The Radio Resource Control (RRC) protocol belongs to the UMTS WCDMA

W-CDMA (UMTS)

W-CDMA , UMTS-FDD, UTRA-FDD, or IMT-2000 CDMA Direct Spread is an air interface standard found in 3G mobile telecommunications networks. It is the basis of Japan's NTT DoCoMo's FOMA service and the most-commonly used member of the UMTS family and sometimes used as a synonym for UMTS...

 protocol stack and handles the control plane

Control plane

In routing, the control plane is the part of the router architecture that is concerned with drawing the network map, or the information in a routing table that defines what to do with incoming packets. Control plane functions, such as participating in routing protocols, run in the architectural...

 signalling of Layer 3 between the UEs

UE (wireless telephone)

In the Universal Mobile Telecommunications System and 3GPP Long Term Evolution , user equipment 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...

 (User Equipment) and the UTRAN

Utran

Utran is a census town in Surat district in the Indian state of Gujarat.-Geography:Utran is located at . It has an average elevation of 12 metres .-Demographics:...

. It includes:

• Functions for connection establishment and release,
• Broadcast of system information,
• Radio bearer establishment/reconfiguration and release,
• RRC connection mobility procedures,
• Paging notification and release,
• Outer loop power control.

There can only be one RRC connection open to a UE at any one time.

RRC inactivity timers

The configuration of RRC inactivity timers in a W-CDMA network has considerable impact on the battery life of a phone when a packet data connection is open.

The RRC idle mode (no connection) has the lowest energy consumption. The states in the RRC connected mode, in order of decreasing power consumption, are CELL_DCH (Dedicated Channel), CELL_FACH (Forward access channel), CELL_PCH (Cell Paging channel) and URA_PCH (URA Paging channel). The power consumption in the CELL_FACH is roughly 50 percent of that in CELL_DCH, and the PCH states use about 1-2 percent of the power consumption of the CELL_DCH state.

The transitions to lower energy consuming states occur when inactivity timers trigger. The T1 timer controls transition from DCH to FACH, the T2 timer controls transition from FACH to PCH, and the T3 timer controls transition from PCH to idle.

Different operators have different configurations for the inactivity timers, which leads to differences in energy consumption . Another factor is that not all operators use the PCH states .

See also

• Radio Resource Management
  Radio resource management
  Radio resource management is the system level control of co-channel interference and other radio transmission characteristics in wireless communication systems, for example cellular networks, wireless networks and broadcasting systems...
  
  
• Mobility management
  Mobility management
  Mobility management is one of the major functions of a GSM ora UMTS network that allows mobile phones to work. The aim of mobility management is to track where the subscribers are, allowing calls, SMS and other mobile phone services to be delivered to them....
  
  
• Radio Network Controller
  Radio Network Controller
  The Radio Network Controller is a governing element in the UMTS radio access network and is responsible for controlling the Node Bs that are connected to it. The RNC carries out radio resource management, some of the mobility management functions and is the point where encryption is done before...
  
  
• UMTS
• WCDMA