Communications-Based Train Control (CBTC) technology is used by transit agencies in large cities to maximize the use of their infrastructure. In comparison with conventional block signal system and cab signaling system, CBTC provides the most efficient capabilities with respect to headway and throughput while being the most economical in terms of maintenance cost . CBTC also provides better diagnostic capabilities compared to traditional signaling systems. It uses limited number of equipment on the trackside compared to traditional signaling systems and allows either a centralized architecture or distributed architecture. For these reasons, CBTC is now the favored system for new lines as well as most signaling system renewals.
Despite widely used CBTC standards, the signaling industry is not in agreement regarding what qualifies as a CBTC system and which projects are the first “real” CBTC projects. This work describes the different CBTC vendors, their genesis, when access point based radio was first introduced (access point based radio is also referred by signaling engineers as free space propagation radio), the different consolidations with other CBTC companies, and their major projects.
From the authors’ viewpoint, it is appropriate to present the CBTC vendors by geographical areas, for instance in North America: Bombardier Transportation, Thales Rail Signaling Solutions, in Europe: Alstom Transport, Hitachi Rail, Siemens Mobility, in Asia: Beijing Traffic Control Technology, China Railway Signal and Communications, Mitsubishi Electric Corporation, and Nippon Signals.