Hindawi Publishing Corporation
International Journal of Distributed Sensor Networks
Volume 2012, Article ID 542389, 9 pages
doi:10.1155/2012/542389
Research Article
A Local World Evolving Model for Energy-Constrained Wireless
Sensor Networks
Nan Jiang, Huan Chen, and Xiang Xiao
College of Information Engineering, East China Jiaotong University, Nanchang 150001, China
Correspondence should be addressed to Nan Jiang, jiangnan1018@gmail.com
Received 23 October 2011; Accepted 23 February 2012
Academic Editor: Sabah Mohammed
Copyright © 2012 Nan Jiang et al. This is an open access article distributed under the Creative Commons At tribution License,
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Energy efficiency is one of the basic requirements of wireless sensor networks (WSNs) yet this problem has not been sufficiently
explored in the context of cluster-based sensor networks. Specifically, the interaction of different types of sensor nodes is one of the
major factors of energy efficiency in large-scale heterogeneous networks. In this paper, we aim at improving the interactions among
sensor nodes, and we present a heterogeneous local-world model to form large-scale wireless sensor networks based on complex
network theory. Two types of nodes, normal nodes and cluster nodes, are added to the networks. The degree distribution for this
model is obtained analytically by mean-field theory. This approach depicts the evolution of the network as having a topological
feature that is not completely exponential and not completely power law; instead, it behaves between them. The experiment and
simulation indicate that the control method has excellent robustness and a satisfactory control effect (interaction of different types
of sensor nodes). Furthermore, the results also s how that the higher the generation rate of the cluster nodes is, the closer the degree
distribution follows the power-law distribution.
1. Introduction
Wireless sensor networks (WSNs) are composed of a large
number of sensor nodes. These nodes are deployed in a speci-
fic area to monitor physical phenomena. Wireless sensor net-
works are poised to revolutionize our abilities for sensing and
controlling our environment. However, sensor nodes rely on
batteries to provide energy in WSNs. As a result, the primary
problem in WSNs is always energy savings for sending and
receiving data. Consequently, power control must be perfor-
med in WSNs. In recent years, with the development of
WSNs, advances in wireless communication and sensing
technology have made it possible to produce a large number
of individually cheap and small units. Usually, these small
pieces of equipment are used in WSNs, as combinations of
sensors and wireless network nodes. With the increasing scale
of WSNs, some c haracteristics of complex networks have
emerged. The problem of coefficient, error, and attack toler-
ance remains to be solved in large-scale networks. As a result,
it is crucial to find out a good way to handle these problems.
In recent years, complex networks have received in-
creasing attention for exhibiting the topological structure,
function and dynamical properties of many real-world net-
works such as the World Wide Web, the Internet [1, 2], social
networks [3], biological networks [4],andadhocnetworks
[5]. One of the most important discoveries is the B-A model
[6]. This model is based on two foundational mechanisms:
growth and preferential attachment. A new node is a dded to
the network at each step and connects with an old node with
a specific probability, which is related to the degree of the
old node. The B-A network has the scale-free property and
follows the power-law distribution.
While the B-A scale-free network model captures the
basic mechanism that is responsible for the power-law degree
distribution, it is still a minimal model with several limita-
tions. As stated in [7], Li Xiang and Chen Guanrong propos-
ed a L i-Chen model to modify a limitation in the B-A model.
They suggested that there should be a local world of each
node in various real-world complex networks. Moreover,
the preferential attachment mechanism of a scale-free net-
work does not work in a global network but does work
in the local world of each node. The Li-Chen model repre-
sents a transition between a power-law and an exponential
distribution. The BA scale-free model is only one of its