Policy and Charging Rules Function

This product was added to computer science because of the content, defects on the quality assurance side of the editor. This is done to bring the quality of the articles from the computer science subject area to an acceptable level. Help us to eliminate the substantive shortcomings of this article and take part you in the discussion! ( )

Policy and Charging Rules Function ( PCRF ) refers to an element in telecommunication data networks. It decides in real time based on rules which service quality is to be ensured for data connections, and how that traffic is to be settled.

Operation

For this, the packet gateways, the network elements be responsible for the actual user traffic, controlled according to generally have a diameter protocol for each connection in the construction and in due course, for example by specifying the bandwidth ( uplink and downlink bit rate ). A PCRF usually has more interfaces to user databases and online charging systems. It is positioned in the internal control systems of the telecommunications network operator.

The PCRF is, inter alia, in relations with PCC ( Policy and Charging Control), PCEF ( Policy and Charging Enforcement Function), QCI (Quality of Service Class Identifier).

Areas of application

As part of the IP Multimedia Subsystem (IMS ) a PCRF as temporarily increasing the bit rate for a voice or video call is the application servers as a control point for influencing the quality of service. This application plays in Evolved Packet System of Long Term Evolution in connection with VoLTE (Voice over LTE ) are more important and often requires the use of a PCRF. Here, the QCI necessary and PCEF is connected via Gx interface. The former identifies the necessary quality of service and final sets this to the network by or prevents this ( gating function in the interaction of the PCRF ).

Other typical applications include fair-use rates, here the user is restricted to a maximum volume about after reaching a monthly commitment to a small bandwidth. The PCRF may further classification (by volume, by time, one-time amounts) enable users. The PCRF can to interact with the OCS online charging system and request a certain amount of data, for example, within a session and monitor its consumption. If the volume is consumed, the session remains active, the PCRF calls for a new release for volume that ensures OCS that is no longer used, as can be utilized by the balance on the account. The same applies for the other Vergebührungsleitsätze (time, volume tariffs, non-recurring amounts, or combinations thereof ). Here are the PCC and PCEF active.

Recent developments in the 3GPP PCRF Interfaces to take scope DPI (deep packet inspection, TDF: traffic detection function ) and for application-specific traffic control with, as well as interfaces to external application providers. Furthermore, the interface Sy is further standardized to the OCS. Currently called the interface to the user database Sp and is not further specified. In newer versions of the 3GPP standards here Ud is called as replacement of Sp.

The interface from the PCRF to the Application Server ( or the application function AF) is called Rx. The interface from the PCRF to the PCEF called Gx.

Standardization

PCRF and the associated interfaces to be standardized, and further developed by the 3rd Generation Partnership Project (3GPP ).