[July 06, 2005] Wednesday TECHtionary.com TECH-Tip - Zigbee Tweet The animated TECH-Tip tutorial available at http://www.techtionary.com Summary Zigbee is an IEEE 802.15.4 standard for data communications with business and consumer devices. Zigbee is designed around low-power consumption allowing batteries to essentially last forever. Details Here is a brief comparison between Zigbee, WiFi and Bluetooth which all operate in unlicensed 2.4 GHz and other frequencies. Zigbee is an IEEE 802.15.4 standard. Zigbee is designed around low-power consumption allowing batteries to essentially last forever. Key features are: - Data rates are 20, 40 and 250 KBPS-Kilo Bits Per Second. - Operates in the unlicensed frequencies used by cordless telephones, WiFi and other devices. - Devices operate in a peer-to-peer (devices talk to other devices) or star (central server) modes. - Network access is via CSMA-CA-Carrier Sense Multiple Access - Collision Avoidance (listen, look, if busy then wait, if not busy wait for a semi-random time, then transmit). Some of the applications for Zigbee are: - Home networking - appliances to lighting - Automobile networking - Industrial networking - Interactive gaming - Remote metering - Active RFID-Radio Frequency IDentification tracking Zigbee network topology can take almost any form: - PP-Point-to-Point - CT-Clustered Tree - CS-Clustered Star - MN-Mesh network A Zigbee network may also be considered a Piconet defined as a collection of devices connected in adhoc (random) manner. In a Piconet, one device acts as a master controller and the other units are slaves. Each Piconet has a unique IDdentification hopping pattern. The master controls the time and the hopping (broadcast) pattern. In a Bluetooth Piconet, each master can have seven active simultaneous slaves. In a Scatternet, is the linking of multiple co-located Piconets organized through the sharing of common master or slave devices. In a Scatternet, a device can be a master or slave. Zigbee uses DSSS-Direct Sequence Spread Spectrum (shown here) which divides the 2.402 - 2.480 GHz-Giga Hertz spectrum into 16 channels or 10 channels in the 915 MHz-Mega Hertz spectrum and 1 channel in the European 868 MHz spectrum. WiFi uses DSSS creating 11 channels. Bluetooth uses FHSS-Frequency Hopping Spread Spectrum which divides the frequency band into 79 channels. About TECHtionary.com – 303-444-6226 TECHtionary Corporation founded in 2001 and headquartered in Boulder, Colorado is the World's First and Largest Animated (rich media) Library/Magazine on Technology. Get the analysis and more than 2,630+ free tutorials on data, internet, wireless, VoIP-Voice over Internet Protocol (internet telephony), PBX systems, central office switching, protocols, telephony, telecommunications, networking, routing, power systems, broadband, WiFi-Wireless Fidelity and other technologies, TECHtionary.com provides "just enough – just-in-time" critical success information. TECHtionary produces web infomercials proven to "increase revenues, decrease customer support costs and increase customer satisfaction." Tom Cross CEO of TECHtionary is a member of the Technical Board of Advisors for the VOIP-Security Alliance. [ Back To TMCnet.com's Homepage ]