against known sources of data within the network the verification process also measures the frequency of exceptions generated and if needed can take a decision to request data collection to regenerate the profile of a particular user if the exception frequency exceeds a predetermined threshold as shown in fig2 the north side of the application has two primary interfaces for distribution of information the interfaces are implemented in an internet friendly format using xml or webservices as the interface technology one of the services is a standard gmlc mlp interface which allows the system embodying the present invention to look and feel like a gmlc but without the overhead of the gmlc having to access the radio network for actual location determination examples of the present invention also allow the use of zone event notification this is used for applications which monitor when users enter and leave predetermined zones the application declares the subscribers and zones at the point of initialisation the application does this by a simple interface which creates zones and subscribers and establishes a relationship between them an example of a zone event notification application is friend alert which establishes the relation in the following steps initially the friend alert application has configuration data for each subscriber his friend zones and his friends the intent is that whenever the subscriber is in a particular locality he would like to meet up with any of his friends the friend alert function initially creates the zone and the subscribers 39 identity and relates the two the location based information system checks.