Scalability of Server-setup and Selection of LoRA Gateway and End-devices for time-sensitive use-case

Applications
1

Hello,

I am in the design stage and trying to find the right things to buy the LoRA Gateway and several LoRA end-devices to suit the following requirements.

  1. Sending sensor data from end-device to the application server via gateways at 1 second time intervals, approximately 20 to 40 Bytes of payload.
  2. I want to set up at least 1000 end-devices to the gateway.
  3. I want to achieve at least 10 km coverage in suburban areas.
  4. There is no limitation on power supply either to Gateways or End-devices as I plan to use a dedicated power supply.
  5. Occasionally send data (approximately 10-20 Bytes of payload) from the application server to multiple end-devices so that they can do actuation.

I would appreciate it if you can suggest options to buy the gateways and end-devices to suit the above requirements. I would also appreciate it if you can suggest an Antenna for maximum distance. Is there any limitation of the server-side setup to handle the number of gateways and end-devices?

Thanks,
GRK

2

You’ll need something that isn’t LoRaWAN. LoRaWAN is designed for small data (closer to 10 bytes than 40) at long intervals (tens of minutes to several hours, not 1 second).

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3

Thanks. I noticed in some research papers and thought of LoRAWAN works, including RP_2-1.0.2. It was mentioned in the RP_2-1.0.2 that US902-928 Data Rate could have a maximum of 21.9 kbps, and 50 kbps could be the maximum for EU863-870 Data Rate. Doesn’t it mean the end-devices can send 40 Bytes or at least 10 Bytes per-second interval? I understand the Duty cycle for EU863-870 Data Rate is <1; however, there is No Limit on the Duty Cycle for US902-928 Data Rate. So my understanding was we can send a maximum of 21.9 kb per second, isn’t that so?

4

US has a dwell time requirement instead. So no, a device can’t send continuously.

And even if there wasn’t a dwell time requirement, LoRa is very bandwidth inefficient so devices would quickly saturate the entire band.

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5

As other already suggested, LoRaWAN might not be the best fit for purpose.
I dont think any of the unlicensed Long Range Bands (WiFi bands are not long range and have other limits…) can provide what you are looking for.

You might need to bite the bullet and go for https://en.wikipedia.org/wiki/Narrowband_IoT which might not be available to you or might increase the costs way over budget.

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6

Thanks. So when they mention 21.9 kbps or 50kbps, what does it mean? Can you provide more details to understand it.

7

So to put it simple:
The Data-Rate just tells you how fast you can get your message over the network, not how much and how often you are allowed to send. For “Duty Cycle” Networks, as in Europe, the faster you can get your message across, the less you will be spending time “on air”. That means you can send more often before you hit the duty-cycle limit. I supposed for “Dwell” Time it might be a bit different, but probably more or less the same principle.

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