A number of parts of the underground already have platform edge doors, and train stopping locations are tightly controlled regardless of the presence of platform edge doors.
> so I wonder if the tube stuff is just a weak public cover for the military/civil emergency applications that make the technology actually interesting.
The project is quite explicitly a defence project. IanVisits is just a transport blog, so the article focus on the transport aspect of this project. But reporting else where makes it quite clear this a defence project.
The only reasons for the Tube being involved is as a test bed for the technology. It’s cheaper to put this box on a train and test it, than it is to put it on a boat or a submarine. It’s also handy that the researchers involved are based in London, so the commute to their test bed is nice and short.
The accumulation might be from the integration, but the error is clearly from the accelerometers. Smaller error means smaller accumulated error, which means your magic box is usefully accurate for longer.
100%, but smoke screen is over selling it. From the article
> The project is being carried out in collaboration with Transport for London, QinetiQ, PA Consulting, Imperial College London and University of Sussex.
QinetiQ is a UK weapons developer, probably the UKs largest. So the defence angle isn’t really being hidden.
Older articles on this project from elsewhere outline the defence angle even more explicitly:
But IanVisits is a transport focused blog, so the article has a transport focus, rather than a defence focus.
As to why any of this is happening on the underground, that’s pretty simple. Tube trains are a good real world test bed for this technology. Shove your quantum box on an existing train, drive it through the existing tunnels a few times as part of a normal tube service. Compare the run result and validate how accurate your technology is.
It’s a lot cheaper than putting it on a boat or a submarine. Not to mention Imperial College London is based in… London. They’re literally a five minute walk from a tube station.
> I would wager that actually this is probably just a way of funnelling money into research around quantum rather than genuinely trying to solve this specific problem.
You’re absolutely correct, from the government’s perspective the interest in the technology is for high accuracy inertial navigation systems for defence purposes, not for the London Tube. If you look at the other companies involved in this project, there’s a number of defence contractors involved.
This project isn’t really new, and historically the pitch has always been: We want to develop GPS grade navigation that doesn’t depend on satellites, and is smaller and better existing inertial navigation units. Oh look the London Underground is the perfect test bed for our technology!
It’s underground, so no GPS or many external signals. It’s already well mapped so we have something to compare against. Tube trains are loud, hot and vibrant a lot, which makes it a challenging environment for inertial systems. Plus it’s cheap and very easy to roll a box on an existing train, drive a few km under the city, and then compare your results to GPS from when you go underground, to when you surface again.
The idea of using it map the underground I think is a bit of a red herring. Makes a good story, and TfL will probably be grateful for the data. But it’s not the kinda thing anyone thinks is worth developing quantum accelerometers for.
Given all the GPS jamming in Russia/Ukraine the defense world needs something not GPS based that works. The civilian world also needs this since they are often hit with the same jamming (both as collateral damage and intentional harm to the enemy)
That is an unusual luxury, especially mobile providers still using IPv4.
Mobile providers have been the first and most aggressive to migrate to IPv6. Probably helped along by the cost and difficulty of running CGNATs when your network clients are constantly moving around. At least in the UK all the mobile providers are IPv6, and I think a handful are IPv6 only.
Using a normal ISP issued router, wouldn’t make a lick of difference if it was IPv4 with a NAT or IPv6 without a NAT. They’re all configured out-of-the-box with a default deny firewall. I’m not actually aware of any residential grade router that doesn’t come configured like this.
Of course if the router is misconfigured, then all bets are off. But that’s true regardless of IPv4 vs IPv6, because people will just compromise your router first and use that as a launch pad for the rest of your network. Just like to do today with plenty of old residential routers.
You literally can. You can just use local link addresses, IPv6 routers are guarantee not to forward those packets out of the network, or forward traffic into the network addresses to one of those IPs. Devices within the network can all still talk to each other.
If you really want to do the full Monty, add a NAT to your IPv6 router to have it translate to the local-link addresses, just like it would on IPv4.
I would highlight this is also identical to IPv4, which notably is also a standard built around the idea that every device in the world can, and should, be given a publicly addressable IP. Many large corporations and universities with /8 IP blocks do exactly this. Unfortunately when they originally wrote the IPv4 standard they slightly underestimated how many devices would eventually connect to the internet.
The early teens didn’t have huge proliferation of ISPs using CGNATs.
These days ISP can’t get hold of new IPv4 blocks, and increasingly don’t provide public IP addresses to residential routers, not without having to pay extra for that lowly single IPv4 address.
Hosting a website behind a NAT isn’t as trivial as it used to be, and for many it’s now impossible without IPv6.
> Hosting a website behind a NAT isn’t as trivial as it used to be, and for many it’s now impossible without IPv6.
The example I keep coming back to is multiplayer games like Mario Kart, where Nintendo tell you to put the Switch in the DMZ or forward a huge range of ports (1024-65535!) to it [1].
If you’ve got more than one Switch in the household, though, then I guess it sucks to be you.
To require that, the person would have needed to disable upnp on their router. I’ve played tons of multiplayer games on the switch and upnp handled it seamlessly on the 7 or 8 home networks I connected it to over its life. Never once even had to think about it.
So yes, if you disable the requisite, standard, built-in feature on your router, you may need a pretty annoying workaround. Weird!
What percentage of users do you imagine disable upnp? Let’s be real. This is a problem that your average user will never, ever experience a problem with.
No they wouldn't. UPnP is not requisite, certainly not standard, or necessarily built-in. For example, the router I've got doesn't implement UPnP.
It's not unusual for it to be disabled, because it's a security issue that something with no authentication can punch enduring holes out through NAT.
It's also irrelevant in a scenario where the ISP's using CGNAT.
I'm sure the Switch deals with conflict resolution with multiple consoles on the same network too but shrug it's another example of how NAT is a pain and also contradicts your assertion that incoming connections would be a breach of ISP ToS [1].
Edit: A quick Google suggests the Switch originally didn't support UPnP, and the Switch 2 now supports IPv6.
Ok, so it didn’t even need upnp then. Are you talking about using their LAN head-to-head feature across the internet? Or perhaps all the times I used my switch on various networks to play head-to-head games it was… my imagination? Sure. If people had to consistently forward every port on their home router to play Fortnite, smash, etc. with a portable console you’d never hear the end of it. This is literally the first time I encountered someone saying this was a problem. Regardless, most people don’t buy routers— they use the ones their ISPs gave them, and I haven’t seen one of those come without upnp in at least a decade. You’re seeking out reasons to dislike NAT.
No the author is highlighting the fact that the aspect ratio a video is stored in doesn’t always match the aspect ratio a video is displayed in. So simply calculating the aspect ratio based on the number of horizontal and vertical pixels gives you the storage ratio, but doesn’t always result in the correct display ratio.
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