The present invention relates to an interface unit comprising a first component for establishing a connection to a radio network controller of a radio network sub-system by means of a first communication protocol, a second component for establishing a connection to at least one access point of a wireless local area network by means of a second communication protocol, a third component for converting the second communication protocol to the first communication protocol and for converting the first communication protocol to the second communication protocol and a fourth component for providing data indicative of a load situation of at least one access point to the radio network controller.