23. Updating of on-board train safety database using wireless technology

Over recent years, the development and introduction into service, of train protection systems using on-board databases (DB) has increased. On-board databases contain safety critical data such as track data and vehicle performance data. However, upgrading these systems is very labor intensive and time consuming, since the compact flash cards used for data storage have to be changed one by one in each system.

In an attempt to improve the efficiency of the DB upgrading process, a system was developed using wireless technology, and a prototype model was built for use with the ATS-Dx train protection system (Figure 1).

The prototype was built to be able to use the license-free general purpose 5.6 GHz frequency band wireless devices for safety data transmission, and the data validity checking method was designed to guarantee safety, taking into consideration the need to cut the volume of data being transmitted (Figure 2), while a special data transmission format was devised to protect data security during transmission.

Results from tests using the prototype show that it was possible to maintain the same level of data validity as previously, and that it was possible to conduct multiple unit upgrades simultaneously.

This method will contribute to the increase in database updating efficiency when trains are brought into a depot for service.