900Mhz Ubiquiti XR9 Settings Scenario Questions

giganet · Fri Apr 03, 2009 3:00 am

Hello Group...

I have a few AP's that utilize the Ubiquiti 900Mhz XR9 cards without amplifiers.

Current conditions/settings

Average noise floor: -92 OR BETTER

AP & CPE Board & Antenna Information
AP Antenna: Pacific Wireless 120 degree 12db HPOL
AP Board: RB333
CPE Antenna: 12db Pacific Wireless 12db ROO2
CPE Board: RB411
Encryption: 504bit WPA2 TKIP

Present settings at AP & CPE's
Band: 2Ghz-5Mhz
Freq: 2442 (922Mhz Supported Channel Widths: 5/10Mhz)
Data Rates: 9MB
Tx Power: 24db
Average CPE Signal: -52 TO -64
Average Transmit/Receive CCQ: 100/100 TO 90/90%
Average SNR: -44 TO -38

My primary objective is to maximize throughput with the following new settings including the use of Nstreme...
Here are the new settings I would like to try, I would like some input prior to doing this though to minimize pain for both my clients and myself alike.

Here are the new setting values I would like to utilize, your input would be greatly appreciated

New Settings at AP & CPE's
Band: 2Ghz-only-G
Freq: 2437 (917Mhz Supported Channel Widths: 5/10/20Mhz)
Data Rates: 9,12,18MB
Tx Power: 24db
Nstreme: Enabled

My farthest reaching client on these AP's does not exceed 4.5 miles in a clear line of site basis.

I realize that utilizing the multiple Data Rates means potential for Connect/Disconnect conditions but I generally do this only during test phases to help me to zero in on the most reliable and best performing Data Rate then I settle in with one rate being the best of all tested.

Another thing I realize is that all clear LOS should be in any band other than 900Mhz.
I may later install a 5Ghz AP at these locations however.
The use of 2.4Ghz is entirely out of the question as another local wireless operator uses 10watt amplifiers and generally walks over top of any other remaining channels in the band making reliable connectivity at even 3 miles out from the AP impossible!

Thanking you all in advance for sharing suggestions and your real-world scenarios with me.

Best Regards

Gunzoid · Fri Apr 03, 2009 5:39 am

I've found 2Ghz-10mhz to work the best for our 900 XR9 APs.
Seems to be a good middle ground that allows for different combinations of distance and obstructions.

giganet · Fri Apr 03, 2009 5:46 am

Hey Gunzoid thanks for the reply!

What is your average SNR in you area? Just curious...

Gunzoid · Fri Apr 03, 2009 6:03 am

Noise average -96, signal -80 to -62

giganet · Fri Apr 03, 2009 7:09 am

Hey Gunzoid thanks again for the reply...

Noise average -96, signal -80 to -62

Hmm, you too have a relatively clean noise floor at -96, one of my buddies in Kentucky tried 900Mhz and couldn't best a -74 for the noise floor!

With resepect to your -80 signal quality clients...

Tell me what is the average PThroughput on those clients and what is the farthest reaching client at that signal level?
I have one client that is 11.25 miles from the AP and at her CPE she sees a PThroughput of 1365Kbps (clear LOS)

Thanks once again Gunzoid
Best Regards

Gunzoid · Fri Apr 03, 2009 5:33 pm

My 900Mhz clients are PCQ'd at the gateway to 2Mbps down and 256K up in the CPE.
Frames/HW Frames runs around 99% for all clients.
I have 25 clients on that AP
I don't know where to find average PThroughput

giganet · Fri Apr 03, 2009 5:40 pm

Hey Gunzoid

You can find the PThroughput on the client side by going to Wireless -> Registration
then double click on the registered connection and then from the tabs select Signal I think it's about the fourth line down.

Gunzoid · Fri Apr 03, 2009 6:12 pm

Sorry-I don't see it.
I have Signal to Noise, then Tx/Rx CCQ

giganet · Sat Apr 04, 2009 12:08 am

Hi Gunzoid...

Hmmm.

Let me go through one of my client CPE's and I will detail the location of 'PThroughput'

-> Wireless -> Registration
Double click the AP registry line.
In the GUI that spawns you select the 'Signal' tab.

The last data field is 'PThroughput' with Tx/Rx CCQ % being the field above that.

Best Regards

Gunzoid · Sat Apr 04, 2009 12:58 am

Ya-figured it out before you wrote back.
We have a mix of 411s on 3.13 and 133c on 2.9.5
I was checking a couple of 133 clients
PThroughput on the -80 client running on a 411 is 7687
Best,
Gunnar

jordantrx · Sat Apr 04, 2009 5:30 am

Hey, Running same setup as you except using omni, clients same frequency same and channel 2422 is the clearest but It is above free license by a little bit, Im getting a filter to put in to see if that will help with noise floor and get me within legal limits, the fastest download I can get with 900 mhz at 2ghz 5 mhz is 2.5 meg down 1.5 meg up. We have alot of canopy equipment in our area though, Running on V-pol. thus making most of the 900 mhz spectrum crap, Need to switch to H-pol to have clearer spectrum, but much more money to do so,. However clients per AP be no more than 25 or less. Putting up 3rd AP shortly going to try yagi back to back on H-pol if no sucess with filter using omni.

900 Mhz is very important here, most of our clients use it, However we installed when the leaves where off the trees not sure how it will effect things once the leaves get on the tree. Anyone know how leaves effect 900mhz, I know rain does, everytime it rains unless link has good signal it will drop out alot. Very annoying. Anyways thats my 20 cents. -Jordan

Gunzoid · Sat Apr 04, 2009 3:07 pm

We do use an Ubiquiti filter on our AP. 11db Vpol Omni.
Clients are mostly Rootenna 12db panel, but a few longer shots are 14db Yagi.

giganet · Mon Apr 06, 2009 6:03 am

Ya-figured it out before you wrote back.
We have a mix of 411s on 3.13 and 133c on 2.9.5
I was checking a couple of 133 clients
PThroughput on the -80 client running on a 411 is 7687
Best,
Gunnar

Hey Gunner

I made the adjustments to my AP's this afternoon...

The overall improvement was huge!
I averaged a PThroughput on clients with a -67 signal around 8422
and my clients further out sitting around -76 are seeing a PThroughput of 7238.

This change should prove to be very worhtwhile all together.

Thank you for sharing your info with me

Best Regards

giganet · Mon Apr 06, 2009 6:22 am

Hey, Running same setup as you except using omni, clients same frequency same and channel 2422 is the clearest but It is above free license by a little bit, Im getting a filter to put in to see if that will help with noise floor and get me within legal limits, the fastest download I can get with 900 mhz at 2ghz 5 mhz is 2.5 meg down 1.5 meg up. We have alot of canopy equipment in our area though, Running on V-pol. thus making most of the 900 mhz spectrum crap, Need to switch to H-pol to have clearer spectrum, but much more money to do so,. However clients per AP be no more than 25 or less. Putting up 3rd AP shortly going to try yagi back to back on H-pol if no sucess with filter using omni.

900 Mhz is very important here, most of our clients use it, However we installed when the leaves where off the trees not sure how it will effect things once the leaves get on the tree. Anyone know how leaves effect 900mhz, I know rain does, everytime it rains unless link has good signal it will drop out alot. Very annoying. Anyways thats my 20 cents. -Jordan

Hi jordantrx...

Technically I think the proper frquencies to be used within the 900Mhz ISM band in the U.S are:

2427 (907Mhz)
2432 (912Mhz)
2437 (917Mhz)
2443 (922Mhz)

As stated on the XR specs: Performance and compliance are not supported outside of these channels.

Yeah Omnis wind up picking up a far great amount of noise and they can in the proper situation see unwanted noise from up to 40 miles away causing you issues.
Unless you are getting a tunable filter of some sort or having a special made filter which as I said above could cause you compliance issue possibly??

I would try testing with a single 900Mhz Pac Wireless 120degree 12db sector, you would find that will greatly improve your SNR and throughput.

I happed to have a few clients which are covered by dense pines at 4 miles out from the AP and their PThroughput is 5894 or better.
This is running at 2Ghz-10Mhz with Nstreme enbaled offering 9,12,18MB Data Rates presently as of tonight.

So long as the clients aren't too much beyond 3.5 miles out from the AP and the floiage on three isn't too highly relfective and water dense you should be alright.
You will just have to watch as spring comes on and be ready to go trim tree branches otherwise.

Hmm rain brings you down?
I never see so much as a whimper even when the snow is falling and visibility is below 1/4 mile.
Once again, thos omnis are most likely causing you strange behaviour..

What's is your average SNR when you view -> Wireless -> Registration then double click on the registered connection to the AP, do this from the clients CPE.
-> Signal tab fourth text box down.

Best Regards

giganet · Mon Apr 06, 2009 6:24 am

Hey, Running same setup as you except using omni, clients same frequency same and channel 2422 is the clearest but It is above free license by a little bit, Im getting a filter to put in to see if that will help with noise floor and get me within legal limits, the fastest download I can get with 900 mhz at 2ghz 5 mhz is 2.5 meg down 1.5 meg up. We have alot of canopy equipment in our area though, Running on V-pol. thus making most of the 900 mhz spectrum crap, Need to switch to H-pol to have clearer spectrum, but much more money to do so,. However clients per AP be no more than 25 or less. Putting up 3rd AP shortly going to try yagi back to back on H-pol if no sucess with filter using omni.

900 Mhz is very important here, most of our clients use it, However we installed when the leaves where off the trees not sure how it will effect things once the leaves get on the tree. Anyone know how leaves effect 900mhz, I know rain does, everytime it rains unless link has good signal it will drop out alot. Very annoying. Anyways thats my 20 cents. -Jordan

Hi jordantrx...

Technically I think the proper frquencies to be used within the 900Mhz ISM band in the U.S are:

2427 (907Mhz)
2432 (912Mhz)
2437 (917Mhz)
2442 (922Mhz)

As stated on the XR specs: Performance and compliance are not supported outside of these channels.

Yeah Omnis wind up picking up a far greater amount of noise and they can in the proper situation see unwanted noise from up to 40 miles away causing you issues.
Unless you are getting a tunable filter of some sort or having a special made filter which as I said above could cause you compliance issue possibly??

I would try testing with a single 900Mhz Pac Wireless 120degree 12db sector, you would find that will greatly improve your SNR and throughput.

I happed to have a few clients which are covered by dense pines at 4 miles out from the AP and their PThroughput is 5894 or better.
This is running at 2Ghz-10Mhz with Nstreme enbaled offering 9,12,18MB Data Rates presently as of tonight.

So long as the clients aren't too much beyond 3.5 miles out from the AP and the floiage on three isn't too highly relfective and water dense you should be alright.
You will just have to watch as spring comes on and be ready to go trim tree branches otherwise.

Hmm rain brings you down?
I never see so much as a whimper even when the snow is falling and visibility is below 1/4 mile.
Once again, thos omnis are most likely causing you strange behaviour..

What's is your average SNR when you view -> Wireless -> Registration then double click on the registered connection to the AP, do this from the clients CPE.
-> Signal tab fourth text box down.

Best Regards

jordantrx · Mon Apr 06, 2009 4:04 pm

Any input on yagi's back to back rather than using pricey sectoral antenna's? -Jordan

Gunzoid · Mon Apr 06, 2009 9:10 pm

That should be 2442-922 for an XR9.
I'm using 2437-917, 2Ghz-10mhz with an Ubiquity filter
Default data rates, default power

ahooper · Tue Apr 07, 2009 2:32 am

I am in he process of setting up a couple of RB411's as a point to point link for a client, range is about 3Km and is reasonable LOS. In NZ we can only use 2442=922@5Mhz wide however i am finding soem very stange issues with the XR9 settings.

If i set the AP end to 2442 the remote/SU end will not connect when it is set to 2442 however if i drop the AP end to 2437=917@5Mhz the link comes up but in the wireless settings on the SU it shows it as being set to 2442 but status reports 2437@5Mhz

Overall CCQ seems to be garbage no matter what frequencey im using frequencey usate shows -80 to -90 from 2437 to 2447. the AP end has a constant noise floor of -87dBm and the SU -94dBm Signal on the AP is -68 and TX Signal -59

TR/RX CCQ is sitting about 65/50% but im guessing this could be as a result of the frequencey missmatch.

Both AP and SU are using Yagi antennas

I would be greatfull of any ideas

Gunzoid · Tue Apr 07, 2009 2:45 am

The client will follow the AP frequency regardless of what you set the client at.
You really need a S/N of around 20 to get a solid connection.
Seems the AP is being interfered with as it doesn't see your clients that well, but your clients see the AP OK.
Look for interference around-or beaming at-the AP.

ahooper · Tue Apr 07, 2009 3:27 am

Thanks, It appears we have a cellphone carrier opposite where we are about 250m pointing in our direction.

On a frequencey scan we are seeing the following channels and noise levels
2452 -64
2457 -33
2462 -33

What is interesting is that if i change the AP and Client from 5Mhz wide to 10Mhz wide things get a little more stable. actually a lot more stable and i can pass the required data. But drop it back to 5Mhz wide and it gets very flakey

regards
Andrew

Gunzoid · Tue Apr 07, 2009 3:48 am

It's always worth giving B-Only a shot as well on all 4 available frequencies.
You just never know.

giganet · Tue Apr 07, 2009 4:01 am

However according to you your current setup is as mine, as you said below.

Present settings at AP & CPE's
Band: 2Ghz-5Mhz
Freq: 2442 (922Mhz Supported Channel Widths: 5/10Mhz)
Data Rates: 9MB
Tx Power: 24db
Average CPE Signal: -52 TO -64
Average Transmit/Receive CCQ: 100/100 TO 90/90%
Average SNR: -44 TO -38

You runnin onf 2442 just as I am. But anyways. Im going to be trying the back to back yagi but seperate radio's. Anybody Have any input on this?

I will get that info about CCQ and SNR later today. Thanks -Jordan
Hey, Running same setup as you except using omni, clients same frequency same and channel 2422 is the clearest but It is above free license by a little bit, Im getting a filter to put in to see if that will help with noise floor and get me within legal limits, the fastest download I can get with 900 mhz at 2ghz 5 mhz is 2.5 meg down 1.5 meg up. We have alot of canopy equipment in our area though, Running on V-pol. thus making most of the 900 mhz spectrum crap, Need to switch to H-pol to have clearer spectrum, but much more money to do so,. However clients per AP be no more than 25 or less. Putting up 3rd AP shortly going to try yagi back to back on H-pol if no sucess with filter using omni. Yea most likly omni is causing this thats why im switching to H-pol with filter. As far as 2422 yes it is outside Ubiquity range thus im going to be installing a filter and changing frequency.

However according to you your current setup is as mine, as you said below.

Present settings at AP & CPE's
Band: 2Ghz-5Mhz
Freq: 2442 (922Mhz Supported Channel Widths: 5/10Mhz)
Data Rates: 9MB
Tx Power: 24db
Average CPE Signal: -52 TO -64
Average Transmit/Receive CCQ: 100/100 TO 90/90%
Average SNR: -44 TO -38

You runnin onf 2442 just as I am. But anyways. Im going to be trying the back to back yagi but seperate radio's. Anybody Have any input on this?

I will get that info about CCQ and SNR later today. Thanks -Jordan

900 Mhz is very important here, most of our clients use it, However we installed when the leaves where off the trees not sure how it will effect things once the leaves get on the tree. Anyone know how leaves effect 900mhz, I know rain does, everytime it rains unless link has good signal it will drop out alot. Very annoying. Anyways thats my 20 cents. -Jordan
Hi jordantrx...

Technically I think the proper frquencies to be used within the 900Mhz ISM band in the U.S are:
Code: Select all
2427 (907Mhz)
2432 (912Mhz)
2437 (917Mhz)
2443 (922Mhz)
As stated on the XR specs: Performance and compliance are not supported outside of these channels.

Yeah Omnis wind up picking up a far greater amount of noise and they can in the proper situation see unwanted noise from up to 40 miles away causing you issues.
Unless you are getting a tunable filter of some sort or having a special made filter which as I said above could cause you compliance issue possibly??

I would try testing with a single 900Mhz Pac Wireless 120degree 12db sector, you would find that will greatly improve your SNR and throughput.

I happed to have a few clients which are covered by dense pines at 4 miles out from the AP and their PThroughput is 5894 or better.
This is running at 2Ghz-10Mhz with Nstreme enbaled offering 9,12,18MB Data Rates presently as of tonight.

So long as the clients aren't too much beyond 3.5 miles out from the AP and the floiage on three isn't too highly relfective and water dense you should be alright.
You will just have to watch as spring comes on and be ready to go trim tree branches otherwise.

Hmm rain brings you down?
I never see so much as a whimper even when the snow is falling and visibility is below 1/4 mile.
Once again, thos omnis are most likely causing you strange behaviour..

What's is your average SNR when you view -> Wireless -> Registration then double click on the registered connection to the AP, do this from the clients CPE.
-> Signal tab fourth text box down.

Best Regards

Hi jordantrx

I am just going verbatum by your orignal post:

clients same frequency same and channel 2422

My posted frequency is 2442 NOT 2422 as you posted...

jordantrx · Tue Apr 07, 2009 4:48 pm

Your right, sorry about that, didn't look long enough at what your posted, My fault. what type of filter do you use on your applications?

But to get back on topic has anyone tried the back to back yagi? using spliter or using it via separate radio's. -Jordan

giganet · Tue Apr 07, 2009 9:18 pm

Hi jordantrx

I am blessed in the matter of not needing filters as my SNR is extremely healthy being no worse than -92.

I do know that if you have to use a filter that you need to first define your quietest channel in the 900Mhz band then make that be the frequency used system-wide.
I have my AP's configured as WDS which allows frequency re-usage from one AP to the next so I don't have to re-channel for each site also allowing one SSID system-wide.

Take a look at http://www.l-com.com/productfamily.aspx?id=6177
One of my buddies uses these filters in his system as his 900Mhz band is somewhat noisy due to paging and cellular systems within his area of operation.

I'm curious why you want to use Yagi's?
Yagi's are highly directional and don't serve well as AP antennas traditionally.
Are you needing to make a point-to-point connection or are you wanting to serve clients with the Yagi's?

One thing to keep in mind is that any time you use a splitter from one radio card to serve multiple antennas is that you are still going to have an elevated noise floor as interference from up to 40 miles away can be seen easily.

Being in a noisy environment you would be best off to consider sectoral antennas that provide adjustability in their coverage.
I beleive TilTec offers a variable beamwidth antenna in 900Mhz, I realize sectors for 900Mhz are not cheep as my 120 degree Pac Wireless sectors cost me about $700 each but the performance is well worth that cost and saves you headache.

I have found also that if you choose HPOL sectors for 900Mhz you will avoid a bunch of noise as most paging and cell sites utilize VPOL with some exceptions of course.

For standard 900Mhz sectorals take a look at: http://www.l-com.com/item.aspx?id=22118
These are really affordable sectors at 120 degrees, the ones listed here are VPOL however HyperLink does do special order builds, you could expect to spend twice the amount for HPOL version of this sector.

To provide a full 360 degree coverage you could take a look at these: http://www.l-com.com/item.aspx?id=22340
Once again the listed items are VPOL and as I stated above you can order special build HPOL versions, just expect your order amount to double.

WOW take a look at this though jordantrx!
Tranzeo 900Mhz 120 degree HPOL sector at DuobleRadius for only $299.00 EACH!!!
http://www.doubleradius.com/Tranzeo-TR-900H-120-12

If I were in your position of having a high noise floor I would first purchase a sectoral antenna and test the performance and noise rejection and only then would I add in the 900Mhz filter.

In closing I do want to re-state this fact: to enjoy the best performance throughput/noise rejection it will be the very best if you operate within the prescribed frequencies according to Ubiquiti's chart;

IEEE 802.11 Channel     Carrier Freq.          Bandwidth Options
       4 (2427)                907Mhz                    5/10Mhz
       5 (2432)                912Mhz                 5/10/20Mhz
       6 (2437)                917Mhz                 5/10/20Mhz
       7 (2442)                922Mhz                    5/10Mhz

Hope this helps you.

Best Regards

jordantrx · Tue Apr 07, 2009 10:59 pm

It did thanks for the links and info. I will probibly go wiht 2 sectors, because I dont need 360 I have that covered by another AP, The only problem I think i will have is channels to run on using sectoral. 2422 is outside of the Xr9 specs thus the reason Im trying to get a filter so I can get rid of some of the noise, Its funny really if you r3eally want to know, My normol noise on the 2422 frequency is 98 however on my CPE's the noise floor is between 83-89. Why is this? My CPE's are directional why would they pickup more noise than a AP which sees 360 degrees of noise. I just dont understand it. However If i set the AP on the supported channels my clients all disconnect and do not pass data and noise floor on AP is 88 or less. Borsha.... Let me know whatcha think. on my worst link it has a Tx/rc CCQ of 60-50 But it can be all over the place lower or higher. my Signal to noise on the AP side is rougly 20. However from CPE its like 2 or 3 because of the NOISE FLOOR on the CPE> Very frustrating, The only reason i use 2422 is because its the only freq that holds my clients up and running. Let me know whatcha think.

Hi jordantrx

I am blessed in the matter of not needing filters as my SNR is extremely healthy being no worse than -92.

I do know that if you have to use a filter that you need to first define your quietest channel in the 900Mhz band then make that be the frequency used system-wide.
I have my AP's configured as WDS which allows frequency re-usage from one AP to the next so I don't have to re-channel for each site also allowing one SSID system-wide.

Take a look at http://www.l-com.com/productfamily.aspx?id=6177
One of my buddies uses these filters in his system as his 900Mhz band is somewhat noisy due to paging and cellular systems within his area of operation.

I'm curious why you want to use Yagi's?
Yagi's are highly directional and don't serve well as AP antennas traditionally.
Are you needing to make a point-to-point connection or are you wanting to serve clients with the Yagi's?

One thing to keep in mind is that any time you use a splitter from one radio card to serve multiple antennas is that you are still going to have an elevated noise floor as interference from up to 40 miles away can be seen easily.

Being in a noisy environment you would be best off to consider sectoral antennas that provide adjustability in their coverage.
I beleive TilTec offers a variable beamwidth antenna in 900Mhz, I realize sectors for 900Mhz are not cheep as my 120 degree Pac Wireless sectors cost me about $700 each but the performance is well worth that cost and saves you headache.

I have found also that if you choose HPOL sectors for 900Mhz you will avoid a bunch of noise as most paging and cell sites utilize VPOL with some exceptions of course.

For standard 900Mhz sectorals take a look at: http://www.l-com.com/item.aspx?id=22118
These are really affordable sectors at 120 degrees, the ones listed here are VPOL however HyperLink does do special order builds, you could expect to spend twice the amount for HPOL version of this sector.

To provide a full 360 degree coverage you could take a look at these: http://www.l-com.com/item.aspx?id=22340
Once again the listed items are VPOL and as I stated above you can order special build HPOL versions, just expect your order amount to double.

WOW take a look at this though jordantrx!
Tranzeo 900Mhz 120 degree HPOL sector at DuobleRadius for only $299.00 EACH!!!
http://www.doubleradius.com/Tranzeo-TR-900H-120-12

If I were in your position of having a high noise floor I would first purchase a sectoral antenna and test the performance and noise rejection and only then would I add in the 900Mhz filter.

In closing I do want to re-state this fact: to enjoy the best performance throughput/noise rejection it will be the very best if you operate within the prescribed frequencies according to Ubiquiti's chart;
Code: Select all
IEEE 802.11 Channel     Carrier Freq.          Bandwidth Options
       4 (2427)                907Mhz                    5/10Mhz
       5 (2432)                912Mhz                 5/10/20Mhz
       6 (2437)                917Mhz                 5/10/20Mhz
       7 (2442)                922Mhz                    5/10Mhz
Hope this helps you.

Best Regards

Gunzoid · Wed Apr 08, 2009 1:56 am

Jordan,
Stick to the defined XR9 frequencies-907.912,917,922.
Using the 802.11 frequency 0f 2422 is only going to give you grief IMHO.
Also stay with default power and data rates.
Do a frequency usage scan with one of your CPE and see what's out there-then stay away from it.
CPE high noise floor can be caused by very local interference-900mhz cordless phones for instance-even a power line transformer.
Try 2Ghz-10 and 5mhz channel on your setup for all the defined frequencies.
Try B Only on the AP and CPE.
H-pol sectors are an excellent idea. Fortunately I'm in a quite area and can use a V pol omni on my AP.
Post back with the results-without quoting all the previous posts TYVM
GB

jordantrx · Wed Apr 08, 2009 2:04 am

Jordan,
Stick to the defined XR9 frequencies-907.912,917,922.
Using the 802.11 frequency 0f 2422 is only going to give you grief IMHO.
Also stay with default power and data rates.
Do a frequency usage scan with one of your CPE and see what's out there-then stay away from it.
CPE high noise floor can be caused by very local interference-900mhz cordless phones for instance-even a power line transformer.
Try 2Ghz-10 and 5mhz channel on your setup for all the defined frequencies.
Try B Only on the AP and CPE.
H-pol sectors are an excellent idea. Fortunately I'm in a quite area and can use a V pol omni on my AP.
Post back with the results-without quoting all the previous posts TYVM
GB

I have tryed every channel every frequency I have ran scans, ONLY 2422 and 2437 have good noise floors, Tryed setting to 2437 which was second best and my clients keep dropping out every couple seconds,

As far as MY CPE's every single client having a 900mhz cordless phone, no they dont, As far as transmission tower, we do have them but there about 5 miles away from the CPE's and AP> So really at a loss here. The only thing Ihavent done was enable n-stream and disable CSMA. Whatcha all think? -Jordan

What I plan on doing is buying a filter and see how that helps, I beleive Isee ALOT better noise floor on CPE within card chart range, But NOT on AP. Next AP is being setup as H-pol.

Gunzoid · Wed Apr 08, 2009 2:25 am

2422>922mhz is the conversion for SR9s
2442>922mhz is the conversion for XR9s

What ROS version are you running?

jordantrx · Wed Apr 08, 2009 3:20 am

2422>922mhz is the conversion for SR9s
2442>922mhz is the conversion for XR9s

What ROS version are you running?

IM running 2422 on Xr9 IT is NOT within charts, Im using ROS 3.17, The only reason im NOT within charts is because everything else does not work, Right next door I have Good ol motorola canopy on my doorstep, on the same Polarity as I am..... So what do you think? I think interference, set my setup as H-pol possibly with filter. However MONEY and alot of it atleat for the AP. my CPE's all I would have to do is turn them.

giganet · Wed Apr 08, 2009 4:07 am

Hi jordantrx

Hmm, you have got quite a mess there.

I only have to deal with earthquake sensors wich transmit in 900Mhz to SDSU in direct proximity to one of my AP's, but my noise floor is still clean at both the AP and CPE end.

I must mention that setting the AP and CPE's to utilize Nstreme increased signal quality and PThroughput alike.
Maybe you should set to use Nstreme to begin with jordan.

What type of antenna are you using at the CPE side?
I use the Pac Wireless ROO2 at 12db and can make high quality LOS connections at almost 12 miles out and very high quality NLOS at around 3.5 miles.

You must also remember that even with a filter at the AP if your clients are within close proximity of a canopy AP or even SU your subscribers will suffer still.

GNW

ahooper · Wed Apr 08, 2009 4:43 am

jordantrx,

As you see it appears we are having similar issues however i have managed to track down the cell opperator who is pushing some 30+ watts into his antenna that is facing my yagi and noly about 120meters away. I am lucky that they seem to be wiling to work with me to resolve this issue and have given me the opportunity to conduct a few tests.

here are a few things i have found. and BTW im using XR9's on RB/411's coupled to a Yagi at each end.

1. The yagi i am using is the Hypergain 9dBi 900Mhz and on the down side when you look at their frequencey curve they will do 890-960 leaving them open to receiving all sorts of interferance.

2. The front to back radio looks OK however im not sure that it is as good as a backfire antenna would be and you would be pulling in interferance both from the sides and front from close range. you only need to look at the smiths chart to see this.

I am tempted to build my own antenna and design it to specificly opperate at 922 as this would/should reduce the reception of unwanted signal and in addition put a cavity filter in line and these can be found for about $200.00.

There is however something I must look at and that is the cell operator is interferaing with 922 and they have an obligation according to the regulations to ensure that whatever they are using does not cause undue interfrance on adjacent channels. This is usually part of their licence agreement.

However if the issue is with unlicenced spectrium then your have problems and the only wayt o deal with this is to create either seperation or figure a way around it. If you have a chanel hopper beside you as is likely the case if its a motorolla then I would track down the owner and ask them niceley if they would fix the channel and work together.

If they dont/wont do this then look at the antenna solution and try and pick something that will isolate you from them by having a very tight side lobe. I have seen some sectors with stearable beamwiths and some pannels that have very tight lobes that may be better suited for your AP end.

Another thing to see is if you can get someone to make you a feed line that is tuned to the frequencey range you are using. a lot of people ignore this and in most cases its not an issue but when dealing with weak signals and interferance every little bit counts.

jordantrx · Wed Apr 08, 2009 4:02 pm

I will try utilizing N-stream and disabling CSMA. Im using the same antennas you are using the 12 db rootenna with Xr9. Same exact setup.

About the clients, Yes but once I put filter on AP I mite be able to get within the correct freq range, also on those freq range my CPE's have ALOT better noise floor, I have done a scan and ONLY on the 2422 do I seem to get the horrible noise floor, thus if AP is set within correct frequency (currently cant because of Noise) Most likely my CPE's noise floor would clear up aswell.

But this is what I figure, you posted a link to the hyperlink tech H-=pol sectors, They look good And I figure I will only need 2 for my operation, So This is what im going to try....

Going to use the 2 yagi design first to see how it works, (yes with splitter on H-pol) If that does not work well and I get alot of issues, I will simply by 2 of those antenna;s run another Lmr 400 coax, buy another routerboard or rb 600 to store all of the cards, 2 Xr9's 1 Xr2 and 1 Cm9 (for backhaul). Thats my plan. Anybody have a better idea let me know. -Jordan

Hi jordantrx

Hmm, you have got quite a mess there.

I only have to deal with earthquake sensors wich transmit in 900Mhz to SDSU in direct proximity to one of my AP's, but my noise floor is still clean at both the AP and CPE end.

I must mention that setting the AP and CPE's to utilize Nstreme increased signal quality and PThroughput alike.
Maybe you should set to use Nstreme to begin with jordan.

What type of antenna are you using at the CPE side?
I use the Pac Wireless ROO2 at 12db and can make high quality LOS connections at almost 12 miles out and very high quality NLOS at around 3.5 miles.

You must also remember that even with a filter at the AP if your clients are within close proximity of a canopy AP or even SU your subscribers will suffer still.

GNW

jordantrx · Wed Apr 08, 2009 4:04 pm

Thanks for that helpfull info, Going to try diff polarity, I have seen good results testing with CPE on H-pol. It was on the ground but i saw a noise floor in the 101's. I know it will be worst 50 feet or 100 feet up. but still better than V-pol. Thanks for the Info.

jordantrx,

As you see it appears we are having similar issues however i have managed to track down the cell opperator who is pushing some 30+ watts into his antenna that is facing my yagi and noly about 120meters away. I am lucky that they seem to be wiling to work with me to resolve this issue and have given me the opportunity to conduct a few tests.

here are a few things i have found. and BTW im using XR9's on RB/411's coupled to a Yagi at each end.

1. The yagi i am using is the Hypergain 9dBi 900Mhz and on the down side when you look at their frequencey curve they will do 890-960 leaving them open to receiving all sorts of interferance.

2. The front to back radio looks OK however im not sure that it is as good as a backfire antenna would be and you would be pulling in interferance both from the sides and front from close range. you only need to look at the smiths chart to see this.

I am tempted to build my own antenna and design it to specificly opperate at 922 as this would/should reduce the reception of unwanted signal and in addition put a cavity filter in line and these can be found for about $200.00.

There is however something I must look at and that is the cell operator is interferaing with 922 and they have an obligation according to the regulations to ensure that whatever they are using does not cause undue interfrance on adjacent channels. This is usually part of their licence agreement.

However if the issue is with unlicenced spectrium then your have problems and the only wayt o deal with this is to create either seperation or figure a way around it. If you have a chanel hopper beside you as is likely the case if its a motorolla then I would track down the owner and ask them niceley if they would fix the channel and work together.

If they dont/wont do this then look at the antenna solution and try and pick something that will isolate you from them by having a very tight side lobe. I have seen some sectors with stearable beamwiths and some pannels that have very tight lobes that may be better suited for your AP end.

Another thing to see is if you can get someone to make you a feed line that is tuned to the frequencey range you are using. a lot of people ignore this and in most cases its not an issue but when dealing with weak signals and interferance every little bit counts.

ahooper · Wed Apr 08, 2009 10:11 pm

jordantrx,

Dont forget that your feed lines from the Yagi's to the splitter have to be exactly the same length. The main feed to the splitter acn be prety much anyting (within reason) but the Splitter to Antenna on both sites needs to be exactly the same as do the antennas or you will end up with a missmatched load.

Regards
Andrew

jordantrx · Thu Apr 09, 2009 1:23 am

jordantrx,

Dont forget that your feed lines from the Yagi's to the splitter have to be exactly the same length. The main feed to the splitter acn be prety much anyting (within reason) but the Splitter to Antenna on both sites needs to be exactly the same as do the antennas or you will end up with a missmatched load.

Regards
Andrew

yea I have heard that before from a streakwave tech, they will be identical antenna's and I will see how they work should be interesting? what do you guys think of the yagi setup? 9dbi x 2 should give me 200+ degree's maybe
but thats all I would need, I have areas I dont need to get to and cant get to if i tried. -Jordan

Gunzoid · Thu Apr 09, 2009 1:52 am

Negative on the Yagi's unless you're doing point to point or for CPE. They are way too directional for AP use.

jordantrx · Thu Apr 09, 2009 3:56 am

Negative on the Yagi's unless you're doing point to point or for CPE. They are way too directional for AP use.

SO basically not enough vertial beamwidth to hit the clients, Vertiacal is to narrow? Eve wiht a low 9 dbi yagi? -Jordan

Gunzoid · Thu Apr 09, 2009 4:55 am

9db Yagi is about 53 degrees
http://www.hillssignalmaster.co.nz/PDF_ ... _Sheet.pdf

Guess it all depends on where your clients are scattered...

A PACWLS Rootenna panel will give you about 50 degrees and not nearly the icing headaches

ahooper · Thu Apr 09, 2009 8:23 am

You can use Yagis as an AP antenna but all your clients have to be within the 53deg beamwidth of the yagi. But in my view 53Degrees is HUGE as im use to working with real point to point antenas that only have 18degree down to about 4degree of beamwidth.

What you also have to take into account is that whatever your beamwidth and front to back ratio is means that this is going to pull in interferance.

I run some software that allows me to put the plots and estimated antenna beams on to a terrain model. this helps heaps when trying to predict what issues you are likley to have and how best to service a region.

In one location im servicing a group of clients at a distance of 30Km from a high gain dish. the beamwith is just enough over that distance to hit all the clients who in turn use a slightly smaller dish to connect back. This site is over water and is in a very noisey enviroment but as we are getting -63's it takes somethign prety dramatic to interfere with the link.

jeremyward · Fri Jul 11, 2014 5:06 pm

I am tempted to build my own antenna and design it to specificly opperate at 922 as this would/should reduce the reception of unwanted signal and in addition put a cavity filter in line and these can be found for about $200.00.

There is however something I must look at and that is the cell operator is interferaing with 922 and they have an obligation according to the regulations to ensure that whatever they are using does not cause undue interfrance on adjacent channels. This is usually part of their licence agreement.

However if the issue is with unlicenced spectrium then your have problems and the only wayt o deal with this is to create either seperation or figure a way around it. If you have a chanel hopper beside you as is likely the case if its a motorolla then I would track down the owner and ask them niceley if they would fix the channel and work together.

If they dont/wont do this then look at the antenna solution and try and pick something that will isolate you from them by having a very tight side lobe. I have seen some sectors with stearable beamwiths and some pannels that have very tight lobes that may be better suited for your AP end.

Another thing to see is if you can get someone to make you a feed line that is tuned to the frequencey range you are using. a lot of people ignore this and in most cases its not an issue but when dealing with weak signals and interferance every little bit counts.

I feel the need to inject a reality-check into this thread.

I realize that the thread is rather old, and as such the discussion is not very recent. However, since this seems to be one of the few posts on the subject of 900MHz wireless, I figured it would be valuable to contribute some additional information to some of what has been said here (specifically RF related) in an effort to further educate others that read this thread.

Here goes:

1. You can not design and build an antenna that specifically operates at a center frequency of 922MHz, and somehow manages to not also receive adjacent frequencies in the 900MHz ISM band (902-926MHz), as well as interference from nearby licensed bands (AMPS, SMR, Paging, etc.) that are often the source of the biggest issues wireless ISPs face when using this spectrum; an antenna design could be optimized for specificaly 922MHz as mentioned earlier, but it will also receive adjacent frequencies at a lower gain. The best way to cope with this is with filtration.

2. Band-pass Filters: When dealing with interference from adjacent bands, a "band-pass" filter is the type of cavity filter that you will most often require There's a company called RFlinx that makes an excellent filter for this purpose. If memory serves me correctly, it reduces out-of-band reception by about 50dB.

3. Notch-filters: if you truly have an issue with a frequency-hopping network (also known as FHSS/GFSK), and the other operator refuses to work with you, a notch filter might be an option provided the other operator doesn't change frequencies. These type of cavity filters "notch" out a few MHz of a band. This is the opposite of how a band-pass filter works. This approach is the least likely to be used, however.

4. ahooper touched on this already, but to reinforce his point -- cellular carriers in the AMPS and SMR bands are under no obligation to protect users of 902-926MHz from interference when the users are operating an FCC Part 15.207 device, which is the case here. There are also licensed operations permitted within this band as well, such as so-called "non-common-carrier" fixed microwave services... While these licenses are for highly directional point-to-point operations, power outputs can often be 100 watts or more.

5. You need to be careful when taking a radio from manufacturer "A" and connecting it to an antenna made by manufacturer "B". The reason is because you, as the operator, need to ensure that the "system" you have assembled is in compliance with FCC regulations in whichever band your network runs in (this applies to more than just 900MHz). The FCC is pretty specific on who is permitted to "self-certify" compliance with FCC regulations. Thus many manufacturers sell compete transmission systems, that consist of a radio, cabling/jumpers, and an antenna. Many consultancies and wireless ISPs lack the personnel sufficiently qualified (from the FCC's perspective that is) to "self-certify" an RF transmission system as compliant with FCC regulations.

6. There realy is not feedline that is "tuned" to a specific frequency. Its more like the specifications of the feedline cover frequencies up to xMHz/GHz. After the cable assembly us built, it is then frequency "swept" (tested) up to and beyond the operating frequency.

7. When dealing with interference, a spectrum analyzer is an essential tool. If you don't have the $5K-$40K to buy your own, you can rent one. For 900MHz use, pickup an Alvarion BreezeACCESS 900 CPE radio from eBay, and download the spectrum analyser firmware and utility. This radio is a frequency-hopping radio, and is a good enough substitute for a spectrum analyzer for most jobs. Price is about $100-$150 used.

8. Hire a consultant if need be. It will save time and money (and subscriber patience = your revenue stream), and you will likely learn a lot from them.

If you have any questions, feel free to send me a message or call me at the number below (I'm in the USA). You can also locate me on LinkedIn by Googling the following:
Jeremy Ward wireless

Happy building!

Jeremy D. Ward, CWNE
+1 (212) 901-5288

P.S. I've been a Mikrotik RouterOS user since March of 2000.

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