VINCE: Exploiting Visible Light Sensing for
Smartphone-based NFC Systems
Jianwei Niu
1
, Fei Gu
1
, Ruogu Zhou
2
, Guoliang Xing
2
, Wei Xiang
1
State Key Laboratory of Virtual Reality Technology and Systems, School of Computer Science and Engineering
Beihang University, Beijing, China
1
Department of Computer Science and Engineering, Michigan State University
2
niujianwei@buaa.edu.cn, {zhouruog, glxing}@msu.edu
Abstract—This paper presents VINCE – a novel visible light
sensing design for smartphone-based Near Field Communication
(NFC) systems. VINCE encodes information as different bright-
ness levels of smartphone screens, while receivers capture the
light signal via light sensors. In contrast to RF technologies, the
direction and distance of such a Visible Light Communication
(VLC) link can be easily controlled, preserving communication
privacy and security. As a result, VINCE can be used in a wide
range of NFC applications such as contactless payments and
device pairing. We experimentally profile the impact of screen
brightness levels and refresh rates of smartphones, and then
use the results to guide the design of light intensity encoding
scheme of VINCE. We adopt several signal processing techniques
and empirically derive a model to deal with the significant
variation of received light intensity caused by noises and low
screen refresh rates. To improve the communication reliability,
VINCE adopts a feedback-based retransmission scheme, and
dynamically adjusts the number of encoding brightness levels
based on the current light channel condition. We also derive
an analytical model that characterizes the relation among the
distance, SNR (Signal to Noise Ratio), and BER (Bit Error
Rate) of VINCE. Our design and theoretical model are validated
via extensive evaluations using a hardware implementation of
VINCE on Android smartphones and the Arduino platform.
I. INTRODUCTION
Visible Light Communication (VLC) [9] [17] is a new
kind of optical wireless communication based on visible light
spectrums (400THz to 790THz). Due to the LoS (Line of
Sight) characteristic, VLC can offer short-range but secure and
interference-free wireless links. Because of these advantages,
VLC has received significant attention recently [19], and
found applications in several scenarios such as vehicular
networks and indoor WLANs.
This work exploits visible light sensing for smartphone-
based near field communication (NFC) systems. We have
designed and implemented a novel system called VINCE
– Visible lIght-based Near field Communication for smart-
phonEs. Specifically, VINCE encodes information as different
light intensities and displayed on the smartphone screen,
while the receiver employs light sensors to sense the light
signal and then decodes the information. In contrast to RF
technologies, the direction and distance of the VLC link
between the phone screen and light sensors can be easily
controlled, preserving communication privacy and security.
As a result, the troublesome authentication process, which
is typically required for Bluetooth and Wi-Fi radios, can
potentially be avoided. Moreover, VINCE can be implemented
on off-the-shelf smartphones without any additional hardware.
These advantages allow VINCE to be used as a potential
alternative to the current Near Field Communication (NFC)
technology. NFC is a new wireless standard whose effec-
tive communication range is only a few centimeters [5]. It
enables a wide range of emerging mobile applications such
as contactless payments, device pairing, and data exchange
between smartphone users [5]. However, currently, only a lim-
ited number of mobile platforms have built-in NFC chipsets.
Encoding information into light intensities of the screen,
VINCE allows an off-the-shelf smartphone to communicate
with another smartphone or a light-sensor-enabled device in
the close proximity. In a typical smart payment scenario,
the consumer may tap the smartphone on a POS (Point-Of-
Sale) terminal that is equipped with light sensors (typically
less than $1/unit). VINCE then transmits the payment in-
formation by modulating the screen brightness. VINCE can
also be used to enable the near field communication between
a smartphone and energy-constrained sensors. For instance,
in a smart home scenario, a user may use a smartphone
to interact with battery-powered sensors like thermometers
in proximity. VINCE receivers decode transmissions using
light sensors, which are significantly more power-efficient
than RF technologies like Bluetooth and WiFi. In summary,
due to the short distance (up to a few centimeters) and high
directionality, the communication link of VINCE provides
a low-cost, easy-to-use, and security-preserving solution for
many NFC applications, without the reliance on additional
wireless interfaces or the Internet infrastructure.
The design of VINCE faces several key challenges. First,
the screens of current smartphones typically have low refresh
rates (about 60 Hz). Moreover, the maximum refresh rate often
has a large variation over time due to unpredictable operating
system overhead. These issues lead to unreliable, low-rate
data transmissions. For instance, the incomplete rendering of
screen frames can lead to significant variation of received light
intensity, making it challenging to decode. Second, the signal
reception is susceptible to the interference of ambient light
in the environment. Unfortunately, off-the-shelf smartphones
support only a limited number of screen brightness levels,
which makes it difficult to mitigate the impact of such noise.
We develop several novel techniques to address these
challenges. First, we experimentally profile the number of