ABSTRACT
Next generation networks (NGN) services are assumed to be a new revenue stream for both network operators and
service providers. New services especially focused on a mobile telecommunications that would be used not only as a
communication de vice but also as a personal gateway to order or consume a variety of services and products [1]. This
type of advanced services can be accomplished when the adaptability of the packet-networks (Internet) and the
quality of service of the circuit switched networks are combined into one network [2]. New challenges appear in the
billing of this heterogeneous multi services network. Some examples of such a services and possible solutions about
charging and billing are examined in this paper. The first steps of mathematical model for billing are also
considered.
Keywords: AAA, Charging, NGN, Service Creation, UMTS