Localization of off-the-shelf mobile devices using audible sound: architectures, protocols and performance assessment

ABSTRACT

Sound source localization will play a major role in the new location-aware applications envisioned in Ubiquitous Computing. We describe the design and performance of three architectures and corresponding protocols that use a variation of the Time-of-Flight method for localizing three different kinds of devices, namely 802.11-enabled PDAs, 3G cell phones, and PDAs without network connectivity. The quantitative assessment is based on the deployment made with 6 sensors in, a 20x9m room, sewing over 10,000 localization requests. Our experiments indicate that all architectures achieve localization within 70cm of the actual position 90% of the time. The accuracy is further improved to 40cm 90% of the time when geometric factors are taken into consideration. The effects of noise and obstructions are also analyzed. Within 1m localization error realistic noise degrades the accuracy by 6 to 10%. The presence of obstacles, such as humans and cement columns, has no observable effect on the performance.

REFERENCES

• 1: X. Bian, G. Abowd and J. Rehg, "Using Sound Source Localization in a Home Environment," In Proceedings of PERVASIVE, Munich, Germany, May 2005, LNCS 3468.
• 2: Jeremy Elson , Lewis Girod , Deborah Estrin, Fine-grained network time synchronization using reference broadcasts, Proceedings of the 5th symposium on Operating systems design and implementation

  Due to copyright restrictions we are not able to make the PDFs for this conference available for downloading

  , December 09-11, 2002, Boston, Massachusetts [doi>10.1145/1060289.1060304]
• 3: Andy Harter , Andy Hopper , Pete Steggles , Andy Ward , Paul Webster, The anatomy of a context-aware application, Proceedings of the 5th annual ACM/IEEE international conference on Mobile computing and networking, p.59-68, August 15-19, 1999, Seattle, Washington, United States [doi>10.1145/313451.313476]
• 4: A. Haghighat, C. V. Lopes, T. Givargis, and A. Mandal, "Location-Aware Web System," OOPSLA Workshop on Building Software for Pervasive Computing, 2004.
• 5: Jeffrey Hightower , Gaetano Borriello, Location Systems for Ubiquitous Computing, Computer, v.34 n.8, p.57-66, August 2001 [doi>10.1109/2.940014]
• 6: S. Holm, O. Hovind, S. Rostad and R. Holm, "Indoors data communications using airborne ultrasound," In proc. of IEEE International Conference on Acoustics, Speech and Signal Processing, 2005.
• 7: Raja Jurdak , Cristina Videira Lopes , Pierre Baldi, An Acoustic Identification Scheme for Location Systems, Proceedings of the The IEEE/ACS International Conference on Pervasive Services (ICPS'04), p.61-70, July 19-23, 2004 [doi>10.1109/ICPS.2004.8]
• 8: C. V. Lopes and P. Aguiar, "Acoustic Modems for Ubiquitous Computing," In IEEE Pervasive Computing, Mobile and Ubiquitous Systems, Volume 2, No.3, pp 62--71. July-September 2003.
• 9: A. Madhavapeddy, D. Scott, R. Sharp, "Context-Aware Computing with Sound," In Proceedings of The 5th International Conference on Ubiquitous Computing, October 2003.
• 10: A. Mandal, C. V. Lopes, T. Givargis, A. Haghighat, R. Jurdak, P. Baldi, "Beep: 3D Indoor positioning using audible sound," In Proceedings of Consumer Communications and Networking Conference (CCNC), January 2005.
• 11: D. E. Manolakis, "Efficient Solution and Performance Analysis of 3-D Position Estimation by Trilateration, " IEEE Trans. on Aerospace and Electronic Systems, Vol. 32, No. 4, October 1996, pp. 1239--1248.
• 12: Nissanka B. Priyantha , Anit Chakraborty , Hari Balakrishnan, The Cricket location-support system, Proceedings of the 6th annual international conference on Mobile computing and networking, p.32-43, August 06-11, 2000, Boston, Massachusetts, United States [doi>10.1145/345910.345917]
• 13: J. Scott and B. Dragovic, "Audio Location: Accurate Low-Cost Location Sensing," In Proceedings of PERVASIVE, Munich, Germany, May 2005, LNCS 3468.
• 14: WebBeep Web pages. www.ics.uci.edu/IopesJbeep

INDEX TERMS

Primary Classification:
  C. Computer Systems Organization
  C.3 SPECIAL-PURPOSE AND APPLICATION-BASED SYSTEMS
      Subjects: Signal processing systems

Additional Classification:
  C. Computer Systems Organization
  C.3 SPECIAL-PURPOSE AND APPLICATION-BASED SYSTEMS
      Subjects: Real-time and embedded systems
  C.5 COMPUTER SYSTEM IMPLEMENTATION
      C.5.3 Microcomputers
          Subjects: Portable devices (e.g., laptops, personal digital assistants)

General Terms:
Design, Management