Following the massive proliferation of sensors in smartphones, many have predicted that mobile devices would soon see new generations of smart sensors. Over the last few years, while sensors in smartphones have gotten smaller, now consume less power, and feature better performance, they haven't gotten much smarter; while the performance of individual sensors has increased, their functionality has not expanded. What happened?
Context awareness has become a hot topic in mobile devices. The idea seems self-evident: design these devices to be smart enough to adapt themselves to their users. In 2009, the Gartner Group defined context-aware computing as "the concept of leveraging information about the end user to improve the quality of interaction." Indeed, context awareness represents a fundamental shift in interactivity: instead of end users programming their devices with their preferences, devices observe their users and deduce what the users want and then adapt themselves accordingly.