On January 6, 2021, a team led by Pan Jianwei, Chen Yuao, and Peng Chengzhi of the University of Science and Technology of China published results in Nature describing the first integrated space-to-ground quantum communication network spanning 4,600 kilometers. The network combined over 700 ground-based optical fiber links with two satellite-to-ground free-space links via the Micius satellite.
As reported by Xinhua, the network consisted of four quantum metropolitan-area networks in Beijing, Jinan, Hefei, and Shanghai, a fiber backbone exceeding 2,000 km, and two ground-satellite links connecting Xinglong ground station in Beijing and Nanshan ground station in Xinjiang, separated by 2,600 km.
More than 150 industrial users across China accessed the network, including state and local banks, municipal power grids, and e-government websites. The integrated network used trusted relays for both the fiber and satellite segments.