Recently I stumbled over this article on the web which says that SIM cards used in GSM and UMTS phones today might soon be extended with a USB interface. Two so far unused pins will be used for the purpose and make the enhancement fully backwards compatible.
A subsequent discussion with a SIM card expert revealed that the new USB 1.1 interface (up to 12 MBit/s transfer rate) can be used in three interface modes:
- Mass Storage: Despite their size, SIM cards can include several megabytes and potentially even gigabytes of flash memory today. In this mode, the mobile device can access the flash memory just like an external memory card today.
- Ethernet Emulation Mode (EEM): In this mode, the SIM card is accessed like a device on an Ethernet (i.e. via IP) and a web server could for example serve local content to the web browser running on the mobile device. Interesting for network operators to deploy SIM cards with content that can be accessed from the device with links to their offerings on the web.
- ICCD: In this mode, all files which are required for GSM/UMTS/IMS/LTE operation can be accessed as over the legacy interface.