ITU‐T's Technical Reports and Specifications 657 IMSSC is to model the information resources of cities uniformly, fuse the data from the information resources to acquire a higher level of information, and share the information to serve people in cities [b‐Nama]. In this Technical Report, information resources are composed of nodes, sensors, data, models, and events, among which nodes include sensing nodes, processing nodes, and application nodes, and sensors are affiliated to sensing nodes. The fusion process aims to fuse the information resources with toponym and maps, respectively. Services mainly include data, model and event service. IMSSC is able to ensure the well‐organized and efficient operation of people, things and streams in cities, so that disastrous events can be detected in advance and timely avoided before the occurrence, so that casualties and economic losses can be reduced as much as possible. At the same time, IMSSC is able to settle the widely‐existing problems, such as traffic congestion, and environmental pollution, etc., improve the living quality of citizens, protect the environment, and implement the sustainable development of cities. The objectives and challenges of IMSSC, as well as the technologies used to address the problems and to achieve the goals of smart sustainable cities development are illustrated in section 2. The specific meta‐models, fusion processing workflows, and services proposed for IMSSC are presented in section 3, while section 4 provides examples pertaining to the application of meta‐models, fusion processing workflows, and services for IMSSC. Section 5 is a summary of this Technical Report. 2 Resources, challenges and technologies of IMSSC 2.1 Resources of IMSSC IMSSC aims at offering a solution to all problems affecting current urban development, including inadequate safety and security protection, increasingly worsened urban environment, damaged city infrastructure, and natural or man‐made emergency events, in a rapid and efficient way. IMSCC is also expected to improve citizen's quality of life, efficiency of urban operation and services, and competitiveness, while ensuring at the same time that the needs of present and future generations with respect to economic, social and environmental aspects are met. These problems are the results of the interaction among people, urban infrastructure, and the corresponding environment in cities. Citizens are the main players of a city. Their activities determine and influence the existence and evolution of the urban infrastructure and environment. There is a saying that \"people who live in cities create the urban landscape.\" It is human beings that constitute the versatility of a city, create a beautiful life and live it. Consequently, citizens are the direct object of IMSSC. Urban infrastructure is a general term for all types of urban facilities on which various economic activities and other social activities occur for the survival and development of cities, and it is divided into the engineering infrastructure and social infrastructure. It is particularly important for production units, and is one of the necessary conditions to reach its economic, environmental and social benefits. Engineering infrastructure generally refers to energy systems, water supply and drainage systems, transportation systems, communication systems, environmental systems, disaster prevention systems and other engineering facilities. Social infrastructure refers to the administration, education, health care, business services, finance and insurance, social welfare and other facilities. The urban infrastructure provides citizens with what they need for their daily life. A good urban infrastructure enables improved quality of life and significant steps toward smart sustainable cities development. Therefore, urban infrastructure is also a direct object of IMSSC.