How does it work?
Customers need a Commercial Mobile Alert System (CMAS)-capable mobile device in order to receive Wireless Emergency Alerts. U.S. Cellular's network will be able to broadcast Wireless Emergency Alerts by the official launch on April 7, 2012. At that time, FEMA will serve as the aggregator to relay emergency alerts from authorized government agencies (including national, state or local officials).
Alerts are geographically targeted; customers with a CMAS-capable mobile device in an area where an alert has been sent will have the ability to receive the alert. Wireless Emergency Alerts are up to 90 characters in length and will contain:
- What is happening
- What area is affected
- When the alert will expire
- What action should be taken
- Who is sending the alert
When an alert is sent customers will receive a unique signal and vibration. Similar to a text message, the alert will be stored in the phone's messaging menu until deleted.
There is no charge for Wireless Emergency Alerts. These alerts do not impact voice, text, or data usage.
Customers with CMAS-capable mobile devices may turn off the Imminent Threat (Extreme & Severe) and/or AMBER alerts; Presidential alerts cannot be turned off.
This diagram illustrates how Wireless Emergency Alerts are sent and received.