B5c PTP loses link at least once a week. Please help!


#1

I’m not an expert with Mimosa, but after this problem started about 2 months ago, I’ve been reading a lot more into them. My link goes down about once a week, sometimes for hours, sometimes for no less than 15 minutes. I can fix it by restarting the Master and that usually gets the link back up and going again. I’m going to give a brief about the point-to-point backhaul and maybe someone can give some insight, it’d be much appreciated!

The PTP link is about 7.5 miles/12km. Before it was a problem, we were able to get 60-90Mbps throughput out of it. Which I feel is kind of slow for the amount of people that use this backhaul. Unfortunately, we don’t have a licensed frequency, but have been looking into it. The radios are set in an area with a lot of noise in the 5GHz spectrum, so choosing frequencies is slim pickins. Currently though we’re using 5795 on 1x80 at 30 TX Power, this seems to do the best. I dropped to 5795 from 5810 because the upper area was heavy with noise.

We have re-aimed the dishes and was able to get more signal, however the problem is consistent… I have a -68 with a noise floor of about -83, so about 15 SNR. The PER seems to jump from 1% to 5%, but usually no more than 5%. I have the Rate Adaptation set to PER and the PHY rate set to Aggressive. I found this works better when dealing with noise.

I’ve tried just about everything and don’t know if I should replace the NMNM cables, which I can’t even find for sale alone. Any help would be appreciated.

Thanks.
-Chris


#2

Hi Chris,

After reading your post, I can see that at the minimum that you should be set to PER Conservative. PER Aggressive is great if you have low PER, but you have spikes to 5%.

You should also visit with our support team. They would need to review the rest of your configuration and view your log files. Being at 7.5 miles, you should have much better signal levels and throughput.