Link Status Page questions

One of my coworkers and I are having trouble making sense of the stats on this page, and are wondering if some of them may be backwards. In the uplink status section, how is it that there is 23 dB of SNR on the V chain? The power level and signal strength ratio are indicating the V chain is very low power.

Since the V is good on the downlink side, I'm guessing that the Uplink Status Power Level V and H are reversed, and the signal strength ratio as well. The uplink V SNR is more likely correct here given the stats on the downlink.

This AP and SM combo had been on 15.1.1, and now I've updated it to 15.2Beta4. No change noticed.

I looked through the forums, maybe this guy is seeing the same thing? 

http://community.cambiumnetworks.com/t5/PMP-450/SNMP-data-reversed-after-upgrade-to-15-1-1/m-p/80416

Hi kelmore,

This issue is fixed in 15.2 BETA 4, defect id CPY-13551.

Could you please try 15.2 BETA 4.

Thanks & Best Regards,

Balaji

Interesting. I am already running 15.2 Beta 4 as indicated above. 

I now see this in the release notes, but missed it when reading over:

CPY-13551 - Vertical and Horizontal polarity values of SNR and RSSI are flipped on radio GUI of PMP450.

I just downloaded this version last night. Maybe I need a newer build? 

BTW Any chance I can get an SNMP Oid added so that I can poll an SM, and get the snmp name of the registered AP? I posted about this recently and would love to see it make it into the next version. Thanks!

I'm sorry, I did not notice that you already upgarded to 15.2 BETA 4.

Could you please send me engineering.cgi files from both AP and SM.

My email id is balaji.grandhi@cambiumnetworks.com.

Balaji is right we fixed a related issue, in the reporting was not the correct path.

However, there's a secondary issue here that has to do with the internals of our implementation. When a radio is in MIMO-A it is receiving the same information on both path and combining it into 1 signal. When that signal gets received processed in MIMO-A it puts all of the SNR information on the one path. So we do not get a SNR reading on the other path, hence the NA on the other path.

This is not easy to solve because of the MIMO-A signal combining. We can try make it more clear to show that it operating in MIMO-A, however.

When in Mimo-A, why not just drop the H/V split reading, and note that it is combined due to Mimo-A? If you always have a N/A on one of the chains, this might help...

Thanks for taking a look, these values have been perplexing us for over a year.

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We're working on a fix that will clean up the page and display MIMO-A and should have it in the next beta load. Thanks for trying the latest beta and reporting this! 

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Charlie,

I am curious if there were any changes implemented to help with this situation. I am not seeing anything about MIMO-A in the 15.2 release notes. Thanks!


@kelmore wrote:

Charlie,

I am curious if there were any changes implemented to help with this situation. I am not seeing anything about MIMO-A in the 15.2 release notes. Thanks!


In 15.2 (under internal issue CPY-14926) Chitrang fixed an issue on the 450 SM's Link Status page the Uplink Receive Power and SNR was swapped. He also fixed a minor display issue where will show now "20 dB MIMO-A" instead of "20 dB V/ NA-H".

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