Communication between a fixed network and a movable network with means for suspending operation of the moveable network

A satellite telephone system for communication between a fixed network (4) and a moveable network (1) on board a vehicle, has means for suspending operation of the moveable network, for example when the moveable network could interfere with a fixed network, during safety-critical stages of a flight, or to enforce "quiet" periods on board. When operation of the moveable network (1) is suspended a control signal is transmitted to the fixed network (4), causing the fixed network (4) to intercept calls directed to the moveable network, thereby avoiding unnecessary signal traffic over the satellite link (3, 6, 13). The moveable network may be a wireless network (FIGS. 1, 2), or a wired network (FIG. 4).