A method of communicating in a wireless network comprises controlling a bandwidth or a transmission mask of a PPDU transmitted by a transmitting STA to a receiving STA within a TXOP based on bandwidth information in at least one preceding frame within the TXOP. The method and associated devices allow a control of TXOP bandwidth or transmission mask where devices capable of both dynamic and static bandwidth operation may be present within the network. The preceding frame may include a non-HT frame of a non-HT duplicate frame exchange, such as a non-HT duplicate RTS/CTS exchange or a BAR/BA exchange, where the bandwidth or the transmission mask would be controlled by being limited to be less than or equal to a bandwidth of the non-HT frame. The preceding frame may include a preceding PPDU, where the bandwidth or the transmission mask would be limited to be less than or equal to a bandwidth of the preceding PPDU.