ACMA - Wireless LANs in the 2.4 GHz band FAQs

Accessing the public telecommunications network and related issues

A recent upsurge in the use of wireless access systems by small businesses and hobbyists using spread spectrum radiocommunications equipment has generated interest in this area of communications.

The equipment, which includes but is not limited to equipment covered by international standard IEEE802.11b, is low-cost and is designed to operate in the 2.4- 2.4835 GHz radiofrequency band. It is particularly suitable for short-range communications applications such as wireless local area networks (WLANs), which can be used to link computers in private networks.

The technology has recently been used to connect such private networks to the public telecommunications network, and this has attracted the attention of the government and media. At the request of the former Minister for Communications, Information Technology and the Arts, Senator Richard Alston, the House of Representatives Standing Committee on Communications, Information Technology and the Arts enquired into wireless broadband technologies in Australia.

On 20 September 2002, the former Minister announced a determination that exempts WLANs in single places or premises (sometimes referred to as 'hotspots') from carrier licensing. The aim of this determination was to preserve technological neutrality and to encourage innovation. The determination removed an anomaly under which cable networks on single premises do not require a carrier licence, while wireless networks on single premises did. There is an accompanying explanatory statement for this determination.

The ACMA has prepared answers to the following frequently asked questions about this issue, based on the current legislative obligations.

What types of devices use the 2.4GHz Band?

Various spread spectrum and other modulation schemes for radiocommunication applications use the 2.4 GHz band. This includes WLAN systems (some from IEEE 802.11b & g), cordless phones, wireless medical telemetry equipment and Bluetooth ™ short-range wireless applications, which include connecting printers to computers and connecting modems or hands-free kits to mobile phones.

Previously, users were licensed to operate any of the spread spectrum transmitters used in these applications under the Radiocommunications (Spread Spectrum Devices) Class Licence 2002 (the Spread Spectrum class licence).

The Spread Spectrum class licence was revoked in August 2005. All WLAN modulation schemes are now licensed under the Radiocommunications (Low Interference Potential Devices) Class Licence 2000 (the LIPD Class Licence). Video security links and various other non-spread spectrum low power devices are also operated under the LIPD Class Licence.

For more examples of short-range radiocommunications applications known to be using particular bands, see Spectrum Opportunities for Short-Range Radiocommunications.

Non-radiocommunication equipment also operates in the band 2.4-2.5 GHz. This band is one of a number of bands designated internationally for industrial, scientific and medical (ISM) applications.ISM equipment uses radiofrequency energy locally for such purposes as heating, drying or welding. Some of this energy will escape and may cause interference to a nearby receiver operating in the same spectrum. The most common ISM equipment in the 2.4 GHz band is the domestic microwave oven.

Under international agreement, radiocommunications services operating in ISM-designated bands must accept any harmful interference caused by ISM applications.

What radiated power limits apply to devices operating in the 2.4 GHz band?

For operation of devices under the LIPD class licence a maximum radiated power of:

four watts EIRP is authorised in the 2.4 – 2.4835 GHz band for digital modulation transmitters
500 milliwatts EIRP is authorised in the 2.4 – 2.4835 GHz band for frequency hopping transmitters that use a minimum of 15 hopping frequencies
four watts EIRP is authorised in the 2.4 – 2.4835 GHz band for frequency hopping transmitters that use a minimum of 75 hopping frequencies
one watt EIRP is authorised in the 2.4 - 2.45 GHz band for telecommand and telemetry transmitters and radiofrequency identification transmitters
10 milliwatts EIRP is authorised in the 2.4 - 2.4835 GHz band for all other transmitters

In addition the LIPD class licence and associated Short Range Devices (SRD) standard include power spectral density limits that must be complied with.

Are there any equipment standards applying to WLAN devices?

Equipment supply is regulated by a labelling regime notice (made under section 182 of the Radiocommunications Act 1992) and suppliers of equipment covered by the ACMA standards (made under section 162) that are listed in that notice must comply with requirements and label equipment accordingly.

There are currently two ACMA standards under that notice that are applicable to 2.4 GHz. The first is the Radiocommunications (Data Transmission Equipment Using Spread Spectrum Modulation Techniques) Standard 2003, which was limited to coverage of WLANS using spread spectrum modulation. This ACMA standard mandated Australian standard AS/NZS 4771:2000. The second is the Radiocommunications (Short Range Devices) Standard 2004, which mandates AS/NZS 4268:2003. All WLAN modulation schemes have been now included into the Short Range Devices standard and by early 2007 the spread spectrum standard should be withdrawn.

The spread spectrum standard has level 2 compliance requirements whereas the short range devices standard is level 1. The compliance level determines what information must be contained in an equipments compliance folder.

What is 802.11?

The 802.11 family is a group of related standards for WLAN equipment produced by the Institute of Electrical and Electronics Engineers (IEEE), a US standards and engineering organisation with worldwide membership.

Different members of the IEEE 802.11 family have different characteristics, including radiofrequency spectrum characteristics, and operate in different frequency bands. They may employ various modulation formats and support various data rates. Even within a particular member of the IEEE 802.11 standards family, there are options that may produce different spectrum characteristics.

IEEE 802.11b is an existing standard for devices operated in the 2.4 GHz band (2.4-2.4835 GHz) using spread spectrum modulation; IEEE 802.11g is an emerging standard for devices operated in the 2.4 GHz band (2.4-2.4835 GHz) using OFDM (orthogonal frequency division multiplex) modulation. Devices might transmit radiated power levels of a few tens of milliwatts, for example, to make wireless connections between adjacent computers.

IEEE 802.11a is another standard in the IEEE802.11 family that covers WLANs that operate in the 5 GHz bands. Further information on regulatory arrangements in those bands is available on the ACMA website (see Radiofrequency planning topics under Planning Developments - Radio LANs).

What are the security risks of operating WLANs using IEEE 802.11 devices?

The IEEE 802.11a and b standards currently specify a security protocol known as Wireless Equivalent Privacy (WEP). This encryption method is considered to be relatively unsophisticated and WLAN operators should consider their overall network set-up and security procedures and not rely on the in-built security measures of IEEE 802.11a and b.

What laws apply to the use of radiocommunications equipment?

The Radiocommunications Act 1992 and the Telecommunications Act 1997 apply to the use of radiocommunications equipment. The two laws cover different aspects of telecommunications services. The Radiocommunications Act covers the use of the radiofrequency spectrum, in which radiocommunications operates. The Telecommunications Act covers the supply of communications to the public using cable or radiocommunications equipment.

If you operate radiocommunications equipment, you need to make sure that you comply with both of these laws. There are licensing requirements for users of radiocommunications equipment under the Radiocommunications Act and the Telecommunications Act.

What can you tell me about radiocommunications licensing?

Radiocommunications licensing relates to the use of the radiofrequency spectrum for communications purposes. There are three types of radiocommunications licences — apparatus, class and spectrum licences.

Apparatus licences authorise the operation of radiocommunications equipment for specific purposes, for example, land mobile, outpost, amateur, maritime or aeronautical communications and broadcasting. You pay a licence fee and the ACMA issues you with a licence to operate the equipment.

Class licences are open, standing authorities that allow anyone to operate particular radiocommunications equipment provided the operation and the device meet the conditions of the licence. Class licences do not have to be applied for and no licence fees are payable. Under class licensing, users may operate various types of radiocommunications equipment including citizen band radios, mobile and cordless phones and a range of other low power devices, such as remote control garage door openers.

Spectrum licences are a tradeable, technology neutral (that is, the licence is not related to any particular technology, system or service) spectrum access right for a fixed non-renewable term. Instead of authorising the use of a specific device, spectrum licences authorise the use of spectrum-space and give licensees the freedom to deploy any device from any site within their spectrum space, provided that use is compatible with the core conditions of the licence and the technical framework.

Is there any 'unlicensed spectrum' in Australia?

There is no unlicensed spectrum in Australia. Users must be licensed to operate radiocommunication transmitters. The Radiocommunications Act provides for three types of radiocommunications licences, which enables the ACMA to offer a type of radiocommunications licence appropriate to the circumstances.

How is access to the 2.4 GHz band managed?

The ACMA management approach to the 2.4 GHz band relies on a 'public park' concept.

Users of WLAN devices operating in this band are required to comply with a prescribed set of conditions that are intended to avoid destructive interference between users, in most situations. Devices may be operated without payment of a licence fee, and without individual frequency coordination or registration of location. Authorised operation is on the basis that no interference is caused to other radiocommunications users and no protection from interference is offered. Overseas regulatory arrangements are essentially the same in their effect. In July 2002, the former ACA published a report which discussed spectrum management arrangements for IEEE 802.11 devices in the USA, Europe and Asia (see Radiofrequency planning topics under Planning Developments - Radio LANs).

In supporting the use of WLAN devices in Australia, there are obvious benefits in aligning domestic spectrum arrangements with world trends where possible. While Europe and North America have different regulatory requirements for the use of short-range spread spectrum WLAN devices, the Australian arrangements accommodate both in the 2.4 GHz band, as far as practicable. In particular, the band of authorised operation is the same (2.4-2.4835 GHz), and the device being used must comply with either the ETSI standard (Europe) or the relevant parts of the Rules and Regulations of the US Federal Communications Commission.

In radiocommunications licensing, what does the 'public park' concept mean?

With some kinds of radiocommunications it is possible to adopt a regulatory approach that allows users to share spectrum without formal frequency coordination between users — the 'public park' concept.

Under the 'public park' concept, the planning objective is for all users to be able to access a small portion of the total resource (in this case a frequency band) and to share that resource in a way that requires minimal regulatory intervention. Such sharing usually requires the power of these devices to be kept well down. This approach avoids the need for ongoing individual frequency co-ordinations and the registering of technical details and locations of equipment for each new user. Access to the band by all potential users is then relatively unconstrained.

To support this objective, the general conditions of operation (including technical conditions for equipment) that apply to all users are constructed to limit the risk of interference between users under most likely situations. Because the locations of users are not coordinated or registered, operations in 'public park' bands do not carry guarantees of interference-free operation. The use of a 'public park' approach is administratively efficient and gives great freedom to users, but the price of this freedom is increased risk of interference.

When establishing suitable limiting conditions of operation under the public park concept, a key requirement is determining an appropriate limit for the maximum power allowed to be transmitted. As radiated power increases, the need to use individual frequency coordination (with its associated complexity, registration requirements and cost) to satisfactorily control interference between users also increases. Usually, it is preferable to not mix un-coordinated and coordinated use in the same band because of the uncertain interference risk this presents to the latter.

The application of the 'public park' concept to radiocommunications licensing is associated with several ACMA class licences. Those class licences include technical conditions promoting a high degree of sharing. Under such circumstances, use would typically be limited to relatively short-range operation.

What risks are there in operating in a 'public park'?

As none of the short-range devices in a 'public park' band is subject to frequency coordination, the risk of unplanned interference between uncoordinated users is always present. There is no coordination between WLANs or between WLANs and other short-range devices sharing the 2.4 GHz band. Interference risk is managed by the combination of class licence technical conditions and equipment design. So, the likelihood of interference is related to whether devices operating at low power will be so close together as to cause interference.

WLAN devices are specifically designed to work in environments where there may be significant and uncertain amounts of interference; however, communications range and the rate of information transfer reduce as levels of interference increase.

In assessing whether operations in a 'public park' would be fit for the intended purpose, users and service providers are encouraged to identify and take into account all possible risks. These would include:

any safety-of-life issues;
potential loss of any core business information that might be carried on the WLAN network; and
the ability to guarantee a minimum service provision or quality of service.

The term 'unlicensed spectrum' is sometimes used to describe radiofrequency spectrum in which a user would not need to be licensed to operate a radiocommunications transmitter. The term may be related to the 'licence-exempt' category of use that applies in some other countries.

What about the use of WLANs in rural areas?

Compared to city use, the same diversity of uses for the 2.4 GHz band can be expected in rural towns but on a smaller scale and possibly at a lower overall density. Changing the regulations to allow higher radiated power levels in rural areas has been suggested. However, this needs to be treated cautiously. The public park concept only works if the radiated power of each device is kept low. Increasing the radiated power for one type of application will diminish the utility of the public park for other users. And even if such arrangements were workable in rural areas, interference and compliance issues may arise if those arrangements could not be effectively contained to such areas.

Is the 2.4 GHz 'public park' band suitable for public telecommunications applications?

Some parts of industry are using WLANs in the 2.4 GHz band to link into the public telecommunications network. This could involve point-to-point or wide-area communication. Where greater range is desired, this usually means using amplifiers and high gain antennas. This increases the risk of mutual interference between users operating in the 'public park'.

Given the uncoordinated nature of operations in the band and the risk of interference from devices like microwave ovens, Bluetooth™ devices, wireless LANs and other devices, it may not be possible to guarantee a quality service for public telecommunications users.

In rural areas, the availability of appropriate telecommunications network infrastructure (for the WLAN network to link into) is anticipated to be a major factor. Providing broadband network backbone links where they do not already exist is costly. This could mean that WLAN deployments would be limited to areas within line-of-sight of existing telecommunications network infrastructure.

What can you tell me about telecommunications licensing?

Under the Telecommunications Act 1997, there are two types of persons or organisations that can provide carriage services to the public — carriers and carriage service providers (CSPs).

Carriers are defined as those persons who own a telecommunications network unit used to supply carriage services to the public. Network units can include cable and radiocommunications facilities. A base station in a WLAN would generally fit the definition of a network unit, that is, a base station in a terrestrial radiocommunications customer access network under section 34 of the Telecommunications Act. Carrier licences are granted by the ACMA under section 56 of the Telecommunications Act.

CSPs use a telecommunications network unit to supply carriage services to the public. Carriage services include those for carrying communications such as telephone and Internet access services. CSPs can include organisations that resell time on a carrier network for phone calls, as well as Internet service providers (ISPs) delivering access to the Internet. CSPs are not required to obtain a licence from the ACMA to supply a carriage service to the public.

Different obligations under the Telecommunications Act apply to carriers and CSPs. Carriers must comply with carrier licensing obligations, while CSPs must comply with service provider rules.

What about telecommunications licensing of WLAN equipment?

WLAN equipment can be a network unit and in many circumstances may require a carrier licence. Whether a carrier licence is needed will depend on what the equipment is being used for and who it is being used to supply services to.

What constitutes supplying services in a single place - hotspots?

In September 2002, the former Minister for Communications, Information Technology and the Arts made a Determination under section 51 of the Telecommunications Act 1997 to exempt wireless networks from the need to be licensed in certain circumstances where a fixed line network would not require a licence. The determination and an accompanying explanatory statement are on the Department of Broadband, Communications and the Digital Economy (DBCDE) website.

As a consequence of this exemption, the operation of wireless equipment to supply carriage services to the public on a single premise (such as an Internet café, shopping centre, airport lounge, hotel or conference centre) does not require a carrier licence.

How do I know if I need a carrier licence?

An owner of a network unit used to supply a carriage service to the public must hold a carrier licence unless an exemption applies or a nominated carrier declaration is in place for that network unit.

You need to answer the following three questions if you are operating WLAN equipment or thinking of doing so.

Is there a network unit involved?
Is the network unit used 'to supply a carriage service to the public'?
Is the network unit exempt?

Is there a network unit involved?

The Telecommunications Act 1997 specifies four types of radiocommunications network units:

a base station that supplies a public mobile telecommunications service;
a base station that is part of a terrestrial radiocommunications customer access network;
a fixed radiocommunications link; and
a satellite-based facility.

Is the network unit used 'to supply a carriage service to the public?'

The second test is whether your WLAN equipment is supplying a carriage service to the public. Supply to the public occurs if the communication is:

between two end-users, where each end-user is outside the immediate circle of the owner of the network unit; or
point-to-multipoint, where at least one end-user is outside the immediate circle of the owner of the network unit.

The immediate circle of the owner of a network unit means:

if the owner is an individual, an employee of the individual;
if the owner is a partnership, an employee of the partnership;
if the owner is a body corporate, an officer of the body corporate and, if another body corporate is related to it, the other body corporate and its officers; or
if there is more than one owner of the network unit, the other owners of the network unit and the overlap of their immediate circles.

Is the network unit an exempt network?

A wireless network may be exempt from the carrier licence requirements if:

it is used or for use for the sole purpose of supplying carriage services on a non-commercial basis; or
the services are supplied in a single place.

What constitutes non-commercial use?

The ACMA has developed a set of questions to assist the owner of WLAN equipment to determine whether its use would be commercial. These are in the ACMA fact sheet Wireless LANs and exempt non-commercial networks.

In general, the outcomes of this approach can be summarised as:

hobbyists and community users such as cooperatives, may not require a licence as long as they meet the 'non-commercial tests' outlined in the fact sheet, and
small businesses such as ISPs who meet the 'commercial' test would require a carrier licence.

What are the conditions of a carrier licence?

Standard carrier licence conditions are found in Schedule 1 to the Telecommunications Act 1997. The Minister may make additional licence conditions which can apply to individuals, classes of people or all carriers.

Under Clause 1 of Schedule 1 to the Telecommunications Act, a carrier must comply with that Act and the Telecommunications (Consumer Protection and Service Standards) Act 1999.

Carriers must comply with the following arrangements:

industry codes and standards;
the universal service regime;
the Customer Service Guarantee Standard;
the Telecommunications Industry Ombudsman scheme;
emergency call services;
the protection of communications;
the protection of national interests;
law enforcement; and
defence requirements and disaster plans.

See the ACMA booklet Know Your Obligations - Carriers, Carriage Service Providers, Internet Service Providers.

The ACMA does not provide legal advice. You are strongly advised to seek your own legal advice to clarify any issues of interpretation in relation to the matters raised above. The ACMA accepts absolutely no liability (including negligence) for any loss or damage suffered as a result of reliance on the accuracy of the information provided.

Wireless LANs in the 2.4 GHz band FAQs

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Related pages

2.4 GHz

802.11

Spectrum licensing

Public park

Telecommunciations licensing

Carrier licensing