Arm Kigen OS – most cellular devices rely on SIM cards, and while with micro and nano SIM, the card has become smaller the electronics and connection remains the same. More recently, we’ve started to see boards featuring eSIM (embedded SIM), a chip soldered directly to the board that’s remotely provisioned by a local mobile network operator, so no more card needed, and the chip should not be tied to a single operator, so you can change plan whenever you want
