Nericell: Rich Monitoring of Road and Traffic Conditions using Mobile Smartphones

We consider the problem of monitoring road and traffic conditions in a city. Prior work in this area has required the deployment of dedicated sensors on vehicles and/or on the roadside, or the tracking of mobile phones by service providers. Furthermore, prior work has largely focused on the developed world, with its relatively simple traffic flow patterns. In fact, traffic flow in the cities of the developing regions, which comprise much of the world, tends to be much more complex owing to varied road conditions (e.g., potholed roads), chaotic traffic (e.g., a lot of braking and honking), and a heterogeneous mix of vehicles (2-wheelers, 3-wheelers, cars, buses, etc.).

To monitor road and traffic conditions in such a setting, we present Nericell, a system that performs rich sensing by piggybacking on smartphones that users carry with them in normal course. In this talk, we focus specifically on the sensing component, which uses the accelerometer, microphone, GSM radio, and/or GPS sensors in these phones to detect potholes, bumps, braking, and honking. Nericell addresses several challenges including virtually reorienting the accelerometer on a phone that is at an arbitrary orientation, and performing honk detection and localization in an energy efficient manner. We also touch upon the idea of triggered sensing, wherein dissimilar sensors are used in tandem to conserve energy. We evaluate the effectiveness of the sensing functions in Nericell based on experiments conducted on the roads of Bangalore, with promising results.

(Joint work with Prashanth Mohan and Ram Ramjee; to appear in ACM SenSys 2008)
Venkat Padmanabhan is a Senior Researcher and Research Manager at Microsoft Research India in Bangalore, where he founded and now leads the Mobility, Networks, and Systems group. Venkat was previously with Microsoft Research Redmond for 8.5 years. His research interests are in networked systems and his current projects focus on mobile and sensor systems, and network management. His professional service has included serving as program (co-)chair for ACM NOSSDAV 2004, ACM IMC 2005, and IEEE HotWeb 2008, and as an affiliate faculty member at the University of Washington, where he has taught and served on student thesis committees. Venkat holds a B.Tech. from IIT Delhi and an M.S. and Ph.D. from UC Berkeley, all in Computer Science.