So the most common way for physical merchants to accept XMR is that they generate an address, display a QR code, the customer scans the QR code on their device and broadcasts a transaction, they see that their address has received the payment and complete the transaction.
This usually works fine, except in situations where the customer can't connect to the internet (e.g. no open WiFi, no mobile subscription).
A way I devised to solve this is by having the customer's device, instead of broadcasting the transaction itself, send the signed transaction via NFC to the merchant who then broadcasts it to the network. This doesn't appear to be something that's been tried before, at least according to my rudimentary Bing search.
Unfortunately I'm not versed enough with Monero's technical implementation to know the viability of this. What do you think—is it possible and a good idea?