title: Using BLE for indoor positioning
body: <p>I have a project that i need to know that if some smartphones are in the same room to implement that i checked several approaches but i found using BLE the best. </p>
  
  <p>The algorithm is that i have a master smartphone that i know is in the room and i want to validate all other smartphones with RSSI that this smartphone get from them. I want to know that does any body have any experience about this approach like that how much the RSSI should be that i be sure that other smartphone is in the same room that master smartphone is?</p>