CoExisting with Spread Spectrum 2.4Ghz video camera

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dsalch
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CoExisting with Spread Spectrum 2.4Ghz video camera

Post by dsalch »

I am looking for any advice on the best way to have 2.4ghz wifi coexist with a spread spectrum 2.4ghz wifi video camera.

Details:

router : netgear wndr3700 running gargoyle 1.8
camera: lorex 4 camera system on 2.4ghz with spread spectrum

When the video camera are running, it gives noticeable interference to the wifi as expected, but I have noticed a couple things odd:

1. the channel in use by the wifi seems to matter. Edge channels (1 and 11) seem to suffer from the least interference

2. There is some timing effect. the longer both run, the slower the wifi gets. But then simply changing the wifi channel or rebooting the router restores wifi speeds for maybe a few hours. It is as if the wifi is "learning" or trying to learn how to coexist and is making a progressively bad decision. This effect is reproducible 100%, where something as simple as changing channels can restore average speed across wifi from only 1 to 2mbps to full 54mbps instantly. But then degrades again over time. It is important to note that signal strength does not change over this time.

I realize this is a no-win scenario... and do plan on replacing the video camera with a more compatible one as soon as possible, but that may be months away. So... until then...
Any advice would be appreciated!

tapper
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Re: CoExisting with Spread Spectrum 2.4Ghz video camera

Post by tapper »

Hi mate. First thing i would do is upgrade to 1.9.2 as there is a lot of bugs fixt. If you do flash then pleas don't save any settings, it's a pane i know but it will save you a lot of trouble in the end! If you have trouble after that post back and we can have a look at any settings for your Wi-Fi.
Linksys WRT3200ACM
NETGEAR Nighthawk R7800
NETGEAR R6260

Lantis
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Re: CoExisting with Spread Spectrum 2.4Ghz video camera

Post by Lantis »

You can't beat wireless interference unless you can move it or remove it.

Get a 5GHz access point and move all of your devices to it, or consider different cameras.

Sorry, it's unfortunately that simple.
http://lantisproject.com/downloads/gargoyle_ispyisail.php for the latest releases
Please be respectful when posting. I do this in my free time on a volunteer basis.

dsalch
Posts: 123
Joined: Wed Jan 06, 2016 2:09 pm
Location: Tx

Re: CoExisting with Spread Spectrum 2.4Ghz video camera

Post by dsalch »

tapper wrote:Hi mate. First thing i would do is upgrade to 1.9.2 as there is a lot of bugs fixt. If you do flash then pleas don't save any settings, it's a pane i know but it will save you a lot of trouble in the end! If you have trouble after that post back and we can have a look at any settings for your Wi-Fi.
I was considering that, but wondered if it would be better to wait for 2.0 since 1.9 is still listed as experimental? I rely heavily on proper operation of QOS in this router for my day job, so I cant afford any unexpected mishaps. Is 1.9 stable enough to rely on now?

dsalch
Posts: 123
Joined: Wed Jan 06, 2016 2:09 pm
Location: Tx

Re: CoExisting with Spread Spectrum 2.4Ghz video camera

Post by dsalch »

Lantis wrote:You can't beat wireless interference unless you can move it or remove it.

Get a 5GHz access point and move all of your devices to it, or consider different cameras.

Sorry, it's unfortunately that simple.
Yes, that is the long term goal. Not possible at the moment. So in the mean time I find it fascinating how the WiFi interfaces are operating against this constant interference.. almost as though they are "conceding" to the interference instead of fighting it for best signal.

I suppose that is the nature of my question... Given a bad situation where there is constant interference, what is hte approach of this Wifi software... to battle it out for best reception or to concede the bandwidth by relaxing the attack? (sorry, dont know how else to explain it).

For instance... I believe that Wifi automatically decreases speed based on errors and SNR, etc... is there anything in that algorithm that tries to overcome the throughput problems or does it just try to find the speed which causes no errors (which seems lik eit would produce lower and lower speeds due to interference until wifi becomes unusable).

Does that make any sense?

Lantis
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Re: CoExisting with Spread Spectrum 2.4Ghz video camera

Post by Lantis »

Yes I believe you are correct. Based on failed transmissions and receives from clients, as well as data it pulls from the spectrum, it lowers its rates until it can perform with minimal errors.
http://lantisproject.com/downloads/gargoyle_ispyisail.php for the latest releases
Please be respectful when posting. I do this in my free time on a volunteer basis.

tapper
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Re: CoExisting with Spread Spectrum 2.4Ghz video camera

Post by tapper »

Hi I would say that 1.9.2 is stable. I have 2 routers a wdr3600 and a WD-mynet n750 on 1.9.2 with good uptimes. Make a backup of your settings and download the file for 1.8 and 1.9.2 that way if you have a bug with 1.9.2 you can flash back to 1.8 in 5 mins.
Linksys WRT3200ACM
NETGEAR Nighthawk R7800
NETGEAR R6260

dsalch
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Location: Tx

Re: CoExisting with Spread Spectrum 2.4Ghz video camera

Post by dsalch »

Lantis wrote:Yes I believe you are correct. Based on failed transmissions and receives from clients, as well as data it pulls from the spectrum, it lowers its rates until it can perform with minimal errors.

I wonder if there a benefit to having a second mode... one that tries to force higher rates at the cost of more retransmits. perhaps just tweaking the "policy" to favor speed over errors? The reason is... in a situation like this where hte interference is frequent but brief, let the errors happen during the short burst of interference without lowering speed, expecting the burst to end and therefore higher speeds are allowed the majority of the time. Average speed would increase?

AS it is, average speed decreases over time, but perhaps this is unnecessary since the higher speeds during no interference would offset the errors during a burst of interference.

In other words.. a policy that says "accept a higher error rate in order to preserve higher average speeds".

I doubt it is possible to find a "one size fits all" solution, since there are a few interacting veriables in this equation, so perhaps a second "mode" ... one that favors speed and accepts errors, where the normal mode favors lower errors at the cost of lower average speed.

does that seem practical?

Lantis
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Re: CoExisting with Spread Spectrum 2.4Ghz video camera

Post by Lantis »

It's out of Gargoyles hands.
You're talking about the fundamentals of wireless transmission and the operation of the drivers.

There is some control over some parameters if you set them manually.
Retry rates, timeout etc.
https://wiki.openwrt.org/doc/uci/wireless

Without understanding them you may cause more harm than good.
http://lantisproject.com/downloads/gargoyle_ispyisail.php for the latest releases
Please be respectful when posting. I do this in my free time on a volunteer basis.

dsalch
Posts: 123
Joined: Wed Jan 06, 2016 2:09 pm
Location: Tx

Re: CoExisting with Spread Spectrum 2.4Ghz video camera

Post by dsalch »

Lantis wrote:It's out of Gargoyles hands.
You're talking about the fundamentals of wireless transmission and the operation of the drivers.

There is some control over some parameters if you set them manually.
Retry rates, timeout etc.
https://wiki.openwrt.org/doc/uci/wireless

Without understanding them you may cause more harm than good.

Thanks! That's a wealth of fun stuff to consider...

One final question.. how about just an option to force a fixed rate instead of auto adjusting? Wouldnt that be a simple fix to a problem such as this? Just stay at a certain rate all the time and live with the errors? Is this possible in gargoyle?

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