Using Acrylic WiFi for Managing WiFi Channel Congestion

Content provided by Peter K1PGV and Mike, VA3MW

WiFi bands are comprised of discrete channels. While every consumer wireless access point claims that it "auto-selects the best channel", it rarely does a good job of this in the real world.

This is where a WiFi Scanner app can help. You can get a very good idea of how many sessions are around you, which sessions are using which channels, and the best channel(s) for your Wireless Router to use. Just about every consumer wireless access point I've seen will let you override the "auto-select channel" setting and select a good channel manually.

For Windows, I suggest the free version of Acrylic WiFi -- It's a very solid product. You can see the various sessions,their channels, and the throughput of each session.

In the screenshot below (I removed the SSIDs) I circled 2 broadcasting nodes. These are HP Printers. Notice that they are in B mode only? Sadly, I don't think those printers are even owned by us.

A broadcasting B node will drag down the entire network regardless of the speed of the rest of the network. This is by design so that other nodes are good neighbours.

So, B drags down G and C modes. G will drag down C nodes.


Amazing what happens when you look under the covers.

Have an ancient "b" device on your wireless network? It'll slow down your other 2.5GHz connections.

What other factors degrade WiFi performance? The best answer is QRM. With so much QRM, the modems are stepping down in speed trying to find a reliable baud rate to run at. Using the Acrylic Analyzer, we find that there is about 57 AP's that I can hear on 2.4Ghz. I can also confirm that the 'network' grinds to a halt after 8pm. So bad that if I am on the 2.4Ghz network i can't even ping Google. 

The strongest one is on channel 9 and that makes him effectively wipe out channels 6 and 11. This is likely the biggest problem, but coupled with the rest just turns this into a 20M pileup for Heard Island. :)

How to fix this?

  • Go wired - it always works
  • Move to 5Ghz
  • Purchase an 802.11ac type wireless router
  • Turning your router from BGN mode to GN helps
  • Make sure your drivers on your devices are fully patched
  • Look for a quiet channel
  • Move to an island or some other RF quiet area

Getting WiFi to "just work" enough to surf the web is one thing. Getting it to work to allow you to constantly support high-speed isochronous data (like for FlexRadio products) is another thing entirely.

In general, it is advised in the strongest possible terms to avoid WiFi for high-speed isochronous streaming if the results matter. Even the best wireless connection is no substitute for a hard-wired one. If you want a solid data stream you can count on (like, for a contest or chasing a new one) I would strongly recommend you stick with a wired connection. If you're casually operating "backyard mobile" and don't mind if you miss an occasional frame or two or ten... WiFi is terrific. This isn't any reflection at all on Flex, of course. It is the undeniable nature of the technology.

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