Huawei is committed to building a fully connected, intelligent world. With the aim to build a nervous system for cities, we are collaborating with partners to build a Smart City ecosystem and provide comprehensive Smart City solutions for customers. This issue (Smart City Extra) describes how we implemented the ‘platform + ecosystem’ strategy in Smart City construction, presents Huawei Digital OS platform and Smart City nervous system, and shares our experience in building a large number of Smart Cities in and outside China with partners.