(1) data volume

The amount of data in the concept of big data refers to a large number of arbitrary types of data generated from various data sources. Under the framework of smart cities, multimedia/social media and other types of networks show geometric growth in data generation.

Even modern industrial products, such as cars, trains, power stations and so on. With the improvement of intelligence, more and more sensors are equipped, and these sensors continue to collect more and more data. The increasing amount of data brings new challenges to data collection and data analysis.

(2) Data speed

Speed in the concept of big data refers to the speed of data generation and transmission. Under the framework of smart cities, the content of data is constantly changing due to the increasing amount of data and data sources and the constant change of data types. For a certain data storage, the speed of data generation and transmission determines the speed of data content change. Data users often have faster data generation and transmission speed, so that they can know the real-time information they care about. Therefore, the speed characteristics of big data put forward higher requirements for data processing methods and algorithms.

(3) data diversity

Data diversity in the concept of big data refers to the diversity of data types, such as video data, audio data, image data, text data, data logs and so on. The diversity of data types is closely related to the diversity of data sources, such as mobile phones, video recorders, sensors and social platforms. Compared with traditional structured data (such as financial data, futures trading records, personnel information, etc.), under the framework of smart cities, the data in the concept of big data includes a large number of complex unstructured data, and there is no fixed data format. Similar to data speed, the diversity of big data also promotes the further development and optimization of data processing methods and algorithms.

(4) Data value

The data value in the concept of big data means that big data contains valuable information, which can provide useful reference for corresponding decision-making. The realization of data value requires big data analysis, which is the process of extracting valuable data information from big data. Under the framework of smart cities, data value assessment is the most important feature of all applications based on big data, precisely because data value assessment can generate the information needed by data users.

(5) data accuracy

Data accuracy in the concept of big data refers to the integrity and accuracy of information contained in big data. Data accuracy is a description of the quality and credibility of big data. The core content of any information management practice is data quality, data control, metadata management and the requirements for data confidentiality and legality. Accurate raw data is helpful to analyze and mine accurate data information, thus providing more accurate reference for corresponding decision-making.