A sanitation worker cleans the smart trash bin in the street. (CNS/Zhou Yi)

People take a rest near a trash bin and play mobile phone. (CNS/Zhou Yi)

150 smart trash bins have been installed in streets in southwest China's Chongqing city. Each trash bin has been equipped with a Wi-Fi transmitter, which can provide free Wi-Fi access to 60 people at the same time. The sensor inside the trash bin can detect smoke and the smoke alarm device will automatically spray mist and dry powders to distinguish fire.