72 comments

[ 3.2 ms ] story [ 197 ms ] thread
4G->5G is the equivalent to upgrading from gigabit to 10 gigabit ethernet yet everyone is treating it like some kind of insane technology.

I have yet to see what exactly the hype is about.

I mostly agree but I want to nitpick.

One of the areas I've heard should be improving with 5G is latency. On 4G we're talking O(10ms)? which on 5G, so says the marketing, should be O(1ms). If this is true, it will make a noticeable impact on the responsiveness of web driven apps (aka almost all apps) as well as video/audio chat liveness. Was this oversold to me (highly probable)?

Latency is the sum of its parts. It doesn't matter if the latency from the cell tower to your phone is 1ms or 10ms if the rest of the trip takes 100ms. It's nice to keep some of the latency down, but it's not going to magically enable 1ms transatlantic communication.
100ms is generally referred to as instantaneous in regards to user experience.

For example: A 10ms video refresh rate would be 100fps.. the average movie is 24fps.

That depends on what the user did, in video games a 100ms delay would be terrible, however in that situation the user is inputing highly timed inputs and is focused on the output.

But in general for web browsing, 100ms would be unnoticeable yeah.

Reducing latency between the tower and your phone by 9ms won't make a big difference to the overall experience of web apps. But I think real world 4G latency is more like 40-50ms?

In addition to mobile network latency you have to add a few more things - depending on how far you are from the data centre serving the web app you're looking at ~20ms-300ms additional network latency, plus however long the server takes to process your request, regardless of 4G or 5G. Check out https://www.cloudping.info/ for some ping times to AWS datacentres around the world

FYI O(10ms) means anything from 10-99ms.
Latency is an active research area and a driver for updating wireless networks. You won't see the results in the current 5G roll outs, which concentrate on eMBB, but the research is feeding into the future URLLC (Ultra-Reliable Low-Latency Communications), which is a 5G protocol aimed at machine-to-machine communications.

Beyond URLLC are protocols aimed at replacing wires in "serious" industrial control systems: things like real time control of grid switchgear and heavy machinery, so you might not see it on your phone. Latencies of the order of microseconds have been demonstrated in recent years and the stretch goal is about 200ns.

> O(10ms)? […] so says the marketing

https://i.imgur.com/Dg4Jit5.png

That's my RTT ping to 8.8.8.8 as I travelled south on CalTrain from SF last week, on T~mobile's network.

Now, this is on an old phone that is only capable of HSPA+. However, the actual performance on the whole is still nowhere near any theoretical limits, or even limits of HSPA+.

Just that: faster speeds, except it'll be far spottier than a 1Gib -> 10Gib ethernet upgrade due to a collection of issues that will make it hard to get full 5G speeds on a regular basis.

I'd take 4G LTE as implemented in much of urban Japan over hypothetical 5G any day. I witnessed nigh-instant web page load times with my phone reporting zero bars in the Tokyo subway once. Over a period of weeks, I can't recall having anything less than a "pretty darn good" level of service, no matter what the signal was reported as. In the US, I find that two bars is slow and sketchy, while one bar (still @ 4G LTE reported service!) is often a "forget about it" level of service. I.e. I'd take service consistency over theoretical-max-speed any time.

On that basis, I suspect the signal consistency challenges 5G faces will make it a very frustrating service for many real-world users.

It sounds like you're mostly frustrated with the fact that the bars on your phone are lying to you, which is true but sorta separate.
No, the bars are peripheral – it's that I want that phenomenal quality of service I experienced while traveling. Bars notwithstanding, I simply always had good service. I didn't have to care about the bars. I'd rather have that kind of ubiquitous and reliable 4G LTE than a few areas of hyper-fast yet finicky 5G.
The indicator "bars" usually show RSSI which doesn't necessarily map to throughput. Or rather, it's closer to a normalized metric for the (mobile+network infra)'s capability, but not an absolute metric like a speedometer.
Any measurement tool for iOS? I guess we cannot use Speedtest day the day, just have an idea ...

Also is signal strength important as some 4g router do report it but they are bigger

Hmmm, capacity for 10 full duplex HD video streams sometimes, or full duplex 1 HD video all the time...

One would like to think that degradation always results in 3G speeds, as the absolute floor of service quality.

Depends of whether to want to stockpile and binge from local device storage (tape delay, podcast style), or live stream current events as them happen, while on the move.

Personally, for me, this just means I’d hit my data cap faster, probably dumping my allowance in 3 days, instead of 30.

On prepaid, this potentially means everything gets ten times more expensive.

Unlimited data usually comes with abusive contract agreements, credit checks, obnoxious customer service, devalued credit scores for late monthly payments, and oh yeah pushy sales people that act like total fucking jerks at retail shops.

Actually, why don’t I just throw all my internet toys in the garbage? Really. Why not?

If you just mean that major Telecom companies are hyping this in their advertisements, well duh. But for technical folks, I've only heard them raving about the techniques being used being insane, and they indeed seem pretty fantastic to me. That this is only (!) increasing bandwidth and lowering latency by an order of magnitude is true, but less important.

Similar things can be said about the insane techniques that have been used to increase processor power each order of magnitude.

People seem to have strong opinion that this is the case even though they are most likely wrong.

Just some changes:

* You will have your own 5G home router micro cells. Factories will have their own 5G networks in unallocate bandwidth. Like Wi-fi but lower latency and better services.

* High quality low latency streaming means that gaming consoles will disappear from homes. You can stream games either from servers or from edge servers. You can have "tactile internet" with 5G latency. Enough to stream games.

* Very low power gadgets in your home will use 5G.

Of course, once you leave your home....
>You can stream games either from servers or from edge servers

Can't wait for the rise of GaaS (gaming as a service) and the associated monthly subscription fees.

Why? I have wifi. It's low enough latency. What better services would I have using 5g vs WiFi as a layer 2?

Nothing about 5g is _unique_ to 5g except that it's controlled by telcos.

5G is less controlled by telcos than 4G.

You can run local networks without buying it from telcos.

But I can already do that with WiFi? I'm really not seeing the advantage unless somehow there's going to be a lot of 5G gear in unlicensed bands that's somehow mystically better than WiFi.
That is gross over-simplification IMHO.
This is a great interview! I have to say, learning about the requirement for multiple antenna modules in a smartphone, each with impressive phased arrays, the massive investment that's going to be required in microcells, and the myriad of other engineering issues to be overcome, properly put in context how ludicrous AT&T's badging of 4G technologies as 5Ge is.

https://arstechnica.com/information-technology/2019/01/att-d...

What I don't understand is if we get faster speeds, will we still see data buckets stay the same? I mean what's the point of a faster network if you're still capped at 2,5,10GB. And will qualcomm be the only game in town thanks to patents? My iPhone Xs feels like a bicycle in terms of data speed, while my Galaxy S8 is 2-3 times faster.
The point is to service more users per cell at the same effective data rate. Premium plans may enjoy prioritization and a larger bandwidth allocation similar to how cable ISPs have segmented their service tiers.
> I mean what's the point of a faster network if you're still capped at 2,5,10GB.

For those (a large majority, I suspect) whose actual data usage is determine by factors that have little to do with the network, the point of a faster network is less time waiting.

For example, I'm going to take about the same number of photos on my phone if I'm on a fast network as I will if I'm on a slow network. The fast network, though, will mean less waiting to transfer the photos to my desktop for editing or for sharing.

A good way to see this is to go the other way. Suppose you have a 10 GB cap. Would you object if your network were slowed down to dial-up modem speed (56 kb/sec)? That's more than enough to transfer 10 GB/month, so what's the point of anything faster if you have a 10 GB cap?

I get what you're saying, but the faster your connection speed is the easier it is to inadvertently use more data. With my carrier if you hit the monthly limit they throttle you to 128Kbps, which is basically unusable. However, they offer a plan that's capped to 3Mbps all the time, which is fast enough for virtually everything I need and makes it much harder to hit the monthly data cap.

I actually prefer always getting 3Mbps any time I want to use my phone compared to the more expensive plan which might get 30-50Mbps... until you hit your cap and you're throttled to 128Kbps. (But, as you'd imagine, if I'm A-OK with 3Mbps, I have a hard time seeing what benefit 5G brings me.)

You might start off taking the same number of photos, but as you can upload them much faster, you will start taking a lot more photos and the photos you take will be a lot larger.

The "if you build it, they will come" model applies to the creation and administration of most any constrained shared resource, whether that be roads or network bandwidth.

>I mean what's the point of a faster network if you're still capped at 2,5,10GB

Bandwidth isn't just increasing to meet future demand but to ease existing demand. I recall a conversation I had with an industry exec a few years back, they told me that bandwidth demand roughly doubled every year while all they could do to keep up was increase cell density, which isn't always viable or cheap.

I think there's way too much marketing on 5G like it's going to revolutionize telecoms overnight. It's going to ease some of the strain on the networks as its rolled out over the next few years, and hopefully provide better QoS eventually.

Great interview. At the start Dave kind of conflates 5G with millimeter wave 5G.

The big difference between LTE networks and 5G networks is not the frequency ranges used, low band 5G is perfectly feasible. The big difference is the linear increase in information capacity per antenna in MIMO (multiple in multiple out, many send many receive antenna) verses the logarithmic increase per antenna with single antenna to single antenna links. (while power his held constant)

If you want to learn more this is a great intro to channel capacity with MIMO, http://complextoreal.com/wp-content/uploads/2013/01/mimo.pdf

Just to be clear, MIMO is not a new feature in 5G. LTE has MIMO. Old Wi-Fi routers from 10 years ago had MIMO.

5G is upping the number of antennas per base station. Theoretically, this allows a linear increase in capacity, but linear scaling is not always achievable in practice.

The advantage of the higher frequency bands is the larger bandwidths available there. Conventional cellular bands typically have 5, 10, or 20 MHz bandwidth, sometimes 100 MHz. 5G's millimeter-wave bands support bandwidths up to 400 MHz. Information rate scales linearly with bandwidth. That said, there are many practical challenges to operating in the millimeter wave bands that might limit real-world performance.

>MIMO is not a new feature in 5G

Or Specifically Massive-MIMO, which is as you said upping the Antennas per base Station. LTE Massive MIMO actually already works in 3GPP Rel 13 for FDD, and Rel 7/ 8 for TDD. However 5G were specially designed with M-MIMO in mind, which brings higher efficiency than using in on LTE.

If you've ever seriously played with wifi tech you very well know the higher the frequency the less penetration you get. In an indoor environment the difference between 800Mhz and 2.7Ghz can be astounding. 5G at 90Ghz is only going to work at certain line of sight distances. If you ever hear anyone talking about terahertz speeds you can almost be guaranteed that would be happening with very specifically located devices or within the confines of an integrated circuit.
In my city, they are dropping poles with 5G radios all over the place, as close as every 150-300 yards. It’s a land rush as the city cannot do anything to stop them, the poles get dropped in all sorts of awkward places. My understanding is that repeaters will be mounted on streetlights as well.

Those radios aren’t for phones, they are for fixed wireless with antennas attached to your home. 5G is the cable killer, and eventually the WiFi killer.

What city is this and why can't the city do anything to stop them?
Because of federal preemption. Thankfully NIMBYs dont have the power to block communications improvements.
Albany, NY.

The FCC is choosing to let the telecoms do whatever. It’s wasteful as they do things like block crosswalks with additional poles (to avoid renting from the electric utility) and place the poles in less attractive spots to reduce cost.

You still need to run fiber to the radios, and at a couple hundred yards apart, you're going to be running fiber down almost every single street. If the goal is fixed installation, you could have just ran it a few feet more directly to the house.

>and eventually the WiFi killer.

How is this going to work? The radios you're talking about are very high frequency, so they require line of site.

Don't underestimate the cost difference between running a fibre down a street versus running it into every house.
Sure, but running it down the street is comparatively a much bigger cost. And I'm not sure the cost of maintaining a radio on every street corner, individual antennas on every house, and maintaining a clear line of site to every individual antenna is going to be cheaper than burying a few extra feet of fiber in the long run.

Plus running fiber from the street to the house means the residents don't have to worry about heavy rain, trees in their neighbor's yard, or buses impacting their internet service.

> Sure, but running it down the street is comparatively a much bigger cost.

The branch factor kills you. I had fiber installed at my house. It took half a day to run it down the main road to the subdivision another half a day to run it to the pole next to my house. Another half a day to trench it under my driveway and install the CPE. If they just ran it to the subdivision and put up a 5G base station, they could serve a couple of hundred users. It would cost far more time to actually pull the fiber to each of those same couple of hundred users.

One tower for a 200 house subdivision isn't going to work.

If you want enough bandwidth to replace fiber to the premises, you're going to use millimeter wave (if you're talking one tower per neighborhood you're already talking about mm wave), so you'd need completely unobstructed line of site to every single house. The pole would need to be high enough that tower would he a more accurate description, you'd have to keep removing trees and cutting branches to maintain that clear line of site, and rain would cause problems.

I've set up microwave transmitters before for a similar use case. At these frequencies it's going to be much harder.

My guess is that they're going to have to run fiber to the end of the hypothetical subdivision anyway and set up multiple towers throughout.

Also you don't need to actually run fiber to every house to get competitive speeds to 5G. And you can run fiber without burying it. I don't think 5G towers in every suburban neighborhood is going to be a viable replacement for cable.

Surely they'd always install the radios above bus/lorry height? Even in low sprawling areas of the U.S. there's sufficient building height available for that?
Above bus height at the tower doesn't mean that every section of the sight lines between the tower and each house is above bus height.
I specifically meant when it comes to mounting it on the office/house endpoint. Everything else in between should have another flexibility when it comes to choosing the location.
(comment deleted)
Yes, both ends the tower and endpoint can be mounted higher than a bus, but because most building are single story, they can't be mounted that much higher.

So a small increases in elevation in an area between the 2 points means that the LOS can still be crossed by a bus.

On my block, they installed about 4 poles. The fiber splicing/install work took about 3 hours. Those poles will serve something like 150 households someday. This is a mid-density urban block with 1-4 family buildings.

It took Verizon two weeks to install external FIOS CPE equipment in my brothers’ subdivision, and probably yielded fewer homes.

That’s a lot of capital cost, and these telcos are looking for margins closer to cellular. They get that by eliminating these costs and getting better regulatory terms.

You're comparing a subdivision to an urban block, and you're not including time and cost to clear LOS obstacles. It's also very unlikely that 4 small poles will have direct line of site to 150 households outside of high density apartment buildings where running fiber directly to the building is already easy.
It's hard for me to understand why anyone is excited about 5G when most carriers aren't running full bandwidth 4G and have significant data caps. Although 5G may be fast in some markets, 5G on the whole just seems so pointless for consumers.
If new bandwidth / more bandwidth means new market entrants / more market entrants, it'll be great!

I am sure that legions of lobbyists, politicians, and businessmen are working diligently as we speak to make sure that doesn't happen, but I want to believe.

>If new bandwidth / more bandwidth means new market entrants / more market entrants, it'll be great!

I doubt it. No one is going to build another network of cell towers just because new bandwidth is available

If they can compete with cable internet they sure will.
Notwithstanding this supposed lobbying, we have four nationwide 4G networks—more competition than we have in putatively lobbying free markets like social media, search engines, and cell phone and tablet operating systems. The biggest roadblock to 5G is not lobbyists, but rather NIMBYs complaining about how small cells will clutter up the neighborhood.
To be fair, a little effort in aesthetics goes a long way.
...and one cable internet provider at nearly any given location.
I'm more excited about the low power aspects than the high speeds.
I think the importance of 5G is not only tied to the consumer wanting a faster internet. It is tied to potential advances in remote surgeries, automated cars, Amazon drone packages, VR for medical purposes, potential improvements in security, cuts in operational cost by the carriers, etc.

It should be seeing similarly to advances in computer power throughout time, to some it makes little difference depending on the time horizon they are viewing, to others it allowed for machine learning to be used by a wider audience for example.

> potential advances in remote surgeries

Whoops, truck drove by, there goes the signal!

This is the difference between the ceo and the engineer, the ceo sees potential, the engineer sees problems.

They're both needed.

Hah, this is my exact experience! Anytime someone's painting the big picture, I'm running it through my head to see how feasible it is, what may go wrong, etc.

While relevant, I find that predisposition limiting...

very low latency sounds nice. Especially for voice and video chat.
My understanding is that 5g is range limited, so those of us who are in non-urban areas are not going to see any benefit, and are likely to see reductions in service as 4g is de-emphasized (judging by Verizon in this area).
Move to an urban area? Non-urban areas are inherently expensive to serve with infrastructure, and as we become ever more infrastructure dependent, they become an inherently less efficient and desirable proposition.
Living in USA Moutain Time Zone, "move to an urban area" seems a very weird approach to address 5G range limits.

Broadband wireless tech has generally helped to address last-mile connection with less infrastructure. But it is very often all or nothing; radio waves don't punch through rocky mountains. Covergage maps are theoretical at best, and won't feel very relevant when you have to go into your kid's bedroom and hold your phone out the window in order to place a call.

Verizon is effectively a monopoly where we live, as its longer-wavelength coverage seems more forgiving of the canyon topography here. They continue to invest in infrastructure upgrades, but I don't know what aspects of 5G will be relevant in actual use in the near term.

In this day and age where a single page can be tens of MBs, high speeds can be useful even subject to data caps that prevent sustained downloading st those speeds. Also, data caps grew dramatically when 4G made more bandwidth available, and the same will happen for 5G. Verizon’s home 5G service has no data cap.
Faster internet is ALWAYS welcome. On wifi, on cell network, always.
If we stop think 5G as a "G" in Generation, and starting thinking it as improved LTE, an evolution rather than what many are trying to spin as revolution. From the point of average consumer is exactly what it is, improved Internet. 2G was about Voice, 3G was Voice + Data, 4G is all about Data. 5G is much improved 4G. Making Data Cheaper.

>>when most carriers aren't running full bandwidth 4G and have significant data

Time and Time again I have seen this everywhere in forums. In Reality is not like Telcos, MNO or Carriers what ever you like to call it, tries to limit your Data Cap. MNO are fundamentally limited by their capacity. There is roughly 10 to 20% YoY increase ( Depending on Nations ) in Mobile Data usage. There is a long tail of users just coming in from 3G to LTE and start enjoying the Mobile Internet. Since their Infrastructure don't improve their capacity 10%+ per year, that is why you have Data Caps and why your Mobile Network isn't getting faster. ( And may in fact be getting slower ).

MNO reframing the 3G spectrum to LTE to help lessen the load, users upgrade to latest Smartphone with better features set to improve network efficiency usage, The faster you finish, the less time you are on the network. Another reason why MNO wants you upgrade to the latest and greatest Smartphone

Once 5G reaches the current stage of 4G, you are likely looking at ~10 to 20x Capacity improvement. ( This is accounting for 128 x 128 Massive MIMO, Small Cell etc ) In theory this gives plenty of room for different MNO to compete, and should lower the price. In the long term, 5G should lower the cost per MB for everybody. That is assuming all else being equal, wages, lease, equipment, etc. In realty those prices are rising as well.

But judging at the current climate we are at least 4 - 5 years away that happening. One being Cell Site infrastructure, despite what AT&T or Verizon wants you to believe, they are far from optimal. It will likely take another year of testing and tuning before widely deployed ( Or to be more precise, Switched on. Since most of the current Cell deployed are software upgradable to support 5G ). Second being 5G Smartphone will be expensive. Everything from Silicon to the Antenna are much more complicated. And as we know technology aren't dropping prices like they are used to. Third is Smartphone replacement cycle are now into 4 years. If you buy an Smartphone in the past 18 months, it wont be until 2022 before you might get a new one. And 5G Smartphone might still be expensive then, which causes delay it for another cycle.

Every 5 years or so, there is a rally to make millimeter-wave communications a thing. Every time it fails. Maybe there's enough money and effort his time around to make it happen, but I wouldn't bet on it myself.