Wednesday, February 1, 2023

LoRa CLA and Santa Christmas DTN Challenge

One of the areas we do Research and Development at Internet Society’s Interplanetary Chapter Projects Working Group is on communication technologies and services that can be used to transport Bundle Protocol data for Delay/Disruption Tolerant Network (DTN,) both for space and terrestrial applications.

One of those technologies is LoRa (short for Long Range) particularly popular for terrestrial application such as IoT and transfer of sensor data, competing with ZigBee and other technologies.

LoRa is a low power spread spectrum modulation that enables wireless exchange of small packets of data up to 27kpbs. It does not require a radio license but depending on your geographic location it is restricted to specific portions of the radio spectrum, in the US 902-928MHz.

You can learn more about LoRa at Semtech's LoRa Developers Portal.

Santa's DTN Christmas Challenge

One of our Working Group members, Dr. Samo Grasic from the Lulea University in Sweden, has put together a CLA or Convergence Layer Adapter for ION to use a LoRa modem via a UART serial connection.

Dr. Grasic has been using DTN and LoRa for some time in the Nomatrack project to track reindeer husbandry in the arctic. He participated in a video presentation by the IPNSIG Projects Working Group talk organized by Utica College. Here is a link to the video.

As a demonstration and a way to have some group fun, Dr. Grasic put together a DTN 2022 Christmas Challenge, where a remote located DTN node using ION communicated via the LoRa CLA through a gateway node part of the IPNSIG test network. The challenge consisted in configuring a local node on the IPNSIG network to send a message using Bundle Protocol all the way to “Santa’s Cabin” that got printed with a webcam pointing to it to see it real-time (See picture above.)

I’ve been using a LoRa modem on several nodes of the IPN-DTN Lab, not yet communicating via ION but using a Python for point-to-point and multipoint messages between some nodes.

Each of the nodes included a breakout board from SparkFun with the RFM97 LoRa modem communicating via the SPI interface with a Raspberry Pi.

On the Lego DSN Antenna mockup, the Raspberry Pi and LoRa modem are inside the antenna mount and the LoRa antenna on one side of the model.

DSN Antenna Mockup Lego Model with LoRa Antenna

Another node with LoRa, is the Lego Lunar Base, where the Raspberry Pi and LoRa modem are inside the model and the antenna is visible mounted on the roof (black rectangle on the back.)

Lunar Base Lego Model with LoRA Antenna

Soon I will start testing other LoRa boards and work on the integration with the ION software, both using the SPI interface, and the UART interface to send messages using the Bundle Protocol.

LoRa Modem Boards

I will soon post an update with some progress.

Meanwhile given that this project is 100% self-funded if you want to provide support you can send me some coffee 😊

Until the next intergalactic communication …


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