Weird (to me) problem w/interference

2.4ghz GE phone
900MHz connectorized SM w/13dBi antenna.
dBm: -72 (AP side)

Customer picks up phone, 900MHz SM gear loses connection.

Customer hangs up phone, 900MHz SM gear regains connectivity.

We moved the base to the opposite end of the house to the basement.

Gear is mounted on TV antenna.

They have a 2.4GHz wireless router also. Not causing disruptive interference afaik.

Is this phone not really 2.4ghz? Is is 900MHz just with 2.4GHz handsets?

This is really hard for me to understand what is happening here. I run a spectrum analysis and I pick up some junk in the 926mhz range. Nothing that would cause immediate service loss though!

Anyone had similar issues? They are going to be getting Vonage, so the phone won’t be an issue shortly, but I’d like to understand what is going on here.



We had an issue like that with a 5.8ghz phone. I don’t remember what brand it was but the customer replaced it and the trouble went away.

I saw it once…a customer had a 2.4ghz phones and an old 900mhz that he would use in his office.

2.4ghz should not cause problems with 900mhz.

how close are his neighbors?

does he live next to a cell site? even though they may not be on the same freq. cell sites can bleed over.

post his jitter/rssi and stuff here so we can take a look at it.

Nearest neighbor probably 2 miles away…he’s in BFE. our tower is 6 miles away. nearest cell tower is about same distance.

RSSI (Avg/Last): 1186/1187 Jitter (Avg/Last): 4/4 Power Level (Avg/Last): -85/-85

HWSched, 2x Enabled

it’s just weird…i laughed when i was testing the anomaly after i discovered. started up a ping and watched it scroll, then it stopped when i turned the handset on. then ~5 seconds later after turning phone off, it immediately started pinging again.

looks like your pwr level is to low, it should be -10 below your noise floor. Our system requires a pwr level of -68 to work good.

We have seen this in the past, some 2.4 and 5.8 phones also use 900 MHz.

Canopy_Support wrote:
We have seen this in the past, some 2.4 and 5.8 phones also use 900 MHz.

Exactly, the main audio transmission occurs on the stated freq but that is not necessarly the only communication between the handset and base -- battery levels, paging tones, auto frequency selection chatter, etc. Anything else could be communicating on any other Part 15 band.

Also, there would be no reason for them to stop using that phone with vonage. You still use a standard phone, you just plug it in to the vonage box instead of the telco jacks. I know of a few clients that just disconnected the telco wiring and hooked up the vonage box to the existing house wiring. No phone changes at all in that case…

Some baby monitors or other wireless devices may be using 900 MHz - phones aren’t the only devices capable of causing interference. 5.8 GHz phones also use the 900 MHz range, although you have to dig deep in the documention usually to find that out. Most 2.4 and 5.2 GHz phones don’t use 900, but you’d need to check the documentation to watch for any anomalies.