Cooperation among smartphones to improve indoor position information

Accurate indoor location information remains a challenge without incorporating extensive fingerprinting approaches or sophisticated infrastructures within buildings. Nevertheless, modern smartphones are equipped with sensors and radios that can detect movement and can be used to predict location. Dead reckoning applications on a smartphone may attempt to track a person´s movement or locate a person within an indoor environment. Nevertheless, smartphone positioning applications continue to be inaccurate. We propose a new approach, CRISP - CoopeRating to Improve Smartphone Positioning, which assumes that dead reckoning approaches have inaccuracies, but leverages opportunities of the interaction of multiple smartphones. Each smartphone computes its own position, and then shares it with other nearby smartphones. The signal strengths of multiple radios that are used on smartphones estimate distances between the devices. While individual smartphones may provide some positioning (possibly inaccurate) information, accuracy may improve when several smartphones cooperate and share position information through multiple iterations. Via indoor experimentation and simulation, we evaluate our approach and believe it is promising as an inexpensive means to improve position information and possibly lead to better results for a number of applications, including exercise profiling.