Mobile devices, network nodes and methods of operating the same According to one aspect, there is provided a method of operating a mobile device that is configured for use in a first radio access network that uses a first radio access technology and a second radio access network that uses a second, different, radio access technology, the mobile device aggregating a plurality of carriers in the first radio access network, the method comprising obtaining information for, or pertaining to, one or more of the plurality of carriers in the first radio access network (101); and processing the obtained information for a single carrier to determine an action for the mobile device to take with respect to the second radio access network (103).