ČSN EN 15531-1 (018234)

Annotation of standard text ČSN EN 15531-1 (018234):

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