Ubiquitous sensor data collection with mobile users

With the advancement of mobile technology, mobile sensing becomes increasingly popular for applications in environmental protection, traffic monitoring, and health care. Apart from sensing, mobile phones have also been suggested to facilitate data collection from wireless sensors in their surroundings. The idea is to use smart phones to collect data from wireless sensors through short range communication, including Bluetooth and Near Field Communication (NFC). In this work, we consider how to optimize this data collection provided by mobile users along their walks in real-time. We formalize the problem as the Sensor Collection Decision (SCD) problem and consider several variations of the problem. In practice, SCD is an online problem in which collection decisions must be taken in real-time, given no pre-knowledge on the user mobility and the sensor locations. We prove that a greedy strategy achieves a competitive ratio of 1/3, compared to the optimal offline solution. We conducted a variety of numerical simulations using actual mobility trace data which demonstrate that our proposed algorithms are near optimal in practice.