ITU‐T's Technical Reports and Specifications 713 Horizontal data link, primarily by the way links can point to other open platforms, and then portals integrate applications and information and present them to the end users as one unified view. Open data portal mainly collect and manage sources of data that is produced by various government departments, enterprises, social groups and individuals. Government departments, enterprises, social groups should regularly publish their open‐access data sets through open data portal, but these data sets should not appear before, or as non‐downloaded format appeared on the network. In order to make all government departments, enterprises, social groups are willing to and can add their data sets throughopen data portal,it should provide a variety of mechanisms to greatly ease publication process. (2) Catalog system Through a comprehensive classification system of data, open data should provide integrated management features for data resources on the platform, and then according to different classification multiple formats of data resources should be compiled into the same level of catalog, such as (a) raw data catalog, (b) tools catalog, (c) geographic data catalog, and so on. Data resources can also be classified based on a different topic and different institutions. By two‐level catalog system, the classification of data resources should be set up macroscopically and microscopically, not only make clear of data resources appearance, but also facilitate discovery and use of data resources. This can easily improve the quality of open data portal and promote high efficiency of data resources. (3) Data availability management Establishing a strict review mechanism to avoid published data malicious use due to legal rules, such as privacy concerns, confidentiality, security,and so on. Government departments should monitor the quality and quantity of the published data so as to ensure full implementation of data publishing and to ensure public needs for relevant data. Establishing a set of effective approachesfor government departments involved in open data, this can provide available indicators to measure the availability of published data, such as web site availability, expected response time, quantity of published data sets, APIs runtime, and so on. Government departments should publish data as a priority, according to main responsibilities, institutional strategy, and public needs, in order to speed up the release of high‐value data sets. (4) Data usage Achieving open data platform statistical functions for key indicators to reflect the situation of data publishing and data using, this can provide the basis for feedback and then promote the quality of data platform construction. The key indicators of statistical functions includes page views, data downloads, API calls number, user rating statistics, top ranking data resources, government departments published data statistics, and so on. Usage metrics should include daily visits of monthly statistics, user visits of monthly statistics, data sets downloads of monthly category statistics, the trend of monthly downloads, monthly views of web site, top 10 downloaded data sets, and so on. (5) Data accessibility Data accessibility can be measured by the feedback of public information. Public users can comment and report issues based on the clarity and completeness of existing published structured data. Other