WiFi proximity detection in mobile web applications

We present a technique for enabling WiFi proximity detection in mobile web applications based on proximity-adaptive HTTP responses (PAHR). The technique requires zero installation on the client and is client platform independent. Our reference implementation ProxiMagic is low-cost and provides robust and responsive interactivity based on proximity detection. We demonstrate the technique's applicability through a real-world example application deployed during a month-long participatory art exhibition. We document the reliability and suitability of the simple proximity detection employed in ProxiMagic through a controlled experiment.