The Katrina Rooftop Problem:
In 2005, Hurricane Katrina took down the fixed communications infrastructure. In a disaster where existing communications infrastructure is disrupted, victims need alternative ways to communicate with each other and with first responders.
Currently, emergency calls can be made by a mobile phone where a signal from any service provider can be found (even if the mobile phone doesn’t have an active service plan). This means that if a phone is under service provider A but cannot detect signal, it can use service provider B given that B has coverage at the phone’s location. With mesh networking, emergency calls can be passed along mobile devices that do not have cell service until a signal can be found.
The Federal Communications Commission is working on an emergency alert system called Personal Localized Alerting Network (PLAN). PLAN allows mobile users with adequate hardware and software configurations to receive three types of geographically targeted text-like alerts (alerts issued by the President, alerts involving imminent threats to safety of life, and Child Abduction/Amber alerts). Wireless carriers must opt-in to activate PLAN technology, and are required by the Warning, Alert, and Response Network (WARN) Act to implement technologies by April 2012 if they opt in. They must otherwise notify consumers if they do not offer PLAN messaging. In turn, subscribers can opt-out of imminent threat and child abduction warnings, but neither providers nor subscribers can opt out of Presidential level PLAN messages.
PLAN is similar to an alert broadcasting system activated in 2011 on iPhones in Japan for earthquake alerts.
Mesh networking capabilities complement emergency alert systems like PLAN. Although authorities would have a way to broadcast important messages to mobile phone users, first responders have no way of knowing the location of disaster victims unless they receive notifications from those in need. Mesh networking can help with this when cell infrastructure is weakened or down. Imagine an “Emergency Mode”, where users volunteer to route, at the bare minimum, emergency messages from victims to first responders.
Mesh networking apps also facilitate local communications in the absence of cell or Internet service. In the event of a disaster which took down means of communications at a college campus, a mesh network could allow students to communicate their condition and location to administrators and each other. Administrators could then keep track of students they’ve (1) heard from and are safe, (2) heard from and need help, and (3) have not heard from.
To be able to enter an “Emergency Mode,” phones need to be able to start and join ad hoc mobile networks. Demand by consumers and/or a push by regulators to mandate this feature on new smart phones would be necessary for this feature.