Software Over-The-Air (SOTA)

Software Over-The-Air (SOTA) refers to technology that remotely updates application software for a vehicle's non-core underlying systems via wireless connectivity. Unlike FOTA, which involves flashing underlying ECU firmware for the powertrain, chassis, ADAS, and other critical systems, SOTA primarily targets application-layer software such as In-Vehicle Infotainment (IVI) systems, navigation maps, and human-machine interfaces (HMI). It is comparable to updating an app on a smartphone rather than executing a major operating system (OS) upgrade.

Technical Positioning and Upgrade Scope

SOTA updates are mainly focused on the file system level of the controller's embedded system, typically utilising differential update packages to modify specific files rather than replacing the complete image of the entire file system. Typical updates include optimising in-car apps on the infotainment screen, refreshing instrument cluster display themes, and updating navigation map data.

Because it does not involve flashing the vehicle's underlying ECU firmware, SOTA has minimal impact on core driving dynamics and active safety. Given its lower technical barrier to entry, it has become the primary method adopted by most legacy carmakers to deliver remote updates for in-car systems.

Technical Implementation and Core Value

SOTA updates generally do not require a full system reboot to take effect, and the file sizes remain relatively compact. Its core value lies in allowing car owners to seamlessly update and optimise in-car apps and connected services without having to visit a 4S centre, keeping the infotainment system fresh and up to date to enhance the day-to-day user experience.

Fundamental Differences from FOTA

While both fall under the OTA umbrella, the key distinction between SOTA and FOTA lies in whether the update touches the vehicle's underlying control logic:

• Differences in upgrade scope: SOTA is limited to application-layer software within domains like infotainment, whereas FOTA covers firmware updates across dozens or even hundreds of critical ECUs throughout the powertrain, chassis, body control, and driver assistance domains.

• Differences in user value: SOTA focuses on adding features and refining user interfaces at the experiential level. Conversely, FOTA can fundamentally alter a vehicle's dynamic characteristics—such as suspension damping, power delivery mapping, and ADAS decision logic—enabling the entire vehicle to continuously evolve and stay genuinely fresh over its lifespan.