ZigBee technology is a bidirectional wireless communication technology that is short-range, low-complexity, low-power, low-rate, and low-cost. It is primarily used for data transmission between various electronic devices that require short distances, low power consumption, and low transmission rates, as well as applications involving periodic data, intermittent data, and low response time data transmission.
Technical Description:
In simple terms, ZigBee is a highly reliable wireless data transmission network, similar to CDMA and GSM networks. ZigBee data transmission modules are akin to mobile network base stations. The communication range varies from a standard 75m to several hundred meters or even kilometers, and it supports unlimited expansion.ZigBee is a wireless data transmission network platform composed of up to 65,535 wireless data transmission modules. Within the entire network range, each ZigBee network data transmission module can communicate with one another, and the distance between each network node can be expanded indefinitely from the standard 75m.Unlike mobile communication networks such as CDMA or GSM, the ZigBee network is primarily established for industrial site automation control data transmission, hence it must be simple, user-friendly, reliable, and cost-effective. In contrast, mobile communication networks are mainly established for voice communication, where each base station typically costs over one million RMB, while each ZigBee ‘base station’ costs less than 1000 RMB.Each ZigBee network node can not only serve as a monitoring object itself, such as directly collecting and monitoring data from its connected sensors, but it can also automatically relay data from other network nodes. Furthermore, each ZigBee network node (FFD) can wirelessly connect to multiple isolated sub-nodes (RFD) that do not undertake network information relay tasks within its signal coverage range.
Technical Features:
ZigBee is a wireless connection that can operate on three frequency bands: 2.4GHz (popular worldwide), 868MHz (popular in Europe), and 915MHz (popular in the USA), with maximum transmission rates of 250kbit/s, 20kbit/s, and 40kbit/s, respectively. Its transmission range is between 10-75m, but it can be further increased. As a wireless communication technology, ZigBee has the following features:(1) Low Power Consumption: Due to ZigBee’s low transmission rate, the transmission power is only 1mW, and it utilizes sleep mode, resulting in low power consumption. Consequently, ZigBee devices are very energy-efficient. It is estimated that ZigBee devices can operate for up to 6 months to 2 years on just two AA batteries, which is unmatched by other wireless devices.(2) Low Cost: The initial cost of ZigBee modules is around $6, which is expected to drop to $1.5-$2.5 soon, and the ZigBee protocol is royalty-free. Low cost is also a key factor for ZigBee.(3) Short Latency: The communication latency and the latency from sleep mode activation are very short, with a typical device search latency of 30ms, a sleep activation latency of 15ms, and an active device channel access latency of 15ms. Therefore, ZigBee technology is suitable for applications that require stringent latency requirements, such as industrial control scenarios.(4) Large Network Capacity: A star-structured ZigBee network can accommodate up to 254 slave devices and one master device, and a maximum of 100 ZigBee networks can coexist in one area, with flexible network composition.(5) Reliability: It employs collision avoidance strategies and reserves dedicated time slots for communication services that require fixed bandwidth, avoiding competition and conflicts in data transmission. The MAC layer uses a fully acknowledged data transmission mode, where each transmitted data packet must wait for confirmation from the receiver. If there are issues during transmission, retransmission can occur.(6) Security: ZigBee provides a data packet integrity check function based on cyclic redundancy check (CRC), supports authentication and authorization, and employs AES-128 encryption algorithms, allowing each application to flexibly determine its security attributes.
