Building height data has become one of the hottest commodities in the telecommunications industry as the latest wireless networks are rolled out across the country. But building heights are not a one-size-fits-all solution. An uninformed choice could result in excessive cost or an inferior solution. This tutorial discusses the differences between the new wireless technologies and the varying characteristics of their radio frequencies. It then clearly differentiates the building height and GIS requirements for each technology, providing the reader with a firm basis for understanding the options and offerings in this burgeoning market.