A device is provided for operating in a communication system that comprises a plurality of individual networks. The device comprises one or more subscriber modules for assisting the device to attach to a network. The number of those one or more subscriber modules is fewer than the number of the plurality of networks. The device being configured to initiate a pre-attach procedure to attach itself to all of the plurality of networks before it establishes a connection with one of those networks. It is also configured to connect to one of the plurality of networks for communicating data with that network while remaining attached to the others of the plurality of networks. The advantage of a device that pre-attaches to more than one network is that it significantly reduces the time needed for the device to switch later from being connected to one network to another network.