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General5G Pin
Dr.Walt Fair, PE21-Dec-18 11:52
professionalDr.Walt Fair, PE21-Dec-18 11:52 
GeneralRe: 5G Pin
Dr.Walt Fair, PE21-Dec-18 12:03
professionalDr.Walt Fair, PE21-Dec-18 12:03 
GeneralRe: 5G Pin
Super Lloyd21-Dec-18 14:27
Super Lloyd21-Dec-18 14:27 
GeneralRe: 5G Pin
kalberts25-Dec-18 11:53
kalberts25-Dec-18 11:53 
GeneralRe: 5G Pin
Super Lloyd25-Dec-18 17:35
Super Lloyd25-Dec-18 17:35 
GeneralRe: 5G Pin
OriginalGriff22-Dec-18 1:06
mveOriginalGriff22-Dec-18 1:06 
GeneralRe: 5G Pin
Gary R. Wheeler22-Dec-18 11:45
Gary R. Wheeler22-Dec-18 11:45 
GeneralRe: 5G Pin
kalberts25-Dec-18 13:48
kalberts25-Dec-18 13:48 
Here in Norway, 99% of those who say "Claude Shannon who? (and that is at least 95% of the public) actually believe in the 5G hype that it will give almost infinte over-the-air capacity. Sustained download speeds in the multi-Gbps range will be the rule, regardless of location. ... This is not particular to Norway; people everywhere seem to think that 5G will do lots of theoretically impossible wonders.

Reality: 4G gets up to 60-70% of the maximum theoretical speed / capacity that Shannon allows. 5G can at the very most utlize a given band 50% better than 4G at the physical level. More efficient protocols reduce bits "wasted" for framing etc, and response times ("ping", for you youngsters) are drastically reduced, thanks to protocol changes. But ten times improved ping does not mean ten times improved sustained throughput.

To increase capacity, we must either reduce cell size, so that each cell has fewer users sharing its capacity, or employ even higher frequencies: The 2 GHz bands are more or less in use now; the next option is in the 5 GHz band. That implicitly gives us smaller cells: 5 GHz signals won't go far. But even with new bands, Shannon limits the maximum throughput for a given channel width and noise level. Believing in Gbps rates is like believing in Santa.

I got my first cellular 20+ years ago when my town (Trondheim, roughly 200,000 inhabitants) had two base stations. Last time I counted, the downtown area, approx 2 by 3 km, had 187 base stations, before 5G and 5 GHz bands. Today, Norway has roughly one base station per 100 inhabitants. With 5G / 5 GHz we might have to double or triple the count, so that each base has 30-50 inhabitants to pay for its installation, maintenance and running. Most areas have double coverage, from both major network vendors, but customers are spread on both. If there was a single network vendor, the required base station count could not be significantly reduced: During peak hours, both networks are close to full utilization.

Is the 5G hype a big lie? In theory: no. In practice: depends on defintion. In a lab setting, totally isolated from all external electromagnetic noise, transmitting and receiving antenna a meter apart, you can easily obtain 60 dB S/N, for a bandwith of 20 bits/Hz. You can allocate 500 MHz analog channel width, and the demo is the sole user of the entire capacity. You can demonstrate 10 Gbps bandwith in that isolated lab setting.

In real life, with all sorts of noise-generating equipment, damping through concrete walls etc. hoping for more than 30 dB S/N is overly optimstic. 20-30 dB is in the realistic range, reducing bandwith to half or a third of the lab setup. The channel allocated is not 500 MHz analog, but 5, 10 or 20 MHz, reducing maximum bandwith by another factor of 25 to 100.

When texting, the average bandwith load is extremely low. Delays in the multiple seconds range really do not matter. Web browsing, with text and gif/jpg images, raises the average load by a couple orders of magnitude; still a hundred users can be active in the cell. Delays of a second doesn't really matter.

Today, users stream real-time data - sound, video - demanding 100 kbps to 1 Mbps or more continuously, maybe for an hour, for each active user within the cell. The base station that easily handled 2000 texters, or 100 web surfers, is saturated by 5 video streamers. Improving bandwith utilization by 50% doesn't really cut it...

In the early 1990s there were 70-80,000 Trondheim inhabitants per cell. It didn't change by very many percent over the day or week. When cell size is reduced to 1/100, one video streamer moving into a cell could alone take up 20% of the cell's capacity. Imagine the Lerkendal soccer field on a regular weekday: Capacity for five video streaming channels may be enough. On a game night, 10-15,000 spectators wait in the rows for the game to start, each with a cellular. How many of them will shorten the wait by streaming some YouTube video to their phone? How many base stations (and how much total analog channel width) will it take to serve them?

Sometimes I turn cynical, saying: Let's get it over with, as soon as possible! Do all you can to stimulate to excessive over-use of mobile frequencies, so force people to realize reality: Moving absolutely all high-bandwidth-demanding services to cellular technologies simply will not work in the future! The radio spectrum is limited, the noise is there. Shannon hasn't been contradicted.

If we abandon broadcasting completely, turning all media access over to "one man, one multi-Mbps channel", we must create a communication structure for it. And that is not "the 5G cellular network will solve all problems"! E.g. we should define 5G as a no-no indoors: At any fixed location, there should always be a WiFi network; this is the backbone. 5G is only for "emergency use", when no WiFi (or cable) access is available. Even outdoors, e.g. at the sports stadion, provisions should be made for e.g. WiFi, or even cable plugin in every armrest.

We could of course also declare that broadcasting is not dead. With frequencies being a scarce resource, it really is crazy that fifty users watching the same transmission from a streamed radio or TV channel should occupy fifty times the bandwith for transferring fifty identical copies. But I do know that any statement in favor of broadcasting is most non-PC in the year 2018.
GeneralRe: 5G Pin
kalberts25-Dec-18 13:56
kalberts25-Dec-18 13:56 
GeneralRe: 5G Pin
BillWoodruff21-Dec-18 12:40
professionalBillWoodruff21-Dec-18 12:40 
GeneralRe: 5G Pin
Super Lloyd21-Dec-18 14:27
Super Lloyd21-Dec-18 14:27 
GeneralRe: 5G Pin
Eddy Vluggen21-Dec-18 14:04
professionalEddy Vluggen21-Dec-18 14:04 
GeneralRe: 5G Pin
Mark_Wallace21-Dec-18 19:02
Mark_Wallace21-Dec-18 19:02 
GeneralSOTW - Nowhere Now Pin
kmoorevs21-Dec-18 10:15
kmoorevs21-Dec-18 10:15 
GeneralRe: SOTW - Nowhere Now Pin
scottgp21-Dec-18 11:25
professionalscottgp21-Dec-18 11:25 
GeneralRe: SOTW - Nowhere Now Pin
Mike Hankey21-Dec-18 14:04
mveMike Hankey21-Dec-18 14:04 
GeneralRe: SOTW - Nowhere Now Pin
kmoorevs22-Dec-18 6:47
kmoorevs22-Dec-18 6:47 
GeneralRe: SOTW - Nowhere Now Pin
User 483504722-Dec-18 9:55
User 483504722-Dec-18 9:55 
GeneralSpider-Man: Into the Spider-Verse Pin
thatraja21-Dec-18 5:38
professionalthatraja21-Dec-18 5:38 
GeneralRe: Spider-Man: Into the Spider-Verse Pin
Eddy Vluggen21-Dec-18 11:20
professionalEddy Vluggen21-Dec-18 11:20 
GeneralThought of the Day PinPopular
OriginalGriff21-Dec-18 4:48
mveOriginalGriff21-Dec-18 4:48 
GeneralRe: Thought of the Day Pin
  Forogar  21-Dec-18 4:54
professional  Forogar  21-Dec-18 4:54 
GeneralRe: Thought of the Day Pin
lopatir21-Dec-18 5:41
lopatir21-Dec-18 5:41 
GeneralRe: Thought of the Day Pin
  Forogar  21-Dec-18 8:22
professional  Forogar  21-Dec-18 8:22 
GeneralRe: Thought of the Day Pin
Gary R. Wheeler22-Dec-18 11:47
Gary R. Wheeler22-Dec-18 11:47 

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