30-08-2013, 04:57 PM
A Study on Topological Characteristics of Wireless Sensor Network Based on Complex Network
Study on Topological Characteristics.pdf (Size: 497.02 KB / Downloads: 41)
Abstract
Topology structure is the first step for designing and
constructing wireless sensor network. A desirable topology can
prolong the life-time of the whole network. This paper focuses
on the complexity of the topology structure of the wireless
sensor network and analyzes its complex characteristics from
the perspective of network science theory. The measurement of
wireless sensor network is analyzed in the research. The results
indicate that for the mesh network, the degree of the node is
uniform distributed, it has comparatively smaller average path
length and higher cluster coefficient. Beside, Compare to other
type of network, the wireless sensor network is neither regular
network nor complete random network. It is between random
network and small-world network and has some property
which is similar to small-world network. In order to reduce the
hops for the network, this paper construct a small-world
wireless sensor network by adding some shortcuts to the
network, which is subject to the distance constraints between
individual nodes.
INTRODUCTION
A wireless sensor network (WSN) is a new information
acquirement system, it is considered to be one of the cutting
edge technologies that would have great impact on human
development in the era of 21st century. WSN is widely
applied to Military, environmental monitoring, smart home
applications and industrial control etc. Network topology is
the fist step for designing and setting up a sensor network, it
lays the foundation for other protocol implementation. A
desirable topology will improve the efficiency of routing and
MAC protocol, besides it provides the basis for data fusion,
time synchronization and object location and so on. Now the
research on WSN topology mainly focuses on the study of
topology control which is to set up an optimized network for
data transfer on the premise of meeting the requirements of
network coverage and connectivity by controlling power,
selecting backbone node and eliminating unnecessary
communication link [1].
THE TOPOLOGY OF WIRELESS SENSOR NETWORK
The topology of wireless sensor networks may be star,
cluster, mesh or hybrid network. Star network is single-hop
wireless sensor network that earliest applied in WNS, it has
the virtue of simple structure and low power consumption.
But the central nodes may be bottle-neck of the network; if it
is attacked the whole network will be paralysed. After star,
cluster network appeared. The typical cluster network is
multi-cluster network with coordinator. Nodes in each cluster
collect data and transmit them to their cluster heads rather
than base station, after aggregating and fusing cluster head
send data to base station. Afterwards, mesh structure with
better fault-tolerant ability is applied in wireless sensor
network.In mesh network node connection is arbitrary, all
nodes are same they can hop to any neighbor then tansmit
data to base.Besides the above three type, hybrid structure is
also applied is in wireless sensor network, which mix two or
three single topology together.
The Analysis ofMeasurement
The degree distribution of the wireless sensor network
which having 100 nodes is showed in figure 2. As illustrated
in the figure, we know that network's degree is evenly
distributed, and the average degree of the network is 3.5. It is
close to possion distribution that majortiy of nodes have
approximately the same degree, close to the average degree
of the network. Most nodes' degree are concentrated within
the range of 3 to 4 and no more than 3% nodes's degree is
less than 1 or more than 6. The results are accord with the
characteristics of mesh network.
In addition, average path length, clustering coefficient
and average degree are calculated respectively in order to
reveal topological features of wireless sensor network, and
then compare with that of random, regular and small world
networks'. Results are showed in table I.
CONCLUSIONS
Based on the complex network property of wireless
sensor networks, this study focus on the topology of wireless
sensor network and carry out series simulation according to
complex network research methods. The characteristic of
topology for the wireless sensor network is probed in the
experiment. The degree distribution, clustering coefficient
and average path length are analyzed during the experimental
process.