Wireless Service Providers → Noisy UBNT gear appearing in our area

We're starting to see some awfully noisy UBNT gear appearing on 2.4 GHz in our area. This week, site surveys have spotted signals with the SSID "UBNTTEST" (all caps) that are radiating at very high (possibly illegal?) power levels. From what I can see, they are obeying no spectrum etiquette whatsoever (not even listen-before-talk), so this must be their new TDMA gear. They're not only stepping on everyone who's on the band but being stepped on by everyone. The result is a mess in which all users of the spectrum (including the one deploying the UBNT gear, because the equipment can't avoid interference from others) will ultimately lose.

Anyone know who might be deploying this stuff in Laramie?

See if anyone is doing something in the UBNT forum.

LOL indeed.

I don't suspect this is the Ubnt AirMax (Their TDMA stuff) as they do NOT appear in any 802.11 scans (At least as far as I've seen when running in AirMax mode). So if you see their SSID, it means you're also running AirMax and are thus pissing on your own self just as much as you claim they are.

This COULD be the AirMax stuff running in 802.11 mode, but then it would make no sense what you're claiming about them not obeying "Etiquette" (Which doesn't exist in any form... Hello CANOPY!!)

So something doesn't make sense in what you're saying. That or there is some serious buggy stuff going on at Ubnt.

Either way, yes, when run in AirMax these things are like chainsaws. They will chop up everything in the band, and don't seem to be that affected by others (Much) because of some things done in the AirMax protocol that makes it a tad different (Last my understanding of it was that it was a psudo TDMA in the fact that it behaved like TDMA with other adjustments to avoid needing GPS timing etc... Which I don't understand how is possible, but anyway that's another topic)

I don't know what you're whining about though as these things are pretty much (Dare I say it and be flamed) like Canopy. They lack some of the nice Canopy things like GPS, but they certainly can kick the shit out of some nearby stuff.

Another thing to keep in mind is most of these things are native MIMO with both V and H polarity. So you're gonna see them from both polarities.

How are measuring/judging that they are radiating at high power levels? Just because you see them everywhere isn't exactly a decent way to measure it. I know many people who set these up with no regards to the power settings, but I also know many people who cry wolf when they see them and scream they are running illegally when they're not.

If one were to read that, one would infer that all other radios have a "listen-before-talk" feature. TDMA has nothing to do with it.

it has been a concern of mine that with the proliferation of UBNT gear and its costs (and power levels!) that we might all see that as a future problem.

Its only going to get worse with time. Those who don't like it should migrate to licensed frequencies (if they can afford it) or deal with it as "pros & cons" of a low cost, widely available? equipment.

We've been there, trust me.

We just had to find locations off their center paths and use reflectors on most customer installs to make sure they don't see the high noise. Use smaller directional sectors helps too.

Not much else you can do until they fold from their own stupidity.

Can always call up Industry Canada up here in the north. They tend to cast a blind eye on anything in the unlicensed or ham bands unless you have the right contacts and can rattle their cages enough. We've had to do it a few times now.

Those nice little things in the GUI that say "Obey country regulations" etc are your friend and can be your biggest downfall if not used

"Can always call up Industry Canada up here in the north. They tend to cast a blind eye on anything in the unlicensed or ham bands unless you have the right contacts and can rattle their cages enough. We've had to do it a few times now."

IC acted on you complaints about problems in the unlicensed band? Can you elaborate to enlightnen alll of us.

I was told my Nokia engineer that they are slow to act on their complaints:

From past posts of yours, I gather you are using Mikrotik ap's with no d IC certification: was that not a concern of yours when calling them in?

That's like comparing General Sherman's march into Atlanta to a Sunday afternoon family BBQ.

We've had a few times where we've had to call IC for interference problems. Most being just boneheaded links set up by local computer shops and outfits that piss all over the place for no reason.

Simple example was an AP running a 1 watt amp into a 15-16dbi (Can't remember exactly) sized sector. And feeding I think it was 3 radios each with panels and amps. All of which were within 2 feet of coax distance to the antennas, so they weren't making up for line loss, just complete stupidity trying to make the links through trees.

This kinda crap is common.

An interesting less common one was a carrier running LICENSED in the 2.4 band and it just happened to spill all over us. It was a wicked old license that existed back before 2.4 became free game. I don't remember what the final wattage was, but it was insane. We actually worked with them to arrange things as there were some other factors involved.

We were running MT boards with XR cards and when speaking with them they did not have a problem with them. They most certainly pulled out their equipment and looked/scanned/muttered when they saw them, but saw that we were within tolerances and said it was fine provided they stayed that way. We don't run full power obviously, and take into account all the line loss etc. Each AP is now tuned right to the mark to be sure it's legal.

(Note to any boneheads wanting to cause trouble for a competitor, think twice before calling FCC or IC just to stir things up, because they WILL check YOU out before they check the competitor. Especially in unlicensed band, they're already in a bad mood because they're essentially wasting their time for something that doesn't make them any money.)

It is also true they are very very very slow to react to anything in unlicensed/ham bands. As I said above it's nothing but a huge waste of money to send someone out to check. (And these guys aren't playing around when they do come, they have a van load of shit and equipment and will go through every single shred of data) I've spent a full day on a mountain top more than once with them sitting there with a spectrum analyzer and other equipment just waiting for a signal to appear at the end of the day. (Sweating bricks the entire time hoping not to look like I'm crying wolf either lol)

As far as unlicensed goes, IC doesn't much care either. Unless there's some very blatant stupidities going on, or very obvious intentional interference... They will just tell you to live with it, even if it doesn't fit the norm. Since it doesn't make them money they really don't care about it. We've got a few licenses with them so they tend to listen rather well when they see that you are paying for other stuff.

This is what I'm concerned about. It's a true tragedy of the commons. The first guy who uses TDMA in an area might mistakenly think, "Hey! I've got a great advantage here!" But that's not correct. Because his radios will not listen for others, they'll experience lots of interference even as they create it it for others. (In fact, CDMA readios may do a little better, because they're opportunistic; they'll take advantage of dips in the noise level.)

But everyone will suffer. And if multiple people use TDMA (multiple users of Ubiquiti, Canopy, etc.), it'll become a total train wreck.

The techniques I've been using to cope with Canopy will also work on UBNT and will make my system at least as hardy as either of them. But I can't break the laws of physics! The laws of physics and information theory (Shannon's Law) dictate that if there's too much noise in the air, it will make it impossible for anyone to provide adequate service on unlicensed spectrum, regardless of the MAC layer protocol or modulation scheme. I might be the last man standing, or one of them, but it'd be a hollow victory (in fact, it wouldn't really be a victory at all). While I might be able to use the band, it'd be far less useful.

At this rate, the telcos won't have to kill WISPs. We'll kill one another off if we go this way.

If "AirMax" is based on the FreeBSD TDMA code (which I am told it is), the packets will still be sniffable as 802.11 packets.

How many WISPS are running on the same 2.4 GHZ channels as the other WISPS in the area, and rely on collisions as their channel sharing mechanism ?

We are using some of the standard 802.11a/b/g Ubiquiti radios in Laramie, but none of the AirMax stuff.

FYI, you will start to see our ESSIDs disappear off of the standard 802.11b 20mhz channels - we are converting all of our 2.4ghz customers to 10mhz channels. Channel centers will remain the same, we will just be using smaller channels. If you sniff in 10mhz mode, you will be able to see the IDs.

Matt Larsen
vistabeam.com

Industry Canada was of help? [/sarcasm]
When a major carrier erected a tower here everyonebegan to experience noise. 2.4 & 5.8 bands. Everyone who contacted IC was given a nice half hour runaround as IC explained how they were underfunded, understaffed, had their hands tied, wasn't their responsibility etc.
They were all told how much easier it would be to take legal action against a multi-billion dollar carrier rather than involve IC.
Add that to the customer-end perception: "Ever since I installed this pager for my guys, your connection is crap. You better fix YOUR stuff"

No, it's not. If you are a plumber, and a new plumber comes into the area and begins to compete with you, he doesn't (or at least shouldn't) slash the tires on your trucks. And if he does, you have the right to call the cops.

The WISP business is unique in that there are more zero-sum games in it than in virtually any other.Not true. There have been four competitors here for years.The gear isn't "old school" -- at least not the way we use it. Most of the models we use are, in fact, still the latest from their respective manufacturers.I'm sorry -- but rules saying that you can't slash your competitor's tires aren't "Shirley MacLaine" stuff. And our industry needs them if we are to survive and prosper.Ubiquiti uses chipsets which, no matter how they're programmed, are vulnerable to noise due to the nature of the hardware itself. But even so, it's irresponsible to "rip through the spectrum like a chainsaw." There's only so much of it.

Matt, if you use 10 MHz channels, it is better not to keep the centers the same, as this prevents splitting the channels with others to coordinate. Most radios that can operate on narrow channels are capable of using just the upper or lower half.

Hey Guys,

Do you happen to know the specific models that are involved here? Are you sure its AirMax gear? If you can find out it would be greatly appreciated.

Also, we are trying to shift our CPE's to higher gain antennas (Airgrid, NanoBridge, PowerBridge) to help make radios more directive and reduce amount of aggregate interference.

Thanks,

Mike

Well, we're seeing packets with the SSID "UBNTTEST". I can't imagine that anyone would be using that SSID unless it were Ubiquiti gear.

As for the antennas on Ubiquiti products: One of the reasons we have not used Ubiquiti gear is that the internal antennas on most models do not meet our standards. Also, they send IPv4 multicast packets and have no way of turning them off. We do not allow IPv4 multicast traffic on our network, so when we found this out we removed the radios. We may use them again if UBNT fixes the multicast issue.

Brett...

I can understand your frustration, but that's all part of doing business. You had a non-competitive comfort zone and now some upstart has moved into your turf and is hosing your old school gear.

Spectrum etiquette might work in Shirley MacLaine's alternative universe, but its not gonna happen anywhere else. In my area, there are four 2.4 competing WISPs. Spot checks show -86 dBm anywhere you point an antenna towards. There simply is no way to effectively coordinate channels. And NONE of it is UBNT gear, much less UBNT AirMax gear.

The days of being able to throw up a two hundred foot stick and try to cover out to ten miles is way over.
Walmart is selling only 2.4 802.11n consumer wireless routers. They'll hose any 2.4 clients within range that your antenna passes over. Are you going to coordinate with every home owner?

As far as been possibly illegal, I would doubt that. Though possible, I just doubt that.

As far as reciprocal interference, UBNT AirMax if fairly tolerant. So to say that they are being stepped on any incumbent gear doesn't hold true that much. Like Kewlkid said, it rips through the spectrum like a chainsaw and leaves nothing standing in the path.

Moderator Action
The post that was here (and all 3 followups to it), has been moved to a new topic .. »54 Mbps speeds?

Beacon frames with SSID are transmitted by all Atheros TDMA protocols and the Intel/FreeBSD RCP protocol (which we assume Ubiquiti is using) makes even slave radios transmit beacons to capture free slots advertised in master radio's beacon. But since the beacons are not complete, some 802.11 firmware will ignore them during scan.

If you (or anyone else) have multiple Airmax radios available, could you kindly pass lots of traffic between 3 of them and scan/capture raw 802.11 frames for some time? You can find Tamos URL and instructions in my old posts - use the free evaluation.

P.S. Save the data for my curiosity.

I thought you ran Mikrotik???? Our Airmax APs show up in the 802.11 scan of our same frequency MT gear (ie XR-5 MT ap will see any 5M aps) not only that but we get the radio name and I believe even a router os version (bogus of course).

WISPs only kill each other if they won't work together. We shared hilltops with other WISPs who were using illegal power levels but didn't bother us as long as we coordinated frequencies.

I wouldn't rely on it as it might not kill you like TDMA but it reduces available spectrum none the less.

I propose that collision back-off has no real world value outside of your own network. My point being that NOBODY is relying on collision back-off as any significant part of their wireless strategy as it relates to on-channel QRM. If true, this would mute the observation from SuperWisp that "... his radios will not listen for others", hence my question ( that you did not address ).

During TDMA protocol research, I always implemented a "nice" mode which would be set between 0 to 10 to share spectrum with others.
»Wanted: 900Mhz WISP volunteers

Anyway there are ways to force a TDMA system to share by transmitting during some slot contention periods. But it requires lots of observation of their protocol and ability to perfectly time your transmissions.

In other words, implement a DoS attack by blotting out the requests of client radios for time slots. Yes, this is an Achilles' heel of most TDMA systems, but obviously it's not nice to do it.