I have a custom carrier board I made for the notecard. All seems to work well however the SINR is extremely low. Is there any other diagnostics I can check in the card to figure out what could be the problem? Below results on a WBAN with main and div antenna
A low SINR value (but high RSSI and RSRP…and high bars) basically means you have a strong signal that’s just not very clean. It could mean external RF noise/interference. Are you using an external (flexible) antenna or an onboard antenna on your PCB?
That antenna should be fine. You could try experimenting with other flexible antennas with a more broad frequency range to see if there is any difference (e.g. the one we sell has proven quite reliable).
I ran some tests today with the note carrier board and 698-4000Mhz and 698-8500Mhz Molex antennas and I can’t seem to get the SNIR up. My SNIR is very low(<=22) in all configs. Pictures of the test setup and results which show good service(2-3 bars), rssi ~-65-61, rsrp -87-90, rsrq -9-10, but SNIR is 6-22 on a NBNA and WBNA. This testing is being done in Manhattan however I do have the some of these deployed in other areas(Kansas, North Carolina, Boston)and seeing similar results where bars are 2/3 but SNIR is extremely low(single digits)
Any ideas what’s going on or suggestions on what to try next?
I just spent some time digging in to this a bit more and learned that about 3 years ago we made a change to Notecard firmware to align SINR values away from Quectel’s format (which ranged from 0-250) to a standard format of -20 to 30db (yes we need to update our docs!). This means the values you are seeing are quite good (even the 6 is “ok”). On the WBNA you could try adding a diversity antenna to the DIV u.fl connector to see if that improves any values.
