Comment by seltzered_ | Hacker News Reader

Comment by seltzered_ | Hacker News Reader

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Friend in Seattle had this experience when trying to use a zipcar truck out of a garage while moving (i.e. Limited time window to get stuff out of one area to another). Ended up calling support, dealing with multiple hours of delays. Despite the issues which has led him to avoid Zipcar these days, he uses ReachNow (now defunct) and car2go (now called ShareNow) regularly and AFAIK ReachNow didn't have these limitations when on long out-of-range trips - they solved the problem by doing sortof a two-factor of having an RFID card (to unlock, on window) and a pin code (entered via the BMW iDrive system to start engine).

I could argue Zipcar has a deep integration problem needed to solve the out-of-comms scenario. They try to support several car vendors in order to have different car types (toyotas, mercedes, ford vans) which limits them to having this cellular-dependent setup. Whereas Reachnow (BMW), car2go / Sharenow (mercedes / smart), and limepod (fiat, for now) have limit the car type for better integration.

In a related front, a friend moved into an apartment building with some bluetooth-based laundry vending machines. The machine requires blootooth, and the payment is done via phone which requires a cellular connection. The laundry room (like any basement area) has a spotty cell connecition, so the friend does some weird positioning exercise to find the area where he can have a cellular connection while still being connected over bluetooth to the laundry machine. Strange future.

Zipcar has RFID-based card access now. Sounds like they just need to cache an auth token locally when there is cell service saying how long the car may be used for. Although there's still an edge case that parking out of cell service range when the token expires will disable the car even if you extend the contract since there's no way to refresh the token.

Perhaps they could create an RFID token in their app and let the RFID-capable phones bear that to the car since it's much easier to move a phone than a car, not to mention potentially get wifi service where there is no cell service.

I haven't used any of the services you mention, but an on-line rental service I have used has a simple system: they unlock the car remotely when you start your rental, and the key is in the glove compartment. You may run into issues starting your rental, but lack of connectivity won't stand you in the middle of nowhere.

Is there a particular reason these services can't just leave the keys in the car? Theft?

ZipCar has keys in the car and it's part of the service rules that the key CANNOT LEAVE THE CAR. I have no idea if they use rfid or something to check, but I felt it was really clear in their "how to use" videos that the keys never leave the car, you can can get banned from ZipCar.

So while there are keys in the car that you could have held onto to use during a cell service outage, you're told to never remove them from the vehicle.

That's pretty dumb. Car2go (Vancouver) has keys in the glovebox in a special holder-device: you're free to take the keys with you if you want to keep paying for the car as it's parked, but it won't let you "end session" or whatever unless the keys are replaced into the holder thingy.

This also avoids some of the problems mentioned in the above article. I assume they have a remote-kill but unless there's a serious problem, you always have the keys so you can always start the car.

If the car has no signal, how is it unlocked?

That's a problem when starting the rental and returning the car. Pickup points should be placed in areas with good reception. But in any case, not being able to start a rental is a nuisance. Not being able to use the car once you've driven it somewhere is potentially dangerous. I don't see why the car should need a connection to unlock once the rental has been started.

In the Netherlands, we have Greenwheels, which in addition to being accessible using an app, also allows you to open the car with an NFC-enabled card (I'm assuming for the case where my phone doesn't have reception?). If the car doesn't have reception either then I'm not sure you would be able to open it.

EDIT: Actually, after you pick up the car and start driving it, you (un)lock the car using the keys that are in the glovebox. In principle, you should be able to drive into dead zones without an issue

They could give your phone a signed token indicating your rental times, and then let your phone directly connect to the car to hand it off.

Presumably it is easier for a human with a phone to move to a location with service than moving a locked car, usually just out of the cave you're in.

I just don't see why that complexity is necessary, when you could just give the user the key to the car.

The whole point of zip car is that you aren't reserving it a week in advance and want to wait for a key to be mailed to you.

Why can't they just leave the key in the glove compartment? That way, Zipcar only needs to unlock the car remotely when the user starts the rental, and lock the car remotely when the rental ends. In between, the user can use the key. like with every other car.

Probably to prevent accidentally taking the key. If you've ever used a zipcar, the key is affixed to the steering column. I assume they have an ignition interrupter that requires a proper unlock signal because otherwise stealing one would be matter of jimmying a lock or breaking a window.

Good question, but if there is no signal how could the previous driver have locked the car? Similar services I'm using don't let me end the rental if there is no signal, simply because either the car or the shop on my phone can't talk with the server.

This sounds like a pretty common scenario for zipcar and certainly cell phone coverage coming in and out is something that they should be planning and designing for! Maybe a series of one-use pass codes or something like that could help. I always make sure there is a failsafe when I have two microcontrollers talking on the same circuit board! Never fully trust anything external.

There are many things they could do with software only without having to change their current scheme.

- Use exponential backoff when looking for network (although I find this part of the story hard to believe, my phone survives much longer when there is no network)

- Have a larger grace period. Let the key card just work for an extra day or indefinitely if the car's last known location is not the garage. Charge the customer for the usage.

- Fail open especially if the battery is low. Once the car starts, you have all the electricity you need to do updates.

- Make the updates small and efficient, so long as a few signed UDP packets get through, you can update the schedule. You can even use SMS. Sync non critical things (e.g. logs) opportunistically and asynchronously.

>my phone survives much longer when there is no network

Interestingly I've had the opposite experience (with a Pixel 2 XL, and before that a Nexus 6P). With both phones, when going on out-of-service hikes the battery drained significantly faster than usual -- despite not using the phone at all, I'd see a 40-50% power drain over ~8 hrs. Putting the phone in airplane mode when I knew I'd be out of service solved the problem, as expected.

My Pixel 3, on Fi, also seems to heat up quite a bit whenever I am at a bad network location!

In the good old days, you could touch your TV's rabbit ear antennas and do some weird positioning exercises to improve your service.

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