Since 1 January 2018, the importation and the possession of a jammer have been strictly prohibited in Switzerland as in several European Union countries. The rules applicable to these devices, also known as "blockers", have therefore been made stricter, since previously the ban related solely to placing them on the market and using them. Because these jammers in particular prevent all communication by mobile telephone, they can represent a danger, since emergency calls are rendered impossible. Most of the time, advertising for this kind of device is misleading: it implies that their use is legal and takes care not to indicate that even their possession is illegal.
Initially expensive, bulky and limited to blocking mobile communications in the GSM 900 MHz frequency band, jammers have mirrored technological development. They have become smaller, cheaper and can now block much more of the spectrum. Indeed, in addition to the mobile telephony bands (GSM, UMTS, LTE, ...), some models allow jamming of devices of navigation satellite systems tracking (GPS, Glonass, Galileo, ...), data transmission (WLAN, RLAN, WiMax, ...) or wireless alarms. Their use has also evolved. Used initially to block communications (in trains, restaurants, cinemas, ...), they have also become an aid to committing crime: the theft of cars or trucks carrying goods of value (by disabling the vehicle tracking system), theft in dwellings (by disabling the wireless alarm system), etc.
Their multiplication has made it necessary to tighten up the law as of 1 January 2018. The entry into force on this date of a change to the telecommunications legislation prohibits the importation and the possession of jammers. The manufacture, placing on the market, commissioning, installation and operation of jammers also remain punishable.
By banning this type of equipment on its territory, Switzerland is supporting the position of the member countries of the European Union and of other States, such as the United States.
A security risk
The use of jammers is strictly prohibited because apart from causing inconvenience to users of the radio spectrum and being used in criminal activities, it can have serious consequences in relation to safety. Indeed, jammers can prevent emergency calls in the case of an accident or alerting emergency services personnel such as firefighters, policemen or paramedics. Jammers can also pose serious problems for civil aviation, which is increasingly based on the worldwide satellite navigation system (Global Satellite Navigation System, GNSS) in order to improve navigation performance and to assist the supervisory functions of the air navigation service.
According to the Telecommunications Act (TCA), their use amounts to a deliberate disruption of the radio spectrum, which is punishable by a fine of up to CHF 100,000. The offering and sale of such devices is illegal and therefore prohibited. OFCOM intervenes systematically in such cases.
Jammers for the authorities
The situation is different in prisons. Inmates could use mobile phones to conduct criminal activities or to plan their escape. Another example is the deming of explosive devices which can be triggered by radio. The Telecommunications Act (TCA) expressly provides options for penal institutions and the police to operate jamming systems for neutralising communications within their boundaries. This type of use is subject to prior approval by OFCOM.