Patent claim: A method of locating the position of a mobile communications device which communicates with a communication network using wireless signals the method comprising detecting wireless signals transmitted between the mobile communications device and a base station and retrieving identification information for the mobile communications device conveyed by the wireless signals and storing said identification information in association with data indicative of a location associated with the base station in a database which is independent from the communication network.

Related passage: Accordingly details of a triggering event which is to be notified to a network application is received.This triggering event is a registration of user equipment within a particular femto cell of a wireless telecommunications network.Such registration of user equipment may comprise registration information exchange between the user equipment and the femtocell required for a handover to the femtocell in active mode or for camping of the user equipment on the femtocell in idle mode.From this triggering event triggering information is then provided to the femto base station which provides communications coverage to the particular femto cell at the location of interest and this triggering information causes the femto base station to provide a trigger notification which indicates when the registration of the particular user equipment occurs within the femto cell thereby indicating the presence of the particular user equipment at a location of interest.When a trigger notification is received from the femto base station location information is provided to the network application which provides the network application with an indication of when a trigger event occurred together with details of the particular user equipment and femto cell where the registration occurred.Through this approach details of triggering events to be notified to an application may be defined.This information is then passed on to the femto base station of interest.When the user equipment registers with that femto base station a notification is provided.That notification may then be used to provide an indication of when a trigger event occurred together with which user equipment and femto base station the event related to.This enables the movement ofuser equipment into specific locations to be detected and provided to network application efficiently without any subsequent location determination processing having to occur.A precise determination of the location of the user equipment can be made because the coverage provided by a femto cell is typically in the range of tens of metres or less.Accordingly this approach is significantly more accurate than the triangularisation technique even when there is connectivity with just one femto base station.Furthermore registration with a femto base station can occur even when the user equipment is idle and so mobility events can be detected without the user equipment needing to operate in the active mode thereby saving power.Furthermore the registration of user equipment with base stations is a standard user equipment feature requiring no additional functionality to be provided and so this technique will work with standard user equipment unlike the GPS approach which requires additional functionality.Also unlike the GPS approach a femto cell will typically provide coverage within buildings.Hence a lowpower scalable accurate and noninvasive approach which requires no modification of user equipment is provided which enables the location of the user equipment to be readily determined and that information provided to network applications for use with usersubscribed services.