Research Article
Fuzzy-Based Sensor Fusion for Cognitive Radio-Based Vehicular
Ad Hoc and Sensor Networks
Mohammad Jalil Piran, Amjad Ali, and Doug Young Suh
Electronics and Radio Engineering Department, Kyung Hee University, 1732 Deogyeong-daero, Giheung-gu, Yongin-si,
Gyeonggi-do 446-701, Republic of Korea
Correspondence should be addressed to Doug Young Suh; suh@khu.ac.kr
Received 3 November 2014; Accepted 3 February 2015
Academic Editor: Chunlin Chen
Copyright © 2015 Mohammad Jalil Piran et al. Tis is an open access article distributed under the Creative Commons Attribution
License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly
cited.
In wireless sensor networks, sensor fusion is employed to integrate the acquired data from diverse sensors to provide a unifed
interpretation. Te best and most salient advantage of sensor fusion is to obtain high-level information in both statistical and
defnitive aspects, which cannot be attained by a single sensor. In this paper, we propose a novel sensor fusion technique based
on fuzzy theory for our earlier proposed Cognitive Radio-based Vehicular Ad Hoc and Sensor Networks (CR-VASNET). In the
proposed technique, we considered four input sensor readings (antecedents) and one output (consequent). Te employed mobile
nodes in CR-VASNET are supposed to be equipped with diverse sensors, which cater to our antecedent variables, for example, Te
Jerk, Collision Intensity, and Temperature and Inclination Degree. Crash Severity is considered as the consequent variable. Te
processing and fusion of the diverse sensory signals are carried out by fuzzy logic scenario. Accuracy and reliability of the proposed
protocol, demonstrated by the simulation results, introduce it as an applicable system to be employed to reduce the causalities rate
of the vehicles’ crashes.
1. Introduction
Wireless sensor networks (WSNs) are composed of a large
number of sensor nodes, which are constrained in power and
communication range and are having multimodal sensing
capacity. Te tiny motes consist of sensing, data processing,
and communication components, which leverage on the idea
of sensor networks based on the collaborative efort ofa
large number of nodes [1]. Te operations of the network
are performed under environmental conditions, which are
characterized by low signal-to-noise ratio, interference, and
multipath efects [2]. Te nodes are randomly distributed
over a region to detect a physical phenomenon or an event.
Te harsh felds and power constraint may make some sen-
sor nodes inoperable. Hence, the network’s lifetime mainly
depends on the power source. Due to the network constraints,
it is necessary to fnd out some techniques that improve the
fow of information. One of the suggested solutions is data
aggregation or data fusion. Data fusion techniques provide
a single data by collecting a set of various source data. Data
fusion can reduce the amount of data fowing and the energy
consumed for data processing and transmission by eliminat-
ing redundant data. As a defnition, data fusion is a process of
combining information from several sources to reduce ben-
efciary and reliable information. In WSNs, data fusion can
be achieved by deletion of redundancy, energy consumption,
and assuring fault-tolerance among sensor nodes.
In order to reduce nodes’ power consumption and con-
sequently enlarge the network life time, numerous research
works considered data aggregation and sensor fusion tech-
niques, such as those regarding aggregation, metadata nego-
tiation, or data fusion [3–8]. Te authors in [3] address
the fusion problem in WSNs where the cross-correlation
between the estimates is unknown. With the assumptions
that the covariance matrix has a prior distribution and
also information about the covariance of each estimate
is known, the conditional distribution of the ofdiagonal
blocks is derived. In [4], the authors focused on a data
aggregation mechanism to the number of transmissions
and thereby minimize energy consumption. For congestion
Hindawi Publishing Corporation
Mathematical Problems in Engineering
Volume 2015, Article ID 439272, 9 pages
http://dx.doi.org/10.1155/2015/439272