For each histogram type (e.g. RSSI), there can be multiple histograms up to this limit. For
example, an interface might have 1 histogram for station-wide RSSI, but also 1 for each of the
antennas used by the interface.
All histograms have a fixed number of buckets. To save space, each histogram type
uses a vector to hold only non-empty buckets (a sparse histogram), with these constants as the
max size of each vector.
Noise floor values range from -255 to -1 dBm.
RSSI values range from -255 to -1 dBm.
Size of RxRateIndexHistogram lookup table (see comments in RxRateIndexHistogram).
SNR values range from 0 to 255 dB.