Jeff Liebermann wrote:
Two independent but incompatible DECT systems, on
the same frequency, are going to cause mutual interference. The
reason the problem is intermittent is that both bases have be on the
same channel in order to cause mutual interference. With 5 (US)
channels to use, you're chances are 1 in 5 of having a collision.
Unplug one base and see if the probleem goes away.


Part of the DECT standard is that a device listens before it transmits. If the
channel is in use, it changes the channel. What happens when all channels are
busy I have no idea.

What you describe was the problem with the old 2.4gHz cordless phones. They
just picked a channel and transmitted on it. The later ones were spread
spectrum, so as far as WiFi was concerned, it interfered on ALL of channels.

Or in plain English, when my upstairs neighbor's phone rang, my WiFi
crashed.

DCT phones work the same way as DECT phones, but on the 2.4gHz or 5.8gHz
band. Again, what they do when all channels are busy I do not know.

This is also why cell phones do not need to be licensed. They only
transmit when asked to by a cell, which in most places is licensed.

If for example, you were to bring a 1900mHz GSM phone to Europe, or a
900/1800mHz EU GSM phone to the US, it won't start transmitting and
interfere with whatever is using those frequencies.


Geoff.

--
Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379