Tuesday 5 May 2020

Wi-Fi 6E (new unlicensed RF spectrum) won't be available any time soon in New Zealand

Wi-Fi just got a major enhancement that will be a game-changer...but not in New Zealand.


The basic limitation with Wi-Fi in our workplaces, schools & universities, public spaces, stadiums, airports and shopping centres is that there is a limited amount of unlicensed RF spectrum available, and everyone needs to share it.

Most parts of the RF spectrum can only be used under government-issued license (think cellular towers, RADAR, public safety radio, etc.) but a couple of little slivers were carved out early on in the 2.4GHz and 5GHz ranges for unlicensed use and for Industrial, Scientific and Medical use.

This then became the backbone of Wi-Fi: the fact that any device we buy off the shelf can talk to practically any Wi-Fi access point in the world is what allowed Wi-Fi to become so ubiquitous and indispensable.

The Problem

As time went by and the number of connected devices skyrocketed, the contention for that available unlicensed spectrum became worse and worse, to the point where today's Wi-Fi designers prefer to pretend that the 2.4GHz spectrum doesn't exist because it is so crowded and unreliable.

The holy grail of "better Wi-Fi" is to have access to a channel, a slice of the RF spectrum, that nobody else around you is using. This is getting harder and harder to find. Even in the 5GHz range where there are more channels, we desire to bond them together to increase total bandwidth, effectively reducing the number of available channels and getting back into the same problematic situation as before.

The News from USA

In early 2020, USA's FCC announced that they would be making another significant chunk of RF spectrum available for unlicensed use (actually they have been working on this for years). This will be in the 6GHz range, so it will have similar characteristics to today's 5GHz Wi-Fi.

Although we refer to it as the 6GHz band, the band actually runs from 5.925–7.125GHz, a significant range resulting in over twice as much available RF space than we've ever had in Wi-Fi before.

This means that we can bond channels together for that delicious bandwidth, and still have plenty to go around uncontested in our local area - a real game-changer!

The Wi-Fi Alliance has also been busy, and they are ready to start certifying devices in 2021, with Broadcom already announcing a chip in February 2020.

The new spectrum will be known as Wi-Fi 6E (building on the Wi-Fi 6 new naming scheme from 2019).

What about all those organisations who already paid for licenses in the 6GHz spectrum?

Avoiding interference for existing license holders (mainly being telcos and broadcasting companies who use it for long distance point-to-point links) will be mitigated in multiple ways.

Firstly, the FCC has determined that the way those licensees use this spectrum is different to the way a business uses Wi-Fi. They don't think that there will be much opportunity for interference to occur to any level that would impact those license holders.

Secondly, even though the new spectrum can be used license-free, usage of channels in this space must still be registered against a central database and coordinated to avoid interference. How this will play out is not clear, but presumably Wi-Fi systems will call in to a regional database and use that to safely and automatically coordinate their available channel-set to avoid licensees' spectrum.

Read all about it

The entire FCC document can be found at https://docs.fcc.gov/public/attachments/DOC-363490A1.pdf

Broadcom has produced a graphic showing how much more RF spectrum is made available by this new notice.

New Zealand's Government Has No Immediate Plans To Follow Suit

In New Zealand the airwaves are regulated by Radio Spectrum Management (RSM), a department of the Ministry of Business, Innovation and Employment (MBIE).

In response to an Official Information Act request from April 2020 asking whether RSM will follow the FCC's lead regarding making the 6GHz spectrum available for unlicensed use, an MBIE representative has made the following statement: 

We have no immediate plans around WiFi 6e  (i.e. WiFi @ 6GHz). Spectrum
above 5925 MHz is currently allocated for bidirectional fixed link use in
NZ. We also have C-band satellite uplink licensed across different parts
of the 6 GHz band.  Fixed and satellite services must coordinate on a
first-come-first-serve basis.

At this stage we don’t have a clear sense of whether the technical
mitigations proposed to allow 6e (low power indoor use and automated
frequency coordination (AFC)) will be sufficient to manage the
interference concerns of the incumbents.  In particular AFC is still
unproven technology in this scenario.  We are watching closely to see
whether a significant device eco-system is evolving and when the large
consumer nations (USA, China, Europe) move.  Once it becomes clear that 6e
is really going to happen elsewhere then we will likely run a domestic
consultation before making a decision.


Kind regards

Ministry of Business, Innovation and Employment

This means that MBIE will be taking a wait and see approach, and in the best case scenario it will be years before we can benefit from Wi-Fi 6E in New Zealand, if at all.