This study highlights the standardisation activities that are being carried out by the International Telecommunication Union (ITU) via its Study Group 20, the United for Smart Sustainable Cities (U4SSC) initiative and other venues, in supporting the adoption of information and communication technologies (ICTs) in smart sustainable cities (SSCs). These standards include common terminologies for the Internet of Things (IoT) and SSCs, the requirements for high performing ICT infrastructures, and the interoperability between different ICT or IoT networks. The work of ITU has encouraged the integration of ICTs into SSC, promoted sustainable and inclusive growth, and supported cities worldwide in reaching the United Nations’ sustainable development goals.

The Internet of Things (IoT) and smart manufacturing (SM) are mutually reinforcing. The establishment of IoT-based common facilities for SM is the premise of building SM system. Industrial IoT (IIoT) infrastructure for SM refers to common facilities based on IoT that support SM in industries or sectors, and plays a dominant role and faces severe challenges in the intelligence of SM. The infrastructure is independent of the products and production process in a specific factory. This paper develops conceptual and capability frameworks of IIoT infrastructure from a unified perspective of IIoT-related SM industries. These frameworks reflect relationships between IIoT and SM with in-depth relationships among basic facilities of IIoT infrastructure and lay the foundation of SM. In this paper the common characteristics and high-level requirements with respect to the different IoT layers of IIoT infrastructure are analyzed, and the capability framework and relevant capabilities of IIoT infrastructure are summarized according to the characteristics and requirements. In order to help service providers implement their systems to meet the needs of SM, the existing and newly developed IIoT infrastructure are integrated partially or in whole according to the intelligence level, so as to provide technical guidance for stakeholders to apply emerging ICTs to SM.

After the Smart City initiative was put forward, cities all over the world started the pilot practice of developing Smart Cities. This triggered a series of thoughts: what is a Smart City, how do we determine the scope of work of a Smart City, and how do we formulate a new strategic agenda of the Smart City to make city smarter and more sustainable? The answer lies not only in finding Smart City solutions, but also leads to the research on the definition of Smart City terminology and the determination of corresponding tasks. Stakeholders of Smart City (e.g., policy makers, municipalities, solution providers, industry, and academia) develop technical and management standards for these tasks jointly. This paper reports the standardization planning on Smart City by the international standardization development organizations (SDOs), that is, the standardization framework of Smart City. It also presents one of the important aspects, namely, the progress of standardization activities on urban infrastructure that are being carried out by the International Telecommunication Union (ITU) via its Study Group 20, in supporting the adoption of information and communication technologies (ICTs) in Smart City. These standards include the classification of urban infrastructure, the interoperability between urban infrastructure and smart city platforms, and the requirements of detailed infrastructure from the perspective of ICT and the Internet of things (IoT). This paper also provides the use cases of application of some standards in global cities.

Lighting simulation and image synthesis for outdoor scenes are difficult because of the geometric complexity and the presence of lighting interaction and atmospheric extinction in the outdoor environment. An efficient method of image synthesis by use of a linear combination of basic images is presented. With respect to linearity of the illumination function, the coefficients of basic images of various Sun positions and sky situations can be calculated. Furthermore, the relationship among visibility distance, image contrast, and resolution is addressed so that the desired images can be generated under all weather conditions. It is shown that a uniform formula is available and feasible for fixed scene and camera geometry.