According to a report in New Scientist, this futuristic scenario might soon be a reality, if a new patent application by Telecommunications Company Motorola is anything to go by.
In an emergency, such as a hurricane or terrorist attack, the US government can operate the Emergency Alert System (EAS), which harnesses all TV and radio frequencies, to broadcast warning messages to people in their homes.
"Unfortunately, a large portion of the intended recipients will not have their TV and radio systems turned on when a disaster occurs," said Motorola engineer Jerome Vogedes of Milwaukee, Wisconsin, in a US patent filed on May 21.
His answer is a new generation of cellphones that can rapidly form a peer-to-peer network when an emergency alert is broadcast.
A phone on the edge of a disaster area, where a cellphone service still operates, receives the alert. It contacts the nearest phone using Wi-Fi, establishes a P2P network with it, and sends it the alert.
That cellphone then does likewise until as many mobiles as possible have received the alert.
This way, the warning message gets out with "minimal use of infrastructure", Vogedes said.