Bluetooth Low Energy Channels & Frequencies

The RF channels used for Bluetooth Low Energy, LE consist of Primary Advertising Channels and Data Channels / Secondary Advertising channels and they are ordered to avoid clashes with Wi-Fi.

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Bluetooth Low Energy, BLE uses the 2.4 GHz ISM, Industrial, Scientific and Medical band which does not require a transmitting licence for its use.

The actual Bluetooth LE frequency range extends from 2402 to 2480 MHz for the centre frequencies of the channels, and this means it utilises the whole of the internationally agreed 2.4GHz allocation.

The Bluetooth uses frequency hopping techniques, utilising the different Bluetooth LE channels which are all spaced 2 MHz apart in frequency from each other and this gives sufficient bandwidth to carry the BLE signals.

There is a total or 40 channels - less than the 79 used for Bluetooth Classic, but the frequency spacing for LE is wider - Bluetooth Classic has a 1 MHz bandwidth against Bluetooth LE which uses 2 MHz.

There are two types of channel, namely the Primary Advertising Channels and the Data Channels which can also be used as a Secondary Advertising Channel.

In order to avoid clashes with Wi-Fi the Primary Advertising channels, which are numbered 37, 38 and 39 are placed at frequencies of 2402 MHz, 2426, and 2480 MHz.

The reason for this is to avoid clashes with Wi-Fi and ensure that the advertising channels are not compromised.

However it does lead to the channel numbering looking a little out of order. The Data Channels are numbered from 0 to 36, and the advertising channels 37, 38, and 39. However they are not all arranged in frequency order because of the interference issues.

Bluetooth LE channels & frequencies list

A list of the Bluetooth Low Energy channel numbers, their frequencies and functions are given in the table below:

Bluetooth LE Channel Listing
Channel Frequency (MHz)	Channel Number	Channel Application
2402	37	P.Adv
2404	0	Data Ch
2406	1	Data Ch
2408	2	Data Ch
2410	3	Data Ch
2412	4	Data Ch
2414	5	Data Ch
2416	6	Data Ch
2418	7	Data Ch
2420	8	Data Ch
2422	9	Data Ch
2424	10	Data Ch
2426	38	P.Adv
2428	11	Data Ch
2430	12	Data Ch
2432	13	Data Ch
2434	14	Data Ch
2436	15	Data Ch
2438	16	Data Ch
2440	17	Data Ch
2442	18	Data Ch
2444	19	Data Ch
2446	20	Data Ch
2448	21	Data Ch
2450	22	Data Ch
2452	23	Data Ch
2454	24	Data Ch
2456	25	Data Ch
2458	26	Data Ch
2460	27	Data Ch
2462	28	Data Ch
2464	29	Data Ch
2466	30	Data Ch
2468	31	Data Ch
2470	32	Data Ch
2472	33	Data Ch
2474	34	Data Ch
2476	35	Data Ch
2478	36	Data Ch
2480	39	P.Adv

Where:
P.Adv = Primary Advertising Channel
Data Ch = Data Channel / Secondary Advertising Channel

The Bluetooth Low Energy system uses 40 channels which are different to those used for Bluetooth Classic with the channel centre frequencies ranging from 2402 MHz to 2480 MHz.

The way in which the channel numbers are selected and numbered with respect to the frequencies may seem a little counter-intuitive, but this results from the fact that the advertising channels need to remain clear of the interference that might be caused by nearby Wi-Fi routers and devices.