User equipment for use in a wireless network, the wireless network including a first radio access network supporting communication using a first radio access technology in first service areas and a second radio access network supporting communication using a second radio access technology in second service areas, the user equipment having a capability to communicate using the first radio access technology, and a capability to communicate using the second radio access technology that may be disabled or enabled, wherein the user equipment is arranged to disable the capability to communicate using the second radio access technology in response to a determination that a preferred mode of voice communication cannot be provided using the second radio access technology in a said second service area, and wherein the user equipment is arranged to enable the capability to communicate using the second radio access technology, on the basis of communications, using the first radio access technology, in a selected one of said first service areas.