Title
WALRUS: wireless acoustic location with room-level resolution using ultrasound
Abstract
In this paper, we propose a system that uses the wireless networking and microphone interfaces of mobile devices to determine location to room-level accuracy. The wireless network provides a synchronizing pulse along with information about the room. This is accompanied by an ultrasound beacon that allows us to resolve locations to the confines of a physical room (since audio is mostly bounded by walls). We generate the wireless data and ultrasound pulses from the existing PCs in each room; a PDA carried by a user listens for both signals. Thus, our approach does not require special hardware. We do not use ultrasound to send data. As a result we dramatically reduce the computational burden on the mobile device while also decreasing the latency of location resolution. Our results indicate that (i) ultrasound detection is robust even in noisy environments with many reflective surfaces; and (ii) that we can determine the correct room within a couple of seconds with high probability even when the ultrasound emitting PCs are not synchronized.
Year
DOI
Venue
2005
10.1145/1067170.1067191
MobiSys
Keywords
Field
DocType
room-level resolution,location resolution,ultrasound pulse,wireless network,mobile device,ultrasound detection,ultrasound beacon,existing pcs,wireless data,physical room,wireless acoustic location,correct room,ultrasound,mobile devices
Wireless network,Wireless,Computer science,Synchronizing,Real-time computing,Mobile device,Wi-Fi array,Acoustic location,Microphone,Content adaptation,Embedded system
Conference
ISBN
Citations 
PageRank 
1-931971-31-5
73
4.77
References 
Authors
10
5
Name
Order
Citations
PageRank
Gaetano Borriello16050777.11
Alan L. Liu222219.06
Tony Offer3734.77
Christopher Palistrant4734.77
Richard Sharp545845.38