%0 Conference Paper %1 liu2012limit %A Liu, Hongbo %A Gan, Yu %A Yang, Jie %A Sidhom, Simon %A Wang, Yan %A Chen, Yingying %A Ye, Fan %B Proceedings of the 18th Annual International Conference on Mobile Computing and Networking %C New York, NY, USA %D 2012 %I ACM %K indoor localisation smartphone topoi wifi wlan %P 305--316 %R 10.1145/2348543.2348581 %T Push the Limit of WiFi Based Localization for Smartphones %U http://doi.acm.org/10.1145/2348543.2348581 %X Highly accurate indoor localization of smartphones is critical to enable novel location based features for users and businesses. In this paper, we first conduct an empirical investigation of the suitability of WiFi localization for this purpose. We find that although reasonable accuracy can be achieved, significant errors (e.g., $6\sim8m$) always exist. The root cause is the existence of distinct locations with similar signatures, which is a fundamental limit of pure WiFi-based methods. Inspired by high densities of smartphones in public spaces, we propose a peer assisted localization approach to eliminate such large errors. It obtains accurate acoustic ranging estimates among peer phones, then maps their locations jointly against WiFi signature map subjecting to ranging constraints. We devise techniques for fast acoustic ranging among multiple phones and build a prototype. Experiments show that it can reduce the maximum and 80-percentile errors to as small as $2m$ and $1m$, in time no longer than the original WiFi scanning, with negligible impact on battery lifetime. %@ 978-1-4503-1159-5

@inproceedings{liu2012limit, abstract = {Highly accurate indoor localization of smartphones is critical to enable novel location based features for users and businesses. In this paper, we first conduct an empirical investigation of the suitability of WiFi localization for this purpose. We find that although reasonable accuracy can be achieved, significant errors (e.g., $6\sim8m$) always exist. The root cause is the existence of distinct locations with similar signatures, which is a fundamental limit of pure WiFi-based methods. Inspired by high densities of smartphones in public spaces, we propose a peer assisted localization approach to eliminate such large errors. It obtains accurate acoustic ranging estimates among peer phones, then maps their locations jointly against WiFi signature map subjecting to ranging constraints. We devise techniques for fast acoustic ranging among multiple phones and build a prototype. Experiments show that it can reduce the maximum and 80-percentile errors to as small as $2m$ and $1m$, in time no longer than the original WiFi scanning, with negligible impact on battery lifetime.}, acmid = {2348581}, added-at = {2015-10-19T20:17:56.000+0200}, address = {New York, NY, USA}, author = {Liu, Hongbo and Gan, Yu and Yang, Jie and Sidhom, Simon and Wang, Yan and Chen, Yingying and Ye, Fan}, biburl = {https://www.bibsonomy.org/bibtex/2be50c21c7e7d22d865f6cfe9346c2a6b/stumme}, booktitle = {Proceedings of the 18th Annual International Conference on Mobile Computing and Networking}, description = {Push the limit of WiFi based localization for smartphones}, doi = {10.1145/2348543.2348581}, interhash = {3b5092f2f302425d13b6fd6f0ce29176}, intrahash = {be50c21c7e7d22d865f6cfe9346c2a6b}, isbn = {978-1-4503-1159-5}, keywords = {indoor localisation smartphone topoi wifi wlan}, location = {Istanbul, Turkey}, numpages = {12}, pages = {305--316}, publisher = {ACM}, series = {Mobicom '12}, timestamp = {2015-10-19T20:18:38.000+0200}, title = {Push the Limit of WiFi Based Localization for Smartphones}, url = {http://doi.acm.org/10.1145/2348543.2348581}, year = 2012 }