Technical Analysis of Wireless Smart Home

Wireless solutions have brought hope to home automation. Cutting off these cumbersome wires reduces a lot of trouble. At present, wireless smart homes are mainly divided into four types: Bluetooth, Wi-Fi, Zwave and ZigBee, depending on the technology used. Wireless technology allows people to remotely control their homes.

WiFi Technology

Smart home products based on WiFi technology are more common. Their advantages lie in fast transmission speed and low product cost. They are also more popular in life. For users, smart home combinations based on WiFi are more convenient. They can just purchase equipment and set up the network directly.

Everything has two sides. Although WiFi has fast transmission speed and wide popularity, it also has its own technical disadvantages: its bigger problem is that its security is very low and its wireless stability is weak; high power consumption is also one of its weaknesses, which will limit its application in the home field. For example, smart door locks, infrared forwarding controllers, various sensors, etc. are not suitable for use; in addition, WiFi's networking capabilities are also relatively low. Currently, the actual scale of WiFi networks generally does not exceed 16 devices, while in actual home environments, the number of switches, lighting, and home appliances alone is far more than 16. Obviously, the development space is subject to certain restrictions.

Compared with the more popular WiFi technology, the ZigBee technology to be discussed below has a relatively high threshold for research and development and application, and not everyone can master it. Some of the world's top 500 companies, such as Schneider, Siemens, Sony, General Electric, and Panasonic, have joined the ZigBee camp, and domestic companies such as Huawei and IoT Sensor are also in the ZigBee camp.

Zigbee Technology

First of all, ZigBee technology is very secure, and there has been no precedent of cracking in the world so far. Its security comes from its systematic design: it uses AES encryption (Advanced Encryption System), which is 12 times more stringent than card encryption technology; secondly, Zigbee uses a honeycomb structure to form a network, and each device can communicate with the gateway in multiple directions, with high network stability; in addition, its network capacity is theoretically 65,300 nodes, which is enough to meet the needs of home network coverage, and even smart communities and smart buildings can still be fully covered; then, Zigbee has the ability of two-way communication, which can not only send commands to devices, but also feedback the execution status of the devices, which is crucial to the terminal user experience, especially security equipment. If you click to close the door, but don’t know whether the door is really locked, how much safety risks will it bring; in addition, Zigbee adopts an extremely low power consumption design and can be powered by a full battery. In theory, a battery can be used for more than 10 years, which is energy-saving and environmentally friendly.

Zwave Technology

Zwave's data transmission rate is 9.6kbps, and the effective signal coverage is 30 meters indoors (more than 100 meters outdoors). It is suitable for narrow bandwidth applications and has certain security and stability. However, it is currently only used in home automation. There are three main disadvantages: First, there are fewer nodes. The theoretical value is 256, and the actual value may be only about 150, which is the upper limit of the number of devices it can accommodate. In fact, many manufacturers can accommodate 20 or 30 devices. The second is the tree-like networking structure. Once the upper end of the branch is broken, all the devices at the lower end will not be able to communicate with the gateway; the third is that there is no encryption method, the security is poor, and it is vulnerable to attacks. (The frequency band used by Zwave is not for civil use in my country. Zwave smart homes are not common in China, and they are more often used abroad.)