One of the first things to disappear in the wake of a major disaster is reliable communication. Without access to cell phone service or the Internet, it’s difficult for first responders–or anyone who wants to help out–to speak with each other. And while satellite phones work in these situations, they’re too expensive for many first responder organizations to purchase en masse. Now researchers from Georgia Tech College of Computing claim to have developed a cheap, easy solution: LifeNet, a piece of software that allows people to communicate after disasters, even if landlines, cell phone networks, and the Internet are all down.

“It’s just a piece of code that you can have on your laptop or phone. Once you have the software, the computers can communicate with each other, and you

don’t need infrastructure,” says Santosh Vempala, the Georgia Tech computer science professor in charge of the project.

Any device that has LifeNet installed acts as both a host and router for the network–meaning the software can route data both to and from any other LifeNet-enabled device. You can read more technical details here.

A group of people using the software can all communicate with each other (texting is the easiest way), but if even one person on the network has access to the Internet, everyone else can access it, too–though the connection probably wouldnt be strong enough to do any powerful surfing, like stream video. And if one user has a satellite phone, the whole network can use its services.

There’s just one catch: Users have to be within range of each other. Outdoors, this could mean up to a kilometer. Indoors, users may have to be as close as a few hundred yards. But as Vempala notes, “you could have a line of people on this network that are spaced 100 yards apart, and the line could go as long as you want.”

Hrushikesh Mehendale, one of Vempala’s former graduate students, plans to bring LifeNet to market. The software will be free, he says, but users will have to pay for specific applications (i.e text messaging). Still, the cost will be cheap compared to satellite phones, which cost up to $600 a pop and charge 50 cents per text.