Quectel BG95 BG96 BG77 extended configuration settings

The article provides some best practices for the most commonly used QCFG commands.

This documentation applies to the following products:

• OmniSIM

• Quectel BG95 BG96 BG77

For all other products, please review their respective documentation

Advised settings

The following settings are advised for non-NB-IoT markets:

Ensures LTE and GSM scanning

AT+QCFG="nwscanmode",0

Ensures LTE scanning first

AT+QCFG="nwscanseq",020103

Ensures no NB-IoT scanning

AT+QCFG="iotopmode",0

The following settings are generally advised:

Ignores SIM preference

AT+QCFG="simeffect",0

PS + CS to support legacy SMS

AT+QCFG="servicedomain",2

These settings are persistent and will remain after the module's power cycling.

As the settings are persistent, it is advised to check these regularly and properly document the setting and reasons for the setting.

Read the sections below to understand the above-advised settings.

Introduction

Quectel offers extended configuration settings for the BG series of modules using the AT+QCFG commands. These settings may impact the proper working of the KORE OmniSIM.

Examples include:

• In some cases, the attach time of the KORE OmniSIM Reach may be impacted by the fact that the module scans all the NB-IoT bands.

• A network combined attach is necessary for proper legacy SMS support.

This note is intended is to provide some best practices of the most common used QCFG commands.

Background

Scanning NB-IoT bands can consume a lot of time, especially when NB-IoT is unavailable locally. During that scan period, the module can be busy and not be responsive for renewing IMSIs as requested by the SIM. This does not affect the Multi IMSI selection process, as the SIM is not getting information from the module, it will wait with switching IMSI, but it will extend the time it takes to attach.

It could be the case that the module accepts new IMSIs from the SIM but cannot start an attach as the scan time is too long.

SMS is supported worldwide by C7 signaling, often called Circuit Switched. The device must request Packet Switched + Circuit Switched connection to force a combined network attach to support C7 signaling.

Checking the settings

Scan mode

Check using the following AT command:

AT+QCFG="nwscanmode"

The module will reply with one of the following modes:

0. Automatic (GSM and LTE)
1. GSM only
2. n/a
3. LTE only

Depending on the market or region, it may be advised to set the scan mode to GSM only or LTE only.

Example: All 2G and 3G networks will be shut down in the USA at the end of 2022. GSM scanning is of no use.

Note: New scan mode is not applicable for BG77 (LTE only).

Scan Sequence

Check using the following AT command:

AT+QCFG="nwscanseq"

The module will reply with one of the following modes:

00. Automatic (eMTC -> NB-IoT -> GSM)
01. GSM
02. eMTC
03. NB-IoT

Depending on the market, it may be advised to set the scanning order.

NB-IoT scanning always takes more time. However, if NB-IoT is preferred, it is advised to set the order accordingly.

Scanning NB-IoT

Check using the following AT command.

AT+QCFG="iotopmode"

The module will reply with one of the following modes:

0. eMTC
1. NB-IoT
2. eMTC and NB-IoT

As NB-IoT scanning takes more time, it is advised to disable NB-IoT scanning in markets where NB-IoT is not available.

Preferred Access Technology

Check using the following AT command.

AT+QCFG="simeffect"

AT+QCFG="simeffect"

The module will reply with one of the following modes:

0. Disable
1. Enable

KORE OmniSIM is not equipped with any access technology preference. However, to avoid confusion, it is advised to disable this feature

Legacy SMS support

Check using the following AT command.

AT+QCFG="servicedomain"

The module will reply with one of the following modes:

1. PS only
2. CS & PS

Although it sounds not logical to use PS+CS, it should be noted that this setting determines the back-end of the networks, not the radio access. This setting doesn’t force the device to use 2G/3G technology.

Default settings

BG77 - Default settings

Quectel BG77

The following are the factory configuration setting of the BG77 module

AT Command	Expected Result
AT+QCFG="nwscanmode"	+QCFG: "nwscanmode", ERROR
AT+QCFG="nwscanseq"	+QCFG: "nwscanseq",00
AT+QCFG="iotopmode"	+QCFG: "iotopmode",2
AT+QCFG="simeffect"	+QCFG: "simeffect",1
AT+QCFG="servicedomain"	+QCFG: "servicedomain",2

BG95 M3 - Default settings

Quectel BG95-M3

The following are the factory configuration setting of the BG95 module

AT Command	Expected Result
AT+QCFG="nwscanmode"	+QCFG: "nwscanmode", 0
AT+QCFG="nwscanseq"	+QCFG: "nwscanseq",00
AT+QCFG="iotopmode"	+QCFG: "iotopmode",2
AT+QCFG="simeffect"	+QCFG: "simeffect",1
AT+QCFG="servicedomain"	+QCFG: "servicedomain",2

BG96 - Default settings

Quectel BG96

The following are the factory configuration setting of the BG96 module

AT Command	Expected Result
AT+QCFG="nwscanmode"	+QCFG: "nwscanmode", 0
AT+QCFG="nwscanseq"	+QCFG: "nwscanseq",00
AT+QCFG="iotopmode"	+QCFG: "iotopmode",2
AT+QCFG="simeffect"	+QCFG: "simeffect",ERROR
AT+QCFG="servicedomain"	+QCFG: "servicedomain",2