by linsomniac on 4/10/19, 3:00 PM
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/
by aequitas on 4/10/19, 12:26 PM
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.
by rb808 on 4/10/19, 12:46 PM
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.
by drewg123 on 4/10/19, 4:46 PM
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.
by alimbada on 4/10/19, 12:47 PM
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?
by aivisol on 4/10/19, 12:03 PM
> 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.
by korethr on 4/10/19, 5:40 PM
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.
by jnty on 4/10/19, 12:12 PM
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!
by devonkim on 4/10/19, 10:02 PM
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.
by oneowl on 4/10/19, 1:04 PM
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
by anonu on 4/10/19, 6:17 PM
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.
by otterpro on 4/10/19, 1:08 PM
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.
by sytelus on 4/10/19, 9:41 PM
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?
by poorman on 4/10/19, 3:49 PM
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.
by amiga-workbench on 4/10/19, 3:00 PM
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.
by zoobab on 4/10/19, 1:40 PM
I tried to explain to Battlemeshers that they should tune down their radios to 1dbm. They kept the settings to "auto" or to 18dbm.
by tehsauce on 4/10/19, 10:44 PM
"It doesn’t matter if the AP has a better antenna or is located higher up."
Why is this?
by purplezooey on 4/10/19, 4:30 PM
But my neighbor is a jackass that reports my garbage cans to the HOA all the time. I ain't turning down shiiiat.
by musicale on 4/11/19, 4:59 PM
Yes, please do this!
by fxbl0i on 4/10/19, 11:56 AM
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.
by AFascistWorld on 4/10/19, 12:55 PM
Just use 5G mode.
by nautilus12 on 4/10/19, 4:53 PM
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?