With the long term business development of smart city project all around the world, both academia and industry are exploring actively into key technologies and business models for the advancement of smart city development. Green sustainability has been envisioned for many smart city project to transform the energy supply and consumption in more renewable and circular ways for better environment. The data economy of smart city, in which the data market place to be formed to share smart city data to generate the intelligence to operate the city in smarter ways, needs significant infrastructure investment to open up a new area of business with enhanced trust values through various technology solutions and partnerships across various smart city industry stakeholders. Smart city innovation and development has a huge potential to revolutionize the quality of life of our society and transform our urban city ecosystem to be more sustainable thanks to the various open opportunities of smart city technology businesses. 4D Imaging Radar as a Building Block to Smart Cities Data Hub Application of Sihueng Smart City Project Planting the SEED: Deploying the Foundation for Global Interconnectivity The future of Smart City Construction and Development with 3D Construction Printing