ZigBee

A specification from the ZigBee Alliance for a set of high-level communications protocols based on the IEEE 802.15.4 standard for a low-data-rate wireless personal area network (WPAN) comprising devices of low complexity and long battery life. ZigBee is designed for connecting devices in ad hoc networks over very short distances with very low power consumption. ZigBee specifies star, peer-to-peer and mesh network topologies, with mesh being the preferred approach for reasons of redundancy and resiliency. ZigBee runs in the ISM band using direct sequence spread spectrum (DSSS) transmission. A ZigBee Coordinator (ZC) initializes the network, coordinates its operation, and is responsible for security. ZigBee End Devices (ZEDs) are terminal devices that are very limited in function, and can communicate only with ZigBee Routers (ZRs), which function to pass messages to other ZRs or to the ZC. In beacon enabled networks, ZigBee Routers (ZRs) periodically beacon their presence and, therefore, need power up only during the beaconing cycle, which conserves battery life. In non