THE ROLE OF ASTRONOMY IN WIFI

DR JOHN O’SULLIVAN

16 SEPTEMBER 2016

PEOPLE, SKILLS AND LEADERSHIP

Ronfest Talk

Bob Frater’s Cosmic Genealogy

Bob Frater, Jean Casse + myself(?) at SU ca ‘70

Ron Ekers & Warwick Wilson

Ronfest Talk

ATMOSPHERIC DISTORTIONS

Atmospheric seeing is a problem for all astronomy Adaptive optical telescopes – Muller and Buffington , 1974

•  Adjust mirror to maximise I(θ)2 – image sharpness •  Related to autofocus on cameras

Westerbork interferometer atmospheric phase problems •  Consider algebraic solving for phases using redundant baselines –

Noordam Fourier again – they are equivalent (Hamaker et al, 1977l)!

I(u)

Baseline u

θ

i(θ) FT

From Muller & Buffington, JOSA, Sep 74

SHORT TIME PULSE SEARCHES

Hawking – 1974 •  Mini black holes from big bang •  Radiate and “thermal run away” because

smaller = hotter è expire in explosion •  EM pulse detectable at astronomical distances

(Rees) Ekers, Shaver and JOS - 1978

•  Simple dual pulse detector at Dwingeloo

Ronfest Talk Lord Rees of Ludlow

Stephen Hawking

MORE SEARCHING…

Westerbork with Tim Hankins et al, 1981 M87 pulse search using Westerbork tied array Acousto-optic spectrograph (Bonn) and film recorder (Dwingeloo solar)

•  100’s metres film with noise Caused me to immediately contemplate hardware FFT options!

•  Not much action on FFT hardware until return to Australia in 1983

Ronfest Talk

ALMOST THE BEGINNING Early 1980s – Prof Bob Frater becomes Chief of Radiophysics Attracts young scientists and engineers back to work on the Australia Telescope Issues challenge: Apply skills to commercial applications

Ronfest Talk

Australia Telescope

1988

Parkes Telescope 1961

Interscan Microwave Landing System

1975

Prof Bob Frater

CSIRAC Computer -1949 (Melb Museum)

THE AUSTEK-CSIRO A41102 FOURIER CHIP

Ronfest Talk

•  Commercial CMOS version – joint CSIRO/Austek design - 1988

•  Various apps such as medical ultrasound imaging, synthetic aperture radar envisaged

•  Used in defence, astronomy •  World speed record holder for

many years

Bill Stroud

Medical Ultrasound application

David Brown

Chip design

WIRELESS NETWORKS University Hawaii – 1971 Alohanet Send short “Packets” of bits from station to

station Simple protocol – Aloha

•  Only transmit if no one else is •  Later taken up for Ethernet cable network

Ronfest Talk

THE HIGH SPEED WIRELESS NETWORK

Ronfest Talk

•  Initial targets •  Laptops to

network •  100 Mbit per sec •  Low power –

indoor •  Offices, meeting

rooms, etc •  Way beyond

(then) existing products

•  Challenge is reverberation!

IT’S THE PEOPLE

Ronfest Talk

John Deane, Denis Redfern, John O’Sullivan, Diet Ostry, Terry Percival, Graham Daniels (some years on!)

ANSWER FOR THE HIGH SPEED WLAN PROBLEM

The FFT is ideal to do the multi-tone modulation - OFDM •  Problem is some tones are kaput

With our FFT chip experience, we saw the FFT as a practical part of the answer!

Ronfest Talk

Multi-tone Demodulation

Multi-tone modulation

IFFT FFT De- mod

Mod Eg BPSK

frequency

Many slower

channels

and, plus much more:

Coding, frequency interleaving to address failed tones, …

è Australian patent 1992, US ‘96

time

Direct path

TEST BED AND OVER AIR TRIALS

1992 onwards Simulations and modelling with Macquarie Uni (Dave Skellern et al) Test bed built and over the air demonstrations led by Terry Percival

Ronfest Talk

RADIATA SUCCESS STORY

Radiata founded by Dave Skellern and Neil Weste

Radiata demonstrated first 802.11a 54 Mbps WiFi chips at Networld+Interop in Atlanta Sep 2000

•  CMOS 5 GHz radio chip – RF5 •  Digital modem chip – RM11a

Radiata acquired by Cisco shortly after – US$295 Million

Ronfest Talk

RF5 chip RM11a chip

Cisco 802.11a/b WiFi Access Point

WI-FI PRODUCTS

Ronfest Talk

OVERVIEW

1940s to 1990s 1991-2001 2002-2009 2010-2016

•  Radar •  Radio

Astronomy •  Building radio

telescopes •  FFT Chip –

Austek/CSIRO

•  Vision •  Invention •  US patent 1996 •  19 patents •  Standards

process •  Radiata –

RM11, RF5 chips

•  Products ship •  Voluntary

programme •  Test case •  Broadening

litigation •  Settlements •  Further

startups • G2 • Taggle

•  Further licensing

•  Endowment fund

Ronfest Talk

Pre invention Breakthrough Commercial Next steps