A subway operator in Shenzhen in Guangdong province is investigating whether passengers' portable Wi-Fi devices were the cause of a brief suspension of metro services on Thursday.
"Unknown signals", as the Shenzhen Metro Group put it, interrupted several trains on the city's Shekou line from 8:15 am to 9:30 am on Thursday, forcing many passengers to transfer to other lines. Others found themselves stranded.
The incident has attracted nationwide attention as more cities in China have started operating subway services. There has been much discussion as to whether portable Wi-Fi devices should be banned on metro lines to ensure their safe operation.
Because of interfering signals, the trains on the Shekou line stalled a number of times under the automatic protection mode or failed to operate at full speed.
Concerns rise over the Communication Based Train Control System - a railway signaling system that uses the telecommunications between the train and track equipment for traffic management and infrastructure control - which may be affected by Wi-Fi signals.
Chen Qi, deputy manager of the Shenzhen Metro, said on Monday that portable Wi-Fi devices may be the cause of the disruption, but there has been no final conclusion.
According to the operator, the Shekou line and Huanzhong line in Shenzhen use the CBTC system.
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