An accounting framework is provided for a communications system having a
plurality of service providers, including cellular service providers
and/or data network service providers, e.g., Internet service providers.
Accounting units containing accounting information are exchanged between
service providers to allow the service providers to charge for usage of
services. The accounting units have a predetermined format to allow them
to be exchanged between different service providers. Each accounting unit
includes a plurality of fields, including a service type field, a usage
of radio interface field, a usage of a visited or external network field,
a usage of mobility management field, a quality of service field, a usage
of a packet data protocol field, and other fields. Users may be charged
for services based on these fields.