Countering Contraband Cell Phone Use in Prisons A Technical Explanation of Available Technologies

Electronic Sniffers Sniffer emits low power radio signal and detects reflections from nearby electronics –Must be close to the cell phone to detect it –Detects cell phones whether they are on or off and does not depend on frequency band Sniffer Emits Signal Detects Response

Passive Detection Listens for cell phone signals –Only detects a cell phone when it is active –Calls can be connected –Network of sensors triangulate cell phones –Hand-held detectors are also available Detector System Provides Location Of Devices Prison Building Footprint

Jamming Jamming is the deliberate radiation for the purpose of disrupting use of electronic devices, equipment, or systems Cell Phone Jammers: –Are frequency band specific, transmit on same radio frequencies as the cell phone to overpower desired signals and disrupt link between phone & tower –Do not discriminate among cell phones within range of the jamming signal – both contraband and legitimate cell phones are disabled Jammer Radio Signal Generator Prison Building Footprint Can be a Network of Individual Jammers or Use “Leaky” Cable All Calls Blocked

Inmate Call Capture Technologies Effectively a mini-cell site Impermissible calls are not connected (blocked) Permissible calls are released and connected as usual Policies selectable by system administrator All 911 calls can be connected Prison Building Footprint Permitted Calls Connected to Cell Network As Usual Prison Managed Access Cell Site Blocks impermissible Calls Captured & Released