Guest onboarding of devices onto 3GPP-based networks with use of realm-based discovery of identity providers and mutual authentication of identity federation peers

A Third Generation Partnership Project (3GPP) based network, such as an enterprise private 3GPP network, is operative to provide a guest onboarding of a device using a realm-based discovery of an identity provider and a mutual authentication of identity federation peers. A secure connection may be established between the peers so that the device may be authenticated based on credentials associated with a Subscriber Identity Module (SIM) provided by its Mobile Network Operator (MNO). Credentials may be extended to those associated with embedded SIMs (eSIMs), digital certificates from private enterprises, login and passwords, and identities from a wide range of identity providers. After device authentication, the 3GPP-based network is operative to select and enforce access policies according to an identity or other attribute of the device.