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Bell Labs Researcher Discusses the Realities of 5G

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Re: Bell Labs Researcher Discusses the Realities of 5G

#11

Post by dharma1 »

johnm1019 wrote: post #3
nimish wrote: post #2

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)?

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

Re: Bell Labs Researcher Discusses the Realities of 5G

#12

Post by saidajigumi »

jessriedel wrote: post #8
saidajigumi wrote: post #4

Earlier quoted context omitted.

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 havi…

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.

Re: Bell Labs Researcher Discusses the Realities of 5G

#13

Post by post_break »

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.

Re: Bell Labs Researcher Discusses the Realities of 5G

#14

Post by wyldfire »

jessriedel wrote: post #8
saidajigumi wrote: post #4

Earlier quoted context omitted.

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 havi…

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.

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.

Re: Bell Labs Researcher Discusses the Realities of 5G

#15

Post by lecakes »

saidajigumi wrote: post #4
nimish wrote: post #2

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.

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 havi…

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?

Re: Bell Labs Researcher Discusses the Realities of 5G

#16

Post by superkuh »

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

Re: Bell Labs Researcher Discusses the Realities of 5G

#17

Post by kevin_thibedeau »

post_break wrote: post #13

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.

Re: Bell Labs Researcher Discusses the Realities of 5G

#18

Post by edoo »

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.

Re: Bell Labs Researcher Discusses the Realities of 5G

#19

Post by femto »

johnm1019 wrote: post #3
nimish wrote: post #2

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 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.

Re: Bell Labs Researcher Discusses the Realities of 5G

#20

Post by tzs »

post_break wrote: post #13

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.

> 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?

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