OT Best explanation of 5G and what it is about I have seen yet.

That is a very nicely presented explanation. However, it misses one key point, which is that in many countries there is no rollout of mm-wave 5G yet. In the UK, for example, none of the operators have been allocated any frequencies above 3.8GHz (except for limited experimental purposes).

It also seems unlikely that mm-wave 5G will be deployed widely except in high user density locations such as shopping centres, sports stadiums and airports due to the very short range.

John

John Walliker snipped-for-privacy@gmail.com wrote in news: snipped-for-privacy@googlegroups.com:

I'd rather they build a football sized test room (anechoic) and try monkeys first with that dense node crap.

Yes, a well-done explanation. Thanks.

The fallacy in the video is the conclusion. She clearly finds that molecular bond breaking requires very much higher frequencies, (like all the other radio frequencies we use) and that lower frequencies require very high power to cause harm (such as microwave ovens). Then she somehow concludes that because this specific frequency band has not been extensively studied we can't conclude it is safe.

It is like saying you can easily drown in the deep end of the pool because the water is over your head. We know you don't drown in the shallow end of the pool where the water only covers your toes. But here is a part of the shallow end of the pool that reaches your ankles and we don't know if that is safe or not.

I don't know why you list those specific locations. The purpose of 5G is to give the wireless companies a level playing field with the wire based cable companies for supplying high data bandwidth connections. The only way this is possible is to use very small cells which allow much more extensive frequency reuse to provide much higher aggregate bandwidth across the network. The new high band frequencies are part of this because they are readily blocked and naturally cover a much smaller area. Otherwise, the new high frequency band is a PITA for providers. Airports aren't even particularly high density actually. No more than a city sidewalk.

Rick C snipped-for-privacy@gmail.com wrote in news: snipped-for-privacy@googlegroups.com:

A cell node array that has node aggregation of 100 yards is pretty dense and would be pretty invasive to install and would have to be low towers in order to remain proximal. The reason he gave the example he gave is becuase nearly anything blocks it, so big open space type enclosed public spaces would be one of the only places to use it. In a mall, ordinary wifi works, but that is a different animal than ordinary cell service and requires logging in at each of those locations. And many malls have interior design elements that would block signals. Any of those location would then become quite RF dense.

They fight some types of cancer by focussing multiple X-ray beams from multiple angles onto the tumor, where each beam does not harm the flesh (much) but the intersection of many does harm the tumor.

Perhaps in a mm wave signal beam rich environment there could be concern over intersecting or multiple wave interaction with flesh.

I say that it is still way to low in energy to amount to much more heating than a rising fart.

We must go to different airports. A captive audience sitting around for an hour or two with nothing else to do could get through a lot of data. Somewhere like London Heathrow (once covid is over) contains a lot of people. A stadium is a natural use-case, because there may be tens of thousands of people with no significant rf barriers between them so a huge bandwidth is needed for all of them to get a good service. It is tricky to get WiFi to work well in such situations.

Busy city centres also make sense, as existing 4G microcells are very densely packed and upgrading to mm-wave transceivers would not require many new locations, just new hardware and higher speed backhaul fibre links.

I don't think the main purpose of 5G was ever intended to be giving a level playing field to the wireless companies. It offers a very different set of advantages and disadvantages to the fibre to the premises which is also being rolled out widely.

5G does have a lot of benefits at more modest data rates on the low- and mid-bands and most of the rollouts at the moment only use those lower frequency bands.

It will be very difficult to get mm-wave 5G to work well inside homes. It is hard enough for many people to get WiFi working reliably a few rooms away within a single home.

John

The "towers" you speak of are often telephone poles, so the range is very limited at 30 GHz.

X-rays are ionizing and so harmful at any concentration. We use them at low levels because the harm is insignificant.

For this to be in effect would require concentration of some 1000 fold or more... SAME as with any radio wave technology at sub ionizing frequencies. Do you stand in a metal lined room when running your microwave. They don't keep 100% of the radio waves inside the oven chamber. There is always low level leakage.

Ok...

You confuse "a lot of data" with a lot of users, i.e. bandwidth. I spend a few hours each week (up to 8) in airports waiting for flights. Out of some 100 people I see maybe 10 using their phones. That's not a big deal and is easily handled by today's technology. That's the point. They don't need 5G at 30 GHz to manage the issue. They already use pico-cells in places like airports to gain adequate signal bandwidth.

They already manage those situations because they don't need RF isolation. They use pico-cells with beam steering. Not really any different from the high cell towers around a city. They see each other well and manage power levels and frequency reuse to isolate the subscribers.

That's not what I've read. The idea of 5G is to gain bandwidth by making the cells only a few city blocks and providing many, many small cells.

Of course it is to be competitive with hardwire. That is the battle going on with wireless picking up speed and cable diminishing. There is little need now for the fastest speeds available on phones. There is no need at all for 5G other than that they want to capture the ENTIRE data market.

The current phones won't use mm wave much because they haven't installed many cells with mm wave.

That is a false comparison because WiFi is limited in power specifically to make it very short range.

The last time I was at an airport almost everyone was using their phone. Video streaming is now so popular that a large number of users really does relate to high bandwidth requirements. Cellular operators are especially keen to have outstanding performance at international airports because they want incoming passengers to roam to their network rather than that of their competitors.

If there is no benefit to mm-wave transmission in that situation it is hard to see where else it would be advantageous. Beam steering is fine for the downlink, but there is little scope for it on the phone which is much more important now that so many people use video apps like facetime on the move. In a stadium, there is no real isolation between all those nearly omnidirectional uplink video streams, so having lots of bandwidth would make a big difference. A facetime call uses about 4Mbit/s in each direction.

Around 15 years ago when I was collaborating on a project with one of the UK cellular networks they had micro-cells mounted low-down on buildings on almost every street corner in central London, so there were many cells per block. By now, the density must be much higher. I saw the maps on their planning system - I didn't need to read it anywhere. The project was about measuring the impact on voice recognition systems of cell handover artefacts, so cell density was an important parameter.

I agree about the lack of need for the fastest speeds on phones. 10Mbit/s per phone would be more than enough for most purposes including video calling if it could be reliably delivered to all the phones that need it simultaneously. However, it is also easy to think of less frequent situations where a few hundred Mbit/s would be of value. Things may vary in different countries. In the UK the main cellular operators also provide high-speed wired (or increasingly optical fibre) connections to premises as well so they make money regardless of the technology used.

I disagree. Uplink bandwidth is increasingly important and rf exposure to the head is likely to be a limiting factor in uplink power. The losses between a phone deep inside a building with infra-red reflective glass and an external base station will be enormous at mm wavelengths.

Using a phone does not equate to video streaming. Most people sitting in airports are talking to each other, not on the phone at all. Next are people on the phone. Then comes surfing the web, and finally video. It's easy to spot those using video because they are not interacting in any way, not touching the phone, gaze downward at the phone.

Every airport I've been to has very good cell service other than perhaps San Juan.

What are you talking about??? Beam steering on the cell tower works in both directions. The downlink reduces the power transmitted from the tower which is nominally high. The uplink improves the signal sensitivity from the low power mobile unit.

People pay $100 for tickets so they can facetime to people outside the stadium? To be honest I'm not familiar with facetime, but when I'm in a stadium I see people wearing fancy clothes, drinking expensive beer and watching a game or a concert.

Exactly! Small cell sizes allow more frequency reuse and higher total bandwidth. In earlier generations of cell service it was more about preventing dead zones, but with 5G this gives the ability to provide full streaming bandwidth to everyone who wants it.

It's still a false comparison because a cell phone signal outputs much more power than a WiFi signal. WiFi is limited to 100 mW in the US while cell phone signals are in the watt range.

I suppose we'll see how it works out.

You can drown in three inches of water...

John

Agreed. However, the beamsteering will be imperfect due to sidelobes in the antenna radiation pattern and reflections from nearby objects, so the largely omnidirectional radiation from very large numbers of handsets in a very densely populated arena is likely to cause problems. Having lots of bandwidth makes everything so much easier. This is why mm-wave transmissions seems useful in such situations, especially as nearly everyone can be within line of sight.

Indeed. However, it will take a long time to find out as in many countries like the UK there is no mm-wave rollout at all right now and it will be some years before it even begins. Returning to the original point of this thread, many people are concerned about the possible dangers of a technology that is not actually being rolled out at the moment. As far as hypothetical hazards go, the version of 5G that is currently being installed is nearly the same as existing 4G transmissions.

John

John Walliker wrote: ===============

** But only in general terms. Sabine is a brilliant and controversial explainer and video maker re Physics. ** The "short range " Sabine only alluded to is less than one inch.

Think it through..

...... Phil

On Thursday, 7 October 2021 at 13:18:08 UTC-7, John Walliker wrote: ...

Rubbish - it uses about 1/10 of that. A few hundred kilobits per second.

A high-definition movie from Netflix uses in the region of 4Mbits/s - one direction.

kw ...

Its not rubbish at all. I have regularly measured 4Mbit/s uplink and downlink on the traffic graphs of my router during Facetime calls. Zoom is typically

2Mbit/s. These are real measurements between two Apple tablet computers.

John

These video protocols automatically adapt to the available bandwidth. You can have a perfectly ok call using a lot less bandwidth, but it it is available, you get smoother and better video.

CH

Rick C snipped-for-privacy@gmail.com wrote in news: snipped-for-privacy@googlegroups.com:

I didn't need a primer on X-rays, ya dope. I made X-Ray HV exiter supplies that made 180kV to look through airport luggage with. The point was that additive beams of the frequency we are discussing means more of an intrusion into the body.

One phone next to one's ear may not be a problem but being in a space where there are twelve nodes nearby all spewing multiple beams...

That they do not know if there will be any effects from that.

Rick C snipped-for-privacy@gmail.com wrote in news: snipped-for-privacy@googlegroups.com:

That is about 5 years behind the current normal use scenario.

Phones and video shorts and right wing retards and passing around their retarded conspiracy theory horseshit is a continual problem in the workplace today, so it is certainly a problem at airports and even rears its ugly head with stupid drivers whom cannot put down the stupid phone long enough to safely drive. Airports are full of folks now without their laptops, which was the old norm.

But we will see 5G in laptops as well, or claims thereof and higher resultant prices therein.

John Robertson snipped-for-privacy@flippers.com wrote in news: snipped-for-privacy@giganews.com:

One can be drowned with a single tablespoon of water.