Signal Inhibitors


Signal inhibitors, also known as jammers, are devices that generate interference or otherwise intentionally disrupt communication services. In the case of mobile services, they interfere with the communication between the mobile terminal and the base station. Their use by private individuals is banned in countries such as Australia, the United Kingdom and the United States.

In some regions, such as Latin America, signal inhibitors are used to prevent the illegal use of mobile phones in specific locations, such as prisons. However, blocking the signal does not address the root cause of the problem — wireless devices illegally ending up in the hands of inmates who then use them for illegal purposes.

Moreover, signal inhibitors don’t prevent mobile devices from connecting to Wi-Fi networks, as they don’t affect the frequency bands used by Wi-Fi routers. As a result, signal inhibitors don’t block people from using over-the-top voice applications to make calls to phone networks.

Mobile network operators invest heavily to provide coverage and capacity through the installation of radio base stations. However, the indiscriminate use of signal inhibitors compromises these investments by causing extensive disruption to the operation of mobile networks, reducing coverage and leading to the deterioration of service for consumers.


Should governments or private organisations be allowed to use signal inhibitors that interfere with the provision of mobile voice and data services to consumers?
Should the marketing and sale of signal inhibitors to private individuals and organisations be prohibited?


GSMA Public Policy Position: Signal Inhibitors in Latin America
GSMA Report: Safety, Privacy and Security Across the Mobile Ecosystem
GSMA Report: Signal-Blocking Solutions — Use of Jammers in Prisons

Industry Position

In some Latin American countries, such as Colombia, El Salvador, Guatemala and Honduras, governments are promoting the deployment of signal inhibitors to limit the use of mobile services in prisons. The GSMA and its members are committed to working with governments to use technology as an aid for keeping mobile phones out of sensitive areas, as well as co-operating on efforts to detect, track and prevent the use of smuggled devices.

However, it is vital that a long-term, practical solution is found that doesn’t negatively impact legitimate users, nor affect the substantial investments that mobile operators have made to improve their coverage.

The nature of radio signals makes it virtually impossible to ensure that the interference generated by inhibitors is confined, for example, within the walls of a building. Consequently, the interference caused by signal inhibitors affects citizens, services and public safety. It restricts network coverage and has a negative effect on the quality of services delivered to mobile users. Furthermore, inhibitors cause problems for other critical services that rely on mobile communications. For example, during an emergency they could limit the ability of mobile users to contact emergency services via numbers such as 999, 911 or 112, and they can interfere with the operation of mobile-connected alarms or personal health devices.

The industry’s position is that signal inhibitors should only be used as a last resort and only deployed in coordination with operators. This coordination must continue for the total duration of the deployment of the devices — from installation through to deactivation — to ensure that interference is minimised in adjacent areas and legitimate mobile phone users are not affected.

Furthermore, to protect the public interest and safeguard the delivery of mobile services, regulatory authorities should ban the use of signal inhibitors by private entities and establish sanctions for private entities that use or commercialise them without permission from relevant authorities. The import and sale of inhibitors or jammers must be restricted to those considered qualified and authorised to do so and their operation must be authorised by the national telecommunications regulator.

Nevertheless, strengthening security to prevent wireless devices being smuggled into sensitive areas, such as prisons, is the most effective measure against the illegal use of mobile devices in these areas, as it would not affect the rights of legitimate users of mobile services.