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GNU Radio software-defined radio (SDR) implementation of a LoRa transceiver
- tamimio 3y agoAwesome, thanks for sharing it!
- RF_Savage 3y agoExcellent, this one supports transmit. None of the previous implementations did that.
- tonyarkles 3y agoWell that’s cool! In practice, I believe there are portions of the protocol that are patented, so do some research before using this commercially. That being said, LoRa is a really interesting protocol. Very adjustable to tune for a use case, somewhat novel modulation scheme. LoRaWAN on top of it is well designed. I implemented it from scratch once and was generally impressed with the design. Easy enough to implement and does a very good job and minimizing how long the radio (both Tx and Rx) need to be on.
- zurn 3y agoSoftware patentability is limited in a lot of places, can this actually be an argument in favour of doing things using SDR?
- mycall 3y agoCould be a few GNURadio templates they are patenting?
- zoobab 3y ago"Software patentability is limited in a lot of places" In Europe, the new Unified Patent Court (UPC) will probably rubberstamp them, using the "as such" and the "technical effect" loopholes. Without any appeal possible to the European Court of Justice.
- mytailorisrich 3y agoIt's not about software, it's the underlying technology. For example, LoRa uses spread spectrum and there are many patents on spread sprectrum in general (don't know about LoRa in particular).
- tonyarkles 3y agoIt's a very specific form of spread spectrum that they've called Chirp Spread Spectrum and as far as I recall it is actually a pretty novel form of modulation.
- zurn 3y agoBut in SDR, the "underlying technology" of radio modulation, spread spectrum, etc is your software, no?
- tonyarkles 3y agoI appreciate where your head is at, but I don't think it's very likely that a court is going to agree with you. Contrast to the canonical "One-Click Shopping" patent, this patent covers radio waves of a specific type that you'll be producing and not just an abstract business process. Just because there's a way to violate that patent by writing code for a programmable radio doesn't mean that it's a software patent. Heck, in the middle ground between "one-click shopping" and LoRa modulation, you have things like audio and video codecs. These are primarily math-based patents, but they have had pretty broad patent protection for a long time compared to more abstract business-process/software patents. Where this might get interesting specifically for LoRa is that France is one of the rare places that doesn't seem to recognize AV codecs as patentable (and which is why VLC is distributed from France) and Semtech is based out of Grenoble!
- mytailorisrich 3y agoNo, for instance Chirp Spread Sprectrum (mentioned by @tonyarkles in another reply), which is what you would patent (and there are patents on it) has nothing to do with software, although it can be implemented in software using SDR.
- tonyarkles 3y agoSorry, replied to one of the child posts. It's not a software patent, it's a radio modulation patent: https://patents.google.com/patent/US20160094269A1/en https://patents.google.com/patent/US20160094269A1/en and I'm not really that confident that it would be struck down if challenged; from what I'm remembering from digging into it, it is actually a pretty novel form of modulation that has some nice properties for the specific application they're using it for.
- vvanders 3y agoThe fact that spreading factors are orthogonal as well is also pretty impressive. In the ham space other than FT-8 you don't really see a whole lot of interesting modulation techniques like you do with LoRa. The fact that it works over ISM bands is pretty neat and you can do some impressive things with just a couple ~$20 AT command based radios.
- mytailorisrich 3y ago> The fact that spreading factors are orthogonal as well is also pretty impressive This has been quite standard for 20+ years. For instance 3G spreading codewords are also orthogonal. If fact, I think LoRa took a lot from mobile/cellular where all those technics have been used for a long time. Edit: As used in 3G, the orthogonal spreading codewords (OVSF) are actually quite simple to generate for a given spreading factor: https://www.mathworks.com/help/comm/ref/ovsfcodegenerator.html https://www.mathworks.com/help/comm/ref/ovsfcodegenerator.ht...
- goodpoint 3y agoLoRaWAN is quite unusable actually. The bandwidth sharing makes it unsuitable for any crowded environment.
- tonyarkles 3y agoI guess it depends a lot on what you're trying to use it for. Long-range low-power radio is pretty much guaranteed to suck in a congested environment; the noise floor is going to be high unless you're using narrow-beam point-to-point antennas (with interference both from other devices using the same protocol and other devices sharing the unlicensed spectrum). I've played with it in two environments so far and it has worked fabulously well in both of them: - Rural sensors attached to things like grain bins, where a pair of AA batteries can last multiple seasons sending periodic temperature updates and alerts if the temperature starts climbing at a faster than expected rate - Mobile rural sensors worked quite well too. These were attached to things like tractors and had GPS receivers attached for real-time position tracking. Power wasn't nearly as much of a concern but rather taking advantage of the long-range capability while staying inside the unlicensed ISM band and respecting FCC/ISED power limits. - Low-density urban where the neighbourhoods are made up primarily of single-family homes and not multi-storey condos or apartments. It worked well but honestly something like Zigbee would have likely been a more appropriate technology since it would have allowed for even lower power in the end devices.
- gxt 3y agoAre there legal and plug and play LoRaWAN devices to setup a shell connection? I'm looking for simple alternatives to internet as a last resort server remote access within 10km urban area, eg between offices, to avoid physically moving to an appliance in case something breaks internet connectivity.
- zurn 3y agoYou're allowed only very fractional duty cycle access. So depends on what you mean by "alternative to internet", but generally no.
- pbmonster 3y agoWhile this is true in many cases, it's worth mentioning that many LoRA use cases can get away with high duty cyles no problem. At the end of the day, the client devices don't have that much broadcast power - so if you run your own LoRA gateway and are not in a densely populated area, nobody cares if you use a lot of bandwidth. Just don't use all of the bandwidth and keep monitoring the band. You can always throttle down your clients if someone else shows up.
- myself248 3y agoThat's a regulatory thing and depends on your location though, no?
- vvanders 3y agoSeeed and RAK make modules that are ~$20 and work over AT commands, however you still need to abide by ISM bands(or relevant band plan for the country you are in) which can limit your duty cycles.
- livueta 3y agoI've run a shell over Meshtastic between Lilygo t-beam devices using Semtech SX1262 chips. It kinda works but is sloooooooooooow in proportion to your spreading factor and error correction choices. Internet alternative is overselling it; telemetry and short text messages are ideal, with things like shell access or low-resolution images pushing the boundaries of what is practically doable. e: rereading I see you're specifying LoRaWAN: that's a protocol on top of the LoRa phy layer stuff, analogous to Meshtastic or Helium, not what's being implemented in this github repo
- 1024core 3y agoWhat is the expected range of this thing? How far can it communicate?
- Gibbon1 3y agoCouple of miles line of sight. But depends on the spreading factor and bandwidth.
- mytailorisrich 3y agoWith good line of sight, LoRa can reach hundreds of km with pretty low power. Extremely low throughput, though, but can still be useful.
- fer 3y agoI mean, with large enough resources it can bounce off the moon: https://www.satelliteevolution.com/post/world-record-european-scientists-bounced-first-ever-lora-message-off-the-moon https://www.satelliteevolution.com/post/world-record-europea...
- Gibbon1 3y agoA few miles with a non-directional antenna and a useful data rate.
- weinzierl 3y agoLine of sight range is huge, current record is a little over 200 km I think, but practical range is much less. TTN Mapper[1] is a map that shows you estimated approximate range of existing public nodes. The guy behind it also has a good video on Youtube about the algorithms used[2]. The Things Network[3] has has their own map. Finally there is Helium that also has a map[4, but I think you have to participate in their crypto thing to use their network. [1] https://ttnmapper.org/heatmap/ https://ttnmapper.org/heatmap/ [2] https://m.youtube.com/watch?v=Y9lMvyTYI3E&pp=ygUJdHRubWFwcGVy https://m.youtube.com/watch?v=Y9lMvyTYI3E&pp=ygUJdHRubWFwcGV... [3] https://www.thethingsnetwork.org/ https://www.thethingsnetwork.org/ [4] https://explorer.helium.com/ https://explorer.helium.com/
- jupp0r 3y agoFrom Wikipedia[1]: Together, LoRa and LoRaWAN define a Low Power, Wide Area (LPWA) networking protocol designed to wirelessly connect battery operated devices to the internet in regional, national or global networks, and targets key Internet of things (IoT) requirements such as bi-directional communication, end-to-end security, mobility and localization services. The low power, low bit rate, and IoT use distinguish this type of network from a wireless WAN that is designed to connect users or businesses, and carry more data, using more power. The LoRaWAN data rate ranges from 0.3 kbit/s to 50 kbit/s per channel. [1]: https://en.m.wikipedia.org/wiki/LoRa https://en.m.wikipedia.org/wiki/LoRa
- londons_explore 3y agoI really wish standards like WiFi simply covered more usecases like this. All it would take is a few extra modulation and coding modes in the standard. I should be able to walk 5 miles from my house, and still have my house wifi work, but at a data rate of 0.3 kbps. I should never have wifi 'cutting in and out' or 'on the edge of the range' - it should be a simple matter of not being fast enough if I'm too far away. If Shannon[1] allows it, the standard should allow it too. Obviously my phone would probably choose to switch to mobile data long before that. But for some use cases, like instant messaging, 0.3 kbps is fine, and there shouldn't be a need to use a totally different standard to achieve it. [1]: https://en.wikipedia.org/wiki/Shannon%E2%80%93Hartley_theorem https://en.wikipedia.org/wiki/Shannon%E2%80%93Hartley_theore...
- cesarb 3y ago> All it would take is a few extra modulation and coding modes in the standard. [...] but at a data rate of 0.3 kbps. It would take more than just "a few extra modulation and coding modes". At 0.3 kbps, even a single 100-byte packet would already use up one whole third of the available airtime for the channel. (On the current slowest WiFi speed of 1 Mb/s, that packet takes a fraction of a percent of the available airtime, and even that's slow enough that some newer APs disable the older 802.11b speeds by default and set the slowest speed to 6 Mb/s.) And due to how the WiFi protocol works, each AP periodically (usually every 100/1024 seconds, so around 10 times per second) broadcasts a beacon at the slowest rate it accepts (and AFAIK the beacon is nowadays larger than 100 bytes). It would probably require at least changing how the clear channel assessment works, to allow for overlapping transmissions, but that's a fundamental part of the standard. Once you're going that far, it probably makes more sense to define a new protocol, one better tuned for that use case.
- deleted 3y ago[deleted]
- mycall 3y agoHow hard would it be to connect this to a YoLink Hub?
- nereid 3y agoSorry for my ignorance, which device is used to transmit with SDR? I know the tv/radio receivers , but what is used to transmit ?
- fer 3y agoNormally an SDR board (which supports transmission, obviously). LimeSDR, HackRF, BladeRF, PlutoSDR are some of the most popular.
- SoylentYellow 3y agoEttus Research USRPs (Universal Software Radio Peripheral) are popular in academia and defense, especially the B200 series. Their software and FPGA designs are open source, and the schematics for most devices are available online.
- goodpoint 3y agoLoRa® is entirely proprietary and patented. We need to focus on better, open alternatives.
- xgbi 3y agoDo you think it could be adapted so that we can use an rpi and pwm on a gpio to have a rx/tx without the RF component?
- klaussilveira 3y agoHurricanes are a problem here in Florida and communication can be though during the outage or hours after. My neighbors and I use a specific channel with cheap BaoFengs to check on each other and make sure we are all stocked, but it would be nice to have the ability to text within a group chat (not everyone understands radios, unfortunately). How can I setup a local area network over radio? I've tried transferring data over the BaoFengs with adapters and a custom app, but it was very slow.
- NegativeLatency 3y agoLook into some LoRa modules with Bluetooth and Meshtastic
- rozap 3y agoThere are lots of tutorials on how to do this with an Arduino and a Lora shield. It just appears as a serial device to the PC. Some friends and I use this type of setup in our car for telemetry in a low budget endurance racing series. It has been pretty bulletproof.
- nvy 3y agoThat's sweet, do you have a link to a tutorial?
- chmod600 3y agoWe've really become accustomed to the centralized internet. If you aren't on it most of the apps people are used to using don't work. Using a LAN effectively probably takes more effort than radios.
- alexose 3y agoLoRa is fantastic for outdoor sensing applications. Shameless plug: I just released a low cost, 3D-printed, LoRa sensor platform: https://www.thingiverse.com/thing:6170483 https://www.thingiverse.com/thing:6170483
- teruakohatu 3y agoThat platform looks great. Can you share how you are using it?
- alexose 3y agoI appreciate that! It took a lot of trial and error to get it to this point :) I live on a small hobby farm, and I use these sensors to measure things around the garden. We have very hot, dry summers so keeping track of the soil moisture is super useful. And in winter, it's nice to be able to track when different parts of the property freeze. Here's a screenshot of my Grafana dashboard, which might shed some more light on it: https://imgur.com/a/vGNnUNW https://imgur.com/a/vGNnUNW
- aftbit 3y agoI'm jealous. I wish one of my Grafana dashboards had a "Creek Depth" panel. Well... really I wish I had a creek. :P Here are some screenshots from my personal Grafana for comparison. https://postimg.cc/gallery/CZrf5Sw https://postimg.cc/gallery/CZrf5Sw
- alexose 3y agoThat's fantastic! And much more comprehensive than mine. I love all the weather station readings.
- ChuckMcM 3y agoThis code works great on a LimeSDR Mini V2. Presumably it will work well with the ANT-SDR as well which makes me think I should get out my ADALM-PLUTO and try it there as well. While vendors often hide their radio stack in encrypted binary blobs that you load into the "radio half" of their chips having a stack like this where you can look at the parts of the signal is really useful for debugging your own stack. Ideally this will result in opensource implementations of LoRa for things like the STM32W series chips.