CAM timestamp resolution about artery HOT 4 CLOSED

The time stamp of VehicleDataProvider is updated whenever vehicle data from SUMO is processed, i.e. at SUMO steps which are by default 100 ms in Artery.
CaService uses the update time stamp from VehicleDataProvider to fill generationDeltaTime, see CaService.cc:132. You can change mTimer->getTimeFor(mVehicleDataProvider->updated()) to mTimer->getCurrentTime() to include the current simulation time instead.

from artery.

Does the time stamp of VehicleDataProvider match the time stamp of CAM generation(mTimer->getCurrentTime())?
According to 6.1.5.2 in https://www.etsi.org/deliver/etsi_en/302600_302699/30263702/01.03.02_60/en_30263702v010302p.pdf,
in the case of vehicle ITS-S, CAM should have the time when VehicleData was determined, not the time when CAM was generated.
And from your information about VehicleDataProvider update interval, if I set fixedRate in CaService to true and updateInterval in Middleware to 0.1s,
I think there should be the time gap from 0ms to 50ms between them.
So is it correct to use mTimer->getCurrentTime() instead of using mTimer->getTimeFor(mVehicleDataProvider->updated()) ?

from artery.

No, VehicleDataProvider reports the time stamp of the latest vehicle data update. Because of the mentioned CAM specification, CaService uses the time stamp from VehicleDataProvider to fill the CAM generationDeltaTime.
Time points of CAM generation and vehicle data updates are not linked, even when a fixed generation rate is used: Vehicle data is updated for all vehicles at the same time point, but services are triggered with some random delay among vehicles so they do not synchronise artificially.
While using mTimer->getCurrentTime() violates the CAM requirements w.r.t. generationDeltaTime, I guess nobody will punish you when you are doing this in a simulation ;-)

from artery.

Okey! Thank you very much!

from artery.