Abstract: The invention relates to a method and a device for setting up connections between communication terminals and data and/or communication networks having wireless transmission links, for example, wireless local area networks (WLAN) and/or mobile telephone networks, and a corresponding computer program and a corresponding computer-readable storage medium, which can be used, in particular, to set up a secure access to WLAN networks.

Abstract: The present invention is directed to a system and a method for roaming in data and/or communication networks, and to a corresponding computer program and a corresponding computer-readable storage medium, which can be used, in particular, to enable users in rapidly moving vehicles to use the Internet. A system for roaming in data and/or communication networks is proposed for clients moving at a high speed, wherein access points (AP) are arranged along the travel route of the clients for providing wireless access to data and/or communication networks, for example the Internet, wherein at least one AP is connected directly via a communication link with the data and/or communication network, and wherein APs without a direct connection to the data and/or communication network are connected to APs that have a direct connection to the data and/or communication network.

Abstract: The invention relates to a method and a system for access to data and/or communication networks via wireless access points, as well as a corresponding computer program and a corresponding computer-readable storage medium, which can be employed, in particular, to enable roaming with mobile terminals between hotspots in the hotspot network of an individual provider and/or between hotspots of different providers. The invention further provides a central support, service and organization center, which includes billing, authentication and accounting systems (BAA). In this way, users of mobile communication terminals obtain standardized, secure, mobile Internet access when changing WLAN hotspots. Existing hotspots are used for access to the Internet. An operator (provider) of a hotspot gains additional customers. Users registered with the BAA system obtain standardized Internet access. In addition to simple access, other value-added services can also be offered. The services are billed via the BAA system.