Transfer Time, Energy, and Quota-Aware Multi-RAT Operation Scheme in Smartphone

Today's smartphones integrate multiple radio access technologies (multi-RAT), e.g., third-generation (3G), fourth-generation (4G), Wi-Fi, and Bluetooth, whereas the number of integrated RATs is increasing. Therefore, it is becoming more important to select the best RAT set among the available RATs and determine how much data to transfer via each selected RAT network. We propose a multi-RAT interface activation algorithm with supporting system design for smartphones' file transfer service (e.g., downloading a movie file). We model a multiattribute cost function incorporating file-transfer completion time, energy consumption, and data usage quota together. The goal of this paper is to find out the optimal multi-RAT set to be activated with the corresponding file segment allocation that minimizes the cost function under given energy and quota constraints. By the proposed algorithm, the suboptimal solution can be found without significant performance degradation from the optimal solution while making the computational complexity linear in the number of RATs.