1.什么是物联网

物联网（internet of Things ，简称IOT），物联网简单来讲就是讲各种物理设备、智能终端、传感器等通过网络的方式连接起来，在局域网也可以在更广域广域网之间进行相互通信，实现信息交换和通信的技术，实现信息的共享和智能化管理。

internet of Things (internet of Things, referred to as IOT), the Internet of things simply refers to a variety of physical devices, intelligent terminals, sensors, etc., connected through the network, the LAN can also communicate with each other between the wider area wide area network, to achieve information exchange and communication technology, to achieve information sharing and intelligent management.

1.1.物联网有什么用处

物联网对于家庭、校园、甚至企业来说，它的应用领域非常广泛，包括工业自动化、智慧城市、农业物联网、医疗健康等领域，利用物联网可以为我们的生活和工作带来了诸多便利和好处。

Internet of Things for home, campus, and even enterprises, its application field is very wide, including industrial automation, smart city, agricultural Internet of things, medical health and other fields, the use of the Internet of things can bring a lot of convenience and benefits for our life and work.

2.物联网的中的三层结构

感知层(Perceptual layer)

位于物联网三层结构中第一层的底层 负责识别外界物体、采集信息，并将信息传递给物联网系统的其他层面

1. 数据采集：温度、湿度、光照、声音、位置、人体、噪声、压力。

2. 设备控制： 通过传感器传输的内容数据、可以根据上层控制指令控制各个执行器的交互动作，从而实现智能化、自动化。

3. 对我们人类而言，是使用五官和皮肤，通过视觉、味觉、嗅觉、听觉和触觉感知外部世界。而感知层就是物联网的五官和皮肤，用于识别外界物体和采集信息。它可以通过传感器、采集外部数据，然后通过RFID、条码、总线、蓝牙、红外等短距离传输技术传递数据。

The bottom layer, located in the first of the three layers of the iot structure, is responsible for identifying external objects, collecting information, and passing information to other layers of the iot system

1. Data collection: temperature, humidity, light, sound, position, human body, noise, pressure.
2. Equipment control: Through the content data transmitted by the sensor, the interactive actions of each actuator can be controlled according to the upper control instructions, so as to achieve intelligence and automation.
3. For us humans, it is the use of our five senses and skin to perceive the external world through sight, taste, smell, hearing and touch. The perception layer is the facial features and skin of the Internet of Things, which are used to identify external objects and collect information. It can collect external data through sensors, and then transmit data through short-range transmission technologies such as RFID, bar codes, buses, Bluetooth, and infrared.

网络层(Network layer)

传输层也叫做网络层，位于三层结构中第二层，其功能为通过通信网络进行安全地传输上下层的数据

1. 物联网的传输层主要负责传递和处理感知层获取的信息， 分为有线传输和无线传输两大类，

2. 网络层作为纽带连接着感知层和应用层，它由各种私有网络、互联网、有线和无线通信网等组成，相当于人的神经中枢系统，负责将感知层获取的信息，安全可靠地传输到应用层，然后根据不同的应用需求进行信息处理。

The transport layer, also known as the network layer, is located at the second layer of the three-layer structure, and its function is to securely transmit data from the upper and lower layers through the communication network

1. The transmission layer of the Internet of Things is mainly responsible for transmitting and processing the information obtained by the perception layer, which is divided into two categories: wired transmission and wireless transmission.
2. The network layer, as a link connecting the perception layer and the application layer, is composed of various private networks, the Internet, wired and wireless communication networks, etc., equivalent to the human nervous system, responsible for transmitting the information obtained by the perception layer to the application layer safely and reliably, and then processing the information according to different application requirements.

中心网关(Central gateway)

中心网关位于物联网三层结构跟二层结构的中间，其功能利用经过分析处理的感知数据为用户提供丰富的特定服务

一般情况下,各个设备是无法与其他设备直接点对点通信的，这时需要一个设备做中转，这个设备就是（中心网关）

中心网关提供安全可靠的连接通信能力，向下连接海量设备，支撑设备数据采集上云；向上提供云端API，并且通过调用云端API将指令下发至设备端，实现远程控制、远程交互的作用。

The central gateway is located in the middle of the three-layer structure and the two-layer structure of the Internet of Things, and its function uses the analyzed and processed perceptual data to provide users with a wealth of specific services Under normal circumstances, each device is unable to directly communicate with other devices point-to-point, then a device is needed for transit, this device is (central gateway). The central gateway provides secure and reliable connectivity and communication capabilities, connects massive devices downward, and supports device data collection to the cloud. The cloud API is provided upward, and commands are sent to the device by invoking the cloud API to achieve remote control and remote interaction.

应用层（Application layer）

  位于三层结构中的顶层，类似人的大脑，下发指令至神经之中，传输到物联网的感知层中，进行设备的交互使用，达到智能化

1. 主要作用是利用从底层感知层和网络层收集到的数据，实现各种应用和服务。基于这些数据进行分析、决策和控制，从而实现各种智能化、自动化的功能。
2. 应用层与感知层具有紧密的联系，一个是获取数据，一个是利用数据，它们之间存在因果的关系。应用层一方面可以对感知层所采集的数据进行计算、处理，

Located in the top layer of the three-layer structure, similar to the human brain, the instruction is sent to the nerve, transmitted to the perception layer of the Internet of Things, and the interactive use of the device to achieve intelligence

1. The main function is to use the data collected from the underlying perception layer and the network layer to realize various applications and services. Based on these data for analysis, decision-making and control, so as to achieve a variety of intelligent, automated functions.
2. The application layer and the perception layer are closely related, one is to obtain data, the other is to use data, and there is a causal relationship between them. On the one hand, the application layer can calculate and process the data collected by the perception layer.