TeleCommunication Systems, Inc. (TCS) carried out research and development on constructing algorithms that utilize Radio Frequency (RF) cell site propagation footprints. Research focused on using RF coverage area footprints to improve geo-targeting granularity and accuracy for delivery of Wireless Emergency Alert (WEA) alert messages.
Today, the WEA standard (J-STD-101) defines two methods that can be used to select cell towers to deliver WEA messages for a given targeted geographical area. The first method calls for the ability to determine the cell towers at the county level of granularity. This level of granularity is a minimum requirement for all mobile carriers that offer the WEA service. The second method is optional and allows the targeted area to be defined by polygons instead of fixed county boundaries.