Offline but connected: how air-gapped IIoT devices stay up to date
Modern production and manufacturing depend on the networking and digitalization of machines, sensors and systems. The Industrial Internet of Things (IIoT) is an essential part of this development. IIoT devices collect and process large amounts of data to enable efficiency improvements, predictive maintenance and optimized operating processes.
Usually, IIoT devices are connected to each other and to the internet to ensure a continuous exchange of data. However, there are scenarios in which an internet connection is not required or not possible - whether for security reasons or due to geographical conditions. These air-gapped edge systems place special demands on data processing and require alternative solutions for updates and data transfers.
Air-gapped systems are networks or individual devices that are deliberately disconnected from the Internet. These systems can therefore not be updated in the conventional way. Their collected data cannot simply be sent to the cloud for analysis. To overcome this challenge, an external transmission medium is required that stores files for software updates.
The solution: smartphone as an update bridge
The illustration shows a solution concept for this special case of Industrial IoT.
Instead of a direct connection to the Internet, we rely on a mobile, flexible and secure bridge: an Android smartphone. With a specially developed app, it takes on the role of a data transfer device. The app downloads update files in the form of Docker images from the Azure Container Registry and stores them locally on the smartphone. The smartphone also serves as a storage medium for the IIoT device's data.
Wifi Direct is used as the data transfer method in this example. Wifi Direct offers high transmission rates and enables direct device-to-device communication between Wi-Fi end devices. This technology is particularly suitable for air-gapped systems, as the devices involved do not require an internet connection and a direct connection is possible. High data rates are important as the size of the update files can vary greatly depending on the container image.
The process in detail:
- establish the connection: For the software update, the smartphone is connected to the IIoT device from the Android app via Wifi Direct. Appropriate Wifi Protected Access (WPS) methods are used to establish a secure connection.
- transfer of the update files: If a connection exists, the already downloaded update files can be sent to the IIoT device via the app. A specially developed system on the IIoT device receives these files and starts the update process.
- data backup: In addition, the generated data of the IIoT device can be downloaded via the Android app and temporarily stored on the smartphone. This backed-up data is then available for further processing.
The solution developed and the technologies used have potential for a practical application scenario. With the increasing spread of IIoT, it can be assumed that solutions for air-gapped systems will play an increasingly important role in making industrial processes efficient, even in safety-critical or remote areas. We support you in this process.
