UTRAN typically refers to the radio access network used in the context of Universal Mobile Telecommunications System (UMTS), which is a 3rd generation (3G) mobile communication system. UMTS is one of the technologies under the International Mobile Telecommunications-2000 (IMT-2000) standard developed by the International Telecommunication Union (ITU).
Components of UTRAN:
Node B (Base Station): In UMTS, the base station is known as Node B. It is responsible for the radio transmission and reception to and from the mobile station (user equipment). It connects to the radio network controller (RNC) via the Iub interface.
Radio Network Controller (RNC): RNC is a key element in UTRAN. It is responsible for radio resource management, mobility management, and handovers. The RNC communicates with multiple Node Bs and manages their resources.
Iub Interface: This interface connects the Node B to the RNC. It carries control and user plane traffic between the RNC and Node B.
Iu Interface: This interface connects the RNC to the core network. It is responsible for connecting the UTRAN to the circuit-switched core network (CS-CN) and the packet-switched core network (PS-CN).
Functions of UTRAN:
Radio Resource Management (RRM): UTRAN manages the allocation of radio resources to the user equipment (UE) efficiently. This includes functions like power control, admission control, and load balancing.
Mobility Management: UTRAN handles the mobility of the UEs, ensuring seamless handovers between different cells and radio network controllers.
Call Control and Session Management: UTRAN is responsible for setting up and releasing connections, managing the quality of service, and handling session-related signaling.
Encryption and Integrity Protection: UTRAN provides security functions such as encryption and integrity protection to ensure the confidentiality and integrity of user data.
Evolution to LTE and Beyond:
With the evolution of mobile networks, Long-Term Evolution (LTE) and later technologies (such as 5G) have become prominent. These technologies have introduced new architectures and terminologies, replacing UTRAN and evolving towards more advanced and efficient radio access networks.
