450m Sounding Statistics - Untrusted / Not Eligible and odd SM SNR readings

Hi,

We were looking at the sounding statistics for one of our 450m 3.65 APs and see that one of the SMs is reporting “UNTRUSTED / Not Eligible” for the downlink. A handful are showing “ASSESSING / Not Eligible” but we have not seen UNTRUSTED before here. The SM also shows some odd readings for the Downlink SNR, 19V / NA H. The V and H chains are also off by quite a lot, (-68.0 V / -49.0 H).

Have never seen numbers like this before, anybody know what it means?

There’s something causing the SM to have chain issues, it might be an issue with the LOS, but it is more likely a problem with the SM. I’d try replacing the SM and also investigating the path to see if there are any LOS issues.

When an SM has chain issues or path issues, this can cause things like link fade, reflections, and/or multipathing to occur which confuses the PMP450m when it’s trying to create sounding groups.

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Thanks for that info, its very odd because looking back in the cnmaestro stats for this customer, their RSSI imbalance and RSSI changed significantly when we moved the AP frequency. You can see in the graph here when that change was made. We’re not sure how it could have really gone from a ~-65dBm to ~-48dBm…

it looks like the RSSI only went up on one chain, which is why the imbalance is so high, and the numbers seem to confirm that at -68.0 V / -49.0 H