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How London cracked mobile phone coverage on the Underground

ianvisits.co.uk

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Re: How London cracked mobile phone coverage on the Underground

#101

Post by fundatus »

userbinator wrote: post #30

I wonder if they considered using the existing metal tracks as antennae, or even https://en.wikipedia.org/wiki/Power_line_communication to feed base stations in the trains themselves. So the ESN in the tunnels runs at 400 MHz, far lower than the 700 to 3,600 MHz range usually used by smartphones. It's worth noting that 450MHz was listed as one of the GSM bands, but apparently was never used: https://en.wikipedia.org/…

> It's worth noting that 450MHz was listed as one of the GSM bands, but apparently was never used

It's specified for 4G/LTE (Band 31, 72 & 73) and 5G (Band n31 & n72) as well! The bandwidth is pretty low though at just 5 MHz, but it's used for special purpose stuff like electricity meters. I'm not aware of any consumer devices that use this frequency.

Re: How London cracked mobile phone coverage on the Underground

#102

Post by hdgvhicv »

cm2187 wrote: post #68
hdgvhicv wrote: post #57

Earlier quoted context omitted.

In the 90s we read the paper and dumbed with our magnetic tickets. In the 00s we listened to MP3s while playing snake on an oyster. In the 10s we played Andy birds and listened to iTunes with a credit card at the turnstile. In the 20s we doom scroll and listen to Spotify while tapping out with our phone. I don’t see the issue.

All of that that they did while they sit. I don’t remember people reading the newspapers while slow walking in the middle of a corridor. And the problem with headphones is that they make people unaware of their surrounding, alone in the world, and therefore for instance unaware that there is someone on their left that they will cut the way to. Small incivilities, but repeat several times a day every day and it gets s…

Certainly people would do that. And sending text messages in the 00s. People have been wearing headphones while commuting for a generation, and (not on the underground but certainly on trains) people in the 80s and 90s were far more obnoxious - get stuck on a busy train between people having conversations about inane stuff while smoking.

Public transport is far better today than it was 30 years ago, annoyances are far less than they were.

Re: How London cracked mobile phone coverage on the Underground

#103

Post by marliechiller »

ljm wrote: post #84
dgxyz wrote: post #61

Earlier quoted context omitted.

That always hurts. I live in a particularly nice bit of London and there is virtually no mobile phone service other than voice and can only get 80 meg ADSL. Yet the mole people get better service. Grr.

I have the opposite problem where I can only get HyperOptic. Not even OpenReach stuff. No problem with bandwidth but zero price competition, and 5G broadband isn’t viable either. Going from £70/mo for gigabit to £65/mo for 500mb is insulting.

Reading this hurts. I'm on £26 a month for a gigabit connection in Z4.

Re: How London cracked mobile phone coverage on the Underground

#104

Post by FridayoLeary »

TheOtherHobbes wrote: post #82
FridayoLeary wrote: post #18

>There’s another distance limit at work here, and that is the speed of light. It takes milliseconds for the signal in your phone to reach the hotel above ground and be handed over to the mobile network. But if it takes too long to get from phone to hotel, then your phone call s..a.rt..s..t o. br..e..ak up. As it happens, that distance is about 12km, so Boldyn needs nine hotels around London to cover the whole of the…

There's a small surface building that doesn't look like a station, platforms are visible if you're paying attention, and it can be used for emergency evacuations.

what's the address of the building?

Re: How London cracked mobile phone coverage on the Underground

#105

Post by ceejayoz »

hotstickyballs wrote: post #96
dgxyz wrote: post #87

Earlier quoted context omitted.

There's plenty of riff raff here. Like me :)

That directly goes against the earlier post where you said you lived in a particularly nice part of town

There are a good number of places in the world where people of varied incomes live relatively close.

Re: How London cracked mobile phone coverage on the Underground

#106

Post by tialaramex »

ljm wrote: post #84
dgxyz wrote: post #61

Earlier quoted context omitted.

That always hurts. I live in a particularly nice bit of London and there is virtually no mobile phone service other than voice and can only get 80 meg ADSL. Yet the mole people get better service. Grr.

I have the opposite problem where I can only get HyperOptic. Not even OpenReach stuff. No problem with bandwidth but zero price competition, and 5G broadband isn’t viable either. Going from £70/mo for gigabit to £65/mo for 500mb is insulting.

Wait, why can't you get Openreach ? Even if it was a new build by idiots who forgot to push the "Free fibre, yes please" button when breaking ground you should have DSL at least.

Re: How London cracked mobile phone coverage on the Underground

#107

Post by DrBazza »

I'm old enough to remember the first attempt at 'mobile underground'. Maybe I've forgotten the name but it was something like BT Phone Zone, though google returns zero relevant results, so perhaps it was called something else. In lieu of public call boxes, BT trialled a base station that was installed in some tube stations (almost certainly Oxford St and Tottenham Court Rd), and with the correct 'wireless handset' as long as you were within 10 feet of it, or thereabouts, you could make a call. I'm sure I remember a semi-circle painted on the ground that if you stood in, you were in range.

Re: How London cracked mobile phone coverage on the Underground

#108

Post by joelkoen »

> What happens if a train has to stop in the middle of the tunnel, and you phone for help? [...] the system has been deliberately configured to transmit the location of the nearest tube station, where access can be arranged. That’s why sometimes you might check your smartphone map, and it will display the “wrong” location, because that’s the best one for a 999 call to use.

This doesn't seem correct - cell towers don't just transmit a location that phones then pickup and use? Unless this is some emergency specific feature I'm not aware of?

Re: How London cracked mobile phone coverage on the Underground

#109

Post by myself248 »

userbinator wrote: post #70
dgxyz wrote: post #64

Earlier quoted context omitted.

There are also some absolute morons out there. Couple of local things around me... First I went to one of the local town planning meetings in my area when they were rolling out FTTC. This one was due to a rather old person objecting to the placement of a streetside box which was not even outside her property and no one who it would have affected could see it or cared about it. I raised my objections about her being a…

Second, they built a 5g mast put didn't put any equipment in it and left it 3 months. Several local threads on Facebook from the tweakers about how it was causing all sorts of completely unrelated problems from tinnitus to covid to mind control. Then someone burned it. There is still no equipment in the cabinet or mast today, nearly 4 years on. No one got 5g. Reminds me of this infamous decade-old story: https://web.…

This is standard advice among ham radio operators. If you're putting up a tower, put it up, mount the antennas, run the feedlines, but resist the temptation to operate for a while. Or use it for receive-only.

Log your activity, or lack thereof, meticulously. Perhaps a critical part was back-ordered, or more expensive than expected, and note in the log how it still hasn't arrived so you still aren't able to operate. If complaints come in, get them to be maximally public about it, ideally in a town meeting or something, then whip out your logbook and coup-fourré. Let the wackos show themselves to be wackos, then quietly start operating some time later.

Re: How London cracked mobile phone coverage on the Underground

#110

Post by redleader55 »

mft_ wrote: post #65
Havoc wrote: post #50

Earlier quoted context omitted.

London’s first line predates tokyos by like 60 years and was literally the test ground for how to make underground’s The challenge isn’t the technology but rather the environment you’re trying to retrofit

So if I follow, you’re saying that because London’s underground is older than Tokyo’s, it somehow changes the physical environment of the tunnels or their surroundings such that installing the required technology is more difficult? Please expand…

The way this is usually done is through a radiating wire that goes on the wall from station to station. This solution requires a lot of power. The stations in London are very small, leaving very little space for a transformer that can provide said power.

Because of that they rely on directional antennas that cover sections of the tunnel - but those need to be straight, otherwise another antenna is required to cover that corner. There is also very little head-room in the tube tunnels in London. You can see how things get more and more complicated as you dig deeper into the problem.

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