In technological terms, it's possible to present roaming architecture as a means of making it possible to accommodate all the access methods and combinations used by its partners. Central to this is the broker's AAA server (authentication, authorisation & accounting), which processes and passes on user information to the home-service provider.
As far as WLAN access methods are concerned, a distinction can be made between the following technologies and standards:
users identify with user name & password via a browser-based login page or via a locally installed client. This information is passed on from the local radius server to the broker and verified by the AAA server on the home network. The accounting data is collected at origin in the Radius server and passed on transparently to the AAA server via the roaming broker. The broker creates the CDR's and processes these on its billing platform.
users identify with their PIN number on a locally installed client. The coded SIM data is passed on to the home operator and verified in its home location register (HLR) via the broker's authentication server. The accounting information is collected and processed in exactly the same way as the "Radius" procedure.
this system is really a combination between using SIM data for identification and Radius as the protocol. Apart from this, the procedure runs much the same as for the SIM authentication method, with hardware according to the 802.1x standard having to be installed in the hotspot.
Radius:
SIM:
EAP SIM:
