COMMUNCATIONS: Bombardier Transportation announced on August 4 that it has certified four telecoms companies that can supply 4G LTE technology to be used with its main line and metro train control systems.

A series of laboratory tests was carried out with Ericsson, Huawei, Nokia and ZTE at simulated speeds of up to 200 km/h. Bombardier’s Cityflo and Interflo signalling was tested, sharing LTE bandwidth with CCTV, passenger information and onboard internet services.

In CBTC tests, uplink and downlink latencies of less than 100 milliseconds were achieved, with packet losses approaching zero.