Smartphone-based data collection from wireless sensor networks in an urban environment

Using smartphones as mobile basestations and leveraging human mobility is a promising approach for urban data collection from Wireless Sensor Networks (WSNs). In this paper, we evaluate the feasibility of this approach applying analyses on a city-wide mobility dataset. Our spatial analysis shows that popular locations cluster close to each other and sensor nodes located in rarely visited locations can transmit their data in a few hops to smartphones visiting these popular locations. Our energy-efficiency analysis indicates the feasibility of employing energy-conserving approaches on both smartphones and WSN nodes based on mobility behavior of smartphone users. We evaluated and compared on-demand and continuous data collection protocols on several WSN islands with different size and connectivity regarding to data collection efficiency. Our simulation results show that continuous data collection protocols surpass on-demand data collection protocols in terms of data delivery ratio and latency. We found that data collection protocols run more efficiently in many-connected small islands compared to fewer connected large islands. (C) 2015 Elsevier Ltd. All rights reserved.