The Layer 0 diagram shows the high level summary view of the integrated architecture diagram for OSS4ITS, showing all the physical elements in the entire project and high-level links or physical interconnects to show which elements are connected to each other and the type of communication that may be required. This diagram does not include the functional objects which will be shown in Layer 1 and Layer 2 diagrams. The Layer 0 diagram is helpful for the external stakeholders or decision makers to quickly get the project-level perspective and see the scope of the project.
The physical objects represent the operational centers, field equipment, vehicle on-board equipment, personal devices and support systems in the ITS environment. They are organized by six classes, which includes a general ITS object that covers all of ITS, while more specific classes are organized as Center, Support, Field, Vehicle and Personal, grouped by where they reside and how they behave fundamentally and interact with other objects. Each of the physical object is shown as a colored rectangle, and the people are depicted as a colored rectangle with a human silhouette.
Please refer to the Physical Viewpoint page https://local.iteris.com/arc-it/html/methodology/vsphysical.html to understand how the physical and functional objects and the information flows are defined in SET-IT.
The general interactions between the physical objects is shown in the figure below: