Can we propogate signal from android application to know another user having the same application in android phone

Question

I am building an android app as my project. I need to implement a functionality which can let me know the same types of users (having my application in their phone) around in 1-5 meter distance. Is there anything that i can use or can i propogates any signals to do so. I dont want to connect those users but I am just interested in knowing the presence of my application in the vicinity/area. The only thing I am aiming is mapping the users who has same applications. You can consider the below given scenario.

Example: suppose My application is 'TESTAPP'. There are 100 students on a floor, out of those 10 have my application. If one of 10 student turn on the application, then 1. I want to know that, there are more 9 students present at the same floor. 2. if possible i wan to map them by propogating a signal through 1st user.

Note: I am Creating a cloud based webservice for android and using geolocation.

Answer 1

You could use Bluetooth or WiFi P2P. See http://developer.android.com/training/connect-devices-wirelessly/nsd-wifi-direct.html