This combo photo shows a couple making a farewell phone call across a train window at the Zhengzhou Railway Station in Zhengzhou, central China's Henan Province, Jan. 23, 2009 (top, photo taken by Zhu Xiang); and a passenger having a video chat with a friend using 4G network aboard a bullet train which travels from Hefei, east China's Anhui Province to Jiangshan, east China's Zhejiang Province, Feb. 4, 2015 (bottom, photo taken by Du Yu). (Xinhua)