Introduction

　　The presence of illegal mobile phones in prisons enables prisoners to continue their criminal activities, posing a serious threat to prisons and social security. signal jammer This article explores the sources, uses, and existing and potential technical solutions for mobile phones in prisons.

　　Use of mobile phones in prisons

　　NOMS reports that prisoners use these mobile phones to carry out a range of criminal activities, including commissioning murders, planning prison breaks, importing automatic firearms and arranging drug smuggling. Wifi jammerThere are multiple cases where prisoners have organized criminal activities in prisons, posing a serious threat to social security.

　　How mobile phones enter prisons

　　The mother of a prisoner at Northumberland County Prison claimed that "this place is full of mobile phones." Mobile phones enter prisons in a variety of ways, such as being thrown over the fence or delivered by prisoners using drones. Glyn Travis of the Prison Officers Association (POA) pointed out that drugs and mobile phones are thrown into prisons at will, and drone delivery completely undermines external security.

　　Technical solutions and costs

　　The technical solutions proposed by the Prison Service include jamming, grabbing, operator disconnection and intercept and search:

　　Interference/jamming: Sending a signal to prevent mobile phones from receiving base station signals, all mobile phones and SIM cards within the jammer's range will be blocked. This method is cheap and very effective, but can cause disruption outside the prison, increasing costs.

　　Grab: Phones are attracted to fake networks, which are selective and can whitelist phones that are not affected. Success can be quantified and illegal phones can be monitored, but the cost is high.

　　Operator disconnection: The Serious Crime Act 2015 introduced the power to force mobile phone operators to disconnect, but the relevant regulations have not yet been enacted. Operators may be reluctant to cooperate, and disconnected phones and SIM cards can be easily replaced.

　　Stop and search: Mobile phones are found by searching visitors and staff, searching cells and prisoners, and training sniffer dogs, but these measures also have their limitations.

　　Although these technical solutions seem effective, NOMS said the costs are "disproportionate". For example, the cost of installing and maintaining jammers is hundreds of millions of pounds.