Detection of whether more than a number N of events have occurred within a duration of time defined by a sliding time window includes performing an event detection procedure in response to each occurrence of an event. The event detection procedure includes associating a timestamp with the event, and determining a value, DeltaTimeStamp, based on a difference between the timestamp associated with the event and an earlier timestamp associated with an Nth previous event. The value DeltaTimeStamp is compared with a value representative of the duration of time defined by the sliding time window, and if a comparison criterion is satisfied then an events detected condition is indicated, wherein the events detected condition is defined as more than the number N of events occurring within the duration of time defined by the sliding time window.