High-speed trains (HSTs) are a major focus in China, Japan, and many European countries. However, high Doppler shift and the consequent decrease in the demodulation performance can adversely affect the performance of mobile devices being used by high-speed train passengers.
LTE designed for usage at high speeds of up to 350km/h, may be fast in ideal conditions. However, there are several challenges such as rapidly changing radio environment and ‘spotty’ coverage that can affect the speed of LTE.
Problems resulting from these challenging conditions include high call drop rates and interrupted streaming. Data connectivity is particularly important for VoLTE calls which use an LTE data bearer with a QoS.
To ensure maximum performance of mobile devices used by high-speed train passengers, IoTAS have developed our own high speed train solution against specifications 3GPP TS 36.104 V8.2.0 and ETSI TR 125 913 V9.0.0.
High Speed Train Testing in Japan
High speed trains are challenging due to the positioning of antennas at the side of the track, which means radio signals change very quickly. Challenges arising from these unfavourable conditions include:
Failure to effectively test LTE capability on high-speed trains can affect the performance of mobile devices for the end user in several ways:
To ensure that the performance of mobile devices used by high-speed train passengers is at maximum performance IoTAS testing shall be conducted so to cover: