Patent attributes
A communication device generates a transmission signal for transmission via a wireless communication channel, wherein the transmission signal corresponds to a physical layer (PHY) data unit that conforms to a range extension mode of a first communication protocol. Generating the PHY data unit includes generating a preamble of a PHY data unit, wherein the preamble is generated to include: a legacy signal field that includes information indicating a duration of the PHY data unit, a duplicate of the legacy signal field, a plurality of subfields of a non-legacy signal field, and a plurality of additional subfields with the same data as the plurality of subfields of the non-legacy signal field. The plurality of subfields of the non-legacy signal field and the plurality of additional subfields are modulated to signal to a receiving device that the PHY data unit conforms to the range extension mode of a first communication protocol.
