Countering Contraband Cell Phone Use in Prisons

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

2. 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 Emits Signal Sniffer Detects Response

3. 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 Detector Detector System Provides Location Of Devices Prison Building Footprint

4. 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 Jammer AllCalls Blocked Radio Signal Generator Can be a Network of Individual Jammers or Use “Leaky” Cable Jammer Prison Building Footprint

5. 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 Captured & Released Prison Managed Access Cell Site Blocks impermissible Calls Permitted Calls Connected to Cell Network As Usual Prison Building Footprint