The Internet of Things is an important part of the new generation of information technology and an important development stage in the "information age". Its English name is: "Internet of things (IoT)". As the name suggests, the Internet of Things is the Internet where things are connected. This has two meanings: First, the core and foundation of the Internet of Things is still the Internet, which is an extension and expansion of the Internet based on the Internet; second, its user end extends and expands to any item to carry out information. Exchange and communication, that is, things relate to each other. The Internet of Things is widely used in the integration of networks through communication sensing technologies such as intelligent sensing, identification technology and ubiquitous computing. It is therefore known as the third wave of the development of the world's information industry after computers and the Internet.
The Internet of Things is an application expansion of the Internet. Rather than saying that the Internet of Things is a network, it is better to say that the Internet of Things is business and applications. Therefore, application innovation is the core of the development of the Internet of Things, and Innovation 2.0 with user experience as the core is the soul of the development of the Internet of Things.
ZigBee technology (www.zigbee.org) is an advanced two-way wireless communication with short range, low complexity, low power consumption, low data rate, low cost, high reliability and high security. technology, the basis of which is the IEEE 802.15.4 international standard protocol. Currently, Zigbee technology has been widely used in medical, agriculture, automobile, communications, electric power, and intelligent control industries around the world.
The main features of Zigbee technology include the following parts:
Low data transmission rate: the maximum is 250k bytes/second, focusing on low transmission rate applications;
< p>Low power consumption: Its working power consumption is much less than that of WiFi;Strong anti-interference: In a low signal-to-noise ratio environment, Zigbee has strong anti-interference performance; in the same In the environment, Zigbee's anti-interference performance is far better than Bluetooth and WiFi;
Low cost: Because Zigbee data transmission rate is low and the protocol is simple, the cost is greatly reduced. And the Zigbee protocol is free of patent fees;
Short latency: usually the latency is between 15 milliseconds and 30 milliseconds;
High security: Zigbee provides data integrity check And authentication function, the encryption algorithm uses AES-128, and its security attributes can be flexibly determined;
High reliability: Zigbee ensures high reliability of communication in terms of physical layer and communication protocol design. Very important for demanding industrial-grade applications;
Large network capacity: Each Zigbee network can support up to 65535 devices, that is to say, each Zigbee device can be connected to another 65535 devices;< /p>
Excellent network topology capabilities: ZigBee has star, tree and grid network topologies, and ZigBee wireless networks have self-organizing and self-healing capabilities;
Effective range Flexible and easy network deployment: The effective coverage of the Zigbee network ranges from the standard 75 meters to the expanded hundreds of meters or even several kilometers, depending on the actual transmit power and various application modes. In addition, the Zigbee wireless router greatly reduces the difficulty and time of Zigbee network deployment and debugging, and eliminates wireless communication dead ends;
The working frequency band is flexible: the frequency bands used are 2.4GHz (global), 868MHz (Europe) and 915MHz (United States) are both license-free frequency bands.