ZigBee is defined by which IEEE standard?

• A. IEEE 802.11
• B. IEEE 802.15.4
• C. IEEE 802.3
• D. IEEE 802.16

Answer: (B)

ZigBee is built on the IEEE 802.15.4 standard, which specifies the physical and MAC layers for low-rate wireless personal area networks. ZigBee uses that foundation to provide its own network and application layers on top, delivering low-power, short-range communication suitable for IoT devices like sensors and actuators. The other standards correspond to different technologies: 802.11 is Wi‑Fi for higher throughput, 802.3 is Ethernet for wired networks, and 802.16 is WiMAX for broadband wireless. So ZigBee is defined by IEEE 802.15.4.