Energy Efficient Wi-Fi Tethering through Fast Convergent Transmission Power Adaptation

Energy-efficient Wi-Fi tethering has received sustained attention. However, most existing Wi-Fi tethering schemes use maximum power to transmit data regardless of the distance between a mobile access point (MAP) on a smartphone and other associated devices. This problem is becoming increasingly important with the popularity of MIMO deployment because they offer more offload traffic and a higher data rate. In this paper, we design a Distance-aware Adaptive Transmission Power Control (called DATPC) scheme. Hence, DATPC can set the appropriate transmission power at the right moment. We have prototyped DATPC on commercial 802.11n WiFi devices and evaluate its performance in various indoor and outdoor scenarios. Experimental results show that within 3m distance, DATPC reduces the energy consumption of a MAP smartphone by up to 60% while ensuring the same transmission quality as the default maximum transmission power when sending data packets.