Abstract:
Wireless Sensor Networks
(WSN’s) have been finding to itself new applications continuously. Many of
these applications need location information of nodes. The localization of
nodes can be made by range based or range free localization methods conventionally.
Angle-of-Arrival (AoA), Time-Difference-of-Arrival (TDoA), Received Signal
Strength Indicator (RSSI), Time-of-Arrival (ToA) are well known range based
methods. Therefore AoA, ToA and TDoA have some hardware and software
difficulties for nodes which have limited processing and power sources. However
RSSI based localization doesn’t cost high processing resources or complex
hardware modifications. Most of the WSN nodes already have RSSI measurement
capability. However RSSI measurements is vulnerable to noise and environmental
effects. Therefore error of RSSI based localization can be over to an
acceptable level.
Centroid,
APIT, DV-Hop and Amorphous are some of the range free localization methods.
Range free methods can only give location information approximately but they
don’t need any extra hardware or high processing capability.
In this study
WSN nodes are assumed randomly or regularly distributed on a certain area. Some
of the nodes are beacon nodes. The beacon nodes are assumed as having higher
power resources and GPS receivers. The locations of nodes are assumed as fixed.
The beacon nodes send their location information sequentially. Localization of
nodes are made through RSSI and location information of beacon nodes. The mean
of RSSI is calculated to reduce effect of noise on it. A rough location
estimation made by weighted centroid. A probabilistic based location estimation
and flower pollination algorithm (FPA) are used separately to make final
decision about the location. Rough estimates are used to limit search area of
flower pollination algorithm in order to reduce convergence time.
Subjects | Engineering |
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Journal Section | Research Article |
Authors | |
Publication Date | December 25, 2016 |
Published in Issue | Year 2016 Volume: 4 Issue: Special Issue-1 |