Interesting ... does this do any kind of store and forward or relaying? Say I send a message to a friend who happens to be out of range, but there was another GoTenna user who neither of us know, but who is in range of us both, will it relay the message via this 3rd party (encrypted) or is it purely a direct connection between sender --> receiver?
from the fAQs i gather that it sends from one gotenna to one or more recipient gotennas only: "Your smartphone will send the message to your goTenna, which will then shoot it out, via long-range radio waves, to the intended goTenna(s). At the other end, the exact same thing happens, in reverse: the recipient goTenna sends your message over BTLE to the smartphone app its paired with."
goTenna is an ad hoc reconfigurable network in that you can create your own network (1:1; groups, 1:all; all:1) but we can't currently mesh due to FCC regulations. So we went with long-range instead, since meshing is most useful in dense, short-range situations. We're on it though... ;)
This could be earth changingly huge if you open source your designs and make one with wifi/ethernet. Store and forward push to talk messages.
You could charge for access to internet side of the store and forward system. Maybe attach cryptocurrency to the messages to pay for routing across the POPs.
For now the chances of finding a third GoTenna user is quite low. In the future though this could be an alternative private Internet. A BitTorrent client could be a hit.
I think you are over estimating the bandwidth involved. They don't state much about the wireless protocol, but I am betting you don't want to send much more than a text message to get that range.
Which means that, no, they probably can't do seriously large amounts of data, but a picture (and definitely texting) can be sent through radio waves without much data retention issues.
We want to do that, but FCC regulations don't enable meshing (currently) on the bands we're using (151-154 MHz, aka the MURS band). We considered releasing a 900 MHz device that the FCC allows to mesh but then you only get, if you're lucky, up to 0.5 km range and it has to be line-of-sight. So we went with MURS because you can get greater range and don't have to be line-of-sight; the propagation characteristics are better down at MURS. Also, when we asked 1000 people (including testers) what they preferred -- a long-range MURS device or a short-range meshing device -- about 8 of 10 picked the former. So that's why the goTenna device you see today is our first release!
Most of the time. We live in NYC and have gotten anywhere from 0.5 mile to 3.5 miles range here, depending what part of the city you're in. There's nearly no such thing as LOS in a city unless, say, you're in a skyscraper ;)
Ah, I'm just surprised that buildings ended up mattering when you were deciding between 150MHz or 900MHz.
While people like to complain about the frequency getting higher and propagation dropping off (especially related to 2.4GHz and 5GHz wifi), I haven't found a good paper that guarantees that's the case. Anecdotally, I can receive a 5GHz signal in my office in Manhattan from a radar in Floyd Bennett Field, 12 miles away, with buildings in the way. Similarly, inside my apartment, I have much better luck with 440MHz radio communication than 144MHz communication. (Ground floor, so not that great either way.)
Being limited to 4W EIRP in the 900MHz ISM band probably played more of a role?
Would it be possible to build a software-level mesh on top of these devices even though they don't officially support meshing? In other words, could someone build an iPhone app that implements some sort of decentralized DNS and routes messages, even though the hardware can't do that on it's own?
MURS stations are prohibited from
operating as a repeater station or as a
signal booster. This prohibition in-
cludes store-and-forward packet oper-
ation.
Pretty clear cut. No packet routing, at all, for any reason, using any method. Doesn't matter if the radio firmware is doing it or if the client is doing it.
(There is a general exemption to all licensing rules, at least in ham radio, in the case of "to provide essential
communication needs in connection with the immediate safety of human life and immediate protection of property when normal communication systems are not available." (§97.403 Safety of life and protection of property.) Not terribly applicable in this situation, but a general "the Constitution is not a suicide pact" kinda thing.)
Then don't use packets, use a streams of hashes or something mathematically similar that doesn't fit the characteristics of a packet, but still retains the security, and integrity of the information.
You're right, that seems to be a very real regulatory risk for this product. Basically, this product is a cross band repeater between the ISM band and the MURS band. Just because the encoding is different doesn't not make it a repeater.
Bluetooth is a short range encrypted point to point link. It would be considered part of the station. Repeaters, in radio jargon, generally accept input from many sources, often without access control.
I think congestion is the main reason. If a transmission had unlimited range (hypothetically), the band would fill up pretty quickly, so it would stop being useful. Natural limits of signal transmission and power limits are what makes public, unlicensed bands feasible. They limit the possible uses, but, stochastically, enables many people to use it at the same time.
At any repeater hop, the transmission uses double the airtime in the overlapping of the sender's and repeater's ranges (once while the sender is sending it, once while the repeater is repeating). And of course, if you use repeaters, a single transmission will use the band in a much larger area than a direct transmission.
With a mesh network, a product like this would be very problematic: From "a way to connect with friends while off the grid" it would turn into "unlimited free texts for a one time charge" (in a country with absurd charges for texting on mobile phones). Soon, neither this nor any other application on the band would be possible anymore.
Congestion is definitely the main reason. What we've done at goTenna's networking layer though, is we've made it listen-before-talk. That, added to the fact that we're only doing short-burst transmissions, makes it highly unlikely goTenna will ever "step on other tranmissions' feet."
Do you intend to release the specifications for the protocol you are using? For example, would I be able to hook a computer with gnuradio up to a MURS radio and write software that could communicate with a goTenna?
This. I am super excited about the GoTenna because it is basically Ham Radio for the masses. But I'd also like to talk to GoTenna users with SDR or similar - in the spririt of non-encrypted ham communication.
That sounds like a way to write programs that use a bluetooth attached gotenna. Is that correct?
What I am asking is, could I talk to a gotenna using another radio setup of my own creation. Are you publishing enough information about gotenna for me to do that?
I ordered mine when the page went live. I hope to get them soon and start enjoying them. I'm actually headed out to Colorado to climb the Collegiate Peaks so I'm hoping they get here before mid-August.
Don't worry. I've got a ham license and I'm bringing my 2m/70cm HT with me and a SatCom set too. Would be nice to give it a go in real-world conditions.
What about for users of GoTenna in other countries that don't have the MURS band mesh restriction? Will they be allowed to enable mesh delivery through a third party on their device?
I slid the range slider all the way down as I'm in the, notoriously flat, Netherlands. Most of the time I'm in a city, Amsterdam, and then I'd have a range of 0 miles. Is that correct? That does not sound very useful to me then.
I think their slider is a bit misleading as if you have the slider at 0ft then the range is 0 but if you have it at 5ft then the range is up in the miles.
I think their point is that if you need to use this then you may need to seek slightly higher ground... or some stairs...
At $150 for two devices, it seems like a good deal for something that you would use once or twice a year. If the price goes up (as the website suggests that it is currently being offered at a 50% off promo), then I doubt it will become a mainstream device.
I love it... I wonder if there will be some kind of base station available? I'm thinking about Scout camps, where we turn up on a campsite with a few hundred kids, and often use radios to talk between important adults. The range would need to be a few miles, so WiFi is out of the question. Too expensive mind, but very very cool!
I can see myself using this during my mountain/road biking trips with friends, although the form format doesn't look very practical on the back pockets of cycling jerseys.
Does anyone have details on the RF layer? What band does it use? What emission type does it use? What bit rate does it send at? What happens when 1000 of these are in the same place at once?
Under the revised rules, MURS units are:
• Permitted to have detachable antennas;
• Permitted to have external antennas up to 6.1 meters (20 feet) above a structure or 18.3 meters (60 feet) above the ground, whichever is higher;
• Permitted to have a total power output (TPO) of up to two (2) watts (instead of two (2) watts effective radiated power);
• Not permitted to be used as cordless telephones, radiofacsimile (imaging), or for continuous carrier mode operations; and
• Not permitted to be used for repeater operations
Without a repeater, I would assume it is very difficult to imagine a hop-by-hop network?
Because repeaters utilize two channels at once (input and
output) and extend the operating range of a single user,
their use would limit the number of users able to share
these frequencies at the same time.
...
some commenters are concerned that MURS frequencies will be
congested and that repeater use will only aggravate this
problem. We agree.
Basically, they want to maximize the number of users that are able to reasonably use this band. At the time (1998-2002), two-way radios were much more popular than they are today (cell phones have largely made them obsolete), so I can understand the concern.
For whatever reason, MURS never did became as popular as GMRS or FRS did.
The part I think is missing is a connection back to the cell network so that you can give people in more remote locations the ability to text the rest of the world using this as a link. I don't see the 2-user walky-talky being that useful, but I would happily leave this and an extra phone in my car if it meant getting text functionality as I hike out 20 miles.
> The part I think is missing is a connection back to the cell network so that you can give people in more remote locations the ability to text the rest of the world using this as a link.
While reading their FAQ I thought of that, and if the API is open sourced or reverse-engineered, it shouldn't be too difficult to write a smartphone application which would act as a relay between to goTenna and the phone network (for instance if the relay-phone receives on the goTenna a message from A saying "SMS <num> foo bar" it could relay the "A says: foo bar" via SMS to <num>.
It could be a whole lot simpler than this. (And a whole less secure.) In high school I had a server running that scanned email for a keyword and my cellphone number; I didn't have a smartphone. So I texted a keyword and some code to my email. Then my server would read the email, see it contained the keyword, then interpret the rest of the code I sent and execute it. This would be insanely easy (and not too secure) to implement on Android for instance.
Then you misunderstood, or I am perpetually misunderstanding. The comment that I responded to asked for a way to use this product to send actual text messages. He wanted to relay a message to another phone via this product and then have his phone send an actual text message using information from the initial message. I gave a suggestion about how to do that.
Daniela, goTenna co-founder here -- back-haul is the 'easy part.' We just wanted to start with the hard part, i.e. a communication system that never requires central connectivity; a smart network with no actual central brain.
It sounds like you don't even need the hard part for a viable product: range extender for cell phones targeted at people engaged in outdoor activities but parked somewhere with cell phone reception.
Technically, this has been possible for a long time, but it is not allowed for regulatory reasons, and those regulations are not just there because somebody enjoys being a killjoy. Radio transmission and networks are a complex subject matter. Most of all, they're a scarce, common resource and it's easy to mess things up for others.
If you want real off the grid connectivity, buy or rent a sat phone or a satellite emergency notification device (there are pretty affordable choices for both).
If there were a band of legitimately useful long range spectrum that was a free for all, wouldn't there be a strong economic incentive for people to invent modulation techniques capable of functioning effectively in such a noisy environment?
Alternatively, wouldn't it be conceivable for transmitting nodes to cooperate with one another to send transmissions. For example, if N nodes all transmit encrypted content on the same band to M receivers, then the signals of all but one of those N transmitters look like noise to each of the M receivers, thus limiting the transmission rate achievable over any given channel. If instead of that approach, what if a transmitter instead used a second frequency solely for the purpose of coordinating transmissions with the other nodes so as to minimize interference which each other. In addition to coordinating when they are or are not transmitting, couldn't they selective choose different modulation techniques that are easily distinguishable from one another, and thus transmittable simultaneously.
Feel free to educate or correct me here. I know very little about this domain.
If somebody reverse engineers their API and their devices are being used illegally for mesh networking, the most likely thing is not a mesh networking revolution [1], but the FCC taking their devices off the market. Daniela's reply to your posting could be seen as endorsing this, which won't help.
[1] you can legally do this in other bands, and there are some pretty cool open source projects.
Totally agree on how the FCC might react, but I don't see how you interpreted Daniela's response as an endorsement of reverse engineering their APIs to enable illegal mesh networking.
All it takes is replacing the actual phone dialer app (which AFAIK can only be done in AOSP-based distributions) to make it work transparently.
You'd also have to add a phone number broadcasting service to make it work with phone numbers though, but I can see the potential. I'm much more skeptical about range, battery or security concerns.
> You'd also have to add a phone number broadcasting service to make it work with phone numbers though, but I can see the potential. I'm much more skeptical about range, battery or security concerns
Have the app sync to a registry online when connectivity is available, and keep the key-value table locally (phone->deviceID).
From the few details [1] I've been able to find it seems like it's unusable in the UK anyway as it uses 151-154 MHz, which is a licensed band. If they moved it up into the 433ishMHz unlicensed band their range claims would all have to be revised.
To me it seemed like part of your sales pitch was infering that you could use it internationally where you don't have service or don't want to pay the high overages ;)
I guess the main difference is that walkie-talkies don't connect to your phone, or share text or GPS data. They also don't mesh network (automatically).
Is it me or is their a guy in the video getting baked? Not only that it is around the security part where he is getting in contact with his mate "Jason Greengrocer" about getting more. That part makes me happy!
I think they are quite deliberately pointing out that dealers can communicate with their users in private, outside of law enforcement spying on them [Use case A1].
All transmissions are end-to-end encrypted, unless you use the "shout" or "emergency" features which are, by definition, messages to everyone within range of you.
Hi! I'm on the mobile development team here at goTenna. We're taking advantage of the Bluetooth LE standard encyption with is AES-CCM. More on that here: http://bit.ly/1teKWvG
For encrypting the data as it's sent between gotennas we're using 1024 bit RSA. Not sure what level of detail you'd like.. but here are a few things to get you started!
So, question: How do you authenticate the person you are trying to message with, i.e. How do I know that I'm sending the message I want to send to (the real) Jason Greengrocer not the FBI pretending to be Jason?
At set up, you can either set up your goTenna ID to be your phone number (recommended, as it will then integrate with your contact list and make it easy for other people you know using goTenna to find you with goTenna) or a randomly generated string we create for you (for the crypto people out there!).
The way we ensure your (or Jason Greengrocer's!) phone number isn't spoofed is we verify your phone number through the regular telephony network when you do have connectivity. If you complete setup without connectivity and enter a telephone number as your ID, you will show up as "Unverified." We don't recommend offline setup though because then you can't download all our awesome detailed offline map packs (you'll just get the world vector map that comes with the app at download).
No voice? That lost all of my interest. So now I need to tap out a message on my expensive, somewhat fragile smartphone with dirty fingers while losing all sight of the road for a minute. Instead of a sturdy walkie-talkie where I can hear the voices of my friends, talk efficiently in real sentences and I can look where I'm going all the time.
I get it's not for everyone, but what we learned as we developed this is that more people wanted asynchronous data comms as opposed to real-time voice. And when I say "more," I mean like, 75% of testers preferred the former.
From a networking perspective, as well, it makes our ad hoc reconfigurable network more scalable if we're focused on short-burst transmissions that are, technically speaking, delay-tolerant. This means that even if you're at a huge event with tons of people using goTenna, even if a gajillion of them press "send" at the exact same femtosecond, all the messages can get through in a matter of seconds if not milliseconds.
I wonder how hackable these will be, or what kind of bandwidth you might be able to push. I could see putting one at my home and one at my office to create a poormans wireless bridge.
It's 2 meter VHF, very low bandwidth. Useful for GPS and text messages only. An Email bridge might be pretty cool, but I'm not sure of the exact speed.
Yes, we're focused, with this first product, on asynchronous, low-bandwidth data comms. Through our R&D for the past 21 months, that's what most testers and people wanted most, especially when they don't have service otherwise.
This is pretty interesting. I work for an NGO and something like this looks really useful for people working in the field to allow some sort of simple communication/location when you don't have service, or it is super expensive.
This is a consumer device that adds a smartphone as a single point of failure.
There's a good reason why handheld or car mounted radios have been quite popular with NGOs all over the world. They're robust, reliable and simple. And in many cases, NGOs can get access to radio bands with more interesting transmission characteristics.
"Early supporters get 50% off for a limited time."
I always wonder about this kind of pricing structure. It seems like selling your product for half of what you plan to eventually charge for it gives you pretty useless data on what the proper price should be. You may sell a ton at $100, but people perceive that as expensive, and then you might sell zero at $200.
178 comments
[ 3.1 ms ] story [ 224 ms ] threadhttps://gotenna.myshopify.com/pages/faqs
building an ad-hoc network with these things would be kind of cool though. DIY city networks anyone...
You could charge for access to internet side of the store and forward system. Maybe attach cryptocurrency to the messages to pay for routing across the POPs.
Are you using the TI chips?
Which means that, no, they probably can't do seriously large amounts of data, but a picture (and definitely texting) can be sent through radio waves without much data retention issues.
While people like to complain about the frequency getting higher and propagation dropping off (especially related to 2.4GHz and 5GHz wifi), I haven't found a good paper that guarantees that's the case. Anecdotally, I can receive a 5GHz signal in my office in Manhattan from a radar in Floyd Bennett Field, 12 miles away, with buildings in the way. Similarly, inside my apartment, I have much better luck with 440MHz radio communication than 144MHz communication. (Ground floor, so not that great either way.)
Being limited to 4W EIRP in the 900MHz ISM band probably played more of a role?
Anyway, you might want to find these guys: https://news.ycombinator.com/item?id=7981431
The combination of your product with their technology could be quite interesting.
Also, follow up question: does your protocol attempt to recover signals from below the noise floor?
Pretty clear cut. No packet routing, at all, for any reason, using any method. Doesn't matter if the radio firmware is doing it or if the client is doing it.
(There is a general exemption to all licensing rules, at least in ham radio, in the case of "to provide essential communication needs in connection with the immediate safety of human life and immediate protection of property when normal communication systems are not available." (§97.403 Safety of life and protection of property.) Not terribly applicable in this situation, but a general "the Constitution is not a suicide pact" kinda thing.)
At any repeater hop, the transmission uses double the airtime in the overlapping of the sender's and repeater's ranges (once while the sender is sending it, once while the repeater is repeating). And of course, if you use repeaters, a single transmission will use the band in a much larger area than a direct transmission.
With a mesh network, a product like this would be very problematic: From "a way to connect with friends while off the grid" it would turn into "unlimited free texts for a one time charge" (in a country with absurd charges for texting on mobile phones). Soon, neither this nor any other application on the band would be possible anymore.
What I am asking is, could I talk to a gotenna using another radio setup of my own creation. Are you publishing enough information about gotenna for me to do that?
Don't worry. I've got a ham license and I'm bringing my 2m/70cm HT with me and a SatCom set too. Would be nice to give it a go in real-world conditions.
Can someone confirm that this is correct?
I think their point is that if you need to use this then you may need to seek slightly higher ground... or some stairs...
Excerpt From https://apps.fcc.gov/edocs_public/attachmatch/FCC-02-139A1.p...
Under the revised rules, MURS units are: • Permitted to have detachable antennas; • Permitted to have external antennas up to 6.1 meters (20 feet) above a structure or 18.3 meters (60 feet) above the ground, whichever is higher; • Permitted to have a total power output (TPO) of up to two (2) watts (instead of two (2) watts effective radiated power); • Not permitted to be used as cordless telephones, radiofacsimile (imaging), or for continuous carrier mode operations; and • Not permitted to be used for repeater operations
Without a repeater, I would assume it is very difficult to imagine a hop-by-hop network?
For whatever reason, MURS never did became as popular as GMRS or FRS did.
While reading their FAQ I thought of that, and if the API is open sourced or reverse-engineered, it shouldn't be too difficult to write a smartphone application which would act as a relay between to goTenna and the phone network (for instance if the relay-phone receives on the goTenna a message from A saying "SMS <num> foo bar" it could relay the "A says: foo bar" via SMS to <num>.
If you want real off the grid connectivity, buy or rent a sat phone or a satellite emergency notification device (there are pretty affordable choices for both).
Alternatively, wouldn't it be conceivable for transmitting nodes to cooperate with one another to send transmissions. For example, if N nodes all transmit encrypted content on the same band to M receivers, then the signals of all but one of those N transmitters look like noise to each of the M receivers, thus limiting the transmission rate achievable over any given channel. If instead of that approach, what if a transmitter instead used a second frequency solely for the purpose of coordinating transmissions with the other nodes so as to minimize interference which each other. In addition to coordinating when they are or are not transmitting, couldn't they selective choose different modulation techniques that are easily distinguishable from one another, and thus transmittable simultaneously.
Feel free to educate or correct me here. I know very little about this domain.
[1] you can legally do this in other bands, and there are some pretty cool open source projects.
Ugh, it's a lot less magical than they make it seem in the video.
You'd also have to add a phone number broadcasting service to make it work with phone numbers though, but I can see the potential. I'm much more skeptical about range, battery or security concerns.
Have the app sync to a registry online when connectivity is available, and keep the key-value table locally (phone->deviceID).
[1] http://gigaom.com/2014/07/17/no-signal-gotenna-has-a-messagi...
For encrypting the data as it's sent between gotennas we're using 1024 bit RSA. Not sure what level of detail you'd like.. but here are a few things to get you started!
RSA itself: http://bit.ly/1kDlTgP Cryptographic Services: http://bit.ly/1teLhPb More on CDSA (see above articles first): http://bit.ly/Ug2CLt
Much of our approach is fairly standard!
From a networking perspective, as well, it makes our ad hoc reconfigurable network more scalable if we're focused on short-burst transmissions that are, technically speaking, delay-tolerant. This means that even if you're at a huge event with tons of people using goTenna, even if a gajillion of them press "send" at the exact same femtosecond, all the messages can get through in a matter of seconds if not milliseconds.
I still believe I'm with the 25% that didn't prefer asynchronous messaging.
If you want walkie-talkies, there's another entire band dedicated to unlicensed voice calls - http://www.fcc.gov/encyclopedia/family-radio-service-frs
You could ask them to make a dual mode device. MURS for text/sms (and greater distance), and FRS for voice and picture messages (with less distance).
You could stop for a second, I guess.
Instead of a sturdy walkie-talkie
Why don't you just buy a walkie-talkie? They're cheaper, they just don't interface with your phone. But it sounds like that's what you want.
http://villagetelco.org/mesh-potato/
There's a good reason why handheld or car mounted radios have been quite popular with NGOs all over the world. They're robust, reliable and simple. And in many cases, NGOs can get access to radio bands with more interesting transmission characteristics.
It didn't bother me much though, it's faded to almost-white and I only noticed because I read this comment before.
Lol, humans.
What radio service and frequencies does it use?
We are now at a device that is Bluetooth LE-enabled that works on the 151-154 MHz range from http://www.cnet.com/news/gotenna-creates-cell-network-out-of...
So this is essentially a mesh network or at least all independent nodes?
I always wonder about this kind of pricing structure. It seems like selling your product for half of what you plan to eventually charge for it gives you pretty useless data on what the proper price should be. You may sell a ton at $100, but people perceive that as expensive, and then you might sell zero at $200.