
Manhole Covers Serve as Antennas Expanding Wireless Network Coverage - Varcht
https://spectrum.ieee.org/tech-talk/telecom/wireless/manhole-covers-serve-as-antennas-expanding-network-coverage
======
lykr0n
The more I hear about 5G, the more I think it's an industry trying to sell a
product that nobody is asking for. I have no complaints about the speed I get
on my iPhone from T-Mobile here in the US. I wish I had better LTE coverage,
but I'm happy with the performance. Most of the time it's snappier than my Wi-
Fi (which is weird). I get a solid 8 to 20 mbits under fair conditions- I can
stream movies and music just fine.

All I hear about 5G is that it requires a large amount of antennas on both
your phone (4 because a hand covering the antenna can cause a drop in signal)
and around you. I don't want to be near a high power transmitter that's low
frequency, and I really don't want to be near a high frequency one.

What's the sell of 5G? I guess the speed, but what? 1 Gbit to my phone? Why.
Considering that I only get 15GB of "Unlimited" data now, it isn't going to
replace Wi-F. Because of the density required of the towers, it's not going to
replace 4G/LTE as some areas it's just unrealistic to have the required
density.

~~~
mdasen
I think there are a few selling points.

First, 5G should increase available bandwidth. Industry analysts are
predicting that data usage will go up 7x between now and 2024. More
speed/bandwidth can help with that. Without increasing capacity, would we just
see our usage stagnate?

Second, 5G should have much better ping times. Not only will this make
browsing noticeably better, but it also means that latency applications can
work well over wireless.

Third, there's a decent possibility that 5G will bring home broadband
competition. If you're fed up with Comcast or Charter, 5G could mean choice in
your internet service.

Fourth, I believe that 5G has a lot more flexibility than LTE. Part of that
might mean low-power narrow connections that will allow cheap and battery-
efficient sensor connections. Part of that might mean ultra-wide-band
connections allowing for high-bandwidth devices that can't be served by the
more limited carrier aggregation of LTE.

Fifth, sometimes applications happen when the technology is there to
accommodate it. The broad availability of broadband let Netflix pivot from
shipping DVDs to streaming. Broadband has meant online gaming, richer online
applications, digital distribution, etc. As mobile bandwidth increased, we
went from loading music from our computer, to streaming music, to streaming
video. I think the broadband speed you have to support in your applications
tends to be 10Mbps+, but if that floor raises over the next 5 years, it could
change which applications and experiences people invent.

I mean, before the iPhone was announced, a lot of people wanted a phone dial
pad on one side and an iPod click wheel on the other. People wanted
Blackberries. The iPhone laid the technological foundation for all sorts of
new experiences that people hadn't really thought about. Successive iPhones
have been comparatively minor upgrades, but even then the faster processors,
better screens, better wireless connectivity, etc. have allowed for better
experiences to be built.

\--

It's also important to remember that there are different deployments of 5G.
While Verizon has pushed out its ultra-high-band, short-range 5G, other
companies are going to be rolling out 5G on more traditional spectrum offering
much the same range as LTE. 5G NR is a new radio interface and it promises
better spectral efficiency than LTE.

I think it's also likely that many areas will see high-density deployments.
Companies like Comcast run a wire to every house they serve and require
coordination with property owners to get it into the building. If you could
run a wire to one point every 18 acres, that's a lot easier (that's assuming a
500 ft transmission range). Higher density than that is certainly achievable
in dense cities.

It can certainly be hard to predict what a new technology might make happen.
It's also possible that 5G won't make a huge impact beyond what LTE has
already done.

~~~
woah
5g is everything, and 5g is nothing. 5g is. To find the true meaning of 5g,
one must look to the government subsidies.

~~~
pjc50
This is an excellent koan, but I thought the true flow of money was in the
other direction with the spectrum auctions.

------
bjt2n3904
When I was in college, I remember taking a class in silicon design. At one
point, a student remarked, "man, silicon is like... black magic."

"No," the teacher sharply rebuked. "It's governed by well understood and
reliable mathematical equations. Though difficult, it is far from magic."

There was a brief pause, the teacher was normally easy going and congenial.
His harsh words caught us off guard.

"...antennas on the other hand, that is black magic."

~~~
andreareina
Indistinguishable From Magic: Manufacturing Modern Computer Chips --
[https://www.youtube.com/watch?v=NGFhc8R_uO4](https://www.youtube.com/watch?v=NGFhc8R_uO4)

~~~
Joona
Same talk (slightly updated perhaps?) in higher quality:
[https://www.youtube.com/watch?v=KL-I3-C-KBk](https://www.youtube.com/watch?v=KL-I3-C-KBk)

~~~
andreareina
Didn't know about that, thanks!

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sandworm101
Are these proper manhole covers? I mean the big heavy metal type that can
support vehicle traffic? The one in the picture seems the type for covering
access to a "manhole" but not one under a street. I do have to wonder whether
the local cell will drop out every time a huge metal object, a bus, rolls over
the cover.

>>It eliminates traffic disruptions from street construction, and there are no
antennas awkwardly placed on buildings, marring the appearance of a
neighborhood.

Said by someone who has never attempted to install anything inside a manhole.
They will need to close the streets. You cannot just creep through the sewers
installing stuff without disrupting the traffic above. Workers are not moles.
They will need to run new lines. And in modern cities, the type without the
huge walk-in storm sewers of NY/London/Paris/SF, there will still be digging.

With many innovations these days it is hard to determine feasibility from
initial articles/claims. Lots of inventions seem to exist only to get grant
money, with no hope of practicality (solar roads, solar windows). If these are
lightweight manhole covers that cannot support traffic (ie just an antenna
mounted atop an aluminum cover) then I'll chalk it up alongside those sidewalk
tiles that generate electricity from pedestrians: might work, but will never
be practical.

[https://en.wikipedia.org/wiki/Solar_Roadways](https://en.wikipedia.org/wiki/Solar_Roadways)
[https://www.6sqft.com/pavegen-opens-worlds-first-smart-
stree...](https://www.6sqft.com/pavegen-opens-worlds-first-smart-street-which-
generates-electricity-from-footsteps/)

~~~
twic
I don't think London has huge walk-in storm sewers. And there are certainly
people digging up everything they can see, all the time, at least on the roads
i use to get to work.

~~~
sandworm101
It does. The old cities have _combined_ systems, storm and sewage together. To
accommodate rainwater and maintenance, they are essentially brick corridors.
Some are huge.

[https://www.telegraph.co.uk/sponsored/why-
not/11621489/sewer...](https://www.telegraph.co.uk/sponsored/why-
not/11621489/sewer-tours-in-london-and-brighton.html)

More modern cities have separate systems for sewage and stormwater, and these
are contained in small pipes that people cannot walk around in. Upgrading from
a combined system is a massive project, well beyond something like 5g imho.

[https://www.thames21.org.uk/combined-sewer-
systems/](https://www.thames21.org.uk/combined-sewer-systems/)

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mevile
I'm curious how this affects the NIMBY fights about antennas. Some of those
fights are about aesthetics of the antennas, but some of the concern is around
the radiation, which is not a finished debate. Mobile phone signals have been
designated as possibly a cause of cancer by the WHO if I recall correctly. It
hasn't been possible to rule out that mobile phones do not cause harm, which
is something I was surprised to learn. I thought it was a settled debate that
mobile phones were safe.

[https://www.cancer.gov/about-cancer/causes-
prevention/risk/r...](https://www.cancer.gov/about-cancer/causes-
prevention/risk/radiation/cell-phones-fact-sheet)

~~~
JumpCrisscross
> _phone signals have been designated as possibly a cause of cancer by the
> WHO_

No, it has not. "To date, research does not suggest any consistent evidence of
adverse health effects from exposure to radiofrequency fields at levels below
those that cause tissue heating" [1].

[1] [https://www.who.int/news-room/fact-
sheets/detail/electromagn...](https://www.who.int/news-room/fact-
sheets/detail/electromagnetic-fields-and-public-health-mobile-phones)

~~~
flatline
And yet the second bullet in that article:

> The electromagnetic fields produced by mobile phones are classified by the
> International Agency for Research on Cancer as possibly carcinogenic to
> humans.

So it's not settled science, even though there is some evidence pointing
toward it not causing cancer.

~~~
steve19
There is a lot of evidence, long term studies, showing they do not do cancer.
So the question is why are they listed as a possible cause? It invalidates the
entire list. My car keys may well "possibly" cause cancer if the bar is so
low.

~~~
JonathonW
The specific item that is on the IARC Group 2B ("possibly carcinogenic") is
"radiofrequency electromagnetic fields", which includes exposures due to cell
phone use-- cell phone radiation specifically is not classified.

So, if your car has keyless entry, your car keys would technically also be on
the list.

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lifeisstillgood
A side issue with 5G is that there are all sorts of fun / unusual effects
being discovered with GSM/wifi suffusing our environments - i remember
Stanford being able to detect people moving behind a wall using the wifi
signals. Simply Monitoring signal strength has had many commercial
opportunities and now we are going to put millimetre wave radar throughout our
cities - expect novel uses to crop up

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cypherpunks01
Wouldn't traffic poles serve as better publicly-owned antenna mount points?
They are powered and have better line of sight to everything (broader range).
I wonder why manholes are considered better.

~~~
ldite
As I understand it, they're owned by different entities; the street
lights/traffic poles are often owned by local authorities (in the UK) while
manhole covers are owner by the utilities.

I suspect that one aspect of this is to give them leverage in getting access
to antenna sites.

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Uberphallus
I'm far from an expert, but aren't manholes (and streetlights and traffic
lights, by extension) effectively grounded, hence incurring into insane loss?

~~~
Johnythree
Many Antennas are grounded (eg for lightning protection), but that has no
relevance for their effectiveness as an antenna.

Because the size is much less than a wavelength, the body can be at ground,
while the active parts can be at RF potential.

Example: Your phone is grounded, but it still works.

~~~
Uberphallus
They are grounded with a precise length of coax (multiples of 1/4 or 1/2 wave,
IIRC) to keep the VSWR ratio low for the intended frequency. In a pole you can
get to do that by probing the signal at certain height, but the active part of
a patch antenna (which I assume a manhole works as) is at the extremes of it
(as such, probes are always off center for circular polarization, and at the
extreme for linear), and those are grounded. Patch antennas are normally
grounded at the center, as the voltage/current there should be close enough to
0 anyway unless there's an electrostatic discharge.

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kenzoid
That's pretty clever, and appears to be already in use even for 4G.

~~~
abbe_k
Yes, I know Swisscom does this already.

~~~
PappaPatat
For a little background [0]:

"Swisscom and Ericsson have proved that city manholes can be used worldwide to
improve capacity with small cells – even below street level – using the
Ericsson Vault Remote Radio Unit and Kathrein’s Street Connect, an in-ground
microcell antenna system. The use of existing street manholes where fiber and
power already exists lowers total cost of ownership by 50 percent.

This, the world’s first vault site for LTE and small cells has been approved
by the Swiss authorities, and 250 new rollouts are due during 2016 in the
country’s cities. The solution effectively addresses cities’ needs by enabling
the reuse of existing assets and underground space."

Really since 2016. Good framing by Voda to present this as "Building on its
heritage of innovation".

[0] [https://www.ericsson.com/en/news/2016/3/swisscom-and-
ericsso...](https://www.ericsson.com/en/news/2016/3/swisscom-and-ericsson-
plant-lte-small-cells-underground)

[1]
[https://ieeexplore.ieee.org/document/7481351](https://ieeexplore.ieee.org/document/7481351)

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liotier
This means we may have to run power supplies to existing fiber manholes...

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shanghaiaway
Wow, that must be why I start itching whenever I pass a manhole cover.

