Principle of zigbee smart home control system

Seeing the name zigbee, we can probably guess that its origin is inseparable from the "bee". The bee (bee) communicates by fluttering its wings "zig", hence the name of the image. Let's talk about the principle of zigbee smart home control system!
Principle of zigbee smart home control system

ZigBee is a low-power LAN protocol based on the IEEE802.15.4 standard. It can work in 3 frequency bands of 2.4GHz (popular in the world), 868MHz (popular in Europe) and 915 MHz (popular in the United States), with up to 250kbit/s and 20kbit/s respectively. s and 40kbit/s transmission rate, its transmission distance is in the range of 10-75m. The technology specified in this agreement is a short-range, low-power wireless communication technology. It is characterized by close proximity, low complexity, self-organization, low power consumption, low data rate, and low cost. Mainly suitable for automatic control and remote control field, can be embedded in various equipment. In short, ZigBee is a cheap, low-power short-range wireless networking communication technology. In terms of network capacity, it can be expanded to 65,000, which absolutely meets the access requirements of only smart home products. The rate is 250K, which is more than enough for home devices that do not require large data transmission. At present, most of the new smart home products use Zigbee for control and networking.

With the continuous popularization of whole-house intelligence, ZigBee will become one of the mainstream communication protocols generally supported by smart homes in the future. ZigBee 3.0 provides unparalleled compatibility, security and reliability, and because of the large equipment carrying capacity of ZigBee 3.0, it can be connected to hundreds of smart home devices, and it is not easy to drop the line. The pain point of unstable state provides a more favorable foundation for the realization of whole-house intelligence.

But why do you need ZigBee when you already have WiFi and Bluetooth?

Although Bluetooth technology has many advantages, it is too complicated for industrial, home automation control and industrial telemetry and remote control fields, with high power consumption, short distance, and too small network scale.

Especially in the field of industrial automation, the demand for wireless data communication is getting stronger and stronger. For industrial sites, this wireless data transmission must have high reliability and be resistant to various electromagnetic interferences in industrial sites.

Therefore, the ZigBee protocol was officially launched in 2003.

The Mac layer and PHY layer of ZigBee are based on the IEEE802.15.4 protocol. The technology specified in this agreement is a short-range, low-complexity, low-power, low-data-rate, low-cost two-way wireless communication technology that can be embedded in various devices while supporting geolocation capabilities.

What is the charm of ZigBee?

1. Low power consumption

In low-power standby mode, two AA batteries can support one node to work for 6-24 months, or even longer. This is the outstanding advantage of ZigBee. In contrast, Bluetooth can work for weeks and WiFi can work for hours;

2. Low cost

By greatly simplifying the protocol, the cost is very low (less than 1/10 of Bluetooth), and the requirements for the communication controller are reduced. According to the prediction analysis, based on the 8051 8-bit microcontroller, the full-featured master node requires 32KB of code, and the sub The function node is as little as 4KB code, and ZigBee's protocol patent is free;

3. Short delay

ZigBee's response speed is relatively fast. Generally, it only takes 15ms to switch from sleep to working state, and it only takes 30ms for nodes to connect to the network, which further saves power. In comparison, Bluetooth needs 3-10s, WiFi needs 3s;

4. High capacity

ZigBee can adopt star, sheet and mesh network structures, and one master node manages several sub-nodes, and one master node can manage up to 254 sub-nodes; at the same time, the master node can also be managed by the upper-layer network node, which can form up to 65,000 sub-nodes. A large network of nodes;

5. High security

ZigBee provides a three-level security mode, including no security settings, the use of access control lists (ACL) to prevent illegal access to data, and symmetric ciphers using the Advanced Encryption Standard (AES128) to flexibly determine its security properties.

BACK TO HOME PAGE