Commercial Mobile Alert System
The Commercial Mobile Alert System (CMAS), also known as Wireless Emergency Alerts (WEA), is an alerting network in the United States designed to disseminate emergency alerts to mobile devices such as cell phones and pagers.
The Federal Communications Commission proposed and adopted the network structure, operational procedures and technical requirements in 2007 and 2008 in response to the Warning, Alert, and Response Network (WARN) Act passed by Congress in 2006, which allocated $106 million to fund the program. CMAS will allow federal agencies to accept and aggregate alerts from the President of the United States, the National Weather Service (NWS) and emergency operations centers, and send the alerts to participating wireless providers who will distribute the alerts to their customers with compatible devices via Cell Broadcast, a technology similar to SMS text messages that simultaneously delivers messages to all phones using a cell tower instead of individual recipients.
The government plans to issue three types of alerts through this system:
- Alerts issued by the President of the United States.
- Alerts involving imminent threats to safety of life.
- AMBER Alerts.
When the alert is received, a sound is played if the ringer is on. This sound varies, from the iOS Alarm ringtone, a police siren, or the old Emergency Broadcast System Attention Signal in bursts.
The system is a collaborative effort between the Federal Emergency Management Agency (FEMA), the Department of Homeland Security Science and Technology Directorate (DHS S&T), the Alliance for Telecommunications Industry Solutions (ATIS), and the Telecommunications Industry Association (TIA), although there has been some controversy regarding the willingness of FEMA to participate.
Within ten months of FEMA making the government’s design specifications for this secure interface for message transfer available, wireless service providers choosing to participate in CMAS must begin development and testing of systems which will allow them to receive alerts from alert originators and distribute them to their customers. Systems must be fully deployed within 28 months of the December 2009 adoption of such standards and are expected to be delivering alert messages to the public by 2012. Although not mandatory, several wireless providers, including T-Mobile, AT&T, Sprint Corporation, and Verizon have announced their willingness to participate in the system. Providers who do not wish to participate must notify their customers. Some phones which are not CMAS-capable may require only a software upgrade; while others may need to be replaced entirely.
CMAS messages, although displayed similarly to SMS text messages, are always free and are routed through a separate service which will give them priority over voice and regular text messages in congested areas. Customers who have the capability of receiving CMAS alerts (also known as PLAN and WEA) will be automatically signed up by their carrier. If they do not want to participate they may opt to block most CMAS messages, however CMAS regulations prohibit participating carriers from configuring phones to allow users to opt out of messages issued by the President.
Public television stations are also required by the FCC to act as a distribution system for CMAS alerts. Within 18 months of receiving funding from the Department of Commerce, all public television stations must be able to receive CMAS alerts from FEMA and transmit them to participating wireless service providers.
National Weather Service
The Commercial Mobile Alert System (CMAS), interface to the Wireless Emergency Alerts (WEA) service, went live in April 2012. The NWS began delivering its Wireless Emergency Alerts on June 28, 2012.
- Boston Marathon bombings — A shelter-in-place warning via CMAS was issued by the Massachusetts Emergency Management Agency
- Child abduction alert for New York City — For a 7-month-old boy who had been abducted. The massive inconvenience caused by the 4am timing raised concerns that many cellphone users will now disable alerts.
- Blizzard warning in February 2013 for New York City. 
- Shelter-in-place warning for New York City due to Hurricane Sandy. 
- Emergency Alert System
- Common Alerting Protocol
- NOAA Weather Radio All Hazards
- National Severe Weather Warning Service
- Integrated Public Alert and Warning System
- Emergency alerts coming to your cellphone via cell broadcast
- Personal Localized Alerting Network (PLAN)
- FEMA News Release HQ-09-148, FEMA And The FCC Announce Adoption Of Standards For Wireless Carriers To Receive And Deliver Emergency Alerts Via Mobile Devices .
- FCC Consumer Facts, New Commercial Mobile Alert System[dead link]
- , FEMA And The FCC Announce Adoption Of Standards For Wireless Carriers To Receive And Deliver Emergency Alerts Via Mobile Devices
- US Code of Federal Regulation Title 47, Part 10, CMAS
- "National Emergency Alert System Goes Live". Government Technology magazine. 10 April 2012.
- "Coming soon: Weather warnings on the go!" National Weather Service website. Retrieved 2012-06-30.
- Karnowski, Steve (2012-06-28). "Weather Alerts Coming Soon to Smartphone near You". Associated Press. Retrieved 2012-06-30.
- "Boston Bombing Shows How Wireless Emergency Alerts Can Work with Other Media"
- "Wake-Up Call for New Yorkers as Police Seek Abducted Boy", NY Times