Method for improved memory utilization of NB-IoT UE with integrated subscriber identity module during provisioning

A method for improving memory utilization of a Narrowband Internet of Things device (UE), the UE comprising a modem and an integrated Subscriber Identity Module (iSIM), the modem and the iSIM comprising respective dedicated memories and both combined on a modem chip, the method comprising:

• switching the modem to a provisioning mode and allocating parts of the dedicated memory of the modem exclusively to the iSIM to reduce memory footprint of the iSIM during provisioning of the iSIM on the modem chip of the UE, and the modem is not accessible to the allocated parts of the dedicated memory of the modem during the provisioning mode;
• reusing, by the iSIM, the allocated parts of the dedicated memory of the modem for processing provisioning data;
• securely cleaning up the allocated parts of the dedicated memory of the modem by overwriting the allocated parts of the modem memory with random data by means of an XOR mask by a protection hardware block after leaving the provisioning mode;
• and
• allocating the parts of the dedicated memory of the modem shared with the iSIM back to the modem.