LoRa-SDR on LimeSDR-USB with Raspberry Pi and Arduino

Dear all,

Is it possible to run a “fully fledged” LoRa network using the LoRa-SDR code [1] with 2 LimeSDR boards [2]? I am thinking about programming one LimeSDR to support a gateway, and another one to support a device. Will I be able to easily accomplish that with the LoRa-SDR code? I am thinking about a gateway running a Raspberry Pi; a client should be in turn running Arduino Uno/Mega. Does anybody have a similar experience and can tell whether everything should be working fine? I am particularly interested in going towards the LoRa-SDR code to introduce modifications such as Listen Before Talk (LBT) [3] that can improve throughput of low density LoRa networks (compatible with regular LoRa devices).

[1] https://github.com/myriadrf/LoRa-SDR
[2] https://wiki.myriadrf.org/LimeSDR-USB
[3] https://ieeexplore.ieee.org/abstract/document/8422800

Thanks in advance,

Best regards,

Eryk Schiller

In a word, no.

The LoRa implementation was never fully compatible with off-the-shelf hardware and I suspect that a bit more work on it is required. May also be that the GNU Radio implementation is further down that path.

Also you mention gateway and so I’m wondering if in fact you mean LoRaWAN? In which case you would also have to integrate a MAC, then on top of this run a packet forwarder stack on the gateway device.

Yes, the idea is to gradually go towards LoRaWAN. Currently, we have a different setup. We have a fully operational LoRaWAN using a Gateway [1,2] with the Semtech SX1301 base-band processor and 2xSX1257 Tx/Rx front-ends. In such a case, our gateway is fully compatible with the official software provided by Semtech [3,4]. As a node, we are using Arduino Uno [5,6] with the Semtech software [7]. There is also a Linux-based implementation [8]. Currently, we would like to migrate our setup towards SDR-based solutions. As an advantage, with LimeSDR, we could simultaneously try to experiment with LoRa and LTE, e.g., using OpenAirInterface [9]. I’ll try to figure out whether the gnu radio implementation with LimeSDR would be a suitable option [10].

Thanks for comments.

[1] Raspberry Pi - Raspberry Pi 3 Model B | Pi-Shop.ch
[2] iC880A-SPI - LoRaWAN Concentrator 868 MHz | LoRa Products | Wireless Modules | IMST GmbH
[3] GitHub - Lora-net/lora_gateway: Driver/HAL to build a gateway using a concentrator board based on Semtech SX1301 multi-channel modem and SX1257/SX1255 RF transceivers.
[4] GitHub - Lora-net/packet_forwarder: A LoRa packet forwarder is a program running on the host of a LoRa gateway that forwards RF packets receive by the concentrator to a server through a IP/UDP link, and emits RF packets that are sent by the server.
[5] https://store.arduino.cc/usa/arduino-uno-rev3
[6] Arduino Shield featuring LoRa® technology
[7] GitHub - arduino-libraries/LoraNodeShield: Arduino library for LoRa Shield
[8] GitHub - Lora-net/LoRaMac-node: Reference implementation and documentation of a LoRa network node.
[9] http://www.openairinterface.org/
[10] GitHub - rpp0/gr-lora: GNU Radio blocks for receiving LoRa modulated radio messages using SDR

Is this for commercial use? If so you would need to licence the LoRa IP from Semtech. The SDR implementation was put together purely for research purposes.

No, it’s a university research setup.