Broadcast network with interactive services

摘要

In an interactive broadcast system signals transmitted by a service provider ( 30 ) are passed via a gateway ( 12 ) to a subscriber terminal ( 2 ). In order to gain access to services, the subscriber terminal ( 2 ) transmits an authorization request message via the gateway ( 12 ) to the RADIUS server ( 18 ). This RADIUS server ( 18 ) transmits in response to the authorization request message an authorization challenge message to the subscriber terminal ( 2 ). In return the subscriber terminal responds to the challenge message with a challenge response. This challenge response is checked by the RADIUS server ( 18 ) and if correct, the RADIUS server ( 18 ) transmits a message to the gateway to give the subscriber terminal access to the service.