Multi-operator Environment: The Accounting Panacea

We are witnessing a technology shift in telecom networks from the TDM-based
circuit switching to packet switching based technologies like ATM and IP. We are
also seeing a growing emergence of revenue based on service differentiation,
with explosion in demand for the Internet and other data services. However, the
increased data traffic volume is congesting the core and access of traditional
telecom networks, which were optimized to handle calls with an average three
minutes of holding time as against the average holding time of 20 minutes for
Internet sessions.

Next-generation Networks

The above, coupled with the global deregulation, has led to the emergence of
next-generation networks (NGNs), with more and more service providers shifting
towards packet-based networks. VoIP, which was initially considered a threat by
service providers, has gained acceptance and the new networks are considered to
be a step toward fulfilling the promise of multimedia. All this has contributed
to a need for a flexible network that is capable of providing the present and
next-generation services. This is the foundation of ‘network convergence’,
with inter-working of packet-based IP and the traditional switched circuit
networks (SCN) or PSTN networks being the first step toward the ‘next-generation
networks’.

Addressing the Multi-operator Environment

In the new multi-operator environment, operators will like to carry the
maximum traffic through their networks to maximize revenues. They also need
flexible charging plans to address different customer segments.

The flexibility in charging depends on the methodology used for charging
calls and issuing bills to customers. In case of long-distance calls, more than
one operator is likely to be involved–two on the access side and at least one
long-distance operator–with the call revenue shared by operators based on some
mutual commercial agreements. Billing may be performed by either the access
provider or by the NLDO.

CDR-based Charging

The CDR-based charging/billing–successfully deployed worldwide and
supported by all switching technologies using CCS7 signaling deployed in India–provides
the highest level of flexibility to operators.

CDRs can be transferred in near real-time to billing centers by switches for
off-line processing and generation of bills as well as other statistics for
subscribers and other operators.

The charging of calls is difficult to perform in real time in today’s
complex environment. Since CDRs are generated at different points in the
network, the real bills can be computed by off-line processing of CDRs at
billing centers and any operator can issue the bill based on a pre-defined
revenue-sharing formula. Thus, the following advantages appear to emerge:

• Flexibility for operators
• Avoid real-time modification of data at exchanges
• Accuracy of charging
• Meet subscribers’ demands on per call basis
• Easier dispute settlement mechanism between operators
• Data can be used for network QoS (as well as other subscriber statistics) and
  can be determined on per call basis.

Standardization

The European Standardization Institute ETSI’s ‘TIPHON’ project was
established to address inter-operability between SCN and IP networks for voice
applications (as well as related multimedia issues) and has an involvement of
both ITU-T and ETSI (www.etsi.org/tiphon). It addresses various inter-working
scenarios between SCN and IP networks as well as functional layers. ETSI’s
document ETR101 619 serves as a comprehensive reference for inter-operator
accounting and charging in a multi-operator environment.

Niraj K Gupta