Usable by 3rd Party Apps

All in VSS defined nodes mapped to vehicle properties must be usable by apps installed from the app store.

SYSTEM vs. VENDOR properties

https://cs.android.com/android/platform/superproject/main/+/main:hardware/interfaces/automotive/vehicle/aidl_property/android/hardware/automotive/vehicle/VehiclePropertyGroup.aidl

Consistent cross-OEM IDs

All vehicle properties must have consistent ID regardless of the OEM.

https://cs.android.com/android/platform/superproject/main/+/main:packages/services/Car/car-lib/src/android/car/VehiclePropertyIds.java

Extensible outside the platform

Vehicle properties should be extendable outside the AOSP platform code.

Permission per vehicle property

Each vehicle property must be protected by a specific permission to enable fine grain access.

https://cs.android.com/android/platform/superproject/main/+/main:packages/services/Car/car-lib/src/android/car/hardware/property/VehicleVendorPermission.java

Permission per read/write

Read and write access must have different permissions to enable read or write-only.

Defined access

Ability to define which app may get access to which properties (read/write) for OEMs (and further, Fleet Managers)

https://developer.android.com/guide/topics/permissions/overview

Dynamic permission grants

Ability to grant or revoke access per app and vehicle property over the lifetime of the vehicle for OEMs (and further, Fleet Managers)

Runtime, Dangerous permissions without user interaction

Consistent VSS based mapping

All vehicle IDs should be deterministically maped to VSS nodes to enable seamless integration with any VSS based communication middleware or similar.

Frequency / Sample Rate

Applications must be able to subscribe for updates to continuous properties.

Sample rate range must be queryable.

(Optional, TBD) OEM must be able to dynamically define which apps can get what sample rate range

https://developer.android.com/reference/android/car/hardware/CarPropertyConfig#VEHICLE_PROPERTY_CHANGE_MODE_CONTINUOUS

https://developer.android.com/reference/android/car/hardware/CarPropertyConfig#getMaxSampleRate()

https://developer.android.com/reference/android/car/hardware/CarPropertyConfig#getMinSampleRate()

Availability of Vehicle Properties across different targets(Emulator vs Hardware)

Android CTS test suite only covers few Vehicle Properties that are in MUST category in CDD. OEMs can opt not to support other Vehicle Property implementation in real targets which creates in-consistent behavior for apps deployed in Emulator vs Hardware.