More 5GHz spectrum goodness

Today Nigel Bowden (definitely worth a follow on twitter) drew attention to Ofcom’s March decision to open up more spectrum for indoor wifi use.

UNII-3 contains channels 149-161 which so far have been available for use in the UK for outdoor links, required a license (albeit a very cheap one) and Ofcom allowed TX power of up to 4w. This was particularly useful for linking remote buildings, and I know a few people who make use of this band because there’s no risk of building Wi-Fi interfering with the outdoor link.

From 17 August 2017 it’s all change and this spectrum is also made available, unlicensed, for indoor Wi-Fi use. The restrictions are much the same as the UNII-1 band, channels 36-48, with power limited to 200mw eirp.

For most Wi-Fi network administrators this is most welcome as it gives us an additional four 20MHz channels to play with. For high density networks, and demand for the high throughput capabilities of channel bonding the more spectrum we have available the better.

There was a great deal of confusion about all this. It should be noted the language is quite specific regarding outdoor use:

“Equipment must not form part of a fixed outdoors installation when operating in 5730 – 5850 MHz”

Immediately it looked to anyone with a licensed wireless bridge using these channels it was game over and they’d have to use….. something else.

However that’s not the case, this is just very badly communicated.

The channels remain available for outdoor use at higher power levels only with a license, otherwise they can be used indoors only as low power levels…. phew.

This does mean you need to make sure any external APs are in a group that respects the regulatory domain… Not all vendors do a very good job of this.

So officially we can start using these channels on our indoor Wi-Fi from the 17th of August. Whether your client devices will actually use these channels is a different matter. Odds are it won’t take Apple very long to push out an update to iOS and Mac OS with the new regulatory domain information. It might be a different matter for the large numbers of Android devices we see on our network that never have any sort of update. Either way, there’s some lab work and testing to do before putting the new channels into production use.

For more information, see the Ofcom website. The pertinent document is Interface Requirements 2030. Here is the decision statement from Ofcom.

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