Free Wi-Fi on Shenzhen Metro

Shenzhen has become the first city on the Chinese mainland to provide a free Wi-Fi service in subway carriages and stations.

The service was launched on Wednesday and will be expanded from Line 1 and Line 2 to cover all five subway lines by the end of the year, Shenzhen Metro Group said.

"The signal will work well even when trains are running at full speed," said Zhou Fazhan, chairman of Southern Galaxy Valley Co, a high-tech company commissioned by Shenzhen Metro to run the project.

To control the number of users, a measure needed to guarantee security and stability of the network in the initial stages, the company is providing different ways to access the free Wi-Fi service, Zhou said.

Users need to download and install an app called Peanut, developed by SGV, then either play a game called Snatch Peanut, follow Weibo Peanut Community or take part in certain Wechat activities to obtain verification codes.

Fan Xiang, a product manager at SGV, said the project operator gave out 88,888 codes in the first batch and this will be increased to 288,888 in two weeks before becoming fully open in a month.