What is Radio Network Controller?

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The Radio Network Controller is used to control the base station in 3G.

The Universal Mobile Telecommunications System is an evolving technology.

We have evolved through three cellular systems; the first generation (GSM), second-generation (2G), and now the third-generation (3G) cellular system.

You may be wondering, what is a radio network controller? Well, not to worry. In this article, we’ll be guiding you through all you need to know about RNC.

In the first generation, a central device was used to control the base stations. And the base station controller was used in 2G.

These controllers were responsible for connecting radio links to wireless devices through the base stations.

However, the RNC does more than just connecting and increasing the quality of services.

Without further ado, here’s all you need to know about the third-generation Radio Network Controller.

What is Radio Network Controller?

A Radio Network Controller is a major component in the UMTS Radio Access Network, controlling several Node B’s connected to it.

The RNC is also responsible for a couple of mobility management functions. Serving as a center of encryption without which the transfer of user data from the mobile would be impossible.

How does it work?

The RNC allocates the resources needed in the Radio Network System. The management of radio resources is a function of the RNC.

When you set up a Mobile Originated Call (MOC), the connection is going to be initiated by the User Equipment.

The User Equipment is notified after the radio network controller has made the required resources available.


  • The User Equipment is made up of two components – the Mobile Equipment and the UMTS Subscriber Identity Module that confirms the authenticity of a user.
  • These components serve as access constituents to the NodeB via the Air Interface that connects the user to services of other networks.
  • The NodeB’s are then controlled and managed by the RNC that ensures adequate resources like voice and data to the User Equipment.
  • The NodeB receives signals from the User Equipment and forwards these signals back to the next user in the network.
  • The Iub interface connects the NodeB to the RNC effectively.
  • The NodeB implements the Radio Access Technology that is used to access the network.
  • In the 3G Radio Access Network the Wideband Code Division Multiple Axis serves as the RAT and is based on coding.
  • The NodeB allocates the different codes to users based on how they’ll be separated on the network because the WBCDMA provides the same frequency and time.
  • The RNC then connects the RAN to the Core Unit, which consists of the Public Switched Telephone Network that connects you to Internet services

For more understanding, watch this video;

Benefits of Radio Network Controller System

The functions of the RNC are similar to that of the Base Station Controller in 2G systems.

The prime functionality of the RNC is to control the number of Node B’s attached to it.

However, the RNC is also responsible for several other operations in the RNS.

Here are some of the benefits of the RNC System;

01. Radio Resource Management

The RNC provides the radio resources to the User Equipment unit and forwards that management to Node B and finally to the user.

The end-user gets easy access to Radio Resources through the management process of the RNC.

02. Employing Protocols for UMTS Network

The RNC is also responsible for employing some important protocols for the UMTS network. These protocols include;

Radio Resource Control (RRC)

The RRC is the unit that governs connection. The connection setup, establishment, and release of such connections are controlled and implemented by the RNC.

The RNC allocates the radio resources to various points of functions where they are needed in a Radio Network System.

Thereby facilitating the setup of these functions.

Radio Access Bearer (RAB)

The RAB is responsible for transporting signals across the network, which improves the Quality of Services that the users will experience.

While the RRC is responsible for the control of connections and functions, the RAB, however, conveys the required information to users.

03. Administration Control

Admission control is a form of validation check that confirms that the resources provided to the User Equipment are adequate.

The RNC ensures that users get the right amount of information they’ve requested while using wireless services.

04. Implementation of iu Protocols

The RNC aids the connection of the RAN to the Core Network using the iu protocols.

This RNC serves as an intermediary between the components of the RAN and the Core Network, as the RNC is connected to the Circuit Switch Domain and the Package Switch Domain.

05. Drift-RNC

When a cell controlled by an external RNC creates a connection between the Service RNC (SRNC) and User Equipment, a DRNC exists.

Generally, the DRNC functions as a switch that transfers information between the UE and the SRNC.

FAQ’s of Radio Network Controller

Q: What is the difference between a BSC and RNC

A: The BSC is the Base Station Control used in the 2G cellular system.

It is responsible for the control of Base Transceiver Stations (BTS) in a telecommunication system, while the RNC is used in the third generation telecommunication system.

Q: What is the function of the eNodeB?

A: The eNodeB is an evolved version of the NodeB used in LTE. eNodeB simply stands for Evolved Node.

It is a component of the E-UTRAN that allows User Equipment to connect to the LTE network.

Q: What is the SGSN used for?

A: The SGSN is used to deliver data packets within its geographical service area to and from mobile stations.

Q: What is the IuPs interface?

A: The interface between the RNC and the SGSN is known as the IuP interface.

It is responsible for accessing the World Wide Web in the UMTS.

Q: Why do you need an Iu Interface?

A: Iu interface is used to carry voice and data, and other control information in a telecommunication system.


The RNC an equivalent to the Base Station Controller used in GSM. Without this component, the transfer of signals to User Equipment will be impossible.

The Radio Access Network of 3G systems will fail to circulate data effectively without the proper setup of the RNC.

RNC is a crucial component of the RAN. It connects the RAN to the Core Unit of the UTMS.

Since the introduction of the LTE, the use of the 3G Radio Access Network is slowly creeping away.

However, the 3G services still come in handy when you’re located on the cell edge of the LTE coverage –  giving you unlimited access to the internet.

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