USIM in 5G Era

If you ask anybody what is the name of the card inside his mobile phone, he will for sure answer SIM card, without knowing it is an acronym for Subscriber Identity Module. But, what about the USIM (Universal Subscriber Identity Module)? The USIM plays a key role in the mobile telecommunication services since it brings a host of fundamental features that are now perfected for 5G. This paper gives an overview of the new functionalities offered by the USIM in 5G system including new authentication schemes, subscriber privacy, Steering of Roaming, UE Parameters Update over NAS, and Long Term Key Update Procedure.