UNE-EN 15531-1:2022

1.1 Interfaces specified by this Standard

1.1.1 Business Context

Real-time information may be exchanged between a number of different organisations, or between different systems belonging to the same organisation. Key interfaces include the following:

" Between public transport vehicle control centres generally, for fleet and network management.

" Between a control centre and an information provision system generally, to provide operational information for presentation to the public.

" Between information provision systems generally, sharing information to ensure that publicly available information is complete and comprehensive.

" Between information provision systems and data aggregation systems that collect and integrate data from many different sources and different types of data supplier and then distribute it onwards.

" Between information provision systems and passenger information devices such as mobile phones, web browsers, etc.

Annex B describes the business context for SIRI in more detail.

SIRI is intended for wide scale, distributed deployment by a wide variety of installations. In such circumstances it is often not practical to upgrade all the systems at the same time. SIRI therefore includes a formal versioning system that allows for the concurrent operation of different levels at the same time and a disciplined upgrade process.

In this general framework, SIRI defines a specific set of concrete functional services. The services separate the communication protocols from the message content ( functional services ). This allows the same functional content to be exchanged using different transport mechanisms, and different patterns of exchange. Figure 1 below shows this diagrammatically.