A Multi-node Renewable Algorithm Based on
Charging Range in Large-scale Wireless Sensor
Network
Guowei Wu, Chi Lin, Ying Li, Lin Yao, Ailun Chen
School of Software
Dalian University of Technology
Dalian, China
Email:wgwdut@dlut.edu.cn
Abstract—Recently, wireless energy transfer technologies have
emerged as a promising approach to address the power constraint
problem in Wireless Sensor Networks(WSNs). In this paper, we
propose an optimized algorithm, Multi-node Renewable based on
Charging Range (MRCR), for large-scale WSNs, where multiple
sensor nodes are charging simultaneously. A mobile charging
vehicle (MCV) is responsible for energy supplement of these
nodes group by group at specified docking spots. These spots
are selected based on charging range of a MCV, which can
not only maximum the charging coverage, but also improve
the energy efficiency as the minimum number of stops and the
shortest travel path. We organize MCV schedule into rounds
and each round is divided into slots: judgment, charging and
rest. Then, we provide the objective output to maximize the
network lifetime and the computation complexity of our MRCR
algorithm. Finally, extensive experimental results show MRCR
algorithm can guarantee a short TSP length in every round and
all sensor nodes live immorally.
Index Terms—multi-node charging; docking spot selection;
large-scale wireless sensor network;
I. INTRODUCTION
In a Wireless Sensor Network (WSN), the constrained
energy storage in batteries limits the network lifetime or
confines its short-term application. Thus, the limited battery
issue has become a big challenge in WSNs. To solve this
problem, energy-efficiency has been widely studied in the liter-
ature where duty-cycling and various energy-efficient medium
access and routing protocols have been proposed. Existing en-
ergy conservation schemes can slow down energy consumption
rate, but cannot compensate energy depletion. To address the
problem of energy decay, harvesting energy from surrounding
energy sources including solar [1], vibration [2], wind [3],
biochemical process [4] or passive human movement [5] has
been proposed. However, the drawback of these schemes lies
in those high reliance on unpredictable and uncontrollable
ambient conditions. For instance, it is impossible to harvest
energy for some sensor nodes deployed in shadow areas or
cloudy weather at a satisfied level.
Wireless energy transfer technology can be adopted to
increase the lifetime of a new class WSN, called wireless
rechargeable sensor network. With this ever-lasting energy
replenishment, we have found two particular breakthroughs in
the areas of wireless energy transfer [6], [7]and rechargeable
lithium batteries [8].It means power can be transferred from
one energy storage device to another without any plugs or
wires. Kurs et al. also have developed an enhanced technology
to transfer energy towards multiple receiving nodes simultane-
ously [9]. Delightfully, they have proved that the overall output
efficiency of charging each device individually is inferior to
that charging multiple devices. And what’s more, wireless
energy transfer is not subject to the objective neighboring
environment and it does not require any mediums between
the mobile charger and the receiver.
Recent advances in charging sensors dispatch a mobile
charging vehicle (MCV) carrying certain amount of energy
to move around the network [10], [11], [12], [13]. A MCV’s
capacity is high enough to maintain the eternal network
lifetime before it returns to the base station. Different from
these works, we also consider about the docking spot selection
to balance the power consumption of a MCV’s movement and
the distance between a MCV and every sensor node. We adopt
Traveling Salesman Problem (TSP) [14], [15] to balance them.
TSP aims to find the shortest Hamiltonian cycle during visiting
every vertex.
In this paper, we propose an optimized algorithm Multi-
node Renewable based on Charging Range (MRCR) in the
large-scale WSN, where a mobile charging vehicle is allowed
to charge a group of sensor nodes. Every MCV only needs
to visit the specified docking spots to charge those nodes at
one time. Though the selection of docking spots with length-
objective is a NP-hard problem, it can certainly be transformed
to the cover-objective problem. We also formulate how to
schedule MCV’s charging sensor nodes. The whole process
is organized into rounds and a round is divided into slots: 1)
judgment, 2) charging, 3) rest. To make a WSN’s lifetime as
long as possible even immortal, we develop a provable solution
combining the number of data packets transmitted over the link
and the total charging time at docking spot.
The remainder of this paper is organized as follows. We
survey the related work in Section II. Section III introduces
the basal information including parameters and system models.
Then in Section IV we investigate the problem formulation and
2015 9th International Conference on Innovative Mobile and Internet Services in Ubiquitous Computing
978-1-4799-8873-0/11 $31.00 © 20115 IEEE
DOI 10.1109/IMIS.2015.19
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