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A good illustration of a flexible application that ensures a high customer experience is bandwidth management.  The initial problem can still be seen as a classic network-centric one: CSPs want to ensure that the bandwidth available to users does not become squeezed as a result of excessive use by a minority of subscribers who do not contribute proportionately to revenues, such as heavy peer-to-peer (P2P) download users.  When that situation occurs, the majority of users experience a reduced quality of experience (QoE), which may lead to churn.  This problem is most acute in mobile networks, where bandwidth is clearly limited.

State-of-the-art bandwidth management solutions allow CSPs to monitor usage in real time and, when congestions occur, to dynamically adjust the access for specific services and specific users (at a cell level for mobile operators) to free up capacity. Such a solution is not just about defending the network—it’s about providing the optimum broadband experience for the majority of users.

Policy control solutions can also be used to help subscribers manage their spending, by informing them when certain pre-set, personal credit limits are reached. At first glance, it may seem counterproductive for CSPs to help their subscribers control their spending, but in actual fact, the consequences of a customer receiving an unexpectedly large bill (commonly referred to as “bill-shock”) is likely to be far more damaging to the CSP in terms of churn, bad publicity and liability for interconnect charges (regardless of any settlement reached with the subscriber). Furthermore, this “cost control” feature can be offered as a service, enhancing the personalization of the relationship between the CSP and the customer.

This last example reminds us of the important link between policy control and charging. Together, they allow CSPs to offer differentiated and personalized services to subscribers; and by doing so, balance revenue, customer satisfaction and resource usage from the operator’s point of view.

Increasingly, CSPs are looking to integrate elements of policy control into their offerings. So, for example, an operator might offer a service based on a monthly flat-fee for a fixed amount of $20 for up to 10 GB of usage, with additional usage charged at one cent per 10 MB, capped at $30.  It might offer a fair-usage policy that means, for example, that P2P traffic might be slower at peak times—though a premium package available

This connection with charging is recognised by the 3GPP standard for policy control.  Originally drawn up in the context of IMS (IP Multimedia Subsystem), this standard defines a number of key components, including the Subscriber Profile Repository (SPR), the Policy and Charging Rules Function (PCRF—the part of a policy control solution that makes the decisions), the Policy Control Enforcement Function (PCEF—the part that implements the decisions), as well as the Offline Charging System (OFCS) and Online Charging System (OCS) to handle post and pre-paid charging, respectively.

Many CSPs currently investigating policy control solutions are demanding compliance to the 3GPP and other related standards.  However, policy control deployments typically take place in existing environments, and some compromises need to be made.  For example, a bandwidth management solution could be deployed using existing network capabilities to throttle usage rather than introducing a standards-compliant PCEF.   

It should also be noted that the 3GPP standard is about the logical capability (or functionality), not the physical architecture.  So a 3GPP-compliant implementation need not have separate physical “boxes” for each of the components.  Formally, the OFCS and the OCS are outside the PCRF, but there is no reason according to the standards why they should not be integrated together. In fact, it makes a great deal of sense to integrate them, not least because of the tight logical link between them and the reduced number of interfaces required.

Ultimately, CSPs must not forget that policy control should be about the customer experience and driven by marketing needs, rather than about network issues.  Therein lays the real potential of policy control.