Star Date: 20260413.
For those of you who remember the launch of 4G, I was in the Ericsson office in Shin-Yokohama on the day we switched it on, and the traffic went up, and up, and up, and up – it was clear that this was a winning technology.
Much in the same way that when GSM came out, that everyone thought “great, I don’t have to carry around a car battery with me any more just to make calls (early 1G days, and those things were enormous.)
(Didn’t it just scream “class”, almost as great as the inventor, Martin Cooper).
2G had shrunken everything into something that fitted neatly into your pocket – you didn’t have to be a bodybuilder to carry it around anymore – and those networks are STILL going, some 30 years later. 3G may have been shut down, but 2G is still too versatile, you can use tiny bits of spectrum to fit a few channels into if you have room. And it goes quite a long way.
3G by contrast was a bit more of the wayward cousin. It was a brilliant technology however, 3G is the technology that I could say I am an expert in – I was trained personally by the Bell Labs engineers who invented the underlying CDMA technology – and their training materials were SO good, they could be given to anyone and they’d learn how it works. Even Henry the Janitor could pick it up. I’ve sifted through many an FCC and 3GPP document and am always impressed by the obvious and immense skill of those who crafted them. As a delegate to the O-RAN Alliance, I saw some of how the sausages got made first hand – excruciating, political, and ultimately quite rewarding as I worked in with one of the most intense working groups – the data model. Anyway, I’m finally now as good with 4G, (but I didn’t have the Zen masters teaching me this time) but because I had so much training and was at the coal face as a fresh engineer so much with 3G, I’ve written entire mobility strategies for major operators (and even got them right – I checked back 10 years later and they were still in place. ***pats himself on back***) – it was one very out there technology – but it was a major leap where everyone stopped thinking about using phones for talking and using them for data. But 3G was kindof slow, took a while to get the call going, and if you’re an operator, started taking up non-negotiable 5MHz chunks of spectrum. Very valuable spectrum. We needed A) something a bit more flexible, and B) something a lot more efficient. 4G is literally 5 times more efficient (and by efficient, I can fit over 5 times the amount of data down that same 5MHz block of spectrum than I could with 3G – so yeah, miles more efficient).
What do you expect though – much newer technology.
For those who like tidy tables:
| Generation | Technology | Typical Spectral Efficiency | Notes |
| 2G (1990-2000) | GSM / EDGE | ~0.05–0.1 bps/Hz | Very low efficiency; optimized for voice |
| 2G (1995-2005) | CDMA | ||
| 3G (2000-2010) | EVDO | ||
| 3G (2000-2015) | UMTS / HSPA+ | ~0.5–1.5 bps/Hz | Better data support, limited by interference |
| 4G (2010-now) | LTE / LTE-Advanced | ~2.5–5 bps/Hz | Efficient multi-user access/high data rates |
| 5G | 5G NR (Sub-6GHz) | ~10–15 bps/Hz (Sub-6 GHz) | Highest efficiency; optimized for dense data demand |
And yes you guessed it – 5G is in theory 3 times as efficient as 4G. Note for non techies – “Typical Spectral Efficiency” just means how much data can we push through the same channel. Think of it as sucking data through a straw. Straw size doesn’t change but the amount of data you can suck through it keeps going up as the tech gets better.
But 5G hasn’t been the runaway success that 4G has. Its had a very unusual start to life as the original 5G wasn’t really 5G 5G, it was sortof a 5G service that piggybacked on top of a 4G service – all the important stuff was done by 4G, call control etc, and 5G was the cherry on top. 5G Standalone is what we really need as this quietly dispenses with the 4G stuff it needed to support it, and its 5G from radio to core – all the way. The business. It consumes WAY more power (think that Massive MiMo ( really nifty tech that essentially means more data straws for you, and the next guy, and all the guys around – without using more precious spectrum. TL/DR – very clever tech. But it doesn’t come free) It was stuck at 3.5GHz as the lowest frequency for some time, although 5G 700MHz is starting to come out – and this may be the “killer app” for reasons I can describe below – in practice this means more base stations = more sales = more money for the vendors…. Wait a second. You need backhaul to those sites. That means fibre. Running fibre is one of the more expensive pastimes for an operator. And we’re still only just starting to hit the limits of 4G in some pockets, and with the 3G shutdown and the refarm mean now 4G can be deployed and buy the operators more time for little to no money. Mid band 5G was the answer no one quite needed yet. Low band 5G was the answer every man and his dog would have loved – more coverage, better efficiency, you didn’t need to build more pesky sites which are uber expensive – ticks in lots of boxes.
Ok, so how this might be the “killer app” for the technology. If I can be a bit controversial and say that 4G never seems to go the same distance as 3G. (you may pelt me with insults in the comments if you wish), there are a lot of holes that have opened up. Read Almost half of Britain cannot browse internet because of poor mobile signal from the Telegraph. Ouch. I would imagine the regulator won’t be too impressed if and when calls can’t be made during emergencies. You might have 2G but that could get bogged down pretty quickly if the other networks are roaming onto the only available channels for emergency calling. Plus, it’s just not great for business – customers don’t like paying for things that disappear. Hence the whole low band is the killer app comment.
Handy table to compare approximate ranges at different frequencies, all other things being equal:
| Frequency band | Typical max reliable range (urban/suburban/rural) |
| 3.5 GHz (band n78) | Urban: ~400–800 m; Suburban: ~1.5–2.5 km; Rural: ~3–4 km |
| 2100 MHz (band 1) | Urban: ~800 m – 1.5 km; Suburban: ~2–3.5 km; Rural: ~5–7 km |
| 850 MHz (band 5/18/19) | Urban: ~1.2–2 km; Suburban: ~4–7 km; Rural: ~10–15 km |
| 700 MHz | |
| 450 MHz (band 31 / legacy bands) | Urban: ~2–3 km; Suburban: ~8–12 km; Rural: ~15–25+ km |
We leave 450MHz in only for reference, and to give a boost to our mates down at the 450MHz Alliance. One love. (there’s about 70 or so major companies, so if such a thing could be, then maybe it should be…). I was in a discussion with Ofcom last year about spectrum management and how this could be done better in the 3.8-4.2GHz band (private networks/industrial public access band) and I mentioned “what about 450MHz” and was scowled at. So maybe not. It was a bit off topic though.
So this might get 5G a bit more recognised. Now, what about 6G. The “G Cycle” comes in 10 year blocks, meaning that by rights, we’re about halfway through the 5G cycle now before 6G is due out. Personally, I think 6G may be the hit that 4G was. And I think a lot of it will be about fixing the issues of 5G. Forget all the AI hype – if you don’t have signal AI won’t save you. Or maybe it might, there could be something that we have not thought of that it whips out and says “and what about this….” But I kind of doubt that will happen. If 6G focuses on fixing the main 5G issues – it will be a winner. What we need to fix:
Power and Environmental Concerns
- The massive MIMO power problem: 5G base stations can consume 3-4x more power than 4G. With energy costs soaring and sustainability targets, 6G needs to deliver performance without the electricity bill shock
- Device battery drain: 5G modems are power-hungry. Your phone hunting for 5G signal kills battery life faster than streaming video
- Cooling requirements: Those massive base station MIMO arrays need active cooling in many climates – more complexity, more failures, more OPEX
Coverage and Deployment Economics
- The fibre trap: Every 5G small cell needs fibre backhaul. In dense urban areas, you might need sites every 200-300m. The civil works costs are killing business cases
- Indoor penetration: 3.5GHz and mmWave struggle with buildings. We’re installing more indoor systems than ever, but who pays?
- Rural coverage gaps: The promise of “5G everywhere” hit the wall of physics and economics. More low-band spectrum helps but on its own isn’t enough.
The Business Case Problem
- ROI timeline: Operators spent billions on 5G licenses and infrastructure but struggle to charge more for 5G services
- Use case reality check: Where are all those autonomous cars and remote surgeries we were promised? Most “5G applications” work fine on 4G
Sooo, what should 6G look like then
Here’s a few things that have grown a bit long in the tooth and might want to be sent to the top paddock.
- Backwards compatibility. Very noble, but this can hold some of the coolest tech back, plus it adds massively to the development cost. And its pretty piecemeal. Time for a complete refresh. (Fun fact – an Ericsson radio from 2009 (RUS 01) can quite happily handle the latest LTE). Ok, some things may be better if they are backwards compatible (and easy to do), *IF* they bring the TCO/Run&Maintain costs down, but that’s probably where that ends.
- Halfway houses. NSA (Non standalone) 5G ain’t 5G. You need the standalone version. For the non technical people think of this:
A Vauxhall with an engine the size of a small town.
But it’s a Vauxhall.
- Why they did this I don’t know, but I’d probably not go down that path again. NSA radios can be turned into SA radios (mostly) but you need to replace a bunch of other components (core network, and some of the controllers, and if the optical network is slowing you down, look at that too – 5G is very low latency). Nice idea but it may just have been easier to come out with a fully new system from the start.
- Costs. LOWER THEM. 5G is a really expensive technology to run.
- Deployment friendly. No one likes hideous new poles in their neighbourhood, so if you think about new modes of deployment (small cells in buildings, low power cells that can be deployed in public buildings etc to reduce the visual impact, and then for the big rural cells using aerostats etc – think outside the box
- Autonomous. We’re gonna need more of them (base stations), just like 5G said we would, but as much as all the new fiber runs blew up the business case, management of all these cells is a sticky problem as well. From the ground up build CSON (the cleverest of clever controllers that keeps your network running well) into the specification. Don’t be afraid to unlock parameters like power levels etc. Most engineers would suggest I need to be carted away to the nearest dungeon for this insolence, but trust me – this is where the networks are going. I should know, I have a working prototype of an engine that does just this. Operators don’t like this idea. But hey, Joe punter doesn’t like coverage holes.
So – as well as introducing a whole bevvy of new tech, the point of this article is (hopefully) to point out that 6G is a good opportunity to fundamentally re-think the ways we’ve done things and assumed they should be done – back to first principles and say “what we did 30 years ago needs a major overhaul”. This could be that opportunity.
Thank you for reading.