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The tiny chip that powers Montreal subway tickets

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Re: The tiny chip that powers Montreal subway tickets

#421

Post by actinium226 »

skeeter2020 wrote: post #370
dghughes wrote: post #368

Earlier quoted context omitted.

I was watching a travel show about France and in Paris it seems tourists can get confused as to where their ticket is for. They can easily end up on a train in an area their ticket isn't for. You get a 100 Euro fine! And that's an honest mistake not trying to get away without buying a ticket.

100 Euros for a travel story you'll tell years into the future, and funding the tourism economy - win-win!

"We got fined for getting off the train at the wrong stop" is not much of a travel story though.

Re: The tiny chip that powers Montreal subway tickets

#422

Post by lucianbr »

woodruffw wrote: post #418
solarized wrote: post #324

To peoples asking: "Why not just QR codes?" Again it's all about latency. QR codes take longer when you tap them at the gate: opening the app, waiting for the scanner to adjust, connecting to inet. While NFC handle these tasks almost instantly. A big difference in super busy places where queues are a nightmare. Again, this problem wouldn't exist if we can optimize WFH methods. We don't need to solving "physical probl…

Why would a QR code require Internet, or an app? You could just print it on paper and track the corresponding balance on the server side. To my understanding this is what most transit networks do anyways, to prevent an enterprising user from modifying their balance on the card itself. (The optical scanning argument makes sense, however.)

Internet is how you get from the client side to the server side. Maybe not internet but some-kind-of-net, and that has latency, failures etc.

Maybe that's not clear: the turnstile needs to connect to a server to check the QR. Need to only have one server, so some turnstiles will be relatively far from it. Latency.

Re: The tiny chip that powers Montreal subway tickets

#423

Post by lxgr »

landedgentry wrote: post #240
lxgr wrote: post #47

Earlier quoted context omitted.

Same here! It seems like a fascinating system, especially in the federated way in which it's being used by various Japanese transit agencies and issuers. Compared to MIFARE, it was definitely ahead of its time. Unfortunately, most things I could find are in Japanese, as expected; I suspect that the really interesting parts aren't public, as usual in this industry (there's still a lot of belief in security by obscurit…

I'm a big fan of this blog: https://atadistance.net/2023/04/04/final-frontiers-how-suica... The author understands Japanese sources and writes about how the various Felica-based systems operate and evolve.

I'm also a big fan!

One small caveat: As much as I appreciate his writing, I'd take some of the technical explanations with a grain of salt – the approach is definitely more that of an (extremely knowledgeable and experienced!) outsider looking at the system and coming up with hypotheses for its workings than that of an authoritative source with hands-on experience working on the system. It's sometimes not that easy to figure out what's hypothesis and what's "confirmed" knowledge as a result.

That said, much of what I've learned about Japanese transit payment systems (without ever having visited) was via that blog. It's amazing!

Somebody from the tiny intersection of people apparently having hands-on experience with Felica and writing about it in English is this pseudonymous Reddit user (often also quoted on the blog): https://www.reddit.com/user/FelicaDude/

Re: The tiny chip that powers Montreal subway tickets

#424

Post by teknologist »

CraigJPerry wrote: post #393
teknologist wrote: post #353

Earlier quoted context omitted.

None in that case. But with these cards there’s less need for centralization of data storage and code logic

>> there’s less need for centralization of data storage and code logic You make it sound like less moving parts are a bad thing :-) I know what you're getting at though - the decentralized tolerance of network partitions and the ability to provide higher availability and faster decision speed at the entry barrier. The system design constraints are hard but not impossible, my back of napkin maths says 5k/ticket scans…

1000ms is a surprisingly long wait at a ticket barrier, though! Latency is everything in this use case...

Re: The tiny chip that powers Montreal subway tickets

#425

Post by vaughnegut »

mardifoufs wrote: post #158
speed_spread wrote: post #152

Earlier quoted context omitted.

You can refill them with the Chrono app since last March. No more queues. Can't do nothing about Laval and Longueuil though.

Yeah they added refills but you can't use your phone as an NFC pass yet :(. I've always been curious to know more about why, you'd think if you can refill your Opus card with your phone, to then use it on the terminal, you could just skip the card step entirely but I'm sure it's not that simple!

They're actively working on allowing you to just use your phone, iirc targeted for like 2026 or something. Basically, its' a work in progress and they delivered the update to the Chrono app as a stop-gap.

Re: The tiny chip that powers Montreal subway tickets

#426

Post by _spduchamp »

OMG! Last time I went to get on the Subway in Montreal, the line up at the station to purchase one of these tickets was crazy long that I just gave up. There was no way to enter the subway by paying directly. You had to purchase one of these tickets. In Toronto, you can just tap your credit card to get on the subway.

Also, you see these Montreal cards laying all over the streets. This card system just seems so messed up in Montreal.

Re: The tiny chip that powers Montreal subway tickets

#427

Post by Delk »

xmcqdpt2 wrote: post #386
Delk wrote: post #374

Earlier quoted context omitted.

I'm not sure that necessarily explains the need for single-use NFC tickets, though. There could be a more durable serial-use or permanent card with NFC that regular commuters could buy, and if those commuters are the vast majority of rush hour passengers, it might not be such a problem if single-use tickets had a slightly slower system. Of course that'd mean having two recognition mechanisms, so the operator might op…

We have those, with two recognition systems. The system the article describes is for the low count, disposable fares (a few tickets or a 3 day pass). Most people in Montreal have a chip card (the OPUS) which is reusable (and 5$ to buy). The OPUS is also super interesting because it's a stored value card that holds the tokens on the card as opposed to a simple ID. The system was developed when cellular connectivity wa…

Ok, that makes sense then. I know that systems with non-disposable cards exist, and we also have one in the Helsinki metro area. I think our present system assumes continuous connectivity, though. Now and then you see buses with the terminal in a non-functioning state. Ends up being a free ride. (You can also buy unlimited travel within a given zone for x days at a time, which is what those who use public transit daily usually get.)

I think most people nowadays use a phone app rather than the card, though. But we also don't have gates at stations, and it's more of a trust and ticket inspections system similarly to what someone said about Norway.

Japan has the Pasmo system which is weird in that it's actually more like a prepaid debit-style card that you can use not only on most public transit but also as a payment method at some shops etc. You can charge it using teller machines at stations. I can't remember the details, though.

Re: The tiny chip that powers Montreal subway tickets

#428

Post by woodruffw »

lucianbr wrote: post #422
woodruffw wrote: post #418

Earlier quoted context omitted.

Why would a QR code require Internet, or an app? You could just print it on paper and track the corresponding balance on the server side. To my understanding this is what most transit networks do anyways, to prevent an enterprising user from modifying their balance on the card itself. (The optical scanning argument makes sense, however.)

Internet is how you get from the client side to the server side. Maybe not internet but some-kind-of-net, and that has latency, failures etc. Maybe that's not clear: the turnstile needs to connect to a server to check the QR. Need to only have one server, so some turnstiles will be relatively far from it. Latency.

> Maybe that's not clear: the turnstile needs to connect to a server to check the QR. Need to only have one server, so some turnstiles will be relatively far from it. Latency.

Sure, but is this a serious design pressure? I've been on a lot of EU train and trolley networks that have a POS terminal on the train for direct sales, which are already doing networking both for the card transaction and to issue the ticket.

(Again to be clear: I'm not saying a QR is better. But I don't think connectivity is a unique problem, since systems that use NFC without tying into payment cards are almost certainly using connectivity to make up for the lack of tamper resistance.)

Re: The tiny chip that powers Montreal subway tickets

#429

Post by scoot »

PaulRobinson wrote: post #417
scoot wrote: post #331

Earlier quoted context omitted.

The UK rail network already supports QR codes, with the busiest station handling over 80M entries/exits per year. Meanwhile, the integrated subway/overground/bus network in London supports direct payment with NFC smartphones, without the need for an intermediate "smart" paper ticket; the infrastructure for vending those; or the (not insignificant) cost of producing the tickets. Not sure what Montreal was thinking!

Even better, London doesn’t need NFC smartphones: if you have a chip bank card with a chip for tap payments, just tap that. For those of us with smart watches, they do the metro fast pay thing as well, so I literally just tap my watch without having to press anything or get anything out of my pocket. If my watch battery is dead, I can just a bank card. The only advantage to having Oyster is if you’re travelling enoug…

Good point, the choices are: smartphone, smart watch, physical bank card (credit or debit), and pre-paid "Oyster" card (think pre-paid debit card specific to the London public transport network), and, yes, legacy paper mag-stripe tickets.

Re: The tiny chip that powers Montreal subway tickets

#430

Post by altacc »

dghughes wrote: post #368
altacc wrote: post #346

Earlier quoted context omitted.

In some places, like Oslo's metro, tram & bus systems, the solution is that there are no ticket barriers, you're trusted to have bought a ticket for your journey. There are occasional ticket checks with big fines for non-compliance.

I was watching a travel show about France and in Paris it seems tourists can get confused as to where their ticket is for. They can easily end up on a train in an area their ticket isn't for. You get a 100 Euro fine! And that's an honest mistake not trying to get away without buying a ticket.

Like a lot of rules, enforcement needs to be realistic, appropriate and not overly harsh. In Oslo at least, the obvious tourists tend to get let off with just buying a ticket, even though the ticket app makes it easy to buy the correct ticket. If you speak Norwegian they often look at your travel history to see if you’re a regular payer who just forgot.
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