Firmware Updates Over-the-Air (FUOTA)
Firmware updates are crucial for large-scale deployments of connected devices. Firmware updates allow for security patches to protect customer and business data and make it possible for new functionality to be added to existing devices. When it comes to LoRa-enabled devices, these updates are even more important: they can also help extend battery life by optimizing the firmware on devices that have already been deployed. This module addresses updating firmware over LoRaWAN networks.
Let’s look into this a bit further.
Enabling Firmware Updates Over LoRaWAN
Most Internet of Things (IoT) devices require long-range connectivity with low power consumption to allow a battery lifetime of several years. Traditional wireless network technologies, such as Cellular and Wi-Fi, cannot accommodate these needs. To facilitate the requirements of these devices, new network technologies, called low power wide area networks (LPWANs), have emerged. Networks such as LoRaWAN®, Sigfox, and NB-IoT are deployed using low-cost radio chips with kilometers of range and low battery consumption.
A downside of these networks is that the data rates are much lower than those of traditional radio networks. Data rates for LPWANs are measured in bits per second (bps), rather than megabytes per second (MBps). Additionally, many of these networks operate in the unlicensed spectrum (ISM band), which requires that devices adhere to regionally-imposed transmission limitations. This means that they may only be allowed to send data very infrequently, even while suffering from interference. These characteristics make it difficult to support firmware updates over-the-air. This might lead you to think that devices deployed in the field cannot be updated easily; especially devices that are deployed in places that are almost impossible to reach, or where the cost of sending a technician is too high.
Challenges of Over-the-Air Updates
Being able to easily update the firmware on IoT devices is a challenge when deploying at scale. First, it is extremely challenging to have 100% secure software. Second, these devices may be in place for up to ten years, so keeping them up to date with the latest standards and protocols is important. Lastly, the ability to add functionality or specialize devices throughout their lifetime (from manufacturing and distribution to transfer of ownership or change of purpose) is critical in many business cases.
Key requirements for firmware
updates are the ability to:
- Efficiently send data to multiple devices at the same time (multicast)
- Recover from packet loss
- Verify the authenticity and integrity of the firmware while following standards for end-to-end encryption
Source: Jongboom, J. (2019). Firmware Updates over LoRaWAN, The Things Conference 2019.
(Duration: 33:34 minutes)