The latest and greatest, WiFi 7, is set to come out as well as all the associated bells and whistles. Geoff Meads looks into what it means for the future of technology.

If there’s one thing we can guarantee in the technology industry, it is that change is constant. In fact, with the advent of AI, there is a lot of chat on industry forums right now about how it’s not change that’s worrying, but the rate of change.

With the IP network being the established communication method for most smart home technology, and wireless being the popular connection choice for a lot of devices, advances in WiFi can be big news. On that subject, WiFi is about to get a big performance boost and the reason is the introduction of WiFi 7.

Why’7′

The more technically minded (and perhaps those that love unnecessarily long naming conventions) might be asking: “Whatever happened to the ‘802.11x’ names for WiFi standards?”

Indeed, most of us learned about 802.11a, g, n and ac as part of our networking education. Well, the WiFi Alliance – the body that looks after such things – decided those names weren’t very consumer-friendly. You can see their point. In fact, the change to a single number naming format happened with the introduction of ‘WiFi 6’. Previous standards were retrospectively renamed at that time too, so 801.11ac became ‘WiFi 5’, 801.11n became ‘WiFi 4’ and so on.

Personally, I think this is a great idea. The only disappointment for me is that the designated UI logos for each standard (designed to be the icon you see on your mobile device when connected) haven’t been deployed by manufacturers. For those upset at the loss of the old convention, the new standard still has an equivalent. WiFi 6 is formally known as ‘802.11ax’ and WiFi 7 as ‘802.11be’.

Thinking about frequencies

For a long time now we’ve been limited to the frequencies we can use for WiFi and similar transmissions. This is for two reasons: firstly, the RF spectrum (in all countries) is already saturated with other transmissions for other uses; secondly, getting the government departments in all countries to agree on a universal frequency band to set aside for a new transmission standard is a huge task!

At the moment, we can use two frequency bands for WiFi – 2.4GHz and 5GHz. The lower 2.4GHz band offers greater penetration through the air, (and construction materials), so greater range. The higher 5Hz band offers more bandwidth (data per second) but less range.

Both are limited in transmission power by local regulation. Each WiFi standard sets a maximum transmission power (in Watts) based on the local territory you are broadcasting in. While frustrating, this is a sensible move as, should larger amounts of power be acceptable, frustrated neighbours could quickly get into a game of ‘the boy with the biggest Access Point wins!’

These bands are called ‘free to air’ bands, meaning you can freely transmit radio signals (like WiFi) in those bands without a licence. That’s if you stay under the power limit of course!

Introducing 6GHz

The WiFi Alliance has recently reached an agreement with certain governments for the use of some additional spectrum for WiFi. We will see this used first with the WiFi 7 standard. Importantly, these territories include some big hitters like the USA, UK, Canada and, yes, Australia! New Zealand is included too, but a noticeably absent entry from the list (at the time of writing) is China.

You can keep up to date with this situation by looking at the WiFi Alliance website – WiFi.org.

This situation is a little more complex than it first appears, as the 6GHz band is split into two parts or ‘subbands’: 5,925HMz to 6,425MHz and 6,425MHz to 7,125MHz. Some countries (including the USA) have agreed to allow both sub-bands to be used, whereas others, including the UK and Australia, have agreed to the use of the lower band and are considering the higher band too. New Zealand has adopted the lower band but is not currently considering the additional higher band, according to the WiFi Alliance.

Wider channels

All RF signals require modulation to transmit data and other content. While amplitude modulation (AM) was fine for simple speech radio, we have long moved on to frequency modulation (FM) for more complex transmissions. Digital modulation (DM), as used in WiFi and other digital transmissions, is a form of FM and, as such, requires a band of frequencies, centred around a single spot frequency, to carry each broadcast. Together, we refer to this band as a “channel” and we fix and measure the width of the channel in MHz.

For the earlier standards, a WiFi channel width was set at 20MHz. Later standards offered an option to double this to 40MHz, allowing more data to be transmitted per second. While this is good news for a single network, it can lead to clashes between networks on adjacent channels when there are more than one network in one physical area (most places)! As there is very limited space in the spectrum (particularly in the 2.4GHz band which only has three non-clashing 20MHz channels) space is at a premium, and stations using 40MHz width could be considered “greedy”.

Fast forward to the present day with newer standards and we find much wider channels can be used. WiFi 5 & 6 brought us 80 & 160MHz channel widths and now WiFi 7 offers channels 320MHz wide.

Are these wider channels a good idea? Well, within the new 6GHz band, where few devices currently operate, this could be very useful. Within the 5GHz band then things are looking a little more congested. So, it may not be quite as useful. That said, the short-range nature of 5GHz transmissions may separate networks enough for this to be a smaller problem than it might be at 2.4 GHz.

What does this all mean to me?

While support for WiFi 7 is small right now (just a few access points and one phone at the time of writing) you can bet the manufacturers of WiFi chipsets are hard at work developing next-generation devices that are WiFi 7 compatible. It’s only a matter of time before the marketers start to go heavy on WiFi 7 in their publicity material and, as always, consumer questions will follow.

There are many more new features to unpack inside WiFi 7, including how it packs data for transmission. These all bring new benefits too. Those topics will have to wait for a future edition of Connected!