Wireless Interference Question

[Network Digger]

Hi there,

I have a question please regarding the wireless interference between 2 radios operating at the same channel, does the RSSI value of the channel causing the interference makes the interference stronger or weeker?

I mean, if we have 2 access points:

- AP-A placed in Room A with Channel 6.

- AP-B placed in Room B with Channel 6.

In scenario 1:

In room A, it is receiving the signal of channel 6 of AP-B, but with very LOW RSSI (for example -83 dB).

In scenario 2:

In room A, it is receiving the signal of channel 6 of AP-B, but with HIGH RSSI (for example -60 dB).

Will the severity of the interference differ in both scenarios? Appreciate to have some detailed feedback if possible, thanks a lot.

[Leo Laohoo]

Are we talking about autonomous or controller-based?
Is RRM/DCA turned on?
What model are the APs?

[Network Digger]

Hi, thanks for the fast response, let's assume WLC based, RRM/DCA is not turned on and an advanced AP model, for example catalyst 9120.

As I am asking about the concept itself, not how the APs or the WLC will react, my question is to understand more the impact of the interference, does it increase/decrease with the severity of the interferer or not, and if it does, what RSSI for the interferer would be negligable & not affecting the transmission there.

Thanks.

[Leo Laohoo]

Nearby "friendly" APs isn't the only source of interference, hence the questions I've asked.
Leaky microwave ovens, old DECT cordless handsets, early generation of BlueTooth are some of the examples of interference.
Is CleanAir enabled?
Is Event-Driven RRM enabled?
If none is turned on, then there's really nothing to discuss: The APs are behaving like autonomous APs.

If RRM, DCA, CleanAir and Event-Driven RRM is enabled then how the APs will try to react to interference depends entirely on the firmware.  Old firmware, not so much. 

Newer firmware makes a balance of either powering down, turning to a different channel or, if FRA is enabled, switching off 2.4 Ghz and turning on the micro-5.0 Ghz radio.

[Scott Fella]

Put it this way. Interference is noise along with co-channel interference. The more noise the lower the SNR which means potentially impacting the RF. How much interference is impacting is hard to say because every device type can act differently. There will always be interference, but mainly on the 2.4ghz space and few on the 5ghz. It’s all the other wireless 802.11 and non wireless 802.11 that is affecting certain channels.