Huawei recently completed the first tests of 4G communications in train signaling systems, showing that trains can be controlled remotely over the cellular networks but also that trains can share detailed passenger information almost instantly.
The new communications system was tested in France with signaling systems built by Alstom, one of the world's largest train manufacturers. These communications-based train control or CBTC systems are typically used in subways and other metropolitan transit networks. With them, trains can communicate their exact position and speed to radio equipment along the tracks.
That equipment shares information with other trains, which can adjust their speed automatically to remain a safe distance from each other. Ideally, transit officials can leverage the system to safely reduce the time intervals between trains, so that people are not left waiting as long for rides.
The Alstom system is based on Huawei's enterprise LTE network for public safety applications. With 4G, the system will be capable of reliably sharing more detailed passenger information between trains. In addition, eLTE is a trunked communications system, sharing the same channels for voice, video, and broadband data.
Huawei, which is based in China, has installed eLTE systems in railways around the world, though Alstom was the first to test 4G communications. For instance, Huawei deployed an eLTE network on China's Zhengzhou Metro Line 1, providing bidirectional wireless channels for its ground-to-train voice and data services.