Now You Can Build Your Own Private Mesh Network With Phones and Radios

If you’re trying to chat with someone online, you could both connect to the internet. But why can’t you connect directly together, through your computers or your phones? The question has motivated a subculture of engineers to develop ways to roll their own networks, through a technique known as “mesh networking.”

It’s a network topology that the internet began with—distributing connections among individuals, not just to them—but resuscitating it hasn’t always been easy. Hackers built dark private networks for Occupy Wall Street (but the equipment was bulky, and then the police confiscated and destroyed some of it); in places like Hong Kong, activists have used FireChat, an app that sends messages between phones over Bluetooth, to communicate when SMS won't work (but Bluetooth can’t travel very far); and people in places like Brooklyn are building their own neighborhood-wide private networks in an effort to subvert the telecom monopolies (but they're limited by the cost and challenge of installing and maintaining rooftop radios, each of which is responsible for receiving and passing along data).

A new device debuting today on Kickstarter, the goTenna Mesh, aims to bring the dream of mesh networking to the masses. The 6" pill-shaped radio connects to phones over Bluetooth and allows them to “mesh” together in order to transmit messages in daisy chains that can reach miles. Relying on a protocol that sends short bursts of data over long-range radio signals, the device, retailing for $179 and preselling for $129, won't replace an internet connection or allow users to watch Netflix. But it may be the first consumer-friendly device for a reliable off-grid peer-to-peer communication network.

For CEO Daniela Perdomo and her brother Jorge, the idea for a way to connect with each other outside of the network began at music festivals, but it took off in the chaos of Hurricane Sandy in October 2012, which disabled some of the city's power and communications for dozens of hours. The Brazilian-born New Yorkers resolved to start working on a solution. After linking up with an engineer at the hackerspace NYC Resistor, the birthplace of MakerBot, they built a prototype, started knocking on investors' doors, and found a manufacturer in Mexico. In 2014, they launched goTenna on Kickstarter: a pair of radio transmitters that pair with a smartphone app, turning phones into their own chat-based communication system, capable of sending messages and GPS coordinates distances of about 3 miles with no internet connection. The device easily surpassed its $50,000 pre-sales crowdfunding goal in only 3 hours.

The new device goes a step further. Unlike the person-to-person networks of the previous gadget, the mesh approach makes the network larger and stronger the more nodes there are. (The network can't grow indefinitely; in the beginning, goTenna expects most meshed connections to include up to four hops between three nodes.) Users needn’t need know the nodes relaying their message, only the person they are communicating with, via the app’s encrypted chat. The app also has a "Shout" feature, allowing a goTenna or goTenna Mesh user to send a message to whomever is in the vicinity.

GoTenna hopes the device will change the way people communicate during outdoor adventures, on field trips, or at large events or protests, when network service is otherwise bad or nonexistent. Powered by $7 million in series A funding earlier this year—and in spite of all the time and energy Daniela devoted to a recent, sudden passion project, building and maintaining the Bernie Sanders website feelthebern.org—the Brooklyn based startup has working on a new set of protocols, called Aspen Grove, designed specifically for meshing. The name refers, says Daniella, to "aspen tree colonies which share a common root structure that can expand over huge areas, and is resilient enough to survive harsh forest fires."

The company is also launching a website where users can register their nodes and find each other on a map, and a new premium service that gives users access to detailed topographic maps, trip statistics, and the ability to relay messages from the mesh network to the cellular network using SMS. The service will cost $9.99 a year for an introductory period of 90 days and $29 a year thereafter, says goTenna.

All users will have access to a software development kit (SDK), allowing capable programmers to build their own apps atop the device, like network relays that would allow for them to transmit any kind of data.

“You could even drip higher bandwidth comms over lots of small packets, respecting our protocols—which make the best use of a shared and scarce resource, the public spectrum—and reconstruct them at your app at the other end," says Daniela. "After all, all media are 1s and 0s, so there's no reason you’re limited to texts and GPS." This data could include images or videos, but would need to be delivered over lots of little packets over time.

While the existing goTenna device faced regulations that prohibited its sale outside of the US, the new Mesh device operates on a different set of frequencies that make it available for purchase internationally. The company is also planning a Pro version for release next year, which will enable users of special licensed radio frequencies, like police, military, and commercial users, to mesh over channels with fewer restrictions on features like power wattage, meaning a wider range.

Normally, you wouldn’t use the goTenna signal to transmit movies or even browse the web, at least not yet: the speed of the network is just fast enough to send and relay text in a reasonable amount of time and over a limited number of hops. But as software improves, so will the network’s functionality and potential size. In most situations, the mesh will involve up to three hops between four nodes/people to start," says Perdomo. "Over time we'll continue to optimize and build intelligence into our protocols to do more hops in a way that is scalable."

Meanwhile, other mesh-friendly protocols like B.A.T.M.A.N. and Babel continue to spread across local mesh networks, like the 30,000-node-strong Guifi.net in Spain, an illegal mesh in Cuba, and efforts by militaries and governments (including the US) to build reliable, decentralized communication platforms, especially in places where network access is monitored or controlled.

'My sense is that idea—of a bottoms-up... people-powered network—is exciting to a lot of people, even if they’ve never thought about or even heard of mesh networks before.'

In the U.S., mesh has remained mostly in the background, eclipsed by more traditional (though far from perfect) methods of connecting to the internet. “Mesh networks have been the only choice for people in a lot of developing economies,” Jinyang Li, a New York University professor who helped develop early mesh networking technology, told Jason Koebler in January. “I think in the United States the infrastructure has been so good, so there hasn’t been incentive to build these networks, but there’s no reason it wouldn’t work.”

Daniela sees many reasons. The infrastructure hasn’t been so good, she argues, which means lack of cellular service in many places, from rural areas with few connections to urban areas where too many users slow the network to a crawl.

There are also more straight-forward, urgent uses than communicating with friends on a hike or at Burning Man or when you want to avoid roaming charges overseas: goTenna could be valuable at providing affordable communication when networks are down during emergencies. Last year, the company won a grant from RISE:NYC, a competition funded by the U.S. Department of Housing and Urban Development, that will give goTennas to over 10,000 small businesses located throughout Manhattan, Queens, Staten Island, and Brooklyn that were victims of Hurricane Sandy.

And given a growing awareness about the internet and its limits, Daniela hopes the product might also help kickstart a broader cultural interest in distributed networking.

“My sense is that idea—of a bottoms-up, totally parallel people-powered network—is exciting to a lot of people, even if they’ve never thought about or even heard of mesh networks before,” she says. “I think I read somewhere that in America in particular after credit card companies or health insurance companies, the next most hated thing is telecommunications. So I think that there’s a hunger for an idea, like could there be something better or different that serves another purpose for different needs? I think there could be.”

I recently spoke with Daniela about the technology and its potential; below is a lightly edited excerpt of our conversation.

Can you talk about the challenge of building a user-friendly mesh network device?
It was very hard. Very hard, and that’s why it took us frankly, you know after Hurricane Sandy, it took us three years from then to release our first product. A lot of the work that we did with [the first protocols called] Aspen Prime includes a lot of the stuff that’s going into this next protocol [Aspen Grove]. We’re able to tackle a lot of the hard things like, how do you get a message to a specific user and not everyone around them? How do get acknowledgement receipts between the recipient and the sender without a third party knowing? How do you do all this routing intelligently in a way that doesn’t make inefficient use of scarce public spectrum? I think all of these things are things that we worked on in the first product, and the mesh is basically the next level of it.

The answer is it’s really hard, and I don’t want to be the person to tell you why there has there been small progress in the mesh world. I know that the reason we think that we’ve been able to do this is because we focused very specifically, we made a decision to focus on burst data. But you know, that doesn’t mean that we’re gonna stop there.

Using burst data sounds like it has its own limitations in terms of bandwidth and speed. Can you describe the thinking behind that choice?
I feel very strongly that it’s a feature not a bug for us to focus on burst data communication. By focusing on burst communication, we actually can create hardware that can do this all that is lighter, longer-lasting, smaller, less expensive. These are all the tradeoffs. But if you want to do something massive and that costs tens of thousands of dollars, for instance like the kind that the military uses, which cost $20,000 or more per unit per person, you could do more with the mesh. But the tradeoff is that they’re huge, like the size of a backpack, expensive, and not available for consumers. And so what we wanted to do is just to create something that’s really simple.

I think that ultimately we just want to create a really easy-to-use, relatively low-cost low-power network capability. Particularly given our very limited means we’re just focused on doing that really well.

goTenna founders Jorge and Daniela Perdomo. Image: goTenna

Who do you think of as your audience for Mesh, versus the initial product?
The idea of our early adopters would be people who already have an identified gap in their coverage or service of some kind, whether it’s, ‘every weekend I go out hiking and I don't have service,’ or ‘I live in an area with bad service and I just want to be able to get in touch when I’m out on the ranch with someone back at the house or I’m out in town.'

I like that idea because the infrastructure is failing. They know it is. With this product I’m excited about the possibility that a lot of people who might buy it are people who haven’t been thinking about mesh, people who have immediate needs versus people who are just futurists.

The idea is just, how do we make it inexpensive enough for people to not have to think about it and just think, ‘Okay, there’s either an immediate use case scenario for me hiking or traveling,' or 'I just like the idea of the mesh possibility and I want to see what happens.’

'There are even groups who technically have more budget than the consumer, but they still think this is really interesting.'

You're building a radio device. Doesn't the government get involved when that happens? What kind of regulatory challenges has this entailed?
We might have made our first product mesh if it weren’t for the fact that the frequencies that our first product works on, meshing is prohibited. Our first frequencies are the MURS frequencies—that stands for multi-use radio service, which operates on the 151-154 MHz frequencies at a maximum limit of 2 watts transmitting power, and the reason meshing is prohibited is that when the rules were written, people were imagining the only way people would use the spectrum was for voice. Think about it: it was fifteen years ago, people were barely texting yet. Using voice is very high bandwidth, and it’s real time, and it clogs the spectrum for everybody.

And people know already that if you use a walkie-talkie and someone says ‘hi!’ no one else can say hi, and plus you hear it even if it’s not for you. So I think the idea was that you can’t do what the FCC calls "store-and-forward," which is effectively meshing, because it would be a really inefficient use of the spectrum. It would be really high bandwidth transmissions all the time, and no one could get anything through, given you can barely get anything through just when you’re saying the word hi. Imagine relaying that message through other people.

For a little bit, we thought about, how could we get an experimental license and go through the regulatory hoops, just to actually change the rules? Like, let’s pick different frequencies where there aren’t those regulatory hurdles and just focus on the lobbying. But that’s not what we want to get stuck doing, and so the new product works on what is known as the ISM band, which is the international series of frequencies that can be used by civilians everywhere, and in the US that’s around 915 MHz. Those frequencies don’t have that limitation, so we didn’t have to go ask for special permission to do this.

What other things are in the 915 MHz part of the spectrum?
It’s sort of like the innovation of the 90’s was happening on this—cordless phones, garage door openers. You know there’s not a ton of other stuff happening on there that I think is super innovative. You know like sort of dinky consumer walkie talkies operate on there too.

The intelligence community has expressed interest in goTenna and the military is testing them. What kind of interest have you seen from law enforcement and public safety groups?
Frankly that’s something we only realized after the fact: Oh, there are even groups who technically have more budget than the consumer, but they still think this is really interesting because of different functionalities and a more affordable price point.

Because we have had interest from public organizations in these ways, alongside the antenna mesh product we’re announcing, we’re developing a version if you’re a licensed user of some frequencies that are only intended for public safety or enterprise users. It’s basically the same thing [but with more bandwidth]. You won’t be surprised to hear that public spectrum has much less restrictions than licensed spectrum. Paying and/or government users have less restrictions. So we are releasing this new version that we’re calling goTenna Pro, which is basically goTenna Mesh except it will work on licensed frequencies [which allow for higher power transmissions, and possibly greater range].

What else is on the landscape when it comes to new approaches to mesh networking? What kind of competition do you have? And how might goTenna connect to or partner with other communication protocols, now and in the future?
First of all, there’s no other device like goTenna, none that exists anyway. Ever since we announced the company in June of 2014 there’s been companies that sprout here or there, threatening to launch something that either have died or continued to be vaporware, so we’re still the first and only of our kind. But I would say in terms of partnerships anything that can enable communication in remote places, or there’s this idea in telecommunications called Last Mile Connectivity— that’s basically a catch-all phrase for communication when it isn’t otherwise available and of course in goTenna’s case ‘last mile’ can be many miles—but international carriers, not really US carriers, have reached out to us to see how we can work together. We’ve also heard from disaster relief organizations.

We’re also releasing something called a network relay—which will also be available to users of our first product. Let’s say there’s a group that’s out hiking and some of us are in the basin of a valley and I’m on the ridge and I actually have service. So we all have goTenna, but whether or not you know me, anyone who has goTenna who doesn’t have service is able to connect through me. So we’re already doing our own integration with things like that. Philosophically, I’m not like, ‘we must be our own network, we cannot use anything else.’ No. I actually think we’re just trying to do one thing really well.

Free The Network, a 2012 Motherboard documentary about Occupy and mesh networks

What might goTenna Mesh mean for communities, and for reinvigorating the network with a sense of community?
[In his new documentary about the internet], I think there’s this possibility Werner Herzog describes, at the beginning of the internet, where people knew each other or people met each other in real life, and in ways a mesh network enabled that possibility.

I think that from a political standpoint, my own personal perspective, I think about the idea of local communication in many ways. Sadly, in the five years I’ve lived in New York I’ve felt distant from my local community board or local legislature, and have been more aware of, say, some New York Times article on Facebook that my friends are discussing in San Francisco. And all of a sudden, the local is what appeals to me: the idea that I could plug into some network of what’s going on around me. The possibility of local organizing based on local information—that’s very different than what we have now.

And how do we bring the internet to emerging markets? The way to connect communities in the far corners of the Earth is not to bring them a Facebook News Feed, or connecting them to the rest of a homogenous set of platforms. It’s about connecting them to each other on a very local basis first I think, and then letting them decide how and when and how often to connect back into everything else.

And I think there’s the whole group of people who are thinking about things like local communications, local connectivity local wireless networks. What is that about? Part of it is about circumnavigating central infrastructure and I think that’s interesting too. But some of it is a little more political, which I think is interesting as well.

Radio Motherboard on NYC Mesh and New York City's Link NYC WiFi program

Speaking of which, how does security work on goTenna?
Like with our first product, all private messages—any message to a specific person or to a specific group, any message that you haven’t designated as public, which we call Shouts—are by definition end-to-end encrypted with public/private key ciphering. So the only person or people who can decrypt the message are the people for whom the message is intended. Even if you have a message that’s ‘meshed’ or relayed or daisy-chained through some other people, they can’t open the message. They don’t even see it in fact.

So let’s pretend in the most simple mesh possible you’re Alex, so you’re node A and I’m node C and I’m out of range of you but node B is between us so the message would be sent through B, but B couldn’t open it.

Even if someone maliciously did something—to make it so that B actually held on to the message instead of just immediately forwarding it to node C—B wouldn’t be able to open it because it’s encrypted.

Now that you can sell this device overseas, I wonder where you expect to find customers, perhaps based on current demand for goTenna. I can think of a number of countries where this could be useful.
Close to 50 percent of the people who’ve tried over time on our website to buy something have abandoned their shopping cart because they were abroad. You can’t choose a country other than the US right now to ship to. So there were a lot of people from India, there’s a lot of people from Europe, there’s a lot of people from the Asia Pacific region generally, so it’s really all over the place. It’s super interesting. I mean look, in some ways a lot of the interest is some of the places you would imagine, like Canada, Europe, Australia, New Zealand.

We also have a lot of people in places like Japan that have seen a lot of disasters of different kinds. You know even though Japan has better wireless you know they think about how to prepare for everything from a tsunami to an earthquake to a nuclear disaster.

We’ve heard from activists in different places, environmental activists doing work in far-flung places in the Asia Pacific region, we’ve heard about people in the developing world, NGO’s in Africa. We talk about mobile banking applications, for instance: how, if we were able to do offline transactions [between goTenna users], then when somebody passes by somewhere that does have WiFi, all the transactions are then verified by the central network. I mean, there’s just all sorts of stuff being sent our way.

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