Mobile User Equipment (UE) is operated in a first mode in which radio functions are enabled. In response to a predetermined condition, the UE is operated in a power saving mode involving disabling all radio functionality for a first period of time during which no connection is maintained with a cellular communication system serving node. After the first period of time, the UE ascertains whether any attempts were made to contact it during the first period of time and if so whether any of the attempted contacts is characterized by an attribute that matches a predefined attribute. If any of the attempted contacts is characterized by the attribute that matches the predefined attribute, then a user alarm is activated. If the response to the user alarm has been made, then the UE is again operated in the first mode; otherwise, the UE is again operated in the power saving mode.