I was expecting some arcane optical-modem procedure where you point the receiving phone's camera at the sender's screen, which flashes a series of glyphs or something like a high-bandwidth QR code. That would've been cool. Instead it turns out that "even when they're offline" just means "we were lying about that part." Oh well.
Heh. Well "offline" probably means you don't see the little WiFi bars on the status bar. You can put a Wifi chip in what is effectively promiscuous mode and have it talk to an ad-hoc network (which appears to be what they are doing) that or a bluetooth PAN connection.
Hmm. "Offline" is a bit more nebulous with a cellphone, since you can reasonably expect it to send and receive data (calls, text messages, GPS) even when there's no active Internet connection. From the article's breathless language, it really sounded like they were trying to say "not sending or receiving any radio signals," only then it turned out that they weren't.
I was expecting some arcane optical-modem procedure where you point the receiving phone's camera at the sender's screen, which flashes a series of glyphs or something like a high-bandwidth QR code. That would've been cool. Instead it turns out that "even when they're offline" just means "we were lying about that part." Oh well.