I watched the Super Bowl, like millions of other viewers. Extreme’s Wi-Fi set another record for the largest connected event and an astounding 70%+ of the fans connected over Wi-Fi. Meanwhile, you’d have thought from the Verizon and T-Mobile advertisements that we are on the verge of 5G taking over the world. My guess is however, at this early stage, it is unlikely much meaningful traffic left the Super Bowl over 5G.
As an overly-avid user addicted to my iPhone 11, it is great to see 5G becoming a reality for my next iPhone. However, 5G is different in many respects to previous “G” versions of cellular technology, and each carrier in the US is taking a somewhat different approach. Further, far too many pundits, in the search for eyeballs, are writing confusing articles making silly claims about 5G displacing a meaningful percentage of Wi-Fi, including Wi-Fi 6 and 6E. Hogwash is what my great grandfather would have said. BS – by the way sonny – is what my dad might have said.
Cellular technologies and new-fangled 5G compared
First, unlike very early cellular technologies, 5G is evolving with one marketing name that is generally covering three very different radio frequency bands. Think of these as the vanilla, chocolate, and strawberry bands, respectively covering the 600MHz-700MHz lower bands, the 2.4 up to 3.5GHz middle / sub-6GHz bands, and the 24, 28 or 39 GHz upper bands. These bands are so different that the user (or machine) experience also differs in terms of range from the nearest cell tower, peak speeds, and ultimately availability of service. The difference in frequencies between the highest and the lowest bands is 65 to 1.
Why does this matter?
The distance radio waves travel is proportional to how “loud” they are, that is, the transmit power, and also the frequency, based upon a 1/f ratio. So, a 600MHz (0.6GHz) radio wave travels four times the distance of a 2.4GHz radio wave, and six times the distance of a 3.6GHz signal or 65 times farther than a 39GHz signal if the “loudness” of each is equivalent. Furthermore, lower frequency signals bend around objects, over hills, and tend to penetrate buildings, go through trees, and travel through the air relatively well. By contrast, a 39GHz so-called millimeter wave frequency behaves a lot more like a concentrated flashlight beam. It doesn’t bend around buildings well, nor penetrate walls, and is more easily absorbed by the atmosphere. However, if you are within the beam – you are golden.
The peak speed that can be achieved is also related to the frequency. The low band has nice peak speed, say in the 400 Mbps range. Mid-band has much better, say in the 1Gbps range. So, if you are in a less dense area and want some real speed but more importantly, great coverage – than vanilla is going to be great for you. If you are in the burbs or the edge of an urban area – chocolate – the mid-band is going to be, as in life, your favorite flavor. If you are the millennial in Manhattan with a Samsung 5G strawberry capable phone or a business with high throughput, low latency business requirements – then the strawberry high band might be ideal for you.
5G and Wi-Fi
How do these 5G flavors boil down when we compare the very different offerings of the 5G marketing goop of the four (soon to be three) major wireless carriers in the US to what can be done with Wi-Fi 6, and in the not-to-distant future, 6E? Like many great questions in life, the answer comes down to “it depends”. OK –depends on what? In general, Wi-Fi 6 and 6E are capable of peak speeds that are superior to what is practical for 5G. But, this depends upon your local carrier. Local carrier? Said differently – the company you work for, or the Wi-Fi provided by the public venue you are connecting to, or your home Wi-Fi AP is your local Wi-Fi carrier so to speak. If they install Wi-Fi at good density and install Wi-Fi 6, or in the future 6E, and if you have a device that can connect to Wi-Fi-6 (like all new cellphones, tablets, and laptops) – wow, you will be smoking. Conversely, if you are in a building with ancient Wi-Fi, but your cellular carrier has great 5G coverage in the 600 MHz or 2.X GHz band – you might have a great experience – though possibly far more expensive, with your cellular carrier.
But what about the strawberry bands – those at 24, 28 or 39GHz bands? The peak speed of these links is impressive – up to 3Gbps or so. However, their range is generally limited (often less than a mile from the cell tower), and they generally don’t penetrate buildings particularly well. This is made up for by using incredibly “loud” signals. For urban areas in particular, where a huge percentage of economic activity is transacted, once enough expensive towers have been built out, this can be awesome. However, don’t expect the strawberry 5G to be widely available in the ‘burbs, and certainly not along the rural interstate.
By contrast with the three 5G flavors, in the not-too-distant future we will essentially have two flavors of Wi-Fi: Wi-Fi 6 along with earlier generation Wi-Fi devices and Wi-Fi 6E, coming in 2021 within the 6GHz to 7GHz band (see The 6GHz Wi-Fi SuperFi-Way Coming in 2021). Both varieties of Wi-Fi can be as fast and even faster than 5G. But, their signals aren’t as “loud” – so you don’t want to be too far away from the Wi-Fi AP versus the distance you can be from a cell tower. So why both? Perhaps a highly oversimplified way to think about this is deterministic service. Say what? By deterministic service I mean that with Wi-Fi, you don’t have to pay a monthly fee for mobile connectivity. You, your employer, your university, the owners of the mall, the train station can all have as good a mobile wireless experience as you wish to invest in, and can do so very cost effectively. As the TV ad says, pay for what you want.
By contrast, licensed spectrum, which costs carriers billions of dollars, performs well, but takes huge capital expenditures to make it available along our streets, through the windows into our buildings, along our highways, etc. You know what your cell phone bill is. If you wanted the best that 5G could offer you anywhere in your office building, it would be far more expensive than your “wi-fi bill”. Further, as a business or homeowner, you have no say whatsoever on the cell coverage you get. With Wi-Fi you get what you want to pay for. Said differently – one technology serves one set of needs, the other a different set of needs – even though both are about delivering mobility. So no, life won’t boil down to just a choice between vanilla, chocolate or strawberry. It will also involve gelato, chocolate mint, and salted caramel.
Anything else about 5G?
Of course. Over time, cellular has gone from a pure voice service, to a voice and texting service, to a voice and email service, to a voice and video service to now with 5G, an entirely-new set of services. The myriad of solutions possible with 5G based upon the sophistication of the architecture is broad. It ranges from new IoT applications, to real time gaming, to network slicing services, and so many others. Like any hype cycle, the TV ads and PowerPoints about the future of 5G will be far in advance of the available services. But as certain as the sun rises, we will see all of these promises become reality in the next few years. Anyone for strawberry to go with their salted caramel?