This is above my pay grade.
One of our customers was contacted by AT&T, and the customer put them in
touch with us. AT&T was tracking down a source of interference. The
interference was on a 10mhz wide channel centered on 828mhz. At their
tower, AT&T is seeing it 15-20db above the noise floor, so it's pretty
significant.
Using their spectrum analyzer they tracked it down to our customer's
house. The customer has a wimax CPE on their roof. Unplugging the CPE
makes the interference go away, plugging it back in brings the
interference back. Every time. AT&T guy goes to another customer's
house and confirms that other CPE at different locations don't produce
this interference.
We figure it's a malfunction in the CPE, so we replace it. Interference
still present.
We replaced the PoE. Interference still present.
So we know the Wimax unit doesn't originate the 828mhz signal, but it's
somehow an accidental component of a system that does.
WTF could be going on?
