IEEE802154

IEEE 802.15.4 is a standard defined by the Institute of Electrical and Electronics Engineers (IEEE) for low‑rate wireless personal area networks (LR‑WANs). It specifies the physical and media access control layers for devices that require low power consumption, modest data rates and simple topologies. The standard is most commonly implemented in protocols such as Zigbee, Thread and 6LoWPAN.

The physical layer supports several frequency bands. In the United States it operates in the 2.4‑GHz ISM band with a data rate of up to 250 kbps, and in the 868‑MHz and 915‑MHz bands with lower data rates of 20 kbps and 40 kbps respectively. Carrier sense multiple access with collision avoidance (CSMA‑CA) is used for medium access control. Devices can form star, peer‑to‑peer, or mesh topologies; however, the standard itself places no restrictions on routing protocols.

Security features are defined in the MAC layer, including optional 128‑bit AES encryption for data and key management. A unique short address and an extended 64‑bit address enable network and device identification. The standard also allows optional high‑throughput Physical layer extensions for future enhancements.

IEEE 802.15.4 was first ratified in 2003 and revised in 2006, 2015 and 2020. Its design prioritises low power use and cost, enabling battery‑operated sensors, control systems and home automation devices to communicate over several meters while occupying minimal spectrum. The widespread adoption of IEEE 802.15.4 underpins many modern Internet of Things applications worldwide.

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