Method performed by a communication device (10) for handling communication in a communication network comprising at least a first wireless communication network (11) and a second wireless communication network (14), which communication device (10) is served by a radio network node (13) in the second wireless communication network (14). The communication device (10) performs a preparation signaling, via the radio network node (13) and transparently through the second wireless communication network (14), to a first network node (12) of the first wireless communication network (11) for preparing the first network node (12) with a pre-configuration for serving the communication device (10).