 I think most of you have heard of the internet of things. Unsurprisingly, it's made of things which connect to the internet. But how do you get the internet to your thing kilometers away from Wi-Fi? Let's give a warm welcome to Tobias and Pea who are going to connect the dots for us. Yeah, welcome and thanks for coming out of you. It's still the first day, so I feel I just arrived, so welcome to the 35 CARES Communication Congress. We want to show you today how you can build your own devices, like he said, using Adreno or some other cheap building blocks to build your own sensor and connect it to the internet. We have one example, which when I start, let's assume you have a fine dust sensor and you want to measure the fine dust level in Leipzig. You can deploy them at other points where you want to measure it, like there's a highway or some living area. What we need next is some internet. Best internet at the moment is probably here at the CARES Communication Congress. Thanks for the knock. And yeah, well, the question is how do you connect your sensors with the internet? Since we don't want to take holes and draw wires, we do it wireless. And that's where we use Laura. And yeah, Laura is a wireless radio technology that's designed for low power usage. It has great coverage at range over several kilometers, even with this low power usage. It is cost efficient, so you basically buy the chip and then you, good, you don't have any additional cost as with GSM. And the data rate is pretty low, but well, we only need a few bytes every few minutes, so that's totally fine. What we actually did was a project with a student from Hamburg. He had his master's thesis and he wanted to collect these fine dust data. And we created a sensor, built a sensor for him. We connected his low cost Nova Fitness fine dust sensor with some, and some other sensors with a radio module. This one was actually from IMST, several on the market that you can use. It's a module where you have the radio transceiver and a microcontroller on it. We connected this with a battery supply and gave it to him so he can collect his data. And there's actually another project that I want to advertise a little bit. It's a Luftdaten.info project, where they also collect Luftdaten or fine dust data all over Germany, all over the world, but mainly with Wi-Fi based boxes. And we want to push the idea a little bit to do this with Laura in future, maybe, because then you don't need your local Wi-Fi and everything. So, yeah, after... So, I want to start with a... So, basically you need two things to connect your device. You first need the lower communication, which is a pure radio transmission, which is when you know the OZ layer model on the physical layer. And then you need some kind of wide area network infrastructure, which will be explained by Pair later, that covers mostly all of the other layers from data link to the session layer, maybe a little bit of the presentation layer as well. So, let's start with the Laura transmission. It's... Yeah, it's a little bit... It has some parameters, so you can use the frequencies at least in Europe. It's a 685 kHz to 1 GHz band, so we cover the free 868 MHz band where you can deploy your own devices when you keep with the regulations of the U. You're also limited by the U to like 40 dBm for transmission power. And the bandwidth can vary between 125 kHz and Laura VOD to 500 kHz. And then you have a special factor that's... Yeah, kind of special for Laura that you don't find in any other technology. That's a spreading factor. And when you see at the laser pointer, but if you see at the graph where you have the time from the bottom to top, and the frequency from left to right, then you can see that Laura Van or Laura is working with chirps. So it modulates the frequency over time and that it's how it somehow encodes 1s and 0s over the air. For the exact details, you can see the talk from two years ago, yes, from midnight. He digged into this because the technology is proprietary by same take, so you can't find any open documentations, but this talk is kind of like a documentation. So with the bandwidth and with the spreading factor, you can have pretty much influence on the link budget. So the link budget can go up to 1.51 dBm, which means that you can in the free field or how it's advertised, you can get up to 15 km in practice when you're in the city or normal environments like here from Hall to Hall, you can get like 3-5 km or indoor maybe 1 km, so it's highly depending on where you are. Data rates are from very low, like 32 bytes per second, but you can get up to 1 over 1 kilobyte per second. And maybe one thing to the spreading factor, so spreading factor 7 is where you have the highest data rates, so when a signal takes, let's say, 20 seconds on spreading factor 7, it will take twice as much on spreading factor 8 and then it doubles to spreading factor 12. So that's basically the parameters you have and how to use those parameters and how to set up your radio and how to set up the gateway that receives all your messages. There's a wide variation of parameters. This can, this is all defined in Laura Vaughn later. And yeah, when you build a Laura Vaughn compatible device, it will just talk with the networks that Paer will explain soon. So it doesn't actually work, yeah? We are building sensors since over two years. We also built our own Laura Vaughn stack on hardware using the IMST module. And if you have any questions also about the lower details, since we don't have the Q&A after this talk, you can also come to our assembly. And now I will hand over to Paer, who can explain how the wide area network works. Thanks. So now you know about Laura and how it works and why it's pretty useful, but Laura is only just, you have a few bytes which are thrown into the area and the rest is up to you. Granted, it throws them pretty far and with only very few energy used, so it's good for IoT devices, but you have to do everything else yourself, like where does the data get, how do I know it's from my device. Luckily, there is something called Laura Vaughn, which does all these things for you already. You, well, you have your devices, they are a little bit like razor blades in this graphic, I think. Those are your devices in the field. You have data there, you want to have some welds, and that somewhere else is over there on the right, the application server. That's where you want your data, and how do you get it over there? Well, Laura Vaughn adds two more parts to the network. You can see these rectangle parts, they are the gateways, which are the pieces of hardware which do the wireless communication with your device, and they are controlled by something called a network server, which is the most intelligent part of the whole system, and they get the data to your application server. This graphic I used from the SYNX network, it's so handy for explaining that we'll take it along with us to the talk. So to get an idea, we'll just build a small device just now because it's easier than explaining it, like just from far away. So what do we need? Four parts, a device, a gateway, a network server, an application server. We started with that. Let's say fun part because that's what you want to do. That's your idea, you put it out there, and now we have to connect it. You can get one device for pretty cheap, actually. You can use an Arduino, which you can pretty cheap. You have seen the modules for Laura Vaughn, which Toby showed, and some power connection that all together is about 10 to 20 years if you know where to look. The next part of the gateways, those are a bit more complicated because they are a bit expensive. They are very many different varieties, but if you're lucky there's already one around, like at the Congress, there are some I've checked. And the network server, well, it's pretty much done already. There's something called the SYNX network, which is free and open with the sharing community. And the last thing as well, your application, whatever you want to do, you'll look into the four parts in a little more detail now. Oops, sorry. So what do we build as a device? We could use the finder sensor. We could something really useful for something like this Congress, which is, well, and the long button you press when you get, well, when you see some cyber at the Congress. So what's in there? Actually not much. There's an Arduino, there's a module, and some power supply. Well, and you need, of course, the button to trigger the button. With this project, the button costs about twice as much as everything I put inside, but that's okay because the button is also the case I used for this. So you can see my lovely soldering skills there. If you looked at the parts earlier, you probably thought, well, there's something missing in there, don't we need an antenna? Yeah, right. But I skipped all the cables I used, and if you see that tiny yellow wire on the left, that's actually the antenna I used to communicate over radio. Of course, there's much room for improvement. You could get a better antenna and do, get more range, but this actually works quite well. I've tried it. So what do we have? This thing, I call the cyber alarm. I built this. This is complete and no wires, as you can see. It's, of course, programmed. Well, it's Arduino, so how does it work? You get the Arduino library, you start from the example, and add the parts you need, and then you are done again. I've walked along about this project. I've linked here. It was with the GPS tracker, so GPS tracker is much more complicated than just having a button, but if you go there, you have a good manual how to do all the thing. So the gateways, the magic parts. They are actually pretty dumb devices. They just pack it forward. They just collect every lower one packet that is out there in the air, and they pass it on to the network server. And when the network server tells them to send something out, they do that. There's a great variety of what kind of gateways exist. I put, well, the upper and the lower end, I would guess. This is an industrial standard. It costs about 1,000 euros, if you put it all together, but has tools and detection, GPS, mobile internet, and everything you would want to just put up your gateway. If you're a little short on the money, well, you can use a Raspberry Pi and this module. This all together is for about 150 euros, you could get that. We actually have one of those in our office for our development process and it works quite well. So if you put it up on your local hacker space, you have coverage for quite a few kilometers if you have a good antenna. So the next thing is a network server. As I told you, that one is done, but that is the most complex part, and it does everything for you, actually. There's this free network server. You can just go there and register your device. It's a bit like Freifunk, but it's for IoT and not for Wi-Fi. You just go there, you say, get your account, you say, well, this is my application, in my case, cyber alarm, and this is my device. I want to register it. And it handles the session when you log on, it handles the encryption, it even handles the decoding of the data because you get just a few bytes up there, but you can insert a piece of JavaScript which will decode them and send you a JSON to wherever. So let's just take a quick look. Well, this is device registration. The most important part is there's the three columns of numbers. The first one is the device theory, which is just the address of this thing. It's like a MAC address for Wi-Fi. The second reference is which application I use, and the third one you probably don't want to show because that is the secret you use for putting up the session and doing the encryption, but this is no real data, you cannot use that for anything that device doesn't really exist. So you still need to reach your application server. That is quite easy because the Sync network does everything for you anyway. There is a protocol which is the easiest to use, it's called MQTT, which is a message protocol for IoT, actually, and if you use Python, you're of course done because it's Python. There are other ways to connect your thing, you can put up a hard HTTPS request or you can have something like this and that network, but we just did this and it's actually that show that I will show you the whole script. This would work, it's just for TTN, put up your handler, well, I didn't put my key there but you probably would, and this would actually work. My script which I'm running is a bit longer but we'll try if it works. It did work. So what happened? Thanks. So what happened there? There is this chip, you've seen it, it just sends out the message. There are gateways for the network at the congress. As I told you, this is some kind of open network, a community. If you put out more TTN gateways, anyone can use them and you can use their gateways. So normally, well, they're not that far spread yet. In Hamburg, we have about seven or eight, I guess, some of us are virus, but we have a basic coverage. If you want to do that, I have one like kilometer away from where I live and it works. Life signal only has zero. I checked like, well, Toby checked like two hours ago, there are about four now, but there are for some reason all at the message, I don't know why. So, yeah, it didn't fail, so that's good. You can also see all the alarms triggered on that URL. And if you don't, you can put your own button. The code is on GitHub. You will need access virus, so you have to contact us, then I can register your thing and then you can also trigger the same cyber alarm I have and we can hook it up to do whatever. If you want to reach us, that's pretty easy. We are over there at the hall. It's a deep cyber assembly. Just come over and talk to us. We are happy to talk to you longer about law one. You can fetch us around here after the talk if you want. Also while there are some URLs we can reach us, you can see us on Twitter. My deck doesn't work yet, but it's the first day I'm starting to do that. So we have two minutes left, so maybe we can have one or two questions, but I don't know what the timing is. So we were fast on our actually sort, but I don't know if the microphone's all ready. Maybe one, one thing to the last link. So that's some manual how you can set up your own private lower one network, but if you connect your gateway to your local network, then of course it's not connected with the public network and they are working on this as well. Feel free to ask us anything. So thanks so much. Let's have a big round of applause for us. So we have time for one question and first I'm going to go to our signal angel to see if the Internet has any questions. It looks like the Internet does have a question. No, the Internet does not have a question. That's very strange. So if anyone in the audience has a question, we have a microphone over there and we have a microphone over there and whoever gets there first gets to ask their question. Five, four, three. Someone is running to the microphone. Microphone to my left. Is it bidirectional? So can you send messages back to your button if you programmed it? Is it bidirectional? Yes, it is bidirectional. I skipped that part. You can have messages sent from your server to the device, but it's of course limited. Your device needs to listen. And the only way I ever used it is when your device uploads a message, then the network has a chance to send a downlink. And while there are other messages, you can have a permanent listening device, but I've never seen it in the open. There are three modes. It's called A-mode, B-ABC-mode, and they are a little bit different. So on C-mode, the device listens all the time. And B-mode, the device talks to the network server to tell the network server when it's alive. Ten seconds. One thing I forgot. Laura is not open. It's appropriate to tell you about the Laura one. It's pretty open. It's a spec. You can read it and build it if you want and use it wherever you like. Tobias, Pear, thank you so much. Let's have a final round of applause. Thanks, Michael, just here.