Milestone-Proposal:Orthogonal Frequency-Division Multiplexing (OFDM) with error correction for wireless networks, 1992
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Docket #:2025-11
This proposal has been submitted for review.
To the proposer’s knowledge, is this achievement subject to litigation? No
Is the achievement you are proposing more than 25 years old? Yes
Is the achievement you are proposing within IEEE’s designated fields as defined by IEEE Bylaw I-104.11, namely: Engineering, Computer Sciences and Information Technology, Physical Sciences, Biological and Medical Sciences, Mathematics, Technical Communications, Education, Management, and Law and Policy. Yes
Did the achievement provide a meaningful benefit for humanity? Yes
Was it of at least regional importance? Yes
Has an IEEE Organizational Unit agreed to pay for the milestone plaque(s)? Yes
Has the IEEE Section(s) in which the plaque(s) will be located agreed to arrange the dedication ceremony? Yes
Has the IEEE Section in which the milestone is located agreed to take responsibility for the plaque after it is dedicated? Yes
Has the owner of the site agreed to have it designated as an IEEE Milestone? Yes
Year or range of years in which the achievement occurred:
1989-1992
Title of the proposed milestone:
Australian Contributions to Wi-Fi®, 1989-1992
Plaque citation summarizing the achievement and its significance; if personal name(s) are included, such name(s) must follow the achievement itself in the citation wording: Text absolutely limited by plaque dimensions to 70 words; 60 is preferable for aesthetic reasons.
From 1989 to 1992, the Commonwealth Scientific and Industrial Research Organisation (CSIRO) in Australia applied orthogonal frequency-division multiplexing (OFDM) with forward error correction to solve the vexing challenge of multi-path signal interference in wireless local area networks (WLANs). When later incorporated into the IEEE 802.11 Wi-Fi® standards, this innovation was foundational for reliable high-speed wireless Internet access for mobile and smart devices within homes, businesses, and public spaces.
200-250 word abstract describing the significance of the technical achievement being proposed, the person(s) involved, historical context, humanitarian and social impact, as well as any possible controversies the advocate might need to review.
From 1989 to 1992, the Commonwealth Scientific and Industrial Research Organisation (CSIRO), under the leadership of Dr. John O’Sullivan, developed a pioneering solution to one of the most persistent problems in wireless communication: multipath interference. Their innovation—orthogonal frequency-division multiplexing (OFDM) combined with forward error correction—enabled reliable, high-speed wireless data transmission, even in complex indoor environments. This breakthrough was granted U.S. Patent 5,487,069 in 1996 and later became a cornerstone of the IEEE 802.11 Wi-Fi® standards.
This invention came at a pivotal time, coinciding with the rapid growth of personal computing and the emergence of mobile devices. By allowing seamless wireless connectivity across homes, workplaces, and public venues, CSIRO’s work fundamentally changed how people accessed and interacted with the digital world. The practical impact was enormous—users could now connect to the internet without wires, leading to mass adoption of laptops, smartphones, and wireless devices. This democratization of internet access not only boosted productivity and innovation but also lowered manufacturing costs through economies of scale, making connected technology more accessible globally.
Despite its widespread adoption, CSIRO’s patented technology was used by many tech giants without compensation, sparking legal battles. The organization eventually secured over AUD 430 million in settlements from companies including HP, Microsoft, Dell, and Apple. These high-profile cases highlighted the often-overlooked value of publicly funded research and reinforced the importance of protecting intellectual property. CSIRO’s Wi-Fi invention remains a landmark achievement, blending scientific excellence with real-world impact.
IEEE technical societies and technical councils within whose fields of interest the Milestone proposal resides.
IEEE Communications Society,
IEEE Signal Processing Society,
IEEE Microwave Theory and Technology Society,
IEEE Antennas and Propagation Society and
IEEE Consumer Electronics Society
In what IEEE section(s) does it reside?
New South Wales
IEEE Organizational Unit(s) which have agreed to sponsor the Milestone:
IEEE Organizational Unit(s) paying for milestone plaque(s):
Unit: New South Wales
Senior Officer Name: Syed Muzahir Abbas
IEEE Organizational Unit(s) arranging the dedication ceremony:
Unit: New South Wales
Senior Officer Name: Syed Muzahir Abbas
IEEE section(s) monitoring the plaque(s):
IEEE Section: New South Wales
IEEE Section Chair name: Syed Muzahir Abbas
Milestone proposer(s):
Proposer name: Ambarish Natu
Proposer email: Proposer's email masked to public
Please note: your email address and contact information will be masked on the website for privacy reasons. Only IEEE History Center Staff will be able to view the email address.
Street address(es) and GPS coordinates in decimal form of the intended milestone plaque site(s):
26 Pembroke Road Marsfield NSW 2122 Australia
Describe briefly the intended site(s) of the milestone plaque(s). The intended site(s) must have a direct connection with the achievement (e.g. where developed, invented, tested, demonstrated, installed, or operated, etc.). A museum where a device or example of the technology is displayed, or the university where the inventor studied, are not, in themselves, sufficient connection for a milestone plaque.
Please give the details of the mounting, i.e. on the outside of the building, in the ground floor entrance hall, on a plinth on the grounds, etc. If visitors to the plaque site will need to go through security, or make an appointment, please give the contact information visitors will need. 26 Pembroke Road Marsfield NSW 2122 Australia - On the white wall by the CSIRO logo at the building's street entrance
Are the original buildings extant?
Yes
Details of the plaque mounting:
On the white wall by the CSIRO logo at the building's street entrance.
How is the site protected/secured, and in what ways is it accessible to the public?
it will be accessible to general public
Who is the present owner of the site(s)?
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
What is the historical significance of the work (its technological, scientific, or social importance)? If personal names are included in citation, include detailed support at the end of this section preceded by "Justification for Inclusion of Name(s)". (see section 6 of Milestone Guidelines)
Historical Context
A 1985 ruling by the U.S. Federal Communications Commission released parts of the ISM bands for unlicensed use for communications [1]. These frequency bands include the same 2.4 GHz bands used by equipment such as microwave ovens, and are thus subject to interference [2].
In 1991 in Nieuwegein, The Netherlands the NCR Corporation and AT&T invented the precursor to IEEE 802.11 [3], intended for use in cashier systems, under the name WaveLAN. NCR's Vic Hayes, who held the chair of IEEE 802.11 for ten years, along with Bell Labs engineer Bruce Tuch, approached the Institute of Electrical and Electronics Engineers (IEEE) to create a standard and were involved in designing the initial IEEE 802.11a and IEEE 802.11b [4] standards.
In 1989 in Australia, a team of scientists began working on wireless LAN technology [6]. A prototype test bed for a wireless local area network (WLAN) was developed in 1992 by a team of researchers from the Radiophysics Division of the CSIRO (Commonwealth Scientific and Industrial Research Organisation) in Australia, led by John O'Sullivan [7]. A patent for Wireless LAN was lodged by the CSIRO in 1992 [8] and granted in 1996 [22].
The first version of the IEEE 802.11 protocol was released in 1997, and provided up to 2 Mbit/s link speeds. This was updated in 1999 with IEEE 802.11b to permit 11 Mbit/s link speeds. The CSIRO developed technology was incorporated into IEEE 802.11a standard in 1999 and in 2003 it was also adopted in the IEEE 802.11g standard [30].
In 1999, the Wi-Fi® Alliance formed as a trade association to hold the Wi-Fi® trademark under which most IEEE 802.11 products are sold [9].
The major commercial breakthrough came with Apple Inc. adopting Wi-Fi® for their iBook series of laptops in 1999 [3]. It was the first mass consumer product to offer Wi-Fi® network connectivity, which was then branded by Apple as AirPort [10]. This was in collaboration with the same group that helped create the standard: Vic Hayes, Bruce Tuch, Cees Links, Rich McGinn, and others from Lucent [11][12].
In 2000, Radiata, a group of Australian scientists connected to the CSIRO, were the first to use the 802.11a standard on semiconductor chips connected to a Wi-Fi® network [8]. CSIRO entered a Technology License Agreement (TLA) with Radiata in February 1998 that, among other things, had a per-Wi-Fi® chip royalty payment. In 2001, Cisco acquired Radiata and started paying Radiata’s license fees under the TLA license agreement for Radiata products [30]. This was a major commercial success story for CSIRO, Radiata and Australia.
Wi-Fi® uses a large number of patents held by multiple different organizations [13]: Australia [14], The United States of America [15], and The Netherlands [16] simultaneously claim the invention of Wi-Fi®, and a consensus has not been reached globally [17][18]. In 2009, the Australian CSIRO was awarded $200 million after a patent settlement with 14 technology companies, with a further $220 million awarded in 2012 after legal proceedings with 23 companies [19][20][21].
In 2016, the CSIRO's WLAN prototype test bed was chosen as Australia's contribution to the exhibition A History of the World in 100 Objects held in the National Museum of Australia [15].
The development of CSIRO’s Wi-Fi® technology occurred during a critical period of innovation in wireless communication. The late 20th century witnessed an explosion of personal computing and mobile communication, yet fast and reliable wireless networking remained an unsolved challenge. The issue of multipath interference, where signals bounce off objects and create distortions, severely limited the practicality of early wireless networks.
Impact on Humanity
CSIRO was able to address this problem using a technique based on orthogonal frequency-division multiplexing (OFDM), which had been developed at Bell Laboratories and published in 1966 [29]. CSIRO's solution used OFDM, but with error correction. This approach allowed Wi-Fi® signals to be transmitted efficiently in indoor environments, making it possible to achieve high-speed, reliable wireless connectivity. This breakthrough laid the foundation for IEEE 802.11 standards, enabling widespread wireless networking that is now essential to global infrastructure.
CSIRO's work democratized internet access enabled mobile phones, laptops and associated devices, enabling reliability in almost all environments. This boosted productivity and innovation and lowered manufacturing costs through economies of scale, thereby making connected technology more accessible globally. Without CSIRO’s work, modern Wi-Fi, mobile computing, and the Internet of Things (IoT) might have developed at a much slower pace or in an entirely different form.
Key Engineering Contribution
Resolution of Multipath Interference: Traditional wireless communication suffered from signal distortions due to reflections. CSIRO’s use of OFDM with error correction provided a practical solution, ensuring stable and high-speed wireless transmission.
Wireless Data Transmission at High Speeds: CSIRO's patented technology allowed for efficient use of bandwidth, significantly increasing the speed and reliability of wireless communication compared to previous systems.
Integration into Global Wireless Standards: CSIRO’s technology became a core part of the IEEE 802.11a (1999), 802.11g (2003), and 802.11n (2009) standards, ensuring global adoption.
Impact on Mobile Computing and IoT: The success of smartphones, tablets, smart home devices, and industrial IoT applications heavily relies on Wi-Fi. CSIRO’s work enabled the creation of ubiquitous wireless connectivity, essential to the evolution of modern digital technology.
What obstacles (technical, political, geographic) needed to be overcome?
The team at CSIRO, led by Dr. John O’Sullivan, was initially working on a problem in radio astronomy related to detecting faint signals from distant galaxies. Specifically, they were trying to process signals distorted by interstellar dispersion—the way radio waves scatter and spread as they travel through space. This work required sophisticated mathematical techniques to filter out unwanted noise and reconstruct clear signals.
While working on these astronomy challenges, O’Sullivan and his team developed a method using Fast Fourier Transform (FFT) techniques and orthogonal frequency-division multiplexing (OFDM) to clean up intergalactic radio wave distortion.
By 1990 CSIRO was looking for ways to commercialise its capability in radio physics. CSIRO realised that their skills with antennas, signal processing, and radio design might allow them to cut the network cable that linked every office computer. From the beginning CSIRO set out to match the speed of the best wired networks of the time. One problem was reflections got in the way, within buildings, rooms, and confined spaces in general. Radio waves bounce off surfaces causing multipath transmission such that a signal arrives at a receiver via multiple paths. The receiver detects a signal and a series of echoes resulting in a fuzzy ambiguous signal akin to ghosting on a television set.
This unexpected connection between astronomy and wireless technology led to the breakthrough that made modern Wi-Fi® both fast and reliable, demonstrating how fundamental research in one field can lead to ground-breaking innovations in another.
Obstacles Overcome in Developing Wi-Fi® Technology
1. Technical Challenges Multipath Interference: One of the most difficult problems in early wireless communication was signal reflection, which caused interference and data loss. CSIRO solved this using orthogonal frequency-division multiplexing (OFDM) with error correction, enabling stable and fast wireless signals.
Hardware Limitations: In the early 1990s, computing power was limited. Implementing complex signal processing algorithms required developing efficient digital hardware that could operate within available processing capabilities.
Compatibility with Existing Standards: The solution had to be adaptable to the emerging IEEE 802.11 standards, ensuring its widespread adoption.
2. Political and Legal Challenges Securing Patent Recognition: CSIRO had to defend its 1996 patent (U.S. Patent 5,487,069) against multinational corporations that initially used the technology without compensation.
Lengthy Legal Battles: It took years of litigation for CSIRO to receive rightful recognition and compensation, with settlements eventually exceeding $430 million from tech giants like Dell, HP, and Microsoft.
3. Geographic Challenges Global Technology Development from Australia: CSIRO had to prove itself on the world stage, competing with larger, well-funded R&D institutions in the US and Europe in the late 1990s.
What features set this work apart from similar achievements?
IEEE Milestone committee has recognised WaveLAN [25] as the precursor to Wi-Fi®. The problem being addressed by WaveLAN was to replace Ethernet cables with a wireless connection for LANs mainly in office and business settings. On the other hand CSIRO was trying to solve the problem of high-speed wireless data reliably despite multipath interference. The CSIRO team used Fast Fourier Transform (FFT) and Orthogonal Frequency Division Multiplexing to separate overlapping signals and withstand multipath propagation issues, handle interference with interleaving techniques and correct errors in transmission by using error correction methods.
The CSIRO patent is no. 5,487,069. However, this original published version no longer represents the current state of the patent. Following re-examination initiated in 2008 by Intel (control number 90/010,367), the patent was amended to delete some claims, amend some others, and add about 80 new ones! The re-examination certificate is made available via Google docs [23]. The certificate shows the claim amendments, along with all of the prior art raised in the re-examination.
The more recent re-examinations, initiated in 2010, are complete, although a further re-examination certificate is yet to issue. Only minor additional amendments have resulted from these proceedings.
The patent, as it currently stands at the conclusion of all re-examination proceedings, contains about 140 claims. Most of these are directed to minor variations and specific features of the particular implementation which is described in detail within the specification. But to understand the maximum extent of CSIRO’s patent rights, it is sufficient to look only at one of the broadest claims of the patent. We have chosen claim 68, which is a method claim defining a procedure for transmitting data in a wireless LAN which is implemented within devices employing the invention:
A method for transmitting data in a confined multipath transmission environment of radio frequencies, said data being provided by an input data channel coupled to transmission signal processing means in turn coupled to antenna means, said method comprising the steps of:
applying data reliability enhancement to said data;
interleaving, by means for interleaving, blocks of said enhanced data;
modulating said data, by modulation means of said transmission signal processing means, into a plurality of sub-channels comprised of a sequence of data symbols such that the period of a sub-channel symbol is longer than a predetermined period representative of significant ones of non-direct transmission paths; and
transmitting, by said antenna means, said sub-channel symbols.
Why was the achievement successful and impactful?
CSIRO does not own the term ‘Wi-Fi®’, nor does it own, or claim to own, multi-frequency modulation, OFDM [28], the Fast Fourier Transform, forward error correction, Trellis Coded Modulation, or interleaving.
The CSIRO contribution was the demonstration of a particular combination of the above said techniques which solved the specific problem of making a wireless LAN work in a confined space with potentially extreme multipath propagation problems. This problem had not been solved before CSIRO’s scientists did it, and the reason it forms the basis for the 802.11a/g Wi-Fi® standards is because no better solution was put forward to the committee at the time [27].
Supporting texts and citations to establish the dates, location, and importance of the achievement: Minimum of five (5), but as many as needed to support the milestone, such as patents, contemporary newspaper articles, journal articles, or chapters in scholarly books. 'Scholarly' is defined as peer-reviewed, with references, and published. You must supply the texts or excerpts themselves, not just the references. At least one of the references must be from a scholarly book or journal article. All supporting materials must be in English, or accompanied by an English translation.
[1] "Authorization of Spread Spectrum Systems Under Parts 15 and 90 of the FCC Rules and Regulations". Federal Communications Commission of the USA. 18 June 1985. https://web.archive.org/web/20070928054826/http://www.marcus-spectrum.com/documents/81413RO.txt
[2] "Do Microwaves Interfere With WiFi Signals?". 17 January 2018 https://www.scienceabc.com/innovation/do-microwaves-interfere-with-wifi-signals.html
[3] Claus Hetting (19 August 2018). "How a 1998 meeting with Steve Jobs gave birth to Wi-Fi". Wi-Fi NOW Global. https://wifinowglobal.com/news-and-blog/how-a-meeting-with-steve-jobs-in-1998-gave-birth-to-wi-fi/
[4] Ben Charny (6 December 2002). "Vic Hayes – Wireless Vision". CNET. https://web.archive.org/web/20120826164642/http://news.cnet.com/1200-1070-975460.html
[5] Hetting, Claus (8 November 2019). "Vic Hayes & Bruce Tuch inducted into the Wi-Fi NOW Hall of Fame". Wi-Fi NOW Global. https://wifinowglobal.com/news-and-blog/vic-hayes-bruce-tuch-inducted-into-the-wi-fi-now-hall-of-fame/
[6] Rimmer, Matthew (27 April 2007). "CSIRO wins Wi-Fi patent litigation" (PDF). Australian Intellectual Property Newsletter.
https://eprints.qut.edu.au/215127/1/132231.pdf
[7] Sibthorpe, Clare (4 August 2016). "CSIRO Wi-Fi invention to feature in upcoming exhibition at National Museum of Australia". The Canberra Times. https://www.canberratimes.com.au/national/act/csiro-wifi-invention-to-feature-in-upcoming-exhibition-at-national-museum-of-australia-20160803-gqjyuv.html
[8] O’Sullivan, John (February 2018). "How we made the wireless network". Nature Electronics. 1 (2): 147. doi:10.1038/s41928-018-0027-y. ISSN 2520-1131. S2CID 257090965 https://www.nature.com/articles/s41928-018-0027-y
[9] "Wi-Fi® Alliance: Organization". Official industry association Web site. Archived from the original on 3 September 2009. https://web.archive.org/web/20090903004711/http://www.wi-fi.org/organization.php
[10] "A brief history of Wi-Fi®". The Economist. 12 July 2004. Archived from the original on 2 January 2023 https://web.archive.org/web/20230102075107/https://www.economist.com/technology-quarterly/2004/06/12/a-brief-history-of-wi-fi
[11] Steve Lohr (22 July 1999). "Apple Offers iMac's Laptop Offspring, the iBook". The New York Times. https://web.archive.org/web/20170202003816/http://www.nytimes.com/1999/07/22/business/apple-offers-imac-s-laptop-offspring-the-ibook.html
[12] Lewis, Peter H. (25 November 1999). "State of the Art; Not Born To Be Wired". The New York Times. https://web.archive.org/web/20170202002735/http://www.nytimes.com/1999/11/25/technology/state-of-the-art-not-born-to-be-wired.html?pagewanted=all
[13] "IEEE SA – Records of IEEE Standards-Related Patent Letters of Assurance". IEEE https://web.archive.org/web/20120410074816/http://standards.ieee.org/about/sasb/patcom/pat802_11.html
[14] "World changing Aussie inventions". Australian Geographic. Archived from the original on 15 December 2011. https://web.archive.org/web/20111215082408/http://www.australiangeographic.com.au/journal/world-changing-aussie-inventions.htm
[15] Field, Shivaune. "Hedy Lamarr: The Incredible Mind Behind Secure WiFi, GPS And Bluetooth". forbes.com. Archived from the original on 19 April 2023. https://www.forbes.com/sites/shivaunefield/2018/02/28/hedy-lamarr-the-incredible-mind-behind-secure-wi-fi-gps-bluetooth/?sh=5871237541b7
[16] Van Der Meer, Hilde (26 March 2018). "10 Inventions You Didn't Know Were Dutch". investinholland.com. Netherlands Foreign Investment Agency. Archived from the original on 19 April 2023. https://web.archive.org/web/20230419124142/https://investinholland.com/news/10-inventions-didnt-know-dutch/
[17] Mullin, Joe (4 April 2012). "How the Aussie government "invented WiFi" and sued its way to $430 million". Ars Technica. Archived from the original on 8 May 2012. https://arstechnica.com/tech-policy/news/2012/04/how-the-aussie-government-invented-wifi-and-sued-its-way-to-430-million.ars
[18] Popper, Ben (3 June 2010). "Australia's Biggest Patent Troll Goes After AT&T, Verizon and T-Mobile". CBS News. Archived from the original on 6 May 2013. https://web.archive.org/web/20130506135649/http://www.cbsnews.com/8301-505124_162-43340647/australias-biggest-patent-troll-goes-after-at038t-verizon-and-t-mobile/
[19] Brodkin, Jon (31 March 2012). "WiFi patent case results in $229 million payment to Australian government". Ars Technica. Archived from the original on 19 April 2023. https://web.archive.org/web/20230419131311/https://arstechnica.com/tech-policy/2012/04/wifi-patent-case-results-in-229m-payment-to-australian-government/
[20] Schubert, Misha (31 March 2012). "Australian scientists cash in on Wi-Fi invention". The Sydney Morning Herald. Archived from the original on 1 April 2012. https://web.archive.org/web/20120401162238/http://www.smh.com.au/it-pro/government-it/australian-scientists-cash-in-on-wifi-invention-20120331-1w5gx.html
[21] "CSIRO wins legal battle over Wi-Fi® patent". ABC News. 1 April 2012. Archived from the original on 7 August 2019. https://web.archive.org/web/20190807090636/https://www.abc.net.au/news/2012-04-01/csiro-receives-payment-for-wifi-technology/3925814
[22] US Patent US5487069A - Wireless LAN granted 23 January 1996. https://patents.google.com/patent/US5487069A/en
[23] US Patent Office Re-examination initiated in 2008 by Intel (control number 90/010,367) - https://docs.google.com/open?id=0B1Qqijz4aI6haU13T3VLME1RV3V6YW0wZ0t0SWVhdw
[24] An Analysis of the CSIRO WLAN Patent https://blog.patentology.com.au/2012/04/analysis-of-csiro-wlan-patent.html
[25] WaveLAN, Precursor of Wi-Fi®, 1987 https://ethw.org/Milestones:WaveLAN,_Precursor_of_Wi-Fi,_1987
[26] The Strange Origins of Wi-Fi® – An Australian Invention? https://www.youtube.com/watch?v=McbsxihcQS0
[27] The story of Wi-Fi (ABC Science) https://www.youtube.com/watch?v=esA9YhdgvIg
[28] R. van Nee and R. Prasad, The history of orthogonal frequency division multiplexing, IEEE Personal Communications, vol. 7, no. 6, pp. 28–48, Dec. 2000.
[29] "OFDM First Implemented" https://www.comsoc.org/node/19451
[30] Judge Davis determines reasonable royalty damages for WiFi standard essential patent (CSIRO v. Cisco) https://www.essentialpatentblog.com/2014/07/judge-davis-sets-royalty-rate-for-wifi-standard-essential-patent-csiro-v-cisco/#:~:text=Background,to%20the%20802.11a%20standard. 28 July 2014.
Supporting materials (supported formats: GIF, JPEG, PNG, PDF, DOC): All supporting materials must be in English, or if not in English, accompanied by an English translation. You must supply the texts or excerpts themselves, not just the references. For documents that are copyright-encumbered, or which you do not have rights to post, email the documents themselves to ieee-history@ieee.org. Please see the Milestone Program Guidelines for more information.
Please email a jpeg or PDF a letter in English, or with English translation, from the site owner(s) giving permission to place IEEE milestone plaque on the property, and a letter (or forwarded email) from the appropriate Section Chair supporting the Milestone application to ieee-history@ieee.org with the subject line "Attention: Milestone Administrator." Note that there are multiple texts of the letter depending on whether an IEEE organizational unit other than the section will be paying for the plaque(s).
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