InternetofThings (IoT) is a network based on information carriers such as the Internet and traditional telecommunication networks, which enables all ordinary objects that can perform independent functions to be interconnected. Its application fields mainly include transportation and logistics, industrial manufacturing, medical care, intelligent environment (home, office, factory) and so on, and it has a very broad market prospect. It was first put forward in 1999 that everything is connected to the Internet according to the agreed agreement through information sensing devices such as radio frequency identification (RFID+ Internet), infrared sensor, global positioning system, laser scanner and gas sensor, so as to exchange information and communicate, thus realizing intelligent identification, positioning, tracking, monitoring and management. In short, the Internet of Things is "the Internet connected with things". China Internet of Things School-Enterprise Alliance defines the Internet of Things as the combination of almost all technologies with computer and Internet technologies, which realizes real-time sharing of environment and state information between objects, as well as intelligent collection, transmission, processing and execution. Broadly speaking, all applications involving information technology can be included in the category of Internet of Things.
Four-layer Architecture and Functions of Internet of Things
1, perception layer
Perception layer is the foundation of the development and application of Internet of Things. The perception layer is equivalent to the skin and facial features of the Internet of Things, and completes the tasks of identifying objects and collecting information. The sensing layer includes two-dimensional code tags and readers, RFID tags and readers, cameras, GPS, various sensors, cameras, terminals, sensor networks and other data acquisition equipment. It also includes the sensor network before the data access gateway. The main technologies involved in the perception layer are RFID technology, sensing and control technology and short-distance wireless communication technology.
2. Access Layer
The access layer is composed of terminal nodes and access gateways, which completes networking control and information collection of terminal node information, or completes forwarding of information sent to terminal nodes. These peripheral nodes constitute a peripheral network or a sensor network (an autonomous network composed of a large number of various sensor nodes).
3. Network layer
The network layer is equivalent to the nerve center and brain of the Internet of Things, which realizes information transmission and processing. The network layer includes the integrated network of communication and Internet, network management center, information center and intelligent processing center. The network layer transmits and processes the information obtained by the sensing layer and the access layer. The network layer also includes information storage and query, network management and other functions.
4. Application layer
The application layer is equivalent to the "social division of labor" of the Internet of Things, that is, it combines the needs of the industry to achieve extensive intelligence. The application layer is the deep integration of the Internet of Things and the professional technology of the industry, which combines the needs of the industry to realize the intelligence of the industry, similar to the social division of labor of people, and finally constitutes the human society.