A look at the differences between IEEE 802.15.4 and ZigBee.
　　Wireless networks are becoming more ubiquitous and are implemented using a variety of protocols specifically designed for radio frequency systems. Some protocols that are in use are proprietary to individual vendors while others are industry standards.
　　ONLINE Extra: link to more than 30 wireless resources, below.
　　Recently控制工程网版权所有, a lot of attention has been given to 802.15.4 and ZigBee, but there is still some ambiguity as to what is di

fferent about them and what kind of networks or systems would benefit from these particular protocols.
　　What is IEEE 802.15.4?
　　IEEE 802.15.4 is a standard for wireless communication established by the Institute for Electrical and Electronics Engineers (IEEE). A few examples of wireless IEEE standards include the 802.11 standard which defines communication for wireless local area networks (LANs) and 802.16 that is used for broadband wireless communication in Metropolitan Area Networks.

　　At 2.4 GHzwww.cechina.cn, communication occurs in one of sixteen 5 MHz channels ranging from 2.405 to 2.480 GHz.
　　This standard is designed specifically for communications in a point-to-point or a point-to-multipoint configuration with sleeping and security also being integral parts of the standard. A typical application involves a central coordinator that often acts as a data collector, with multiple remote nodes connecting back to this central host. While both 802.11 and 802.16 standards are concerned with higher bandwidth Internet access applications, 802.15.4 was developed with a lower data rate控制工程网版权所有, simple connectivityCONTROL ENGINEERING China版权所有, and battery-powered applications in mind. The 802.15.4 standard specifies that communication can occur in the 868.0-868.8 MHz控制工程网版权所有, the 902-928 MHz or the 2.400-2.4835 GHz industrial scientific and medical (ISM) bands. The 868 MHz and 902 MHz bands offer the least amount of bandwidth under the specification, with 20 kHz and 40 kHz available, respectively, for each channel. While any of thes