mercoledì 9 aprile 2014

Policy and Charging Rules Function (PCRF) and how it reflects on mobile subscribers.

Policy and Charging Rules Function (PCRF) is the software node designated in real-time to determine policy rules in a multimedia network.[1] 

As a policy tool, the PCRF plays a central role in next-generation networks.[2] 
Unlike earlier policy engines that were added onto an existing network to enforce policy, the PCRF is a software component that operates at the network core and accesses subscriber databases and other specialized functions, such as a charging system, in a centralized manner.[3] 

Because it operates in real time, the PCRF has an increased strategic significance and broader potential role than traditional policy engines. This has led to a proliferation of PCRF products since 2008.[4] 

Mobile carriers need PCRF to dictate the rules their subscribers must follow when using the network. These rules could include data allowance, mobility and roaming to name but a few. The Policing and Charging function has been defined both for 3G and Long Term Evolution (LTE) scenarios by the 3rd Generation Partnership Project (3GPP) , and is typically done by a dedicated system with access to subscriber information databases, charging systems and mobile gateways. 

The PCRF is the part of the network architecture that aggregates information to and from the network, operational support systems, and other sources (such as portals) in real time, supporting the creation of rules and then automatically making policy decisions for each subscriber active on the network. Such a network might offer multiple services, quality of service (QoS) levels, and charging rules.[5]

PCRF can provide a network agnostic solution (wire line and wireless) and can also enable multi-dimensional approach which helps in creating a lucrative and innovative platform for operators.[6]

PCRF can also be integrated with different platforms like billing, rating, charging, and subscriber database or can also be deployed as a standalone entity.[6] 

With this software component, mobile carriers have a real-time control on their subscribers as for example they can regulate the maximum permitted speed for data transmission of every registered mobile equipment.

I am facing a clear example of PCRF data speed limitation by my mobile carrier Tim Brazil, in fact my subscribed LTE (4G) line is being forcibly limited to work at a speed of 0.3Mbps in download and upload, whereas it could reach a medium rate of 20 Mbps or beyond, we know that theoretically 4G is capable of the following data speeds:

Peak download: 100 Mbps; Peak upload: 50 Mbps 

In the image below, the result obtained on April 9th 2014 from my mobile equipment, a Nokia Lumia 920: