BG95-M3, signal strength often unkown (QNWINFO, QCSQ,CSQ)

Hi all,

we are using the BG95-M3 for our new product. In the past we used the BC95-G. With the BC95 the command “AT+NUESTATS” was used to get a signal strength from the module which worked very reliable.

Now with the BG95-M3 we use the commant AT+QCSQ as well as AT+QNWINFO to get the signal stength. However, very often the signal strength is “0”, sometimes “-127”, sometimes a reasonable value we would expect between “-50” to “-120”.

Can you please advice which commands to use with the BG95-M3 to get reliable signal strength readings?

Thanks and best wishes
Michael


Thanks for the fast respond. We are aware of CSQ but wanted to get the additional information QCSQ provides. Are there conditions to get reliable values from the command?
Thanks

Update from our side. The CSQ command also gives “99”.
We know that the RSSI at the test site is around -50 to -65.

Are there any prerequisites to get reliable RSSI readings. Below you find a log from our device showing the AT commands.

(27698) at: event: +CEREG: 5,“BBA4”,“1402F03”,8,“00000000”,“01100000”[1B][0m
(27699) nb-bg95: CEREG[4]: 5, bba4, 1402f03, 8, 0, 0[1B][0m
(27701) net/nb-iot: net_registration_cb status: 5, ATTACH_SEARCHING [1B][0m
(27708) at: req: AT+COPS?[1B][0m
(27712) at: res: OK [1][1B][0m
(27715) at: res: 0: +COPS: 1,2,“26202”,8[1B][0m
(27719) at: req: AT+QNWINFO[1B][0m
(27726) at: res: OK [1][1B][0m
(27726) at: res: 0: +QNWINFO: “eMTC”,“26202”,“LTE BAND 20”,6300[1B][0m
(27733) at: req: AT+QCSQ[1B][0m
(27738) at: res: OK [1][1B][0m
(27740) at: res: 0: +QCSQ: “eMTC”,-125,0,8,0[1B][0m
(27745) at: req: AT+CSQ[1B][0m
(27748) at: res: OK [1][1B][0m
(27751) at: res: 0: +CSQ: 99,99[1B][0m
(27755) at: req: AT+QCSQ[1B][0m
(27760) at: res: OK [1][1B][0m
(27762) at: res: 0: +QCSQ: “eMTC”,-125,0,8,0[1B][0m

Same with BG77 + QuecOpen APP (AT Command Pipe)

14:28:44.58: ATC: +QNWINFO: “NBIoT”,“23003”,“LTE BAND 20”,6447
14:28:44.58: ATC: +CEREG: 4,5,“A032”,“DEC1F”,9,“00011110”,“10001010”
14:28:44.58: ATC: +QCSQ: “NBIoT”,-125,0,8,0
14:28:44.69: ATC: +QCSQ: “NBIoT”,-125,0,8,0
14:28:45.85: ATC: +QCSQ: “NBIoT”,-125,0,8,0
14:28:47.00: ATC: +QCSQ: “NBIoT”,-125,0,8,0
14:28:48.20: ATC: +QCSQ: “NBIoT”,-59,-70,204,-10

I am currently waiting until it returns rssi > -125
but would as well like to hear how to speed this up.

Same with my BG95-M3,

See my Post

I was able to get a log where AT+CSQ return 99,99 for 5 minutes. Then I restart the modem and I get 11,99 in few second. See log:

10:25:09: 
RDY

APP RDY
ATV1

OK
ATE1

OK
AT+CSQ

+CSQ: 99,99

OK
AT+QGPS=1

OK
AT+CSQ

+CSQ: 99,99

OK
10:25:20: AT+CSQ

+CSQ: 99,99

OK
10:25:30: AT+CSQ

+CSQ: 99,99

OK
10:25:40: AT+CSQ

+CSQ: 99,99

OK
10:25:50: AT+CSQ

+CSQ: 99,99

OK
10:26:00: AT+CSQ

+CSQ: 99,99

OK
10:26:10: AT+CSQ

+CSQ: 99,99

OK
10:26:20: AT+CSQ

+CSQ: 99,99

OK
10:26:30: AT+CSQ

+CSQ: 99,99

OK
10:26:40: AT+CSQ

+CSQ: 99,99

OK
10:26:50: AT+CSQ

+CSQ: 99,99

OK
10:27:00: AT+CSQ

+CSQ: 99,99

OK
10:27:10: AT+CSQ

+CSQ: 99,99

OK
10:27:20: AT+CSQ

+CSQ: 99,99

OK
10:27:30: AT+CSQ

+CSQ: 99,99

OK
10:27:40: AT+CSQ

+CSQ: 99,99

OK
10:27:50: AT+CSQ

+CSQ: 99,99

OK
10:28:00: AT+CSQ

+CSQ: 99,99

OK
10:28:10: AT+CSQ

+CSQ: 99,99

OK
10:28:20: AT+CSQ

+CSQ: 99,99

OK
10:28:30: AT+CSQ

+CSQ: 99,99

OK
10:28:40: AT+CSQ

+CSQ: 99,99

OK
10:28:50: AT+CSQ

+CSQ: 99,99

OK
10:29:00: AT+CSQ

+CSQ: 99,99

OK
10:29:10: AT+CSQ

+CSQ: 99,99

OK
10:29:20: AT+CSQ

+CSQ: 99,99

OK
10:29:30: AT+CSQ

+CSQ: 99,99

OK
10:29:40: AT+CSQ

+CSQ: 99,99

OK
10:29:50: AT+CSQ

+CSQ: 99,99

OK
10:30:00: AT+CSQ

+CSQ: 99,99

OK
10:30:10: AT+CSQ

+CSQ: 99,99

OK
10:30:20: AT+CSQ

+CSQ: 99,99

OK
10:30:28: AT+GMI

Quectel

OK

NORMAL POWER DOWN
10:30:35: 
RDY
10:30:36: 
APP RDY
ATV1

OK
ATE1

OK
AT+CSQ

+CSQ: 99,99

OK
AT+QGPS=1

OK
AT+CSQ

+CSQ: 99,99

OK
10:30:46: AT+CSQ

+CSQ: 11,99

OK
AT+QMTDISC=0

OK
AT+QMTCLOSE=0

ERROR
AT+QICSGP=1,1,"myApn","","",1

OK
AT+QFDEL="*"

OK
AT+QFUPL="ca.crt",1432,500

CONNECT
+QFUPL: 1432,1470

OK
AT+QFUPL="client.crt",1322,500

CONNECT
+QFUPL: 1322,421

OK
AT+QFUPL="client.key",1675,500

CONNECT
+QFUPL: 1675,704a

OK
AT+QSSLCFG="cacert",2,"ca.crt"

OK
AT+QSSLCFG="clientcert",2,"client.crt"

OK
AT+QSSLCFG="clientKey",2,"client.key"

OK
AT+QSSLCFG="sslversion",2,4

OK
AT+QSSLCFG="seclevel",2,2

OK
AT+QSSLCFG="ciphersuite",2,0xFFFF

OK
AT+QSSLCFG="sni",2,0

OK
AT+QMTCFG="version",0,4

OK
AT+QMTCFG="keepalive",0,10

OK
AT+QMTCFG="session",0,0

OK
AT+QMTCFG="ssl",0,1,2

OK
AT+QMTCFG="will",0,1,2,0,"will","Disconnected"

OK
AT+QMTOPEN=0,"xx.xx.xx.xx",8883

OK

Found the issue,

check Quectel_BG95&BG77&BG600L_Series_GNSS_Application_Note_V1.1.pdf

The modules are based on a cost-optimized architecture in which WWAN (LTE Cat-M1, LTE Cat-NB2 and
GSM) and GNSS Rx chains share certain hardware blocks. However, the modules do not support
concurrent operation of WWAN and GNSS.

The solution adopted in the modules is a form of coarse time-division multiplexing (TDM) between WWAN
and GNSS Rx chains. Given the relaxed latency requirements of most LPWA applications, time-division
sharing of resources can be made largely transparent to applications.

1.3. GNSS and WWAN Coexistence Management

As GNSS and WWAN cannot work simultaneously, either WWAN or GNSS takes priority during
implementation. By default, the modules are configured into the GNSS priority mode, which can be switched to the WWAN priority mode with AT+QGPSCFG=“priority”. The command takes effect
immediately. For more details, see Chapter 2.2.1.11.

2 Likes

Hi,

We have similar issue on BG95-M4. Tried the above priority setting, it still doesn’t work.
It lists the network but does not register. The signal strength is always unknown.

Modem: BG95M4LA-64-SGNS
Sim: vodafone
location: Great Britain

Logs:

APP RDY
AT+CPIN?

+CPIN: READY

OK
ATI

Quectel
BG95-M4
Revision: BG95M4LAR02A02

OK
AT+CEREG?

+CEREG: 0,0

OK
AT+CSQ

+CSQ: 99,99

OK
AT+QGPSCFG=“priority”

+QGPSCFG: “priority”,1,3

OK
AT+COPS=?

+COPS: (1,“vodafone UK”,“voda UK”,“23415”,9),(0,1,2,3,4),(0,1,2)

OK
AT+QICSGP=1

+QICSGP: 1,“PAYG - pp.vodafone.co.uk”,“wap”,“wap”,1

OK
AT+CSQ

+CSQ: 99,99

OK

Is this issue been closed ?
having the same issues with BG95 M3
asking for AT+CSQ right after registration (CEREG=0,1) will always yield 99,99 response.
we ended up doing AT+CSQ at the end of the connection ( for us it is a fw seconds) , but still around 50% of the time we get 99,99 as reply.
We don’t use GPS ( we turn it off on every cycle , just in case)