Tecnologia sem fio Zigbee, WiFi e 433 MHz suas características

Tecnologia sem fio Zigbee, WiFi e 433 MHz suas características

Zigbee, WiFi and 433MHz are three different technologies for short range wireless communication. Each technology has its pros and cons.

Zigbee is a low power, highly reliable, wireless mesh networking technology. By using the routers, not only the network coverage area can easily be expanded and adjusted, but also the “blind spot” in wireless communication environment can be eliminated. Além disso, Zigbee supports star, tree and mesh topologies. Assim sendo, Zigbee is well-suited for both simple and complex built environment. Compared to the WiFi, Contudo, Zigbee’s data rate is 250kbps, lower than WiFi’s 11Mbps-54Mbps. That makes Zigbee inappropriate for high data rate applications, such as internet surfing, large file downloading or uploading. For restaurant and catering industry, Contudo, the data exchanged between server and terminals generally are just small amount. Assim sendo, Zigbee is a quite suitable technology for ordering application.

WiFi can support high-data-rate applications. It also supports “always-on” feature, which makes the WiFi attractive for some applications. Contudo, it has some drawbacks which have been noticed by the consumers, such as high power consumption, low reliability, long reconnection time, etc.

433MHz technology has been widely used in China for restaurant ordering application. Since it uses relatively low frequency band, its wireless signal can be transmitted further than Zigbee and WiFi, which operates in 2.4GHz band. Contudo, the data rate of 433MHz is only 9.6kbps, much lower than WiFi and Zigbee’s data rate. Assim sendo, 433MHz suits the application in which only small amount of data needs to be transmitted. Além disso, same as WiFi, 433MHz supports star topology only, which may cause “blind spot” within the wireless network coverage area.

Different from the WiFi’s “always-on” feature, in Zigbee and 433MHz system, the wireless link is established only when there is data need to be transmitted. This mechanism can dramatically reduce the interference to other devices in the network. The power consumption of the device is also reduced. Contudo, If “always-on” is requested in Zigbee or 433MHz system, a function can be designed in the application software to support this feature.
(Fonte: Shehzhen Seabreeze Smart Card Co., Ltd.)