SmartVLC

Abstract

Visible Light Communication (VLC) based on LEDs has been a hot topic investigated for over a decade. However, most of the research efforts in this area assume the intensity of the light emitted from LEDs is constant. This is not true any more when Smart Lighting is introduced to VLC in recent years, which requires the LEDs to adapt their brightness according to the intensity of the natural ambient light. Smart lighting saves power consumption and improves user comfort. However, intensity adaptation severely affects the throughput performance of the data communication. In this paper, we propose SmartVLC, a system that can maximize the throughput (benefit communication) while still maintaining the LEDs' illumination function (benefit smart lighting). A new adaptive multiple pulse position modulation scheme is proposed to support fine-grained dimming levels to avoid flickering and at the same time, maximize the throughput under each dimming level. SmartVLC is implemented on low-cost commodity hardware and several real-life challenges in both hardware and software are addressed to make SmartVLC a robust realtime system. Comprehensive experiments are carried out to evaluate the performance of SmartVLC under multifaceted scenarios. The results demonstrate that SmartVLC supports a communication distance up to 3.6m, and improves the throughput achieved with two state-of-the-art approaches by 40% and 12% on average, respectively, without bringing any flickering to users.