Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Design and Modeling Billing solution to Next Generation Networks   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.

27
The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
21
The categories of this paper are: adap-org
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
26
The categories of this paper are: bayes-an
25
The categories of this paper are: patt-sol
34
The categories of this paper are: chem-ph
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
30
The categories of this paper are: q-alg
8
The categories of this paper are: hep-ex