Summary：Passengers are pictured in a subway train in Shenzhen city, South China's Guangdong province, June 26, 2017.SH...

The test on the Line 11 saw a train, after arriving at the terminal Futian Station, transmit 25 GB of data to the station's control room in just 150 seconds.

Wan Jian, a director with the Shenzhen Metro, said that in the past, workers had to manually download data from the train's hard disk after a trip finishes, due to low speed of the wireless network.

The speedy transmission of data, including the train's operation information and surveillance video, is thus expected to boost subway efficiency and support futuristic tech applications such as automatic searches for lost luggage.

"In times of emergency, the 5G train-station communication will work with facial recognition and intelligent behavior analysis to locate dangerous people and behaviors in the train," said Ren Bo, a manager with Shenzhen Metro's communication center.

"In the future, the technology will also help realize functions such as alerts for lost luggage and searching for missing passengers," Ren said.