Indoor Positioning with GNSS-Like Local Signal Transmitters - Global Navigation Satellite Systems: Signal,Theory and Applications - page 299

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Indoor Positioning with
GNSS-Like Local Signal Transmitters
Nel Samama
Institut Telecom / Telecom SudParis
France
1. Introduction
After more than ten years of research into indoor positioning and localisation techniques,
whose aim has been to provide real continuity of service, as with GNSS outdoors, one has to
conclude that no solution has yet been found.
1.1 A very brief history
The real story started a little bit more than ten years ago, in the context of the Galileo project,
with the very interesting idea of the so-called “ local elements ”. The question was to do better
than the future competitor GPS in designing a real positioning service for the twenty first
century: technology transparency to the end user, simple and intuitive operation, performance
and of course continuity of the positioning in all possible environments that the modern
citizen will face with his/her mobile phone.
One technology followed another: Ultra Wide band (UWB) was the first candidate, at the
end of the 20 th century. But, facing the problem of considering the proposed approaches as a
real “ indoor GPS ”, Assisted-GPS (A-GPS, shortly followed by the Assisted-GNSS) was the
next one, typically between 2003 and 2007. It was at that time that the positioning
community seemed to realise that the problem was really hard and that a huge research
effort would be necessary. For instance, this was the time that ubiquitous positioning was
no longer described as imminent and works being carried out in many directions now had
a chance to be heard. A few industrial partners, often small organisations, proposed various
technical solutions, from the well-known WiFi to the use of TV (television) signals for
example.
On the other hand, the market of “ Location Based Services ” developed very slowly, probably
due to the complexity and diversity of the environments to be addressed: “one” is still
waiting for THE FREE technological solution (as in the case of GPS : this system is one
example of the numerous modern “costly free” services) (Kupper 2005). Current techniques
proposed in order to provide this continuity of service are mainly oriented, for commercially
available solutions, towards WiFi. Some R&D partners also propose inertial sensors or
vision based approaches.