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Analog telephone to SIP

Started by PeteMc, August 21, 2014, 12:47:20 PM

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PeteMc

Hi,

I'm hoping someone here may have an solution to an issue I'm having.

We apparently have high interference in the 1.9 GHz range, so standard cordless phones are useless more than a few feet away from the base station.  But there's no issue with our 5 GHz WiFi. 

I'm looking to see if there are phones that use 5 GHz WiFi and a way to convert analog lines to SIP (or whatever) to use with these devices?

Anyone have any suggestions on how to do this or where else to go ask?

Thx!

drgeoff

My understanding is that the 1.9 GHz channels used by DECT 6 in the US are reserved for voice communication.  Why are you suffering high interference?

PeteMc

Yes, it is the reserved band, but interference is interference....


SteveInWA


  • Like drgeoff said, the DECT 1.9 GHz band is reserved.  There shouldn't be any legal RF interference.  You can complain to the FCC if someone is polluting that band; otherwise, you have a problem with your own DECT equpment.
  • WiFi is terrible for voice calling.  WiFi just isn't designed for low-latency, high signal-quality use as needed for voice.  As far as I know, almost every vendor that tried to sell a "WiFi phone", withdrew the product.
  • If you're intent on using WiFi, any modern Android phone can use a SIP client like CSIPSimple or X-Lite or Bria, configured with SIP credentials from a SIP VoIP service provider.  You can decide for yourself if you are satisfied with the call quality.
  • Prior to DECT, Uniden (and that other cordless phone company, name escapes me) and Panasonic all sold 5.8GHz cordless phones.  They worked fine, and that band isn't impacted by interference from WiFi.  If you can still find them, that would be your best alternative.

giqcass

I would try to find the interference.  It could be a sign of serious problems to come.
Long live our new ObiLords!

PeteMc

Not sure if the interference is "illegal" or a combination of high usage along with a mix of RFI.  (I live in a densely populated area.)

And it's interesting that you say WiFi doesn't work, when so many people are using it for the VoIP/SIP connections.  Quality may not be as good as a high end digital line, but certainly acceptable for basic voice on an extension.

Thanks for the feedback.

SteveInWA

What I meant was, it works, but nowhere as well as the cheapest cordless phone works.  No consumer electronics company could sell a dedicated cordless phone that worked on WiFi -- too many customers would return it.  If you think you're having trouble with DECT, imagine all the other WiFi radios within range of you right now.  And, as soon as somebody starts streaming Netflix or some torrent, fuggedabodit.  The WiFi 5GHz band has poor signal propagation qualities, and is quite short-range.

Bottom line:  try it on an Android phone or iPhone.  You'll either be happy with it, or hate it.

giqcass

What I was suggesting was that the interference is most likely coming from a malfunctioning device. The balun in fluorescent lighting for instance.  If a device is causing RF it may fail soon.  When a device fails it may(worst case) even start a fire.  In my opinion it's worth tracking down the source if it's as bad as you indicated.

In response to SteveInWA. I actually make a lot of WiFi calls since I use Republic Wireless.  WiFi phones can work very well.  However SteveInWA is still correct that a WiFi phone is not an ideal solution.  His recomendation sounds like the optimal resolution if you can't eliminate the interference.

Have you attempted moving the base for the cordless phone?  You might be surprised what a difference that can make particularly in the high wireless bands.
Long live our new ObiLords!

drgeoff

Quote from: PeteMc on August 21, 2014, 08:46:18 PM
Not sure if the interference is "illegal" or a combination of high usage along with a mix of RFI.  (I live in a densely populated area.)
1. If illegal, something can be done about it.
2. Can't be "high usage" because the only other legal users are DECT phones and they shouldn't be strong enough to overpower your gear when base and handset are mere feet apart.  There are 5 carriers and 12 time slots available so unless there are 60 other systems very close to you, system capacity will not be a problem either.
3. General RF "noise" from intentional transmitters will be not be in the 1.9 GHz band.
4. Other possibility is from unintentional emitter, ie faulty equipment. If so the emissions may not be confined to 1.9 Ghz and may be impacting other comms and monitoring services including those where safety of life is involved.  And as mentioned above there is risk of fire or explosion.

Even if you don't care about your own safety, if you live somewhere "densely populated" you are possibly endangering others if you ignore the situation.