EG91 Connection/Authentication Failure with CMW500

Hello Quectel team,

We are currently working with the EG91NAXD and EG91EX LTE Cellular Module in our devices; during our validation processes we are trying to connect the cellular module to a CMW500 R&S equipment, we are using a CMX-Z01 SIM from R&S as well, but we did not get connection between both devices, the process always ends in an Authentication Failure.

Do we need to run an specific AT commands to achieve the connection between the CMW500 and our device


  • Our device has a Main MCU that sends all the AT commands through a UART interface
  • If we use a global SIM we can connect to any carrier.

Your guidance will be greatly appreciated.

Now we are getting a connection between the EG91(with CMX-Z01 SIM) and CMW500 by modifying the LTE signaling configuration, specifically the Network Security Setting → Mileange (disabled) because the CMX-Z01 uses a “XOR” for the authentication algorithm.

Thanks for your feedback, thank you.