New Face Of Purchasing

Online Charging System for IMS provides convergence between
prepaid, post paid, voice, data, fixed, and mobile

Mobile
operators have begun introducing IMS networks. A new challenge now is to profit
from the wealth of newly enabled services. Voice and SMS are already the most
popular and mature data services and more of such kinds are growing in
popularity. This new environment demands flexible charging capabilities—for
content, with third parties, and for IMS value-ads such as presence-based and
conference services. It also demands real-time rating and service control so
that operators may interact with consumers and play a more significant role in
the 'call experience.' Hence, there is a belief among industry experts that
over time all calls and data sessions will require real-time control and
charging capabilities. This scenario demands far more of a charging system-it
must be smarter, faster, immensely scaleable, and absolutely reliable-at the
same time very cost effective.

Business Challenges in IMS Charging

IMS is an access and network-independent IP architecture that enables
inter-working between existing voice and data networks providing multimedia
services for both fixed and mobile users. Considering IMS as a vehicle for
service convergence, operators need to support it through truly convergent
systems. It also demands a range of functions and capabilities that can only be
provided by an advanced charging system-the key elements of which are outlined
below.

Network Independence

Traditionally, operators have developed or adopted charging systems designed
to support specific services or networks. In the case of incumbents, complex
businesses have often been supported by a vast range of disparate systems, each
dedicated to a particular functional area. IMS having one of the core features
as network independence expects a charging system that can mediate and hence,
rate and bill for any combination of voice, video, and data services across any
type of network.

Flexible Rating and Discounting

With the advent of more sophisticated, content-rich services, comes a need
to provide flexible pricing. Sessions involving streamed music purchases,
video-conferencing sessions, and interactive games will all be priced by
different measures. The rating engine must be able to handle all existing
pricing criteria and support rating of newer services that emerge in the future.

Apart from the above,
there is a need for a real-time processing infrastructure required to deliver
pre-and postpaid convergence. In this all the subscribers must have access to
the same services, price models, offers, and roaming facilities. For this the
charging system must offer full support for real-time transactions, including
the ability to check credit balances, charges, discounts, loyalty points, and
provide authorization in real time before the service can be accessed. For
example, in case of creating a single account for a family, with the ability to
create 'sub accounts' or in case of online purchasing, scenarios are
difficult with today's charging solutions, both prepaid and postpaid. All of
these involve some form of 'convergence', which is an inherent capability of
an online charging system.

Online Charging System

The system is a modular, configurable, and converged solution for both
service control and charging. This solution can collect usage data or
authorization requests

from virtually any source including all the major real-time standard interfaces
for both voice and data, fixed and mobile, prepaid and postpaid. In IMS, the
convergence is across payment, technology, mobility, and service lines.

To support
sophisticated new data services the solution collects critical usage data from
virtually any network or service element. The core part of an online charging
solution consists of the following flexible components:

• Predefined
  Service Logic: This comes with a rich set of real-time charging tools,
  which include Bearer Charging, Session and Event Charging functions. It also
  includes a service creation environment that allows fast, easy and
  inexpensive creation of new service flows.

• Event Charging
  Function (ECF): The event charging with unit reservation is suitable
  when the required amount of resources is not known prior to the use of a
  specific service (e.g. duration of the conference). The amount of resources
  could be time or allowed data volume.

• Session
  Charging Function (SCF): The SCF is intended to perform charging
  according to session resource usage. The SCF controls session establishment
  by allowing or denying session establishment after checking the user's
  account. In addition, it also terminates an existing session when the
  user's account is empty.

• Bearer Charging
  Function (BCF): The BCF controls bearer usage (e.g., in terms of time or
  traffic) in case of GPRS.

• '3rd
  generation' Advanced Rating Engine: The rating engine has rules-based
  machinery that incorporates tables and user functions to optimize
  flexibility, speed and maintainability. The rating engine is designed
  recognizing that pricing and charging must be not only operationally
  efficient but also technically efficient in the IMS world.

• Fast and
  Efficient In-memory Database:  A
  fully distributed and fault-tolerant implementation of an in memory database
  (storing customer related information) will allow online charging system to
  provide real-time replication, excellent throughput, scalability, and thus,
  a very low cost per transaction.

• Benefits: Online
  charging system addresses the billing concerns of operators. The benefits
  can be summarized as follows:

• Strategic:
  
              »
  Provides a modular approach for service creation and deployment.
  
              » Fully
  comply with IMS technology. 

• Commercial:
  
              »
  Processes all chargeable events in real time.
  
              » Fraud
  is limited and minimized by controlling the amount of activity for all
  subscribers.

Online charging system
provides convergence between: prepaid and post-paid, voice and data, and fixed
and mobile. 

Flexibility is a key
in today's rapidly changing services environment and especially for IMS.
Online charging system is the best option to provide real-time processing
platform ensuring reliability coupled with real-time performance. This enables
better performance than traditional off-line billing systems.

Prasad BV Satyanarayana,

HP OpenView Research & Development Team


vadmail@cybermedia.co.in