Mobile signal strength check

This page provides detailed information how to check mobile signal reception quality from command line. For general information on mobile networks and modems, please go to Mobile network - 3G/4G modem installation and configuration.

This link shows a good description of what signal quality is needed: [1]

4G (MC74xx) modem modules

Login to the camera system locally or remotely, in text console run the following commands.

Verbose receive signal print:

 root@XXXXXX:~# qmicli -d /dev/cdc-wdm1 --nas-get-signal-strength
 [/dev/cdc-wdm1] Successfully got signal strength
 Current:
       Network 'lte': '-68 dBm'
 RSSI:
       Network 'lte': '-68 dBm'
 ECIO:
       Network 'lte': '-2.5 dBm'
 IO: '-106 dBm'
 SINR: (8) '9.0 dB'
 RSRQ:
       Network 'lte': '-12 dB'
 SNR:
       Network 'lte': '1.0 dB'
 RSRP:
       Network 'lte': '-104 dBm'

Brief receive signal print:

 root@XXXXXX:~# qmicli -d /dev/cdc-wdm1 --nas-get-signal-info
 [/dev/cdc-wdm1] Successfully got signal info
 LTE:
       RSSI: '-68 dBm'
       RSRQ: '-12 dB'
       RSRP: '-104 dBm'
       SNR: '-4.4 dB'

Note: if device /dev/cdc-wdm1 was not working, try substitute 1 with 0 or 2. List devices available in your system with 'ls -l /dev/cdc-wdm*'.

 ls -l /dev/cdc-wdm*
 crw------- 1 root root 180, 0 Nov 26 11:53 /dev/cdc-wdm0
 crw------- 1 root root 180, 1 Nov 26 11:53 /dev/cdc-wdm1

3G modem modules (MC8705)

Login to the camera system, in text console run command 'minicom'. It should be preset to use the correct virtual serial port /dev/ttyS3. If not, run 'minicom -s' and select this port.

Rype following AT modem commands:

 at+csq
 +CSQ: 14,99
 
 OK
 at!gstatus?
 !GSTATUS: 
 Current Time:  7833862          Temperature: 61
 Bootup Time:   6442483          Mode:        ONLINE         
 System mode:   WCDMA            PS state:    Attached     
 WCDMA band:    WCDMA800         GSM band:    Unknown    
 WCDMA channel: 4436             GSM channel: 65535
 GMM (PS) state:REGISTERED       NORMAL SERVICE 
 MM (CS) state: IDLE             NORMAL SERVICE 
 
 WCDMA L1 State:L1M_DCH          RRC State:   CELL_DCH       
 RX level (dBm):-85
   
 OK

Signal strength (CSQ) >=5 is acceptable, although in country areas the internet may work even with lower signal quality as the masts are not too busy. In any case, the more the better. More than ~ 10 is very realiable connection.

To exit minicom, pres Ctrl+a q.