Details of Research Outputs

In real life, there is an application scenario when people participate in group activities. One user may want to check the “relative locations” of other users, that is, whether these users are in his/her vicinity every once in a while. If someone is missing, emergency measures can be taken immediately. However, existing technologies such as localization methods cannot address this problem well. Most of methods require the supporting of pre-built infrastructures such as satellites, base stations, or databases. Moreover, they may fail in some circumstances such as the environments where it is difficult to receive good signals from infrastructures. For example, there is almost no GPS signal indoors. To address these problems, BlueCat, an infrastructure-free system is implemented on smartphones. The names of Bluetooth devices are used as the communication media, which is free and convenient to use. Through interactions in the neighborhood, a suspected missing person can be detected in a given time. We also design an energy-efficient algorithm for saving the limited battery power of devices. The feasibility and effectiveness of the system are validated by using both experiments and simulations where real mobility traces are used. © 2015 Old City Publishing, Inc.