2.4ghz Phones + 802.11 wifi (1 Viewer)

Skittled

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(If you can't be bothered reading all this, just read the stuff that's been bolded. )

Just a quick post in case this info is useful to anyone. A while ago I move into my girlfriend's house, and we had a wireless router put into the flat (above their garage, so near the house) so we could use our laptops. Within a few weeks her dad went out and bought a fantastic set of 2.4ghz phones, which of course cause massive interference with the wifi.

So, after a few months of continually resetting the router at the power switch (becuase the signal gradually drops off until you are either disconnected from it, or it simply doesn't respond... I assume there's something in the firmware trying to differentiate the interference from signal, and it raises the threshhold or something), I finally decided to look into it and believe I've found a solution... or at least something that menas I've only had to reset it once in 2 days, becuase it had a fit rather than becuase I couldn't connect...

Problem: 2.4ghz phone causes interference with 802.11 wireless network.

Background to the solution: 2.4ghz use frequency hopping (there's some wonderful acronym for this but i've forgotten it). That means that as it cycled through those frequencies, it totally obliterated the set of frequencies that our 802.11b router used (if we had a 11g router it'd have been worse becuase it uses a wider set of frequencies). 802.11x, as I implied above, uses a specific set of frequncies. However, back in the day before it was standardised they used frequency hopping -- it's easier, and cheaper (Which is why it's used in phones) to implement, but cannot support datarates faster than 1 or 2 mbps, which is why they changed to the set-frequency method, to get huge speeds
*deep breath*.

Solution: Everything in the 802.11 world is backward compatible (give or take, ie 11a is not compatible with 11b, but that's a totally different story). Solution was to force the router back into using the non-standard method (ie frequency hopping), by telling it to only ever let anything connect at 1-2mbps.

End result? Phone works with less interference (because it got it too when you were using the internet), the internet works for longer than a 30 minute period without resetting the router, and I'm a lot less frustrated!

Hope that's useful for someone in the future at some time. Feel free to pm me if it doesn't make sense and you need help.

(Before anyone bitches about having a data rate of 1-2mbps, when they think that 11 or 54 or 108 is desirable, work out how fast your internet connection actually is and whether you really ever need 11 to 108mps. Yes, admitedly for file transfers 1-2mbps isn't fantastic but if you need to do that, then you'll have to find some other way around the interference, or sit and twiddle your thumbs for a while ;) )
 

MedNez

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Awesome post. I've FAQ'd it for future reference =)
 

Skittled

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playboy2njoy said:
Yeah, I always make a note of warning people who decide to get a wireless network setup to ensure they dont have any of the new panasonic/uniden's. btw you can use the older 800mhz digi's though.
True. The 800/900mhz ("DECT") phones are the surefire way of avoiding all interference... These aren't truly digital, though, I believe, just "Digitally Enhanced Cordless Telephones"... not technically digital transmission like the new ones. Using a DECT phone (or anything in the 800/900 mhz range) will avoid interference.

Similarly, there are new Panasonic/Uniden/other brand phones which work on 5.8ghz. These will not interfere with 802.11b or g or g+ or anything like that. However, they will interfere with 802.11a, though, which uses this same frequency (however I've never seen 802.11a routers sold to the general public, and the things that can do A tend to do B (and sometimes G, too)...

Bottom line to a consumer purchasing a new phone:, if you're not sure what wireless setup you've got, it's probably B or G (ie 2.4ghz, rather than 5.8), and you'll be safe with wither a 800/900mhz "DECT" system (or similar -- manufacturers usually specify the frequencies it seems), or a 5.8ghz one. Or a mobile phone -- that'll be fine, too ;)

Decent retailers should be able to swap your phone over if you find it causes you a problem, so if you're buying a new phone and unsure, ask about return policies. Dick Smith (or Dick Smith Powerhouse, or Tandy, all of whom are owned by Woolworths and run by the same people and have the same policies) is good for this (but I hate them as an employer) - you've got 14 days to try it out. Beware of other places, though -- you migth be stuck with it. Caveat Emptor.
 

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