This is un. fucking. real. I work in the IoT space (specifically on health devices), and something like this would be absolutely a GOD SEND for the things that we're doing.
The current "hottness" in our space is bluetooth low energy (BLE). This is super low power (or, rather: chips that are really good at going to deep sleep, and then coming online very quickly to burst some data out), but the range on BLE isn't great.
Some companies use general purpose radios (these guys: http://www.glowcaps.com/ are basically an couple of atmega 328s and some 433mhz radios) for range, but it seems like everything is moving towards BLE because you can use your cellphone/tablet as a base station.
If LORA can seriously get this sort of range (I'm skeptical, honestly), then that is a total game-changer for IoT.
A friend of mine at a chip manufacturer in town was telling me about some radio thing they were doing that had range like this about a year ago, but I didn't believe him. That little of power, for that long of range seems like straight-up magic.
Super cool stuff! Very excited to see this really happening!
We're putting up a LoRa network here in SF, and plan to publish a bunch of our test data, including link error rates and throughput. Urban deployments are new so more data will help us all understand what's doable. (There are a few rural deployments in production; less uncertainty there.)
We (Amerihub) craft custom data transit solutions and manage the networks and tech assets for a lot of medical and manufacturing clients in the Chicago area. This could have HUGE applications in those spaces.
I signed up for your beta via your site. We want in asap.
Anything similar going on in Europe? London specifically? I would love to create some pocketable hardware that never needs recharging and sends text and (compact) vector-based graphical market updates to people.
Yes, on the Continent, at least! I'm not sure about the UK.
Both LoRa and Sigfox came out of French companies, and several wireless carriers have announced plans to build networks. Also check out The Things Network guys in Amsterdam who are trying to crowdsource a network, very cool stuff.
Sigfox is being used in the roll out of smart gas/electricity meters in the north of England/Scotland. Unfortunately Telefonica won the south any they will use the GSM network.
LoRa basestation gateways are available off-the-shelf for from Kerlink, Multitech, and Link Labs. The gateways are actually quite simple, they just forward packets to the cloud network server, and back to the clients.
This is all that IoT needs, though. It's not about streaming video or music or something, it's about a sensor that goes high when somebody is sitting in a chair, or that sends an integer value once every few minutes.
I think you answered your own question -- of course WiFi makes sense for small/short range networks. Its cheap and fast.
These technologies are more exciting because you are talking about realistic coverage areas of square kilometers with inexpensive, unlicensed radios. Think of something like a large natural gas pumping field -- there are tons of industrial sensors and controls spread out over a fairly large area that don't need to send much data. I work in the radio industry, and these technologies, if they live up to their hype, will be industry disrupting.
Maybe -- throughput depends on which radio tech we're talking about, and the networks need to get built with density appropriate for the task.
LoRa radios that are close to a gateway can dynamically shift to a 300 Kbps mode, or down to a long-range mode that's ~10Kbps (but yes could also be degraded further by error rate if at edge-of-range).
Great question. It depends on the technology. For example with LoRa, in the US there are 64 usable channels. In addition there are 5 available "spreading factors" per channel that are orthogonal to each other. A lower spreading factor device may communicate at twice the data rate of the one above it (but with worse range). So for example one device may communicate at 1kbps at SF12, another may communicate at SF11 at 2kpbs at the same time. This means you can have 31 devices communicating 1kb within a 1 second window, on a single channel.
Other technologies can have many more simultaneously communicating devices. In the case of OnRamp/Ingenu, a factor of 1600 more due to their encoding scheme.
Narrowband technologies like SigFox (based on TI radios), have way more than 64 channels available in the US, I believe in the range of 1000, but are more susceptible to interference.
Forgot to add that Sigfox isn't based on TI radios, but is hardware-agnostic.
Basically, most sub-GHz radio transceivers are compatible, and it's all about adding the soft stack.
Current HW partners include TI, SiLabs, Atmel, Axsem, ..
Sigfox doesn't have channels per se.
Each Sigfox message is concentrated on ~100Hz, with the base stations listening to a 200KHz part of the available spectrum.
Regarding interferors, the Ultra Narrow Band technology offers a great resistence: energy concentrated on a tiny width, plus the "random frequency" effect of the sigfox protocol.
If you're skeptical about LPWAN range claims .. better thing to do is to test :)
We (Sigfox) are running a hackathon in SF on Nov 20th, in partnership with the City.
Good occasion to test the live network, and get your hands on a dev kit
The Akeru board is still quite expensive (€100), as it's a full Arduino/Genuino board + sigfox module + subscription. And the guy is producing them himself, with small batches.
This one is not FCC-ready yet anyway.
That's exactly my problem too, and I decided to develop a prototype protocol for it. I wrote a reference implementation in python, feedback very much desired:
* The weaknesses you outline in the introduction are pretty serious.
* How to exchange the topic key is described as out of scope, but totally critical since you also propose renewing the topic key as a way of attaining forward secrecy.
* You totally hand-waved away the exchange of participant keys.
* I'm pretty sure you've exposed some cryptographic weaknesses in the core protocol but I'm not going to spend the time to keep analyzing.
So in short, your protocol is not very useful. Sorry.
The biggest problems in IoT space are key agreement and machine trust among a hugely heterogeneous population. Solutions will come in the form of standards adoption, hegemony, government regulation, and probably a combination of all three. Multicast security is somewhat of a solved problem (e.g. wifi.)
Communications security between actual people is an entirely different and more easily solved problem.
> The weaknesses you outline in the introduction are pretty serious.
There's no weakness there that's not fixable. Replay protection can be easily added in the layer above, and rolling the topic key can also be done. The nonce problem can go away with using the wider Salsa variant.
> How to exchange the topic key is described as out of scope, but totally critical since you also propose renewing the topic key as a way of attaining forward secrecy.
Are you going after people or machines as your target? It matters which, because machines can't do human trust, so then the issue of how you exchange keys and establish trust is forced.
What's the stop a MITM between a client and any other client from intercepting the conversation? In your protocol, nothing, except that if the MITM isn't there at the start, they can't join in right away. This is not a very useful assurance. So please, keep working on it, but I think your challenges are pretty serious. If the problems are fixable, then go ahead and fix them. I'd be happy to take another look - after that.
Link encryption and authentication is pretty much "solved" in that we have the components we need already. Then there's the issue of code bugs and lack of updates - I think this should be solved in most cases by devices exclusively talking over a filtered API via a trusted gateway to prevent exploit attempts from succeeding.
You can amplify a signal and send it far. But due to FCC regulation in the 900MHz band for example you can only instantaneously transmit at 30W.
Another way to make a signal go further is to transmit at a lower data rate (thus spreading your signal out over time so that in effect you have more power in the signal). The FCC limits "dwell time" in a single channel to .4s in the 900MHz band.
Yet another way to increase range is to increase your receive sensitivity. Lora's Chirp Spread Spectrum coding actually allows signals to be received below the noise floor. You can liken this to decrypting data: to an observer the signal looks like noise, but if you know how to look within the noise you can pull the actual coded information out.
All of these LPWAN technologies use different forms of coding and signal spreading over time to get long range. Note how spreading your signal over time means your throughput goes down.
It's important to realise that - at least if I'm understanding spread spectrum technology correctly - there's no such thing as a free lunch, or free receive sensitivity. If you take an ordinary narrowband signal and convert it to spread-spectrum, you can indeed make it disappear beneath the noise floor by spreading it out, and a receiver that knows where to look can despread it and pull a signal out from what looks like noise, but the effective received signal strength and signal to noise ratio after despreading is still exactly the same as it was with the narrowband signal. You haven't gained anything, you're just moving your signal around a bit. The only advantage of this spread-spectrum technique is that other signals that don't use the same spreading code are spread out by the despreading process and look like wideband noise to the receiver.
Any MU-MIMO technology in sight for these radio protocols? Would be a great way to potentially extend range and throughout if multiple spatial channels could be used on each frequency / radio channel for every pair of connected devices. If it could be done efficiently enough, it could also reduce congestion even in tight crowds for things like wearables by reducing interference.
I haven't seen anything using MIMO yet. Not sure how that would affect power usage. The closest thing now is that a key aspect of Ingenu's solution is receive diversity. All of their client radios require two antennas.
Not limited by the protocol per se, but limited by the design requirements of BLE.
BLE; you're talking about power requirements of ~10mA transmit (current consumption), and averages in the <10μA range. That's the whole point of the tech. It's stuff that can run for years on a watch battery.
Now: how LORA is accomplishing such crazy long ranges when supposedly consuming similar amounts of current goes a little beyond my understanding of RF. There are a few people commenting in this thread that seem to have the knowledge, though!
They're achieving those ranges by being very, very slow.
It's probably easiest to explain how this works with conventional narrowband digital modulation schemes. For a typical modulation scheme, the bandwidth of the modulated signal is proportional to the bitrate. There's also some minimum signal-to-noise ratio below which the receiver can't decode it. By sending more slowly, you get a narrower signal, which means that the receiver can listen to a narrower slice of spectrum. Even though the received signal's no more powerful than before, because the receiver is no longer hearing all the noise outside of that narrower band the SNR improves and it can decode much weaker signals.
LORA appears to use direct-sequence spread spectrum, which basically means that the transmitter applies a spreading code to convert the narrow signal to a very wide one and the receiver uses the same code to despread it again and pick out the signal. Its range improvement is still based on the exact same principle of speaking very slowly to improve your SNR though.
Lower power, but highly processed radio signals are fascinating to me. I've been playing with WSPR on the 10 meter band which is fixing (hopefully) to open up a little here over the next couple of months. With about 1/10th of the power of my Wi-Fi router and a long wire over top of the house, I've been picked up so far this year in California from Ohio. Last year I was heard almost daily in Europe. A blogger I follow with a bit more power but still less than a watt has been heard on several continents almost every other day from the UK.
Anyway, signals are a function of time as well as bandwidth, and with more precise clocks in our devices and higher CPU power to make sense of it, it is an exciting time live and see what's next.
What's your callsign? I'll see if I can pick you up with my RTL-SDR+Ham-it-up and maybe once I have my ham license I'll talk back.
Every now and then I find a post on HN that really makes my day and I realize how awesome this community is and how our interests overlap beyond computer programming and entrepreneurship. This is one of them.
Well, I'd appreciate a report on the WSPRNet page once you get your ticket. I'm W8KV, but I don't know that I'm putting out all that much, and when I look at streetview of the houses of the people that pick up the signal they have some crazy setups! That said, I was able to receive PSK31 from France here in Ohio back before I got my ticket with just an old AC extension cord strung along the ceiling as an antenna, so keep playing with things, you never know what all will work.
One of my most memorable moments in amateur radio was making a JT65 contact - 1 watt, from the north-central US to the island of Reunion, roughly 10k Kilometers.
Ok, since there are some radio wizards in this thread: if I want to log low bandwidth sensor data (so < 1kbps) on a unidirectional (if that helps) link over ~ 500m, almost clean line-of-sight with some trees in there, what are my options? I'd prefer to spend little money and use little power on the sensor end. I'm considering an ESP8266 (so 802.11) with a high-gain directional antenna. Sender and receiver are fixed locations.
Here are two low cost options (I recommend #1 for most people and #2 if you have an impressive beard):
1. The esp8266 like you have already mentioned. Get one with a u.fl connector and make your own cantenna to attach to it. You can use the microcontroller in the esp8266 to take the sensor readings (it even has an ADC to read analog sensors). This is the new hotness and there are tons of examples.
2. Even cheaper but less user friendly is a very low tech 433 MHz RF transmitter like you can get on eBay. You then need an external microcontroller to run it so you might actually be less cost effective overall and these things take quite a bit of effort to implement a reliable comm system because of the on-off keying system and zero built in error correction. There are libraries like VirtualWire or RadioHead that take quite a bit of pain away. You can get other frequencies if your country doesn't allow unlicensed 433MHz transmissions. Example of what I'm talking about: http://www.ebay.com/itm/like/140719918135?ul_noapp=true&chn=...
ESP8266 is worth checking out because its dirt cheap, but it really depends how "clean" your line of sight is. 900 MHz radios will have better propagation. Might want to check out something like this: http://rpi900.com/hardware/introduction.html
I'm not sure what you mean by "little money" but for less than $100 per location, you could have a 100+ Mbps link using Ubiquiti NanoStations. You can use Wi-Fi or their proprietary protocol and the radios are available on 2.4, 3.65, and 5 GHz. These little things will cover your 500m link with ease but might very well be extreme overkill if all you really want is <= 1 Kbps throughput.
Yeah, that's definitely overkill, but those are cool for applications needing the bandwidth. For comparison, the ESP8266 costs ~ $5, so that's "little money".
Our offices are equipped with sensors with LoRa radio's. We're partnering with a local cell service provider (proximus.be) who are upgrading their base stations to be LoRa base stations and we're a pilot installation because we're developing software that does things with the sensor data (smart office type stuff, like adaptive cleaning schedules based on space utilization). The sensors are pre-configured for their network. You stick them to the wall, pull a latch, and they connect directly to the public base station, no additional hardware involved. Surprisingly, it works, and they're claiming five years battery life.
There are some downsides though. The sensor+radio combo's are custom orders for now, meaning they take too long to arrive and are too expensive. That issue will get solved over time. They also have an extremely low data rate. A single set of values every 15 minutes. That issue probably won't be solved. Still, you can learn a lot from a CO2 reading or a door opening counter reading even if it's only every 15 minutes.
The hard bit is the intelligent software that processes the data. If anything is the achilles heel of IoT it's that lots of data does not necessarily lead to any insights.
Don't get too excited. Low-power devices get really interesting when they start to scale up in numbers. None of the technologies listed in this article have demonstrated that capability. The coming IoT shakedown is going to leave quite a few ebullient "visionaries" crying in their martini while they consider their next startup.
* Star networks are infrastructure heavy, requiring build-outs on part with cellular networks, and having low per-base density.
* LoRa's CSS (Chirp Spread Spectrum) approach doesn't promise to scale well, as devices start to interfere with each other over its very wide spectrum scattershot. There are other problems.
Disclaimer: I work for an IoT mesh company (SSNI/WiSun) and we're busy cranking out massive networks that actually work. Sadly you can't get a dev kit at Fry's yet.
Shawn from BeepNetworks here. Check out OnRamp (now Ingenu). Their coding scheme allows 1600 simultaneously communicating devices per spread factor per channel. That 1600 factor means their base station can handle massive numbers of clients compared to cellular. http://www.scribd.com/doc/273814075/On-Ramp-Wireless-White-P.... That paper is certainly biased in their favor, but the tech is real and they have serious deployments.
The counterpoint to mesh is that it's a) much more complex to implement b) uses more power since nodes need to relay each others' communications.
It will be interesting to see how it plays out, and who ends up crying in whose martinis as you say.
Hmmm. I'd pay very careful attention to the fine print on that. The way their scheme works is that each node chooses a random time to start its transmission, which means that all their chipping sequences are hopefully desynchronised. Then the AP tries decoding from all possible starting points at once. If I'm understanding spread-spectrum correctly, each parallel receiver pulls out only the signal from the node (or nodes) whose chipping sequences are synchronized with it, while all the other node's signals appear as noise to it.
Which is the catch. Run too many nodes at once, and the signal-to-noise ratio will rise and your signals will start to fail to decode. What this generally means is that nodes at the edge of the network - the ones with the lowest SNR budget - start to drop out first. I'd be interested to see what their link budget and range is with 1600 devices on the same node, or conversely how many devices they can fit on a node at the advertised link budget and range. (Also, just how well they cope with a mixture of near and far nodes.)
that's 1600 devices simultaneously communicating. a sensor might only spend a fraction of a percent of its time transmitting data, so the number of devices supported is orders of magnitude higher.
These radios have been available for quite some time, it's the Semtech SX127x line (e.g. SX1276). I was looking into LoRa and other long-range IoT WAN radios about a year ago for a research project.
You can get cheap (22 USD) Arduino-compatible development boards here using HopeRF modules, which work great with the RadioHead library:
The main innovation here is battery life. You can do most of these things now with two-way pager technology.[1] There are a lot of commercial air conditioning units and vending machines phoning home that way right now. They all have AC power, so battery life isn't an issue.
Two way pagers have more or less died out for humans, but for M2M (machine to machine) communication they are alive and well.
For LoRa, check out Multitech, LinkLabs, and Libelium. Semtech has a development board, too, though it would need to be paired with a microcontroller. Warning that most of this stuff is not for the faint of heart -- you need to be ready to dive into datasheets, bring up radio drivers, etc.
Ingenu has radio modules and dev boards, but I don't think they're set up to sell single-unit quantity.
If you're in San Francisco, we're making a going to be distributing dev boards that will work out of the box and come with a bunch of sensors. Just sign up on our website: www.beepnetworks.com
If you haven't lost your faith in Kickstarter yet, this project has $180k committed. A €40 pledge will get you a LoRa board and €200 for a LoRa gateway and what is essentially a demo dongle.
Like the author mentioned, these are new-ish/emerging standards and there isn't a de-facto board like Arduino just yet. Therefore it's kind of hard to recommend a board that I know has a ton of documentation and a big community.
However, if you are the adventurous type and don't mind working with unpolished libraries and figuring things out from function descriptions, there are tons of smaller people putting out boards on Tindie: https://www.tindie.com/
But bottom line is that this tech isn't (yet) popular enough to try without getting a little dirty. If you can afford a bigger battery, try 900 MHz Xbee transmitters for an easy to interface serial with long range.
Try out Low Power Labs Monteino with the HopeRF, RFM95 LoRa module. The radio library is lacking but you can get up and running quickly. https://lowpowerlab.com
If you want something a little more enterprisy and turn-key, try the new guys (I work for them). The Patch module has both a BLE and LoRa radio. https://www.filament.com
I attended this bootcamp in Zurich, Switzerland a couple of days ago and it was quite interesting. Swisscom, the biggest Telco here covered Zurich and Geneva already with a lorawan net and they will give access to it during an upcoming hackathon (http://iot-hackathon.swisscom.com/).
> So now you can buy a radio chip for a few bucks and add it to any device.
Where?
> Think kilobits-per-second, not megabits-per-second.
Well, voice is (or was...) 32kbps, so technically you could make a voice call over these radios, if they can give you 32kbps? I've heard of voice compression as low as 8kbps too. Imagine a cellphone that lasts months :)
Opus SILK can go as low as 6000 bs. You can use it in existing VoIP solutions, VoIP over LoRa radio's would be very cool.. but I'm not sure if you can layer tcp/ip on top them yet.
LoRa is a really cool technology. We are incorporating it into our networking stack/ hardware module. From field testing, we've seen about 4-6 miles line of sight, and about a mile through an urban environment (parking garage, apartment building, etc). Plus the bare radio chips are less than $10 bucks.
I wonder how it will scale. Sure, you can use spread spectrum but to other unlicensed users it will look like the noise floor is increasing. As more people connect, the more noise there will be, and the players will either increase their power to maintain their SNRs, or have to slow down their rates.
Gets about 1.6 miles with basic wire antenna. More if you play with directional yagis or the like
The problem with LoRa is that yes you can get ten miles, assuming you chose the right antenna and radio, but you wont be able to transmit for very long.
I have a number of sensors that have RFM29 radios in them, and they run off solar and super caps. However they only transmit once a minute, and they don't stay on for a reply.
Power management is key at low power levels. To get ten years battery life, you either need massive batteries, or only transmit once every day/hour.
Would this open possibilities for a direct machine to machine network that didn't go over the internet? (I.e. could I set up something to ssh to my home server from my laptop without needing wifi/cellular coverage?
Where you get squeezed is, output power is limited by regulation (for good reason). And sensitivity is limited by noise which is related to your signal bandwidth. The wider the band, the more noise you capture. There is a signal to noise 'wall/floor' defined by information theory, etc etc. Encoding technologies+ allow you to operate closer to the wall, but it's still here as a hard limit. Once your signal/noise drops below 3-6db game over+.
These new technologies/products try to solve the problem from both ends. Increasing transmit power to the max allowed. Some early Zigbee chips for instance had transmit powers of 0db, big fail. These new radios transmit 10 to 20 db output power. On the receive side reduce bandwidth to increase the sensitivity by 10-30 db, at the expense of data rate.
The cost of all this is very low bandwidth. Not just in bps, but also packets per minute due to duty cycle regulations. This poses some problems if you want encrypt your packets. Add at least 32-64 bytes overhead. Another problem is as the coverage area gets wider so does the number of interfering radio's.
+ Sometimes you hear comments that spread spectrum allows you operate below the noise floor, but that's only for the spread signal. Once the signal is despread at the receiver, same rules apply.
Sure, you can hook up a low power serial transmitter to a Raspberry Pi's UART and have a text only console to operate over. But you are pretty much limited to text only and very slow file transer over a serial transmission like Kermit or Xmodem. You'll hate it for the type of computing you're used to. If you want a graphical remote desktop you are better off setting up a WiFi router/WLAN and connecting through a remote desktop connection. This will consume much more battery life, but I power a WiFi router with an RC LiPo battery and a voltage regulator and it lasts for several hours (but you certainly aren't getting days of battery life).
Probably not. Not only are they very slow, but radio propagation at the frequencies they're using is still more or less line-of-sight, which means that your range is going to be limited by the horizon. See https://en.wikipedia.org/wiki/Line-of-sight_propagation
Isn't 11 Kbps fine for SSH? That's 11 thousand ascii characters per second. The latency is the important part, I assume this is low as well but I don't know.
Actually each ascii character takes up a byte (8 bits). You can get this down to just 7 bits if you aren't using the extended table, but a byte is very convenient and what most programs use for the size of a char.
That means that with an 11Kbps line you are getting about 1,000 characters per second once you factor in other communication over head (stop bits, parity bits, etc). While this may sound fast it is painfully slow for anything other than typing in single line commands and reading single line responses. The transfer of a blank 4KB text file will take three seconds. The transfer of a plain text file the size of a book would take a few minutes.
With the additional overhead of SSH you will actually see the characters appearing on the screen like a lame 80s hacker movie.
As someone who remembers 300 baud modems used in a trans-atlantic connection, I also remember that you could get stuff done if you set your expections accordingly.
Perhaps use mosh? It hides the lag on low bandwidth links. I remember using Citrix remote desktop on a 14k4 link. I remember using the internet at 14k4 - worked fine.
The current "hottness" in our space is bluetooth low energy (BLE). This is super low power (or, rather: chips that are really good at going to deep sleep, and then coming online very quickly to burst some data out), but the range on BLE isn't great.
Some companies use general purpose radios (these guys: http://www.glowcaps.com/ are basically an couple of atmega 328s and some 433mhz radios) for range, but it seems like everything is moving towards BLE because you can use your cellphone/tablet as a base station.
If LORA can seriously get this sort of range (I'm skeptical, honestly), then that is a total game-changer for IoT.
A friend of mine at a chip manufacturer in town was telling me about some radio thing they were doing that had range like this about a year ago, but I didn't believe him. That little of power, for that long of range seems like straight-up magic.
Super cool stuff! Very excited to see this really happening!
Not to get too silly, but this about sums up how this makes me feel with regards to IoT: https://media.giphy.com/media/rl0FOxdz7CcxO/giphy.gif