https://en.wikipedia.org/wiki/IEEE_802.15.4
WebIEEE 802.15.4 is a technical standard which defines the operation of a low-rate wireless personal area network (LR-WPAN).It specifies the physical layer and media access control for LR-WPANs, and is maintained by the IEEE 802.15 working group, which defined the standard in 2003. It is the basis for the Zigbee, ISA100.11a, WirelessHART, MiWi, …