Frequencies: cordless phone interference

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PhilANZ

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#80958 6-Apr-2011 17:05

Don't know if this is the right place to ask this - but talking to staff at retail outlets certainly isn't - that's made my confusion worse.

We're about to buy 2 new phones - each with three base units for different rooms. Trouble is no-one can make it clear to me how they;re going to interfere with my LAN. That is usually cabled, but we also use wireless more and more. We have a WAG120N router.

So does that mean we should use or avoid particular frequencies? I have the impression that 2.4GHz is dangerous. Instinct tells me that bigger is better - but I've seen some people suggest that 1.8GHz systems are less problematic than 5.6GHz systems.

Does anyone have any advice om the bext ways to minimise potential problems?

Thanks

Beccara

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#456025 6-Apr-2011 17:06

5.8ghz is affected more by walls than 1.8ghz, some nice plain DECT phones should do the job nicely

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sbiddle

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#456031 6-Apr-2011 17:18

You're best to stick to a stock standard DECT phone on 1.8Ghz. Most cordless phones don't use 2.4Ghz, and those that do aren't DECT compatible.

If you opt for a GAP compliant DECT device you can also mix and match handsets between brands if you want to in the future.

Uniden do make some nice phones but are the major manufacturer of 2.4Ghz phones, and their DECT phones are typically non GAP compatible.

PhilANZ

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#456051 6-Apr-2011 18:11

Well that's a bit tricky. Not the 1.8 - hear what you're both saying there - but I thought DECT was a Uniden marketing name - didn't realise it's a wider standard. Panasonic don't seem to use the terminology.

Any point in using the same / different makes - or does DECT mean that's not really such an issue?

Thanks

sbiddle

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#456061 6-Apr-2011 18:53

PhilANZ: Well that's a bit tricky. Not the 1.8 - hear what you're both saying there - but I thought DECT was a Uniden marketing name - didn't realise it's a wider standard. Panasonic don't seem to use the terminology.

Any point in using the same / different makes - or does DECT mean that's not really such an issue?

Thanks

DECT is a standard originally developed in Europe for cordless phones. All of Panasonic's 1.8GHz handsets use DECT and most Panasonic handsets are also GAP compliant.

Uniden have only adopted DECT in recent years and do a very poor job of it since there devices not fully standards compliant.

raytaylor

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#456131 6-Apr-2011 21:53

Even a cheap $30 cordless phone from the warehouse 4 years ago i bought was DECT.

DECT was also a format for wireless computer networking. Sort of like betamax / VHS it was also DECT / 802.11b
In europe its possible to get second hand the PCI DECT wireless networking cards and use them to sniff dect cordless phone traffic and listen to phone calls on your computer. Though the cards are really rear.

I tell people to either get a 1.8 or 1.7ghz cordless phone rather than a 2.4 or 5.8.
Modern 2.4ghz phones wont interfere with wifi - they are digital and use only a slither of the spectrum but the early 2.4ghz ones did cause wifi to completley drop.
5.8's are also compatible but the technical specification is that they cant output more than 4 watts EIRP. 4 watts at 2.4ghz goes much further in direct line of sight than 5.8ghz so the marketing bull about the higher frequency going a longer range to me is crap as the free space path loss is more, and walls block more of the signal.
Unless they do other things like put on a bigger antenna which doesnt really have much to do with the frequency, I would much rather have a 1.7ghz DECT for features, range and compatibility with other wireless devices.

Oh also Stay away from 900mhz. They are hopeless around computers.

Ray Taylor

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tdgeek

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#456151 6-Apr-2011 22:29

Good Question

Great Answers

Forums = +1

cyril7

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#456248 7-Apr-2011 09:40

DECT has been around for quite sometime, 20yrs or more, and is a very stable and efficient standard for cordless phones.

I remember when it was first released and we (AWA/Exicom) designed a series of basestations for the Oz market, this was before GSM was released and placing DECT public hotspots around the place for folk to use their DECT handsets was quite hip!, these were cheaper than AMP/TACs handsets/cellular plans on the main networks, the handsets were very compact (just like current DECT handsets) compared to AMP's Bricks and battery life was never ending it seemed, and it was Digital, wooo hoooo

Anyway, DECT as a standard and technology in general is one of the better thought out ones out there, very efficient (relatively narrowband for digital so has a good power/distance performance) , provides great voice quality (ADPCM 32kb/s), and good features such as intecom, with multi handsets under the GAP standard you can setup 6phones as a home cordless PABX.

LG have a rather nice SOHO type product if your after something a little more up market.

http://atlasgentech.co.nz/documents/Communications/LG/LG_wireless_soho.pdf

Cyril

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PhilANZ

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#456272 7-Apr-2011 10:27

Thanks Cyril - what I didn't say in this message was the phones are to be connected to a VoIP system - so the extra features that system has are largely looked after. Otherwise it would be of interest. We used to have and old SBX / PABX, but we didn't bring that home when we closed office - it was just a bit old and didn't work with one supplier's phone system. But I'm quite impressed with the way the VoIP system works - and it's price. Just need new phones for our situation - going to consider these today.

timmmay

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#456291 7-Apr-2011 10:56

I have some cordless phones that totally stop the wireless network, obviously they use the wrong frequency. An older ugly old phone worked fine though, doubt any of them were dect. I solved the problem by cancelling my home phone line :)

Just make sure the frequencies don't clash. If you can buy from Dick Smith do, they have a great return policy.

webwat

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#456881 8-Apr-2011 22:50

cyril7: DECT has been around for quite sometime, 20yrs or more, and is a very stable and efficient standard for cordless phones.

I remember when it was first released and we (AWA/Exicom) designed a series of basestations for the Oz market, this was before GSM was released and placing DECT public hotspots around the place for folk to use their DECT handsets was quite hip!, these were cheaper than AMP/TACs handsets/cellular plans on the main networks, the handsets were very compact (just like current DECT handsets) compared to AMP's Bricks and battery life was never ending it seemed, and it was Digital, wooo hoooo

Anyway, DECT as a standard and technology in general is one of the better thought out ones out there, very efficient (relatively narrowband for digital so has a good power/distance performance) , provides great voice quality (ADPCM 32kb/s), and good features such as intecom, with multi handsets under the GAP standard you can setup 6phones as a home cordless PABX.

Apparently DECT uses the G.726 codec so should be quite clear, and the Generic Access Profile (GAP) thing sounds like a brilliant idea. Might be time to update my old Panasonic with a multi-handset version.

Time to find a new industry!

webwat

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#456886 8-Apr-2011 23:12

Not sure if an IP-DECT base station would make sense to link up with your voip system and eliminate the need for an ATA, but I found some links for you but they look expensive...

http://www.nec-ipdect.com/

Polycom DECT Server

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PhilANZ

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#456977 9-Apr-2011 11:07

Thanks for this info - we've bought a couple of triple handset Panasonics - the first worked as wanted with no interference - so then we bought the second. I still have no real idea about the more technical stuff - but what we've got now works for us. So thanks for all the help. Since my stroke I've lost the ability to make even simple decisions (and that's with my type-a personality), so the help's much appreciated.