Collaborative Recognition of Queuing Behavior on Mobile Phones

Nowadays people spend a substantial amount of time waiting in different places such as supermarkets and amusement parks. Detecting the status of queuing may benefit both users and business. In this paper, we present QueueSense, a queuing recognition system to assist in a queue management system. QueueSense consists of clients on smartphones that provide automatic, energy-efficient, and accurate queuing recognition, and a server in the cloud that collects data, identifies multi-queue lines, and provides waiting time estimation. In order to be useful, QueueSense should be able to recognize queuing behavior in various queuing scenarios without greatly decreasing the battery life of mobile phones. We present features of queuing and build the classifier on smartphones to automatically recognize queue classifier without human input. We investigate the complicated nature of energy consumption for queue recognition on phones and design an effective algorithm to maximize energy savings while guaranteeing accuracy of queue recognition. We evaluate QueueSense performance using the data set from real world queuing scenarios collected over a three-month period. Empirical results show that QueueSense is adaptive to various queuing scenarios with both high recognition accuracy and energy efficiency. We further implemented a prototype of QueueSense, the first queue detection system using smartphones. We conducted real-world experiments in a dining hall and a supermarket near a university campus. Through implementation and evaluation, we demonstrate that QueueSense is capable of detecting waiting lines that occur in our daily lives.