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Re: M2HP 20MHz BW ok, 10 and 5 MHz No Link - Help?!

Going to have to "back out" of my previous statement about verifying "N" REQUIRES 20|40MHz. Took the intiative to scower ieee802.org's website and could find no such affirmation. Without such, people's individual interpretation doesn't mean "squat"! I should have done such before making such a statement. Sorry folks.

However, still trying to interpret several of our observations...

Sig
SouthEast WiMAX
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Re: M2HP 20MHz BW ok, 10 and 5 MHz No Link - Help?!

On my M2HP Bullets, the AirOS wireless mode choice is " Ng ". If I click the select tab, to change modes, " Ng " is the only choice. There really is no option, in other words.

The units are on tall push-up steel masts (Rohn) and a pain in the butt to raise and lower, and I also taped the cat5 to the pole every few feet, with slack in it, to avoid stress on the line or the connector. So lowering one to take the unit off, transporting it and the antenna to the other site, lowering that one so that I can put the two a few feet apart, is not going to happen. My back is still sore from putting all that stuff up and getting things pointed.

Reducing the bandwidth from 20 to 10 or to 5 breaks the link. So does channel shifting. And obviously, this means the same change was made at the same time to both ends.

Right now the link is working with 20MHz but with very slim fade margin - best signal seen was -87, worst to still function at all was -94, with a floor of -96. I was anticipating at least 6 dB, or better, S/N improvement at a 5MHz bandwidth, but obviously with a lower max thruput...

If it rains, we lose the link until foliage dries out.
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Re: M2HP 20MHz BW ok, 10 and 5 MHz No Link - Help?!

I certainly hope that's not the case. Mike?



Hello,
The N protocol (at least with our chip and drivers) works fine in 5/10/20 and 40Mhz.
However, I believ it may have something to do with very low RSSI's (less then 16)when operatingin 10/5Mhz. I will let you know more when I know more.
Thanks,
New Member
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Re: M2HP 20MHz BW ok, 10 and 5 MHz No Link - Help?!

Thanks Mike. If I interpret that correctly, it means that at present you can't use 10 or 5 to improve a lousy S/N on a link because they don't work if the signal is lousy. Kind of defeats the purpose of a reduced BW. Hope you find a way around it, or perhaps build a fix into the next firmware.

Joe
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Re: M2HP 20MHz BW ok, 10 and 5 MHz No Link - Help?!

Thanks Mike. If I interpret that correctly, it means that at present you can't use 10 or 5 to improve a lousy S/N on a link because they don't work if the signal is lousy. Kind of defeats the purpose of a reduced BW. Hope you find a way around it, or perhaps build a fix into the next firmware.

Joe



Hey Joe,
Im thinking of really lousy signals (around -82 or less percieved signal strength while in 10Mhz. This would be a -86 signal in 20Mhz). And its a just a software fix we are looking into.

Thanks,
New Member
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Re: M2HP 20MHz BW ok, 10 and 5 MHz No Link - Help?!

Thanks Mike. This current S/N qualifies as a really, REALLY lousy signal, -86 is about as high as the received signal gets, with an occasional giddy foray to -84 when the planets and the moon are properly aligned and the wind is calm, with a noise floor that stays at -96. Most of the problem, I'm pretty sure, is co-channel interference, and that also should drop down since the interference sources will stay the same spread but we won't. Theoretically, I would expect the effective punch of the spectrum slice of ours us to go up by 6 dB, while at the same time the effective interference potential from a given co-channel source will drop to 1/4 what it was, or something along those lines. Being able to half-channel slide will probably be additional help after the 5 MHZ BW works as it should, and THAT does not work NOW even at 20MHz BW - the link disappears and does not return until that feature is turned off (and obviously we are doing this simultaneously at both ends).
Believe it or not, though, it is currently a usable data link about 75-90 percent of the time even at these levels and 20MHz, with a throughput of (rarely) up to 11 Mb/s. But you can see, I think, why I REALLY want to be able to narrow it down. It'll be slow, (probably not, on average much slower than it is now) but it should be MUCH more robust.
Previous Employee
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Re: M2HP 20MHz BW ok, 10 and 5 MHz No Link - Help?!

Thanks Mike. This current S/N qualifies as a really, REALLY lousy signal, -86 is about as high as the received signal gets, with an occasional giddy foray to -84 when the planets and the moon are properly aligned and the wind is calm, with a noise floor that stays at -96. Most of the problem, I'm pretty sure, is co-channel interference, and that also should drop down since the interference sources will stay the same spread but we won't. Theoretically, I would expect the effective punch of the spectrum slice of ours us to go up by 6 dB, while at the same time the effective interference potential from a given co-channel source will drop to 1/4 what it was, or something along those lines. Being able to half-channel slide will probably be additional help after the 5 MHZ BW works as it should, and THAT does not work NOW even at 20MHz BW - the link disappears and does not return until that feature is turned off (and obviously we are doing this simultaneously at both ends).
Believe it or not, though, it is currently a usable data link about 75-90 percent of the time even at these levels and 20MHz, with a throughput of (rarely) up to 11 Mb/s. But you can see, I think, why I REALLY want to be able to narrow it down. It'll be slow, (probably not, on average much slower than it is now) but it should be MUCH more robust.


Hello,
Please update to the new RC2 firmware I released today at the top of the forum. Once update, disable the noise immunity option on the advanced tab and your problem should be resolved.
Thanks,
Mike
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Re: M2HP 20MHz BW ok, 10 and 5 MHz No Link - Help?!

But are you using linking to those M2HP clients with an M2HP set to 10MHz RF BW AP? Or are you using the M2HP's just as clients with something other than an M2HP as the AP?

Bullet2HP's are the AP's.
New Member
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Registered: ‎09-14-2009

Re: M2HP 20MHz BW ok, 10 and 5 MHz No Link - Help?!

Mike, I downloaded build 2732 RC2 090918.1605, and successfully uploaded it to both and installed, and rebooted both and they show they are running it, but there is no "noise immunity tab anywhere that I can see. I do notice that the link is a little more robust, immediately. However, I notice that the "Country Code" select on the M2HP I am using as the far end "Station" is blank, and there are no countries shown as options when I click that tab. The M2HP AP unit shows the countries and the select tab works. Should I try to upload again to the "Station" Bullet?
Joe
UPDATE: I re-uploaded the new firmware to the Station Bullet and now Country Select works. Then I took a deep breath and tried 10MHz. IT WORKS, and improved the signal levels and CCQs. Then I went to 5 MHz, and have even more improvement, as I had hoped. CCQs now running 80-100%. THANK YOU!!! Signal levels now in the -87 to -81 dbM level, Huge improvement in link. Still no "noise immunity tab anywhere, though. Running MCS1 - MCS3 modes now.
Previous Employee
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Re: M2HP 20MHz BW ok, 10 and 5 MHz No Link - Help?!

Mike, I downloaded build 2732 RC2 090918.1605, and successfully uploaded it to both and installed, and rebooted both and they show they are running it, but there is no "noise immunity tab anywhere that I can see. I do notice that the link is a little more robust, immediately. However, I notice that the "Country Code" select on the M2HP I am using as the far end "Station" is blank, and there are no countries shown as options when I click that tab. The M2HP AP unit shows the countries and the select tab works. Should I try to upload again to the "Station" Bullet?
Joe
UPDATE: I re-uploaded the new firmware to the Station Bullet and now Country Select works. Then I took a deep breath and tried 10MHz. IT WORKS, and improved the signal levels and CCQs. Then I went to 5 MHz, and have even more improvement, as I had hoped. CCQs now running 80-100%. THANK YOU!!! Signal levels now in the -87 to -81 dbM level, Huge improvement in link. Still no "noise immunity tab anywhere, though. Running MCS1 - MCS3 modes now.


Thanks for the update. THe noise Immunity button should be on the advanced tab of the Web GUI.
Thanks,
Mike
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Re: M2HP 20MHz BW ok, 10 and 5 MHz No Link - Help?!

The noise Immunity button should be on the advanced tab of the Web GUI.
One of my techs said he wished his wife had a Noise Immunity button.
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Hardware Problem

I have a marginal link (noise -96, signal varies from -94 to -86, with a 24dBi dish at each end)..

Seems like everything after that statement should have come to a screeching halt. With a pair of 24 dB grids at a range of 3 KM you should have a signal in the -30 dB range. Google up a link calculator, and then check your antennas for water.
I spent most of my money on women and beer, and the rest I just wasted.
New Member
Posts: 17
Registered: ‎09-14-2009

Re: M2HP 20MHz BW ok, 10 and 5 MHz No Link - Help?!

Mike, no noise tab or button on Advanced or anywhere else on either Bullet. And on the AP now the distance slider is an empty box, and the two RTS and fragmentation boxes say "off" rather than having a numerical value. If I go to change any value on that page now, it complains that RTS and frag must have numerical values. But when I input them and Apply, they go back to "off". Station Bullet does not have this problem. I have both open in the same browser, different windows, via the link.

Joe
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Re: M2HP 20MHz BW ok, 10 and 5 MHz No Link - Help?!

To Full Power - I know. I am only up 50' at one end and 40' at the other, Rohn push-ups. Several heavy forested areas are the culprit, I am going to try to give it another 6' at each end and see what happens. If I had a couple of 100' towers I could use two tin cans and a string.
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Re: M2HP 20MHz BW ok, 10 and 5 MHz No Link - Help?!

Several heavy forested areas are the culprit..
Forgive my presumption, I should have asked about it first.

As coincidence would have it I just finished a 2 km link through a forest, with a 24 grid at one end. I have a -63 but cannot hold a link rate any faster than 6 Mbps with 1 Mbps TCP throughput. Maybe the trees are blurring the RF sufficiently to cause a loss of data purity. This was my first shot through trees.
I spent most of my money on women and beer, and the rest I just wasted.
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Re: M2HP 20MHz BW ok, 10 and 5 MHz No Link - Help?!

Trees are weird. I have seen stuff through trees that would make your hair fall out. If you go through trees, all bets are off. Trees I can see through can't get a signal 600'. Trees that look like the great wall of China act as though they aren't even there. The best test would be to change polarity and see what happens.
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Re: M2HP 20MHz BW ok, 10 and 5 MHz No Link - Help?!

"Blurring" is exactly what is happening. Its called the "grove effect" where a thick grove of trees will have a similar effect of Fresnel distortion. As you have a plenty strong -65 signal level, intentionally misaligning the antennas won't hurt that much; but may get a more clean of path.
I have University of Texas and U.S. Dept. of Commerce citations if you'd like...
...for anyone that might think I don't know what I'm talking about.
BTW...
whtonline.com/Team_Ubiquiti/5.8_tree_blockage1.jpg
whtonline.com/Team_Ubiquiti/5.8_tree_blockage2.jpg
whtonline.com/Team_Ubiquiti/5.8_tree_blockage3.jpg
WHT = Short Form Acronym for "You couldn't handle me even if I came with instructions!"
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Re: M2HP 20MHz BW ok, 10 and 5 MHz No Link - Help?!

Shapiros says you are good so at least you have one fan. However, in this case you are right. The water content in the tree wigs out the Fresnel zone.
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Re: M2HP 20MHz BW ok, 10 and 5 MHz No Link - Help?!

and if you live where it rains frequently (like I do), you can typically just turn everything off until it gets at least somewhat dry again. Truly wet foliage, or heavy fog, heavy rain, can turn a usable path into a linear dummy load. I don't know whether circular polarization might help or not. You lose some total gain but it may be less blurred overall. Didn't look at those hyperlinks, so dunno if they investigated that or not. Left-or-right-hand circular polarization is usually used for satellite up/downlinks in relatively LEO sats b/c of faraday rotation. Antenna hardware and phasing harnesses are more complex than simple linear polarization antennae. And cost more, of course, per dB of gain.
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Re: M2HP 20MHz BW ok, 10 and 5 MHz No Link - Help?!

Shapiros says you are good so at least you have one fan. However, in this case you are right. The water content in the tree wigs out the Fresnel zone.

I worked out a model for tree grazing, and you know and seen how I tend to get very elaborate at times in my dissertations...to the point you need a dictionary.

I couldn't see anything that resembled knife-edge Fresnel distortion, rather a multi-point scatter seem to be the right fit. Nevertheless, it would have the same effect as a crappy Fresnel clearance, but with a different process.
WHT = Short Form Acronym for "You couldn't handle me even if I came with instructions!"
Well engineered projects are indistinguishable from crazy ideas.

Speed, distance, reliability, cost...Pick three.
...World's First Ubiquiti AirMax WISP....