A method of tracking user terminals in a mobile communication network includes, at a tracking node, determining that a user terminal is located in a first tracking area, storing data associated with the first tracking area, the data comprising a number of observations of all user terminals at the first tracking area at a first time, receiving a page response from the user terminal located in one of the first tracking area and a second tracking area, and in an event that the user terminal remains located at the first tracking area, updating the data to include a number of page responses received at the first tracking area after a first time interval, and in an event that the user terminal is located at the second tracking area, updating the data to include a number of page responses received at the second tracking area after the first time interval.