Pre-paid Schemes Considered Harmless for All-IP Networks

Burkhard Stiller
University of Zurich and ETH Zurich, Switzerland

Future all-IP networks will support a variety of high-value IP-based 
services including the upcoming integration of today's non-IP services 
offered by mobile telecommunication providers. Besides post-paid 
charging, pre-paid charging will play an important role in all-IP 
environments due to the financial control of providers and customers, 
thus, determining effective economic management means for Internet 
services. Therefore, the enhancement of service management functionality 
by such economic mechanisms determines one important area of research, 
especially since the support of such mechanisms within an Internet 
without any business-related restrictions is essential for the 
provisioning of open standards and technology.

Since existing pre-paid charging solutions do not meet key all-IP 
requirements imposed, a novel approach termed TICA (Time Interval 
Calculation Algorithm), including three algorithmic variants has been 
developed. TICA introduces the concept of service bundles which are 
composed out of different services. For consecutive time intervals, TICA 
estimates the maximum resource consumption of a vector of any 
pre-determined and service-related parameters, e.g., available from an 
accounting system. While the time is divided into intervals, the 
resource estimation is performed by TICA. Finally, TICA calculates the 
maximal charge for all services of that service bundle, yielding the 
total maximal charge per service bundle in that time interval under 
consideration.

To show TICA's optimized performance for many service mixes foreseen, a 
thorough evaluation has been performed, being based on different 
scenarios. Additionally, comparing TICA's overall performance with 
existing online charging solutions yields TICA's promising results in 
terms of a way smaller quantity of credit checks required and smaller 
financial risks for providers to be achieved. Finally, the three 
different TICA algorithmic variants reveal a clear sensitivity to input 
parameters defined. These findings indicate that a number of suitable 
parameter settings can be used by today's Internet Service Providers 
already. Thus, TICA determines a valuable extension to current service 
management approaches.