SIM card

Tutorial: SIM card

This tutorial describes how you can read out the phone number of the SIM card and control the SIM card by using AT commands.

The AT commands are a set of commands which are used, among other things, to control certain basic commands of the telephone system, such as dialing a number or hanging up.

1. Over which number can I reach my SIM card?

2. Query and configuration of the mobile network provider


1. Over which number can I reach my SIM card?

If you do not have the written documents for your SIM card on hand, it may be helpful to take a look at the SIM card provider's administration portal.

The international name for the subscriber number is Mobile Station International Subscriber Directory Number. Or short MSISDN. Please search for this name.



2. Query and configuration of the mobile network provider

With AT commands you can query and control the mobile connection from the SIM card provider of the mbNET.

In this tutorial the AT command AT+COPS is used.

This AT command knows three formats:

  • AT+COPS?

Returns the current selected network.


  • AT+COPS=?

Provides a list of the available networks currently.

Please note:
This command set the mobile phone module "offline" and takes a longer time to deliver a result. 
The mbNET can not display this result, due to technical reasons.
  • AT+COPS= mode, format, network

Control of the provider choice.


0 = Automatic provider selection (at+cops=0 does not require any further parameters)

1 = Manual provider selection

4 = Preferred provider choice: If the specified network is not available, a different one is searched for



0 = Provider is specified as a character string

2 = Provider is specified via its key figure (MCCMNC).



The desired network, depending on the format, for example

26201 (Telekom) or ""

Please ask your provider for the appropriate information.


Below you can find an example where the AT commands for the provider change were sent by SMS from a smartphone to the phone number of the SIM card:

Please note:
You can only change the provider by AT command if the respective SIM card has the possibility to use another provider. 
You can get this information from your provider.



Revision: V1.0