A user equipment is operated in a mobile communications system, wherein a network part of the mobile communications system is capable of operating in a synchronized mode or in an asynchronous mode. Operation includes recording timing information about a periodically occurring signal received from a neighboring cell. The recorded timing information is used in a blind detection process that ascertains whether the network part of the mobile communications system is operating in the synchronized mode or in the asynchronous mode by detecting at least whether the periodically occurring signal received from the neighboring cell occurred within a predetermined window of time of a corresponding periodically occurring signal received from a serving cell. The detected operating mode of the network part of the mobile communications system is used for controlling subsequent operation of the user equipment.