Developing indoor navigation inside of buildings: thesis overview

The urban environment is composed of both outdoor space and buildings composed of floors and each floor is composed of rooms and corridors. People transit between outdoors and inside buildings. At one point we can all get lost inside a large multifloor building (university, campus, hospital, shopping mall, airport, etc), we can have a trouble finding our door at the airport or we can be late to attend a class at the beginning of academic year at the university because we can not find the room identified by a number inside the building. That is why a map is often needed to display the path and the points of interest (POI) inside the building.


Pedestrian navigation service is fundamental to any environment that requires movement across large spaces. It is a complex negotiation process mainly made up of path finding elements. Nowadays, there are standards for outdoor navigation such as Google Maps and Open Street Map [1]. Whereas, indoor navigation is still under development stage and depends mainly on the architecture of the building [2]. In fact, buildings are vary varied, they have different structures and some of them are large. Moreover, indoor maps are often proprietary and/or expensive [3] and most of the indoor navigation services focus on only one floor [4-5].

In addition, the main component of an indoor navigation service is the path finding which is based on the graph of the considered building. A graph is a set of nodes representing rooms (doors) and edges representing corridors. And at the simplest level, this takes the form of a floor plan of a building (should contain relevant information for navigation that means information about doors, corridors, etc). Many of the developed prototypes have generated the graph manually [6]. Furthermore, to the best of our knowledge there is no standard for indoor-outdoor navigation.

Research questions

Two questions are relevant to be answered in this master thesis.

The first question is: How to develop a multi-floor indoor navigation service compatible with outdoor navigation service ? Which includes the essential parts to construct the indoor navigation service that lead it to be multi-floor with interoperable format data representation to get easily integrated with the outdoor navigation service (Google Maps).

The second question is: How to switch seamlessly between the indoor navigation service and the outdoor navigation service ? Which means the navigation algorithm that ensures a continuous navigation without intervention of the user to switch between the indoor

and the outdoor navigation services. Whatever is the query of the user, the path has to be displayed, the computation of the path and the integration with the outdoor navigation service has to be transparent to the user.

Objective and contribution

This project, titled ”Seamless indoor outdoor navigation service”, falls under the theme of indoor navigation. It is carried out in the ITZ building. In this master thesis project, we have proposed a modification of the odd-even numbering algorithm for room identification, as the navigation is based on room numbers. The first part of our contribution is the building multi-floor graph generation algorithm. Therefore, it is interesting and useful for indoor navigation to integrate this graph to employ it in different computations of the navigation process.

The second and the most important path of our contribution is the seamless navigation algorithm which includes the seamless multi-floor navigation, the seamless switch between the indoor and the outdoor maps and the continuous display of the path between the indoor and the outdoor spaces. These contributions are made to achieve the objective of a seamless navigation of the user either between rooms or between the building and the outdoor space.

Master thesis outline

This master thesis report is structured in four main parts.

The first chapter: Represents an overview of the background information and the state of the art related to the navigation field of research. We have firstly compared the indoor and the outdoor environments, then, we have introduced the main parts of a navigation service including optimal path finding algorithms, We have indoor map types and elements, room numbering patterns, existing indoor graph generation methods and indoor-outdoor navigation services and their limitations.

Through the second chapter, entitled ”Methods” we have detailed our contribution, we have described the developed algorithms to meet the requirements of our project named ITZ Maps.

The third chapter is an illustration of the implementation details of our work which performs real experimentations and tests. We have also presented screenshots of the different test cases.

Thereafter, in the fourth chapter, we have evaluated the performance of our application. We have discussed the results, we have checked how pretty have the preidentified objectives been achieved and if the research questions have been answered.

Finally, we have ended up with the conclusion of our work and the perspectives opened to further upgrades and future work.