l, and building automation network applications in the indus- trial and consumer markets. ZigBee supports three network topologies: Star-This topology can provide for very long-life operation and is the most common topology. Mesh-This topology enables high levels of reliability and scalability while providing more than one communications path through the network wire- less link. Cluster tree-This topology uses a hybrid star/mesh topology that com- bines the benefits of both for high levels of reliability and support for battery-powered nodes. The Future of ZigBee Future applications of the ZigBee protocol include its use in tracking and asset management systems, generators, elevators, and SO on, gathering data that can be transformed into viable information and enabling users to run their businesses more efficiently. The IEEE 802.15.4 group says that one day it might be common to find 50 ZigBee radio chips in a house. Those chips could serve duty in a home's 10 to 15 light switches, several fire and smoke detectors, thermostats, 5 or 6 toys and interactive game machines, and other human input devices. Radio-frequency-based ZigBee will eventually replace all the infrared (IR) links at home. ZigBee is not designed Chapter 15 WMANs, WLANs, and WPANs for video or CD-quality audio, but it could be used to send text or voice messages. No QoS provision is built into ZigBee. In January 2006, the ZigBee Alliance announced its ZigBee Certification pro- gram, which ensures that products are fully interoperable out of the box and can easily participate in a ZigBee network. Member companies can now test the growing number of ZigBee-ready products already on the consumer market so they can be fully branded as ZigBee Certified for home, industrial, or commercial use. Indepen- dent test service providers will oversee and conduct the ZigBee Alliance's certifica- tion testing to ensure that products are interoperable in a variety of environments and end-user applications. RFID is a method of remotely storing and retrieving data by