CONTRABAND CELL PHONES IN PRISONS 

Possible Wireless Technology Solutions

U.S. Department of Commerce

Gary Locke

Secretary of Commerce

Lawrence E. Strickling

Assistant Secretary for

Communications and

Information

December 2010

TABLE OF CONTENTS

Executive Summary............................................................................. 1

Section 1 – Introduction

Overview.................................................................................. 3

About This Report........................................................................ 4

Section 2 – Federal Efforts

NTIA....................................................................................... 7

Federal Communications Commission............................................... 9

Federal Bureau of Prisons............................................................... 10

National Institute of Justice............................................................. 11

Section 3 – Jamming

Overview.................................................................................. 13

Summary of Comments................................................................. 13

Observations.............................................................................. 18

Section 4 – Managed Access

Overview................................................................................... 19

Summary of Comments................................................................. 19

Observations.............................................................................. 25

Section 5 – Detection

Overview................................................................................. 27

Summary of Comments................................................................. 27

Observations.............................................................................. 31

Section 6 – Other Technologies

Standardized Protocols.................................................................. 33

Hybrid Systems.......................................................................... 34

Non-Linear Junction Detectors........................................................ 34

Observations.............................................................................. 35

Section 7 – Summary............................................................................ 37

Appendix A – NTIA NOI on Contraband Cell Phones.................................. 41

Appendix B – List of Commenters by Group.............................................. 47

Appendix C – Vendors and Solutions........................................................ 49

Appendix D – Commonly Used Acronyms.................................................. 51

Table 7-1: Approaches for Contraband Cell Phones...................................... 39

Table 7-2: Advantages and Disadvantages of Various Technologies.................. 40
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1

EXECUTIVE SUMMARY

The National Telecommunications and Information Administration (NTIA) submits this report in 

response to a direction from Congress in December 2009 that NTIA, in coordination with the 

Federal Communications Commission (FCC), the Federal Bureau of Prisons (BOP), and the 

National Institute of Justice (NIJ), develop a plan to investigate and evaluate wireless jamming,

detection, and other technologies that might be used to prevent contraband cell phone use by 

prison inmates. NTIA has identified and evaluated several technology solutions for this report 

that can be used in a prison environment, including jamming, managed access, and detection 

techniques. In the preparation of this report, NTIA sought input from the FCC, NIJ, and BOP

regarding their efforts to combat contraband cell phone use.

The Administration believes that contraband cell phone use by prison inmates to carry out 

criminal enterprises is intolerable and demands an effective solution. Prison officials should 

have access to technology to disrupt prison cell phone use in a manner that protects nearby 

public safety and Federal Government spectrum users from harmful disruption of vital services, 

and preserves the rights of law-abiding citizens to enjoy the benefits of the public airwaves 

without interference.

To obtain public input on these issues to assist in developing this report, NTIA issued a Notice of 

Inquiry (NOI) in May 2010 soliciting comment on a series of detailed questions to help identify, 

clarify, and characterize these solutions. NTIA received comments from forty-six sources. In 

addition to providing input regarding the three technologies identified in the NOI, commenters 

identified additional technologies for consideration. 

Working in coordination with its Institute for Telecommunication Sciences, NTIA performed 

both laboratory and field measurements on a selected jammer. NTIA subsequently analyzed the 

results of those measurements to determine, as far as possible, the potential impact of that 

jammer on other authorized radio operations.

This report discusses the characteristics and capabilities of the various technologies and 

considers the potential interference effects that they may have on authorized radio services, 

including commercial wireless, public safety communications, and 9-1-1 calls. Three possible 

wireless technology solutions were identified in the NOI that commenters further expounded 

upon: jamming, managed access, and detection. NTIA‘s observations on each of these 

technologies are as follows.

A jamming device transmits on the same radio frequencies as the cell phone, disrupts the 

communication link between the phone and the cell phone base station, and essentially renders

the hand-held device unusable until such time as the jamming stops. A cell phone jammer has 

the potential to cause interference outside of the prison or to adjacent bands unless properly 

designed. Jamming interferes with 9-1-1 and authorized calls and violates the Communications 

Act of 1934 when performed by non-Federal officials. Implementation costs vary with the 

complexity of the prison site.
2

Managed access systems intercept calls in order to prevent inmates from accessing carrier 

networks. The cell signal is not blocked by a jamming signal, but rather, is captured (or rerouted) and prevented from reaching other network base stations, thereby preventing the 

completion of the call. Managed access systems have the potential to cause interference outside 

of the prison or to adjacent bands unless properly designed. However, such systems do permit

9-1-1 and known authorized calls. They require FCC approval and carrier consent for 

deployment. Costs can vary based on the complexity of the prison site.

Detection is the process of locating, tracking, and identifying various sources of radio 

transmissions – in this case, cell phone signals from prisons. Detection systems are passive in 

that they do not transmit, and therefore do not cause interference. Such systems protect 9-1-1 

and authorized calls and, unless they are used for data gathering for law enforcement 

intelligence, raise no regulatory or legal issues.

Commenters on the NOI identified the following additional possible wireless technology

solutions: standardized protocols, hybrid systems, and Non-Linear Junction Detectors (NLJDs). 

Standardized protocols rely on ―sets of instructions‖ communicating with the hand-held device 

by essentially locking the device and making it unusable. This suggested solution is predicated 

on the adoption and implementation of standardized protocols (by the wireless industry) 

embedded in the firmware of mobile devices. Hybrid systems use a combination of both 

managed access and detection techniques to locate and control contraband cell phone use. 

Hybrid systems do not cause interference if using detection-only; however, for managed access, 

the potential exists to cause interference outside prison or to adjacent bands unless properly 

designed. Hybrid systems permit 9-1-1 and authorized calls but require FCC approval and 

carrier consent. Costs could vary based upon the complexity of the prison site. NLJDs are handheld devices that require staff to physically search a prisoner‘s cell for the contraband phone. 

They present no regulatory or legal issues and do not interfere with other authorized users.

Each of the technologies identified has trade-offs and its own set of advantages and 

disadvantages. Some of the approaches come with legal hurdles or limitations. Furthermore, 

each prison‘s own unique characteristics (e.g., size and configuration of the prison), environment 

(rural versus urban setting), resources (e.g., financial and staff), and requirements (e.g., need for 

law enforcement intelligence) will help determine which approach is the most practical, feasible, 

and economical to implement.
3

SECTION 1

INTRODUCTION

OVERVIEW

The mobile phone industry has experienced significant growth since the inception of the analog 

wireless cell phone network in the early 1980s.1The 1990s saw the development of digital 

networks, and thereafter, high-speed data networks became available to consumers. The growth

of the mobile phone industry has been fueled, in part, by consumer demand for instant access to 

communication services anywhere and anytime. Features such as data, image, and video 

communications have also contributed to the overwhelming demand for mobile services and 

applications. Mobile devices have become a critical component of our information society, 

contributing to public knowledge, commerce, and public safety.

Just as consumer demands for mobile devices have risen rapidly, the use of cell phones by prison 

inmates has grown as the U.S. prison population continues to expand.

2

 This use is considered 

contraband by prison officials. The number of cell phones confiscated by prison officials has 

dramatically increased in only a few years. For example, during 2006, California correctional 

officers seized approximately 261 cell phones in the State‘s prisons and camps; by 2008, that 

number increased ten-fold to 2,811.

3

Similarly, in 2009, Maryland prison officials confiscated 

nearly 1,700 phones, up from approximately 1,200 phones the year before.4 NTIA did not 

investigate the causes of increased confiscation of contraband cell phones. This increase in 

unauthorized cell phone use by inmates is a mounting concern among correctional administrators 

across the country.5

 

1

For the purpose of this report, the use of the word ―cell phone‖ refers to any wireless, portable device that is 

available to the public on a subscription or prepaid basis for delivering voice and/or data services such as text 

messages. It includes, for example, phones operating within the Cellular Radio Service in the 800 MHz bands; 

broadband Personal Communications Services (PCS) in the 1.9 GHz bands; the Advanced Wireless Services (AWS) 

in the 1.7 GHz band; Specialized Mobile Radio (SMR) services in the 800 and 900 MHz bands; and any future 

mobile wireless devices that plan to operate in bands such as the 700 MHz band.

2 At the end of 2008, Federal and State correctional authorities had jurisdiction over roughly 1.6 million prisoners, of 

which over 200,000 (about 13 percent) were housed in Federal facilities. The Federal and State prison population 

rose by approximately 1 percent from year-end 2007 to 2008. See Sabol, William J., Heather C. West, and Matthew 

Cooper, ―Prisoners in 2008,‖ Bureau of Justice Statistics Bulletin, U.S. Department of Justice, Office of Justice

Programs, Bureau of Justice Statistics, Dec. 2009, page 16, available at 

http://bjs.ojp.usdoj.gov/content/pub/pdf/p08.pdf.

3

Special Report, Inmate Cell Phone Use Endangers Prison and Public Safety, Office of the Inspector General, State 

of California, May 2009, available at

http://www.oig.ca.gov/media/reports/BCI/Special%20Report%20of%20Inmate%20Cell%20Phone%20Use.pdf. 

4

State of Maryland Fact Sheet, Keeping Communities Safe, Maryland Department of Public Safety and Correctional 

Services, Feb. 2010.

5

See Department of Justice, Office of Justice Programs, National Institute of Justice, Cell Phones Behind Bars, Dec.

2009, available at http://www.ncjrs.gov/pdffiles1/nij/227539.pdf; Washington Examiner, Drug Dealer Who Planned 

Murder Gets Life Sentence, Scott McCabe, May 4, 2009, available at 

http://www.washingtonexaminer.com/local/crime/Drug-dealer-who-planned-murder-gets-life-sentence44327767.html; Wired Magazine, ―Prisoners Run Gangs, Plan Escapes, and Even Order Hits With Smuggled 

Cellphones‖, Vince Beiser, May 22, 2009, available at http://www.wired.com/politics/law/magazine/17-
4

In December 2009, Congress directed the National Telecommunications and Information 

Administration (NTIA), in coordination with the Federal Communications Commission (FCC), 

Federal Bureau of Prisons (BOP), and the National Institute of Justice (NIJ), to develop a plan to 

investigate and evaluate how wireless jamming, detection, and other technologies might be 

utilized for law enforcement and corrections applications in Federal and State prison facilities.6 

In response to Congress, this report presents the results from NTIA‘s plan—coordinated with 

other agencies—for the investigation and evaluation of those technologies.

ABOUT THIS REPORT

This report is the outcome of an overall plan to investigate and evaluate wireless technologies to 

prevent contraband cell phone use in prisons. NTIA has taken a number of actions and steps on 

issues that deal with contraband cell phone use. 

NTIA‘s Institute for Telecommunication Sciences (ITS) performed laboratory measurements on 

a jamming system at its laboratory in Boulder, Colorado in 2009. Further, ITS performed field 

measurements on the same jamming system at a Federal Corrections Facility in Cumberland, 

Maryland in 2010. Subsequently, NTIA performed a technical analysis based on these

measurements. The results and findings from these efforts are discussed in Section 2 and in 

separate NTIA reports.

7

Also in 2010, NTIA formed an interagency working group with the FCC, BOP, and NIJ to

coordinate the activities of this effort as required by Congress, and to become cognizant of other 

Federal agency efforts concerning contraband cell phones.

Further, NTIA, in coordination with the FCC, BOP, and NIJ, issued a comprehensive Notice of 

Inquiry (NOI – see Appendix A) on May 12, 2010 to seek public input in order to assist NTIA 

with its investigation and evaluation of technologies to prevent the use of contraband cell 

phones in Federal and State facilities. NTIA received forty-six comments (see Appendix B)

from a variety of interested and concerned parties categorized as follows:

 

06/ff_prisonphones. Contraband cell phone use has been noted to be a problem in Federal prison facilities as well. 

See Testimony of Harley J. Lappin, Director, U.S. Bureau of Prisons before the U.S. Congress, Hearing on the 

Fiscal Year 2009 Budget Request for the Bureau of Prisons, the U.S. Marshal Service, and the Office of the Federal 

Detention Trustee, available at http://www.november.org/stayinfo/breaking08/LappinTestimony.html. 

6 H.R. Conf. Rep. No. 111-366 (2009), Division B, Title 1, Page 619, available at 

http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=111_cong_reports&docid=f:hr366.111.pdf. 

7

Sanders, Frank, H., Johnk, Robert, T., McFarland, Mark, A., Hoffman, Randall, J., Emission Measurements for a 

Cellular and PCS Signal-Jamming Transmitter, NTIA Institute for Telecommunication Sciences, NTIA Report TR10-465, February 2010, available at http://www.its.bldrdoc.gov/pub/ntia-rpt/10-465/10-465.pdf (hereinafter TR-10-

465); NTIA Report TR-10-466, Emission Measurements of a Cellular and PCS Jammer at a Prison Facility, May 

2010, available at 

http://www.ntia.doc.gov/osmhome/contrabandcellphones/NTIAPrisoncelljammerreport_TR_10_466.pdf (hereinafter 

TR-10-466); NTIA Technical Memorandum 10-468, Initial Assessment of the Potential Impact From a Jamming 

Transmitter on Selected In-Band and Out-of-Band Receivers, May 2010, available at 

http://www.ntia.doc.gov/osmhome/contrabandcellphones/NTIATechnicalMemorandum_10_468.pdf (hereinafter 

TM-10-468).
5

 manufacturers, vendors and consultants (representing 41% of comments filed); 

 public safety, government, and correctional officials (representing 33% of comments 

filed); 

 wireless service providers and associations (11%); and

 others (15%). 

These comments, including information from various manufacturers of these technologies (see 

Appendix C) and NTIA‘s efforts on contraband cell phone use, are available at

http://www.ntia.doc.gov/osmhome/contrabandcellphones/index.html.

This report first details Federal agency activities to investigate and evaluate methods to prevent 

contraband cell phone use, and then describes the various wireless intervention technologies. 
6

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7

SECTION 2

FEDERAL EFFORTS

The Administration supports the goal of combating contraband cell phone use while protecting 

critical Federal Government and public safety operations.8 Given that a number of Federal 

agencies have a vested interest in preventing contraband cell phone use in prisons, Congress 

directed NTIA to coordinate the development of this evaluation with the FCC, BOP, and NIJ. 

Along with NTIA, these agencies have been dealing with issues relative to contraband cell phone

use, some for a number of years. Each of the agencies provided their respective input for 

inclusion into the report, based on their efforts, experiences, insights, and evaluations.

NTIA

Laboratory Measurements

In December 2009, in response to the growing concern over contraband cell phone use and the 

interest at that time in jamming as a solution, NTIA‘s ITS measured, at its laboratory in Boulder, 

Colorado, the radiated emission levels for a jammer designed to deny service for 

communications devices operating in the 869-894 MHz Cellular Radiotelephone Service 

(―Cellular‖) and 1930-1990 MHz Personal Communications Service (PCS) frequency bands.9

Laboratory measurements were performed for the purpose of obtaining a set of peak-detected 

and root mean square (RMS, or average) emission spectrum data, in the form of effective 

isotropic radiated power (EIRP), of a jammer transmitter that can be used to characterize the 

jammer‘s radiated emissions. The jammer used in the measurements operated at a power level of 

up to 100 watts in each band, repetitively sweeping a carrier-wave signal across the range of 

frequencies in which service was to be denied. ITS performed frequency domain emission

measurements from 100 MHz to 6 GHz with 100 dB of dynamic range. With the installation of 

a diplexer on the jamming transmitter output – acting as a radio frequency (RF) filter – some 

measurable out-of-band (OOB) emissions occurred in spectrum adjacent to the fundamental

frequency bands. Across the rest of the 100 MHz to 6 GHz spectrum range, unwanted emission 

levels were suppressed by 100 dB or more with the diplexer installed. OOB emissions in 

adjacent bands may be reduced by sweeping across less than the full width of the targeted bands

at a cost of jamming effectiveness, or by installing custom-designed RF output filtering.10

 

8 Letter from Cameron Kerry, U.S. Department of Commerce General Counsel, to John D. Rockefeller, IV, 

Chairman, Senate Committee on Commerce, Science and Transportation (Oct. 2, 2009), available at 

http://www.ogc.doc.gov/ogc/legreg/letters/111/S251Oct209.pdf. See also Letter from Gary Locke, Secretary of the 

U.S. Department of Commerce, to Martin O'Malley, Governor of Maryland (Oct. 21, 2009).

9 TR-10-465. 

10 Id. at xiii.
8

Field Measurements

As a follow-on effort to the above laboratory measurements, ITS performed in February 2010 

field measurements of limited deployment of a device similar to that tested at the ITS Lab in 

Boulder, Colorado at a Federal Correctional Institution in Cumberland, Maryland.

11 The purpose 

of these field measurements was to perform emission spectrum measurements on jammer signals 

inside and outside a jamming zone at the BOP facility with multiple measurement bandwidths 

and detectors, both in-band and in selected Federal land mobile radio (LMR) and Global 

Positioning System (GPS) spectrum bands. Measurements at each location were performed with 

the jammer ―on‖ versus ―off‖ so as to show the relative power levels of the jamming signal and 

the ambient Cellular and PCS signals at each location. ITS measured in-band jammer emissions 

outside the targeted zone at distances of up to 127 meters from the edge of the targeted zone. 

The device, deployed strictly for test purposes, produced measureable signal levels in the 869-

894 MHz Cellular and 1930-1990 MHz PCS radio bands. It also produced measureable levels in 

the bands used for GPS and bands used for Federal public safety and law enforcement operations 

such as may be used in and around a Federal prison. However, use of the diplexer suppressed 

the levels outside the cellular and PCS bands by 100 dB or more, making the installed device 

unlikely to interfere with Federal operations. The report also noted a significant number of 

variables with each jammer implementation. Some of these variables pertained to the jamming 

technology and some pertained to the prison facility.

Technical Analysis

In May 2010, NTIA published a technical memorandum to examine issues related to the 

potential interference impact of a specific cellular and PCS jammer transmitter on selected outof-band and in-band receivers.

12 The report is based on the measurements taken by ITS at the 

Cumberland, Maryland facility. When operating at full power and jamming in the cellular and

PCS bands, the tested jammer transmitter could cause some impact to LMR receivers at the 

prison and to GPS receiver use in and around the facility. However, the use of a diplexer 

decreased the potential interference and reduced the required distance separations to such low 

values as to be negligible. Therefore, the specific jammer tested could be implemented with the 

diplexer or another appropriate filter without risk to Federal operations. However, because of the 

limited deployment of the jammer transmitter at the Federal facility, NTIA could not draw any 

conclusions from the field measurements about the potential of aggregate interference to out-ofband receivers if multiple jammer transmitters of this same type were operated throughout the 

facility. Further, the results of this study are unique to the location where the jammer was tested. 

Each prison differs in size, shape and structure and the limited conclusions cannot be applied 

across the board.

Interference protection criteria (IPC) values for cellular and PCS handsets are required to assess 

potential interference to in-band receivers (e.g., establish distance from a facility where 

communication is not disrupted). The field measurements only examined one type of jammer 

transmitter, thus the results of the measurements and analysis cannot be broadly applied to all 

jammer transmitters. For example, the measurements did not examine the in-band emission 

 

11TR-10-466.

12 TM-10-468.
9

levels outside targeted jamming areas that would result from jamming inside different building 

structures or jamming inside larger building interiors. Due to the limited deployment of the 

jammer transmitter at the Federal facility, NTIA could not draw conclusions from the field 

measurements assessing the potential of aggregate interference to in-band receivers if multiple 

jammer transmitters were operated throughout the facility. That is, NTIA could not determine 

the effects of the jammer on cellular and PCS devices outside the prison facility.

FEDERAL COMMUNICATIONS COMMISSION (FCC)

The FCC has assisted with regulatory approvals (e.g., special temporary authorizations, 

applications to lease spectrum from carriers to managed access providers, etc.) related to testing 

and deployments of non-jamming cell phone detection and signal-control technologies. These 

initiatives have included tests conducted by the Maryland Department of Public Safety and 

Correctional Services in 2009 at a decommissioned facility in Jessup, Maryland, and a 

subsequent study of non-jamming technologies in three commissioned correctional facilities. 

Two vendors, AirPatrol of Columbia, Maryland, and Digital Receiving Technology of 

Germantown, Maryland, deployed passive technology that they indicate detects cell phone use, 

collects data from active cell phones and does not interfere with Cellular and PCS frequencies. 

A third vendor, Tecore of Columbia, Maryland, deployed its managed access system, which 

required and received prior FCC approval for its operation.

13

 FCC staff has also assisted the 

State of Mississippi‘s decision to deploy Tecore‘s managed access system throughout its State 

prisons, beginning with the Mississippi State Penitentiary, a maximum security prison in 

Parchman, Mississippi. In July 2010, the FCC‘s Wireless Telecommunications Bureau issued a 

letter to Tecore clarifying various legal issues/concerns raised by carriers regarding the proposed 

Parchman deployment.14 FCC staff has also assisted Tecore and the affected wireless carriers in 

Mississippi with required regulatory filings and initially issued temporary authorizations 

permitting the deployment of Tecore‘s managed access systems at the Parchman facility, and 

have now granted Tecore/carrier applications for permanent authority. FCC staff is also working 

to develop a streamlined regulatory process for similar future applications involving managed 

access technology. 

In addition to these regulatory actions, the FCC assists prison authorities in identifying and 

evaluating available technologies to defeat contraband cell phone use in prisons. To this end, 

FCC staff has regularly interacted with State corrections officials from across the country, 

organizations including the American Correctional Association (ACA) and the Association of 

State Correctional Administrators (ASCA); vendors; wireless providers; and Federal agency 

partners including the NIJ, NTIA, and BOP.

 

13 The FCC conditioned Tecore‘s temporary authorizations such that the operation could not commence without the 

consent of the local carriers. The FCC granted Tecore two temporary experimental authorizations to demonstrate 

and test its equipment in the Maryland Correctional Institution in Jessup, Maryland. 

14 Specifically, the letter addressed issues related to the application of Sections 201, 202, and 333 of the 

Communications Act of 1934, as amended, to Tecore‘s proposed system.
10

On September 30, 2010, the FCC held a public workshop/webinar to discuss contraband cell 

phones in prisons.15 The workshop/webinar was conducted in partnership with NIJ and the 

ASCA. This workshop/webinar discussed technologies currently available to combat contraband 

cell phone use in prisons, as well as the need to address statutory barriers and policy concerns 

relating to cell jamming and other interfering technologies. In addition, discussion focused on 

ensuring that available technologies are operated in accordance with the law without 

jeopardizing public safety or the lawful use of cell phones by the public, including calls to 9-1-1. 

The session also addressed possible solutions, including previous tests and pilots, and a recentlydeployed managed access system in Mississippi.

FEDERAL BUREAU OF PRISONS (BOP)

Over the past 15 years, the BOP has evaluated a large number of cell phone interdiction 

technologies. The BOP has set four basic requirements in the context of these evaluations: 

1. The equipment must work without impacting or collecting information from the 

general public located outside the secure perimeter;

2. The solution should have no legal restrictions;

3. The equipment must work with all cellular phone protocols; and

4. The overall cost of equipment and installation must be reasonable.

BOP, in its quest for a solution, continues to investigate a wide variety of technical solutions.16 

These options include jamming, spoofing, denial of service, managed access, direction-finding, 

scanners, hand-held frequency detectors, voice recognition, non-linear junction detectors, 

picocells and femtocells. 

Based on BOP‘s observations of product demonstrations and vendor outreach, review of 

technical specifications, and/or actual testing in BOP facilities, BOP has found that each of the 

solutions has one or more shortcomings, such as: (1) equipment is not covert; inmates see staff 

coming with portable sensors and shut off the phones; (2) many systems do not detect all cell 

phone frequencies and protocols or those which are designed for the European market with a 

single protocol; (3) very short detection distance; (4) direction-finding systems are ineffective 

and confused due to the large amount of metal (doors, rebar, etc.) in the hardened construction of 

prisons reflecting multiple-path RF signals; (5) systems are too sophisticated and/or expensive 

for daily operations by non-technical staff; (6) some systems detect or interfere with cell phones 

outside the secure perimeter of a prison, such as on a public street or visitor parking lot; (7) many 

systems designed for the military and law enforcement have a wide variety of expensive features 

that go beyond most of the requirements of the correctional community and/or require legal 

authority to operate (these include voice monitoring and collecting cell phone identifying 

information); and (8) many systems are impractical to implement with prison compounds that 

have large acreage and dozens of buildings. 

 

15Public Safety and Homeland Security Bureau to Hold Workshop/Webinar on Contraband Cell Phone Use in 

Prisons, Public Notice (Sept. 13, 2010), available at

http://www.fcc.gov/Daily_Releases/Daily_Business/2010/db0913/DOC-301424A1.pdf

16 The BOP continues to work with other Federal, State and local agencies on the problem of inmates with cell 

phones, including via a close working relationship with NIJ. Along with NIJ and a variety of State departments of 

corrections, BOP will continue to exchange information and participate on numerous technical committees working 

toward solutions. 
11

To date, only cell phone detection systems have been able to meet BOP‘s requirements. At one 

high-security facility, BOP is evaluating sophisticated fixed sensors that detect RF signals 

emitted from unauthorized cell phones. The evaluation has shown this technology to be 

effective, but costly (more than $200,000 per site), in order to achieve a high level of detection 

accuracy. In an effort to reduce the cost, BOP plans to evaluate an RF detection system with 

fewer sensors, thereby sacrificing system accuracy for cost.

NATIONAL INSTITUTE OF JUSTICE (NIJ)

The NIJ has been actively engaged in the issue of contraband cell phone use in prisons for a 

number of years. It has examined a number of potential approaches to dealing with this issue. 

Most recently, it funded the development of an electronic surveillance system to detect the 

presence of cell phones within a known structure, for example a prison, and pin-point the 

location of the cell phone to within a one to two prison-cell area. The design and execution of 

the initial testing of this device was conducted on April 4, 2010 within the Virginia Department 

of Corrections. Concurrently, NIJ is funding significant research in developing improved means 

to collect digital forensic evidence from cell phones and other mobile devices. 

In July 2010, NIJ convened a Conference Plenary Panel: Cell Phones in Prisons as part of its 

annual conference. As a result of that panel and the public interest surrounding this issue, NIJ

established a Federal agency working group including all relevant Federal agencies (BOP, FCC, 

and NTIA). The group is expected to expand internal NIJ conversations; enhance cross-agency 

collaboration; and further discussion of next steps. 

In addition, NIJ has been working with the FCC, ASCA, and practitioner networks to further 

explore and understand this issue. Most recently, NIJ co-sponsored a contraband cell phone 

webinar with the FCC, which drew nearly 700 participants and included Federal, State and 

practitioner panelists. Initial investigation by NIJ in this area suggests that technology is only 

one of a number of options to be considered when attempting to limit illegal cell phone use in 

prisons and jails. Just as important is a review and possible revisions of existing institutional 

policies, procedures, training, and enforcement efforts.
12

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13

SECTION 3

JAMMING

OVERVIEW

Radio jamming is the deliberate radiation, re-radiation, or reflection of electromagnetic energy 

for the purpose of disrupting use of electronic devices, equipment, or systems – in this case, 

mobile devices such as cell phones. A cell phone works by communicating with its service 

network through a cell tower or base station. These cell towers divide an area of coverage into 

cells, which range in size from a few city blocks to hundreds of square miles. The base station 

links callers into the local public switched telephone network, another wireless network, or even 

the Internet.

A jamming device transmits on the same radio frequencies as the cell phone, disrupting the 

communication link between the phone and the cell phone base station, essentially rendering the 

hand-held device unusable until such time as the jamming stops. The jamming device may vary 

its signal over an entire band used for cell phone operations, disrupting, on any particular 

channel, the connection between the base station and handset for a short period of time. The 

jammer cycles through its range of channels rapidly and frequently enough to prevent 

functioning connections over all the range of its capability. Jamming devices do not discriminate 

among cell phones within range of the jamming signal – both contraband and legitimate cell 

phones are disabled. Currently, the operation by non-Federal entities of transmitters designed to 

jam or block wireless communications violates the Communications Act of 1934, as amended.17 

SUMMARY OF COMMENTS

Many NOI commenters oppose the use of jammers to block cell phone signals. In particular, the 

wireless industry suggests the use of technologies other than jammers.

18

 Verizon Wireless 

provides three primary points on jamming: (1) small scale jamming can create a significant threat 

of interference; (2) jamming becomes more complex when multiple frequency bands are 

involved: and (3) managed access is the best way to stop contraband cell phone use.19 Similarly, 

the public safety community, such as the National Emergency Number Association (NENA) and 

the Association of Public Safety Communications Officials (APCO) cite concerns over the 

effects that jammers could have on critical public safety communications and 9-1-1 calls.

20

Zocalo Data Systems believes that jamming would be too problematic a solution to deploy.

21

 

17 47 U.S.C. § 301, 302a, 333. The FCC had reiterated this fact. See Sale or Use of Transmitters Designed to 

Prevent, Jam or Interfere with Cell Phone Communications is Prohibited in the United States, Public Notice, DA05-1776, June 27, 2005, available at http://hraunfoss.fcc.gov/edocs_public/attachmatch/DA-05-1776A1.pdf. 

18 See, e.g., CTIA comments at 9-17; T-Mobile USA comments at 7-9; Verizon Wireless comments at 9-11; AT&T

comments at 10-13.

19 Verizon Wireless comments at 4.

20 See generally NENA comments; APCO comments; Rappahannock Regional Jail comments.

21 Zocalo Data Systems comments at 1.
14

However, one respondent, without further explanation or elaboration, suggests buying ―a cell 

phone jammer to block the transmission.‖22 Kentucky Correctional Industries suggests an 

interference device could be installed that would render cell phones useless.23 Additionally, a

number of correctional departments, citing NTIA‘s testing of jammers, express support for the 

use of cell phone jammers in prisons.

24

 

Devices and Frequency Bands

In the NOI, NTIA asked a number of questions regarding whether the various technologies could 

transverse multiple frequency bands. CellAntenna states that jamming is the only technology 

that can prevent the use of any and all frequencies/protocols and that blocking the cellular 

communications would solve 90-95% of illegal use in prisons.25 ITT notes that jamming would 

be able to cover newer bands such as the 700 MHz band, but will require new transmitters, new 

hardware and software to be scalable.26 Similarly, ShawnTech states that jamming can stop all 

calls on cellular devices with all technologies available.27 

The wireless providers also respond on this issue. Sprint Nextel submits that ―today‘s jamming 

systems lack the capability to block all of the frequency bands that prisoners could use...‖

28

 As 

Verizon Wireless notes, jammers will not work to block all of the wireless signals in the vicinity 

of the prisons, citing the fact that some smart phones switch to Wi-Fi when commercial signals 

are not available.29 Additionally, T-Mobile USA asserts that jammers installed at prisons will 

not sufficiently block all forms of communications.

30

 

Interference to Other Radio Services

Many of the commenters, particularly the wireless industry, express concern over the potential 

for interference from jammers to other radio services near prisons.

31

 Furthermore, many of the

respondents specifically mention interference to the critical public safety radio service operating 

 

22 Paul Velasquez comments at 1.

23 Kentucky Correctional Industries comments at 1.

24 South Carolina Department of Corrections comments at 2; State of Maryland/Department of Public Safety and 

Corrections comments at 2; California Department of Corrections and Rehabilitation comments at 2. Several groups 

have filed with the FCC petitions for waivers to permit the use of cell phone jammers in prisons. Stating that it did 

not have the authority to permit such jamming, the FCC has denied the petitions. See, e.g., Letter from James D. 

Schlichting, Acting Chief Wireless Telecommunications Bureau, Federal Communications Commission to Devon 

Brown, Director, District of Columbia Department of Corrections, DA 09-354, Feb. 18, 2009, available at 

http://fjallfoss.fcc.gov/edocs_public/attachmatch/DA-09-354A1.pdf; Letter from James D. Schlichting, Acting Chief 

Wireless Telecommunications Bureau, Federal Communications Commission to Howard Melamed, CEO, 

CellAntenna Corporation, DA 09-622, March 17, 2009, available at 

http://fjallfoss.fcc.gov/edocs_public/attachmatch/DA-09-622A1.pdf.

25 CellAntenna comments at 3-4. 

26 ITT comments at 8.

27 ShawnTech comments (slides) at 23.

28 Sprint Nextel comments at 2.

29 Verizon Wireless comments at 6-7.

30 T-Mobile USA comments at 6.

31 See, e.g., AT&T comments at 7-9; Verizon Wireless comments at 5-8; T-Mobile USA comments at 2-5; Sprint 

Nextel comments at 2; CTIA comments at 18-25.
15

within or adjacent to jammers.32 Motorola notes that the deployment of jammers could cause 

intermodulation effect in public safety receivers with ―devastating effects.‖33

However, South Carolina argues that surgical jamming does not cause interference to public 

safety radios, and calls/frequencies, including calls to 9-1-1, are not blocked outside of the prison 

perimeter.34 Maryland, citing the results from the NTIA test demonstration at the Federal 

Correctional Facility, submits that jamming can work without interference or compromising 

public safety.35 Similarly, California cites the results of the NTIA tests as a reason why 

jammers should be tested and approved in other jurisdiction such as in California.36

Protecting 9-1-1 and Authorized Calls

Many respondents express concern over the effects that jammers could have on critical 

communications such as 9-1-1, public safety and everyday cellular communications.37 NENA 

has concerns about the possibility of wireless jammers blocking 9-1-1 calls.38 APCO concurs 

that jammers could block calls to 9-1-1 to report an emergency.39 Jamming of signals could 

potentially interfere with other authorized cell phone frequencies used by laptop computers for 

broadband access, security and alarm systems.40 But CellAntenna states that if the system is 

properly engineered and the signal levels of the jamming units are much lower than any outside 

the prison, 911 calls by the public are not affected.41 

The wireless carriers express concern about the interference that jammers could cause to in-band 

cell phones, based upon the NTIA tests at the Cumberland, Maryland facility. In its comments,

Sprint Nextel contends that after analyzing data gathered at one of its cell sites, interference may 

have occurred to cell phones attempting to communicate with that cell site.42 Sprint Nextel notes 

that this cell site provides coverage to the area immediately north of the jamming zone.43 

Additionally, Sprint Nextel states that during the test period, there was a ―definite trend upward 

in the rate of dropped calls and a trend downward in successful call attempts.‖44 Verizon

Wireless concludes that ―signal measurements from the NTIA jamming tests taken at the furthest 

distance outside the prison from the jammer location are strong enough to cause harmful 

 

32 See, e.g., NENA comments; APCO comments; Motorola comments.

33 Motorola comments at 3.

34 South Carolina Department of Corrections comments at 2.

35 State of Maryland/Department of Public Safety and Corrections comments at 2. However, the technical analysis 

on the field measurements taken by NTIA at the Cumberland facility do not support drawing any conclusions about 

either the potential of aggregate interference to out-of-band or in-band receivers if multiple jamming transmitters of 

this same type were operated throughout the facility. See Supra note 12.

36 California Department of Corrections and Rehabilitation comments at 2. 

37 For example, Rappahannock Regional Jail states that by jamming the ―800 MHz and 1900 MHz frequency ranges 

you will affect most if not all cell phones (especially Nextel phones) and some PCS EMS Public Safety portable 

radio systems used inside of the jails and prisons today.‖ Rappahannock Regional Jail comments at 1.

38 NENA comments at 3.

39 APCO comments at 2.

40 Paul Kruger comments at 1.

41 CellAntenna comments at 5.

42 Sprint Nextel comments at 3-6.

43 Id.

44 Id.
16

interference to commercial mobile subscriber devices.‖45 Other carriers note their concerns over 

the results of the NTIA testing and the potential for interference.46

Cost Considerations

The affordability of technologies to prevent contraband cell phone use in prisons is a concern

among the commenters.47 CellAntenna states that jammers provide the best and most 

economical way to prevent cell phone use in prisons, require very little staff time, and that the 

cost of the system depends on a number of factors such as the size and shape of prison, the area 

to be covered, and incoming tower signal levels.48 However, Enterprise Electronics states that 

because jammers need certification, type acceptance/approval, this process will increase the costs 

of the product, thereby making it potentially cost-prohibitive to deploy.

49

 ITT notes that the 

biggest costs associated with jamming systems are infrastructure costs (number of antenna, cable 

type) and these costs can vary according to building codes and local laws and compliance.50 

Further, ITT states that for a particular scenario, a jamming system could cost two to three times 

more than a detection system.51 

Locating Contraband Cell Phones

As the NOI points out, RF jamming equipment cannot locate the source of the contraband call. 

CellAntenna affirms that this is the case, noting that there is really no need to locate the phone

and spend time doing so.

52

 Other commenters note that jamming does not have the capability to 

locate the phone.53

Regulatory/Legal Issues

The Communications Act of 1934 prohibits non-Federal entities from intentionally interfering 

with radio signals.

54 Many of the respondents reaffirm this as well. For example, the wireless 

industry expresses their concerns over deploying a device that violates the Communications Act 

of 1934.55 Manufacturers, vendors and industry also note the problems of using cell phone 

jammers.56 One respondent suggests adopting strict rules to address the issue of contraband cell 

phones with jamming where it can be done safely.57

 

45 Verizon Wireless comments at 5.

46 T-Mobile USA comments at 5; AT&T comments at 9.

47 See, e.g., ICSolutions comments at 4; Big Spring Correctional Center comments at 1.

48 CellAntenna comments at 5.

49 Enterprise Electronics comments at 2.

50 ITT comments at 14-15.

51 Id.

52 CellAntenna comments at 6.

53 See, e.g., Enterprise Electronics comments at 2; Berkeley Varitronics Systems comments at 2.

54 47 U.S.C. § 333.

55 See, e.g., CTIA comments at 6-9; Sprint Nextel comments at 2; T-Mobile USA comments at 10-12; AT&T 

comments at 4-7.

56 See, e.g., Enterprise Electronics comments at 2; Tecore comments at 15-17; ShawnTech comment (slides) at 24.

57 Marcus Spectrum Solutions comments at 4.
17

In October 2009, the United States Senate passed a bill, the Safe Prisons Act of 2009, that would 

amend the Communications Act of 1934 to authorize the FCC to permit the supervisory authority 

of a correctional facility to operate a jamming system within the facility to prevent, jam, or 

otherwise interfere with unauthorized wireless communications by individuals held in the 

facility.58 The House of Representatives has not taken up similar legislation. A number of 

respondents indicate support for the proposed legislation.59

Still other respondents question the applicability of the Communications Act of 1934 as it relates 

to the use of jammers by prisons. CellAntenna explains:

The 1934 Communications act deals only with legal 

communications. The act specifically states that local and state 

governments cannot interfere with Licensed and Authorized 

communications. The fact is that the cell phone is illegal to use in 

prisons. It is therefore not licensed or authorized and can be 

stopped.60

Further, Global Tel*Link (GTL) questions whether Section 333 of the Communication Act of 

1934 is applicable in a prison setting.61 Additionally, Marcus Spectrum Solutions, while 

recognizing that jamming of cellular communications by non-Federal entities is illegal, states 

that this is the case only because the FCC has ―never adopted rules authorizing such jamming.‖62

Technical Issues

In the NOI, NTIA asked if there are any technical issues to be considered for the various 

technologies. CellAntenna states that there are a number of technical factors that can be used to 

ensure that the signal levels of the jammer are substantially less than those transmitted by the 

carrier cell towers that cover the prison, including: (1) deployment in each prison must be 

designed separately because antennas, power levels, and jamming protocols can be a determining 

factor; (2) quality of amplifiers; (3) refining jamming to be more dynamic by adjusting power 

levels based upon incoming signals; (4) vigilant monitoring to reduce communication disruption 

outside of the prison; and (5) coordination with cellular carriers on signal levels to adjust 

jamming signals.63

Bahia 21 states that, although pure jamming alone disrupts cellular communications without 

differentiating the source of the call, it has developed ―location selective jamming.‖ It notes that 

this system is reactive, radiating only when an attempt to communicate is detected in an 

unauthorized location, thus limiting the impact on the network.64 It indicates that the advantages 

 

58 S. 251, Safe Prisons Communications Act of 2009, available at http://frwebgate.access.gpo.gov/cgibin/getdoc.cgi?dbname=111_cong_bills&docid=f:s251es.txt.pdf. 

59 See, e.g., State of Maryland/Department of Public Safety and Corrections comments at 2; Oklahoma Department 

of Corrections comments at 1; California Department of Corrections and Rehabilitation comments at 2.

60 CellAntenna comments at 6.

61 GTL comments at 4.

62 Marcus Spectrum Solutions comments at 1.

63 CellAntenna comments at 4.

64 Bahia 21 comments at 1.
18

of this approach include: no interference to cell phones outside of the prison perimeter, access to 

9-1-1 is unaffected, very low radiated power is required to jam small or large prisons, and 

selective jamming can be tailored to the denial service area.65

In comments to the NOI, ITT states that jamming systems are effective against: voice, text and 

data; short-burst transmissions (because jamming is constant); and new modulation formats such 

as in the 700 MHz band.66

OBSERVATIONS

The following key observations highlight the use of jamming as a possible solution to mitigate

contraband cell phone use by inmates:

 Any transmitter has the potential to cause interference to other radio services.67 

Jammers are transmitters that are specifically designed to disrupt cellular and other 

mobile radios. To prevent over-jamming, proper RF site engineering and extensive 

testing at each prison is essential to reduce interference to other radio services. This 

is likely to increase the cost of deployment, perhaps substantially.

 As required by FCC Rules, all mobile phones operating on commercial mobile radio 

spectrum must be able to call 9-1-1 for assistance during emergencies.68 Cell phone 

jammers cannot differentiate between contraband cell phone calls and authorized 

calls, including 9-1-1 calls. 

 The use of jammers by State or local prison officials is a violation of the 

Communications Act of 1934, and hence illegal. The FCC has denied previous 

requests to operate cell phone jammers at State correctional facilities. A bill passed 

by the U.S. Senate would allow State and local prison officials to petition the FCC to 

allow jamming at prisons on a case-by-case basis. This bill, however, is not law.

 NTIA sought comment through the NOI on an appropriate Interference Protection 

Criteria (IPC) value for mobile phones. No commenters recommended any values.69 

If the law is changed, the mobile phone industry may need to come to agreement on 

an acceptable value to enable in-band interference effects to mobile devices to be 

evaluated.

 Incomplete areas of coverage in which prisoners have access to cell phones could 

lead to the prisoners identifying and exploiting dead-zones. 

 Jamming that is limited to specific bands and technologies could lead to inmates 

selecting certain technologies and service providers as the ―technology-of-choice.‖

 

65 Id. at 2.

66 ITT comments at 19.

67 As examples, in India and Brazil, jamming prisons affected authorized cell phone users up to 5 km away. In 

Ireland, a jamming system interfered with cell phone users in a hospital, which was across the street from the prison. 

See ―Technical Issues in Checking Contraband Cell Phone Use in Jails and Prisons,‖ Terry Bittner, April 5, 2010, 

available at http://www.corrections.com/articles/24025-technical-issues-in-checking-contraband-cell-phone-use-injails-and-prisons. See also CTIA comments at 20-21.

68 Under FCC Rules, the 9-1-1 requirements are only applicable to Commercial Mobile Radio Service providers. See

47 C.F.R. § 20.18. 

69 ITT suggests that an acceptable IPC would require analysis and characterization and be established by lab 

measurements. ITT comments at 10.
19

SECTION 4

MANAGED ACCESS

OVERVIEW

Managed access systems intercept calls in order to prevent inmates from accessing carrier 

networks. The cell signal is not blocked by a jamming signal, but rather, is captured (or rerouted) and prevented from reaching other base stations, thereby disallowing completion of the 

call. This technology permits calls by known users (i.e., prison-authorized cell phone numbers) 

by handing them off to the network, but prevents others by denying access to the network.

70

 

Managed access systems include one or more base stations configured to cover the borders of the 

target area, as well as the technologies and frequency bands of the wireless provider networks. 

The footprint is optimized through the use of power control, directional antennas, and repeaters 

to limit the coverage of the base stations to the desired target areas. When a cell phone within 

the target area attempts to connect to the wireless provider network, it will be captured by the 

managed access network because its base stations serve the target area with relatively stronger 

signals than the nearest base stations of the wireless provider network. Therefore, the devices 

will connect first to the managed access network. Based on policies selectable by the system 

administrator, devices can be either locked to the managed access network and prevented from 

initiating or receiving communications, or cleared and redirected to the applicable commercial 

networks. The systems can also be used in a passive manner to simply detect cell phone use and 

collect data from active cell phones. While an unapproved device is locked to the managed 

access network, the display and appearance of the device will be the same as if it were connected 

to the commercial network. Once a device is captured by the managed access network, if the 

caller attempts to place a call, send a text message, connect to the Internet or otherwise access a 

wireless network, the attempt will fail. Once the device is located outside of the managed access 

system‘s target coverage area, it will re-register with the appropriate commercial network.

SUMMARY OF COMMENTS

A number of commenters, including the wireless carriers, mention the viability of using managed 

access technologies as a method of controlling contraband cell phone use.71 GTL contends that 

managed access is the frontrunner for technology of choice from the wireless industry‘s point of 

 

70 In 2009, the Maryland Department of Public Safety and Correctional Services hosted a demonstration of various 

non-jamming technologies, including managed access systems. In January 2010, it issued a follow-on report. The 

demonstration showed, among other things, that: (1) several intelligence gathering abilities could be implemented 

depending upon specific laws governing each State; and (2) the types of technology tested could allow certain 

phones to operate and allow 9-1-1 calls to be processed. See Maryland Department of Public Safety and Correctional 

Services, Overview of Cell Phone Demonstration, available at 

http://www.dpscs.state.md.us/publicinfo/media/pdf/FinalReport_2008-09-10.pdf. One managed access technology 

(Tecore) was demonstrated and operated pursuant to an experimental license granted by the FCC for this occasion. 

See also Maryland Department of Public Safety and Correctional Services, Non-Jamming Cell Phone Pilot 

Summary, Jan. 20, 2010, available at http://www.dpscs.state.md.us/media/Cell-Phone-Pilot-Summary_Final.pdf.

71 See, e.g., Tecore comments at 2-5; AT&T comments 10-14; T-Mobile USA comments at 7-8.
20

view.72 While not specifically mentioning managed access, several commenters suggest that 

methods of dropping calls or dead zones would be a solution.

73

Device and Frequency Bands

Any solution to the contraband cell phone problem in prisons needs to address the growing 

number of telecommunications methods. This includes, for example, the Cellular, PCS, AWS, 

SMR, WiMAX, 700 MHz and General Mobile Radio bands. Additional methods of 

telecommunication include satellite, Wi-Fi, and Bluetooth mobile devices. Managed access 

solutions focus on the more common, licensed commercially available bands, but can be 

upgraded to cover Long Term Evolution (LTE) and the 700 MHz band.

74 Prohibiting access to 

the commercial cellular networks ―would solve 90-95% of all illegal communications within a 

prison.‖

75 Verizon Wireless mentions that a managed access system can ―prevent phones from 

switching to other bands and would not need to intercept as many spectrum bands within 

prisons.‖76 Yet a managed access solution is ―unlikely to operate with unlicensed solutions,‖ 

leaving potential avenues for prison inmates to exploit.77 Sprint Nextel recommends that ―for a 

time period, it may be appropriate that managed access systems be supplemented with cell phone 

detection systems that cover a wide range of frequency bands.‖ 78

In its comments, AT&T expresses certainty that a managed access system can ―evolve to support 

new frequencies and technologies.‖

79

 It is possible with new technologies and available 

communication frequencies that a managed access system will need hardware and software 

upgrades. Any operator of a managed access system will also require prior notification from the 

local service providers when they update their own systems.80 This is to be expected – and the 

process can be streamlined – as the managed access solution requires a high level of 

communication between the service provider(s) and system operators. The wireless industry

commenters express their resolve to do so.81

Interference to Other Radio Services

An effective solution must not interfere with legitimate use of the radio spectrum. This includes 

use within and beyond the boundaries of a correctional facility, and particularly 9-1-1 calls and 

public safety communications. According to comments submitted by Berkeley Varitronics 

Systems (BVS), ―[t]he only strategy which may be subject to this concern is jamming.‖

82 AT&T 

 

72 GTL comments at 5.

73 See, e.g., Rich Veach comments at 1; B.B. Sixty Rayburn Correctional Center comments at 1; Madison Juvenile 

Correctional Facility comments at 1; Dayton Correctional Institution comments at 1; Mike Kouri comments at 1.

74 Tecore comments at 6.

75 CellAntenna comments at 4.

76 Verizon Wireless comments at 14.

77 ITT comments at 7.

78 Sprint Nextel comments at 2.

79 AT&T comments at 11.

80 Marcus Spectrum Solution comments (citing letter to FCC Chairman Genachowski from the South Carolina 

Department of Corrections, Oct. 21, 2009, at 3), available at http://www.ntia.doc.gov/comments/100504212-0212-

01/attachments/09-30_10-21-2009_South_Carolina_Department_of_Corrections_7020142659-2.pdf .

81 See, e.g., CTIA comments at 9; AT&T comments at 19.

82 BVS comments at 5.
21

points to Tecore‘s iNAC managed access solution as having a ―great potential for addressing the 

problem . . . without jeopardizing public safety and commercial communications.‖83 Of 

particular concern are Nextel/SMR devices, which operate in close proximity to public safety 

frequencies and use proprietary protocols. Verizon Wireless states that a managed access system 

―can intercept Nextel/SMR calls within prisons without interfering with public safety radios.‖

84

Sprint Nextel believes ―that a properly configured managed access system that has been 

coordinated with the relevant commercial mobile operators would have little likelihood of 

causing interference to cell phone users outside the prison facility.‖85

Comments from T-Mobile USA reinforce the effectiveness of a managed access solution 

(compared to a jamming solution) in protecting public safety spectrum. T-Mobile USA states 

that a managed access system will ―provide more precise control over the bands selected for 

disruption, thus preventing interference with public safety wireless communication .... 

unexpected interference to other services is reduced.‖86

Coordination with commercial service providers ensures that the managed access solution 

conforms to the boundaries of a correctional facility by matching power output levels. This 

prevents the system from adversely affecting legitimate radio frequencies outside of the prison, 

while commanding the spectrum within the prison. CTIA adds that, ―[m]anaged access solutions 

can use location determination-technologies to ensure that the controls apply only in the 

geographic area of the prison.‖87

Wireless communication systems deployed by prison officials must not encounter interference. 

The managed access solution has a list of authorized and unauthorized phones enabling it to 

exclude authorized communication from its coverage by adding those devices to the list of 

authorized users.88

Protecting 9-1-1 and Authorized Calls

In a managed access system, 9-1-1 and authorized calls can connect to the cellular network.89 

NENA and APCO support non-jamming solutions to the problem because jammers cannot 

discern between legitimate, illegitimate, 9-1-1 and public safety communications.90 The wireless 

providers – AT&T, Verizon Wireless, Sprint Nextel, and T-Mobile USA – all respond in favor of 

a managed access solution. This is due in large part to the system‘s ability to allow public safety, 

9-1-1, and authorized calls to reach the cellular networks. Verizon Wireless states:

 

83 AT&T comments at 2.

84 Verizon Wireless comments (slides) at 14.

85 Sprint Nextel comments at 1-2.

86 T-Mobile USA comments at 8. 

87 CTIA comments at 10.

88 ShawnTech comments (slides) at 25-28.

89 Tecore comments at 11. See also CellAntenna comments at 5; ITT comments at 13. Enterprise Electronics raises 

the concern that inmates are not a reliable reporting source for 9-1-1 and, given the chance, will abuse the privilege 

and create harmful traffic for the 9-1-1 operators. Enterprise Electronics comments at 5.

90 See generally NENA comments; APCO comments. Tecore notes in its comments that ―certain jamming systems 

can detect the initiation of a 9-1-1 call, and can switch off the jamming transmission to allow such a call to connect 

to the commercial network. However, [d]uring that period, other devices including contraband cell phones may also 

have access to the commercial network.‖ Tecore comments at Appendix B, n.10.
22

Managed access can allow the system operator to maintain a list of 

approved callers – a list that can be amended constantly as 

subscribers that live, work, or frequently visit areas near the prison 

and are captured by the system are identified – whose calls will be 

allowed to [be] completed rather than blocked.91

Further, Verizon Wireless states that:

Managed access systems allow prison officials, working with the 

system operator and nearby licensees, to set the parameters of how 

captured calls are handled. For example, prison officials can decide 

to allow the first call from a device not on the approved list to be 

completed, but block subsequent calls (in order to prevent blocking 

calls from random subscribers near the prison), can decide to limit 

the duration of calls from non-approved callers, or can deliver a 

message to non-approved callers letting them know their call is 

being blocked by the prison system and advising them to move 

away from the prison to try again.92

Cost Considerations

ShawnTech contends that a managed access system is costly (> $200K per site).93 Marcus 

Spectrum Solutions believes that the ―proponents [of managed access] have never addressed the 

full ... cost implications.‖94 According to Tecore Networks, a managed access provider, there 

are three primary cost factors: (1) the number of different commercial networks and utilized

frequencies in the target area; (2) the geography/topology of the area; and (3) the range of 

functions the system will perform.95 RF surveys of each facility are necessary to determine the 

proper hardware configuration. Post-installation RF surveys will confirm site coverage. Each 

facility will need to train staff to operate the system.

Commenters note that there are methods to reduce the costs associated with a managed access 

solution. If the managed access vendors are responsible for operating the system(s), it would 

reduce the cost of staff training.96 Tecore asserts that ―[t]he iNAC operating expenses can 

further be minimized if it is deployed centrally at a managed access facility.‖97 ManTech‘s 

response supports Tecore‘s assertion, stating that, ―centralizing control and data management, 

even when operations are site-specific, can minimize cost by networking, systematic planning, 

and systems operations.‖98 The first managed access system deployed in the United States (by 

 

91 Verizon Wireless comments at 10.

92 Id., n. 21.

93 ShawnTech comments (slides) at 26.

94 Marcus Spectrum Solutions comments at 3.

95 Tecore comments at 11. A system is less expensive, for instance, without the additional location or data-mining 

technology.

96 ITT comments at 15.

97 Tecore comments at 12.

98 ManTech comments at 16.
23

Tecore in Mississippi) was deployed at no cost to the prison authority, because Tecore entered 

into a separate arrangement with the pay phone service provider through its contract obligations 

with the agency for inmate telephone service.

99

Locating Contraband Cell Phones

A basic managed access system does not locate contraband phones.100 A managed access system 

equipped with data-mining technology could locate phones with a built-in GPS. However, a 

prisoner can turn off the GPS function on the phone, disabling that capability. There is also the 

potential for a managed access system to locate cell phones using RF triangulation.101 As stated 

previously, a managed access system can work in conjunction with detection technologies.102

Some respondents recommend this approach, at least in the short-term, until the managed access 

systems can capture all forms of wireless communication.103 Others recommend utilizing 

detection technologies for aiding managed access operators in determining whether a call is 

legitimate (e.g., if the call originates from a cell block, the operator can add the number to the list 

of unauthorized callers).104

According to BVS, the forensic value within phones is in the subscriber identity module (SIM) 

card. Because managed access systems do not locate cell phones, BVS states that managed 

access systems do not provide information.105 But a managed access solution can provide 

important data according to Tecore Networks:

[t]he iNAC [managed access system] can provide the type and 

detail of information available from a commercial network 

operator. Information about device identity, activity record 

including numbers dialed and text messages sent, along with the 

capability for CALEA compliant interfacing to Law Enforcement 

Agencies.106

T-Mobile USA expounds upon additional information that a managed access solution can 

provide for prison and law enforcement intelligence purposes, stating that ―[c]onsistent with 

local wiretap and surveillance laws, managed access systems may allow prison officials to 

observe who is using illicit phones in prisons, identify whom they are contacting or being 

contacted by, and perhaps even monitor the content of the communications.‖107

 

99 Mississippi Department of Corrections, Office of Communications, Press Release, Operation CellblockCommissioner Epps Shuts Down Illegal Inmate Cell Phone Usage, Sept. 8, 2010, available at 

http://www.mdoc.state.ms.us/PressReleases/2010NewsReleases/Illegal%20Cell%20Phone%20Press%20Conference

%20Release.pdf.

100 See, e.g., BVS comments at 2; Boeing comments at 3; ITT comments at 16.

101 ITT comments 16.

102 Boeing‘s comments to the NOI propose a piece of ―hybrid‖ technology that is a combination of managed access 

and detection systems. Boeing comments at 3. This technology is described in Section Six: Other Technologies.

103 Sprint Nextel comments at 2.

104 Id.

105 BVS comments at 3.

106 Tecore comments at 12.

107 T-Mobile USA comments at 9.
24

CellAntenna makes comment that a managed access solution nulls the necessity to confiscate 

contraband phones.108 Tecore discusses the topic further, stating:

Tecore does not believe it is effective to require contraband 

cellular devices to be physically located and removed. This 

approach entails additional resources and time from the prison 

administration. Managed access is designed to assure the 

prevention of unauthorized communications without requiring the 

retrieval of devices, which is manpower-intensive.109

Regulatory/Legal Issues

Managed access technology, in hand with proper authorizations from the FCC, may be an 

effective tool to combat the contraband cell phone problem in correctional facilities.110 In order 

to operate a managed access system, the managed access provider ―would require both a license 

to transmit and authorization by the carriers servicing the area.‖

111 Tecore Networks was able to 

provide a demonstration of its iNAC managed access solution after it acquired an FCC issued 

Special Temporary Authority (STA) ―as well as a coordinated sublease of spectrum from the 

carriers.‖

112 If utilized, long-term spectrum leases, which serve as transmitting authorizations

upon FCC approval, will be necessary. The wireless carriers, in contract, must ―retain the right 

to terminate the lease or take other action in the event of harmful interference outside the 

prison.‖

113

 For the managed access deployment in Parchman, the FCC has approved all required 

filings from Tecore and the wireless carriers, including long-term spectrum lease agreements.

ITT raises a privacy concern, specifically questioning whether, ―[e]ven though it might be 

forbidden for an inmate to possess and use a cell phone ... are calls from the inmate to his lawyer 

or doctor protected, and if so, how would the system distinguish these calls from other calls?‖114

Technical Issues

Prior to installing a managed access system, an RF survey should be conducted to identify the 

correct system configuration. Once installed and activated, the managed access system will 

perform its duties, including the passage of 9-1-1 calls to the commercial carrier networks 

without interference. A managed access system intercepts calls and text messages utilizing both 

GSM and CDMA modulation schemes, and as stated previously, can be upgraded to cover LTE 

and the 700 MHz band.

115

In their comments to the NOI, Verizon Wireless notes that they are working on a spectrum lease

agreement to enable Tecore to operate a managed access system in Mississippi on frequencies 

 

108 CellAntenna comments at 6.

109 Tecore comments at 12.

110 ShawnTech comments (slides) at 26.

111 ITT comments at 17.

112 Tecore comments at 26.

113 AT&T comments at 12.

114 ITT comments at 17.

115 Tecore comments at 6.
25

licensed to Verizon Wireless.116 Since then, with the actual deployment of that managed access 

system in Mississippi, the technology was shown to be able to discriminate between authorized 

calls (including to 9-1-1) and calls from contraband, unknown, and unregistered phones.

117

 As 

described by the Mississippi Department of Corrections, the deployed managed access system 

has the following effect: ―[n]ow, instead of a hearing a familiar voice on the other end of the 

line, Parchman inmates communicating with illegal cell phones are going to hear a voice 

recording that states,  ̳the cellular device you are using at the Mississippi State Penitentiary has 

been identified as contraband and is illegal to possess under the criminal statute, 47-5-193. The 

device will no longer function.‘ ‖

118

OBSERVATIONS

The following key observations highlight the use of managed access technologies as a possible 

solution to mitigate contraband cell phone use by inmates:

 A managed access system can and must be designed to operate at specific boundaries.

Managed access systems intercept calls within those boundaries in order to allow 

corrections officials to prevent inmates from accessing carrier networks. The cell 

signal is not blocked by a jamming signal, but rather, is captured (or re-routed) and 

prevented from reaching the intended base station, thereby disallowing the 

completion of the call. 

 A managed access system can provide the desirable result – preventing prisoners 

from communicating by cell phone with people outside of the prison. However, the 

system permits authorized users to pass through to the network and all 9-1-1 calls are 

forwarded as well.

 Managed access techniques do not violate the Communications Act if the FCC issues 

the proper authorizations and the users comply with the terms of those authorizations. 

It is unclear, however, whether the use complies with other statutes.

119

 Managed access requires structured coordination and cooperation between a managed 

access system vendor and the wireless service providers in the affected area. The 

partnership with the wireless carriers is critical to ensuring the long-term efficacy of 

the solution as new products and different frequencies are utilized in the wireless 

landscape. Coordination of spectrum issues between the FCC, the wireless carriers,

and the managed access provider is critical for successful implementation.

 

116 Verizon Wireless comments at 11.

117 Supra note 99.

118 Id. Since its deployment, Mississippi Corrections blocked over 216,000 communication attempts in one month. 

See http://www.mdoc.state.ms.us/PressReleases/2010NewsReleases/2010-09-01 Combined Final.ppt, page 29. The 

report does not address whether there were unauthorized calls that were not captured by the managed access system.

119 For example, interception of signals may risk violating certain wiretap statutes. In particular, managed access 

operations may be subject to the ―pen/trap‖ statute. Generally, managed access operations fit the definition of a 

―trap and trace device,‖ 18 U.S.C. § 3127(4), because they capture ―dialing, routing, addressing, and signaling 

information reasonably likely to identify the source of the wire or electronic communication.‖ Trap and trace 

devices are allowed only pursuant to a court order or under one of the exceptions to the pen/trap statute found in 18 

U.S.C. § 3121(b). One of the exceptions applies when the consent of the user of the wire or electronic 

communications has been obtained. To the extent that a managed access operation is strictly limited to the prison 

grounds, it should be possible to establish a regime of consent for the usage of a trap and trace device, which in turn 

would eliminate the risk of violation of the pen/trap statute.
26

 Costs to implement a managed access system can have a number of variables (such as 

the number of frequency bands to cover). Centralizing control and management of 

the systems is an important method to lower the cost of installation as well as longterm operational and maintenance costs. Deploying a managed access system that 

covers multiple frequency bands will increase costs.

 Managed access systems can be operated remotely and the controlling base station

antenna can be mounted on towers, mobile platforms, or other locations outside of the 

prison confines, which are not accessible to inmates or prison staff. 

 As experienced in the Mississippi deployment, managed access systems also can be 

potentially deployed at no cost to the prison authority, based on a separate 

arrangement between the managed access and pay phone service vendors.
27

SECTION 5

DETECTION

OVERVIEW

Detection is the process of locating, tracking, and identifying various sources of radio 

transmissions – in this case, cell phone signals from prisons. Detection, or direction-finding, is 

used in a wide variety of applications including, for example, cell phone assignments, the 

location of 9-1-1 emergency calls and marine distress calls. For accurate position location in an 

environment such as within a prison facility, detection technology triangulates a cell phone 

signal and requires correctional staff to physically search a small area (such as a prison cell) and 

seize the identified cell phone. This may involve placing direction-finding antennas or sensors 

(connected wire-line or wirelessly) to a computer to identify a cell phone call and locate the 

origin of the call. Additionally, hand-held cell phone detectors are able to scan frequencies 

within correctional facilities and detect the location of the caller. These systems can only detect 

a cell phone when it is in use – either placing or receiving a call. The devices are ―passive‖ 

receive-only devices, and do not necessarily require any authorization or license for the 

equipment or the user to implement and operate.

SUMMARY OF COMMENTS

A number of commenters to the NOI support the use of detection technologies to eliminate 

contraband cell phone use. For example, ICSolutions notes that location and detection of cell

phone calls provides investigators with real time information, call timing, and call patterns that 

assist with law enforcement intelligence gathering capabilities.120 Motorola believes that 

detection methods (in combination with managed access) are the preferred approaches as they 

are far less likely to cause interference.121 CTIA contends that detection methods have 

advantages over jamming and would better enable correctional officials to confiscate contraband 

cells phones and investigate contraband use habits.122 Similarly, Sprint Nextel supports detection 

technologies as a preferred solution over jamming.

123 Canada correctional facilities have 

deployed a number of capabilities to fight this problem such as interception and detection.124

Devices and Frequency Bands

A number of commenters affirm that detection systems are receive-only solutions that have a 

frequency band or bands programmed into the system. For example, Enterprise Electronics

submits that certain types of detectors have multiple frequency bands and formats in them to do 

the necessary analysis to detect and locate the phones of interest.125 ITT states that detection 

 

120 ICSolutions comments at 3.

121 Motorola comments at 3-4.

122 CTIA comments at 4.

123 Sprint Nextel comments at 1. 

124 Correctional Services of Canada comments at 1.

125 Enterprise Electronics comments at 9.
28

systems are compatible with any device since they do not require protocol participation, and 

hence offer the widest range of coverage and are easily scalable to any frequency band.126 The 

BVS hand-held bloodhound cell detector is a multi-band receiver that can detect in a number of 

frequency bands.127 ShawnTech notes that all detection systems (hand-held, portable and fixed 

sensor) detect all technologies available.128 BINJ confirms that detection systems have the 

ability to adapt to new frequency bands.129 The AirPatrol Wireless Locator System can detect 

Wi-Fi and cellular service.130

Interference to Other Radio Services

Because detection systems do not emit RF energy, a number of commenters tout the value in 

detection systems as not interfering with other radio services. For example, ICSolutions states 

that ―detection-location is a non-invasive solution that will not interfere with administrative radio 

or other facility administrative equipment.‖131 AirPatrol states that its solution does not cause 

interference to cellular services or public safety communications.132 ITT also notes that RF 

detection systems do not interfere with any communication system.133 BVS implies that 

jamming is the only solution that would cause concern of interference to other radio services.134

Protecting 9-1-1 and Authorized Calls

The NOI asked several questions with regard to the technologies capable of protecting both 9-1-1 

and authorized calls, as Congress specifically directed that NTIA evaluate this in its tasking. 

Several commenters elaborate on the fact that detection systems do not block 9-1-1 or authorized 

calls from being completed since they do not transmit any RF energy to block a signal. For 

instance, BINJ notes that cell detection systems do not block or deny cell phone use.135 ITT 

notes that detection systems do not disrupt cellular traffic.136 T-Mobile USA contends that this 

is the case and asserts that detection is preferable over jamming since detection systems do not 

interfere with critical public safety and legitimate communications.137 Similarly, ManTech states 

that ―passive detection systems do not impact the neighboring commercial networks.‖138

Cost Considerations

The cost for implementing detection systems varies according to the complexity of the detection 

system deployed, and the time and labor required to retrofit the facility. Hand-held units are at 

 

126 ITT comments at 6-7.

127 BVS comments at 5.

128 ShawnTech comments (slides) at 19-21.

129 BINJ comments at 3.

130 AirPatrol comments at 2.

131 ICSolutions comments at 4.

132 AirPatrol comments at 2.

133 ITT comments at 3.

134 BVS comments at 5.

135 BINJ comments at 8.

136 ITT comments at 3.

137 T-Mobile USA comments at 9.

138 ManTech comments at 6.
29

the low-end of the cost scale since they require no infrastructure. BVS contends that these units 

are attractive in terms of costs.139

More sophisticated systems increase costs. ITT suggests that the largest unknown cost for a 

detection system is in the infrastructure, while detection systems have much lower on-going and 

recurring costs than jamming and managed access solutions.140 ITT provides cost estimates for 

their detection system: $20,000 to $600,000 depending on area of coverage, number of 

buildings/sensors, and number of inmates.141 One-day training for staff costs $1,500.142 

BINJ offers that software and technical support are on-going costs and that the size of the facility 

and the accuracy (that is, number of sensors) most likely affect costs.143 Further, BINJ states that 

the hardware and software for a 500-cell facility with accuracy down to an inmate‘s cell costs 

$350,000.144

Locating Contraband Cell Phones

The NOI asked several questions with regard to the capabilities of the technologies on location 

and location accuracy.145 The size of the devices makes them easily hidden so that finding them 

is a concern.146 By design, detection systems identify, with a certain degree of accuracy, the 

location of the caller.147 The location accuracy depends on the number of sensors installed,

prison composition, and other factors. ITT notes that its system can obtain an accuracy of 3-5 

meters.148 AirPatrol states that the Wireless Location System has an accuracy of 3 meters.149

Additionally, BINJ asserts that the age of the facility and composition affect the accuracy, but 

with newer facilities, the resolution is to the prisoner‘s cell.150 Bahia 21 claims a geo-location 

accuracy of 10-15 meters is sufficient to initiate a physical search of the contraband cell 

phone.151 Using triangulation, the location of the cell phone can be determined to within a few 

yards.152

 

139 BVS comments at 3.

140 ITT comments at 13-14.

141 Id. ITT contends that for the same area of coverage, a distributed jamming system would cost two to three times 

more. Id.

142 Id.

143 BINJ comments at 5.

144 Id. at 6.

145 The Maryland Department of Public Safety and Correctional Services demonstrated a number of detection 

technologies, and the report concluded that there were varying degrees of accuracy in terms of cell phone detection 

based upon each vendor‘s technological abilities. See Supra note 70.

146 Art Beller comments at 1.

147 BVS states in its comments that during a 2-hour sweep of cell blocks in the Maryland demonstration, the 

Bloodhound hand-held device successfully located 5 smuggled contraband phones. BVS comments at 4.

148 ITT comments at 16.

149 AirPatrol comments at 1.

150 BINJ comments at 7. The BINJ system (CellScan) was tested with the Washington, DC Department of 

Corrections with an accuracy of detection of 100%. See CTIA comments at 15.

151 Bahia 21 comments at 3.

152 Peter McDonald comments at 1.
30

Regulatory/Legal Issues

As is the case with all potential technologies, one the chief concerns of regulatory agencies is the 

effects that these technologies have on the rules and regulations promulgated within the structure 

of the U.S. telecommunications environment. Noting this concern, the NOI asks a series of 

questions on this topic. The consensus of the commenters is that there are no regulatory and/or 

legal issues associated with detection technologies. ITT states that no regulatory agreements are 

needed for their system.153 BVS notes that, because of the passive nature of its product as 

detecting signal strength in cell phone uplink signals, it has no regulatory/legal issues.154 

ShawnTech concurs that the use of detections systems is legal.155 According to AirPatrol, no 

FCC licenses, waivers, or permits are required to deploy the Wireless Locator System.

156

 

As is the case for all potential solutions, however, if detection goes beyond direction-finding to 

include recording of information, such as numbers called or even the number of the contraband 

cell phone, legal issues may be invoked. These capabilities may reside within a detection 

technology as additional features, but are not necessary for locating a transmitting cell phone.

Technical Issues

A number of technical issues are discussed in the comments to the NOI. TruePosition argues 

that location accuracy depends upon the type of location solution that is employed and that 

network-based location Uplink Time Difference of Arrival provides ―more than reliable location 

information for corrections officials to detect and find the contraband cell phones.‖157 Contrary, 

location detection by Advanced GPS will not work in a prison because of the prison structure 

(and hence signal loss) and the ability of the end user to turn off this capability.158 ITT similarly 

notes that GPS is easily defeated by turning off the GPS receiver.

159

On other technical issues, ITT notes that the detection system it uses is independent of 

modulation, requires very little on-site RF engineering, and can perform detection during text 

messaging.160 BINJ concurs and notes that no site engineering is needed, modulation schemes or 

channel access methods do not impact the BINJ detection system, shorter air time from text 

messages do not present problems, and the system is effective against high-speed, high-data rate 

formats such as LTE that are expected to operate in the 700 MHz band.161 AirPatrol‘s Wireless 

Locator System can locate the phone during voice conversations, internet browsing, sending and 

receiving emails, or text messaging.162

 

153 ITT comments at 17.

154 BVS comments at 5.

155 ShawnTech comments (slides) at 18.

156 AirPatrol comments at 2.

157 TruePosition comments at 3.

158 Id.

159 ITT comments at 16.

160 Id. at 18-19.

161 BINJ comments at 7-8.

162 AirPatrol comments at 2.
31

OBSERVATIONS

The following key observations highlight the use of detection systems as a possible solution to 

mitigate contraband cell phone use by inmates:

 Detection systems can range from simple hand-held and portable units to more 

complex fixed units with sensors attached by wireless or by wire-line to the sensing 

hardware and software.

 Hand-held detection units offer the least expensive equipment costs to find the 

contraband cell phones, yet require staff resources and time to physically locate them. 

However, inmates may react to movement of prison staff and avoid using cell phones 

during times when prison staff are known to be on patrol. Fixed detection sensors 

require more equipment and installation, and increase the costs for these technologies.

 Sensors used to identify the location of the contraband cell phones should be placed 

in a location where inmates cannot tamper with or destroy them, or be tamper-proof. 

Location accuracy of these systems depends upon a number of factors including the 

number of sensors used and prison construction.

 Detection systems are passive by nature and, unless they are used for data mining,

have no regulatory or legal issues; do not transmit and therefore do not interfere with 

authorized and 9-1-1 calls. They do not cause interference to other radio services and 

have the capability to cover a wide array of frequency bands and access methods used 

by mobile devices.

 Locating and then confiscating contraband cell phones provides law enforcement 

officials with opportunities for intelligence-gathering. Correctional and law 

enforcement officials may seek to obtain the illegal cell phones and conduct forensic 

analysis on the devices for further investigation.
32

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33

SECTION 6

OTHER TECHNOLOGIES

The NOI asked if there are technologies available other than the three categories previously 

described. A number of respondents indicated that standardized protocols, hybrid systems, and 

Non-Linear Junction Detectors (NLJDs) are other technologies to consider for preventing 

contraband cell phone use in prisons.

163

STANDARDIZED PROTOCOLS

In their comments to the NOI, Try Safety First notes that it has developed a simple, costeffective, comprehensive solution for contraband prison cell phones as it believes that, in 

addition to enormous costs and possible violation of law, jamming equipment cannot jam Skype 

and satellite phones.164 Further, Try Safety First contends that managed access and detection 

systems are not the best solution due to the need for constant monitoring and the inability to 

detect, confiscate, and prevent many of the illegal activities prior to the directives being carried 

out.165 

The Try Safety First solution is based upon using a series of low-cost Bluetooth sensors located 

throughout the prison (programmed for coverage between 1 to 60 meters) coupled with universal 

and standardized protocols that would have to be incorporated into the firmware of the handsets. 

These ―sets of instructions‖ communicate with the hand-held device by essentially locking the 

device and making it unusable. Try Safety First contends that this solution is inexpensive, 

cannot be turned off nor tampered with by inmates, and protocols can be incorporated into the 

handset as new units are introduced into the market.166 For funding, Try Safety First proposes a

$1 per phone fee that would offset the expenses to retrofit the prisons with the Bluetooth 

sensors.167

 

163 A number of commenters suggest that decreasing prison landline phone rates reduces contraband cell phone use. 

See, e.g., Letter to the Honorable Larry Strickling, Assistant Secretary for Communications and Information, from 

the Honorable Rick Boucher, Member of Congress, and the Honorable Bobby Rush, Member of Congress (May 27, 

2010) (citing Paul Hammel, ―Prison Phone Smuggling Reduced,‖ Omaha World-Herald (May 17, 2010)); Paul 

Kruger comments. Some commenters suggest more vigilant screening of staff and visitors (Ann Worth comments), 

using shielding on prison walls such as copper mesh (Roy Stratton comments), or metal detectors, body scanners 

and x-rays (Enterprise Electronics comments). Although these all may have merit, they are beyond the scope of this 

report. However, Section 3 of the Cell Phone Contraband Act of 2010 requires the Government Accountability 

Office to conduct a study of landline rates in prisons and efforts to prevent the smuggling of cell phones. Pub. L. 

No. 111-225, 124 Stat. 2387 (Aug. 10, 2010). Also, the FCC is considering prison land-line rates in an open docket, 

CC Docket No. 96-128, Alternative Rulemaking Proposal Related to Inmate Calling Services.

164 See generally Try Safety First comments. 

165 Id.

166 Id.

167 Id.
34

HYBRID SYSTEMS 

Boeing suggests that NTIA consider another category for a potential solution – a combination of 

technologies known as hybrid systems.168 Boeing states that its Digital Receiver Technology 

(DRT) uses a combination of both managed access and detection techniques to locate and control

contraband cell phone use. In arguing against other technologies, Boeing states that jamming 

does not discriminate between users, is imprecise and excessive, and does not locate the actual 

device; and detection technologies are the least effective in preventing contraband cell phone 

use.

169

 Boeing asserts that managed access technologies are the most effective solution for 

preventing use in prisons.170

Boeing explains that the DRT device mimics a cellular base station to:

cause dormant cell phones to perform a registration with the DRT 

device. Cell phones not of interest are released. Cell phones of 

interest are forced to transmit location information to the DRT device 

operator who can then assist prison personnel to locate the contraband 

phone and user. Depending on the DRT device mode used, cell 

phones of interest can then be returned to their network or locked into 

the DRT device, preventing contraband use.171

NON-LINEAR JUNCTION DETECTORS (NLJDs)

A number of commenters offer another category for inclusion into the technologies used to 

prevent contraband cell phone use – NLJDs.172 NLJDs hunt for semiconductor junctions in the 

electronics (transistors, diodes, etc.). The Orion NLJD has an antenna that is passed over an 

electronic device (in this case, a cell phone) and alerts when it is in the presence of such devices 

by sending a signal similar to a metal detector.

173

 Research Electronics International (REI) 

submits that this device detects cell phones regardless of the device being on or off, does not 

depend on frequency band, is FCC compliant and has no regulatory or legal issues, and will not 

interfere with other radio services, other cell phone calls or 9-1-1 calls.174 Bahia 21 notes that its

device is currently used by many customers for the detection of contraband cell phones in 

prisons.175 A number of commenters note the success at correctional facilities in finding and 

locating contraband cell phones using NLJDs.

176

A few commenters note the drawbacks of using such devices. For example, Enterprise 

Electronics notes that NLJDs send a radio signal invasive to people, are large in size, and cannot 

 

168 Boeing comments at 3.

169 Boeing comments at 2. 

170 Boeing comments at 3. 

171 Boeing comments at 6.

172 See, e.g., REI comments at 1-3; Enterprise Electronics comments at 7; BVS comments at 1; Bahia 21 comments 

at 2. 

173 REI comments at 1-2. A unit costs $15,800 and training is required.

174 Id.

175 Bahia 21 comments at 2.

176 See, e.g., CTIA comments at 16; REI comments at 2.
35

be deployed in open areas to detect cell phones.177 BVS suggests that NLJDs are not stealthy; 

they must be in very close proximity to the device to detect it and require excessive amounts of 

time by correctional officials to scan for contraband cell phones.

178

OBSERVATIONS

The following key observations highlight the use of the above technologies as possible solutions 

to mitigate contraband cell phone use by inmates:

 The Try Safety First solution is predicated upon standardized protocols being 

developed, adopted, and implemented by the wireless industry. To date, no such 

standards exist and this potential solution will not come to fruition until the wireless 

industry adopts standardized protocols for wireless mobile devices.

 Hybrid systems utilize a combination of techniques, such as managed access and 

detection, to control and locate contraband cell phones. The Boeing DRT system 

uses technology that detects cell phone usage, collects data from active cell phones

and then releases or locks the phone.

179

 Like some other solutions, costs may be a 

consideration for correctional officials. Additionally, holding cell phone signals and 

collecting data present potential legal issues as ―trap and trace‖ devices.

 NLJDs are hand-held, overt devices that require staff to physically search a prisoner‘s 

cell for the phone. They present no regulatory or legal issues and do not interfere 

with other authorized users. 

 

177 Enterprise Electronics comments at 7.

178 BVS comments at 1.

179 The DRT was part of the Maryland Department of Corrections December 2009 testing and the DRT sensors 

identified 11 phones that may have been contraband. The managed access portion of the DRT was not used.
36

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37

SECTION 7

SUMMARY

As commenters note, prisoners are using contraband cell phones to conduct criminal activity. 

Although some facilities are making progress, correctional officials must be vigilant and use all 

available means to stop the phones from making their way to inmates in the first place.180 

Nevertheless, the record indicates that prison authorities are devoting increasing financial 

resources and personnel time to ferreting out, confiscating, and eradicating contraband cell 

phones in their prisons. Further, the record identifies a number of technologies that can reduce 

or eliminate contraband cell phone use in prisons. Signal jamming, cell phone detection,

managed access, and other technologies are ways to mitigate cell phone use by inmates.

All the solutions involve a wide array of issues, including: complex technical, legal and 

regulatory issues; installation and operational costs; and interference potential. Each approach

has trade-offs and each offers advantages and disadvantages. The use of jammers by State or 

local prison officials is a violation of the Communications Act of 1934, and hence illegal. 

Jamming cell signals may be effective where legal in Federal applications, and in some settings 

with careful design, but its effectiveness and utility may be greatly diminished by interference 

with other communications, including critical police, firefighter and emergency medical 

communications and 9-1-1 calls. Managed access technologies hold promise as a solution. The 

technology requires close coordination with the FCC and wireless carriers; and the FCC has 

already developed the necessary regulatory requirements. Further, while the first managed 

access deployment in Mississippi was accomplished at no cost to the prison authority, it is 

uncertain whether this business model can be applied successfully in other States. Thus, 

implementing such systems elsewhere, especially for large-prison environments, may be costly, 

although comparable to other methods including cell jamming. Detection technologies and 

NLJDs have no regulatory or legal issues, but involve additional costs and time for searches if 

locating the contraband phones is a requirement for correction officials. 

What may be a reasonable approach for one institution may not work for another. Each prison is

unique in size, shape, structure, security level, and location. As such, one technology does not fit 

all and a particular solution may be preferable over the other choices based upon each 

institution‘s requirements and setting. For instance, a prison located in a rural setting may opt 

for a different solution than a prison located in an urban area where there is a greater density of 

wireless communications devices operating nearby. Also, a combination of approaches, for 

example, managed access with detection technologies, may be a ―best-fit‖ for correctional 

officials at their respective prisons. Further, costs and time are drivers for correctional officials 

to consider when implementing these technologies, and these costs will vary based upon 

 

180 The Maryland Department of Corrections has seen a drop in the number of cell phones found in their prisons by 

nearly one-third from 2009. They attribute this to increased intelligence, search and seizure, and investments in 

technology. See http://www.dpscs.state.md.us/publicinfo/news_stories/press_releases/20100727a.shtml. Also, a 

new law has been enacted that prohibits Federal prisoners from possessing or using cell phones and similar wireless 

devices. See Cell Phone Contraband Act of 2010, Pub. L. No. 111-225.
38

coverage area at each prison, among other things. Some correctional facilities may have a 

requirement to physically locate and confiscate the phones. If this is the case, detection 

technologies may be preferable over other solutions.

When considering the solutions, it is essential to maintain and protect authorized radio 

communications (for example, authorized cell phone calls by consumers, 9-1-1 calls and public 

safety communication networks), both inside and outside of the prison walls. Proper RF site 

engineering and testing specific to a particular location are critical when implementing some of 

these technologies in order to reduce interference by creating an RF footprint that matches as 

closely as possible to the prison confines. 

The proliferation of mobile devices will lead to more services and features such as high-speed 

data and video. With that comes new frequency bands in which they operate, such as the 700 

MHz band. Technologies used against contraband cell phones will need to keep pace with the 

speed at which mobile devices are introduced into the marketplace. It is reasonable to assume 

that interdiction efforts will not prevent access to a plethora of devices by inmates and that it will 

not take long for them to find out which devices work and which ones are blocked, dropped, or 

detected. Deploying technologies that transverse all available parts of the radio spectrum in 

which these mobile devices operate comes with a price and prison officials must consider the 

cost-benefit analysis. Equipment upgrades to these ―contraband-fighting‖ technologies will be 

required, and close coordination with the wireless industry will be necessary. Correctional 

officials will need to decide what devices and hence frequency bands will be targeted (i.e.,

cellular and/or PCS and/or SMR/iDEN and/or 700 MHz, etc.). 

The risk that prisoners will tamper with equipment is an issue that needs to be considered. 

Managed access systems can be operated remotely and the controlling base station antenna(s)

can be mounted on towers or other locations within their permissible range of operation that are 

not accessible to inmates or prison staff. Jamming or detection systems in particular have to be 

installed in closer proximity to prisoners‘ living areas, and unless mounted in secure or 

inaccessible locations, may be subject to damage or removal.

Table 7-1 shows a general summary of the various technologies as possible solutions to prevent 

contraband cell phone use in prisons. There are various iterations within each category. For 

instance, there are fixed detection sensing systems or hand-held portable detection units; 

managed access techniques may be performed differently among the vendors; detection 

techniques will vary from one vendor to another and may offer additional capabilities and 

features. Therefore, correctional officials should consult with the manufacturers and vendors of 

these technologies for specific details regarding their prison and unique requirements.

Table 7-2 summarizes the advantages and disadvantages for each of the technologies discussed 

in this report. Some of the approaches come with legal hurdles or limitations. Furthermore, each 

prison‘s own unique characteristics (e.g., size and configuration of the prison), environment 

(rural versus urban setting), resources (e.g., financial and staff), and requirements (e.g., need for 

law enforcement intelligence) will help determine which approach is the most practical, feasible, 

and economical to implement.
39

Table 7-1

Technological Approaches to Combat Contraband Cell Phone Use in Prisons

Jamming Managed access Detection NLJDs Hybrid/DRT Standard protocols

Covers all frequency 

bands

New hard/software 

needed to upgrade as 

bands change

Could match any band 

used in area where 

service providers agree

Yes Detects devices With equipment 

changes and 

carrier consent

If protocols are 

established in the 

various devices

Potential to interfere

with other radio 

services

Yes-emits RF energy Yes-emits RF energy; 

requires proper 

installation and 

operation

No-does not 

transmit

No No for 

detection-only; 

yes for managed 

access

No

Protects 9-1-1 and 

authorized calls

No-pure jamming does 

not discriminate

9-1-1 yes; authorized 

calls if in database of 

known users

Yes-only 

detects

Yes Yes No-all phones are 

locked within the 

boundaries

Identifies location No No Yes Through 

physical search

Yes, with 

portable device

No

Cost considerations Extensive testing prior 

to implementation; can 

vary based on 

complexity of site; 

infrastructure costs

Depends on coverage, 

frequency bands, etc;

can be at no-cost to 

prison authority or vary 

based on complexity of 

site; infrastructure costs

Hand-held 

units less 

expensive;

number of 

sensors, 

installation

Less expensive; 

requires staff 

time

Implementation 

costs can be 

expensive

Inexpensive Bluetooth 

communications

Regulatory/legal issues Illegal for non-Federal 

entities; pending 

legislation for case-bycase jamming

Requires FCC 

regulatory 

authorizations and 

agreements between 

system vendor and 

carriers; any data 

mining may have legal 

implications; trap and 

trace issues with State 

and locals

No 

authorization 

required for

directionfinding, but 

any data 

mining may 

have legal 

implications

None Trap and trace

issues with State 

and locals for 

data mining 

capabilities; 

requires 

regulatory 

authorizations 

between vendor 

and carriers

Impose a $1 per-phone 

fee to offset 

installation costs

Technical issues/other 

issues

Depends on size, shape, 

structure; 

RF engineering needed

RF engineering needed; 

all forms of 

communication

Location 

accuracy; sense 

any technology

Must be very 

close to phone; 

overt

RF engineering 

needed

Adoption of protocols 

by industry; 

conceptual only
40

Table 7-2

Advantages and Disadvantages of Various Technologies

to Mitigate Contraband Cell Phone Use

Jamming

Potential to cause interference outside prison or to adjacent bands unless properly 

designed

Does not permit 9-1-1 and authorized calls 

Violates the Communications Act of 1934 when performed by non-Federal officials

Costs vary with complexity of the site

Significant site analysis and testing needed

Detection

Does not cause interference

Protects 9-1-1 and authorized calls

Provides general location of devices

May require legal authorization unless 

limited to direction-finding

Low-cost hand-held solutions available

Managed access

Potential to cause interference outside prison or to adjacent bands unless properly 

designed

Permits 9-1-1 and known authorized calls 

Legal under the Communications Act but requires FCC approval and carrier consent

Multiple formats and technologies

Costs can vary with complexity of site, yet in first deployment was zero for the 

prison authority

Non-linear junction detectors

Does not cause interference

Protects 9-1-1 and authorized calls

No regulatory or legal issues

Requires staff time to locate phones

Hybrid systems/digital receiver technology

Does not cause interference if using detection-only; for managed access, potential to 

cause interference outside prison or to adjacent bands unless properly designed

Permits 9-1-1 and authorized calls

Regulatory or legal issues; requires FCC approval and carrier consent

Costs could be high based upon complexity of the site

Standardized protocols

Would not cause interference

Conceptual

Need for adoption and implementation of 

standardized protocols in mobile devices

Proposed $1 per-phone fee to offset 

installation
41

Appendix A

NTIA NOI on Contraband Cell Phones
42
43
44
45
46
47

Appendix B

List of Commenters by Group181

Public Safety

(Correctional, Governments, 

Associations, etc.)

Industry 

(Vendors, Consultants 

Manufacturers, etc.)

Wireless Providers

(Carriers, 

Associations)

Others

(Citizens, nonaffiliated)

Association of Public Safety 

Communications Officials 

(APCO)

AirPatrol AT&T Art Beeler

B.B. Sixty Rayburn Correctional 

Center 

Bahia 21 CTIA Mike Kouri

Big Spring Correctional Center Berkeley Varitronics 

Systems (BVS)

Sprint Nextel Paul C. Kruger

California Department of 

Corrections and Rehabilitation

BINJ Laboratories 

(BINJ)

T-Mobile USA Peter McDonald

Correctional Services of Canada Boeing Company Verizon Wireless Roy Stratton

Dayton Correctional Institution CellAntenna Paul Velasquez

Kentucky Correctional Industries Enterprise Electronics Ann Worth

Madison Juvenile Correctional 

Facility

Global Tel*Link Corp 

(GTL)

National Emergency Number 

Association (NENA)

ICSolutions 

Oklahoma Department of 

Corrections

ITT

Rappahannock Regional Jail ManTech International

Rick Veach, Warden Marcus Spectrum 

Solutions

South Carolina Department of 

Corrections

Motorola

State of Maryland/Department of 

Public Safety and Corrections

Research Electronics 

International (REI)

Letter from Members of 

Congress, Honorable Rick 

Boucher and Honorable Bobby 

Rush

ShawnTech

Communications

Tecore Networks

TruePosition

Try Safety First

Zocalo Data Systems

 

181 The comments are available at http://www.ntia.doc.gov/comments/100504212-0212-01/. 
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Appendix C

Vendors and Solutions for Contraband 

Cell Phone Interdiction

Vendor Technology(ies) Web Address

AirPatrol Detection http://www.airpatrolcorp.com/

Bahia 21 Jamming, NLJDs, 

detection,

managed access

http://www.bahia21.com/

Berkeley 

Varitronics 

Systems

Detection http://www.bvsystems.com/Products/Security/Bloodhound/

bloodhound.htm

BINJ Labs Detection http://www.binjlabs.com/index.html

Boeing Hybrid http://www.drti.com/

CellAntenna Jamming, 

managed access

http://www.cellantenna.com/

Enterprise 

Electronics

Detection http://www.eeontheweb.com/cell_phone_detectors.htm

ITT Detection http://iiw.itt.com/products/cellHound/prodCell.shtml

Research

Electronics 

International

NLJDs http://www.research-electronics.com/cgi-bin/main.cgi

Tecore

Networks

Managed access http://www.tecore.com/

Try Safety 

First

Standardized

Protocols

http://trysafetyfirst.com/
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Appendix D

Commonly Used Acronyms

APCO Association of Public Safety Communications Officials

AWS Advanced Wireless Services

BOP Bureau of Prisons

BVS Berkeley Varitronics Systems

DRT Digital Receiver Technology

FCC Federal Communications Commission 

GPS Global Positioning System

IPC Interference Protection Criteria

ITS Institute for Telecommunication Sciences

LMR Land Mobile Radio

LTE Long Term Evolution

NENA National Emergency Number Association

NIJ National Institute of Justice

NLJD Non-Linear Junction Detector

NOI Notice of Inquiry

NTIA National Telecommunications and Information Administration

PCS Personal Communications Services

REI Research Electronics International

RF Radio Frequency

SMR Specialized Mobile Radio
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