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(d) DMI of the onboard unit of TCAS shall provide assistance to Loco Pilots by
means of real-time display of the aspect of approaching signal.

(e) TCAS shall provide bi-directional track train communication.

(f) Train movements shall be supervised continually by the Stationary unit in
its territory.

(g) The Stationary unit which provides the information to the trains shall know
each TCAS controlled train individually by the identity of its leading TCAS
on-board equipment.

(h) The movement authority is transmitted to the vehicle continuously via UHF/
GSMR/LTE radio together with speed information and track description data.

(i) The RFID Tags act as reference points and shall be used to correct the
accumulated odometry error. Between two RFID Tags, the train shall
determine its position via Pulse Generators.

(j) The fixing arrangement of the RFID Tag on the sleeper shall be such that it
does not require any drilling to the sleeper.

(k) The on-board computer shall continuously compare the train speed with the
permitted speed and commands the brake application, if necessary.

(L) Multi-vendor interoperability shall be provided.

13.3.5 Three levels of brake commands in TCAS are:

(a) Normal brake command

(b) Service brake command

(c) Emergency brake command

Simulated Braking Distance Calculations for service and emergency brakes
are given at Annexure:13-A1.

Chapter 13: ATP, ETCS, IRATP (TCAS) & TMS Page 287 of 535