Patent attributes
A communication device determines whether a PHY data unit is to be transmitted in a first frequency band from among multiple frequency bands in which a WLAN communication protocol permits operation. The multiple frequency bands also include a second frequency band. The communication device determines whether the PHY data unit is to include a PS-Poll frame, and whether a BSS color is currently disabled for the WLAN. In response to i) determining that the PHY data unit is to be transmitted in the first frequency band, ii) determining that the PHY data unit is not to include a PS-Poll frame, and iii) determining that the BSS color is not currently disabled for the WLAN: the communication device determines that a TXOP duration subfield in a PHY preamble of the PHY data unit cannot be set to a value defined by the WLAN communication protocol for indicating a TXOP duration that is unspecified.
