An Emergency Communication System (ECS) is defined as a system that is organized for the primary purpose of supporting one-way and two-way communication of emergency messages between both individuals and groups of individuals.137
There are two methods of communicating to devices during an emergency. The first is using infrastructure dependent technologies, such as phones, internet, radio, television, etc. — provided they are still operational. The second is using infrastructure-independent network connections, such as Google’s Project Loon (which uses unmanned hot air balloons housing network equipment — see later in this section for more details). This offers the potential for networked communication when infrastructure communication is hindered in emergency situations.
Public Emergency Alerts
First Responder Communication Systems
References
137. Wikipedia. Emergency Communication System. Accessed July 12, 2016