A method for managing access to a macro mobile operator core network (250) by a guest terminal device (225) through a femto cell (210), and more particularly through a femto cell (210) connected to the Internet (240). When a guest terminal seeks guest access to network services at a site for example while a guest at a person's home, or a customer in a shop, or a traveler in a transportation station, access may be granted by information exchange between the proprietor of the site and the macro mobile operator core network (250). Access may be granted via the proprietor via a terminal device (220) connected wirelessly to the core network, or by any device connected to the Internet. Once access is granted, the guest terminal device (225) receives sufficient information to initiate communication with femto cells (210) in the proximity of the site, and thereby begin using Internet-based communication.