Methods and systems are disclosed for the operation of wireless communication networks, in which communication channels can have possibly overlapping bandwidths of different sizes, including sensor networks operating by the IEEE 802.11ah standard. A first method of signaling to negotiate the channel bandwidth conveys the needed information in the SIG field of the PPDUs of duplicate RTS/CTS frames, and uses the SIG field of PPDUs of duplicated data, control and management frames to perform transmit opportunity protection. A second method of signaling to negotiate the channel bandwidth conveys the needed information in the scrambling sequence field of PPDUs of duplicate RTS, and uses the scrambling sequence field of PPDUs of duplicated data, control and management frames to perform transmit opportunity protection.