The charging model in telecommunications networks has evolved greatly in the last years. The original model in legacy fixed telephony networks was in most cases quite simple: the price of the communication depended on the destination, time, and duration of the call. With the emergence of mobile and multimedia networks, the charging model became more complicated. More and more frequently, a subscriber is able to choose between a variety of options on top of the standard tariff. Each option is then applicable to a certain kind of traffic only. The goal of this article is to study how these new charging models impact the technology of online charging systems.
