ISO 14813-5:2020 pdf download – Intelligent transport systems – Reference model architecture(s) for the ITS sector
1 Scope An intelligent transport system (ITS) reference architecture is a tool that describes how an ITS delivers one or more ITS services. It includes a high-level description of the major elements and the interconnections among them that are needed for the service(s) to be provided to stakeholders. It provides the framework around which the interfaces, specifications, and detailed ITS designs can be standardized within ITS standards. By contrast, ITS standards are often focused on design details. While the development of these standards may be initiated by a single ITS user need, they are often (and properly) written in a generic format that allows for application in a broad array of contexts. However, this can present a challenge to the reader in understanding the original purpose of a standard and whether the standard is intended for other environments.
This document defines documentation rules for standards that define interfaces between or among system elements of an ITS reference architecture. This includes:
a) requirements for documenting aspects of the ITS reference architecture;
b) terminology to be used when documenting or referencing aspects of the ITS reference architecture.
In compiling this document, the authors have assumed that contemporary systems engineering practices are used. Such practices are not defined within this document.
6.2 Levels of abstraction
Within the ITS industry, architectures are often presented in three distinct levels of abstraction as depicted in Figure 1. Reference architectures reflect the requirements set forth by the industry-wide stakeholder community. These architectures provide a relatively generic template that characterizes how ITS elements typically interact with one another to provide services that are widely deployed. At this level of abstraction, system elements are entirely conceptual – they describe types of elements that might be deployed. Because a reference architecture represents typical deployments, it is useful for identifying interfaces between system elements that can be standardized. Planning architectures are intended to address stakeholder concerns in developing a long-term vision (e.g. 5 to 20 years) of ITS deployments within a geographic area at a level that facilitates project planning. At this level of abstraction, the architecture identifies the specific system elements to be deployed and identifies which elements and ITS services are existing, if any, and which are merely planned. Ideally, the planning architecture should be used as the primary source for the deployment plans (e.g. timeframe) for each planned system element. Planning architectures should generally be derived from a reference architecture in order to benefit from the previous work and standardization, but the derivation process will typically omit some ITS services that are not envisioned for the region while perhaps also adding new ITS services that are specific to the region. Deployment architectures are intended to address local stakeholder concerns related to a specific deployment project. At this level of abstraction, the architecture must identify the system elements that will be separately procured and identify how these system elements will interface with one another (ideally using some set of the standards created in response to the associated reference architecture).