OTA(Over The Air) refers to managing the SIM card data and application remotely and wirelessly through the mobile communication interface. The OTA upgrade technology is a remote wireless upgrade technology that allows the software data to be remotely transmitted to the target device for upgrading.

Automotive OTA upgrades are divided into two categories: one is FOTA (Firmware-over-the-air), which refers to downloading a complete firmware image to a device or ECU to repair existing firmware or to update flash memory, and the other is SOTA (Software-over-the-air), which refers to applications and maps upgrades that look closer to the end user.

The complexity and difficulty of FOTA is more challenging than SOTA, and whether it is FOTA or SOTA, they are all divided into three stages in practice:

1. Generate update package
2. Transfer update package
3. Install update package

1. Synchronize models, vehicles, and ECUs from the TSP/MES system
2. Upload the upgrade software/firmware of each ECU to the OTA cloud platform, and automatically generate the update package online
3. Create the upgrade campaign on the OTA platform based on target vehicle model and ECUs.
4. Send the upgrade campaign to the target vehicle remotely
5. User confirms the contents of the upgrade and executes the upgrade
6. Report the upgrade result back to the OTA platform

The automotive OTA system is a cloud-to-vehicle collaborative product, primarily composed of a cloud-based OTA management platform and vehicle-side OTA clients.

The two are connected through a mobile network to jointly complete the OTA upgrade process.

In addition, a PKI (Public Key Infrastructure) system will be added to protect the integrity of the upgrade package to ensure cybersecurity for remote upgrades.

The CDN (Content Delivery Network) system can redirect the user's request to the service node closest to the user based on comprehensive information such as network traffic, load status, distance to the user and response time in real time. 

Its purpose is to enable users to obtain the required content nearby, solve the problem of Internet congestion, and improve the response speed of users visiting the website. 

When an upgrade campaign involves a large number of vehicles, these vehicles will access the OTA server at the same time, which may cause network congestion, and the server may not be able to handle such large concurrent downloads.

Thus, you can utilize the CDN service to accelerate the downloading of the update packages.

Full upgrade refers to using an upgrade package containing complete content to overwrite the target device to replace the original content in its own image.

Differential upgrade uses a differential algorithm to compare the content before and after the upgrade, identify differences to generate a differential upgrade package, and then use the same algorithm to patch the original content on the target device to restore the final target content.

Utilizing differential upgrade has multiple benefits such as saving storage space, shortening transmission time, and reducing data usage.

The A/B partition setting indicates that there are two systems A and B in the ECU, and both systems are mutually redundant.

During normal operation of the ECU, system A is operating normally and system B is in standby state. When the ECU receives an upgrade campaign, system B starts to upgrade, while system A is still running normally.

After system B is upgraded and the ECU reboots, system B will start running normally, and system A will enter the standby state instead.

If system B fails during the upgrade process, the operation of system A will not be affected, and the ECU can still work normally.

This design improves the safety of ECU upgrades and avoids situations when the hardware cannot operate normally due to failure of the update.

UDS (Unified Diagnostic Services) is a generic automotive diagnostic protocol defined by ISO 15765 and ISO 14229, it can be implemented on different automotive buses (such as CAN, LIN, Flexray, Ethernet and K-line).

The UDS flashing is based on a set of ECU software flashing procedures defined by the UDS diagnostic service.

Corota's OTA solution fully supports the UDS flashing specification, which can update all ECUs on the CAN and Ethernet buses, thereby eliminating some hardware restrictions when small ECUs need to integrate the OTA clients.

The security of OTA process includes communication security and upgrade package security, which requires the OTA platform to engage with the KMS or PKI system. Through the security gateway established by the security provider, all network services within the vehicle communicate with the server through a secure channel.

The upgrade package on the OTA server must be signed before downloading to the vehicle, and after the vehicle receives the upgrade package, it needs to verify the signature and confirm that it comes from a legitimate server before allowing subsequent upgrades.

1. Quickly repair system defects
In case the traditional cars have system defects in the user driving verification, there is only one solution to these problems. The car manufacturer initiates the recall procedure and returns the car to the factory for a unified system upgrade after the user receives the recall procedure. The OTA technology can quickly and remotely complete the defect repairs in the form of data packets, which greatly avoids the risk of recalls that can last for several months.

2. Quickly Iterate, improve products and user experience
Due to the advanced hardware in the product design, the intelligent networked car operating system can be upgraded through OTA to continuously open new functions to the car owner, optimize the product experience, perform rapid iterations, and provide more high-quality system services. Truly let the car owners feel what "usually open and often new" is.

3. Save time and money for both parties
Traditional recalls require internal and external approval processes, and the cost of time and money is very high. Through OTA upgrades, the cost of recalls caused by software defects can be greatly reduced, and this money can be saved for everyone to develop new products. Isn't it good?