Patent attributes
A wireless network interface device selects a guard interval from a set of guard intervals including a first guard interval, a second guard interval, and a third guard interval, where in the first guard interval has a length that is 50% of a length of the second guard interval, and wherein the length of the second guard interval is 50% of a length of the third guard interval. The wireless network interface device generates a preamble of a data unit to include: a legacy signal field, a repetition of the legacy field, and a non-legacy field that includes a field that indicates the selected guard interval. The wireless network interface device generates a data portion of the data unit, including generating orthogonal frequency division multiplexing (OFDM) symbols of the data portion using the selected guard interval.
