The frequency is changed immediately and is only changeable in ad-hoc network mode. You may enter a frequency value in the 2.4 GHz band or the channel number. This affects modem and roaming thresholds. To be used when you have interference on the radio, because it significantly decreases the performance. You may want to set it to a fixed value for high number of nodes.
Noise refer to the signal level and noise level in dBm.
This functionality allow to set a number of signal level intervals and to count the number of packets received in each of those defined intervals. This distribution might be used to calculate the mean value and standard deviation of the signal level. Some of the mentioned features are optional. You may enable to disable them by changing flags in the driver header and recompile. I would like to thank Lucent Technology for making the necessary information available to public.