You Can Now Send Messages Even When You Don't Have Cell Service

GoTenna takes mobile communication totally off the grid.

Jul 17 2014, 9:03pm
Screenshot: goTenna

When Hurricane Sandy hit New York City, taking out a fourth of the city's cell towers and widely wiping out power and wifi, tech creator Daniela Perdomo had an idea. Finding it ridiculous that communication failed so spectacularly without centralized connectivity, she began thinking of a way around the problem. 

What if there was a way to enable completely decentralized, direct smartphone-to-smartphone communications? A system that required no towers, routers, or satellites—just a network of smartphones communicating with each other. Thus, goTenna, which launches today, was born.

The hardest thing to do, said Perdomo, is to enable your phone to communicate over many, many miles. Bluetooth, with its limited connectivity range of 20 feet, wouldn't cut it. (Firechat, a decentralized communications app that runs on bluetooth, isn't practical for this same reason.) To pull this off, the goTenna team realized that their device would have to be an external hard drive that only made use of bluetooth in its transmission and receiving processes. 

The goTenna team began their tool's systems architecture at NYC Resistor, a hackerspace in New York, last November. By Februrary 2014, the team had populated their first circuit board. The first prototypes followed in March, marrying radio frequency (RF) signal and smartphone technology. 

Some see it as an engine for Bitcoin transactions, while another person said they would like to build a "totally private Grindr" on the goTenna platform.

As Perdomo told me, a smartphone's bluetooth sends the message to the goTenna external hard drive (equipped with a BluetoothLE data interface), which converts it into an RS signal through a 2-watt radio. The smartphone on the other end then converts the RS signal back into a bluetooth signal, so the message can be read.

"Using either an Android or IOS app, you enter a message, and direct it to an individual or group," said Perdomo. "Everyone's username is associated with a number. We recommend phone numbers so that users can find each other through their contact lists, but if you want to be anonymous, we can generate a random string for you so that it's encrypted."

The app's messages have end-to-end encryption through RSA-1024 public-private key ciphering. Messages can also be set to self-destruct, and aren't stored anywhere. While this isn't really important for friends trying to communicate at a music festival like Coachella, it would be a vital resource for protestors and activists who rely on privacy and anonymity.

The app lets you send and receive texts for free, and "shout" broadcasts to any goTenna users within range—an emergency chat function. It also includes a map of friends in close proximity and location pinging. 

Mapping also gets tweaked in the goTenna app, as the device uses neither Apple or Google maps, since they rely on internet connectivity. Early on, Perdomo and the team decided goTenna's maps needed to be able to function offline, so had maps developed specifically for the Android and iOS apps.

Users can also create their own private network, somewhat like a mini-mesh network, and in this way speak or message with other nearby goTenna users. Practically speaking, if enough goTennas were daisy-chained, a quite large mesh network could be created. But, at this point, current FCC regulations won't allow this to happen. 

While personal communications networks were an obvious goal, the developers also very quickly realized goTenna's other various applications, from outdoors excursions and journalists working in dicey areas to big events where wifi becomes overloaded and privacy-sensitive situations.

"When you're outdoors hiking in the middle of nowhere or skiing, this enables you to communicate with others you've been separated from," Perdomo said. "Cell towers can become overtaxed at music festivals, so this becomes a solution. It's also good for traveling with other people abroad, especially when you want to communicate or coordinate with travel mates without paying roaming fees."

Perdomo also said that goTenna should not just be seen as off-grid communication, but a tool for those who want to go off-grid. 

"Because it's completely decentralized, end-to-end encrypted, with messages that self-destruct upon reading and anonymous ID, well, the possibilities for private communication are endless," she said. "We've had activists of all kinds reach out to us for access to goTenna."

"There is also it's potential in emergency preparation, what I affectionately call the A-to-Z market—apocalypse to zombies," Perdomo said. "And finally, people who may want to build on goTenna as a platform, via our development kits and SDK, to figure out other uses for our tech."

People have already asked goTenna for access to development kits for a wide variety of ventures. Some imagine using it for wireless door locks, while others want to deploy it for LARPing (live action role playing games). Still others see it as an engine for Bitcoin transactions, while another person said they would like to build a "totally private Grindr" on the goTenna platform.

"What happens when you can communicate totally off-grid?" Perdomo mused. "I hope to find out what the hive mind comes up with; surely stuff I can't even think of. The entire idea is that you can create a network on your own terms, though of course the main point is we're building off-grid mobile messaging."

Ultimately, the team wants people to use goTenna to "make wild things happen." They realize that the average consumer won't be into development on goTenna. But, the enthusiasm is already coming from the hacker and maker communities. F.A.T., the Free Art and Technology Lab, has already shown some interest in goTenna. 

GoTenna's industrial design was a challenge. For one, it had to be suited for all its unique uses, from a hiker to a festival attendee. "So, it's water resistant, dust-tight, with a long lasting battery (3 days) and it's light at two ounces," Perdomo said. 

GoTenna is launching at $149.99 for two units—half the eventual selling price. The idea is to incentivize people to buy early so that they can put in a big order and keep prices low moving forward.

"But, what I'd really like to get across is that we think decentralizing communication is a really powerful concept, which is why we're so excited to work on this and put it out in the world," Perdomo said. "The idea that communication can be defined according to need as opposed to access is, I think, really important."

"I am Brazilian-Guatemalan, so I haven't forgotten the rest of the world, where it's important to have the ability to communicate between tiny villages when big carriers have no interest in providing service," she continued. "The philosophical idea behind decentralizing is important, too, but not every audience will get that futurist mission perspective."

For goTenna to reach its full potential, both as a decentralized messaging service and development platform, it will have to amass a healthy number of users. Now couldn't be a better time: people are looking for alternatives to centralized communications controlled by multinationals and exploited by spy bureaus like the NSA. GoTenna could make a nice alternative impact on the wired age.