CBTC – Communication Based
Train Control
Rail Signalling Solutions
Igor Silajev
Introduction
 Communication Based Train Control is an automated
control system that ensures safe operation of rail
vehicles using data communication between control
entities.
 CBTC is based on basic principles from
telecommunication and automation
 There are different levels of automation:

Automatic Train Protection (ATP)
 Automatic Train Operation (ATO)
 Automatic Train Supervision (ATS)
Rail Signalling Solutions
Igor Silajev
THALES CBTC
 Characteristic of THALES CBTC :
 Standard network and radio based communication
system based on the Internet Protocol (IP) Standard.
 Remote train monitoring in real time
 Constant high-speed connectivity between train and
trackside
 Centralized network management
 A flexible network architecture
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Igor Silajev
THALES CBTC Functional Components
 Detection of train location, speed and direction

Transponder tags, tachometer,

Accelerometer,

Switch/route info
 Route and switch interlocking
 Safe train separation using Progressive Movement
Authority
 Work Zone protection
 Train handover between neighboring Zone Controller
 Emergency Stop Device response
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Igor Silajev
CBTC Digital Communication Network (DCS)
Rail Signalling Solutions
Igor Silajev
CBTC communication subsystem
CENTRAL EQUIPMENT
External
Connection
STATION
EQUIPMENT
WAYSIDE
EQUIPMENT
Wired Network (backbone)
Wireless network (wayside)
On-board (vehicle) network
COMMUNICATIONS NETWORK
'
OBE
OBE
ON-BOARD EQUIPMENT
CENTRAL EQUIPMENT
External
Connection
STATION
EQUIPMENT
y
ox
Pr
WAYSIDE
EQUIPMENT
LAN
LAN
SD
SD
LAN
SD
SD
LAN
COMMUNICATIONS NETWORK
MOBILE NETWORK
SD
LAN
SD
'
OBE
OBE
LAN
ON-BOARD EQUIPMENT
Rail Signalling Solutions
Igor Silajev
Wired communication subsystem (backbone)
 The wired portion of the CBTC consists of a backbone network
that provides IP network services between the central or
wayside equipment
 It consists of one or more 100/1000 Mbps fibre optic Ethernet
rings allowing exclusive full duplex use of a 100/1000 Mbps
channel to each connected node. The network uses layer 2
switches to provide flat connectivity to all the application
equipment. It could also use layer 3 routers (or routing
functionality in multi-purpose switches) to provide traffic
protection and in some cases additional security
CENTRAL
APPLICATION
WAYSIDE
APPLICATION
BACKBONE SWITCHES
BACKBONE NETWORK
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Igor Silajev
Wireless communication (wayside network)
The wayside network utilizes the backbone switches to
connect the WRU’s (Wayside Radio Unit) to the overall network
Groups of WRUs are connected in a ring topology. Each end
of the ring has a bridge connection to a different backbone
switch. This configuration requires a managed switch (that
provides ring reconfiguring following a switch failure). If a single
WRU or a single switch fails all the unaffected WRUs remain
connected.
'
Rail Signalling Solutions
Igor Silajev
SD
OBE
SD
On-board communication subsystem (vehicle)
Each onboard network device is a modular component, with two
(2) IEEE 802.3 interfaces, as well as one CAN bus interface.
CAN bus is provided for data transfer through the couplers. It
requires only a single twisted pair wire and can operate in poorer
transmission environments than Ethernet.
IEEE 802.11
IEEE 802.11
RF
RF
MRU
ND
ND
ND
IEEE 802.3
CAN
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ND
MRU
VOBC
2 x twisted pair copper
Igor Silajev
2 x twisted pair copper
CAN
Physical component of communication system
 Mobile Radio Unit (MRU, OBRU, DCU)
“Station Adapter (SA)”
 Wayside Radio Unit (WRU)
“Access Point (AP)”
Diversity Separation
STA
Antenna
STA
Antenna
Front or Rear of Train
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Platform
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CBTC Automation Control Subsystems
 Central control subsystem (System Regulation Servers -SRS):
Man – Machine interface
Overview of tracks and train positions and status
 Headway and schedule regulation
 Automatic and Manual Train Routing and scheduling

 Wayside control subsystem (Zone Controller - ZC):

Zone Controller on the trackside is the recipient for all position messages sent from the trains within
its region of control and the status of the obstructions such as axle counter blocks, signals, switches,
floodgates, guideway intruder detection.
The ZC is responsible for route setting based on the commands received from the Central control
subsystem. It supports fully bidirectional operation.
 On-board vehicle control subsystem (Vehicle On-Board Controller – VOBC):
The
vital component of the system is a Vehicle On-board Controller (VOBC) on the train
The Vehicle On-board Controller establishes the position of the train on the guideway by detecting
transponders located in the track bed, and uses the transponder data to extract information from the
database
The database on the Vehicle On-board Controller contains all relevant guideway information,
including station stops, gradients, civil speed limits, switch locations, axle counter blocks locations
and trackside signal locations.
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Igor Silajev
Overview of all CBTC Control Subsystems
OCC
Mimic Display
Line Controller
Workstation
Line Controller
Workstation
Line Controller
Workstation
Backup OCC
Network
Monitoring
System
Data
Recorder/
Viewer
Network
Printer
Mimic Display
Line Controller
Workstation
Line Controller
Workstation
Line Controller
Workstation
Data
Recorder/
Viewer
Network
Printer
Network
Monitoring
System
Terminal
Server
Network
Printer
ATS
Servers
Network
Printer
ATS
Workstation
Backup ATS
Servers
External Devices
Network
Printer
ATS Schedule
Display Workstation
ATS
Workstation
ATS Workstation 2
Certification
Authority
Timetable
Compiler
Network
Printer
ATS Schedule
Display Workstation
VOBC & ZC
Simulator
Terminal
Server
Certification
Authority
Timetable
Compiler
Training Centre
External Devices
Router
(Firewall)
Environment
Simulator
ATS Workstation 1
Network
Printer
Router
(Firewall)
DCS
DCS
DCS
DCS Backbone
Interlocking Station
Depot
Test Track
DCS
DCS DCS
DCS
Zone
Controller
Interring DCS
ACE
ACE
Zone
Controller
ATS
Server
Data
Logger
Router
(Firewall)
ATS
Data
Recorder
Non-Interlocking Station
Data Recorder
Workstation
AP
Depot
Interlocking
equipment
Relay Rack
Interring DCS
AP
Relay Rack
Wireless LAN IEEE 802.11
Crew
Protection
Switches
CTF
CTF
CTF
Switch
Machines
Signals
PSD
Sim
Crew
Sw
Transponders
Depot I/L
Trackside Equipment
PSDs
Axle Counters
APs
Crew Sw
DIs
GIDS/PIDS
Switch
Machines
Cab A
Signals
PSDs
Crew Sw
DIs
30 C20 Existing Trains
54 C30 New Trains
Cab B
GIDS/PIDS
2oo3
VOBC
Proximity
Plates
Maintenance Centre
Interring DCS
DCS
Trackside Equipment
Wayside
SLMD
ATS Maintenance
Workstation
Network
Printer
ATS Fault Report
Workstation
Depot
Maintenance
Workstation
Legend:
IPS Server
Transponders
Provisioned for Future Upgrade
VOBC
SLMD
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Igor Silajev
Proximity Plates
CBTC Man Machine Interface capabilities
 Central control Man Machine
interface. Line overview
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Igor Silajev
CBTC Man Machine Interface capabilities
 CBTC MMI operations “menu”
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CBTC Man Machine Interface capabilities
 Assigning a Train
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Igor Silajev
CBTC Man Machine Interface capabilities
Schedule definition, assignment and adjustment
Predefine
different schedule for weekday, weekend, holiday, etc.
Predefine
distribution of trains between buildups and reductions
throughout the day
Assign
/ clear predefined schedule for System Regulation Server
to implement
Apply
automatic or manual global schedule slide
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Igor Silajev
THALES CBTC implementation
THALES CBTC implementation worldwide:

Canada
Toronto Scarborough LRT and Subway
Vancouver Canada-Line
Vancouver SkyTrain
 Korea
Busan-Gimhae Line
Seoul Sin Bundang Line
 Malaysia/Asia
Kuala Lumpur LRT II
Beijing Line 4
Guangzhou Line 3
MTR Disneyland Resort, Hong Kong
MTR Ma On Shan Rail , Hong Kong
Wuhan LRT
 United Arab Emirates
Dubai Metro: Green Line
 United Kingdom / Europe
London Dockland
London Underground: Jubilee Line
Paris Line 13
 USA
AirTrain JFK
Detroit DPM
Las Vegas Monorail
NYC Flushing Line
Washington Dulles Airport


Rail Signalling Solutions
Igor Silajev
Questions / Answers
Q & A
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Igor Silajev