RUCKCast #119 - Stop Mounting Your APs Like You Hate Physics

The podcast is back. After a year on the road fixing broken networks, Jim's recommitting to RUCKCast — and kicking off the return with the one problem that kept showing up everywhere he traveled: people mounting APs like they hate physics.

This one's about outdoor and external antennas — the RUCKUS T-series — and the mistakes that quietly wreck a good design. The big one: everybody's got directional antennas backwards. A directional antenna's real job isn't getting signal where you want it — it's keeping signal away from where you don't. Get that reversed and you end up doing what Jim keeps finding in the field: back-to-back directionals on a pole, double the APs, double the channels, double the cost, for gain you're probably not even getting.

Then the practical half: how to tell a correctly-mounted AP from a botched one just by looking at a photo. Dome-down vs. the arrow in your design tool. The N-female ports with the weatherproof caps that tell you an AP is directional, not omni — two on a T350 SE, four on a T750 SE. Because no good design survives first contact with an installer, and the fix is catching it from the picture before they leave the site.

Plus a live walk-through of a predictive tool on a football field — what each pattern actually looks like, and a non-standard rotate-and-downtilt trick for tight warehouse-aisle cells.

Watch it on YouTube if you can — there's a lot to see.

Intro music by Alex Grohl, available here:
https://www.youtube.com/watch?v=ZsRWpx8VJ_E
and
https://pixabay.com/users/alexgrohl-25289918/

Transcript

Hey, everybody. Jim here. I know it's been a minute. It's been more than a minute since I've been on the podcast. And so I apologize for that. You know, the job got in the way life got in the way. But today is a new day. I am recommitting back to the podcast. I have a whole long laundry list of things and topics that I want to talk about. And so we're gonna start off again today. 

The scheduling is going to be about every two weeks right now, as we kind of get our feedback underneath of us and get going. But yes, the podcast is back. I'm re-energized. I'm excited. And we're going to talk about Wi-Fi, we're going to talk about ruckus. We're going to talk about anything and everything that you kind of come to expect from this channel. So again, I apologize for the long absence, but I'm back. And we're going to make make this a good season. So stay with me got a good show coming up next. So
hopefully you forgive me and and we'll keep going.

Welcome back to the podcast. I'm Jim Palmer, your host. I'm gonna go solo for
a while and so you're just gonna have to listen to me ramble on about everything
that comes into my mind. And today, if you can't tell, if you're watching it on
YouTube, you've already figured it out, but if you're listening to the podcast,
today's episode is titled Stop Mounting Your APs Like You Hate Physics. Over the
past year or so, I've been traveling the country. I've been dealing with problems.
I've been, you know, working on problem networks, designs, stuff like that. And I
got to tell you that there was one thing that kept sort of coming back up as I
was, you know, traveling around and fixing problems and solving problems and
stuff like that. And it has to do with the mounting orientation of APs. You can
see over my shoulder here, I got a couple of APs. I got an R850. That's an R770
actually that I use for testing and stuff like that. And what you'll see is
I've actually mounted those things hanging from the shelf. All right, I got a
shelf right there. We've got some WLAN Pis. I got some sniffers. Got hats. Got
stuff. But what you notice is those APs are hanging with what we call dome down.
And we do that because that's how the AP is engineered. That's how the AP is
designed to be mounted. We do have a type of AP, you know, the wall plate AP that is
designed to be mounted on the wall. You know, we call that on the wall like a
clock. And, you know, those are designed to be mounted that way. And it used to be
in the past, we would come up and we would, we would see stuff and we'd see
APs that were mounted incorrectly. And we keep saying stuff like, oh, this is bad
fi. This is bad fi. And it's funny because twice over the past month, I've
been traveling with my wife and I've pointed at different APs that have been
mounted. I've basically given up and she's given up. And she just knows that
when we go places, I'm going to point out APs and either tell her why it's like
that, why it shouldn't be like that, or, and this is really weird, it was on two
separate occasions. We were traveling where I pointed to an AP and it was
mounted on the wall like a clock. And I looked at her and I said, I said, now
normally we would call that bad fi. We would say, hey, this is the incorrect way
in which we want to mount an AP. I said, but I give them a pass on this one. I was
like, because I understand what they're trying to do. They're literally trying to
limit the RF to keep it from where they want it to go. As most of you know, I'm
sort of an antenna guy. And so one of the things I always tell people is, hey, you
know, directional antennas are good for really two things. And everybody kind of
gets those reversed. Most people will tell you a directional antenna is great
for getting the signal where you want it. That's true, but it's not the primary
reason why I use a directional antenna. I use a directional antenna to keep the
signal from where I don't want it. And so there's actually been a couple of
different projects I've worked on over the past few months where the designer,
not me, had called for directional antennas and they put the directional
antenna on a pole and they had to put two of them because they wanted one
directional antenna to point this direction and one antenna to point the
other direction. Because you're like, oh, I'm trying to get that signal as far
out to the sides as I can. You know, you're trying to push that, push that
envelope, get it out there. Except, you know, sadly enough, in a lot of
different scenarios, that's not the right call. The right call is actually to use
an Omni because you've doubled the number of APs you need. You've doubled the
number of channels that you need. And a lot of times you don't get that
additional signal where you actually think you're getting it. That gain that
you're getting isn't quite as good as you might hope and you might think. But
you've doubled your cost. You've doubled your port counts. You've doubled all
these other different things. You know, your cable runs, your monitoring. I mean,
there's licensing, all these things that happen when you put in a back to back
because you're like, oh, I'm trying to get that signal into one spot. But you
know, sort of forget that whole thing of the point of a directional antenna is
not to really get it into the spot. It's to keep the the other RF from where you
don't want it. And so that's kind of the challenge that we run into. And a lot of
times designers will know that. And, you know, we put it on our designs, we show
it stuff like that. And then what ends up happening is we hand it off to the
installer. And if you've watched my presentation from WLPC a few years ago,
you know that one of my sayings is, you know, no good design survives first
contact with an installer. So what I want to talk about today is not
necessarily indoor APs, right? You know, there and there, if I can point the
right way, not talking about those today. Those are pretty simple, right? The R
series hangs the H series on the wall, you know, wall plate. What's the other
term for it? Hospitality AP, you know, that has the ethernet ports, you know, we
all get that we all know that. And for the most part, that's a pretty well
solved thing. What I want to talk to you about today are external antennas, the T
series, the ruckus T series APs. Now, I actually have learned to love over the
past year, year and a half really learned to love our external antennas.
I'll be honest with you before. He didn't have it. But, you know, after the past 18
months of being in the job, I mean, I realized that, hey, you know what, we
actually make some really good external APs. And then I started traveling to
these sites because they were like, oh, it's not working the way that we want it
to work. It's not working the way that we hoped it would work. And so I would get
there. And what I would notice is they mounted them wrong. And I don't think it
was a malicious thing. I don't think it was something where they said, Hey, we're
just going to wake up today and we're going to choose violence when it comes to
how we install the APs. I think they just get used to this is how APs are
installed. And unlike some of our competitors, you know, because of BeamFlex and because of the way we do things at ruckus, it's not as clear cut and it's
not as easy to the untrained installer. So today I'm going to take some time and
we're going to talk about an external AP, what that looks like, how you can tell
the difference and then what that means when you start talking about an
installer, because what you'll notice is you can, you can actually, if you can get
some pictures back from your installer, it's really easy to kind of look at and
go, Oh, you know what? This is a problem. And if they can send them to you before
they leave the site, you can tell them, Hey, you have to change the way that that
AP is installed because you've installed it incorrectly and we need to get it in
the correct orientation so that the signal level that we predict in our
predictive modeling tools and I'm not any predictive modeling tool is going to
work exactly the same. So it doesn't even matter which tool you use, right?
Because it's more about how the AP is designed and engineered. So let's talk
about that. Now, for the sake of this thing and having my lovely camera here
for you guys to see me, if you're listening to this, you should probably go
to the to YouTube and watch the watch the video here because we're going to go
we're going to take a look at things. And the first thing I want to show is the
ruckus T350 C. Let's see if I can get the glare off of it a little bit.
I really like this AP. Uh, this is, and ruckus has three different versions of
the T350. There's a T350 C, the T350 D and a T350 S E.
Now I don't have an S E model to hold up, but we're going to start with the base
model, which is the C model. This is this guy right here. As you can tell, you
know, it's not much bigger than your hand. It's a nice little AP. You know,
it's got the LEDs down here on the bottom, stuff like that. And what I want
to pay special attention to is you're going to have one side right down here.
There'll have your PoE port and other models will have other types of thing.
You know, you'll, you'll have a port here or you'll have it like a USB port
here. All right. So those, and those are just ancillary stuff, but more
importantly, I don't want to talk about this side. I want to talk about this
side right here because the C and the D models, these are classified as
omnidirectional APs, right? I'm going to hold this over here so I can kind of get
it on screen. We're going to do it just like this. So the C and the D models are
what they call omnidirectional. Um, that's the marketing term. Technically
it's actually a semi-hemispherical antenna. And what that means is, is
designed to be mounted just like the APs behind me here, behind my head is
designed to be mounted with the dome right here. Here's our dome, right? That
dome facing down because then we get the signal that comes down this way. Now
it's a 360 pattern that goes horizontally, but it's not a 360 pattern
that goes vertically, right? And we're going to see this here in a minute, but
because the energy from this AP is focused from the midpoint of the AP
right here, down, and then in a 360 pattern around it. So if I were to hold
this thing over my head, right, all the signal is going to be coming around me.
This way. And it's going to be focused down. That's a semi-hemispherical antenna.
And so that's really the pattern we're looking at. But like I said, this is a C
model and there's a D model. Um, and it has, like I said, the D model will have
some other little, uh, has another port and the USB and. The radios work the
same. Uh, the other, the third difference or the other difference is that the D
model has a higher temperature rating, but these are both of these APs are
designed to be mounted dome down, right? So if you see the picture and you said,
Hey, I want to see an C model antenna or C model C or D model AP. Um, and they go,
and you go, yep, this is how it's mounted. It's mounted dome down. Then they've
mounted it correctly. And if it's in the correct spot and you get to
configuration, right, it's going to perform and behave exactly the way that
you want it to. So problem solved. Now let's talk about the third model that
Ruckus makes in the, in the T350 series. It's the T350 se. There's
also a T750 and a T750 se. I didn't get those because quite frankly,
they're really, really big. And if I were to hold it, it would be like just the
camera doesn't work. So that's why we stuck with the T350 because, uh, we
can show it. I can get my hands, we can do all that stuff. So T750 se T
those se models, those are the models that really want to talk about because
those are not semi hemispherical or direct or, um, omni APs. Those are
directional APs. They have BeamFlex arrays inside the AP. So when you look
at it like this, it looks very similar. It's a little bit bigger, but it's very
similar. So if you're not a, an AP nerd, like most of us, the installers will
look at it and go, that's the same thing because they're not going to realize
that the AP is a little bit larger than the other models, especially if you have
just a few of the C or the D models and a bunch of the se models. It's really
hard to just look at it and pick it out by the size and go, I can tell you that
size is different. And so it needs to be mounted differently. The way you can tell
the difference between an se model and a normal omni or semi hemispherical and
the supplies for the T750 is T350 is actually right here on this
side away from the ethernet ports. So ethernet ports are down on this side,
along with the USB, the opposite side of the AP up here, where you have your
little ground grounding lug, the grounding lug is the tell. So you take a
look at the side that has the grounding lug. It's also opposite the LEDs and
it's the same side where it'll have the logo ruckus. So we're gonna look at this
side right here, has some cooling fins and then the grounding lug. However, if
we switch over and we take a look, this is a quick install guide for the T three
50 se, the AP right here, that rear view right here, what you'll notice is we have
the ruckus logo. And then underneath that, where you'd have the grounding lug,
there's a couple of N-female ports labeled one and two here on the screen.
And female ports with a cap, it's a weatherproof cap that ships with it. If
you see an AP that has those N-female ports with the cap on it, and it's
installed dome down, that is not the traditional installation orientation for
that AP. So technically, we could call that bad fi. Now, I'm not going to call
it bad fi because there are times, especially in warehouses, where I'll take
a T350 se, and I'll point that thing straight down, mounted on the
ceiling, like you would a normal AP like it's up here over my shoulder, like we
were talking about, right. And I do that for a very specific reason. And I want
to show you what that is. But you can tell the T350 will have two of
those two of those N-female ports, the T750 se will have four of those n
female ports with the caps on it. So if you see that, and you see those those
ports, and they're, they're sitting, you know, pointing out to the sides, that is
a non standard orientation of mounting that AP if they're up, you have they're
pointed up in the air. That's the standard orientation. Now let me show you
why we're gonna now we're gonna take a look at the physics, because that's where
I live. That's where I love. So here's the physics, right? Now, I have this is
a actually school. It's not too far from my house. Well, not too far. I live in the
western part of the US. So not too far as this is about eight miles away. And I
like using athletic fields, as you can see here, because it's actually showing
like distances and lanes and stuff like that. All right. And so what I have right
here is I have an AP here in the center of this field. And we have an AP at the
end. Now this is a standard American size football field at a high school. So
it is 300 feet or 100 yards from end zone to end zone. The end zones are 10
yards. So it's 320 yards across that. And what I want to point out is we're going
to come down here to the bottom. And if we zoom in, what you're going to notice
on this AP here, as I zoom really in, because I want to show you this arrow. So
when you see an arrow in your design tool, that is a directional AP. So you
only have to click on the model yet to find out what directional AP that is.
What that tells you is that arrow means that has a face, the AP has a face. And
where that AP faces is going to really determine and dictate the type of
coverage that you have. Right. So now that we've seen this, that little arrow,
we're going to zoom back out. This is here at the end of the end zone. We're to
come back up here to the one at midfield, move this guy up here. So he's right at
midfield, suggesting down here. And what you'll notice is on this guy, no arrow,
zero arrow. So that arrow isn't pointing anywhere because, because it doesn't
have an arrow pointing somewhere. That means it's domed down. So when we click
on it, you can see this is a T350 C right here. Um, it's mounting type is
on the ceiling because it's a dome down, right? Now, the other way you could do
this would be in a wall mount or an L mount because it's going to go either on
a wall or a pole and you're going to have it sort of, so it's going to be
mounted perpendicular to the mounting surface, um, like this. And, you know,
that, and that radiation pattern comes down, um, that did both of these APs at
12 feet. And I, I left the powers at six and 10 power doesn't matter here. We're
talking about antenna patterns and that's what I want to really focus on. So
let's talk about this AP that I have here in my hands that we were looking at.
So, yeah, let's come up here. I'm going to turn on some wifi signals so we can
take a look at that signal. We're looking at five gigahertz right here.
We're going to click on this one AP. Now what you're going to notice here is that
this AP literally has a very omnidirectional type of pattern to it.
All right. If we take a look at the pattern right here, what you'll notice,
you know, in the 3d settings is, yeah, you got a little bit of nulls right there
on the bottom. Um, if we rotate this way, we actually kind of let that thing go
until we say, oh, you know, that's probably about here is what the pattern
is that we're looking at. You know, so that's literally how we're looking at it.
And so from a visual perspective, what we're doing is, is we're standing over
top of it, looking straight down. And so we have that 360 pattern this way. What
you'll notice is if you were to stand and look at it from the side, then you
definitely don't have a 360 pattern. What you'll see is on this green part
right up here, there's like that little green ridge right here. That's the
middle of the AP. Now this is how it's supposed to be mounted.
What happens if we take our AP right here and we say, oh, we're going to mount
it and we're going to point it on like on, on it's on a wall and it's on a pole
and we're going to point that thing with the dome facing somewhere. What happens
to that signal when we do that? Yeah, so what you're going to notice is this is
not a standard pattern that you would expect to get from any AP. So if you've
designed and you've called for a T350C and you want that thing mounted in a
standard normal type of configuration, which would either be a ceiling or a wall,
but either way, you want that AP pointed down. As soon as you take it and you say,
oh, we're going to turn it the right, we're going to have this AP up here and
we're going to mount it like it's an AP, like a wall and a clock. And then you go,
oh, you know, let's put it here. Now you can put some down tilt on it. Watch what
happens when we add a little bit about about 15 degree down tilt onto this AP.
Right now you're pointing like this. If you're a little bit higher,
let's make that a 25 degree down tilt like this, right? What you're seeing is
these nulls here and here are getting very pronounced. And so even though you
think you're shooting directly at it, what's happening is you have these lobes
that come out here to the sides and you have nothing behind it. But remember,
this AP does not have any of those N-female ports right there. So what happens
is you take this AP, you say, I'm going to mount it, you know, on a pole, give it
a little bit of down tilt. This is the signal that you're going to end up with
here, not the signal that you were planning for, which should be mounted
like this. Now, let's do the inverse of this. Let's say we have an SE model.
Remember, it's got the two, two or the four N-female ports on there. So we're
going to come down here. We're going to take a look at this AP. This is a T350
SC. It's mounted on a wall or a pole at 12 feet. We can come down here, same
power level, doesn't matter. And what you notice is this gives you that
directional pattern like you were really expecting. We have nothing coming off
that back lobe, right? Because what we're doing is we're trying to, more
importantly, we're trying to keep that signal from coming back here. Now, you
want to do that if you're in a high dense environment and you're trying to
separate cells and you're trying to separate cells and keep those things
sort of contained. You're like, I want to make sure I don't get anything back
there. Or, you know, and especially if you were to say, Hey, I'm in a, in a
situation like this. Whereas you come down here, you know, we got some tennis
courts here, but then we got the main road, we got this parking lot. So you
could in, in essence, take this AP here and you can move this AP over to here
and you'd be like, Hey, you know what? I want to get all of my signal over here
I want it. We can put some real power into this thing. We'll make that 22, which
is three dB down for max power. We'll put a little bit of down tilt on this
thing. Or no, that's the orientation we're going to put about a 15 degree
down tilt onto this thing. And even then, right, what you notice when we do that
is we still end up with this null right here. So that's even the way it's
supposed to be mounted, that directional, you're still ending up with that null.
Now I'll show you one little other thing that I like to do. What if you take that
thing and you rotate it. Look at that. I took a T350 SE that has a 110, but has a
very narrow vertical and I rotated that AP. I'm going to take, I'm going to switch
back over to just me right for a second, right? Because normally you say, Hey, I
want this AP like this. I'm going to give it a little bit of down tilt. But if you
take that AP and you rotate it and you mount it like this, so you're pointing
down like that, right? So this is very non-standard. You would not, most people
wouldn't say, Hey, I'm going to take my AP, rotate it 90 degrees from how, you
know, because look, we've got the nice label, you know, we got the, the
ethernet cable that's going to come out the bottom, you know, all looks really
nice and fun. But if you take that thing and you rotate it 90 degrees so
that you have your LEDs on one side and then you'd have your, you know, your
other, your little two N-females. And then you have this guy right here, right
down here, right? If you take that thing and you mount it like this and you angle
it down like that, take a look at what it looks like. We now have a very narrow,
very focused. And so now I can start putting in multiple APs mounted
horizontally the way they're not supposed to be like this. And I can get
you some really nice coverage, some really tight cells that are going to
reach out and really touch somebody. So the problem we have now is we're
actually reaching out really far. And those clients that are on the other side
of this football field are not going to be able to talk back as well. So we're
going to add in a little bit more down till like that. And we can actually start
to contain these APs so that we can get these really tight cells that we really
want to get. Look at that. Like this is some crazy. I love this stuff. I love
physics. So now look at that. Now I have a very tight cell, but I'm very pointed
out right now. I'm going to show you one last thing before I run out of time.
What happens if we take the same AP and we don't mount it on a wall, we don't
mount it on a pole. What if we mounted on a ceiling, drag it back here into the
center of my football field, right? I have a very nice narrow beam. Now, if
I'm doing a warehouse, I have aisles, right? And I want to be able to reuse
channels throughout my aisles. Now, my aisles are going to help me contain that
signal so it doesn't leak left and right into the other aisles. But I have more
than three channels, we said five and six, right? And so what you do is you
take that AP, you mount it on the ceiling like it's not supposed to be. And
then that arrow right here, right? This arrow that we see, that is now the top,
that is the top of the AP. That's where the logo is. And that's where those two
and female ports are. And then if you need to rotate that thing, all you do is
you grab that thing, you rotate it. And now you can have an SE AP mounted on the
ceiling, pointed straight down in a very long type of configuration. Remember,
this is a 12 feet. If you take a look at a warehouse that maybe it's got like,
we'll say 30 feet. Look at that. We have a very nice signal right there. That,
you know, and then it's still going to be contained, but it'll go. I mean,
that's easily, I mean, as that's 300 feet, that's 100 meters easy, if not
more. I mean, that fills up the whole entire inside of that track. So if you're
doing warehouses, use physics, don't go ahead and try to, you know, try to be,
you know, other things that pay attention to your, your APs pay attention to how
they're mounted, how they're rotated, and get that signal to make sure. And then
as a designer, learn what that looks like from a picture standpoint. So when
that installer sends you a picture, you're sitting there in your, in your
office, at your house, in your, in your place of business, and they send you that
thing, take a look at it, and you can immediately know, hey, did they put that
AP, whether it's an SE model directional, you know, or an Omni, did they, did they
put it where I want it? And did they point it the way I wanted it to? And you
can very quickly tell just by looking at a picture very fast, whether or not
you're going to get that signal that you designed is going to actually show up in
the end product. So thanks for suffering through the episode with me. And
hopefully you'll join me on the next episode. I got some good stuff coming up.
I don't want to jinx it, so I'm not going to talk about it. But hopefully
you'll join me next time when I ramble on about some more stuff that has to do
with Wi-Fi and technology.

Hey there, thanks for listening. If you like the show and haven't done so, please
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And as always, thank you for listening.