Dect 6.0 cordless phone interferes with wireless... what phones don't ???

Sorry, slight imprecision. The frequency bands allocated for cordless phone use are 800MHz, 2.4GHz and 5.8GHz. Hence, the only overlapping and possible interference is in the 2.4GHz band shared with 802.11 b/g/n networking. The new [DECT 6.0 cordless phone standard|http://en.wikipedia.org/wiki/DECT] has been allocated the 1.920 to 1.930GHz band in the US, so it should cause no interference at all.

Hi lisajoy: From your post I get the impression that the cordless phone interferes with the router, even when it is not in use. This makes me think there is some other issue happening. You say there is only one phone jack, does it have a working DSL filter on that jack prior to the phone cord? Was this an issue with other phones, wired or wireless? It is also possible that the line is filtered outside the house.

Stedman

Given that the [802.11 b/g/n wireless networks|http://en.wikipedia.org/wiki/IEEE_802.11] operate at a frequency band of 2.4GHz, under some conditions a long-range cordless phone can cause some interference if it uses the same frequency. The original cordless phones used 800MHz, then they came out at 2.4GHz and the newer models now use the 5.2GHz band. In this last case, there could be interference with the old 802.11a and the alternate band for 802.11n, although the technology for the n standard (which is interim for now) incorporates interference reduction mechanisms not found in older standards. To be on the safe side, I would opt either for the older models or the very latest; most phones will say somewhere in the box at what frequency band they operate.

Also worthy of noting is that Bluetooth uses the same frequency band and has been mistakenly blamed for interference. However, it uses much lower power and a frequency hopping multiplexing technique and cannot interfere with 802.11b/g/n.

If you want to get real technical, there's a cute gadget called the [WiSpy spectrum analyzer|http://www.metageek.net> that can give you a graphical view of how your wireless devices interact in their frequency bands. However, the Lite version goes for $200 and the Pro model for $400, so this is strictly for hardcore geeks... 😉

Cool that you got the problem solved.

I'll have to test my Vtech Dect 6.0 phone at home with the WiSpy, now that you mention it. Since I use a patchcord at home to keep the wireless card on my 2Wire ADSL off (got tired of seeing the neighbors keep trying to crack it constantly), I never even thought of sniffing on the phone. Good point.

Hope you enjoyed your WiFi whodunnit adventure! 😀

I was at the Apple Store yesterday, and one of the floor people insisted that the 5.8 ghz phones actually are better than the 6.0 DETC phones for avoiding issues with Airport Extreme.

There are so few 6.0s on the market that a 5.8 would be a better choice, if this is true. My 2.4 phones are a real problem........

Thoughts?

Hi lisajoy: Good find, glad you got back to the speedy side.

Stedman