What is ZigBee for smart home? What's the difference?

16/09/2021
Due to the rise of smart home, now everyone has more or less smart home, whether it is speaker, fan or socket, dimmer switch, it seems that every device in the family electric can become intelligent.

And in so many devices gathered in the same family environment, and the standards between manufacturers are not the same, if only buy a single ZigBee equipment, there will be no use, then white users should buy what protocol of intelligent hardware equipment?

At present, ZigBee, WiFi and BLE are the three most popular communication protocols in smart home iot.
 

As a short-distance, low-power wireless communication protocol, Zigbee's biggest advantage is that it can automatically form a device network and link the data transmission of each device directly. However, in this self-organizing network, a central node is needed to manage the whole Zigbee network. This means that there must be a component similar to a "router" in the Zigbee device network to connect all devices together to achieve the linkage effect between Zigbee devices.
And this additional "router" component is what we call a gateway. In addition, Zigbee's access ceiling is very high, theoretically, Zigbee network nodes can be up to 65,000!

In addition to advantages, Zigbee also has many disadvantages. For users, the installation threshold of Zigbee still exists. Because most Zigbee devices do not come with their own gateways, a single Zigbee device is basically unable to be directly controlled by our mobile phones, and a gateway is needed as the connection hub between devices and mobile phones.
 

WiFi
Compared with Zigbee, the advantage of WiFi is faster speed, large data transmission, and users' first experience is very good. Wifi-enabled smart devices can easily connect to a phone, unlike Zigbee devices, which need a gateway to connect to a phone.
The advantage of Wi-Fi is that it is relatively fast, can be directly connected to the Internet without a bridge, and can communicate seamlessly with your mobile phone.
The main disadvantage of WiFi lies in power consumption. The standby power consumption of general WiFi devices is about 1W, while that of BLE devices and Zigbee devices is within 0.1W. By comparison, the power consumption of WiFi devices is much higher. In addition, the number of WiFi smart devices is also a big problem. Theoretically, the upper limit of WiFi access is mainly determined by the number of router nodes.

As far as home routers are concerned, if there are more than dozens of electronic devices that need to be connected to the router, the router will be unable to withstand, or even connect to WiFi.

BlueTooth
BLE (Low power Bluetooth technology) is equivalent to the intermediate between WiFi and Zigbee. It not only has Zigbee's low power consumption (lower power consumption than WiFi), fast response characteristics, but also has the advantage of easy use of WiFi (no gateway can be connected to the mobile network), especially in the use of mobile phones, Bluetooth protocol is the same as WiFi. Become a standard protocol in smart phones.
The biggest disadvantage of BLE technology is that it has a weak ability to pass through walls, and the signal behind walls is very weak. The linkage fails.

How to purchase smart home devices according to the agreement?
At present, smart home manufacturers, generally smart equipment selection principle is:

1) Use WiFi protocol for plugged devices;

2) For interaction with mobile phones, use BLE protocol;

3) Sensor with Zigbee.
 

But because manufacturers in the replacement of equipment, due to a variety of reasons, resulting in different agreements of equipment is sold at the same time, so we buy smart home equipment, we must pay attention to the following points: When buying a "Zigbee edition" device, make sure you have a Zigbee gateway at home, or most single Zigbee devices cannot be controlled directly from a mobile phone. WiFi/BLE devices, most WiFi/BLE devices can connect directly to the mobile network without a gateway, unlike Zigbee devices, which must have a gateway to connect to the mobile phone. You can pick your WiFi and BLE devices. BLE devices generally interact with mobile phones in close proximity, and the signal is not good behind the partition wall. Therefore, it is not recommended to purchase "only" BLE protocol for devices requiring remote control. If the home router is just an ordinary home router, it is not recommended to adopt the WiFi protocol in a large number of smart home devices, because it is very likely that the device is always offline. (Because common routers have limited WiFi access nodes, too many WiFi devices will affect normal WiFi connection.)