How the vehicle's V2X middleware turns raw ASN.1 UPER-encoded SPaT and MAP byte streams into structured, application-ready signal-phase and intersection-geometry objects.
The V2I application service runs the ASN.1 decoder on a dedicated worker thread separate from the ADAS control loop, publishing decoded intersection objects over a lock-free ring buffer so that a malformed or oversized MAP message cannot stall time-critical path-planning cycles.
A single MAP message can describe a dozen signal groups covering straight, left-turn, and protected pedestrian phases. The application layer must match the vehicle's current lane assignment, derived from HD-map matching, against the correct SignalGroupID before any phase countdown is meaningful to the driver-assist system.