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Status->Network->Mobile and gsmctl -q, -W, -M, -Z seem to be aligned. However the gsmctl -A AT+QCAINFO returns

+QCAINFO: "pcc",6300,50,"LTE BAND 20",1,316,-64,-7,-38,22

+QCAINFO: "scc",323,75,"LTE BAND 1",1,351,-84,-6,-68,28

RSSI, RSRQ and SINR values never match for pcc/scc and Mobile Information page. At first I assumed RSSI shown on that page was 

an average of two CC's however it stays static at -51dBm in my case while RSSI for each CC fluctuates.

RSRQ is consistent at -11 on that page while it's -6 or -7 when running a command above.

Could you please explain how are these calculated and correlate? 

/azik

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Hello, Azik!

Could you tell me on which device this situation occurs?

BR

Aliaksandr
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Hi Aliaksandr,

Model: RUTX11

Firmware: RUTX_R_00.02.04.3

Modem: EG06ELAR03A05M4G

Thanks,

Azik

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For this request, the following response sequence is:

+ QCAINFO:

“PCC”, <freq>, <bandwidth>, <band>, <pcell_state>, <pcid>,

<rsrp>, <rsrq>, <rssi>, <sinr>

“SCC”, <freq>, <bandwidth>, <band>, <scell_state>, <pcid>,

<rsrp>, <rsrq>, <rssi>, <sinr>

And the decoding of the parameters:

<PCC> Primary carrier component

<SCC> Secondary carrier component

<freq> EARFCN

<bandwidth> Bandwidth

6 1.4MHZ

15 3MHZ

25 5MHZ

50 10MHZ

75 15MHZ

100 20MHZ

<band> Band information.

<pcell_state> Primary cell state

0 No serving

1 Registered

<scell_state> Secondary cell state

0 Deconfigured

1 Configured deactivated

2 Configured activated

<pcid> Physical Cell ID

<rsrp> Reference Signal Received Power (see 3GPP 36.214 Section 5.1.1.)

<rsrq> Reference Signal Received Quality (see 3GPP 36.214 Section 5.1.2.)

<rssi> Number format. The parameter shows the Received Signal Strength Indication

<sinr> Number format. Logarithmic value of SINR. Values are in 1/5th of a dB. Range: 0-250, which translates to -20dB -+30dB.

So SINR sholud not be the same in command response and Mobile page.

As for the rest of the parameters, they may not always coincide, since the command returns a static value received from the modem, while Mobile displays real information, which can constantly change. I advise you to try testing different sim cards and different locations.

BR,

Aliaksandr
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I did try 4 different sim cards of different providers. Result is the same. SINR isn't adjusted to the logarithmic scale so what both command and page shows isn't really in dB but as long as both show the same value and they do it's fine. Others however don't match between these two ways of seeing values. RSSI and RSRQ only for the primary CC get stuck on the mobile page as if they are read once during initialisation and never get updated later on. The scc values seem to be bound to the output of this command and always "tick".

There is a clearly a UI binding/web server parsing bug somewhere in that web page workflow. Could be as simple as string concatenation issue.

/azik
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You are viewing it from SHH or CLI?

BR

Aliaksandr
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Both the SSH and the CLI show the same results but this is expected, isn't it? Both are just consoles to the same OS.

They obviously fluctuate a bit and I would struggle to catch exactly the same values as I need to flip between the two but over a few runs they do show similar values and more importantly they do fluctuate on both carrier components as can be seen on the screenshot attached.

The mobile information page though is different. The pcc values get stuck and the scc values tick, so definitely something is wrong there.

by

Hello,

Information might not match, because router calculates RSSI from "AT+CSQ" AT command. Attaching screenshot from LTE module documentation for you regarding this command.

RSRQ, RSRP and SINR are returned to the router by "AT+QCSQ" AT command (RSSI, RSRP, SINR, RSRQ)

If you want to read/use mobile signal quality parameters through SSH, you can use the following gsmctl options:

  • gsmctl -q
  • gsmctl -W
  • gsmctl -M
  • gsmctl -Z

BR

Aliaksandr