Communicating between two smartphones without using a Cellular Tower - Peer to Peer

Question

Lets say I have 2 mobile phones which are 50 meters away from each other and I would like to send a very small packet of data from mobile-A to mobile-B, without using any communication to cellular tower.

To make it simpler, I would like to build an app which implements a Peer to Peer connection for 2 mobiles in the same radius (in the same area).

Is this feasible using the technology of smartphones these days? (Android for example)

Answer 1

No. The radio services the mobile networks are licensed under vary by country, but none that I know of allows for that kind of ad-hoc communication.

50 meters would be a stretch for WiFi, especially in a pair of handsets with less-than-ideal antennas. Bluetooth would also be right out.

Answer 2

Bluetooth is your best bet, but even in an open field 50 meters would be too far apart.