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.
Note: This link shows a good description of what signal quality is needed: [1]
Contents
Standard method
In 2021 the software in most of the camera systems was upgraded to provide relatively user friendly mobile signal check functions.
Web GUI
click on tab "Network" then "Check modem signal"
Commandline
dfn_print_mobile_signal_quality.sh
Critical details of the printed info explained
Both these print the same information - the Web GUI menu command just calls the script. The printed information depends on the type of modem installed in the camera system. The key things are:
There actually is a modem module, it is powered, and the host operating system can detect it on the USB bus: This is the 3G modem module:
Detecting modem type... Bus 001 Device 042: ID 1199:68a3 Sierra Wireless, Inc. MC8700 Modem
This is the 4G modem module (Americas/EU version):
Detecting modem type... Bus 001 Device 012: ID 1199:9071 Sierra Wireless, Inc.
Modem missing or defunct:
Detecting modem type... Error: no supported Sierra Wireless modem found. Modem missing? Or broken? Wiring problem? Here is a list of devices on USB:
It is possible to send AT commands to configure/query the modem, and it responds (3G+ modem module):
Manufacturer: Sierra Wireless, Incorporated Model: MC8705
This is the 4G modem module (Americas/EMEA version):
Manufacturer: Sierra Wireless, Incorporated Model: MC7455
Modem hardware and firmware version
Revision: XXXXXXXXX YYYY XXXXXXXXX
Temperature reading! (In Celsius degrees, sensor in the modem module)
Temperature: 40
Connection and registration state - this means whether the modem is attached/registered to the operator's network
All good:
PS state: Attached GMM (PS) state:REGISTERED NORMAL SERVICE MM (CS) state: IDLE NORMAL SERVICE
Not good - in this case, missing SIM card:
PS state: Not attached GMM (PS) state:DEREGISTERED PLMN SEARCH MM (CS) state: IDLE NO IMSI
Mobile technology, band and channel used to connect with the tower
3G/WCDMA - example:
System mode: WCDMA WCDMA band: WCDMA800 WCDMA channel: XXXX
4G/LTE - example:
LTE band: B2 LTE bw: 20 MHz LTE Rx chan: XXX LTE Tx chan: XXXXX
Signal reception quality:
Note: This link shows a good description of what signal quality is needed: [2]
3G/WCDMA:
RX level (dBm):-85
4G/LTS:
PCC RxM RSSI: -75 RSRP (dBm): -112
RSRQ (dB): -19.0
...
LTE:
RSSI: '-73 dBm'
RSRQ: '-16 dB'
RSRP: '-113 dBm'
SNR: '0.0 dB'
Simple signal quality print - should be at least 5-6 in remote areas, > ~12-15 with busy tower:
AT+CSQ +CSQ: 12,99
Lowest possible signal
AT+CSQ +CSQ: 0,99
No signal
AT+CSQ +CSQ: 99,99
Missing SIM card
AT+CSQ ERROR
Mobile network operator - examples:
+COPS: 0,0,"Telstra Mobile",2
or
+COPS: 0,0,"OMANTEL",2
or
+COPS: 0,0,"TELUS",7
missing SIM card or missing antenna or no reception
+COPS: 0,0,"Limited Service",2
Low level commands for advanced users
4G (MC74xx) modem modules
Login to the camera system locally or remotely, in text console run the following commands.
Verbose signal reception print - 4G/LTE connection, good signal quality:
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 signal reception print - 4G/LTE connection, good signal quality:
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'
Brief signal reception print - 4G/LTE connection, excellent signal quality:
root@XXXXXX:~# qmicli -d /dev/cdc-wdm1 --nas-get-signal-info
[/dev/cdc-wdm1] Successfully got signal info
LTE:
RSSI: '-62 dBm'
RSRQ: '-7 dB'
RSRP: '-90 dBm'
SNR: '23.8 dB'
Brief signal reception print - 3G/WCDMA connection, marginal signal strength, but still good signal quality thanks to low noise/interference; typical for remote areas with low population:
root@DFNEXT043:~# qmicli -d /dev/cdc-wdm1 --nas-get-signal-info
[/dev/cdc-wdm1] Successfully got signal info
WCDMA:
RSSI: '-103 dBm'
ECIO: '-6.5 dBm'
Verbose signal reception print - 3G/WCDMA connection, marginal signal strength, but still good signal quality thanks to low noise/interference; typical for remote areas with low population:
root@DFNEXT043:~# qmicli -d /dev/cdc-wdm1 --nas-get-signal-strength
[/dev/cdc-wdm1] Successfully got signal strength
Current:
Network 'umts': '-103 dBm'
RSSI:
Network 'umts': '-103 dBm'
ECIO:
Network 'umts': '-7.5 dBm'
IO: '-106 dBm'
SINR: (8) '9.0 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.
(To exit minicom, press 'Ctrl+a q'.)
Type 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 usually very reliable connection in the remote areas. In urban areas with busy mobile network, better signal quality is required for reliable connection and data transfers - other devices connected to the same telco tower might "shout down" the communication of the camera system.
