Good Day
Can’t find Noise Floor Threshold settings in new wireless AC (wireless-fp) package.
I need to increase or decrease the noise value, how I can do that?
How it will be? I have to change the noise value, because the noises in real air are to much 
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Noise floor is a measurement of the ambient RF noise as seen by your wifi interface. It is not configurable, it is a read only value. It is however used in conjunction with signal strength to calculate the SNR value.
Hi Skillful,
sorry but I dont agree, with N cards you could set the noise floor manually to make the card less vulnerable to the noise. I am using this in the city for some short links, lowering the automatic noise by 5dB to keep my links running stable with 100% CCQ. It really helps because the automatic noise floor is sometimes just too high (-110dB in center of the city)…
I am also missing this feature on the AC products, already posted here a week ago but no answer from support. There is still many features not finished in the AC driver like current tx-power readings etc. I guess we need to wait.
Lukas
I noticed when lowering noise floor to -120 signal on N cards increased from -64 to -53 and SNR=67dB, back to -110 and -64 and SNR=48dB, by lowering another -5dB apart from signal will SNR be reduced further, could someone explain how reduced SNR will improve performance on noisy links, unless the actual numbers being displayed are not accurate?
Well mostly only on the very short links in the noisy environment. I am using jirous parabolic 2x2 antennas on 367m link so my txpower is 0 (minus values did not have any effect) and even with that value the signal is quite strong - so lowered the noise floor threshold from around -110 (do not remember the exact automatic value) to -105 to achieve SNR 37dBm which is just enough to have the link running with 300/300Mbps and 100% CCQ.
With the default value the SNR was quite high and from my experience too high SNR makes the link performing worse, there could also be a little of interference so it solved either the too high SNR or less noise to keep my link performing better.
A quick web search and more interesting reading -
A ratio of 10-15dB is the accepted minimum to establish an unreliable connection; 16-24dB (decibels) is usually considered poor; 25-40dB is good and a ratio of 41dB or higher is considered excellent.
Has Mikrotik got SIR -
The signal-to-interference ratio (SIR) is similar to the signal-to-noise ratio, but in this case the interference is specific to co-channel interference from other radio transmitters. The general consensus is that wireless devices will work reliably with the SIR ratio of 0dBm (decibels) or less.
Dear friends
My question is when “Noise Floor Threshold” parametr will be in future mikrotik packages.
I need it because im useing in practice just now.
That is very important parametr for useing in real air where work many other radios.
I am agree with you.
Wait… 
UP
On base BOX5 change noise flor from auto (-110) to -95 give me 100% stable links & good latency for NV2. Netmetal AC still waiting…
Noise Floor Threshold is the Most Important Parameter of Wireless Configuration. The Others Parameters don’t Matter when Stabilizing a Network Due to Noise at Frequencies. If the Noise Threshold is -110, Setting the Noise Floor Threshold 2 or 3 Points Above (-107 o -108) Achieves Stability and a Higher Throughput in Unstable Frequencies.
I Have in a Node 1 Basebox5 and 1 Netbox5, both working on n. In the Basebox I have 50 Clients Connected Controlling the Noise Floor and Very Stable, but in the Netbox I Cannot Stabilize 16 Clients. And if I invert the frequencies, it doesn’t Change Nothing. This Parameter is the Big Difference because Ubiquiti TDMA Works Bad with Many Connected Clients, I Can Get Better Results with CSMA on Mikrotik.
I Would Only Like Mikrotik to Analyze This Question, If the Integrated Wireless Doesn’t Support Noise Floor Threshold, It’s Not Worth It.
Or Maybe You Can Update This Firmware And Fix Many Problems.
Thanks.
From the Wiki:
noise-floor-threshold (default | integer [-128..127]; Default: default)
For advanced use only, as it can badly affect the performance of the interface. It is possible to manually set noise floor threshold value. By default, it is dynamically calculated. This property also affects received signal strength. This property is only effective on non-AC chips.
From the Forum: http://forum.mikrotik.com/t/wireless-signal-strength-vs-noise-floor-threshold/92923/1
The Wiki explains it all …
adaptive-noise-immunity (ap-and-client-mode | client-mode | none; Default: none) This property is only effective for cards based on Atheros chipset.
FAQ:
What is adaptive-noise-immunity setting?
Adaptive Noise Immunity (ANI) adjusts various receiver parameters dynamically to minimize interference and noise effect on the signal quality [1] This setting is added in the wireless driver for Atheros AR5212 and newer chipset cards
[1] http://www.patentstorm.us/patents/7349503.html … dead link (404) … checking patent number https://portal.unifiedpatents.com/patents/patent/US-7349503-B2