Can beacon deployments cause Wi-Fi interference?

I’ve now worked on innovations projects that use Bluetooth BLE and iBeacons for over three years. In my series of blog posts over this time I have extolled the virtues of iBeacon whilst using the technology to deliver an Apple and Android mobile apps for various organisations in India and abroad providing both analytics and end-to-end experiences using these new technologies.

To answer the WI-FI question directly – No it doesn’t (As with all these things this assumes the Wi-FI network is set up correctly)

I am posting this question about WI-FI purely because when this question is posed to me and I need to provide sound evidence and answer it, I found it really difficult to get a straight answer.

The technical reasons why you should not be worried at all about Wi-Fi interference and iBeacons are set out below. Please use this handy diagram to refer to the channels.

Credit: https://microchip.wikidot.com/wifi:channels

First of all, the 2 2 MHz channels at the edges are unlikely to affect anything Wi-Fi related. The lowest channel is 1, centered at 2412Mhz and highest is 13 centered at 2472MHz.

802.11g/n OFDM transmissions have 22Mhz channel width but only 16.25Mhz used by sub-carriers, so there’s zero overlap with BLE channel 37 which is centered at 2402MHz and 2MHz wide and certainly no overlap with the BLE channel 39 which is centered at 2480MHz.

This would only potentially interfere with channel 14 which is ONLY supposed to be used for DSSS in Japan, hence it’s physically impossible for these channels to interfere with Wi-Fi.

This leaves just channel 38, which is centred at 2426 MHz and potentially can interfere with Wi-Fi. It’s quite near the centre of channel 3 and 4 (2422/2427) so they might be slightly affected, but 2 and 5 will probably be negligibly affected as it’s going to be at the edge of their 16.25 MHz band.

So, to summarise, 2 channels might have negligible interference, and 2 might have more measurable. In most well planned installations these two wouldn’t be used, which is why the clever folks that designed the standard picked that slightly off centre frequency for the centre one.