Future work OWS-7 Event Architecture Engineering Report

4 Copyright © 2010 Open Geospatial Consortium, Inc. Improve Event Filtering – Various aspects of event filtering are described in this report. Issues but also ideas to significantly improve filtering of events have been documented. Especially spatial filtering using dynamic filter properties event processing functionality could benefit the filtering results. In addition, well- defined structures and mechanisms to enable automatic conversion transformation of the reference systems used by filter operands and filtered properties would be a valuable feature. Further work on these aspects could considerably improve the filtering functionality available at OGC services, especially when event filtering is concerned. Performed as a cross thread activity, this work would benefit multiple domains and avoid duplicate work. Event Security – Initial work has been performed to identify security threats that apply specifically to an Event Architecture. Measures to mitigate these threats have briefly been described as well. Further work on Event Architecture in general and especially Event Service developments should always take into account relevant security aspects. Work on event security should continuously be improved and actually be tested to achieve the building blocks to deploy an enterprise ready Event-Driven SDI. Specification Guidelines – Work that was started in OWS-6 to support users implementers and standards architects of the Event Architecture was continued in OWS-7. Tutorials how to use Event Architecture components as well as guidelines that define which information is needed in standards that want to include Eventing Architecture functionality publish subscribe interfaces, event channels etc form one important building block of the OGC Event Architecture. Further work on aspects of the Event Architecture should always include the continued development and refinement of tutorials and guidelines for using and deploying the architecture. Event Discovery o Event information acquisition – In OWS-7 the TopicSet data type from OASIS WS-Notification was used to provide eventing information for an Event Service. We need to determine how best to acquire a TopicSet document from an Event Service. One option is to make use of WS- Notification accessor methods to get a services TopicSet . Another possible way to obtain the TopicSet eventing information would be to put it into a services Capabilities document like the SWE 2.0 services intend to do it. Depending on which publish subscribe interface is going to be used in a given OWS binding, the event information may also be provided in a different way. These approaches have yet to be tested and thus are potential areas for follow-on investigation. o Event channel scheme – Consider whether discovery is better served by introduction of a classification scheme to identify all event channels. This may be useful if a set of channels is not large and fairly stable. Use of a scheme would make them more accessible to client software and offers Copyright © 2010 Open Geospatial Consortium, Inc. 5 alternative discovery mode: browsing. Also, better documentation of known channels could be achieved. Currently, event channels are matched by name see EventChannel Name which may be weak fragile matching of text strings compared with the precise, discoverable and extensible use of a scheme. o Event type scheme – As with event channel sets, consider whether event types could usefully be codified as a scheme. o Discovery of ChannelsEvents via Spatial Query – While not demonstrated during the OWS-7 project, it is possible to associate geometry with any RegistryObject, including EventChannels and EventTypes. This would support searches for channels or events in a registry using a spatial query. To facilitate this, a representative Extent e.g. gml:Polygon could be added to each target object via rim:Slotwrs:ValueListwrs:AnyValue property and then queries could use a spatial operator. The according extent information would need to be available in the encoding of events event channels. o Support multiple aliases on event channel objects – As event channels may be used by i.e. referenced from multiple different application domains, each of which may refer to the particular channel via a distinct label or name, it may be useful to consider adding support for multiple aliases to the discovery model. This would primarily be for event channel objects but may also be valid for event types as well. o Complex Spatial Metadata – Expanding on the Discovery of ChannelsEvents via Spatial Query work item where channels and events may have a single geometry property that identifies their area of applicability, the possibilities of the spatial extent of a channelevent being a multi-geometry should be explored. 6 Copyright © 2010 Open Geospatial Consortium, Inc.

1.5 Foreword

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The Open Geospatial Consortium Inc. shall not be held responsible for identifying any or all such patent rights. Recipients of this document are requested to submit, with their comments, notification of any relevant patent claims or other intellectual property rights of which they may be aware that might be infringed by any implementation of the standard set forth in this document, and to provide supporting documentation. Copyright © 2010 Open Geospatial Consortium, Inc. 7 2 References The following documents are referenced in this document. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. For undated references, the latest edition of the normative document referred to applies. OGC 06-121r3, OpenGIS ® Web Services Common Standard NOTE This OWS Common Specification contains a list of normative references that are also applicable to this Engineering Report. OGC 07-036 , OpenGIS® Geography Markup Language GML Encoding Standard OGC 08-132 , OpenGIS® Event Pattern Markup Language EML OGC 08-133, OpenGIS® Sensor Event Service Interface Specification OGC 09-031r1, OWS-6 SWE Information Model Harmonization ER OGC 09-032, OGC ® OWS-6 SWE Event Architecture Engineering Report OGC 09-050r1, OGC OWS-6-AIM Engineering Report OGC 10-061 , OWS-7 Dynamic Sensor Notification Engineering Report OGC 10-069 , OWS 7 Engineering Report - GeoSynchronization service OGC 10-079 , OGC® OWS-7 Aviation Architecture Engineering Report OASIS Web Services Base Notification 1.3 OASIS Web Services Brokered Notification 1.3 OASIS Web Services Topics 1.3