RSU Deployment Scheme with Power Control for
Highway Message Propagation in VANETs
Jun Tao, Limin Zhu, Xiaoxiao Wang, Jian He, and Ying Liu
Key Lab of CNII, MOE, Southeast University, Nanjing, China
Abstract—Nowadays, message propagation has been one of
the major tasks of Vehicular Ad-Hoc Networks (VANETs).The
main obstacle of message propagation, which relies on the
data forwarding among vehicles, is the frequent change in
network topology, as the intermittent link between the vehicles
will degrade the performance of message propagation. Hence,
RSUs are deployed to extend vehicle coverage and improve
network performance in VANETs. However, non-optimal RSU
deployment may result in greater power consumption and lower
quality of network performance. In this paper, we study the
vehicle mobility characteristics along the highway and propose a
Cluster-based RSU Deployment (CRD) scheme with the Traffic-
Aware Power Control (TAPC) method to maximize the network
performance, as well as minimizing the energy consumption
of RSUs. Moreover, we develop a data propagation algorithm,
Data-Driven Message Propagation (DDMP), to improve the
performance of message propagation in RSU-assisted VANETs.
The performance of the proposed scheme is analytically evaluated
by comparing performance in with and without our scheme
scenarios. Through extensive simulations, with the aid of our
scheme, the performance of message propagation is improved
significantly, in terms of the propagation latency and the power
consumption.
Index Terms—VANETs, RSU deployment, power control, mes-
sage propagation
I. INTRODUCTION
As a type of ad hoc networks, Vehicular Ad Hoc Networks
(VANETs) [1] are proposed to serve message propagation for
vehicles, equipped with the wireless interfaces through multi-
hop transmission among vehicles in the extreme networking
environments, where most of the time there does not exist a
stable end-to-end path between any two vehicles. Therefore,
Road Side Units (RSUs) are deployed to improve the network
performance, e.g., network connectivity, through communica-
tions between vehicles and RSUs. VANETs are able to accom-
modate a variety of applications including traffic safety [2],
[3], traffic control [4], entertainment [5], commercial and daily
information [6].
In many existing routing schemes of VANETs, data propa-
gation depends on vehicle to vehicle (V2V) communications.
However, due to the frequent change in network topology
caused by unpredictable mobility of vehicles [8], the intermit-
tent link between the vehicles will degrade the performance
of message propagation. Moreover, limited transmission range
and maldistribution of vehicles also narrow the coverage of
VANETs [9], which may result in high data latency and low
delivery ratio of message propagation. Therefore, RSUs, which
can extend coverage of VANETs and offer a more stable
network topology, are exploited to improve the performance
of the message propagation in VANETs.
With the help of RSUs in VANETs, the performance of mes-
sage propagation can be improved obviously. However, non-
optimal RSU deployment may also introduce the problems,
e.g., the redundant RSUs contributing little to the performance
improvement and leading to the high cost of the deployment.
On the other side, the interference generated by the densely
deployed RSUs may also decrease the performance of message
propagation. Besides, the power consumption of the RSUs is
extremely high because they continuously working and pro-
viding service all the time. Therefore, how to properly deploy
the RSUs to improve the performance of message propagation
and conduct power control for RSUs to achieve the trade-
off between the performance improvement and the energy
saving is of great importance. Then the message propagation
algorithm is expected to achieve higher performance in RSU-
assisted VANETs.
In this paper, we investigate the cluster characteristics of the
vehicles along the highway and propose a cluster-based RSU
deployment scheme with power control to achieve the trade-off
between network performance and power consumption. Then
we design a message propagation algorithm to improve the
performance of data dissemination in VANETs. The contribu-
tions of this paper are as follows.
1) We mathematically derive the characteristics of the traffic
cluster with the vehicle mobility along the highway. Then
an efficient cluster-based RSU deployment scheme is
proposed to improve the network connectivity.
2) Considering the energy consumption, we exploit the
power control method to reduce the energy consumption
of RSUs without degrading the network connectivity. In
the power control method, the RSUs are aware of the
traffic change and conduct distributed power control to
set their proper transmission ranges individually.
3) A corresponding data-driven message propagation algo-
rithm, which takes the message size into account, is
proposed to reduce the transmission latency with the aid
of the RSUs. Finally, we evaluate our scheme in terms
of the propagation latency and the power consumption.
The rest of this paper is organized as follows. In Section II,
we explore the existing work and the achievements on RSU
deployment and power control in VANETs. We investigate
the characteristics of the vehicle cluster and present the
RSU deployment scheme with detailed explanation on the
power control process for the highway message propagation
in Section III. The performance of our scheme is shown in
terms of the propagation latency and the power consumption
Globecom 2014 - Ad Hoc and Sensor Networking Symposium
978-1-4799-3512-3/14/$31.00 ©2014 IEEE 175