Hi I have a SM 1.1km from my tower with a -76 downlink and a -60 uplink.... im in Canada so I can only have total 36db between sector and radio for the unlincensed spectrum. Any thoughts? Clear line of sight... do I have faulty equipment... latest firmware on both.
Best way to check to make sure you're getting the proper signal is to put the path into LinkPlanner. It will tell you pretty much exactly what sort of RSSI and throughput to expect using those radios in your region.
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I will definetly do that but lets be honest, 1.1 km distance from the sector.. no hills, no obstructions and I am getting -76 for signal.... Ive seen ubiquiti nanostations perform better than this.... everyday that passes I am wondering why I switched from ubiquiti to cambium.....
Sounds possibly like a downtilt problem on the sector. Have you calculated what appropriate downtilt should be for the area you are attempting to serve?
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The signal is math and physics. There's no "better signal" for Ubiquiti/MikroTik and Cambium.
Same output power, same antenna gain, you'll have same signal with all vendors.
What changes is what the radio does with that signal :-)
You should mention about your sector antenna gain and your output power.
If you're using a Force 300-19 you have 19dBi gain on your SM, and if you're using ePMP 3000 sector you have 18dBi gain if you are in its coverage (it's less than 90 degrees for 18dBi gain).
To have -76 signal at 1.1km, you should put your max output power to 0dBm on both AP and SM.
If you can have 36dB between sector and radio, you can have 18dBm output power, right?
If yes, you should have about -56dBm signal if pointed correctly.
I think there is some alignment issue. We had some faulty F300 losing 20dB. It's rare (3 over more than 1000 SMs), but can happen.
Please try to check output power settings, then check for correct alignment, and then try with another SM.
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Not to take away from your otherwise spot on information but
"The signal is math and physics. There's no "better signal" for Ubiquiti/MikroTik and Cambium.
Same output power, same antenna gain, you'll have same signal with all vendors."
So while physically this is 100% true, in reality the signal strength displayed is not the same dB for dB from one manufacturer to another. When we first started swapping out Ubiquiti Nanostation M2's with their 12.2-13.7 dBi with ePMP 1000 integrated with 12 dBi the ePMP's always showed 4 to 6 dBi less signal strength, always. When we reached out to Cambium for an explanation they said it was because the RSSI numbers Ubiquiti radios showed were not as accurate as ePMP and even suggested Ubiquiti was fudging the numbers.
For the most part the ePMP radios performed better with the lower RSSI numbers than the Ubiquiti radios they were replacing.
At some point there was a firmware update that lowered the RSSI numbers again on ePMP, almost 3 dBi if I remember correctly. Of course this was undocumented and anyone who's radio dipped below the minimum RSSI to connect threshold required a truck roll to correct the setting... Cambium explained they were just even more accurate numbers now ! Meaning at that time an ePMP could show as much as 9dBi less than a NS of the same gain antenna.
So not only is the signal not the same from one vendor to another ( I mean, we aren't even getting into the numbers not being completely accurate from one antenna to another) it's not even always the same from one firmware version to another.
Even the link planners from various makers do not always agree with one another.
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Fault in equipment, bad alignment or interference. What does the Chain balance look like on the CPE end ?
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@DigitalMan2020 wrote:I will definetly do that but lets be honest, 1.1 km distance from the sector.. no hills, no obstructions and I am getting -76 for signal.... Ive seen ubiquiti nanostations perform better than this.... everyday that passes I am wondering why I switched from ubiquiti to cambium.....
Hi DigitalMan. Yes, for sure the signal should be better than that - - all things being correct of course. :) We have client installations at 20KM which are working great, so this isn't some fundamental fault of Cambium - or a 1.1km maximum possible link with Cambium - or anything like that. :)
When Eric was suggesting you check LinkPlanner, he wasn't saying "-76 might be the best Cambium can do at 1.1km"... he was more saying "Linkplanner will tell you what RSSI and throughput is expected" and you can then know what your targets are.
As mentioned, we (everyone here) has clients a lot farther out than 1.1km, and with the proper antennas, aiming, settings, etc, etc - you can get remarkable performance. This client for example is 11.4 KM away, signals well balanced at -56 --- and we have him QOS set to 30mbit/6 mbit. He get's DS9 most of the time, and he can pull 30+/6+ all day long. I can set his QOS to 60 Mbit, or 100 Mbit, or 120 Mbit, or 150 Mbit and he cruises along at that just fine too.
Here is another example - I am 6.3 KM out from my AP, my signals are -60, and I have a 100 Mbit Up/Down connection to the AP I'm on. So, there's something amiss with your hardware (broken) or with aiming, settings, configuration, connectors - something. This isn't ''cambium has sucky signals'' :)
So - lots of the guys here are willing to help. :) I would recommend (as Eric said) figure out your link in LinkPlanner, and then share some of the configuration screens in your AP and SM's Wireless Configuration setting, and we can help narrow down what the problem is for you.
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Thank you to everyone for their comments! I am going to look at everything and defietly look at a climb and do some aligning. One thing that I may be dealing with is some self interference... any way the SA can help me with this?
I doubt that self interference might cause low signal levels. For what its worth it makes sense to share tech support dump with our tech support team. We might see something in the logs.
Dmitry
Thanks Dmitry I will do that
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