Firmware Over-The-Air: A Key Success Factor for the Internet of Things

Firmware Over-The-Air, or FOTA, refers to the process of remotely updating the code on an embedded system. Not every device supports this mechanism. The initial firmware must include the necessary capabilities for this. In the case of LoRaWAN, FOTA is also considered at the Standard Specification 1.1. The specification of FOTA by the committee ensures high quality and a consistent approach to the challenge of transmitting firmware updates via so-called delta packs with a relatively small payload. (We all experience the success of such a specification with the relatively low failure rates of iOS and Android mobile phones after they receive an update.)

Why FOTA?

To quickly illustrate the significance of FOTA, a brief description of the process without “over the air” suffices: To update the firmware on a device, physical access to the hardware is required. It must be connected to a computer in some way (usually via USB or a serial adapter), which then transfers the new software to the device. However, this process cannot be scaled. The Internet of Things involves not just a single device but countless devices, often with no one knowing exactly where they are located. The logistical challenge of manually installing a firmware update is a Sisyphean task. Jeffree Lee cites Chrysler as a famous example, a company that did not shy away from such an undertaking. The media's response to this action was not long in coming:

“Six weeks after hackers revealed vulnerabilities in a 2014 Jeep Cherokee that they could use to take over its transmission and brakes, Chrysler has pushed out its patch for that epic exploit. Now it's getting another round of criticism for what some are calling a sloppy method of distributing that patch: On more than a million USB drives mailed to drivers via the US Postal Service.” (wired.com)

The Advantages of FOTA

That firmware updates can indeed make positive headlines was demonstrated by Tesla in 2016, when it equipped its customers' cars with an intelligent parking system overnight. Besides good PR, there are of course other advantages for Firmware Over-The-Air:

• As a responsible manufacturer, firmware updates always provide an opportunity to respond to software malfunctions and security vulnerabilities.
• Updates with new or modified features can be sent only to subsets of devices to test them in real application environments. A sensitive approach and open communication with test customers should be a matter of course.
• The cost savings compared to firmware updates that require physical presence are obvious. This is further optimized by a uniform interface for updating large fleets of devices. From experience, we know that many areas still work at the command line level. We ourselves are big fans of consoles, but we believe that to avoid errors in firmware updates in the IoT world, applications specifically developed for this purpose should be used. An error in a software update can, in the worst case, render a device completely useless if it can no longer be accessed wirelessly afterward (the humorous term for this is One-Click-to-Brick).
• Development teams can continue to safely develop, adapt, and continuously optimize the device with small and manageable updates even after the sale of a product. With FOTA, functions can also be activated for a large number of devices once they are in the field. This makes products more sustainable and future-proof.

Challenges of Implementing a FOTA Ecosystem

Even though FOTA has become part of the LoRaWAN standard, it is by no means guaranteed that the use of this capability will proceed smoothly. Our engineers participated in one of the first FOTA workshops at The Things Conference and were able to see how sensor manufacturers prepare the FOTA function on the hardware and software side and what challenges still need to be overcome. Reliable systems for managing large numbers of devices that can communicate with the microprocessors and local software on IoT devices are among the important aspects. The challenge becomes even greater when Mixed Connectivity, i.e., the use of different radio standards, is employed. The basic communication for FOTA is different for devices communicating via NB-IoT compared to other LPWAN technologies. Here, the system should homogenize the processes for the user. Security is, alongside smooth execution, the most important aspect of FOTA: Communication channels should meet high security standards, and update packages must be digitally signed. The keys for this must be well protected both on the manufacturer's management system and on the device in the field. Since this ecosystem often needs to be developed and established across manufacturer boundaries, this challenge should not be underestimated. As a manufacturer of an IoT product, there are usually two options: Either the manufacturer implements everything from hardware, firmware, and keys to update servers themselves, or they turn to experts who offer ready-made system components for this.

What is Your FOTA Strategy?

Let us know what your questions about FOTA are. What is your opinion on this? We are particularly interested in how we can further support you on this topic. We have started working on the newly specified FOTA for LoRaWAN 1.1, which we will implement in our software module. Our maxim is to work very universally and create internal standards so that other radio protocols can also be served with the same usage paradigms. Our focus is clearly on the uniformity of application across all LPWAN technologies. There are already many sensors, adapters, and IoT devices on the market that, thanks to their remote configurability, offer considerable flexibility. In our IoT online shop, you will find a selection of hardware tested by us that, in many cases, supports the function of remote configuration. On the software side, our component offers everything to efficiently use these functions in operation with large numbers of devices. The extended possibilities of Firmware Over-The-Air are, in our view, another very important evolutionary step for IoT devices, which - if carefully implemented - ensures more security, more flexibility, higher quality, and overall more sustainable products. This will quickly gain traction in the market.