ZigBee Wireless Communications Protocol 
ZigBee is an open industry specification for unlicensed RF untethered peripheral control requiring the lowest power consumption between compliant devices.
The ZigBee specification is a combination of HomeRF Lite and 802.15.4v specification. The spec operates in the 2.4GHz (ISM) radio band, the same band as 802.11b standard, Bluetooth, microwave and some other devices. It is capable of connecting 255 devices per network. The specification supports data transmission rates of up to 250Kbps at a range of 30 meters.