time into at least an uplink zone and a downlink zone, the data framing scheme comprising a logical frame having a logical frame start position that is offset by a rational number of said symbols from a reference symbol, said reference symbol is selected from said definite number of symbols, wherein said logical frame extends in time to coincide with at least part of the duration of said physical frame and at least part of the duration of another physical frame in said plurality of discrete physical frames.