LocalVLC: Augmenting Smart IoT Services with Practical Visible Light Communication

Abstract

case for smart homes changing the light color to indicate a successful user authorization.However, in spite of those distinct advantages, many VLC designs focus mainly on the communication performance and novel functionality [3]- [10]. This results in a dilemma for deploying VLC in practice because existing solutions either entail high energy overhead or exhibit unpleasant visual experiences due to the perceptible light flickering effects for end users [11]. The light flickering effect greatly limits the deployment and applicable scenarios of VLC (e.g., to be used as a regular light source for indoor). In light of this challenge, the DarkLight design [11] tackles the problem sphere by emitting extremely-low luminance of light pulses, which makes the lighting device appear as a unnoticeable "dark" bulb. Although DarkLight addressed the flickering issue through an unconventional design, their solution provides a shorter communication range (1.3 m) and cannot replace existing regular light sources compared to our custom light bulb. Specifically, a dedicated DarkLight bulb should be installed besides normal LED lamps where DarkLight services are needed which causes light pollution by overlapping light signals for illumination and communication.This leads to the fundamental question of adopting VLC: how to achieve a practically deployable VLC with low cost and power footprint? Given that common VLC modulation schemes can hardly keep light pulses imperceptible and hence causing light flickering effects [11], we tackle the usability challenge for VLC by proposing a holistic system solution named LocalVLC. In its core, LocalVLC introduces a Morsecode inspired modulation scheme that can operate on off-theshelf LEDs with low energy overhead. We have implemented and evaluated a full-fledged system prototype based on Lo-calVLC design. In practical settings, our LocalVLC prototype can support up to 10 meters of range and attain reasonable throughput (up to 1.4 Kbps) with low error rate and energy consumption. Compared to the widely adopted Manchester encoding, LocalVLC yields 8x improvement on both throughput and energy consumption. Our design can effectively overcome the light flickering effect by encoding data into high frequency light pulses but does not require extra processing hardware such as FPGA or micro-controller. As inspired by but different from DarkLight, LocalVLC can be deployed as standard light source to overcome the light pollution problem by replacing existing lighting. The unique features of VLC can benefit many Abstract-Visible Light Communication (VLC) emerges as a communication technology for Internet of Things (IoT) services with appealing benefits n ot p resent i n e xisting r adio-based communication. However, current VLC designs commonly require dedicated LED lights to emit modulated light beams which entail high energy overhead and unpleasant visual experiences due to the perceptible light blinking effects for end users. This greatly limits the deployment and applicable scenarios of VLC. In this pap...

The Road Towards Private Proximity Services

“…Besides that, we improved users privacy from a system point of view with a private personal data hub [2], private indoor service discovery, and a countermeasure against relay attacks. Moreover, we realized a distance-bounding authorization based on visible light communication (VLC) [3] and analyzed the feasibility to apply homomorphic encryption for timeseries data like ambient light. Mobile and wearable devices like smartphones or tablets are data hubs of our digital life and contain a large amount of sensitive data, which makes them a potential target for attackers.…”

“…We use our custom light bulb [3] to enable semidecentralized device-to-device grouping. We detect nearby devices by their similarity of ambient light patterns and associate them together for data sharing.…”

“…We realized of set of proximity services at different spatial resolutions. For small-scale (∼ 0.5 m) securing remote access to smart homes via two-factor authentication [3] and for midscale (10-20 m) to manage nearby IoT devices [4], [5] and offer fine-grained indoor service discovery [3]. With respect to large-scale services (100 m), we implemented a device grouping via similarity of light patterns, ambient sound, Wi-Fi signals, and ultrasound communication [6] which is restricted by spatial barriers.…”

“…Regarding distance-bounding wireless communication, we realized LocalVLC: Augmenting Smart IoT Services with Practical Visible Light Communication (Completed) [3]. Current VLC designs commonly require dedicated LEDs to emit modulated light beams which entail high energy overhead and unpleasant visual experiences due to the perceptible light blinking effects for end users.…”

“…We take further advantage of our custom light [3] which serves as decentralized communication hub for device grouping based on ambient light patterns (In Progress). We use multiple distance metrics, correlations methods, and machine learning models to automatically group proximate devices based on the similarity of time-series signals like ambient light.…”