Bluetooth® technology , operating on the 2.4 GHz unlicensed industrial, scientific, and medical (ISM) frequency band, uses low-power radio frequency to enable short-range communication at a low cost. The two variants of the Bluetooth technology are –
Bluetooth basic rate/enhanced data rate (BR/EDR) or classic Bluetooth
Bluetooth low energy (BLE) or Bluetooth Smart
The Bluetooth Core Specification , specified by the Special Interest Group (SIG) consortium, defines the technologies required to create interoperable Bluetooth BR/EDR and BLE devices.
Bluetooth BR/EDR radio is primarily designed for low power, high data throughput operations. In Bluetooth BR/EDR, the radio hops in a pseudo-random way on 79 designated Bluetooth channels. Each Bluetooth BR/EDR channel has a bandwidth of 1 MHz. Each frequency is located at (2402 + k) MHz, where k = 0,1, …, 78.
In 2010, the SIG introduced BLE with the Bluetooth 4.0 version. The BLE radio is designed and optimized to support applications and use cases that have a relatively low duty cycle. For example, suppose a person wears a heart rate monitoring device for several hours. Because this device transmits only a few bytes of data every second, its radio is in the 'on' state for a very short period of time. In BLE, the operating radio frequency is in the range from 2.4000 GHz to 2.4835 GHz. The channel bandwidth is 2 MHz, and the operating band is divided into 40 channels, (k = 0, 1, …, 39). The center frequency of the kth channel is located at (2402 + k × 2) MHz.
This table summarizes and compares different features of Bluetooth BR/EDR and BLE.
|Frequency band||Operates on a 2.4 GHz Industrial, Scientific, and Medical (ISM) band, with the values in the range from 2.4000 GHz to 2.4835 GHz||Operates on 2.4 GHz ISM band, with the values in the range from 2.4000 GHz to 2.4835 GHz|
40 channels (37 data channels and 3 advertising channels)
|Channel bandwidth||1 MHz||2 MHz|
|Spread spectrum technique||1600 hops/sec frequency-hopping spread spectrum (FHSS)||FHSS|
|Power usage||1 W (reference value)||~0.01x W to 0.5x W of reference (depending on the use case scenario)|
|Maximum transmission power||
|Device discovery||Inquiry or paging||Advertising|
|Device address privacy||None||Private device addressing supported|
|Audio capable||Yes||Yes (BLE audio is introduced in Bluetooth Core Specification 5.2)|
|Network topology||Point-to-point (including piconet)||
This table summarizes prominent applications of Bluetooth BR/EDR and BLE.
Audio streaming applications such as:
Location and direction finding applications such as:
Data transmission applications such as:
Device network applications such as:
 Bluetooth Technology Website. “Bluetooth Technology Website | The Official Website of Bluetooth Technology.” Accessed September 14, 2020. https://www.bluetooth.com/.
 Bluetooth Special Interest Group (SIG). "Bluetooth Core Specification." Version 5.2. https://www.bluetooth.com/.