Device allows cellphones to communicate without reception

SAN FRANCISCO (KGO) -- Most people have tried to pull out their cellphones only to find that there was no service right when they needed it the most. One gadget is on the market that could help people communicate anyways -- at least if the other person has one, too.

Super storm Sandy took down fences, doors, even entire houses -- it also took down something else.

"A fourth of all cell towers were downed and sitting there thinking, you know, it's ridiculous that during the time when you need to communicate most, you're unable to," GoTenna co-founder Daniela Perdomo said.

Even if people could find a place to charge their phones, it was useless due to the lack of a signal.

That's when Perdomo got the idea for an app that would let phones talk to each other without a network, but there was a problem.

"You know, the most that you can get point-to-point with your phone is 20 feet over Bluetooth, at which point you might as well yell," Perdomo said.

Cellphones just don't have the right hardware, but there's something else that does.

First-responders use high-powered two-way radios with long antennas. "Walkie-talkies are very resilient technology, and that's why everybody from the military to disaster relief organizations still use them," Perdomo said.

So she took the parts out of an old VHF radio and put them into a tiny package called GoTenna.

It's about five inches long and weighs under two ounces. There's no speaker, microphone or battery pack because GoTenna is not for talking -- it's for texting.

"The entire idea is that this is supposed to work exactly the way you use your phone normally," Perdomo said.

GoTenna acts as a relay. A user types a message on their phone, and sends it to GoTenna via Bluetooth. The device automatically sends it to somebody up to a few miles away, even farther depending on where you are.

"A definite use case is for a lot of people who do outdoor activities," CNET News staff writer Nick Statt said.

He thinks skiers and hikers could snatch these up on pre-order, $150 for two of them. It's sold in pairs because just one won't do a person any good. GoTenna only allows a person to communicate with another person who has the device.

In the wilderness, the signal can travel up to 50 miles. It could also work at music festivals where cell networks get overloaded.

Statt said it's truly off-the-grid. "The messages are end-to-end encrypted, and have, they're not stored anywhere so you can definitely speak to another person completely privately," he said.

Perdomo said she's had interest from disaster relief groups who could give GoTennas to their volunteers.

"No service, no problem, for sure," Perdomo said.