BG95 can't activate PDP Context

IoT Modules LPWA Module
1

I don’t know why, but sometimes, my BG95-M3 cannot activate the PDP context.

Infos:
My SIM card supports only EGPRS.

The steps I’m making trying to activate it are the following:

  1. I’m setting the AT+QCFG=“nwcanmode” to 1, i.e.: GSM only.
  2. I’m ensuring that CREG gives the Reg Status 5 or 1.
  3. I’ve checked that we are attached to PS, via AT+CGATT=1
  4. Then, I configure the PDP Context using AT+QIGSGP=1,1"myapn.com","myuser,“mypasswd”. The command returns ok. And I can see the context when I query AT+QICSGP=1.
  5. I check ATQIACT? And it returs nothing (expected, right? Since I’ve not tried to activate it yet)
  6. When I issue the command AT+QIACT=1, I got ERROR.

I’ve tried to restart the module and issuing AT+QIDEACT=1 before trying to activate the context, but none of these have worked.

The (strange) thing I’ve done that sometimes seems to work is:

  1. I set the AT+QCFG=“nwscanmode” to 3 (LTE only).
  2. BG95 stays on a “No Service” status when I query the network info via AT+QNWINFO.
  3. I force a software restart on the module by sending AT+CFUN=1,1.
  4. The module starts and the MT rejects the registration, since my sim card does not support this technology.
  5. I switch back to AT+QCFG=“nwscanmod”, 1 (GSM only).
  6. The module automatically changes to a valid GSM network, with AT+CREG equal to 1.
  7. I’m finally able to connect the PDP context by AT+QIACT=1.

But I’m not sure if this is a realiable procedure, if it will work always or not.

I would like an expert opinion on this. Is it possible that this issue is SIM Card or Operator-related?

What is the safest and guaranteed way to properly activate a PDP context?

2

Can you provide a complete AT log？

3

Some tips as a fellow user:

  • For GPRS registering, check with “AT+CGREG”, instead of “AT+CREG?”
  • Other thing that can help is to send the command “AT+CMEE=2”. It will make some errors more verbose.
  • Can you send the command “AT+COPS=?”, wait the module response (it can take some seconds) and post here? It could be a network/antennae issue, not a module issue.
  • On GPRS, you need to configure APN/user/password only before PDP activation, but on LTE, you need to configure before registering.
  • Did you try to configure AT+QCFG=“nwscanmode”,0 (automatic?). Maybe the module try to register on LTE first, but go to GPRS automatically in sequence.