Prisons are to become a radio hole: Handyblocker in the test

Osnabrück. Strictly speaking, phoning with mobile phones is forbidden in German prisons. Strictly speaking. In fact, detainees always find a way to contact the outside world via mobile phones. In Bavaria, Berlin and Offenburg are currently being tested so-called Mobilfunkblocker. Also at the Technical University Braunschweig is tinkering. The goal: mobile phone-free jail.

Anyone entering a prison in Germany must actually hand in their cell phone at the gate. This applies to inmates as well as visitors. But somehow the devices find their way into the cells again and again. Sometimes they are thrown over the wall, sometimes smuggled in by other means.

Roland Schauer knows the problem. He heads the prison Lingen. “With today’s devices, we can barely prevent cell phones from finding their way to jail every now and then,” said the head of the facility. “The perceived need to own a mobile phone is no different in a prison than it is outside.”

The problem from the perspective of the judiciary: Not all prisoners call only their relatives. There is a danger that the witness may be intimidated by mobile phone or that the criminal business may continue by telephone. For the cell phone, says Head of Jury Schauer, speaking from the point of view of detainees also: “It is cheaper. We have possibilities to telephone – but only to the tariff of a telephone booth. ”

And so find the guards within the prison Lingen every now and then a cell phone. So far, so-called mobile phone finders were used in the search. According to Schauer, this alarm will sound as soon as a mobile phone goes into operation. Then the phone can be located approximately.

That’s not enough for many. In Knestern radio silence should prevail. That is why a test has been running in Offenburg for a good year – with success, as the Ministry of Justice in Baden-Württemberg has now announced. According to ministry information, 700 small cell phone jammer have created an artificial radio hole over the prison in Offenburg for one year. Now the project is to be extended to other prisons in the country.

In Lower Saxony one behaves wait and see. Two reasons put forward a spokesman for the Ministry of Justice against the Handyblocker in the field: First, the installations with an investment of several million euros per prison are still too expensive. Second, a technical adjustment is difficult only on the grounds of the prison.

Jörg Schöbel is currently looking for a solution for both problems. He is a professor at the Technical University of Braunschweig and researches together with two partner companies from the economy – including a producer of jamming transmitters for military and police from Schleswig-Holstein. Among other things, the company develops devices that are designed to paralyze the detonating mechanisms of explosive devices. With 143,000 euros in subsidies, the Federal Ministry of Economics and Technology supports the project, according to information from our newspaper.

Schöbel takes a different approach than the one in Offenburg. “Our solution relies on detectors and interferers, which are installed in the corridors and outdoor areas, so out of reach of the occupants. They are therefore not as easy to manipulate as the cells in the systems in Offenburg. “The professor fears namely, that jammers could already put in a room with a wet towel override.

The researcher must observe certain framework guidelines. Permanent disturbers are hardly enforceable in Germany. Schöbels goal: A detector detects a mobile signal, then sets a jammer in operation, the funks until the phone is the connection setup. And all this under the condition that the world outside the prison walls remains untouched by the attempts to disrupt.

Schöbel is optiistic that this is possible at a reasonable cost. Yet another advantage of his method: “Because the detectors have only a certain range, you can also specify the location of the cell phone using the detector that has triggered. So only a few cells would have to be searched to find the mobile phone. ”

Incidentally, the professor attaches great importance to a statement: the mobile phones can not be eavesdropped on with their technology. That would be contrary to the Telecommunications Act. In Bavaria, for example, where a mobile phone blocker test is also running, so-called IMSI catchers are used. The not only allow the approximate location of the cell phone. Also listening in would be possible.