Come and see our groundbreaking firmware update over-the-air (FUOTA) on a LoRaWAN™ architecture thanks to a significant collaboration between our engineers and Actility, the World leader in low power wide area network connectivity management for the Internet of Things. We are taking advantage of the Embedded World conference currently taking place in Nuremberg, Germany, to present the future of IoT at the ST Booth and show developers that FUOTA on LoRa systems is closer than ever. The demo is fully compliant with the specifications and recommendations from the FUOTA Working Group of the LoRa Alliance Technical Committee. Additionally, the implementation that we showcase is running on a real-world production server from Actility. Actility and ST are thus celebrating a milestone, and we thought it was important to go into some of the details of the process on display today.
Actility: RMC, Fragmentation, and Clock Sync
Our FUOTA demo starts with a Reliable MultiCast (RMC) server from Actility. Unlike a unicast protocol, where a server talks to one device, and a broadcast system, where a server talks to all devices, RMC can target a subset of devices for more efficiency, without fearing packet losses or out-of-order deliveries, which may happen on other traditional multicast platforms.
Actility’s ThingPark RMC server features two critical modules: fragmentation and clock sync. The first one breaks down the update into chunks compatible with the traditional LoRaWAN payload (maximum of 255 bytes). The solution also included a forward error correction system and redundant packets to protect against losses or corruptions. Engineers often overlook this aspect, but properly fragmenting an update to send it over the air is complex and a vital part of the process. The clock synchronization is for Class-C LoRaWAN devices, meaning products that are constantly listening to RF spectrum. By offering a clock sync system, Actility can enable FUOTA on Class-C devices and make upgrading firmware over-the-air a reality with existing systems.
ST: Update Agent, Secure Boot, and Secure Firmware Update, Development Tools
Once the update leaves the RMC server, it reaches the LoRa end-device, which is where our engineering team comes in. Their first job was to develop a solution able to interact with FUOTA servers at any desired time during an update campaign, among others. The next step was to create an update agent that acts as an intermediary between Actility’s modules, and our Secure Boot and Secure Firmware Update (SBSFU) system. Once the stack using Actility’s modules processes the packages from the RMC server, the update agent ensures that the SBSFU system on the ST microcontroller writes the proper information on the right memory space before the SBSFU module securely updates the firmware. Parsing these small packages on the LoRa terminal is challenging, and the update agent is a remarkable tool that took the innovations from Actility and carried this collaboration with our partner to the end zone.
The beauty of this whole solution is that it is fully part of the existing STM32Cube ecosystem. The code that we use in this demo currently runs on an STM32L4 with 256 KB of Flash, but it is only targeting alpha-customers at the moment. Hence, even though it is not publicly available yet, developers can already use try our SBSFU software expansion (X-CUBE-SBSFU) to quickly implement a Secure Boot and Software Update solution on their device, regardless of the network protocol they are using. Engineers can also use our existing to start working on their application, our tutorials show how to setup a LoRa node in 10 minutes. Our B-L072Z-LRWAN1 and I-NUCLEO-LRWAN1 boards will help them prepare for the upcoming public release of our FUOTA solution in collaboration with Actility.
When Will You Jump on the Bandwagon?
Sub-Gigahertz networks are increasingly popular. Without FUOTA, companies need an army on the ground, physically attending to each device to perform maintenance operations, which is costly and impractical. Actility is a member of theand the company already offers solutions compatible with our LoRaWAN stack. This new collaboration was thus an extension of our existing relationship because the industry knows that FUOTA is an essential technology that will tip the scale when it comes to the massive adoption of LoRaWAN. Check out the ST Booth at Embedded World to see for yourself what the future of LoRaWAN looks like.