Anybody been contacted by Sprint/Nextel about 906 MHz AP’s causing interference?
They hit me up today claiming that they are licensed to 901MHz and that our Canopy AP’s on 906 are causing trouble.
Is 901MHz a licensed freq?
Reay
Yep. You may need to install a high pass filter at 902.
All my Ap’s are APF’s that have a band pass filter built in. What else can I do?
Switch to the next non overlapping freq at 915
I already use all three non overlapping freqs on evry tower
if they could tell you where they are seeing the problem you could try rotating the freqs so that the one facing there way is on 915 or 924
You could try swapping the non-overlap freq. around on your equip. Was your equip. there first?
Yes I have been there for two years.
I have already swapped freqs around to optimize signal penetration a couple of years ago.
If I rotate my freqs again I will loose customers. 906 works where 924 does not in some directions.
Sprint/Nextel claims they have two towers neither are within 3 miles of my stuff that is seeing the problem. One is North of town and the other id East of town. Both transmitters looking my way are seeing the increased noise floor.
They claim that their ambient noise floor has always been -120db and about two weeks ago, the floor raised to -102 db’s causing them trouble.
I have not installed or changed and transmitters since March of this year.
If they operate in a licensed band of 896-901 and we operate in 900-930, how are we conflicting?
a -102 noise floor is causing them problems? i find that hard to believe, unless they are running some really low powered stuff. you are fully operating within FCC limits, so i dont see how they can have a legal beef, since they are out of band. I mean we have to put up with pager companys who blast in the 926-930 and can cause problems.
Welcome to my world…Going through this with a HAM as we speak.
Guess what - Part-15 will ALWAYS lose in the face of a licensed operator claiming interference - even in an adjacent band. Doesn’t matter who was their first, the licensed operator trumps the non-licensed operator.
The RX sensitivity of cellular is -110. They use the licensed frequencies to ensure control of the noise floor.
If you did not change anything, then it’s probably not you - particularly if you pointed your 906 away from their tower and they saw no change.
I would call the engineer and ask them to watch their system as you turn off your tower. If they see a change, you have to fix it. If they don’t see a change they will leave you alone.
We did a twenty minute full system shutdown for them this morning. They could or would not, tell me their results.
They are supposed to gather their thoughts and contact me early next week.
Thanks for you input, I figured someone had dealt with this before.
Jerry Richardson wrote: Welcome to my world.....Going through this with a HAM as we speak.
you have no idea.
we just had some ham guys broadcasting on 909mhz on a 400ft tower that was on top of a 300 ft hill. so they were close to 800ft above sealevel............oh yea and they were transmitting at about 80watts.
we couldnt track them down for a month.....knocked close to 100 customers offline...........thankfully they are willing to work with us........but 80watts?!?!?!?!?
wtf!
I think I have a pretty good idea. We are at 3450 on one peak. they are at 3500 1/2 mile away with 150w amp. 6MHz wide channel at 910.
They have a licence and are using it and I have zero recourse but to work around it
rculp wrote: We did a twenty minute full system shutdown for them this morning. They could or would not, tell me their results.
They are supposed to gather their thoughts and contact me early next week.
Thanks for you input, I figured someone had dealt with this before.
If they figure it is not you I'd bill them for the time they have wasted.
They are carriers. You should see how they rape everyone else on tower rent and what not. Push back and take what you can.
Jerry Richardson wrote: I think I have a pretty good idea. We are at 3450 on one peak. they are at 3500 1/2 mile away with 150w amp. 6MHz wide channel at 910.
They have a licence and are using it and I have zero recourse but to work around it
If he is on 910 "910.2500" then that is the input frequency for a ATV repeater, if you could contact him he may work with you to eliminate the interference.
Do you know his location? Is it a house? Is the interference random, mostly at the same times?
Jerry Richardson wrote: I think I have a pretty good idea. We are at 3450 on one peak. they are at 3500 1/2 mile away with 150w amp. 6MHz wide channel at 910.
They have a licence and are using it and I have zero recourse but to work around it
ouch.
it really sucks that they dont use one of the non overlapping channels.
makes things that much harder
I did get them to try moving to 919, but that frequency is unusable for them so they are moving back to 910.
This is an amateur Radio group, not a single person. At least one of the members feels that I’m freeloading off the 900 band (even though it’s open spectrum) and that it’s my problem to deal with.
This is the problem with using unlicensed spectrum and it can happen to anyone.
Hams have sore spot in the frequencies that we use. Our old shop manager would gripe about how the FCC shafted the hams when they permitted ISM/UNII to industry/consumers.
Unfortunately wisp operators take back seat because they are part-15.
amd phreak wrote: Hams have sore spot in the frequencies that we use. Our old shop manager would gripe about how the FCC shafted the hams when they permitted ISM/UNII to industry/consumers.
Unfortunately wisp operators take back seat because they are part-15.
ISM devices were already there in 1985 when the hams was granted use of 902-928 and they were the primary users, hams who are secondary cannot cause interference to primary users and must accept interference from them.
I remember in 1985 the noise floor was -120, but in the 90's came all the Part15 stuff and the wireless networking, the band started to get noisy. WISP are by far the worst polluters of the unlicensed devices on the band today.
In 1986 I could communicate with other hams 20 miles away with 200mw, because of the noise floor more power is needed today to get over the noise and maintain communications. Different modes require different amount of power to stay above the noise. More power cost more money, that is the only thing the ham gripe about, is the need to spend more money to get above the part15 noise.
I believe that was his primary gripe… the cost associated with the need for increased spectral power density.
Hams, in my experience, are notoriously cheap people.