Study on Formal Modeling and Safety Verification of Train-to-Train Communication

Table 1

Comparison between VBTC and CBTC system.

Property	VBTC	CBTC
System components	Central ITS; TMC; IVOBC; DCS; OC	Central ATS (automatic train supervision); DSU (digital storage unit); VOBC (vehicle on board controller); DCS; ZC (zone controller ); CI (computer interlocking)
Train to train communication mode	Direct radio communication between trains	Indirect communication between trains, interactive information needs to be relayed by wayside equipment
Train control mode	IVOBC is center of system, ground only provides auxiliary functions, such as schedule plan, emergency procedure	Train operation is controlled by ATP from ground and vehicle
Wayside equipment	Little wayside equipment, only balises, switch controller	Amount of axle counting, balises, semaphores
Daily maintenance	less maintenance data mainly involving of train	Amount of maintenance data including train, wayside equipment