WSN based on Lora modulation

Hello everybody,
I am student and I am working on my final thesis.
I would realize a simple sensor network with some actuators, based on Arduino for nodes, RPi for packet forwarder and RFM95W lora transceiver.
I am using Lora modulation for signal transmission between nodes and the packet forwarder, but not LoRaWAN.
My questions are :

  • How could the packet forwarder treat more than one node signal (uplink) (in my case there are two nodes)
  • Hoiw could I send commands to the actuator through the packet forwarder (downlink). I am thinking about making a multiplexing technique for uplink & downlink, or putting second lora transceiver in the same packet forwarder in order to make the downlink signal in a seperate channel than the uplink; But how to acheive this objectif ??
    Thanks for your help

Wouldn’t the LoRa Gateway Bridge solve your issue? It would allow you to communicate with the packet-forwarder using MQTT for sending and receiving payloads:

Thank you brocaar,
May be, I was not able to clearly express my idea.
I have to build a single channel bridge that relays packets, received from many nodes, to the internet. I will only use Lora modulaiton for packet transmission from nodes to bridge, and this has no relation to LoRaWAN, so I will never use LoRaWAN in this project.

  • Do you have codes that could help me ?
  • I want to know how that single channel bridge will be able to handle with many packets, coming from many nodes, simultaneously without loosing any of them using different SF for nodes ?
  • How to do in order to make possible sending packets from bridge to one node ?
  • As said, you can use the LoRa Gateway Bridge when using LoRa only (only LoRa Server knows about LoRaWAN) :slight_smile: It is just an easier interface to your gateway (assuming you’re using something compatible with
  • Are you sure your single-channel gateway is able to process different LoRa packets simultaneously at different SF?
  • That is up to you to implement. A gateway does not direct a packet specifically to one node, this is part of the LoRa frame and you need to design your own protocol for this. This is one of the things that LoRaWAN facilitates :slight_smile:

So brocaar thank you so much for your helps.
Could I use loramac in my case ??
Or could you give me protocols that would be used in my case ?

One of these protocols is called LoRaWAN :wink: The rest I leave up to you as an exercise.

I feel lost. I want only a confirm from your side, Can I use LoRaWAN protocol with my private server that I am implementing ?? Thanks

When you operate on LoRa then there is no concept of addressing a payload to a specific device. You’re just sending a slice of bytes from one device to a (group of) devices that are able to receive the data. Compare this with a radio station, everybody tuning in on the frequency (and modulation etc…) of the radio station will hear the same music.

You can use the LoRa Gateway Bridge to send and receive these LoRa frames to / from the gateway. It provides an easier API to your gateway, but effectively it allows you to do the same thing.

When you want to target specific frames to specific devices, then you need a protocol. You either design your own protocol on top of the LoRa modulation, or you could use LoRaWAN which gives you the feature where every device is addressable, including AES encryption and data integrity validation + a lot of other features to manage the state of your devices.