
Reasons to turn down the transmit power of your Wi-Fi (2017) - nameequalsmain
https://metis.fi/en/2017/10/txpower/
======
linsomniac
This is what I did when running the WiFi at PyCon. For 5GHz we generally had
enough channels that we could run higher power, but for 2.4GHz I would run it
on the lowest power settings.

I'd also set the APs on the tables, rather than trying to elevate them, so
that the bodies would limit propagation.

Whenever someone asked, which happened at least a couple times each
conference, I explained it like this: Imagine you have 10 groups in the
ballroom all trying to have discussions. Turning the power up is like giving
each group a bullhorn: the whole room becomes a noisy mess. Lower power is
like each group gathering close and talking at normal volume.

It worked well, mostly because the venue-provided wireless at the time were
all trying the "few, big AP" solution.

More details are in a series of blog posts I did, starting with:
[https://www.tummy.com/articles/pycon2007-network/](https://www.tummy.com/articles/pycon2007-network/)

~~~
noobermin
Random question then. In your experience, do people who set up the conference
halls the nation over understand physics (geometry and logic, really).

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aequitas
I've heard at tech conferences like CCC instead of using a few big powerful
AP's at central and high locations, they put lower power units in between the
audience's seats. Humans, as water bags, are good at dampening signals. So you
end up with a lot of small networks cells with high throughput, that don't
interfere with each other. Compared to the few big central cells where
thousands of devices are fighting for the same frequency slots.

~~~
oneowl
Yep I think this is a very good idea too. It is a way of reusing existing
spectrum space. Besides small cell networks use low powers and being portable
they can deployed on demand.

In fact small cell networks might be how the networks are deployed in future.
Website below has some interesting research on this topic

[https://www.smallcellforum.org/](https://www.smallcellforum.org/)

~~~
dontbenebby
Very interesting work.

One unintended side effect of this is that tracking becomes incredibly
precise.

Well, to be fair wifi tracking was already fairly precise but soon cellular
tracking will have similar granularity:

[https://www.fastcompany.com/90314058/5g-means-youll-have-
to-...](https://www.fastcompany.com/90314058/5g-means-youll-have-to-say-
goodbye-to-your-location-privacy)

------
rb808
Best thing I did was wire my house with cat6, so my TV, computer, server,
security cam, nas and printer are all wired. Its so worth the effort. Wifi is
now for a rarely used laptop and phones.

~~~
sergius
Don't forget Ethernet over Power... works great on some houses and you don't
need to lay out cables. But if you can nothing beats wiring the hole house.

~~~
josteink
In my experience this works worse in newer houses with modern (more complex,
less transparent) electrical systems, and at best you get sub-WiFi speeds.

You have little to lose by _trying_ , but there’s no guarantee it will work at
all, even less work well.

~~~
PaulHoule
I have a very old house and it works well for me.

I think you do best to have just two stations in a powerline network situation
because the contention and overhead of contention control is much less.
(Compare that to gigabit ethernet which is full duplex and switched so there
is little or no contention)

You can connect a "distant" powerline NIC to an ethernet switch and plug
multiple devices into that if they are close together, that works better than
plugging in multiple powerline NICs.

Unfortunately new houses have circuit breakers that detect broadband noise
caused by arcing. These are good for catching fires early, but will blow if
you use powerline NICs.

~~~
mcguire
I have an older house that has been expanded several times, with some rather
amateurish wiring. One outlet works, the one next to it doesn't. Slow speed,
interruptions that require resets...

Google wifi pucks work much better, in spite of the cinder block walls.

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drewg123
What about all the wifi direct printers?

Inside my house, on 1/3 of an acre (so not up against neighbors), the
strongest 2.4GHz signals I see are from 2-3 HP printers in houses around me.
This includes my own 2 Ubiquity APs that are inside my house.

I even noticed that I have a device screaming on 5GHz .. an Nvidia Shield.
AFAICT, I cannot turn that off, even if I disable wifi.

I hate wifi direct.

~~~
Baeocystin
One of my clients has a Wemo light switch that is stuck blasting its wifi on
what must be illegal levels of power, as I can pick it up through two brick
walls, across the street, and in another home(!).

Also, none of the other devices that share the same room as the dimmer can use
anything on the 2.4GHz spectrum. It's almost impressive how effective a jammer
it is.

~~~
ChickeNES
>Also, none of the other devices that share the same room as the dimmer can
use anything on the 2.4GHz spectrum. It's almost impressive how effective a
jammer it is.

If it's really as bad as you say it is, you need to report it to the FCC (or
other local governing body)

~~~
Baeocystin
I'll be ripping all of the wemo devices out next week. Then I'll be able to
test if it's a one-off, or if they really are that far out of compliance.

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alimbada
Can't this be fixed with smarter software in the AP that can:

* Dynamically adjust the power level to match the furthest client

* Boost the power level on an interval to check if there are clients further away waiting to connect

Additionally, what do mesh Wi-Fi networks do when clients are holding onto a
connection? Are they smart enough to know that another node has a stronger
signal to the client and trigger a disconnect from the clients' current node
so that the it can associate with the stronger node?

~~~
jdietrich
We can do better than that - beamforming. Better 802.11ac routers use a phased
antenna array to change their radiation pattern, steering the RF energy in the
desired direction.

[https://www.oreilly.com/library/view/80211ac-a-
survival/9781...](https://www.oreilly.com/library/view/80211ac-a-
survival/9781449357702/ch04.html)

~~~
fulafel
Heh, eventually the tech changes enough that the "wifi router" misnomer might
become correct.

~~~
penagwin
To be fair a lot of people only have a cable box (one ethernet port) and plug
everything into their wifi router, which is also the DHCP server, firewall,
etc.

I'd guess this is the most common setup for residences, it requires next to no
technical skill other then plugging in the cables. Should definitely count as
a router here no?

~~~
progval
That's also what I do.

Not that I lack the technical skills to do otherwise, but my ISP's router
works remarkably well (biband 802.11ac, IPv6, no packet loss, 4 ethernet
ports, ...), so it's all I need.

And if I have a weird issue, that's a single device that I need to reboot (and
I can even do it remotely).

~~~
penagwin
Same situation for me too. I've done a bunch of networking stuff before with
pfsense and plan to again, but I just moved and wanted something working. And
it works great!

To be honest it's all _most_ residences need, even if you're a technical
person. Half of common home devices (xbox, printers, laptops, etc) have wifi,
so for most people 4 ethernet ports is all you need(if any). It's almost 0
setup other then changing the passwords, and it works.

The only reason why it wouldn't work for you is if you have many wired
devices, or want to get into the networking stuff.

~~~
frosted-flakes
I'm going to go out on a limb and say that most people don't need _any_
ethernet ports. Most people just have a phone and maybe a laptop, tablet,
printer, or smart television, all of which function perfectly adequately over
wireless.

Even I don't bother with ethernet. There's no point; with <10 Mbps Internet
speeds, too slow is too slow. The only thing plugged into the router is a
second router for the detached garage/shop. Occasionally, there's need to
transfer large files between two computers (games which can take multiple days
to download), but temporarily stringing an ethernet cable directly between
them does the trick.

------
aivisol
> The bidirectional connection is symmetrical. It doesn’t matter if the AP has
> a better antenna or is located higher up. The antennas and amplifiers work
> symmetrically in both directions.

It does matter if antenna is located higher up. This will allow it to pickup
weaker signal from clients. Better antenna is also probably more sensitive.

~~~
superice
Yeah, that sticks out like a sore thumb in an otherwise accurate article.
Antennas have a certain radiation pattern for transmitting, but there is also
improved reception in the directions it radiates strongly in.

With wifi, there is usually little you can do since you probably want a
spherical radiation pattern, which prevents you from getting any significant
gain over a perfect isotropic radiator, but that's a different story.

~~~
muxator
Spherical -> Toroidal

------
korethr
While I generally agree with this article, and turned down the transmit power
on my AP in my apartment to be neighborly, coordinating this across the many
APs present in a residential area is tricky. In my experience, many of your
neighbors are going to be running either the stock AP provided by the ISP, or
some "gaming class" thing that advertises _very_ optimistic speeds. In either
case, you're going to be fighting with stock firmware. And it seems to me that
the stock firmware of most consumer-grade APs doesn't expose options like
channel assignment or Tx power, not even behind a secret advanced settings
page with a big scary "You will void your warranty" header. To compare the
stock firmware on most consumer-grade APs to a dumpster fire is to commit a
gross and unjustifiable insult to dumpster fires.

When I tried to coordinate better channel assignment and transmit power with
my neighbors in my apartment complex, the effort very quickly died for the
reasons above. Most neighbors didn't know or care about the settings on the
magic box that made their Netflix or Xbox work, and even if they did, the
config options simply weren't there.

I wish there were more I could do to change this situation. As it is, all I
can do is vote with my wallet and buy less horrible brands like Ubquiti, where
advanced options like channel assignment and Tx power are available to me if I
want them.

~~~
mikelward
I get a higher signal strength from my neighbor's Xfinity/Pegatron than my own
access point on max power.

------
jnty
The roaming point is very interesting - I do have a problem with devices
'hanging on' to the wrong AP in my home. I'm gonna try it!

~~~
kiallmacinnes
Another few possibilities for this which were not mentioned in the article:

* Check that all your APs are broadcasting the same name. No devices I know of will naturally roam to an AP with a different name.

* Check that all your APs are broadcasting identical security features (e.g. WPA1, WPA2, WPA1 or WPA2 .. as well as the encryption methods like TKIP, AES/CCMP, etc). Many devices will check these too, and roam only to matching APs.

~~~
throwmeback
Some devices also have a AP priority list, it's worth checking out if they can
be modified (e.g. like on macOS).

------
devonkim
Decades into the future I will be an old man screaming that wireless will
never replace wired networking while some insane people have come up with
real-world 10 Gbps wi-fi connections. The realities of wireless communications
don't seem to have changed much since the early days of wi-fi at 802.11b and
prior and while wired networking has somewhat hit a wall for consumers in the
datacenter it's still kicking ass and taking names at 400 Gbps and software is
among the bigger limitations than the hardware.

------
oneowl
2.4ghz also has 3 non overlapping channels (iirc). Most people use the default
channel of their WiFi so if you choose a different channel you can get a
better signal at a lower power.

Edit

If you want low coverage area it would also not be such a bad idea to use the
5ghz frequency if your router supports it. Much less crowded shorter range by
default and higher speeds

~~~
rzwitserloot
WiFi routers will hop to less congested channels automatically these days; the
odds that your neighbourhood has lots of WiFi base stations you can see, but
there is still a frequency that's almost entirely free is _very_ low.

~~~
baking
There are effectively three 2.4 GHz channels and about six 5 GHz channels, but
because the range of 5 GHz is so much smaller you should be able to find on
open 5 GHz channel even in the densest, tech heavy, apartment building.

As the author said in the comment section: "I usually suggest turning 2.4 GHz
off altogether so none of your users will ever connect to it by accident."

As for AP's sharing channels, this is great in concept but our (3 unit)
building became so overcrowded in the 2.4 GHz spectrum that devices couldn't
connect which caused people to add more routers and repeaters to "boost" the
signal making it even worse. If you can't connect, you can't share.

------
anonu
Another solution for the 2.4GHz range and if you have a slightly more advanced
router: switch to channels 12 and 13 in low-powered mode. In the US you'll be
operating on channels that I would suspect 99% of APs don't operate in by
default. Channel 14 is only allowed in Japan - illegal in USA.

------
otterpro
I was just thinking about this. My idea was to have the power low enough so
that WIFI is restricted to a very small area of the house. It would be like a
smoking area, except it would be for WIFI usage. For personal application, I
wanted to create a WIFI-free zone for the family in the living room and other
common area, so that we're less distracted, while we have WIFI in the other
parts of the house. Of course, we still get 4G signal, but it is very weak
where I live, and we are also on pre-pay plan on Tracfone so we are
discouraged from using data on 4G.

------
sytelus
The article proposes reasons such as interference and generally being nice to
neighbours. I actually do this just to reduce RF radiation at microwave
frequency in my environment due to potential long term health consequences.
Research on this has lot of contradiction with most governments saying there
is no impact but some saying there is adverse health effects due to long term
RF exposure. Why to take chance when you don't have to?

------
poorman
Someone should create an app that detects wifi APs that are transmitting at
high power so you can track them down.

It would be super useful for someone like me where there are dozens of
different APs in an apartment building all competing with each other. Then I
could kindly go to my neighbor and ask/assist them in turning theirs down.

~~~
mises
I've used this one before, and it does a good job:
[https://play.google.com/store/apps/details?id=com.farproc.wi...](https://play.google.com/store/apps/details?id=com.farproc.wifi.analyzer&hl=en_US)

It's great for finding unused channels for your AP.

------
amiga-workbench
I've got 4 Unifi AP's spread around the office and turning the transmit power
down has solved the issue of clingy MacBooks not migrating to the closest AP
as people move between rooms.

------
zoobab
I tried to explain to Battlemeshers that they should tune down their radios to
1dbm. They kept the settings to "auto" or to 18dbm.

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tehsauce
"It doesn’t matter if the AP has a better antenna or is located higher up."
Why is this?

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purplezooey
But my neighbor is a jackass that reports my garbage cans to the HOA all the
time. I ain't turning down shiiiat.

~~~
jimmaswell
You couldn't pay me enough to live in an HoA. They should be illegal. Land is
scarce enough already without those mobs ruining so much of it. If my neighbor
wants to cover their lawn in rusted cars and paint their house pink so be it.

I've heard if you install a giant ham radio tower they're not legally allowed
to do anything about it. Any little bit of sticking it to those organizations
is a good thing.

~~~
mises
A good reason why, at least in Houston, is no zoning. I had a friend who had
every area outside the HOA taken over and covered with office buildings,
apartment complexes, etc. by stupid MetroNational. There's now a very abrupt
line between the all residential pocket and the towers, mall, etc.

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musicale
Yes, please do this!

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fxbl0i
Many of those depend on all of your neighbours doing the same thing. They
won't, so you'll be the loser. I don't want to be the loser.

~~~
snarf21
Exactly, and they all have the crappy Comcast combo which advertises the extra
XFINITY AP that I don't think you can turn off. As a Comcast customer, I have
_NEVER_ been able to connect to that and get data. 2.4 ghz is a sh!tshow and
everyone is just spamming it with more and more noise.

~~~
baking
Don't pay the $10 monthly fee to rent a Comcast cable modem and instead buy
your own cable modem and router for $110. Side benefit: no extraneous Xfinity
AP clogging up your precious wifi bandwidth.

~~~
snarf21
Yeah, I don't but literally all the neighbors do.

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AFascistWorld
Just use 5G mode.

~~~
zamadatix
In a suburb sure but apartment 5 is often more crowded than suburb 2.4.I can't
wait for 6 to open up...

~~~
AFascistWorld
I can't fathom the situation you described since 5.8GHz has far more
unoverlapped channels instead of just 3.

~~~
baking
He said "apartment 5 is often more crowded than suburb 2.4"

2.4 is unusable in an apartment building because the range is so great. I live
in a 3 unit so I am happy with my 5 Ghz but in a very dense building I could
see problems.

------
nautilus12
Aren't there also possible health considerations with running 5G as well? I
feel like there is some preliminary data that its not good to be sitting in a
bath of 5G all day long. Can someone comment?

~~~
justatdotin
maybe?

but first I'd like to identify the mode of harm. How would this low-energy,
non-ionising radiation present a biological impact?

The theories I've heard (induced currents in the dna base stack? magnetic
stimulation of cryptochrome that modulates intracellular reactive oxygen
species?) describe very rare, unlikely and low (negligible?) impact.

I am open to the theory of hypersensitivity, however I've never found anyone
who suffers it.

~~~
woetoh
[https://europaem.eu/attachments/article/131/2018-04_EU-
EMF20...](https://europaem.eu/attachments/article/131/2018-04_EU-
EMF2018-5US.pdf)

These studies indicate a mechanism of EMF stimulation on voltage-gated ca++
channels.

Personally, I've never noticed issues with RF-EMF until I tested my sleep
using the oura ring. WiFi didn't seem to bother my sleep but shutting off the
power to my bedroom at the breaker improved my sleep tremendously. Even if
their effects on sleep are small, the negative, non-linear health impact of
sleep loss is significant...to me.

Maybe in 20 years we'll view EMFs akin to cigarettes, maybe not. I'm not
wearing a tinfoil hat just yet but it has changed the way I intreact with
these non-native frequencies. It seems prudent to take simple precautions like
avoiding microwave use, utilizing airplane mode and turning off/unplugging
appliances, lights and WiFi when not in use.

