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Analysis of Wi-Fi-based and Perceptual Congestion
Masaki Igarashi, Atsushi Shimada, Kaito Oka and Rin-ichiro Taniguchi
Kyushu University, 744, Motooka, Nishi-ku, Fukuoka, Japan
{igarashi, atsushi, kaito}@limu.ait.kyushu-u.ac.jp, rin@kyudai.jp
Keywords:
Congestion Estimate, Perceptual Congestion, Probe Request.
Abstract:
Conventional works for congestion estimates focus on estimating quantitative congestion (e.g., actual number
of people, mobile devices, and crowd density). Meanwhile, we focus on perceptual congestion rather than
quantitative congestion toward providing perceptual congestion information. We analyze the relationship
between quantitative and perceptual congestion. For this analysis, we construct a system for estimating and
visualizing congestion and collecting user reports about congestion. We use the number of mobile devices as
quantitative congestion measurements obtained from Wi-Fi packet sensors, and user-report-based congestion
as a perceptual congestion measurement collected via our Web service. Base on the obtained quantitative and
perceptual congestion, we investigate the relationship between these values.
1 INTRODUCTION
Congestion measurements and estimates are useful
and important for various applications. Congestion
information can assist congestion avoidance and mit-
igation. It is also important that we grasp the num-
ber of visitors to retail stores for customer analysis
and marketing strategies. Additionally, evacuation
planning for disasters requires congestion information
(Choi et al., 2011).
The extent of congestion is measured or estimated
manually or using sensors such as cameras and Wi-
Fi packet sensors. Vision-based congestion estimates
using cameras have recently been developed, and the
accuracy of these methods improves with each year.
Cameras must be carefully installed in the target area
considering occlusion and blind areas, and the initial
costs tend to be high. Wi-Fi packet sensors estimate
the number of mobile devices (e.g., smartphones and
laptop computers). The number of mobile devices
tends to be proportional to the number of people, so
we can use them to roughly estimate congestion. Wi-
Fi packet sensors cover distances between dozens to
a hundred meters. A Wi-Fi radio wave has a higher
transmittance than visible light, therefore we can in-
stall packet sensors in typical situations without con-
sidering blind areas.
The above-mentioned techniques are aimed at es-
timating quantitative congestion measurements such
as people count, crowd density, and the number of
mobile devices. For customer analysis, the actual
(a) Dining hall (b) Bus stop
Figure 1: Two spots with similar crowd density.
people count and density are useful and important fac-
tors.
Meanwhile, in terms of providing congestion in-
formation to people, qualitative congestion measure-
ments such as a person’s perception are also impor-
tant. Figure 1 shows two spots with almost the same
crowd density. There are few vacant seats in the
dining hall, so we would feel that the dining hall is
crowded. The crowd density at the bus stop is similar
as the dining hall, but the bus stop cannot be consid-
ered crowded. Human perception about congestion
depends on the people count and density and also the
locations characteristics, such as area and seating ca-
pacity.
In this paper, we focus on the relationship between
quantitative and perceptual congestion toward provid-
ing perceptual congestion information. We use the
number of mobile devices as quantitative congestion
measurements obtained from Wi-Fi packet sensors,
and user-report-based congestion as a perceptual con-
gestion measurement collected via our Web service.
We investigate the relationship between these values.
Igarashi, M., Shimada, A., Oka, K. and Taniguchi, R-i.
Analysis of Wi-Fi-based and Perceptual Congestion.
DOI: 10.5220/0006206102250232
In Proceedings of the 6th International Conference on Pattern Recognition Applications and Methods (ICPRAM 2017), pages 225-232
ISBN: 978-989-758-222-6
Copyright
c
2017 by SCITEPRESS – Science and Technology Publications, Lda. All rights reserved
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