Large-scale multi-building and multi-floor indoor localization has
recently been the focus of intense research in indoor localization based
on Wi-Fi fingerprinting. Although significant progress has been made in
developing indoor localization algorithms, few studies are dedicated to
the critical issues of using existing and constructing new Wi-Fi
fingerprint databases, especially for large-scale multi-building and
multi-floor indoor localization. In this paper, we first identify the
challenges in using and constructing Wi-Fi fingerprint databases for
largescale multi-building and multi-floor indoor localization and then
provide our recommendations for those challenges based on a case study
of the UJIIndoorLoc database, which is the most popular,
publicly-available Wi-Fi fingerprint multi-building and multi-floor
database. Through the case study, we investigate its statistical
characteristics with a focus on the three aspects of (1) the properties
of detected wireless access points, (2) the number, distribution, and
quality of labels, and (3) the composition of the database records, and
then identify potential issues and ways to address them in using the
UJIIndoorLoc database. Based on the results from the case study, we not
only provide valuable insights on the use of existing databases but also
give important directions for the design and construction of new
databases for large-scale multi-building and multi-floor indoor
localization in the future.