This document describes research being done on a new Wireless Emergency Alerts (WEA) geotargeting mechanism by the Johns Hopkins University Applied Physics Laboratory (JHU/APL). This work was undertaken with the support of the U.S. Department of Homeland Security (DHS) Science and Technology Directorate (S&T). The WEA service provides the ability to send geographically targeted text alerts to the public. However, the current WEA geotargeting mechanism is limited by the relatively coarse granularity of cellular network sites. JHU/APL investigated methods of improving the geotargeting accuracy of WEA.
The new WEA geotargeting mechanism is called Arbitrary-Size Location-Aware Targeting (ASLAT). This document compares the performance of the new mechanism with existing WEA geotargeting, discusses the requirements for the new mechanism and identifies the required changes to existing WEA standards. ASLAT utilizes the location awareness of mobile devices to improve geotargeting accuracy.