
Ask HN: Ideas for high speed one-to-many communication between smartphones - msaad99
Here&#x27;s the scenario: You have a bus driver with a smartphone connected to the internet. Then you have the passengers(who have booked seats on the bus) with smartphones as well but NO internet connection. The bus will pick up passengers at every stop and each of these passengers needs to quickly perform a &quot;check-in&quot; once they on board (there&#x27;s no internet on the bus either). Because of budget constraints, it is not possible to provide internet on the bus or install any 3rd party device (like QR code reader) that could handle check-ins.<p>Ideally what should happen is: The passengers&#x27; offline phone somehow communicates quickly to the drivers and shares its boarding id (Bluetooth conns are a hassle and won&#x27;t work well when multiple people onboarding). The driver phone (connected to the internet) verifies booking from the server and communicates back to the offline phone with a success message. All without any intermediary device and while handling multiple passengers at the same time.<p>One idea is to use something like chirp.io to transfer data using sound. Any other ideas?
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anovikov
One could possibly expose a wifi network who's SSID will act as a boarding id.
So a driver's phone only needs to scan for wifi networks frequently enough,
and when it recognizes one that can be a boarding id, connect to that network
and supply a password which can be interpreted as a success reply? Connection
may fail then, it's ok - all that's needed is knowing a SSID and trying to
connect, thus supplying a password.

Idk how difficult it is for the mobile apps to create wifi hotspots from
phones, but should be doable.

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phillipseamore
Already solved with QR codes

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anovikov
>it is not possible to provide internet on the bus or install any 3rd party
device (like QR code reader)

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phillipseamore
>> You have a bus driver with a smartphone connected to the internet

>> [Y]ou have the passengers(who have booked seats on the bus) with
smartphones

Any smarthpone can display a QR code and all can read them. No internet
required.

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msaad99
It'll be a big hassle for the bus driver to scan QR code from every
passenger's phone. Please also keep in mind that these bus drivers are tech-
illiterate and they have very little idea of how to use a smart phone. Their
main role is basically to open up maps and follow the route.

