We recently came upon a news story from Arizona highlighting one of the challenges with the Commercial Mobile Alert Service (CMAS): geo-targeting an alert to those for whom it is most relevant. On July 12, the National Weather Service sent a CMAS message (also known as a Wireless Emergency Alert) for flash flooding in a portion of Maricopa County. However, CMAS-enabled phones throughout the county received the alert, including those in Phoenix, who were not experiencing flash flooding. Maricopa County is home to nearly 4 million people and is geographically large, covering more than 9,000 square miles.

CBS 5 – KPHO

As the usage of CMAS continues to increase (New York City just issued its first CMAS message), we may see more instances like this. Some have called this the “cry wolf” phenomenon: if people outside of a target zone receive an alert that is not relevant to them, they may decide to opt out of the service, constricting the population that emergency managers can notify. At the same time, an alert could spur an unnecessary or inappropriate response among those that are not in danger.

As the video states, wireless carriers are working on ways to send alerts to more granularly targeted areas. Although the current standard requires the alerts to be sent to the county level, carriers are working to be able to send them to the cell tower or cell sector levels, which would hone in on a target population with much greater precision. We have also been reporting on future-looking technologies and trends that could enhance geo-targeting capabilities.