US Patent 7138913 Selective reporting of events in asset tracking system

In GPS based and other types of asset tracking system, event masking rules may be applied at asset tracking units and/or at a central station to determine whether to report events detected by the asset tracking units. The events may pertain to transportation vehicles such as truck trailers or cargo containers to which the asset tracking units are attached. The event masking rules may be defined at the central station and downloaded by satellite communication to the asset tracking units and/or the rules may be defined locally, at the asset tracking units.