In the Universal Mobile Telecommunications System (UMTS) and 3GPP Long Term Evolution (LTE), user equipment (UE) is any device used directly by an end-user to communicate.
It can be a hand-held telephone, a laptop computer equipped with a mobile broadband adapter, or any other device.
It roughly corresponds to the mobile station (MS) in GSM systems.
The radio interface between the UE and the Node B is called Uu.
In the context of UMTS (Universal Mobile Telecommunications System), Uu stands for the interface between UTRAN (UMTS Terrestrial Radio Access Network) and the UE (User Equipment).