Energy Modeling and Optimization for BSN and WiFi Networks Using Joint Data Rate Adaptation.

In this paper, we propose to model and optimize the communication energy consumption of devices in BSN and WiFi (BSN-WiFi) networks by using a method of joint data rate adaptation. First, we detail the BSN-WiFi network system in four consecutive phases. Then, we analyze the communication energy consumption, illustrate throughput and time delay constraints, and derive mappings of signal-to-noise ratio to packet delivery ratio (SNR-PDR) of BSN and WiFi networks. Next, we build an energy optimization model with constraints of SNR-PDR mappings, throughput, and time delay, which minimizes the communication energy consumption. With cvx, we solve this model with inputs of SNR values to obtain optimal data rates, which are used for online data rate adaptation. Finally, from a specific BSN-WiFi network system, we collect 20-minute traces for performance evaluation, and our results demonstrate that our solution achieves up to 86% energy savings compared to solutions using fixed data rates, and saves 10% energy than the optimal packet size solution.