When it comes to SIM cards, we often “set it and forget it”. Unless you do a lot of travel overseas, chances are that the SIM card is popped in the moment you purchase a new smartphone and isn’t touched again throughout the life of the device. However, that SIM card — even tiny Nano SIMs — can take up a valuable space in a smartphone’s frame.
ARM,

Source: Hot Hardware – ARM Wants To Integrate A SIM Card Into Your Future Smartphone’s Processor