Unsupervised locating of WiFi access points using smartphones

Jahyoung Koo, Hojung Cha

Research output: Contribution to journalArticlepeer-review

63 Citations (Scopus)


WiFi positioning systems require radio maps in the form of either RF fingerprints or positions of WiFi access points (APs). In particular, knowledge of the AP positions is essential to enable a locating mechanism as well as to understand the nature of underlying WiFi networks, such as density, connectivity, interference characteristics, and so on. In this paper, we propose an approach called Serendipity, which locates WiFi APs in an unsupervised manner using radio scans collected by ordinary smartphone users. From the radio scans, we extract dissimilarities between all pairs of WiFi APs and estimate relative positions of APs by analyzing the dissimilarities based on a multidimensional scaling technique. We then find the absolute positions with additional radio scans whose positions are known. The discovered positions of WiFi APs are used for the positioning of smartphones or the management of the WiFi networks. To validate the proposed approach, we conducted experiments on several indoor locations.

Original languageEnglish
Article number6168850
Pages (from-to)1341-1353
Number of pages13
JournalIEEE Transactions on Systems, Man and Cybernetics Part C: Applications and Reviews
Issue number6
Publication statusPublished - 2012

Bibliographical note

Funding Information:
Manuscript received May 20, 2011; revised October 31, 2011 and January 13, 2012; accepted January 20, 2012. Date of publication March 13, 2012; date of current version December 17, 2012. This work was supported by the National Research Foundation of Korea under Grant 2011-0000156 and Grant 2011-0015332, funded by the Ministry of Education, Science and Technology, Korea government. This paper was recommended by Associate Editor F. Chu.

All Science Journal Classification (ASJC) codes

  • Control and Systems Engineering
  • Software
  • Information Systems
  • Human-Computer Interaction
  • Computer Science Applications
  • Electrical and Electronic Engineering


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