A method and system for providing telecommunication services to a mobile-subscriber terminal roaming between private and public-wireless networks is disclosed. After roaming from the public-wireless network into the private-wireless network, for example, an entity in the private-wireless network executes an application that retrieves from a roaming-agreement database roaming-agreement information for operating the mobile-subscriber terminal in the private-wireless network. Using this information as an input, the application may determine one or more roaming rules for operating in the private-wireless network.