Thread: Wifi cameras
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Old September 16th 20, 08:24 PM posted to alt.comp.os.windows-10
Paul[_32_]
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Default Wifi cameras

Pat wrote:
This is sort of off topic, but I know there are some very
knowledgeable people here. I live in a small condo association (20
units) and volunteer to manage our security cameras (15 IP Cameras).
Since my unit is near the center of the property and I was able to run
fiber to a utility building elsewhere on the property, most of the
cameras are hard wired using p.o.e. and work very reliably. However,
3 of the cameras must use 2.4 GHz wifi. My personal wifi easily
covers my unit and surrounding area, but barely covers the common area
where those 3 cameras are located. That area is roughly 180 feet from
my router, so the limited coverage is not a surprise. Quite a few
years ago, I purchased a TP-Link WA7210N access point. It is
connected to my router via ethernet and is aimed toward those 3
cameras. Adding that AP, made a huge improvement, but it is still not
as good as I want. Depending on the weather, whether there are leaves
on the trees, and what vehicles are parked nearby, anywhere from 5% to
10% of the messages are lost. Sometimes, no messages are lost for
hours. Other times, no contact can be made for 3 or 4 minutes.
Usually, it is something in between - a few lost messages per minute.

I believe there are three things causing my issues. 1) At 180 feet,
the signals are still fairly weak. 2) Being is a well populated area,
interference from other wifi networks are a likely problem (one of the
cameras can "see" over 50 SSIDs), and 3) being restricted to 2.4 GHz,
all my neighbors' microwave ovens are probably causing problems. (My
own microwave wipes out those 3 cameras while running, so other
people's microwaves are likely to do the same). I have AC power
available near the cameras, but there is no protection from the
weather available for things like range extenders. I also have no way
to run new cables or fiber to that area without digging under long
runs of concrete driveway. I am hoping one of you might have an idea
I haven't thought of yet.

Pat


They give an overview (of sorts) here.

https://www.waveform.com/pages/wifi-...er-differences

Powerline networking only works, if the two units are on the seoondary of
the same power transformer. Your cameras in the parking lot are unlikely
(by chance) to be on the same transformer as your unit in the condo.

I don't know if it's the Extender idea I don't like, as much as the possibility
of foliage in the way. And you want to test before leaf-fall, to get the full
effect. If your Wifi kit was pointed at a second floor window as its outlet,
you might be shooting through foliage all the way to the destination. With
extensive attenuation.

As for other exotic solutions, now you've got multiple layers of
equipment. Which doesn't make for the easiest setup and debug.

https://www.telcoantennas.com.au/sit...ti-nanostation

There is only so much you can do from a signal strength point of view.
Strong signals can cause detectable multipath, confusing the
device at the other end. The FCC defines power limits based
on EIRP (equivalent power), which means if you stick a 30dB dish
on one end, the beamwidth might drop to 5 degrees wide, and
maybe not all the cameras would be within the cone of the beam,
and the "equivalent power" is way above what the FCC allows.
By writing a power limit that takes antenna gain into account,
they cut out the "sharks with lasers on their heads" crowd, that
try to beat the limit using antenna gain.

If people complain to a communications authority, that's when
someone comes out and checks for the interfering source. And
that's when they might notice the usage of a dish which just
happens to spew part of its beam into someones house, wiping
out their "ordinary" signals. The whole purpose of having
a low unlicensed limit, is to try to avoid trouble requiring
truck rolls from the authorities.

The radios on the units themselves, can adjust the transmitter
power according to situation. If the equipment detects that
each receiver is having no trouble "seeing it", the
transmitter power can be reduced (automatically and maybe without
even showing in a status dialog). They only go to full power
if reception is marginal.

There *is* a radio standard which can be used by consumers to
go long distances. Like all the way across a ranch. The problem
is, the data rate is maybe 2 Kilobits, suitable for taking
temperature readings or wind speed readings. You can't carry
video on a standard like that. Still, it's impressive that
at least some communications was possible. As far as I know, that's
a wideband technique and works across multiple bands.

Paul
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