en:users:documentation:acs
Differences
This shows you the differences between two versions of the page.
| Both sides previous revision Previous revision | Next revision Both sides next revision | ||
|
en:users:documentation:acs [2018/02/12 08:19] Chaitanya T K Fix typo in the heading |
en:users:documentation:acs [2021/02/21 02:57] Scott Almes removed inexplicable mailto link |
||
|---|---|---|---|
| Line 24: | Line 24: | ||
| <code>(busy time - tx time) / (active time - tx time) * 2^(chan_nf - band_min_nf)</code> | <code>(busy time - tx time) / (active time - tx time) * 2^(chan_nf - band_min_nf)</code> | ||
| - | The coefficient of of 2 reflects the way power in "far-field" radiation decreases as [[linux-wireless@vger.kernel.org|the square of distance from the antenna]] What this does is it decreases the observed busy time ratio if the noise observed was low but increases it if the noise was high, proportionally to the way "far field" radiation changes over distance. Using a minimum noise instead of some "known low noise" value allows this code to be agnostic to any card used, even if the card is yielding incorrect values for noise floor. The minimum noise floor would be the lowest recorded noise floor from all surveyed channels. It is worth showing a few examples of what the multiplier produces to demonstrate how it amplifies the value for high noise. Since we have recorded the lowest observed noise floor by using the delta between what we observed and the lowest observed noise floor on the band we would get multipliers that are always positive and the lowest multiplier would be a value of 1 given that 2^0 = 1. Lets assume the lowest recorded noise floor was -110 dBm here are a few example values: | + | The coefficient of of 2 reflects the way power in "far-field" radiation decreases as the square of distance from the antenna. What this does is it decreases the observed busy time ratio if the noise observed was low but increases it if the noise was high, proportionally to the way "far field" radiation changes over distance. Using a minimum noise instead of some "known low noise" value allows this code to be agnostic to any card used, even if the card is yielding incorrect values for noise floor. The minimum noise floor would be the lowest recorded noise floor from all surveyed channels. It is worth showing a few examples of what the multiplier produces to demonstrate how it amplifies the value for high noise. Since we have recorded the lowest observed noise floor by using the delta between what we observed and the lowest observed noise floor on the band we would get multipliers that are always positive and the lowest multiplier would be a value of 1 given that 2^0 = 1. Lets assume the lowest recorded noise floor was -110 dBm here are a few example values: |
en/users/documentation/acs.txt · Last modified: 2021/03/01 04:28 by Nikolas Nyby
Page Tools
