Lifeline is a group of systems designed for mobile phones and battery powered wireless routers for forming emergency Ad hoc networks.
Devices installed with Lifeline program can automatically form Ad hoc networks when cellular signal is unavailable or disrupted during natural disasters. For instance, large scale earthquakes can cause extensive damages to land-based telecommunication infrastructures. In such circumstances, mobile phones installed with Lifeline program can be used to send emergency messages by the victims who are trapped under collapsed buildings. In addition, Lifeline also provides a function for the rescuers to estimate the positions of the victims based on network propagation techniques. Lifeline also has the ability to recover from partial crash of network and nodes lost.
The details and implementation are described in this paper: Se-Hang Cheong, Kai-Ip Lee, and Yain-Whar Si. "Lifeline: emergency ad hoc network." In Computational Intelligence and Security (CIS), 2011 Seventh International Conference on, pp. 283-289. IEEE, 2011. The author’s version of a work that was accepted for publication can be downloaded from http://eric.lostcity-studio.com/wp-content/uploads/2019/08/lifeline.pdf.