OFDM ANI Level 9

  • 1 February 2014
  • 35 replies
  • 13680 views

Everything works and I shouldnt worry but......

My BT HH2 expired last week and I replaced it with a Netgear D6200 (dual band). After getting everything setup and SONOS working, I thought I would have a quick peek at the matrix and was surprised to see a red box - on my Play1 due to an OFDM ANI level 9.

The noise floor is around -100, and the physical error count is consistently in the 1000 range, and more importantly it works fine. The other 7 sonos components show green and yellow and 1 amber.

The play 1 is positioned in my study , along with the router, the digital phone base , the QNAP. the bridge, a PC witha wireless keyboard and mouse - there is a lot of stuff going on and i have spread them out as far as I can, but its no Tardis in there.

So I can live with a red box on a matrix, as long as the music sounds good which it does, but with the play 1 being 5 feet away from any potential source of interference and still suffering so badly, I wonder whether I can afford to be so complacent. Is this a sign of other conflicts and problems elsewhere - with that level of interference should I be concerned about other non-sonos devices ? - could my router performance be impacted by sonos ?

Maybe I shouldn't worry if it all seems to work, but its a red box and I'm male - its my instinct to fix it

Any thoughts ?

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35 replies

Non-WiFi users of the 2.4GHz band can push the ANI to the highest level. Look for Bluetooth, proprietary 2.4GHz mice/keyboards, wireless headphones, etc.

FWIW some WiFi scanners will detect SonosNet if any Android devices have been configured to connect to it.
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I use a RF scanner. much better than Ubiquity which I tried too. I can see the full spectrum in intensity and hit frequency. My band is extremely clean and found that the ANI correlates to nothing RF related. Or if it is, it is very oversensitive to something I cannot see.
Which channel is SonosNet using? Which channel(s) -- and bandwidth -- is the WiFi using?
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See comparison with Sonos and without. Sonos is obviously on channel 1. I started looking at it because my channel 11 zigbee were failing
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This is without. Needless to say that microwave makes a mess out of this. But the bottom line is that I am not seeing any correlation between the noise and the ANI number.
There looks to be substantial noise in the same passband as Sonos' channel 1, at a similar RSSI.
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No. The noise you are seeing is actually the sonos. It is sonos playing and idle. Without the sonos (unplugged), it is a flat. I also changed the sonos channel and it clearly follows. Again, not very surprising but the point I was trying to make is that the OFDM ANI is not representative of anything.
ANI is representative of the noise rejection doing its work. I can immediately tell if there's a 2.4GHz wireless mouse active in the house, and roughly where, on the basis of the pattern of elevated ANI. In a quiet environment all my ANIs are zero. A long-range Bluetooth transmitter drives the ANI levels up to 9.
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Interesting... I do have a few computers with their bluetooth on, some with wireless keyboards. I see a sharp narrow and small spike on my scan when I use them. It could contribute to the high ANI but... when I see the power generated by the SONOSnet transmission, I think that noise is negligible... The Sonos is actually the largest source of noise (pun intended) to all other devices by several orders of magnitude. My ubiquity wifi APs are on 40mHz width and is spread on channel 11 and 7 and they don't come close to intensity and frequency of the sonos...
Is your Sonos system actually performing correctly? If you're not suffering from dropouts -- and with yellow/green in the matrix the signal strengths are more than adequate -- then whatever the ANI is doing to reject local noise it's succeeding. I suspect it is quite sensitive. There are times when I can see elevated ANI levels which nothing in the house would explain. Interference could well be coming in from the outside, maybe even mains-borne.