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Structured Travel Incidents & Situations SIRI - Service Interface for Real Time Information (CEN-OO278181 ) http://www.siri.org.uk CENTC278 WG3. 27- 29 Cursitor Street London, EC4A 1LT nick_knowles@kizoom.com Siri 0.1g v3.6c. Topics. SIRI UK Guidance Possible Further CEN Work Items
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Structured Travel Incidents & SituationsSIRI - Service Interface for Real Time Information(CEN-OO278181 ) http://www.siri.org.ukCENTC278 WG3 27- 29 Cursitor StreetLondon, EC4A 1LT nick_knowles@kizoom.com Siri 0.1g v3.6c
Topics • SIRI • UK Guidance • Possible Further CEN Work Items • Additional Functional Services • Further convergence / interoperability • TIH, Datex ?
SIRI Structured Incidents - Rationale • SIRI GMS is currently agnostic on incident structure. • Can embed any message structure • But Can’t relate incident content to SIRI functional service payload / location model • Want a richer semantics • Need to choose an incident structure model • TPEG is popular standard for PT & ROAD incidents, with TpegML • Has message identity management suitable for distributed model • Has systematic classification scheme of causes & effects • Has NL translations • Why not just use TPEG as it is? • Function • Is missing some function e.g.control action and distribution data that experience shows we need • Technology • Predates TransModel – • Model derived from binary optimised form – complex rules to endcode/decode • DTD based • Process
Structured Situations - Concept • XML schema designed with semantics tied to SIRI model & other functional services • Effects / Location Model • Control Actions: eg cancellation, addition, short working • Equipment • TransModel concepts and termonology • Full TPEG interoperability : can translate into /out of TPEG, retaining message identity • Exchange with GMS • Other services use existing support for Situation References
Distributed Computerised Incident Processing Computer-generated, computer readable Trackable : Timestamp, Id, Cross-references • Processing by Computers • XML & other renderings • Presenting to Humans • Multi-channel delivery • Incident is self describing object • Rich Structured Model • Identity Management • Standards based Classification • Standards based Location Model • Distribution Actions & directives • Quality data • Many Distribution “Rules Engine” Business Rules Relate to This Model Start, End, Duration/ Expiry Line, Section, Station, Area Reason, Severity Effect Summary, Detail Human readable Advisory Actions, Channels, Workgroups, etc
Distributed Message (ie Incident) Management • Life Cycle Events • New message • Publish message • Update to message • Expiry of message Applications Applications Applications Incident Database Incident Database Incident Database Applications Interface Interface Incident Database Interface • Solution Architecture • Store & Forward • Write only + Cross-reference • XML Exchange Interface • Interface versioning • Structured Distribution rules Applications Interface Incident Database • Challenges • Many different participants & sources • Heterogeneous systems • Multi-way flow • Real time, mission critical • Many point of failure Interface
The Incident Lifecycle • All participants need to apply the same rules to incidents • E.g. How long valid, precedence of update, location model interpretation. • Identity & version management rules allow reconciliation of updates • State Model incident describes allowed states and transitions. • Eg once published must be closed • Cross referencing allows linking of independent into causal chains
Situation Contents • Message Identity • Identity & version • Cross reference • Message Content • Status • Temporal Scope • Classification: TPEG • Textual Descriptions (where different from derived) • Network Scope (Affects) • Location Model: Lines, VehicleJourneys, StopPoints, Operators • Resulting Disruption (Effects) • Location Model • Delays, Mobility, Blocking, : TPEG • Textual Advice • Distribution Channel Directives (Actions) • Guidance to delivery systems: for content management
Related Additional Work Items • Situation/Event Structured Incident model UK/FR • Enhance GMS to have preferred structured incident model for describing disruptions to services, model relates to SIRI, Based on TPEG + TransModel • Real-time Facility Changes Service FR • Allows changes to availability of facilities and equipment of stop, vehicle and service to be exchanged in real time . This can be used for example to communicate equipment changes affecting impaired access to PT such as lift or escalator changes. Information is of use to real-time journey-planning and alert services. Should consider interchange aspects. • Control Actions Server Interface SE • Service for distributing control actions amongst participants, for example for coordinating management of late services.
XTIS – An “Existence proof” • Incident Situation Schema • Encoded using SIRI elements & terms • TPEG categories • In use with SIRI GMS in TfL. (Kizoom/MDV) • Open Points • Road • Relationship to Control Actions • Relationship to Facility/Equipment • Textual Descriptions (where different from derived) • Categorisation TPEG
SIRI - Separation of concerns Data Content Exchange Behaviour Transport Protocol defined XML Schema For payload well-defined interactions with XML schema Representations parameterising behaviour Independent e.g. HTTP POST, SOAP.
TIH Data Content Exchange Behaviour Transport Protocol define through registry simple GET request/response (+ allows more complex if required, but does not define) HTTP GET (or CORBA)