Cue xkcd on standards. I've been interested in mesh radio, and I keep hoping that a winner will emerge. Probably won't until a large commercial vendor gets interested and picks one.
Correct me if I am wrong but I thought the primary appeal of LoRa was range? Also isn't the primary factor in making long range radio go through things is the frequency? So 2.4ghz is the same frequency as consumer wifi right and thus would propagate about the same right?
It doesn't seem like this would be that useful except that the protocol is LoRa so you can have higher bandwidth between two devices if they happen to be close enough together.
FSP loss for 915 MHz at 10 kms is ~ -111.67 dB while for 2.4 GHz is -120 dB.
That is a 9 dB loss which is significant. It could mean the difference between a copy or just plain static though the LoRa is supposed to be copyable down to -140 dBm.
The max tx power is around 150 mW (21.76 dBm), so at 10 kms, the RSSI is 21.76-120 = -98.24 dBm which is above the -140 dBm limit.
This calculation is assuming there is no loss due to vegetation or humidity or other barriers.
I know it’s all open source and I’m not paying for anything so I cant be choosy. But after playing with a bunch of Lora peer to peer chat systems. All I wish is a chat service that uses haloW. Since it uses wifi backend, regular wifi should work as well.
Seems like this would support institutional/campus environments or changing environments where the sensors at the edge are sending higher bandwidth ultimately back to an Internet node using LoRA mesh--instead of directional WiFi?
I'm trying to envision the application of a mesh like this. These could be examples?
- interconnected nodes need to share data (like images)
- interconnected nodes are acting as a collective array of sensors (eg. geolocation)
- interconnected mesh nodes provide redundant pathways back to the central node
- interconnected mesh nodes provide spatial diversity in case of interference or jamming
- nodes are mobile (eg. drone or vehicle) and mesh provides alternative connectivity based on node location and RF attenuation (also provides longer range with mesh connectivity)
> an Internet node using LoRA mesh--instead of directional WiFi?
not really, the reason why Wifi is useful is that its reasonably efficient and high bandwidth. Unless you need to cover hectares of land without any buildings, its easier just to use decent wifi (ie unfi)
Mesh networking with multi-path is really hard to tune for bandwidth efficiency, throughput and power efficiency at the same time
The "100x bandwidth" claim needs to be substantiated.
There are some significant regulatory issues with the current popular mesh network protocols in the USA, namely that neither MeshCore or Meshtastic are compliant with the actual FCC regulations. 100x bandwidth because you're breaking the rules isn't the same as 100x bandwidth legally.
The issue you linked to is about MeshCore using channels that are too narrow. A mesh system claiming to offer 100x bandwidth is probably not violating regulations in that particular way.
I never understood the popularity of these protocols, because when I looked at the legal duty cycles and multiplied that by time in a day and instantaneous bitrate, the result was a disappointing amount of data per day...
So many spectrum rules are totally weird though: should they be interpreted per radio device? or per user?
What -apart from cost- prevents a user who wants more bandwidth from installing 10 devices in parallel and alternate each radio so none of the radios exceed their allowed transmit duty cycle?
How are they increasing the bandwidth? It's a hardware limitation of the radios. Even if you run the lowest spread factor (SF) and highest bandwidth setting on the radio, it's still not great. And the radio buffer is 255 bytes. I'm also curious why they're starting a new project with the SX1276 instead of SX1262.
Is the poster maybe confusing bandwidth (range of frequencies over which a single board can work) with bandwidth (data transfer speeds in bits per second)?
That stuff is good for drone warfare, mesh networks already been used in Ukraine
E.g. drones geographically organize themselves into a chain with each of them serving as a mesh-network node, then each of them, including the tip of a chain, can be controlled by operators, and the whole setup is a closed network which works without requiring Internet access
Sounds like bs. Why would someone pay $50 for almost 10 years old hardware when there are plenty of well-supported and cheaper options like MuziWorks Duo / Ebyte / etc with newer LR1121 or LR2021 which combine both 2.4G and SubG bands in single and modern chip at 1/2 of the cost less? SX1281 and SX1281 are relics.
Is the design for this open source? I’m not an rf guy so it would be really handy to be able to reuse some parts of this in my sensor network on our farm. I can do the digital and sensor part all day, but I respect the skill of rf engineering in getting decent performance out of tiny pcbs.
44 comments
[ 1.2 ms ] story [ 56.3 ms ] threadNetwork doesn't usually care much about the apps running on top of it.
It doesn't seem like this would be that useful except that the protocol is LoRa so you can have higher bandwidth between two devices if they happen to be close enough together.
No. Free space loss increases with frequency.
FSP loss for 915 MHz at 10 kms is ~ -111.67 dB while for 2.4 GHz is -120 dB.
That is a 9 dB loss which is significant. It could mean the difference between a copy or just plain static though the LoRa is supposed to be copyable down to -140 dBm.
The max tx power is around 150 mW (21.76 dBm), so at 10 kms, the RSSI is 21.76-120 = -98.24 dBm which is above the -140 dBm limit.
This calculation is assuming there is no loss due to vegetation or humidity or other barriers.
Say I start the node and then what?
I'm trying to envision the application of a mesh like this. These could be examples?
- interconnected nodes need to share data (like images)
- interconnected nodes are acting as a collective array of sensors (eg. geolocation)
- interconnected mesh nodes provide redundant pathways back to the central node
- interconnected mesh nodes provide spatial diversity in case of interference or jamming
- nodes are mobile (eg. drone or vehicle) and mesh provides alternative connectivity based on node location and RF attenuation (also provides longer range with mesh connectivity)
not really, the reason why Wifi is useful is that its reasonably efficient and high bandwidth. Unless you need to cover hectares of land without any buildings, its easier just to use decent wifi (ie unfi)
Mesh networking with multi-path is really hard to tune for bandwidth efficiency, throughput and power efficiency at the same time
There are some significant regulatory issues with the current popular mesh network protocols in the USA, namely that neither MeshCore or Meshtastic are compliant with the actual FCC regulations. 100x bandwidth because you're breaking the rules isn't the same as 100x bandwidth legally.
Here is the issue discussing this in the MeshCore repository: https://github.com/meshcore-dev/MeshCore/issues/945
There are other countries in the world.
And there are also places where there is no electromagnetic policies (think about over the oceans).
So many spectrum rules are totally weird though: should they be interpreted per radio device? or per user?
What -apart from cost- prevents a user who wants more bandwidth from installing 10 devices in parallel and alternate each radio so none of the radios exceed their allowed transmit duty cycle?
https://www.nordicsemi.com/Products/Wireless/DECT-NR
https://en.wikipedia.org/wiki/DECT-2020
Doesn’t change my excitement about it a bit though. Eager to get this onto my workbench!
E.g. drones geographically organize themselves into a chain with each of them serving as a mesh-network node, then each of them, including the tip of a chain, can be controlled by operators, and the whole setup is a closed network which works without requiring Internet access
[0] https://en.wikipedia.org/wiki/LoRA_(machine_learning)
AFAICT, this just combined two chips on a board. And the 100x bandwidth is due to using a higher frequency chip. Nothing revolutionary.