Abstract:
Location-aware applications are steadily gaining popularity
across the world. However lack of GPS in low-end programmable
phones (< $100) and general absence of Wi-Fi infrastructure
in developing countries prevents users of low-end phones (majority
of population in developing countries) from using such
applications as their phones can not get location. GSM-based
approaches, such as using Cell IDs, have been developed as they
do not require specific hardware on phone and need no additional
infrastructural support. However, Cell ID based approaches
require access to a comprehensive database of Cell IDs which
does not exist in developing countries and its growth is not
promising either.
In this paper, we present a novel GSM-based approach of
using Cell Broadcast Service (CBS) messages for localization.
Unlike Cell ID based approach, our approach does not depend
on comprehensive database and can run on programmable low
end phones. We demonstrate the effectiveness of our approach on
data collected in New Delhi, India.We further propose two spacetime
history based algorithms to improve upon the localization
accuracy of our baseline CBS approach. The proposed algorithms
provide up to 35% improvement in accuracy over the baseline
method. We test our algorithms for two different cell phone operators
and show that the algorithms perform consistently better. At
the end, we present potential location-aware applications which
can be built using CBS based localization.
