Exploiting multiple wireless interfaces in smartphones for traffic offloading

Smartphones are evolving at a fast rate in terms of their computational, storage, and communications capabilities. A high-end smartphone is equipped with multiple wireless interfaces with varying bit rates, energy consumption requirements, and coverage ranges. The joint utilization of the existing wireless interfaces facilitates the development of advanced techniques to boost the performance of wireless networks and enhance the experience of mobile users. Among these techniques is device-to-device cooperation where a smartphone receives content from a base station on a given wireless interface and distributes it to other devices in its vicinity via another wireless interface. Another technique is traffic offloading in heterogeneous network scenarios where a smartphone downloads content using multiple wireless interfaces. In this paper, we study the readiness of high-end smartphones to utilize multiple wireless interfaces simultaneously focusing on capabilities and challenges. We adopt an experimental approach using a mobile cooperative video distribution testbed to obtain and evaluate performance results with focus on energy consumption. We consider various scenarios involving a combination of wireless technologies that include Bluetooth, WiFi, WiFi-Direct, and 3G.