JAMMERS IN PRISONS: Characteristics, impact and alternative solutions Signal Inhibitor Solutions Use of jammers in prisons GSMA LA 1 JAMMERS IN PRISONS: Characteristics, impact and alternative solutions The GSMA represents the interests of mobile operators BlueNote Management Consulting specialises in worldwide, uniting more than 750 operators with over the telecommunications and media sector, working 350 companies in the broader mobile ecosystem, on strategy, public policy and regulation projects including handset and device makers, software in collaboration with the private sector, official companies, equipment providers and internet agencies and regional entities. companies, as well as organisations in adjacent industry sectors. The GSMA also produces industry-leading BlueNote has two offices, in Buenos Aires events such as Mobile World Congress, Mobile World (Argentina) and Bogotá (Colombia). Its team of Congress Shanghai, Mobile World Congress Americas consultants has a wide range of qualifications and and the Mobile 360 Series of conferences. experience in the telecommunications and media sector, gained in consultancy and public and For more information, please visit the GSMA corporate executive positions. BlueNote operates primarily website at www.gsma.com in Latin America, where its consultants have been Follow the GSMA on Twitter: Twitter: @GSMA and @ involved in technical, regulatory and economic GSMALatam aspects of the sector for more than 15 years. www.bluenotemc.com 2 GSMA LA JAMMERS IN PRISONS: Characteristics, impact and alternative solutions Table of Contents 1. EXECUTIVE SUMMARY 4 2. INTRODUCTIONS 7 3. GENERAL CONCEPTS OF SIGNAL INHIBITORS AND MOBILE NETWORKS 8 3.1. RADIO PROPAGATION BASICS 9 3.2 BASIC PRINCIPLES OF MOBILE NETWORKS 10 3.3 MOBILE SIGNAL INHIBITORS (JAMMERS) 14 3.4 IMPACT OF MOBILE SIGNAL INHIBITORS (JAMMERS) 19 4. INTERNATIONAL EXPERIENCE 22 4.1. OVERVIEW OF MOBILE SIGNAL INHIBITORS (JAMMERS) IN LATIN AMERICA 23 4.2. COMPARATIVE ANALYSIS OF REGULATORY FRAMEWORKS ON THE USE OF 25 JAMMERS 4.3. GOOD PRACTICE IDENTIFIED 29 5. ALTERNATIVE TECHNICAL SOLUTIONS 30 5.1. DESCRIPTION OF ALTERNATIVE TECHNIQUES AVAILABLE ON THE MARKET 31 5.2. ANALYSIS OF ALTERNATIVES 34 5.3. CONCLUSIONS AND RECOMMENDATIONS 36 6. REFERENCES 37 ANNEX I. CASE STUDIES 38 ANNEX II. REGULATORY FRAMEWORKS ON THE USE OF JAMMERS 40 GSMA LA 3 JAMMERS IN PRISONS: Characteristics, impact and alternative solutions Executive summary The use of mobile communication devices smuggled establish or maintain stable communication. Jammers into prisons is one of the main drivers for implementing treat all communication attempts the same and do not technical solutions to block, restrict or inhibit mobile distinguish between different users trying to establish communications signals. One of these solutions is the a connection. This means they cannot discriminate use of mobile signal inhibitors (jammers). between terminals in their coverage area or prevent blocking of emergency numbers. Signal inhibitors or blockers, commonly known as jammers, are radio devices that intentionally transmit In other words, regardless of whether communications signals to affect, block, interfere with or saturate the are authorised or targeted for restriction, blocking will communications services of mobile users. This includes depend on the power level of the signals generated calls, text messages, GPS positioning signals, data by the base station or the mobile device and the services and Wi-Fi networks. power level of the interfering signal. Given the inherent functionalities of mobile phone networks and the These devices are governed by commercial many radio propagation characteristics that affect communications systems and radio propagation the definition of a coverage area, there may be points characteristics. Their coverage depends on two factors in the area targeted for blocking, where calls can be - 1) its design (e.g. including transmission power and established or data services can be accessed. Similarly, filter quality) and 2) radio propagation factors (the there may be points beyond the defined area where frequency it transmits on environmental obstacles communications services are blocked. such as buildings, trees and bodies of water, which can reflect or refract signals or cause them to take several Blocking mobile frequency bands is not sufficient paths). to prevent covert communications, because other services or technologies can be used, including Wi-Fi, Signal inhibitors (jammers) generate a signal that is VHF (walkie talkies) and satellite. intended to interrupt communication between the base station of a communications network and a user’s mobile device. This reduces the ratio between the useful or real signal and the interfering signal measured on the device or at the base station. In these conditions, no digital signal recovery mechanism can differentiate between the signals and it is impossible to 4 EXECUTIVE SUMMARY JAMMERS IN PRISONS: Characteristics, impact and alternative solutions The most common impacts of the use of jammers are: The Latin American countries surveyed all have similar experiences in respect to addressing unauthorised a. Communications are blocked beyond the communications from prisons. Points in common prison grounds, preventing users from accessing include the background context, the initiatives for authorised communications services, including solutions and the institutions involved. In the countries emergency calls. studied, unauthorised use of radio devices that intentionally or maliciously interfere with authorised b. Communications services are degraded the communications is classified as a clandestine, or area surrounding prisons, resulting in constantly unlawful use of spectrum. In the United States, the sale, dropped calls, poor quality of communications marketing and importing of these devices is restricted and slow data services. by legislation, although exceptions based on public safety or general interest allow their use in confined c. Using jammers with poor quality filters and spaces, such as prisons. In all the cases examined, it is a transmitters can generate harmful emissions requirement that communications services beyond the outside the operating band, affecting radio prison grounds must not be affected. services that operate in other bands. The following table provides a summary of the main d. When jammers operate in multiple frequency regulations passed in Latin America on the use of bands, they can generate harmful interfering jammers. signals in other bands and affect all types of services. They may even obstruct the work of police by blocking law enforcement radio communications systems, due to a phenomenon known as intermodulation products 1. e. Blind spots can occur inside prisons, where unauthorised communications can still be established. FIGURE 1 Regulations on jammer characteristics and installation procedures Source: BNMC 1. Comments made to the NTIA by the industry about the deployment of jammers in prisons (NTIA, 2010) EXECUTIVE SUMMARY 5 JAMMERS IN PRISONS: Characteristics, impact and alternative solutions In the countries studied, national laws and regulations ShawnTech, CellAntenna and SESP, five basic categories state that under prison regulations and the of technology solutions for controlling unauthorised competences of the institutions involved, responsibility communications from correctional centres can be for implementing signal blocking solutions lies with identified: i) blocking by generating interfering radio detention centres and prisons. Telecommunications signals with some selectivity, ii) capturing communications authorities have a role in advising and developing to control access to commercial networks (Managed regulations applicable to the sector, while Access Systems), iii) techniques that mimic a mobile communications service operators have a cooperation network cell but do not allow access to services (dummy and advisory role. cells), iv) detection, and v) hybrid solutions combining two or more of these techniques. Based on the experience in the countries studied and the product portfolio of some of the leading The following table provides a comparative analysis of the manufacturers of call restriction solutions, such as Harris, alternatives available. FIGURE 2 Comparative analysis of alternatives Source: BNMC The table shows that the technical alternatives available The problem of unauthorised communications from on the market to restrict unauthorised communications prisons must be addressed across the board. This from prisons do not perform satisfactorily across involves revising security procedures to restrict the the differing factors analysed. Thus, each prison entry of communications devices into prisons, blocking should be studied individually to identify the solution or restricting unauthorised communications, detecting that best meets its needs and priorities. It is also and seizing contraband terminals that have entered advisable to adopt good practice in the installation of prisons, and analysing intelligence information to follow radiocommunication systems suggested by the industry up incidents and identify patterns of behaviour to avoid and constantly monitor their impact. reoccurrence. 6 EXECUTIVE SUMMARY INTRODUCTION 7 JAMMERS IN PRISONS: Characteristics, impact and alternative solutions Introduction The use of mobile communication devices smuggled This document is structured as follows: into prisons to commit offences such as threats, extortion