seesaw upstream snr

Products PMP
1

anyone have any ideas what would make upstream snr see-saw (see pic). I have a number of people on a site with this,  but only a handfull.

customer is connected to a 450m AP

2

I Have forwarded this to our support and development teams.

3

What frequency band is this, and what firmware?

j

4

It's in the 5.4 GHz band, using firmware 16.1.

I've tried a few different channels with the same results (5.4 - 5.7).

I've tested it on another access point that this customer can see, with same results.

both sectors are gps synced with the same frame setup.

I've seen this show up on a few other locations we have as well. I need to confirm, but we've had reports from these customers of their connection dropping, even though their signal looks good and I don't see any session drops.

5

We're running 16.1 in 900MHz band and see similar problems, though we've been tentatively blaming it on 900MHz electric meter polling equipment.

6

What's odd about this, is it's the uplink side doing it, but not everyone on the site is doing it.

Other sites I have doing this, again is only affecting 1 person, or sometimes a few.

7

Arakasi,

I haven't looked into this issue, but here's some info in the meantime.

The SNR in 450 is an estimate based upon the current modulation rate and the data received. If there is no packets flowing, then it can not make SNR readings. Also if there are only a few small size packets going through the network, it too can lead to lower readings than actuality.

In 16.1 we added the EVM feature which does not have any of these limitations. How is EVM looking?

Charlie

8

here is the link status for one of the sm's with this issue.

I am noticing that the mu-mimo rate shows pretty low for uplink while the su-mimo looks good, what could cause that?

these are all recent installations, is it possible we have a hardware problem with some of the sm's?

9
@Arakasi wrote:

here is the link status for one of the sm's with this issue.

I am noticing that the mu-mimo rate shows pretty low for uplink while the su-mimo looks good, what could cause that?

these are all recent installations, is it possible we have a hardware problem with some of the sm's?

I'm not a 450m expert, so not sure what could cause that. But that SM is getting 8X in the uplink, so I do not think it is a hardware issue with that SM. As far as the other SMs, not sure about that either. We'd have to investigate. Sorry I don't have any quick answers. Maybe want to open a support ticket so someone can investigate further.