3 ms·
Both phones send a precise timestamp of the "bump" to the server. The server finds bumps that happen at the same time, and "connects" the phones. If multiple b
by jakobegger 8y ago
Both phones send a precise timestamp of the "bump" to the server. The server finds bumps that happen at the same time, and "connects" the phones.
If multiple bumps happen at the same time, the server would probably use approximate geolocation or something like that additionally, but the better the resolution of the time stamp, the lower the probability of collisions between bumps.
- Jagat 8y ago"precise timestamps" from two phones is a hard distributed systems problem. If timestamp and geo were the only things that the app used, I wonder if it worked well only because there weren't too many people 'bumping' at the same time from that geo.