Looking for Tower/Spectrum Analysis Experience & Feedback

Hi everyone,

I’m in the process of beginning my journey as a start-up WISP in a rural area, but I’ve hit a snag with the local tower owner & and would like to get some feedback & understanding on the situation.

In short:
The tower owner isn’t truly a WISP, but is providing some wireless networking for individuals in the community; he is the only one in the area, so he is the monopoly.

I approached him the other day & asked for quotes on leasing for the tower, and he informed me that the tower was fairly full, lots of spectrum in use, and wouldn’t be worth my time trying to get equipment on there.

I, myself, took the A5c that I have & just drove to the tower, powered it on, and sat at the base of the tower for roughly 45 minutes watching the “Spectrum Analyzer” that’s built into the device.

After 45 minutes, I saw heavy use on no channels in the unlicensed band (really, no use at all). I called the tower owner back & provided him with my results, and inquired about tower leasing again.

He then informed me that Ubiquiti equipment can only see Ubiquiti spectrum (he assumed I was using Ubiquiti) and that the spectrum is quite full, but he will next week go do some measuring for me.

I guess, my question really is – how true is his statement? Can the Mimosa’s analyzer not see all the spectrum’s in use? Could there be a lot of the spectrum being used that I just couldn’t see?

I, myself, have over 10 years of data center & network architecture design experience, so this technology isn’t new or foreign to me.

I’m looking for honest feedback here, and I do fear that this gentlemen is trying to possibly dissuade me from being a competitor.

Thanks everyone!

His story is not true. The spectrum analyzer does not just see its own brand of radio. We have a Mimosa radio on a busy rooftop and its analyzer certainly sees the Ubiquiti radios, Cambium radios, and whatever else is in the area.
There are some Wi-Fi “spectrum analyzer” programs (phone apps, some vendors’ radios) that only show actual Wi-Fi beacon levels. But a real spectrum analyzer sees everything. That includes both Mimosa’s and the AirView function on Ubiquiti.
Some tower owners do give exclusive deals to some tenants, which may be what he’s actually up to.

  1. Spectrum is Spectrum. If they are in the same spectrum they will see each other and interfere with each other. Admittedly you will probably not be able to connect to his equipment with a Mimosa CPE, but radios are lightbulbs, everyone can see when it is on. Which leads me to my next point.

  2. What UBNT stuff is he using and what channels? If it’s 2 GHz, then you won’t interfere with him. Same for 3 GHz and 900 MHz. If he is using 5 GHz, he may not have his antennas pointed at the ground where you are standing. I would get a directional antenna and point it at the tower and see what you can see from further away. (FYI, antennas have a Beamwidth, both horizontally and vertically, at the base of the tower you could very easily be under his signal)

  3. IMO He is BSing you, either intentionally or through ignorance. He probably doesn’t want you on the tower and will keep running you around, in which case the quote is “good luck” (Marco, Taken 2008)

BTW, Welcome @Zack, sorry your introduction to the WISP Industry is starting off so poorly. If you have any questions feel free to ask. We are getting more and more new faces around here.:partying_face:

Here is a Mimosa sector sitting ~3 ft infront of 1 UBNT sector and about 10 ft from two other UBNT sectors. (Rocket Prism 5AC all of them)

Here is a summary about radio signals I gave to someone who was having trouble with 80 MHz wide channels on a Mikrotik

Think of your Access Point (AP) as a light bulb (maybe a bright LED) and your Client device also as an light bulb (A less so bright LED)

To talk to each other they have to be making the same color light and can “see” each other. What color of light your AP and Client are using is the channel you are using, if you are using a really wide channel (like 80 MHz) you are going to be using several colors of light put together to get more information through at the same time.

Noise then is “light” that is the same “color” as your two little light bulbs that isn’t from your light bulbs. They are not very smart so they can only tell that they are getting light, not from who/what/where it is from. If you are using a lot of different colors you are way more likely to have noise and it also becomes harder to tell noise from the signal you actually care about.

Moving “around the spectrum” then would be changing what channel you are using, using different colors, to see if you can avoid noise from whatever is making it.

“the local spectrum” is how much and what noise is being made by other Access Points and Clients in your area. (Radio signals will oftentimes not travel all that far. So you normally don’t have to care about what the rest of the world is doing, just what is happening in your area)

@William5 & @Fred

Thank you both very much. My intention is to obviously mount the A5c I was using to analyze with + (2) N5-45 sectors. As you can see from the image I attached, the spectrum is damn near empty; as it should be, since my rural area has numerous dead zones even for cell service.

I also had the thought that maybe I was too close to the base of the tower (mind you the A5c was sitting on my front dashboard pointing directly up @ the tower). I drove around the area, parked for 20 minutes, and watched the analyzer again – had the same results.

I also have a A5-14 sitting on my farm that I have been using for testing, and this A5-14 is less than 1 mile away from the tower – it also shows no spectrum use, and is almost identical to the spectrum I was seeing while at the base.

With this being said – I just wanted to feel confident that I wasn’t being an idiot (or ignorant) about something, and to also validate my findings. This will allow me to be much more confident when I approach this tower owner next week.

Thank you guys so much for feedback, as this as helped me immensely.

Ya, I have towers that are 8 miles away from UBNT sectors that can see the signals coming through.

At a mile away you should see something from his sectors if he is using 5 GHz even if they are not directly pointed at you.

I would bet the tower owner is running one or more 900 MHz, 2.4 GHz or 3.65 GHz. Each of which doesn’t have nearly as much spectrum that 5 GHz does. Which would explain his spectrum issues. If his antennas look like TV antennas then it’s 900 MHz. 2.4 and 3.65 are harder to figure out, but you can check with the FCC and see if he has any 3.65 light licenses, which he would have to have if he is running 3.65. If he doesn’t then he is probably 2.4, or going to be in a lot of hot water. (FCC really doesn’t like it when people use spectrum they are supposed to pay to use.)

I didn’t realize I could engage the FCC to find out spectrum use from businesses.

I do believe I will pursue this. Any quick tips on doing this? (I’m going to do some Googling, of course.)

Thank you @William5

Only for licensed frequencies. Such as 3.65, 6, 11 GHz etc…

Here is my favorite place to look: https://wireless2.fcc.gov/UlsApp/UlsSearch/searchAdvanced.jsp

An example of our 3.65 License (Each radio must be listed with antenna, height and direction, Under the Locations Tab)

Obviously, FCC doesn’t track unlicensed frequencies. In which case people are just supposed to follow the rules.


This has been extremely helpful. I’ve been able to identify the equipment on his tower to the licensing that he’s purchased.

I’ve also been able to see the hops that he uses in order to pull bandwidth from our major carrier hotel (downtown) to our rural area; I now know exactly how to hop to get bandwidth to my area once I’m ready to bring in the big data.

Thanks a ton for all your help. This information has been priceless.


Glad to be of help. Is he on 3.65?

Negative. It’s all on the 10/11Ghz frequency, with (1) link on the 5.9Ghz & 6Ghz frequency.

Ahh, so you found his backhauls, no idea what the APs are yet though?

I honestly don’t think he has any. Once I started mapping out all of the equipment from the FCC licensing, who the manufacturer was, what the gear looked liked, etc.; There’s only (1) sector antenna on the entire tower & not the slightest idea if it’s even online anymore.

The entire tower appears to be filled with only backhauls, owned by the tower owner, or owned by the local municipalities (fire dept, sheriff, etc.).

Got any pictures? If I can’t ID them there are a couple groups on Facebook that seem to take pleasure in showing off their knowledge of obscure radios.

As an aside, do you listen to The Brothers WISP podcast? A lot of the time they talk about issues for bigger guys, but overall I have found it to be quite helpful. They have a Slack Group as well that if you run into issues is pretty good at pointing in the right direction especially for those weird one off questions.

If you are on Facebook lookup some of the WISP groups. If nothing else you can learn a lot from what other people post.

I have heard of The Brothers WISP, but I’ve not ever looked at it – sounds like it would be something worth my time at this point.

I’ve also attached all of the images that I took during the day. As you can see, almost (if not all) of these devices are backhauls.

Good luck getting space. That is a busy tower.

Looks like he might have a 2.4 GHz link in that last picture, maybe a couple UBNT PowerBeams. But those are normally PTP links. (Admittedly, I have run them as APs for bunched up clients far away, but they don’t do that very well.)

Looks like you have your work cut out for you. Good luck.

In the long run it may not be worth forcing the issue. “Don’t p*** off your landlord.” Who owns the land the tower is on? If it not him, you might try to find out if there were any constraints in his lease, i.e. “You must allow other users”.