Bluetooth
Bluetooth is a short-range wireless technology standard used for exchanging data between fixed and mobile devices over short distances using ultra-high frequency (UHF) radio waves, from 2.402 GHz to 2.48 GHz. Bluetooth uses low-power transmission which gives it a very short range of up to 10 metres but with the benefit of low battery power consumption.
Bluetooth and Wi-Fi are similar in that both are used to exchange data between devices. The difference is that Wi-Fi is access point-centered, with all traffic routed through the access point, while Bluetooth is symmetrical, with data exchanged directly between two Bluetooth devices. Bluetooth serves well in simple applications where two devices need to connect without a dependency on additional devices such as those required for a WiFi access point.
While Ethernet, WiFi, and cellular connections are networking protocols and can be used for data transfer across large networks, Bluetooth is a device-to-device communication protocol, not a networking protocol.
Bluetooth is widely used to exchange files between two devices and connect smartphones to audio playback systems such as headphones, eliminating the need for wires. Bluetooth is also used to connect smartphones to Arduino circuits and IoT appliances to send control signals over a very short distance.
With the advent and increasing implementation of the Internet of Things, there was a need to have network connections that were much less resources intensive than the options listed above, since IoT devices generally operate on low power and bandwith. For this, LoRa, or long-range radio, a proprietary radio communication technique was designed to transmit data for the Internet of Things (IoT) and machine-to-machine (M2M) devices. We will use LoRa extensively in our IoT projects.