OTA Update: over-the-air updates for IoT devices

Enable an over-the-air (OTA) update service on your product to make your software update process seamless, minimizing service interruptions and maximizing end-user satisfaction.

What is an OTA update?

Applicable to various connected devices, over-the-air (OTA) updates allow for remote software updates of embedded devices without necessitating a physical connection to a computer, enabling the target device to receive enhancements, bug fixes, and new features autonomously.

The main challenges of OTA updates

System robustness

Over-the-air (OTA) updates help maintain system functionality and thus, user trust. Devices must handle software updates without compromising operation, including managing power interruptions and providing rollback mechanisms for failed updates.

Deployment on the field

Deploying OTA updates in remote or hard-to-reach areas with inconsistent network connectivity poses logistical challenges. Implementing differential software updates and resuming interrupted downloads ensures efficient and reliable update delivery despite network constraints.

Security

Security is critical to protect devices against unauthorized access and cyber threats during their lifecycle. Robust measures such as secure boot, encryption, and authentication mechanisms are essential to verify the integrity and authenticity of updates, safeguarding device and user data.

Key elements to consider when managing & deploying OTA updates for your device

Communication method

Selecting the appropriate communication technology (e.g., 4G, 5G, LTE-M, NB-IoT, or Wi-Fi) based on data transfer speed, cost, and energy consumption is critical. Secure communication channels (e.g., HTTPS) must be employed to encrypt data exchanges.

Device firmware build & testing

Constructing, versioning, and signing the firmware ensures its authenticity. Comprehensive testing guarantees compatibility with existing functionalities and environmental interoperability.

Deployment strategy

Utilizing secure servers for firmware deployment and implementing robust mechanisms for handling download interruptions and verifying firmware integrity are essential for successful over the air (OTA) updates.

SUCCESS STORY

Implement a complete OTA update system for Adeunis smart building application

Our engineers proposed, developed, and integrated a complete reliable firmware update system for Adeunis STM32 sensors. Since the Adeunis sensors are using batteries that are not replaceable by the final user, the over-the-air (OTA) update solution developed by Witekio had to respect a mandatory requirement of power management. The Witekio engineering team investigated different update strategies for the dievices and tested them against Adeunis’ constraints before making the final choice.

Among the strategies compared by the team were a mesh network viral update strategy and a multi-hop strategy that allows maintenance technician to check update deployments live.
Developing the overall energy saving firmware update system was a major success in this project.
Radio frequency signals were used to allow the update of all the sensors and the firmware update system was developed with the real time operating system, FreeRTOS.

The benefits of OTA updates

Fixing security vulnerabilities

Over the air updates facilitate real-time delivery of security patches, safeguarding sensitive user data against cyberattacks and ensuring continuous data protection.

Compliance with Evolving Standards

OTA updates ensure that your product remains compliant with rapidly changing technological standards and regulations, allowing for quick adaptation to new protocols and market demands.

Enhanced Features and User Loyalty

OTA updates enable the introduction of new functionalities, personalization options for users, user interface improvements, performance optimizations and allows to fix software bugs, resulting in a consistently satisfying user experience and increased user trust.

Long-term Cost Reduction

Addressing issues early through OTA updates helps prevent major problems, saving on support and maintenance costs and avoiding large-scale product recalls.

FAQ

How to implement OTA firmware updates?

Selecting the communication method for over the air updates: Choose the appropriate wireless technology for your device, considering data transfer speed, cost, and energy consumption. Ensure secure communication with protocols like HTTPS.

Firmware Build and Signing: Construct and sign the new firmware updates to authenticate it and ensure it remains unaltered during transmission. The device verifies the firmware’s authenticity from the build server.

Firmware Testing: Test the firmware comprehensively to ensure functionality, compatibility, and interoperability within the product’s environment. Validate backward compatibility to ensure seamless operation with older firmware versions and software components.

Secure Binary Deployment: Deploy the firmware on a secure server. Platforms such as AWS, Azure, Mender and Hawkbit facilitate this process, ensuring secure communication and update delivery.

Software Download and Verification: Ensure secure download of the firmware using dual authentication and secure protocols. Verify the firmware’s integrity using hashing mechanisms such as SHA-256.

Installation and Failure Management: Inform users about software updates for devices with notifications and obtain their consent. Provide clear installation instructions and fallback options such as backup firmware or reversion capability in case of failure.

Post-Installation Validation: Validate the firmware’s functionality post-installation, ensuring it operates correctly. If invalid, revert to a previous or recovery version unless it poses a security risk.

Over the air update: OTA update tools

SWUpdate: SWUpdate is a flexible and extensible software update tool designed for embedded systems. It supports various update methods and can handle complex update scenarios, ensuring reliable and secure firmware deployment.
RAUC: RAUC (Robust Auto-Update Controller) is a highly reliable update mechanism for embedded IoT devices. It emphasizes robustness and security, providing features like atomic updates and rollback capabilities to maintain device integrity.
Mender: Mender is an end-to-end OTA update manager for connected devices. It focuses on providing robust security features and efficient update processes for systems, including delta updates and state scripts for customization.
The Embedded Kit: The Embedded Kit offers a comprehensive suite of tools including a platform for managing OTA updates in embedded systems.
FreeRTOS: FreeRTOS, with its OTA Update feature, provides a real-time operating system with integrated update capabilities. It ensures minimal downtime and secure updates, making it ideal for IoT applications requiring reliable and timely software updates.

Best practices

Strategic Update Planning: Establish a long-term update strategy, scheduling regular over the air updates to keep your product responsive to user needs and technological advancements.
Error and Failure Management: Implement mechanisms for handling software update errors and provide recovery solutions. Ensure clear, understandable error messages for users.
Rigorous Testing and Validation: Perform exhaustive testing before deploying OTA updates with tools. Validate the product’s functionality post-update to ensure stability and compatibility.
Performance Monitoring: Monitor product performance post-update and gather user feedback to address issues promptly.
Resource Management: Optimize device performance while managing energy consumption. Offer deferred firmware update options to suit users’ network or battery constraints.
Enhanced Security: Regularly update security protocols and offer encrypted OTA updates to protect data confidentiality. Strengthen security measures to safeguard user data.
Platform Upgrades (Multi MCU/MPU): Implement strategies for managing updates across devices with multiple microcontroller units (MCUs) or microprocessing units (MPUs) to ensure consistent and reliable performance.
Robustness and Rollback Interest: Design OTA update processes to handle unexpected issues gracefully. Enable rollback options to previous stable versions to maintain system robustness and user trust in case of update failures.

How Witekio can help with OTA updates

Witekio offers comprehensive over the air update integration services, ensuring your devices remain secure, robust, and future-proof. With over 20 years of expertise in the market of embedded systems and IoT product development, Witekio excels at creating seamless OTA update solutions tailored to your specific hardware and software needs for devices.

Our “secure by design” approach ensures that your IoT devices receive and support OTA updates with top-notch protection against potential threats and data breaches. We prioritize minimizing downtime and scaling our solutions to accommodate your growing device ecosystem. Whether you need integration with Mender, SWUpdate, The Embedded Kit or any other framework, Witekio tool-agnostic methodology ensures efficient and reliable OTA updates, enhancing end-user satisfaction and device longevity.