Communication Patterns
The Subject Interface supports two primary communication patterns that accommodate different C-ITS deployment scenarios and system topologies.
Roadside to Central Communication
Direct communication between roadside infrastructure and central management systems forms the foundation of C-ITS deployments. This pattern supports bidirectional data exchange between field devices and central operations centers.
| Direction | Examples |
|---|---|
| Roadside → Central | Signal states, detection data, sensor measurements, operational status |
| Central → Roadside | Commands, timing updates, configuration changes, operational parameters |
Central to Central Communication
Communication between central systems, service providers, and management platforms supports data sharing and coordination across organizational boundaries.
| Scenario | Examples |
|---|---|
| Service Provider Integration | Data feeds for navigation, routing, and traveler information services |
| Multi-jurisdictional Coordination | Cross-boundary traffic management, incident coordination |
| System-to-System Integration | Data exchange with external systems and platforms for visualization, data collection, analysis, etc... |
Communication Characteristics
Both patterns support:
- Continuous bidirectional streaming
- Multiple concurrent connections
- Role-based access control
- Configurable security modes
- Message-agnostic payloads
Application Domains
The communication patterns support various C-ITS applications, for example:
| Domain | Use Cases |
|---|---|
| Traffic Management | Signal optimization, incident response, transit priority |
| Safety Applications | Collision avoidance, vulnerable user protection, emergency preemption |
| Mobility Services | Green Light Optimal Speed Advisory (GLOSA), traffic information, route optimization |
| Infrastructure Integration | Smart city platforms, environmental monitoring, emergency coordination |