I need advice / C5C signal

Hello guys,

I’m new on the Mimosa products. just joined the MIMO family recently, when first installed my PTP C5C everything was just amazing all the reading was on their best 650/650 Mbps, it was running on the old firmware, but after i have updated to the latest one 2.8.0.2 i was very satisfied with the auto power. and after one week from updating everything started to fall down the rates, signal, noise, and an increment of 5 in RX power , signal CINR etc… have contacted my ISP an told them to re-aim the dishes because I think that there are something wrong with aiming, but they refused to do that and said that this is normal thing with the C5C. i’m asking to your advice to discuss it with my ISP so they will try to re-aim the heads.!!

http://backhaul.help.mimosa.co/backhaul-faq-snr-mcs

It looks like 2 things are biting you.

  1. You have a lot of interference so lot’s of noise to deal with. Solutions to that are getting higher isolation antennas and such for your radios and possibly shielding for the radios themselves if they are nearby other 5 GHz radios. (Metal boxes that are grounded help, good grounding being a primary requirement.)

  2. It looks like you are probably out of alignment from what the Alignment tool is saying as well as how strong of a signal you are getting if you actually are using 31 dB antennas. I would recommend dropping your TX power on each side and realigning the antennas. Big gain antennas are very sensitive and it is very very easy to align on a side lobe. By dropping your TX power on both sides it will make it harder to align on the side lobe. After you are certain you have a good alignment feel free to increase your TX power.

Finally, with auto power, the link will attempt to lower the TX power on each side when the bandwidth requirements are not very high. Don’t worry too much about lowering of MCS values when the link isn’t under stress. The radios will go to as high of a TX power and negotiate the highest MCS value they can when there is bandwidth to require it.

Thank You for answering me, as I said that i think that my antennas are out of alignment so that is why i have asked the ISP to realign them but they have been saying that these readings are normal with mimosa, but i have been following up with you guys and i feel that there is something wrong with the alignment.
Thank you Wiliam. For the support

I would recommend using the Mimosa Design tool to get the readings that you should be seeing. It is free and pretty accurate as far as what your expected signal should be on each side of the link. The C5c doesn’t have GPS so all it can use is the distance measurement for expected RSSI, the Mimosa Design Tool will be able to account for link obstructions and the such.

Now, if there are obstructions in the link you will never get the full signal strength. Buildings, trees or even just a hill will obstruct 5GHz and kill the signal you are supposed to have.

If you see wide signal fluctuations in short periods of time, then there could be moving objects that are killing you. (I frequently have people setup stacks of hay in front of their antennas then call me saying the internet is down…) Or there is a thing called thermal inversion, most frequently seen when shooting over water, but in other climates there are plenty of occasions for it to happen as well. For me, every year at this time I struggle with Corn Fields that are watered, the very wet and cool plants along with the very dry and hot air around will really mess with your signals, I loose between 15-25 dB on some days to individual customers.

If you are dealing with Thermal Inversion, then the solution is to get wider beamwidth antennas. Which will allow for your signal to be deflected, but still keep the link up and happy. That said, in your situation going for a wider beamwidth is probably not a good idea because of all the local interference.

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