Abstract
In order to cope with recent changes in the environment surrounding railways and railway signalling systems as represented by Communications-Based Train Control (CBTC) systems, integrated train control systems that can evolve as customer needs change are now under development. Conventional systems have a vertical structure in which individual pieces of equipment such as Automatic Train Control (ATC) equipment, electronic interlocking equipment and facility monitoring equipment operate independently. However, this vertical structure has raised some problems due to the structural complexity, functional overlaps and different principles between different pieces of equipment. In contrast, integrated train control systems are horizontally and hierarchically structured, consisting of a "function layer", a "network layer and a "terminal layer. This horizontal hierarchical structure is intended to make the systems lean, simple and evolvable according to customer needs.
