Hello All 900Mhz'rs

My newest issue is colo interferance. A new competitor has moved in with Moto Canopy at one of my sites. If they turn on their unit all traffic on my 912, 917 and 922 sectors stop... they are at 906. They have it shut off right now since I was the first at the site they are being good about trying to make it work with my equip. They have purchased Notch filters which I will be installing on Tuesday. I will be removing the current Ubiquiti filters. They (AND I)are hoping that these will clean out any inband or out of band interference from the Canopy equipment. At 1K per filter I hope so! As a further benefit, I am hoping this will eliminate disconnects on the client end and give even better performance charactoristics.

I will let you all know what the results are once the filters are installed and the Canopy is up and running.

They or you need to use opposite polorization from the other.

I really don't understand the issue people are talking about. I have canopy 900 gear 30' from my SR9's with no issues...

They or you need to use opposite polorization from the other.

I really don't understand the issue people are talking about. I have canopy 900 gear 30' from my SR9's with no issues...

They are running horizontal... i doubt I can get them to move to vertical.

The spectrum is absolutely clean. I'm telling you that the MOTO stops the SR9 in it's tracks. It's bizzarre... but true.

How many clients do you have?

About 45 spread over 3 sectors.

I know that integrated Canopy 900 SM's are by default HPOL. I have my Canopy AP's on HPOL so I can use both integrated and non-integrated SM's. I'm guessing they too have them in HPOL.

You guess right... hpol they are.

I know that a few questions have been asked about the new XR9's and noise from canopy, and while I don't have any advice about canopy interference, I can tell you that the XR9 seems to do much better with interference. I have an old 900mhz cordless phone that I keep around simply for the sake of seeing how it affects my noise floors.

With SR9 cards, the noise floor always got 20-25db worse when I turned the phone on. With the XR9, the noise floor was ony 4db worse.

Not sure if you would see the same improvement with canopy, but maybe switching to XR9's would be a possibility. Or at least to test with.

One of the biggest gotchas with SR9 is how unreliably it measures real noise floors.

Perhaps the XR9 is simply more accurate, and this accounts for the differences you are seeing at your test sites? If so, that is excellent news.

George

Yeah, that had crossed my mind also as a possible reason for the noise floor differences.

Here is an update on that Moto system running on 906 Hpol

We switched to DCI filters on each sector and 922, 917 are performing flawlessly with the Moto on full power. 912 recieves fine but TX is practically dead. I am going to switch out the 912 sector with the new XR9 and a test client and see if this fixes our issue.

I'll report back.

One of the biggest gotchas with SR9 is how unreliably it measures real noise floors.

Perhaps the XR9 is simply more accurate, and this accounts for the differences you are seeing at your test sites? If so, that is excellent news.

George

we just got our batch of test XR9's from ubiquiti, the first thing we noticed was the noise floor differences, and came to the same likley conclusion, the XR9 is far closer to accurate. I'm going to do some testing tomorrow with our spectrum analyzer plugged into the same antenna as the XR9 was to see how they match up.

Does the XR9 read higher or lower?

The XR9 has always reported more noise than the SR9 did. For example -95 with the XR vs -98 with the SR.

Here are the results of my testing. As you can see the XR9 reported significantly higher noise floors, and if you closely examine the spectrum analyzer output, the XR9 is reporting much closer to accurate peak noise readings. The difference between the XR9's reading and the analyzer is almost appreciable to difference in the pigtails used to connect the two to the yagi, although I feel there is still a slight mis-calibration on the part of one or the other causing 1-3 db of skew.

in summary: the XR9 seems to report accurately, based on the highest reading in the channel, although maybe falsely a few db worse then actual, where the SR9 reports a completely false and grossly inaccurate picture of the noise floor. If I had to guess, I would say the SR9 is reporting the average noise floor across the channel, where the XR9 reports the peak noise floor.

I also took some output graphs of the of the XR9 in 5, 10 and 20mhz channel widths to show actual channel usage. While the bulk of the output is clearly 5 or 10mhz, there is still a large bell curve showing that it would be very bad to have 2 radio's operating near by each other on adjacent channels, in any channel width.

For all of you that have been following my thread....I've exhausted my options at this site....

Tonight I tried the new XR9 at 912 .....,when the Motorola is runnig it still shuts me down. :.(

I am going to put the SR9 back and switch to vertical polarity and see if the Motorola still shuts me down when running at 906Mhz.

If you like, call me at (647) 723-6284 x102. We have a similar issue we have been dealing with. Sun Tzu had some great advice .

George

I tried the new XR9 at 912 .....,when the Motorola is runnig it still shuts me down.

Since you are running 3 sectors, I assume you must be running in 5Mhz channels...

Motorola - 8Mhz Channel Width
center 906Mhz
low 902Mhz
high 910Mhz

XR9 - 5Mhz Channel Width
center 912Mhz
low 909.5
high 914.5

Since there is a 1Mhz channel spacing on the canopy, we must assume that it can bleed up to 1 extra Mhz beyond it's rated channel width, making the upper boundry of which it will interfere 911Mhz

Since the XR9 when running in 5Mhz channels, on center channel 912, goes down to 909.5Mhz for data purposes (see my other post about how far it actually bleeds down to) you have 1.5Mhz, or 30% of your channel being overlaped by the canopy signal. The only thing you can do is to switch to a higher channel (already in use), or one of you must change polarities.

I would suggest keeping the XR9 as you're going to want the extra noise handleing abilities it is claimed to have (just got them yesterday, haven't done any outdoor testing with them as of yet)...

I just got my XR9's in.
I sent my SR9's back to UB for replacement(haven't got them back so I bought some).
I have only one of the same problems with the XR9s as the SR9's - the 5-10mhz channels didn't have the range I needed so I put them in straight B mode with just B data rates and got better TX/RX and SNR.
They deffinately perform a lot better!!
I'm wondering if there is a recommended antenna vendor for the XR9's.
The Rootenna 900 works really great but some of the Yagi's seem to not like the split ranges.
Rod Neal

Forepoint,

So why does the canopy cause issues with my 917 and 922?? They are 906.

I have no idea... take a spectrum analyzer out there and see exactly what they are outputing. maybe they don't have them on the channel you think they do?