Using a Linux system with lsusb and modemmanager , you dump the modem’s QMI (Qualcomm MSM Interface – ironically, Intel uses a similar protocol) or MBIM (Mobile Broadband Interface Model) descriptors. The IMEI is buried in the NVM folder.
Общая тема по модемам Fibocom L8x0-GL - 4PDA fibocom l850gl change imei