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Super SIM: Working with Cat-M1 Devices

To get the best experience when using Super SIM with Cat-M1 modems, we suggest that you make the following configuration changes on your devices. These changes will make sure the Cat-M1 modem in your IoT device connects quickly and successfully. We’ve included examples showing you how to make these changes on popular Cat-M1 modems.

If your IoT device uses a regular LTE modem, the following changes do not apply.

Disable NB-IoT

Super SIM does not currently support Narrowband IoT (NB-IoT). If NB-IoT is enabled, a Cat-M1 device will scan all NB-IoT bands, which can take some time, before switching to Cat-M. To minimize the time to connect and avoid wasting power scanning NB-IoT bands, you should disable NB-IoT.

Quectel modules

On the BG96 and BG95 modules, you can disable NB-IoT using the following AT command, which forces the modem to use Cat-M only:


u-blox modules

On the u-blox SARA-R410M-02b, you must first set UMNOPROF to 0 for Super SIM and restart the module:


When the module comes back, you can select the Radio Access Technology (RAT):


Disable 2G

Some modems, such as the Quectel BG95 and BG96, support both Cat-M and 2G. If your modem supports 2G, we recommend that you disable it unless your IoT device can perform optimally on 2G, or Cat-M is not available where you will deploy your IoT device. There is a risk that if the initial connection is made over a cellular network (VPLMN) that does not support Cat-M, your device will instead connect using 2G. It may then stay attached to the 2G network and may therefore be unable to receive over-the-air (OTA) updates from our platform. If 2G is disabled, then the device will only connect over a Cat-M network.

For Cat-M1 devices that don’t support 2G, this is not an issue.

We are actively exploring improvements to our mobile core to deliver OTA updates over 2G.

Quectel modules

To disable 2G on the BG96:


Known issue

Even with 2G disabled, there are some instances where a Cat-M1 device with Super SIM can take up to five minutes to connect. This can occur when the first IMSI presented by the SIM to the modem doesn’t permit it to connect to a Cat-M capable network in a specific region. After five minutes of no service, the SIM will switch to another IMSI and the device should then be able to connect over Cat-M.

There is an OTA campaign in process to update the preferred IMSIs for countries like the US and Australia. Once your SIM gets the OTA update, this issue will be fixed and the SIM will not take the extra time to connect on reboots.

To learn more about Super SIM IMSI switching, please see Super SIM: the Multi-IMSI Applet.

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