SIEMENS and DAMM complete testing of ETCS over Tetra Packet Data
SIEMENS and DAMM have together successfully implemented and tested an open and interoperable Tetra packet data solution which complies with the demands for ETCS (European Train Control System) Level 2.
The tests were mainly focused on bandwidth requirements and the reliability of data delivery. They were performed according to UNISIG Subset-093 (PS version) – the communication requirement specification for ETCS describing the worst-case conditions for ETCS communication.
Siemens decided to use packet data as this service provides scalable and sufficient bandwidth for ETCS level 2. Furthermore, unlike circuit-switch service the data are fully interoperable between vendors of a train-borne OBU (onboard unit) and a wayside RBC (radio broadcast centre) along the rail track.
The solution tested provided two dimensions of interoperability. First the interoperability between Tetra vendors who have completed interoperability tests for packet data. Secondly, the interoperability between OBU and wayside RBC vendors secured by the use of standard ETCS L2, which is also specified for GSM-R packet data. Within the solution tested the standard was kept; the main change was the replacement of the GSM-R hardware with TETRA hardware. In this way the SIL (safety integrity level) was kept between both train-borne OBU and wayside RBC.
Results of these tests have proven that data transmission quality in both directions was always above requirements of the standard and that TETRA delivered equal or even better results than a GSM-R system.
“Thanks to the easy integration based on a pure IP interface and the longer life time expectation of TETRA systems, this solution can be beneficial or be an alternative, wherever GSM-R is not mandatory due to authority regulations,” explained Sven Hagenbuck, responsible for Siemens Mobility sales in Australia.
