ITU‐T's Technical Reports and Specifications 667 3.2.1.2 Scope The node meta‐model defines the sharing metadata for node resources in the comprehensive smart cities management. The metadata content is confined to the unified description for inherent properties, capabilities, and status and space‐time information of the nodes. The structure, physical characteristics of the nodes themselves, as well as node observation data and the following processing and services are all excluded. The meta‐model can be applied in the integrated discovery and sharing, integrated management, planning, dispatching, as well as collaborative observing for all kinds of nodes. The specific application scope of the node meta‐model is given in Figure 13. Figure 13 – Application scope for node meta‐model 3.2.1.3 Content Based on the node description components and different metadata requirements from all kinds of nodes, the node metadata is organized into the general information description framework, with five components, including the sensor tag, performance, state, service and accessibility, and a nine‐tuple structure [b‐ISO 19115‐2]. The node meta‐model is shown as follows: Node metadata = {Identification, Characteristics, Capability, Quality, Space‐time, Working, Service, Administration, Constraint}. Among all the meta‐model components, identification and characteristics information are tessellations for sensor tag component, capability and quality information for performance, service information for service, and administration and constraint for accessibility. The relationship between the five components and the nine‐tuple structure is demonstrated in Figure 14 [b‐Chenh]. Heterogeneous smart city nodes sharing metadata Unified encoding and sharing for node resources Publishing and service for node resources Efficient discovery and access for node resources Collaborative Observation for node resources Dispatching and planing for node resources Integrated management for node management Ground-based Processing Nodes Application Nodes Airborne Space -borne Sensing Nodes Data Fusion Data Computation Hydrologi-cal Atmospheric Disaster