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xal1124 t1_j1zm2il wrote

Reply to comment by ersatzgiraffe in A new novel antenna bringing us closer to 6G wireless communications by Vailhem

What is the slight difference between 4G and 5G?

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Jyith t1_j208pld wrote

Literally just different frequencies. Multiple different frequencies from "both ends" and the "middle". We've been utilizing these frequencies for other things previously, but with 5G they've specifically started utilizing them for mobile networks.

The low-band 5G is close to 4G in every aspect - including speeds.

Mid-band 5G offers faster speeds in the hundreds of Mb's but has various downsides, like crappy range and getting blocked by thick walls etc.

High-band 5G or "the gigabit internet" is like mid-band on crack. Extremely high speeds, but absolutely lousy range and penetration. The idea on the implementation is more like high-range WiFi than an actual cellular network: antennas on top of every house in dense urban areas.

6G would likely utilize same frequencies as high-band 5G and then up from there, which makes one question how they are going to make it viable. The whole article seems to me like an excerpt from some 10-year-old's sci-fi book, with terms like "space-time coding" and "sideband-free metasurface antenna", but I'm not an expert so I'm not going beyond anything but healthy skepticism.

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xal1124 t1_j20bk72 wrote

5G only adds different frequencies?

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Jyith t1_j20d6kb wrote

Well, it's a simplification, but yes. All different generations are just different frequencies. And the borders between them are mostly arbitrary.

The G after the number just means "generation", by the way (5G being the 5th generation of telecommunication networks).

There are international groups that declare the "official" criteria for every generation, and seems that usually they are just expansions on the frequencies of the previous generation - with some speed, latency, bandwidth and coverage requirements tacked on top.

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xal1124 t1_j20f02z wrote

Why are there huge changes to the core network and to the physical layer between 4G and 5G then? Aside from some changes to support millimeter wave, the difference should be minimal, if you are correct.

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Jyith t1_j20iiws wrote

Because of the frequency? Obviously, if the range of even the mid-band 5G is a fraction of 4G, you need to build a lot more cell towers. And you know where that 4G, 5G and future 6G data travels the majority of the time? In the same fiber-optic cables as everything else. Operators need to build the cables all the way up to the 5G towers. And as far as I'm aware, the 5G towers don't generally communicate with each other.

Also, the core network needs to be fast enough to accommodate increased traffic. More undersea cables between continents, more underground cables within countries.

So no, the difference in infrastructure is obviously not minimal.

There are probably tons more nuances. Like I said, I'm not an expert.

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nicuramar t1_j21l7nt wrote

No. There are other changes as well.

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xal1124 t1_j21m983 wrote

It was more rhetorical. But I think marketing has really created jaded consumers.

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nicuramar t1_j21l4be wrote

> Literally just different frequencies.

There are many more changes than that. But it’s true that 5G NR uses the same overall modulation scheme as LTE.

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Jyith t1_j21mgv7 wrote

Yes, changes that were required due to the different frequencies mainly.

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nicuramar t1_j21mrul wrote

No, in general 5G NR is an evolution of LTE, with improvements in many areas (such as latency and flexibility). Most are just too technical to make sense in marketing.

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Jyith t1_j21n6hu wrote

I said mainly, not completely.

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xal1124 t1_j21ndhz wrote

The changes were required for decreased latency, less time required on the network for power saving, bandwidth agility to support less capable power-conscious devices, and increased performance by making more efficient use of the available bandwidth. Many improvements were made to support higher frequencies of course, and the ability for the core network to effectively load-balance is essential for supporting the throughput requirements of the higher bandwidths.

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ersatzgiraffe t1_j1zuz58 wrote

In my experience a minor speed improvement for a major range reduction. Speed was already good enough.

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xal1124 t1_j1zvuik wrote

Yeah, LTE speed is very good, but it’s not easily expandable. To get very high speeds you have to connect to several towers or be very close to one with a high bandwidth. And, with increased bandwidth, higher resolution video, and more downloads and uploads will be supported. There are new applications that would saturate LTE infrastructure. Also, 5G is used for home internet service, which requires much more data volume than mobile devices do.

Edit: Additionally, 5G deployed in current LTE bands will only show a minor speed improvement, especially when only connected to one cell. It’s still confined to the limits of physics.

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desertsardine t1_j1zydsi wrote

Latency, throughput etc… actually loads of improvements but the major benefits are to enterprises not consumers at the moment

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xal1124 t1_j1zz928 wrote

I wouldn’t really consider the difference to be slight. That said, it’s easy to get lost in the hype, which can easily overshadow the important parts.

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