Bluetooth? has some attractions as an alternative， but historically it has not fit comfortably with some aspects of the IoT. Its power consumption has been relatively high， data rates have been faster than typically necessary， and the first Bluetooth specifications were based on one-to-one rather than one-to-many connectivity.

　　The emergence of the Bluetooth Low Energy （BLE） standards （version 4.0/4.1/4.2）， which complement the Basic Rate （BR） and Enhanced Data Rate （EDR） （version 2.0/2.1） standards， have changed Bluetooth’s relationship with the IoT. BLE is supported on every smartphone， tablet and smart watch shipped since 2012， allowing users to interact easily and directly with IoT applications using their own device without the restrictions imposed by the need for a gateway.