Bluetooth Primer

Bluetooth technology has been around for a very long time… ever since 1989! But it has been improved, updated and is currently found in most of our personal devices. But many don’t know the details about it, other than it just works.

The Bluetooth logo is made up of merging the Nordic Runes from  Hagall and  (Bjarkan) the initials of the tenth-century King Harald Bluetooth.

Bluetooth operates in the same unlicensed frequency ranges as 2.4GHz 802.11b,g, and now ax. From 2402 MHz to 2480 MHz (Or including the guard bands – from 2.4GHz to 2.4835GHz) – the same ISM band used by many other technologies.

One major difference, is the use of Frequency-Hopping Spread Spectrum – where the data is divided into packets, and each is transmitting on one of 79 possible Bluetooth Channels. Each channel is 1MHz – and these ‘hops’ change at 1600 hops per second!

The newer Bluetooth Low Energy (BLE) uses 2MHz wide spacing and only 40 Channels.

Though the protocol offers a wide variety of ‘Classes’ – from Class 1 devices that can transmit at a full 20dBM (100mW) – to Class 4 devices that can barely transmit at a -3dBm (.5mW) level. Most devices we use day to day are Class 2 – and they transmit at a max of 4dBm (2.5mW) and have a range of around 10m.

Over the past decades, Bluetooth has evolved from the initial Bluetooth 1.0 – to today’s BLE (Bluetooth 4.0) and the current Bluetooth 5.1. With each version picking up newer and faster technology, coupled with more features and capabilities.

To learn more about Bluetooth Technology check out this site:

Sometimes folks get a bit confused between Bluetooth and Bluetooth Low Energy (BLE) – both use much of the same technology – but for different purposes.

You can also download the entire technical specifications in PDF format by clicking here.


You have personally been using Bluetooth for quite some time. Isn’t it time you spent a bit of time learning about the underlying technology?