Aspects describe using mobile device telemetry data with location reports from a small fraction of reporting devices to pre-compute a set of categorizing formulas that can quickly assign devices of unknown latitude, longitude, and/or altitude to specific values of latitude, longitude, and/or altitude. The described aspects perform a large percentage of complicated calculations in advance of a particular device of unknown location presenting itself on the radio network. Thus, the categorizing formulas can be applied to categorize the device into a particular range of latitude, longitude, and/or altitude with minimal delays. Various aspects relate to enabling an efficient and highly scalable implementation of mobile device advertising, social networking, and other applications that may reply in rapid, real time delivery of “WITHIN” or NOT WITHIN a “fenced-in” region or geography or shape of space.