Indoor Navigation in OWS-6

Copyright © 2010 Open Geospatial Consortium 22

7.3 Indoor Navigation in OWS-6

The “Outdoor and Indoor 3D Routing Services Engineering Report” OGC Doc. No. 09-067r2 specified in OWS-6 proposes a service-based framework for indoor navigation utilizing 3D building data encoded in CityGML for route planning and the OGC WMS interface for position and route communication. Fig. 7: Overview of the OWS-6 Outdoor and Indoor Routing Services architecture The Engineering Report defines a network topology model which can be derived from 3D building models given in CityGML and which facilitates route planning in indoor areas. In order to derive the topological graph struc- ture, rooms are subdivided into areas called “cells”. Each cell is mapped onto a node within the topological graph. Further nodes are introduced at points where two adjacent cells touch. Edges denote topological adjacen- cy between the nodes. The resulting cell-adjacency graph also has an embedding in geometric space cf. fig. 8. The partitioning of topographic space into smaller cells is mainly based on the positioning accuracy of the localization infrastructure and the corresponding capabilities of the end-user device. The derivation of the net- work topology model from building topography is only defined in a semi-automatic way. The result is a fixed but non-deterministic graph facilitating routing in a specific navigation context with a predefined and fixed type of locomotion and localization method. Fig. 8 OWS-6 proposed derivation of network topology focused on the center points of each cell The indoor navigation approach proposed in OWS-6 already addresses some of the challenges and requirements introduced in chapter 5, e.g. the possibility to subdivide topographic space into smaller cells. However, it still faces open issues such as the usage of a fixed localization method as well as the lacking support for additional modes of locomotion and further space concepts like logical spaces including navigation constraints. The con- cepts discussed in OWS-6 and proposed by the OGC “Outdoor and Indoor 3D Routing Services Engineering Report” have been considered in the development of the Multilayered Space-Event Model which is presented in the following chapters of this OpenGIS ® Discussion Paper. The proposed framework fully covers the OWS-6 approach and additionally meets the further requirements specified in chapter 5. Copyright © 2010 Open Geospatial Consortium 23 8 Proposed Indoor Navigation Model In this OpenGIS ® Discussion Paper, we introduce a novel framework for a generic multilayered space-event model [21, 22]. A crucial aspect of this framework is the clear separation of different space models, such as topographic space, sensor space, and logical space. This approach allows for the decomposition of a specific space into smaller units according to respective semantics, without influencing other space representations. Furthermore, we show how to connect the layers, i.e., space models, in a well-defined way and to derive a valid and unique joint state embracing all linked layers at a given point in time. Based on joint states, e.g., between topographic space and sensor space, the proposed multilayer modeling approach can be utilized to enable locali- zation and route planning strategies in indoor navigation.

8.1 Structured Space Model