O'Reilly logo

Advances in Communications-Based Train Control Systems by F. Richard Yu

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

xv
Preface
Introduction
With rapid population explosion, improving rail transit speed and capacity is
strongly desirable around the world. Communications-based train control (CBTC)
is an automated train control system using high capacity and bidirectional train–
ground communications to ensure the safe operation of rail vehicles. As a modern
successor to traditional railway signaling systems using track circuits, interlockings,
and signals, CBTC can improve the capacity of railway network infrastructure and
enhance the level of safety and service oered to customers.
CBTC systems have opened up several areas of research, which have been
explored extensively and continue to attract research and development eorts. is
book features some of the major advances in the research on CBTC systems. e
contributed chapters in this book from leading experts in this eld cover dierent
aspects of modeling, analysis, design, testing, management, deployment, and opti-
mization of algorithms, protocols, and architectures of CBTC systems. A summary
of all of the chapters is provided in the following sections.
As the rst chapter of this book, Chapter 1, authored by Li Zhu, F. Richard Yu,
and Fei Wang, presents the background and evolution of train signaling/train con-
trol systems. en it introduces the main features and architecture of CBTC sys-
tems. Some challenges of CBTC systems are presented. e chapter also describes
the main CBTC projects around the world.
Chapter 2, authored by Kenneth Diemunsch, explains why transit agencies
decide to use CBTC for new lines or for upgrading their signaling systems. en,
the author explains the reason for performing specic tests at the factory or in the
eld and provides insight based on experience with several CBTC projects in the
last decade.
Chapter 3, authored by Vassilios Kappatos, Tat-Hean Gan, and Dimitris
Stamatelos, discusses nondestructive testing techniques that can be employed
to inspect rails and fastening parts as well as relevant research and development
work in this eld. As nondestructive testing techniques signicantly depend on
the nature of defects, a discussion about the defects that emerge on the rail infra-
structure is included. Finally, an overview of the capacity of the recent train
xvi Preface
protectionmethods mainly based on the CBTC is carried out for a complete
overview of all measures (nondestructive testing, train protection) that can be
used to avoid any potential and serious rail accidents.
Channel Modeling
Chapter 4, authored by Hongwei Wang, F. Richard Yu, Li Zhu, and Tao Tang,
develops a nite-state Markov channel (FSMC) model for tunnel channels in
CBTC systems. e proposed FSMC model is based on real eld CBTC channel
measurements obtained from a business operating subway line. Unlike most exist-
ing channel models, which are not related to specic locations, the proposed FSMC
channel model takes train locations into account to have a more accurate channel
model. e distance between the transmitter and the receiver is divided into inter-
vals, and an FSMC model is applied in each interval. e accuracy of the proposed
FSMC model is illustrated by the simulation results generated from the model and
the real eld measurement results.
Chapter 5, authored by Hongwei Wang, F. Richard Yu, Li Zhu, and Tao Tang,
discusses modeling the wireless channels with a leaky waveguide for CBTC sys-
tems. For viaduct scenarios, leaky rectangular waveguides are a popular approach,
as they provide better performance and stronger anti-interference ability com-
pared to free space. Based on the measurement results on the Beijing Subway
Yizhuang Line, the authors use polynomial tting and an equivalent magnetic
dipole method to build the path loss model. In addition, the Akaike information
criterion with a correction is applied to determine the distribution model of small-
scale fading. e proposed path loss model of the channel with a leaky waveguide
in CBTC systems is linear; the path loss exponent can be approximated by the
transmission loss of the leaky waveguide. e authors show that small-scale fading
follows a log-normal distribution, which is often referred to as the distribution
model of small scale fading in body area communication propagation channels. In
addition, the corresponding parameters of log-normal distribution are also deter-
mined from the measurement results.
Performance Analysis and Improvement
withAdvanced Communication Technologies
Chapter 6, authored by Li Zhu and F. Richard Yu, discusses the availability issue
of WLAN-based data communication systems in CBTC. e authors propose two
WLAN-based data communication systems with redundancy to improve availabil-
ity in CBTC systems. e availability of WLAN-based data communication sys-
tems is analyzed using the continuous time Markov chain model. e transmission

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required