Put an intro here
Here is a typical wireless Modem from the cable company and a
wireless router installed by a building owner in Seattle. All
photos are thumbnails - click for a larger version. On top
marked in red is the cable modem, on the bottom marked in blue
is the router & wireless access point.
I’ll use this as my first example - but first some theory and
knowledge are necessary before we look at solving this one. The building
is two stories and a basement, 5 apartments, bulit in the 1920s with
brick outside and plaster walls inside, and this router provides Wi-Fi
for about 3500 ft.².
Wi-Fi signals travel over radio waves. There are two
frequency bands or areas of radio spectrum that are currently
allocated, 2.4 GHz and 5.8 GHz. 2.4 GHz ("B/G band") typically
reaches about 100 feet in open air and 5.8 GHz ("A" band)
typically reaches about 1/3 of that or 33 feet. 2.4 has greater
range but less speed and less channels, 5.8 has more channels so
less chance for interference and has greater speed but also
doesn't go as far or go through obstacles as well. This is a
gross oversimplification aimed at non-engineering folks, so if
you’re an engineer keep in mind I’ve taken a lot of liberties
aimed at non-engineers so don’t beat me up too badly.
You can think of the signals coming from the antennas of this access
point is creating a balloon around those antennas. The antennas are in
the center of the balloon and everywhere inside the balloon you have
some signal. If you are outside the balloon, you have no signal.
It isn't quite that "Good/Bad" but "Great, Good, Not as great but still
usable, connects but barely usable, not able to connect" as you get
further away. At that furthest distance, your signal still reaches but
you just can't connect both ways. Signal strength follows the "Inverse
square law" so at half the distance the signal doubles; half again and
it doubles again ... and the reverse is also true. So to get to "Good
signal" I'll draw a circle 50 feet around the antennas.
overhead down on the property let me plot this balloon in two
The little red plus sign around the center of the building numbered
311 in the center of the picture represents the location of the wireless
router in the building. I drew some concentric circles around the WAP to
show some approximate sizes of the balloon of signal - if the building
wasn't there... Plus the scales are off as the building is more like 55'
deep and 40' across from the bulding is already inside the next
building. But these are all approximations anyway to give you an idea.
This should illustrate the problem - do you see it?
Over half of this access points green & good signal is going into the
street, into the cars, and the not as good portion is touching the
building on the other side of the street.
Which leads me to the first, best and cheapest way to make things
Improvement #1: position
the wireless access point to optimize its signal
So for this example, the first thing I would
recommend is to move that wireless access point, the center of
the balloon, to the very center of the building. If you do this,
you’ll get better coverage in the back half of the building,
better coverage in the middle of the building because you’re
near the access point, and as an added benefit your signals
won’t necessarily spill out into the street where other people
can potentially try to access those signals. Right now the
wireless signal hits the white truck parked outside the front
door better than it hits anyone living inside the building.
This is usually the cheapest and easiest solution - you
might have to run a cable to a central location or if you have a
cable outlet nearby move the access point ... but move the
center of the balloon so the air is in more of your house is my
number one choice.
Keep in mind if you have an upstairs
but no basement, the best position might be on the floor
upstairs and not on your main floor on a table or in a cabinet.
Again, visualize the center of the balloon - where is the air
inside the balloon in your house?
My next option is really my third choice for effectiveness, but I'm
listing it next as it can be the next in line as far as cost goes:
Improvement #3: Wireless
Another option is a commercially
available wireless repeater. This radio device picks up frequencies that
you set it to and re-broadcast it on another channel, extending your
wireless perimeter. This is probably the most common over hyped
advertisement that you’ll see on the Internet after you searched for
improve my wireless performance. Inside there are usually instructions
that few people will actually read about how to get the best performance
out of your wireless repeater.
The key here is to position the wireless repeater so it gets a GREAT
signal from your main station. That means it has to be in the brighter
green zone, not the grey zone. If you put it in the grey zone, you might
get a great signal around the repeater but it is repeating a so-so
signal which means your internet will be only as good as the repeater's
so-so signal is receiving.
Which is what the owner of this building did - they have another
balloon extending the Wi-Fi signal to the back of the building but it is
on an edge and upstairs so it is wasting 3/4 of its balloon of signal
and in the grey zone repeating a kind of sometimes OK signal. Look at
the second red plus sign in the grey zone here:
Since it is upstairs it is actually getting worse than the grey would
A quick shout out to Google Maps for the images above! If you haven't
used Google Maps, you are missing out. Seriously!
I mentioned this apartment was built in the 1920s. This calls for a
short bit of geeky stuff.
Radio power, signal strength,
distance, and obstacles
The more power a radio transmits with, the more air is in
the balloon, the bigger the balloon is and the farther the signal go.
There are limits to how much power can be radiated based on the license
free status of the Wi-Fi radio spectrum and not every wireless radio can
do the maximum allowed radio power. So that is certainly one aspect to
take a look at and optimize for your environment.
you are trying to reach and their ability to send a signal back to your
wireless access point are the opposite direction of the same problem. If
my voice is twice as loud as your voice, as we walk away from each other
we will get to a point where you can hear me but I cannot hear you. The
same will be true for wireless, so consideration has to be given to what
devices you are trying to reach with your wireless access bubble.
A laptop computer with an external wireless network connection and a
nice antenna is going to do better than a laptop with a built-in antenna
which is going to do better than a cell phone which will do better than
a small printed circuit board mounted antenna like you might find inside
of an Amazon FireStick or Chromecast.
All of these will take a backseat to a wired network connection,
which is always your best fastest most reliable connection.
Here is my laptop - on the left with the built-in antennas and on the
right with a cheap USB dongle and an external antenna; note the speed of
each connection - even though the laptop built in claims more bars of
signal the speed is less than the external antenna:
The laptop has an antenna built in that is probably right behind the
display panel ... and surrounded by metal, a display panel, other
electronics, ... it just can't speak and hear as well as an antenna not
surrounded by all that stuff.
Here is the external antenna, then with the plastic cover removed:
Some quick physics: You can calculate the wavelength in millimeters =
300 / Frequency in GHz.
2.45 is right in the middle of the B/G band, so 300 / 2.45 = 122.45
mm. A common antenna shortening technique is to divide by 2 or 4 for a
"Half wave" or "Quarter wave" length antenna... if I divide 122.45 / 4 =
30.6 mm. Here is the antenna insides measured:
So there are two metal tubes, one is about 20mm the other is about
28mm covered with heat shrink tubing.
Close to optimal, but it was a cheap antenna.
What does this mean for you? Lets say you have good coverage for the
most part but that one spot is just a little weak. If your radio in that
device isn't optimal maybe a spot improvement would help for that device
in its position.
Here is an antenna on a printed circuit board - the squiggly thing on
the top of the picture. The whole board is about the size of my thumb.
There is no way this antenna is better than the longer external antenna:
Here is a miniature wireless adapter that fits into a USB socket:
It is sitting on a bottle cap for a size reference. Any guesses how
big its antenna is or how well it performs VS the other two access point
Yes, size does matter unless you are in a very well covered wi-fi
Another possible improvement for your coverage can be made with
antennas on your wireless access point. Your radio signal balloon
doesn't have to be a round sphere - it can be more compact and pointed,
extending outward like ... well like a certain body part - use your
This is one example - a patch antenna that throws very little signal
behind it but pushes all the air in its balloon mostly in one direction.
There is more than you ever wanted to know about antennas, types and
radition patterns here:
One big catch: Not all access points support changing out antennas.
All those little possible improvements ... None of them are my
Improvement Choice #2: Distributed
wireless access points wired together
mind-visual on this is "Balloons to fill my home or office and all them
conneced by strings so they are sending their data wired to my network
Everything above is cheaper and quicker and >hopefully< solves your
problem. But for me, I want my entire living and working areas bathed in
a wonderful sea of wireless signals such that I don't have to worry
about where I am or do I have enough transmit strength from my phone to
reach an access point or a new device comes in and I'm not worried that
I've overloaded my setup.
I just want everything to work.
We have 4 wireless access points spread through a 2500 sq. ft. home
built in 1929 that has plaster walls. Plaster walls are absolute hell on
radio signals - the plaster with its metal screen they put behind it to
hold the plaster acts like a
shielding radio waves from each room to the next.
Ours are spread out:
1 in the attic shooting down through the dining area and barely
hitting the kitchen
1 in the family room covering the family room,
the master bedroom above it, and the living room behind the family room
1 in the master bedroom for double coverage of the bedroom and the
family room below it
1 in the basement covering the basement and the
and I'm actually thinking of adding another to give better coverage
upstairs ... but that hasn't happeend yet.
I'm not worried about dropping a phone call made on Wi-Fi - they all
seamlessly roam between access points.
In another case, I have a client that had horrible WiFi in their
house. They asked me the same question, hoping they could buy a product,
plug it in and be done with it. Their house is L-O-N-G, has an equally
long basement, built in the 1970s with aluminum plates behind the walls
(??) and was a horrible mess for wireless.
I spent a half day, installed 3 access points, wired them all
together, we positioned them in strategic locations in the basement
above the drop ceiling, and now their whole house is bathed in a
luxurious sea of Wi-Fi signals. They can watch movies on a tablet in one
room on one edge of the house and walk to the other edge and it never
misses a beat.
I had a similar problem here at my temporary residence in Seattle,
ended up buying a couple of flat Ethernet cables I can run along
baseboards or along picture molding and I went from sucky disconnecting
wi-fi on my laptop and an Amazon FireTV that couldn't watch a program
without pausing to beautiful mostly wired fast connections with wifi in
the apartment that nobody else in the building can touch as I'm behind
my own firewall.
It took a couple of flat Ethernet cables I snaked up the stairs to
the apartment and hung an access point and firewall down from the
picture molding. Not pretty but very functional.
<add link to sample flat cables>
<everything below this line are my own notes in what to include above
and will be deleted or moved up top once published>
Zones of good coverage and what hurts that coverage - walls doors
plaster metal screens etc.
Interference - testing videos and
person walked in with cell phone on belt.
Double problem with repeaters - latency. bad for gamers as everyting
has to be received and forwareded both direcitons, adding significantly
talk about mesh networks - latest real world fad, it tries to do what
a good network design with proper infrastructure will do only with all
the WAPs acting as repeaters for each other.
If you have no choice, do mesh ... but I'd go with a good
infrastructure before thinking about implementing a mesh.
Typical range - 100’ outside unobstructed. 1/3 of this for 5.8
Antenna to beam / push the
signal / air to a different shape.
Get a table showing all the
typical building materials and how they eat / degrade your radio signal
Drywall, Sheet rock, Tile
Doors, Brick, Plaster, Glass
Metal (garage door?)
Multiple access points with overlapping coverage
on Hoisington's house.
Tools for measuring wifi signals - need to talk about them:
If you've gotten this far hopefully you realize there is no "Just buy
this product, plug it in and all your problems will be history"
solution. And anyone that is trying to sell you such a product without
knowing the corner of your world you are trying to get better wifi
signals in is selling you a load of bullshit.
<plug for services>
<thanks and call for feedback or questions>
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