LoRa (not LoRaWAN!)

I am embarking on my first large scale LoRa project. And in my research i cant seem to find any meaningful information about plain old vanilla LoRa without the documentation ending up focusing on LoRaWAN

I thought I would throw my questions out here for some comment and see how i go. But first some background on the project.

I am involved in setting up a star network of LoRa Devices, with up to 50 end points and a single gateway. The end points must report back to the gateway with self test info every hour (Battery voltage etc). The Gateway must be able to send out requests for information to the endpoints on demand. The Endpoints must be able to contact the gateway on demand when an event is triggered (On the end point)

So now my questions

  • Using LoRa only, am i able to secure my gateways from rouge connections and ensure only the endpoints with the correct auth connect to the specified gateway?

  • Would i need a multi channel gateway for this application or would a single channel application work ok for these small private start configuration networks.?

  • Assuming a single channel gateway and reasonable distance (ie less then 1km) How many endpoints would i be able to support with a single gateway.

  • Lora performance indoors: I Cant find too much information on details of LoRa performance indoors or in a built up structural area where the gateway might be located at or below ground level. Is there any info i can read on this? Most of the information i see is relating to LoRaWAN and higher bandwidth applications then what I require.

Be glad of any LoRa experts or aficionados that can help me out.

Hi Arnold,

I’ll answer as many of these as I can for you:
As far as point to point LoRa goes, on a device like the Pycom Lopy4 its very simple:

A single Gateway using LoRaWAN (I know you are not using this) can support ~100,000 connected devices.

LoRa is a line-of-sight frequency, while it does have the ability to penetrate into buildings and bounce around a bit, that is very limited. You can connect up to 20km away with line of sight and a good antenna, but I had a gateway in my apartment and I couldn’t connect over one block from my house.

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I don’t have direct answers for all of your questions, though here are some context tips. LoRa and LoRaWAN are entirely different, to the point where the only similarity is the way radio frequencies are encapsulated/sequenced.

If using plain LoRa encapsulation to transmit data from point A to point B, no gateway is needed. A device could be configured as a master to control data in that application, though that would be a hand-crafted implementation.

Otherwise, if you are using a gateway then it’s likely you are using LoRaWAN, though are breaking/bypassing some LoRaWAN specifications:

  • Less than 8 channels in use
  • More than 30s air time per node per day
  • Use of a LoRaWAN cloud application that allows either/both of the above scenarios

Chances are that if significant node transmissions are used throughout the day, you could be in breach of LIPD ACMA regulations, though I’m no expert on that other than LoRaWAN compliant devices usually fall into that class just fine.

If however the Antenna was mounted externally at roof height on the building, you’d likely get 1-3kms pretty easily (if not further). Just clarifying that as 915Mhz (LoRaWAN regions AU915 and AS923) perform very well in urban environments, compared to other ISM bands such as 433Mhz and 2.4Ghz.

Indoor antennas simply won’t have the SNR or RSSI to cope with decent range. Though your whole building would likely have sensational LoRaWAN coverage, well beyond what your WiFi Modem would be offering by comparison.

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It’s also worth mentioning that my apartment building is essentially a hardened bunker with no line of site to anywhere. :slight_smile:

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Thanks for this gentlemen! great help.

So ignoring LoRaWAN is it possible to setup a LoRa device as a gateway and have multiple nodes connect to it? I am envisioning using just plain Lora in star config. IE A, B C all communicate (Rx/TX) with Z ?

Technically no - as LoRa is just a way of describing how data is modulated into radio frequencies. It’s no different than using FSK or other common RF modulation methods, the protocol and/or way objects behave would be crafted by you and your code.

There’s an exception whereby some LoRaWAN devices are so powerful, they could act as nano-gateways though often are < 8 Channels and/or other limitations.

You could have one device act as a master and control the others, by observation you could call it a gateway. Though it’s nothing like a LoRaWAN gateway in reality.

It’d be like you and your friends on mobile phones with some star topology rules.

  • Only you can initiate a conversation
  • Conversations begin with the target person’s name
  • Conversations are had
  • Conversations end with you saying “that’s all”

You’d be able to effectively interact with everyone in a controlled way. No one would be confused if the rules were understood by all. Same same for LoRa and making your own protocols.

There are some examples out there of how to use LoRa from device-to-device, that could be remixed for your own needs.

I doubt they’ll ever be as robust as LoRaWAN or as commercially viable.

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hi Arnold, how did you go with this setup? What did you end up doing?