BG95-M3 Problem with MQTT Subscription

Hello everyone,

I am using BG95-M3 evaluation board and the public MQTT broker (

The connection between the MQTT broker and BG95 is successfully established.

So that, from the BG95 module I subscribe to one topic and publish the message to the same topic from the another client such as MQTTBox tool. As well as I had subscribe to the same topic from the MQTTBox tool.

The messages I send from the tool to the particular topic is either received lately or some times not received by the BG95 module. But in the MQTTBox tool all the published messages are received immediately.

is that anything I missed to configure the MQTT?

Thanks in Advance,


Hi, Sivasubramanian_R:

The default KeepAlive time for BG95 to connect to MQTT Broker is 120 seconds (2 minutes),So,It is very easy to disconnect the device from the MQTT server,It is reguested that you change the KeepAlive time(such as 3600),Also pay attention to check the connection between the broker and the MQTT server (online or offline).
You can try publishing and subscribing again to see if the problem persists.

Hi Herbert.pan,

Nice to see your response, I configure the MQTT “Keep alive time” as you said, but I still have the issue.




+QMTCFG: “keepalive”,3600


The Connection between the MQTT broker and the BG95 is alive while I publish the message from the another client to the BG95 subscribed topic.

The logs of my work is listed below,

[2021-04-26 18:17:35:032_S:] ATI

[2021-04-26 18:17:35:086_R:] Quectel
[2021-04-26 18:17:35:086_R:] BG95-M3
[2021-04-26 18:17:35:086_R:] Revision: BG95M3LAR02A03

[2021-04-26 18:17:35:086_R:] OK
[2021-04-26 18:17:57:253_S:] at+cfun?

[2021-04-26 18:17:57:311_R:] +CFUN: 1

[2021-04-26 18:17:57:311_R:] OK
[2021-04-26 18:18:13:429_S:] at+qcfg=“nwscanmode”

[2021-04-26 18:18:13:486_R:] +QCFG: “nwscanmode”,1

[2021-04-26 18:18:13:486_R:] OK
[2021-04-26 18:18:25:290_S:] at+qcfg=“nwscanseq”

[2021-04-26 18:18:25:345_R:] +QCFG: “nwscanseq”,010203

[2021-04-26 18:18:25:345_R:] OK
[2021-04-26 18:18:34:741_S:] at+qcfg=“iotopmode”

[2021-04-26 18:18:34:795_R:] +QCFG: “iotopmode”,2

[2021-04-26 18:18:34:795_R:] OK
[2021-04-26 18:18:37:012_S:] AT+QCFG=“servicedomain”

[2021-04-26 18:18:37:067_R:] +QCFG: “servicedomain”,2

[2021-04-26 18:18:37:067_R:] OK
[2021-04-26 18:18:39:351_S:] AT+QURCCFG=“urcport”

[2021-04-26 18:18:39:405_R:] +QURCCFG: “urcport”,“usbmodem”

[2021-04-26 18:18:39:405_R:] OK
[2021-04-26 18:18:41:658_S:] at+creg?

[2021-04-26 18:18:41:715_R:] +CREG: 0,5

[2021-04-26 18:18:42:725_R:] OK
[2021-04-26 18:18:44:257_S:] at+cgreg?

[2021-04-26 18:18:44:312_R:] +CGREG: 0,5

[2021-04-26 18:18:44:312_R:] OK
[2021-04-26 18:18:46:669_S:] at+cops?

[2021-04-26 18:18:46:724_R:] +cops: 0,0,“Vi is here”,0

[2021-04-26 18:18:46:724_R:] OK
[2021-04-26 18:18:48:149_S:] AT+CSQ

[2021-04-26 18:18:48:206_R:] +CSQ: 13,99

[2021-04-26 18:18:48:206_R:] OK
[2021-04-26 18:18:49:390_S:] at+qcsq

[2021-04-26 18:18:49:448_R:] +QCSQ: “GSM”,-88

[2021-04-26 18:18:49:448_R:] OK
[2021-04-26 18:18:50:353_S:] AT+QNWINFO

[2021-04-26 18:18:50:408_R:] +QNWINFO: “GPRS”,“40484”,“GSM 1800”,743

[2021-04-26 18:18:50:408_R:] OK
[2021-04-26 18:18:53:169_S:] at+cgatt?

[2021-04-26 18:18:53:226_R:] +CGATT: 1

[2021-04-26 18:18:53:226_R:] OK
[2021-04-26 18:18:57:161_S:] at+cgact?

[2021-04-26 18:18:57:218_R:] +CGACT: 1,0
[2021-04-26 18:18:57:218_R:] +CGACT: 2,0

[2021-04-26 18:18:57:218_R:] OK
[2021-04-26 18:19:01:969_S:] AT+CGDCONT?

[2021-04-26 18:19:02:024_R:] +CGDCONT: 1,“IP”,“SUPER”,“”,0,0,0
[2021-04-26 18:19:02:024_R:] +CGDCONT: 2,“IP”,“ota.super”,“”,0,0,0

[2021-04-26 18:19:02:024_R:] OK
[2021-04-26 18:27:10:296_S:] AT+QMTCFG=“pdpcid”,0,1

[2021-04-26 18:27:10:351_R:] OK
[2021-04-26 18:27:12:725_S:] AT+QMTCFG=“keepalive”,0,3600

[2021-04-26 18:27:12:779_R:] OK
[2021-04-26 18:27:15:276_S:] AT+QMTOPEN=0,“”,1883

[2021-04-26 18:27:15:330_R:] OK

[2021-04-26 18:27:19:242_R:] +QMTOPEN: 0,0
[2021-04-26 18:27:19:762_S:] AT+QMTCONN=0,“bg95”,“radinno”,""

[2021-04-26 18:27:19:817_R:] OK

[2021-04-26 18:27:20:345_R:] +QMTCONN: 0,0,0
[2021-04-26 18:27:21:962_S:] AT+QMTCONN?

[2021-04-26 18:27:22:016_R:] +QMTCONN: 0,3

[2021-04-26 18:27:22:016_R:] OK
[2021-04-26 18:27:22:416_S:] AT+CGACT?

[2021-04-26 18:27:22:471_R:] +CGACT: 1,1
[2021-04-26 18:27:22:471_R:] +CGACT: 2,0

[2021-04-26 18:27:22:471_R:] OK
[2021-04-26 18:27:22:917_S:] AT+QMTSUB=0,1,“bg95/mqtt/topic1”,0

[2021-04-26 18:27:22:971_R:] OK

[2021-04-26 18:27:23:843_R:] +QMTSUB: 0,1,0,0

[2021-04-26 18:27:25:126_S:] AT+QMTPUB=0,0,0,0,"bg95/mqtt/topic1"

[2021-04-26 18:27:25:182_R:] > test
[2021-04-26 18:27:28:864_R:] OK

[2021-04-26 18:27:28:864_R:] +QMTPUB: 0,0,0

[2021-04-26 18:27:29:744_R:] +QMTRECV: 0,0,“bg95/mqtt/topic1”,"test"

[2021-04-26 18:32:49:031_S:] AT+QMTPUB=0,0,0,0,"bg95/mqtt/topic1"

[2021-04-26 18:32:49:085_R:] > test1
[2021-04-26 18:32:55:114_R:] OK

[2021-04-26 18:32:55:114_R:] +QMTPUB: 0,0,0

[2021-04-26 18:32:55:683_R:] +QMTRECV: 0,0,“bg95/mqtt/topic1”,"rad1"

[2021-04-26 18:32:57:744_R:] +QMTRECV: 0,0,“bg95/mqtt/topic1”,"test1"

[2021-04-26 18:40:04:125_S:] AT+QMTPUB=0,0,0,0,"bg95/mqtt/topic1"

[2021-04-26 18:40:04:179_R:] > test2
[2021-04-26 18:40:09:543_R:] DSR:0 CTS:0 (RI:1) DCD:0

[2021-04-26 18:40:09:590_R:] OK

[2021-04-26 18:40:09:590_R:] +QMTPUB: 0,0,0

[2021-04-26 18:40:09:642_R:] DSR:0 CTS:0 (RI:0) DCD:0

[2021-04-26 18:40:13:330_R:] +QMTRECV: 0,0,“bg95/mqtt/topic1”,"rad2"

[2021-04-26 18:40:13:869_R:] +QMTRECV: 0,0,“bg95/mqtt/topic1”,"test2"

From the above log, the messages (rad1 & rad2) published from the another client to the BG95 subscribed topic is received only when I publish the message (test1 & test2 ) to the same topic from the BG95 itself, otherwise it took long time to receive the another clients message or not able to receive that message.

In some worst cases, the message published to the topic from the BG95 is also not received by the BG95, even the connection is good.

try this:

in the GNSS application note, find the command to set GNSS/WWAN priority to WWAN.

many network functions are slowed down or broken while GNSS has priority.