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4.2 UML Notation
The data model specification is presented in this document in diagrams using the Unified Modeling Language UML static structure diagram cf. [23]. The UML notations used in this standard are described in the diagram
below Fig. 1.
Fig. 1: UML notation cf. ISO TS 19103, Geographic information - Conceptual schema language.
The following stereotypes are used: Geometry represents the geometry of an object. The geometry is an identifiable and distinguishable object
that is derived from the abstract GML type AbstractGeometryType. Topology represents the topology of an object. The topology is an identifiable and distinguishable object
that is derived from the abstract GML type AbstractTopologyType. Feature represents a thematic feature according to the definition in ISO 19109. A feature is an identifiable
and distinguishable object that is derived from the abstract GML type AbstractFeatureType. Enumeration enumerates the valid attribute values.
4.3 XML-Schema
The normative parts of the specification use the W3C XML schema language to describe the grammar of con- formant data instances. XML schema is a rich language with many capabilities. While a reader who is unfamiliar
with an XML schema may be able to follow the description in a general fashion, this specification is not intend- ed to serve as an introduction to XML schema. In order to have a full understanding of this Discussion Paper, it
is necessary for the reader to have a reasonable knowledge of XML schema.
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5 Requirements for an Indoor Navigation Standard
Indoor navigation faces a large number of challenges that differ from well established outdoor navigation meth- ods. Absolute positioning and localization methods like GPS are usually not available in indoor environments.
Route planning requires geoinformation about the interior navigable space of buildings. The navigable space may not only reflect the physical built environment but has to consider the mode of locomotion of the moving
subject or object and logical navigation constraints such as security zones and opening hours. Spatial reference systems are required both for the localization method and for the end-user. Whereas the former might be a locale
or world coordinate system, the latter is rather a natural spatial reference system which is used, e.g., for naming of route start and end points. The communication of the current position and of routing commands poses further
challenges.
In the following subsections of this chapter, mandatory requirements are deduced from these challenges which have to be addressed and answered by any proposals and approaches aiming at establishing an Indoor Navigation
Standard. Based on this discussion, a novel and generic Multilayered Space-Event Model is introduced in the further course of this Discussion Paper which meets these requirements and thus forms the basis and a general
framework for an Indoor Navigation Standard.
5.1 Support of Different Navigation Contexts
Kategori