Channel bandwidth. Cbw80P80 requires the specification of
channel index corresponding to the center frequency
of the secondary consecutive frequency segment.
Derive channel given DSSS param set, HT operation, and VHT operation IEs from
beacon or probe response, and the primary channel from which such frame is
received on.
Derive a CBW for a primary channel or channel switch.
VHT parameter derivation is defined identically by:
IEEE Std 802.11-2016 9.4.2.159 Table 9-252 for channel switching
IEEE Std 802.11-2016 11.40.1 Table 11-24 for VHT operation
SecChanOffset is defined identially by:
IEEE Std 802.11-2016 9.4.2.20 for channel switching
IEEE Std 802.11-2016 9.4.2.57 Table 9-168 for HT operation