FOTA Update | Firmware Over The Air – For IoT And Automotive Devices

Ans. This decision regarding the method of firmware flashing will depend on the following factors:

• Number of devices to be updated ( A Gateway device is preferred if the number of deployed target devices is on the higher side)
• The type of communication interfaces available
• The operating environment of the deployed devices
• Desired cost-effectiveness of the FOTA feature

Ans: We had ensured to make security features part of the FOTA solution at the design stage of the SDLC.

Following are the details regarding our FOTA security features:

• Integrated HTTPS & SSL certifications: to ensure Secure data exchange
• Encryption Keys and security certificates for secure communication between server and target devices
• Role based Access Control to avoid any unauthorized data access
• Code Signing: to verify the authenticity and integrity of firmware executables and scripts and to safeguard them against any malicious tampering by unauthorized agents.

Ans: Based on our experience, a subscribe –publish mechanism for FOTA upgrade is ideal for large scale implementations. Additionally, a subscribe –publish mechanism offers following advantages over the Polling mechanism:

• Cost effective
• Minimizes data usage

Reason – field-deployed devices are not required to check for new firmware update every now & then . Any new firmware update package or image that gets published in the server, is notified to the devices as per the schedule.

Polling mechanism is easier to implement but consumes more data.

• Ready to deploy Bootloader Software
• Software components deployed for secure file transfer, update notifications.
• Reusable Algorithms for accurately
  • updating the new firmware,
  • Identifying the update requirements
  • Validating the existing firmware versions

Ans: IoT gateway devices that support firmware OTA flashing on connected devices can belong to one of the following categories:

• Processor and OS based Gateway: preferred for large scale (industrial) deployments. These are easily scalable and depend on application processor and the base OS ( Android/Linux).Cost of such IoT gateway devices is also comparatively higher.
• Microcontroller based Gateways: These are preferred for applications which require specific functionalities like – better device connectivity, reduced memory and power consumption; and involve lower BOM cost.
• Mobile Device as a Gateway: These are preferred when target devices are fewer in number and individually owned.

At Embitel, we have developed IoT gateway devices at various scales and for different application domains, specifically for telematics and industrial automation systems.

Ans: Following are the details regarding our backend server architecture:

• We have deployed Postgress relational database to leverage the following benefits:
  
  • Open Source nature and support for an enterprise-class performance
  • Cross platform compatibility ( UNIX, Windows, Native Windows)
  • Responsive in high volume environments
  • Exhaustive library and framework support
  • Full database encryption to ensure security
• Our solution is backed by an Nginx server for file transfer. Our team took this decision based on the following features of an Nginx server:
  
  • Versatile, efficient and light-weight web server
  • Easy and simpler installations
  • Ideal for serving static files pdf, zip, html, mp4 & others
  • Support for high concurrent traffic
  • Compatible with commonly-used web apps like WordPress, ruby, python, Joomla, drupal etc.
• We have also leveraged Django framework for developing interfaces for the target devices. The Django framework is known for its scalability, security and ease of execution – features that make it a favorite among the web developers.

Ans: In order to ensure security of backend operations in the server and to avoid unauthorized access of the backend data, we implement:

• Password based authentication control, or
• Certificate based authentication (CA)

Ans.All details related to firmware file and each of the versions (previous and the new) are stored systematically in the tables of the relational database.

The tables would include information such as the file name, the version number, and the action required (upgrade or delete) pertaining to each firmware package.

This ensures accurate version management  of the firmware package, which is being deployed in the target devices.

In case a new version of the firmware has a bug or does not meet the desired expectations, there are provisions to roll back to the previous firmware version, using the information in the backend database.

Ans. We use the Nginx server for backend operations which provides robust support for load balancing The NGINX server is an efficient (HTTP) load balancer, suitable for wide range of web applications.

The NGINX server has an event-driven (event as in any communication request) architecture that empowers it to manage thousands of connections within a single process with efficient use of hardware and memory.

Thus, even if the number of connected devices that needs a FOTA upgrade increases post initial-deployment, the NGINX server can easily process their connection request without creating traffic spikes.

Ans. Our experienced solution development is a vibrant bunch of Industrial Automation and Automotive domain experts, with the following core skill-sets:

Expertise in IoT communication protocols (MQTT, CoAP, HTTPS)

Testing and validation expertise
Experience in Bootloader Software Development
Know-how and hands-on in system security best practices