I'm currently a student and I am looking to start doing some side projects. I've thought of trying to detect a cell phone from a certain range (5 meters max).

Is this possible to do with a cell phone that is idle? From what I have been reading, it's easy to do while someone is talking on the phone, sending text messages, etc but haven't seen much while idle.

Im looking to do something like in this video:


  • \$\begingroup\$ You can do it with a broadband antennna, preamp, spectrum analyser, interface, computer and analysis software. \$\endgroup\$ Mar 16, 2017 at 8:41
  • \$\begingroup\$ The referenced video detects incoming/outgoing transmissions. As in, the phone is NOT idle. \$\endgroup\$ Mar 16, 2017 at 13:09

1 Answer 1


A cell phone is never 'idle' as such. It periodically measures the RSS (Received Signal Strength) from all the nearby Base Stations, and chooses the one which offers the highest RSS. This is how a cell phone remains connected to the network. Hence, you could still detect the cell phone even while it's not being used as such.


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