An improved Narrowband Internet of Things device (UE) supporting resource sharing for integrated Subscriber Identity Modules (iSIM) is provided. The cost per UE is reduced by reducing the chip area and energy consumption of an integrated UICC chip therein since identical components of the modem and the iSIM are designed as shared components, whereas a hardware arbiter manages an access to THE shared components by the modem or the iSIM and prevents information leaking.