Automatic Train Protection

Communication Based Train Control system (CBTC)
Information Technology - Automatic Train Protection system (IT-ATP)

Radio based ATP system with realizing downsize facilities and power-saving significantly.
IT-ATP, a train control system, meets the following requirements of CBTC which is defined in standard of
Institute of Electrical and Electronics Engineers (IEEE Std. 1474.1TM - 2004)a) High-resolution train location determination, independent of track circuitsb) Continuous, high capacity, bidirectional train-to-wayside data communicationsc) Train-borne and wayside processors performing vital functions
Features of IT-ATP

IT-ATP on-board equipment adopts train control
by optimization of speed profile which has provento be used for a long time.

IT-ATP wayside system can be connected toexisting Electronic Interlocking system andAutomatic Train Supervision system.

Radio communication frequency band adopts 2.4
GHz ISM band, and thus no application for radio
station license is required.

As for radio communication, the following twooptions are available: either LCX (Leaky Coaxial)
Cable, which is strong against radio-frequency
interference by proximity communication, orSpace Wave with antenna.

Components

Switching hub Bay

ATP Bay

ATP wayside equipment

Wayside radio

BaliseOn-board radio

On-board radio antenna

ATP/ATO controller

ATP/ATO transceiver

ATP/ATO on-board equipment
2019

(1/2)

Advantages

Significant equipment reduction and power-saving can be realized because ATC/TD signal transceiver, anessential equipment for ATC/TD-type train control system, is not required.
Adoption of radio communication and optical network provides flexibility for the layout of equipment inequipment room.
This system doesn’t need track circuit adjustment works and can significantly save maintenance works
because of adoption of radio-based system.
Functions and configurations of IT-ATP

Transceiving antenna
for space wave

Bidirectional communication between wayside and on-board
All trains in the section communicate with ATP wayside equipment via
Access points and networks in fixed-cycle.

Decision and notification of Movement
Authority (MA)All the train report the own location to ATP
wayside system cyclically. ATP wayside system
traces the all train locations in the section anddecides MA for each train based on routesetting information from Interlocking system,
then notifies the MA to each train.

To other system, e.g.,
Electronic interlocking system

ATP wayside system

cal nOptietworkLCX

Access point

ileProfdee
Sp

Target points
where eachtrain should stop

Safety Margin
Safety Margin

BaliseATP on-board equipment
Alignment of Train Location
ATP on-board equipment corrects the own
location based on the position data from Balise
and the running distance from Tacho-generator.

Calculation of Speed profile
ATP on-board equipment calculates the own speed profile
based on the MA and various data such as curves, gradientsand safety margin, notified from ATP wayside system.

To other equipment

On-board radio
antennaOn-board radioBrakeControl

ATP/ATO
controller

ATP/ATOtransceiver
On-board
antenna

TachoGenerator

2019

(2/2)