Zigbee

Zigbee is a specification for a low-power wireless mesh networking standard designed for short-range, low-rate communications between devices in personal area networks. It is built on the IEEE 802.15.4 standard and is used mainly in home automation, consumer electronics, and industrial applications.

The Zigbee stack defines the physical and medium access control layers from 802.15.4 and additional network and application layers. The network layer manages addressing and routing; the upper layers include the Zigbee Device Object (ZDO), the Application Support Sub-layer (APS), and the Zigbee Cluster Library (ZCL) for device functionality and interoperability.

Zigbee supports several network topologies, including star, tree, and mesh, enabling multiple hops between devices. Devices come in three roles: coordinators, routers, and end devices. Mesh networking allows self-healing paths, extended range, and resilience in environments with interference.

Security features include AES-128 encryption, network keys, and optional link keys, with secure key distribution and device commissioning.

Zigbee profiles define how devices interact. Commonly used profiles include Zigbee Home Automation (ZHA), Zigbee Light Link (ZLL), and Zigbee Smart Energy. Zigbee 3.0 unified these profiles into a single specification, simplifying interoperability across device types.

The Zigbee Alliance, now the Connectivity Standards Alliance (CSA), oversees certification and interoperability programs. While Zigbee IP provided a path to IPv6 networking, most deployments remain non-IP, with IP-based solutions often using gateways. Zigbee remains widely used in inexpensive, low-power sensor and control networks.