Simulation of a RSSI-Based Indoor Localization
System Using Wireless Sensor Network
Hyochang Ahn
#1
, Sang-Burm Rhee
#2
#
Department of Computer Science and Engineering, Dankook University
Jukjeon-dong, Yongin-si, Gyeonggi-do, Republic of Korea
1
youcu92@dankook.ac.kr,
2
sbrhee@dankook.ac.kr
Abstract— In recent years, with advance in wireless
communication technology, sensing technology, micro-electronics
technology and embedded system, wireless sensor network
(WSN) can be used for various application areas, such as home
health care, military and industry. The localization service which
provides the location information of mobile user is one of
important service provided by WSN, because many applications
need to locate the source of incoming measurements. The current
localization algorithm in WSN can be divided into two
categories: range-based and range-free schemes. Most of the
range-based localization method proposed use of the received
signal strength indication (RSSI) to make an estimation of the
distance between transmitter and receiver. The localization
algorithm used the values of RSSI received from the cluster
included the mobile node to minimize frequency of the
diffraction, reflection, and attenuation. Closer nodes to the
router from mobile node are given more weight and location of
the node is determined the center of gravity of router nodes. Our
localization algorithm used the values of RSSI received from the
cluster included the mobile node and used weighted centroid
method in which closer nodes to the router from mobile node are
given more weight and location of the node is determined the
center of gravity of router nodes. CC2420 RF module and
ATmega128L MCU are used to be the hardware platform of
nodes on the location experiment is designed and implemented in
this paper.
Keywords— RSSI, WSN, Localization, Mobile Node, Indoor
I. INTRODUCTION
The increasing miniaturization of electronic components
and advances in radio communication technologies lead to the
development of extreme small, low cost, and smart sensor
nodes. Each node is made up of a low power processor,
battery supply, limited sensors and a transceiver for
communication. The transceivers carry out via interconnection
between nodes. Nodes measure conditions of the environment
and transmit this data to a base station. Numerous nodes form
a large wireless sensor network (WSN) to observe huge
inaccessible area [1], [2].
WSN has several applications that include object tracking,
traffic monitoring, habitat monitoring, fire detecting, nuclear
reactor controlling, seismic activities detecting, ships
navigating, and so on. In a typical application, WSN is
scattered in an area where it is meant to collect information by
sensor nodes. Several distributed sensor nodes should be
communicated and cooperated in our circumstance. Therefore,
the localization of sensor node by itself was considered as the
most essential feature in WSN. Accurate localization that
consumed low power and cost is an important requirement for
the deployment of WSN in numerous applications [3]. One of
the important issues in WSN is the localization of sensor
nodes because the location information is useful for coverage,
routing, location service, target tracking, and rescues [4].
Within WSN, location aware is a primitive essential
research to support different attractive application. Existing
localization method can be divided into two categories: range-
based and range-free schemes. The difference between the
two kinds of methods is information used for localization.
Range-based methods use range measurements, and range-
free techniques only use the content of messages. The range-
based methods require the node-to-node distances or angles
for measuring the node locations. The range-based methods
belong to this category included the angle of arrival (AOA)
method, the time of arrival (TOA), and time difference of
arrival (TDOA) and received signal strength indicator (RSSI)
techniques [5]. The typical localization system using TOA
scheme is GPS. Others are the process of locating an object by
accurately computing the TDOA of a signal emitted from its
object to three or more receivers [6], [7]. Some others
compute the comparative angles between the neighbouring
nodes for localization [8], [9]. Most of the localization
algorithms made use of the RSSI to make an estimation of the
distance between transmitter and receiver. The application of
localization systems based RSSI may have some restrictions
when used in different environment.
Several approaches based on range-free are proposed to
determine sensor node locations to reduce the localization cost
in WSN. A simple approach computes the centroid location of
anchor nodes, which is the approximate of the sensor node
location. In the APIT scheme, a sensor node is limited in the
intersection of beacon triangles, where the beacon triangle is
the triangle formed by three arbitrary beacons [10]. DV-Hop
measures hop counts to obtain the approximate distance from
each node to the specific anchor nodes [11]. Using the
distance information, the sensor nodes can obtain their own
locations with triangulation methods.
Range-based localization is of low location error, but it is
supported with expensive hardware, and it consumes more
energy. Range-free localization is of low hardware cost, and it
requires less energy; but its location error is much more than
range-based one.
The remainder of this paper is organized as follows.
Section 2 gives a short survey of some existing work for
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