Patent attributes
A communication device generates a legacy portion of a physical layer (PHY) preamble of a PHY data unit. The legacy portion includes a plurality of legacy training fields and a legacy signal field that indicates a duration of the PHY data unit. The communication device generates a non-legacy portion of the PHY preamble to include a multi-bit signal field header to indicate a packet type of the PHY data unit from among a plurality of packet types defined by a wireless communication protocol, the plurality of packet types corresponding to a plurality of non-legacy signal field formats. The communication device generates a non-legacy portion of the PHY preamble to also include a non-legacy signal field having a field format i) selected from the plurality of non-legacy signal field formats and ii) consistent with the packet type indicated by the multi-bit signal field header.