dslreports logo
 
    All Forums Hot Topics Gallery
spc
uniqs
13
scobywhru
join:2006-12-29
Fresno, CA

scobywhru to jcremin

Member

to jcremin

Re: UBNT Disconnect Issue

Looks like it just disconnected from noise, the SNR isn't enough to have a reliable link, -77 noisefloor only gives 27db on a -50 link, I believe the RM2 has to have 30db for the highest speed. -50 is also a bit loud for a link but shouldn't be a problem as long as it doesn't get louder. Have you been able to identify where the noise is coming from? What antenna are you using with the RM2? What does the airview show for frequency usage? You might be able to find a cleaner piece of frequency by using an offset. With a link RX at 3.25mbps it is eating up a lot of airtime vs a 65.
jcremin
join:2009-12-22
Siren, WI

jcremin

Member

said by scobywhru:

Looks like it just disconnected from noise, the SNR isn't enough to have a reliable link, -77 noisefloor only gives 27db on a -50 link, I believe the RM2 has to have 30db for the highest speed. -50 is also a bit loud for a link but shouldn't be a problem as long as it doesn't get louder. Have you been able to identify where the noise is coming from? What antenna are you using with the RM2? What does the airview show for frequency usage? You might be able to find a cleaner piece of frequency by using an offset. With a link RX at 3.25mbps it is eating up a lot of airtime vs a 65.

Most of my clients on almost all of my Mikrotik AP's have FAR less than 27db SNR, and none of them seem to have this problem other than some that are -80's signal, which is to be expected. It doesn't make sense to me why this tower (which has about the best overall signals of any AP on my network) would act up but not the ones that have twice as many clients, many with signals in the -70's and -80's.

I haven't yet tried doing an offset, partially because my own office runs on the connection and it is tough to mess with it during the day, when we've got VoIP phones and such, and partially because every change seems to take an eternity compared to doing it on an MT system.

If it is truly noise, I can't tell where it is coming from. The noise floor never changes more than a dB, and neither side seems to change at all whenever I have the disconnect issue. The part that seems most suspicious to me is the fact that when I change frequencies, signals get worse as noise floors get better. Makes me think that there's something wrong with the Rocket or the antenna. It's the same kind of thing I see on a 900mhz with a bandpass filter. Obviously the frequencies outside of the filter range have bad signals because the filter is doing it's job, but the noise floors are also better for the same reason.