MOBILE PHONE JAMMERS
Following recent publicity surrounding the use of mobile phones in a NSW prison, the
Australian Communications Authority (ACA) has further investigated the legal, social
and technical issues associated with the use of mobile phone jammers.
The ACA understands the concerns raised by the NSW Department of Corrective
Services and counterparts in other States and Territories and recognises that the use of
mobile phones in prisons is a serious problem that needs to be addressed. However, it
needs to be recognised that the ACA’s role in considering the problems caused by
mobile phones in prisons is limited to its responsibilities for radiocommunications and
telecommunications regulation. The ACA believes that a wider consideration of
options, outside of the ACA’s responsibilities, is more likely to provide a solution.
The ACA interprets the word “jamming” to mean the deliberate transmission of
interfering signals to disrupt the normal operation of mobile phones.
THE ACA’s ROLE
As a government regulator of radiocommunications and telecommunications in
Australia, the ACA is responsible for managing the radiofrequency spectrum to
provide access for all forms of radiocommunications, including those used to deliver
mobile phone services. These responsibilities include provisions designed to minimise
interference to radiocommunications.
The ACA is also responsible for regulatory arrangements to limit public exposure to
the potentially harmful effects of electromagnetic radiation (EMR).
THE ACA’s DECLARATION PROHIBITING MOBILE PHONE JAMMERS
In 1999 the ACA declared mobile phone jammers, in certain frequency bands, to be
prohibited devices under the Radiocommunications Act 1992 (the Act). The
prohibition makes it an offence to operate or supply, or possess for the purpose of
operation or supply, such a device. The ACA’s decision to make the declaration (see
Attachment A) was made after public consultation.
The reasons for the prohibition included:
• mobile phone jammers cause deliberate interference to licensed services and
may cause interference to other services operating in adjacent spectrum bands.
• All mobile phones being used within a radius of up to four kilometres from the
jamming device could be ‘jammed’.
• Concern that radiation levels of high-powered devices may result in human
exposure to levels of EMR that exceed the maximum permitted under
Australian health exposure standards. This has implications for public health
and safety, especially in confined areas.
In making the declaration, the ACA was also concerned about the substantial social
costs that could arise if mobile phone jammers were allowed to proliferate. Jamming
would be likely, among other things, to substantially interfere with, or disrupt or
disturb, public mobile phone services and have serious adverse consequences for
public mobile phone users by jeopardising the quality and extent of carrier services,
preventing access to emergency services and causing inconvenience to or loss of
business for mobile phone users.
The ACA declaration describes the prohibited devices as ‘a device designed to
operate within the frequency bands 870-960 MHz or 825-845 MHz and to interfere
with radiocommunications or disrupt or disturb radiocommunications’.
Under the Act, the ACA can take action, including prosecuting any person operating
or supplying a jammer, or possessing a jammer for the purpose of operation or supply,
that is likely to affect these frequency bands. Penalties include up to two years
imprisonment or a fine of up to $165,000.
The present declaration does not cover GSM 1800 frequencies or new 3G frequencies.
The ACA is preparing to amend the current declaration to include these frequencies.
There will be a public consultation process associated with the proposed amendments.
The ACA’s creation of a prohibition declaration for mobile phone jammers is
consistent with the position of a number of other countries (see Attachment B).
MOBILE PHONE JAMMER INTERFERENCE
Mobile phone jammers are designed to deliberately interfere with licensed services
operated by mobile carriers. They may also interfere with other services in the same
bands and adjacent bands.
Jammers are available for all radiofrequency bands used by mobile phones in
Australia. The potential for interference to other radiocommunications services in
these bands is difficult to quantify because it depends on the design of the jammer and
on the radiocommunications service type, operating frequency and location.
Available jammers include wide bandwidth devices capable of simultaneously
covering all frequencies in a band. In addition, some are also capable of causing
interference in bands which are harmonics of their operating frequencies.
OTHER SERVICES LIKELY TO BE AFFECTED BY JAMMERS
Examples of the types of radiocommunications services operating in bands near those
used by mobile phones and potentially affected by mobile phone jammers are:
• trunked land mobile systems;
• fixed point-to-point links which carry anything from data to multi-channel
• sound outside broadcast and studio-to-transmitter links;
• cordless telephones; and
• the large number of devices authorised to operate under ACA class licences.
These comprise low power devices which would be susceptible to interference
from radiofrequency emissions from jammers, for example garage door
openers and wireless LANs.
There is also potential for jamming to interfere with the provision of standard
telephone services under the Universal Service Obligation if, for example, a standard
telephone service in the vicinity of a prison was being provided by way of CDMA
wireless loop technology as Telstra is currently doing in the Extended Zones.
SAFETY OF LIFE ISSUES
If a prison were to use a mobile phone jamming device, the ACA believes it would be
difficult, if not impossible, to limit the effect of the jamming to within the prison’s
walls. Radiofrequency transmissions diminish in energy gradually as they travel from
a transmitter. They do not stop unless blocked by an electromagnetic shield. Typical
building walls and enclosures will weaken the signal but do not act as a solid shield.
Although some jamming devices claim to be able to limit the coverage area or
strength of the jamming signal, given the nature of radiofrequency propagation the
ACA is not confident that jamming could be contained and prevented from spilling
over beyond the area intended to be jammed.
The potential for jamming effects to extend beyond the intended area creates a very
real risk that any use of mobile phone jamming devices in a specific location,
including a prison, will unintentionally affect legitimate mobile phone users outside,
but close to, those locations. This would be of significant concern to carriers, carriage
service providers, and end-users who may not be aware which locations are using
jamming devices or the extent or effect beyond the intended areas. Legitimate mobile
phone users are entitled to use their mobile phones when they are within the coverage
area of their carriage service provider, without deliberate interference by a third party.
Of greater concern is the potential for jamming spill-over to create a serious and
otherwise avoidable risk to human life in that legitimate mobile phone users could be
prevented from accessing the emergency call service, via either of the emergency
service numbers 000 or 112, or calls to other emergency organisations (such as poison
information centres and other medical services) or to the normal phone numbers for
police, fire and ambulance.
Mobile phones are increasingly being used to request emergency assistance from the
police, fire or ambulance services in life-threatening or time-critical situations.
During 2002-03, 29 per cent (or 1,128,339) of the 3,953,564 genuine calls to
emergency call service originated from mobile phones. As many prisons are located
in close proximity to populated areas, major roads and highways, there is a very real
risk that legitimate users could be prevented from accessing help in an emergency
with serious consequences.
There is some evidence of a potential for mobile phone jammers to cause mobile
phones to “lock up” and to remain so after leaving the jammed area until the phone is
“reset” (eg by turning it off and on again). The user may be unaware that this has
occurred and of the need to reset the phone.
The ACA is also concerned that jamming might compromise the health and safety of
prison staff, and any medical staff or ambulance officers who may be called to
prisons, and may have to use a mobile phone while they are within prison grounds.
ALTERNATIVES TO JAMMING
In 2002 a working group under the ACA’s Law Enforcement Advisory Committee
(LEAC) was convened to identify alternatives to the jamming of mobile phones
within prisons. The working group comprised representatives from various state
prisons and carriers and identified both technical and operational/procedural
Handset disablers are designed to prevent call attempts from being authorised by
detecting the presence of a handset and signalling an instruction to the base station to
disallow the call attempt.
Also available are intelligent beacon disablers that act as a beacon to instruct handsets
within its vicinity to disable their ringing function or discontinue operation. However,
this technique requires new intelligent handsets with special receivers for the beacon
signals and is therefore not a solution for those handsets already in existence.
A micro-cell is essentially a scaled down version of a mobile phone base station
designed to supplement coverage in areas of high traffic density. (A pico-cell is
smaller again.) A micro-cell (or pico-cell) could be installed in or around a prison
either on a permanent or temporary basis. As that micro-cell would offer the strongest
signal to any mobile phones operating within the prison, the micro-cell would
effectively carry all traffic originating from, or terminating in, the prison confines.
This differs from the existing arrangements in that any prison within a carrier’s
coverage area probably receive signal from a number of base stations (i.e. macro-
cells) which also serve legitimate users in the surrounding areas.
Corralling all traffic through a single micro-cell in this way presents options to
address the use of mobile phones in prisons. Carriers could identify those mobile
phones that only ever use the prison micro-cell to make or receive calls and do not
appear elsewhere in the network, as other mobile phones typically would. Steps could
then be taken under existing legislative arrangements to gather intelligence through
analysis of the call records or interception of the communications, or to disable
specific handsets through either SIM-blocking or IMEI-blocking.
However, micro-cells are quite expensive—estimated to cost in excess of $150,000
each—and would be expected to require funding by correctional services.1 Costs
could be minimised to some extent by, perhaps, deploying micro-cells that all carriers
could share, thereby avoiding the need for each carrier to install its own micro-cell.
Further, portable ‘cells-on-wheels’ could be used under temporary or ad hoc
arrangements to avoid the need for every prison to be fitted with its own micro -cell.
Nevertheless, the associated costs would remain high.
A Faraday cage is a wire mesh enclosure that provides a shield to radio waves. The
application of the Faraday cage principle within prisons would block the transmission
of mobile phone signals to or from a mobile handset within the ‘cage’. Although the
retrospective creation of Faraday cages within prisons would be resource intensive,
LEAC regarded it as appropriate to be taken into account in the design and
construction of new prisons.
The LEAC working group also identified a number of activities that correctional
services could undertake to target problem areas cost effectively and without
amendment to legislation. These principally included:
• improved searching at the point of entry to prevent mobile phones or their
components being smuggled into prisons, similar to other contraband items;
• the use of fixed and/or mobile electronic detection devices that can detect
when a mobile phone is in operation or in standby mode (and could then be
used in conjunction with devices that locate the origin of the signal).
If mobile phones are being used to conduct criminal activities, existing legislative
arrangements already provide the opportunity for intelligence gathering through
analysis of call records or the interception of communications. Further, specific
mobile phones could be disabled remotely by carriers through SIM-blocking or IMEI-
The LEAC working group also considered it important that appropriate legislation is
in place to support any efforts to prevent mobile phones being used within prisons.
This included legislation to prohibit the carriage of mobile phones or mobile phone
components into prisons (as has been adopted in the ACT, Qld and WA) and
appropriate penalties for offenders.
Section 314 of the Telecommunications Act 1997 provides that a carrier or carriage service provider
that is required (under section 313) to provide assistance to officers and authorities of the
Commonwealth and of the states and territories must provide that assistance on the basis that they
neither profit from, nor bear the costs of, providing that assistance. That is, carriers and carriage
service providers are entitled to recover the costs of providing assistance.
LEGAL ISSUES IN RELATION TO A TRIAL OF MOBILE JAMMERS
Much of the attention has focused on the operation of the ACA’s prohibition
declaration prohibiting the possession, use and supply of mobile phone jammers. It
should be noted that even if Corrective Services were exempted from the operation of
the prohibition declaration, and there is doubt that this could be done legally at
present, it is an offence to operate these devices as they are designed to deliberately
interfere with radiocommunications which deliver telecommunications services. It is
an offence to interfere with radiocommunications under section 197 of the Act and it
is an offence to interfere with a carriage service supplied by a carrier under subsection
85ZG(2) of the Crimes Act 1914.
Under the present legislation, which is designed to protect both radiocommunications
and telecommunications it is doubtful whether a trial of mobile phone jammers could
be conducted legally.
SUMMARY AND RECOMMENDATION
While the ACA recognises and is sympathetic to the difficulties facing Corrective
Services in relation to use of mobile phones in prisons, the ACA considers that the
disadvantages of allowing the use of mobile phone jammers appear to outweigh the
The legal issues surrounding the use of mobile phone jammers are complex. There is
significant doubt as to whether mobile phone jammers could be used without a change
to existing legislation.
The ACA does not support the introduction of mobile phone jammers because they:
• interfere with licensed radiocommunications;
• disrupt telecommunications networks; and
• raise serious safety of life issues.
Therefore, the ACA recommends that the available alternatives to mobile phone
jammers described above be further explored by Corrective Services in consultation
Legislative Arrangements for the Declaration Prohibiting Mobile Phone
The power to declare the operation or supply, or possession for the purposes of
operation or supply, of radiocommunications devices to be prohibited stems from Part
4.1, Division 8 of the Act.
Section 189 of the Act makes it an offence to operate or supply, or possess for the
purposes of operation or supply, a prohibited device, without reasonable excuse.
Section 189 also details the penalties that apply if a person is found guilty:
• if the offender is an individual – imprisonment for two years; or
• otherwise – 1,500 penalty units (currently $165,000).
Section 190 of the Act describes the manner in which the ACA may declare a device
to be prohibited and the kinds of devices that may be declared to be prohibited. Such
devices must be devices that:
• are designed to have an adverse effect on radiocommunications or
• would be likely substantially to:
- interfere with radiocommunications; or
- disrupt or disturb radiocommunications in any other way; or
• are radiocommunications transmitters or radiocommunications
receivers that would be reasonably likely to have an adverse effect on
the health or safety of persons who:
- operate the devices; or
- work on the devices; or
- use services supplied by means of the devices; or
- are reasonably likely to be affected by the operation of the
A declaration is a disallowable instrument for the purposes of section 46A of the Acts
Interpretation Act 1901. A declaration is taken to be a statutory rule within the
meaning of the Statutory Rules Publication Act 1903.
Section 191 of the Act requires the ACA to undertake public consultation in a
specified manner before making a declaration that a device is prohibited. The ACA, in
a notice published in the Commonwealth of Australia Gazette must:
• describe the device; and
• specify the reasons why the ACA proposes to make a declaration; and
• invite interested persons to make representations about the proposed
declaration within a period not less than one month after the date of
publication of the notice; and
• specify the address to which representations may be sent.
The ACA must give due consideration to any representations made by a person within
the period specified in the notice. The ACA is not required to undertake a public
consultation process if it is satisfied that making the declaration is a matter of
Policies of other countries
Other countries are dealing with the issue of whether mobile phone jamming should
be allowed. There have been a number of positions taken by these countries.
United Kingdom (UK): It is illegal to install or use these devices in the UK. Use of
these devices constitutes an offence contrary to sections 1 (unlicensed use) and 13
(deliberate interference) of the Wireless Telegraphy Act 1949. Outlets marketing the
device are prosecuted for inciting the public to commit an offence.
Ireland: It is illegal to use mobile phone jammers in Ireland and prosecutions in
relation to jammers have occurred.
United States of America (USA): It is illegal to install or use these devices as FCC
Part 15(5b) Rule precludes the use of intentional interferers.
Europe: It is illegal under European Directive 99/05/CE to sell or use mobile phone
jammers. However, there is anecdotal evidence that Spanish authorities are not
prosecuting misuse once these devices arrive at the final user. Also France has passed
regulations that will allow the use of a type of mobile phone jammers in theatres,
temples and other places. Before permitting installation, it will be verified that the
influence of the system is null outside the place protected, health-related radiation
limits are fulfilled, and the system allows specific calls such as emergencies, police,
and fire department. Both the administration and mobile telephony operators will be
involved in the verification of these conditions, and their permission will be required
for installation. Misuse will be considered a major offence. The French authorities
consider that these conditions guarantee the rights of mobile operators, since they
must grant cell phone installation. In this scenario, cell phone jammers would become
similar to base stations, although, in this case, they would filter communications
instead of establishing them. The French authorities consider that those selective
devices would fulfil Directive 99/05/CE under adequate license terms subject to the
conditions of each member state. The ACA understanding of this arrangement is that
it does not constitute jamming, but is a micro-cell arrangement. Its success may be
due to cooperation between carriers and relevant authorities.
Canada: After a period of public consultation Industry Canada announced on 14 June
2002 in Gazette Notice No. DGTP – 005 – 02 that it would not authorise the use of
mobile phone jammers. It stated that this decision was consistent with the
Departments mandate to manage the radiofrequency spectrum. With respect to the use
of jamming devices in connection with federal security and law enforcement functions
for national security purposes, an alternative authorisation process is under review.
Jamaica: Mobile phone jammers are used in prisons. There is a media report which
suggests that legitimate services outside the prison boundaries are affected.