How can I establish a full duplex LoRa communication between two LoRa nodes?

What is the most efficient way to transmit and receive data at the same time between 2 nodes over LoRa other than having 2 pairs of nodes in parallel (transmit line, receive line)?

A radio chip can either transmit or receive at any given time, on one frequency channel. You should be able to take it from there.

jremington:
A radio chip can either transmit or receive at any given time, on one frequency channel. You should be able to take it from there.

So what is this "full duplex mode" that I've seen in the specifications of some LoRa gateways?

BrainTrance:
What is the most efficient way to transmit and receive data at the same time between 2 nodes over LoRa other than having 2 pairs of nodes in parallel (transmit line, receive line)?

Any transmitter close to your receiver will wipe out it's receiving capability during that transmission and for a short time after the transmission ends.

Full duplex requires the two frequencies to be very far apart and requires filters on the receiver to block the signal from the adjacent transmitter.

Paul

So what is this "full duplex mode" that I've seen in the specifications of some LoRa gateways?

I imagine that the details could be discovered by examining the specs and the operating manual of such a gateway.

BrainTrance:
What is the most efficient way to transmit and receive data at the same time between 2 nodes over LoRa other than having 2 pairs of nodes in parallel (transmit line, receive line)?

You cannot with the normal LoRa devices used in nodes, they are either transmitting or receiving.

Gateways use multi channel LoRa devices so reperesent a device that has the equivalent of maybe 8 single node LoRa devices.

And the obvious question, why do you want to use full duplex communication between nodes ?

srnet:
You cannot with the normal LoRa devices used in nodes, they are either transmitting or receiving.

Gateways use multi channel LoRa devices so reperesent a device that has the equivalent of maybe 8 single node LoRa devices.

And the obvious question, why do you want to use full duplex communication between nodes ?

I'm trying to intervene an ethernet connection with LoRa. And that would be my next question to this forum.

It would seem that if the project requires full duplex. Then your comment about needing one pair of nodes for each direction would be correct.

so, your primary question remains. "What is the most efficient way"

There are lots of devices, it may be a full duplex pair or 4 individual units.

Hi,
I googled lora full duplex arduino

and got

https://hutscape.com/tutorials/lora-duplex-a

https://hutscape.com/tutorials/lora-duplex-b

I think use have to use both a and b.

I'm not sure if it will help, I haven't dabbled in full Lora duplex.

Tom... :slight_smile:

Thats just sending a packet, waiting for it to finish sending, then receiving a packet, i.e. half duplex, most all LoRa libraries will let you do that.

The LoRa device in that so called tutorial, is an RFM9x, it can either be in RX mode or it can be in TX mode.

dave-in-nj:
It would seem that if the project requires full duplex. Then your comment about needing one pair of nodes for each direction would be correct.

so, your primary question remains. “What is the most efficient way”

There are lots of devices, it may be a full duplex pair or 4 individual units.

Can you provide a link with a full duplex device? I’ve searched for such devices but I’ve only found LoRa gateways
Thanks all for the valuable feedback.

Hi,
Why do you need full duplex?
What is the application?
What is the data?
How often do you need to update the data?
What is the communication range you are looking for?

Thanks... Tom... :slight_smile:

BrainTrance:
Can you provide a link with a full duplex device? I've searched for such devices but I've only found LoRa gateways
Thanks all for the valuable feedback.

There is no link.

Standard LoRa devices are half duplex.

TomGeorge:
Hi,
Why do you need full duplex?
What is the application?
What is the data?
How often do you need to update the data?
What is the communication range you are looking for?

Thanks... Tom... :slight_smile:

  1. I'm not really sure I need a full duplex communication yet.
  2. I'm trying to intervene an ethernet communication with Lora (ethernet to Lora - transmission - Lora to ethernet)
  3. Data is NMEA0183 sentences, that is, 4-5 lines of strings with numbers, symbols and letters (800 bytes maximum)
  4. About 5 seconds
  5. 8-10 km. It will be above the sea (no obstacles).

I'm working with two Arduino yuns' and Dragino Lora shields

You will never do full duplex with the equipment you have chosen. Read the documentation for the LoRa that was given a bit back. It uses SPI interface, Do you have a full duplex SPI interface on your Arduino? No. Does your Arduino have multiple processors and I-O processors so it can process in full duplex? no.

Paul

There is no conceivable need for “full duplex” in the situation you describe: transmission of some NMEA sentences.

Proceed with what you have.

jremington:
There is no conceivable need for "full duplex" in the situation you describe: transmission of some NMEA sentences.

Proceed with what you have.

Yes, I will.

I doubt even Ethernet is relevant to this project.